mirror of https://gitee.com/openkylin/linux.git
6117 lines
151 KiB
C
6117 lines
151 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Routines having to do with the 'struct sk_buff' memory handlers.
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*
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* Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>
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* Florian La Roche <rzsfl@rz.uni-sb.de>
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*
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* Fixes:
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* Alan Cox : Fixed the worst of the load
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* balancer bugs.
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* Dave Platt : Interrupt stacking fix.
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* Richard Kooijman : Timestamp fixes.
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* Alan Cox : Changed buffer format.
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* Alan Cox : destructor hook for AF_UNIX etc.
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* Linus Torvalds : Better skb_clone.
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* Alan Cox : Added skb_copy.
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* Alan Cox : Added all the changed routines Linus
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* only put in the headers
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* Ray VanTassle : Fixed --skb->lock in free
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* Alan Cox : skb_copy copy arp field
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* Andi Kleen : slabified it.
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* Robert Olsson : Removed skb_head_pool
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*
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* NOTE:
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* The __skb_ routines should be called with interrupts
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* disabled, or you better be *real* sure that the operation is atomic
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* with respect to whatever list is being frobbed (e.g. via lock_sock()
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* or via disabling bottom half handlers, etc).
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*/
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/*
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* The functions in this file will not compile correctly with gcc 2.4.x
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/in.h>
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#include <linux/inet.h>
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#include <linux/slab.h>
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <linux/sctp.h>
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#include <linux/netdevice.h>
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#ifdef CONFIG_NET_CLS_ACT
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#include <net/pkt_sched.h>
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#endif
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#include <linux/string.h>
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#include <linux/skbuff.h>
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#include <linux/splice.h>
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#include <linux/cache.h>
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#include <linux/rtnetlink.h>
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#include <linux/init.h>
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#include <linux/scatterlist.h>
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#include <linux/errqueue.h>
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#include <linux/prefetch.h>
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#include <linux/if_vlan.h>
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#include <linux/mpls.h>
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#include <net/protocol.h>
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#include <net/dst.h>
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#include <net/sock.h>
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#include <net/checksum.h>
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#include <net/ip6_checksum.h>
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#include <net/xfrm.h>
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#include <net/mpls.h>
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#include <linux/uaccess.h>
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#include <trace/events/skb.h>
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#include <linux/highmem.h>
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#include <linux/capability.h>
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#include <linux/user_namespace.h>
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#include <linux/indirect_call_wrapper.h>
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#include "datagram.h"
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struct kmem_cache *skbuff_head_cache __ro_after_init;
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static struct kmem_cache *skbuff_fclone_cache __ro_after_init;
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#ifdef CONFIG_SKB_EXTENSIONS
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static struct kmem_cache *skbuff_ext_cache __ro_after_init;
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#endif
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int sysctl_max_skb_frags __read_mostly = MAX_SKB_FRAGS;
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EXPORT_SYMBOL(sysctl_max_skb_frags);
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/**
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* skb_panic - private function for out-of-line support
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* @skb: buffer
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* @sz: size
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* @addr: address
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* @msg: skb_over_panic or skb_under_panic
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*
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* Out-of-line support for skb_put() and skb_push().
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* Called via the wrapper skb_over_panic() or skb_under_panic().
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* Keep out of line to prevent kernel bloat.
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* __builtin_return_address is not used because it is not always reliable.
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*/
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static void skb_panic(struct sk_buff *skb, unsigned int sz, void *addr,
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const char msg[])
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{
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pr_emerg("%s: text:%p len:%d put:%d head:%p data:%p tail:%#lx end:%#lx dev:%s\n",
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msg, addr, skb->len, sz, skb->head, skb->data,
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(unsigned long)skb->tail, (unsigned long)skb->end,
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skb->dev ? skb->dev->name : "<NULL>");
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BUG();
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}
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static void skb_over_panic(struct sk_buff *skb, unsigned int sz, void *addr)
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{
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skb_panic(skb, sz, addr, __func__);
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}
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static void skb_under_panic(struct sk_buff *skb, unsigned int sz, void *addr)
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{
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skb_panic(skb, sz, addr, __func__);
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}
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/*
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* kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells
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* the caller if emergency pfmemalloc reserves are being used. If it is and
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* the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves
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* may be used. Otherwise, the packet data may be discarded until enough
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* memory is free
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*/
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#define kmalloc_reserve(size, gfp, node, pfmemalloc) \
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__kmalloc_reserve(size, gfp, node, _RET_IP_, pfmemalloc)
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static void *__kmalloc_reserve(size_t size, gfp_t flags, int node,
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unsigned long ip, bool *pfmemalloc)
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{
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void *obj;
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bool ret_pfmemalloc = false;
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/*
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* Try a regular allocation, when that fails and we're not entitled
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* to the reserves, fail.
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*/
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obj = kmalloc_node_track_caller(size,
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flags | __GFP_NOMEMALLOC | __GFP_NOWARN,
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node);
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if (obj || !(gfp_pfmemalloc_allowed(flags)))
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goto out;
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/* Try again but now we are using pfmemalloc reserves */
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ret_pfmemalloc = true;
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obj = kmalloc_node_track_caller(size, flags, node);
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out:
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if (pfmemalloc)
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*pfmemalloc = ret_pfmemalloc;
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return obj;
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}
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/* Allocate a new skbuff. We do this ourselves so we can fill in a few
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* 'private' fields and also do memory statistics to find all the
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* [BEEP] leaks.
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*
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*/
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/**
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* __alloc_skb - allocate a network buffer
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* @size: size to allocate
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* @gfp_mask: allocation mask
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* @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache
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* instead of head cache and allocate a cloned (child) skb.
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* If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for
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* allocations in case the data is required for writeback
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* @node: numa node to allocate memory on
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*
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* Allocate a new &sk_buff. The returned buffer has no headroom and a
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* tail room of at least size bytes. The object has a reference count
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* of one. The return is the buffer. On a failure the return is %NULL.
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*
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* Buffers may only be allocated from interrupts using a @gfp_mask of
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* %GFP_ATOMIC.
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*/
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struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
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int flags, int node)
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{
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struct kmem_cache *cache;
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struct skb_shared_info *shinfo;
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struct sk_buff *skb;
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u8 *data;
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bool pfmemalloc;
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cache = (flags & SKB_ALLOC_FCLONE)
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? skbuff_fclone_cache : skbuff_head_cache;
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if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX))
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gfp_mask |= __GFP_MEMALLOC;
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/* Get the HEAD */
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skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node);
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if (!skb)
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goto out;
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prefetchw(skb);
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/* We do our best to align skb_shared_info on a separate cache
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* line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives
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* aligned memory blocks, unless SLUB/SLAB debug is enabled.
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* Both skb->head and skb_shared_info are cache line aligned.
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*/
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size = SKB_DATA_ALIGN(size);
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size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
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data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc);
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if (!data)
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goto nodata;
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/* kmalloc(size) might give us more room than requested.
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* Put skb_shared_info exactly at the end of allocated zone,
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* to allow max possible filling before reallocation.
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*/
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size = SKB_WITH_OVERHEAD(ksize(data));
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prefetchw(data + size);
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/*
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* Only clear those fields we need to clear, not those that we will
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* actually initialise below. Hence, don't put any more fields after
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* the tail pointer in struct sk_buff!
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*/
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memset(skb, 0, offsetof(struct sk_buff, tail));
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/* Account for allocated memory : skb + skb->head */
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skb->truesize = SKB_TRUESIZE(size);
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skb->pfmemalloc = pfmemalloc;
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refcount_set(&skb->users, 1);
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skb->head = data;
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skb->data = data;
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skb_reset_tail_pointer(skb);
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skb->end = skb->tail + size;
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skb->mac_header = (typeof(skb->mac_header))~0U;
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skb->transport_header = (typeof(skb->transport_header))~0U;
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/* make sure we initialize shinfo sequentially */
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shinfo = skb_shinfo(skb);
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memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
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atomic_set(&shinfo->dataref, 1);
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if (flags & SKB_ALLOC_FCLONE) {
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struct sk_buff_fclones *fclones;
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fclones = container_of(skb, struct sk_buff_fclones, skb1);
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skb->fclone = SKB_FCLONE_ORIG;
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refcount_set(&fclones->fclone_ref, 1);
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fclones->skb2.fclone = SKB_FCLONE_CLONE;
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}
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out:
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return skb;
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nodata:
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kmem_cache_free(cache, skb);
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skb = NULL;
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goto out;
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}
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EXPORT_SYMBOL(__alloc_skb);
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/* Caller must provide SKB that is memset cleared */
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static struct sk_buff *__build_skb_around(struct sk_buff *skb,
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void *data, unsigned int frag_size)
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{
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struct skb_shared_info *shinfo;
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unsigned int size = frag_size ? : ksize(data);
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size -= SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
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/* Assumes caller memset cleared SKB */
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skb->truesize = SKB_TRUESIZE(size);
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refcount_set(&skb->users, 1);
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skb->head = data;
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skb->data = data;
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skb_reset_tail_pointer(skb);
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skb->end = skb->tail + size;
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skb->mac_header = (typeof(skb->mac_header))~0U;
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skb->transport_header = (typeof(skb->transport_header))~0U;
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/* make sure we initialize shinfo sequentially */
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shinfo = skb_shinfo(skb);
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memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
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atomic_set(&shinfo->dataref, 1);
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return skb;
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}
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/**
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* __build_skb - build a network buffer
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* @data: data buffer provided by caller
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* @frag_size: size of data, or 0 if head was kmalloced
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*
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* Allocate a new &sk_buff. Caller provides space holding head and
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* skb_shared_info. @data must have been allocated by kmalloc() only if
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* @frag_size is 0, otherwise data should come from the page allocator
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* or vmalloc()
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* The return is the new skb buffer.
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* On a failure the return is %NULL, and @data is not freed.
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* Notes :
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* Before IO, driver allocates only data buffer where NIC put incoming frame
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* Driver should add room at head (NET_SKB_PAD) and
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* MUST add room at tail (SKB_DATA_ALIGN(skb_shared_info))
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* After IO, driver calls build_skb(), to allocate sk_buff and populate it
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* before giving packet to stack.
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* RX rings only contains data buffers, not full skbs.
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*/
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struct sk_buff *__build_skb(void *data, unsigned int frag_size)
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{
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struct sk_buff *skb;
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skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC);
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if (unlikely(!skb))
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return NULL;
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memset(skb, 0, offsetof(struct sk_buff, tail));
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return __build_skb_around(skb, data, frag_size);
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}
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/* build_skb() is wrapper over __build_skb(), that specifically
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* takes care of skb->head and skb->pfmemalloc
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* This means that if @frag_size is not zero, then @data must be backed
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* by a page fragment, not kmalloc() or vmalloc()
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*/
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struct sk_buff *build_skb(void *data, unsigned int frag_size)
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{
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struct sk_buff *skb = __build_skb(data, frag_size);
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if (skb && frag_size) {
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skb->head_frag = 1;
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if (page_is_pfmemalloc(virt_to_head_page(data)))
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skb->pfmemalloc = 1;
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}
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return skb;
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}
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EXPORT_SYMBOL(build_skb);
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/**
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* build_skb_around - build a network buffer around provided skb
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* @skb: sk_buff provide by caller, must be memset cleared
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* @data: data buffer provided by caller
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* @frag_size: size of data, or 0 if head was kmalloced
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*/
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struct sk_buff *build_skb_around(struct sk_buff *skb,
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void *data, unsigned int frag_size)
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{
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if (unlikely(!skb))
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return NULL;
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skb = __build_skb_around(skb, data, frag_size);
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if (skb && frag_size) {
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skb->head_frag = 1;
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if (page_is_pfmemalloc(virt_to_head_page(data)))
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skb->pfmemalloc = 1;
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}
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return skb;
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}
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EXPORT_SYMBOL(build_skb_around);
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#define NAPI_SKB_CACHE_SIZE 64
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struct napi_alloc_cache {
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struct page_frag_cache page;
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unsigned int skb_count;
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void *skb_cache[NAPI_SKB_CACHE_SIZE];
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};
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static DEFINE_PER_CPU(struct page_frag_cache, netdev_alloc_cache);
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static DEFINE_PER_CPU(struct napi_alloc_cache, napi_alloc_cache);
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static void *__napi_alloc_frag(unsigned int fragsz, gfp_t gfp_mask)
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{
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struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache);
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return page_frag_alloc(&nc->page, fragsz, gfp_mask);
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}
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void *napi_alloc_frag(unsigned int fragsz)
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{
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fragsz = SKB_DATA_ALIGN(fragsz);
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return __napi_alloc_frag(fragsz, GFP_ATOMIC);
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}
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EXPORT_SYMBOL(napi_alloc_frag);
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|
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/**
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* netdev_alloc_frag - allocate a page fragment
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* @fragsz: fragment size
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*
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* Allocates a frag from a page for receive buffer.
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* Uses GFP_ATOMIC allocations.
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*/
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void *netdev_alloc_frag(unsigned int fragsz)
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{
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struct page_frag_cache *nc;
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void *data;
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|
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fragsz = SKB_DATA_ALIGN(fragsz);
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if (in_irq() || irqs_disabled()) {
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nc = this_cpu_ptr(&netdev_alloc_cache);
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data = page_frag_alloc(nc, fragsz, GFP_ATOMIC);
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} else {
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local_bh_disable();
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data = __napi_alloc_frag(fragsz, GFP_ATOMIC);
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local_bh_enable();
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}
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return data;
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}
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EXPORT_SYMBOL(netdev_alloc_frag);
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|
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/**
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* __netdev_alloc_skb - allocate an skbuff for rx on a specific device
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* @dev: network device to receive on
|
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* @len: length to allocate
|
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* @gfp_mask: get_free_pages mask, passed to alloc_skb
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*
|
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* Allocate a new &sk_buff and assign it a usage count of one. The
|
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* buffer has NET_SKB_PAD headroom built in. Users should allocate
|
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* the headroom they think they need without accounting for the
|
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* built in space. The built in space is used for optimisations.
|
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*
|
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* %NULL is returned if there is no free memory.
|
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*/
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struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int len,
|
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gfp_t gfp_mask)
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{
|
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struct page_frag_cache *nc;
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struct sk_buff *skb;
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bool pfmemalloc;
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void *data;
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|
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len += NET_SKB_PAD;
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|
|
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if ((len > SKB_WITH_OVERHEAD(PAGE_SIZE)) ||
|
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(gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) {
|
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skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE);
|
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if (!skb)
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goto skb_fail;
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goto skb_success;
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|
}
|
|
|
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len += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
|
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len = SKB_DATA_ALIGN(len);
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|
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if (sk_memalloc_socks())
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gfp_mask |= __GFP_MEMALLOC;
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|
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if (in_irq() || irqs_disabled()) {
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nc = this_cpu_ptr(&netdev_alloc_cache);
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data = page_frag_alloc(nc, len, gfp_mask);
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pfmemalloc = nc->pfmemalloc;
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} else {
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local_bh_disable();
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nc = this_cpu_ptr(&napi_alloc_cache.page);
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data = page_frag_alloc(nc, len, gfp_mask);
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pfmemalloc = nc->pfmemalloc;
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local_bh_enable();
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}
|
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|
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if (unlikely(!data))
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return NULL;
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|
|
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skb = __build_skb(data, len);
|
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if (unlikely(!skb)) {
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skb_free_frag(data);
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return NULL;
|
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}
|
|
|
|
/* use OR instead of assignment to avoid clearing of bits in mask */
|
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if (pfmemalloc)
|
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skb->pfmemalloc = 1;
|
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skb->head_frag = 1;
|
|
|
|
skb_success:
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skb_reserve(skb, NET_SKB_PAD);
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|
skb->dev = dev;
|
|
|
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skb_fail:
|
|
return skb;
|
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}
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EXPORT_SYMBOL(__netdev_alloc_skb);
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|
|
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/**
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|
* __napi_alloc_skb - allocate skbuff for rx in a specific NAPI instance
|
|
* @napi: napi instance this buffer was allocated for
|
|
* @len: length to allocate
|
|
* @gfp_mask: get_free_pages mask, passed to alloc_skb and alloc_pages
|
|
*
|
|
* Allocate a new sk_buff for use in NAPI receive. This buffer will
|
|
* attempt to allocate the head from a special reserved region used
|
|
* only for NAPI Rx allocation. By doing this we can save several
|
|
* CPU cycles by avoiding having to disable and re-enable IRQs.
|
|
*
|
|
* %NULL is returned if there is no free memory.
|
|
*/
|
|
struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len,
|
|
gfp_t gfp_mask)
|
|
{
|
|
struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache);
|
|
struct sk_buff *skb;
|
|
void *data;
|
|
|
|
len += NET_SKB_PAD + NET_IP_ALIGN;
|
|
|
|
if ((len > SKB_WITH_OVERHEAD(PAGE_SIZE)) ||
|
|
(gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) {
|
|
skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE);
|
|
if (!skb)
|
|
goto skb_fail;
|
|
goto skb_success;
|
|
}
|
|
|
|
len += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
|
|
len = SKB_DATA_ALIGN(len);
|
|
|
|
if (sk_memalloc_socks())
|
|
gfp_mask |= __GFP_MEMALLOC;
|
|
|
|
data = page_frag_alloc(&nc->page, len, gfp_mask);
|
|
if (unlikely(!data))
|
|
return NULL;
|
|
|
|
skb = __build_skb(data, len);
|
|
if (unlikely(!skb)) {
|
|
skb_free_frag(data);
|
|
return NULL;
|
|
}
|
|
|
|
/* use OR instead of assignment to avoid clearing of bits in mask */
|
|
if (nc->page.pfmemalloc)
|
|
skb->pfmemalloc = 1;
|
|
skb->head_frag = 1;
|
|
|
|
skb_success:
|
|
skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
|
|
skb->dev = napi->dev;
|
|
|
|
skb_fail:
|
|
return skb;
|
|
}
|
|
EXPORT_SYMBOL(__napi_alloc_skb);
|
|
|
|
void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
|
|
int size, unsigned int truesize)
|
|
{
|
|
skb_fill_page_desc(skb, i, page, off, size);
|
|
skb->len += size;
|
|
skb->data_len += size;
|
|
skb->truesize += truesize;
|
|
}
|
|
EXPORT_SYMBOL(skb_add_rx_frag);
|
|
|
|
void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
|
|
unsigned int truesize)
|
|
{
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
|
|
|
|
skb_frag_size_add(frag, size);
|
|
skb->len += size;
|
|
skb->data_len += size;
|
|
skb->truesize += truesize;
|
|
}
|
|
EXPORT_SYMBOL(skb_coalesce_rx_frag);
|
|
|
|
static void skb_drop_list(struct sk_buff **listp)
|
|
{
|
|
kfree_skb_list(*listp);
|
|
*listp = NULL;
|
|
}
|
|
|
|
static inline void skb_drop_fraglist(struct sk_buff *skb)
|
|
{
|
|
skb_drop_list(&skb_shinfo(skb)->frag_list);
|
|
}
|
|
|
|
static void skb_clone_fraglist(struct sk_buff *skb)
|
|
{
|
|
struct sk_buff *list;
|
|
|
|
skb_walk_frags(skb, list)
|
|
skb_get(list);
|
|
}
|
|
|
|
static void skb_free_head(struct sk_buff *skb)
|
|
{
|
|
unsigned char *head = skb->head;
|
|
|
|
if (skb->head_frag)
|
|
skb_free_frag(head);
|
|
else
|
|
kfree(head);
|
|
}
|
|
|
|
static void skb_release_data(struct sk_buff *skb)
|
|
{
|
|
struct skb_shared_info *shinfo = skb_shinfo(skb);
|
|
int i;
|
|
|
|
if (skb->cloned &&
|
|
atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1,
|
|
&shinfo->dataref))
|
|
return;
|
|
|
|
for (i = 0; i < shinfo->nr_frags; i++)
|
|
__skb_frag_unref(&shinfo->frags[i]);
|
|
|
|
if (shinfo->frag_list)
|
|
kfree_skb_list(shinfo->frag_list);
|
|
|
|
skb_zcopy_clear(skb, true);
|
|
skb_free_head(skb);
|
|
}
|
|
|
|
/*
|
|
* Free an skbuff by memory without cleaning the state.
|
|
*/
|
|
static void kfree_skbmem(struct sk_buff *skb)
|
|
{
|
|
struct sk_buff_fclones *fclones;
|
|
|
|
switch (skb->fclone) {
|
|
case SKB_FCLONE_UNAVAILABLE:
|
|
kmem_cache_free(skbuff_head_cache, skb);
|
|
return;
|
|
|
|
case SKB_FCLONE_ORIG:
|
|
fclones = container_of(skb, struct sk_buff_fclones, skb1);
|
|
|
|
/* We usually free the clone (TX completion) before original skb
|
|
* This test would have no chance to be true for the clone,
|
|
* while here, branch prediction will be good.
|
|
*/
|
|
if (refcount_read(&fclones->fclone_ref) == 1)
|
|
goto fastpath;
|
|
break;
|
|
|
|
default: /* SKB_FCLONE_CLONE */
|
|
fclones = container_of(skb, struct sk_buff_fclones, skb2);
|
|
break;
|
|
}
|
|
if (!refcount_dec_and_test(&fclones->fclone_ref))
|
|
return;
|
|
fastpath:
|
|
kmem_cache_free(skbuff_fclone_cache, fclones);
|
|
}
|
|
|
|
void skb_release_head_state(struct sk_buff *skb)
|
|
{
|
|
skb_dst_drop(skb);
|
|
if (skb->destructor) {
|
|
WARN_ON(in_irq());
|
|
skb->destructor(skb);
|
|
}
|
|
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
|
|
nf_conntrack_put(skb_nfct(skb));
|
|
#endif
|
|
skb_ext_put(skb);
|
|
}
|
|
|
|
/* Free everything but the sk_buff shell. */
|
|
static void skb_release_all(struct sk_buff *skb)
|
|
{
|
|
skb_release_head_state(skb);
|
|
if (likely(skb->head))
|
|
skb_release_data(skb);
|
|
}
|
|
|
|
/**
|
|
* __kfree_skb - private function
|
|
* @skb: buffer
|
|
*
|
|
* Free an sk_buff. Release anything attached to the buffer.
|
|
* Clean the state. This is an internal helper function. Users should
|
|
* always call kfree_skb
|
|
*/
|
|
|
|
void __kfree_skb(struct sk_buff *skb)
|
|
{
|
|
skb_release_all(skb);
|
|
kfree_skbmem(skb);
|
|
}
|
|
EXPORT_SYMBOL(__kfree_skb);
|
|
|
|
/**
|
|
* kfree_skb - free an sk_buff
|
|
* @skb: buffer to free
|
|
*
|
|
* Drop a reference to the buffer and free it if the usage count has
|
|
* hit zero.
|
|
*/
|
|
void kfree_skb(struct sk_buff *skb)
|
|
{
|
|
if (!skb_unref(skb))
|
|
return;
|
|
|
|
trace_kfree_skb(skb, __builtin_return_address(0));
|
|
__kfree_skb(skb);
|
|
}
|
|
EXPORT_SYMBOL(kfree_skb);
|
|
|
|
void kfree_skb_list(struct sk_buff *segs)
|
|
{
|
|
while (segs) {
|
|
struct sk_buff *next = segs->next;
|
|
|
|
kfree_skb(segs);
|
|
segs = next;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(kfree_skb_list);
|
|
|
|
/* Dump skb information and contents.
|
|
*
|
|
* Must only be called from net_ratelimit()-ed paths.
|
|
*
|
|
* Dumps up to can_dump_full whole packets if full_pkt, headers otherwise.
|
|
*/
|
|
void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt)
|
|
{
|
|
static atomic_t can_dump_full = ATOMIC_INIT(5);
|
|
struct skb_shared_info *sh = skb_shinfo(skb);
|
|
struct net_device *dev = skb->dev;
|
|
struct sock *sk = skb->sk;
|
|
struct sk_buff *list_skb;
|
|
bool has_mac, has_trans;
|
|
int headroom, tailroom;
|
|
int i, len, seg_len;
|
|
|
|
if (full_pkt)
|
|
full_pkt = atomic_dec_if_positive(&can_dump_full) >= 0;
|
|
|
|
if (full_pkt)
|
|
len = skb->len;
|
|
else
|
|
len = min_t(int, skb->len, MAX_HEADER + 128);
|
|
|
|
headroom = skb_headroom(skb);
|
|
tailroom = skb_tailroom(skb);
|
|
|
|
has_mac = skb_mac_header_was_set(skb);
|
|
has_trans = skb_transport_header_was_set(skb);
|
|
|
|
printk("%sskb len=%u headroom=%u headlen=%u tailroom=%u\n"
|
|
"mac=(%d,%d) net=(%d,%d) trans=%d\n"
|
|
"shinfo(txflags=%u nr_frags=%u gso(size=%hu type=%u segs=%hu))\n"
|
|
"csum(0x%x ip_summed=%u complete_sw=%u valid=%u level=%u)\n"
|
|
"hash(0x%x sw=%u l4=%u) proto=0x%04x pkttype=%u iif=%d\n",
|
|
level, skb->len, headroom, skb_headlen(skb), tailroom,
|
|
has_mac ? skb->mac_header : -1,
|
|
has_mac ? skb_mac_header_len(skb) : -1,
|
|
skb->network_header,
|
|
has_trans ? skb_network_header_len(skb) : -1,
|
|
has_trans ? skb->transport_header : -1,
|
|
sh->tx_flags, sh->nr_frags,
|
|
sh->gso_size, sh->gso_type, sh->gso_segs,
|
|
skb->csum, skb->ip_summed, skb->csum_complete_sw,
|
|
skb->csum_valid, skb->csum_level,
|
|
skb->hash, skb->sw_hash, skb->l4_hash,
|
|
ntohs(skb->protocol), skb->pkt_type, skb->skb_iif);
|
|
|
|
if (dev)
|
|
printk("%sdev name=%s feat=0x%pNF\n",
|
|
level, dev->name, &dev->features);
|
|
if (sk)
|
|
printk("%ssk family=%hu type=%u proto=%u\n",
|
|
level, sk->sk_family, sk->sk_type, sk->sk_protocol);
|
|
|
|
if (full_pkt && headroom)
|
|
print_hex_dump(level, "skb headroom: ", DUMP_PREFIX_OFFSET,
|
|
16, 1, skb->head, headroom, false);
|
|
|
|
seg_len = min_t(int, skb_headlen(skb), len);
|
|
if (seg_len)
|
|
print_hex_dump(level, "skb linear: ", DUMP_PREFIX_OFFSET,
|
|
16, 1, skb->data, seg_len, false);
|
|
len -= seg_len;
|
|
|
|
if (full_pkt && tailroom)
|
|
print_hex_dump(level, "skb tailroom: ", DUMP_PREFIX_OFFSET,
|
|
16, 1, skb_tail_pointer(skb), tailroom, false);
|
|
|
|
for (i = 0; len && i < skb_shinfo(skb)->nr_frags; i++) {
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
|
|
u32 p_off, p_len, copied;
|
|
struct page *p;
|
|
u8 *vaddr;
|
|
|
|
skb_frag_foreach_page(frag, skb_frag_off(frag),
|
|
skb_frag_size(frag), p, p_off, p_len,
|
|
copied) {
|
|
seg_len = min_t(int, p_len, len);
|
|
vaddr = kmap_atomic(p);
|
|
print_hex_dump(level, "skb frag: ",
|
|
DUMP_PREFIX_OFFSET,
|
|
16, 1, vaddr + p_off, seg_len, false);
|
|
kunmap_atomic(vaddr);
|
|
len -= seg_len;
|
|
if (!len)
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (full_pkt && skb_has_frag_list(skb)) {
|
|
printk("skb fraglist:\n");
|
|
skb_walk_frags(skb, list_skb)
|
|
skb_dump(level, list_skb, true);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(skb_dump);
|
|
|
|
/**
|
|
* skb_tx_error - report an sk_buff xmit error
|
|
* @skb: buffer that triggered an error
|
|
*
|
|
* Report xmit error if a device callback is tracking this skb.
