/// Sets the dest_info structure in a pjsip_tx_data structure to the IP address,
/// port and transport in the specified AddrInfo structure.
void PJUtils::set_dest_info(pjsip_tx_data* tdata, const AddrInfo& ai)
{
  tdata->dest_info.cur_addr = 0;
  tdata->dest_info.addr.count = 1;
  tdata->dest_info.addr.entry[0].priority = 0;
  tdata->dest_info.addr.entry[0].weight = 0;

  if (ai.address.af == AF_INET)
  {
    // IPv4 address.
    tdata->dest_info.addr.entry[0].type =
                          (ai.transport == IPPROTO_TCP) ? PJSIP_TRANSPORT_TCP :
                                                          PJSIP_TRANSPORT_UDP;
    tdata->dest_info.addr.entry[0].addr.ipv4.sin_family = pj_AF_INET();
    tdata->dest_info.addr.entry[0].addr.ipv4.sin_addr.s_addr = ai.address.addr.ipv4.s_addr;
    tdata->dest_info.addr.entry[0].addr_len = sizeof(pj_sockaddr_in);
  }
  else if (ai.address.af == AF_INET6)
  {
    // IPv6 address.
    tdata->dest_info.addr.entry[0].type =
                         (ai.transport == IPPROTO_TCP) ? PJSIP_TRANSPORT_TCP6 :
                                                         PJSIP_TRANSPORT_UDP6;
    tdata->dest_info.addr.entry[0].addr.ipv6.sin6_family = pj_AF_INET6();
    tdata->dest_info.addr.entry[0].addr.ipv6.sin6_flowinfo = 0;
    memcpy((char*)&tdata->dest_info.addr.entry[0].addr.ipv6.sin6_addr,
           (char*)&ai.address.addr.ipv6,
           sizeof(pj_in6_addr));
    tdata->dest_info.addr.entry[0].addr.ipv6.sin6_scope_id = 0;
    tdata->dest_info.addr.entry[0].addr_len = sizeof(pj_sockaddr_in6);
  }
  pj_sockaddr_set_port(&tdata->dest_info.addr.entry[0].addr, ai.port);
}

/*
 * Bind socket at random port.
 */
PJ_DEF(pj_status_t) pj_sock_bind_random(  pj_sock_t sockfd,
				          const pj_sockaddr_t *addr,
				          pj_uint16_t port_range,
				          pj_uint16_t max_try)
{
    pj_sockaddr bind_addr;
    int addr_len;
    pj_uint16_t base_port;
    pj_status_t status = PJ_SUCCESS;

    PJ_CHECK_STACK();

    PJ_ASSERT_RETURN(addr, PJ_EINVAL);

    pj_sockaddr_cp(&bind_addr, addr);
    addr_len = pj_sockaddr_get_len(addr);
    base_port = pj_sockaddr_get_port(addr);

    if (base_port == 0 || port_range == 0) {
	return pj_sock_bind(sockfd, &bind_addr, addr_len);
    }

    for (; max_try; --max_try) {
	pj_uint16_t port;
	port = (pj_uint16_t)(base_port + pj_rand() % (port_range + 1));
	pj_sockaddr_set_port(&bind_addr, port);
	status = pj_sock_bind(sockfd, &bind_addr, addr_len);
	if (status == PJ_SUCCESS)
	    break;
    }

    return status;
}

/* Start socket. */
PJ_DEF(pj_status_t) pj_stun_sock_start( pj_stun_sock *stun_sock,
				        const pj_str_t *domain,
				        pj_uint16_t default_port,
				        pj_dns_resolver *resolver)
{
    pj_status_t status;

    PJ_ASSERT_RETURN(stun_sock && domain && default_port, PJ_EINVAL);

    /* Check whether the domain contains IP address */
    stun_sock->srv_addr.addr.sa_family = (pj_uint16_t)stun_sock->af;
    status = pj_inet_pton(stun_sock->af, domain, 
			  pj_sockaddr_get_addr(&stun_sock->srv_addr));
    if (status != PJ_SUCCESS) {
	stun_sock->srv_addr.addr.sa_family = (pj_uint16_t)0;
    }

    /* If resolver is set, try to resolve with DNS SRV first. It
     * will fallback to DNS A/AAAA when no SRV record is found.
     */
    if (status != PJ_SUCCESS && resolver) {
	const pj_str_t res_name = pj_str("_stun._udp.");
	unsigned opt;

	pj_assert(stun_sock->q == NULL);

	opt = PJ_DNS_SRV_FALLBACK_A;
	if (stun_sock->af == pj_AF_INET6()) {
	    opt |= (PJ_DNS_SRV_RESOLVE_AAAA | PJ_DNS_SRV_FALLBACK_AAAA);
	}

	status = pj_dns_srv_resolve(domain, &res_name, default_port, 
				    stun_sock->pool, resolver, opt,
				    stun_sock, &dns_srv_resolver_cb, 
				    &stun_sock->q);

	/* Processing will resume when the DNS SRV callback is called */
	return status;

    } else {

	if (status != PJ_SUCCESS) {
	    pj_addrinfo ai;
	    unsigned cnt = 1;

	    status = pj_getaddrinfo(stun_sock->af, domain, &cnt, &ai);
	    if (status != PJ_SUCCESS)
		return status;

	    pj_sockaddr_cp(&stun_sock->srv_addr, &ai.ai_addr);
	}

	pj_sockaddr_set_port(&stun_sock->srv_addr, (pj_uint16_t)default_port);

	/* Start sending Binding request */
	return get_mapped_addr(stun_sock);
    }
}

pj_status_t ConnectionPool::resolve_host(const pj_str_t* host,
                                         int port,
                                         pj_sockaddr* addr)
{
  pj_status_t status = PJ_ENOTFOUND;

