示例#1
0
static int extract_sdp_to_xml(struct ice_trans_s* icetrans,char buffer[], unsigned maxlen, ice_option_t opt, char *usrid)
{
    char *p = buffer;
    unsigned comp;
    int printed;
    pj_str_t local_ufrag, local_pwd;
    pj_status_t status;

    //Me: add

    PRINT(" <registerPeer>");
    PRINT("<device> <uniqueId>%s</uniqueId> </device>", usrid);



    /* Write "dummy" SDP v=, o=, s=, and t= lines */
    // Me: comment
    //PRINT("v=0\no=- 3414953978 3414953978 IN IP4 localhost\ns=ice\nt=0 0\n");

    /* Get ufrag and pwd from current session */
    pj_ice_strans_get_ufrag_pwd(icetrans->icest, &local_ufrag, &local_pwd,
                                NULL, NULL);


    /* Write the a=ice-ufrag and a=ice-pwd attributes */
    // Me: comment
    //PRINT("a=ice-ufrag:%.*s\na=ice-pwd:%.*s\n",
    //      (int)local_ufrag.slen,
    //      local_ufrag.ptr,
    //      (int)local_pwd.slen,
    //      local_pwd.ptr);

    PRINT("<ufrag>%.*s</ufrag> <pwd>%.*s</pwd>",
          (int)local_ufrag.slen,
          local_ufrag.ptr,
          (int)local_pwd.slen,
          local_pwd.ptr);


    PRINT(" <candidateList>");

    /* Write each component */
    for (comp=0; comp<opt.comp_cnt; ++comp) {
        unsigned j, cand_cnt;
        pj_ice_sess_cand cand[PJ_ICE_ST_MAX_CAND];
        char ipaddr[PJ_INET6_ADDRSTRLEN];

        /* Get default candidate for the component */
        status = pj_ice_strans_get_def_cand(icetrans->icest, comp+1, &cand[0]);
        if (status != PJ_SUCCESS)
            return -status;

        /* Write the default address */
        if (comp==0) {
            /* For component 1, default address is in m= and c= lines */
            // Me: comment
            // PRINT("m=audio %d RTP/AVP 0\n"
            //      "c=IN IP4 %s\n",
            //      (int)pj_sockaddr_get_port(&cand[0].addr),
            //      pj_sockaddr_print(&cand[0].addr, ipaddr,
            //                        sizeof(ipaddr), 0));

            PRINT("<comp_1> <port>%d</port>"
                  "<ip>%s</ip> </comp_1>",
                  (int)pj_sockaddr_get_port(&cand[0].addr),
                  pj_sockaddr_print(&cand[0].addr, ipaddr,
                                    sizeof(ipaddr), 0));

        } else if (comp==1) {
            /* For component 2, default address is in a=rtcp line */
            //Me: comment
            //PRINT("a=rtcp:%d IN IP4 %s\n",
            //      (int)pj_sockaddr_get_port(&cand[0].addr),
            //      pj_sockaddr_print(&cand[0].addr, ipaddr,
            //                        sizeof(ipaddr), 0));
        } else {
            /* For other components, we'll just invent this.. */
            // Me: comment
            //PRINT("a=Xice-defcand:%d IN IP4 %s\n",
            //      (int)pj_sockaddr_get_port(&cand[0].addr),
            //      pj_sockaddr_print(&cand[0].addr, ipaddr,
            //                        sizeof(ipaddr), 0));
        }

        /* Enumerate all candidates for this component */
        cand_cnt = PJ_ARRAY_SIZE(cand);
        status = pj_ice_strans_enum_cands(icetrans->icest, comp+1,
                                          &cand_cnt, cand);
        if (status != PJ_SUCCESS)
            return -status;

        /* And encode the candidates as SDP */
        //const int buffer_xml_len = 2048;
        //char buffer_xml[buffer_xml_len];
        for (j=0; j<cand_cnt; ++j) {
            printed = print_cand_to_xml(p, maxlen - (unsigned)(p-buffer), &cand[j]);
            if (printed < 0)
                return -PJ_ETOOSMALL;
         //   printed = print_cand_to_xml(p, maxlen - (unsigned)(p-buffer), &cand[j]);
         //   if (printed < 0)
          //      return -PJ_ETOOSMALL;
            p += printed;
        }
    }
    PRINT("</candidateList>");

