Commit 357b6cc5 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller

netfilter: revert introduction of egress hook

This reverts the following commits:

  8537f786 ("netfilter: Introduce egress hook")
  5418d388 ("netfilter: Generalize ingress hook")
  b030f194 ("netfilter: Rename ingress hook include file")

>From the discussion in [0], the author's main motivation to add a hook
in fast path is for an out of tree kernel module, which is a red flag
to begin with. Other mentioned potential use cases like NAT{64,46}
is on future extensions w/o concrete code in the tree yet. Revert as
suggested [1] given the weak justification to add more hooks to critical
fast-path.

  [0] https://lore.kernel.org/netdev/cover.1583927267.git.lukas@wunner.de/
  [1] https://lore.kernel.org/netdev/20200318.011152.72770718915606186.davem@davemloft.net/Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Cc: David Miller <davem@davemloft.net>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Nacked-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ce7964bd
......@@ -1751,7 +1751,6 @@ enum netdev_priv_flags {
* @xps_maps: XXX: need comments on this one
* @miniq_egress: clsact qdisc specific data for
* egress processing
* @nf_hooks_egress: netfilter hooks executed for egress packets
* @qdisc_hash: qdisc hash table
* @watchdog_timeo: Represents the timeout that is used by
* the watchdog (see dev_watchdog())
......@@ -2027,9 +2026,6 @@ struct net_device {
#ifdef CONFIG_NET_CLS_ACT
struct mini_Qdisc __rcu *miniq_egress;
#endif
#ifdef CONFIG_NETFILTER_EGRESS
struct nf_hook_entries __rcu *nf_hooks_egress;
#endif
#ifdef CONFIG_NET_SCHED
DECLARE_HASHTABLE (qdisc_hash, 4);
......
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _NETFILTER_NETDEV_H_
#define _NETFILTER_NETDEV_H_
#ifndef _NETFILTER_INGRESS_H_
#define _NETFILTER_INGRESS_H_
#include <linux/netfilter.h>
#include <linux/netdevice.h>
#ifdef CONFIG_NETFILTER
static __always_inline bool nf_hook_netdev_active(enum nf_dev_hooks hooknum,
struct nf_hook_entries __rcu *hooks)
#ifdef CONFIG_NETFILTER_INGRESS
static inline bool nf_hook_ingress_active(const struct sk_buff *skb)
{
#ifdef CONFIG_JUMP_LABEL
if (!static_key_false(&nf_hooks_needed[NFPROTO_NETDEV][hooknum]))
if (!static_key_false(&nf_hooks_needed[NFPROTO_NETDEV][NF_NETDEV_INGRESS]))
return false;
#endif
return rcu_access_pointer(hooks);
return rcu_access_pointer(skb->dev->nf_hooks_ingress);
}
/* caller must hold rcu_read_lock */
static __always_inline int nf_hook_netdev(struct sk_buff *skb,
enum nf_dev_hooks hooknum,
struct nf_hook_entries __rcu *hooks)
static inline int nf_hook_ingress(struct sk_buff *skb)
{
struct nf_hook_entries *e = rcu_dereference(hooks);
struct nf_hook_entries *e = rcu_dereference(skb->dev->nf_hooks_ingress);
struct nf_hook_state state;
int ret;
/* Must recheck the hook head, in the event it became NULL
* after the check in nf_hook_netdev_active evaluated to true.
/* Must recheck the ingress hook head, in the event it became NULL
* after the check in nf_hook_ingress_active evaluated to true.
*/
if (unlikely(!e))
return 0;