  // Select a server for this connection.
  std::vector<AddrInfo> servers;
  PJUtils::resolve(std::string(host->ptr, host->slen),
                   port,
                   IPPROTO_TCP,
                   1,
                   servers);
  memset(addr, 0, sizeof(pj_sockaddr));

  if (!servers.empty())
  {
    if (servers[0].address.af == AF_INET)
    {
      TRC_DEBUG("Successfully resolved %.*s to IPv4 address", host->slen, host->ptr);
      addr->ipv4.sin_family = AF_INET;
      addr->ipv4.sin_addr.s_addr = servers[0].address.addr.ipv4.s_addr;
      pj_sockaddr_set_port(addr, servers[0].port);
      status = PJ_SUCCESS;
    }
    else if (servers[0].address.af == AF_INET6)
    {
      TRC_DEBUG("Successfully resolved %.*s to IPv6 address", host->slen, host->ptr);
      addr->ipv6.sin6_family = AF_INET6;
      memcpy((char*)&addr->ipv6.sin6_addr,
             (char*)&servers[0].address.addr.ipv6,
             sizeof(struct in6_addr));
      pj_sockaddr_set_port(addr, servers[0].port);
      status = PJ_SUCCESS;
    }
    else
    {
      TRC_ERROR("Resolved %.*s to address of unknown family %d - failing connection!", host->slen, host->ptr); //LCOV_EXCL_LINE
    }
  }

  return status;
}

void IpTest::testIpAddr()
{
	TITLE();

	IpAddr ip = {"8.8.8.8"};
	CPPUNIT_ASSERT(ip);
	CPPUNIT_ASSERT(ip.toString() == "8.8.8.8");
	CPPUNIT_ASSERT(ip.getPort() == 0);
	CPPUNIT_ASSERT(ip.isIpv4());
	CPPUNIT_ASSERT(not ip.isIpv6());
	CPPUNIT_ASSERT(not ip.isLoopback());
	CPPUNIT_ASSERT(not ip.isPrivate());
	CPPUNIT_ASSERT(not ip.isUnspecified());

	IpAddr ip_2 = ip.toString();
	CPPUNIT_ASSERT(ip_2 == ip);

	ip = IpAddr();
	CPPUNIT_ASSERT(not ip);
	CPPUNIT_ASSERT(ip.isUnspecified());
	CPPUNIT_ASSERT(not ip.isIpv4());
	CPPUNIT_ASSERT(not ip.isIpv6());
	CPPUNIT_ASSERT(ip.getPort() == 0);

	ip = IpAddr("8.8.8.8:42");
	CPPUNIT_ASSERT(ip);
	CPPUNIT_ASSERT(ip.toString() == "8.8.8.8");
	CPPUNIT_ASSERT(ip.getPort() == 42);

	pj_sockaddr_set_port(ip.pjPtr(), 5042);
	CPPUNIT_ASSERT(ip.getPort() == 5042);

#if HAVE_IPV6
	const in6_addr native_ip = {{
		0x3f, 0xfe, 0x05, 0x01,
		0x00, 0x08, 0x00, 0x00,
		0x02, 0x60, 0x97, 0xff,
		0xfe, 0x40, 0xef, 0xab
	}};
	ip = IpAddr(native_ip);
	CPPUNIT_ASSERT(ip);
	CPPUNIT_ASSERT(ip == IpAddr("3ffe:0501:0008:0000:0260:97ff:fe40:efab"));
	CPPUNIT_ASSERT(not ip.isIpv4());
	CPPUNIT_ASSERT(ip.isIpv6());

	CPPUNIT_ASSERT(IpAddr::isValid("3ffe:0501:0008:0000:0260:97ff:fe40:efab"));
	CPPUNIT_ASSERT(IpAddr::isValid("[3ffe:0501:0008:0000:0260:97ff:fe40:efab]"));
	CPPUNIT_ASSERT(IpAddr::isValid("[3ffe:0501:0008:0000:0260:97ff:fe40:efab]:4242"));
	CPPUNIT_ASSERT(IpAddr::isValid("[3ffe:501:8::260:97ff:fe40:efab]:4242"));
#endif
}

//.........这里部分代码省略.........
	    local_af = pj_AF_INET();
	} else if (pj_stricmp(&local_conn->addr_type, &ID_IP6)==0) {
	    local_af = pj_AF_INET6();
	}
    }

    if (local_af==pj_AF_UNSPEC()) {
	/* Unsupported address family */
	return PJ_SUCCESS;
    }

    /* Set remote address: */
    status = pj_sockaddr_init(local_af, &local_addr, &local_conn->addr,
			      local_m->desc.port);
    if (status != PJ_SUCCESS) {
	/* Invalid IP address. */
	return PJMEDIA_EINVALIDIP;
    }

    /* Local and remote address family must match */
    if (local_af != rem_af)
	return PJ_EAFNOTSUP;

    /* Media direction: */

    if (local_m->desc.port == 0 ||
	pj_sockaddr_has_addr(&local_addr)==PJ_FALSE ||
	pj_sockaddr_has_addr(&si->rem_addr)==PJ_FALSE ||
	pjmedia_sdp_media_find_attr(local_m, &STR_INACTIVE, NULL)!=NULL)
    {
	/* Inactive stream. */

	si->dir = PJMEDIA_DIR_NONE;

    } else if (pjmedia_sdp_media_find_attr(local_m, &STR_SENDONLY, NULL)!=NULL) {

	/* Send only stream. */

	si->dir = PJMEDIA_DIR_ENCODING;

    } else if (pjmedia_sdp_media_find_attr(local_m, &STR_RECVONLY, NULL)!=NULL) {

	/* Recv only stream. */

	si->dir = PJMEDIA_DIR_DECODING;

    } else {

	/* Send and receive stream. */

	si->dir = PJMEDIA_DIR_ENCODING_DECODING;

    }

    /* No need to do anything else if stream is rejected */
    if (local_m->desc.port == 0) {
	return PJ_SUCCESS;
    }

