i have played with idea of adding new ICE flag value 'force_relay' to rtpengine. if differs from ICE=force in that only existing ICE candidates of typ relay are replaced using rtpengine relay candidates.

i would appreciate if owners of rtpengine module and rtpengine itself could review the patches below and if ok, commit the changes. if committed, i can update rtpengine module README.

-- juha

diff -c /usr/src/orig/sip-router/modules/rtpengine/rtpengine.c ./rtpengine.c *** /usr/src/orig/sip-router/modules/rtpengine/rtpengine.c Wed Apr 9 08:55:16 2014 --- ./rtpengine.c Tue Apr 22 19:09:03 2014 *************** *** 1160,1166 **** if (!val.s) goto error; err = "invalid value"; ! if (str_eq(&val, "force") || str_eq(&val, "remove")) bencode_dictionary_add_str(ng_flags->dict, "ICE", &val); else goto error; --- 1160,1166 ---- if (!val.s) goto error; err = "invalid value"; ! if (str_eq(&val, "force") || str_eq(&val, "force_relay")|| str_eq(&val, "remove")) bencode_dictionary_add_str(ng_flags->dict, "ICE", &val); else goto error;

diff -c /usr/src/orig/rtpengine/daemon/call_interfaces.c ./call_interfaces.c *** /usr/src/orig/rtpengine/daemon/call_interfaces.c Mon Apr 7 09:38:28 2014 --- ./call_interfaces.c Tue Apr 22 21:31:59 2014 *************** *** 462,467 **** --- 462,469 ---- out->ice_remove = 1; else if (!str_cmp(&s, "force")) out->ice_force = 1; + else if (!str_cmp(&s, "force_relay")) + out->ice_force_relay = 1; }

if ((list = bencode_dictionary_get_expect(input, "rtcp-mux", BENCODE_LIST))) { diff -c /usr/src/orig/rtpengine/daemon/sdp.c ./sdp.c *** /usr/src/orig/rtpengine/daemon/sdp.c Mon Apr 7 21:34:48 2014 --- ./sdp.c Tue Apr 22 21:33:47 2014 *************** *** 78,84 **** str component_str; str transport; str priority_str; ! /* incomplete */

unsigned long component; unsigned long priority; --- 78,87 ---- str component_str; str transport; str priority_str; ! str ip_str; ! str port_str; ! str typ_str; ! str type_str;

unsigned long component; unsigned long priority; *************** *** 554,559 **** --- 557,566 ---- EXTRACT_TOKEN(u.candidate.component_str); EXTRACT_TOKEN(u.candidate.transport); EXTRACT_TOKEN(u.candidate.priority_str); + EXTRACT_TOKEN(u.candidate.ip_str); + EXTRACT_TOKEN(u.candidate.port_str); + EXTRACT_TOKEN(u.candidate.typ_str); + EXTRACT_TOKEN(u.candidate.type_str);

output->u.candidate.component = strtoul(output->u.candidate.component_str.s, &ep, 10); if (ep == output->u.candidate.component_str.s) *************** *** 1311,1317 **** --- 1319,1336 ---- switch (attr->attr) { case ATTR_ICE: case ATTR_ICE_UFRAG: + if (!flags->ice_remove && !flags->ice_force) + break; + goto strip; + case ATTR_CANDIDATE: + if (flags->ice_force_relay) { + if ((attr->u.candidate.type_str.len == 5) && + (strncasecmp(attr->u.candidate.type_str.s, "relay", 5) == 0)) + goto strip; + else + break; + } if (!flags->ice_remove && !flags->ice_force) break; goto strip; *************** *** 1359,1367 **** --- 1378,1399 ---- switch (attr->attr) { case ATTR_ICE: case ATTR_ICE_UFRAG: + if (MEDIA_ISSET(media, PASSTHRU)) + break; + if (!flags->ice_remove && !flags->ice_force) + break; + goto strip; + case ATTR_CANDIDATE: if (MEDIA_ISSET(media, PASSTHRU)) break; + if (flags->ice_force_relay) { + if ((attr->u.candidate.type_str.len == 5) && + (strncasecmp(attr->u.candidate.type_str.s, "relay", 5) == 0)) + goto strip; + else + break; + } if (!flags->ice_remove && !flags->ice_force) break; goto strip; *************** *** 1442,1454 **** }

static void insert_candidates(struct sdp_chopper *chop, struct packet_stream *rtp, struct packet_stream *rtcp, ! unsigned long priority, struct sdp_media *media) { chopper_append_c(chop, "a=candidate:"); chopper_append_str(chop, &ice_foundation_str); chopper_append_printf(chop, " 1 UDP %lu ", priority); insert_ice_address(chop, rtp); ! chopper_append_c(chop, " typ host\r\n");

