I am currently preparing a kamailio-asterisk combination. The asterisk installation uses realtime for SIP. The kamailio configuration (attached) was based on the reference at http://kb.asipto.com/asterisk:realtime:kamailio-4.0.x-asterisk-11.3.0-astdb but has been heavily modified. Currently asterisk runs on localhost and only listens on SIP/RTP at 127.0.0.1 . Therefore, all of the SIP traffic appears to come from localhost, from the point of view of asterisk.

Currently I have a model on which internal SIP phones get identified by the authentication username, and then the contact names at From: and To: get massaged to incorporate the SIP domain, in order to emulate multiple-domain support. The 'sip' table in Asterisk defines all such contacts as SIP accounts of the form name_domain.com, and the SIP phones are configured to use 'name' as authentication username for domain 'domain.com'. However, SIP providers that register on the server with authentication names are left with their original names, since in the model, SIP trunks are available to all domains.

Now I have to add support for SIP providers which are to be authorized on the basis of IP only. Apparently, the permissions.so (WITH_IPAUTH) is made for just this purpose, so I enabled it. After authentication, I need to route the INVITE to asterisk, and asterisk must somehow match the account for the SIP trunk from the available information on the INVITE request.

A typical INVITE for this scenario looks like this, before being processed by 
kamailio:

INVITE sip:6008010@172.28.161.218:5060;transport=udp;user=phone SIP/2.0
Via: SIP/2.0/UDP 
200.25.144.58:5060;branch=z9hG4bK+676ea13f680e853fd847230512a347561+32e3da76+1
Call-ID: FBE75B3A@32e3da76
From: 
<sip:042294440@200.25.144.58:5060;user=phone>;tag=32e3da76+1+544c000c+52be771c
To: <sip:6008010@172.28.161.218:5060;user=phone>
CSeq: 975469826 INVITE
Expires: 180
Organization: SetelGYE
Min-SE: 90
Session-Expires: 18000
Supported: replaces, 100rel, timer
Contact: <sip:042294440@200.25.144.58:5060;transport=udp;user=phone>
Content-Length: 149
Content-Type: application/sdp
Max-Forwards: 70
Allow: INVITE, ACK, CANCEL, BYE, OPTIONS, NOTIFY, PRACK, UPDATE, INFO, REFER

v=0
o=- 0 0 IN IP4 201.217.79.3
s=-
c=IN IP4 201.217.79.3
t=0 0
m=audio 5388 RTP/AVP 8 101
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15

Here, 6008010 is the phone number that was dialed at the provider in order to reach my system, and 042294440 is the provider-supplied Caller-ID, which I want to preserve all the way to Asterisk. In particular, 042294440 appears as the value that ends up as $fU (From: username) while being processed in kamailio. If I pass the SIP packet as-is to asterisk, asterisk first tries to match by the value of $fU, which obviously fails to match the trunk name. It then tries to match by incoming IP, which also fails because asterisk received this packet from 127.0.0.1 . Finally, asterisk sort of matches to the first record in the sip table, which is *not* the SIP account for this trunk, but some other random account.

I have a partial solution that uses sqlops to make a query to the sip table, using the $si (source IP) and reads the trunk name in order to replace $fU. This works, as now $fU will have the trunk name and asterisk will now recognize the intended SIP account for the trunk. However, this has the unfortunate side effect of throwing out the Caller-ID information.

What is the standard/proper way to deal with this situation? Is there a well-known way to make Asterisk match the trunk name, without overwriting the Caller-ID information? Before you ask, requesting the provider to modify its INVITEs is not an option. I believe there is a standard way to deal with this, since this scenario should also arise with a kamailio that faces the internet, and relays INVITEs (after authentication) to an asterisk in a local network. As far as I can tell, the fact that in my case the 'local network' is localhost should be irrelevant.
#!KAMAILIO
 
#!define WITH_ODBC
#!define WITH_AUTH
#!define WITH_IPAUTH
#!define WITH_USRLOCDB
#!define WITH_ASTERISK
#!define WITH_PRESENCE
#!define WITH_NAT
#!define WITH_MULTIDOMAIN
#!define WITH_XHTTP
#!define WITH_WEBSOCKET
#!define WITH_TLS
 
