void SessionExpiresHelper::process_request(pjsip_msg* req,
pj_pool_t* pool,
SAS::TrailId trail)
{
// Session expires is only allowed on INVITE and UPDATE methods.
pjsip_method* method = &req->line.req.method;
if ((pjsip_method_cmp(method, pjsip_get_invite_method()) != 0) &&
(pjsip_method_cmp(method, &METHOD_UPDATE) != 0))
{
return;
}
// Store if this is the initial transaction on a dialog, and if the UAC
// supports session timers. We need both of these when processing the
// response.
_initial_request = (PJSIP_MSG_TO_HDR(req)->tag.slen == 0);
_uac_supports_timer = timer_supported(req);
// Find the session-expires header (if present) and the minimum
// session-expires. Note that the latter has a default value.
pjsip_session_expires_hdr* se_hdr = (pjsip_session_expires_hdr*)
pjsip_msg_find_hdr_by_name(req, &STR_SESSION_EXPIRES, NULL);
pjsip_min_se_hdr* min_se_hdr = (pjsip_min_se_hdr*)
pjsip_msg_find_hdr_by_name(req, &STR_MIN_SE, NULL);
SessionInterval min_se = (min_se_hdr != NULL) ?
min_se_hdr->expires :
DEFAULT_MIN_SE;
if ((se_hdr != NULL) && (se_hdr->expires < _target_se))
{
// The request already has a session expires that is below our target. We
// don't need to change the value.
TRC_DEBUG("Session expires already set to %d", se_hdr->expires);
}
else
{
// No pre-existing session expires, or the current value is greater than
// our target. Set it to as close to our target as possible, but don't set
// it below the min-SE.
if (se_hdr == NULL)
{
se_hdr = pjsip_session_expires_hdr_create(pool);
pjsip_msg_add_hdr(req, (pjsip_hdr*)se_hdr);
}
se_hdr->expires = std::max(_target_se, min_se);
TRC_DEBUG("Set session expires to %d", se_hdr->expires);
}
// Make a note of the session expires (we may need it when processing the
// response)
_se_on_req = se_hdr->expires;
}
void SessionExpiresHelper::process_response(pjsip_msg* rsp,
pj_pool_t* pool,
SAS::TrailId trail)
{
// Session expires is only allowed on INVITE and UPDATE methods.
pjsip_method* method = &PJSIP_MSG_CSEQ_HDR(rsp)->method;
if ((pjsip_method_cmp(method, pjsip_get_invite_method()) != 0) &&
(pjsip_method_cmp(method, &METHOD_UPDATE) != 0))
{
return;
}
// We only need to process successful final responses.
if (!PJSIP_IS_STATUS_IN_CLASS(rsp->line.status.code, 200))
{
return;
}
pjsip_session_expires_hdr* se_hdr = (pjsip_session_expires_hdr*)
pjsip_msg_find_hdr_by_name(rsp, &STR_SESSION_EXPIRES, NULL);
if (se_hdr == NULL)
{
// There is no session-expires header. This means we are most downstream
// device that supports session timers, and in particular the UAS does not
// support them.
//
// If the UAC does not support session timers, there's nothing more we can
// do - session timers will not be used for this dialog.
//
// If the UAC *does* support session timers, re-add a session-expires header
// that instructs the UAC to be the refresher.
if (_uac_supports_timer)
{
se_hdr = pjsip_session_expires_hdr_create(pool);
pjsip_msg_add_hdr(rsp, (pjsip_hdr*)se_hdr);
se_hdr->expires = _se_on_req;
se_hdr->refresher = SESSION_REFRESHER_UAC;
// Also update (or add) the require header to force the UAC to do session
// refreshes.
pjsip_require_hdr* require_hdr = (pjsip_require_hdr*)
pjsip_msg_find_hdr(rsp, PJSIP_H_REQUIRE, NULL);
if (require_hdr == NULL)
{
require_hdr = (pjsip_require_hdr*)pjsip_require_hdr_create(pool);
pjsip_msg_add_hdr(rsp, (pjsip_hdr*)require_hdr);
}
pj_strdup(pool, &require_hdr->values[require_hdr->count], &STR_TIMER);
require_hdr->count++;
}
}
if (_initial_request)
{
if (se_hdr == NULL)
{
SAS::Event event(trail, SASEvent::SESS_TIMER_NO_UA_SUPPORT, 0);
SAS::report_event(event);
}
else if (se_hdr->expires > _target_se)
{
SAS::Event event(trail, SASEvent::SESS_TIMER_INTERVAL_TOO_LONG, 0);
event.add_static_param(_target_se);
event.add_static_param(se_hdr->expires);
SAS::report_event(event);
}
}
}
static void sas_log_rx_msg(pjsip_rx_data* rdata)
{
SAS::TrailId trail = 0;
if (rdata->msg_info.msg->type == PJSIP_RESPONSE_MSG)
{
// Message is a response, so try to correlate to an existing UAC
// transaction using the top-most Via header.
