Need help with a Script

Need help with a Script

Postby edlentz » Thu Jul 21, 2016 2:27 pm

First of all I am a complete noob here. I found a script that is supposed to respond to a SIP subscribe message with the server information. The phone when it boots up does a multicast broadcast to The message looks like this Message Header
Code: Select all
Via: SIP/2.0/UDP;branch=z9hG4bKPj32c51c53-374e-4f4b-be6c-40e46d770844
Max-Forwards: 70
From: <sip:MAC%3a8082870390AC@>;tag=e84d3089-ac51-4979-8009-bde552f0242f
To: <sip:MAC%3a8082870390AC@>
Contact: <sip:>
Call-ID: b428161c-2a94-4ebf-b021-401d76530efe
Event: ua-profile;profile-type="device";vendor="ATCOM";model="1.1.4.;version=""
Expires: 3600
Supported: replaces, eventlist
Accept: application/url
Allow-Events: refer, message-summary, dialog, ua-profile
Content-Length:  0

Here is the python script that I found that is supposed to respond:
Code: Select all
#! /usr/bin/python
# snom multicast telephone discovery
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    GNU General Public License for more details.
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <>.

import socket
import struct
import sys
import re

from optparse import OptionParser

class snom_phone(object):
    """Basic representation of a snom phone."""

    def __init__(self, mac=None, ip=None, mod=None, fw=None, subs=None):
        """Default constructor."""
        self.mac_addr = mac
        self.ip_addr = ip
        self.sip_port = 5060
        self.model = mod
        self.fw_version = fw
        self.subscribe = subs

    def __repr__(self):
        """Gets a string representation of the phone"""
        return "%s (MAC: %s) running Firmware %s found at IP %s" % (self.model, self.__macrepr(self.mac_addr), self.fw_version, self.ip_addr)

    def __macrepr(self, m):
        """ Normalize a MAC address to lower case unix style """ 
        m = re.sub("[.:-]", "", m)
        m = m.lower()
        n =  "%s:%s:%s:%s:%s:%s" % (m[0:2], m[2:4], m[4:6], m[6:8], m[8:10], m[10:])
        return n

def parse(text):
    """Parses the incoming SUBSCRIBE."""
        lines = text.split('\r\n')
        # Line 1 conatains the SUBSCRIBE and our MAC
        new_phone = snom_phone(subs=text)
        new_phone.mac_addr = lines[0][20:32]
        # We can read the IP address from line 2
        new_phone.ip_addr = lines[1][17:].split(';')[0].split(':')[0]
        new_phone.sip_port = lines[1][17:].split(';')[0].split(':')[1]
        # The other interesting information can be found in line 7
        model_info = lines[6]
        l_model_info = model_info.split(';')
        new_phone.model = l_model_info[3].split('=')[1][1:-1]
        new_phone.fw_version = l_model_info[4].split('=')[1][1:-1]
        print new_phone
        return new_phone
        # Parsing failed. Probably not a SUBSCRIBE
        return None

def get_sip_info(text):
    """Get some relevant SIP information which we need in order to generate the responses."""
    lines = text.split('\r\n')
    # Some SIP info we need
    call_id = lines[4][9:]
    cseq = lines[5][6]
    via_header = lines[1]
    from_header = lines[2]
    to_header = lines[3]
    if options.verbose: print "CallId: " + call_id + "; CSeq: " + cseq + "\r\n";   
    return (call_id, cseq, via_header, from_header, to_header)

def get_ip_address():
        # This is a simple hack to find our IP address
        # AFAIK this is the only platform-independent way to obtain the address

        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
            s.connect(('', 0))
            return s.getsockname()[0]

prov_uri = None
parser = OptionParser()
parser.add_option('-u', '--url', action="store", dest="prov_uri", help="URI of the provisioning server")
parser.add_option('-l', '--local-ip', action="store", dest="local_ip", help="Local IP address")
parser.add_option("-v", "--verbose",
                  action="store_true", dest="verbose", default=False,
                  help="make lots of noise")

(options, args) = parser.parse_args()

print """                                                                               
      .ijjt;     ..... :tjt:           LLLi    ..... .ijt,    :tjt:             
   LLLL     :t   LLLLL   jLLLf. LLLLL:   :LLLL fLLLL.  :LLLLL   jLLLL           
   LLLLL;.       LLLLt   ,LLLf.;LLLL      LLLL.fLLLL    LLLLj   :LLLL           
   jLLLLLLLLf,   LLLLt   ,LLLf.fLLL;      LLLL:fLLLL    LLLLj   .LLLL           
    LLLLLLLLLLL  LLLLt   ,LLLf.LLLL:      fLLL:fLLLL    LLLLj   .LLLL           
     ,fLLLLLLLLt LLLLt   ,LLLf.LLLL.      LLLL.fLLLL    LLLLj   .LLLL           
         :iLLLLL LLLLt   ,LLLf.LLLL,     .LLLL fLLLL    LLLLj   .LLLL           
    L;      LLLL LLLLt   ,LLLf.jLLLj    .LLLLf fLLLL    LLLLj   .LLLL           
   iLL:    .LLLL LLLLt   ,LLLf.iLLLL   ;fLLLL; fLLLL    LLLLj   .LLLL           
  tLLLLLjjfLLLL; LLLLt   ,LLLf. LLLLf. fLLLLf  fLLLL    LLLLj   .LLLL           
   fLLLLLLLLLLf  LLLLt   ,LLLf. ;LLLLL jLLLt   fLLLL    LLLLj   .LLLL           
    ,LLLLLLLLi   LLLLt   ,LLLf.  iLLLL tf;     LLLLL    LLLLj   .LLLL           
       :,,:.                      .jLL                                         
print "\nsnom multicast PnP Provisioning Server (mcserv)\n"
print "(c) 2008-2009 snom technology AG\n"
print "=" * 80
print "Provisioning URI is %s\n" % options.prov_uri

