// SPDX-License-Identifier: GPL-2.0-or-later
/*
* xfrm_device.c - IPsec device offloading code.
*
* Copyright (c) 2015 secunet Security Networks AG
*
* Author:
* Steffen Klassert <[email protected]>
*/
#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/gso.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);
if (xo->flags & XFRM_GSO_SEGMENT)
skb->transport_header -= x->props.header_len;
pskb_pull(skb, skb_transport_offset(skb) + 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);
}
static void __xfrm_mode_beet_prep(struct xfrm_state *x, struct sk_buff *skb,
unsigned int hsize)
{
struct xfrm_offload *xo = xfrm_offload(skb);
int phlen = 0;
if (xo->flags & XFRM_GSO_SEGMENT)
skb->transport_header = skb->network_header + hsize;
skb_reset_mac_len(skb);
if (x->sel.family != AF_INET6) {
phlen = IPV4_BEET_PHMAXLEN;
if (x->outer_mode.family == AF_INET6)
phlen += sizeof(struct ipv6hdr) - sizeof(struct iphdr);
}
pskb_pull(skb, skb->mac_len + hsize + (x->props.header_len - phlen));
}
/* 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_BEET:
if (x->outer_mode.family == AF_INET)
return __xfrm_mode_beet_prep(x, skb,
sizeof(struct iphdr));
if (x->outer_mode.family == AF_INET6)
return __xfrm_mode_beet_prep(x, skb,
sizeof(struct ipv6hdr));
break;
case XFRM_MODE_ROUTEOPTIMIZATION:
case XFRM_MODE_IN_TRIGGER:
break;
}
}
static inline bool xmit_xfrm_check_overflow(struct sk_buff *skb)
{
struct xfrm_offload *xo = xfrm_offload(skb);
__u32 seq = xo->seq.low;
seq += skb_shinfo(skb)->gso_segs;
if (unlikely(seq < xo->seq.low))
return true;
return false;
}
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 softnet_data *sd;
struct sk_buff *skb2, *nskb, *pskb = NULL;
netdev_features_t esp_features = features;
struct xfrm_offload *xo = xfrm_offload(skb);
struct net_device *dev = skb->dev;
struct sec_path *sp;
if (!xo || (xo->flags & XFRM_XMIT))
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.dir == XFRM_DEV_OFFLOAD_IN)
return skb;
/* The packet was sent to HW IPsec packet offload engine,
* but to wrong device. Drop the packet, so it won't skip
* XFRM stack.
*/
if (x->xso.type == XFRM_DEV_OFFLOAD_PACKET && x->xso.dev != dev) {
kfree_skb(skb);
dev_core_stats_tx_dropped_inc(dev);
return NULL;
}
/* This skb was already validated on the upper/virtual dev */
if ((x->xso.dev != dev) && (x->xso.real_dev == dev))
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) && (unlikely(x->xso.dev != dev) ||
unlikely(xmit_xfrm_check_overflow(skb)))) {
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);
dev_core_stats_tx_dropped_inc(dev);
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;
}
skb_list_walk_safe(skb, skb2, nskb) {
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;
else
pskb->next = nskb;
continue;
}
skb_push(skb2, skb2->data - skb_mac_header(skb2));
pskb = 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,
struct netlink_ext_ack *extack)
{
int err;
struct dst_entry *dst;
struct net_device *dev;
struct xfrm_dev_offload *xso = &x->xso;
xfrm_address_t *saddr;
xfrm_address_t *daddr;
bool is_packet_offload;
if (!x->type_offload) {
NL_SET_ERR_MSG(extack, "Type doesn't support offload");
return -EINVAL;
}
if (xuo->flags &
~(XFRM_OFFLOAD_IPV6 | XFRM_OFFLOAD_INBOUND | XFRM_OFFLOAD_PACKET)) {
NL_SET_ERR_MSG(extack, "Unrecognized flags in offload request");
return -EINVAL;
}
if ((xuo->flags & XFRM_OFFLOAD_INBOUND && x->dir == XFRM_SA_DIR_OUT) ||
(!(xuo->flags & XFRM_OFFLOAD_INBOUND) && x->dir == XFRM_SA_DIR_IN)) {
NL_SET_ERR_MSG(extack, "Mismatched SA and offload direction");
return -EINVAL;
}
is_packet_offload = xuo->flags & XFRM_OFFLOAD_PACKET;
/* We don't yet support TFC padding. */
if (x->tfcpad) {
