[asterisk-commits] mmichelson: testsuite/asterisk/trunk r5157 - /asterisk/trunk/lib/python/aster...
SVN commits to the Asterisk project
asterisk-commits at lists.digium.com
Fri Jun 20 11:50:28 CDT 2014
Author: mmichelson
Date: Fri Jun 20 11:50:22 2014
New Revision: 5157
URL: http://svnview.digium.com/svn/testsuite?view=rev&rev=5157
Log:
Add a library of pcap tools.
As you can see from the header of the file, Matt actually wrote
this, but I'm committing it. He's either being gracious or this
is some subversive attempt to get my name to show up in 'svn blame'
forever on this file, leading to finger-pointing and laughing in
my general direction.
It's probably the former, though.
Either way, this sort of thing is useful in general, but it will
be sorely needed for RLS tests to come. I'm placing this section
of code directly into trunk's testsuite though so that the changes
I actually make will be apparent when it comes time to do code
reviews for RLS stuff.
Added:
asterisk/trunk/lib/python/asterisk/pcap.py (with props)
Added: asterisk/trunk/lib/python/asterisk/pcap.py
URL: http://svnview.digium.com/svn/testsuite/asterisk/trunk/lib/python/asterisk/pcap.py?view=auto&rev=5157
==============================================================================
--- asterisk/trunk/lib/python/asterisk/pcap.py (added)
+++ asterisk/trunk/lib/python/asterisk/pcap.py Fri Jun 20 11:50:22 2014
@@ -1,0 +1,453 @@
+#!/usr/bin/env python
+"""Asterisk pcap pluggable modules
+
+This module implements a suite of pluggable module for the Asterisk Test Suite
+that will generate and manipulate a pcap of the message traffic during a test.
+
+Copyright (C) 2013, Digium, Inc.
+Matt Jordan <mjordan at digium.com>
+
+This program is free software, distributed under the terms of
+the GNU General Public License Version 2.
+"""
+
+import sys
+import logging
+import binascii
+
+sys.path.append('lib/python')
+
+from construct import *
+from construct.protocols.ipstack import ip_stack
+try:
+ from yappcap import PcapOffline
+ PCAP_AVAILABLE = True
+except:
+ PCAP_AVAILABLE = False
+
+LOGGER = logging.getLogger(__name__)
+
+class PcapListener(object):
+ '''
+ A class that creates a pcap file from a test and optionally provides
+ runttime inspection of the received packets
+ '''
+
+ def __init__(self, module_config, test_object):
+ ''' Constructor
+
+ Keyword arguments:
+ module_config The YAML config object for this module
+ test_object The test object this module will attach to
+ '''
+
+ if not PCAP_AVAILABLE:
+ raise Exception('yappcap not installed')
+
+ self.debug_packets = False
+
+ device = module_config.get('device')
+ bpf_filter = module_config.get('bpf-filter')
+ filename = module_config.get('filename')
+ if (module_config.get('register-observer')):
+ test_object.register_pcap_observer(self.__pcap_callback)
+ if (module_config.get('debug-packets')):
+ self.debug_packets = True
+
+ # Let exceptions propagate - if we can't create the pcap, this should
+ # throw the exception to the pluggable module creation routines
+ test_object.create_pcap_listener(
+ device=None,
+ bpf_filter=bpf_filter,
+ dumpfile=filename)
+
+ def __pcap_callback(self, packet):
+ ''' Private callback. Will log packets out as DEBUG messages if
+ configured to do so. '''
+ if (self.debug_packets):
+ LOGGER.debug(str(packet))
+ self.pcap_callback(packet)
+
+ def pcap_callback(self, packet):
+ ''' Function that can be overridden by derived classes to inspect
+ packets as they arrive from the listener '''
+ pass
+
+class Packet():