    /* If "rtcp" attribute is present in the SDP, set the RTCP address
     * from that attribute. Otherwise, calculate from RTP address.
     */
    attr = pjmedia_sdp_attr_find2(rem_m->attr_count, rem_m->attr,
				  "rtcp", NULL);
    if (attr) {
	pjmedia_sdp_rtcp_attr rtcp;
	status = pjmedia_sdp_attr_get_rtcp(attr, &rtcp);
	if (status == PJ_SUCCESS) {
	    if (rtcp.addr.slen) {
		status = pj_sockaddr_init(rem_af, &si->rem_rtcp, &rtcp.addr,
					  (pj_uint16_t)rtcp.port);
	    } else {
		pj_sockaddr_init(rem_af, &si->rem_rtcp, NULL,
				 (pj_uint16_t)rtcp.port);
		pj_memcpy(pj_sockaddr_get_addr(&si->rem_rtcp),
		          pj_sockaddr_get_addr(&si->rem_addr),
			  pj_sockaddr_get_addr_len(&si->rem_addr));
	    }
	}
    }

    if (!pj_sockaddr_has_addr(&si->rem_rtcp)) {
	int rtcp_port;

	pj_memcpy(&si->rem_rtcp, &si->rem_addr, sizeof(pj_sockaddr));
	rtcp_port = pj_sockaddr_get_port(&si->rem_addr) + 1;
	pj_sockaddr_set_port(&si->rem_rtcp, (pj_uint16_t)rtcp_port);
    }

    /* Get codec info and param */
    status = get_video_codec_info_param(si, pool, NULL, local_m, rem_m);

    /* Leave SSRC to random. */
    si->ssrc = pj_rand();

    /* Set default jitter buffer parameter. */
    si->jb_init = si->jb_max = si->jb_min_pre = si->jb_max_pre = -1;

    return status;
}

//.........这里部分代码省略.........
	}
    };
    pj_addrinfo ai;
    pj_status_t status;

    /* May not be used if TRACE_ is disabled */
    PJ_UNUSED_ARG(strip);

#ifdef _MSC_VER
    /* Get rid of "uninitialized he variable" with MS compilers */
    pj_bzero(&ai, sizeof(ai));
#endif

    cand_cnt = 0;
    pj_bzero(cand_addr, sizeof(cand_addr));
    pj_bzero(cand_weight, sizeof(cand_weight));
    for (i=0; i<PJ_ARRAY_SIZE(cand_addr); ++i) {
	cand_addr[i].addr.sa_family = (pj_uint16_t)af;
	PJ_SOCKADDR_RESET_LEN(&cand_addr[i]);
    }

    addr->addr.sa_family = (pj_uint16_t)af;
    PJ_SOCKADDR_RESET_LEN(addr);

#if !defined(PJ_GETHOSTIP_DISABLE_LOCAL_RESOLUTION) || \
	PJ_GETHOSTIP_DISABLE_LOCAL_RESOLUTION == 0
	TRACE_((THIS_FILE, "pj_gethostip() pj_getaddrinfo1"));
    /* Get hostname's IP address */
    count = 1;
    status = pj_getaddrinfo(af, pj_gethostname(), &count, &ai);
    if (status == PJ_SUCCESS) {
    	pj_assert(ai.ai_addr.addr.sa_family == (pj_uint16_t)af);
    	pj_sockaddr_copy_addr(&cand_addr[cand_cnt], &ai.ai_addr);
	pj_sockaddr_set_port(&cand_addr[cand_cnt], 0);
	cand_weight[cand_cnt] += WEIGHT_HOSTNAME;
	++cand_cnt;

	TRACE_((THIS_FILE, "hostname IP is %s",
		pj_sockaddr_print(&ai.ai_addr, strip, sizeof(strip), 0)));
	}
	TRACE_((THIS_FILE, "pj_gethostip() pj_getaddrinfo2"));
#else
    PJ_UNUSED_ARG(ai);
    PJ_UNUSED_ARG(count);
#endif

    /* Get default interface (interface for default route) */
    if (cand_cnt < PJ_ARRAY_SIZE(cand_addr)) {
	status = pj_getdefaultipinterface(af, addr);
	if (status == PJ_SUCCESS) {
	    TRACE_((THIS_FILE, "default IP is %s",
		    pj_sockaddr_print(addr, strip, sizeof(strip), 0)));

	    pj_sockaddr_set_port(addr, 0);
	    for (i=0; i<cand_cnt; ++i) {
		if (pj_sockaddr_cmp(&cand_addr[i], addr)==0)
		    break;
	    }

	    cand_weight[i] += WEIGHT_DEF_ROUTE;
	    if (i >= cand_cnt) {
		pj_sockaddr_copy_addr(&cand_addr[i], addr);
		++cand_cnt;
	    }
	}
    }

//.........这里部分代码省略.........

	    PJ_LOG(5,(THIS_FILE,
		      "DNS resolver not available, target '%.*s:%d' type=%s "
		      "will be resolved with getaddrinfo()",
		      target->addr.host.slen,
		      target->addr.host.ptr,
		      target->addr.port,
		      pjsip_transport_get_type_name(target->type)));

	    if (type & PJSIP_TRANSPORT_IPV6) {
		af = pj_AF_INET6();
	    } else {
		af = pj_AF_INET();
	    }

	    /* Resolve */
	    count = 1;
	    status = pj_getaddrinfo(af, &target->addr.host, &count, &ai);
	    if (status != PJ_SUCCESS)
		goto on_error;

	    svr_addr.entry[0].addr.addr.sa_family = (pj_uint16_t)af;
	    pj_memcpy(&svr_addr.entry[0].addr, &ai.ai_addr,
		      sizeof(pj_sockaddr));
	}

	/* Set the port number */
	if (target->addr.port == 0) {
	   srv_port = (pj_uint16_t)
		      pjsip_transport_get_default_port_for_type(type);
	} else {
	   srv_port = (pj_uint16_t)target->addr.port;
	}
	pj_sockaddr_set_port(&svr_addr.entry[0].addr, srv_port);

	/* Call the callback. */
	PJ_LOG(5,(THIS_FILE, 
		  "Target '%.*s:%d' type=%s resolved to "
		  "'%s' type=%s (%s)",
		  (int)target->addr.host.slen,
		  target->addr.host.ptr,
		  target->addr.port,
		  pjsip_transport_get_type_name(target->type),
		  pj_sockaddr_print(&svr_addr.entry[0].addr, addr_str,
				    sizeof(addr_str), 3),
		  pjsip_transport_get_type_name(type),
		  pjsip_transport_get_type_desc(type)));
	svr_addr.count = 1;
	svr_addr.entry[0].priority = 0;
	svr_addr.entry[0].weight = 0;
	svr_addr.entry[0].type = type;
	svr_addr.entry[0].addr_len = pj_sockaddr_get_len(&svr_addr.entry[0].addr);
	(*cb)(status, token, &svr_addr);

