#
# $Id$
#

# First start SER sample config script with:
#   database, accounting, authentication, multi-domain support
#   PSTN GW section, named flags, named routes, global-,
#   domain- and user-preferences with AVPs
# Several of these features are only here for demonstration purpose
# what can be achieved with the SER config script language.
#
# If you look for a simpler version with a lot less dependencies
# please refer to the ser-basic.cfg file in your SER distribution.

# To get this config running you need to execute the following commands
# with the new serctl (the capital word are just place holders)
# - ser_ctl domain add DOMAINNAME
# - ser_ctl user add USERNAME@DOMAINNAME -p PASSWORD
# If you want to have PID header for your user
# - ser_attr add uid=UID asserted_id="PID"
# If you want to have gateway support
# - ser_db add attr_types name=gw_ip rich_type=string raw_type=2 description="The gateway IP for the default ser.cfg" default_flags=33
# - ser_attr add global gw_ip=GATEWAY-IP

# ----------- global configuration parameters ------------------------

debug=3         # debug level (cmd line: -dddddddddd)
#memdbg=10 # memory debug log level
#memlog=10 # memory statistics log level
#log_facility=LOG_LOCAL0 # sets the facility used for logging (see syslog(3))

/* Uncomment these lines to enter debugging mode 
fork=no
log_stderror=yes
*/

check_via=no    # (cmd. line: -v)
dns=no          # (cmd. line: -r)
rev_dns=no      # (cmd. line: -R)
#port=5060
#children=4
#user=ser
#group=ser
#disable_core=yes #disables core dumping
#open_fd_limit=1024 # sets the open file descriptors limit
#mhomed=yes  # usefull for multihomed hosts, small performance penalty
#disable_tcp=yes 
#tcp_accept_aliases=yes # accepts the tcp alias via option (see NEWS)
enable_tls=yes

#

# ------------------ module loading ----------------------------------

# load a SQL database for authentication, domains, user AVPs etc.
loadmodule "/usr/local/lib/ser/modules/mysql.so"

loadmodule "/usr/local/lib/ser/modules/sl.so"
loadmodule "/usr/local/lib/ser/modules/tm.so"
loadmodule "/usr/local/lib/ser/modules/rr.so"
loadmodule "/usr/local/lib/ser/modules/maxfwd.so"
loadmodule "/usr/local/lib/ser/modules/usrloc.so"
loadmodule "/usr/local/lib/ser/modules/registrar.so"
loadmodule "/usr/local/lib/ser/modules/xlog.so"
loadmodule "/usr/local/lib/ser/modules/textops.so"
loadmodule "/usr/local/lib/ser/modules/ctl.so"
loadmodule "/usr/local/lib/ser/modules/fifo.so"
loadmodule "/usr/local/lib/ser/modules/auth.so"
loadmodule "/usr/local/lib/ser/modules/auth_db.so"
loadmodule "/usr/local/lib/ser/modules/gflags.so"
loadmodule "/usr/local/lib/ser/modules/domain.so"
loadmodule "/usr/local/lib/ser/modules/uri_db.so"
loadmodule "/usr/local/lib/ser/modules/avp.so"
loadmodule "/usr/local/lib/ser/modules/avp_db.so"
loadmodule "/usr/local/lib/ser/modules/acc_db.so"
loadmodule "/usr/local/lib/ser/modules/xmlrpc.so"
#loadmodule "/usr/local/lib/ser/modules/tls.so"

# ----------------- setting script FLAGS -----------------------------
flags
  FLAG_ACC          : 1,  # include message in accounting
  FLAG_FAILUREROUTE : 2;  # we are operating from a failure route

avpflags
  dialog_cookie;        # handled by rr module

# ----------------- setting module-specific parameters ---------------

# specify the path to you database here
modparam("acc_db|auth_db|avp_db|domain|gflags|usrloc|uri_db", "db_url", "mysql://ser:heslo@127.0.0.1/ser")

# -- usrloc params --

# as we use the database anyway we will use it for usrloc as well
modparam("usrloc", "db_mode", 1)

# -- auth params --
modparam("auth_db", "calculate_ha1", yes)
modparam("auth_db", "plain_password_column", "password")

# -- rr params --
# add value to ;lr param to make some broken UAs happy
modparam("rr", "enable_full_lr", 1)
#
# limit the length of the AVP cookie to only necessary ones
modparam("rr", "cookie_filter", "(account)")
#
# you probably do not want that someone can simply read and change
# the AVP cookie in your Routes, thus should really change this
# secret value below
modparam("rr", "cookie_secret", "MyRRAVPcookiesecret")