pj_str_t key;
pjsip_tsx_create_key(rdata->tp_info.pool, &key, PJSIP_ROLE_UAC,
&rdata->msg_info.cseq->method, rdata);
pjsip_transaction* tsx = pjsip_tsx_layer_find_tsx(&key, PJ_TRUE);
if (tsx)
{
// Found the UAC transaction, so get the trail if there is one.
trail = get_trail(tsx);
// Unlock tsx because it is locked in find_tsx()
pj_grp_lock_release(tsx->grp_lock);
}
}
else if (rdata->msg_info.msg->line.req.method.id == PJSIP_ACK_METHOD)
{
// Message is an ACK, so try to correlate it to the existing UAS
// transaction using the top-most Via header.
pj_str_t key;
pjsip_tsx_create_key(rdata->tp_info.pool, &key, PJSIP_UAS_ROLE,
&rdata->msg_info.cseq->method, rdata);
pjsip_transaction* tsx = pjsip_tsx_layer_find_tsx(&key, PJ_TRUE);
if (tsx)
{
// Found the UAS transaction, so get the trail if there is one.
trail = get_trail(tsx);
// Unlock tsx because it is locked in find_tsx()
pj_grp_lock_release(tsx->grp_lock);
}
}
else if (rdata->msg_info.msg->line.req.method.id == PJSIP_CANCEL_METHOD)
{
// Message is a CANCEL request chasing an INVITE, so we want to try to
// correlate it to the INVITE trail for the purposes of SAS tracing.
pj_str_t key;
pjsip_tsx_create_key(rdata->tp_info.pool, &key, PJSIP_UAS_ROLE,
pjsip_get_invite_method(), rdata);
pjsip_transaction* tsx = pjsip_tsx_layer_find_tsx(&key, PJ_TRUE);
if (tsx)
{
// Found the INVITE UAS transaction, so get the trail if there is one.
trail = get_trail(tsx);
// Unlock tsx because it is locked in find_tsx()
pj_grp_lock_release(tsx->grp_lock);
}
}
if (trail == 0)
{
// The message doesn't correlate to an existing trail, so create a new
// one.
trail = SAS::new_trail(1u);
}
// Store the trail in the message as it gets passed up the stack.
set_trail(rdata, trail);
// Log the message event.
SAS::Event event(trail, SASEvent::RX_SIP_MSG, 1u);
event.add_static_param(pjsip_transport_get_type_from_flag(rdata->tp_info.transport->flag));
event.add_static_param(rdata->pkt_info.src_port);
event.add_var_param(rdata->pkt_info.src_name);
event.add_var_param(rdata->msg_info.len, rdata->msg_info.msg_buf);
SAS::report_event(event);
}
/* Callback to be called to handle new incoming requests. */
static pj_bool_t proxy_on_rx_request( pjsip_rx_data *rdata )
{
pjsip_transaction *uas_tsx, *uac_tsx;
struct uac_data *uac_data;
struct uas_data *uas_data;
pjsip_tx_data *tdata;
pj_status_t status;
if (rdata->msg_info.msg->line.req.method.id != PJSIP_CANCEL_METHOD) {
/* Verify incoming request */
status = proxy_verify_request(rdata);
if (status != PJ_SUCCESS) {
app_perror("RX invalid request", status);
return PJ_TRUE;
}
/*
* Request looks sane, next clone the request to create transmit data.
*/
status = pjsip_endpt_create_request_fwd(global.endpt, rdata, NULL,
NULL, 0, &tdata);
if (status != PJ_SUCCESS) {
pjsip_endpt_respond_stateless(global.endpt, rdata,
PJSIP_SC_INTERNAL_SERVER_ERROR,
NULL, NULL, NULL);
return PJ_TRUE;
}
/* Process routing */
status = proxy_process_routing(tdata);
if (status != PJ_SUCCESS) {
app_perror("Error processing route", status);
return PJ_TRUE;
}
/* Calculate target */
status = proxy_calculate_target(rdata, tdata);
if (status != PJ_SUCCESS) {
app_perror("Error calculating target", status);
return PJ_TRUE;
}
/* Everything is set to forward the request. */
/* If this is an ACK request, forward statelessly.