|
|
* skb must be freed afterwards.
|
|
*/
|
|
void skb_tx_error(struct sk_buff *skb)
|
|
{
|
|
skb_zcopy_clear(skb, true);
|
|
}
|
|
EXPORT_SYMBOL(skb_tx_error);
|
|
|
|
/**
|
|
* consume_skb - free an skbuff
|
|
* @skb: buffer to free
|
|
*
|
|
* Drop a ref to the buffer and free it if the usage count has hit zero
|
|
* Functions identically to kfree_skb, but kfree_skb assumes that the frame
|
|
* is being dropped after a failure and notes that
|
|
*/
|
|
void consume_skb(struct sk_buff *skb)
|
|
{
|
|
if (!skb_unref(skb))
|
|
return;
|
|
|
|
trace_consume_skb(skb);
|
|
__kfree_skb(skb);
|
|
}
|
|
EXPORT_SYMBOL(consume_skb);
|
|
|
|
/**
|
|
* consume_stateless_skb - free an skbuff, assuming it is stateless
|
|
* @skb: buffer to free
|
|
*
|
|
* Alike consume_skb(), but this variant assumes that this is the last
|
|
* skb reference and all the head states have been already dropped
|
|
*/
|
|
void __consume_stateless_skb(struct sk_buff *skb)
|
|
{
|
|
trace_consume_skb(skb);
|
|
skb_release_data(skb);
|
|
kfree_skbmem(skb);
|
|
}
|
|
|
|
void __kfree_skb_flush(void)
|
|
{
|
|
struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache);
|
|
|
|
/* flush skb_cache if containing objects */
|
|
if (nc->skb_count) {
|
|
kmem_cache_free_bulk(skbuff_head_cache, nc->skb_count,
|
|
nc->skb_cache);
|
|
nc->skb_count = 0;
|
|
}
|
|
}
|
|
|
|
static inline void _kfree_skb_defer(struct sk_buff *skb)
|
|
{
|
|
struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache);
|
|
|
|
/* drop skb->head and call any destructors for packet */
|
|
skb_release_all(skb);
|
|
|
|
/* record skb to CPU local list */
|
|
nc->skb_cache[nc->skb_count++] = skb;
|
|
|
|
#ifdef CONFIG_SLUB
|
|
/* SLUB writes into objects when freeing */
|
|
prefetchw(skb);
|
|
#endif
|
|
|
|
/* flush skb_cache if it is filled */
|
|
if (unlikely(nc->skb_count == NAPI_SKB_CACHE_SIZE)) {
|
|
kmem_cache_free_bulk(skbuff_head_cache, NAPI_SKB_CACHE_SIZE,
|
|
nc->skb_cache);
|
|
nc->skb_count = 0;
|
|
}
|
|
}
|
|
void __kfree_skb_defer(struct sk_buff *skb)
|
|
{
|
|
_kfree_skb_defer(skb);
|
|
}
|
|
|
|
void napi_consume_skb(struct sk_buff *skb, int budget)
|
|
{
|
|
if (unlikely(!skb))
|
|
return;
|
|
|
|
/* Zero budget indicate non-NAPI context called us, like netpoll */
|
|
if (unlikely(!budget)) {
|
|
dev_consume_skb_any(skb);
|
|
return;
|
|
}
|
|
|
|
if (!skb_unref(skb))
|
|
return;
|
|
|
|
/* if reaching here SKB is ready to free */
|
|
trace_consume_skb(skb);
|
|
|
|
/* if SKB is a clone, don't handle this case */
|
|
if (skb->fclone != SKB_FCLONE_UNAVAILABLE) {
|
|
__kfree_skb(skb);
|
|
return;
|
|
}
|
|
|
|
_kfree_skb_defer(skb);
|
|
}
|
|
EXPORT_SYMBOL(napi_consume_skb);
|
|
|
|
/* Make sure a field is enclosed inside headers_start/headers_end section */
|
|
#define CHECK_SKB_FIELD(field) \
|
|
BUILD_BUG_ON(offsetof(struct sk_buff, field) < \
|
|
offsetof(struct sk_buff, headers_start)); \
|
|
BUILD_BUG_ON(offsetof(struct sk_buff, field) > \
|
|
offsetof(struct sk_buff, headers_end)); \
|
|
|
|
static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
|
|
{
|
|
new->tstamp = old->tstamp;
|
|
/* We do not copy old->sk */
|
|
new->dev = old->dev;
|
|
memcpy(new->cb, old->cb, sizeof(old->cb));
|
|
skb_dst_copy(new, old);
|
|
__skb_ext_copy(new, old);
|
|
__nf_copy(new, old, false);
|
|
|
|
/* Note : this field could be in headers_start/headers_end section
|
|
* It is not yet because we do not want to have a 16 bit hole
|
|
*/
|
|
new->queue_mapping = old->queue_mapping;
|
|
|
|
memcpy(&new->headers_start, &old->headers_start,
|
|
offsetof(struct sk_buff, headers_end) -
|
|
offsetof(struct sk_buff, headers_start));
|
|
CHECK_SKB_FIELD(protocol);
|
|
CHECK_SKB_FIELD(csum);
|
|
CHECK_SKB_FIELD(hash);
|
|
CHECK_SKB_FIELD(priority);
|
|
CHECK_SKB_FIELD(skb_iif);
|
|
CHECK_SKB_FIELD(vlan_proto);
|
|
CHECK_SKB_FIELD(vlan_tci);
|
|
CHECK_SKB_FIELD(transport_header);
|
|
CHECK_SKB_FIELD(network_header);
|
|
CHECK_SKB_FIELD(mac_header);
|
|
CHECK_SKB_FIELD(inner_protocol);
|
|
CHECK_SKB_FIELD(inner_transport_header);
|
|
CHECK_SKB_FIELD(inner_network_header);
|
|
CHECK_SKB_FIELD(inner_mac_header);
|
|
CHECK_SKB_FIELD(mark);
|
|
#ifdef CONFIG_NETWORK_SECMARK
|
|
CHECK_SKB_FIELD(secmark);
|
|
#endif
|
|
#ifdef CONFIG_NET_RX_BUSY_POLL
|
|
CHECK_SKB_FIELD(napi_id);
|
|
#endif
|
|
#ifdef CONFIG_XPS
|
|
CHECK_SKB_FIELD(sender_cpu);
|
|
#endif
|
|
#ifdef CONFIG_NET_SCHED
|
|
CHECK_SKB_FIELD(tc_index);
|
|
#endif
|
|
|
|
}
|
|
|
|
/*
|
|
* You should not add any new code to this function. Add it to
|
|
* __copy_skb_header above instead.
|
|
*/
|
|
static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb)
|
|
{
|
|
#define C(x) n->x = skb->x
|
|
|
|
n->next = n->prev = NULL;
|
|
n->sk = NULL;
|
|
__copy_skb_header(n, skb);
|
|
|
|
C(len);
|
|
C(data_len);
|
|
C(mac_len);
|
|
n->hdr_len = skb->nohdr ? skb_headroom(skb) : skb->hdr_len;
|
|
n->cloned = 1;
|
|
n->nohdr = 0;
|
|
n->peeked = 0;
|
|
C(pfmemalloc);
|
|
n->destructor = NULL;
|
|
C(tail);
|
|
C(end);
|
|
C(head);
|
|
C(head_frag);
|
|
C(data);
|
|
C(truesize);
|
|
refcount_set(&n->users, 1);
|
|
|
|
atomic_inc(&(skb_shinfo(skb)->dataref));
|
|
skb->cloned = 1;
|
|
|
|
return n;
|
|
#undef C
|
|
}
|
|
|
|
/**
|
|
* alloc_skb_for_msg() - allocate sk_buff to wrap frag list forming a msg
|
|
* @first: first sk_buff of the msg
|
|
*/
|
|
struct sk_buff *alloc_skb_for_msg(struct sk_buff *first)
|
|
{
|
|
struct sk_buff *n;
|
|
|
|
n = alloc_skb(0, GFP_ATOMIC);
|
|
if (!n)
|
|
return NULL;
|
|
|
|
n->len = first->len;
|
|
n->data_len = first->len;
|
|
n->truesize = first->truesize;
|
|
|
|
skb_shinfo(n)->frag_list = first;
|
|
|
|
__copy_skb_header(n, first);
|
|
n->destructor = NULL;
|
|
|
|
return n;
|
|
}
|
|
EXPORT_SYMBOL_GPL(alloc_skb_for_msg);
|
|
|
|
/**
|
|
* skb_morph - morph one skb into another
|
|
* @dst: the skb to receive the contents
|
|
* @src: the skb to supply the contents
|
|
*
|
|
* This is identical to skb_clone except that the target skb is
|
|
* supplied by the user.
|
|
*
|
|
* The target skb is returned upon exit.
|
|
*/
|
|
struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src)
|
|
{
|
|
skb_release_all(dst);
|
|
return __skb_clone(dst, src);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_morph);
|
|
|
|
int mm_account_pinned_pages(struct mmpin *mmp, size_t size)
|
|
{
|
|
unsigned long max_pg, num_pg, new_pg, old_pg;
|
|
struct user_struct *user;
|
|
|
|
if (capable(CAP_IPC_LOCK) || !size)
|
|
return 0;
|
|
|
|
num_pg = (size >> PAGE_SHIFT) + 2; /* worst case */
|
|
max_pg = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
|
|
user = mmp->user ? : current_user();
|
|
|
|
do {
|
|
old_pg = atomic_long_read(&user->locked_vm);
|
|
new_pg = old_pg + num_pg;
|
|
if (new_pg > max_pg)
|
|
return -ENOBUFS;
|
|
} while (atomic_long_cmpxchg(&user->locked_vm, old_pg, new_pg) !=
|
|
old_pg);
|
|
|
|
if (!mmp->user) {
|
|
mmp->user = get_uid(user);
|
|
mmp->num_pg = num_pg;
|
|
} else {
|
|
mmp->num_pg += num_pg;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(mm_account_pinned_pages);
|
|
|
|
void mm_unaccount_pinned_pages(struct mmpin *mmp)
|
|
{
|
|
if (mmp->user) {
|
|
atomic_long_sub(mmp->num_pg, &mmp->user->locked_vm);
|
|
free_uid(mmp->user);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(mm_unaccount_pinned_pages);
|
|
|
|
struct ubuf_info *sock_zerocopy_alloc(struct sock *sk, size_t size)
|
|
{
|
|
struct ubuf_info *uarg;
|
|
struct sk_buff *skb;
|
|
|
|
WARN_ON_ONCE(!in_task());
|
|
|
|
skb = sock_omalloc(sk, 0, GFP_KERNEL);
|
|
if (!skb)
|
|
return NULL;
|
|
|
|
BUILD_BUG_ON(sizeof(*uarg) > sizeof(skb->cb));
|
|
uarg = (void *)skb->cb;
|
|
uarg->mmp.user = NULL;
|
|
|
|
if (mm_account_pinned_pages(&uarg->mmp, size)) {
|
|
kfree_skb(skb);
|
|
return NULL;
|
|
}
|
|
|
|
uarg->callback = sock_zerocopy_callback;
|
|
uarg->id = ((u32)atomic_inc_return(&sk->sk_zckey)) - 1;
|
|
uarg->len = 1;
|
|
uarg->bytelen = size;
|
|
uarg->zerocopy = 1;
|
|
refcount_set(&uarg->refcnt, 1);
|
|
sock_hold(sk);
|
|
|
|
return uarg;
|
|
}
|
|
EXPORT_SYMBOL_GPL(sock_zerocopy_alloc);
|
|
|
|
static inline struct sk_buff *skb_from_uarg(struct ubuf_info *uarg)
|
|
{
|
|
return container_of((void *)uarg, struct sk_buff, cb);
|
|
}
|
|
|
|
struct ubuf_info *sock_zerocopy_realloc(struct sock *sk, size_t size,
|
|
struct ubuf_info *uarg)
|
|
{
|
|
if (uarg) {
|
|
const u32 byte_limit = 1 << 19; /* limit to a few TSO */
|
|
u32 bytelen, next;
|
|
|
|
/* realloc only when socket is locked (TCP, UDP cork),
|
|
* so uarg->len and sk_zckey access is serialized
|
|
*/
|
|
if (!sock_owned_by_user(sk)) {
|
|
WARN_ON_ONCE(1);
|
|
return NULL;
|
|
}
|
|
|
|
bytelen = uarg->bytelen + size;
|
|
if (uarg->len == USHRT_MAX - 1 || bytelen > byte_limit) {
|
|
/* TCP can create new skb to attach new uarg */
|
|
if (sk->sk_type == SOCK_STREAM)
|
|
goto new_alloc;
|
|
return NULL;
|
|
}
|
|
|
|
next = (u32)atomic_read(&sk->sk_zckey);
|
|
if ((u32)(uarg->id + uarg->len) == next) {
|
|
if (mm_account_pinned_pages(&uarg->mmp, size))
|
|
return NULL;
|
|
uarg->len++;
|
|
uarg->bytelen = bytelen;
|
|
atomic_set(&sk->sk_zckey, ++next);
|
|
|
|
/* no extra ref when appending to datagram (MSG_MORE) */
|
|
if (sk->sk_type == SOCK_STREAM)
|
|
sock_zerocopy_get(uarg);
|
|
|
|
return uarg;
|
|
}
|
|
}
|
|
|
|
new_alloc:
|
|
return sock_zerocopy_alloc(sk, size);
|
|
}
|
|
EXPORT_SYMBOL_GPL(sock_zerocopy_realloc);
|
|
|
|
static bool skb_zerocopy_notify_extend(struct sk_buff *skb, u32 lo, u16 len)
|
|
{
|
|
struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
|
|
u32 old_lo, old_hi;
|
|
u64 sum_len;
|
|
|
|
old_lo = serr->ee.ee_info;
|
|
old_hi = serr->ee.ee_data;
|
|
sum_len = old_hi - old_lo + 1ULL + len;
|
|
|
|
if (sum_len >= (1ULL << 32))
|
|
return false;
|
|
|
|
if (lo != old_hi + 1)
|
|
return false;
|
|
|
|
serr->ee.ee_data += len;
|
|
return true;
|
|
}
|
|
|
|
void sock_zerocopy_callback(struct ubuf_info *uarg, bool success)
|
|
{
|
|
struct sk_buff *tail, *skb = skb_from_uarg(uarg);
|
|
struct sock_exterr_skb *serr;
|
|
struct sock *sk = skb->sk;
|
|
struct sk_buff_head *q;
|
|
unsigned long flags;
|
|
u32 lo, hi;
|
|
u16 len;
|
|
|
|
mm_unaccount_pinned_pages(&uarg->mmp);
|
|
|
|
/* if !len, there was only 1 call, and it was aborted
|
|
* so do not queue a completion notification
|
|
*/
|
|
if (!uarg->len || sock_flag(sk, SOCK_DEAD))
|
|
goto release;
|
|
|
|
len = uarg->len;
|
|
lo = uarg->id;
|
|
hi = uarg->id + len - 1;
|
|
|
|
serr = SKB_EXT_ERR(skb);
|
|
memset(serr, 0, sizeof(*serr));
|
|
serr->ee.ee_errno = 0;
|
|
serr->ee.ee_origin = SO_EE_ORIGIN_ZEROCOPY;
|
|
serr->ee.ee_data = hi;
|
|
serr->ee.ee_info = lo;
|
|
if (!success)
|
|
serr->ee.ee_code |= SO_EE_CODE_ZEROCOPY_COPIED;
|
|
|
|
q = &sk->sk_error_queue;
|
|
spin_lock_irqsave(&q->lock, flags);
|
|
tail = skb_peek_tail(q);
|
|
if (!tail || SKB_EXT_ERR(tail)->ee.ee_origin != SO_EE_ORIGIN_ZEROCOPY ||
|
|
!skb_zerocopy_notify_extend(tail, lo, len)) {
|
|
__skb_queue_tail(q, skb);
|
|
skb = NULL;
|
|
}
|
|
spin_unlock_irqrestore(&q->lock, flags);
|
|
|
|
sk->sk_error_report(sk);
|
|
|
|
release:
|
|
consume_skb(skb);
|
|
sock_put(sk);
|
|
}
|
|
EXPORT_SYMBOL_GPL(sock_zerocopy_callback);
|
|
|
|
void sock_zerocopy_put(struct ubuf_info *uarg)
|
|
{
|
|
if (uarg && refcount_dec_and_test(&uarg->refcnt)) {
|
|
if (uarg->callback)
|
|
uarg->callback(uarg, uarg->zerocopy);
|
|
else
|
|
consume_skb(skb_from_uarg(uarg));
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(sock_zerocopy_put);
|
|
|
|
void sock_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref)
|
|
{
|
|
if (uarg) {
|
|
struct sock *sk = skb_from_uarg(uarg)->sk;
|
|
|
|
atomic_dec(&sk->sk_zckey);
|
|
uarg->len--;
|
|
|
|
if (have_uref)
|
|
sock_zerocopy_put(uarg);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(sock_zerocopy_put_abort);
|
|
|
|
int skb_zerocopy_iter_dgram(struct sk_buff *skb, struct msghdr *msg, int len)
|
|
{
|
|
return __zerocopy_sg_from_iter(skb->sk, skb, &msg->msg_iter, len);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_zerocopy_iter_dgram);
|
|
|
|
int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
|
|
struct msghdr *msg, int len,
|
|
struct ubuf_info *uarg)
|
|
{
|
|
struct ubuf_info *orig_uarg = skb_zcopy(skb);
|
|
struct iov_iter orig_iter = msg->msg_iter;
|
|
int err, orig_len = skb->len;
|
|
|
|
/* An skb can only point to one uarg. This edge case happens when
|
|
* TCP appends to an skb, but zerocopy_realloc triggered a new alloc.
|
|
*/
|
|
if (orig_uarg && uarg != orig_uarg)
|
|
return -EEXIST;
|
|
|
|
err = __zerocopy_sg_from_iter(sk, skb, &msg->msg_iter, len);
|
|
if (err == -EFAULT || (err == -EMSGSIZE && skb->len == orig_len)) {
|
|
struct sock *save_sk = skb->sk;
|
|
|
|
/* Streams do not free skb on error. Reset to prev state. */
|
|
msg->msg_iter = orig_iter;
|
|
skb->sk = sk;
|
|
___pskb_trim(skb, orig_len);
|
|
skb->sk = save_sk;
|
|
return err;
|
|
}
|
|
|
|
skb_zcopy_set(skb, uarg, NULL);
|
|
return skb->len - orig_len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_zerocopy_iter_stream);
|
|
|
|
static int skb_zerocopy_clone(struct sk_buff *nskb, struct sk_buff *orig,
|
|
gfp_t gfp_mask)
|
|
{
|
|
if (skb_zcopy(orig)) {
|
|
if (skb_zcopy(nskb)) {
|
|
/* !gfp_mask callers are verified to !skb_zcopy(nskb) */
|
|
if (!gfp_mask) {
|
|
WARN_ON_ONCE(1);
|
|
return -ENOMEM;
|
|
}
|
|
if (skb_uarg(nskb) == skb_uarg(orig))
|
|
return 0;
|
|
if (skb_copy_ubufs(nskb, GFP_ATOMIC))
|
|
return -EIO;
|
|
}
|
|
skb_zcopy_set(nskb, skb_uarg(orig), NULL);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* skb_copy_ubufs - copy userspace skb frags buffers to kernel
|
|
* @skb: the skb to modify
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* This must be called on SKBTX_DEV_ZEROCOPY skb.
|
|
* It will copy all frags into kernel and drop the reference
|
|
* to userspace pages.
|
|
*
|
|
* If this function is called from an interrupt gfp_mask() must be
|
|
* %GFP_ATOMIC.
|
|
*
|
|
* Returns 0 on success or a negative error code on failure
|
|
* to allocate kernel memory to copy to.
|
|
*/
|
|
int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask)
|
|
{
|
|
int num_frags = skb_shinfo(skb)->nr_frags;
|
|
struct page *page, *head = NULL;
|
|
int i, new_frags;
|
|
u32 d_off;
|
|
|
|
if (skb_shared(skb) || skb_unclone(skb, gfp_mask))
|
|
return -EINVAL;
|
|
|
|
if (!num_frags)
|
|
goto release;
|
|
|
|
new_frags = (__skb_pagelen(skb) + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
for (i = 0; i < new_frags; i++) {
|
|
page = alloc_page(gfp_mask);
|
|
if (!page) {
|
|
while (head) {
|
|
struct page *next = (struct page *)page_private(head);
|
|
put_page(head);
|
|
head = next;
|
|
}
|
|
return -ENOMEM;
|
|
}
|
|
set_page_private(page, (unsigned long)head);
|
|
head = page;
|
|
}
|
|
|
|
page = head;
|
|
d_off = 0;
|
|
for (i = 0; i < num_frags; i++) {
|
|
skb_frag_t *f = &skb_shinfo(skb)->frags[i];
|
|
u32 p_off, p_len, copied;
|
|
struct page *p;
|
|
u8 *vaddr;
|
|
|
|
skb_frag_foreach_page(f, skb_frag_off(f), skb_frag_size(f),
|
|
p, p_off, p_len, copied) {
|
|
u32 copy, done = 0;
|
|
vaddr = kmap_atomic(p);
|
|
|
|
while (done < p_len) {
|
|
if (d_off == PAGE_SIZE) {
|
|
d_off = 0;
|
|
page = (struct page *)page_private(page);
|
|
}
|
|
copy = min_t(u32, PAGE_SIZE - d_off, p_len - done);
|
|
memcpy(page_address(page) + d_off,
|
|
vaddr + p_off + done, copy);
|
|
done += copy;
|
|
d_off += copy;
|
|
}
|
|
kunmap_atomic(vaddr);
|
|
}
|
|
}
|
|
|
|
/* skb frags release userspace buffers */
|
|
for (i = 0; i < num_frags; i++)
|
|
skb_frag_unref(skb, i);
|
|
|
|
/* skb frags point to kernel buffers */
|
|
for (i = 0; i < new_frags - 1; i++) {
|
|
__skb_fill_page_desc(skb, i, head, 0, PAGE_SIZE);
|
|
head = (struct page *)page_private(head);
|
|
}
|
|
__skb_fill_page_desc(skb, new_frags - 1, head, 0, d_off);
|
|
skb_shinfo(skb)->nr_frags = new_frags;
|
|
|
|
release:
|
|
skb_zcopy_clear(skb, false);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_copy_ubufs);
|
|
|
|
/**
|
|
* skb_clone - duplicate an sk_buff
|
|
* @skb: buffer to clone
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Duplicate an &sk_buff. The new one is not owned by a socket. Both
|
|
* copies share the same packet data but not structure. The new
|
|
* buffer has a reference count of 1. If the allocation fails the
|
|
* function returns %NULL otherwise the new buffer is returned.
|
|
*
|
|
* If this function is called from an interrupt gfp_mask() must be
|
|
* %GFP_ATOMIC.
|
|
*/
|
|
|
|
struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
|
|
{
|
|
struct sk_buff_fclones *fclones = container_of(skb,
|
|
struct sk_buff_fclones,
|
|
skb1);
|
|
struct sk_buff *n;
|
|
|
|
if (skb_orphan_frags(skb, gfp_mask))
|
|
return NULL;
|
|
|
|
if (skb->fclone == SKB_FCLONE_ORIG &&
|
|
refcount_read(&fclones->fclone_ref) == 1) {
|
|
n = &fclones->skb2;
|
|
refcount_set(&fclones->fclone_ref, 2);
|
|
} else {
|
|
if (skb_pfmemalloc(skb))
|
|
gfp_mask |= __GFP_MEMALLOC;
|
|
|
|
n = kmem_cache_alloc(skbuff_head_cache, gfp_mask);
|
|
if (!n)
|
|
return NULL;
|
|
|
|
n->fclone = SKB_FCLONE_UNAVAILABLE;
|
|
}
|
|
|
|
return __skb_clone(n, skb);
|
|
}
|
|
EXPORT_SYMBOL(skb_clone);
|
|
|
|
void skb_headers_offset_update(struct sk_buff *skb, int off)
|
|
{
|
|
/* Only adjust this if it actually is csum_start rather than csum */
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL)
|
|
skb->csum_start += off;
|
|
/* {transport,network,mac}_header and tail are relative to skb->head */
|
|
skb->transport_header += off;
|
|
skb->network_header += off;
|
|
if (skb_mac_header_was_set(skb))
|
|
skb->mac_header += off;
|
|
skb->inner_transport_header += off;
|
|
skb->inner_network_header += off;
|
|
skb->inner_mac_header += off;
|
|
}
|
|
EXPORT_SYMBOL(skb_headers_offset_update);
|
|
|
|
void skb_copy_header(struct sk_buff *new, const struct sk_buff *old)
|
|
{
|
|
__copy_skb_header(new, old);
|
|
|
|
skb_shinfo(new)->gso_size = skb_shinfo(old)->gso_size;
|
|
skb_shinfo(new)->gso_segs = skb_shinfo(old)->gso_segs;
|
|
skb_shinfo(new)->gso_type = skb_shinfo(old)->gso_type;
|
|
}
|
|
EXPORT_SYMBOL(skb_copy_header);
|
|
|
|
static inline int skb_alloc_rx_flag(const struct sk_buff *skb)
|
|
{
|
|
if (skb_pfmemalloc(skb))
|
|
return SKB_ALLOC_RX;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* skb_copy - create private copy of an sk_buff
|
|
* @skb: buffer to copy
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Make a copy of both an &sk_buff and its data. This is used when the
|
|
* caller wishes to modify the data and needs a private copy of the
|
|
* data to alter. Returns %NULL on failure or the pointer to the buffer
|
|
* on success. The returned buffer has a reference count of 1.
