message.c: Support 'To' header override with AMI's MessageSend.

The MessageSend AMI action has been updated to allow the Destination
and the To addresses to be provided separately. This brings the
MessageSend manager command in line with the capabilities of the
MessageSend dialplan application.

ASTERISK-29663 #close

Change-Id: I8513168d3e189a9fed88aaab6f5547ccb50d332c

doc/CHANGES-staging/manager_message_send.txt

+Subject: MessageSend
+
+The MessageSend AMI action has been updated to allow the Destination
+and the To addresses to be provided separately. This brings the
+MessageSend manager command in line with the capabilities of the
+MessageSend dialplan application.

main/message.c

@@ -190,8 +190,22 @@
 		</synopsis>
 		<syntax>
 			<xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
-			<parameter name="To" required="true">
-				<para>The URI the message is to be sent to.</para>
+			<parameter name="Destination" required="false">
+				<para>A To URI for the message. If Destination is provided, the To
+				parameter can also be supplied and may alter the message based on
+				the specified message technology.</para>
+				<para>For backwards compatibility, if Destination is not provided,
+				the To parameter must be provided and will be used as the message
+				destination.</para>
+				<xi:include xpointer="xpointer(/docs/info[@name='MessageDestinationInfo'])" />
+			</parameter>
+			<parameter name="To" required="false">
+				<para>A To URI for the message if needed for the
+				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>,
+				or a string in the format <literal>alice@atlanta.com</literal>.</para>
+				<para>This parameter is required if the Destination parameter is not
+				provided.</para>
 				<xi:include xpointer="xpointer(/docs/info[@name='MessageToInfo'])" />
 			</parameter>
 			<parameter name="From">
@@ -1305,10 +1319,12 @@ exit_cleanup:
 
 static int action_messagesend(struct mansession *s, const struct message *m)
 {
-	const char *to = ast_strdupa(astman_get_header(m, "To"));
+	const char *destination = astman_get_header(m, "Destination");
+	const char *to = astman_get_header(m, "To");
 	const char *from = astman_get_header(m, "From");
 	const char *body = astman_get_header(m, "Body");
 	const char *base64body = astman_get_header(m, "Base64Body");
+	const char *to_override = NULL;
 	char base64decoded[1301] = { 0, };
 	char *tech_name = NULL;
 	struct ast_variable *vars = NULL;
@@ -1317,9 +1333,16 @@ static int action_messagesend(struct mansession *s, const struct message *m)
 	struct ast_msg *msg;
 	int res = -1;
 
-	if (ast_strlen_zero(to)) {
-		astman_send_error(s, m, "No 'To' address specified.");
-		return 0;
+	if (!ast_strlen_zero(destination)) {
+		if (!ast_strlen_zero(to)) {
+			to_override = to;
+		}
+		to = destination;
+	} else {
+		if (ast_strlen_zero(to)) {
+			astman_send_error(s, m, "No 'To' address specified.");
+			return 0;
+		}
 	}
 
 	if (!ast_strlen_zero(base64body)) {
@@ -1351,6 +1374,10 @@ static int action_messagesend(struct mansession *s, const struct message *m)
 
 	ast_msg_set_body(msg, "%s", body);
 
+	if (to_override) {
+		ast_string_field_set(msg, to, to_override);
+	}
+
 	res = msg_tech->msg_send(msg, S_OR(to, ""), S_OR(from, ""));
 
 	ast_rwlock_unlock(&msg_techs_lock);