/* Match format in the SDP media offer and answer. */
PJ_DEF(pj_status_t) pjmedia_sdp_neg_fmt_match(pj_pool_t *pool,
pjmedia_sdp_media *offer,
unsigned o_fmt_idx,
pjmedia_sdp_media *answer,
unsigned a_fmt_idx,
unsigned option)
{
const pjmedia_sdp_attr *attr;
pjmedia_sdp_rtpmap o_rtpmap, a_rtpmap;
unsigned o_pt;
unsigned a_pt;
o_pt = pj_strtoul(&offer->desc.fmt[o_fmt_idx]);
a_pt = pj_strtoul(&answer->desc.fmt[a_fmt_idx]);
if (o_pt < 96 || a_pt < 96) {
if (o_pt == a_pt)
return PJ_SUCCESS;
else
return PJMEDIA_SDP_EFORMATNOTEQUAL;
}
/* Get the format rtpmap from the offer. */
attr = pjmedia_sdp_media_find_attr2(offer, "rtpmap",
&offer->desc.fmt[o_fmt_idx]);
if (!attr) {
pj_assert(!"Bug! Offer haven't been validated");
return PJ_EBUG;
}
pjmedia_sdp_attr_get_rtpmap(attr, &o_rtpmap);
/* Get the format rtpmap from the answer. */
attr = pjmedia_sdp_media_find_attr2(answer, "rtpmap",
&answer->desc.fmt[a_fmt_idx]);
if (!attr) {
pj_assert(!"Bug! Answer haven't been validated");
return PJ_EBUG;
}
pjmedia_sdp_attr_get_rtpmap(attr, &a_rtpmap);
if (pj_stricmp(&o_rtpmap.enc_name, &a_rtpmap.enc_name) != 0 ||
(o_rtpmap.clock_rate != a_rtpmap.clock_rate) ||
(!(pj_stricmp(&o_rtpmap.param, &a_rtpmap.param) == 0 ||
(a_rtpmap.param.slen == 0 && o_rtpmap.param.slen == 1 &&
*o_rtpmap.param.ptr == '1') ||
(o_rtpmap.param.slen == 0 && a_rtpmap.param.slen == 1 &&
*a_rtpmap.param.ptr=='1'))))
{
return PJMEDIA_SDP_EFORMATNOTEQUAL;
}
return custom_fmt_match(pool, &o_rtpmap.enc_name,
offer, o_fmt_idx, answer, a_fmt_idx, option);
}
/* Internal function to apply symmetric PT for the local answer. */
static void apply_answer_symmetric_pt(pj_pool_t *pool,
pjmedia_sdp_media *answer,
unsigned pt_cnt,
const pj_str_t pt_offer[],
const pj_str_t pt_answer[])
{
pjmedia_sdp_attr *a_tmp[PJMEDIA_MAX_SDP_ATTR];
unsigned i, a_tmp_cnt = 0;
/* Rewrite the payload types in the answer if different to
* the ones in the offer.
*/
for (i = 0; i < pt_cnt; ++i) {
pjmedia_sdp_attr *a;
/* Skip if the PTs are the same already, e.g: static PT. */
if (pj_strcmp(&pt_answer[i], &pt_offer[i]) == 0)
continue;
/* Rewrite payload type in the answer to match to the offer */
pj_strdup(pool, &answer->desc.fmt[i], &pt_offer[i]);
/* Also update payload type in rtpmap */
a = pjmedia_sdp_media_find_attr2(answer, "rtpmap", &pt_answer[i]);
if (a) {
rewrite_pt(pool, &a->value, &pt_answer[i], &pt_offer[i]);
/* Temporarily remove the attribute in case the new payload
* type is being used by another format in the media.
*/
pjmedia_sdp_media_remove_attr(answer, a);
a_tmp[a_tmp_cnt++] = a;
}
/* Also update payload type in fmtp */
a = pjmedia_sdp_media_find_attr2(answer, "fmtp", &pt_answer[i]);
if (a) {
rewrite_pt(pool, &a->value, &pt_answer[i], &pt_offer[i]);
/* Temporarily remove the attribute in case the new payload
* type is being used by another format in the media.
*/
pjmedia_sdp_media_remove_attr(answer, a);
a_tmp[a_tmp_cnt++] = a;
}
}
/* Return back 'rtpmap' and 'fmtp' attributes */
for (i = 0; i < a_tmp_cnt; ++i)
pjmedia_sdp_media_add_attr(answer, a_tmp[i]);
}
static void apply_packetization(struct ast_sip_session *session, struct ast_sip_session_media *session_media,
const struct pjmedia_sdp_media *remote_stream)
{
pjmedia_sdp_attr *attr;
pj_str_t value;
unsigned long framing;
int codec;
struct ast_codec_pref *pref = &ast_rtp_instance_get_codecs(session_media->rtp)->pref;
/* Apply packetization if available and configured to do so */
if (!session->endpoint->media.rtp.use_ptime || !(attr = pjmedia_sdp_media_find_attr2(remote_stream, "ptime", NULL))) {
return;
}
value = attr->value;
framing = pj_strtoul(pj_strltrim(&value));
for (codec = 0; codec < AST_RTP_MAX_PT; codec++) {
struct ast_rtp_payload_type format = ast_rtp_codecs_payload_lookup(ast_rtp_instance_get_codecs(
session_media->rtp), codec);
if (!format.asterisk_format) {
continue;
}
ast_codec_pref_setsize(pref, &format.format, framing);
}
ast_rtp_codecs_packetization_set(ast_rtp_instance_get_codecs(session_media->rtp),
session_media->rtp, pref);
}
PJ_DEF(pj_status_t) pjmedia_codec_g7221_match_sdp(pj_pool_t *pool,
pjmedia_sdp_media *offer,
unsigned o_fmt_idx,
pjmedia_sdp_media *answer,
unsigned a_fmt_idx,
unsigned option)
{
const pjmedia_sdp_attr *attr_ans;
const pjmedia_sdp_attr *attr_ofr;
pjmedia_sdp_fmtp fmtp;
unsigned a_bitrate, o_bitrate;
const pj_str_t bitrate = {"bitrate=", 8};
pj_status_t status;
PJ_UNUSED_ARG(pool);
PJ_UNUSED_ARG(option);
/* Parse offer */
attr_ofr = pjmedia_sdp_media_find_attr2(offer, "fmtp",
&offer->desc.fmt[o_fmt_idx]);
if (!attr_ofr)
return PJMEDIA_SDP_EINFMTP;
status = pjmedia_sdp_attr_get_fmtp(attr_ofr, &fmtp);
if (status != PJ_SUCCESS)
return status;
GET_FMTP_IVAL(o_bitrate, fmtp, bitrate, 0);
/* Parse answer */
attr_ans = pjmedia_sdp_media_find_attr2(answer, "fmtp",
&answer->desc.fmt[a_fmt_idx]);
if (!attr_ans)
return PJMEDIA_SDP_EINFMTP;
status = pjmedia_sdp_attr_get_fmtp(attr_ans, &fmtp);
if (status != PJ_SUCCESS)
return status;
GET_FMTP_IVAL(a_bitrate, fmtp, bitrate, 0);
/* Compare bitrate in answer and offer. */
if (a_bitrate != o_bitrate)
return PJMEDIA_SDP_EFORMATNOTEQUAL;
return PJ_SUCCESS;
}
static void get_codecs(struct ast_sip_session *session, const struct pjmedia_sdp_media *stream, struct ast_rtp_codecs *codecs)
{
pjmedia_sdp_attr *attr;
pjmedia_sdp_rtpmap *rtpmap;
pjmedia_sdp_fmtp fmtp;
struct ast_format *format;
int i, num = 0;
char name[256];
char media[20];
char fmt_param[256];
ast_rtp_codecs_payloads_initialize(codecs);
/* Iterate through provided formats */
for (i = 0; i < stream->desc.fmt_count; ++i) {
/* The payload is kept as a string for things like t38 but for video it is always numerical */
ast_rtp_codecs_payloads_set_m_type(codecs, NULL, pj_strtoul(&stream->desc.fmt[i]));
/* Look for the optional rtpmap attribute */
if (!(attr = pjmedia_sdp_media_find_attr2(stream, "rtpmap", &stream->desc.fmt[i]))) {
continue;
}
/* Interpret the attribute as an rtpmap */
if ((pjmedia_sdp_attr_to_rtpmap(session->inv_session->pool_prov, attr, &rtpmap)) != PJ_SUCCESS) {
continue;
}
ast_copy_pj_str(name, &rtpmap->enc_name, sizeof(name));
ast_copy_pj_str(media, (pj_str_t*)&stream->desc.media, sizeof(media));
ast_rtp_codecs_payloads_set_rtpmap_type_rate(codecs, NULL, pj_strtoul(&stream->desc.fmt[i]),
media, name, 0, rtpmap->clock_rate);
/* Look for an optional associated fmtp attribute */
if (!(attr = pjmedia_sdp_media_find_attr2(stream, "fmtp", &rtpmap->pt))) {
continue;
}
if ((pjmedia_sdp_attr_get_fmtp(attr, &fmtp)) == PJ_SUCCESS) {
sscanf(pj_strbuf(&fmtp.fmt), "%d", &num);
if ((format = ast_rtp_codecs_get_payload_format(codecs, num))) {
ast_copy_pj_str(fmt_param, &fmtp.fmt_param, sizeof(fmt_param));
ast_format_sdp_parse(format, fmt_param);
}
}
}
}
/* Toggle AMR octet-align setting in the fmtp.
