/**
* Every time a new dialog is created (from a new INVITE) the dialog
* module will call this callback function. We need to track the
* dialogs lifespan from this point forward until it is terminated
* with a BYE, CANCEL, etc. In the process, we will see if either or
* both ends of the conversation are trying to re-negotiate the media.
*
* This function will setup the other types of dialog callbacks
* required to track the lifespan of the dialog.
*
*
* @param did - The dialog ID
* @param type - The trigger event type (CREATED)
* @param msg - The SIP message that triggered the callback (INVITE)
* @param param - The pointer to nothing. As we did not attach
* anything to this callback in the dialog module.
*/
void qos_dialog_created_CB(struct dlg_cell *did, int type, struct dlg_cb_params * params)
{
qos_ctx_t *qos_ctx = NULL;
struct sip_msg* msg = params->req;
unsigned int dir = params->direction, role, other_role;
if (dir == DLG_DIR_UPSTREAM) {
role = QOS_CALLEE;
other_role = QOS_CALLER;
} else if (dir == DLG_DIR_DOWNSTREAM) {
role = QOS_CALLER;
other_role = QOS_CALLEE;
} else {
LM_ERR("Unknown dir %d\n", dir);
return;
}
if (msg == NULL || msg == FAKED_REPLY) {
LM_ERR("Improper msg\n");
return;
}
/* look only at INVITE */
if (msg->first_line.type != SIP_REQUEST ||
msg->first_line.u.request.method_value != METHOD_INVITE) {
LM_WARN("Dialog create callback called with a non-INVITE req.\n");
return;
}
qos_ctx = build_new_qos_ctx();
if (qos_ctx==NULL) {
/* Error message printed in build_new_qos_ctx() */
return;
}
LM_DBG("setup_dialog_callbacks( %p , %p )\n", did, qos_ctx);
setup_dialog_callbacks(did, qos_ctx);
run_create_cbs(qos_ctx, msg);
if (0 == parse_sdp(msg)) {
lock_get(&qos_ctx->lock);
add_sdp(qos_ctx, dir, msg, role, other_role);
lock_release(&qos_ctx->lock);
}
return;
}
void sst_dialog_loaded_CB(struct dlg_cell *did, int type,
struct dlg_cb_params *params){
/* Check if this is previously marked by sst module */
if (!dlg_binds->is_mod_flag_set(did, SST_DIALOG_FLAG))
return;
/* We try to get the original sst info back */
sst_info_t *info = (sst_info_t *)shm_malloc(sizeof(sst_info_t));
if (info == NULL) {
LM_ERR ("No more shared memory!\n");
return;
}
str raw_info = {(char*)info, sizeof(sst_info_t)};
if (dlg_binds->fetch_dlg_value(did, &info_val_name, &raw_info, 1) != 0){
LM_ERR ("No sst_info found!\n");
return;
}
setup_dialog_callbacks(did, info);
}
/**
* Every time a new dialog is created (from a new INVITE) the dialog
* module will call this callback function. We need to track the
* dialogs lifespan from this point forward until it is terminated
* with a BYE, CANCEL, etc. In the process, we will see if either or
* both ends of the conversation supports SIP Session Timers and setup
* the dialog timeout to expire at the session timer expire time. Each
* time the new re-INVITE is seen to update the SST, we will reset the
* life span of the dialog to match it.
*
* This function will setup the other types of dialog callbacks
* required to track the lifespan of the dialog. It will also start
* the state tracking to figure out if and who supports SST.
*
* As per RFC4028: Request handling:
*
* - The proxy may insert a SE header if none found.
* - The SE value can be anything >= Min-SE (if found)
* - The proxy MUST NOT add a refresher parameter to the SE.
*
* - If SE is already there, the Proxy can reduce its value but no
* lower then the Min-SE value if present.
* - If the SE value is >= Min-SE the proxy MUST NOT increase it!
* - If the SE value is < Min-SE (settable by the proxy) the proxy
* MUST increase the SE value to >= the new Min-SE.
* - The proxy MUST NOT insert or change the refresher parameter.
*
* - If the supported=timer is found, the proxy may reject the request
* with a 422 if the SE value is smaller then the local policy. The
* 422 MUST hold the proxies Min-SE value >= 90.
* - If support=timer is NOT indecated, the proxy can't reject with a
* 422 but can include/increase the MIN-SE: to be = to local policy.
* and increase the SE to match the new Min-SE value.