	/* Done. */
	return;
    }

    /* Target is not an IP address so we need to resolve it. */
#if PJSIP_HAS_RESOLVER

    /* Build the query state */
    query = PJ_POOL_ZALLOC_T(pool, struct query);
    query->objname = THIS_FILE;
    query->token = token;
    query->cb = cb;

//.........这里部分代码省略.........
	return PJ_EAFNOTSUP;

    /* Media direction: */

    if (local_m->desc.port == 0 ||
	pj_sockaddr_has_addr(&local_addr)==PJ_FALSE ||
	pj_sockaddr_has_addr(&si->rem_addr)==PJ_FALSE ||
	pjmedia_sdp_media_find_attr(local_m, &STR_INACTIVE, NULL)!=NULL)
    {
	/* Inactive stream. */

	si->dir = PJMEDIA_DIR_NONE;

    } else if (pjmedia_sdp_media_find_attr(local_m, &STR_SENDONLY, NULL)!=NULL) {

	/* Send only stream. */

	si->dir = PJMEDIA_DIR_ENCODING;

    } else if (pjmedia_sdp_media_find_attr(local_m, &STR_RECVONLY, NULL)!=NULL) {

	/* Recv only stream. */

	si->dir = PJMEDIA_DIR_DECODING;

    } else {

	/* Send and receive stream. */

	si->dir = PJMEDIA_DIR_ENCODING_DECODING;

    }

    /* No need to do anything else if stream is rejected */
    if (local_m->desc.port == 0) {
	return PJ_SUCCESS;
    }

    /* If "rtcp" attribute is present in the SDP, set the RTCP address
     * from that attribute. Otherwise, calculate from RTP address.
     */
    attr = pjmedia_sdp_attr_find2(rem_m->attr_count, rem_m->attr,
				  "rtcp", NULL);
    if (attr) {
	pjmedia_sdp_rtcp_attr rtcp;
	status = pjmedia_sdp_attr_get_rtcp(attr, &rtcp);
	if (status == PJ_SUCCESS) {
	    if (rtcp.addr.slen) {
		status = pj_sockaddr_init(rem_af, &si->rem_rtcp, &rtcp.addr,
					  (pj_uint16_t)rtcp.port);
	    } else {
		pj_sockaddr_init(rem_af, &si->rem_rtcp, NULL,
				 (pj_uint16_t)rtcp.port);
		pj_memcpy(pj_sockaddr_get_addr(&si->rem_rtcp),
		          pj_sockaddr_get_addr(&si->rem_addr),
			  pj_sockaddr_get_addr_len(&si->rem_addr));
	    }
	}
    }

    if (!pj_sockaddr_has_addr(&si->rem_rtcp)) {
	int rtcp_port;

	pj_memcpy(&si->rem_rtcp, &si->rem_addr, sizeof(pj_sockaddr));
	rtcp_port = pj_sockaddr_get_port(&si->rem_addr) + 1;
	pj_sockaddr_set_port(&si->rem_rtcp, (pj_uint16_t)rtcp_port);
    }


    /* Get the payload number for receive channel. */
    /*
       Previously we used to rely on fmt[0] being the selected codec,
       but some UA sends telephone-event as fmt[0] and this would
       cause assert failure below.

       Thanks Chris Hamilton <chamilton .at. cs.dal.ca> for this patch.

    // And codec must be numeric!
    if (!pj_isdigit(*local_m->desc.fmt[0].ptr) ||
	!pj_isdigit(*rem_m->desc.fmt[0].ptr))
    {
	return PJMEDIA_EINVALIDPT;
    }

    pt = pj_strtoul(&local_m->desc.fmt[0]);
    pj_assert(PJMEDIA_RTP_PT_TELEPHONE_EVENTS==0 ||
	      pt != PJMEDIA_RTP_PT_TELEPHONE_EVENTS);
    */

    /* Get codec info and param */
    status = get_audio_codec_info_param(si, pool, mgr, local_m, rem_m);

    /* Leave SSRC to random. */
    si->ssrc = pj_rand();

    /* Set default jitter buffer parameter. */
    si->jb_init = si->jb_max = si->jb_min_pre = si->jb_max_pre = -1;

    return status;
}

//.........这里部分代码省略.........
		      target->addr.host.slen,
		      target->addr.host.ptr,
		      target->addr.port,
		      pjsip_transport_get_type_name(target->type)));

	    /* Resolve */
	    count = 1;
	    status = pj_getaddrinfo(af, &target->addr.host, &count, &ai);
	    if (status != PJ_SUCCESS) {
		/* "Normalize" error to PJ_ERESOLVE. This is a special error
		 * because it will be translated to SIP status 502 by
		 * sip_transaction.c
		 */
		status = PJ_ERESOLVE;
		goto on_error;
	    }

	    pj_sockaddr_cp(&svr_addr.entry[0].addr, &ai.ai_addr);
	    if (af == pj_AF_UNSPEC())
		af = ai.ai_addr.addr.sa_family;
	}

	/* After address resolution, update IPv6 bitflag in transport type. */
	if (af == pj_AF_INET6())
	    type |= PJSIP_TRANSPORT_IPV6;

	/* Set the port number */
	if (target->addr.port == 0) {
	   srv_port = (pj_uint16_t)
		      pjsip_transport_get_default_port_for_type(type);
	} else {
	   srv_port = (pj_uint16_t)target->addr.port;
	}
	pj_sockaddr_set_port(&svr_addr.entry[0].addr, srv_port);

	/* Call the callback. */
	PJ_LOG(5,(THIS_FILE, 
		  "Target '%.*s:%d' type=%s resolved to "
		  "'%s' type=%s (%s)",
		  (int)target->addr.host.slen,
		  target->addr.host.ptr,
		  target->addr.port,
		  pjsip_transport_get_type_name(target->type),
		  pj_sockaddr_print(&svr_addr.entry[0].addr, addr_str,
				    sizeof(addr_str), 3),
		  pjsip_transport_get_type_name(type),
		  pjsip_transport_get_type_desc(type)));
	svr_addr.count = 1;
	svr_addr.entry[0].priority = 0;
	svr_addr.entry[0].weight = 0;
	svr_addr.entry[0].type = type;
	svr_addr.entry[0].addr_len = 
				pj_sockaddr_get_len(&svr_addr.entry[0].addr);
	(*cb)(status, token, &svr_addr);

	/* Done. */
	return;
    }

    /* Target is not an IP address so we need to resolve it. */
#if PJSIP_HAS_RESOLVER

    /* Build the query state */
    query = PJ_POOL_ZALLOC_T(pool, struct query);
    query->objname = THIS_FILE;
    query->token = token;

//.........这里部分代码省略.........