*/
static pj_status_t amr_toggle_octet_align(pj_pool_t *pool,
pjmedia_sdp_media *media,
unsigned fmt_idx)
{
pjmedia_sdp_attr *attr;
pjmedia_sdp_fmtp fmtp;
const pj_str_t STR_OCTET_ALIGN = {"octet-align=", 12};
enum { MAX_FMTP_STR_LEN = 160 };
attr = pjmedia_sdp_media_find_attr2(media, "fmtp",
&media->desc.fmt[fmt_idx]);
/* Check if the AMR media format has FMTP attribute */
if (attr) {
char *p;
pj_status_t status;
status = pjmedia_sdp_attr_get_fmtp(attr, &fmtp);
if (status != PJ_SUCCESS)
return status;
/* Check if the fmtp has octet-align field. */
p = pj_stristr(&fmtp.fmt_param, &STR_OCTET_ALIGN);
if (p) {
/* It has, just toggle the value */
unsigned octet_align;
pj_str_t s;
pj_strset(&s, p + STR_OCTET_ALIGN.slen, fmtp.fmt_param.slen -
(p - fmtp.fmt_param.ptr) - STR_OCTET_ALIGN.slen);
octet_align = pj_strtoul(&s);
*(p + STR_OCTET_ALIGN.slen) = (char)(octet_align? '0' : '1');
} else {
/* It doesn't, append octet-align field */
char buf[MAX_FMTP_STR_LEN];
pj_ansi_snprintf(buf, MAX_FMTP_STR_LEN, "%.*s;octet-align=1",
(int)fmtp.fmt_param.slen, fmtp.fmt_param.ptr);
attr->value = pj_strdup3(pool, buf);
}
} else {
/* Add new attribute for the AMR media format with octet-align
* field set.
*/
char buf[MAX_FMTP_STR_LEN];
attr = PJ_POOL_ZALLOC_T(pool, pjmedia_sdp_attr);
attr->name = pj_str("fmtp");
pj_ansi_snprintf(buf, MAX_FMTP_STR_LEN, "%.*s octet-align=1",
(int)media->desc.fmt[fmt_idx].slen,
media->desc.fmt[fmt_idx].ptr);
attr->value = pj_strdup3(pool, buf);
media->attr[media->attr_count++] = attr;
}
return PJ_SUCCESS;
}
/* Matching G722.1 bitrates between offer and answer.
*/
static pj_bool_t match_g7221( const pjmedia_sdp_media *offer,
unsigned o_fmt_idx,
const pjmedia_sdp_media *answer,
unsigned a_fmt_idx)
{
const pjmedia_sdp_attr *a_ans;
const pjmedia_sdp_attr *a_off;
pjmedia_sdp_fmtp fmtp;
unsigned a_bitrate = 0, o_bitrate = 0;
const pj_str_t bitrate = {"bitrate=", 8};
const char *p;
a_ans = pjmedia_sdp_media_find_attr2(answer, "fmtp",
&answer->desc.fmt[a_fmt_idx]);
if (!a_ans)
return PJ_FALSE;
if (pjmedia_sdp_attr_get_fmtp(a_ans, &fmtp) != PJ_SUCCESS)
return PJ_FALSE;
p = pj_stristr(&fmtp.fmt_param, &bitrate);
if (p == NULL)
return PJ_FALSE;
a_bitrate = atoi(p + bitrate.slen);
a_off = pjmedia_sdp_media_find_attr2(offer, "fmtp",
&offer->desc.fmt[o_fmt_idx]);
if (!a_off)
return PJ_FALSE;
if (pjmedia_sdp_attr_get_fmtp(a_off, &fmtp) != PJ_SUCCESS)
return PJ_FALSE;
p = pj_stristr(&fmtp.fmt_param, &bitrate);
if (p == NULL)
return PJ_FALSE;
o_bitrate = atoi(p + bitrate.slen);
return (a_bitrate == o_bitrate);
}
/* Matching G722.1 bitrates between offer and answer.
*/
static pj_bool_t match_g7221( const pjmedia_sdp_media *offer,
unsigned o_fmt_idx,
const pjmedia_sdp_media *answer,
unsigned a_fmt_idx)
{
const pjmedia_sdp_attr *attr_ans;
const pjmedia_sdp_attr *attr_ofr;
pjmedia_sdp_fmtp fmtp;
unsigned a_bitrate, o_bitrate;
const pj_str_t bitrate = {"bitrate=", 8};
/* Parse offer */
attr_ofr = pjmedia_sdp_media_find_attr2(offer, "fmtp",
&offer->desc.fmt[o_fmt_idx]);
if (!attr_ofr)
return PJ_FALSE;
if (pjmedia_sdp_attr_get_fmtp(attr_ofr, &fmtp) != PJ_SUCCESS)
return PJ_FALSE;
GET_FMTP_IVAL(o_bitrate, fmtp, bitrate, 0);
/* Parse answer */
attr_ans = pjmedia_sdp_media_find_attr2(answer, "fmtp",
&answer->desc.fmt[a_fmt_idx]);
if (!attr_ans)
return PJ_FALSE;
if (pjmedia_sdp_attr_get_fmtp(attr_ans, &fmtp) != PJ_SUCCESS)
return PJ_FALSE;
GET_FMTP_IVAL(a_bitrate, fmtp, bitrate, 0);
/* Compare bitrate in answer and offer. */
return (a_bitrate == o_bitrate);
}
/*
* Get fmtp mode parameter associated with the codec.
