1191 lines
29 KiB
C
1191 lines
29 KiB
C
/*
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* IPv6 output functions
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* Linux INET6 implementation
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*
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* Authors:
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* Pedro Roque <roque@di.fc.ul.pt>
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*
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* $Id: ip6_output.c,v 1.34 2002/02/01 22:01:04 davem Exp $
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*
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* Based on linux/net/ipv4/ip_output.c
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Changes:
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* A.N.Kuznetsov : airthmetics in fragmentation.
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* extension headers are implemented.
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* route changes now work.
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* ip6_forward does not confuse sniffers.
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* etc.
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*
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* H. von Brand : Added missing #include <linux/string.h>
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* Imran Patel : frag id should be in NBO
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* Kazunori MIYAZAWA @USAGI
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* : add ip6_append_data and related functions
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* for datagram xmit
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*/
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#include <linux/config.h>
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/socket.h>
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#include <linux/net.h>
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#include <linux/netdevice.h>
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#include <linux/if_arp.h>
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#include <linux/in6.h>
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#include <linux/tcp.h>
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#include <linux/route.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter_ipv6.h>
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#include <net/sock.h>
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#include <net/snmp.h>
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#include <net/ipv6.h>
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#include <net/ndisc.h>
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#include <net/protocol.h>
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#include <net/ip6_route.h>
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#include <net/addrconf.h>
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#include <net/rawv6.h>
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#include <net/icmp.h>
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#include <net/xfrm.h>
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#include <net/checksum.h>
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static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
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static __inline__ void ipv6_select_ident(struct sk_buff *skb, struct frag_hdr *fhdr)
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{
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static u32 ipv6_fragmentation_id = 1;
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static DEFINE_SPINLOCK(ip6_id_lock);
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spin_lock_bh(&ip6_id_lock);
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fhdr->identification = htonl(ipv6_fragmentation_id);
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if (++ipv6_fragmentation_id == 0)
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ipv6_fragmentation_id = 1;
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spin_unlock_bh(&ip6_id_lock);
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}
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static inline int ip6_output_finish(struct sk_buff *skb)
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{
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struct dst_entry *dst = skb->dst;
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struct hh_cache *hh = dst->hh;
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if (hh) {
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int hh_alen;
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read_lock_bh(&hh->hh_lock);
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hh_alen = HH_DATA_ALIGN(hh->hh_len);
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memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
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read_unlock_bh(&hh->hh_lock);
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skb_push(skb, hh->hh_len);
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return hh->hh_output(skb);
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} else if (dst->neighbour)
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return dst->neighbour->output(skb);
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IP6_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
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kfree_skb(skb);
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return -EINVAL;
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}
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/* dev_loopback_xmit for use with netfilter. */
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static int ip6_dev_loopback_xmit(struct sk_buff *newskb)
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{
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newskb->mac.raw = newskb->data;
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__skb_pull(newskb, newskb->nh.raw - newskb->data);
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newskb->pkt_type = PACKET_LOOPBACK;
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newskb->ip_summed = CHECKSUM_UNNECESSARY;
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BUG_TRAP(newskb->dst);
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netif_rx(newskb);
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return 0;
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}
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static int ip6_output2(struct sk_buff *skb)
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{
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struct dst_entry *dst = skb->dst;
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struct net_device *dev = dst->dev;
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skb->protocol = htons(ETH_P_IPV6);
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skb->dev = dev;
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if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr)) {
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struct ipv6_pinfo* np = skb->sk ? inet6_sk(skb->sk) : NULL;
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if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
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ipv6_chk_mcast_addr(dev, &skb->nh.ipv6h->daddr,
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&skb->nh.ipv6h->saddr)) {
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struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
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/* Do not check for IFF_ALLMULTI; multicast routing
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is not supported in any case.
