linux/net/xfrm/xfrm_device.c

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/*
* xfrm_device.c - IPsec device offloading code.
*
* Copyright (c) 2015 secunet Security Networks AG
*
* Author:
* Steffen Klassert <steffen.klassert@secunet.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <net/dst.h>
#include <net/xfrm.h>
#include <linux/notifier.h>
#ifdef CONFIG_XFRM_OFFLOAD
static void __xfrm_transport_prep(struct xfrm_state *x, struct sk_buff *skb,
unsigned int hsize)
{
struct xfrm_offload *xo = xfrm_offload(skb);
skb_reset_mac_len(skb);
pskb_pull(skb, skb->mac_len + hsize + x->props.header_len);
if (xo->flags & XFRM_GSO_SEGMENT) {
skb_reset_transport_header(skb);
skb->transport_header -= x->props.header_len;
}
}
static void __xfrm_mode_tunnel_prep(struct xfrm_state *x, struct sk_buff *skb,
unsigned int hsize)
{
struct xfrm_offload *xo = xfrm_offload(skb);
if (xo->flags & XFRM_GSO_SEGMENT)
skb->transport_header = skb->network_header + hsize;
skb_reset_mac_len(skb);
pskb_pull(skb, skb->mac_len + x->props.header_len);
}
/* Adjust pointers into the packet when IPsec is done at layer2 */
static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb)
{
switch (x->outer_mode.encap) {
case XFRM_MODE_TUNNEL:
if (x->outer_mode.family == AF_INET)
return __xfrm_mode_tunnel_prep(x, skb,
sizeof(struct iphdr));
if (x->outer_mode.family == AF_INET6)
return __xfrm_mode_tunnel_prep(x, skb,
sizeof(struct ipv6hdr));
break;
case XFRM_MODE_TRANSPORT:
if (x->outer_mode.family == AF_INET)
return __xfrm_transport_prep(x, skb,
sizeof(struct iphdr));
if (x->outer_mode.family == AF_INET6)
return __xfrm_transport_prep(x, skb,
sizeof(struct ipv6hdr));
break;
case XFRM_MODE_ROUTEOPTIMIZATION:
case XFRM_MODE_IN_TRIGGER:
case XFRM_MODE_BEET:
break;
}
}
struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features, bool *again)
{
int err;
unsigned long flags;
struct xfrm_state *x;
struct sk_buff *skb2;
struct softnet_data *sd;
netdev_features_t esp_features = features;
struct xfrm_offload *xo = xfrm_offload(skb);
struct sec_path *sp;
if (!xo)
return skb;
if (!(features & NETIF_F_HW_ESP))
esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
sp = skb_sec_path(skb);
x = sp->xvec[sp->len - 1];
if (xo->flags & XFRM_GRO || x->xso.flags & XFRM_OFFLOAD_INBOUND)
return skb;
local_irq_save(flags);
sd = this_cpu_ptr(&softnet_data);
err = !skb_queue_empty(&sd->xfrm_backlog);
local_irq_restore(flags);
if (err) {
*again = true;
return skb;
}
if (skb_is_gso(skb)) {
struct net_device *dev = skb->dev;
if (unlikely(x->xso.dev != dev)) {
struct sk_buff *segs;
/* Packet got rerouted, fixup features and segment it. */
esp_features = esp_features & ~(NETIF_F_HW_ESP
| NETIF_F_GSO_ESP);
segs = skb_gso_segment(skb, esp_features);
if (IS_ERR(segs)) {
kfree_skb(skb);
atomic_long_inc(&dev->tx_dropped);
return NULL;
} else {
consume_skb(skb);
skb = segs;
}
}
}
if (!skb->next) {
esp_features |= skb->dev->gso_partial_features;
xfrm_outer_mode_prep(x, skb);
xo->flags |= XFRM_DEV_RESUME;
err = x->type_offload->xmit(x, skb, esp_features);
if (err) {
if (err == -EINPROGRESS)
return NULL;
XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
kfree_skb(skb);
return NULL;
}
skb_push(skb, skb->data - skb_mac_header(skb));
return skb;
}
skb2 = skb;
do {
struct sk_buff *nskb = skb2->next;
esp_features |= skb->dev->gso_partial_features;
skb_mark_not_on_list(skb2);
xo = xfrm_offload(skb2);
