res_pjsip_messaging: Check URI type before dereferencing

We aren't validating that the URI we just parsed is a SIP/SIPS one before
trying to access the user, host, and port members of a possibly uninitialized
structure.

Also update the MessageSend documentation to indicate what 'from' formats are
accepted.

ASTERISK-26484 #close
Reported by: Vinod Dharashive

Change-Id: I476b5cc5f18a7713d0ee945374f2a1c164857d30

main/message.c

@@ -125,8 +125,10 @@
 			</parameter>
 			<parameter name="from" required="false">
 				<para>A From URI for the message if needed for the
-				message technology being used to send this message.</para>
-				<xi:include xpointer="xpointer(/docs/info[@name='MessageFromInfo'])" />
+				message technology being used to send this message. This can be a
+				SIP(S) URI, such as <literal>Alice &lt;sip:alice@atlanta.com&gt;</literal>,
+				a string in the format <literal>alice@atlanta.com</literal>, or simply
+				a username such as <literal>alice</literal>.</para>
 			</parameter>
 		</syntax>
 		<description>

res/res_pjsip_messaging.c

@@ -235,7 +235,15 @@ static void update_from(pjsip_tx_data *tdata, char *from)
 	parsed_name_addr = (pjsip_name_addr *) pjsip_parse_uri(tdata->pool, from,
 		strlen(from), PJSIP_PARSE_URI_AS_NAMEADDR);
 	if (parsed_name_addr) {
-		pjsip_sip_uri *parsed_uri = pjsip_uri_get_uri(parsed_name_addr->uri);
+		pjsip_sip_uri *parsed_uri;
+
+		if (!PJSIP_URI_SCHEME_IS_SIP(parsed_name_addr->uri)
+				&& !PJSIP_URI_SCHEME_IS_SIPS(parsed_name_addr->uri)) {
+			ast_log(LOG_WARNING, "From address '%s' is not a valid SIP/SIPS URI\n", from);
+			return;
+		}
+
+		parsed_uri = pjsip_uri_get_uri(parsed_name_addr->uri);
 
 		if (pj_strlen(&parsed_name_addr->display)) {
 			pj_strdup(tdata->pool, &name_addr->display, &parsed_name_addr->display);