|
|
*
|
|
* As by-product this function converts non-linear &sk_buff to linear
|
|
* one, so that &sk_buff becomes completely private and caller is allowed
|
|
* to modify all the data of returned buffer. This means that this
|
|
* function is not recommended for use in circumstances when only
|
|
* header is going to be modified. Use pskb_copy() instead.
|
|
*/
|
|
|
|
struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask)
|
|
{
|
|
int headerlen = skb_headroom(skb);
|
|
unsigned int size = skb_end_offset(skb) + skb->data_len;
|
|
struct sk_buff *n = __alloc_skb(size, gfp_mask,
|
|
skb_alloc_rx_flag(skb), NUMA_NO_NODE);
|
|
|
|
if (!n)
|
|
return NULL;
|
|
|
|
/* Set the data pointer */
|
|
skb_reserve(n, headerlen);
|
|
/* Set the tail pointer and length */
|
|
skb_put(n, skb->len);
|
|
|
|
BUG_ON(skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len));
|
|
|
|
skb_copy_header(n, skb);
|
|
return n;
|
|
}
|
|
EXPORT_SYMBOL(skb_copy);
|
|
|
|
/**
|
|
* __pskb_copy_fclone - create copy of an sk_buff with private head.
|
|
* @skb: buffer to copy
|
|
* @headroom: headroom of new skb
|
|
* @gfp_mask: allocation priority
|
|
* @fclone: if true allocate the copy of the skb from the fclone
|
|
* cache instead of the head cache; it is recommended to set this
|
|
* to true for the cases where the copy will likely be cloned
|
|
*
|
|
* Make a copy of both an &sk_buff and part of its data, located
|
|
* in header. Fragmented data remain shared. This is used when
|
|
* the caller wishes to modify only header of &sk_buff and needs
|
|
* private copy of the header to alter. Returns %NULL on failure
|
|
* or the pointer to the buffer on success.
|
|
* The returned buffer has a reference count of 1.
|
|
*/
|
|
|
|
struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
|
|
gfp_t gfp_mask, bool fclone)
|
|
{
|
|
unsigned int size = skb_headlen(skb) + headroom;
|
|
int flags = skb_alloc_rx_flag(skb) | (fclone ? SKB_ALLOC_FCLONE : 0);
|
|
struct sk_buff *n = __alloc_skb(size, gfp_mask, flags, NUMA_NO_NODE);
|
|
|
|
if (!n)
|
|
goto out;
|
|
|
|
/* Set the data pointer */
|
|
skb_reserve(n, headroom);
|
|
/* Set the tail pointer and length */
|
|
skb_put(n, skb_headlen(skb));
|
|
/* Copy the bytes */
|
|
skb_copy_from_linear_data(skb, n->data, n->len);
|
|
|
|
n->truesize += skb->data_len;
|
|
n->data_len = skb->data_len;
|
|
n->len = skb->len;
|
|
|
|
if (skb_shinfo(skb)->nr_frags) {
|
|
int i;
|
|
|
|
if (skb_orphan_frags(skb, gfp_mask) ||
|
|
skb_zerocopy_clone(n, skb, gfp_mask)) {
|
|
kfree_skb(n);
|
|
n = NULL;
|
|
goto out;
|
|
}
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
skb_shinfo(n)->frags[i] = skb_shinfo(skb)->frags[i];
|
|
skb_frag_ref(skb, i);
|
|
}
|
|
skb_shinfo(n)->nr_frags = i;
|
|
}
|
|
|
|
if (skb_has_frag_list(skb)) {
|
|
skb_shinfo(n)->frag_list = skb_shinfo(skb)->frag_list;
|
|
skb_clone_fraglist(n);
|
|
}
|
|
|
|
skb_copy_header(n, skb);
|
|
out:
|
|
return n;
|
|
}
|
|
EXPORT_SYMBOL(__pskb_copy_fclone);
|
|
|
|
/**
|
|
* pskb_expand_head - reallocate header of &sk_buff
|
|
* @skb: buffer to reallocate
|
|
* @nhead: room to add at head
|
|
* @ntail: room to add at tail
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Expands (or creates identical copy, if @nhead and @ntail are zero)
|
|
* header of @skb. &sk_buff itself is not changed. &sk_buff MUST have
|
|
* reference count of 1. Returns zero in the case of success or error,
|
|
* if expansion failed. In the last case, &sk_buff is not changed.
|
|
*
|
|
* All the pointers pointing into skb header may change and must be
|
|
* reloaded after call to this function.
|
|
*/
|
|
|
|
int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
|
|
gfp_t gfp_mask)
|
|
{
|
|
int i, osize = skb_end_offset(skb);
|
|
int size = osize + nhead + ntail;
|
|
long off;
|
|
u8 *data;
|
|
|
|
BUG_ON(nhead < 0);
|
|
|
|
BUG_ON(skb_shared(skb));
|
|
|
|
size = SKB_DATA_ALIGN(size);
|
|
|
|
if (skb_pfmemalloc(skb))
|
|
gfp_mask |= __GFP_MEMALLOC;
|
|
data = kmalloc_reserve(size + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
|
|
gfp_mask, NUMA_NO_NODE, NULL);
|
|
if (!data)
|
|
goto nodata;
|
|
size = SKB_WITH_OVERHEAD(ksize(data));
|
|
|
|
/* Copy only real data... and, alas, header. This should be
|
|
* optimized for the cases when header is void.
|
|
*/
|
|
memcpy(data + nhead, skb->head, skb_tail_pointer(skb) - skb->head);
|
|
|
|
memcpy((struct skb_shared_info *)(data + size),
|
|
skb_shinfo(skb),
|
|
offsetof(struct skb_shared_info, frags[skb_shinfo(skb)->nr_frags]));
|
|
|
|
/*
|
|
* if shinfo is shared we must drop the old head gracefully, but if it
|
|
* is not we can just drop the old head and let the existing refcount
|
|
* be since all we did is relocate the values
|
|
*/
|
|
if (skb_cloned(skb)) {
|
|
if (skb_orphan_frags(skb, gfp_mask))
|
|
goto nofrags;
|
|
if (skb_zcopy(skb))
|
|
refcount_inc(&skb_uarg(skb)->refcnt);
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
|
|
skb_frag_ref(skb, i);
|
|
|
|
if (skb_has_frag_list(skb))
|
|
skb_clone_fraglist(skb);
|
|
|
|
skb_release_data(skb);
|
|
} else {
|
|
skb_free_head(skb);
|
|
}
|
|
off = (data + nhead) - skb->head;
|
|
|
|
skb->head = data;
|
|
skb->head_frag = 0;
|
|
skb->data += off;
|
|
#ifdef NET_SKBUFF_DATA_USES_OFFSET
|
|
skb->end = size;
|
|
off = nhead;
|
|
#else
|
|
skb->end = skb->head + size;
|
|
#endif
|
|
skb->tail += off;
|
|
skb_headers_offset_update(skb, nhead);
|
|
skb->cloned = 0;
|
|
skb->hdr_len = 0;
|
|
skb->nohdr = 0;
|
|
atomic_set(&skb_shinfo(skb)->dataref, 1);
|
|
|
|
skb_metadata_clear(skb);
|
|
|
|
/* It is not generally safe to change skb->truesize.
|
|
* For the moment, we really care of rx path, or
|
|
* when skb is orphaned (not attached to a socket).
|
|
*/
|
|
if (!skb->sk || skb->destructor == sock_edemux)
|
|
skb->truesize += size - osize;
|
|
|
|
return 0;
|
|
|
|
nofrags:
|
|
kfree(data);
|
|
nodata:
|
|
return -ENOMEM;
|
|
}
|
|
EXPORT_SYMBOL(pskb_expand_head);
|
|
|
|
/* Make private copy of skb with writable head and some headroom */
|
|
|
|
struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom)
|
|
{
|
|
struct sk_buff *skb2;
|
|
int delta = headroom - skb_headroom(skb);
|
|
|
|
if (delta <= 0)
|
|
skb2 = pskb_copy(skb, GFP_ATOMIC);
|
|
else {
|
|
skb2 = skb_clone(skb, GFP_ATOMIC);
|
|
if (skb2 && pskb_expand_head(skb2, SKB_DATA_ALIGN(delta), 0,
|
|
GFP_ATOMIC)) {
|
|
kfree_skb(skb2);
|
|
skb2 = NULL;
|
|
}
|
|
}
|
|
return skb2;
|
|
}
|
|
EXPORT_SYMBOL(skb_realloc_headroom);
|
|
|
|
/**
|
|
* skb_copy_expand - copy and expand sk_buff
|
|
* @skb: buffer to copy
|
|
* @newheadroom: new free bytes at head
|
|
* @newtailroom: new free bytes at tail
|
|
* @gfp_mask: allocation priority
|
|
*
|
|
* Make a copy of both an &sk_buff and its data and while doing so
|
|
* allocate additional space.
|
|
*
|
|
* This is used when the caller wishes to modify the data and needs a
|
|
* private copy of the data to alter as well as more space for new fields.
|
|
* Returns %NULL on failure or the pointer to the buffer
|
|
* on success. The returned buffer has a reference count of 1.
|
|
*
|
|
* You must pass %GFP_ATOMIC as the allocation priority if this function
|
|
* is called from an interrupt.
|
|
*/
|
|
struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
|
|
int newheadroom, int newtailroom,
|
|
gfp_t gfp_mask)
|
|
{
|
|
/*
|
|
* Allocate the copy buffer
|
|
*/
|
|
struct sk_buff *n = __alloc_skb(newheadroom + skb->len + newtailroom,
|
|
gfp_mask, skb_alloc_rx_flag(skb),
|
|
NUMA_NO_NODE);
|
|
int oldheadroom = skb_headroom(skb);
|
|
int head_copy_len, head_copy_off;
|
|
|
|
if (!n)
|
|
return NULL;
|
|
|
|
skb_reserve(n, newheadroom);
|
|
|
|
/* Set the tail pointer and length */
|
|
skb_put(n, skb->len);
|
|
|
|
head_copy_len = oldheadroom;
|
|
head_copy_off = 0;
|
|
if (newheadroom <= head_copy_len)
|
|
head_copy_len = newheadroom;
|
|
else
|
|
head_copy_off = newheadroom - head_copy_len;
|
|
|
|
/* Copy the linear header and data. */
|
|
BUG_ON(skb_copy_bits(skb, -head_copy_len, n->head + head_copy_off,
|
|
skb->len + head_copy_len));
|
|
|
|
skb_copy_header(n, skb);
|
|
|
|
skb_headers_offset_update(n, newheadroom - oldheadroom);
|
|
|
|
return n;
|
|
}
|
|
EXPORT_SYMBOL(skb_copy_expand);
|
|
|
|
/**
|
|
* __skb_pad - zero pad the tail of an skb
|
|
* @skb: buffer to pad
|
|
* @pad: space to pad
|
|
* @free_on_error: free buffer on error
|
|
*
|
|
* Ensure that a buffer is followed by a padding area that is zero
|
|
* filled. Used by network drivers which may DMA or transfer data
|
|
* beyond the buffer end onto the wire.
|
|
*
|
|
* May return error in out of memory cases. The skb is freed on error
|
|
* if @free_on_error is true.
|
|
*/
|
|
|
|
int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error)
|
|
{
|
|
int err;
|
|
int ntail;
|
|
|
|
/* If the skbuff is non linear tailroom is always zero.. */
|
|
if (!skb_cloned(skb) && skb_tailroom(skb) >= pad) {
|
|
memset(skb->data+skb->len, 0, pad);
|
|
return 0;
|
|
}
|
|
|
|
ntail = skb->data_len + pad - (skb->end - skb->tail);
|
|
if (likely(skb_cloned(skb) || ntail > 0)) {
|
|
err = pskb_expand_head(skb, 0, ntail, GFP_ATOMIC);
|
|
if (unlikely(err))
|
|
goto free_skb;
|
|
}
|
|
|
|
/* FIXME: The use of this function with non-linear skb's really needs
|
|
* to be audited.
|
|
*/
|
|
err = skb_linearize(skb);
|
|
if (unlikely(err))
|
|
goto free_skb;
|
|
|
|
memset(skb->data + skb->len, 0, pad);
|
|
return 0;
|
|
|
|
free_skb:
|
|
if (free_on_error)
|
|
kfree_skb(skb);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(__skb_pad);
|
|
|
|
/**
|
|
* pskb_put - add data to the tail of a potentially fragmented buffer
|
|
* @skb: start of the buffer to use
|
|
* @tail: tail fragment of the buffer to use
|
|
* @len: amount of data to add
|
|
*
|
|
* This function extends the used data area of the potentially
|
|
* fragmented buffer. @tail must be the last fragment of @skb -- or
|
|
* @skb itself. If this would exceed the total buffer size the kernel
|
|
* will panic. A pointer to the first byte of the extra data is
|
|
* returned.
|
|
*/
|
|
|
|
void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len)
|
|
{
|
|
if (tail != skb) {
|
|
skb->data_len += len;
|
|
skb->len += len;
|
|
}
|
|
return skb_put(tail, len);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pskb_put);
|
|
|
|
/**
|
|
* skb_put - add data to a buffer
|
|
* @skb: buffer to use
|
|
* @len: amount of data to add
|
|
*
|
|
* This function extends the used data area of the buffer. If this would
|
|
* exceed the total buffer size the kernel will panic. A pointer to the
|
|
* first byte of the extra data is returned.
|
|
*/
|
|
void *skb_put(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
void *tmp = skb_tail_pointer(skb);
|
|
SKB_LINEAR_ASSERT(skb);
|
|
skb->tail += len;
|
|
skb->len += len;
|
|
if (unlikely(skb->tail > skb->end))
|
|
skb_over_panic(skb, len, __builtin_return_address(0));
|
|
return tmp;
|
|
}
|
|
EXPORT_SYMBOL(skb_put);
|
|
|
|
/**
|
|
* skb_push - add data to the start of a buffer
|
|
* @skb: buffer to use
|
|
* @len: amount of data to add
|
|
*
|
|
* This function extends the used data area of the buffer at the buffer
|
|
* start. If this would exceed the total buffer headroom the kernel will
|
|
* panic. A pointer to the first byte of the extra data is returned.
|
|
*/
|
|
void *skb_push(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
skb->data -= len;
|
|
skb->len += len;
|
|
if (unlikely(skb->data < skb->head))
|
|
skb_under_panic(skb, len, __builtin_return_address(0));
|
|
return skb->data;
|
|
}
|
|
EXPORT_SYMBOL(skb_push);
|
|
|
|
/**
|
|
* skb_pull - remove data from the start of a buffer
|
|
* @skb: buffer to use
|
|
* @len: amount of data to remove
|
|
*
|
|
* This function removes data from the start of a buffer, returning
|
|
* the memory to the headroom. A pointer to the next data in the buffer
|
|
* is returned. Once the data has been pulled future pushes will overwrite
|
|
* the old data.
|
|
*/
|
|
void *skb_pull(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
return skb_pull_inline(skb, len);
|
|
}
|
|
EXPORT_SYMBOL(skb_pull);
|
|
|
|
/**
|
|
* skb_trim - remove end from a buffer
|
|
* @skb: buffer to alter
|
|
* @len: new length
|
|
*
|
|
* Cut the length of a buffer down by removing data from the tail. If
|
|
* the buffer is already under the length specified it is not modified.
|
|
* The skb must be linear.
|
|
*/
|
|
void skb_trim(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
if (skb->len > len)
|
|
__skb_trim(skb, len);
|
|
}
|
|
EXPORT_SYMBOL(skb_trim);
|
|
|
|
/* Trims skb to length len. It can change skb pointers.
|
|
*/
|
|
|
|
int ___pskb_trim(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
struct sk_buff **fragp;
|
|
struct sk_buff *frag;
|
|
int offset = skb_headlen(skb);
|
|
int nfrags = skb_shinfo(skb)->nr_frags;
|
|
int i;
|
|
int err;
|
|
|
|
if (skb_cloned(skb) &&
|
|
unlikely((err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))))
|
|
return err;
|
|
|
|
i = 0;
|
|
if (offset >= len)
|
|
goto drop_pages;
|
|
|
|
for (; i < nfrags; i++) {
|
|
int end = offset + skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
|
|
if (end < len) {
|
|
offset = end;
|
|
continue;
|
|
}
|
|
|
|
skb_frag_size_set(&skb_shinfo(skb)->frags[i++], len - offset);
|
|
|
|
drop_pages:
|
|
skb_shinfo(skb)->nr_frags = i;
|
|
|
|
for (; i < nfrags; i++)
|
|
skb_frag_unref(skb, i);
|
|
|
|
if (skb_has_frag_list(skb))
|
|
skb_drop_fraglist(skb);
|
|
goto done;
|
|
}
|
|
|
|
for (fragp = &skb_shinfo(skb)->frag_list; (frag = *fragp);
|
|
fragp = &frag->next) {
|
|
int end = offset + frag->len;
|
|
|
|
if (skb_shared(frag)) {
|
|
struct sk_buff *nfrag;
|
|
|
|
nfrag = skb_clone(frag, GFP_ATOMIC);
|
|
if (unlikely(!nfrag))
|
|
return -ENOMEM;
|
|
|
|
nfrag->next = frag->next;
|
|
consume_skb(frag);
|
|
frag = nfrag;
|
|
*fragp = frag;
|
|
}
|
|
|
|
if (end < len) {
|
|
offset = end;
|
|
continue;
|
|
}
|
|
|
|
if (end > len &&
|
|
unlikely((err = pskb_trim(frag, len - offset))))
|
|
return err;
|
|
|
|
if (frag->next)
|
|
skb_drop_list(&frag->next);
|
|
break;
|
|
}
|
|
|
|
done:
|
|
if (len > skb_headlen(skb)) {
|
|
skb->data_len -= skb->len - len;
|
|
skb->len = len;
|
|
} else {
|
|
skb->len = len;
|
|
skb->data_len = 0;
|
|
skb_set_tail_pointer(skb, len);
|
|
}
|
|
|
|
if (!skb->sk || skb->destructor == sock_edemux)
|
|
skb_condense(skb);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(___pskb_trim);
|
|
|
|
/* Note : use pskb_trim_rcsum() instead of calling this directly
|
|
*/
|
|
int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
if (skb->ip_summed == CHECKSUM_COMPLETE) {
|
|
int delta = skb->len - len;
|
|
|
|
skb->csum = csum_block_sub(skb->csum,
|
|
skb_checksum(skb, len, delta, 0),
|
|
len);
|
|
}
|
|
return __pskb_trim(skb, len);
|
|
}
|
|
EXPORT_SYMBOL(pskb_trim_rcsum_slow);
|
|
|
|
/**
|
|
* __pskb_pull_tail - advance tail of skb header
|
|
* @skb: buffer to reallocate
|
|
* @delta: number of bytes to advance tail
|
|
*
|
|
* The function makes a sense only on a fragmented &sk_buff,
|
|
* it expands header moving its tail forward and copying necessary
|
|
* data from fragmented part.
|
|
*
|
|
* &sk_buff MUST have reference count of 1.
|
|
*
|
|
* Returns %NULL (and &sk_buff does not change) if pull failed
|
|
* or value of new tail of skb in the case of success.
|
|
*
|
|
* All the pointers pointing into skb header may change and must be
|
|
* reloaded after call to this function.
|
|
*/
|
|
|
|
/* Moves tail of skb head forward, copying data from fragmented part,
|
|
* when it is necessary.
|
|
* 1. It may fail due to malloc failure.
|
|
* 2. It may change skb pointers.
|
|
*
|
|
* It is pretty complicated. Luckily, it is called only in exceptional cases.
|
|
*/
|
|
void *__pskb_pull_tail(struct sk_buff *skb, int delta)
|
|
{
|
|
/* If skb has not enough free space at tail, get new one
|
|
* plus 128 bytes for future expansions. If we have enough
|
|
* room at tail, reallocate without expansion only if skb is cloned.
|
|
*/
|
|
int i, k, eat = (skb->tail + delta) - skb->end;
|
|
|
|
if (eat > 0 || skb_cloned(skb)) {
|
|
if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0,
|
|
GFP_ATOMIC))
|
|
return NULL;
|
|
}
|
|
|
|
BUG_ON(skb_copy_bits(skb, skb_headlen(skb),
|
|
skb_tail_pointer(skb), delta));
|
|
|
|
/* Optimization: no fragments, no reasons to preestimate
|
|
* size of pulled pages. Superb.
|
|
*/
|
|
if (!skb_has_frag_list(skb))
|
|
goto pull_pages;
|
|
|
|
/* Estimate size of pulled pages. */
|
|
eat = delta;
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
|
|
if (size >= eat)
|
|
goto pull_pages;
|
|
eat -= size;
|
|
}
|
|
|
|
/* If we need update frag list, we are in troubles.
|
|
* Certainly, it is possible to add an offset to skb data,
|
|
* but taking into account that pulling is expected to
|
|
* be very rare operation, it is worth to fight against
|
|
* further bloating skb head and crucify ourselves here instead.
|
|
* Pure masohism, indeed. 8)8)
|
|
*/
|
|
if (eat) {
|
|
struct sk_buff *list = skb_shinfo(skb)->frag_list;
|
|
struct sk_buff *clone = NULL;
|
|
struct sk_buff *insp = NULL;
|
|
|
|
do {
|
|
if (list->len <= eat) {
|
|
/* Eaten as whole. */
|
|
eat -= list->len;
|
|
list = list->next;
|
|
insp = list;
|
|
} else {
|
|
/* Eaten partially. */
|
|
|
|
if (skb_shared(list)) {
|
|
/* Sucks! We need to fork list. :-( */
|
|
clone = skb_clone(list, GFP_ATOMIC);
|
|
if (!clone)
|
|
return NULL;
|
|
insp = list->next;
|
|
list = clone;
|
|
} else {
|
|
/* This may be pulled without
|
|
* problems. */
|
|
insp = list;
|
|
}
|
|
if (!pskb_pull(list, eat)) {
|
|
kfree_skb(clone);
|
|
return NULL;
|
|
}
|
|
break;
|
|
}
|
|
} while (eat);
|
|
|
|
/* Free pulled out fragments. */
|
|
while ((list = skb_shinfo(skb)->frag_list) != insp) {
|
|
skb_shinfo(skb)->frag_list = list->next;
|
|
kfree_skb(list);
|
|
}
|
|
/* And insert new clone at head. */
|
|
if (clone) {
|
|
clone->next = list;
|
|
skb_shinfo(skb)->frag_list = clone;
|
|
}
|
|
}
|
|
/* Success! Now we may commit changes to skb data. */
|
|
|
|
pull_pages:
|
|
eat = delta;
|
|
k = 0;
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
|
|
if (size <= eat) {
|
|
skb_frag_unref(skb, i);
|
|
eat -= size;
|
|
} else {
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[k];
|
|
|
|
*frag = skb_shinfo(skb)->frags[i];
|
|
if (eat) {
|
|
skb_frag_off_add(frag, eat);
|
|
skb_frag_size_sub(frag, eat);
|
|
if (!i)
|
|
goto end;
|
|
eat = 0;
|
|
}
|
|
k++;
|
|
}
|
|
}
|
|
skb_shinfo(skb)->nr_frags = k;
|
|
|
|
end:
|
|
skb->tail += delta;
|
|
skb->data_len -= delta;
|
|
|
|
if (!skb->data_len)
|
|
skb_zcopy_clear(skb, false);
|
|
|
|
return skb_tail_pointer(skb);
|
|
}
|
|
EXPORT_SYMBOL(__pskb_pull_tail);
|
|
|
|
/**
|
|
* skb_copy_bits - copy bits from skb to kernel buffer
|
|
* @skb: source skb
|
|
* @offset: offset in source
|
|
* @to: destination buffer
|
|
* @len: number of bytes to copy
|
|
*
|
|
* Copy the specified number of bytes from the source skb to the
|
|
* destination buffer.
|
|
*
|
|
* CAUTION ! :
|
|
* If its prototype is ever changed,
|
|
* check arch/{*}/net/{*}.S files,
|
|
* since it is called from BPF assembly code.
|
|
*/
|
|
int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len)
|
|
{
|
|
int start = skb_headlen(skb);
|
|
struct sk_buff *frag_iter;
|
|
int i, copy;
|
|
|
|
if (offset > (int)skb->len - len)
|
|
goto fault;
|
|
|
|
/* Copy header. */
|
|
if ((copy = start - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
skb_copy_from_linear_data_offset(skb, offset, to, copy);
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
to += copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int end;
|
|
skb_frag_t *f = &skb_shinfo(skb)->frags[i];
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + skb_frag_size(f);
|
|
if ((copy = end - offset) > 0) {
|
|
u32 p_off, p_len, copied;
|
|
struct page *p;
|
|
u8 *vaddr;
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
|
|
skb_frag_foreach_page(f,
|
|
skb_frag_off(f) + offset - start,
|
|
copy, p, p_off, p_len, copied) {
|
|
vaddr = kmap_atomic(p);
|
|
memcpy(to + copied, vaddr + p_off, p_len);
|
|
kunmap_atomic(vaddr);
|
|
}
|
|
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
to += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
skb_walk_frags(skb, frag_iter) {
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + frag_iter->len;
|
|
if ((copy = end - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
if (skb_copy_bits(frag_iter, offset - start, to, copy))
|
|
goto fault;
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
to += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
if (!len)
|
|
return 0;
|
|
|
|
fault:
|
|
return -EFAULT;
|
|
}
|
|
EXPORT_SYMBOL(skb_copy_bits);
|
|
|
|
/*
|
|
* Callback from splice_to_pipe(), if we need to release some pages
|
|
* at the end of the spd in case we error'ed out in filling the pipe.
|
|
*/
|
|
static void sock_spd_release(struct splice_pipe_desc *spd, unsigned int i)
|
|
{
|
|
put_page(spd->pages[i]);
|
|
}
|
|
|
|
static struct page *linear_to_page(struct page *page, unsigned int *len,
|
|
unsigned int *offset,
|
|
struct sock *sk)
|
|
{
|
|
struct page_frag *pfrag = sk_page_frag(sk);
|
|
|
|
if (!sk_page_frag_refill(sk, pfrag))
|
|
return NULL;
|
|
|
|
*len = min_t(unsigned int, *len, pfrag->size - pfrag->offset);
|
|
|
|
memcpy(page_address(pfrag->page) + pfrag->offset,
|
|
page_address(page) + *offset, *len);
|
|
*offset = pfrag->offset;
|
|
pfrag->offset += *len;
|
|
|
|
return pfrag->page;
|
|
}
|
|
|
|
static bool spd_can_coalesce(const struct splice_pipe_desc *spd,
|
|
struct page *page,
|
|
unsigned int offset)
|
|
{
|
|
return spd->nr_pages &&
|
|
spd->pages[spd->nr_pages - 1] == page &&
|
|
(spd->partial[spd->nr_pages - 1].offset +
|
|
spd->partial[spd->nr_pages - 1].len == offset);
|
|
}
|
|
|
|
/*
|
|
* Fill page/offset/length into spd, if it can hold more pages.