#
# Kamailio (OpenSER) SIP Server v4.1 - default configuration script
#     - web: http://www.kamailio.org
#     - git: http://sip-router.org
#
# Direct your questions about this file to: <sr-users@lists.sip-router.org>
#
# Refer to the Core CookBook at http://www.kamailio.org/wiki/
# for an explanation of possible statements, functions and parameters.
#
# Several features can be enabled using '#!define WITH_FEATURE' directives:
#
# *** To run in debug mode: 
#     - define WITH_DEBUG
#
# *** To enable mysql: 
#     - define WITH_MYSQL
#
# *** To enable authentication execute:
#     - enable mysql
#     - define WITH_AUTH
#     - add users using 'kamctl'
#
# *** To enable IP authentication execute:
#     - enable mysql
#     - enable authentication
#     - define WITH_IPAUTH
#     - add IP addresses with group id '1' to 'address' table
#
# *** To enable persistent user location execute:
#     - enable mysql
#     - define WITH_USRLOCDB
#
# *** To enable presence server execute:
#     - enable mysql
#     - define WITH_PRESENCE
#
# *** To enable nat traversal execute:
#     - define WITH_NAT
#     - install RTPProxy: http://www.rtpproxy.org
#     - start RTPProxy:
#        rtpproxy -l _your_public_ip_ -s udp:localhost:7722
#
# *** To enable PSTN gateway routing execute:
#     - define WITH_PSTN
#     - set the value of pstn.gw_ip
#     - check route[PSTN] for regexp routing condition
#
# *** To enable database aliases lookup execute:
#     - enable mysql
#     - define WITH_ALIASDB
#
# *** To enable speed dial lookup execute:
#     - enable mysql
#     - define WITH_SPEEDDIAL
#
# *** To enable multi-domain support execute:
#     - enable mysql
#     - define WITH_MULTIDOMAIN
#
# *** To enable TLS support execute:
#     - adjust CFGDIR/tls.cfg as needed
#     - define WITH_TLS
#
# *** To enable XMLRPC support execute:
#     - define WITH_XMLRPC
#     - adjust route[XMLRPC] for access policy
#
# *** To enable anti-flood detection execute:
#     - adjust pike and htable=>ipban settings as needed (default is
#       block if more than 16 requests in 2 seconds and ban for 300 seconds)
#     - define WITH_ANTIFLOOD
#
# *** To block 3XX redirect replies execute:
#     - define WITH_BLOCK3XX
#
# *** To enable VoiceMail routing execute:
#     - define WITH_VOICEMAIL
#     - set the value of voicemail.srv_ip
#     - adjust the value of voicemail.srv_port
#
# *** To enhance accounting execute:
#     - enable mysql
#     - define WITH_ACCDB
#     - add following columns to database
#!ifdef ACCDB_COMMENT
  ALTER TABLE acc ADD COLUMN src_user VARCHAR(64) NOT NULL DEFAULT '';
  ALTER TABLE acc ADD COLUMN src_domain VARCHAR(128) NOT NULL DEFAULT '';
  ALTER TABLE acc ADD COLUMN src_ip varchar(64) NOT NULL default '';
  ALTER TABLE acc ADD COLUMN dst_ouser VARCHAR(64) NOT NULL DEFAULT '';
  ALTER TABLE acc ADD COLUMN dst_user VARCHAR(64) NOT NULL DEFAULT '';
  ALTER TABLE acc ADD COLUMN dst_domain VARCHAR(128) NOT NULL DEFAULT '';
  ALTER TABLE missed_calls ADD COLUMN src_user VARCHAR(64) NOT NULL DEFAULT '';
  ALTER TABLE missed_calls ADD COLUMN src_domain VARCHAR(128) NOT NULL DEFAULT 
'';
  ALTER TABLE missed_calls ADD COLUMN src_ip varchar(64) NOT NULL default '';
  ALTER TABLE missed_calls ADD COLUMN dst_ouser VARCHAR(64) NOT NULL DEFAULT '';
  ALTER TABLE missed_calls ADD COLUMN dst_user VARCHAR(64) NOT NULL DEFAULT '';
  ALTER TABLE missed_calls ADD COLUMN dst_domain VARCHAR(128) NOT NULL DEFAULT 
'';
#!endif

####### Include Local Config If Exists #########
import_file "kamailio-local.cfg"

####### Defined Values #########

# *** Value defines - IDs used later in config
#!ifdef WITH_ODBC
#!ifndef DBURL
#!define DBURL "unixodbc:///kamailio-connector"
#!endif
#!ifdef WITH_ASTERISK
#!define DBASTURL "unixodbc:///elxpbx-connector"
#!endif
#!endif
#!ifdef WITH_MYSQL
# - database URL - used to connect to database server by modules such
#       as: auth_db, acc, usrloc, a.s.o.
#!ifndef DBURL
#!define DBURL "mysql://kamailio:kamailiorw@localhost/kamailio"
#!endif
#!endif
#!ifdef WITH_MULTIDOMAIN
# - the value for 'use_domain' parameters
#!define MULTIDOMAIN 1
#!else
#!define MULTIDOMAIN 0
#!endif

# - flags
#   FLT_ - per transaction (message) flags
#       FLB_ - per branch flags
#!define FLT_ACC 1
#!define FLT_ACCMISSED 2
#!define FLT_ACCFAILED 3
#!define FLT_NATS 5