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*/
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if (newskb)
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NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, newskb, NULL,
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newskb->dev,
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ip6_dev_loopback_xmit);
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if (skb->nh.ipv6h->hop_limit == 0) {
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IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
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kfree_skb(skb);
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return 0;
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}
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}
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IP6_INC_STATS(IPSTATS_MIB_OUTMCASTPKTS);
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}
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return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb,NULL, skb->dev,ip6_output_finish);
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}
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int ip6_output(struct sk_buff *skb)
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{
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if (skb->len > dst_mtu(skb->dst) || dst_allfrag(skb->dst))
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return ip6_fragment(skb, ip6_output2);
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else
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return ip6_output2(skb);
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}
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#ifdef CONFIG_NETFILTER
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int ip6_route_me_harder(struct sk_buff *skb)
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{
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struct ipv6hdr *iph = skb->nh.ipv6h;
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struct dst_entry *dst;
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struct flowi fl = {
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.oif = skb->sk ? skb->sk->sk_bound_dev_if : 0,
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.nl_u =
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{ .ip6_u =
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{ .daddr = iph->daddr,
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.saddr = iph->saddr, } },
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.proto = iph->nexthdr,
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};
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dst = ip6_route_output(skb->sk, &fl);
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if (dst->error) {
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IP6_INC_STATS(IPSTATS_MIB_OUTNOROUTES);
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LIMIT_NETDEBUG(
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printk(KERN_DEBUG "ip6_route_me_harder: No more route.\n"));
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dst_release(dst);
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return -EINVAL;
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}
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/* Drop old route. */
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dst_release(skb->dst);
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skb->dst = dst;
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return 0;
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}
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#endif
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static inline int ip6_maybe_reroute(struct sk_buff *skb)
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{
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#ifdef CONFIG_NETFILTER
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if (skb->nfcache & NFC_ALTERED){
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if (ip6_route_me_harder(skb) != 0){
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kfree_skb(skb);
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return -EINVAL;
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}
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}
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#endif /* CONFIG_NETFILTER */
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return dst_output(skb);
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}
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/*
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* xmit an sk_buff (used by TCP)
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*/
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int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
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struct ipv6_txoptions *opt, int ipfragok)
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{
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struct ipv6_pinfo *np = sk ? inet6_sk(sk) : NULL;
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struct in6_addr *first_hop = &fl->fl6_dst;
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struct dst_entry *dst = skb->dst;
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struct ipv6hdr *hdr;
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u8 proto = fl->proto;
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int seg_len = skb->len;
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int hlimit;
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u32 mtu;
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if (opt) {
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int head_room;
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/* First: exthdrs may take lots of space (~8K for now)
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MAX_HEADER is not enough.
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*/
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head_room = opt->opt_nflen + opt->opt_flen;
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seg_len += head_room;
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head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
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if (skb_headroom(skb) < head_room) {
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struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
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kfree_skb(skb);
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skb = skb2;
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if (skb == NULL) {
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IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
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return -ENOBUFS;
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}
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if (sk)
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skb_set_owner_w(skb, sk);
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}
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if (opt->opt_flen)
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ipv6_push_frag_opts(skb, opt, &proto);
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if (opt->opt_nflen)
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ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
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}
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hdr = skb->nh.ipv6h = (struct ipv6hdr*)skb_push(skb, sizeof(struct ipv6hdr));
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/*
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* Fill in the IPv6 header
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*/
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*(u32*)hdr = htonl(0x60000000) | fl->fl6_flowlabel;
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hlimit = -1;
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if (np)
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hlimit = np->hop_limit;
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if (hlimit < 0)
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hlimit = dst_metric(dst, RTAX_HOPLIMIT);
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if (hlimit < 0)
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hlimit = ipv6_get_hoplimit(dst->dev);
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hdr->payload_len = htons(seg_len);
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hdr->nexthdr = proto;
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hdr->hop_limit = hlimit;
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ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
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ipv6_addr_copy(&hdr->daddr, first_hop);
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mtu = dst_mtu(dst);
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if ((skb->len <= mtu) || ipfragok) {
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IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
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return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, ip6_maybe_reroute);
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}
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if (net_ratelimit())
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printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
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skb->dev = dst->dev;
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icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
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IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
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kfree_skb(skb);
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return -EMSGSIZE;
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}
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/*
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* To avoid extra problems ND packets are send through this
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* routine. It's code duplication but I really want to avoid
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* extra checks since ipv6_build_header is used by TCP (which
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* is for us performance critical)
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*/
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int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
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struct in6_addr *saddr, struct in6_addr *daddr,
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int proto, int len)
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{
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struct ipv6_pinfo *np = inet6_sk(sk);
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struct ipv6hdr *hdr;
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int totlen;
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skb->protocol = htons(ETH_P_IPV6);
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skb->dev = dev;
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totlen = len + sizeof(struct ipv6hdr);
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hdr = (struct ipv6hdr *) skb_put(skb, sizeof(struct ipv6hdr));
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skb->nh.ipv6h = hdr;
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*(u32*)hdr = htonl(0x60000000);
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hdr->payload_len = htons(len);
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hdr->nexthdr = proto;
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hdr->hop_limit = np->hop_limit;
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ipv6_addr_copy(&hdr->saddr, saddr);
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ipv6_addr_copy(&hdr->daddr, daddr);
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return 0;
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}
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static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
|
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{
|
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struct ip6_ra_chain *ra;
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struct sock *last = NULL;
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|
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read_lock(&ip6_ra_lock);
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for (ra = ip6_ra_chain; ra; ra = ra->next) {
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struct sock *sk = ra->sk;
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if (sk && ra->sel == sel) {
|
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if (last) {
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struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
|
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if (skb2)
|
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rawv6_rcv(last, skb2);
|
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}
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last = sk;
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}
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}
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if (last) {
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rawv6_rcv(last, skb);
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read_unlock(&ip6_ra_lock);
|
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return 1;
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}
|
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read_unlock(&ip6_ra_lock);
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return 0;
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}
|
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|
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static inline int ip6_forward_finish(struct sk_buff *skb)
|
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{
|
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return dst_output(skb);
|
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}
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|
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int ip6_forward(struct sk_buff *skb)
|
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{
|
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struct dst_entry *dst = skb->dst;
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struct ipv6hdr *hdr = skb->nh.ipv6h;
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struct inet6_skb_parm *opt = IP6CB(skb);
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|
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if (ipv6_devconf.forwarding == 0)
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goto error;
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|
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if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
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IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
|
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goto drop;
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}
|
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skb->ip_summed = CHECKSUM_NONE;
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|
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/*
|
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* We DO NOT make any processing on
|
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* RA packets, pushing them to user level AS IS
|
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* without ane WARRANTY that application will be able
|
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* to interpret them. The reason is that we
|
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* cannot make anything clever here.