# -- gflags params --
# load the global AVPs
modparam("gflags", "load_global_attrs", 1)

# -- domain params --
# load the domain AVPs
modparam("domain", "load_domain_attrs", 1)

# -- ctl params --
# by default ctl listens on unixs:/tmp/ser_ctl if no other address is
# specified in modparams; this is also the default for sercmd
modparam("ctl", "binrpc", "unixs:/tmp/ser_ctl")
# listen on the "standard" fifo for backward compatibility
modparam("ctl", "fifo", "fifo:/tmp/ser_fifo")
# listen on tcp, localhost
#modparam("ctl", "binrpc", "tcp:localhost:2046")

# -- acc_db params --
# failed transactions (=negative responses) should be logged to
modparam("acc_db", "failed_transactions", 1)

# comment the next line if you dont want to have accounting to DB
modparam("acc_db", "log_flag", "FLAG_ACC")

# -- tm params --
# uncomment the following line if you want to avoid that each new reply
# restarts the resend timer (see INBOUND route below)
#modparam("tm", "restart_fr_on_each_reply", "0")

# -- xmlrpc params --
# using a sub-route from the module is a lot safer then relying on the
# request method to distinguish HTTP from SIP
modparam("xmlrpc", "route", "RPC");

# -------------------------  request routing logic -------------------

# main routing logic

route{
	# if you have a PSTN gateway just un-comment the follwoing line and 
	# specify the IP address of it to route calls to it
	#$gw_ip = "1.2.3.4"

	# first do some initial sanity checks
	route(INIT);

	# bypass the rest of the script for CANCELs if possible
	route(CATCH_CANCEL);

	# check if the request is routed via Route header or
	# needs a Record-Route header
	route(RR);

	# check if the request belongs to our proxy
	route(DOMAIN);

	# handle REGISTER requests
	route(REGISTRAR);

	# from here on we want to know you is calling
	route(AUTHENTICATION);

	# check if we should be outbound proxy for a local user
	route(OUTBOUND);

	# check if the request is for a local user
	route(INBOUND);

	# here you could for example try to do an ENUM lookup before
	# the call gets routed to the PSTN
	#route(ENUM);

	# lets see if someone wants to call a PSTN number
	route(PSTN);

	# nothing matched, reject it finally
	sl_reply("404", "No route matched");
}

route[FORWARD]
{
	# here you could decide wether this call needs a RTP relay or not

	# if this is called from the failure route we need to open a new branch
	if (isflagset(FLAG_FAILUREROUTE)) {
		append_branch();
	}

	# if this is an initial INVITE (without a To-tag) we might try another
	# (forwarding or voicemail) target after receiving an error
	if (method=="INVITE" && !@to.tag) {
		t_on_failure("FAILURE_ROUTE");
	}

	# send it out now; use stateful forwarding as it works reliably
	# even for UDP2TCP
	if (!t_relay()) {
		sl_reply_error();
	}
	drop;
}

route[INIT]
{
	# initial sanity checks -- messages with
	# max_forwards==0, or excessively long requests
	if (!mf_process_maxfwd_header("10")) {
		sl_reply("483","Too Many Hops");
		drop;
	}

	if (msg:len >=  max_len ) {
		sl_reply("513", "Message too big");
		drop;
	}

	# you could add some NAT detection here for example

	# or you cuold call here some of the check from the sanity module

	# lets account all initial INVITEs
	# further in-dialog requests are accounted by a RR cookie (see below)
	if (method=="INVITE" && !@to.tag) {
		setflag(FLAG_ACC);
	}
}

route[RPC]
{
	# allow XMLRPC from localhost
	if ((method=="POST" || method=="GET") &&
		src_ip==127.0.0.1) {

		if (msg:len >= 8192) {
			sl_reply("513", "Request to big");
			drop;
		}

		# lets see if a module wants to answer this
		dispatch_rpc();
		drop;
	}
}

route[RR]
{
	# subsequent messages withing a dialog should take the
	# path determined by record-routing
	if (loose_route()) {
		# mark routing logic in request
		append_hf("P-hint: rr-enforced\r\n"); 