#!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

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

/* uncomment the next line to disable the auto discovery of local aliases
   based on reverse DNS on IPs (default on) */
#auto_aliases=no

/* add local domain aliases */
#alias="sip.mydomain.com"

/* uncomment and configure the following line if you want Kamailio to 
   bind on a specific interface/port/proto (default bind on all available) */
#listen=udp:10.0.0.10:5060

/* port to listen to
 * - can be specified more than once if needed to listen on many ports */
port=5060

#!ifdef WITH_TLS
enable_tls=yes
#!endif

# 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

#!ifdef WITH_XHTTP
tcp_accept_no_cl=yes
#!endif

####### Custom Parameters #########

# These parameters can be modified runtime via RPC interface
# - see the documentation of 'cfg_rpc' module.
#
# Format: group.id = value 'desc' description
# Access: $sel(cfg_get.group.id) or @cfg_get.group.id
#

#!ifdef WITH_PSTN
# PSTN GW Routing
#
# - pstn.gw_ip: valid IP or hostname as string value, example:
# pstn.gw_ip = "10.0.0.101" desc "My PSTN GW Address"
#
# - by default is empty to avoid misrouting
pstn.gw_ip = "" desc "PSTN GW Address"
pstn.gw_port = "" desc "PSTN GW Port"
#!endif

#!ifdef WITH_VOICEMAIL
# VoiceMail Routing on offline, busy or no answer
#
# - by default Voicemail server IP is empty to avoid misrouting
voicemail.srv_ip = "" desc "VoiceMail IP Address"
voicemail.srv_port = "5060" desc "VoiceMail Port"
#!endif

####### Modules Section ########

# set paths to location of modules (to sources or installation folders)
#!ifdef WITH_SRCPATH
mpath="modules/"
#!else
mpath="/usr/lib64/kamailio/modules/"
#!endif

#!ifdef WITH_MYSQL
loadmodule "db_mysql.so"
#!endif

#!ifdef WITH_ODBC
loadmodule "db_unixodbc.so"
#!endif

loadmodule "mi_fifo.so"
loadmodule "kex.so"
loadmodule "corex.so"
loadmodule "tm.so"
loadmodule "tmx.so"
loadmodule "sl.so"
loadmodule "rr.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 "mi_rpc.so"
loadmodule "acc.so"

loadmodule "sqlops.so"

#!ifdef WITH_AUTH
loadmodule "auth.so"
loadmodule "auth_db.so"
#!ifdef WITH_IPAUTH
loadmodule "permissions.so"
#!endif
#!endif

#!ifdef WITH_ALIASDB
loadmodule "alias_db.so"
#!endif

#!ifdef WITH_SPEEDDIAL
loadmodule "speeddial.so"
#!endif

#!ifdef WITH_MULTIDOMAIN
loadmodule "domain.so"
#!endif

#!ifdef WITH_PRESENCE
loadmodule "presence.so"
loadmodule "presence_xml.so"
#!endif

#!ifdef WITH_NAT
loadmodule "nathelper.so"
loadmodule "rtpproxy.so"
loadmodule "ipops.so"
#!endif

#!ifdef WITH_TLS
loadmodule "tls.so"
#!endif

#!ifdef WITH_ANTIFLOOD
loadmodule "htable.so"
loadmodule "pike.so"
#!endif

#!ifdef WITH_XMLRPC
loadmodule "xmlrpc.so"
#!endif

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

#!ifdef WITH_ASTERISK
loadmodule "uac.so"
#!endif
 
#!ifdef WITH_XHTTP
loadmodule "xhttp.so"
#!ifdef WITH_WEBSOCKET
loadmodule "msrp.so"
loadmodule "websocket.so"
#endif
#!endif

#!ifdef WITH_XHTTP_RPC
loadmodule "xhttp_rpc.so"
#!endif

#!ifdef WITH_XHTTP_PI
loadmodule "xhttp_pi.so"
#!endif

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


# ----- mi_fifo params -----
modparam("mi_fifo", "fifo_name", "/tmp/kamailio_fifo")


# ----- 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 -----
# add value to ;lr param to cope with most of the UAs
modparam("rr", "enable_full_lr", 1)
# do not append from tag to the RR (no need for this script)
#!ifdef WITH_ASTERISK
modparam("rr", "append_fromtag", 1)
#!else
modparam("rr", "append_fromtag", 0)
#!endif

# ----- registrar params -----
modparam("registrar", "method_filtering", 1)
/* uncomment the next line to disable parallel forking via location */
# modparam("registrar", "append_branches", 0)
/* uncomment the next line not to allow more than 10 contacts per AOR */
#modparam("registrar", "max_contacts", 10)
# max value for expires of registrations
modparam("registrar", "max_expires", 3600)
# set it to 1 to enable GRUU
modparam("registrar", "gruu_enabled", 0)


