I installed 'simple_ostinato' on a new Ubuntu 16.04 VM and tried to import the library into the python interpreter and received the following error:

$ python
Python 2.7.12 (default, Nov 19 2016, 06:48:10)
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import simple_ostinato
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/simple_ostinato/__init__.py", line 1, in <module>
    from .stream import Stream
  File "/usr/local/lib/python2.7/dist-packages/simple_ostinato/stream.py", line 8, in <module>
    from . import protocols
  File "/usr/local/lib/python2.7/dist-packages/simple_ostinato/protocols/__init__.py", line 2, in <module>
    from .overrides import MacAddress, Mac, Ethernet, IPv4Address, IPv4, Payload, \
  File "/usr/local/lib/python2.7/dist-packages/simple_ostinato/protocols/overrides.py", line 3, in <module>
    from . import autogenerates
  File "/usr/local/lib/python2.7/dist-packages/simple_ostinato/protocols/autogenerates.py", line 1, in <module>
    from ostinato.protocols import arp_pb2, gmp_pb2, ip4over6_pb2, mld_pb2, \
  File "/usr/local/lib/python2.7/dist-packages/ostinato/protocols/dot2llc_pb2.py", line 13, in <module>
    serialized_pb='\n\rdot2llc.proto\x12\x08OstProto\x1a\x0eprotocol.proto\x1a\ndot3.proto\x1a\tllc.proto\"\t\n\x07\x44ot2Llc:7\n\x07\x64ot2Llc\x12\x12.OstProto.Protocol\x18\xce\x01 \x01(\x0b\x32\x11.OstProto.Dot2Llc')
  File "/usr/local/lib/python2.7/dist-packages/google/protobuf/descriptor.py", line 824, in __new__
    return _message.default_pool.AddSerializedFile(serialized_pb)
TypeError: Couldn't build proto file into descriptor pool!
Invalid proto descriptor for file "dot2llc.proto":
  dot2llc.proto: Import "dot3.proto" has not been loaded.
  dot2llc.proto: Import "llc.proto" has not been loaded.

I'm not exactly what the issue is, however, I'm thinking it may have to do with an update that was done to protobuf.

ostinato supports many protocols, but we currently only support Ethernet, IPv4, UDP and TCP. The other needs to be implemented.

Part of the code can be generated. Here is how I processed for IPv4.

Create a new item in the protocol list in the generator module:

{
  'class_name':   'IPv4',   # name of the class to generate
  'doc':          'Represent the IPv4 layer.',  # docstring of the class
  'protocol_id':  constants._Protocols.IP4,  # protocol ID, see https://github.com/little-dude/simple-ostinato/blob/master/simple_ostinato/constants.py#L29
  'extension':    'ip4_pb2.ip4',
  'attributes': {
      # TODO
  }
},

The extension is the protocol buffer class that correspond to IPv4 in the native ostinato library:

>>> from ostinato.protocols import ip4_pb2
>>> type(ip4_pb2.Ip4)
google.protobuf.reflection.GeneratedProtocolMessageType

populate the attributes, using the corresponding protobuf file in the ostinato repo.

Each attribute looks like this:

'attribute name': (offset, default value, full mask, mask, protobuf name, override name, docstring),

• the offset is the offset of the field in the layer, in bytes
• the default value is the default value of the protocol
• the full mask is the mask in "entire" bytes. For example, in the IP protocol, the version field occupies 4 first bits, so we consider the full mask is 1 byte. It's somewhat confusing, and we could (should) probably get rid of the concept of "full mask" but it made it easier to generate the code at the beginning.
• the mask is the actuall mask of the field. For the version, which occupied the 4 first bits of a byte, it is 0xf0.
• the protobuf name is the name of the field in the protobuf message (see above the google.protobuf.reflection.GeneratedProtocolMessageType object)
• the override name is generally None. It is used for fields that normally have default values (like checksums, which Ostinato computes automatically), but that can be overriden through an override attribute in the protobuf message. These override attributes are declared in the protobuf file.
  ` the doctring is the docstring of the attribute.

