| From ac75b5da2649383f6cd77177bac9d919fb3f9791 Mon Sep 17 00:00:00 2001 |
| From: Lingpeng Chen <forrest0579@gmail.com> |
| Date: Thu, 9 Jan 2020 09:48:33 +0800 |
| Subject: [PATCH] bpf/sockmap: Read psock ingress_msg before sk_receive_queue |
| |
| commit e7a5f1f1cd0008e5ad379270a8657e121eedb669 upstream. |
| |
| Right now in tcp_bpf_recvmsg, sock read data first from sk_receive_queue |
| if not empty than psock->ingress_msg otherwise. If a FIN packet arrives |
| and there's also some data in psock->ingress_msg, the data in |
| psock->ingress_msg will be purged. It is always happen when request to a |
| HTTP1.0 server like python SimpleHTTPServer since the server send FIN |
| packet after data is sent out. |
| |
| Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") |
| Reported-by: Arika Chen <eaglesora@gmail.com> |
| Suggested-by: Arika Chen <eaglesora@gmail.com> |
| Signed-off-by: Lingpeng Chen <forrest0579@gmail.com> |
| Signed-off-by: John Fastabend <john.fastabend@gmail.com> |
| Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> |
| Acked-by: Song Liu <songliubraving@fb.com> |
| Link: https://lore.kernel.org/bpf/20200109014833.18951-1-forrest0579@gmail.com |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c |
| index 587d55611814..8a01428f80c1 100644 |
| --- a/net/ipv4/tcp_bpf.c |
| +++ b/net/ipv4/tcp_bpf.c |
| @@ -121,14 +121,14 @@ int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
| struct sk_psock *psock; |
| int copied, ret; |
| |
| - if (unlikely(flags & MSG_ERRQUEUE)) |
| - return inet_recv_error(sk, msg, len, addr_len); |
| - if (!skb_queue_empty(&sk->sk_receive_queue)) |
| - return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); |
| - |
| psock = sk_psock_get(sk); |
| if (unlikely(!psock)) |
| return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); |
| + if (unlikely(flags & MSG_ERRQUEUE)) |
| + return inet_recv_error(sk, msg, len, addr_len); |
| + if (!skb_queue_empty(&sk->sk_receive_queue) && |
| + sk_psock_queue_empty(psock)) |
| + return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); |
| lock_sock(sk); |
| msg_bytes_ready: |
| copied = __tcp_bpf_recvmsg(sk, psock, msg, len, flags); |
| @@ -139,7 +139,7 @@ int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
| timeo = sock_rcvtimeo(sk, nonblock); |
| data = tcp_bpf_wait_data(sk, psock, flags, timeo, &err); |
| if (data) { |
| - if (skb_queue_empty(&sk->sk_receive_queue)) |
| + if (!sk_psock_queue_empty(psock)) |
| goto msg_bytes_ready; |
| release_sock(sk); |
| sk_psock_put(sk, psock); |
| -- |
| 2.7.4 |
| |