*/
static pj_status_t get_fmtp_mode(const pjmedia_sdp_media *m,
const pj_str_t *fmt,
int *p_mode)
{
const pjmedia_sdp_attr *attr;
pjmedia_sdp_fmtp fmtp;
const pj_str_t str_mode = { "mode=", 5 };
char *pos;
/* Get "fmtp" attribute for the format */
attr = pjmedia_sdp_media_find_attr2(m, "fmtp", fmt);
if (attr == NULL)
return -1;
/* Parse "fmtp" attribute */
if (pjmedia_sdp_attr_get_fmtp(attr, &fmtp) != PJ_SUCCESS)
return -1;
/* Look for "mode=" string in the fmtp */
while (fmtp.fmt_param.slen >= str_mode.slen + 1) {
if (pj_strnicmp(&fmtp.fmt_param, &str_mode, str_mode.slen)==0) {
/* Found "mode=" string */
break;
}
fmtp.fmt_param.ptr++;
fmtp.fmt_param.slen--;
}
if (fmtp.fmt_param.slen < str_mode.slen + 1) {
/* "mode=" param not found */
return -1;
}
/* Get the mode */
pos = fmtp.fmt_param.ptr + str_mode.slen;
*p_mode = 0;
while (pj_isdigit(*pos)) {
*p_mode = *p_mode * 10 + (*pos - '0');
++pos;
}
return PJ_SUCCESS;
}
/* Try to match offer with answer. */
static pj_status_t match_offer(pj_pool_t *pool,
const pjmedia_sdp_media *offer,
const pjmedia_sdp_media *preanswer,
const pjmedia_sdp_media *orig_local,
pjmedia_sdp_media **p_answer)
{
unsigned i;
pj_bool_t offer_has_codec = 0,
offer_has_telephone_event = 0,
offer_has_other = 0,
found_matching_codec = 0,
found_matching_telephone_event = 0,
found_matching_other = 0;
unsigned pt_answer_count = 0;
pj_str_t pt_answer[PJMEDIA_MAX_SDP_FMT];
pjmedia_sdp_media *answer;
/* With the addition of telephone-event and dodgy MS RTC SDP,
* the answer generation algorithm looks really shitty...
*/
for (i=0; i<offer->desc.fmt_count; ++i) {
unsigned j;
if (pj_isdigit(*offer->desc.fmt[i].ptr)) {
/* This is normal/standard payload type, where it's identified
* by payload number.
*/
unsigned pt;
pt = pj_strtoul(&offer->desc.fmt[i]);
if (pt < 96) {
/* For static payload type, it's enough to compare just
* the payload number.
*/
offer_has_codec = 1;
/* We just need to select one codec.
* Continue if we have selected matching codec for previous
* payload.
*/
if (found_matching_codec)
continue;
/* Find matching codec in local descriptor. */
for (j=0; j<preanswer->desc.fmt_count; ++j) {
unsigned p;
p = pj_strtoul(&preanswer->desc.fmt[j]);
if (p == pt && pj_isdigit(*preanswer->desc.fmt[j].ptr)) {
found_matching_codec = 1;
pt_answer[pt_answer_count++] = preanswer->desc.fmt[j];
break;
}
}
} else {
/* This is dynamic payload type.
* For dynamic payload type, we must look the rtpmap and
* compare the encoding name.
*/
const pjmedia_sdp_attr *a;
pjmedia_sdp_rtpmap or_;
pj_bool_t is_codec;
/* Get the rtpmap for the payload type in the offer. */
a = pjmedia_sdp_media_find_attr2(offer, "rtpmap",
&offer->desc.fmt[i]);
if (!a) {
pj_assert(!"Bug! Offer should have been validated");
return PJMEDIA_SDP_EMISSINGRTPMAP;
}
pjmedia_sdp_attr_get_rtpmap(a, &or_);
if (!pj_strcmp2(&or_.enc_name, "telephone-event")) {
offer_has_telephone_event = 1;
if (found_matching_telephone_event)
continue;
is_codec = 0;
} else {
offer_has_codec = 1;
if (found_matching_codec)
continue;
is_codec = 1;
}
/* Find paylaod in our initial SDP with matching
* encoding name and clock rate.
*/
for (j=0; j<preanswer->desc.fmt_count; ++j) {
a = pjmedia_sdp_media_find_attr2(preanswer, "rtpmap",
&preanswer->desc.fmt[j]);
if (a) {
pjmedia_sdp_rtpmap lr;
pjmedia_sdp_attr_get_rtpmap(a, &lr);
/* See if encoding name, clock rate, and
* channel count match
*/
if (!pj_stricmp(&or_.enc_name, &lr.enc_name) &&
or_.clock_rate == lr.clock_rate &&
(pj_strcmp(&or_.param, &lr.param)==0 ||
(or_.param.slen==1 && *or_.param.ptr=='1')))
{
/* Match! */
if (is_codec) {
/* Further check for G7221, negotiate bitrate. */
if (pj_strcmp2(&or_.enc_name, "G7221") == 0 &&
match_g7221(offer, i, preanswer, j) == 0)
{
continue;
}
found_matching_codec = 1;
} else {
found_matching_telephone_event = 1;
}
pt_answer[pt_answer_count++] = preanswer->desc.fmt[j];
break;
}
}
}
}
} else {
/* This is a non-standard, brain damaged SDP where the payload
* type is non-numeric. It exists e.g. in Microsoft RTC based
* UA, to indicate instant messaging capability.
* Example:
* - m=x-ms-message 5060 sip null
*/
offer_has_other = 1;
if (found_matching_other)
continue;
for (j=0; j<preanswer->desc.fmt_count; ++j) {
if (!pj_strcmp(&offer->desc.fmt[i], &preanswer->desc.fmt[j])) {
/* Match */
found_matching_other = 1;
pt_answer[pt_answer_count++] = preanswer->desc.fmt[j];
break;
}
}
}
}
/* See if all types of offer can be matched. */
if (offer_has_codec && !found_matching_codec) {
return PJMEDIA_SDPNEG_NOANSCODEC;
}
/* If this comment is removed, negotiation will fail if remote has offered
telephone-event and local is not configured with telephone-event
if (offer_has_telephone_event && !found_matching_telephone_event) {
return PJMEDIA_SDPNEG_NOANSTELEVENT;
}
*/
if (offer_has_other && !found_matching_other) {
return PJMEDIA_SDPNEG_NOANSUNKNOWN;
}
/* Seems like everything is in order.
* Build the answer by cloning from local media, but rearrange the payload
* to suit the offer.
*/
answer = pjmedia_sdp_media_clone(pool, orig_local);
for (i=0; i<pt_answer_count; ++i) {
unsigned j;
for (j=i; j<answer->desc.fmt_count; ++j) {
if (!pj_strcmp(&answer->desc.fmt[j], &pt_answer[i]))
break;
}
pj_assert(j != answer->desc.fmt_count);
str_swap(&answer->desc.fmt[i], &answer->desc.fmt[j]);
}
/* Remove unwanted local formats. */
for (i=pt_answer_count; i<answer->desc.fmt_count; ++i) {
pjmedia_sdp_attr *a;
/* Remove rtpmap for this format */
a = pjmedia_sdp_media_find_attr2(answer, "rtpmap",
&answer->desc.fmt[i]);
if (a) {
pjmedia_sdp_media_remove_attr(answer, a);
}
/* Remove fmtp for this format */
a = pjmedia_sdp_media_find_attr2(answer, "fmtp",
&answer->desc.fmt[i]);
if (a) {
pjmedia_sdp_media_remove_attr(answer, a);
}
}
answer->desc.fmt_count = pt_answer_count;
/* If offer has zero port, set our answer with zero port too */
if (offer->desc.port==0)
answer->desc.port = 0;
/* Update media direction. */
update_media_direction(pool, offer, answer);
*p_answer = answer;
return PJ_SUCCESS;
}
/* Update single local media description to after receiving answer
* from remote.
*/
static pj_status_t process_m_answer( pj_pool_t *pool,
pjmedia_sdp_media *offer,
pjmedia_sdp_media *answer,
pj_bool_t allow_asym)
{
unsigned i;
/* Check that the media type match our offer. */
if (pj_strcmp(&answer->desc.media, &offer->desc.media)!=0) {
/* The media type in the answer is different than the offer! */
return PJMEDIA_SDPNEG_EINVANSMEDIA;
}
/* Check that transport in the answer match our offer. */
/* At this point, transport type must be compatible,
* the transport instance will do more validation later.
*/
if (pjmedia_sdp_transport_cmp(&answer->desc.transport,
&offer->desc.transport)
!= PJ_SUCCESS)
{
return PJMEDIA_SDPNEG_EINVANSTP;
}
/* Check if remote has rejected our offer */
if (answer->desc.port == 0) {
/* Remote has rejected our offer.