The source field of the IP protocol looks like this for example:

'source': (12, '127.0.0.1', 0xffffffff, 0xffffffff, 'src_ip' , None, 'Source IP address'),

Generate the code

python -m simple_ostinato.generator

This generates the code in simple_ostinato/autogenerates.py. For the IPv4 class, it generates an _IPv4 class.

Make you protocol available in the stream module

Add an override class

Declare your class in the simple_ostinato/protocols/overrides.py. This is where you can also customize you protocol if you want.

1. Write tests :)

I created a stream with a TCP destination port and the destination_override set to True.

stream.layers = [
... Mac(source='52:54:00:00:02:21', destination='52:54:00:00:02:20'),
... Ethernet(),
... IPv4(source='96.6.54.84', destination='141.193.37.5'),
... Tcp(destination_override=True, destination=443),
... Payload()]

The layer in the list looks to be correct.

print stream.layers[3]
Tcp(flag_ack=0,header_length=0,reserved=0,ack_num=0,flag_rst=0,window_size=0,destination=443,flag_psh=0,urgent_pointer=0,source=49152,flag_ece=0,flag_urg=0,sequence_num=0,checksum=0,flag_syn=0,flag_cwr=0,flag_fin=0,flag_ns=0,)

However, when I start the traffic and do a tcpdump of the packets, both the source and destination ports are set to 0.

13:46:49.671815 IP 96.6.54.84.0 > 141.193.37.5.0: Flags [none], seq 0:361, win 0, length 361
13:46:49.747704 IP 96.6.54.84.0 > 141.193.37.5.0: Flags [none], seq 0:1359, win 0, length 1359
13:46:49.819851 IP 96.6.54.84.0 > 141.193.37.5.0: Flags [none], seq 0:569, win 0, length 569
13:46:49.895964 IP 96.6.54.84.0 > 141.193.37.5.0: Flags [none], seq 0:762, win 0, length 762
13:46:49.975706 IP 96.6.54.84.0 > 141.193.37.5.0: Flags [none], seq 0:1423, win 0, length 1423

Hi, pal.
Looks like it is impossible to get rid of some added layers using code like this

stream.layers.append(proto_layer)
stream.save()
del stream.layers[:]
stream.save()

Because looks like you're fetching layers while saving stream thus preventing them from being deleted. Am I missing something or there are actually issue persists?

Hi,

Can you advise me what to do?

I tried to install using "python setup.py install" in virtualenv.

And try to run sample introduced, https://github.com/little-dude/simple-ostinato.
However, it returns many errors below;

Traceback (most recent call last):
File "d:\Programming\GTAC\test_automation\test\simple_ostinato_test.py", line 2, in
from simple_ostinato import Drone
File "D:\Programming\venv\venv27\lib\site-packages\simple_ostinato-0.0.4-py2.7.egg\simple_ostinato_init_.py", line 1, in
from .stream import Stream
File "D:\Programming\venv\venv27\lib\site-packages\simple_ostinato-0.0.4-py2.7.egg\simple_ostinato\stream.py", line 8, in
from . import protocols
File "D:\Programming\venv\venv27\lib\site-packages\simple_ostinato-0.0.4-py2.7.egg\simple_ostinato\protocols_init_.py", line 2, in
from .overrides import Mac, Ethernet, IPv4, Payload, Tcp, Udp
File "D:\Programming\venv\venv27\lib\site-packages\simple_ostinato-0.0.4-py2.7.egg\simple_ostinato\protocols\overrides.py", line 3, in
from . import autogenerates
File "D:\Programming\venv\venv27\lib\site-packages\simple_ostinato-0.0.4-py2.7.egg\simple_ostinato\protocols\autogenerates.py", line 2, in
from ostinato.protocols import arp_pb2, gmp_pb2, ip4over6_pb2, mld_pb2,
ImportError: cannot import name sample_pb2

Listed example doesn't work as you are saving the stream before adding the protocol layers. This will result in malformed packet.

Currently the newest version of python-ostinato on pypi is 0.7 - https://pypi.python.org/pypi/python-ostinato/.
Because of this it is impossible to use simple-ostinato when only using pip to install missing requirements.

Is it possible to support version 0.7 as well and/or add an explanation on how to install python-ostinato not via pypi?

Current requirements - f8fbf96