    PRINT(" </registerPeer>");

    if (p == buffer+maxlen)
        return -PJ_ETOOSMALL;

    *p = '\0';

    //printf("DEBUGGGGGG: %s \n", (p - buffer);
    return (int)(p - buffer);
}
示例#2
0
/* Verify incoming offer */
static pj_status_t verify_ice_sdp(struct transport_ice *tp_ice,
				  pj_pool_t *tmp_pool,
				  const pjmedia_sdp_session *rem_sdp,
				  unsigned media_index,
				  pj_ice_sess_role current_ice_role,
				  struct sdp_state *sdp_state)
{
    const pjmedia_sdp_media *rem_m;
    const pjmedia_sdp_attr *ufrag_attr, *pwd_attr;
    const pjmedia_sdp_conn *rem_conn;
    pj_bool_t comp1_found=PJ_FALSE, comp2_found=PJ_FALSE, has_rtcp=PJ_FALSE;
    pj_sockaddr rem_conn_addr, rtcp_addr;
    unsigned i;
    pj_status_t status;

    rem_m = rem_sdp->media[media_index];

    /* Get the "ice-ufrag" and "ice-pwd" attributes */
    get_ice_attr(rem_sdp, rem_m, &ufrag_attr, &pwd_attr);

    /* If "ice-ufrag" or "ice-pwd" are not found, disable ICE */
    if (ufrag_attr==NULL || pwd_attr==NULL) {
	sdp_state->match_comp_cnt = 0;
	return PJ_SUCCESS;
    }

    /* Verify that default target for each component matches one of the 
     * candidate for the component. Otherwise stop ICE with ICE ice_mismatch 
     * error.
     */

    /* Component 1 is the c= line */
    rem_conn = rem_m->conn;
    if (rem_conn == NULL)
	rem_conn = rem_sdp->conn;
    if (!rem_conn)
	return PJMEDIA_SDP_EMISSINGCONN;

    /* Verify address family matches */
    if ((tp_ice->af==pj_AF_INET() && 
	 pj_strcmp(&rem_conn->addr_type, &STR_IP4)!=0) ||
	(tp_ice->af==pj_AF_INET6() && 
	 pj_strcmp(&rem_conn->addr_type, &STR_IP6)!=0))
    {
	return PJMEDIA_SDP_ETPORTNOTEQUAL;
    }

    /* Assign remote connection address */
    status = pj_sockaddr_init(tp_ice->af, &rem_conn_addr, &rem_conn->addr,
			      (pj_uint16_t)rem_m->desc.port);
    if (status != PJ_SUCCESS)
	return status;

    if (tp_ice->comp_cnt > 1) {
	const pjmedia_sdp_attr *attr;

	/* Get default RTCP candidate from a=rtcp line, if present, otherwise
	 * calculate default RTCP candidate from default RTP target.
	 */
	attr = pjmedia_sdp_attr_find(rem_m->attr_count, rem_m->attr, 
				     &STR_RTCP, NULL);
	has_rtcp = (attr != NULL);

	if (attr) {
	    pjmedia_sdp_rtcp_attr rtcp_attr;

	    status = pjmedia_sdp_attr_get_rtcp(attr, &rtcp_attr);
	    if (status != PJ_SUCCESS) {
		/* Error parsing a=rtcp attribute */
		return status;
	    }
    	
	    if (rtcp_attr.addr.slen) {
		/* Verify address family matches */
		if ((tp_ice->af==pj_AF_INET() && 
		     pj_strcmp(&rtcp_attr.addr_type, &STR_IP4)!=0) ||
		    (tp_ice->af==pj_AF_INET6() && 
		     pj_strcmp(&rtcp_attr.addr_type, &STR_IP6)!=0))
		{
		    return PJMEDIA_SDP_ETPORTNOTEQUAL;
		}