                        value = (char *)xml_xmlnode_get_content_by_name(cur_node, "type");
                        strcpy(type, value);
                        free(value);

                        PJ_LOG(4,(__FUNCTION__, "DEBUG %s %d %s %d %s %d typ %s",
                               foundation,
                               comp_id,
                               transport,
                               prio,
                               ipaddr,
                               port,
                               type));


                        cand = &icetrans->rem.cand[icetrans->rem.cand_cnt];
                        pj_bzero(cand, sizeof(*cand));

                        if (strcmp(type, "host")==0)
                            cand->type = PJ_ICE_CAND_TYPE_HOST;
                        else if (strcmp(type, "srflx")==0)
                            cand->type = PJ_ICE_CAND_TYPE_SRFLX;
                        else if (strcmp(type, "relay")==0)
                            cand->type = PJ_ICE_CAND_TYPE_RELAYED;
                        else {
                            PJ_LOG(1, (THIS_FILE, "Error: invalid candidate type '%s'",
                                       type));
                            goto on_error;
                        }

                        cand->comp_id = (pj_uint8_t)comp_id;
                        pj_strdup2(icetrans->pool, &cand->foundation, foundation);
                        cand->prio = prio;

                        if (strchr(ipaddr, ':'))
                            af = pj_AF_INET6();
                        else
                            af = pj_AF_INET();

                        tmpaddr = pj_str(ipaddr);
                        pj_sockaddr_init(af, &cand->addr, NULL, 0);
                        status = pj_sockaddr_set_str_addr(af, &cand->addr, &tmpaddr);
                        if (status != PJ_SUCCESS) {
                            PJ_LOG(1,(THIS_FILE, "Error: invalid IP address '%s'",
                                      ipaddr));
                            goto on_error;
                        }

                        pj_sockaddr_set_port(&cand->addr, (pj_uint16_t)port);

                        ++icetrans->rem.cand_cnt;

                        if (cand->comp_id > icetrans->rem.comp_cnt)
                            icetrans->rem.comp_cnt = cand->comp_id;
                    }
                }
                }


    if (icetrans->rem.cand_cnt==0 ||
            icetrans->rem.ufrag[0]==0 ||
            icetrans->rem.pwd[0]==0 ||
            icetrans->rem.comp_cnt == 0)
    {
        PJ_LOG(1, (THIS_FILE, "Error: not enough info"));
        goto on_error;
    }

    if (comp0_port==0 || comp0_addr[0]=='\0') {
        PJ_LOG(1, (THIS_FILE, "Error: default address for component 0 not found"));
        goto on_error;
    } else {
        int af;
        pj_str_t tmp_addr;
        pj_status_t status;

        if (strchr(comp0_addr, ':'))
            af = pj_AF_INET6();
        else
            af = pj_AF_INET();

        pj_sockaddr_init(af, &icetrans->rem.def_addr[0], NULL, 0);
        tmp_addr = pj_str(comp0_addr);
        status = pj_sockaddr_set_str_addr(af, &icetrans->rem.def_addr[0],
                                          &tmp_addr);
        if (status != PJ_SUCCESS) {
            PJ_LOG(1,(THIS_FILE, "Invalid IP address in c= line"));
            goto on_error;
        }
        pj_sockaddr_set_port(&icetrans->rem.def_addr[0], (pj_uint16_t)comp0_port);
    }

    PJ_LOG(3, (THIS_FILE, "Done, %d remote candidate(s) added",
               icetrans->rem.cand_cnt));

    return;

on_error:
    reset_rem_info(icetrans);
}

//.........这里部分代码省略.........
	    {
		char *attr = strtok(line+2, ": \t\r\n");
		if (strcmp(attr, "ice-ufrag")==0) {
		    strcpy(icedemo.rem.ufrag, attr+strlen(attr)+1);
		} else if (strcmp(attr, "ice-pwd")==0) {
		    strcpy(icedemo.rem.pwd, attr+strlen(attr)+1);
		} else if (strcmp(attr, "rtcp")==0) {
		    char *val = attr+strlen(attr)+1;
		    int af, cnt;
		    int port;
		    char net[32], ip[64];
		    pj_str_t tmp_addr;
		    pj_status_t status;

		    cnt = sscanf(val, "%d IN %s %s", &port, net, ip);
		    if (cnt != 3) {
			PJ_LOG(1,(THIS_FILE, "Error parsing rtcp attribute"));
			goto on_error;
		    }

		    if (strchr(ip, ':'))
			af = pj_AF_INET6();
		    else
			af = pj_AF_INET();

		    pj_sockaddr_init(af, &icedemo.rem.def_addr[1], NULL, 0);
		    tmp_addr = pj_str(ip);
		    status = pj_sockaddr_set_str_addr(af, &icedemo.rem.def_addr[1],
						      &tmp_addr);
		    if (status != PJ_SUCCESS) {
			PJ_LOG(1,(THIS_FILE, "Invalid IP address"));
			goto on_error;
		    }
		    pj_sockaddr_set_port(&icedemo.rem.def_addr[1], (pj_uint16_t)port);

		} else if (strcmp(attr, "candidate")==0) {
		    char *sdpcand = attr+strlen(attr)+1;
		    int af, cnt;
		    char foundation[32], transport[12], ipaddr[80], type[32];
		    pj_str_t tmpaddr;
		    int comp_id, prio, port;
		    pj_ice_sess_cand *cand;
		    pj_status_t status;

		    cnt = sscanf(sdpcand, "%s %d %s %d %s %d typ %s",
				 foundation,
				 &comp_id,
				 transport,
				 &prio,
				 ipaddr,
				 &port,
				 type);
		    if (cnt != 7) {
			PJ_LOG(1, (THIS_FILE, "error: Invalid ICE candidate line"));
			goto on_error;
		    }

		    cand = &icedemo.rem.cand[icedemo.rem.cand_cnt];
		    pj_bzero(cand, sizeof(*cand));
		    
		    if (strcmp(type, "host")==0)
			cand->type = PJ_ICE_CAND_TYPE_HOST;
		    else if (strcmp(type, "srflx")==0)
			cand->type = PJ_ICE_CAND_TYPE_SRFLX;
		    else if (strcmp(type, "relay")==0)
			cand->type = PJ_ICE_CAND_TYPE_RELAYED;

//.........这里部分代码省略.........