* This happens if the proxy records route and this ACK
* is sent for 2xx response. An ACK that is sent for non-2xx
* final response will be absorbed by transaction layer, and
* it will not be received by on_rx_request() callback.
*/
if (tdata->msg->line.req.method.id == PJSIP_ACK_METHOD) {
status = pjsip_endpt_send_request_stateless(global.endpt, tdata,
NULL, NULL);
if (status != PJ_SUCCESS) {
app_perror("Error forwarding request", status);
return PJ_TRUE;
}
return PJ_TRUE;
}
/* Create UAC transaction for forwarding the request.
* Set our module as the transaction user to receive further
* events from this transaction.
*/
status = pjsip_tsx_create_uac(&mod_tu, tdata, &uac_tsx);
if (status != PJ_SUCCESS) {
pjsip_tx_data_dec_ref(tdata);
pjsip_endpt_respond_stateless(global.endpt, rdata,
PJSIP_SC_INTERNAL_SERVER_ERROR,
NULL, NULL, NULL);
return PJ_TRUE;
}
/* Create UAS transaction to handle incoming request */
status = pjsip_tsx_create_uas(&mod_tu, rdata, &uas_tsx);
if (status != PJ_SUCCESS) {
pjsip_tx_data_dec_ref(tdata);
pjsip_endpt_respond_stateless(global.endpt, rdata,
PJSIP_SC_INTERNAL_SERVER_ERROR,
NULL, NULL, NULL);
pjsip_tsx_terminate(uac_tsx, PJSIP_SC_INTERNAL_SERVER_ERROR);
return PJ_TRUE;
}
/* Feed the request to the UAS transaction to drive it's state
* out of NULL state.
*/
pjsip_tsx_recv_msg(uas_tsx, rdata);
/* Attach a data to the UAC transaction, to be used to find the
* UAS transaction when we receive response in the UAC side.
*/
uac_data = (struct uac_data*)
pj_pool_alloc(uac_tsx->pool, sizeof(struct uac_data));
uac_data->uas_tsx = uas_tsx;
uac_tsx->mod_data[mod_tu.id] = (void*)uac_data;
/* Attach data to the UAS transaction, to find the UAC transaction
* when cancelling INVITE request.
*/
uas_data = (struct uas_data*)
pj_pool_alloc(uas_tsx->pool, sizeof(struct uas_data));
uas_data->uac_tsx = uac_tsx;
uas_tsx->mod_data[mod_tu.id] = (void*)uas_data;
/* Everything is setup, forward the request */
status = pjsip_tsx_send_msg(uac_tsx, tdata);
if (status != PJ_SUCCESS) {
pjsip_tx_data *err_res;
/* Fail to send request, for some reason */
/* Destroy transmit data */
pjsip_tx_data_dec_ref(tdata);
/* I think UAC transaction should have been destroyed when
* it fails to send request, so no need to destroy it.
pjsip_tsx_terminate(uac_tsx, PJSIP_SC_INTERNAL_SERVER_ERROR);
*/
/* Send 500/Internal Server Error to UAS transaction */
pjsip_endpt_create_response(global.endpt, rdata,
500, NULL, &err_res);
pjsip_tsx_send_msg(uas_tsx, err_res);
return PJ_TRUE;
}
/* Send 100/Trying if this is an INVITE */
if (rdata->msg_info.msg->line.req.method.id == PJSIP_INVITE_METHOD) {
pjsip_tx_data *res100;
pjsip_endpt_create_response(global.endpt, rdata, 100, NULL,
&res100);
pjsip_tsx_send_msg(uas_tsx, res100);
}
} else {
/* This is CANCEL request */
pjsip_transaction *invite_uas;
struct uas_data *uas_data;
pj_str_t key;
/* Find the UAS INVITE transaction */
pjsip_tsx_create_key(rdata->tp_info.pool, &key, PJSIP_UAS_ROLE,
pjsip_get_invite_method(), rdata);
invite_uas = pjsip_tsx_layer_find_tsx(&key, PJ_TRUE);
if (!invite_uas) {
/* Invite transaction not found, respond CANCEL with 481 */
pjsip_endpt_respond_stateless(global.endpt, rdata, 481, NULL,
NULL, NULL);
return PJ_TRUE;
}
/* Respond 200 OK to CANCEL */
pjsip_endpt_respond(global.endpt, NULL, rdata, 200, NULL, NULL,
NULL, NULL);
/* Send CANCEL to cancel the UAC transaction.
