# ========================================================================== #
# opensips.cfg.tt - OpenSIPS load balancer configuration                     #
# Chase Venters <chase@exceleron.com>                                        #
# ========================================================================== #

# ========================================================================== #
# ============================ Import Variables ============================ #
# ========================================================================== #

[% SET pwd_mysql = cfg.Password.MYSQL_OPENSIPS %]
[% SET ip_public1 = cfg.Interface.UTM_PUBLIC.IpDef.IVR1 %]
[% SET ip_public2 = cfg.Interface.UTM_PUBLIC.IpDef.IVR2 %]
[% SET ip_private_ivr = cfg.VlanByIfDef.IVR.IpAddress %]

#============================================================================#
#=============================== Configuration ==============================#
#============================================================================#

# No debugging, do fork 4 children
debug=3
fork=yes
children=4
log_stderror=yes

# Accept traffic on our public IPs via UDP or TLS, and on our private IP
listen=udp:[% ip_public1 %]:5060
listen=udp:[% ip_public2 %]:5060
listen=udp:[% ip_private_ivr %]:5060

# Do not blacklist peers if they report temporary failure
disable_dns_blacklist=yes

# Security settings
check_via=1
server_signature=no

# Don't do any DNS lookups on myself
dns=no
rev_dns=no

# Module path
mpath="/usr/lib64/opensips/modules/"

#============================================================================#
#================================== Modules =================================#
#============================================================================#

loadmodule "sl.so"
loadmodule "tm.so"
loadmodule "rr.so"
loadmodule "maxfwd.so"
loadmodule "avpops.so"
loadmodule "uac.so"
loadmodule "db_mysql.so"
loadmodule "textops.so"
loadmodule "options.so"
loadmodule "uri.so"
loadmodule "mi_datagram.so"
loadmodule "nathelper.so"
loadmodule "acc.so"
loadmodule "dialog.so"
loadmodule "load_balancer.so"
loadmodule "signaling.so"
loadmodule "cfgutils.so"
loadmodule "sst.so"

#============================================================================#
#================================ Parameters ================================#
#============================================================================#

# Database connection for avpops
modparam("avpops", "db_url", "mysql://opensipsd:[% pwd_mysql %]@localhost/opensips")

# For compatibility
modparam("rr", "enable_full_lr", 1)

# Encrypt original From header
modparam("uac", "restore_passwd", "[% cfg.Password.OPENSIPS_FROM %]")

# Store dialogs in the database, as this might eventually be used to sync
# call state across UTMs, and could make debugging easy
modparam("dialog", "db_url", "mysql://opensipsd:[% pwd_mysql %]@localhost/opensips")
modparam("dialog", "db_mode", 1)
modparam("dialog", "timeout_avp", "$avp(s:d_timeout)")

# Create a group-accessible control socket that the media-dispatcher can talk
# to
modparam("mi_datagram", "socket_name", "/etc/supervise/opensipsd/runtime/opensipsd.sock")
modparam("mi_datagram", "unix_socket_mode", 0660)

# RTPProxy socket
modparam("nathelper", "rtpproxy_sock", "udp:127.0.0.1:9999")
modparam("nathelper", "nortpproxy_str", "")

# ACC
modparam("acc", "log_flag", 2)
modparam("acc", "report_cancels", 1)
#modparam("acc", "log_extra",
#	"uaA=$hdr(User-Agent);to=$hdr(To);from=$hdr(From);si=$si;ruri=$ruri")

# Load balancer
modparam("load_balancer", "db_url", "mysql://opensipsd:[% pwd_mysql %]@localhost/opensips")
modparam("load_balancer", "db_table", "destinations")
modparam("load_balancer", "probing_interval", 0)

# Set up SIP Session Timers to help drop old calls
modparam("sst", "sst_flag", 5)
modparam("sst", "timeout_avp", "$avp(s:d_timeout)")
modparam("sst", "min_se", 2400)

# Set more aggressive timeouts
modparam("tm", "fr_timer", 3)
modparam("tm", "fr_inv_timer", 60)

# ========================================================================== #
# ================================== Route ================================= #
# ========================================================================== #

route {
	# Hop count sanity check
	if (!mf_process_maxfwd_header("10")) {
		xlog("LOOPWARN: Message from \"$fu\" ($si:$sp) to \"$tu\" had more than 10 hops\n");
		setflag(2);
		sl_send_reply("483", "Too many hops");
		return;
	}

	# Message size sanity check
	if (msg:len >= 8192) {
		xlog("SIZEWARN: Message from \"$fu\" ($si:$sp) to \"$tu\" had more than 8192 bytes\n");
		setflag(2);
		sl_send_reply("513", "Message too large");
		return;
	}