    /* No need to do anything else if stream is rejected */
    if (local_m->desc.port == 0) {
	return PJ_SUCCESS;
    }

    /* If "rtcp" attribute is present in the SDP, set the RTCP address
     * from that attribute. Otherwise, calculate from RTP address.
     */
    attr = pjmedia_sdp_attr_find2(rem_m->attr_count, rem_m->attr,
				  "rtcp", NULL);
    if (attr) {
	pjmedia_sdp_rtcp_attr rtcp;
	status = pjmedia_sdp_attr_get_rtcp(attr, &rtcp);
	if (status == PJ_SUCCESS) {
	    if (rtcp.addr.slen) {
		status = pj_sockaddr_init(rem_af, &si->rem_rtcp, &rtcp.addr,
					  (pj_uint16_t)rtcp.port);
	    } else {
		pj_sockaddr_init(rem_af, &si->rem_rtcp, NULL, 
				 (pj_uint16_t)rtcp.port);
		pj_memcpy(pj_sockaddr_get_addr(&si->rem_rtcp),
		          pj_sockaddr_get_addr(&si->rem_addr),
			  pj_sockaddr_get_addr_len(&si->rem_addr));
	    }
	}
    }
    
    if (!pj_sockaddr_has_addr(&si->rem_rtcp)) {
	int rtcp_port;

	pj_memcpy(&si->rem_rtcp, &si->rem_addr, sizeof(pj_sockaddr));
	rtcp_port = pj_sockaddr_get_port(&si->rem_addr) + 1;
	pj_sockaddr_set_port(&si->rem_rtcp, (pj_uint16_t)rtcp_port);
    }


    /* Get the payload number for receive channel. */
    /*
       Previously we used to rely on fmt[0] being the selected codec,
       but some UA sends telephone-event as fmt[0] and this would
       cause assert failure below.

       Thanks Chris Hamilton <chamilton .at. cs.dal.ca> for this patch.

    // And codec must be numeric!
    if (!pj_isdigit(*local_m->desc.fmt[0].ptr) || 
	!pj_isdigit(*rem_m->desc.fmt[0].ptr))
    {
	return PJMEDIA_EINVALIDPT;
    }

    pt = pj_strtoul(&local_m->desc.fmt[0]);
    pj_assert(PJMEDIA_RTP_PT_TELEPHONE_EVENTS==0 ||
	      pt != PJMEDIA_RTP_PT_TELEPHONE_EVENTS);
    */

    /* This is to suppress MSVC warning about uninitialized var */
    pt = 0;

    /* Find the first codec which is not telephone-event */
    for ( fmti = 0; fmti < local_m->desc.fmt_count; ++fmti ) {
	if ( !pj_isdigit(*local_m->desc.fmt[fmti].ptr) )
	    return PJMEDIA_EINVALIDPT;
	pt = pj_strtoul(&local_m->desc.fmt[fmti]);
	if ( PJMEDIA_RTP_PT_TELEPHONE_EVENTS == 0 ||

/*! \brief Apply handler for transports */
static int transport_apply(const struct ast_sorcery *sorcery, void *obj)
{
	struct ast_sip_transport *transport = obj;
	const char *transport_id = ast_sorcery_object_get_id(obj);
	RAII_VAR(struct ao2_container *, states, transport_states, states_cleanup);
	RAII_VAR(struct internal_state *, temp_state, NULL, ao2_cleanup);
	RAII_VAR(struct internal_state *, perm_state, NULL, ao2_cleanup);
	RAII_VAR(struct ast_variable *, changes, NULL, ast_variables_destroy);
	pj_status_t res = -1;
	int i;
#define BIND_TRIES 3
#define BIND_DELAY_US 100000

	if (!states) {
		return -1;
	}

	/*
	 * transport_apply gets called for EVERY retrieval of a transport when using realtime.
	 * We need to prevent multiple threads from trying to mess with underlying transports
	 * at the same time.  The container is the only thing we have to lock on.
	 */
	ao2_wrlock(states);

	temp_state = internal_state_alloc(transport);
	if (!temp_state) {
		ast_log(LOG_ERROR, "Transport '%s' failed to allocate memory\n", transport_id);
		return -1;
	}

	perm_state = find_internal_state_by_transport(transport);
	if (perm_state) {
		ast_sorcery_diff(sorcery, perm_state->transport, transport, &changes);
		if (!changes && !has_state_changed(perm_state->state, temp_state->state)) {
			/* In case someone is using the deprecated fields, reset them */
			transport->state = perm_state->state;
			copy_state_to_transport(transport);
			ao2_replace(perm_state->transport, transport);
			return 0;
		}

		if (!transport->allow_reload) {
			if (!perm_state->change_detected) {
				perm_state->change_detected = 1;
				ast_log(LOG_WARNING, "Transport '%s' is not reloadable, maintaining previous values\n", transport_id);
			}
			/* In case someone is using the deprecated fields, reset them */
			transport->state = perm_state->state;
			copy_state_to_transport(transport);
			ao2_replace(perm_state->transport, transport);
			return 0;
		}
	}

	if (temp_state->state->host.addr.sa_family != PJ_AF_INET && temp_state->state->host.addr.sa_family != PJ_AF_INET6) {
		ast_log(LOG_ERROR, "Transport '%s' could not be started as binding not specified\n", transport_id);
		return -1;
	}

