res_pjsip_rfc3326.c: Account for more than one 'Reason' header

ASTERISK-27741

Change-Id: I0aa59a54735c6d20b95c54db1bd095dbf93e7adf

res/res_pjsip_rfc3326.c

@@ -35,32 +35,35 @@
 
 static void rfc3326_use_reason_header(struct ast_sip_session *session, struct pjsip_rx_data *rdata)
 {
-	const pj_str_t str_reason = { "Reason", 6 };
-	pjsip_generic_string_hdr *header = pjsip_msg_find_hdr_by_name(rdata->msg_info.msg, &str_reason, NULL);
-	char buf[20], *cause, *text;
+	static const pj_str_t str_reason = { "Reason", 6 };
+	pjsip_generic_string_hdr *header;
+	char buf[20];
+	char *cause;
+	char *text;
 	int code;
 
-	if (!header) {
-		return;
-	}
+	header = pjsip_msg_find_hdr_by_name(rdata->msg_info.msg, &str_reason, NULL);
+	for (; header;
+		header = pjsip_msg_find_hdr_by_name(rdata->msg_info.msg, &str_reason, header->next)) {
+		ast_copy_pj_str(buf, &header->hvalue, sizeof(buf));
+		cause = ast_skip_blanks(buf);
 
-	ast_copy_pj_str(buf, &header->hvalue, sizeof(buf));
-	cause = ast_skip_blanks(buf);
+		if (strncasecmp(cause, "Q.850", 5) || !(cause = strstr(cause, "cause="))) {
+			continue;
+		}
 
-	if (strncasecmp(cause, "Q.850", 5) || !(cause = strstr(cause, "cause="))) {
-		return;
-	}
+		/* If text is present get rid of it */
+		if ((text = strstr(cause, ";"))) {
+			*text = '\0';
+		}
 
-	/* If text is present get rid of it */
-	if ((text = strstr(cause, ";"))) {
-		*text = '\0';
-	}
+		if (sscanf(cause, "cause=%30d", &code) != 1) {
+			continue;
+		}
 
-	if (sscanf(cause, "cause=%30d", &code) != 1) {
-		return;
+		ast_channel_hangupcause_set(session->channel, code & 0x7f);
+		break;
 	}
-
-	ast_channel_hangupcause_set(session->channel, code & 0x7f);
 }
 
 static int rfc3326_incoming_request(struct ast_sip_session *session, struct pjsip_rx_data *rdata)