if (rtcp) { /* rtcp-mux only possible in answer */ --- 1474,1490 ---- }

static void insert_candidates(struct sdp_chopper *chop, struct packet_stream *rtp, struct packet_stream *rtcp, ! unsigned long priority, struct sdp_media *media, ! unsigned int relay) { chopper_append_c(chop, "a=candidate:"); chopper_append_str(chop, &ice_foundation_str); chopper_append_printf(chop, " 1 UDP %lu ", priority); insert_ice_address(chop, rtp); ! if (relay == 1) ! chopper_append_c(chop, " typ relay\r\n"); ! else ! chopper_append_c(chop, " typ host\r\n");

if (rtcp) { /* rtcp-mux only possible in answer */ *************** *** 1456,1481 **** chopper_append_str(chop, &ice_foundation_str); chopper_append_printf(chop, " 2 UDP %lu ", priority - 1); insert_ice_address(chop, rtcp); ! chopper_append_c(chop, " typ host\r\n"); }

}

static void insert_candidates_alt(struct sdp_chopper *chop, struct packet_stream *rtp, struct packet_stream *rtcp, ! unsigned long priority, struct sdp_media *media) { chopper_append_c(chop, "a=candidate:"); chopper_append_str(chop, &ice_foundation_str_alt); chopper_append_printf(chop, " 1 UDP %lu ", priority); insert_ice_address_alt(chop, rtp); ! chopper_append_c(chop, " typ host\r\n");

if (rtcp) { chopper_append_c(chop, "a=candidate:"); chopper_append_str(chop, &ice_foundation_str_alt); chopper_append_printf(chop, " 2 UDP %lu ", priority - 1); insert_ice_address_alt(chop, rtcp); ! chopper_append_c(chop, " typ host\r\n"); }

} --- 1492,1527 ---- chopper_append_str(chop, &ice_foundation_str); chopper_append_printf(chop, " 2 UDP %lu ", priority - 1); insert_ice_address(chop, rtcp); ! if (relay) ! chopper_append_c(chop, " typ relay\r\n"); ! else ! chopper_append_c(chop, " typ host\r\n"); }

}

static void insert_candidates_alt(struct sdp_chopper *chop, struct packet_stream *rtp, struct packet_stream *rtcp, ! unsigned long priority, struct sdp_media *media, ! unsigned int relay) { chopper_append_c(chop, "a=candidate:"); chopper_append_str(chop, &ice_foundation_str_alt); chopper_append_printf(chop, " 1 UDP %lu ", priority); insert_ice_address_alt(chop, rtp); ! if (relay == 1) ! chopper_append_c(chop, " typ relay\r\n"); ! else ! chopper_append_c(chop, " typ host\r\n");

if (rtcp) { chopper_append_c(chop, "a=candidate:"); chopper_append_str(chop, &ice_foundation_str_alt); chopper_append_printf(chop, " 2 UDP %lu ", priority - 1); insert_ice_address_alt(chop, rtcp); ! if (relay) ! chopper_append_c(chop, " typ relay\r\n"); ! else ! chopper_append_c(chop, " typ host\r\n"); }

} *************** *** 1591,1597 **** struct call *call;

m = monologue->medias.head; ! do_ice = (flags->ice_force || (!has_ice(sessions) && !flags->ice_remove)) ? 1 : 0; call = monologue->call;

for (l = sessions->head; l; l = l->next) { --- 1637,1644 ---- struct call *call;

m = monologue->medias.head; ! do_ice = (flags->ice_force || flags->ice_force_relay || ! (!has_ice(sessions) && !flags->ice_remove)) ? 1 : 0; call = monologue->call;

for (l = sessions->head; l; l = l->next) { *************** *** 1730,1741 **** priority = new_priority(flags->ice_force ? NULL : sdp_media);

insert_candidates(chop, ps, ps_rtcp, ! priority, sdp_media);

if (callmaster_has_ipv6(call->callmaster)) { priority -= 256; insert_candidates_alt(chop, ps, ps_rtcp, ! priority, sdp_media); } }

--- 1777,1789 ---- priority = new_priority(flags->ice_force ? NULL : sdp_media);

insert_candidates(chop, ps, ps_rtcp, ! priority, sdp_media, flags->ice_force_relay);

if (callmaster_has_ipv6(call->callmaster)) { priority -= 256; insert_candidates_alt(chop, ps, ps_rtcp, ! priority, sdp_media, ! flags->ice_force_relay); } }

diff -c /usr/src/orig/rtpengine/daemon/sdp.h ./sdp.h *** /usr/src/orig/rtpengine/daemon/sdp.h Mon Apr 7 09:38:28 2014 --- ./sdp.h Tue Apr 22 17:35:58 2014 *************** *** 25,30 **** --- 25,31 ---- replace_sess_conn:1, ice_remove:1, ice_force:1, + ice_force_relay:1, rtcp_mux_offer:1, rtcp_mux_demux:1, rtcp_mux_accept:1,