		# if the Route contained the accounting AVP cookie we
		# set the accounting flag for the acc_db module.
		# this is more for demonstration purpose as this could
		# also be solved without RR cookies.
		# Note: this means all in-dialog request will show up in the
		# accounting tables, so prepare your accounting software for this ;-)
		if ($account == "yes") {
			setflag(FLAG_ACC);
		}

		# for broken devices which overwrite their Route's with each
		# (not present) RR from within dialog requests it is better
		# to repeat the RRing
		# and if we call rr after loose_route the AVP cookies are restored
		# automatically :)
		record_route();

		route(FORWARD);
	} else if (!method=="REGISTER") {
		# we record-route all messages -- to make sure that
		# subsequent messages will go through our proxy; that's
		# particularly good if upstream and downstream entities
		# use different transport protocol

		# if the inital INVITE got the ACC flag store this in
		# an RR AVP cookie. this is more for demonstration purpose
		if (isflagset(FLAG_ACC)) {
			$account = "yes";
			setavpflag($account, "dialog_cookie");
		}

		record_route();
	}
}

route[DOMAIN]
{
	# check if the caller is from a local domain
	lookup_domain("$fd", "@from.uri.host");

	# check if the callee is at a local domain
	lookup_domain("$td", "@ruri.host");

	# we dont know the domain of the caller and also not
	# the domain of the callee -> somone uses our proxy as
	# a relay
	if (!$t.did && !$f.did) {
		sl_reply("403", "Relaying Forbidden");
		drop;
	}
}

route[REGISTRAR]
{
	# if the request is a REGISTER lets take care of it
	if (method=="REGISTER") {
		# check if the REGISTER if for one of our local domains
		if (!$t.did) {
			sl_reply("403", "Register forwarding forbidden");
			drop;
		}

		# we want only authenticated users to be registered
		if (!www_authenticate("$fd.digest_realm", "credentials")) {
			if ($? == -2) {
				sl_reply("500", "Internal Server Error");
			} else if ($? == -3) {
				sl_reply("400", "Bad Request");
			} else {
				if ($digest_challenge) {
					append_to_reply("%$digest_challenge");
				}
				sl_reply("401", "Unauthorized");
			}
			drop;
		}

		# check if the authenticated user is the same as the target user
		if (!lookup_user("$tu.uid", "@to.uri")) {
			sl_reply("404", "Unknown user in To");
			drop;
		}

		if ($f.uid != $t.uid) {
			sl_reply("403", "Authentication and To-Header mismatch");
			drop;
		}

		# check if the authenticated user is the same as the request originator
		# you may uncomment it if you care, what uri is in From header
		#if (!lookup_user("$fu.uid", "@from.uri")) {
		#	sl_reply("404", "Unknown user in From");
		#	drop;
		#}
		#if ($fu.uid != $tu.uid) {
		#	sl_reply("403", "Authentication and From-Header mismatch");
		#	drop;
		#}

		# everyhting is fine so lets store the binding
		if (!save_contacts("location")) {
			sl_reply("400", "Invalid REGISTER Request");
			drop;
		}
		drop;
	}
}

route[AUTHENTICATION]
{
	if (method=="CANCEL" || method=="ACK") {
		# you are not allowed to challenge these methods
		break;
	}

	# requests from non-local to local domains should be permitted
	# remove this if you want a walled garden
	if (! $f.did) {
		break;
	}

	# as gateways are usually not able to authenticate for their
	# requests you will have trust them base on some other information
	# like the source IP address. WARNING: if at all this is only safe
	# in a local network!!!
	#if (src_ip==a.b.c.d) {
	#	break;
	#}

	if (!proxy_authenticate("$fd.digest_realm", "credentials")) {
		if ($? == -2) {
			sl_reply("500", "Internal Server Error");
		} else if ($? == -3) {
			sl_reply("400", "Bad Request");
		} else {
			if ($digest_challenge) {
				append_to_reply("%$digest_challenge");
			}
			sl_reply("407", "Proxy Authentication Required");
		}
		drop;
	}