nf_hook_state_init(&state, hooknum,
nf_hook_state_init(&state, NF_NETDEV_INGRESS,
NFPROTO_NETDEV, skb->dev, NULL, NULL,
dev_net(skb->dev), NULL);
ret = nf_hook_slow(skb, &state, e, 0);
......@@ -40,29 +37,10 @@ static __always_inline int nf_hook_netdev(struct sk_buff *skb,
return ret;
}
#endif /* CONFIG_NETFILTER */
static inline void nf_hook_netdev_init(struct net_device *dev)
static inline void nf_hook_ingress_init(struct net_device *dev)
{
#ifdef CONFIG_NETFILTER_INGRESS
RCU_INIT_POINTER(dev->nf_hooks_ingress, NULL);
#endif
#ifdef CONFIG_NETFILTER_EGRESS
RCU_INIT_POINTER(dev->nf_hooks_egress, NULL);
#endif
}
#ifdef CONFIG_NETFILTER_INGRESS
static inline bool nf_hook_ingress_active(const struct sk_buff *skb)
{
return nf_hook_netdev_active(NF_NETDEV_INGRESS,
skb->dev->nf_hooks_ingress);
}
static inline int nf_hook_ingress(struct sk_buff *skb)
{
return nf_hook_netdev(skb, NF_NETDEV_INGRESS,
skb->dev->nf_hooks_ingress);
}
#else /* CONFIG_NETFILTER_INGRESS */
static inline int nf_hook_ingress_active(struct sk_buff *skb)
......@@ -74,29 +52,7 @@ static inline int nf_hook_ingress(struct sk_buff *skb)
{
return 0;
}
#endif /* CONFIG_NETFILTER_INGRESS */
#ifdef CONFIG_NETFILTER_EGRESS
static inline bool nf_hook_egress_active(const struct sk_buff *skb)
{
return nf_hook_netdev_active(NF_NETDEV_EGRESS,
skb->dev->nf_hooks_egress);
}
static inline int nf_hook_egress(struct sk_buff *skb)
{
return nf_hook_netdev(skb, NF_NETDEV_EGRESS,
skb->dev->nf_hooks_egress);
}
#else /* CONFIG_NETFILTER_EGRESS */
static inline int nf_hook_egress_active(struct sk_buff *skb)
{
return 0;
}
static inline int nf_hook_egress(struct sk_buff *skb)
{
return 0;
}
#endif /* CONFIG_NETFILTER_EGRESS */
static inline void nf_hook_ingress_init(struct net_device *dev) {}
#endif /* CONFIG_NETFILTER_INGRESS */
#endif /* _NETFILTER_INGRESS_H_ */
......@@ -50,7 +50,6 @@ enum nf_inet_hooks {
enum nf_dev_hooks {
NF_NETDEV_INGRESS,
NF_NETDEV_EGRESS,
NF_NETDEV_NUMHOOKS
};
......
......@@ -135,7 +135,7 @@
#include <linux/if_macvlan.h>
#include <linux/errqueue.h>
#include <linux/hrtimer.h>
#include <linux/netfilter_netdev.h>
#include <linux/netfilter_ingress.h>
#include <linux/crash_dump.h>
#include <linux/sctp.h>
#include <net/udp_tunnel.h>
......@@ -3773,7 +3773,6 @@ EXPORT_SYMBOL(dev_loopback_xmit);
static struct sk_buff *
sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
{
#ifdef CONFIG_NET_CLS_ACT
struct mini_Qdisc *miniq = rcu_dereference_bh(dev->miniq_egress);
struct tcf_result cl_res;
......@@ -3807,24 +3806,11 @@ sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
default:
break;
}
#endif /* CONFIG_NET_CLS_ACT */
return skb;
}
#endif /* CONFIG_NET_EGRESS */
static inline int nf_egress(struct sk_buff *skb)
{
if (nf_hook_egress_active(skb)) {
int ret;
rcu_read_lock();
ret = nf_hook_egress(skb);
rcu_read_unlock();
return ret;
}
return 0;
}
#ifdef CONFIG_XPS
static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
struct xps_dev_maps *dev_maps, unsigned int tci)
......@@ -4011,16 +3997,13 @@ static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
qdisc_pkt_len_init(skb);