+ ''' Some IP packet. Base class for everything else '''
+
+ def __init__(self, packet_type, raw_packet):
+ ''' Constructor
+
+ Keyword Arguments:
+ packet_type A text string describing what type of packet this is
+ raw_packet The bytes comprising the packet
+ '''
+
+ self.packet_type = packet_type
+ self.raw_packet = raw_packet
+ self.eth_layer = ip_stack.parse(raw_packet.data)
+ self.ip_layer = self.eth_layer.next
+ self.transport_layer = self.ip_layer.next
+
+
+class RTCPPacket(Packet):
+ ''' An RTCP Packet '''
+
+ def __init__(self, raw_packet, factory_manager):
+ ''' Constructor
+
+ Keyword Arguments:
+ raw_packet The bytes comprising this RTCP packet
+ factory_manager The packet manager that created this packet
+ '''
+ Packet.__init__(self, packet_type='RTCP', raw_packet=raw_packet)
+ self.rtcp_header = None
+ self.sender_report = None
+ self.receiver_report = None
+ ports = factory_manager.get_global_data(self.ip_layer.header.source)
+ if ports == None:
+ raise Exception()
+ if (ports['rtcp'] != self.ip_layer.next.header.source):
+ raise Exception()
+ self.__parse_raw_data(self.transport_layer.next)
+
+ def __parse_raw_data(self, binary_blob):
+ header_def = Struct('rtcp_header',
+ BitStruct('header',
+ BitField('version', 2),
+ Padding(1),
+ BitField('reception_report_count', 5),
+ ),
+ UBInt8('packet_type'),
+ UBInt16('length'),
+ UBInt32('ssrc'))
+ self.rtcp_header = header_def.parse(binary_blob)
+ report_block_def = GreedyRange(Struct('report_block',
+ UBInt32('ssrc'),
+ BitStruct('lost_counts',
+ BitField('fraction_lost', 8),
+ BitField('packets_lost', 24)),
+ UBInt32('sequence_number_received'),
+ UBInt32('interarrival_jitter'),
+ UBInt32('last_sr'),
+ UBInt32('delay_last_sr')))
+ if self.rtcp_header.packet_type == 200:
+ sender_def = Struct('sr',
+ Struct('sender_info',
+ UBInt32('ntp_msw'),
+ UBInt32('ntp_lsw'),
+ UBInt32('rtp_timestamp'),
+ UBInt32('sender_packet_count'),
+ UBInt32('sender_octet_count')),
+ report_block_def)
+
+ self.sender_report = sender_def.parse(binary_blob[8:])
+ elif self.rtcp_header.packet_type == 201:
+ receiver_def = Struct('rr',
+ report_block_def)
+ self.receiver_report = receiver_def.parse(binary_blob[8:])
+
+ def __str__(self):
+ return 'Header: %s\n%s: %s' % (self.rtcp_header,
+ 'SR' if self.sender_report is not None else 'RR',
+ self.sender_report if self.sender_report is not None else self.receiver_report)
+
+
+class RTPPacket(Packet):
+ ''' An RTP Packet '''
+
+ def __init__(self, raw_packet, factory_manager):
+ ''' Constructor
+
+ Keyword Arguments:
+ raw_packet The bytes comprising this RTP packet
+ factory_manager The packet manager that created this packet
+ '''
+ Packet.__init__(self, packet_type='RTP', raw_packet=raw_packet)
+ ports = factory_manager.get_global_data(self.ip_layer.header.source)
+ if ports == None:
+ raise Exception()
+ if (ports['rtp'] != self.ip_layer.next.header.source):
+ raise Exception()
+
+class SDPPacket(Packet):
+ ''' An SDP packet. Should be owned by a SIPPacket '''
+
+ def __init__(self, ascii_packet, raw_packet):
+ ''' Constructor
+
+ Keyword Arguments:
+ ascii_packet The text of the SDP packet
+ raw_packet The bytes comprising this SDP packet
+ '''
+ Packet.__init__(self, packet_type='SDP', raw_packet=raw_packet)
+ self.ascii_packet = ascii_packet
+ self.sdp_lines = ascii_packet.strip('\r\n').split('\r\n')
+ self.rtp_port = 0
+ self.rtcp_port = 0
+
+ # Okay. So the only reason I'm looking at the SDP is to get the RTP
+ # and RTCP ports out, so we can sniff those packets. A good parser here
+ # would be nice, but parsing SDP sucks.
