#!KAMAILIO
#
# vim: ai

####### Defined Values #########
#!define FLB_NATB 6
#!define FLB_NATSIPPING 7

####### Global Parameters #########

### LOG Levels: 3=DBG, 2=INFO, 1=NOTICE, 0=WARN, -1=ERR
#!ifdef WITH_DEBUG
debug=4
log_stderror=yes
#!else
debug=2
log_stderror=no
#!endif

memdbg=5
memlog=5

log_facility=LOG_LOCAL0

fork=yes
children=4

dns_srv_lb=yes
dns_try_ipv6=no
dns_use_search_list=no
use_dns_failover=yes
dns_retr_time=1
dns_retr_no=1
dns_try_naptr=no
use_dns_cache=on
dns=no
rev_dns=no
check_via=no

/* uncomment the next line to disable TCP (default on) */
#disable_tcp=yes

/* add local domain aliases */
import_file "kamailio-aliases.cfg"

enable_tls=yes

# life time of TCP connection when there is no traffic
# - a bit higher than registration expires to cope with UA behind NAT
tcp_connection_lifetime=3605
force_rport=yes

mpath="/usr/lib/x86_64-linux-gnu/kamailio/modules/"

loadmodule "tm.so"
loadmodule "sl.so"
loadmodule "rr.so"
loadmodule "kex.so"
loadmodule "corex.so"
loadmodule "tmx.so"
loadmodule "pv.so"
loadmodule "maxfwd.so"
loadmodule "usrloc.so"
loadmodule "registrar.so"
loadmodule "textops.so"
loadmodule "siputils.so"
loadmodule "xlog.so"
loadmodule "sanity.so"
loadmodule "ctl.so"
loadmodule "cfg_rpc.so"
loadmodule "ipops.so"

loadmodule "nathelper.so"

loadmodule "tls.so"

loadmodule "htable.so"
loadmodule "pike.so"

loadmodule "db_mysql.so"
loadmodule "topos.so"

#!ifdef WITH_DEBUG
loadmodule "debugger.so"
#!endif

loadmodule "path.so"
loadmodule "dispatcher.so"

loadmodule "siptrace.so"

modparam("path", "use_received", 1)

#!define DBURL "mysql://kam:kam@127.0.0.1:3306/kam"

modparam("db_mysql", "ping_interval", 10)
modparam("db_mysql", "auto_reconnect", 1)
modparam("db_mysql", "timeout_interval", 5)

modparam("topos", "storage", "db")
modparam("topos", "db_url", DBURL)

modparam("topos", "mask_callid", 0)
modparam("topos", "sanity_checks", 0)
modparam("topos", "branch_expire", 10800)
modparam("topos", "dialog_expire", 10800)
modparam("topos", "clean_interval", 60)

# ----- dispatcher -----
modparam("dispatcher", "list_file", "/etc/kamailio/dispatcher.list")
modparam("dispatcher", "flags", 2)
modparam("dispatcher", "dst_avp", "$avp(AVP_DST)")
modparam("dispatcher", "grp_avp", "$avp(AVP_GRP)")
modparam("dispatcher", "cnt_avp", "$avp(AVP_CNT)")
modparam("dispatcher", "ds_ping_method", "OPTIONS");
modparam("dispatcher", "ds_ping_interval", 1);
modparam("dispatcher", "ds_probing_mode", 1);
modparam("dispatcher", "ds_ping_from", "sip:loadbalancer@proxy");


# ----- tm params -----
# auto-discard branches from previous serial forking leg
modparam("tm", "failure_reply_mode", 3)
# default retransmission timeout: 30sec
modparam("tm", "fr_timer", 30000)
# default invite retransmission timeout after 1xx: 120sec
modparam("tm", "fr_inv_timer", 120000)


# ----- rr params -----
# set next param to 1 to add value to ;lr param (helps with some UAs)
modparam("rr", "enable_full_lr", 0)
# do not append from tag to the RR (no need for this script)
modparam("rr", "append_fromtag", 0)

# ----- nathelper params -----
modparam("nathelper", "natping_interval", 30)
modparam("nathelper", "ping_nated_only", 0)
modparam("nathelper", "sipping_bflag", FLB_NATSIPPING)
modparam("nathelper", "sipping_from", "sip:pinger@kamailio.org")

# params needed for NAT traversal in other modules
modparam("nathelper|registrar", "received_avp", "$avp(RECEIVED)")
modparam("usrloc", "nat_bflag", FLB_NATB)

# ----- tls params -----
modparam("tls", "config", "/etc/kamailio/tls.cfg")

# ----- pike params -----
modparam("pike", "sampling_time_unit", 2)
modparam("pike", "reqs_density_per_unit", 64)
modparam("pike", "remove_latency", 4)

# ----- htable params -----
# ip ban htable with autoexpire after 5 minutes
modparam("htable", "htable", "ipban=>size=8;autoexpire=300;")


#!ifdef WITH_DEBUG
# ----- debugger params -----
modparam("debugger", "cfgtrace", 1)
modparam("debugger", "log_level_name", "exec")
#!endif

modparam("siptrace", "duplicate_uri", "sip:homer:9060")
modparam("siptrace", "hep_mode_on", 1)
modparam("siptrace", "hep_version", 2)
modparam("siptrace", "hep_capture_id", 800)
modparam("siptrace", "trace_to_database", 0)
modparam("siptrace", "trace_flag", 22)
modparam("siptrace", "trace_on", 1)
modparam("siptrace", "trace_mode", 1)

