MT#63317 support extmap-strip for SDP

Change-Id: Iaa38fa3c24d69abbfdb8f0e457d406ccf0c6d5bd

daemon/call.c

@@ -2885,6 +2885,17 @@ static void media_init_extmap(struct call_media *media, struct rtp_extension *ex
 		media->extmap_lookup = call_media_ext_lookup_ht;
 }
 
+__attribute__((nonnull(1, 2)))
+static bool media_extmap_strip(const str *name, const struct sdp_ng_flags *flags) {
+	if (t_hash_table_is_set(flags->rtpext_strip)) {
+		if (t_hash_table_lookup(flags->rtpext_strip, STR_PTR("all")))
+			return false;
+		if (t_hash_table_lookup(flags->rtpext_strip, name))
+			return false;
+	}
+	return true;
+}
+
 __attribute__((nonnull(1, 2)))
 static void media_update_extmap(struct call_media *media, struct stream_params *sp) {
 	media_reset_extmap(media);
@@ -2901,13 +2912,18 @@ static void media_update_extmap(struct call_media *media, struct stream_params *
 	}
 }
 
-__attribute__((nonnull(1, 2)))
-static void media_set_extmap(struct call_media *media, const extmap_q *emq) {
+__attribute__((nonnull(1, 2, 4)))
+static void media_set_extmap(struct call_media *media, const extmap_q *emq,
+		bool (*manip)(const str *, const struct sdp_ng_flags *), const struct sdp_ng_flags *flags)
+{
 	media_reset_extmap(media);
 
 	// copy entries
 	for (__auto_type ll = emq->head; ll; ll = ll->next) {
 		__auto_type ext_o = ll->data;
+		if (manip && !manip(&ext_o->name, flags))
+			continue;
+
 		__auto_type ext = g_new(__typeof(*ext_o), 1);
 		*ext = *ext_o;
 		t_queue_push_tail(&media->extmap, ext);
@@ -3154,7 +3170,7 @@ static struct call_media * monologue_add_zero_media(struct call_monologue *sende
 	media_update_attrs(sender_media, sp);
 	media_update_format(sender_media, sp);
 	media_set_ptime(sender_media, sp, flags->rev_ptime, flags->ptime);
-	media_set_extmap(sender_media, &sp->extmap);
+	media_set_extmap(sender_media, &sp->extmap, NULL, flags);
 	*num_ports_other = proto_num_ports(sp->num_ports, sender_media, flags,
 			(flags->rtcp_mux_demux || flags->rtcp_mux_accept) ? true : false);
 	__disable_streams(sender_media, *num_ports_other);
@@ -3286,7 +3302,7 @@ int monologue_offer_answer(struct call_monologue *monologues[2], sdp_streams_q *
 		media_set_ptime(sender_media, sp, flags->rev_ptime, flags->ptime);
 		media_set_ptime(receiver_media, sp, flags->ptime, flags->rev_ptime);
 		media_update_extmap(sender_media, sp);
-		media_set_extmap(receiver_media, &sender_media->extmap);
+		media_set_extmap(receiver_media, &sender_media->extmap, media_extmap_strip, flags);
 
 		if (flags->opmode == OP_OFFER) {
 			ilog(LOG_DEBUG, "Setting media recording slots to %u", flags->media_rec_slot_offer);
@@ -3799,7 +3815,7 @@ static int monologue_subscribe_request1(struct call_monologue *src_ml, struct ca
 		media_set_address_family(dst_media, src_media, flags);
 		media_set_ptime(src_media, sp, flags->rev_ptime, flags->ptime);
 		media_set_ptime(dst_media, sp, flags->ptime, flags->rev_ptime);
-		media_set_extmap(dst_media, &src_media->extmap);
+		media_set_extmap(dst_media, &src_media->extmap, media_extmap_strip, flags);
 
 		codec_store_populate(&dst_media->codecs, &src_media->codecs,
 				.allow_asymmetric = !!flags->allow_asymmetric_codecs);