|
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*
|
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* We are not end-node, so that if packet contains
|
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* AH/ESP, we cannot make anything.
|
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* Defragmentation also would be mistake, RA packets
|
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* cannot be fragmented, because there is no warranty
|
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* that different fragments will go along one path. --ANK
|
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*/
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if (opt->ra) {
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u8 *ptr = skb->nh.raw + opt->ra;
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if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
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return 0;
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}
|
|
|
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/*
|
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* check and decrement ttl
|
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*/
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if (hdr->hop_limit <= 1) {
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/* Force OUTPUT device used as source address */
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skb->dev = dst->dev;
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icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
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0, skb->dev);
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|
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kfree_skb(skb);
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return -ETIMEDOUT;
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}
|
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|
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if (!xfrm6_route_forward(skb)) {
|
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IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
|
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goto drop;
|
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}
|
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dst = skb->dst;
|
|
|
|
/* IPv6 specs say nothing about it, but it is clear that we cannot
|
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send redirects to source routed frames.
|
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*/
|
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if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0) {
|
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struct in6_addr *target = NULL;
|
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struct rt6_info *rt;
|
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struct neighbour *n = dst->neighbour;
|
|
|
|
/*
|
|
* incoming and outgoing devices are the same
|
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* send a redirect.
|
|
*/
|
|
|
|
rt = (struct rt6_info *) dst;
|
|
if ((rt->rt6i_flags & RTF_GATEWAY))
|
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target = (struct in6_addr*)&n->primary_key;
|
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else
|
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target = &hdr->daddr;
|
|
|
|
/* Limit redirects both by destination (here)
|
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and by source (inside ndisc_send_redirect)
|
|
*/
|
|
if (xrlim_allow(dst, 1*HZ))
|
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ndisc_send_redirect(skb, n, target);
|
|
} else if (ipv6_addr_type(&hdr->saddr)&(IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK
|
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|IPV6_ADDR_LINKLOCAL)) {
|
|
/* This check is security critical. */
|
|
goto error;
|
|
}
|
|
|
|
if (skb->len > dst_mtu(dst)) {
|
|
/* Again, force OUTPUT device used as source address */
|
|
skb->dev = dst->dev;
|
|
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
|
|
IP6_INC_STATS_BH(IPSTATS_MIB_INTOOBIGERRORS);
|
|
IP6_INC_STATS_BH(IPSTATS_MIB_FRAGFAILS);
|
|
kfree_skb(skb);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
if (skb_cow(skb, dst->dev->hard_header_len)) {
|
|
IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
|
|
goto drop;
|
|
}
|
|
|
|
hdr = skb->nh.ipv6h;
|
|
|
|
/* Mangling hops number delayed to point after skb COW */
|
|
|
|
hdr->hop_limit--;
|
|
|
|
IP6_INC_STATS_BH(IPSTATS_MIB_OUTFORWDATAGRAMS);
|
|
return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);
|
|
|
|
error:
|
|
IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
|
|
drop:
|
|
kfree_skb(skb);
|
|
return -EINVAL;
|
|
}
|
