RTP out: robustify send error handling

For error other than congestion (EAGAIN, EWOULDBLOCK, ENOBUFS, ENOMEM),
check the socket type. If the socket is a datagram, retry. Otherwise,
the socket is connection-oriented and we assume the connection broke,
close it.

modules/stream_out/rtp.c

@@ -1425,32 +1425,21 @@ static void* ThreadSend( void *data )
 #endif
                 SendRTCP( id->sinkv[i].rtcp, out );
 
-            if( send( id->sinkv[i].rtp_fd, out->p_buffer, len, 0 ) >= 0 )
-                continue;
-            switch( net_errno )
-            {
-                /* Soft errors (e.g. ICMP): */
-                case ECONNREFUSED: /* Port unreachable */
-                case ENOPROTOOPT:
-#ifdef EPROTO
-                case EPROTO:       /* Protocol unreachable */
-#endif
-                case EHOSTUNREACH: /* Host unreachable */
-                case ENETUNREACH:  /* Network unreachable */
-                case ENETDOWN:     /* Entire network down */
+            if( send( id->sinkv[i].rtp_fd, out->p_buffer, len, 0 ) == -1
+             && net_errno != EAGAIN && net_errno != EWOULDBLOCK
+             && net_errno != ENOBUFS && net_errno != ENOMEM )
+            {
+                int type;
+                getsockopt( id->sinkv[i].rtp_fd, SOL_SOCKET, SO_TYPE,
+                            &type, &(socklen_t){ sizeof(type) });
+                if( type == SOCK_DGRAM )
+                    /* ICMP soft error: ignore and retry */
                     send( id->sinkv[i].rtp_fd, out->p_buffer, len, 0 );
-                /* Transient congestion: */
-                case ENOMEM: /* out of socket buffers */
-                case ENOBUFS:
-                case EAGAIN:
-#if (EAGAIN != EWOULDBLOCK)
-                case EWOULDBLOCK:
-#endif
-                    continue;
-            }
-
+                else
+                    /* Broken connection */
                     deadv[deadc++] = id->sinkv[i].rtp_fd;
             }
+        }
         id->i_seq_sent_next = ntohs(((uint16_t *) out->p_buffer)[1]) + 1;
         vlc_mutex_unlock( &id->lock_sink );
         block_Release( out );