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Merge "res/res_pjsip_nat: Fix logic for REINVITES" into 16

This commit is contained in:
George Joseph 2018-11-18 08:46:53 -06:00 committed by Gerrit Code Review
parent 7d11718a80 7b2282c890
commit 9bb155d95e
1 changed files with 68 additions and 8 deletions
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76
res/res_pjsip_nat.c
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@ -45,10 +45,42 @@ static void rewrite_uri(pjsip_rx_data *rdata, pjsip_sip_uri *uri)
}
}
/*
* Update the Record-Route headers in the request or response and in the dialog
* object if exists.
*
* When NAT is in use, the address of the next hop in the SIP may be incorrect.
* To address this asterisk uses two strategies in parallel:
* 1. intercept the messages at the transaction level and rewrite the
* messages before arriving at the dialog layer
* 2. after the application processing, update the dialog object with the
* correct information
*
* The first strategy has a limitation that the SIP message may not have all
* the information required to determine if the next hop is in the route set
* or in the contact. Causing risk that asterisk will update the Contact on
* receipt of an in-dialog message despite there being a route set saved in
* the dialog.
*
* The second strategy has a limitation that not all UAC layers have interfaces
* available to invoke this module after dialog creation. (pjsip_sesion does
* but pjsip_pubsub does not), thus this strategy can't update the dialog in
* all cases needed.
*
* The ideal solution would be to implement an "incomming_request" event
* in pubsub module that can then pass the dialog object to this module
* on SUBSCRIBE, this module then should add itself as a listener to the dialog
* for the subsequent requests and responses & then be able to properly update
* the dialog object for all required events.
*/
static int rewrite_route_set(pjsip_rx_data *rdata, pjsip_dialog *dlg)
{
pjsip_rr_hdr *rr = NULL;
pjsip_sip_uri *uri;
int res = -1;
int ignore_rr = 0;
int pubsub = 0;
if (rdata->msg_info.msg->type == PJSIP_RESPONSE_MSG) {
pjsip_hdr *iter;
@ -60,21 +92,49 @@ static int rewrite_route_set(pjsip_rx_data *rdata, pjsip_dialog *dlg)
}
} else if (pjsip_method_cmp(&rdata->msg_info.msg->line.req.method, &pjsip_register_method)) {
rr = pjsip_msg_find_hdr(rdata->msg_info.msg, PJSIP_H_RECORD_ROUTE, NULL);
} else {
/**
* Record-Route header has no meaning in REGISTER requests
* and should be ignored
*/
ignore_rr = 1;
}
if (!pjsip_method_cmp(&rdata->msg_info.cseq->method, &pjsip_subscribe_method) ||
!pjsip_method_cmp(&rdata->msg_info.cseq->method, &pjsip_notify_method)) {
/**
* There is currently no good way to get the dlg object for a pubsub dialog
* so we will just look at the rr & contact of the current message and
* hope for the best
*/
pubsub = 1;
}
if (rr) {
uri = pjsip_uri_get_uri(&rr->name_addr);
rewrite_uri(rdata, uri);
if (dlg && !pj_list_empty(&dlg->route_set) && !dlg->route_set_frozen) {
pjsip_routing_hdr *route = dlg->route_set.next;
uri = pjsip_uri_get_uri(&route->name_addr);
rewrite_uri(rdata, uri);
}
return 0;
res = 0;
}
return -1;
if (dlg && !pj_list_empty(&dlg->route_set) && !dlg->route_set_frozen) {
pjsip_routing_hdr *route = dlg->route_set.next;
uri = pjsip_uri_get_uri(&route->name_addr);
rewrite_uri(rdata, uri);
res = 0;
}
if (!dlg && !rr && !ignore_rr && !pubsub && rdata->msg_info.to->tag.slen){
/**
* Even if this message doesn't have any route headers
* the dialog may, so wait until a later invocation that
* has a dialog reference to make sure there isn't a
* previously saved routset in the dialog before deciding
* the contact needs to be modified
*/
res = 0;
}
return res;
}
static int rewrite_contact(pjsip_rx_data *rdata, pjsip_dialog *dlg)