* Set our port to zero too in active SDP.
*/
offer->desc.port = 0;
}
/* Process direction attributes */
update_media_direction(pool, answer, offer);
/* If asymetric media is allowed, then just check that remote answer has
* codecs that are within the offer.
*
* Otherwise if asymetric media is not allowed, then we will choose only
* one codec in our initial offer to match the answer.
*/
if (allow_asym) {
for (i=0; i<answer->desc.fmt_count; ++i) {
unsigned j;
pj_str_t *rem_fmt = &answer->desc.fmt[i];
for (j=0; j<offer->desc.fmt_count; ++j) {
if (pj_strcmp(rem_fmt, &answer->desc.fmt[j])==0)
break;
}
if (j != offer->desc.fmt_count) {
/* Found at least one common codec. */
break;
}
}
if (i == answer->desc.fmt_count) {
/* No common codec in the answer! */
return PJMEDIA_SDPNEG_EANSNOMEDIA;
}
PJ_TODO(CHECK_SDP_NEGOTIATION_WHEN_ASYMETRIC_MEDIA_IS_ALLOWED);
} else {
/* Remove all format in the offer that has no matching answer */
for (i=0; i<offer->desc.fmt_count;) {
unsigned pt;
pj_uint32_t j;
pj_str_t *fmt = &offer->desc.fmt[i];
/* Find matching answer */
pt = pj_strtoul(fmt);
if (pt < 96) {
for (j=0; j<answer->desc.fmt_count; ++j) {
if (pj_strcmp(fmt, &answer->desc.fmt[j])==0)
break;
}
} else {
/* This is dynamic payload type.
* For dynamic payload type, we must look the rtpmap and
* compare the encoding name.
*/
const pjmedia_sdp_attr *a;
pjmedia_sdp_rtpmap or_;
/* Get the rtpmap for the payload type in the offer. */
a = pjmedia_sdp_media_find_attr2(offer, "rtpmap", fmt);
if (!a) {
pj_assert(!"Bug! Offer should have been validated");
return PJ_EBUG;
}
pjmedia_sdp_attr_get_rtpmap(a, &or_);
/* Find paylaod in answer SDP with matching
* encoding name and clock rate.
*/
for (j=0; j<answer->desc.fmt_count; ++j) {
a = pjmedia_sdp_media_find_attr2(answer, "rtpmap",
&answer->desc.fmt[j]);
if (a) {
pjmedia_sdp_rtpmap ar;
pjmedia_sdp_attr_get_rtpmap(a, &ar);
/* See if encoding name, clock rate, and channel
* count match
*/
if (!pj_stricmp(&or_.enc_name, &ar.enc_name) &&
or_.clock_rate == ar.clock_rate &&
(pj_stricmp(&or_.param, &ar.param)==0 ||
(ar.param.slen==1 && *ar.param.ptr=='1')))
{
/* Further check for G7221, negotiate bitrate. */
if (pj_strcmp2(&or_.enc_name, "G7221") == 0) {
if (match_g7221(offer, i, answer, j))
break;
} else {
/* Match! */
break;
}
}
}
}
}
if (j == answer->desc.fmt_count) {
/* This format has no matching answer.
* Remove it from our offer.
*/
pjmedia_sdp_attr *a;
/* Remove rtpmap associated with this format */
a = pjmedia_sdp_media_find_attr2(offer, "rtpmap", fmt);
if (a)
pjmedia_sdp_media_remove_attr(offer, a);
/* Remove fmtp associated with this format */
a = pjmedia_sdp_media_find_attr2(offer, "fmtp", fmt);
if (a)
pjmedia_sdp_media_remove_attr(offer, a);
/* Remove this format from offer's array */
pj_array_erase(offer->desc.fmt, sizeof(offer->desc.fmt[0]),
offer->desc.fmt_count, i);
--offer->desc.fmt_count;
} else {
++i;
}
}
/* Arrange format in the offer so the order match the priority
* in the answer
*/
for (i=0; i<answer->desc.fmt_count; ++i) {
unsigned j;
pj_str_t *fmt = &answer->desc.fmt[i];
for (j=i; j<offer->desc.fmt_count; ++j) {
if (pj_strcmp(fmt, &offer->desc.fmt[j])==0) {
str_swap(&offer->desc.fmt[i], &offer->desc.fmt[j]);
break;
}
}
}
}
/* Looks okay */
return PJ_SUCCESS;
}
/* Update media direction based on peer's media direction */
static void update_media_direction(pj_pool_t *pool,
const pjmedia_sdp_media *remote,
pjmedia_sdp_media *local)
{
pjmedia_dir old_dir = PJMEDIA_DIR_ENCODING_DECODING,
new_dir;
/* Get the media direction of local SDP */
if (pjmedia_sdp_media_find_attr2(local, "sendonly", NULL))
old_dir = PJMEDIA_DIR_ENCODING;
else if (pjmedia_sdp_media_find_attr2(local, "recvonly", NULL))
old_dir = PJMEDIA_DIR_DECODING;
else if (pjmedia_sdp_media_find_attr2(local, "inactive", NULL))
old_dir = PJMEDIA_DIR_NONE;
new_dir = old_dir;
/* Adjust local media direction based on remote media direction */
if (pjmedia_sdp_media_find_attr2(remote, "inactive", NULL) != NULL) {
/* If remote has "a=inactive", then local is inactive too */
new_dir = PJMEDIA_DIR_NONE;
} else if(pjmedia_sdp_media_find_attr2(remote, "sendonly", NULL) != NULL) {
/* If remote has "a=sendonly", then set local to "recvonly" if
* it is currently "sendrecv". Otherwise if local is NOT "recvonly",
* then set local direction to "inactive".