* - the proxy MUST NOT insert/change the Min-SE header if
* supported=timer is present. (DoS attacks)
*
* @param did - The dialog ID
* @param type - The trigger event type (CREATED)
* @param params - The pointer to nothing. As we did not attach
* anything to this callback in the dialog module.
*/
void sst_dialog_created_CB(struct dlg_cell *did, int type,
struct dlg_cb_params * params)
{
sst_info_t *info = NULL;
sst_msg_info_t minfo;
struct sip_msg* msg = params->msg;
memset(&minfo, 0, sizeof(sst_msg_info_t));
/*
* Only deal with messages flaged as SST interested.
*/
if ((msg->flags & sst_flag) != sst_flag) {
LM_DBG("SST flag was not set for this request\n");
return;
}
/*
* look only at INVITE
*/
if (msg->first_line.type != SIP_REQUEST ||
msg->first_line.u.request.method_value != METHOD_INVITE) {
LM_WARN("dialog create callback called with a non-INVITE request.\n");
return;
}
/*
* Gather all he information about SST for this message
*/
if (parse_msg_for_sst_info(msg, &minfo)) {
LM_ERR("failed to parse sst information\n");
return;
}
info = (sst_info_t *)shm_malloc(sizeof(sst_info_t));
memset(info, 0, sizeof(sst_info_t));
info->requester = (minfo.se?SST_UAC:SST_UNDF);
info->supported = (minfo.supported?SST_UAC:SST_UNDF);
info->interval = MAX(sst_interval, 90); /* For now, will set for real
* later */
if (minfo.se != 0) {
/*
* There is a SE already there, this is good, we just need to
* check the values out a little before passing it along.
*/
if (minfo.se < sst_min_se) {
/*
* Problem, the requested Session-Expires is too small for
* our local policy. We need to fix it, or reject it or
* ignore it.
*/
if (!minfo.supported) {
/*
* Increase the Min-SE: value in the request and
* forward it.
*/
char buf[80];
if (minfo.min_se) {
/* We need to update, which means, remove +
* insert */
remove_minse_header(msg);
}
info->interval = MAX(sst_min_se, minfo.min_se);
snprintf(buf, 80, "Min-SE: %d\r\n", info->interval);
if (append_header(msg, buf)) {
LM_ERR("Could not append modified Min-SE: header\n");
}
}
else if (sst_reject) {
/* Make sure that that all are at least 90 */
send_reject(msg, MAX(MAX(sst_min_se, minfo.min_se), 90));
shm_free(info);
return;
}
} /* end of se < sst_min_se */
else {
/* Use the INVITE SE: value */
info->interval = minfo.se;
}
}
else {
/*
* No Session-Expire: stated in request.
*/
char buf[80];
info->interval = MAX(minfo.min_se, sst_min_se);
if (minfo.min_se && minfo.min_se < sst_min_se) {
remove_minse_header(msg);
snprintf(buf, 80, "Min-SE: %d\r\n", info->interval);
if (append_header(msg, buf)) {
LM_ERR("failed to append modified Min-SE: header\n");
/* What to do? Let is slide, we can still work */
}
}
info->interval = MAX(info->interval, sst_interval);
info->requester = SST_PXY;
snprintf(buf, 80, "Session-Expires: %d\r\n", info->interval);
if (append_header(msg, buf)) {
LM_ERR("failed to append Session-Expires header to proxy "
"requested SST.\n");
shm_free(info);
return; /* Nothing we can do! */
}
}
/* We keep the sst_info in the dialog's vals in case of restarting */
/* No const here because of store_dlg_value's definition */
str raw_info = {(char*)info, sizeof(sst_info_t)};
if (dlg_binds->store_dlg_value(did, &info_val_name, &raw_info) != 0) {
LM_ERR("No sst_info can be added to the dialog."
"This dialog won't be considered after restart!\n");
}
dlg_binds->set_mod_flag(did, SST_DIALOG_FLAG);
setup_dialog_callbacks(did, info);
/* Early setup of default timeout */
set_dialog_lifetime(did, info->interval);
return;
}
/**
* Every time a new dialog is created (from a new INVITE) the dialog
* module will call this callback function. We need to track the
* dialogs lifespan from this point forward until it is terminated
* with a BYE, CANCEL, etc. In the process, we will see if either or
* both ends of the conversation supports SIP Session Timers and setup
* the dialog timeout to expire at the session timer expire time. Each
* time the new re-INVITE is seen to update the SST, we will reset the
* life span of the dialog to match it.
*
* This function will setup the other types of dialog callbacks
* required to track the lifespan of the dialog. It will also start
* the state tracking to figure out if and who supports SST.