* The UAS INVITE transaction will get final response when
* we receive final response from the UAC INVITE transaction.
*/
uas_data = (struct uas_data*) invite_uas->mod_data[mod_tu.id];
if (uas_data->uac_tsx && uas_data->uac_tsx->status_code < 200) {
pjsip_tx_data *cancel;
pj_mutex_lock(uas_data->uac_tsx->mutex);
pjsip_endpt_create_cancel(global.endpt, uas_data->uac_tsx->last_tx,
&cancel);
pjsip_endpt_send_request(global.endpt, cancel, -1, NULL, NULL);
pj_mutex_unlock(uas_data->uac_tsx->mutex);
}
/* Unlock UAS tsx because it is locked in find_tsx() */
pj_mutex_unlock(invite_uas->mutex);
}
return PJ_TRUE;
}
// LCOV_EXCL_START - can't meaningfully test SAS in UT
static void sas_log_rx_msg(pjsip_rx_data* rdata)
{
bool first_message_in_trail = false;
SAS::TrailId trail = 0;
// Look for the SAS Trail ID for the corresponding transaction object.
//
// Note that we are NOT locking the transaction object before we fetch the
// trail ID from it. This is deliberate - we cannot get a group lock from
// this routine as we may already have obtained the IO lock (which is lower
// in the locking hierarchy) higher up the stack.
// (e.g. from ioqueue_common_abs::ioqueue_dispatch_read_event) and grabbing
// the group lock here may cause us to deadlock with a thread using the locks
// in the right order.
//
// This is safe for the following reasons
// - The transaction objects are only ever invalidated by the current thread
// (i.e. the transport thread), so we don't need to worry about the tsx
// pointers being invalid.
// - In principle, the trail IDs (which are 64 bit numbers stored as void*s
// since thats the format of the generic PJSIP user data area) might be
// being written to as we are reading them, thereby invalidating them.
// However, the chances of this happening are exceedingly remote and, if it
// ever happened, the worst that could happen is that the trail ID would be
// invalid and the log we're about to make unreachable by SAS. This is
// assumed to be sufficiently low impact as to be ignorable for practical
// purposes.
if (rdata->msg_info.msg->type == PJSIP_RESPONSE_MSG)
{
// Message is a response, so try to correlate to an existing UAC
// transaction using the top-most Via header.
pj_str_t key;
pjsip_tsx_create_key(rdata->tp_info.pool, &key, PJSIP_ROLE_UAC,
&rdata->msg_info.cseq->method, rdata);
pjsip_transaction* tsx = pjsip_tsx_layer_find_tsx(&key, PJ_FALSE);
if (tsx)
{
// Found the UAC transaction, so get the trail if there is one.
trail = get_trail(tsx);
}
}
else if (rdata->msg_info.msg->line.req.method.id == PJSIP_ACK_METHOD)
{
// Message is an ACK, so try to correlate it to the existing UAS
// transaction using the top-most Via header.
pj_str_t key;
pjsip_tsx_create_key(rdata->tp_info.pool, &key, PJSIP_UAS_ROLE,
&rdata->msg_info.cseq->method, rdata);
pjsip_transaction* tsx = pjsip_tsx_layer_find_tsx(&key, PJ_FALSE);
if (tsx)
{
// Found the UAS transaction, so get the trail if there is one.
trail = get_trail(tsx);
}
}
else if (rdata->msg_info.msg->line.req.method.id == PJSIP_CANCEL_METHOD)
{
// Message is a CANCEL request chasing an INVITE, so we want to try to
// correlate it to the INVITE trail for the purposes of SAS tracing.
pj_str_t key;
pjsip_tsx_create_key(rdata->tp_info.pool, &key, PJSIP_UAS_ROLE,
pjsip_get_invite_method(), rdata);
pjsip_transaction* tsx = pjsip_tsx_layer_find_tsx(&key, PJ_FALSE);
if (tsx)
{
// Found the INVITE UAS transaction, so get the trail if there is one.
trail = get_trail(tsx);
}
}
else if ((rdata->msg_info.msg->line.req.method.id == PJSIP_OPTIONS_METHOD) &&
(URIClassifier::classify_uri(rdata->msg_info.msg->line.req.uri) == NODE_LOCAL_SIP_URI))
{
// This is an OPTIONS poll directed at this node. Don't log it to SAS, and set the trail ID to a sentinel value so we don't log the response either.