# ----- acc params -----
/* what special events should be accounted ? */
modparam("acc", "early_media", 0)
modparam("acc", "report_ack", 0)
modparam("acc", "report_cancels", 0)
/* by default ww do not adjust the direct of the sequential requests.
   if you enable this parameter, be sure the enable "append_fromtag"
   in "rr" module */
modparam("acc", "detect_direction", 0)
/* account triggers (flags) */
modparam("acc", "log_flag", FLT_ACC)
modparam("acc", "log_missed_flag", FLT_ACCMISSED)
modparam("acc", "log_extra", 
        "src_user=$fU;src_domain=$fd;src_ip=$si;"
        "dst_ouser=$tU;dst_user=$rU;dst_domain=$rd")
modparam("acc", "failed_transaction_flag", FLT_ACCFAILED)
/* enhanced DB accounting */
#!ifdef WITH_ACCDB
modparam("acc", "db_flag", FLT_ACC)
modparam("acc", "db_missed_flag", FLT_ACCMISSED)
modparam("acc", "db_url", DBURL)
modparam("acc", "db_extra",
        "src_user=$fU;src_domain=$fd;src_ip=$si;"
        "dst_ouser=$tU;dst_user=$rU;dst_domain=$rd")
#!endif


# ----- usrloc params -----
/* enable DB persistency for location entries */
#!ifdef WITH_USRLOCDB
modparam("usrloc", "db_url", DBURL)
modparam("usrloc", "db_mode", 2)
modparam("usrloc", "use_domain", MULTIDOMAIN)
#!endif


# ----- auth_db params -----
#!ifdef WITH_AUTH
modparam("auth_db", "calculate_ha1", yes)
modparam("auth_db", "load_credentials", "")
 
#!ifdef WITH_ASTERISK
# subscriber table is actually a view in DBASTURL
modparam("auth_db", "use_domain", 1)
modparam("auth_db", "db_url", DBASTURL)
modparam("auth_db", "version_table", 0)
#!else
modparam("auth_db", "db_url", DBURL)
modparam("auth_db", "password_column", "password")
modparam("auth_db", "use_domain", MULTIDOMAIN)
#!endif

# ----- permissions params -----
#!ifdef WITH_IPAUTH
modparam("permissions", "db_url", DBURL)
modparam("permissions", "db_mode", 1)
#!endif

#!endif


# ----- alias_db params -----
#!ifdef WITH_ALIASDB
modparam("alias_db", "db_url", DBURL)
modparam("alias_db", "use_domain", MULTIDOMAIN)
#!endif


# ----- speeddial params -----
#!ifdef WITH_SPEEDDIAL
modparam("speeddial", "db_url", DBURL)
modparam("speeddial", "use_domain", MULTIDOMAIN)
#!endif


# ----- domain params -----
#!ifdef WITH_MULTIDOMAIN
modparam("domain", "db_url", DBURL)
# register callback to match myself condition with domains list
modparam("domain", "register_myself", 1)
#!endif


#!ifdef WITH_PRESENCE
# ----- presence params -----
modparam("presence", "db_url", DBURL)

# ----- presence_xml params -----
modparam("presence_xml", "db_url", DBURL)
modparam("presence_xml", "force_active", 1)
#!endif


#!ifdef WITH_NAT
# ----- rtpproxy params -----
#modparam("rtpproxy", "rtpproxy_sock", "udp:127.0.0.1:7722")

# ----- nathelper params -----
modparam("nathelper", "natping_interval", 30)
modparam("nathelper", "ping_nated_only", 1)
modparam("nathelper", "sipping_bflag", FLB_NATSIPPING)
modparam("nathelper", "sipping_from", "sip:pin...@kamailio.org")

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


#!ifdef WITH_TLS
# ----- tls params -----
modparam("tls", "config", "//etc/kamailio/tls.cfg")
#!endif

#!ifdef WITH_ANTIFLOOD
# ----- pike params -----
modparam("pike", "sampling_time_unit", 2)
modparam("pike", "reqs_density_per_unit", 16)
modparam("pike", "remove_latency", 4)

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

#!ifdef WITH_XMLRPC
# ----- xmlrpc params -----
modparam("xmlrpc", "route", "XMLRPC");
modparam("xmlrpc", "url_match", "^/RPC")
#!endif

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

#!ifdef WITH_XHTTP
#!ifdef WITH_WEBSOCKET
modparam("websocket", "keepalive_mechanism", 2)
#!endif
#!endif