|
|
|
static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
|
|
{
|
|
to->pkt_type = from->pkt_type;
|
|
to->priority = from->priority;
|
|
to->protocol = from->protocol;
|
|
dst_release(to->dst);
|
|
to->dst = dst_clone(from->dst);
|
|
to->dev = from->dev;
|
|
|
|
#ifdef CONFIG_NET_SCHED
|
|
to->tc_index = from->tc_index;
|
|
#endif
|
|
#ifdef CONFIG_NETFILTER
|
|
to->nfmark = from->nfmark;
|
|
/* Connection association is same as pre-frag packet */
|
|
to->nfct = from->nfct;
|
|
nf_conntrack_get(to->nfct);
|
|
to->nfctinfo = from->nfctinfo;
|
|
#ifdef CONFIG_BRIDGE_NETFILTER
|
|
nf_bridge_put(to->nf_bridge);
|
|
to->nf_bridge = from->nf_bridge;
|
|
nf_bridge_get(to->nf_bridge);
|
|
#endif
|
|
#endif
|
|
}
|
|
|
|
int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
|
|
{
|
|
u16 offset = sizeof(struct ipv6hdr);
|
|
struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1);
|
|
unsigned int packet_len = skb->tail - skb->nh.raw;
|
|
int found_rhdr = 0;
|
|
*nexthdr = &skb->nh.ipv6h->nexthdr;
|
|
|
|
while (offset + 1 <= packet_len) {
|
|
|
|
switch (**nexthdr) {
|
|
|
|
case NEXTHDR_HOP:
|
|
case NEXTHDR_ROUTING:
|
|
case NEXTHDR_DEST:
|
|
if (**nexthdr == NEXTHDR_ROUTING) found_rhdr = 1;
|
|
if (**nexthdr == NEXTHDR_DEST && found_rhdr) return offset;
|
|
offset += ipv6_optlen(exthdr);
|
|
*nexthdr = &exthdr->nexthdr;
|
|
exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
|
|
break;
|
|
default :
|
|
return offset;
|
|
}
|
|
}
|
|
|
|
return offset;
|
|
}
|
|
|
|
static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
|
|
{
|
|
struct net_device *dev;
|
|
struct sk_buff *frag;
|
|
struct rt6_info *rt = (struct rt6_info*)skb->dst;
|
|
struct ipv6hdr *tmp_hdr;
|
|
struct frag_hdr *fh;
|
|
unsigned int mtu, hlen, left, len;
|
|
u32 frag_id = 0;
|
|
int ptr, offset = 0, err=0;
|
|
u8 *prevhdr, nexthdr = 0;
|
|
|
|
dev = rt->u.dst.dev;
|
|
hlen = ip6_find_1stfragopt(skb, &prevhdr);
|
|
nexthdr = *prevhdr;
|
|
|
|
mtu = dst_mtu(&rt->u.dst) - hlen - sizeof(struct frag_hdr);
|
|
|
|
if (skb_shinfo(skb)->frag_list) {
|
|
int first_len = skb_pagelen(skb);
|
|
|
|
if (first_len - hlen > mtu ||
|
|
((first_len - hlen) & 7) ||
|
|
skb_cloned(skb))
|
|
goto slow_path;
|
|
|
|
for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
|
|
/* Correct geometry. */
|
|
if (frag->len > mtu ||
|
|
((frag->len & 7) && frag->next) ||
|
|
skb_headroom(frag) < hlen)
|
|
goto slow_path;
|
|
|
|
/* Partially cloned skb? */
|
|
if (skb_shared(frag))
|
|
goto slow_path;
|
|
|
|
BUG_ON(frag->sk);
|
|
if (skb->sk) {
|
|
sock_hold(skb->sk);
|
|
frag->sk = skb->sk;
|
|
frag->destructor = sock_wfree;
|
|
skb->truesize -= frag->truesize;
|
|
}
|
|
}
|
|
|
|
err = 0;
|
|
offset = 0;
|
|
frag = skb_shinfo(skb)->frag_list;
|
|
skb_shinfo(skb)->frag_list = NULL;
|
|
/* BUILD HEADER */
|
|
|
|
tmp_hdr = kmalloc(hlen, GFP_ATOMIC);
|
|
if (!tmp_hdr) {
|
|
IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
*prevhdr = NEXTHDR_FRAGMENT;
|
|
memcpy(tmp_hdr, skb->nh.raw, hlen);
|
|
__skb_pull(skb, hlen);
|
|
fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
|
|
skb->nh.raw = __skb_push(skb, hlen);
|
|
memcpy(skb->nh.raw, tmp_hdr, hlen);
|
|
|
|
ipv6_select_ident(skb, fh);
|
|
fh->nexthdr = nexthdr;
|
|
fh->reserved = 0;
|
|
fh->frag_off = htons(IP6_MF);
|
|
frag_id = fh->identification;
|
|
|
|
first_len = skb_pagelen(skb);
|
|
skb->data_len = first_len - skb_headlen(skb);
|
|
skb->len = first_len;
|
|
skb->nh.ipv6h->payload_len = htons(first_len - sizeof(struct ipv6hdr));
|
|
|
|
|
|
for (;;) {
|
|
/* Prepare header of the next frame,
|
|
* before previous one went down. */
|
|
if (frag) {
|
|
frag->ip_summed = CHECKSUM_NONE;
|
|
frag->h.raw = frag->data;
|
|
fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
|
|
frag->nh.raw = __skb_push(frag, hlen);
|
|
memcpy(frag->nh.raw, tmp_hdr, hlen);
|
|
offset += skb->len - hlen - sizeof(struct frag_hdr);
|
|
fh->nexthdr = nexthdr;
|
|
fh->reserved = 0;
|
|
fh->frag_off = htons(offset);
|
|
if (frag->next != NULL)
|
|
fh->frag_off |= htons(IP6_MF);
|
|
fh->identification = frag_id;
|
|
frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
|
|
ip6_copy_metadata(frag, skb);
|
|
}
|
|
|
|
err = output(skb);
|
|
if (err || !frag)
|
|
break;
|
|
|
|
skb = frag;
|
|
frag = skb->next;
|
|
skb->next = NULL;
|
|
}
|
|
|
|
if (tmp_hdr)
|
|
kfree(tmp_hdr);
|
|
|
|
if (err == 0) {
|
|
IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
|
|
return 0;
|
|
}
|
|
|
|
while (frag) {
|
|
skb = frag->next;
|
|
kfree_skb(frag);
|
|
frag = skb;
|
|
}
|
|
|
|
IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
|
|
return err;
|
|
}
|
|
|
|
slow_path:
|
|
left = skb->len - hlen; /* Space per frame */
|
|
ptr = hlen; /* Where to start from */
|
|
|
|
/*
|
|
* Fragment the datagram.