xo->flags |= XFRM_DEV_RESUME;
xfrm_outer_mode_prep(x, skb2);
err = x->type_offload->xmit(x, skb2, esp_features);
if (!err) {
skb2->next = nskb;
} else if (err != -EINPROGRESS) {
XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
skb2->next = nskb;
kfree_skb_list(skb2);
return NULL;
} else {
if (skb == skb2)
skb = nskb;
if (!skb)
return NULL;
goto skip_push;
}
skb_push(skb2, skb2->data - skb_mac_header(skb2));
skip_push:
skb2 = nskb;
} while (skb2);
return skb;
}
EXPORT_SYMBOL_GPL(validate_xmit_xfrm);
int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
struct xfrm_user_offload *xuo)
{
int err;
struct dst_entry *dst;
struct net_device *dev;
struct xfrm_state_offload *xso = &x->xso;
xfrm_address_t *saddr;
xfrm_address_t *daddr;
if (!x->type_offload)
return -EINVAL;
/* We don't yet support UDP encapsulation and TFC padding. */
if (x->encap || x->tfcpad)
return -EINVAL;
dev = dev_get_by_index(net, xuo->ifindex);
if (!dev) {
if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) {
saddr = &x->props.saddr;
daddr = &x->id.daddr;
} else {
saddr = &x->id.daddr;
daddr = &x->props.saddr;
}
net: xfrm: support setting an output mark. On systems that use mark-based routing it may be necessary for routing lookups to use marks in order for packets to be routed correctly. An example of such a system is Android, which uses socket marks to route packets via different networks. Currently, routing lookups in tunnel mode always use a mark of zero, making routing incorrect on such systems. This patch adds a new output_mark element to the xfrm state and a corresponding XFRMA_OUTPUT_MARK netlink attribute. The output mark differs from the existing xfrm mark in two ways: 1. The xfrm mark is used to match xfrm policies and states, while the xfrm output mark is used to set the mark (and influence the routing) of the packets emitted by those states. 2. The existing mark is constrained to be a subset of the bits of the originating socket or transformed packet, but the output mark is arbitrary and depends only on the state. The use of a separate mark provides additional flexibility. For example: - A packet subject to two transforms (e.g., transport mode inside tunnel mode) can have two different output marks applied to it, one for the transport mode SA and one for the tunnel mode SA. - On a system where socket marks determine routing, the packets emitted by an IPsec tunnel can be routed based on a mark that is determined by the tunnel, not by the marks of the unencrypted packets. - Support for setting the output marks can be introduced without breaking any existing setups that employ both mark-based routing and xfrm tunnel mode. Simply changing the code to use the xfrm mark for routing output packets could xfrm mark could change behaviour in a way that breaks these setups. If the output mark is unspecified or set to zero, the mark is not set or changed. Tested: make allyesconfig; make -j64 Tested: https://android-review.googlesource.com/452776 Signed-off-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2017-08-11 01:11:33 +08:00
dst = __xfrm_dst_lookup(net, 0, 0, saddr, daddr,
x->props.family,
xfrm_smark_get(0, x));
if (IS_ERR(dst))
return 0;
dev = dst->dev;
dev_hold(dev);
dst_release(dst);
}
if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) {
xso->dev = NULL;
dev_put(dev);
return 0;
}
if (x->props.flags & XFRM_STATE_ESN &&