#!ifdef WITH_XHTTP_RPC
modparam("xhttp_rpc", "xhttp_rpc_root", "http_rpc")
#!endif

#!ifdef WITH_XHTTP_PI
modparam("xhttp_pi", "xhttp_pi_root", "http_pi")
modparam("xhttp_pi", "framework", "//etc/kamailio/pi_framework.xml")
#!endif

modparam("sqlops", "sqlcon", "elxpbx=>unixodbc:///elxpbx-connector")

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

import_file "kamailio-mhomed-elastix.cfg"

# Main SIP request routing logic
# - processing of any incoming SIP request starts with this route
# - note: this is the same as route { ... }
request_route {

        # per request initial checks
        route(REQINIT);

        # NAT detection
        route(NATDETECT);

        # CANCEL processing
        if (is_method("CANCEL"))
        {
                if (t_check_trans()) {
                        route(RELAY);
                }
                exit;
        }

        # handle requests within SIP dialogs
        route(WITHINDLG);

        ### only initial requests (no To tag)

        t_check_trans();

        # authentication
        route(AUTH);

        # record routing for dialog forming requests (in case they are routed)
        # - remove preloaded route headers
        remove_hf("Route");
        if (is_method("INVITE|SUBSCRIBE"))
                record_route();

        # account only INVITEs
        if (is_method("INVITE"))
        {
                setflag(FLT_ACC); # do accounting
        }

        # dispatch requests to foreign domains
        route(SIPOUT);

        ### requests for my local domains

        # handle presence related requests
        route(PRESENCE);

        # handle registrations
        route(REGISTRAR);

        if ($rU==$null)
        {
                # request with no Username in RURI
                sl_send_reply("484","Address Incomplete");
                exit;
        }

        # dispatch destinations to PSTN
        route(PSTN);

        # user location service
        route(LOCATION);
}


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] {
#!ifdef WITH_ANTIFLOOD
        # 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;
                }
        }
#!endif

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

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

# Handle requests within SIP dialogs
route[WITHINDLG] {
        if (has_totag()) {
                # sequential request withing a dialog should
                # take the path determined by record-routing
                if (loose_route()) {
                        route(DLGURI);
                        if (is_method("BYE")) {
                                setflag(FLT_ACC); # do accounting ...
                                setflag(FLT_ACCFAILED); # ... even if the 
transaction fails
                        }
                        else 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);
                } else {
                        if (is_method("SUBSCRIBE") && uri == myself) {
                                # in-dialog subscribe requests
                                route(PRESENCE);
                                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;
        }
}

# Handle SIP registrations
route[REGISTRAR] {
        if (is_method("REGISTER"))
        {
                if(isflagset(FLT_NATS))
                {
                        setbflag(FLB_NATB);
                        # uncomment next line to do SIP NAT pinging 
                        ## setbflag(FLB_NATSIPPING);
                }
                if (!save("location"))
                        sl_reply_error();

#!ifdef WITH_ASTERISK
#               route(REGFWD);
                route(TOASTERISK);
#!endif

                exit;
        }
}

# USER location service
route[LOCATION] {

#!ifdef WITH_SPEEDDIAL
        # search for short dialing - 2-digit extension
        if($rU=~"^[0-9][0-9]$")
                if(sd_lookup("speed_dial"))
                        route(SIPOUT);
#!endif

#!ifdef WITH_ALIASDB
        # search in DB-based aliases
        if(alias_db_lookup("dbaliases"))
                route(SIPOUT);
#!endif

#!ifdef WITH_ASTERISK
        if(is_method("INVITE") && (!route(FROMASTERISK))) {
                # if new call from out there - send to Asterisk
                # - non-INVITE request are routed directly by Kamailio
                # - traffic from Asterisk is routed also directy by Kamailio
                route(TOASTERISK);
                exit;
        }
#!endif
 
        $avp(oexten) = $rU;
        #xlog("L_ALERT", "ALERT: received routing request for ru=$ru rU=$rU 
rd=$rd ou=$ou\n");
        uac_restore_from();
        uac_restore_to();
        if (!lookup("location")) {
                $var(rc) = $rc;
                route(TOVOICEMAIL);
                t_newtran();
                switch ($var(rc)) {
                        case -1:
                        case -3:
                                send_reply("404", "Not Found");
                                exit;
                        case -2:
                                send_reply("405", "Method Not Allowed");
                                exit;
                }
        }

        # when routing via usrloc, log the missed calls also
        if (is_method("INVITE"))
        {
                setflag(FLT_ACCMISSED);
        }

        route(RELAY);
        exit;
}

# Presence server route
route[PRESENCE] {
        if(!is_method("PUBLISH|SUBSCRIBE"))
                return;

        if(is_method("SUBSCRIBE") && $hdr(Event)=="message-summary") {
                route(TOVOICEMAIL);
                # returns here if no voicemail server is configured
                sl_send_reply("404", "No voicemail service");
                exit;
        }

