/* Check that the pair in both agents are matched */
static int check_pair(const struct ice_ept *ept1, const struct ice_ept *ept2,
int start_err)
{
unsigned i, min_cnt, max_cnt;
if (ept1->cfg.comp_cnt < ept2->cfg.comp_cnt) {
min_cnt = ept1->cfg.comp_cnt;
max_cnt = ept2->cfg.comp_cnt;
} else {
min_cnt = ept2->cfg.comp_cnt;
max_cnt = ept1->cfg.comp_cnt;
}
/* Must have valid pair for common components */
for (i=0; i<min_cnt; ++i) {
const pj_ice_sess_check *c1;
const pj_ice_sess_check *c2;
c1 = pj_ice_strans_get_valid_pair(ept1->ice, i+1);
if (c1 == NULL) {
PJ_LOG(3,("", INDENT "err: unable to get valid pair for ice1 "
"component %d", i+1));
return start_err - 2;
}
c2 = pj_ice_strans_get_valid_pair(ept2->ice, i+1);
if (c2 == NULL) {
PJ_LOG(3,("", INDENT "err: unable to get valid pair for ice2 "
"component %d", i+1));
return start_err - 4;
}
if (pj_sockaddr_cmp(&c1->rcand->addr, &c2->lcand->addr) != 0) {
PJ_LOG(3,("", INDENT "err: candidate pair does not match "
"for component %d", i+1));
return start_err - 6;
}
}
/* Extra components must not have valid pair */
for (; i<max_cnt; ++i) {
if (ept1->cfg.comp_cnt>i &&
pj_ice_strans_get_valid_pair(ept1->ice, i+1) != NULL)
{
PJ_LOG(3,("", INDENT "err: ice1 shouldn't have valid pair "
"for component %d", i+1));
return start_err - 8;
}
if (ept2->cfg.comp_cnt>i &&
pj_ice_strans_get_valid_pair(ept2->ice, i+1) != NULL)
{
PJ_LOG(3,("", INDENT "err: ice2 shouldn't have valid pair "
"for component %d", i+1));
return start_err - 9;
}
}
return 0;
}
/* Encode ICE information in SDP */
static pj_status_t encode_session_in_sdp(struct transport_ice *tp_ice,
pj_pool_t *sdp_pool,
pjmedia_sdp_session *sdp_local,
unsigned media_index,
unsigned comp_cnt,
pj_bool_t restart_session)
{
enum {
ATTR_BUF_LEN = 160, /* Max len of a=candidate attr */
RATTR_BUF_LEN= 160 /* Max len of a=remote-candidates attr */
};
pjmedia_sdp_media *m = sdp_local->media[media_index];
pj_str_t local_ufrag, local_pwd;
pjmedia_sdp_attr *attr;
pj_status_t status;
/* Must have a session */
PJ_ASSERT_RETURN(pj_ice_strans_has_sess(tp_ice->ice_st), PJ_EBUG);
/* Get ufrag and pwd from current session */
pj_ice_strans_get_ufrag_pwd(tp_ice->ice_st, &local_ufrag, &local_pwd,
NULL, NULL);
/* The listing of candidates depends on whether ICE has completed
* or not. When ICE has completed:
*
* 9.1.2.2: Existing Media Streams with ICE Completed
* The agent MUST include a candidate attributes for candidates
* matching the default destination for each component of the
* media stream, and MUST NOT include any other candidates.
*
* When ICE has not completed, we shall include all candidates.
*
* Except when we have detected that remote is offering to restart
* the session, in this case we will answer with full ICE SDP and
* new ufrag/pwd pair.