+ # This assumes a single media description; assumes its audio; and
+ # assumes that the RTCP port will be one greater than the RTP port.
+ # That's a lot of assumptions, but I'm not going to justify the
+ # engineering effort to go beyond that.
+ for line in self.sdp_lines:
+ if 'm=audio' not in line:
+ continue
+ self.rtp_port = int(line[7:line.find(' ', 8)])
+ self.rtcp_port = self.rtp_port + 1
+
+
+class SIPPacket(Packet):
+ ''' A SIP packet '''
+
+ def __init__(self, ascii_packet, raw_packet):
+ ''' Constructor
+
+ Keyword Arguments:
+ ascii_packet The text of the SIP packet
+ raw_packet The bytes comprising this SIP packet
+ '''
+ Packet.__init__(self, packet_type='SIP', raw_packet=raw_packet)
+
+ self.sdp_packet = None
+ self.headers = {}
+ self.request_line = ''
+ self.ascii_packet = ascii_packet
+
+ ascii_packet = ascii_packet.strip()
+ last_pos = ascii_packet.find('\r\n',
+ ascii_packet.find('Content-Length'))
+ header_count = 0
+ sip_packet = ascii_packet[:last_pos].split('\r\n')
+ remainder_packet = ascii_packet[last_pos:]
+ for header in sip_packet:
+ header_count += 1
+ if header_count == 1:
+ self.request_line = header
+ continue
+ colon_pos = header.find(':')
+ self.headers[header[:colon_pos]] = header[colon_pos + 1:].strip()
+ if int(self.headers.get('Content-Length')) > 0:
+ self.sdp_packet = SDPPacket(ascii_packet=remainder_packet,
+ raw_packet=raw_packet)
+
+
+class SIPPacketFactory():
+ ''' A packet factory for producing SIP (and SDP) packets '''
+
+ def __init__(self, factory_manager):
+ ''' Constructor
+
+ Keyword Arguments:
+ factory_manager The factory manager this class factory registers to
+ '''
+ self._factory_manager = factory_manager
+
+ def interpret_packet(self, packet):
+ ''' Interpret a packet
+
+ Keyword Arguments:
+ packet The packet to interpret
+
+ Returns:
+ None if we couldn't interpret this packet
+ A SIPPacket if we could
+ '''
+ ret_packet = None
+ hex_string = binascii.b2a_hex(packet.data[42:])
+
+ try:
+ ascii_string = hex_string.decode('hex')
+ if ('SIP/2.0' in ascii_string):
+ ret_packet = SIPPacket(ascii_string, packet)
+ except:
+ pass
+ # If we got a SIP packet, it has an SDP, and that SDP specified an
+ # RTP port and RTCP port; then set that information for this particular
+ # stream in the factory manager so that the factories for RTP can
+ # interpret packets correctly
+ if ret_packet != None and ret_packet.sdp_packet != None and \
+ ret_packet.sdp_packet.rtp_port != 0 and \
+ ret_packet.sdp_packet.rtcp_port != 0:
+ self._factory_manager.add_global_data(ret_packet.ip_layer.header.source,
+ {'rtp': ret_packet.sdp_packet.rtp_port,
+ 'rtcp': ret_packet.sdp_packet.rtcp_port})
+ return ret_packet
+
+
+class RTPPacketFactory():
+ ''' A packet factory for producing RTP packets '''
+
+ def __init__(self, factory_manager):
+ ''' Constructor
+
+ Keyword Arguments:
+ factory_manager The factory manager this class factory registers to
+ '''
+ self._factory_manager = factory_manager
+
+ def interpret_packet(self, packet):
+ ''' Interpret a packet
+
+ Keyword Arguments:
+ packet The packet to interpret
+
+ Returns:
+ None if we couldn't interpret this packet
+ A RTPPacket if we could
+ '''
+ ret_packet = None
+ try:
+ ret_packet = RTPPacket(packet, self._factory_manager)
+ except:
+ pass
+ return ret_packet
+
+
+class RTCPPacketFactory():
+ ''' A packet factory for producing RTCP packets '''
+
+ def __init__(self, factory_manager):
+ ''' Constructor
+
+ Keyword Arguments:
+ factory_manager The factory manager this class factory registers to
+ '''
+ self._factory_manager = factory_manager
+
+ def interpret_packet(self, packet):
+ ''' Interpret a packet
+
+ Keyword Arguments:
+ packet The packet to interpret
+
+ Returns:
+ None if we couldn't interpret this packet
+ A RTCPPacket if we could
+ '''
+ ret_packet = None
+ try:
+ ret_packet = RTCPPacket(packet, self._factory_manager)
+ except:
+ pass
+ return ret_packet
+
+
+class PacketFactoryManager():
+ ''' Manager for packet factories. Also exposes shared data between
+ factories. '''
+
+ def __init__(self):
+ ''' Constructor '''
+ self._packet_factories = []
+ self._global_data = {}
+
+ def create_factory(self, factory_type):
+ ''' Make me a factory!