#!ifdef WITH_PRESENCE
        if (!t_newtran())
        {
                sl_reply_error();
                exit;
        }

        if(is_method("PUBLISH"))
        {
                handle_publish();
                t_release();
        } else if(is_method("SUBSCRIBE")) {
                handle_subscribe();
                t_release();
        }
        exit;
#!endif
        
        # if presence enabled, this part will not be executed
        if (is_method("PUBLISH") || $rU==$null)
        {
                sl_send_reply("404", "Not here");
                exit;
        }
        return;
}

# Authentication route
route[AUTH] {
#!ifdef WITH_AUTH

#!ifdef WITH_ASTERISK
        # do not auth traffic from Asterisk - trusted!
        if(route(FROMASTERISK))
                return;
#!endif
 
#!ifdef WITH_IPAUTH
        if((!is_method("REGISTER")) && allow_source_address() && $au == "")
        {
        # Loading $fU from database using IP
        xlog("L_ALERT", "WITH_IPAUTH: before load fU=$fU");

        sql_pvquery("elxpbx", "SELECT name FROM sip WHERE host = '$si' AND 
sippasswd IS NULL", "$fU");

        xlog("L_ALERT", "WITH_IPAUTH: after load fU=$fU");
        
                # source IP allowed
                return;
        }
#!endif

        if (is_method("REGISTER|INVITE") || from_uri==myself)
        {
                # authenticate requests
                #if (!auth_check("$fd", "subscriber", "1")) {
                if (!auth_check("$fd", "subscriber", "0")) {
                        auth_challenge("$fd", "0");
                        exit;
                }
                # user authenticated - remove auth header
                if(!is_method("REGISTER|PUBLISH"))
                        consume_credentials();
        }
        # if caller is not local subscriber, then check if it calls
        # a local destination, otherwise deny, not an open relay here
        if (from_uri!=myself && uri!=myself)
        {
                sl_send_reply("403","Not relaying");
                exit;
        }

#!endif
        return;
}

# Caller NAT detection route
route[NATDETECT] {
#!ifdef WITH_NAT
        force_rport();
        if (nat_uac_test("19")) {
                if (is_method("REGISTER")) {
                        fix_nated_register();
                } else {
                        if(is_first_hop())
                                set_contact_alias();
                }
                setflag(FLT_NATS);
        }
#!endif

        if (nat_uac_test(64)) {
                # Do NAT traversal stuff for requests from a WebSocket
                # connection - even if it is not behind a NAT!
                # This won't be needed in the future if Kamailio and the
                # WebSocket client support Outbound and Path.
                force_rport();
                if (is_method("REGISTER"))
                        fix_nated_register();
                else {
                        if (!add_contact_alias()) {
                                xlog("L_ERR", "Error aliasing contact <$ct>\n");
                                sl_send_reply("400", "Bad Request");
                                exit;
                        }
                }
        }

        return;
}

# RTPProxy control
route[NATMANAGE] {
#!ifdef WITH_NAT
        if (is_request()) {
#               if(has_totag()) {
#                       if(check_route_param("nat=yes")) {
                                setbflag(FLB_NATB);
#                       }
#               }
        }
        if (!(isflagset(FLT_NATS) || isbflagset(FLB_NATB))) {
                return;
        }

        #rtpproxy_manage("co");
        route(MHOMED_ELASTIX);

        if (is_request()) {
                if (!has_totag()) {
                        if(t_is_branch_route()) {
                                add_rr_param(";nat=yes");
                        }
                }
        }
        if (is_reply()) {
                if(isbflagset(FLB_NATB)) {
                        if(is_first_hop())
                                set_contact_alias();
                }
        }
#!endif
        return;
}

# URI update for dialog requests
route[DLGURI] {
#!ifdef WITH_NAT
        if(!isdsturiset()) {
                if (!handle_ruri_alias()) {
                        xlog("L_ERR", "Bad alias <$ru>\n");
                        sl_send_reply("400", "Bad Request");
                        exit;
                }
        }
#!endif
        return;
}

# Routing to foreign domains
route[SIPOUT] {
        if (!uri==myself)
        {
                append_hf("P-hint: outbound\r\n");
                route(RELAY);
        }
}

# PSTN GW routing
route[PSTN] {
#!ifdef WITH_PSTN
        # check if PSTN GW IP is defined
        if (strempty($sel(cfg_get.pstn.gw_ip))) {
                xlog("SCRIPT: PSTN rotuing enabled but pstn.gw_ip not 
defined\n");
                return;
        }

