MT#56861 support RTP seq no adjustments in kernel

DTMF requires the "end" event to be sent multiple times, requiring
sequence number adjustments after DTMF injection has finished. Add
support for this to the kernel module.

Change-Id: Ie5c8f18eda39553a6ebbdd35ef2341be01f2a59f

daemon/media_socket.c

@@ -1545,9 +1545,13 @@ output:
 
 	__re_address_translate_ep(&redi->output.dst_addr, &sink->endpoint);
 	__re_address_translate_ep(&redi->output.src_addr, &sink->selected_sfd->socket.local);
-	if (redi->output.ssrc_subst) {
+
+	if (reti->track_ssrc) {
 		for (unsigned int u = 0; u < G_N_ELEMENTS(stream->ssrc_in); u++) {
-			if (stream->ssrc_in[u])
+			if (sink->ssrc_out[u])
+				redi->output.seq_offset[u] = sink->ssrc_out[u]->parent->seq_diff;
+
+			if (redi->output.ssrc_subst && stream->ssrc_in[u])
 				redi->output.ssrc_out[u] = htonl(stream->ssrc_in[u]->ssrc_map_out);
 		}
 	}

kernel-module/xt_RTPENGINE.c

@@ -1708,17 +1708,14 @@ static int proc_list_show(struct seq_file *f, void *v) {
 			(unsigned long long) atomic64_read(&o->stats_out.packets),
 			(unsigned long long) atomic64_read(&o->stats_out.errors));
 
-		if (o->output.ssrc_subst) {
-			seq_printf(f, " SSRC out:");
-			for (j = 0; j < ARRAY_SIZE(o->output.ssrc_out); j++) {
-				if (!o->output.ssrc_out[j])
-					break;
-				seq_printf(f, "%s %lx",
-						(j == 0) ? "" : ",",
-						(unsigned long) ntohl(o->output.ssrc_out[j]));
-			}
-			seq_printf(f, "\n");
+		seq_printf(f, " SSRC out:");
+		for (j = 0; j < ARRAY_SIZE(o->output.ssrc_out); j++) {
+			seq_printf(f, "%s %lx [seq +%u]",
+					(j == 0) ? "" : ",",
+					(unsigned long) ntohl(o->output.ssrc_out[j]),
+					(unsigned int) o->output.seq_offset[j]);
 		}
+		seq_printf(f, "\n");
 
 		for (j = 0; j < g->target.num_payload_types; j++) {
 			if (o->output.pt_output[j].replace_pattern_len)
@@ -4857,9 +4854,13 @@ no_intercept:
 		}
 
 		if (rtp2.ok) {
-			// SSRC substitution
-			if (o->output.ssrc_subst && ssrc_idx != -1 && o->output.ssrc_out[ssrc_idx])
-				rtp2.header->ssrc = o->output.ssrc_out[ssrc_idx];
+			// SSRC substitution and seq manipulation
+			if (ssrc_idx != -1) {
+				rtp2.header->seq_num = htons(ntohs(rtp2.header->seq_num)
+						+ o->output.seq_offset[ssrc_idx]);
+				if (o->output.ssrc_subst && o->output.ssrc_out[ssrc_idx])
+					rtp2.header->ssrc = o->output.ssrc_out[ssrc_idx];
+			}
 
 			pkt_idx = packet_index(&o->encrypt, &o->output.encrypt, rtp2.header, ssrc_idx);
 			pllen = rtp2.payload_len;

kernel-module/xt_RTPENGINE.h

@@ -134,6 +134,7 @@ struct rtpengine_output_info {
 
 	struct rtpengine_srtp		encrypt;
 	uint32_t			ssrc_out[RTPE_NUM_SSRC_TRACKING]; // Rewrite SSRC
+	uint32_t			seq_offset[RTPE_NUM_SSRC_TRACKING]; // Rewrite output seq
 	struct rtpengine_pt_output	pt_output[RTPE_NUM_PAYLOAD_TYPES]; // same indexes as pt_input
 
 	unsigned char			tos;