res_pjsip_caller_id: Fix segfault when replacing rpid or pai header

If the PJSIP_HEADER dialplan function adds a PAI or RPID header and send_rpid
or send_pai is set, res_pjsip_caller_id attemps to retrieve, parse and modify
the header added by the dialplan function.  Since the header added by the
dialplan function is generic string, there are no virtual functions to parse
the uri and we get a segfault when we try.  Since the modify, was really only
an overwrite, we now just delete the old header if it was type PJSIP_H_OTHER
and recreate it.

This raises a question for another time though:  What should happen with
duplicate headers?  Right now res_pjsip_header_funcs doesn't check for dups
so if it's session supplement is loaded after res_pjsip_caller_id's (or any
other module that adds headers), there'll be dups in the message.

ASTERISK-25337 #close

Change-Id: I5e296b52d30f106b822c0eb27c4c2b0e0f71c7fa

1 files changed, 32 insertions, 6 deletions

diff --git a/res/res_pjsip_caller_id.c b/res/res_pjsip_caller_id.c
index 07b12669d..8227cacda 100644
--- a/res/res_pjsip_caller_id.c
+++ b/res/res_pjsip_caller_id.c
@@ -511,9 +511,22 @@ static void add_pai_header(pjsip_tx_data *tdata, const struct ast_party_id *id)
 	 */
 	old_pai = pjsip_msg_find_hdr_by_name(tdata->msg, &pj_pai_name, NULL);
 	if (old_pai) {
-		modify_id_header(tdata->pool, old_pai, id);
-		add_privacy_header(tdata, id);
-		return;
+		/* If type is OTHER, then the existing header was most likely
+		 * added by the PJSIP_HEADER dial plan function as a simple
+		 * name/value pair.  We can't pass this to modify_id_header because
+		 * there are no virtual functions to get the uri.  We could parse
+		 * it into a pjsip_fromto_hdr but it isn't worth it since
+		 * modify_id_header is just going to overwrite the name and number
+		 * anyway.  We'll just remove it from the header list instead
+		 * and create a new one.
+		 */
+		if (old_pai->type == PJSIP_H_OTHER) {
+			pj_list_erase(old_pai);
+		} else {
+			modify_id_header(tdata->pool, old_pai, id);
+			add_privacy_header(tdata, id);
+			return;
+		}
 	}
 
 	pai_hdr = create_new_id_hdr(&pj_pai_name, tdata, id);
@@ -600,9 +613,22 @@ static void add_rpid_header(pjsip_tx_data *tdata, const struct ast_party_id *id)
 	 */
 	old_rpid = pjsip_msg_find_hdr_by_name(tdata->msg, &pj_rpid_name, NULL);
 	if (old_rpid) {
-		modify_id_header(tdata->pool, old_rpid, id);
-		add_privacy_params(tdata, old_rpid, id);
-		return;
+		/* If type is OTHER, then the existing header was most likely
+		 * added by the PJSIP_HEADER dial plan function as a simple
+		 * name/value pair.  We can't pass this to modify_id_header because
+		 * there are no virtual functions to get the uri.  We could parse
+		 * it into a pjsip_fromto_hdr but it isn't worth it since
+		 * modify_id_header is just going to overwrite the name and number
+		 * anyway.  We'll just remove it from the header list instead
+		 * and create a new one.
+		 */
+		if (old_rpid->type == PJSIP_H_OTHER) {
+			pj_list_erase(old_rpid);
+		} else {
+			modify_id_header(tdata->pool, old_rpid, id);
+			add_privacy_params(tdata, old_rpid, id);
+			return;
+		}
 	}
 
 	rpid_hdr = create_new_id_hdr(&pj_rpid_name, tdata, id);