        # route to PSTN dialed numbers starting with '+' or '00'
        #     (international format)
        # - update the condition to match your dialing rules for PSTN routing
        if(!($rU=~"^(\+|00)[1-9][0-9]{3,20}$"))
                return;

        # only local users allowed to call
        if(from_uri!=myself) {
                sl_send_reply("403", "Not Allowed");
                exit;
        }

        if (strempty($sel(cfg_get.pstn.gw_port))) {
                $ru = "sip:" + $rU + "@" + $sel(cfg_get.pstn.gw_ip);
        } else {
                $ru = "sip:" + $rU + "@" + $sel(cfg_get.pstn.gw_ip) + ":"
                                        + $sel(cfg_get.pstn.gw_port);
        }

        route(RELAY);
        exit;
#!endif

        return;
}

# XMLRPC routing
#!ifdef WITH_XMLRPC
route[XMLRPC] {
        # allow XMLRPC from localhost
        if ((method=="POST" || method=="GET")
                        && (src_ip==127.0.0.1)) {
                # close connection only for xmlrpclib user agents (there is a 
bug in
                # xmlrpclib: it waits for EOF before interpreting the response).
                if ($hdr(User-Agent) =~ "xmlrpclib")
                        set_reply_close();
                set_reply_no_connect();
                dispatch_rpc();
                exit;
        }
        send_reply("403", "Forbidden");
        exit;
}
#!endif

# route to voicemail server
route[TOVOICEMAIL] {
#!ifdef WITH_VOICEMAIL
        if(!is_method("INVITE|SUBSCRIBE"))
                return;

        # check if VoiceMail server IP is defined
        if (strempty($sel(cfg_get.voicemail.srv_ip))) {
                xlog("SCRIPT: VoiceMail rotuing enabled but IP not defined\n");
                return;
        }
        if(is_method("INVITE")) {
                if($avp(oexten)==$null)
                        return;
                $ru = "sip:" + $avp(oexten) + "@" + 
$sel(cfg_get.voicemail.srv_ip)
                                + ":" + $sel(cfg_get.voicemail.srv_port);
        } else {
                if($rU==$null)
                        return;
                $ru = "sip:" + $rU + "@" + $sel(cfg_get.voicemail.srv_ip)
                                + ":" + $sel(cfg_get.voicemail.srv_port);
        }
        route(RELAY);
        exit;
#!endif

        return;
}

# manage outgoing branches
branch_route[MANAGE_BRANCH] {
        xdbg("new branch [$T_branch_idx] to $ru\n");
        route(NATMANAGE);
}

# manage incoming replies
onreply_route[MANAGE_REPLY] {
        xdbg("incoming reply\n");
        if(status=~"[12][0-9][0-9]")
                route(NATMANAGE);

        # manage websocket reply
        if (nat_uac_test(64)) {
                # Do NAT traversal stuff for replies to a WebSocket connection
                # - even if it is not behind a NAT!
                # This won't be needed in the future if Kamailio and the
                # WebSocket client support Outbound and Path.
                add_contact_alias();
        }
}

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

        if (t_is_canceled()) {
                exit;
        }

#!ifdef WITH_BLOCK3XX
        # block call redirect based on 3xx replies.
        if (t_check_status("3[0-9][0-9]")) {
                t_reply("404","Not found");
                exit;
        }
#!endif

#!ifdef WITH_VOICEMAIL
        # serial forking
        # - route to voicemail on busy or no answer (timeout)
        if (t_check_status("486|408")) {
                $du = $null;
                route(TOVOICEMAIL);
                exit;
        }
#!endif
}

#!ifdef WITH_XHTTP
event_route[xhttp:request] {
#!ifdef WITH_XHTTP_RPC
       $var(xhttp_rpc_root) = $(hu{s.substr,0,9});
       if ($var(xhttp_rpc_root) == "/http_rpc") {
               dispatch_xhttp_rpc();
       }
#!endif
#!ifdef WITH_XHTTP_PI
       $var(xhttp_rpc_root) = $(hu{s.substr,0,8});
       if ($var(xhttp_rpc_root) == "/http_pi") {
               dispatch_xhttp_pi();
       }
#!endif


        set_reply_close();
        set_reply_no_connect();

#        if ($Rp != 80
##!ifdef WITH_TLS
#            && $Rp != 443
##!endif
#        ) {
#
#                xlog("L_WARN", "HTTP request received on $Rp\n");
#                xhttp_reply("403", "Forbidden", "text/html", "Forbidden");
#                exit;
#        }

        xlog("L_DBG", "HTTP Request Received\n");

        if ($hdr(Upgrade)=~"websocket"
                        && $hdr(Connection)=~"Upgrade"
                        && $rm=~"GET") {