	# Handle OPTIONS requests... don't bother logging them since they are
	# used as high frequency pings!
	if (uri == myself) {
		if (method == "OPTIONS") {
			options_reply();
			exit;
		}
	}

	# All further messages should be sent through our system
	record_route();

	# Enable logging
	setflag(2);

	# Handle loose routing
	if (loose_route()) {
		# Make sure we're not being used for toll fraud
		if (!has_totag()) {
			xlog("SECURITY: Rejected initial loose-routing attempt from \"$fu\" ($si:$sp) to \"$tu\"\n");
			sl_send_reply("403", "Initial Loose-Routing Rejected");
			setflag(2);
			exit;
		}

		# Add routing hint
		append_hf("P-hint: rr-enforced\r\n");

		# Activate rtpproxy??
		if (method == "ACK" && has_body("application/sdp")) {
			route("rtpproxy_answer");
		}

		# Relay message
		if (!t_relay()) {
			sl_reply_error();
		}

		# Disengage RTP proxy at the end of the call
		if (method == "CANCEL" || method == "BYE") {
			route("cleanup");
			exit;
		}

		exit;
	}

	# Handle cancel and re-transmissions
	if (method == "CANCEL") {
		unforce_rtp_proxy();
		if (t_check_trans()) {
			t_relay();
		}
		exit;
	}

	# Handle INVITE requests
	if (method == "INVITE") {
		# Consume retransmissions
		t_check_trans();

		# Check SST
		if (sstCheckMin("1")) {
			xlog("422 Session Timer Too Small reply sent for call from \"$fu\" ($si:$sp) to \"$tu\"\n");
			exit;
		}
		setflag(5);

		# Sanitize to and from for DB query
		$avp(s:from) = $fU;
		$avp(s:to) = $rU;
		avp_subst("$avp(s:from)", "/[^0-9]//g");
		avp_subst("$avp(s:to)", "/[^0-9]//g");

		# Check to see if we should be recording or simulating a failure mode
		avp_db_query( "SELECT `recording_enabled`,`recording_probability`,`failmode` FROM `callctrl` WHERE (`from`='$avp(s:from)' OR `to`='$avp(s:to)') AND ((`from`='$avp(s:from)' AND `to`='$avp(s:to)') OR `from` IS NULL OR `to` IS NULL)", "$avp(s:rec_enabled);$avp(s:rec_prob);$avp(s:failmode)");
		if ($avp(s:failmode) == "503") {
			sl_send_reply("503", "Service Disabled");
			exit;
		}
		else if ($avp(s:failmode) == "500") {
			sl_send_reply("500", "Service Disabled");
			exit;
		}
		else if ($avp(s:failmode) == "drop") {
			exit;
		}
		avp_delete("$avp(s:failmode)");

		# To prevent retransmits, let the caller know we're working
		sl_send_reply("100", "Trying");

		# Create a dialog to track call parameters
		create_dialog();

		# Apply probability to recording
		if ($avp(s:rec_enabled) > 0 && $avp(s:rec_prob) > 0) {
			# Run probability function.
			$var(prob) = $RANDOM % 100;
			if ($var(prob) >= $avp(s:rec_prob)) {
				$avp(s:rec_enabled) = 0;
			}
		}
		if ($avp(s:rec_enabled) > 0) {
			$dlg_val(record) = "y";
			$var(recording) = "RECORDING\n";
		}
		else {
			$dlg_val(record) = "n";
			$var(recording) = "\n";
		}
		avp_delete("$avp(s:rec_enabled)");
		avp_delete("$avp(s:rec_prob)");
		avp_delete("$avp(s:from)");
		avp_delete("$avp(s:to)");

		# Calls are proxied in both directions. Which way are we going?
		$var(srcnet) = $(si{s.substr,0,8});
		$dlg_val(old_ru) = $ru;
		if ($var(srcnet) != "10.[% cfg.NetNum %].20.") {
			# Incoming call from the Internet. Pick out an IVR to receive
			# the call
			force_send_socket([% ip_private_ivr %]:5060);
			$dlg_val(lbdir) = "in";
			load_balance("101", "calls", "1");
			$var(lbret) = $retcode;
		}
		else {
			# Outgoing call to the Internet. Pick out an upstream provider to
			# handle the call
			force_send_socket([% ip_public1 %]:5060);
			$dlg_val(lbdir) = "out";
			load_balance("201", "calls", "1");
			$var(lbret) = $retcode;
		}

		# Make sure we got a destination set
		if ($var(lbret) < 0) {
			sl_send_reply("503", "Service full");
			xlog("ACC: $dlg_val(dir) $si $ci $fu -> $ru FAILED Service full\n");
			exit;
		}