	/* Set default port if not present */
	if (!pj_sockaddr_get_port(&temp_state->state->host)) {
		pj_sockaddr_set_port(&temp_state->state->host, (transport->type == AST_TRANSPORT_TLS) ? 5061 : 5060);
	}

	/* Now that we know what address family we can set up a dnsmgr refresh for the external media address if present */
	if (!ast_strlen_zero(transport->external_signaling_address)) {
		if (temp_state->state->host.addr.sa_family == pj_AF_INET()) {
			temp_state->state->external_address.ss.ss_family = AF_INET;
		} else if (temp_state->state->host.addr.sa_family == pj_AF_INET6()) {
			temp_state->state->external_address.ss.ss_family = AF_INET6;
		} else {
			ast_log(LOG_ERROR, "Unknown address family for transport '%s', could not get external signaling address\n",
					transport_id);
			return -1;
		}

		if (ast_dnsmgr_lookup(transport->external_signaling_address, &temp_state->state->external_address, &temp_state->state->external_address_refresher, NULL) < 0) {
			ast_log(LOG_ERROR, "Could not create dnsmgr for external signaling address on '%s'\n", transport_id);
			return -1;
		}
	}

	if (transport->type == AST_TRANSPORT_UDP) {

		for (i = 0; i < BIND_TRIES && res != PJ_SUCCESS; i++) {
			if (perm_state && perm_state->state && perm_state->state->transport) {
				pjsip_udp_transport_pause(perm_state->state->transport,
					PJSIP_UDP_TRANSPORT_DESTROY_SOCKET);
				usleep(BIND_DELAY_US);
			}

			if (temp_state->state->host.addr.sa_family == pj_AF_INET()) {
				res = pjsip_udp_transport_start(ast_sip_get_pjsip_endpoint(),
					&temp_state->state->host.ipv4, NULL, transport->async_operations,
					&temp_state->state->transport);
			} else if (temp_state->state->host.addr.sa_family == pj_AF_INET6()) {
				res = pjsip_udp_transport_start6(ast_sip_get_pjsip_endpoint(),
					&temp_state->state->host.ipv6, NULL, transport->async_operations,
					&temp_state->state->transport);
//.........这里部分代码省略.........

/*! \brief Apply handler for transports */
static int transport_apply(const struct ast_sorcery *sorcery, void *obj)
{
	struct ast_sip_transport *transport = obj;
	RAII_VAR(struct ast_sip_transport *, existing, ast_sorcery_retrieve_by_id(sorcery, "transport", ast_sorcery_object_get_id(obj)), ao2_cleanup);
	pj_status_t res = -1;

	if (!existing || !existing->state) {
		if (!(transport->state = ao2_alloc(sizeof(*transport->state), transport_state_destroy))) {
			ast_log(LOG_ERROR, "Transport state for '%s' could not be allocated\n", ast_sorcery_object_get_id(obj));
			return -1;
		}
	} else {
		transport->state = existing->state;
		ao2_ref(transport->state, +1);
	}

	/* Once active a transport can not be reconfigured */
	if (transport->state->transport || transport->state->factory) {
		return -1;
	}

	if (transport->host.addr.sa_family != PJ_AF_INET && transport->host.addr.sa_family != PJ_AF_INET6) {
		ast_log(LOG_ERROR, "Transport '%s' could not be started as binding not specified\n", ast_sorcery_object_get_id(obj));
		return -1;
	}

	/* Set default port if not present */
	if (!pj_sockaddr_get_port(&transport->host)) {
		pj_sockaddr_set_port(&transport->host, (transport->type == AST_TRANSPORT_TLS) ? 5061 : 5060);
	}

	/* Now that we know what address family we can set up a dnsmgr refresh for the external media address if present */
	if (!ast_strlen_zero(transport->external_signaling_address)) {
		if (transport->host.addr.sa_family == pj_AF_INET()) {
			transport->external_address.ss.ss_family = AF_INET;
		} else if (transport->host.addr.sa_family == pj_AF_INET6()) {
			transport->external_address.ss.ss_family = AF_INET6;
		} else {
			ast_log(LOG_ERROR, "Unknown address family for transport '%s', could not get external signaling address\n",
					ast_sorcery_object_get_id(obj));
			return -1;
		}

		if (ast_dnsmgr_lookup(transport->external_signaling_address, &transport->external_address, &transport->external_address_refresher, NULL) < 0) {
			ast_log(LOG_ERROR, "Could not create dnsmgr for external signaling address on '%s'\n", ast_sorcery_object_get_id(obj));
			return -1;
		}
	}

	if (transport->type == AST_TRANSPORT_UDP) {
		if (transport->host.addr.sa_family == pj_AF_INET()) {
			res = pjsip_udp_transport_start(ast_sip_get_pjsip_endpoint(), &transport->host.ipv4, NULL, transport->async_operations, &transport->state->transport);
		} else if (transport->host.addr.sa_family == pj_AF_INET6()) {
			res = pjsip_udp_transport_start6(ast_sip_get_pjsip_endpoint(), &transport->host.ipv6, NULL, transport->async_operations, &transport->state->transport);
		}

		if (res == PJ_SUCCESS && (transport->tos || transport->cos)) {
			pj_sock_t sock;
			pj_qos_params qos_params;

			sock = pjsip_udp_transport_get_socket(transport->state->transport);
			pj_sock_get_qos_params(sock, &qos_params);
			set_qos(transport, &qos_params);
			pj_sock_set_qos_params(sock, &qos_params);
		}
	} else if (transport->type == AST_TRANSPORT_TCP) {
		pjsip_tcp_transport_cfg cfg;

		pjsip_tcp_transport_cfg_default(&cfg, transport->host.addr.sa_family);
		cfg.bind_addr = transport->host;
		cfg.async_cnt = transport->async_operations;
		set_qos(transport, &cfg.qos_params);