	# check if the UID from the authentication meets the From header
	$authuid = $uid;
	if (!lookup_user("$fu.uid", "@from.uri")) {
		del_attr("$uid");
	}
	if ($fu.uid != $fr.authuid) {
		sl_reply("403", "Fake Identity");
		drop;
	}
	# load the user AVPs (preferences) of the caller, e.g. for RPID header
	load_attrs("$fu", "$f.uid");
}

route[OUTBOUND]
{
	# if a local user calls to a foreign domain we play outbound proxy for him
	# comment this out if you want a walled garden
	if ($f.did && ! $t.did) {
		append_hf("P-hint: outbound\r\n");
		route(FORWARD);
	}
}

route[INBOUND]
{
	# lets see if know the callee
	if (lookup_user("$tu.uid", "@ruri")) {

		# load the preferences of the callee to have his timeout values loaded
		load_attrs("$tu", "$t.uid");

		# if you want to know if the callee username was an alias
		# check it like this
		#if (! $tu.uri_canonical) {
			# if the alias URI has different AVPs/preferences
			# you can load them into the URI track like this
			#load_attrs("$tr", "@ruri");
		#}

		# check for call forwarding of the callee
		# Note: the forwarding target has to be full routable URI
		#       in this example
		if ($tu.fwd_always_target) {
			attr2uri("$tu.fwd_always_target");
			route(FORWARD);
		}

		# native SIP destinations are handled using our USRLOC DB
		if (lookup_contacts("location")) {
			append_hf("P-hint: usrloc applied\r\n");

			# we set the TM module timers according to the prefences
			# of the callee (avoid too long ringing of his phones)
			# Note1: timer values have to be in ms now!
			# Note2: this makes even more sense if you switch to a voicemail
			#        from the FAILURE_ROUTE below
			if ($t.fr_inv_timer) {
				if ($t.fr_timer) {
					t_set_fr("$t.fr_inv_timer", "$t.fr_timer");
				} else {
					t_set_fr("$t.fr_inv_timer");
				}
			}

			route(FORWARD);
		} else {
			sl_reply("480", "User temporarily not available");
			drop;
		}
	}
}

route[PSTN]
{
	# Only if the AVP 'gw_ip' is set and the request URI contains
	# only a number we consider sending this to the PSTN GW.
	# Only users from a local domain are permitted to make calls.
	# Additionally you might want to check the acl AVP to verify
	# that the user is allowed to make such expensives calls.
	if ($f.did && $gw_ip &&
		uri=~"sips?:\+?[0-9]{3,18}@.*") {
		# probably you need to convert the number in the request
		# URI according to the requirements of your gateway here

		# if an AVP 'asserted_id' is set we insert an RPID header
		if ($asserted_id) {
			xlset_attr("$rpidheader", "<sip:%$asserted_id@%@ruri.host>;screen=yes");
			replace_attr_hf("Remote-Party-ID", "$rpidheader");
		}

		# just replace the domain part of the RURI with the
		# value from the AVP and send it out
		attr2uri("$gw_ip", "domain");
		route(FORWARD);
	}
}

route[CATCH_CANCEL] {
	# check whether there is a corresponding INVITE to the CANCEL,
	# and bypass the rest of the script if possible

	if (method == CANCEL) {
		if (!t_relay_cancel()) { # implicit drop if the INVITE was found

			# INVITE was found but some error occurred
			sl_reply("500", "Internal Server Error");
			drop;
		}
		# bad luck, no corresponding INVITE was found,
		# we have to continue with the script
	}
}

failure_route[FAILURE_ROUTE]
{
	# mark for the other routes that we are operating from here on from a
	# failure route
	setflag(FLAG_FAILUREROUTE);

	if (t_check_status("486|600")) {
		# if we received a busy and a busy target is set, forward it there
		# Note: again the forwarding target has to be a routeable URI
		if ($tu.fwd_busy_target) {
			attr2uri("$tu.fwd_busy_target");
			route(FORWARD);
		}
		# alternatively you could forward the request to SEMS/voicemail here
	}
	else if (t_check_status("408|480")) {
		# if we received no answer and the noanswer target is set,
		# forward it there
		# Note: again the target has to be a routeable URI
		if ($tu.fwd_noanswer_target) {
			attr2uri("$tu.fwd_noanswer_target");
			route(FORWARD);
		}
		# alternatively you could forward the request to SEMS/voicemail here
	}
}