initial commit of example showing how a proxy server can serve

a voicemail server

examples/vm_proxy.cfg

@@ -0,0 +1,101 @@
+#
+# $Id$
+#
+# simple proxy script for forwarding to voicemail server
+# for unavailable users
+#
+
+loadmodule "modules/sl/sl.so"
+loadmodule "modules/tm/tm.so"
+loadmodule "modules/rr/rr.so"
+loadmodule "modules/maxfwd/maxfwd.so"
+loadmodule "modules/mysql/mysql.so"
+loadmodule "modules/group/group.so"
+loadmodule "modules/usrloc/usrloc.so"
+loadmodule "modules/registrar/registrar.so"
+
+# time to give up on ringing -- global timer, applies to 
+#    all transactions
+modparam("tm", "fr_inv_timer", 90)
+
+# database with user group membership
+modparam("group", "db_url", "sql://ser:heslo@localhost/ser")
+
+
+# ---------------------  request routing logic -------------------
+route {
+
+	if (!mf_process_maxfwd_header("10")) {
+		log("LOG: Too many hops\n");
+		sl_send_reply("483", "Alas Too Many Hops");
+		break;
+	};
+
+	if (!(method=="REGISTER")) record_route();
+	if (loose_route()) {
+		t_relay();
+		break;
+	};
+
+	if (!uri==myself) {
+		t_relay();
+		break;
+	};
+
+	if (method == "REGISTER") {
+		if (!save("location")) {
+			sl_reply_error();
+		};
+		break;
+	};
+
+	# does the user wish redirection on no availability? (i.e., is he
+	# in the voicemail group?) -- determine it now and store it in
+	# flag 4, before we rewrite the flag using UsrLoc
+	if (is_user_in("Request-URI", "voicemail")) {
+		setflag(4);
+	};
+
+	# native SIP destinations are handled using our USRLOC DB
+	if (!lookup("location")) {
+		# handle user which was not found
+		route(4);
+		break;
+	};
+
+	# if user is on-line and is in voicemail group, enable redirection
+	if (method == "INVITE" && isflagset(4)) {
+		t_on_failure("1");
+	};
+	t_relay();
+}
+
+# ------------- handling of unavailable user ------------------
+route[4] {
+
+	# non-Voip -- just send "off-line"
+	if (!(method == "INVITE" || method == "ACK" || method == "CANCEL")) {
+		sl_send_reply("404", "Not Found");
+		break;
+	};
+
+	# not voicemail subscriber
+	if (!isflagset(4)) { 
+		sl_send_reply("404", "Not Found and no voicemail turned on");
+		break;
+	};
+
+	# forward to voicemail now
+	rewritehostport("bat.iptel.org:5090");
+	t_relay_to_udp("bat.iptel.org", "5090");	
+}
+
+# if forwarding downstream did not succeed, try voicemail running
+# at bat.iptel.org:5090
+
+failure_route[1] {
+	revert_uri();
+	rewritehostport("bat.iptel.org:5090");
+	append_branch();
+	t_relay_to_udp("bat.iptel.org", "5090");
+}