		res = pjsip_tcp_transport_start3(ast_sip_get_pjsip_endpoint(), &cfg, &transport->state->factory);
	} else if (transport->type == AST_TRANSPORT_TLS) {
		transport->tls.ca_list_file = pj_str((char*)transport->ca_list_file);
		transport->tls.cert_file = pj_str((char*)transport->cert_file);
		transport->tls.privkey_file = pj_str((char*)transport->privkey_file);
		transport->tls.password = pj_str((char*)transport->password);
		set_qos(transport, &transport->tls.qos_params);

		res = pjsip_tls_transport_start2(ast_sip_get_pjsip_endpoint(), &transport->tls, &transport->host, NULL, transport->async_operations, &transport->state->factory);
	} else if ((transport->type == AST_TRANSPORT_WS) || (transport->type == AST_TRANSPORT_WSS)) {
		if (transport->cos || transport->tos) {
			ast_log(LOG_WARNING, "TOS and COS values ignored for websocket transport\n");
		}
		res = PJ_SUCCESS;
	}

	if (res != PJ_SUCCESS) {
		char msg[PJ_ERR_MSG_SIZE];

		pjsip_strerror(res, msg, sizeof(msg));
		ast_log(LOG_ERROR, "Transport '%s' could not be started: %s\n", ast_sorcery_object_get_id(obj), msg);
		return -1;
	}
	return 0;
}

/* Called by application to initialize the transport */
static pj_status_t transport_attach(   pjmedia_transport *tp,
				       void *user_data,
				       const pj_sockaddr_t *rem_addr,
				       const pj_sockaddr_t *rem_rtcp,
				       unsigned addr_len,
				       void (*rtp_cb)(void*,
						      void*,
						      pj_ssize_t),
				       void (*rtcp_cb)(void*,
						       void*,
						       pj_ssize_t))
{
    struct transport_udp *udp = (struct transport_udp*) tp;
    const pj_sockaddr *rtcp_addr;

    /* Validate arguments */
    PJ_ASSERT_RETURN(tp && rem_addr && addr_len, PJ_EINVAL);

    /* Must not be "attached" to existing application */
    PJ_ASSERT_RETURN(!udp->attached, PJ_EINVALIDOP);

    /* Lock the ioqueue keys to make sure that callbacks are
     * not executed. See ticket #844 for details.
     */
    pj_ioqueue_lock_key(udp->rtp_key);
    pj_ioqueue_lock_key(udp->rtcp_key);

    /* "Attach" the application: */

    /* Copy remote RTP address */
    pj_memcpy(&udp->rem_rtp_addr, rem_addr, addr_len);

    /* Copy remote RTP address, if one is specified. */
    rtcp_addr = (const pj_sockaddr*) rem_rtcp;
    if (rtcp_addr && pj_sockaddr_has_addr(rtcp_addr)) {
	pj_memcpy(&udp->rem_rtcp_addr, rem_rtcp, addr_len);

    } else {
	unsigned rtcp_port;

	/* Otherwise guess the RTCP address from the RTP address */
	pj_memcpy(&udp->rem_rtcp_addr, rem_addr, addr_len);
	rtcp_port = pj_sockaddr_get_port(&udp->rem_rtp_addr) + 1;
	pj_sockaddr_set_port(&udp->rem_rtcp_addr, (pj_uint16_t)rtcp_port);
    }

    /* Save the callbacks */
    udp->rtp_cb = rtp_cb;
    udp->rtcp_cb = rtcp_cb;
    udp->user_data = user_data;

    /* Save address length */
    udp->addr_len = addr_len;

    /* Last, mark transport as attached */
    udp->attached = PJ_TRUE;

    /* Reset source RTP & RTCP addresses and counter */
    pj_bzero(&udp->rtp_src_addr, sizeof(udp->rtp_src_addr));
    pj_bzero(&udp->rtcp_src_addr, sizeof(udp->rtcp_src_addr));
    udp->rtp_src_cnt = 0;
    udp->rtcp_src_cnt = 0;

    /* Set buffer size for RTP socket */
#if PJMEDIA_TRANSPORT_SO_RCVBUF_SIZE
    {
	unsigned sobuf_size = PJMEDIA_TRANSPORT_SO_RCVBUF_SIZE;
	pj_status_t status;
	status = pj_sock_setsockopt_sobuf(udp->rtp_sock, pj_SO_RCVBUF(),
					  PJ_TRUE, &sobuf_size);
	if (status != PJ_SUCCESS) {
	    pj_perror(3, tp->name, status, "Failed setting SO_RCVBUF");
	} else {
	    if (sobuf_size < PJMEDIA_TRANSPORT_SO_RCVBUF_SIZE) {
		PJ_LOG(4, (tp->name, 
			   "Warning! Cannot set SO_RCVBUF as configured, "
			   "now=%d, configured=%d",
			   sobuf_size, PJMEDIA_TRANSPORT_SO_RCVBUF_SIZE));
	    } else {
		PJ_LOG(5, (tp->name, "SO_RCVBUF set to %d", sobuf_size));
	    }
	}
    }
#endif
#if PJMEDIA_TRANSPORT_SO_SNDBUF_SIZE
    {
	unsigned sobuf_size = PJMEDIA_TRANSPORT_SO_SNDBUF_SIZE;
	pj_status_t status;
	status = pj_sock_setsockopt_sobuf(udp->rtp_sock, pj_SO_SNDBUF(),
					  PJ_TRUE, &sobuf_size);
	if (status != PJ_SUCCESS) {
	    pj_perror(3, tp->name, status, "Failed setting SO_SNDBUF");
	} else {
	    if (sobuf_size < PJMEDIA_TRANSPORT_SO_SNDBUF_SIZE) {
		PJ_LOG(4, (tp->name, 
			   "Warning! Cannot set SO_SNDBUF as configured, "
			   "now=%d, configured=%d",
			   sobuf_size, PJMEDIA_TRANSPORT_SO_SNDBUF_SIZE));
	    } else {
//.........这里部分代码省略.........

/* This callback is called by transport manager for the TCP factory
 * to create outgoing transport to the specified destination.
 */
static pj_status_t lis_create_transport(pjsip_tpfactory *factory,
					pjsip_tpmgr *mgr,
					pjsip_endpoint *endpt,
					const pj_sockaddr *rem_addr,
					int addr_len,
					pjsip_transport **p_transport)
{
    struct tcp_listener *li