Commit 6c419a1e authored Mar 01, 2019 by Vic Lee Committed by Samuel Thibault Mar 06, 2019

slirp: check for ioctlsocket error and 0-length udp payload.



Sometimes sorecvfrom() is called from slirp.c because revents == G_IO_IN,
but there is 0 bytes available and recvfrom could be blocking indefinitely.
This is likely due to 0-length udp payload. This also adds an error
checking for ioctlsocket.

Signed-off-by: Vic Lee <llyzs.vic@gmail.com>
Message-Id: <20190301064809.3074-1-llyzs.vic@gmail.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

parent 8cabd877

slirp/socket.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -529,6 +529,15 @@ sorecvfrom(struct socket *so)
		int n;
		#endif

		if (ioctlsocket(so->s, FIONREAD, &n) != 0) {
		DEBUG_MISC(" ioctlsocket errno = %d-%s\n",
		errno,strerror(errno));
		return;
		}
		if (n == 0) {
		return;
		}

		m = m_get(so->slirp);
		if (!m) {
		return;
		@@ -552,7 +561,6 @@ sorecvfrom(struct socket *so)
		*/
		len = M_FREEROOM(m);
		/* if (so->so_fport != htons(53)) { */
		ioctlsocket(so->s, FIONREAD, &n);

		if (n > len) {
		n = (m->m_data - m->m_dat) + m->m_len + n + 1;