*/
if (!restart_session && pj_ice_strans_sess_is_complete(tp_ice->ice_st)) {
const pj_ice_sess_check *check;
char *attr_buf;
pjmedia_sdp_conn *conn;
pjmedia_sdp_attr *a_rtcp;
pj_str_t rem_cand;
unsigned comp;
/* Encode ice-ufrag attribute */
attr = pjmedia_sdp_attr_create(sdp_pool, STR_ICE_UFRAG.ptr,
&local_ufrag);
pjmedia_sdp_attr_add(&m->attr_count, m->attr, attr);
/* Encode ice-pwd attribute */
attr = pjmedia_sdp_attr_create(sdp_pool, STR_ICE_PWD.ptr,
&local_pwd);
pjmedia_sdp_attr_add(&m->attr_count, m->attr, attr);
/* Prepare buffer */
attr_buf = (char*) pj_pool_alloc(sdp_pool, ATTR_BUF_LEN);
rem_cand.ptr = (char*) pj_pool_alloc(sdp_pool, RATTR_BUF_LEN);
rem_cand.slen = 0;
/* 9.1.2.2: Existing Media Streams with ICE Completed
* The default destination for media (i.e., the values of
* the IP addresses and ports in the m and c line used for
* that media stream) MUST be the local candidate from the
* highest priority nominated pair in the valid list for each
* component.
*/
check = pj_ice_strans_get_valid_pair(tp_ice->ice_st, 1);
if (check == NULL) {
pj_assert(!"Shouldn't happen");
return PJ_EBUG;
}
/* Override connection line address and media port number */
conn = m->conn;
if (conn == NULL)
conn = sdp_local->conn;
conn->addr.ptr = (char*) pj_pool_alloc(sdp_pool,
PJ_INET6_ADDRSTRLEN);
pj_sockaddr_print(&check->lcand->addr, conn->addr.ptr,
PJ_INET6_ADDRSTRLEN, 0);
conn->addr.slen = pj_ansi_strlen(conn->addr.ptr);
m->desc.port = pj_sockaddr_get_port(&check->lcand->addr);
/* Override address RTCP attribute if it's present */
if (comp_cnt == 2 &&
(check = pj_ice_strans_get_valid_pair(tp_ice->ice_st,
COMP_RTCP)) != NULL &&
(a_rtcp = pjmedia_sdp_attr_find(m->attr_count, m->attr,
&STR_RTCP, 0)) != NULL)
{
pjmedia_sdp_attr_remove(&m->attr_count, m->attr, a_rtcp);
a_rtcp = pjmedia_sdp_attr_create_rtcp(sdp_pool,
&check->lcand->addr);
if (a_rtcp)
pjmedia_sdp_attr_add(&m->attr_count, m->attr, a_rtcp);
}
/* Encode only candidates matching the default destination
* for each component
*/
for (comp=0; comp < comp_cnt; ++comp) {
int len;
pj_str_t value;
/* Get valid pair for this component */
check = pj_ice_strans_get_valid_pair(tp_ice->ice_st, comp+1);
if (check == NULL)
continue;
/* Print and add local candidate in the pair */
value.ptr = attr_buf;
value.slen = print_sdp_cand_attr(attr_buf, ATTR_BUF_LEN,
check->lcand);
if (value.slen < 0) {
pj_assert(!"Not enough attr_buf to print candidate");
return PJ_EBUG;
}
attr = pjmedia_sdp_attr_create(sdp_pool, STR_CANDIDATE.ptr,
&value);
pjmedia_sdp_attr_add(&m->attr_count, m->attr, attr);
/* Append to a=remote-candidates attribute */
if (pj_ice_strans_get_role(tp_ice->ice_st) ==
PJ_ICE_SESS_ROLE_CONTROLLING)
{
char rem_addr[PJ_INET6_ADDRSTRLEN];
pj_sockaddr_print(&check->rcand->addr, rem_addr,
sizeof(rem_addr), 0);
len = pj_ansi_snprintf(
rem_cand.ptr + rem_cand.slen,
RATTR_BUF_LEN - rem_cand.slen,
"%s%u %s %u",
(rem_cand.slen==0? "" : " "),
comp+1, rem_addr,
pj_sockaddr_get_port(&check->rcand->addr)
);
if (len < 1 || len >= RATTR_BUF_LEN) {
pj_assert(!"Not enough buffer to print "
"remote-candidates");
return PJ_EBUG;
}
rem_cand.slen += len;
}
}
/* 9.1.2.2: Existing Media Streams with ICE Completed
* In addition, if the agent is controlling, it MUST include
* the a=remote-candidates attribute for each media stream
* whose check list is in the Completed state. The attribute
* contains the remote candidates from the highest priority
* nominated pair in the valid list for each component of that
* media stream.
