Commit 5fa2ca7c authored May 13, 2019 by John Fastabend Committed by Daniel Borkmann May 16, 2019

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: 604326b4 ("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>

parent 3d21b652

net/ipv4/tcp_bpf.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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);