+
+ Keyword Arguments:
+ factory_type The typename of the factory to create
+ '''
+ factory = factory_type(self)
+ self._packet_factories.append(factory)
+
+ def add_global_data(self, key, value):
+ ''' Add a global data value to track
+
+ A global data value is a piece of data that a factory has discovered
+ that may be of use to other factories that construct packets. This is
+ basically how we can figure out what ports the RTP/RTCP packets are
+ coming across.
+
+ Keyword Arguments:
+ key The key of the global data
+ value The key's value (oooo)
+ '''
+ self._global_data[key] = value
+
+ def get_global_data(self, key):
+ ''' Get the global data associated with some key
+
+ Keyword Arguments:
+ key The key of the global data to obtain
+
+ Returns:
+ None if we don't have it
+ Something if we do
+ '''
+ return self._global_data.get(key)
+
+ def interpret_packet(self, packet):
+ ''' Interpret a packet
+
+ Iterate over all of the factories and ask them to interpret a packet.
+ Keep going until one of them says they got it.
+
+ Returns:
+ An interpreted packet if some packet factory handled it
+ None otherwise
+ '''
+ interpreted_packet = None
+ for factory in self._packet_factories:
+ try:
+ interpreted_packet = factory.interpret_packet(packet)
+ except:
+ pass
+ if interpreted_packet is not None:
+ break;
+ return interpreted_packet
+
+
+class VOIPListener(PcapListener):
+ ''' Pluggable module class that sniffs for SIP, RTP, and RTCP packets and
+ stores them according to the source '''
+
+ def __init__(self, module_config, test_object):
+ ''' Constructor
+
+ Keyword Arguments:
+ module_config The module configuration for this pluggable module
+ test_object The object we will attach to
+ '''
+ PcapListener.__init__(self, module_config, test_object)
+
+ if not 'register-observer' in module_config:
+ raise Exception('VOIPListener needs register-observer to be set')
+
+ self.packet_factory = PacketFactoryManager()
+ self.packet_factory.create_factory(SIPPacketFactory)
+ self.packet_factory.create_factory(RTPPacketFactory)
+ self.packet_factory.create_factory(RTCPPacketFactory)
+ self._callbacks = {}
+ self.traces = {}
+
+ def pcap_callback(self, packet):
+ ''' Packet capture callback function - overrides PcapListener's virtual
+ function '''
+
+ try:
+ packet = self.packet_factory.interpret_packet(packet)
+ except:
+ pass
+ if packet is None:
+ return
+ LOGGER.debug('Got packet %s from %s' % (str(packet), packet.ip_layer.header.source))
+ if packet.ip_layer.header.source not in self.traces:
+ self.traces[packet.ip_layer.header.source] = []
+ self.traces[packet.ip_layer.header.source].append(packet)
+ if packet.packet_type not in self._callbacks:
+ return
+ for callback in self._callbacks[packet.packet_type]:
+ callback(packet)
+
+
+ def add_callback(self, packet_type, callback):
+ ''' Add a callback function for when a packet of a particular type
+ is received '''
+ if packet_type not in self._callbacks:
+ self._callbacks[packet_type] = []
+ self._callbacks[packet_type].append(callback)
Propchange: asterisk/trunk/lib/python/asterisk/pcap.py
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