daemon/call_interfaces.c

@@ -1308,7 +1308,7 @@ void call_ng_flags_flags(str *s, unsigned int idx, helper_arg arg) {
 			break;
 		case CSH_LOOKUP("strip-extmap"):
 		case CSH_LOOKUP("strip extmap"):
-			out->strip_extmap = true;
+			call_ng_flags_str_ht(STR_PTR("all"), 0, &out->rtpext_strip);
 			break;
 		case CSH_LOOKUP("symmetric-codecs"):
 		case CSH_LOOKUP("symmetric codecs"):
@@ -1517,6 +1517,16 @@ void call_ng_codec_flags(const ng_parser_t *parser, str *key, parser_arg value,
 #endif
 	ilog(LOG_WARN, "Unknown 'codec' operation encountered: '" STR_FORMAT "'", STR_FMT(key));
 }
+
+void call_ng_extmap_flags(const ng_parser_t *parser, str *key, parser_arg value, helper_arg arg) {
+	sdp_ng_flags *out = arg.flags;
+	switch (__csh_lookup(key)) {
+		case CSH_LOOKUP("strip"):
+			call_ng_flags_str_list(parser, value, call_ng_flags_str_ht, &out->rtpext_strip);
+			break;
+	}
+}
+
 #ifdef WITH_TRANSCODING
 static void call_ng_parse_block_mode(str *s, enum block_dtmf_mode *output) {
 	switch (__csh_lookup(s)) {
@@ -1899,7 +1909,9 @@ void call_ng_main_flags(const ng_parser_t *parser, str *key, parser_arg value, h
 		case CSH_LOOKUP("endpoint learning"):
 			call_ng_flags_str_list(parser, value, ng_el_option, out);
 			break;
-
+		case CSH_LOOKUP("extmap"):
+			parser->dict_iter(parser, value, call_ng_extmap_flags, out);
+			break;
 		case CSH_LOOKUP("file"):
 			out->file = s;
 			break;

daemon/sdp.c

@@ -2255,8 +2255,6 @@ void sdp_insert_all_attributes(GString *s, struct call_media *media, struct sdp_
 static void sdp_print_extmap(GString *s, struct call_media *source_media, const sdp_ng_flags *flags) {
 	if (!source_media)
 		return;
-	if (flags->strip_extmap && !MEDIA_ISSET(source_media, PASSTHRU))
-		return;
 
 	for (__auto_type l = source_media->extmap.head; l; l = l->next) {
 		__auto_type ext = l->data;

docs/ng_control_protocol.md

@@ -178,6 +178,18 @@ Optionally included keys are:
     audio player regardless of the global config setting. The option `default`
     results in the behaviour mandated by the global config setting.
 
+* `extmap`
+
+    Contains a dictionary to allow manipulation of RFC-8285-style RTP header
+    extensions.
+
+    The contained key `strip` points to a list of header extensions to remove
+    from the SDP. Header extensions must be named by their full name as they
+    appear in the SDP, usually an URI or an `ietf:` registered name. The string
+    `all` can be given to strip all extensions.
+
+    Example in string syntax: `extmap=[strip=[all]]`
+
 * `delay-buffer`
 
 	Takes an integer as value. When set to non-zero, enables the delay
@@ -1213,7 +1225,8 @@ Spaces in each string may be replaced by hyphens.
 
 * `strip extmap`
 
-	Remove `a=rtpmap` attributes from the outgoing SDP.
+    Legacy alias for `extmap=[strip=[all]]` to remove all `a=rtpmap` attributes
+    from the outgoing SDP.
 
 * `strict source`
 

include/call_interfaces.h

@@ -45,6 +45,7 @@ struct ng_media {
 	X(all_attributes)	/* top-level (not part of an m= section) SDP session attributes */
 
 #define RTPE_NG_FLAGS_STR_CASE_HT_PARAMS \
+	X(rtpext_strip) \
 	X(codec_except) \
 	X(sdes_no)		/* individual crypto suites which are excluded */ \
 	X(sdes_only)		/* individual crypto suites which are only accepted */
@@ -214,7 +215,6 @@ RTPE_NG_FLAGS_STR_CASE_HT_PARAMS
 	             generate_rtcp:1,
 	             generate_rtcp_off:1,
 	             generate_mid:1,
-		     strip_extmap:1,
 	             strict_source:1,
 	             media_handover:1,
 	             dtls_passive:1,