bpf, tcp: correctly handle DONT_WAIT flags and timeo == 0

The tcp_bpf_wait_data() routine needs to check timeo != 0 before
calling sk_wait_event() otherwise we may see unexpected stalls
on receiver.

Arika did all the leg work here I just formatted, posted and ran
a few tests.

Fixes: 604326b41a ("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: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
John Fastabend 2019-05-13 21:42:03 -07:00 committed by Daniel Borkmann
parent 3d21b6525c
commit 5fa2ca7c4a
1 changed files with 4 additions and 1 deletions

View File

@ -27,7 +27,10 @@ static int tcp_bpf_wait_data(struct sock *sk, struct sk_psock *psock,
int flags, long timeo, int *err)
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
int ret;
int ret = 0;
if (!timeo)
return ret;
add_wait_queue(sk_sleep(sk), &wait);
sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);