		# Cache the original request URI incase we have to rewrite it
		# multiple times
		$dlg_val(orig_to) = $rU;

		route("sendcall");
		exit;
	}
	else {
		# Other methods are not allowed
		sl_send_reply("405", "Method not allowed");
		exit;
	}
}

#============================================================================#

# Sends a call
route["sendcall"]
{
	# Rewrite RURI host based on what the load balancer gave us
	$rd = $dd;

	# Check for, and apply, any necessary prefix
	avp_db_query("SELECT `prefix` FROM `destinations` WHERE dst_uri='sip:$dd'", "$avp(s:prefix)");
	$rU = $avp(s:prefix) + $dlg_val(orig_to);
	avp_delete("$avp(s:prefix)");

	# Log call
	if ($dlg_val(record) == "y") {
		$var(recording) = "RECORDING\n";
	}
	else {
		$var(recording) = "\n";
	}
	if ($dlg_val(lbdir) == "in") {
		$var(dir) = "[in] ";
	}
	else {
		$var(dir) = "[out]";
	}
	xlog("ACC: $var(dir) $si $ci $fu -> $dlg_val(old_ru) $ru $var(recording)");

	# Use the RTP proxy
	if (has_body("application/sdp")) {
		if (route("rtpproxy_offer")) {
			t_on_reply("do_rtpproxy_answer");
		}
	}
	else {
		t_on_reply("do_rtpproxy_offer");
	}
	t_on_failure("invite_failure");

	# Send the call
	if (!t_relay("0x01")) {
		sl_reply_error();
		route("cleanup");
		exit;
	}

	exit;
}

#============================================================================#

# Invokes rtpproxy for an answer section
route["rtpproxy_answer"]
{
	if (dst_ip == [% ip_private_ivr %]) {
		rtpproxy_answer("FIEW");
	}
	else {
		rtpproxy_answer("FEIW");
	}
	return($retcode);
}

#============================================================================#

# Invokes rtpproxy for an offer section
route["rtpproxy_offer"]
{
	if ($dlg_val("sent_rtpproxy_offer") == "yes") {
		return(1);
	}
	$dlg_val("sent_rtpproxy_offer") = "yes";
	if (dst_ip == [% ip_private_ivr %]) {
		rtpproxy_offer("FIEW");
		$var(ret) = $retcode;
	}
	else {
		rtpproxy_offer("FEIW");
		$var(ret) = $retcode;
	}
	if ($var(ret) && $dlg_val(record) == "y") {
		xlog("Starting recording for $ci\n");
		start_recording();
	}
	return($var(ret));
}

#============================================================================#

# onReply 1: We activated rtpproxy on the SDP already
onreply_route["do_rtpproxy_answer"]
{
	if (has_body("application/sdp")) {
		route("rtpproxy_answer");
	}
}

#============================================================================#

# onReply 2: We haven't activated rtpproxy yet but we need to
onreply_route["do_rtpproxy_offer"]
{
	if (has_body("application/sdp")) {
		route("rtpproxy_offer");
	}
}

#============================================================================#

# failure 1: We need to stop the RTP proxy
failure_route["invite_failure"]
{
	xlog("ACC: txn fail: call_id=$ci;status=$T_reply_code\n");

	if (t_check_status("([45][0-9][0-9])")) {
		# Certain 4xx/5xx codes really do pertain to the PSTN endpoint
		# but most of the others are probably related to a SIP peering
		# misconfiguration or temporary failure. But the codes that
		# really can occur from a normal PSTN condition (eg, noanswer
		# or busy) shouldn't generate an additional call immediately.
		if (t_check_status("404|408|410|480|482|486|487")) {
			route("cleanup");
			exit;
		}
		
		# Try additional load balancing destinations
		if ($dlg_val(lbdir) == "in") {
			load_balance("101", "calls", "1");
			$var(lbret) = $retcode;
		}
		else if ($dlg_val(lbdir) == "out") {
			load_balance("201", "calls", "1");
			$var(lbret) = $retcode;
		}
		else {
			t_reply("503", "Internal Server Error");
			route("cleanup");
			exit;
		}

		# Make sure we got a destination set
		if ($var(lbret) < 0) {
			t_reply("503", "Internal Server Error");
			xlog("ACC: giving up: $ci\n");
			route("cleanup");
			exit;
		}

		route("sendcall");
		exit;
	}

	route("cleanup");
}

#============================================================================#

# cleans up the call
route["cleanup"]
{
	unforce_rtp_proxy();
	avp_delete("*");
	exit;
}

#============================================================================#