diff options
| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2021-10-08 22:06:04 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2021-10-14 23:06:44 +0200 |
| commit | 0d7308c0ff5fa7c77164ab8491a91e0589da66e3 (patch) | |
| tree | f2109eb0066f5fffae3ef82b5f9cb175df338c3e /net/packet | |
| parent | 42df6e1d221dddc0f2acf2be37e68d553ad65f96 (diff) | |
af_packet: Introduce egress hook
Add egress hook for AF_PACKET sockets that have the PACKET_QDISC_BYPASS
socket option set to on, which allows packets to escape without being
filtered in the egress path.
This patch only updates the AF_PACKET path, it does not update
dev_direct_xmit() so the XDP infrastructure has a chance to bypass
Netfilter.
[lukas: acquire rcu_read_lock, fix typos, rebase]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/packet')
| -rw-r--r-- | net/packet/af_packet.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 2a2bc64f75cf..46943a18a10d 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -91,6 +91,7 @@ #endif #include <linux/bpf.h> #include <net/compat.h> +#include <linux/netfilter_netdev.h> #include "internal.h" @@ -241,8 +242,42 @@ struct packet_skb_cb { static void __fanout_unlink(struct sock *sk, struct packet_sock *po); static void __fanout_link(struct sock *sk, struct packet_sock *po); +#ifdef CONFIG_NETFILTER_EGRESS +static noinline struct sk_buff *nf_hook_direct_egress(struct sk_buff *skb) +{ + struct sk_buff *next, *head = NULL, *tail; + int rc; + + rcu_read_lock(); + for (; skb != NULL; skb = next) { + next = skb->next; + skb_mark_not_on_list(skb); + + if (!nf_hook_egress(skb, &rc, skb->dev)) + continue; + + if (!head) + head = skb; + else + tail->next = skb; + + tail = skb; + } + rcu_read_unlock(); + + return head; +} +#endif + static int packet_direct_xmit(struct sk_buff *skb) { +#ifdef CONFIG_NETFILTER_EGRESS + if (nf_hook_egress_active()) { + skb = nf_hook_direct_egress(skb); + if (!skb) + return NET_XMIT_DROP; + } +#endif return dev_direct_xmit(skb, packet_pick_tx_queue(skb)); } |