|
|
*/
|
|
|
|
*prevhdr = NEXTHDR_FRAGMENT;
|
|
|
|
/*
|
|
* Keep copying data until we run out.
|
|
*/
|
|
while(left > 0) {
|
|
len = left;
|
|
/* IF: it doesn't fit, use 'mtu' - the data space left */
|
|
if (len > mtu)
|
|
len = mtu;
|
|
/* IF: we are not sending upto and including the packet end
|
|
then align the next start on an eight byte boundary */
|
|
if (len < left) {
|
|
len &= ~7;
|
|
}
|
|
/*
|
|
* Allocate buffer.
|
|
*/
|
|
|
|
if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
|
|
NETDEBUG(printk(KERN_INFO "IPv6: frag: no memory for new fragment!\n"));
|
|
IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
|
|
err = -ENOMEM;
|
|
goto fail;
|
|
}
|
|
|
|
/*
|
|
* Set up data on packet
|
|
*/
|
|
|
|
ip6_copy_metadata(frag, skb);
|
|
skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
|
|
skb_put(frag, len + hlen + sizeof(struct frag_hdr));
|
|
frag->nh.raw = frag->data;
|
|
fh = (struct frag_hdr*)(frag->data + hlen);
|
|
frag->h.raw = frag->data + hlen + sizeof(struct frag_hdr);
|
|
|
|
/*
|
|
* Charge the memory for the fragment to any owner
|
|
* it might possess
|
|
*/
|
|
if (skb->sk)
|
|
skb_set_owner_w(frag, skb->sk);
|
|
|
|
/*
|
|
* Copy the packet header into the new buffer.
|
|
*/
|
|
memcpy(frag->nh.raw, skb->data, hlen);
|
|
|
|
/*
|
|
* Build fragment header.
|
|
*/
|
|
fh->nexthdr = nexthdr;
|
|
fh->reserved = 0;
|
|
if (frag_id) {
|
|
ipv6_select_ident(skb, fh);
|
|
frag_id = fh->identification;
|
|
} else
|
|
fh->identification = frag_id;
|
|
|
|
/*
|
|
* Copy a block of the IP datagram.
|
|
*/
|
|
if (skb_copy_bits(skb, ptr, frag->h.raw, len))
|
|
BUG();
|
|
left -= len;
|
|
|
|
fh->frag_off = htons(offset);
|
|
if (left > 0)
|
|
fh->frag_off |= htons(IP6_MF);
|
|
frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
|
|
|
|
ptr += len;
|
|
offset += len;
|
|
|
|
/*
|
|
* Put this fragment into the sending queue.
|
|
*/
|
|
|
|
IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
|
|
|
|
err = output(frag);
|
|
if (err)
|
|
goto fail;
|
|
}
|
|
kfree_skb(skb);
|
|
IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
|
|
return err;
|
|
|
|
fail:
|
|
kfree_skb(skb);
|
|
IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
|
|
return err;
|
|
}
|
|
|
|
int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
|
|
{
|
|
int err = 0;
|
|
|
|
*dst = NULL;
|
|
if (sk) {
|
|
struct ipv6_pinfo *np = inet6_sk(sk);
|
|
|
|
*dst = sk_dst_check(sk, np->dst_cookie);
|
|
if (*dst) {
|
|
struct rt6_info *rt = (struct rt6_info*)*dst;
|
|
|
|
/* Yes, checking route validity in not connected
|
|
case is not very simple. Take into account,
|
|
that we do not support routing by source, TOS,
|
|
and MSG_DONTROUTE --ANK (980726)
|
|
|
|
1. If route was host route, check that
|
|
cached destination is current.
|
|
If it is network route, we still may
|
|
check its validity using saved pointer
|
|
to the last used address: daddr_cache.
|
|
We do not want to save whole address now,
|
|
(because main consumer of this service
|
|
is tcp, which has not this problem),
|
|
so that the last trick works only on connected
|
|
sockets.
|
|
2. oif also should be the same.