#ifdef CONFIG_NET_CLS_ACT
skb->tc_at_ingress = 0;
#endif
#ifdef CONFIG_NET_EGRESS
# ifdef CONFIG_NET_EGRESS
if (static_branch_unlikely(&egress_needed_key)) {
if (nf_egress(skb) < 0)
goto out;
skb = sch_handle_egress(skb, &rc, dev);
if (!skb)
goto out;
}
# endif
#endif
/* If device/qdisc don't need skb->dst, release it right now while
* its hot in this cpu cache.
......@@ -9867,7 +9850,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
if (!dev->ethtool_ops)
dev->ethtool_ops = &default_ethtool_ops;
nf_hook_netdev_init(dev);
nf_hook_ingress_init(dev);
return dev;
......
......@@ -10,14 +10,6 @@ config NETFILTER_INGRESS
This allows you to classify packets from ingress using the Netfilter
infrastructure.
config NETFILTER_EGRESS
bool "Netfilter egress support"
default y
select NET_EGRESS
help
This allows you to classify packets before transmission using the
Netfilter infrastructure.
config NETFILTER_NETLINK
tristate
......
......@@ -306,12 +306,6 @@ nf_hook_entry_head(struct net *net, int pf, unsigned int hooknum,
if (dev && dev_net(dev) == net)
return &dev->nf_hooks_ingress;
}
#endif
#ifdef CONFIG_NETFILTER_EGRESS
if (hooknum == NF_NETDEV_EGRESS) {
if (dev && dev_net(dev) == net)
return &dev->nf_hooks_egress;
}
#endif
WARN_ON_ONCE(1);
return NULL;
......@@ -324,13 +318,11 @@ static int __nf_register_net_hook(struct net *net, int pf,
struct nf_hook_entries __rcu **pp;
if (pf == NFPROTO_NETDEV) {
if ((!IS_ENABLED(CONFIG_NETFILTER_INGRESS) &&
reg->hooknum == NF_NETDEV_INGRESS) ||
(!IS_ENABLED(CONFIG_NETFILTER_EGRESS) &&
reg->hooknum == NF_NETDEV_EGRESS))
#ifndef CONFIG_NETFILTER_INGRESS
if (reg->hooknum == NF_NETDEV_INGRESS)
return -EOPNOTSUPP;
if ((reg->hooknum != NF_NETDEV_INGRESS &&
reg->hooknum != NF_NETDEV_EGRESS) ||
#endif
if (reg->hooknum != NF_NETDEV_INGRESS ||
!reg->dev || dev_net(reg->dev) != net)
return -EINVAL;
}
......@@ -356,10 +348,6 @@ static int __nf_register_net_hook(struct net *net, int pf,
if (pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_INGRESS)
net_inc_ingress_queue();
#endif
#ifdef CONFIG_NETFILTER_EGRESS
if (pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_EGRESS)
net_inc_egress_queue();
#endif
#ifdef CONFIG_JUMP_LABEL
static_key_slow_inc(&nf_hooks_needed[pf][reg->hooknum]);
#endif
......@@ -418,10 +406,6 @@ static void __nf_unregister_net_hook(struct net *net, int pf,
if (pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_INGRESS)
net_dec_ingress_queue();
#endif
#ifdef CONFIG_NETFILTER_EGRESS
if (pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_EGRESS)
net_dec_egress_queue();
#endif
#ifdef CONFIG_JUMP_LABEL
static_key_slow_dec(&nf_hooks_needed[pf][reg->hooknum]);
#endif
......
......@@ -277,11 +277,9 @@ static const struct nft_chain_type nft_chain_filter_netdev = {
.name = "filter",
.type = NFT_CHAIN_T_DEFAULT,
.family = NFPROTO_NETDEV,
.hook_mask = (1 << NF_NETDEV_INGRESS) |
(1 << NF_NETDEV_EGRESS),
.hook_mask = (1 << NF_NETDEV_INGRESS),
.hooks = {
[NF_NETDEV_INGRESS] = nft_do_chain_netdev,
[NF_NETDEV_EGRESS] = nft_do_chain_netdev,
},
};
......
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