                # Validate Host - make sure the client is using the correct
                # alias for WebSockets
                if ($hdr(Host) == $null || !is_myself("sip:" + $hdr(Host))) {
                        xlog("L_WARN", "Bad host $hdr(Host)\n");
                        xhttp_reply("403", "Forbidden", "", "");
                        exit;
                }

                # Optional... validate Origin - make sure the client is from an
                # authorised website.  For example,
                #
                # if ($hdr(Origin) != "http://communicator.MY_DOMAIN";
                #     && $hdr(Origin) != "https://communicator.MY_DOMAIN";) {
                #       xlog("L_WARN", "Unauthorised client $hdr(Origin)\n");
                #       xhttp_reply("403", "Forbidden", "", "");
                #       exit;
                # }

                # Optional... perform HTTP authentication

                # ws_handle_handshake() exits (no further configuration file
                # processing of the request) when complete.
                if (ws_handle_handshake())
                {
                        # Optional... cache some information about the
                        # successful connection
                        exit;
                }
        }



       xhttp_reply("200", "OK", "text/html",
               "<html><body>Wrong URL $hu</body></html>");
}
#!endif

#!ifdef WITH_ASTERISK
# Test if coming from Asterisk
route[FROMASTERISK] {
        if($si==$sel(cfg_get.asterisk.bindip)
                        && $sp==$sel(cfg_get.asterisk.bindport))
                return 1;
        return -1;
}
 
# Send to Asterisk
route[TOASTERISK] {
        $var(rip) = $sel(cfg_get.asterisk.bindip);
        $du = "sip:" + $sel(cfg_get.asterisk.bindip) + ":"
                        + $sel(cfg_get.asterisk.bindport);

        # If authorization user is identical to From: username, I will assume 
this is
        # a call coming from an extension within a domain. Otherwise, this 
request
        # will be unchanged, for incoming SIP trunks.
        if ($au == $fU) {
                #xlog("L_ALERT", "INFO: Authorization user=$au From user=$fU , 
mangling...");
                # Encode domain part into username
                $var(newfrom) = $fU + "_" + $fd;
                $var(newfromuri) = "sip:" + $(var(newfrom){s.escape.user}) + 
"@" + $sel(cfg_get.asterisk.bindip) + ":" + $sel(cfg_get.asterisk.bindport);
                uac_replace_from("$var(newfromuri)");
                $var(newto) = $tU + "_" + $td;
                $var(newtouri) = "sip:" + $(var(newto){s.escape.user}) + "@" + 
$sel(cfg_get.asterisk.bindip) + ":" + $sel(cfg_get.asterisk.bindport);
                uac_replace_to("$var(newtouri)");
        } else {
                #xlog("L_ALERT", "INFO: Authorization user=$au From user=$fU , 
NOT mangling...");
                if ($au != "") {
                        $var(newfromuri) = "sip:" + $au + "@" + $fd;
                        uac_replace_from("$var(newfromuri)");
                }
        }
        route(RELAY);
        exit;
}
 
# Forward REGISTER to Asterisk
route[REGFWD] {
        if(!is_method("REGISTER"))
        {
                return;
        }
        $var(rip) = $sel(cfg_get.asterisk.bindip);
        $uac_req(method)="REGISTER";
        $uac_req(ruri)="sip:" + $var(rip) + ":" + 
$sel(cfg_get.asterisk.bindport);

        # Encode domain part into username
        $var(newfrom) = $fU + "_" + $fd;
        $var(newfromuri) = "sip:" + $(var(newfrom){s.escape.user}) + "@" + 
$sel(cfg_get.asterisk.bindip) + ":" + $sel(cfg_get.asterisk.bindport);
        uac_replace_from("$var(newfromuri)");
        $var(newto) = $tU + "_" + $td;
        $var(newtouri) = "sip:" + $(var(newto){s.escape.user}) + "@" + 
$sel(cfg_get.asterisk.bindip) + ":" + $sel(cfg_get.asterisk.bindport);
        uac_replace_to("$var(newtouri)");

        $var(encodeuser) = $au + "_" + $fd;
        $uac_req(furi)=$var(newfromuri);

        $uac_req(turi)=$var(newtouri);

        $var(encodeuser) = $au + "_" + $fd;
        $uac_req(hdrs)="Contact: <sip:" + $(var(encodeuser){s.escape.user}) + 
"@"
                                + $sel(cfg_get.kamailio.bindip)
                                + ":" + $sel(cfg_get.kamailio.bindport) + 
">\r\n";
        if($sel(contact.expires) != $null)
                $uac_req(hdrs)= $uac_req(hdrs) + "Expires: " + 
$sel(contact.expires) + "\r\n";
        else
                $uac_req(hdrs)= $uac_req(hdrs) + "Expires: " + $hdr(Expires) + 
"\r\n";
        uac_req_send();
}
#!endif
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