*/
if (pj_ice_strans_get_role(tp_ice->ice_st) ==
PJ_ICE_SESS_ROLE_CONTROLLING)
{
attr = pjmedia_sdp_attr_create(sdp_pool, STR_REM_CAND.ptr,
&rem_cand);
pjmedia_sdp_attr_add(&m->attr_count, m->attr, attr);
}
} else if (pj_ice_strans_has_sess(tp_ice->ice_st)) {
/* Encode all candidates to SDP media */
char *attr_buf;
unsigned comp;
/* If ICE is not restarted, encode current ICE ufrag/pwd.
* Otherwise generate new one.
*/
if (!restart_session) {
attr = pjmedia_sdp_attr_create(sdp_pool, STR_ICE_UFRAG.ptr,
&local_ufrag);
pjmedia_sdp_attr_add(&m->attr_count, m->attr, attr);
attr = pjmedia_sdp_attr_create(sdp_pool, STR_ICE_PWD.ptr,
&local_pwd);
pjmedia_sdp_attr_add(&m->attr_count, m->attr, attr);
} else {
pj_str_t str;
str.slen = PJ_ICE_UFRAG_LEN;
str.ptr = (char*) pj_pool_alloc(sdp_pool, str.slen);
pj_create_random_string(str.ptr, str.slen);
attr = pjmedia_sdp_attr_create(sdp_pool, STR_ICE_UFRAG.ptr, &str);
pjmedia_sdp_attr_add(&m->attr_count, m->attr, attr);
str.ptr = (char*) pj_pool_alloc(sdp_pool, str.slen);
pj_create_random_string(str.ptr, str.slen);
attr = pjmedia_sdp_attr_create(sdp_pool, STR_ICE_PWD.ptr, &str);
pjmedia_sdp_attr_add(&m->attr_count, m->attr, attr);
}
/* Create buffer to encode candidates as SDP attribute */
attr_buf = (char*) pj_pool_alloc(sdp_pool, ATTR_BUF_LEN);
for (comp=0; comp < comp_cnt; ++comp) {
unsigned cand_cnt;
pj_ice_sess_cand cand[PJ_ICE_ST_MAX_CAND];
unsigned i;
cand_cnt = PJ_ARRAY_SIZE(cand);
status = pj_ice_strans_enum_cands(tp_ice->ice_st, comp+1,
&cand_cnt, cand);
if (status != PJ_SUCCESS)
return status;
for (i=0; i<cand_cnt; ++i) {
pj_str_t value;
value.slen = print_sdp_cand_attr(attr_buf, ATTR_BUF_LEN,
&cand[i]);
if (value.slen < 0) {
pj_assert(!"Not enough attr_buf to print candidate");
return PJ_EBUG;
}
value.ptr = attr_buf;
attr = pjmedia_sdp_attr_create(sdp_pool,
STR_CANDIDATE.ptr,
&value);
pjmedia_sdp_attr_add(&m->attr_count, m->attr, attr);
}
}
} else {
/* ICE has failed, application should have terminated this call */
}
/* Removing a=rtcp line when there is only one component. */
if (comp_cnt == 1) {
attr = pjmedia_sdp_attr_find(m->attr_count, m->attr, &STR_RTCP, NULL);
if (attr)
pjmedia_sdp_attr_remove(&m->attr_count, m->attr, attr);
}
return PJ_SUCCESS;
}