*/
switch (old_dir) {
case PJMEDIA_DIR_ENCODING_DECODING:
new_dir = PJMEDIA_DIR_DECODING;
break;
case PJMEDIA_DIR_DECODING:
/* No change */
break;
default:
new_dir = PJMEDIA_DIR_NONE;
break;
}
} else if(pjmedia_sdp_media_find_attr2(remote, "recvonly", NULL) != NULL) {
/* If remote has "a=recvonly", then set local to "sendonly" if
* it is currently "sendrecv". Otherwise if local is NOT "sendonly",
* then set local direction to "inactive"
*/
switch (old_dir) {
case PJMEDIA_DIR_ENCODING_DECODING:
new_dir = PJMEDIA_DIR_ENCODING;
break;
case PJMEDIA_DIR_ENCODING:
/* No change */
break;
default:
new_dir = PJMEDIA_DIR_NONE;
break;
}
} else {
/* Remote indicates "sendrecv" capability. No change to local
* direction
*/
}
if (new_dir != old_dir) {
pjmedia_sdp_attr *a = NULL;
remove_all_media_directions(local);
switch (new_dir) {
case PJMEDIA_DIR_NONE:
a = pjmedia_sdp_attr_create(pool, "inactive", NULL);
break;
case PJMEDIA_DIR_ENCODING:
a = pjmedia_sdp_attr_create(pool, "sendonly", NULL);
break;
case PJMEDIA_DIR_DECODING:
a = pjmedia_sdp_attr_create(pool, "recvonly", NULL);
break;
default:
/* sendrecv */
break;
}
if (a) {
pjmedia_sdp_media_add_attr(local, a);
}
}
}
PJ_DEF(pj_status_t) pjmedia_codec_amr_match_sdp( pj_pool_t *pool,
pjmedia_sdp_media *offer,
unsigned o_fmt_idx,
pjmedia_sdp_media *answer,
unsigned a_fmt_idx,
unsigned option)
{
/* Negotiated format-param field-names constants. */
const pj_str_t STR_OCTET_ALIGN = {"octet-align=", 12};
const pj_str_t STR_CRC = {"crc=", 4};
const pj_str_t STR_ROBUST_SORTING = {"robust-sorting=", 15};
const pj_str_t STR_INTERLEAVING = {"interleaving=", 13};
/* Negotiated params and their default values. */
unsigned a_octet_align = 0, o_octet_align = 0;
unsigned a_crc = 0, o_crc = 0;
unsigned a_robust_sorting = 0, o_robust_sorting = 0;
unsigned a_interleaving = 0, o_interleaving = 0;
const pjmedia_sdp_attr *attr_ans;
const pjmedia_sdp_attr *attr_ofr;
pjmedia_sdp_fmtp fmtp;
pj_status_t status;
/* Parse offerer FMTP */
attr_ofr = pjmedia_sdp_media_find_attr2(offer, "fmtp",
&offer->desc.fmt[o_fmt_idx]);
if (attr_ofr) {
status = pjmedia_sdp_attr_get_fmtp(attr_ofr, &fmtp);
if (status != PJ_SUCCESS)
return status;
GET_FMTP_IVAL(o_octet_align, fmtp, STR_OCTET_ALIGN, 0);
GET_FMTP_IVAL(o_crc, fmtp, STR_CRC, 0);
GET_FMTP_IVAL(o_robust_sorting, fmtp, STR_ROBUST_SORTING, 0);
GET_FMTP_IVAL(o_interleaving, fmtp, STR_INTERLEAVING, 0);
}
/* Parse answerer FMTP */
attr_ans = pjmedia_sdp_media_find_attr2(answer, "fmtp",
&answer->desc.fmt[a_fmt_idx]);
if (attr_ans) {
status = pjmedia_sdp_attr_get_fmtp(attr_ans, &fmtp);
if (status != PJ_SUCCESS)
return status;
GET_FMTP_IVAL(a_octet_align, fmtp, STR_OCTET_ALIGN, 0);
GET_FMTP_IVAL(a_crc, fmtp, STR_CRC, 0);
GET_FMTP_IVAL(a_robust_sorting, fmtp, STR_ROBUST_SORTING, 0);
GET_FMTP_IVAL(a_interleaving, fmtp, STR_INTERLEAVING, 0);
}
/* First, match crc, robust-sorting, interleaving settings */
if (a_crc != o_crc ||
a_robust_sorting != o_robust_sorting ||
a_interleaving != o_interleaving)
{
return PJMEDIA_SDP_EFORMATNOTEQUAL;
}
/* Match octet-align setting */
if (a_octet_align != o_octet_align) {
/* Check if answer can be modified to match to the offer */
if (option & PJMEDIA_SDP_NEG_FMT_MATCH_ALLOW_MODIFY_ANSWER) {
status = amr_toggle_octet_align(pool, answer, a_fmt_idx);
return status;
} else {
return PJMEDIA_SDP_EFORMATNOTEQUAL;
}
}
return PJ_SUCCESS;
}
/*
* Parse fmtp for specified format/payload type.
*/
static void parse_fmtp( pj_pool_t *pool,
const pjmedia_sdp_media *m,
unsigned pt,
pjmedia_codec_fmtp *fmtp)
{
const pjmedia_sdp_attr *attr;
pjmedia_sdp_fmtp sdp_fmtp;
char *p, *p_end, fmt_buf[8];
pj_str_t fmt;
pj_assert(m && fmtp);
pj_bzero(fmtp, sizeof(pjmedia_codec_fmtp));
/* Get "fmtp" attribute for the format */
pj_ansi_sprintf(fmt_buf, "%d", pt);
fmt = pj_str(fmt_buf);
attr = pjmedia_sdp_media_find_attr2(m, "fmtp", &fmt);
if (attr == NULL)
return;
/* Parse "fmtp" attribute */
if (pjmedia_sdp_attr_get_fmtp(attr, &sdp_fmtp) != PJ_SUCCESS)
return;
/* Prepare parsing */
p = sdp_fmtp.fmt_param.ptr;
p_end = p + sdp_fmtp.fmt_param.slen;
/* Parse */
while (p < p_end) {
char *token, *start, *end;
/* Skip whitespaces */
while (p < p_end && (*p == ' ' || *p == '\t')) ++p;
if (p == p_end)
break;
/* Get token */
start = p;
while (p < p_end && *p != ';' && *p != '=') ++p;
end = p - 1;
/* Right trim */
while (end >= start && (*end == ' ' || *end == '\t' ||
*end == '\r' || *end == '\n' ))
--end;
/* Forward a char after trimming */
++end;
/* Store token */
if (end > start) {
token = (char*)pj_pool_alloc(pool, end - start);
pj_ansi_strncpy(token, start, end - start);
if (*p == '=')
/* Got param name */
pj_strset(&fmtp->param[fmtp->cnt].name, token, end - start);
else
/* Got param value */
pj_strset(&fmtp->param[fmtp->cnt++].val, token, end - start);
} else if (*p != '=') {
++fmtp->cnt;
}
/* Next */
++p;
}
}
/* Negotiate AMR format params between offer and answer. Format params
* to be matched are: octet-align, crc, robust-sorting, interleaving,
* and channels (channels is negotiated by rtpmap line negotiation).
* Note: For answerer, octet-align mode setting is adaptable to offerer
* setting. In the case that octet-align mode need to be adjusted,
* pt_need_adapt will be set to the format ID.
*
*/
static pj_bool_t match_amr( const pjmedia_sdp_media *offer,
unsigned o_fmt_idx,
const pjmedia_sdp_media *answer,
unsigned a_fmt_idx,
pj_bool_t answerer,
pj_str_t *pt_need_adapt)
{
/* Negotiated format-param field-names constants. */
const pj_str_t STR_OCTET_ALIGN = {"octet-align=", 12};
const pj_str_t STR_CRC = {"crc=", 4};
const pj_str_t STR_ROBUST_SORTING = {"robust-sorting=", 15};
const pj_str_t STR_INTERLEAVING = {"interleaving=", 13};
/* Negotiated params and their default values. */
unsigned a_octet_align = 0, o_octet_align = 0;
unsigned a_crc = 0, o_crc = 0;
unsigned a_robust_sorting = 0, o_robust_sorting = 0;
unsigned a_interleaving = 0, o_interleaving = 0;
const pjmedia_sdp_attr *attr_ans;
const pjmedia_sdp_attr *attr_ofr;
pjmedia_sdp_fmtp fmtp;
pj_bool_t match;
/* Parse offerer FMTP */
attr_ofr = pjmedia_sdp_media_find_attr2(offer, "fmtp",
&offer->desc.fmt[o_fmt_idx]);
if (attr_ofr) {
if (pjmedia_sdp_attr_get_fmtp(attr_ofr, &fmtp) != PJ_SUCCESS)
/* Invalid fmtp format. */
return PJ_FALSE;
GET_FMTP_IVAL(o_octet_align, fmtp, STR_OCTET_ALIGN, 0);
GET_FMTP_IVAL(o_crc, fmtp, STR_CRC, 0);
GET_FMTP_IVAL(o_robust_sorting, fmtp, STR_ROBUST_SORTING, 0);
GET_FMTP_IVAL(o_interleaving, fmtp, STR_INTERLEAVING, 0);
}
/* Parse answerer FMTP */
attr_ans = pjmedia_sdp_media_find_attr2(answer, "fmtp",
&answer->desc.fmt[a_fmt_idx]);
if (attr_ans) {
if (pjmedia_sdp_attr_get_fmtp(attr_ans, &fmtp) != PJ_SUCCESS)
/* Invalid fmtp format. */
return PJ_FALSE;
GET_FMTP_IVAL(a_octet_align, fmtp, STR_OCTET_ALIGN, 0);
GET_FMTP_IVAL(a_crc, fmtp, STR_CRC, 0);
GET_FMTP_IVAL(a_robust_sorting, fmtp, STR_ROBUST_SORTING, 0);
GET_FMTP_IVAL(a_interleaving, fmtp, STR_INTERLEAVING, 0);
}
if (answerer) {
match = a_crc == o_crc &&
a_robust_sorting == o_robust_sorting &&
a_interleaving == o_interleaving;
/* If answerer octet-align setting doesn't match to the offerer's,
* set pt_need_adapt to this media format ID to signal the caller
* that this format ID needs to be adjusted.
