Datagram sockets may return 0 and stream sockets can return 0 if the requested number of bytes to read is 0. This may happen if the socket buffer is full. Bird event loop will asynchronously process the socket buffer and restore the socket rpos pointer. Thus reading data from the socket will happen again as soon as the input is processed. Signed-off-by: Kenth Eriksson <kenth.eriksson@infinera.com> --- sysdep/unix/io.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c index d1d86e3b..a1d3197a 100644 --- a/sysdep/unix/io.c +++ b/sysdep/unix/io.c @@ -1873,8 +1873,14 @@ sk_read(sock *s, int revents) s->err_hook(s, 0); } } - else if (!c) + else if (revents & POLLHUP) + { s->err_hook(s, 0); + } + else if (!c) + { + log(L_WARN "Socket got 0 bytes, buffer full!? c=%d, rpos=%d, rbsize=%d, rbuf=%d", c, s->rpos, s->rbsize, s->rbuf); + } else { s->rpos += c; -- 2.21.0