		/* Assign RTCP address */
		status = pj_sockaddr_init(tp_ice->af, &rtcp_addr,
					  &rtcp_attr.addr,
					  (pj_uint16_t)rtcp_attr.port);
		if (status != PJ_SUCCESS) {
		    return PJMEDIA_SDP_EINRTCP;
		}
	    } else {
		/* Assign RTCP address */
		status = pj_sockaddr_init(tp_ice->af, &rtcp_addr, 
					  NULL, 
					  (pj_uint16_t)rtcp_attr.port);
		if (status != PJ_SUCCESS) {
		    return PJMEDIA_SDP_EINRTCP;
		}
		pj_sockaddr_copy_addr(&rtcp_addr, &rem_conn_addr);
	    }
	} else {
	    unsigned rtcp_port;
    	
	    rtcp_port = pj_sockaddr_get_port(&rem_conn_addr) + 1;
	    pj_sockaddr_cp(&rtcp_addr, &rem_conn_addr);
	    pj_sockaddr_set_port(&rtcp_addr, (pj_uint16_t)rtcp_port);
	}
    }

    /* Find the default addresses in a=candidate attributes. 
     */
    for (i=0; i<rem_m->attr_count; ++i) {
	pj_ice_sess_cand cand;

	if (pj_strcmp(&rem_m->attr[i]->name, &STR_CANDIDATE)!=0)
	    continue;

	status = parse_cand(tp_ice->base.name, tmp_pool, 
			    &rem_m->attr[i]->value, &cand);
	if (status != PJ_SUCCESS) {
	    PJ_LOG(4,(tp_ice->base.name, 
		      "Error in parsing SDP candidate attribute '%.*s', "
		      "candidate is ignored",
		      (int)rem_m->attr[i]->value.slen, 
		      rem_m->attr[i]->value.ptr));
	    continue;
	}

	if (!comp1_found && cand.comp_id==COMP_RTP &&
	    pj_sockaddr_cmp(&rem_conn_addr, &cand.addr)==0) 
	{
	    comp1_found = PJ_TRUE;
	} else if (!comp2_found && cand.comp_id==COMP_RTCP &&
		    pj_sockaddr_cmp(&rtcp_addr, &cand.addr)==0) 
	{
	    comp2_found = PJ_TRUE;
	}

	if (cand.comp_id == COMP_RTCP)
	    has_rtcp = PJ_TRUE;

	if (comp1_found && (comp2_found || tp_ice->comp_cnt==1))
	    break;
    }

    /* Check matched component count and ice_mismatch */
    if (comp1_found && (tp_ice->comp_cnt==1 || !has_rtcp)) {
	sdp_state->match_comp_cnt = 1;
	sdp_state->ice_mismatch = PJ_FALSE;
    } else if (comp1_found && comp2_found) {
	sdp_state->match_comp_cnt = 2;
	sdp_state->ice_mismatch = PJ_FALSE;
    } else {
	sdp_state->match_comp_cnt = (tp_ice->comp_cnt > 1 && has_rtcp)? 2 : 1;
	sdp_state->ice_mismatch = PJ_TRUE;
    }


    /* Detect remote restarting session */
    if (pj_ice_strans_has_sess(tp_ice->ice_st) &&
	(pj_ice_strans_sess_is_running(tp_ice->ice_st) ||
	 pj_ice_strans_sess_is_complete(tp_ice->ice_st))) 
    {
	pj_str_t rem_run_ufrag, rem_run_pwd;
	pj_ice_strans_get_ufrag_pwd(tp_ice->ice_st, NULL, NULL,
				    &rem_run_ufrag, &rem_run_pwd);
	if (pj_strcmp(&ufrag_attr->value, &rem_run_ufrag) ||
	    pj_strcmp(&pwd_attr->value, &rem_run_pwd))
	{
	    /* Remote offers to restart ICE */
	    sdp_state->ice_restart = PJ_TRUE;
	} else {
	    sdp_state->ice_restart = PJ_FALSE;
	}
    } else {
	sdp_state->ice_restart = PJ_FALSE;
    }

    /* Detect our role */
    if (current_ice_role==PJ_ICE_SESS_ROLE_CONTROLLING) {
	sdp_state->local_role = PJ_ICE_SESS_ROLE_CONTROLLING;
    } else {
	if (pjmedia_sdp_attr_find(rem_sdp->attr_count, rem_sdp->attr,
				  &STR_ICE_LITE, NULL) != NULL)
	{
	    /* Remote is ICE Lite */
	    sdp_state->local_role = PJ_ICE_SESS_ROLE_CONTROLLING;
	} else {
	    sdp_state->local_role = PJ_ICE_SESS_ROLE_CONTROLLED;
	}
    }