|
|
*/
|
|
|
|
if (((rt->rt6i_dst.plen != 128 ||
|
|
!ipv6_addr_equal(&fl->fl6_dst, &rt->rt6i_dst.addr))
|
|
&& (np->daddr_cache == NULL ||
|
|
!ipv6_addr_equal(&fl->fl6_dst, np->daddr_cache)))
|
|
|| (fl->oif && fl->oif != (*dst)->dev->ifindex)) {
|
|
dst_release(*dst);
|
|
*dst = NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (*dst == NULL)
|
|
*dst = ip6_route_output(sk, fl);
|
|
|
|
if ((err = (*dst)->error))
|
|
goto out_err_release;
|
|
|
|
if (ipv6_addr_any(&fl->fl6_src)) {
|
|
err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
|
|
|
|
if (err)
|
|
goto out_err_release;
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_err_release:
|
|
dst_release(*dst);
|
|
*dst = NULL;
|
|
return err;
|
|
}
|
|
|
|
int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb),
|
|
void *from, int length, int transhdrlen,
|
|
int hlimit, struct ipv6_txoptions *opt, struct flowi *fl, struct rt6_info *rt,
|
|
unsigned int flags)
|
|
{
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
struct ipv6_pinfo *np = inet6_sk(sk);
|
|
struct sk_buff *skb;
|
|
unsigned int maxfraglen, fragheaderlen;
|
|
int exthdrlen;
|
|
int hh_len;
|
|
int mtu;
|
|
int copy;
|
|
int err;
|
|
int offset = 0;
|
|
int csummode = CHECKSUM_NONE;
|
|
|
|
if (flags&MSG_PROBE)
|
|
return 0;
|
|
if (skb_queue_empty(&sk->sk_write_queue)) {
|
|
/*
|
|
* setup for corking
|
|
*/
|
|
if (opt) {
|
|
if (np->cork.opt == NULL) {
|
|
np->cork.opt = kmalloc(opt->tot_len,
|
|
sk->sk_allocation);
|
|
if (unlikely(np->cork.opt == NULL))
|
|
return -ENOBUFS;
|
|
} else if (np->cork.opt->tot_len < opt->tot_len) {
|
|
printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
|
|
return -EINVAL;
|
|
}
|
|
memcpy(np->cork.opt, opt, opt->tot_len);
|
|
inet->cork.flags |= IPCORK_OPT;
|
|
/* need source address above miyazawa*/
|
|
}
|
|
dst_hold(&rt->u.dst);
|
|
np->cork.rt = rt;
|
|
inet->cork.fl = *fl;
|
|
np->cork.hop_limit = hlimit;
|
|
inet->cork.fragsize = mtu = dst_mtu(rt->u.dst.path);
|
|
if (dst_allfrag(rt->u.dst.path))
|
|
inet->cork.flags |= IPCORK_ALLFRAG;
|
|
inet->cork.length = 0;
|
|
sk->sk_sndmsg_page = NULL;
|
|
sk->sk_sndmsg_off = 0;
|
|
exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
|
|
length += exthdrlen;
|
|
transhdrlen += exthdrlen;
|
|
} else {
|
|
rt = np->cork.rt;
|
|
fl = &inet->cork.fl;
|
|
if (inet->cork.flags & IPCORK_OPT)
|
|
opt = np->cork.opt;
|
|
transhdrlen = 0;
|
|
exthdrlen = 0;
|
|
mtu = inet->cork.fragsize;
|
|
}
|
|
|
|
hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
|
|
|
|
fragheaderlen = sizeof(struct ipv6hdr) + (opt ? opt->opt_nflen : 0);
|
|
maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
|
|
|
|
if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
|
|
if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
|
|
ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
|
|
return -EMSGSIZE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Let's try using as much space as possible.
|
|
* Use MTU if total length of the message fits into the MTU.
|
|
* Otherwise, we need to reserve fragment header and
|
|
* fragment alignment (= 8-15 octects, in total).
|
|
*
|
|
* Note that we may need to "move" the data from the tail of
|
|
* of the buffer to the new fragment when we split
|
|
* the message.
|
|
*
|
|
* FIXME: It may be fragmented into multiple chunks
|
|
* at once if non-fragmentable extension headers
|
|
* are too large.
|
|
* --yoshfuji
|
|
*/
|
|
|
|
inet->cork.length += length;
|
|
|
|
if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
|
|
goto alloc_new_skb;
|
|
|
|
while (length > 0) {
|
|
/* Check if the remaining data fits into current packet. */
|
|
copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
|
|
if (copy < length)
|
|
copy = maxfraglen - skb->len;
|
|
|
|
if (copy <= 0) {
|
|
char *data;
|
|
unsigned int datalen;
|
|
unsigned int fraglen;
|
|
unsigned int fraggap;
|
|
unsigned int alloclen;
|
|
struct sk_buff *skb_prev;
|
|
alloc_new_skb:
|
|
skb_prev = skb;
|
|
|
|
/* There's no room in the current skb */
|
|
if (skb_prev)
|
|
fraggap = skb_prev->len - maxfraglen;
|
|
else
|
|
fraggap = 0;
|
|
|
|
/*
|
|
* If remaining data exceeds the mtu,
|
|
* we know we need more fragment(s).