|
|
*/
|
|
static bool spd_fill_page(struct splice_pipe_desc *spd,
|
|
struct pipe_inode_info *pipe, struct page *page,
|
|
unsigned int *len, unsigned int offset,
|
|
bool linear,
|
|
struct sock *sk)
|
|
{
|
|
if (unlikely(spd->nr_pages == MAX_SKB_FRAGS))
|
|
return true;
|
|
|
|
if (linear) {
|
|
page = linear_to_page(page, len, &offset, sk);
|
|
if (!page)
|
|
return true;
|
|
}
|
|
if (spd_can_coalesce(spd, page, offset)) {
|
|
spd->partial[spd->nr_pages - 1].len += *len;
|
|
return false;
|
|
}
|
|
get_page(page);
|
|
spd->pages[spd->nr_pages] = page;
|
|
spd->partial[spd->nr_pages].len = *len;
|
|
spd->partial[spd->nr_pages].offset = offset;
|
|
spd->nr_pages++;
|
|
|
|
return false;
|
|
}
|
|
|
|
static bool __splice_segment(struct page *page, unsigned int poff,
|
|
unsigned int plen, unsigned int *off,
|
|
unsigned int *len,
|
|
struct splice_pipe_desc *spd, bool linear,
|
|
struct sock *sk,
|
|
struct pipe_inode_info *pipe)
|
|
{
|
|
if (!*len)
|
|
return true;
|
|
|
|
/* skip this segment if already processed */
|
|
if (*off >= plen) {
|
|
*off -= plen;
|
|
return false;
|
|
}
|
|
|
|
/* ignore any bits we already processed */
|
|
poff += *off;
|
|
plen -= *off;
|
|
*off = 0;
|
|
|
|
do {
|
|
unsigned int flen = min(*len, plen);
|
|
|
|
if (spd_fill_page(spd, pipe, page, &flen, poff,
|
|
linear, sk))
|
|
return true;
|
|
poff += flen;
|
|
plen -= flen;
|
|
*len -= flen;
|
|
} while (*len && plen);
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Map linear and fragment data from the skb to spd. It reports true if the
|
|
* pipe is full or if we already spliced the requested length.
|
|
*/
|
|
static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
|
|
unsigned int *offset, unsigned int *len,
|
|
struct splice_pipe_desc *spd, struct sock *sk)
|
|
{
|
|
int seg;
|
|
struct sk_buff *iter;
|
|
|
|
/* map the linear part :
|
|
* If skb->head_frag is set, this 'linear' part is backed by a
|
|
* fragment, and if the head is not shared with any clones then
|
|
* we can avoid a copy since we own the head portion of this page.
|
|
*/
|
|
if (__splice_segment(virt_to_page(skb->data),
|
|
(unsigned long) skb->data & (PAGE_SIZE - 1),
|
|
skb_headlen(skb),
|
|
offset, len, spd,
|
|
skb_head_is_locked(skb),
|
|
sk, pipe))
|
|
return true;
|
|
|
|
/*
|
|
* then map the fragments
|
|
*/
|
|
for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) {
|
|
const skb_frag_t *f = &skb_shinfo(skb)->frags[seg];
|
|
|
|
if (__splice_segment(skb_frag_page(f),
|
|
skb_frag_off(f), skb_frag_size(f),
|
|
offset, len, spd, false, sk, pipe))
|
|
return true;
|
|
}
|
|
|
|
skb_walk_frags(skb, iter) {
|
|
if (*offset >= iter->len) {
|
|
*offset -= iter->len;
|
|
continue;
|
|
}
|
|
/* __skb_splice_bits() only fails if the output has no room
|
|
* left, so no point in going over the frag_list for the error
|
|
* case.
|
|
*/
|
|
if (__skb_splice_bits(iter, pipe, offset, len, spd, sk))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Map data from the skb to a pipe. Should handle both the linear part,
|
|
* the fragments, and the frag list.
|
|
*/
|
|
int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
|
|
struct pipe_inode_info *pipe, unsigned int tlen,
|
|
unsigned int flags)
|
|
{
|
|
struct partial_page partial[MAX_SKB_FRAGS];
|
|
struct page *pages[MAX_SKB_FRAGS];
|
|
struct splice_pipe_desc spd = {
|
|
.pages = pages,
|
|
.partial = partial,
|
|
.nr_pages_max = MAX_SKB_FRAGS,
|
|
.ops = &nosteal_pipe_buf_ops,
|
|
.spd_release = sock_spd_release,
|
|
};
|
|
int ret = 0;
|
|
|
|
__skb_splice_bits(skb, pipe, &offset, &tlen, &spd, sk);
|
|
|
|
if (spd.nr_pages)
|
|
ret = splice_to_pipe(pipe, &spd);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_splice_bits);
|
|
|
|
/* Send skb data on a socket. Socket must be locked. */
|
|
int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
|
|
int len)
|
|
{
|
|
unsigned int orig_len = len;
|
|
struct sk_buff *head = skb;
|
|
unsigned short fragidx;
|
|
int slen, ret;
|
|
|
|
do_frag_list:
|
|
|
|
/* Deal with head data */
|
|
while (offset < skb_headlen(skb) && len) {
|
|
struct kvec kv;
|
|
struct msghdr msg;
|
|
|
|
slen = min_t(int, len, skb_headlen(skb) - offset);
|
|
kv.iov_base = skb->data + offset;
|
|
kv.iov_len = slen;
|
|
memset(&msg, 0, sizeof(msg));
|
|
msg.msg_flags = MSG_DONTWAIT;
|
|
|
|
ret = kernel_sendmsg_locked(sk, &msg, &kv, 1, slen);
|
|
if (ret <= 0)
|
|
goto error;
|
|
|
|
offset += ret;
|
|
len -= ret;
|
|
}
|
|
|
|
/* All the data was skb head? */
|
|
if (!len)
|
|
goto out;
|
|
|
|
/* Make offset relative to start of frags */
|
|
offset -= skb_headlen(skb);
|
|
|
|
/* Find where we are in frag list */
|
|
for (fragidx = 0; fragidx < skb_shinfo(skb)->nr_frags; fragidx++) {
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[fragidx];
|
|
|
|
if (offset < skb_frag_size(frag))
|
|
break;
|
|
|
|
offset -= skb_frag_size(frag);
|
|
}
|
|
|
|
for (; len && fragidx < skb_shinfo(skb)->nr_frags; fragidx++) {
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[fragidx];
|
|
|
|
slen = min_t(size_t, len, skb_frag_size(frag) - offset);
|
|
|
|
while (slen) {
|
|
ret = kernel_sendpage_locked(sk, skb_frag_page(frag),
|
|
skb_frag_off(frag) + offset,
|
|
slen, MSG_DONTWAIT);
|
|
if (ret <= 0)
|
|
goto error;
|
|
|
|
len -= ret;
|
|
offset += ret;
|
|
slen -= ret;
|
|
}
|
|
|
|
offset = 0;
|
|
}
|
|
|
|
if (len) {
|
|
/* Process any frag lists */
|
|
|
|
if (skb == head) {
|
|
if (skb_has_frag_list(skb)) {
|
|
skb = skb_shinfo(skb)->frag_list;
|
|
goto do_frag_list;
|
|
}
|
|
} else if (skb->next) {
|
|
skb = skb->next;
|
|
goto do_frag_list;
|
|
}
|
|
}
|
|
|
|
out:
|
|
return orig_len - len;
|
|
|
|
error:
|
|
return orig_len == len ? ret : orig_len - len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_send_sock_locked);
|
|
|
|
/**
|
|
* skb_store_bits - store bits from kernel buffer to skb
|
|
* @skb: destination buffer
|
|
* @offset: offset in destination
|
|
* @from: source buffer
|
|
* @len: number of bytes to copy
|
|
*
|
|
* Copy the specified number of bytes from the source buffer to the
|
|
* destination skb. This function handles all the messy bits of
|
|
* traversing fragment lists and such.
|
|
*/
|
|
|
|
int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len)
|
|
{
|
|
int start = skb_headlen(skb);
|
|
struct sk_buff *frag_iter;
|
|
int i, copy;
|
|
|
|
if (offset > (int)skb->len - len)
|
|
goto fault;
|
|
|
|
if ((copy = start - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
skb_copy_to_linear_data_offset(skb, offset, from, copy);
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
from += copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + skb_frag_size(frag);
|
|
if ((copy = end - offset) > 0) {
|
|
u32 p_off, p_len, copied;
|
|
struct page *p;
|
|
u8 *vaddr;
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
|
|
skb_frag_foreach_page(frag,
|
|
skb_frag_off(frag) + offset - start,
|
|
copy, p, p_off, p_len, copied) {
|
|
vaddr = kmap_atomic(p);
|
|
memcpy(vaddr + p_off, from + copied, p_len);
|
|
kunmap_atomic(vaddr);
|
|
}
|
|
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
from += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
skb_walk_frags(skb, frag_iter) {
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + frag_iter->len;
|
|
if ((copy = end - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
if (skb_store_bits(frag_iter, offset - start,
|
|
from, copy))
|
|
goto fault;
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
from += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
if (!len)
|
|
return 0;
|
|
|
|
fault:
|
|
return -EFAULT;
|
|
}
|
|
EXPORT_SYMBOL(skb_store_bits);
|
|
|
|
/* Checksum skb data. */
|
|
__wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
|
|
__wsum csum, const struct skb_checksum_ops *ops)
|
|
{
|
|
int start = skb_headlen(skb);
|
|
int i, copy = start - offset;
|
|
struct sk_buff *frag_iter;
|
|
int pos = 0;
|
|
|
|
/* Checksum header. */
|
|
if (copy > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
csum = INDIRECT_CALL_1(ops->update, csum_partial_ext,
|
|
skb->data + offset, copy, csum);
|
|
if ((len -= copy) == 0)
|
|
return csum;
|
|
offset += copy;
|
|
pos = copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int end;
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + skb_frag_size(frag);
|
|
if ((copy = end - offset) > 0) {
|
|
u32 p_off, p_len, copied;
|
|
struct page *p;
|
|
__wsum csum2;
|
|
u8 *vaddr;
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
|
|
skb_frag_foreach_page(frag,
|
|
skb_frag_off(frag) + offset - start,
|
|
copy, p, p_off, p_len, copied) {
|
|
vaddr = kmap_atomic(p);
|
|
csum2 = INDIRECT_CALL_1(ops->update,
|
|
csum_partial_ext,
|
|
vaddr + p_off, p_len, 0);
|
|
kunmap_atomic(vaddr);
|
|
csum = INDIRECT_CALL_1(ops->combine,
|
|
csum_block_add_ext, csum,
|
|
csum2, pos, p_len);
|
|
pos += p_len;
|
|
}
|
|
|
|
if (!(len -= copy))
|
|
return csum;
|
|
offset += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
skb_walk_frags(skb, frag_iter) {
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + frag_iter->len;
|
|
if ((copy = end - offset) > 0) {
|
|
__wsum csum2;
|
|
if (copy > len)
|
|
copy = len;
|
|
csum2 = __skb_checksum(frag_iter, offset - start,
|
|
copy, 0, ops);
|
|
csum = INDIRECT_CALL_1(ops->combine, csum_block_add_ext,
|
|
csum, csum2, pos, copy);
|
|
if ((len -= copy) == 0)
|
|
return csum;
|
|
offset += copy;
|
|
pos += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
BUG_ON(len);
|
|
|
|
return csum;
|
|
}
|
|
EXPORT_SYMBOL(__skb_checksum);
|
|
|
|
__wsum skb_checksum(const struct sk_buff *skb, int offset,
|
|
int len, __wsum csum)
|
|
{
|
|
const struct skb_checksum_ops ops = {
|
|
.update = csum_partial_ext,
|
|
.combine = csum_block_add_ext,
|
|
};
|
|
|
|
return __skb_checksum(skb, offset, len, csum, &ops);
|
|
}
|
|
EXPORT_SYMBOL(skb_checksum);
|
|
|
|
/* Both of above in one bottle. */
|
|
|
|
__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
|
|
u8 *to, int len, __wsum csum)
|
|
{
|
|
int start = skb_headlen(skb);
|
|
int i, copy = start - offset;
|
|
struct sk_buff *frag_iter;
|
|
int pos = 0;
|
|
|
|
/* Copy header. */
|
|
if (copy > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
csum = csum_partial_copy_nocheck(skb->data + offset, to,
|
|
copy, csum);
|
|
if ((len -= copy) == 0)
|
|
return csum;
|
|
offset += copy;
|
|
to += copy;
|
|
pos = copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
if ((copy = end - offset) > 0) {
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
|
|
u32 p_off, p_len, copied;
|
|
struct page *p;
|
|
__wsum csum2;
|
|
u8 *vaddr;
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
|
|
skb_frag_foreach_page(frag,
|
|
skb_frag_off(frag) + offset - start,
|
|
copy, p, p_off, p_len, copied) {
|
|
vaddr = kmap_atomic(p);
|
|
csum2 = csum_partial_copy_nocheck(vaddr + p_off,
|
|
to + copied,
|
|
p_len, 0);
|
|
kunmap_atomic(vaddr);
|
|
csum = csum_block_add(csum, csum2, pos);
|
|
pos += p_len;
|
|
}
|
|
|
|
if (!(len -= copy))
|
|
return csum;
|
|
offset += copy;
|
|
to += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
skb_walk_frags(skb, frag_iter) {
|
|
__wsum csum2;
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + frag_iter->len;
|
|
if ((copy = end - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
csum2 = skb_copy_and_csum_bits(frag_iter,
|
|
offset - start,
|
|
to, copy, 0);
|
|
csum = csum_block_add(csum, csum2, pos);
|
|
if ((len -= copy) == 0)
|
|
return csum;
|
|
offset += copy;
|
|
to += copy;
|
|
pos += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
BUG_ON(len);
|
|
return csum;
|
|
}
|
|
EXPORT_SYMBOL(skb_copy_and_csum_bits);
|
|
|
|
__sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len)
|
|
{
|
|
__sum16 sum;
|
|
|
|
sum = csum_fold(skb_checksum(skb, 0, len, skb->csum));
|
|
/* See comments in __skb_checksum_complete(). */
|
|
if (likely(!sum)) {
|
|
if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
|
|
!skb->csum_complete_sw)
|
|
netdev_rx_csum_fault(skb->dev, skb);
|
|
}
|
|
if (!skb_shared(skb))
|
|
skb->csum_valid = !sum;
|
|
return sum;
|
|
}
|
|
EXPORT_SYMBOL(__skb_checksum_complete_head);
|
|
|
|
/* This function assumes skb->csum already holds pseudo header's checksum,
|
|
* which has been changed from the hardware checksum, for example, by
|
|
* __skb_checksum_validate_complete(). And, the original skb->csum must
|
|
* have been validated unsuccessfully for CHECKSUM_COMPLETE case.
|
|
*
|
|
* It returns non-zero if the recomputed checksum is still invalid, otherwise
|
|
* zero. The new checksum is stored back into skb->csum unless the skb is
|
|
* shared.
|
|
*/
|
|
__sum16 __skb_checksum_complete(struct sk_buff *skb)
|
|
{
|
|
__wsum csum;
|
|
__sum16 sum;
|
|
|
|
csum = skb_checksum(skb, 0, skb->len, 0);
|
|
|
|
sum = csum_fold(csum_add(skb->csum, csum));
|
|
/* This check is inverted, because we already knew the hardware
|
|
* checksum is invalid before calling this function. So, if the
|
|
* re-computed checksum is valid instead, then we have a mismatch
|
|
* between the original skb->csum and skb_checksum(). This means either
|
|
* the original hardware checksum is incorrect or we screw up skb->csum
|
|
* when moving skb->data around.
|
|
*/
|
|
if (likely(!sum)) {
|
|
if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
|
|
!skb->csum_complete_sw)
|
|
netdev_rx_csum_fault(skb->dev, skb);
|
|
}
|
|
|
|
if (!skb_shared(skb)) {
|
|
/* Save full packet checksum */
|
|
skb->csum = csum;
|
|
skb->ip_summed = CHECKSUM_COMPLETE;
|
|
skb->csum_complete_sw = 1;
|
|
skb->csum_valid = !sum;
|
|
}
|
|
|
|
return sum;
|
|
}
|
|
EXPORT_SYMBOL(__skb_checksum_complete);
|
|
|
|
static __wsum warn_crc32c_csum_update(const void *buff, int len, __wsum sum)
|
|
{
|
|
net_warn_ratelimited(
|
|
"%s: attempt to compute crc32c without libcrc32c.ko\n",
|
|
__func__);
|
|
return 0;
|
|
}
|
|
|
|
static __wsum warn_crc32c_csum_combine(__wsum csum, __wsum csum2,
|
|
int offset, int len)
|
|
{
|
|
net_warn_ratelimited(
|
|
"%s: attempt to compute crc32c without libcrc32c.ko\n",
|
|
__func__);
|
|
return 0;
|
|
}
|
|
|
|
static const struct skb_checksum_ops default_crc32c_ops = {
|
|
.update = warn_crc32c_csum_update,
|
|
.combine = warn_crc32c_csum_combine,
|
|
};
|
|
|
|
const struct skb_checksum_ops *crc32c_csum_stub __read_mostly =
|
|
&default_crc32c_ops;
|
|
EXPORT_SYMBOL(crc32c_csum_stub);
|
|
|
|
/**
|
|
* skb_zerocopy_headlen - Calculate headroom needed for skb_zerocopy()
|
|
* @from: source buffer
|
|
*
|
|
* Calculates the amount of linear headroom needed in the 'to' skb passed
|
|
* into skb_zerocopy().
|
|
*/
|
|
unsigned int
|
|
skb_zerocopy_headlen(const struct sk_buff *from)
|
|
{
|
|
unsigned int hlen = 0;
|
|
|
|
if (!from->head_frag ||
|
|
skb_headlen(from) < L1_CACHE_BYTES ||
|
|
skb_shinfo(from)->nr_frags >= MAX_SKB_FRAGS)
|
|
hlen = skb_headlen(from);
|
|
|
|
if (skb_has_frag_list(from))
|
|
hlen = from->len;
|
|
|
|
return hlen;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_zerocopy_headlen);
|
|
|
|
/**
|
|
* skb_zerocopy - Zero copy skb to skb
|
|
* @to: destination buffer
|
|
* @from: source buffer
|
|
* @len: number of bytes to copy from source buffer
|
|
* @hlen: size of linear headroom in destination buffer
|
|
*
|
|
* Copies up to `len` bytes from `from` to `to` by creating references
|
|
* to the frags in the source buffer.
|
|
*
|
|
* The `hlen` as calculated by skb_zerocopy_headlen() specifies the
|
|
* headroom in the `to` buffer.
|
|
*
|
|
* Return value:
|
|
* 0: everything is OK
|
|
* -ENOMEM: couldn't orphan frags of @from due to lack of memory
|
|
* -EFAULT: skb_copy_bits() found some problem with skb geometry
|
|
*/
|
|
int
|
|
skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen)
|
|
{
|
|
int i, j = 0;
|
|
int plen = 0; /* length of skb->head fragment */
|
|
int ret;
|
|
struct page *page;
|
|
unsigned int offset;
|
|
|
|
BUG_ON(!from->head_frag && !hlen);
|
|
|
|
/* dont bother with small payloads */
|
|
if (len <= skb_tailroom(to))
|
|
return skb_copy_bits(from, 0, skb_put(to, len), len);
|
|
|
|
if (hlen) {
|
|
ret = skb_copy_bits(from, 0, skb_put(to, hlen), hlen);
|
|
if (unlikely(ret))
|
|
return ret;
|
|
len -= hlen;
|
|
} else {
|
|
plen = min_t(int, skb_headlen(from), len);
|
|
if (plen) {
|
|
page = virt_to_head_page(from->head);
|
|
offset = from->data - (unsigned char *)page_address(page);
|
|
__skb_fill_page_desc(to, 0, page, offset, plen);
|
|
get_page(page);
|
|
j = 1;
|
|
len -= plen;
|
|
}
|
|
}
|
|
|
|
to->truesize += len + plen;
|
|
to->len += len + plen;
|
|
to->data_len += len + plen;
|
|
|
|
if (unlikely(skb_orphan_frags(from, GFP_ATOMIC))) {
|
|
skb_tx_error(from);
|
|
return -ENOMEM;
|
|
}
|
|
skb_zerocopy_clone(to, from, GFP_ATOMIC);
|
|
|
|
for (i = 0; i < skb_shinfo(from)->nr_frags; i++) {
|
|
int size;
|
|
|
|
if (!len)
|
|
break;
|
|
skb_shinfo(to)->frags[j] = skb_shinfo(from)->frags[i];
|
|
size = min_t(int, skb_frag_size(&skb_shinfo(to)->frags[j]),
|
|
len);
|
|
skb_frag_size_set(&skb_shinfo(to)->frags[j], size);
|
|
len -= size;
|
|
skb_frag_ref(to, j);
|
|
j++;
|
|
}
|
|
skb_shinfo(to)->nr_frags = j;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_zerocopy);
|
|
|
|
void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to)
|
|
{
|
|
__wsum csum;
|
|
long csstart;
|
|
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL)
|
|
csstart = skb_checksum_start_offset(skb);
|
|
else
|
|
csstart = skb_headlen(skb);
|
|
|
|
BUG_ON(csstart > skb_headlen(skb));
|
|
|
|
skb_copy_from_linear_data(skb, to, csstart);
|
|
|
|
csum = 0;
|
|
if (csstart != skb->len)
|
|
csum = skb_copy_and_csum_bits(skb, csstart, to + csstart,
|
|
skb->len - csstart, 0);
|
|
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL) {
|
|
long csstuff = csstart + skb->csum_offset;
|
|
|
|
*((__sum16 *)(to + csstuff)) = csum_fold(csum);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(skb_copy_and_csum_dev);
|
|
|
|
/**
|
|
* skb_dequeue - remove from the head of the queue
|
|
* @list: list to dequeue from
|
|
*
|
|
* Remove the head of the list. The list lock is taken so the function
|
|
* may be used safely with other locking list functions. The head item is
|
|
* returned or %NULL if the list is empty.
|
|
*/
|
|
|
|
struct sk_buff *skb_dequeue(struct sk_buff_head *list)
|
|
{
|
|
unsigned long flags;
|
|
struct sk_buff *result;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
result = __skb_dequeue(list);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL(skb_dequeue);
|
|
|
|
/**
|
|
* skb_dequeue_tail - remove from the tail of the queue
|
|
* @list: list to dequeue from
|
|
*
|
|
* Remove the tail of the list. The list lock is taken so the function
|
|
* may be used safely with other locking list functions. The tail item is
|
|
* returned or %NULL if the list is empty.
|
|
*/
|
|
struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list)
|
|
{
|
|
unsigned long flags;
|
|
struct sk_buff *result;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
result = __skb_dequeue_tail(list);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL(skb_dequeue_tail);
|
|
|
|
/**
|
|
* skb_queue_purge - empty a list
|
|
* @list: list to empty
|
|
*
|
|
* Delete all buffers on an &sk_buff list. Each buffer is removed from
|
|
* the list and one reference dropped. This function takes the list
|
|
* lock and is atomic with respect to other list locking functions.
|
|
*/
|
|
void skb_queue_purge(struct sk_buff_head *list)
|
|
{
|
|
struct sk_buff *skb;
|
|
while ((skb = skb_dequeue(list)) != NULL)
|
|
kfree_skb(skb);
|
|
}
|
|
EXPORT_SYMBOL(skb_queue_purge);
|
|
|
|
/**
|
|
* skb_rbtree_purge - empty a skb rbtree
|
|
* @root: root of the rbtree to empty
|
|
* Return value: the sum of truesizes of all purged skbs.
|
|
*
|
|
* Delete all buffers on an &sk_buff rbtree. Each buffer is removed from
|
|
* the list and one reference dropped. This function does not take
|
|
* any lock. Synchronization should be handled by the caller (e.g., TCP
|
|
* out-of-order queue is protected by the socket lock).
|
|
*/
|
|
unsigned int skb_rbtree_purge(struct rb_root *root)
|
|
{
|
|
struct rb_node *p = rb_first(root);
|
|
unsigned int sum = 0;
|
|
|
|
while (p) {
|
|
struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode);
|
|
|
|
p = rb_next(p);
|
|
rb_erase(&skb->rbnode, root);
|
|
sum += skb->truesize;
|
|
kfree_skb(skb);
|
|
}
|
|
return sum;
|
|
}
|
|
|
|
/**
|
|
* skb_queue_head - queue a buffer at the list head
|
|
* @list: list to use
|
|
* @newsk: buffer to queue
|
|
*
|
|
* Queue a buffer at the start of the list. This function takes the
|
|
* list lock and can be used safely with other locking &sk_buff functions
|
|
* safely.
|
|
*
|
|
* A buffer cannot be placed on two lists at the same time.
|
|
*/
|
|
void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
__skb_queue_head(list, newsk);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(skb_queue_head);
|
|
|
|
/**
|
|
* skb_queue_tail - queue a buffer at the list tail
|
|
* @list: list to use
|
|
* @newsk: buffer to queue
|
|
*
|
|
* Queue a buffer at the tail of the list. This function takes the
|
|
* list lock and can be used safely with other locking &sk_buff functions
|
|
* safely.
|
|
*
|
|
* A buffer cannot be placed on two lists at the same time.
|
|
*/
|
|
void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
__skb_queue_tail(list, newsk);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(skb_queue_tail);
|
|
|
|
/**
|
|
* skb_unlink - remove a buffer from a list
|
|
* @skb: buffer to remove
|
|
* @list: list to use
|
|
*
|
|
* Remove a packet from a list. The list locks are taken and this
|
|
* function is atomic with respect to other list locked calls
|
|
*
|
|
* You must know what list the SKB is on.
|
|
*/
|
|
void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
__skb_unlink(skb, list);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(skb_unlink);
|
|
|
|
/**
|
|
* skb_append - append a buffer
|
|
* @old: buffer to insert after
|
|
* @newsk: buffer to insert
|
|
* @list: list to use
|
|
*
|
|
* Place a packet after a given packet in a list. The list locks are taken
|
|
* and this function is atomic with respect to other list locked calls.
|
|
* A buffer cannot be placed on two lists at the same time.