*/
if (a_octet_align != o_octet_align && match) {
pj_assert(pt_need_adapt != NULL);
*pt_need_adapt = answer->desc.fmt[a_fmt_idx];
}
} else {
match = (a_octet_align == o_octet_align &&
a_crc == o_crc &&
a_robust_sorting == o_robust_sorting &&
a_interleaving == o_interleaving);
}
return match;
}
static void get_codecs(struct ast_sip_session *session, const struct pjmedia_sdp_media *stream, struct ast_rtp_codecs *codecs,
struct ast_sip_session_media *session_media)
{
pjmedia_sdp_attr *attr;
pjmedia_sdp_rtpmap *rtpmap;
pjmedia_sdp_fmtp fmtp;
struct ast_format *format;
int i, num = 0, tel_event = 0;
char name[256];
char media[20];
char fmt_param[256];
enum ast_rtp_options options = session->endpoint->media.g726_non_standard ?
AST_RTP_OPT_G726_NONSTANDARD : 0;
ast_rtp_codecs_payloads_initialize(codecs);
/* Iterate through provided formats */
for (i = 0; i < stream->desc.fmt_count; ++i) {
/* The payload is kept as a string for things like t38 but for video it is always numerical */
ast_rtp_codecs_payloads_set_m_type(codecs, NULL, pj_strtoul(&stream->desc.fmt[i]));
/* Look for the optional rtpmap attribute */
if (!(attr = pjmedia_sdp_media_find_attr2(stream, "rtpmap", &stream->desc.fmt[i]))) {
continue;
}
/* Interpret the attribute as an rtpmap */
if ((pjmedia_sdp_attr_to_rtpmap(session->inv_session->pool_prov, attr, &rtpmap)) != PJ_SUCCESS) {
continue;
}
ast_copy_pj_str(name, &rtpmap->enc_name, sizeof(name));
if (strcmp(name,"telephone-event") == 0) {
tel_event++;
}
ast_copy_pj_str(media, (pj_str_t*)&stream->desc.media, sizeof(media));
ast_rtp_codecs_payloads_set_rtpmap_type_rate(codecs, NULL, pj_strtoul(&stream->desc.fmt[i]),
media, name, options, rtpmap->clock_rate);
/* Look for an optional associated fmtp attribute */
if (!(attr = pjmedia_sdp_media_find_attr2(stream, "fmtp", &rtpmap->pt))) {
continue;
}
if ((pjmedia_sdp_attr_get_fmtp(attr, &fmtp)) == PJ_SUCCESS) {
ast_copy_pj_str(fmt_param, &fmtp.fmt, sizeof(fmt_param));
if (sscanf(fmt_param, "%30d", &num) != 1) {
continue;
}
if ((format = ast_rtp_codecs_get_payload_format(codecs, num))) {
struct ast_format *format_parsed;
ast_copy_pj_str(fmt_param, &fmtp.fmt_param, sizeof(fmt_param));
format_parsed = ast_format_parse_sdp_fmtp(format, fmt_param);
if (format_parsed) {
ast_rtp_codecs_payload_replace_format(codecs, num, format_parsed);
ao2_ref(format_parsed, -1);
}
ao2_ref(format, -1);
}
}
}
if ((tel_event==0) && (session->endpoint->dtmf == AST_SIP_DTMF_AUTO)) {
ast_rtp_instance_dtmf_mode_set(session_media->rtp, AST_RTP_DTMF_MODE_INBAND);
}
/* Get the packetization, if it exists */
if ((attr = pjmedia_sdp_media_find_attr2(stream, "ptime", NULL))) {
unsigned long framing = pj_strtoul(pj_strltrim(&attr->value));
if (framing && session->endpoint->media.rtp.use_ptime) {
ast_rtp_codecs_set_framing(codecs, framing);
}
}
}
/* Try to match offer with answer. */
static pj_status_t match_offer(pj_pool_t *pool,
pj_bool_t prefer_remote_codec_order,
pj_bool_t answer_with_multiple_codecs,
const pjmedia_sdp_media *offer,
const pjmedia_sdp_media *preanswer,
const pjmedia_sdp_session *preanswer_sdp,
pjmedia_sdp_media **p_answer)
{
unsigned i;
pj_bool_t master_has_codec = 0,
master_has_other = 0,
found_matching_codec = 0,
found_matching_telephone_event = 0,
found_matching_other = 0;
unsigned pt_answer_count = 0;
pj_str_t pt_answer[PJMEDIA_MAX_SDP_FMT];
pj_str_t pt_offer[PJMEDIA_MAX_SDP_FMT];
pjmedia_sdp_media *answer;
const pjmedia_sdp_media *master, *slave;
/* If offer has zero port, just clone the offer */
if (offer->desc.port == 0) {
answer = sdp_media_clone_deactivate(pool, offer, preanswer,
preanswer_sdp);
*p_answer = answer;
return PJ_SUCCESS;
}
/* If the preanswer define zero port, this media is being rejected,
* just clone the preanswer.
*/
if (preanswer->desc.port == 0) {
answer = pjmedia_sdp_media_clone(pool, preanswer);
*p_answer = answer;
return PJ_SUCCESS;
}
/* Set master/slave negotiator based on prefer_remote_codec_order. */
if (prefer_remote_codec_order) {
master = offer;
slave = preanswer;
} else {
master = preanswer;
slave = offer;
}
/* With the addition of telephone-event and dodgy MS RTC SDP,
* the answer generation algorithm looks really shitty...
*/
for (i=0; i<master->desc.fmt_count; ++i) {
unsigned j;
if (pj_isdigit(*master->desc.fmt[i].ptr)) {
/* This is normal/standard payload type, where it's identified
* by payload number.
*/
unsigned pt;
pt = pj_strtoul(&master->desc.fmt[i]);
if (pt < 96) {
/* For static payload type, it's enough to compare just
* the payload number.
*/
master_has_codec = 1;
/* We just need to select one codec if not allowing multiple.
* Continue if we have selected matching codec for previous
* payload.
*/
if (!answer_with_multiple_codecs && found_matching_codec)
continue;
/* Find matching codec in local descriptor. */
for (j=0; j<slave->desc.fmt_count; ++j) {
unsigned p;
p = pj_strtoul(&slave->desc.fmt[j]);
if (p == pt && pj_isdigit(*slave->desc.fmt[j].ptr)) {
found_matching_codec = 1;
pt_offer[pt_answer_count] = slave->desc.fmt[j];
pt_answer[pt_answer_count++] = slave->desc.fmt[j];
break;
}
}
} else {
/* This is dynamic payload type.
* For dynamic payload type, we must look the rtpmap and
* compare the encoding name.
*/
const pjmedia_sdp_attr *a;
pjmedia_sdp_rtpmap or_;
pj_bool_t is_codec;
/* Get the rtpmap for the payload type in the master. */
a = pjmedia_sdp_media_find_attr2(master, "rtpmap",
&master->desc.fmt[i]);
if (!a) {
pj_assert(!"Bug! Offer should have been validated");
return PJMEDIA_SDP_EMISSINGRTPMAP;
}
pjmedia_sdp_attr_get_rtpmap(a, &or_);
if (!pj_stricmp2(&or_.enc_name, "telephone-event")) {
if (found_matching_telephone_event)
continue;
is_codec = 0;
} else {
master_has_codec = 1;
if (!answer_with_multiple_codecs && found_matching_codec)
continue;
is_codec = 1;
}
/* Find paylaod in our initial SDP with matching
* encoding name and clock rate.
