MT#55283 add dedicated "unknown" transport protocol

Instead of just leaving the transport protocol unset when we know we're
not supposed to be aware of the protocol, add a special entry to
suppress the pointless warning message.

Change-Id: I228c2f1652320627f974d9d7bcb0b1345adce2be
(cherry picked from commit 7ed04c3949)

daemon/media_socket.c

@@ -189,6 +189,14 @@ const struct transport_protocol transport_protocols[] = {
 		.avpf		= 1,
 		.tcp		= 0,
 	},
+	[PROTO_UNKNOWN] = {
+		.index		= PROTO_UNKNOWN,
+		.name		= "unknown (legacy)",
+		.rtp		= 0,
+		.srtp		= 0,
+		.avpf		= 0,
+		.tcp		= 0,
+	},
 };
 const int num_transport_protocols = G_N_ELEMENTS(transport_protocols);
 
@@ -351,6 +359,7 @@ static const struct streamhandler * const __sh_matrix_noop[__PROTO_LAST] = { //
 	[PROTO_UDPTL]			= &__sh_noop,
 	[PROTO_RTP_SAVP_OSRTP]		= &__sh_noop,
 	[PROTO_RTP_SAVPF_OSRTP]		= &__sh_noop,
+	[PROTO_UNKNOWN]			= &__sh_noop,
 };
 
 /* ********** */
@@ -365,6 +374,7 @@ static const struct streamhandler * const * const __sh_matrix[__PROTO_LAST] = {
 	[PROTO_UDPTL]			= __sh_matrix_noop,
 	[PROTO_RTP_SAVP_OSRTP]		= __sh_matrix_in_rtp_savp,
 	[PROTO_RTP_SAVPF_OSRTP]		= __sh_matrix_in_rtp_savpf,
+	[PROTO_UNKNOWN]			= __sh_matrix_noop,
 };
 /* special case for DTLS as we can't pass through SRTP<>SRTP */
 static const struct streamhandler * const * const __sh_matrix_recrypt[__PROTO_LAST] = {
@@ -377,6 +387,7 @@ static const struct streamhandler * const * const __sh_matrix_recrypt[__PROTO_LA
 	[PROTO_UDPTL]			= __sh_matrix_noop,
 	[PROTO_RTP_SAVP_OSRTP]		= __sh_matrix_in_rtp_savp_recrypt,
 	[PROTO_RTP_SAVPF_OSRTP]		= __sh_matrix_in_rtp_savpf_recrypt,
+	[PROTO_UNKNOWN]			= __sh_matrix_noop,
 };
 
 /* ********** */

include/media_socket.h

@@ -39,6 +39,7 @@ enum transport_protocol_index {
 	PROTO_UDPTL,
 	PROTO_RTP_SAVP_OSRTP,
 	PROTO_RTP_SAVPF_OSRTP,
+	PROTO_UNKNOWN,
 
 	__PROTO_LAST,
 };