TRC_DEBUG("Skipping SAS logging for OPTIONS request");
set_trail(rdata, DONT_LOG_TO_SAS);
return;
}
if (trail == 0)
{
// The message doesn't correlate to an existing trail, so create a new
// one.
// If SAS::new_trail returns 0 or DONT_LOG_TO_SAS, keep going.
while ((trail == 0) || (trail == DONT_LOG_TO_SAS))
{
trail = SAS::new_trail(1u);
}
first_message_in_trail = true;
}
// Store the trail in the message as it gets passed up the stack.
set_trail(rdata, trail);
// Raise SAS markers on the first message in a trail only - subsequent
// messages with the same trail ID don't need additional markers
if (first_message_in_trail)
{
PJUtils::report_sas_to_from_markers(trail, rdata->msg_info.msg);
pjsip_cid_hdr* cid = (pjsip_cid_hdr*)rdata->msg_info.cid;
PJUtils::mark_sas_call_branch_ids(trail, cid, rdata->msg_info.msg);
}
// Log the message event.
SAS::Event event(trail, SASEvent::RX_SIP_MSG, 0);
event.add_static_param(pjsip_transport_get_type_from_flag(rdata->tp_info.transport->flag));
event.add_static_param(rdata->pkt_info.src_port);
event.add_var_param(rdata->pkt_info.src_name);
event.add_compressed_param(rdata->msg_info.len, rdata->msg_info.msg_buf, &SASEvent::PROFILE_SIP);
SAS::report_event(event);
}
static pjsip_dialog *find_dialog(pjsip_rx_data *rdata)
{
pj_str_t tsx_key;
pjsip_transaction *tsx;
pjsip_dialog *dlg;
pj_str_t *local_tag;
pj_str_t *remote_tag;
if (!rdata->msg_info.msg) {
return NULL;
}
if (rdata->msg_info.msg->type == PJSIP_REQUEST_MSG) {
local_tag = &rdata->msg_info.to->tag;
remote_tag = &rdata->msg_info.from->tag;
} else {
local_tag = &rdata->msg_info.from->tag;
remote_tag = &rdata->msg_info.to->tag;
}
/* We can only call the convenient method for
* 1) responses
* 2) non-CANCEL requests
* 3) CANCEL requests with a to-tag
*/
if (rdata->msg_info.msg->type == PJSIP_RESPONSE_MSG ||
pjsip_method_cmp(&rdata->msg_info.msg->line.req.method, &pjsip_cancel_method) ||
rdata->msg_info.to->tag.slen != 0) {
dlg = pjsip_ua_find_dialog(&rdata->msg_info.cid->id, local_tag,
remote_tag, PJ_FALSE);
if (dlg) {
return dlg;
}
}
/*
* There may still be a matching dialog if this is
* 1) an incoming CANCEL request without a to-tag
* 2) an incoming response to a dialog-creating request.
*/
if (rdata->msg_info.msg->type == PJSIP_REQUEST_MSG) {
/* CANCEL requests will need to match the INVITE we initially received. Any
* other request type will either have been matched already or is not in
* dialog
*/
pjsip_tsx_create_key(rdata->tp_info.pool, &tsx_key, PJSIP_ROLE_UAS,
pjsip_get_invite_method(), rdata);
} else {
pjsip_tsx_create_key(rdata->tp_info.pool, &tsx_key, PJSIP_ROLE_UAC,
&rdata->msg_info.cseq->method, rdata);
}
tsx = pjsip_tsx_layer_find_tsx(&tsx_key, PJ_TRUE);
if (!tsx) {
ast_debug(3, "Could not find matching transaction for %s\n",
pjsip_rx_data_get_info(rdata));
return NULL;
}
dlg = pjsip_tsx_get_dlg(tsx);
#ifdef HAVE_PJ_TRANSACTION_GRP_LOCK
pj_grp_lock_release(tsx->grp_lock);
#else
pj_mutex_unlock(tsx->mutex);
#endif
return dlg;
}