*/
for (j=0; j<slave->desc.fmt_count; ++j) {
a = pjmedia_sdp_media_find_attr2(slave, "rtpmap",
&slave->desc.fmt[j]);
if (a) {
pjmedia_sdp_rtpmap lr;
pjmedia_sdp_attr_get_rtpmap(a, &lr);
/* See if encoding name, clock rate, and
* channel count match
*/
if (!pj_stricmp(&or_.enc_name, &lr.enc_name) &&
or_.clock_rate == lr.clock_rate &&
(pj_stricmp(&or_.param, &lr.param)==0 ||
(lr.param.slen==0 && or_.param.slen==1 &&
*or_.param.ptr=='1') ||
(or_.param.slen==0 && lr.param.slen==1 &&
*lr.param.ptr=='1')))
{
/* Match! */
if (is_codec) {
pjmedia_sdp_media *o_med, *a_med;
unsigned o_fmt_idx, a_fmt_idx;
o_med = (pjmedia_sdp_media*)offer;
a_med = (pjmedia_sdp_media*)preanswer;
o_fmt_idx = prefer_remote_codec_order? i:j;
a_fmt_idx = prefer_remote_codec_order? j:i;
/* Call custom format matching callbacks */
if (custom_fmt_match(pool, &or_.enc_name,
o_med, o_fmt_idx,
a_med, a_fmt_idx,
ALLOW_MODIFY_ANSWER) !=
PJ_SUCCESS)
{
continue;
}
found_matching_codec = 1;
} else {
found_matching_telephone_event = 1;
}
pt_offer[pt_answer_count] =
prefer_remote_codec_order?
offer->desc.fmt[i]:
offer->desc.fmt[j];
pt_answer[pt_answer_count++] =
prefer_remote_codec_order?
preanswer->desc.fmt[j]:
preanswer->desc.fmt[i];
break;
}
}
}
}
} else {
/* This is a non-standard, brain damaged SDP where the payload
* type is non-numeric. It exists e.g. in Microsoft RTC based
* UA, to indicate instant messaging capability.
* Example:
* - m=x-ms-message 5060 sip null
*/
master_has_other = 1;
if (found_matching_other)
continue;
for (j=0; j<slave->desc.fmt_count; ++j) {
if (!pj_strcmp(&master->desc.fmt[i], &slave->desc.fmt[j])) {
/* Match */
found_matching_other = 1;
pt_offer[pt_answer_count] = prefer_remote_codec_order?
offer->desc.fmt[i]:
offer->desc.fmt[j];
pt_answer[pt_answer_count++] = prefer_remote_codec_order?
preanswer->desc.fmt[j]:
preanswer->desc.fmt[i];
break;
}
}
}
}
/* See if all types of master can be matched. */
if (master_has_codec && !found_matching_codec) {
return PJMEDIA_SDPNEG_NOANSCODEC;
}
/* If this comment is removed, negotiation will fail if remote has offered
telephone-event and local is not configured with telephone-event
if (offer_has_telephone_event && !found_matching_telephone_event) {
return PJMEDIA_SDPNEG_NOANSTELEVENT;
}
*/
if (master_has_other && !found_matching_other) {
return PJMEDIA_SDPNEG_NOANSUNKNOWN;
}
/* Seems like everything is in order.
* Build the answer by cloning from preanswer, but rearrange the payload
* to suit the offer.
*/
answer = pjmedia_sdp_media_clone(pool, preanswer);
for (i=0; i<pt_answer_count; ++i) {
unsigned j;
for (j=i; j<answer->desc.fmt_count; ++j) {
if (!pj_strcmp(&answer->desc.fmt[j], &pt_answer[i]))
break;
}
pj_assert(j != answer->desc.fmt_count);
str_swap(&answer->desc.fmt[i], &answer->desc.fmt[j]);
}
/* Remove unwanted local formats. */
for (i=pt_answer_count; i<answer->desc.fmt_count; ++i) {
pjmedia_sdp_attr *a;
/* Remove rtpmap for this format */
a = pjmedia_sdp_media_find_attr2(answer, "rtpmap",
&answer->desc.fmt[i]);
if (a) {
pjmedia_sdp_media_remove_attr(answer, a);
}
/* Remove fmtp for this format */
a = pjmedia_sdp_media_find_attr2(answer, "fmtp",
&answer->desc.fmt[i]);
if (a) {
pjmedia_sdp_media_remove_attr(answer, a);
}
}
answer->desc.fmt_count = pt_answer_count;
#if PJMEDIA_SDP_NEG_ANSWER_SYMMETRIC_PT
apply_answer_symmetric_pt(pool, answer, pt_answer_count,
pt_offer, pt_answer);
#endif
/* Update media direction. */
update_media_direction(pool, offer, answer);
*p_answer = answer;
return PJ_SUCCESS;
}
/*! \brief Function which processes ICE attributes in an audio stream */
static void process_ice_attributes(struct ast_sip_session *session, struct ast_sip_session_media *session_media,
const struct pjmedia_sdp_session *remote, const struct pjmedia_sdp_media *remote_stream)
{
struct ast_rtp_engine_ice *ice;
const pjmedia_sdp_attr *attr;
char attr_value[256];
unsigned int attr_i;
/* If ICE support is not enabled or available exit early */
if (!session->endpoint->media.rtp.ice_support || !(ice = ast_rtp_instance_get_ice(session_media->rtp))) {
return;
}
attr = pjmedia_sdp_media_find_attr2(remote_stream, "ice-ufrag", NULL);
if (!attr) {
attr = pjmedia_sdp_attr_find2(remote->attr_count, remote->attr, "ice-ufrag", NULL);
}
if (attr) {
ast_copy_pj_str(attr_value, (pj_str_t*)&attr->value, sizeof(attr_value));
ice->set_authentication(session_media->rtp, attr_value, NULL);
} else {
return;
}
attr = pjmedia_sdp_media_find_attr2(remote_stream, "ice-pwd", NULL);
if (!attr) {
attr = pjmedia_sdp_attr_find2(remote->attr_count, remote->attr, "ice-pwd", NULL);
}
if (attr) {
ast_copy_pj_str(attr_value, (pj_str_t*)&attr->value, sizeof(attr_value));
ice->set_authentication(session_media->rtp, NULL, attr_value);
} else {
return;
}
if (pjmedia_sdp_media_find_attr2(remote_stream, "ice-lite", NULL)) {
ice->ice_lite(session_media->rtp);
}
/* Find all of the candidates */
for (attr_i = 0; attr_i < remote_stream->attr_count; ++attr_i) {
char foundation[32], transport[32], address[PJ_INET6_ADDRSTRLEN + 1], cand_type[6], relay_address[PJ_INET6_ADDRSTRLEN + 1] = "";
unsigned int port, relay_port = 0;
struct ast_rtp_engine_ice_candidate candidate = { 0, };
attr = remote_stream->attr[attr_i];
/* If this is not a candidate line skip it */
if (pj_strcmp2(&attr->name, "candidate")) {
continue;
}
ast_copy_pj_str(attr_value, (pj_str_t*)&attr->value, sizeof(attr_value));
if (sscanf(attr_value, "%31s %30u %31s %30u %46s %30u typ %5s %*s %23s %*s %30u", foundation, &candidate.id, transport,
(unsigned *)&candidate.priority, address, &port, cand_type, relay_address, &relay_port) < 7) {
/* Candidate did not parse properly */
continue;
}
candidate.foundation = foundation;
candidate.transport = transport;
ast_sockaddr_parse(&candidate.address, address, PARSE_PORT_FORBID);
ast_sockaddr_set_port(&candidate.address, port);
if (!strcasecmp(cand_type, "host")) {
candidate.type = AST_RTP_ICE_CANDIDATE_TYPE_HOST;
} else if (!strcasecmp(cand_type, "srflx")) {
candidate.type = AST_RTP_ICE_CANDIDATE_TYPE_SRFLX;
} else if (!strcasecmp(cand_type, "relay")) {
candidate.type = AST_RTP_ICE_CANDIDATE_TYPE_RELAYED;
} else {
continue;
}
if (!ast_strlen_zero(relay_address)) {
ast_sockaddr_parse(&candidate.relay_address, relay_address, PARSE_PORT_FORBID);
}
if (relay_port) {
ast_sockaddr_set_port(&candidate.relay_address, relay_port);
}
ice->add_remote_candidate(session_media->rtp, &candidate);
}
ice->set_role(session_media->rtp, pjmedia_sdp_neg_was_answer_remote(session->inv_session->neg) == PJ_TRUE ?
