MT#57848 safeguard against NULL dereferences

Make sure we don't try to send on closed sockets or to endpoints which
haven't been initialised.

Fixes unexpected fallout from 83c7336e

Change-Id: If73d61e52edeb72257515adab7428ecef82c2797

daemon/call.c

@@ -1055,6 +1055,8 @@ enum call_stream_state call_stream_state_machine(struct packet_stream *ps) {
 			static const str fake_rtp = STR_CONST_INIT("\x80\x7f\xff\xff\x00\x00\x00\x00"
 					"\x00\x00\x00\x00");
 			struct stream_fd *sfd = l->data;
+			if (sfd->socket.fd == -1 || ps->endpoint.address.family == NULL)
+				continue;
 			socket_sendto(&sfd->socket, fake_rtp.s, fake_rtp.len, &ps->endpoint);
 			atomic64_inc(&ps->stats_out.packets);
 			atomic64_add(&ps->stats_out.bytes, fake_rtp.len);

daemon/media_player.c

@@ -230,7 +230,7 @@ static void send_timer_rtcp(struct send_timer *st, struct ssrc_ctx *ssrc_out) {
 static bool __send_timer_send_1(struct rtp_header *rh, struct packet_stream *sink, struct codec_packet *cp) {
 	struct stream_fd *sink_fd = sink->selected_sfd;
 
-	if (!sink_fd || sink_fd->socket.fd == -1)
+	if (!sink_fd || sink_fd->socket.fd == -1 || sink->endpoint.address.family == NULL)
 		return false;
 
 	log_info_stream_fd(sink->selected_sfd);

daemon/rtcp.c

@@ -1575,6 +1575,8 @@ void rtcp_send_report(struct call_media *media, struct ssrc_ctx *ssrc_out) {
 
 	if (!ps->selected_sfd || !rtcp_ps->selected_sfd)
 		return;
+	if (ps->selected_sfd->socket.fd == -1 || ps->endpoint.address.family == NULL)
+		return;
 
 	media_update_stats(media);
 

daemon/t38.c

@@ -223,7 +223,7 @@ static int t38_gateway_handler(t38_core_state_t *stat, void *user_data, const ui
 	struct stream_fd *sfd = NULL;
 	if (ps)
 		sfd = ps->selected_sfd;
-	if (sfd) {
+	if (sfd && sfd->socket.fd != -1 && ps->endpoint.address.family != NULL) {
 		for (int i = 0; i < count; i++) {
 			ilog(LOG_DEBUG, "Sending %u UDPTL bytes", (unsigned int) s->len);
 			socket_sendto(&sfd->socket, s->str, s->len, &ps->endpoint);

lib/socket.c

@@ -359,6 +359,8 @@ static ssize_t __ip_sendmsg(socket_t *s, struct msghdr *mh, const endpoint_t *ep
 static ssize_t __ip_sendto(socket_t *s, const void *buf, size_t len, const endpoint_t *ep) {
 	struct sockaddr_storage sin;
 
+	if (!ep->address.family)
+		return -1;
 	ep->address.family->endpoint2sockaddr(&sin, ep);
 	return sendto(s->fd, buf, len, 0, (void *) &sin, ep->address.family->sockaddr_size);
 }