*
* As per RFC4028: Request handling:
*
* - The proxy may insert a SE header if none found.
* - The SE value can be anything >= Min-SE (if found)
* - The proxy MUST NOT add a refresher parameter to the SE.
*
* - If SE is already there, the Proxy can reduce its value but no
* lower then the Min-SE value if present.
* - If the SE value is >= Min-SE the proxy MUST NOT increase it!
* - If the SE value is < Min-SE (settable by the proxy) the proxy
* MUST increase the SE value to >= the new Min-SE.
* - The proxy MUST NOT insert or change the refresher parameter.
*
* - If the supported=timer is found, the proxy may reject the request
* with a 422 if the SE value is smaller then the local policy. The
* 422 MUST hold the proxies Min-SE value >= 90.
* - If support=timer is NOT indecated, the proxy can't reject with a
* 422 but can include/increase the MIN-SE: to be = to local policy.
* and increase the SE to match the new Min-SE value.
* - the proxy MUST NOT insert/change the Min-SE header if
* supported=timer is present. (DoS attacks)
*
* @param did - The dialog ID
* @param type - The trigger event type (CREATED)
* @param params - The pointer to nothing. As we did not attach
* anything to this callback in the dialog module.
*/
void sst_dialog_created_CB(struct dlg_cell *did, int type,
struct dlg_cb_params * params)
{
sst_info_t *info = NULL;
sst_msg_info_t minfo;
struct sip_msg* msg = params->req;
memset(&minfo, 0, sizeof(sst_msg_info_t));
/*
* Only deal with messages flaged as SST interested.
*/
if ((msg->flags & sst_flag) != sst_flag) {
LM_DBG("SST flag was not set for this request\n");
return;
}
/*
* look only at INVITE
*/
if (msg->first_line.type != SIP_REQUEST ||
msg->first_line.u.request.method_value != METHOD_INVITE) {
LM_WARN("dialog create callback called with a non-INVITE request.\n");
return;
}
/*
* Gather all he information about SST for this message
*/
if (parse_msg_for_sst_info(msg, &minfo)) {
LM_ERR("failed to parse sst information\n");
return;
}
info = (sst_info_t *)shm_malloc(sizeof(sst_info_t));
memset(info, 0, sizeof(sst_info_t));
info->requester = (minfo.se?SST_UAC:SST_UNDF);
info->supported = (minfo.supported?SST_UAC:SST_UNDF);
info->interval = MAX(sst_min_se, 90); /* For now, will set for real
* later */
if (minfo.se != 0) {
/*
* There is a SE already there, this is good, we just need to
* check the values out a little before passing it along.
*/
if (minfo.se < sst_min_se) {
/*
* Problem, the requested Session-Expires is too small for
* our local policy. We need to fix it, or reject it or
* ignore it.
*/
if (!minfo.supported) {
/*
* Increase the Min-SE: value in the request and
* forward it.
*/
str msehdr;
if (minfo.min_se) {
/* We need to update, which means, remove +
* insert */
remove_header(msg, "Min-SE");
}
info->interval = MAX(sst_min_se, minfo.min_se);
sst_build_minse_hdr(info->interval, &msehdr);
if (append_header(msg, msehdr.s)) {
LM_ERR("Could not append modified Min-SE: header\n");
}
}
else if (sst_reject) {
/* Make sure that that all are at least 90 */
send_reject(msg, MAX(MAX(sst_min_se, minfo.min_se), 90));
shm_free(info);
return;
}
} /* end of se < sst_min_se */
else {
/* Use the INVITE SE: value */
info->interval = minfo.se;
}
}
else {
/*
* No Session-Expire: stated in request.
*/
str msehdr;
info->interval = MAX(minfo.min_se, sst_min_se);
if (minfo.min_se && minfo.min_se < sst_min_se) {
remove_header(msg, "Min-SE");
sst_build_minse_hdr(info->interval, &msehdr);
if (append_header(msg, msehdr.s)) {
LM_ERR("failed to append modified Min-SE: header\n");
/* What to do? Let is slide, we can still work */
}
}
info->requester = SST_PXY;
sst_build_se_hdr(info->interval, &msehdr, NULL);
if (append_header(msg, msehdr.s)) {
LM_ERR("failed to append Session-Expires header to proxy "
"requested SST.\n");
shm_free(info);
return; /* Nothing we can do! */
}
}
setup_dialog_callbacks(did, info);
set_timeout_avp(msg, info->interval);
return;
}