|
|
*/
|
|
void skb_append(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&list->lock, flags);
|
|
__skb_queue_after(list, old, newsk);
|
|
spin_unlock_irqrestore(&list->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(skb_append);
|
|
|
|
static inline void skb_split_inside_header(struct sk_buff *skb,
|
|
struct sk_buff* skb1,
|
|
const u32 len, const int pos)
|
|
{
|
|
int i;
|
|
|
|
skb_copy_from_linear_data_offset(skb, len, skb_put(skb1, pos - len),
|
|
pos - len);
|
|
/* And move data appendix as is. */
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
|
|
skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i];
|
|
|
|
skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags;
|
|
skb_shinfo(skb)->nr_frags = 0;
|
|
skb1->data_len = skb->data_len;
|
|
skb1->len += skb1->data_len;
|
|
skb->data_len = 0;
|
|
skb->len = len;
|
|
skb_set_tail_pointer(skb, len);
|
|
}
|
|
|
|
static inline void skb_split_no_header(struct sk_buff *skb,
|
|
struct sk_buff* skb1,
|
|
const u32 len, int pos)
|
|
{
|
|
int i, k = 0;
|
|
const int nfrags = skb_shinfo(skb)->nr_frags;
|
|
|
|
skb_shinfo(skb)->nr_frags = 0;
|
|
skb1->len = skb1->data_len = skb->len - len;
|
|
skb->len = len;
|
|
skb->data_len = len - pos;
|
|
|
|
for (i = 0; i < nfrags; i++) {
|
|
int size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
|
|
if (pos + size > len) {
|
|
skb_shinfo(skb1)->frags[k] = skb_shinfo(skb)->frags[i];
|
|
|
|
if (pos < len) {
|
|
/* Split frag.
|
|
* We have two variants in this case:
|
|
* 1. Move all the frag to the second
|
|
* part, if it is possible. F.e.
|
|
* this approach is mandatory for TUX,
|
|
* where splitting is expensive.
|
|
* 2. Split is accurately. We make this.
|
|
*/
|
|
skb_frag_ref(skb, i);
|
|
skb_frag_off_add(&skb_shinfo(skb1)->frags[0], len - pos);
|
|
skb_frag_size_sub(&skb_shinfo(skb1)->frags[0], len - pos);
|
|
skb_frag_size_set(&skb_shinfo(skb)->frags[i], len - pos);
|
|
skb_shinfo(skb)->nr_frags++;
|
|
}
|
|
k++;
|
|
} else
|
|
skb_shinfo(skb)->nr_frags++;
|
|
pos += size;
|
|
}
|
|
skb_shinfo(skb1)->nr_frags = k;
|
|
}
|
|
|
|
/**
|
|
* skb_split - Split fragmented skb to two parts at length len.
|
|
* @skb: the buffer to split
|
|
* @skb1: the buffer to receive the second part
|
|
* @len: new length for skb
|
|
*/
|
|
void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len)
|
|
{
|
|
int pos = skb_headlen(skb);
|
|
|
|
skb_shinfo(skb1)->tx_flags |= skb_shinfo(skb)->tx_flags &
|
|
SKBTX_SHARED_FRAG;
|
|
skb_zerocopy_clone(skb1, skb, 0);
|
|
if (len < pos) /* Split line is inside header. */
|
|
skb_split_inside_header(skb, skb1, len, pos);
|
|
else /* Second chunk has no header, nothing to copy. */
|
|
skb_split_no_header(skb, skb1, len, pos);
|
|
}
|
|
EXPORT_SYMBOL(skb_split);
|
|
|
|
/* Shifting from/to a cloned skb is a no-go.
|
|
*
|
|
* Caller cannot keep skb_shinfo related pointers past calling here!
|
|
*/
|
|
static int skb_prepare_for_shift(struct sk_buff *skb)
|
|
{
|
|
return skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
|
|
}
|
|
|
|
/**
|
|
* skb_shift - Shifts paged data partially from skb to another
|
|
* @tgt: buffer into which tail data gets added
|
|
* @skb: buffer from which the paged data comes from
|
|
* @shiftlen: shift up to this many bytes
|
|
*
|
|
* Attempts to shift up to shiftlen worth of bytes, which may be less than
|
|
* the length of the skb, from skb to tgt. Returns number bytes shifted.
|
|
* It's up to caller to free skb if everything was shifted.
|
|
*
|
|
* If @tgt runs out of frags, the whole operation is aborted.
|
|
*
|
|
* Skb cannot include anything else but paged data while tgt is allowed
|
|
* to have non-paged data as well.
|
|
*
|
|
* TODO: full sized shift could be optimized but that would need
|
|
* specialized skb free'er to handle frags without up-to-date nr_frags.
|
|
*/
|
|
int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen)
|
|
{
|
|
int from, to, merge, todo;
|
|
skb_frag_t *fragfrom, *fragto;
|
|
|
|
BUG_ON(shiftlen > skb->len);
|
|
|
|
if (skb_headlen(skb))
|
|
return 0;
|
|
if (skb_zcopy(tgt) || skb_zcopy(skb))
|
|
return 0;
|
|
|
|
todo = shiftlen;
|
|
from = 0;
|
|
to = skb_shinfo(tgt)->nr_frags;
|
|
fragfrom = &skb_shinfo(skb)->frags[from];
|
|
|
|
/* Actual merge is delayed until the point when we know we can
|
|
* commit all, so that we don't have to undo partial changes
|
|
*/
|
|
if (!to ||
|
|
!skb_can_coalesce(tgt, to, skb_frag_page(fragfrom),
|
|
skb_frag_off(fragfrom))) {
|
|
merge = -1;
|
|
} else {
|
|
merge = to - 1;
|
|
|
|
todo -= skb_frag_size(fragfrom);
|
|
if (todo < 0) {
|
|
if (skb_prepare_for_shift(skb) ||
|
|
skb_prepare_for_shift(tgt))
|
|
return 0;
|
|
|
|
/* All previous frag pointers might be stale! */
|
|
fragfrom = &skb_shinfo(skb)->frags[from];
|
|
fragto = &skb_shinfo(tgt)->frags[merge];
|
|
|
|
skb_frag_size_add(fragto, shiftlen);
|
|
skb_frag_size_sub(fragfrom, shiftlen);
|
|
skb_frag_off_add(fragfrom, shiftlen);
|
|
|
|
goto onlymerged;
|
|
}
|
|
|
|
from++;
|
|
}
|
|
|
|
/* Skip full, not-fitting skb to avoid expensive operations */
|
|
if ((shiftlen == skb->len) &&
|
|
(skb_shinfo(skb)->nr_frags - from) > (MAX_SKB_FRAGS - to))
|
|
return 0;
|
|
|
|
if (skb_prepare_for_shift(skb) || skb_prepare_for_shift(tgt))
|
|
return 0;
|
|
|
|
while ((todo > 0) && (from < skb_shinfo(skb)->nr_frags)) {
|
|
if (to == MAX_SKB_FRAGS)
|
|
return 0;
|
|
|
|
fragfrom = &skb_shinfo(skb)->frags[from];
|
|
fragto = &skb_shinfo(tgt)->frags[to];
|
|
|
|
if (todo >= skb_frag_size(fragfrom)) {
|
|
*fragto = *fragfrom;
|
|
todo -= skb_frag_size(fragfrom);
|
|
from++;
|
|
to++;
|
|
|
|
} else {
|
|
__skb_frag_ref(fragfrom);
|
|
skb_frag_page_copy(fragto, fragfrom);
|
|
skb_frag_off_copy(fragto, fragfrom);
|
|
skb_frag_size_set(fragto, todo);
|
|
|
|
skb_frag_off_add(fragfrom, todo);
|
|
skb_frag_size_sub(fragfrom, todo);
|
|
todo = 0;
|
|
|
|
to++;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Ready to "commit" this state change to tgt */
|
|
skb_shinfo(tgt)->nr_frags = to;
|
|
|
|
if (merge >= 0) {
|
|
fragfrom = &skb_shinfo(skb)->frags[0];
|
|
fragto = &skb_shinfo(tgt)->frags[merge];
|
|
|
|
skb_frag_size_add(fragto, skb_frag_size(fragfrom));
|
|
__skb_frag_unref(fragfrom);
|
|
}
|
|
|
|
/* Reposition in the original skb */
|
|
to = 0;
|
|
while (from < skb_shinfo(skb)->nr_frags)
|
|
skb_shinfo(skb)->frags[to++] = skb_shinfo(skb)->frags[from++];
|
|
skb_shinfo(skb)->nr_frags = to;
|
|
|
|
BUG_ON(todo > 0 && !skb_shinfo(skb)->nr_frags);
|
|
|
|
onlymerged:
|
|
/* Most likely the tgt won't ever need its checksum anymore, skb on
|
|
* the other hand might need it if it needs to be resent
|
|
*/
|
|
tgt->ip_summed = CHECKSUM_PARTIAL;
|
|
skb->ip_summed = CHECKSUM_PARTIAL;
|
|
|
|
/* Yak, is it really working this way? Some helper please? */
|
|
skb->len -= shiftlen;
|
|
skb->data_len -= shiftlen;
|
|
skb->truesize -= shiftlen;
|
|
tgt->len += shiftlen;
|
|
tgt->data_len += shiftlen;
|
|
tgt->truesize += shiftlen;
|
|
|
|
return shiftlen;
|
|
}
|
|
|
|
/**
|
|
* skb_prepare_seq_read - Prepare a sequential read of skb data
|
|
* @skb: the buffer to read
|
|
* @from: lower offset of data to be read
|
|
* @to: upper offset of data to be read
|
|
* @st: state variable
|
|
*
|
|
* Initializes the specified state variable. Must be called before
|
|
* invoking skb_seq_read() for the first time.
|
|
*/
|
|
void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
|
|
unsigned int to, struct skb_seq_state *st)
|
|
{
|
|
st->lower_offset = from;
|
|
st->upper_offset = to;
|
|
st->root_skb = st->cur_skb = skb;
|
|
st->frag_idx = st->stepped_offset = 0;
|
|
st->frag_data = NULL;
|
|
}
|
|
EXPORT_SYMBOL(skb_prepare_seq_read);
|
|
|
|
/**
|
|
* skb_seq_read - Sequentially read skb data
|
|
* @consumed: number of bytes consumed by the caller so far
|
|
* @data: destination pointer for data to be returned
|
|
* @st: state variable
|
|
*
|
|
* Reads a block of skb data at @consumed relative to the
|
|
* lower offset specified to skb_prepare_seq_read(). Assigns
|
|
* the head of the data block to @data and returns the length
|
|
* of the block or 0 if the end of the skb data or the upper
|
|
* offset has been reached.
|
|
*
|
|
* The caller is not required to consume all of the data
|
|
* returned, i.e. @consumed is typically set to the number
|
|
* of bytes already consumed and the next call to
|
|
* skb_seq_read() will return the remaining part of the block.
|
|
*
|
|
* Note 1: The size of each block of data returned can be arbitrary,
|
|
* this limitation is the cost for zerocopy sequential
|
|
* reads of potentially non linear data.
|
|
*
|
|
* Note 2: Fragment lists within fragments are not implemented
|
|
* at the moment, state->root_skb could be replaced with
|
|
* a stack for this purpose.
|
|
*/
|
|
unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
|
|
struct skb_seq_state *st)
|
|
{
|
|
unsigned int block_limit, abs_offset = consumed + st->lower_offset;
|
|
skb_frag_t *frag;
|
|
|
|
if (unlikely(abs_offset >= st->upper_offset)) {
|
|
if (st->frag_data) {
|
|
kunmap_atomic(st->frag_data);
|
|
st->frag_data = NULL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
next_skb:
|
|
block_limit = skb_headlen(st->cur_skb) + st->stepped_offset;
|
|
|
|
if (abs_offset < block_limit && !st->frag_data) {
|
|
*data = st->cur_skb->data + (abs_offset - st->stepped_offset);
|
|
return block_limit - abs_offset;
|
|
}
|
|
|
|
if (st->frag_idx == 0 && !st->frag_data)
|
|
st->stepped_offset += skb_headlen(st->cur_skb);
|
|
|
|
while (st->frag_idx < skb_shinfo(st->cur_skb)->nr_frags) {
|
|
frag = &skb_shinfo(st->cur_skb)->frags[st->frag_idx];
|
|
block_limit = skb_frag_size(frag) + st->stepped_offset;
|
|
|
|
if (abs_offset < block_limit) {
|
|
if (!st->frag_data)
|
|
st->frag_data = kmap_atomic(skb_frag_page(frag));
|
|
|
|
*data = (u8 *) st->frag_data + skb_frag_off(frag) +
|
|
(abs_offset - st->stepped_offset);
|
|
|
|
return block_limit - abs_offset;
|
|
}
|
|
|
|
if (st->frag_data) {
|
|
kunmap_atomic(st->frag_data);
|
|
st->frag_data = NULL;
|
|
}
|
|
|
|
st->frag_idx++;
|
|
st->stepped_offset += skb_frag_size(frag);
|
|
}
|
|
|
|
if (st->frag_data) {
|
|
kunmap_atomic(st->frag_data);
|
|
st->frag_data = NULL;
|
|
}
|
|
|
|
if (st->root_skb == st->cur_skb && skb_has_frag_list(st->root_skb)) {
|
|
st->cur_skb = skb_shinfo(st->root_skb)->frag_list;
|
|
st->frag_idx = 0;
|
|
goto next_skb;
|
|
} else if (st->cur_skb->next) {
|
|
st->cur_skb = st->cur_skb->next;
|
|
st->frag_idx = 0;
|
|
goto next_skb;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(skb_seq_read);
|
|
|
|
/**
|
|
* skb_abort_seq_read - Abort a sequential read of skb data
|
|
* @st: state variable
|
|
*
|
|
* Must be called if skb_seq_read() was not called until it
|
|
* returned 0.
|
|
*/
|
|
void skb_abort_seq_read(struct skb_seq_state *st)
|
|
{
|
|
if (st->frag_data)
|
|
kunmap_atomic(st->frag_data);
|
|
}
|
|
EXPORT_SYMBOL(skb_abort_seq_read);
|
|
|
|
#define TS_SKB_CB(state) ((struct skb_seq_state *) &((state)->cb))
|
|
|
|
static unsigned int skb_ts_get_next_block(unsigned int offset, const u8 **text,
|
|
struct ts_config *conf,
|
|
struct ts_state *state)
|
|
{
|
|
return skb_seq_read(offset, text, TS_SKB_CB(state));
|
|
}
|
|
|
|
static void skb_ts_finish(struct ts_config *conf, struct ts_state *state)
|
|
{
|
|
skb_abort_seq_read(TS_SKB_CB(state));
|
|
}
|
|
|
|
/**
|
|
* skb_find_text - Find a text pattern in skb data
|
|
* @skb: the buffer to look in
|
|
* @from: search offset
|
|
* @to: search limit
|
|
* @config: textsearch configuration
|
|
*
|
|
* Finds a pattern in the skb data according to the specified
|
|
* textsearch configuration. Use textsearch_next() to retrieve
|
|
* subsequent occurrences of the pattern. Returns the offset
|
|
* to the first occurrence or UINT_MAX if no match was found.
|
|
*/
|
|
unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
|
|
unsigned int to, struct ts_config *config)
|
|
{
|
|
struct ts_state state;
|
|
unsigned int ret;
|
|
|
|
config->get_next_block = skb_ts_get_next_block;
|
|
config->finish = skb_ts_finish;
|
|
|
|
skb_prepare_seq_read(skb, from, to, TS_SKB_CB(&state));
|
|
|
|
ret = textsearch_find(config, &state);
|
|
return (ret <= to - from ? ret : UINT_MAX);
|
|
}
|
|
EXPORT_SYMBOL(skb_find_text);
|
|
|
|
int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
|
|
int offset, size_t size)
|
|
{
|
|
int i = skb_shinfo(skb)->nr_frags;
|
|
|
|
if (skb_can_coalesce(skb, i, page, offset)) {
|
|
skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size);
|
|
} else if (i < MAX_SKB_FRAGS) {
|
|
get_page(page);
|
|
skb_fill_page_desc(skb, i, page, offset, size);
|
|
} else {
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_append_pagefrags);
|
|
|
|
/**
|
|
* skb_pull_rcsum - pull skb and update receive checksum
|
|
* @skb: buffer to update
|
|
* @len: length of data pulled
|
|
*
|
|
* This function performs an skb_pull on the packet and updates
|
|
* the CHECKSUM_COMPLETE checksum. It should be used on
|
|
* receive path processing instead of skb_pull unless you know
|
|
* that the checksum difference is zero (e.g., a valid IP header)
|
|
* or you are setting ip_summed to CHECKSUM_NONE.
|
|
*/
|
|
void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len)
|
|
{
|
|
unsigned char *data = skb->data;
|
|
|
|
BUG_ON(len > skb->len);
|
|
__skb_pull(skb, len);
|
|
skb_postpull_rcsum(skb, data, len);
|
|
return skb->data;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_pull_rcsum);
|
|
|
|
static inline skb_frag_t skb_head_frag_to_page_desc(struct sk_buff *frag_skb)
|
|
{
|
|
skb_frag_t head_frag;
|
|
struct page *page;
|
|
|
|
page = virt_to_head_page(frag_skb->head);
|
|
__skb_frag_set_page(&head_frag, page);
|
|
skb_frag_off_set(&head_frag, frag_skb->data -
|
|
(unsigned char *)page_address(page));
|
|
skb_frag_size_set(&head_frag, skb_headlen(frag_skb));
|
|
return head_frag;
|
|
}
|
|
|
|
/**
|
|
* skb_segment - Perform protocol segmentation on skb.
|
|
* @head_skb: buffer to segment
|
|
* @features: features for the output path (see dev->features)
|
|
*
|
|
* This function performs segmentation on the given skb. It returns
|
|
* a pointer to the first in a list of new skbs for the segments.
|
|
* In case of error it returns ERR_PTR(err).
|
|
*/
|
|
struct sk_buff *skb_segment(struct sk_buff *head_skb,
|
|
netdev_features_t features)
|
|
{
|
|
struct sk_buff *segs = NULL;
|
|
struct sk_buff *tail = NULL;
|
|
struct sk_buff *list_skb = skb_shinfo(head_skb)->frag_list;
|
|
skb_frag_t *frag = skb_shinfo(head_skb)->frags;
|
|
unsigned int mss = skb_shinfo(head_skb)->gso_size;
|
|
unsigned int doffset = head_skb->data - skb_mac_header(head_skb);
|
|
struct sk_buff *frag_skb = head_skb;
|
|
unsigned int offset = doffset;
|
|
unsigned int tnl_hlen = skb_tnl_header_len(head_skb);
|
|
unsigned int partial_segs = 0;
|
|
unsigned int headroom;
|
|
unsigned int len = head_skb->len;
|
|
__be16 proto;
|
|
bool csum, sg;
|
|
int nfrags = skb_shinfo(head_skb)->nr_frags;
|
|
int err = -ENOMEM;
|
|
int i = 0;
|
|
int pos;
|
|
int dummy;
|
|
|
|
if (list_skb && !list_skb->head_frag && skb_headlen(list_skb) &&
|
|
(skb_shinfo(head_skb)->gso_type & SKB_GSO_DODGY)) {
|
|
/* gso_size is untrusted, and we have a frag_list with a linear
|
|
* non head_frag head.
|
|
*
|
|
* (we assume checking the first list_skb member suffices;
|
|
* i.e if either of the list_skb members have non head_frag
|
|
* head, then the first one has too).
|
|
*
|
|
* If head_skb's headlen does not fit requested gso_size, it
|
|
* means that the frag_list members do NOT terminate on exact
|
|
* gso_size boundaries. Hence we cannot perform skb_frag_t page
|
|
* sharing. Therefore we must fallback to copying the frag_list
|
|
* skbs; we do so by disabling SG.
|
|
*/
|
|
if (mss != GSO_BY_FRAGS && mss != skb_headlen(head_skb))
|
|
features &= ~NETIF_F_SG;
|
|
}
|
|
|
|
__skb_push(head_skb, doffset);
|
|
proto = skb_network_protocol(head_skb, &dummy);
|
|
if (unlikely(!proto))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
sg = !!(features & NETIF_F_SG);
|
|
csum = !!can_checksum_protocol(features, proto);
|
|
|
|
if (sg && csum && (mss != GSO_BY_FRAGS)) {
|
|
if (!(features & NETIF_F_GSO_PARTIAL)) {
|
|
struct sk_buff *iter;
|
|
unsigned int frag_len;
|
|
|
|
if (!list_skb ||
|
|
!net_gso_ok(features, skb_shinfo(head_skb)->gso_type))
|
|
goto normal;
|
|
|
|
/* If we get here then all the required
|
|
* GSO features except frag_list are supported.
|
|
* Try to split the SKB to multiple GSO SKBs
|
|
* with no frag_list.
|
|
* Currently we can do that only when the buffers don't
|
|
* have a linear part and all the buffers except
|
|
* the last are of the same length.
|
|
*/
|
|
frag_len = list_skb->len;
|
|
skb_walk_frags(head_skb, iter) {
|
|
if (frag_len != iter->len && iter->next)
|
|
goto normal;
|
|
if (skb_headlen(iter) && !iter->head_frag)
|
|
goto normal;
|
|
|
|
len -= iter->len;
|
|
}
|
|
|
|
if (len != frag_len)
|
|
goto normal;
|
|
}
|
|
|
|
/* GSO partial only requires that we trim off any excess that
|
|
* doesn't fit into an MSS sized block, so take care of that
|
|
* now.
|
|
*/
|
|
partial_segs = len / mss;
|
|
if (partial_segs > 1)
|
|
mss *= partial_segs;
|
|
else
|
|
partial_segs = 0;
|
|
}
|
|
|
|
normal:
|
|
headroom = skb_headroom(head_skb);
|
|
pos = skb_headlen(head_skb);
|
|
|
|
do {
|
|
struct sk_buff *nskb;
|
|
skb_frag_t *nskb_frag;
|
|
int hsize;
|
|
int size;
|
|
|
|
if (unlikely(mss == GSO_BY_FRAGS)) {
|
|
len = list_skb->len;
|
|
} else {
|
|
len = head_skb->len - offset;
|
|
if (len > mss)
|
|
len = mss;
|
|
}
|
|
|
|
hsize = skb_headlen(head_skb) - offset;
|
|
if (hsize < 0)
|
|
hsize = 0;
|
|
if (hsize > len || !sg)
|
|
hsize = len;
|
|
|
|
if (!hsize && i >= nfrags && skb_headlen(list_skb) &&
|
|
(skb_headlen(list_skb) == len || sg)) {
|
|
BUG_ON(skb_headlen(list_skb) > len);
|
|
|
|
i = 0;
|
|
nfrags = skb_shinfo(list_skb)->nr_frags;
|
|
frag = skb_shinfo(list_skb)->frags;
|
|
frag_skb = list_skb;
|
|
pos += skb_headlen(list_skb);
|
|
|
|
while (pos < offset + len) {
|
|
BUG_ON(i >= nfrags);
|
|
|
|
size = skb_frag_size(frag);
|
|
if (pos + size > offset + len)
|
|
break;
|
|
|
|
i++;
|
|
pos += size;
|
|
frag++;
|
|
}
|
|
|
|
nskb = skb_clone(list_skb, GFP_ATOMIC);
|
|
list_skb = list_skb->next;
|
|
|
|
if (unlikely(!nskb))
|
|
goto err;
|
|
|
|
if (unlikely(pskb_trim(nskb, len))) {
|
|
kfree_skb(nskb);
|
|
goto err;
|
|
}
|
|
|
|
hsize = skb_end_offset(nskb);
|
|
if (skb_cow_head(nskb, doffset + headroom)) {
|
|
kfree_skb(nskb);
|
|
goto err;
|
|
}
|
|
|
|
nskb->truesize += skb_end_offset(nskb) - hsize;
|
|
skb_release_head_state(nskb);
|
|
__skb_push(nskb, doffset);
|
|
} else {
|
|
nskb = __alloc_skb(hsize + doffset + headroom,
|
|
GFP_ATOMIC, skb_alloc_rx_flag(head_skb),
|
|
NUMA_NO_NODE);
|
|
|
|
if (unlikely(!nskb))
|
|
goto err;
|
|
|
|
skb_reserve(nskb, headroom);
|
|
__skb_put(nskb, doffset);
|
|
}
|
|
|
|
if (segs)
|
|
tail->next = nskb;
|
|
else
|
|
segs = nskb;
|
|
tail = nskb;
|
|
|
|
__copy_skb_header(nskb, head_skb);
|
|
|
|
skb_headers_offset_update(nskb, skb_headroom(nskb) - headroom);
|
|
skb_reset_mac_len(nskb);
|
|
|
|
skb_copy_from_linear_data_offset(head_skb, -tnl_hlen,
|
|
nskb->data - tnl_hlen,
|
|
doffset + tnl_hlen);
|
|
|
|
if (nskb->len == len + doffset)
|
|
goto perform_csum_check;
|
|
|
|
if (!sg) {
|
|
if (!nskb->remcsum_offload)
|
|
nskb->ip_summed = CHECKSUM_NONE;
|
|
SKB_GSO_CB(nskb)->csum =
|
|
skb_copy_and_csum_bits(head_skb, offset,
|
|
skb_put(nskb, len),
|
|
len, 0);
|
|
SKB_GSO_CB(nskb)->csum_start =
|
|
skb_headroom(nskb) + doffset;
|
|
continue;
|
|
}
|
|
|
|
nskb_frag = skb_shinfo(nskb)->frags;
|
|
|
|
skb_copy_from_linear_data_offset(head_skb, offset,
|
|
skb_put(nskb, hsize), hsize);
|
|
|
|
skb_shinfo(nskb)->tx_flags |= skb_shinfo(head_skb)->tx_flags &
|
|
SKBTX_SHARED_FRAG;
|
|
|
|
if (skb_orphan_frags(frag_skb, GFP_ATOMIC) ||
|
|
skb_zerocopy_clone(nskb, frag_skb, GFP_ATOMIC))
|
|
goto err;
|
|
|
|
while (pos < offset + len) {
|
|
if (i >= nfrags) {
|
|
i = 0;
|
|
nfrags = skb_shinfo(list_skb)->nr_frags;
|
|
frag = skb_shinfo(list_skb)->frags;
|
|
frag_skb = list_skb;
|
|
if (!skb_headlen(list_skb)) {
|
|
BUG_ON(!nfrags);
|
|
} else {
|
|
BUG_ON(!list_skb->head_frag);
|
|
|
|
/* to make room for head_frag. */
|
|
i--;
|
|
frag--;
|
|
}
|
|
if (skb_orphan_frags(frag_skb, GFP_ATOMIC) ||
|
|
skb_zerocopy_clone(nskb, frag_skb,
|
|
GFP_ATOMIC))
|
|
goto err;
|
|
|
|
list_skb = list_skb->next;
|
|
}
|
|
|
|
if (unlikely(skb_shinfo(nskb)->nr_frags >=
|
|
MAX_SKB_FRAGS)) {
|
|
net_warn_ratelimited(
|
|
"skb_segment: too many frags: %u %u\n",
|
|
pos, mss);
|
|
err = -EINVAL;
|
|
goto err;
|
|
}
|
|
|
|
*nskb_frag = (i < 0) ? skb_head_frag_to_page_desc(frag_skb) : *frag;
|
|
__skb_frag_ref(nskb_frag);
|
|
size = skb_frag_size(nskb_frag);
|
|
|
|
if (pos < offset) {
|
|
skb_frag_off_add(nskb_frag, offset - pos);
|
|
skb_frag_size_sub(nskb_frag, offset - pos);
|
|
}
|
|
|
|
skb_shinfo(nskb)->nr_frags++;
|
|
|
|
if (pos + size <= offset + len) {
|
|
i++;
|
|
frag++;
|
|
pos += size;
|
|
} else {
|
|
skb_frag_size_sub(nskb_frag, pos + size - (offset + len));
|
|
goto skip_fraglist;
|
|
}
|
|
|
|
nskb_frag++;
|
|
}
|
|
|
|
skip_fraglist:
|
|
nskb->data_len = len - hsize;
|
|
nskb->len += nskb->data_len;
|
|
nskb->truesize += nskb->data_len;
|
|
|
|
perform_csum_check:
|
|
if (!csum) {
|
|
if (skb_has_shared_frag(nskb) &&
|
|
__skb_linearize(nskb))
|
|
goto err;
|
|
|
|
if (!nskb->remcsum_offload)
|
|
nskb->ip_summed = CHECKSUM_NONE;
|
|
SKB_GSO_CB(nskb)->csum =
|
|
skb_checksum(nskb, doffset,
|
|
nskb->len - doffset, 0);
|
|
SKB_GSO_CB(nskb)->csum_start =
|
|
skb_headroom(nskb) + doffset;
|
|
}
|
|
} while ((offset += len) < head_skb->len);
|
|
|
|
/* Some callers want to get the end of the list.