AST_RTP_ICE_ROLE_CONTROLLING : AST_RTP_ICE_ROLE_CONTROLLED);
ice->start(session_media->rtp);
}
/* Update single local media description to after receiving answer
* from remote.
*/
static pj_status_t process_m_answer( pj_pool_t *pool,
pjmedia_sdp_media *offer,
pjmedia_sdp_media *answer,
pj_bool_t allow_asym)
{
unsigned i;
/* Check that the media type match our offer. */
if (pj_strcmp(&answer->desc.media, &offer->desc.media)!=0) {
/* The media type in the answer is different than the offer! */
return PJMEDIA_SDPNEG_EINVANSMEDIA;
}
/* Check that transport in the answer match our offer. */
/* At this point, transport type must be compatible,
* the transport instance will do more validation later.
*/
if (pjmedia_sdp_transport_cmp(&answer->desc.transport,
&offer->desc.transport)
!= PJ_SUCCESS)
{
return PJMEDIA_SDPNEG_EINVANSTP;
}
/* Check if remote has rejected our offer */
if (answer->desc.port == 0) {
/* Remote has rejected our offer.
* Deactivate our media too.
*/
pjmedia_sdp_media_deactivate(pool, offer);
/* Don't need to proceed */
return PJ_SUCCESS;
}
/* Ticket #1148: check if remote answer does not set port to zero when
* offered with port zero. Let's just tolerate it.
*/
if (offer->desc.port == 0) {
/* Don't need to proceed */
return PJ_SUCCESS;
}
/* Process direction attributes */
update_media_direction(pool, answer, offer);
/* If asymetric media is allowed, then just check that remote answer has
* codecs that are within the offer.
*
* Otherwise if asymetric media is not allowed, then we will choose only
* one codec in our initial offer to match the answer.
*/
if (allow_asym) {
for (i=0; i<answer->desc.fmt_count; ++i) {
unsigned j;
pj_str_t *rem_fmt = &answer->desc.fmt[i];
for (j=0; j<offer->desc.fmt_count; ++j) {
if (pj_strcmp(rem_fmt, &answer->desc.fmt[j])==0)
break;
}
if (j != offer->desc.fmt_count) {
/* Found at least one common codec. */
break;
}
}
if (i == answer->desc.fmt_count) {
/* No common codec in the answer! */
return PJMEDIA_SDPNEG_EANSNOMEDIA;
}
PJ_TODO(CHECK_SDP_NEGOTIATION_WHEN_ASYMETRIC_MEDIA_IS_ALLOWED);
} else {
/* Offer format priority based on answer format index/priority */
unsigned offer_fmt_prior[PJMEDIA_MAX_SDP_FMT];
/* Remove all format in the offer that has no matching answer */
for (i=0; i<offer->desc.fmt_count;) {
unsigned pt;
pj_uint32_t j;
pj_str_t *fmt = &offer->desc.fmt[i];
/* Find matching answer */
pt = pj_strtoul(fmt);
if (pt < 96) {
for (j=0; j<answer->desc.fmt_count; ++j) {
if (pj_strcmp(fmt, &answer->desc.fmt[j])==0)
break;
}
} else {
/* This is dynamic payload type.
* For dynamic payload type, we must look the rtpmap and
* compare the encoding name.
*/
const pjmedia_sdp_attr *a;
pjmedia_sdp_rtpmap or_;
/* Get the rtpmap for the payload type in the offer. */
a = pjmedia_sdp_media_find_attr2(offer, "rtpmap", fmt);
if (!a) {
pj_assert(!"Bug! Offer should have been validated");
return PJ_EBUG;
}
pjmedia_sdp_attr_get_rtpmap(a, &or_);
/* Find paylaod in answer SDP with matching
* encoding name and clock rate.
*/
for (j=0; j<answer->desc.fmt_count; ++j) {
a = pjmedia_sdp_media_find_attr2(answer, "rtpmap",
&answer->desc.fmt[j]);
if (a) {
pjmedia_sdp_rtpmap ar;
pjmedia_sdp_attr_get_rtpmap(a, &ar);
/* See if encoding name, clock rate, and channel
* count match
*/
if (!pj_stricmp(&or_.enc_name, &ar.enc_name) &&
or_.clock_rate == ar.clock_rate &&
(pj_stricmp(&or_.param, &ar.param)==0 ||
(ar.param.slen==1 && *ar.param.ptr=='1')))
{
/* Call custom format matching callbacks */
if (custom_fmt_match(pool, &or_.enc_name,
offer, i, answer, j, 0) ==
PJ_SUCCESS)
{
/* Match! */
break;
}
}
}
}
}
if (j == answer->desc.fmt_count) {
/* This format has no matching answer.
* Remove it from our offer.
*/
pjmedia_sdp_attr *a;
/* Remove rtpmap associated with this format */
a = pjmedia_sdp_media_find_attr2(offer, "rtpmap", fmt);
if (a)
pjmedia_sdp_media_remove_attr(offer, a);
/* Remove fmtp associated with this format */
a = pjmedia_sdp_media_find_attr2(offer, "fmtp", fmt);
if (a)
pjmedia_sdp_media_remove_attr(offer, a);
/* Remove this format from offer's array */
pj_array_erase(offer->desc.fmt, sizeof(offer->desc.fmt[0]),
offer->desc.fmt_count, i);
--offer->desc.fmt_count;
} else {
offer_fmt_prior[i] = j;
++i;
}
}
if (0 == offer->desc.fmt_count) {
/* No common codec in the answer! */
return PJMEDIA_SDPNEG_EANSNOMEDIA;
}
/* Post process:
* - Resort offer formats so the order match to the answer.
* - Remove answer formats that unmatches to the offer.
*/
/* Resort offer formats */
for (i=0; i<offer->desc.fmt_count; ++i) {
unsigned j;
for (j=i+1; j<offer->desc.fmt_count; ++j) {
if (offer_fmt_prior[i] > offer_fmt_prior[j]) {
unsigned tmp = offer_fmt_prior[i];
offer_fmt_prior[i] = offer_fmt_prior[j];
offer_fmt_prior[j] = tmp;
str_swap(&offer->desc.fmt[i], &offer->desc.fmt[j]);
}
}
}
/* Remove unmatched answer formats */
{
unsigned del_cnt = 0;
for (i=0; i<answer->desc.fmt_count;) {
/* The offer is ordered now, also the offer_fmt_prior */
if (i >= offer->desc.fmt_count ||
offer_fmt_prior[i]-del_cnt != i)
{
pj_str_t *fmt = &answer->desc.fmt[i];
pjmedia_sdp_attr *a;
/* Remove rtpmap associated with this format */
a = pjmedia_sdp_media_find_attr2(answer, "rtpmap", fmt);
if (a)
pjmedia_sdp_media_remove_attr(answer, a);
/* Remove fmtp associated with this format */
a = pjmedia_sdp_media_find_attr2(answer, "fmtp", fmt);
if (a)
pjmedia_sdp_media_remove_attr(answer, a);
/* Remove this format from answer's array */
pj_array_erase(answer->desc.fmt,
sizeof(answer->desc.fmt[0]),
answer->desc.fmt_count, i);
--answer->desc.fmt_count;
++del_cnt;
} else {
++i;
}
}
}
}
/* Looks okay */
return PJ_SUCCESS;
}
