res_pjsip_nat.c: Create deep copies of strings when appropriate

In rewrite_uri asterisk was not making deep copies of strings when
changing the uri. This was in some cases causing garbage in the route
header and in other cases even crashing asterisk when receiving a
message with a record-route header set. Thanks to Ralf Kubis for
pointing out why this happens. A similar problem was found in
res_pjsip_transport_websocket.c. Pjproject needs as well to be patched
to avoid garbage in CANCEL messages.

ASTERISK-29024 #close

Change-Id: Ic5acd7fa2fbda3080f5f36ef12e46804939b198b

res/res_pjsip_nat.c

@@ -66,14 +66,14 @@ static void save_orig_contact_host(pjsip_rx_data *rdata, pjsip_sip_uri *uri)
 	return;
 }
 
-static void rewrite_uri(pjsip_rx_data *rdata, pjsip_sip_uri *uri)
+static void rewrite_uri(pjsip_rx_data *rdata, pjsip_sip_uri *uri, pj_pool_t *pool)
 {
 
 	if (pj_strcmp2(&uri->host, rdata->pkt_info.src_name) != 0) {
 		save_orig_contact_host(rdata, uri);
 	}
 
-	pj_cstr(&uri->host, rdata->pkt_info.src_name);
+	pj_strdup2(pool, &uri->host, rdata->pkt_info.src_name);
 	uri->port = rdata->pkt_info.src_port;
 	if (!strcasecmp("WSS", rdata->tp_info.transport->type_name)) {
 		/* WSS is special, we don't want to overwrite the URI at all as it needs to be ws */
@@ -151,14 +151,14 @@ static int rewrite_route_set(pjsip_rx_data *rdata, pjsip_dialog *dlg)
 
 	if (rr) {
 		uri = pjsip_uri_get_uri(&rr->name_addr);
-		rewrite_uri(rdata, uri);
+		rewrite_uri(rdata, uri, rdata->tp_info.pool);
 		res = 0;
 	}
 
 	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);
+		rewrite_uri(rdata, uri, dlg->pool);
 		res = 0;
 	}
 
@@ -184,7 +184,7 @@ static int rewrite_contact(pjsip_rx_data *rdata, pjsip_dialog *dlg)
 	if (contact && !contact->star && (PJSIP_URI_SCHEME_IS_SIP(contact->uri) || PJSIP_URI_SCHEME_IS_SIPS(contact->uri))) {
 		pjsip_sip_uri *uri = pjsip_uri_get_uri(contact->uri);
 
-		rewrite_uri(rdata, uri);
+		rewrite_uri(rdata, uri, rdata->tp_info.pool);
 
 		if (dlg && pj_list_empty(&dlg->route_set) && (!dlg->remote.contact
 			|| pjsip_uri_cmp(PJSIP_URI_IN_REQ_URI, dlg->remote.contact->uri, contact->uri))) {

res/res_pjsip_transport_websocket.c

@@ -454,7 +454,7 @@ static pj_bool_t websocket_on_rx_msg(pjsip_rx_data *rdata)
 				pj_strbuf(txp_str));
 		}
 
-		pj_cstr(&uri->host, rdata->pkt_info.src_name);
+		pj_strdup2(rdata->tp_info.pool, &uri->host, rdata->pkt_info.src_name);
 		uri->port = rdata->pkt_info.src_port;
 		pj_strdup(rdata->tp_info.pool, &uri->transport_param, txp_str);
 	}

third-party/pjproject/patches/0070-fix-incorrect-copying-when-creating-cancel.patch

@@ -0,0 +1,37 @@
+From ce18018cc17bef8f80c08686e3a7b28384ef3ba5 Mon Sep 17 00:00:00 2001
+From: sauwming <ming@teluu.com>
+Date: Mon, 12 Oct 2020 13:31:25 +0800
+Subject: [PATCH] Fix incorrect copying of destination info when creating
+ CANCEL (#2546)
+
+---
+ pjsip/src/pjsip/sip_util.c | 10 +++++-----
+ 1 file changed, 5 insertions(+), 5 deletions(-)
+
+diff --git a/pjsip/src/pjsip/sip_util.c b/pjsip/src/pjsip/sip_util.c
+index d10a6fa30..a1bf878ea 100644
+--- a/pjsip/src/pjsip/sip_util.c
++++ b/pjsip/src/pjsip/sip_util.c
+@@ -779,14 +779,14 @@ PJ_DEF(pj_status_t) pjsip_endpt_create_cancel( pjsip_endpoint *endpt,
+ 	    pjsip_hdr_clone(cancel_tdata->pool, req_tdata->saved_strict_route);
+     }
+ 
+-    /* Copy the destination host name from the original request */
+-    pj_strdup(cancel_tdata->pool, &cancel_tdata->dest_info.name,
+-	      &req_tdata->dest_info.name);
+-
+-    /* Finally copy the destination info from the original request */
++    /* Copy the destination info from the original request */
+     pj_memcpy(&cancel_tdata->dest_info, &req_tdata->dest_info,
+ 	      sizeof(req_tdata->dest_info));
+ 
++    /* Finally, copy the destination host name from the original request */
++    pj_strdup(cancel_tdata->pool, &cancel_tdata->dest_info.name,
++	      &req_tdata->dest_info.name);
++
+     /* Done.
+      * Return the transmit buffer containing the CANCEL request.
+      */
+-- 
+2.25.1
+