|
|
* Put it in segs->prev to avoid walking the list.
|
|
* (see validate_xmit_skb_list() for example)
|
|
*/
|
|
segs->prev = tail;
|
|
|
|
if (partial_segs) {
|
|
struct sk_buff *iter;
|
|
int type = skb_shinfo(head_skb)->gso_type;
|
|
unsigned short gso_size = skb_shinfo(head_skb)->gso_size;
|
|
|
|
/* Update type to add partial and then remove dodgy if set */
|
|
type |= (features & NETIF_F_GSO_PARTIAL) / NETIF_F_GSO_PARTIAL * SKB_GSO_PARTIAL;
|
|
type &= ~SKB_GSO_DODGY;
|
|
|
|
/* Update GSO info and prepare to start updating headers on
|
|
* our way back down the stack of protocols.
|
|
*/
|
|
for (iter = segs; iter; iter = iter->next) {
|
|
skb_shinfo(iter)->gso_size = gso_size;
|
|
skb_shinfo(iter)->gso_segs = partial_segs;
|
|
skb_shinfo(iter)->gso_type = type;
|
|
SKB_GSO_CB(iter)->data_offset = skb_headroom(iter) + doffset;
|
|
}
|
|
|
|
if (tail->len - doffset <= gso_size)
|
|
skb_shinfo(tail)->gso_size = 0;
|
|
else if (tail != segs)
|
|
skb_shinfo(tail)->gso_segs = DIV_ROUND_UP(tail->len - doffset, gso_size);
|
|
}
|
|
|
|
/* Following permits correct backpressure, for protocols
|
|
* using skb_set_owner_w().
|
|
* Idea is to tranfert ownership from head_skb to last segment.
|
|
*/
|
|
if (head_skb->destructor == sock_wfree) {
|
|
swap(tail->truesize, head_skb->truesize);
|
|
swap(tail->destructor, head_skb->destructor);
|
|
swap(tail->sk, head_skb->sk);
|
|
}
|
|
return segs;
|
|
|
|
err:
|
|
kfree_skb_list(segs);
|
|
return ERR_PTR(err);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_segment);
|
|
|
|
int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
|
|
{
|
|
struct skb_shared_info *pinfo, *skbinfo = skb_shinfo(skb);
|
|
unsigned int offset = skb_gro_offset(skb);
|
|
unsigned int headlen = skb_headlen(skb);
|
|
unsigned int len = skb_gro_len(skb);
|
|
unsigned int delta_truesize;
|
|
struct sk_buff *lp;
|
|
|
|
if (unlikely(p->len + len >= 65536 || NAPI_GRO_CB(skb)->flush))
|
|
return -E2BIG;
|
|
|
|
lp = NAPI_GRO_CB(p)->last;
|
|
pinfo = skb_shinfo(lp);
|
|
|
|
if (headlen <= offset) {
|
|
skb_frag_t *frag;
|
|
skb_frag_t *frag2;
|
|
int i = skbinfo->nr_frags;
|
|
int nr_frags = pinfo->nr_frags + i;
|
|
|
|
if (nr_frags > MAX_SKB_FRAGS)
|
|
goto merge;
|
|
|
|
offset -= headlen;
|
|
pinfo->nr_frags = nr_frags;
|
|
skbinfo->nr_frags = 0;
|
|
|
|
frag = pinfo->frags + nr_frags;
|
|
frag2 = skbinfo->frags + i;
|
|
do {
|
|
*--frag = *--frag2;
|
|
} while (--i);
|
|
|
|
skb_frag_off_add(frag, offset);
|
|
skb_frag_size_sub(frag, offset);
|
|
|
|
/* all fragments truesize : remove (head size + sk_buff) */
|
|
delta_truesize = skb->truesize -
|
|
SKB_TRUESIZE(skb_end_offset(skb));
|
|
|
|
skb->truesize -= skb->data_len;
|
|
skb->len -= skb->data_len;
|
|
skb->data_len = 0;
|
|
|
|
NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE;
|
|
goto done;
|
|
} else if (skb->head_frag) {
|
|
int nr_frags = pinfo->nr_frags;
|
|
skb_frag_t *frag = pinfo->frags + nr_frags;
|
|
struct page *page = virt_to_head_page(skb->head);
|
|
unsigned int first_size = headlen - offset;
|
|
unsigned int first_offset;
|
|
|
|
if (nr_frags + 1 + skbinfo->nr_frags > MAX_SKB_FRAGS)
|
|
goto merge;
|
|
|
|
first_offset = skb->data -
|
|
(unsigned char *)page_address(page) +
|
|
offset;
|
|
|
|
pinfo->nr_frags = nr_frags + 1 + skbinfo->nr_frags;
|
|
|
|
__skb_frag_set_page(frag, page);
|
|
skb_frag_off_set(frag, first_offset);
|
|
skb_frag_size_set(frag, first_size);
|
|
|
|
memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags);
|
|
/* We dont need to clear skbinfo->nr_frags here */
|
|
|
|
delta_truesize = skb->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));
|
|
NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD;
|
|
goto done;
|
|
}
|
|
|
|
merge:
|
|
delta_truesize = skb->truesize;
|
|
if (offset > headlen) {
|
|
unsigned int eat = offset - headlen;
|
|
|
|
skb_frag_off_add(&skbinfo->frags[0], eat);
|
|
skb_frag_size_sub(&skbinfo->frags[0], eat);
|
|
skb->data_len -= eat;
|
|
skb->len -= eat;
|
|
offset = headlen;
|
|
}
|
|
|
|
__skb_pull(skb, offset);
|
|
|
|
if (NAPI_GRO_CB(p)->last == p)
|
|
skb_shinfo(p)->frag_list = skb;
|
|
else
|
|
NAPI_GRO_CB(p)->last->next = skb;
|
|
NAPI_GRO_CB(p)->last = skb;
|
|
__skb_header_release(skb);
|
|
lp = p;
|
|
|
|
done:
|
|
NAPI_GRO_CB(p)->count++;
|
|
p->data_len += len;
|
|
p->truesize += delta_truesize;
|
|
p->len += len;
|
|
if (lp != p) {
|
|
lp->data_len += len;
|
|
lp->truesize += delta_truesize;
|
|
lp->len += len;
|
|
}
|
|
NAPI_GRO_CB(skb)->same_flow = 1;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_gro_receive);
|
|
|
|
#ifdef CONFIG_SKB_EXTENSIONS
|
|
#define SKB_EXT_ALIGN_VALUE 8
|
|
#define SKB_EXT_CHUNKSIZEOF(x) (ALIGN((sizeof(x)), SKB_EXT_ALIGN_VALUE) / SKB_EXT_ALIGN_VALUE)
|
|
|
|
static const u8 skb_ext_type_len[] = {
|
|
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
|
|
[SKB_EXT_BRIDGE_NF] = SKB_EXT_CHUNKSIZEOF(struct nf_bridge_info),
|
|
#endif
|
|
#ifdef CONFIG_XFRM
|
|
[SKB_EXT_SEC_PATH] = SKB_EXT_CHUNKSIZEOF(struct sec_path),
|
|
#endif
|
|
#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
|
|
[TC_SKB_EXT] = SKB_EXT_CHUNKSIZEOF(struct tc_skb_ext),
|
|
#endif
|
|
};
|
|
|
|
static __always_inline unsigned int skb_ext_total_length(void)
|
|
{
|
|
return SKB_EXT_CHUNKSIZEOF(struct skb_ext) +
|
|
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
|
|
skb_ext_type_len[SKB_EXT_BRIDGE_NF] +
|
|
#endif
|
|
#ifdef CONFIG_XFRM
|
|
skb_ext_type_len[SKB_EXT_SEC_PATH] +
|
|
#endif
|
|
#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
|
|
skb_ext_type_len[TC_SKB_EXT] +
|
|
#endif
|
|
0;
|
|
}
|
|
|
|
static void skb_extensions_init(void)
|
|
{
|
|
BUILD_BUG_ON(SKB_EXT_NUM >= 8);
|
|
BUILD_BUG_ON(skb_ext_total_length() > 255);
|
|
|
|
skbuff_ext_cache = kmem_cache_create("skbuff_ext_cache",
|
|
SKB_EXT_ALIGN_VALUE * skb_ext_total_length(),
|
|
0,
|
|
SLAB_HWCACHE_ALIGN|SLAB_PANIC,
|
|
NULL);
|
|
}
|
|
#else
|
|
static void skb_extensions_init(void) {}
|
|
#endif
|
|
|
|
void __init skb_init(void)
|
|
{
|
|
skbuff_head_cache = kmem_cache_create_usercopy("skbuff_head_cache",
|
|
sizeof(struct sk_buff),
|
|
0,
|
|
SLAB_HWCACHE_ALIGN|SLAB_PANIC,
|
|
offsetof(struct sk_buff, cb),
|
|
sizeof_field(struct sk_buff, cb),
|
|
NULL);
|
|
skbuff_fclone_cache = kmem_cache_create("skbuff_fclone_cache",
|
|
sizeof(struct sk_buff_fclones),
|
|
0,
|
|
SLAB_HWCACHE_ALIGN|SLAB_PANIC,
|
|
NULL);
|
|
skb_extensions_init();
|
|
}
|
|
|
|
static int
|
|
__skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len,
|
|
unsigned int recursion_level)
|
|
{
|
|
int start = skb_headlen(skb);
|
|
int i, copy = start - offset;
|
|
struct sk_buff *frag_iter;
|
|
int elt = 0;
|
|
|
|
if (unlikely(recursion_level >= 24))
|
|
return -EMSGSIZE;
|
|
|
|
if (copy > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
sg_set_buf(sg, skb->data + offset, copy);
|
|
elt++;
|
|
if ((len -= copy) == 0)
|
|
return elt;
|
|
offset += copy;
|
|
}
|
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
|
|
int end;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
if ((copy = end - offset) > 0) {
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
|
|
if (unlikely(elt && sg_is_last(&sg[elt - 1])))
|
|
return -EMSGSIZE;
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
sg_set_page(&sg[elt], skb_frag_page(frag), copy,
|
|
skb_frag_off(frag) + offset - start);
|
|
elt++;
|
|
if (!(len -= copy))
|
|
return elt;
|
|
offset += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
|
|
skb_walk_frags(skb, frag_iter) {
|
|
int end, ret;
|
|
|
|
WARN_ON(start > offset + len);
|
|
|
|
end = start + frag_iter->len;
|
|
if ((copy = end - offset) > 0) {
|
|
if (unlikely(elt && sg_is_last(&sg[elt - 1])))
|
|
return -EMSGSIZE;
|
|
|
|
if (copy > len)
|
|
copy = len;
|
|
ret = __skb_to_sgvec(frag_iter, sg+elt, offset - start,
|
|
copy, recursion_level + 1);
|
|
if (unlikely(ret < 0))
|
|
return ret;
|
|
elt += ret;
|
|
if ((len -= copy) == 0)
|
|
return elt;
|
|
offset += copy;
|
|
}
|
|
start = end;
|
|
}
|
|
BUG_ON(len);
|
|
return elt;
|
|
}
|
|
|
|
/**
|
|
* skb_to_sgvec - Fill a scatter-gather list from a socket buffer
|
|
* @skb: Socket buffer containing the buffers to be mapped
|
|
* @sg: The scatter-gather list to map into
|
|
* @offset: The offset into the buffer's contents to start mapping
|
|
* @len: Length of buffer space to be mapped
|
|
*
|
|
* Fill the specified scatter-gather list with mappings/pointers into a
|
|
* region of the buffer space attached to a socket buffer. Returns either
|
|
* the number of scatterlist items used, or -EMSGSIZE if the contents
|
|
* could not fit.
|
|
*/
|
|
int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len)
|
|
{
|
|
int nsg = __skb_to_sgvec(skb, sg, offset, len, 0);
|
|
|
|
if (nsg <= 0)
|
|
return nsg;
|
|
|
|
sg_mark_end(&sg[nsg - 1]);
|
|
|
|
return nsg;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_to_sgvec);
|
|
|
|
/* As compared with skb_to_sgvec, skb_to_sgvec_nomark only map skb to given
|
|
* sglist without mark the sg which contain last skb data as the end.
|
|
* So the caller can mannipulate sg list as will when padding new data after
|
|
* the first call without calling sg_unmark_end to expend sg list.
|
|
*
|
|
* Scenario to use skb_to_sgvec_nomark:
|
|
* 1. sg_init_table
|
|
* 2. skb_to_sgvec_nomark(payload1)
|
|
* 3. skb_to_sgvec_nomark(payload2)
|
|
*
|
|
* This is equivalent to:
|
|
* 1. sg_init_table
|
|
* 2. skb_to_sgvec(payload1)
|
|
* 3. sg_unmark_end
|
|
* 4. skb_to_sgvec(payload2)
|
|
*
|
|
* When mapping mutilple payload conditionally, skb_to_sgvec_nomark
|
|
* is more preferable.
|
|
*/
|
|
int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
|
|
int offset, int len)
|
|
{
|
|
return __skb_to_sgvec(skb, sg, offset, len, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_to_sgvec_nomark);
|
|
|
|
|
|
|
|
/**
|
|
* skb_cow_data - Check that a socket buffer's data buffers are writable
|
|
* @skb: The socket buffer to check.
|
|
* @tailbits: Amount of trailing space to be added
|
|
* @trailer: Returned pointer to the skb where the @tailbits space begins
|
|
*
|
|
* Make sure that the data buffers attached to a socket buffer are
|
|
* writable. If they are not, private copies are made of the data buffers
|
|
* and the socket buffer is set to use these instead.
|
|
*
|
|
* If @tailbits is given, make sure that there is space to write @tailbits
|
|
* bytes of data beyond current end of socket buffer. @trailer will be
|
|
* set to point to the skb in which this space begins.
|
|
*
|
|
* The number of scatterlist elements required to completely map the
|
|
* COW'd and extended socket buffer will be returned.
|
|
*/
|
|
int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer)
|
|
{
|
|
int copyflag;
|
|
int elt;
|
|
struct sk_buff *skb1, **skb_p;
|
|
|
|
/* If skb is cloned or its head is paged, reallocate
|
|
* head pulling out all the pages (pages are considered not writable
|
|
* at the moment even if they are anonymous).
|
|
*/
|
|
if ((skb_cloned(skb) || skb_shinfo(skb)->nr_frags) &&
|
|
__pskb_pull_tail(skb, skb_pagelen(skb)-skb_headlen(skb)) == NULL)
|
|
return -ENOMEM;
|
|
|
|
/* Easy case. Most of packets will go this way. */
|
|
if (!skb_has_frag_list(skb)) {
|
|
/* A little of trouble, not enough of space for trailer.
|
|
* This should not happen, when stack is tuned to generate
|
|
* good frames. OK, on miss we reallocate and reserve even more
|
|
* space, 128 bytes is fair. */
|
|
|
|
if (skb_tailroom(skb) < tailbits &&
|
|
pskb_expand_head(skb, 0, tailbits-skb_tailroom(skb)+128, GFP_ATOMIC))
|
|
return -ENOMEM;
|
|
|
|
/* Voila! */
|
|
*trailer = skb;
|
|
return 1;
|
|
}
|
|
|
|
/* Misery. We are in troubles, going to mincer fragments... */
|
|
|
|
elt = 1;
|
|
skb_p = &skb_shinfo(skb)->frag_list;
|
|
copyflag = 0;
|
|
|
|
while ((skb1 = *skb_p) != NULL) {
|
|
int ntail = 0;
|
|
|
|
/* The fragment is partially pulled by someone,
|
|
* this can happen on input. Copy it and everything
|
|
* after it. */
|
|
|
|
if (skb_shared(skb1))
|
|
copyflag = 1;
|
|
|
|
/* If the skb is the last, worry about trailer. */
|
|
|
|
if (skb1->next == NULL && tailbits) {
|
|
if (skb_shinfo(skb1)->nr_frags ||
|
|
skb_has_frag_list(skb1) ||
|
|
skb_tailroom(skb1) < tailbits)
|
|
ntail = tailbits + 128;
|
|
}
|
|
|
|
if (copyflag ||
|
|
skb_cloned(skb1) ||
|
|
ntail ||
|
|
skb_shinfo(skb1)->nr_frags ||
|
|
skb_has_frag_list(skb1)) {
|
|
struct sk_buff *skb2;
|
|
|
|
/* Fuck, we are miserable poor guys... */
|
|
if (ntail == 0)
|
|
skb2 = skb_copy(skb1, GFP_ATOMIC);
|
|
else
|
|
skb2 = skb_copy_expand(skb1,
|
|
skb_headroom(skb1),
|
|
ntail,
|
|
GFP_ATOMIC);
|
|
if (unlikely(skb2 == NULL))
|
|
return -ENOMEM;
|
|
|
|
if (skb1->sk)
|
|
skb_set_owner_w(skb2, skb1->sk);
|
|
|
|
/* Looking around. Are we still alive?
|
|
* OK, link new skb, drop old one */
|
|
|
|
skb2->next = skb1->next;
|
|
*skb_p = skb2;
|
|
kfree_skb(skb1);
|
|
skb1 = skb2;
|
|
}
|
|
elt++;
|
|
*trailer = skb1;
|
|
skb_p = &skb1->next;
|
|
}
|
|
|
|
return elt;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_cow_data);
|
|
|
|
static void sock_rmem_free(struct sk_buff *skb)
|
|
{
|
|
struct sock *sk = skb->sk;
|
|
|
|
atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
|
|
}
|
|
|
|
static void skb_set_err_queue(struct sk_buff *skb)
|
|
{
|
|
/* pkt_type of skbs received on local sockets is never PACKET_OUTGOING.
|
|
* So, it is safe to (mis)use it to mark skbs on the error queue.
|
|
*/
|
|
skb->pkt_type = PACKET_OUTGOING;
|
|
BUILD_BUG_ON(PACKET_OUTGOING == 0);
|
|
}
|
|
|
|
/*
|
|
* Note: We dont mem charge error packets (no sk_forward_alloc changes)
|
|
*/
|
|
int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
|
|
(unsigned int)READ_ONCE(sk->sk_rcvbuf))
|
|
return -ENOMEM;
|
|
|
|
skb_orphan(skb);
|
|
skb->sk = sk;
|
|
skb->destructor = sock_rmem_free;
|
|
atomic_add(skb->truesize, &sk->sk_rmem_alloc);
|
|
skb_set_err_queue(skb);
|
|
|
|
/* before exiting rcu section, make sure dst is refcounted */
|
|
skb_dst_force(skb);
|
|
|
|
skb_queue_tail(&sk->sk_error_queue, skb);
|
|
if (!sock_flag(sk, SOCK_DEAD))
|
|
sk->sk_error_report(sk);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(sock_queue_err_skb);
|
|
|
|
static bool is_icmp_err_skb(const struct sk_buff *skb)
|
|
{
|
|
return skb && (SKB_EXT_ERR(skb)->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
|
|
SKB_EXT_ERR(skb)->ee.ee_origin == SO_EE_ORIGIN_ICMP6);
|
|
}
|
|
|
|
struct sk_buff *sock_dequeue_err_skb(struct sock *sk)
|
|
{
|
|
struct sk_buff_head *q = &sk->sk_error_queue;
|
|
struct sk_buff *skb, *skb_next = NULL;
|
|
bool icmp_next = false;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&q->lock, flags);
|
|
skb = __skb_dequeue(q);
|
|
if (skb && (skb_next = skb_peek(q))) {
|
|
icmp_next = is_icmp_err_skb(skb_next);
|
|
if (icmp_next)
|
|
sk->sk_err = SKB_EXT_ERR(skb_next)->ee.ee_origin;
|
|
}
|
|
spin_unlock_irqrestore(&q->lock, flags);
|
|
|
|
if (is_icmp_err_skb(skb) && !icmp_next)
|
|
sk->sk_err = 0;
|
|
|
|
if (skb_next)
|
|
sk->sk_error_report(sk);
|
|
|
|
return skb;
|
|
}
|
|
EXPORT_SYMBOL(sock_dequeue_err_skb);
|
|
|
|
/**
|
|
* skb_clone_sk - create clone of skb, and take reference to socket
|
|
* @skb: the skb to clone
|
|
*
|
|
* This function creates a clone of a buffer that holds a reference on
|
|
* sk_refcnt. Buffers created via this function are meant to be
|
|
* returned using sock_queue_err_skb, or free via kfree_skb.
|
|
*
|
|
* When passing buffers allocated with this function to sock_queue_err_skb
|
|
* it is necessary to wrap the call with sock_hold/sock_put in order to
|
|
* prevent the socket from being released prior to being enqueued on
|
|
* the sk_error_queue.
|
|
*/
|
|
struct sk_buff *skb_clone_sk(struct sk_buff *skb)
|
|
{
|
|
struct sock *sk = skb->sk;
|
|
struct sk_buff *clone;
|
|
|
|
if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
|
|
return NULL;
|
|
|
|
clone = skb_clone(skb, GFP_ATOMIC);
|
|
if (!clone) {
|
|
sock_put(sk);
|
|
return NULL;
|
|
}
|
|
|
|
clone->sk = sk;
|
|
clone->destructor = sock_efree;
|
|
|
|
return clone;
|
|
}
|
|
EXPORT_SYMBOL(skb_clone_sk);
|
|
|
|
static void __skb_complete_tx_timestamp(struct sk_buff *skb,
|
|
struct sock *sk,
|
|
int tstype,
|
|
bool opt_stats)
|
|
{
|
|
struct sock_exterr_skb *serr;
|
|
int err;
|
|
|
|
BUILD_BUG_ON(sizeof(struct sock_exterr_skb) > sizeof(skb->cb));
|
|
|
|
serr = SKB_EXT_ERR(skb);
|
|
memset(serr, 0, sizeof(*serr));
|
|
serr->ee.ee_errno = ENOMSG;
|
|
serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
|
|
serr->ee.ee_info = tstype;
|
|
serr->opt_stats = opt_stats;
|
|
serr->header.h4.iif = skb->dev ? skb->dev->ifindex : 0;
|
|
if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) {
|
|
serr->ee.ee_data = skb_shinfo(skb)->tskey;
|
|
if (sk->sk_protocol == IPPROTO_TCP &&
|
|
sk->sk_type == SOCK_STREAM)
|
|
serr->ee.ee_data -= sk->sk_tskey;
|
|
}
|
|
|
|
err = sock_queue_err_skb(sk, skb);
|
|
|
|
if (err)
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
static bool skb_may_tx_timestamp(struct sock *sk, bool tsonly)
|
|
{
|
|
bool ret;
|
|
|
|
if (likely(sysctl_tstamp_allow_data || tsonly))
|
|
return true;
|
|
|
|
read_lock_bh(&sk->sk_callback_lock);
|
|
ret = sk->sk_socket && sk->sk_socket->file &&
|
|
file_ns_capable(sk->sk_socket->file, &init_user_ns, CAP_NET_RAW);
|
|
read_unlock_bh(&sk->sk_callback_lock);
|
|
return ret;
|
|
}
|
|
|
|
void skb_complete_tx_timestamp(struct sk_buff *skb,
|
|
struct skb_shared_hwtstamps *hwtstamps)
|
|
{
|
|
struct sock *sk = skb->sk;
|
|
|
|
if (!skb_may_tx_timestamp(sk, false))
|
|
goto err;
|
|
|
|
/* Take a reference to prevent skb_orphan() from freeing the socket,
|
|
* but only if the socket refcount is not zero.
|
|
*/
|
|
if (likely(refcount_inc_not_zero(&sk->sk_refcnt))) {
|
|
*skb_hwtstamps(skb) = *hwtstamps;
|
|
__skb_complete_tx_timestamp(skb, sk, SCM_TSTAMP_SND, false);
|
|
sock_put(sk);
|
|
return;
|
|
}
|
|
|
|
err:
|
|
kfree_skb(skb);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
|
|
|
|
void __skb_tstamp_tx(struct sk_buff *orig_skb,
|
|
struct skb_shared_hwtstamps *hwtstamps,
|
|
struct sock *sk, int tstype)
|
|
{
|
|
struct sk_buff *skb;
|
|
bool tsonly, opt_stats = false;
|
|
|
|
if (!sk)
|
|
return;
|
|
|
|
if (!hwtstamps && !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TX_SWHW) &&
|
|
skb_shinfo(orig_skb)->tx_flags & SKBTX_IN_PROGRESS)
|
|
return;
|
|
|
|
tsonly = sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TSONLY;
|
|
if (!skb_may_tx_timestamp(sk, tsonly))
|
|
return;
|
|
|
|
if (tsonly) {
|
|
#ifdef CONFIG_INET
|
|
if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_STATS) &&
|
|
sk->sk_protocol == IPPROTO_TCP &&
|
|
sk->sk_type == SOCK_STREAM) {
|
|
skb = tcp_get_timestamping_opt_stats(sk);
|
|
opt_stats = true;
|
|
} else
|
|
#endif
|
|
skb = alloc_skb(0, GFP_ATOMIC);
|
|
} else {
|
|
skb = skb_clone(orig_skb, GFP_ATOMIC);
|
|
}
|
|
if (!skb)
|
|
return;
|
|
|
|
if (tsonly) {
|
|
skb_shinfo(skb)->tx_flags |= skb_shinfo(orig_skb)->tx_flags &
|
|
SKBTX_ANY_TSTAMP;
|
|
skb_shinfo(skb)->tskey = skb_shinfo(orig_skb)->tskey;
|
|
}
|
|
|
|
if (hwtstamps)
|
|
*skb_hwtstamps(skb) = *hwtstamps;
|
|
else
|
|
skb->tstamp = ktime_get_real();
|
|
|
|
__skb_complete_tx_timestamp(skb, sk, tstype, opt_stats);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__skb_tstamp_tx);
|
|
|
|
void skb_tstamp_tx(struct sk_buff *orig_skb,
|
|
struct skb_shared_hwtstamps *hwtstamps)
|
|
{
|
|
return __skb_tstamp_tx(orig_skb, hwtstamps, orig_skb->sk,
|
|
SCM_TSTAMP_SND);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_tstamp_tx);
|
|
|
|
void skb_complete_wifi_ack(struct sk_buff *skb, bool acked)
|
|
{
|
|
struct sock *sk = skb->sk;
|
|
struct sock_exterr_skb *serr;
|
|
int err = 1;
|
|
|
|
skb->wifi_acked_valid = 1;
|
|
skb->wifi_acked = acked;
|
|
|
|
serr = SKB_EXT_ERR(skb);
|
|
memset(serr, 0, sizeof(*serr));
|
|
serr->ee.ee_errno = ENOMSG;
|
|
serr->ee.ee_origin = SO_EE_ORIGIN_TXSTATUS;
|
|
|
|
/* Take a reference to prevent skb_orphan() from freeing the socket,
|
|
* but only if the socket refcount is not zero.
