diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2024-01-15 12:55:11 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-01-23 14:40:24 -0800 |
| commit | 8b5ac68fb5ee416537c1214cbacf0ddc4293cce9 (patch) | |
| tree | b34d2e597746829ffeb492a42a3532605e5ddb3c | |
| parent | 95e752b5299fa8c90099f7bc2aa1ee3e2e2c95ab (diff) | |
bpf: tcp: Handle BPF SYN Cookie in skb_steal_sock().
We will support arbitrary SYN Cookie with BPF.
If BPF prog validates ACK and kfunc allocates a reqsk, it will
be carried to TCP stack as skb->sk with req->syncookie 1. Also,
the reqsk has its listener as req->rsk_listener with no refcnt
taken.
When the TCP stack looks up a socket from the skb, we steal
inet_reqsk(skb->sk)->rsk_listener in skb_steal_sock() so that
the skb will be processed in cookie_v[46]_check() with the
listener.
Note that we do not clear skb->sk and skb->destructor so that we
can carry the reqsk to cookie_v[46]_check().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240115205514.68364-4-kuniyu@amazon.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | include/net/request_sock.h | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/include/net/request_sock.h b/include/net/request_sock.h index 26c630c40abb..8839133d6f6b 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -101,10 +101,21 @@ static inline struct sock *skb_steal_sock(struct sk_buff *skb, } *prefetched = skb_sk_is_prefetched(skb); - if (*prefetched) + if (*prefetched) { +#if IS_ENABLED(CONFIG_SYN_COOKIES) + if (sk->sk_state == TCP_NEW_SYN_RECV && inet_reqsk(sk)->syncookie) { + struct request_sock *req = inet_reqsk(sk); + + *refcounted = false; + sk = req->rsk_listener; + req->rsk_listener = NULL; + return sk; + } +#endif *refcounted = sk_is_refcounted(sk); - else + } else { *refcounted = true; + } skb->destructor = NULL; skb->sk = NULL; |