    PJ_LOG(4,(tp_ice->base.name, 
	      "Processing SDP: support ICE=%u, common comp_cnt=%u, "
	      "ice_mismatch=%u, ice_restart=%u, local_role=%s",
	      (sdp_state->match_comp_cnt != 0), 
	      sdp_state->match_comp_cnt, 
	      sdp_state->ice_mismatch, 
	      sdp_state->ice_restart,
	      pj_ice_sess_role_name(sdp_state->local_role)));

    return PJ_SUCCESS;

}
示例#3
0
文件: icedemo.c 项目: conght/BLM-Lib
/* 
 * Encode ICE information in SDP.
 */
static int encode_session(char buffer[], unsigned maxlen)
{
    char *p = buffer;
    unsigned comp;
    int printed;
    pj_str_t local_ufrag, local_pwd;
    pj_status_t status;

    /* Write "dummy" SDP v=, o=, s=, and t= lines */
    PRINT("v=0\no=- 3414953978 3414953978 IN IP4 localhost\ns=ice\nt=0 0\n", 
	  0, 0, 0, 0, 0, 0);

    /* Get ufrag and pwd from current session */
    pj_ice_strans_get_ufrag_pwd(icedemo.icest, &local_ufrag, &local_pwd,
				NULL, NULL);

    /* Write the a=ice-ufrag and a=ice-pwd attributes */
    PRINT("a=ice-ufrag:%.*s\na=ice-pwd:%.*s\n",
	   (int)local_ufrag.slen,
	   local_ufrag.ptr,
	   (int)local_pwd.slen,
	   local_pwd.ptr, 
	   0, 0);

    /* Write each component */
    for (comp=0; comp<icedemo.opt.comp_cnt; ++comp) {
	unsigned j, cand_cnt;
	pj_ice_sess_cand cand[PJ_ICE_ST_MAX_CAND];
	char ipaddr[PJ_INET6_ADDRSTRLEN];

	/* Get default candidate for the component */
	status = pj_ice_strans_get_def_cand(icedemo.icest, comp+1, &cand[0]);
	if (status != PJ_SUCCESS)
	    return -status;

	/* Write the default address */
	if (comp==0) {
	    /* For component 1, default address is in m= and c= lines */
	    PRINT("m=audio %d RTP/AVP 0\n"
		  "c=IN IP4 %s\n",
		  (int)pj_sockaddr_get_port(&cand[0].addr),
		  pj_sockaddr_print(&cand[0].addr, ipaddr,
				    sizeof(ipaddr), 0),
		  0, 0, 0, 0);
	} else if (comp==1) {
	    /* For component 2, default address is in a=rtcp line */
	    PRINT("a=rtcp:%d IN IP4 %s\n",
		  (int)pj_sockaddr_get_port(&cand[0].addr),
		  pj_sockaddr_print(&cand[0].addr, ipaddr,
				    sizeof(ipaddr), 0),
		  0, 0, 0, 0);
	} else {
	    /* For other components, we'll just invent this.. */
	    PRINT("a=Xice-defcand:%d IN IP4 %s\n",
		  (int)pj_sockaddr_get_port(&cand[0].addr),
		  pj_sockaddr_print(&cand[0].addr, ipaddr,
				    sizeof(ipaddr), 0),
		  0, 0, 0, 0);
	}

	/* Enumerate all candidates for this component */
	status = pj_ice_strans_enum_cands(icedemo.icest, comp+1,
					  &cand_cnt, cand);
	if (status != PJ_SUCCESS)
	    return -status;

	/* And encode the candidates as SDP */
	for (j=0; j<cand_cnt; ++j) {
	    printed = print_cand(p, maxlen - (p-buffer), &cand[j]);
	    if (printed < 0)
		return -PJ_ETOOSMALL;
	    p += printed;
	}
    }

    if (p == buffer+maxlen)
	return -PJ_ETOOSMALL;

    *p = '\0';
    return p - buffer;
}
示例#4
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;
}