|
|
*/
|
|
if (likely(refcount_inc_not_zero(&sk->sk_refcnt))) {
|
|
err = sock_queue_err_skb(sk, skb);
|
|
sock_put(sk);
|
|
}
|
|
if (err)
|
|
kfree_skb(skb);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_complete_wifi_ack);
|
|
|
|
/**
|
|
* skb_partial_csum_set - set up and verify partial csum values for packet
|
|
* @skb: the skb to set
|
|
* @start: the number of bytes after skb->data to start checksumming.
|
|
* @off: the offset from start to place the checksum.
|
|
*
|
|
* For untrusted partially-checksummed packets, we need to make sure the values
|
|
* for skb->csum_start and skb->csum_offset are valid so we don't oops.
|
|
*
|
|
* This function checks and sets those values and skb->ip_summed: if this
|
|
* returns false you should drop the packet.
|
|
*/
|
|
bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off)
|
|
{
|
|
u32 csum_end = (u32)start + (u32)off + sizeof(__sum16);
|
|
u32 csum_start = skb_headroom(skb) + (u32)start;
|
|
|
|
if (unlikely(csum_start > U16_MAX || csum_end > skb_headlen(skb))) {
|
|
net_warn_ratelimited("bad partial csum: csum=%u/%u headroom=%u headlen=%u\n",
|
|
start, off, skb_headroom(skb), skb_headlen(skb));
|
|
return false;
|
|
}
|
|
skb->ip_summed = CHECKSUM_PARTIAL;
|
|
skb->csum_start = csum_start;
|
|
skb->csum_offset = off;
|
|
skb_set_transport_header(skb, start);
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_partial_csum_set);
|
|
|
|
static int skb_maybe_pull_tail(struct sk_buff *skb, unsigned int len,
|
|
unsigned int max)
|
|
{
|
|
if (skb_headlen(skb) >= len)
|
|
return 0;
|
|
|
|
/* If we need to pullup then pullup to the max, so we
|
|
* won't need to do it again.
|
|
*/
|
|
if (max > skb->len)
|
|
max = skb->len;
|
|
|
|
if (__pskb_pull_tail(skb, max - skb_headlen(skb)) == NULL)
|
|
return -ENOMEM;
|
|
|
|
if (skb_headlen(skb) < len)
|
|
return -EPROTO;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define MAX_TCP_HDR_LEN (15 * 4)
|
|
|
|
static __sum16 *skb_checksum_setup_ip(struct sk_buff *skb,
|
|
typeof(IPPROTO_IP) proto,
|
|
unsigned int off)
|
|
{
|
|
switch (proto) {
|
|
int err;
|
|
|
|
case IPPROTO_TCP:
|
|
err = skb_maybe_pull_tail(skb, off + sizeof(struct tcphdr),
|
|
off + MAX_TCP_HDR_LEN);
|
|
if (!err && !skb_partial_csum_set(skb, off,
|
|
offsetof(struct tcphdr,
|
|
check)))
|
|
err = -EPROTO;
|
|
return err ? ERR_PTR(err) : &tcp_hdr(skb)->check;
|
|
|
|
case IPPROTO_UDP:
|
|
err = skb_maybe_pull_tail(skb, off + sizeof(struct udphdr),
|
|
off + sizeof(struct udphdr));
|
|
if (!err && !skb_partial_csum_set(skb, off,
|
|
offsetof(struct udphdr,
|
|
check)))
|
|
err = -EPROTO;
|
|
return err ? ERR_PTR(err) : &udp_hdr(skb)->check;
|
|
}
|
|
|
|
return ERR_PTR(-EPROTO);
|
|
}
|
|
|
|
/* This value should be large enough to cover a tagged ethernet header plus
|
|
* maximally sized IP and TCP or UDP headers.
|
|
*/
|
|
#define MAX_IP_HDR_LEN 128
|
|
|
|
static int skb_checksum_setup_ipv4(struct sk_buff *skb, bool recalculate)
|
|
{
|
|
unsigned int off;
|
|
bool fragment;
|
|
__sum16 *csum;
|
|
int err;
|
|
|
|
fragment = false;
|
|
|
|
err = skb_maybe_pull_tail(skb,
|
|
sizeof(struct iphdr),
|
|
MAX_IP_HDR_LEN);
|
|
if (err < 0)
|
|
goto out;
|
|
|
|
if (ip_hdr(skb)->frag_off & htons(IP_OFFSET | IP_MF))
|
|
fragment = true;
|
|
|
|
off = ip_hdrlen(skb);
|
|
|
|
err = -EPROTO;
|
|
|
|
if (fragment)
|
|
goto out;
|
|
|
|
csum = skb_checksum_setup_ip(skb, ip_hdr(skb)->protocol, off);
|
|
if (IS_ERR(csum))
|
|
return PTR_ERR(csum);
|
|
|
|
if (recalculate)
|
|
*csum = ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
|
|
ip_hdr(skb)->daddr,
|
|
skb->len - off,
|
|
ip_hdr(skb)->protocol, 0);
|
|
err = 0;
|
|
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/* This value should be large enough to cover a tagged ethernet header plus
|
|
* an IPv6 header, all options, and a maximal TCP or UDP header.
|
|
*/
|
|
#define MAX_IPV6_HDR_LEN 256
|
|
|
|
#define OPT_HDR(type, skb, off) \
|
|
(type *)(skb_network_header(skb) + (off))
|
|
|
|
static int skb_checksum_setup_ipv6(struct sk_buff *skb, bool recalculate)
|
|
{
|
|
int err;
|
|
u8 nexthdr;
|
|
unsigned int off;
|
|
unsigned int len;
|
|
bool fragment;
|
|
bool done;
|
|
__sum16 *csum;
|
|
|
|
fragment = false;
|
|
done = false;
|
|
|
|
off = sizeof(struct ipv6hdr);
|
|
|
|
err = skb_maybe_pull_tail(skb, off, MAX_IPV6_HDR_LEN);
|
|
if (err < 0)
|
|
goto out;
|
|
|
|
nexthdr = ipv6_hdr(skb)->nexthdr;
|
|
|
|
len = sizeof(struct ipv6hdr) + ntohs(ipv6_hdr(skb)->payload_len);
|
|
while (off <= len && !done) {
|
|
switch (nexthdr) {
|
|
case IPPROTO_DSTOPTS:
|
|
case IPPROTO_HOPOPTS:
|
|
case IPPROTO_ROUTING: {
|
|
struct ipv6_opt_hdr *hp;
|
|
|
|
err = skb_maybe_pull_tail(skb,
|
|
off +
|
|
sizeof(struct ipv6_opt_hdr),
|
|
MAX_IPV6_HDR_LEN);
|
|
if (err < 0)
|
|
goto out;
|
|
|
|
hp = OPT_HDR(struct ipv6_opt_hdr, skb, off);
|
|
nexthdr = hp->nexthdr;
|
|
off += ipv6_optlen(hp);
|
|
break;
|
|
}
|
|
case IPPROTO_AH: {
|
|
struct ip_auth_hdr *hp;
|
|
|
|
err = skb_maybe_pull_tail(skb,
|
|
off +
|
|
sizeof(struct ip_auth_hdr),
|
|
MAX_IPV6_HDR_LEN);
|
|
if (err < 0)
|
|
goto out;
|
|
|
|
hp = OPT_HDR(struct ip_auth_hdr, skb, off);
|
|
nexthdr = hp->nexthdr;
|
|
off += ipv6_authlen(hp);
|
|
break;
|
|
}
|
|
case IPPROTO_FRAGMENT: {
|
|
struct frag_hdr *hp;
|
|
|
|
err = skb_maybe_pull_tail(skb,
|
|
off +
|
|
sizeof(struct frag_hdr),
|
|
MAX_IPV6_HDR_LEN);
|
|
if (err < 0)
|
|
goto out;
|
|
|
|
hp = OPT_HDR(struct frag_hdr, skb, off);
|
|
|
|
if (hp->frag_off & htons(IP6_OFFSET | IP6_MF))
|
|
fragment = true;
|
|
|
|
nexthdr = hp->nexthdr;
|
|
off += sizeof(struct frag_hdr);
|
|
break;
|
|
}
|
|
default:
|
|
done = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
err = -EPROTO;
|
|
|
|
if (!done || fragment)
|
|
goto out;
|
|
|
|
csum = skb_checksum_setup_ip(skb, nexthdr, off);
|
|
if (IS_ERR(csum))
|
|
return PTR_ERR(csum);
|
|
|
|
if (recalculate)
|
|
*csum = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
|
|
&ipv6_hdr(skb)->daddr,
|
|
skb->len - off, nexthdr, 0);
|
|
err = 0;
|
|
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* skb_checksum_setup - set up partial checksum offset
|
|
* @skb: the skb to set up
|
|
* @recalculate: if true the pseudo-header checksum will be recalculated
|
|
*/
|
|
int skb_checksum_setup(struct sk_buff *skb, bool recalculate)
|
|
{
|
|
int err;
|
|
|
|
switch (skb->protocol) {
|
|
case htons(ETH_P_IP):
|
|
err = skb_checksum_setup_ipv4(skb, recalculate);
|
|
break;
|
|
|
|
case htons(ETH_P_IPV6):
|
|
err = skb_checksum_setup_ipv6(skb, recalculate);
|
|
break;
|
|
|
|
default:
|
|
err = -EPROTO;
|
|
break;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(skb_checksum_setup);
|
|
|
|
/**
|
|
* skb_checksum_maybe_trim - maybe trims the given skb
|
|
* @skb: the skb to check
|
|
* @transport_len: the data length beyond the network header
|
|
*
|
|
* Checks whether the given skb has data beyond the given transport length.
|
|
* If so, returns a cloned skb trimmed to this transport length.
|
|
* Otherwise returns the provided skb. Returns NULL in error cases
|
|
* (e.g. transport_len exceeds skb length or out-of-memory).
|
|
*
|
|
* Caller needs to set the skb transport header and free any returned skb if it
|
|
* differs from the provided skb.
|
|
*/
|
|
static struct sk_buff *skb_checksum_maybe_trim(struct sk_buff *skb,
|
|
unsigned int transport_len)
|
|
{
|
|
struct sk_buff *skb_chk;
|
|
unsigned int len = skb_transport_offset(skb) + transport_len;
|
|
int ret;
|
|
|
|
if (skb->len < len)
|
|
return NULL;
|
|
else if (skb->len == len)
|
|
return skb;
|
|
|
|
skb_chk = skb_clone(skb, GFP_ATOMIC);
|
|
if (!skb_chk)
|
|
return NULL;
|
|
|
|
ret = pskb_trim_rcsum(skb_chk, len);
|
|
if (ret) {
|
|
kfree_skb(skb_chk);
|
|
return NULL;
|
|
}
|
|
|
|
return skb_chk;
|
|
}
|
|
|
|
/**
|
|
* skb_checksum_trimmed - validate checksum of an skb
|
|
* @skb: the skb to check
|
|
* @transport_len: the data length beyond the network header
|
|
* @skb_chkf: checksum function to use
|
|
*
|
|
* Applies the given checksum function skb_chkf to the provided skb.
|
|
* Returns a checked and maybe trimmed skb. Returns NULL on error.
|
|
*
|
|
* If the skb has data beyond the given transport length, then a
|
|
* trimmed & cloned skb is checked and returned.
|
|
*
|
|
* Caller needs to set the skb transport header and free any returned skb if it
|
|
* differs from the provided skb.
|
|
*/
|
|
struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
|
|
unsigned int transport_len,
|
|
__sum16(*skb_chkf)(struct sk_buff *skb))
|
|
{
|
|
struct sk_buff *skb_chk;
|
|
unsigned int offset = skb_transport_offset(skb);
|
|
__sum16 ret;
|
|
|
|
skb_chk = skb_checksum_maybe_trim(skb, transport_len);
|
|
if (!skb_chk)
|
|
goto err;
|
|
|
|
if (!pskb_may_pull(skb_chk, offset))
|
|
goto err;
|
|
|
|
skb_pull_rcsum(skb_chk, offset);
|
|
ret = skb_chkf(skb_chk);
|
|
skb_push_rcsum(skb_chk, offset);
|
|
|
|
if (ret)
|
|
goto err;
|
|
|
|
return skb_chk;
|
|
|
|
err:
|
|
if (skb_chk && skb_chk != skb)
|
|
kfree_skb(skb_chk);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
EXPORT_SYMBOL(skb_checksum_trimmed);
|
|
|
|
void __skb_warn_lro_forwarding(const struct sk_buff *skb)
|
|
{
|
|
net_warn_ratelimited("%s: received packets cannot be forwarded while LRO is enabled\n",
|
|
skb->dev->name);
|
|
}
|
|
EXPORT_SYMBOL(__skb_warn_lro_forwarding);
|
|
|
|
void kfree_skb_partial(struct sk_buff *skb, bool head_stolen)
|
|
{
|
|
if (head_stolen) {
|
|
skb_release_head_state(skb);
|
|
kmem_cache_free(skbuff_head_cache, skb);
|
|
} else {
|
|
__kfree_skb(skb);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(kfree_skb_partial);
|
|
|
|
/**
|
|
* skb_try_coalesce - try to merge skb to prior one
|
|
* @to: prior buffer
|
|
* @from: buffer to add
|
|
* @fragstolen: pointer to boolean
|
|
* @delta_truesize: how much more was allocated than was requested
|
|
*/
|
|
bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
|
|
bool *fragstolen, int *delta_truesize)
|
|
{
|
|
struct skb_shared_info *to_shinfo, *from_shinfo;
|
|
int i, delta, len = from->len;
|
|
|
|
*fragstolen = false;
|
|
|
|
if (skb_cloned(to))
|
|
return false;
|
|
|
|
if (len <= skb_tailroom(to)) {
|
|
if (len)
|
|
BUG_ON(skb_copy_bits(from, 0, skb_put(to, len), len));
|
|
*delta_truesize = 0;
|
|
return true;
|
|
}
|
|
|
|
to_shinfo = skb_shinfo(to);
|
|
from_shinfo = skb_shinfo(from);
|
|
if (to_shinfo->frag_list || from_shinfo->frag_list)
|
|
return false;
|
|
if (skb_zcopy(to) || skb_zcopy(from))
|
|
return false;
|
|
|
|
if (skb_headlen(from) != 0) {
|
|
struct page *page;
|
|
unsigned int offset;
|
|
|
|
if (to_shinfo->nr_frags +
|
|
from_shinfo->nr_frags >= MAX_SKB_FRAGS)
|
|
return false;
|
|
|
|
if (skb_head_is_locked(from))
|
|
return false;
|
|
|
|
delta = from->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));
|
|
|
|
page = virt_to_head_page(from->head);
|
|
offset = from->data - (unsigned char *)page_address(page);
|
|
|
|
skb_fill_page_desc(to, to_shinfo->nr_frags,
|
|
page, offset, skb_headlen(from));
|
|
*fragstolen = true;
|
|
} else {
|
|
if (to_shinfo->nr_frags +
|
|
from_shinfo->nr_frags > MAX_SKB_FRAGS)
|
|
return false;
|
|
|
|
delta = from->truesize - SKB_TRUESIZE(skb_end_offset(from));
|
|
}
|
|
|
|
WARN_ON_ONCE(delta < len);
|
|
|
|
memcpy(to_shinfo->frags + to_shinfo->nr_frags,
|
|
from_shinfo->frags,
|
|
from_shinfo->nr_frags * sizeof(skb_frag_t));
|
|
to_shinfo->nr_frags += from_shinfo->nr_frags;
|
|
|
|
if (!skb_cloned(from))
|
|
from_shinfo->nr_frags = 0;
|
|
|
|
/* if the skb is not cloned this does nothing
|
|
* since we set nr_frags to 0.
|
|
*/
|
|
for (i = 0; i < from_shinfo->nr_frags; i++)
|
|
__skb_frag_ref(&from_shinfo->frags[i]);
|
|
|
|
to->truesize += delta;
|
|
to->len += len;
|
|
to->data_len += len;
|
|
|
|
*delta_truesize = delta;
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL(skb_try_coalesce);
|
|
|
|
/**
|
|
* skb_scrub_packet - scrub an skb
|
|
*
|
|
* @skb: buffer to clean
|
|
* @xnet: packet is crossing netns
|
|
*
|
|
* skb_scrub_packet can be used after encapsulating or decapsulting a packet
|
|
* into/from a tunnel. Some information have to be cleared during these
|
|
* operations.
|
|
* skb_scrub_packet can also be used to clean a skb before injecting it in
|
|
* another namespace (@xnet == true). We have to clear all information in the
|
|
* skb that could impact namespace isolation.
|
|
*/
|
|
void skb_scrub_packet(struct sk_buff *skb, bool xnet)
|
|
{
|
|
skb->pkt_type = PACKET_HOST;
|
|
skb->skb_iif = 0;
|
|
skb->ignore_df = 0;
|
|
skb_dst_drop(skb);
|
|
skb_ext_reset(skb);
|
|
nf_reset_ct(skb);
|
|
nf_reset_trace(skb);
|
|
|
|
#ifdef CONFIG_NET_SWITCHDEV
|
|
skb->offload_fwd_mark = 0;
|
|
skb->offload_l3_fwd_mark = 0;
|
|
#endif
|
|
|
|
if (!xnet)
|
|
return;
|
|
|
|
ipvs_reset(skb);
|
|
skb->mark = 0;
|
|
skb->tstamp = 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_scrub_packet);
|
|
|
|
/**
|
|
* skb_gso_transport_seglen - Return length of individual segments of a gso packet
|
|
*
|
|
* @skb: GSO skb
|
|
*
|
|
* skb_gso_transport_seglen is used to determine the real size of the
|
|
* individual segments, including Layer4 headers (TCP/UDP).
|
|
*
|
|
* The MAC/L2 or network (IP, IPv6) headers are not accounted for.
|
|
*/
|
|
static unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
|
|
{
|
|
const struct skb_shared_info *shinfo = skb_shinfo(skb);
|
|
unsigned int thlen = 0;
|
|
|
|
if (skb->encapsulation) {
|
|
thlen = skb_inner_transport_header(skb) -
|
|
skb_transport_header(skb);
|
|
|
|
if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
|
|
thlen += inner_tcp_hdrlen(skb);
|
|
} else if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
|
|
thlen = tcp_hdrlen(skb);
|
|
} else if (unlikely(skb_is_gso_sctp(skb))) {
|
|
thlen = sizeof(struct sctphdr);
|
|
} else if (shinfo->gso_type & SKB_GSO_UDP_L4) {
|
|
thlen = sizeof(struct udphdr);
|
|
}
|
|
/* UFO sets gso_size to the size of the fragmentation
|
|
* payload, i.e. the size of the L4 (UDP) header is already
|
|
* accounted for.
|
|
*/
|
|
return thlen + shinfo->gso_size;
|
|
}
|
|
|
|
/**
|
|
* skb_gso_network_seglen - Return length of individual segments of a gso packet
|
|
*
|
|
* @skb: GSO skb
|
|
*
|
|
* skb_gso_network_seglen is used to determine the real size of the
|
|
* individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
|
|
*
|
|
* The MAC/L2 header is not accounted for.
|
|
*/
|
|
static unsigned int skb_gso_network_seglen(const struct sk_buff *skb)
|
|
{
|
|
unsigned int hdr_len = skb_transport_header(skb) -
|
|
skb_network_header(skb);
|
|
|
|
return hdr_len + skb_gso_transport_seglen(skb);
|
|
}
|
|
|
|
/**
|
|
* skb_gso_mac_seglen - Return length of individual segments of a gso packet
|
|
*
|
|
* @skb: GSO skb
|
|
*
|
|
* skb_gso_mac_seglen is used to determine the real size of the
|
|
* individual segments, including MAC/L2, Layer3 (IP, IPv6) and L4
|
|
* headers (TCP/UDP).
|
|
*/
|
|
static unsigned int skb_gso_mac_seglen(const struct sk_buff *skb)
|
|
{
|
|
unsigned int hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
|
|
|
|
return hdr_len + skb_gso_transport_seglen(skb);
|
|
}
|
|
|
|
/**
|
|
* skb_gso_size_check - check the skb size, considering GSO_BY_FRAGS
|
|
*
|
|
* There are a couple of instances where we have a GSO skb, and we
|
|
* want to determine what size it would be after it is segmented.
|
|
*
|
|
* We might want to check:
|
|
* - L3+L4+payload size (e.g. IP forwarding)
|
|
* - L2+L3+L4+payload size (e.g. sanity check before passing to driver)
|
|
*
|
|
* This is a helper to do that correctly considering GSO_BY_FRAGS.
|
|
*
|
|
* @skb: GSO skb
|
|
*
|
|
* @seg_len: The segmented length (from skb_gso_*_seglen). In the
|
|
* GSO_BY_FRAGS case this will be [header sizes + GSO_BY_FRAGS].
|
|
*
|
|
* @max_len: The maximum permissible length.
|
|
*
|
|
* Returns true if the segmented length <= max length.
|
|
*/
|
|
static inline bool skb_gso_size_check(const struct sk_buff *skb,
|
|
unsigned int seg_len,
|
|
unsigned int max_len) {
|
|
const struct skb_shared_info *shinfo = skb_shinfo(skb);
|
|
const struct sk_buff *iter;
|
|
|
|
if (shinfo->gso_size != GSO_BY_FRAGS)
|
|
return seg_len <= max_len;
|
|
|
|
/* Undo this so we can re-use header sizes */
|
|
seg_len -= GSO_BY_FRAGS;
|
|
|
|
skb_walk_frags(skb, iter) {
|
|
if (seg_len + skb_headlen(iter) > max_len)
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* skb_gso_validate_network_len - Will a split GSO skb fit into a given MTU?
|
|
*
|
|
* @skb: GSO skb
|
|
* @mtu: MTU to validate against
|
|
*
|
|
* skb_gso_validate_network_len validates if a given skb will fit a
|
|
* wanted MTU once split. It considers L3 headers, L4 headers, and the
|
|
* payload.
|
|
*/
|
|
bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu)
|
|
{
|
|
return skb_gso_size_check(skb, skb_gso_network_seglen(skb), mtu);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_gso_validate_network_len);
|
|
|
|
/**
|
|
* skb_gso_validate_mac_len - Will a split GSO skb fit in a given length?
|
|
*
|
|
* @skb: GSO skb
|
|
* @len: length to validate against
|
|
*
|
|
* skb_gso_validate_mac_len validates if a given skb will fit a wanted
|
|
* length once split, including L2, L3 and L4 headers and the payload.
|
|
*/
|
|
bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len)
|
|
{
|
|
return skb_gso_size_check(skb, skb_gso_mac_seglen(skb), len);
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_gso_validate_mac_len);
|
|
|
|
static struct sk_buff *skb_reorder_vlan_header(struct sk_buff *skb)
|
|
{
|
|
int mac_len, meta_len;
|
|
void *meta;
|
|
|
|
if (skb_cow(skb, skb_headroom(skb)) < 0) {
|
|
kfree_skb(skb);
|
|
return NULL;
|
|
}
|
|
|
|
mac_len = skb->data - skb_mac_header(skb);
|
|
if (likely(mac_len > VLAN_HLEN + ETH_TLEN)) {
|
|
memmove(skb_mac_header(skb) + VLAN_HLEN, skb_mac_header(skb),
|
|
mac_len - VLAN_HLEN - ETH_TLEN);
|
|
}
|
|
|
|
meta_len = skb_metadata_len(skb);
|
|
if (meta_len) {
|
|
meta = skb_metadata_end(skb) - meta_len;
|
|
memmove(meta + VLAN_HLEN, meta, meta_len);
|
|
}
|
|
|
|
skb->mac_header += VLAN_HLEN;
|
|
return skb;
|
|
}
|
|
|
|
struct sk_buff *skb_vlan_untag(struct sk_buff *skb)
|
|
{
|
|
struct vlan_hdr *vhdr;
|
|
u16 vlan_tci;
|
|
|
|
if (unlikely(skb_vlan_tag_present(skb))) {
|
|
/* vlan_tci is already set-up so leave this for another time */
|
|
return skb;
|
|
}
|
|
|
|
skb = skb_share_check(skb, GFP_ATOMIC);
|
|
if (unlikely(!skb))
|
|
goto err_free;
|
|
|
|
if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
|
|
goto err_free;
|
|
|
|
vhdr = (struct vlan_hdr *)skb->data;
|
|
vlan_tci = ntohs(vhdr->h_vlan_TCI);
|
|
__vlan_hwaccel_put_tag(skb, skb->protocol, vlan_tci);
|
|
|
|
skb_pull_rcsum(skb, VLAN_HLEN);
|
|
vlan_set_encap_proto(skb, vhdr);
|
|
|
|
skb = skb_reorder_vlan_header(skb);
|
|
if (unlikely(!skb))
|
|
goto err_free;
|
|
|
|
skb_reset_network_header(skb);
|
|
skb_reset_transport_header(skb);
|
|
skb_reset_mac_len(skb);
|
|
|
|
return skb;
|
|
|
|
err_free:
|
|
kfree_skb(skb);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(skb_vlan_untag);
|
|
|
|
int skb_ensure_writable(struct sk_buff *skb, int write_len)
|
|
{
|
|
if (!pskb_may_pull(skb, write_len))
|
|
return -ENOMEM;
|
|
|
|
if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
|
|
return 0;
|
|
|
|
return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
|
|
}
|
|
EXPORT_SYMBOL(skb_ensure_writable);
|
|
|
|
/* remove VLAN header from packet and update csum accordingly.