####### Routing Logic ########

# Main SIP request routing logic
# - processing of any incoming SIP request starts with this route
# - note: this is the same as route { ... }
request_route {
	if(t_precheck_trans())
	{
		t_check_trans();
		exit;
	}
	else
	{
		if(is_method("INVITE") && !has_totag())
		{
			t_newtran();
			t_reply("100","Trying");
		}
	}

	route(REQINIT);

	remove_hf_re("^[XP]-");
	remove_hf_re("^User-Agent");
	remove_hf_re("^Server");

	route(NATDETECT);
	route(WITHINDLG);

	if (is_method("INVITE|SUBSCRIBE"))
	{
		record_route();
	}

	if(!is_in_subnet($si, "backend/30"))
	{
		if($ai!=$null)
		{
			append_hf("P-Asserted-Identity: <$ai>\r\n");
		}

		add_path_received("loadbalancer");

		ds_select_dst(1, 11);

	    t_on_failure("RTF_DISPATCH");
	}
	else
	{
		remove_hf_re("^Diversion");
		remove_hf("Route");

		loose_route();
	}
	
	route(RELAY);
}

# Wrapper for relaying requests
route[RELAY] {

	# enable additional event routes for forwarded requests
	# - serial forking, RTP relaying handling, a.s.o.
	if (is_method("INVITE|BYE|SUBSCRIBE|UPDATE")) {
		if(!t_is_set("branch_route")) t_on_branch("MANAGE_BRANCH");
	}
	if (is_method("INVITE|SUBSCRIBE|UPDATE")) {
		if(!t_is_set("onreply_route")) t_on_reply("MANAGE_REPLY");
	}
	if (is_method("INVITE")) {
		if(!t_is_set("failure_route")) t_on_failure("MANAGE_FAILURE");
	}

	if (!t_relay()) {
		sl_reply_error();
	}
	exit;
}

# Per SIP request initial checks
route[REQINIT] {
	# flood dection from same IP and traffic ban for a while
	# be sure you exclude checking trusted peers, such as pstn gateways
	# - local host excluded (e.g., loop to self)
	if(src_ip!=myself) {
		if($sht(ipban=>$si)!=$null) {
			# ip is already blocked
			xdbg("request from blocked IP - $rm from $fu (IP:$si:$sp)\n");
			exit;
		}
		if (!pike_check_req()) {
			xlog("L_ALERT","ALERT: pike blocking $rm from $fu (IP:$si:$sp)\n");
			$sht(ipban=>$si) = 1;
			exit;
		}
	}

	if(!sanity_check("1511", "7")) {
		xlog("Malformed SIP message from $si:$sp\n");
		sl_send_reply("400","Insane request");
		exit;
	}

	if($ua =~ "friendly-scanner") {
		drop;
	}

	if($ua =~ "sipcli") {
		drop;
	}

	if($ua =~ "VaxSIPUserAgent") {
		drop;
	}

	if (!mf_process_maxfwd_header("10")) {
		sl_send_reply("483","Too Many Hops");
		exit;
	}

	if(is_method("OPTIONS")) {
		sl_send_reply("200","Keepalive");
		exit;
	}
}

# Handle requests within SIP dialogs
route[WITHINDLG] {
	if (!has_totag()) return;

	# sequential request withing a dialog should
	# take the path determined by record-routing
	if (loose_route()) {
		route(DLGURI);
		if ( is_method("ACK") ) {
			# ACK is forwarded statelessy
			route(NATMANAGE);
		}
		else if ( is_method("NOTIFY") ) {
			# Add Record-Route for in-dialog NOTIFY as per RFC 6665.
			record_route();
		}
		route(RELAY);
		exit;
	}

	if (is_method("SUBSCRIBE") && uri == myself) {
		# in-dialog subscribe requests
		exit;
	}
	if ( is_method("ACK") ) {
		if ( t_check_trans() ) {
			# no loose-route, but stateful ACK;
			# must be an ACK after a 487
			# or e.g. 404 from upstream server
			route(RELAY);
			exit;
		} else {
			# ACK without matching transaction ... ignore and discard
			exit;
		}
	}
	sl_send_reply("404","Not here");
	exit;
}

# Caller NAT detection
route[NATDETECT] {
	if(!is_in_subnet($si, "backends/30"))
	{
		if (!is_method("REGISTER") && is_first_hop()) 
		{
			set_contact_alias();
		}
	}

	return;
}

route[NATMANAGE] {
	if(!is_in_subnet($si, "backends/30"))
	{
		if (is_reply() && is_first_hop())
		{
			set_contact_alias();
		}
	}

	return;
}

# URI update for dialog requests
route[DLGURI] {
	if(!isdsturiset()) {
		handle_ruri_alias();
	}
	return;
}

# Manage outgoing branches
branch_route[MANAGE_BRANCH] {
	route(NATMANAGE);
}

# Manage incoming replies
onreply_route[MANAGE_REPLY] {
	remove_hf_re("^[XP]-");

	if(status=~"[12][0-9][0-9]")
		route(NATMANAGE);
}

# Manage failure routing cases
failure_route[MANAGE_FAILURE] {
	route(NATMANAGE);

	if (t_is_canceled()) {
		exit;
	}
}

failure_route[RTF_DISPATCH]
{
	if (t_is_canceled()) {
		exit;
	}

	if (t_check_status("500") or (t_branch_timeout() and !t_branch_replied()))
	{
		if(ds_next_dst())
		{
			t_on_failure("RTF_DISPATCH");
			route(RELAY);
			exit;
		}
	}
}

failure_route[RTF_OPTIONS_DISPATCH]
{
	if (t_is_canceled()) {
		exit;
	}

	if (t_check_status("500") or (t_branch_timeout() and !t_branch_replied()))
	{
		ds_mark_dst("ip");

		if(ds_next_dst())
		{
			t_on_failure("RTF_OPTIONS_DISPATCH");
			route(RELAY);
			exit;
		}
	}
}