obs-outputs: Fix librtmp IP bind / resolve behavior

Fixes a case where OBS would prefer trying to connect
to an IPv4 address even though you had bound it to an
IPv6 interface for example.

plugins/obs-outputs/librtmp/rtmp.c

@@ -650,7 +650,7 @@ int RTMP_AddStream(RTMP *r, const char *playpath)
 }
 
 static int
-add_addr_info(struct sockaddr_storage *service, socklen_t *addrlen, AVal *host, int port)
+add_addr_info(struct sockaddr_storage *service, socklen_t *addrlen, AVal *host, int port, socklen_t addrlen_hint)
 {
     char *hostname;
     int ret = TRUE;
@@ -698,7 +698,7 @@ add_addr_info(struct sockaddr_storage *service, socklen_t *addrlen, AVal *host,
     // prefer ipv4 results, since lots of ISPs have broken ipv6 connectivity
     for (ptr = result; ptr != NULL; ptr = ptr->ai_next)
     {
-        if (ptr->ai_family == AF_INET)
+        if (ptr->ai_family == AF_INET && (!addrlen_hint || ptr->ai_addrlen == addrlen_hint))
         {
             memcpy(service, ptr->ai_addr, ptr->ai_addrlen);
             *addrlen = (socklen_t)ptr->ai_addrlen;
@@ -710,7 +710,7 @@ add_addr_info(struct sockaddr_storage *service, socklen_t *addrlen, AVal *host,
 	{
 		for (ptr = result; ptr != NULL; ptr = ptr->ai_next)
 		{
-			if (ptr->ai_family == AF_INET6)
+            if (ptr->ai_family == AF_INET6 && (!addrlen_hint || ptr->ai_addrlen == addrlen_hint))
 			{
 				memcpy(service, ptr->ai_addr, ptr->ai_addrlen);
 				*addrlen = (socklen_t)ptr->ai_addrlen;
@@ -905,6 +905,7 @@ RTMP_Connect(RTMP *r, RTMPPacket *cp)
 #endif
     struct sockaddr_storage service;
     socklen_t addrlen = 0;
+    socklen_t addrlen_hint = 0;
     if (!r->Link.hostname.av_len)
         return FALSE;
 
@@ -920,16 +921,19 @@ RTMP_Connect(RTMP *r, RTMPPacket *cp)
 
     memset(&service, 0, sizeof(service));
 
+    if (r->m_bindIP.addrLen)
+        addrlen_hint = r->m_bindIP.addrLen;
+
     if (r->Link.socksport)
     {
         /* Connect via SOCKS */
-        if (!add_addr_info(&service, &addrlen, &r->Link.sockshost, r->Link.socksport))
+        if (!add_addr_info(&service, &addrlen, &r->Link.sockshost, r->Link.socksport, addrlen_hint))
             return FALSE;
     }
     else
     {
         /* Connect directly */
-        if (!add_addr_info(&service, &addrlen, &r->Link.hostname, r->Link.port))
+        if (!add_addr_info(&service, &addrlen, &r->Link.hostname, r->Link.port, addrlen_hint))
             return FALSE;
     }
 
@@ -949,7 +953,7 @@ SocksNegotiate(RTMP *r)
     socklen_t addrlen = 0;
     memset(&service, 0, sizeof(service));
 
-    add_addr_info(&service, &addrlen, &r->Link.hostname, r->Link.port);
+    add_addr_info(&service, &addrlen, &r->Link.hostname, r->Link.port, 0);
 
     // not doing IPv6 socks
     if (service.ss_family == AF_INET6)

plugins/obs-outputs/rtmp-stream.c

@@ -676,8 +676,10 @@ static int try_connect(struct rtmp_stream *stream)
 		bool success = netif_str_to_addr(&stream->rtmp.m_bindIP.addr,
 				&stream->rtmp.m_bindIP.addrLen,
 				stream->bind_ip.array);
-		if (success)
-			info("Binding to IP");
+		if (success) {
+			info("Binding to IPv%d", (stream->rtmp.m_bindIP.addrLen ==
+				sizeof(struct sockaddr_in6) ? 6 : 4));
+		}
 	}
 
 	RTMP_AddStream(&stream->rtmp, stream->key.array);