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('', 5060))
mreq = struct.pack('4sl', socket.inet_aton(''), socket.INADDR_ANY)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
if not options.local_ip:
    ip_adr = get_ip_address()
    ip_adr = options.local_ip
print "Local IP Address is :: %s" % ip_adr
print "=" * 80

while True:
    subs = sock.recv(10240)
    if options.verbose: print subs
    phone = parse(subs)
    (call_id, cseq, via_header, from_header, to_header) = get_sip_info(subs)
    if phone:
        # Create a socket to send data
        sendsock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
        sendsock.bind(('%s' % ip_adr, 1036))

            # If a phone has been recognized first send 200 OK
        ok_response = "SIP/2.0 200 OK\r\n"
        ok_response += via_header + "\r\n"
        ok_response += "Contact: <sip:" + phone.ip_addr + ":" + phone.sip_port + ";transport=tcp;handler=dum>\r\n"
        ok_response += to_header + "\r\n"
        ok_response += from_header + "\r\n"
        ok_response += "Call-ID: %s\r\n" % call_id
        ok_response += "CSeq: %s SUBSCRIBE\r\nExpires: 0\r\nContent-Length: 0\r\n" % cseq
        sendsock.sendto(ok_response, ("%s" % phone.ip_addr, int(phone.sip_port)))

        # Now send a NOTIFY with the configuration URL
        if not options.prov_uri:
            prov_uri = "{mac}" % (phone.model, phone.model)
            prov_uri = options.prov_uri
            prov_uri = "%s/%s.htm" % (prov_uri,phone.model)

        notify = "NOTIFY sip:%s:%s SIP/2.0\r\n" % (phone.ip_addr, phone.sip_port)
        notify += via_header + "\r\n"
        notify += "Max-Forwards: 20\r\n"
        notify += "Contact: <sip:%s:1036;transport=TCP;handler=dum>\r\n" % ip_adr
        notify += to_header + "\r\n"
        notify += from_header + "\r\n"
        notify += "Call-ID: %s\r\n" % call_id
        notify += "CSeq: 3 NOTIFY\r\n"
        notify += "Content-Type: application/url\r\n"
        notify += "Subscription-State: terminated;reason=timeout\r\n"
        notify += "Event: ua-profile;profile-type=\"device\";vendor=\"OEM\";model=\"OEM\";version=\"7.1.19\"\r\n"
        notify += "Content-Length: %i\r\n" % (len(prov_uri))
        notify += "\r\n%s" % prov_uri

        print "Sending NOTIFY with URI :: %s\n" % prov_uri
        if options.verbose: print notify
        sendsock.sendto(notify, ("%s" % phone.ip_addr, int(phone.sip_port)))

This script was written for a Snom phone, I do not believe that it is that specific since the SIP messages are standard for all devices. When I run the script I get the print statement that show th eserver address, and all the graphics and stuff. It looks like to me that the script is supposed to output some information as it is contacted by phones. That is not happening.

Can anyone comment , give a guess on what is happening?

Thanks so much
Last edited by Yoriz on Thu Jul 21, 2016 4:36 pm, edited 1 time in total.
Reason: First post lock.
Posts: 2
Joined: Thu Jul 21, 2016 2:09 pm

Re: Need help with a Script

Postby edlentz » Wed Aug 10, 2016 1:46 pm

Posts: 2
Joined: Thu Jul 21, 2016 2:09 pm

Re: Need help with a Script

Postby micseydel » Wed Aug 10, 2016 6:51 pm

There's a great deal to this which sounds domain-specific, so someone would likely have to do a lot of research in order to answer it (it's incredibly unlikely anyone already has the domain-specific knowledge). That said, your question is still incredibly vague

edlentz wrote:It looks like to me that the script is supposed to output some information as it is contacted by phones. That is not happening.

"some information"? "it looks like"?

Make sure to read this with careful attention given to asking good questions. Then, when making your post, imagine that the people you're talking to are extremely well-versed in Python, and general computing and perhaps networking, but not with SIP, the phone stuff, this script, or anything else.

We also like some attempt on your part (even from "noobs" - check out a tutorial if needed). Have you narrowed down the problem? Does your script have the code to parse the information out of the header and something else is wrong, or does it lack the parsing too? Can you describe precisely what you want out of the header? Can you write that code yourself as a stand-alone? Can you add a simple print statement in your script that produces output when you want, if not what you want? (If you can do the previous two, you're nearly to your goal.)

If you believe the script has a bug, you can contact the author. We're here to help you learn how to change it yourself if that's what you want.
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