|
|
* expects a non skb_vlan_tag_present skb with a vlan tag payload
|
|
*/
|
|
int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci)
|
|
{
|
|
struct vlan_hdr *vhdr;
|
|
int offset = skb->data - skb_mac_header(skb);
|
|
int err;
|
|
|
|
if (WARN_ONCE(offset,
|
|
"__skb_vlan_pop got skb with skb->data not at mac header (offset %d)\n",
|
|
offset)) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
err = skb_ensure_writable(skb, VLAN_ETH_HLEN);
|
|
if (unlikely(err))
|
|
return err;
|
|
|
|
skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN);
|
|
|
|
vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
|
|
*vlan_tci = ntohs(vhdr->h_vlan_TCI);
|
|
|
|
memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
|
|
__skb_pull(skb, VLAN_HLEN);
|
|
|
|
vlan_set_encap_proto(skb, vhdr);
|
|
skb->mac_header += VLAN_HLEN;
|
|
|
|
if (skb_network_offset(skb) < ETH_HLEN)
|
|
skb_set_network_header(skb, ETH_HLEN);
|
|
|
|
skb_reset_mac_len(skb);
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(__skb_vlan_pop);
|
|
|
|
/* Pop a vlan tag either from hwaccel or from payload.
|
|
* Expects skb->data at mac header.
|
|
*/
|
|
int skb_vlan_pop(struct sk_buff *skb)
|
|
{
|
|
u16 vlan_tci;
|
|
__be16 vlan_proto;
|
|
int err;
|
|
|
|
if (likely(skb_vlan_tag_present(skb))) {
|
|
__vlan_hwaccel_clear_tag(skb);
|
|
} else {
|
|
if (unlikely(!eth_type_vlan(skb->protocol)))
|
|
return 0;
|
|
|
|
err = __skb_vlan_pop(skb, &vlan_tci);
|
|
if (err)
|
|
return err;
|
|
}
|
|
/* move next vlan tag to hw accel tag */
|
|
if (likely(!eth_type_vlan(skb->protocol)))
|
|
return 0;
|
|
|
|
vlan_proto = skb->protocol;
|
|
err = __skb_vlan_pop(skb, &vlan_tci);
|
|
if (unlikely(err))
|
|
return err;
|
|
|
|
__vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(skb_vlan_pop);
|
|
|
|
/* Push a vlan tag either into hwaccel or into payload (if hwaccel tag present).
|
|
* Expects skb->data at mac header.
|
|
*/
|
|
int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
|
|
{
|
|
if (skb_vlan_tag_present(skb)) {
|
|
int offset = skb->data - skb_mac_header(skb);
|
|
int err;
|
|
|
|
if (WARN_ONCE(offset,
|
|
"skb_vlan_push got skb with skb->data not at mac header (offset %d)\n",
|
|
offset)) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
err = __vlan_insert_tag(skb, skb->vlan_proto,
|
|
skb_vlan_tag_get(skb));
|
|
if (err)
|
|
return err;
|
|
|
|
skb->protocol = skb->vlan_proto;
|
|
skb->mac_len += VLAN_HLEN;
|
|
|
|
skb_postpush_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN);
|
|
}
|
|
__vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(skb_vlan_push);
|
|
|
|
/* Update the ethertype of hdr and the skb csum value if required. */
|
|
static void skb_mod_eth_type(struct sk_buff *skb, struct ethhdr *hdr,
|
|
__be16 ethertype)
|
|
{
|
|
if (skb->ip_summed == CHECKSUM_COMPLETE) {
|
|
__be16 diff[] = { ~hdr->h_proto, ethertype };
|
|
|
|
skb->csum = csum_partial((char *)diff, sizeof(diff), skb->csum);
|
|
}
|
|
|
|
hdr->h_proto = ethertype;
|
|
}
|
|
|
|
/**
|
|
* skb_mpls_push() - push a new MPLS header after the mac header
|
|
*
|
|
* @skb: buffer
|
|
* @mpls_lse: MPLS label stack entry to push
|
|
* @mpls_proto: ethertype of the new MPLS header (expects 0x8847 or 0x8848)
|
|
* @mac_len: length of the MAC header
|
|
*
|
|
* Expects skb->data at mac header.
|
|
*
|
|
* Returns 0 on success, -errno otherwise.
|
|
*/
|
|
int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
|
|
int mac_len, bool ethernet)
|
|
{
|
|
struct mpls_shim_hdr *lse;
|
|
int err;
|
|
|
|
if (unlikely(!eth_p_mpls(mpls_proto)))
|
|
return -EINVAL;
|
|
|
|
/* Networking stack does not allow simultaneous Tunnel and MPLS GSO. */
|
|
if (skb->encapsulation)
|
|
return -EINVAL;
|
|
|
|
err = skb_cow_head(skb, MPLS_HLEN);
|
|
if (unlikely(err))
|
|
return err;
|
|
|
|
if (!skb->inner_protocol) {
|
|
skb_set_inner_network_header(skb, mac_len);
|
|
skb_set_inner_protocol(skb, skb->protocol);
|
|
}
|
|
|
|
skb_push(skb, MPLS_HLEN);
|
|
memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb),
|
|
mac_len);
|
|
skb_reset_mac_header(skb);
|
|
skb_set_network_header(skb, mac_len);
|
|
|
|
lse = mpls_hdr(skb);
|
|
lse->label_stack_entry = mpls_lse;
|
|
skb_postpush_rcsum(skb, lse, MPLS_HLEN);
|
|
|
|
if (ethernet)
|
|
skb_mod_eth_type(skb, eth_hdr(skb), mpls_proto);
|
|
skb->protocol = mpls_proto;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_mpls_push);
|
|
|
|
/**
|
|
* skb_mpls_pop() - pop the outermost MPLS header
|
|
*
|
|
* @skb: buffer
|
|
* @next_proto: ethertype of header after popped MPLS header
|
|
* @mac_len: length of the MAC header
|
|
* @ethernet: flag to indicate if ethernet header is present in packet
|
|
*
|
|
* Expects skb->data at mac header.
|
|
*
|
|
* Returns 0 on success, -errno otherwise.
|
|
*/
|
|
int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len,
|
|
bool ethernet)
|
|
{
|
|
int err;
|
|
|
|
if (unlikely(!eth_p_mpls(skb->protocol)))
|
|
return 0;
|
|
|
|
err = skb_ensure_writable(skb, mac_len + MPLS_HLEN);
|
|
if (unlikely(err))
|
|
return err;
|
|
|
|
skb_postpull_rcsum(skb, mpls_hdr(skb), MPLS_HLEN);
|
|
memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
|
|
mac_len);
|
|
|
|
__skb_pull(skb, MPLS_HLEN);
|
|
skb_reset_mac_header(skb);
|
|
skb_set_network_header(skb, mac_len);
|
|
|
|
if (ethernet) {
|
|
struct ethhdr *hdr;
|
|
|
|
/* use mpls_hdr() to get ethertype to account for VLANs. */
|
|
hdr = (struct ethhdr *)((void *)mpls_hdr(skb) - ETH_HLEN);
|
|
skb_mod_eth_type(skb, hdr, next_proto);
|
|
}
|
|
skb->protocol = next_proto;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_mpls_pop);
|
|
|
|
/**
|
|
* skb_mpls_update_lse() - modify outermost MPLS header and update csum
|
|
*
|
|
* @skb: buffer
|
|
* @mpls_lse: new MPLS label stack entry to update to
|
|
*
|
|
* Expects skb->data at mac header.
|
|
*
|
|
* Returns 0 on success, -errno otherwise.
|
|
*/
|
|
int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse)
|
|
{
|
|
int err;
|
|
|
|
if (unlikely(!eth_p_mpls(skb->protocol)))
|
|
return -EINVAL;
|
|
|
|
err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
|
|
if (unlikely(err))
|
|
return err;
|
|
|
|
if (skb->ip_summed == CHECKSUM_COMPLETE) {
|
|
__be32 diff[] = { ~mpls_hdr(skb)->label_stack_entry, mpls_lse };
|
|
|
|
skb->csum = csum_partial((char *)diff, sizeof(diff), skb->csum);
|
|
}
|
|
|
|
mpls_hdr(skb)->label_stack_entry = mpls_lse;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_mpls_update_lse);
|
|
|
|
/**
|
|
* skb_mpls_dec_ttl() - decrement the TTL of the outermost MPLS header
|
|
*
|
|
* @skb: buffer
|
|
*
|
|
* Expects skb->data at mac header.
|
|
*
|
|
* Returns 0 on success, -errno otherwise.
|
|
*/
|
|
int skb_mpls_dec_ttl(struct sk_buff *skb)
|
|
{
|
|
u32 lse;
|
|
u8 ttl;
|
|
|
|
if (unlikely(!eth_p_mpls(skb->protocol)))
|
|
return -EINVAL;
|
|
|
|
lse = be32_to_cpu(mpls_hdr(skb)->label_stack_entry);
|
|
ttl = (lse & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
|
|
if (!--ttl)
|
|
return -EINVAL;
|
|
|
|
lse &= ~MPLS_LS_TTL_MASK;
|
|
lse |= ttl << MPLS_LS_TTL_SHIFT;
|
|
|
|
return skb_mpls_update_lse(skb, cpu_to_be32(lse));
|
|
}
|
|
EXPORT_SYMBOL_GPL(skb_mpls_dec_ttl);
|
|
|
|
/**
|
|
* alloc_skb_with_frags - allocate skb with page frags
|
|
*
|
|
* @header_len: size of linear part
|
|
* @data_len: needed length in frags
|
|
* @max_page_order: max page order desired.
|
|
* @errcode: pointer to error code if any
|
|
* @gfp_mask: allocation mask
|
|
*
|
|
* This can be used to allocate a paged skb, given a maximal order for frags.
|
|
*/
|
|
struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
|
|
unsigned long data_len,
|
|
int max_page_order,
|
|
int *errcode,
|
|
gfp_t gfp_mask)
|
|
{
|
|
int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
|
|
unsigned long chunk;
|
|
struct sk_buff *skb;
|
|
struct page *page;
|
|
int i;
|
|
|
|
*errcode = -EMSGSIZE;
|
|
/* Note this test could be relaxed, if we succeed to allocate
|
|
* high order pages...
|
|
*/
|
|
if (npages > MAX_SKB_FRAGS)
|
|
return NULL;
|
|
|
|
*errcode = -ENOBUFS;
|
|
skb = alloc_skb(header_len, gfp_mask);
|
|
if (!skb)
|
|
return NULL;
|
|
|
|
skb->truesize += npages << PAGE_SHIFT;
|
|
|
|
for (i = 0; npages > 0; i++) {
|
|
int order = max_page_order;
|
|
|
|
while (order) {
|
|
if (npages >= 1 << order) {
|
|
page = alloc_pages((gfp_mask & ~__GFP_DIRECT_RECLAIM) |
|
|
__GFP_COMP |
|
|
__GFP_NOWARN,
|
|
order);
|
|
if (page)
|
|
goto fill_page;
|
|
/* Do not retry other high order allocations */
|
|
order = 1;
|
|
max_page_order = 0;
|
|
}
|
|
order--;
|
|
}
|
|
page = alloc_page(gfp_mask);
|
|
if (!page)
|
|
goto failure;
|
|
fill_page:
|
|
chunk = min_t(unsigned long, data_len,
|
|
PAGE_SIZE << order);
|
|
skb_fill_page_desc(skb, i, page, 0, chunk);
|
|
data_len -= chunk;
|
|
npages -= 1 << order;
|
|
}
|
|
return skb;
|
|
|
|
failure:
|
|
kfree_skb(skb);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(alloc_skb_with_frags);
|
|
|
|
/* carve out the first off bytes from skb when off < headlen */
|
|
static int pskb_carve_inside_header(struct sk_buff *skb, const u32 off,
|
|
const int headlen, gfp_t gfp_mask)
|
|
{
|
|
int i;
|
|
int size = skb_end_offset(skb);
|
|
int new_hlen = headlen - off;
|
|
u8 *data;
|
|
|
|
size = SKB_DATA_ALIGN(size);
|
|
|
|
if (skb_pfmemalloc(skb))
|
|
gfp_mask |= __GFP_MEMALLOC;
|
|
data = kmalloc_reserve(size +
|
|
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
|
|
gfp_mask, NUMA_NO_NODE, NULL);
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
size = SKB_WITH_OVERHEAD(ksize(data));
|
|
|
|
/* Copy real data, and all frags */
|
|
skb_copy_from_linear_data_offset(skb, off, data, new_hlen);
|
|
skb->len -= off;
|
|
|
|
memcpy((struct skb_shared_info *)(data + size),
|
|
skb_shinfo(skb),
|
|
offsetof(struct skb_shared_info,
|
|
frags[skb_shinfo(skb)->nr_frags]));
|
|
if (skb_cloned(skb)) {
|
|
/* drop the old head gracefully */
|
|
if (skb_orphan_frags(skb, gfp_mask)) {
|
|
kfree(data);
|
|
return -ENOMEM;
|
|
}
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
|
|
skb_frag_ref(skb, i);
|
|
if (skb_has_frag_list(skb))
|
|
skb_clone_fraglist(skb);
|
|
skb_release_data(skb);
|
|
} else {
|
|
/* we can reuse existing recount- all we did was
|
|
* relocate values
|
|
*/
|
|
skb_free_head(skb);
|
|
}
|
|
|
|
skb->head = data;
|
|
skb->data = data;
|
|
skb->head_frag = 0;
|
|
#ifdef NET_SKBUFF_DATA_USES_OFFSET
|
|
skb->end = size;
|
|
#else
|
|
skb->end = skb->head + size;
|
|
#endif
|
|
skb_set_tail_pointer(skb, skb_headlen(skb));
|
|
skb_headers_offset_update(skb, 0);
|
|
skb->cloned = 0;
|
|
skb->hdr_len = 0;
|
|
skb->nohdr = 0;
|
|
atomic_set(&skb_shinfo(skb)->dataref, 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pskb_carve(struct sk_buff *skb, const u32 off, gfp_t gfp);
|
|
|
|
/* carve out the first eat bytes from skb's frag_list. May recurse into
|
|
* pskb_carve()
|
|
*/
|
|
static int pskb_carve_frag_list(struct sk_buff *skb,
|
|
struct skb_shared_info *shinfo, int eat,
|
|
gfp_t gfp_mask)
|
|
{
|
|
struct sk_buff *list = shinfo->frag_list;
|
|
struct sk_buff *clone = NULL;
|
|
struct sk_buff *insp = NULL;
|
|
|
|
do {
|
|
if (!list) {
|
|
pr_err("Not enough bytes to eat. Want %d\n", eat);
|
|
return -EFAULT;
|
|
}
|
|
if (list->len <= eat) {
|
|
/* Eaten as whole. */
|
|
eat -= list->len;
|
|
list = list->next;
|
|
insp = list;
|
|
} else {
|
|
/* Eaten partially. */
|
|
if (skb_shared(list)) {
|
|
clone = skb_clone(list, gfp_mask);
|
|
if (!clone)
|
|
return -ENOMEM;
|
|
insp = list->next;
|
|
list = clone;
|
|
} else {
|
|
/* This may be pulled without problems. */
|
|
insp = list;
|
|
}
|
|
if (pskb_carve(list, eat, gfp_mask) < 0) {
|
|
kfree_skb(clone);
|
|
return -ENOMEM;
|
|
}
|
|
break;
|
|
}
|
|
} while (eat);
|
|
|
|
/* Free pulled out fragments. */
|
|
while ((list = shinfo->frag_list) != insp) {
|
|
shinfo->frag_list = list->next;
|
|
kfree_skb(list);
|
|
}
|
|
/* And insert new clone at head. */
|
|
if (clone) {
|
|
clone->next = list;
|
|
shinfo->frag_list = clone;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* carve off first len bytes from skb. Split line (off) is in the
|
|
* non-linear part of skb
|
|
*/
|
|
static int pskb_carve_inside_nonlinear(struct sk_buff *skb, const u32 off,
|
|
int pos, gfp_t gfp_mask)
|
|
{
|
|
int i, k = 0;
|
|
int size = skb_end_offset(skb);
|
|
u8 *data;
|
|
const int nfrags = skb_shinfo(skb)->nr_frags;
|
|
struct skb_shared_info *shinfo;
|
|
|
|
size = SKB_DATA_ALIGN(size);
|
|
|
|
if (skb_pfmemalloc(skb))
|
|
gfp_mask |= __GFP_MEMALLOC;
|
|
data = kmalloc_reserve(size +
|
|
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
|
|
gfp_mask, NUMA_NO_NODE, NULL);
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
size = SKB_WITH_OVERHEAD(ksize(data));
|
|
|
|
memcpy((struct skb_shared_info *)(data + size),
|
|
skb_shinfo(skb), offsetof(struct skb_shared_info,
|
|
frags[skb_shinfo(skb)->nr_frags]));
|
|
if (skb_orphan_frags(skb, gfp_mask)) {
|
|
kfree(data);
|
|
return -ENOMEM;
|
|
}
|
|
shinfo = (struct skb_shared_info *)(data + size);
|
|
for (i = 0; i < nfrags; i++) {
|
|
int fsize = skb_frag_size(&skb_shinfo(skb)->frags[i]);
|
|
|
|
if (pos + fsize > off) {
|
|
shinfo->frags[k] = skb_shinfo(skb)->frags[i];
|
|
|
|
if (pos < off) {
|
|
/* Split frag.
|
|
* We have two variants in this case:
|
|
* 1. Move all the frag to the second
|
|
* part, if it is possible. F.e.
|
|
* this approach is mandatory for TUX,
|
|
* where splitting is expensive.
|
|
* 2. Split is accurately. We make this.
|
|
*/
|
|
skb_frag_off_add(&shinfo->frags[0], off - pos);
|
|
skb_frag_size_sub(&shinfo->frags[0], off - pos);
|
|
}
|
|
skb_frag_ref(skb, i);
|
|
k++;
|
|
}
|
|
pos += fsize;
|
|
}
|
|
shinfo->nr_frags = k;
|
|
if (skb_has_frag_list(skb))
|
|
skb_clone_fraglist(skb);
|
|
|
|
if (k == 0) {
|
|
/* split line is in frag list */
|
|
pskb_carve_frag_list(skb, shinfo, off - pos, gfp_mask);
|
|
}
|
|
skb_release_data(skb);
|
|
|
|
skb->head = data;
|
|
skb->head_frag = 0;
|
|
skb->data = data;
|
|
#ifdef NET_SKBUFF_DATA_USES_OFFSET
|
|
skb->end = size;
|
|
#else
|
|
skb->end = skb->head + size;
|
|
#endif
|
|
skb_reset_tail_pointer(skb);
|
|
skb_headers_offset_update(skb, 0);
|
|
skb->cloned = 0;
|
|
skb->hdr_len = 0;
|
|
skb->nohdr = 0;
|
|
skb->len -= off;
|
|
skb->data_len = skb->len;
|
|
atomic_set(&skb_shinfo(skb)->dataref, 1);
|
|
return 0;
|
|
}
|
|
|
|
/* remove len bytes from the beginning of the skb */
|
|
static int pskb_carve(struct sk_buff *skb, const u32 len, gfp_t gfp)
|
|
{
|
|
int headlen = skb_headlen(skb);
|
|
|
|
if (len < headlen)
|
|
return pskb_carve_inside_header(skb, len, headlen, gfp);
|
|
else
|
|
return pskb_carve_inside_nonlinear(skb, len, headlen, gfp);
|
|
}
|
|
|
|
/* Extract to_copy bytes starting at off from skb, and return this in
|
|
* a new skb
|
|
*/
|
|
struct sk_buff *pskb_extract(struct sk_buff *skb, int off,
|
|
int to_copy, gfp_t gfp)
|
|
{
|
|
struct sk_buff *clone = skb_clone(skb, gfp);
|
|
|
|
if (!clone)
|
|
return NULL;
|
|
|
|
if (pskb_carve(clone, off, gfp) < 0 ||
|
|
pskb_trim(clone, to_copy)) {
|
|
kfree_skb(clone);
|
|
return NULL;
|
|
}
|
|
return clone;
|
|
}
|
|
EXPORT_SYMBOL(pskb_extract);
|
|
|
|
/**
|
|
* skb_condense - try to get rid of fragments/frag_list if possible
|
|
* @skb: buffer
|
|
*
|
|
* Can be used to save memory before skb is added to a busy queue.
|
|
* If packet has bytes in frags and enough tail room in skb->head,
|
|
* pull all of them, so that we can free the frags right now and adjust
|
|
* truesize.
|
|
* Notes:
|
|
* We do not reallocate skb->head thus can not fail.
|
|
* Caller must re-evaluate skb->truesize if needed.
|
|
*/
|
|
void skb_condense(struct sk_buff *skb)
|
|
{
|
|
if (skb->data_len) {
|
|
if (skb->data_len > skb->end - skb->tail ||
|
|
skb_cloned(skb))
|
|
return;
|
|
|
|
/* Nice, we can free page frag(s) right now */
|
|
__pskb_pull_tail(skb, skb->data_len);
|
|
}
|
|
/* At this point, skb->truesize might be over estimated,
|
|
* because skb had a fragment, and fragments do not tell
|
|
* their truesize.
|
|
* When we pulled its content into skb->head, fragment
|
|
* was freed, but __pskb_pull_tail() could not possibly
|
|
* adjust skb->truesize, not knowing the frag truesize.
|
|
*/
|
|
skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
|
|
}
|
|
|
|
#ifdef CONFIG_SKB_EXTENSIONS
|
|
static void *skb_ext_get_ptr(struct skb_ext *ext, enum skb_ext_id id)
|
|
{
|
|
return (void *)ext + (ext->offset[id] * SKB_EXT_ALIGN_VALUE);
|
|
}
|
|
|
|
static struct skb_ext *skb_ext_alloc(void)
|
|
{
|
|
struct skb_ext *new = kmem_cache_alloc(skbuff_ext_cache, GFP_ATOMIC);
|
|
|
|
if (new) {
|
|
memset(new->offset, 0, sizeof(new->offset));
|
|
refcount_set(&new->refcnt, 1);
|
|
}
|
|
|
|
return new;
|
|
}
|
|
|
|
static struct skb_ext *skb_ext_maybe_cow(struct skb_ext *old,
|
|
unsigned int old_active)
|
|
{
|
|
struct skb_ext *new;
|
|
|
|
if (refcount_read(&old->refcnt) == 1)
|
|
return old;
|
|
|
|
new = kmem_cache_alloc(skbuff_ext_cache, GFP_ATOMIC);
|
|
if (!new)
|
|
return NULL;
|
|
|
|
memcpy(new, old, old->chunks * SKB_EXT_ALIGN_VALUE);
|
|
refcount_set(&new->refcnt, 1);
|
|
|
|
#ifdef CONFIG_XFRM
|
|
if (old_active & (1 << SKB_EXT_SEC_PATH)) {
|
|
struct sec_path *sp = skb_ext_get_ptr(old, SKB_EXT_SEC_PATH);
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < sp->len; i++)
|
|
xfrm_state_hold(sp->xvec[i]);
|
|
}
|
|
#endif
|
|
__skb_ext_put(old);
|
|
return new;
|
|
}
|
|
|
|
/**
|
|
* skb_ext_add - allocate space for given extension, COW if needed
|
|
* @skb: buffer
|
|
* @id: extension to allocate space for
|
|
*
|
|
* Allocates enough space for the given extension.
|
|
* If the extension is already present, a pointer to that extension
|
|
* is returned.
|
|
*
|
|
* If the skb was cloned, COW applies and the returned memory can be
|
|
* modified without changing the extension space of clones buffers.
|
|
*
|
|
* Returns pointer to the extension or NULL on allocation failure.
|
|
*/
|
|
void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id)
|
|
{
|
|
struct skb_ext *new, *old = NULL;
|
|
unsigned int newlen, newoff;
|
|
|
|
if (skb->active_extensions) {
|
|
old = skb->extensions;
|
|
|
|
new = skb_ext_maybe_cow(old, skb->active_extensions);
|
|
if (!new)
|
|
return NULL;
|
|
|
|
if (__skb_ext_exist(new, id))
|
|
goto set_active;
|
|
|
|
newoff = new->chunks;
|
|
} else {
|
|
newoff = SKB_EXT_CHUNKSIZEOF(*new);
|
|
|
|
new = skb_ext_alloc();
|
|
if (!new)
|
|
return NULL;
|
|
}
|
|
|
|
newlen = newoff + skb_ext_type_len[id];
|
|
new->chunks = newlen;
|
|
new->offset[id] = newoff;
|
|
set_active:
|
|
skb->extensions = new;
|
|
skb->active_extensions |= 1 << id;
|
|
return skb_ext_get_ptr(new, id);
|
|
}
|
|
EXPORT_SYMBOL(skb_ext_add);
|
|
|
|
#ifdef CONFIG_XFRM
|
|
static void skb_ext_put_sp(struct sec_path *sp)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < sp->len; i++)
|
|
xfrm_state_put(sp->xvec[i]);
|
|
}
|
|
#endif
|
|
|
|
void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id)
|
|
{
|
|
struct skb_ext *ext = skb->extensions;
|
|
|
|
skb->active_extensions &= ~(1 << id);
|
|
if (skb->active_extensions == 0) {
|
|
skb->extensions = NULL;
|
|
__skb_ext_put(ext);
|
|
#ifdef CONFIG_XFRM
|
|
} else if (id == SKB_EXT_SEC_PATH &&
|
|
refcount_read(&ext->refcnt) == 1) {
|
|
struct sec_path *sp = skb_ext_get_ptr(ext, SKB_EXT_SEC_PATH);
|
|
|
|
skb_ext_put_sp(sp);
|
|
sp->len = 0;
|
|
#endif
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(__skb_ext_del);
|
|
|
|
void __skb_ext_put(struct skb_ext *ext)
|
|
{
|
|
/* If this is last clone, nothing can increment
|
|
* it after check passes. Avoids one atomic op.
|
|
*/
|
|
if (refcount_read(&ext->refcnt) == 1)
|
|
goto free_now;
|
|
|
|
if (!refcount_dec_and_test(&ext->refcnt))
|
|
return;
|
|
free_now:
|
|
#ifdef CONFIG_XFRM
|
|
if (__skb_ext_exist(ext, SKB_EXT_SEC_PATH))
|
|
skb_ext_put_sp(skb_ext_get_ptr(ext, SKB_EXT_SEC_PATH));
|
|
#endif
|
|
|
|
kmem_cache_free(skbuff_ext_cache, ext);
|
|
}
|
|
EXPORT_SYMBOL(__skb_ext_put);
|
|
#endif /* CONFIG_SKB_EXTENSIONS */
|