NL_SET_ERR_MSG(extack, "TFC padding can't be offloaded");
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;
}
dst = __xfrm_dst_lookup(net, 0, 0, saddr, daddr,
x->props.family,
xfrm_smark_get(0, x));
if (IS_ERR(dst))
return (is_packet_offload) ? -EINVAL : 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 (is_packet_offload) ? -EINVAL : 0;
}
if (!is_packet_offload && x->props.flags & XFRM_STATE_ESN &&
!dev->xfrmdev_ops->xdo_dev_state_advance_esn) {
NL_SET_ERR_MSG(extack, "Device doesn't support offload with ESN");
xso->dev = NULL;
dev_put(dev);
return -EINVAL;
}
xso->dev = dev;
netdev_tracker_alloc(dev, &xso->dev_tracker, GFP_ATOMIC);
xso->real_dev = dev;
if (xuo->flags & XFRM_OFFLOAD_INBOUND)
xso->dir = XFRM_DEV_OFFLOAD_IN;
else
xso->dir = XFRM_DEV_OFFLOAD_OUT;
if (is_packet_offload)
xso->type = XFRM_DEV_OFFLOAD_PACKET;
else
xso->type = XFRM_DEV_OFFLOAD_CRYPTO;
err = dev->xfrmdev_ops->xdo_dev_state_add(x, extack);
if (err) {
xso->dev = NULL;
xso->dir = 0;
xso->real_dev = NULL;
netdev_put(dev, &xso->dev_tracker);
xso->type = XFRM_DEV_OFFLOAD_UNSPECIFIED;
/* User explicitly requested packet offload mode and configured
* policy in addition to the XFRM state. So be civil to users,
* and return an error instead of taking fallback path.
*/
if ((err != -EOPNOTSUPP && !is_packet_offload) || is_packet_offload) {
NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this state");
return err;
}
}
return 0;
}
EXPORT_SYMBOL_GPL(xfrm_dev_state_add);
int xfrm_dev_policy_add(struct net *net, struct xfrm_policy *xp,
struct xfrm_user_offload *xuo, u8 dir,
struct netlink_ext_ack *extack)
{
struct xfrm_dev_offload *xdo = &xp->xdo;
struct net_device *dev;
int err;
if (!xuo->flags || xuo->flags & ~XFRM_OFFLOAD_PACKET) {
/* We support only packet offload mode and it means
* that user must set XFRM_OFFLOAD_PACKET bit.
*/
NL_SET_ERR_MSG(extack, "Unrecognized flags in offload request");
return -EINVAL;
}
dev = dev_get_by_index(net, xuo->ifindex);
if (!dev)
return -EINVAL;
if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_policy_add) {
xdo->dev = NULL;
dev_put(dev);
NL_SET_ERR_MSG(extack, "Policy offload is not supported");
return -EINVAL;
}
xdo->dev = dev;
netdev_tracker_alloc(dev, &xdo->dev_tracker, GFP_ATOMIC);
xdo->real_dev = dev;
xdo->type = XFRM_DEV_OFFLOAD_PACKET;
switch (dir) {
case XFRM_POLICY_IN:
xdo->dir = XFRM_DEV_OFFLOAD_IN;
break;
case XFRM_POLICY_OUT:
xdo->dir = XFRM_DEV_OFFLOAD_OUT;
break;
case XFRM_POLICY_FWD:
xdo->dir = XFRM_DEV_OFFLOAD_FWD;
break;
default:
xdo->dev = NULL;
netdev_put(dev, &xdo->dev_tracker);
NL_SET_ERR_MSG(extack, "Unrecognized offload direction");
return -EINVAL;
}
err = dev->xfrmdev_ops->xdo_dev_policy_add(xp, extack);
if (err) {
xdo->dev = NULL;
xdo->real_dev = NULL;
xdo->type = XFRM_DEV_OFFLOAD_UNSPECIFIED;
xdo->dir = 0;
netdev_put(dev, &xdo->dev_tracker);
NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this policy");
return err;
}
return 0;
}
EXPORT_SYMBOL_GPL(xfrm_dev_policy_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->xso.type == XFRM_DEV_OFFLOAD_UNSPECIFIED && x->encap))
return false;
if (x->xso.type == XFRM_DEV_OFFLOAD_PACKET ||
((!dev || (dev == xfrm_dst_path(dst)->dev)) &&
!xdst->child->xfrm)) {
mtu = xfrm_state_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_down(struct net_device *dev)
{
if (dev->features & NETIF_F_HW_ESP) {
xfrm_dev_state_flush(dev_net(dev), dev, true);
xfrm_dev_policy_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_api_check(dev);
case NETDEV_FEAT_CHANGE:
return xfrm_api_check(dev);
case NETDEV_DOWN:
case NETDEV_UNREGISTER:
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);
}
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