|
|
*/
|
|
datalen = length + fraggap;
|
|
if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
|
|
datalen = maxfraglen - fragheaderlen;
|
|
|
|
fraglen = datalen + fragheaderlen;
|
|
if ((flags & MSG_MORE) &&
|
|
!(rt->u.dst.dev->features&NETIF_F_SG))
|
|
alloclen = mtu;
|
|
else
|
|
alloclen = datalen + fragheaderlen;
|
|
|
|
/*
|
|
* The last fragment gets additional space at tail.
|
|
* Note: we overallocate on fragments with MSG_MODE
|
|
* because we have no idea if we're the last one.
|
|
*/
|
|
if (datalen == length + fraggap)
|
|
alloclen += rt->u.dst.trailer_len;
|
|
|
|
/*
|
|
* We just reserve space for fragment header.
|
|
* Note: this may be overallocation if the message
|
|
* (without MSG_MORE) fits into the MTU.
|
|
*/
|
|
alloclen += sizeof(struct frag_hdr);
|
|
|
|
if (transhdrlen) {
|
|
skb = sock_alloc_send_skb(sk,
|
|
alloclen + hh_len,
|
|
(flags & MSG_DONTWAIT), &err);
|
|
} else {
|
|
skb = NULL;
|
|
if (atomic_read(&sk->sk_wmem_alloc) <=
|
|
2 * sk->sk_sndbuf)
|
|
skb = sock_wmalloc(sk,
|
|
alloclen + hh_len, 1,
|
|
sk->sk_allocation);
|
|
if (unlikely(skb == NULL))
|
|
err = -ENOBUFS;
|
|
}
|
|
if (skb == NULL)
|
|
goto error;
|
|
/*
|
|
* Fill in the control structures
|
|
*/
|
|
skb->ip_summed = csummode;
|
|
skb->csum = 0;
|
|
/* reserve for fragmentation */
|
|
skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
|
|
|
|
/*
|
|
* Find where to start putting bytes
|
|
*/
|
|
data = skb_put(skb, fraglen);
|
|
skb->nh.raw = data + exthdrlen;
|
|
data += fragheaderlen;
|
|
skb->h.raw = data + exthdrlen;
|
|
|
|
if (fraggap) {
|
|
skb->csum = skb_copy_and_csum_bits(
|
|
skb_prev, maxfraglen,
|
|
data + transhdrlen, fraggap, 0);
|
|
skb_prev->csum = csum_sub(skb_prev->csum,
|
|
skb->csum);
|
|
data += fraggap;
|
|
skb_trim(skb_prev, maxfraglen);
|
|
}
|
|
copy = datalen - transhdrlen - fraggap;
|
|
if (copy < 0) {
|
|
err = -EINVAL;
|
|
kfree_skb(skb);
|
|
goto error;
|
|
} else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
|
|
err = -EFAULT;
|
|
kfree_skb(skb);
|
|
goto error;
|
|
}
|
|
|
|
offset += copy;
|
|
length -= datalen - fraggap;
|
|
transhdrlen = 0;
|
|
exthdrlen = 0;
|
|
csummode = CHECKSUM_NONE;
|
|
|
|
/*
|
|
* Put the packet on the pending queue
|
|
*/
|
|
__skb_queue_tail(&sk->sk_write_queue, skb);
|
|
continue;
|
|
}
|
|
|
|
if (copy > length)
|
|
copy = length;
|
|
|
|
if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
|
|
unsigned int off;
|
|
|
|
off = skb->len;
|
|
if (getfrag(from, skb_put(skb, copy),
|
|
offset, copy, off, skb) < 0) {
|
|
__skb_trim(skb, off);
|
|
err = -EFAULT;
|
|
goto error;
|
|
}
|
|
} else {
|
|
int i = skb_shinfo(skb)->nr_frags;
|
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
|
|
struct page *page = sk->sk_sndmsg_page;
|
|
int off = sk->sk_sndmsg_off;
|
|
unsigned int left;
|
|
|
|
if (page && (left = PAGE_SIZE - off) > 0) {
|
|
if (copy >= left)
|
|
copy = left;
|
|
if (page != frag->page) {
|
|
if (i == MAX_SKB_FRAGS) {
|
|
err = -EMSGSIZE;
|
|
goto error;
|
|
}
|
|
get_page(page);
|
|
skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
|
|
frag = &skb_shinfo(skb)->frags[i];
|
|
}
|
|
} else if(i < MAX_SKB_FRAGS) {
|
|
if (copy > PAGE_SIZE)
|
|
copy = PAGE_SIZE;
|
|
page = alloc_pages(sk->sk_allocation, 0);
|
|
if (page == NULL) {
|
|
err = -ENOMEM;
|
|
goto error;
|
|
}
|
|
sk->sk_sndmsg_page = page;
|
|
sk->sk_sndmsg_off = 0;
|
|
|
|
skb_fill_page_desc(skb, i, page, 0, 0);
|
|
frag = &skb_shinfo(skb)->frags[i];
|
|
skb->truesize += PAGE_SIZE;
|
|
atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