!dev->xfrmdev_ops->xdo_dev_state_advance_esn) {
xso->dev = NULL;
dev_put(dev);
return -EINVAL;
}
xso->dev = dev;
xso->num_exthdrs = 1;
xso->flags = xuo->flags;
err = dev->xfrmdev_ops->xdo_dev_state_add(x);
if (err) {
xso->num_exthdrs = 0;
xso->flags = 0;
xso->dev = NULL;
dev_put(dev);
if (err != -EOPNOTSUPP)
return err;
}
return 0;
}
EXPORT_SYMBOL_GPL(xfrm_dev_state_add);
bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
{
int mtu;
struct dst_entry *dst = skb_dst(skb);
struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
struct net_device *dev = x->xso.dev;
if (!x->type_offload || x->encap)
return false;
if ((!dev || (dev == xfrm_dst_path(dst)->dev)) &&
(!xdst->child->xfrm && x->type->get_mtu)) {
mtu = x->type->get_mtu(x, xdst->child_mtu_cached);
if (skb->len <= mtu)
goto ok;
if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
goto ok;
}
return false;
ok:
if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok)
return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x);
return true;
}
EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok);
void xfrm_dev_resume(struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
int ret = NETDEV_TX_BUSY;
struct netdev_queue *txq;
struct softnet_data *sd;
unsigned long flags;
rcu_read_lock();
txq = netdev_core_pick_tx(dev, skb, NULL);
HARD_TX_LOCK(dev, txq, smp_processor_id());
if (!netif_xmit_frozen_or_stopped(txq))
skb = dev_hard_start_xmit(skb, dev, txq, &ret);
HARD_TX_UNLOCK(dev, txq);
if (!dev_xmit_complete(ret)) {
local_irq_save(flags);
sd = this_cpu_ptr(&softnet_data);
skb_queue_tail(&sd->xfrm_backlog, skb);
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_restore(flags);
}
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(xfrm_dev_resume);
void xfrm_dev_backlog(struct softnet_data *sd)
{
struct sk_buff_head *xfrm_backlog = &sd->xfrm_backlog;
struct sk_buff_head list;
struct sk_buff *skb;
if (skb_queue_empty(xfrm_backlog))
return;
__skb_queue_head_init(&list);
spin_lock(&xfrm_backlog->lock);
skb_queue_splice_init(xfrm_backlog, &list);
spin_unlock(&xfrm_backlog->lock);
while (!skb_queue_empty(&list)) {
skb = __skb_dequeue(&list);
xfrm_dev_resume(skb);
}
}
#endif
static int xfrm_api_check(struct net_device *dev)
{
#ifdef CONFIG_XFRM_OFFLOAD
if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) &&
!(dev->features & NETIF_F_HW_ESP))
return NOTIFY_BAD;
if ((dev->features & NETIF_F_HW_ESP) &&
(!(dev->xfrmdev_ops &&
dev->xfrmdev_ops->xdo_dev_state_add &&
dev->xfrmdev_ops->xdo_dev_state_delete)))
return NOTIFY_BAD;
#else
if (dev->features & (NETIF_F_HW_ESP | NETIF_F_HW_ESP_TX_CSUM))
return NOTIFY_BAD;
#endif
return NOTIFY_DONE;
}
static int xfrm_dev_register(struct net_device *dev)
{
return xfrm_api_check(dev);
}
static int xfrm_dev_feat_change(struct net_device *dev)
{
return xfrm_api_check(dev);
}
static int xfrm_dev_down(struct net_device *dev)
{
if (dev->features & NETIF_F_HW_ESP)
xfrm_dev_state_flush(dev_net(dev), dev, true);
return NOTIFY_DONE;
}
static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
switch (event) {
case NETDEV_REGISTER:
return xfrm_dev_register(dev);
case NETDEV_FEAT_CHANGE:
return xfrm_dev_feat_change(dev);
case NETDEV_DOWN:
return xfrm_dev_down(dev);
}
return NOTIFY_DONE;
}
static struct notifier_block xfrm_dev_notifier = {
.notifier_call = xfrm_dev_event,
};
void __init xfrm_dev_init(void)
{
register_netdevice_notifier(&xfrm_dev_notifier);
}