|
|
} else {
|
|
err = -EMSGSIZE;
|
|
goto error;
|
|
}
|
|
if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
|
|
err = -EFAULT;
|
|
goto error;
|
|
}
|
|
sk->sk_sndmsg_off += copy;
|
|
frag->size += copy;
|
|
skb->len += copy;
|
|
skb->data_len += copy;
|
|
}
|
|
offset += copy;
|
|
length -= copy;
|
|
}
|
|
return 0;
|
|
error:
|
|
inet->cork.length -= length;
|
|
IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
|
|
return err;
|
|
}
|
|
|
|
int ip6_push_pending_frames(struct sock *sk)
|
|
{
|
|
struct sk_buff *skb, *tmp_skb;
|
|
struct sk_buff **tail_skb;
|
|
struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
struct ipv6_pinfo *np = inet6_sk(sk);
|
|
struct ipv6hdr *hdr;
|
|
struct ipv6_txoptions *opt = np->cork.opt;
|
|
struct rt6_info *rt = np->cork.rt;
|
|
struct flowi *fl = &inet->cork.fl;
|
|
unsigned char proto = fl->proto;
|
|
int err = 0;
|
|
|
|
if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
|
|
goto out;
|
|
tail_skb = &(skb_shinfo(skb)->frag_list);
|
|
|
|
/* move skb->data to ip header from ext header */
|
|
if (skb->data < skb->nh.raw)
|
|
__skb_pull(skb, skb->nh.raw - skb->data);
|
|
while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
|
|
__skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
|
|
*tail_skb = tmp_skb;
|
|
tail_skb = &(tmp_skb->next);
|
|
skb->len += tmp_skb->len;
|
|
skb->data_len += tmp_skb->len;
|
|
skb->truesize += tmp_skb->truesize;
|
|
__sock_put(tmp_skb->sk);
|
|
tmp_skb->destructor = NULL;
|
|
tmp_skb->sk = NULL;
|
|
}
|
|
|
|
ipv6_addr_copy(final_dst, &fl->fl6_dst);
|
|
__skb_pull(skb, skb->h.raw - skb->nh.raw);
|
|
if (opt && opt->opt_flen)
|
|
ipv6_push_frag_opts(skb, opt, &proto);
|
|
if (opt && opt->opt_nflen)
|
|
ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
|
|
|
|
skb->nh.ipv6h = hdr = (struct ipv6hdr*) skb_push(skb, sizeof(struct ipv6hdr));
|
|
|
|
*(u32*)hdr = fl->fl6_flowlabel | htonl(0x60000000);
|
|
|
|
if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
|
|
hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
|
|
else
|
|
hdr->payload_len = 0;
|
|
hdr->hop_limit = np->cork.hop_limit;
|
|
hdr->nexthdr = proto;
|
|
ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
|
|
ipv6_addr_copy(&hdr->daddr, final_dst);
|
|
|
|
skb->dst = dst_clone(&rt->u.dst);
|
|
IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
|
|
err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
|
|
if (err) {
|
|
if (err > 0)
|
|
err = np->recverr ? net_xmit_errno(err) : 0;
|
|
if (err)
|
|
goto error;
|
|
}
|
|
|
|
out:
|
|
inet->cork.flags &= ~IPCORK_OPT;
|
|
if (np->cork.opt) {
|
|
kfree(np->cork.opt);
|
|
np->cork.opt = NULL;
|
|
}
|
|
if (np->cork.rt) {
|
|
dst_release(&np->cork.rt->u.dst);
|
|
np->cork.rt = NULL;
|
|
inet->cork.flags &= ~IPCORK_ALLFRAG;
|
|
}
|
|
memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
|
|
return err;
|
|
error:
|
|
goto out;
|
|
}
|
|
|
|
void ip6_flush_pending_frames(struct sock *sk)
|
|
{
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
struct ipv6_pinfo *np = inet6_sk(sk);
|
|
struct sk_buff *skb;
|
|
|
|
while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
|
|
IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
inet->cork.flags &= ~IPCORK_OPT;
|
|
|
|
if (np->cork.opt) {
|
|
kfree(np->cork.opt);
|
|
np->cork.opt = NULL;
|
|
}
|
|
if (np->cork.rt) {
|
|
dst_release(&np->cork.rt->u.dst);
|
|
np->cork.rt = NULL;
|
|
inet->cork.flags &= ~IPCORK_ALLFRAG;
|
|
}
|
|
memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
|
|
}
|