bf-pktpy

Barefoot Python Packet Generator (aka bf-pktpy)

Requirements

Note: Intel recommends to use Ubuntu 18.04.

• Python v2.7.X (bf-pktpy is compatible with Python v3.5+)

• PIP (preferred installer program) v9.0.1+

Install pre-requirements (for Python v2.7.X)

On debian based systems:

sudo apt-get -y update

sudo apt-get -y install python-pip python-setuptools git python-lxml python-dev

The Python requirements are in the requirements.txt, to install it on the system, type:

pip install -r requirements.txt

Install pre-requirements (for Python v3.5+)

On debian based systems:

sudo apt-get -y update

sudo apt-get -y install python3-pip python3-setuptools git python3-lxml python3-dev

To install pip:

pip install --upgrade pip>=9.0.3

sudo apt install python-pip

The Python requirements are in the requirements.txt, to install it on the system, type:

pip install -r requirements.txt

Build

To build a package, go to the root directory and type in the command line. The wheel package is necessary to execute this action.

python setup.py sdist bdist_wheel

Install

To install a bf-pktpy, you can use a PIP. Type in the command line:

pip install bf-pktpy*  

bf-pktpy and PTF

Bf-pktpy can be used with PTF (https://github.com/p4lang/ptf). In order to use them together, please install PTF (using pip). One can also use requirements file:

pip install -r requirements-ptf.txt

What is more, when running PTF script, one needs to add additional flag -pmm with module name:

ptf <other parameters> -pmm bf_pktpy.ptf.packet_pktpy

Please make sure that bf_pktpy is loaded into the runtime before running PTF script!

Available packets

All available packets you can import from bf_pktpy.packets.

How to import

Example for import the Ether:

from bf_pktpy.packets import Ether

Available packets:

• ARP
• BFD
• BOOTP
• DHCP
• Ether (Ethernet)
• ERSPAN (II & III)
• GRE
• ICMP
• IPv4
• IPv6
• MPLS
• TCP
• UDP
• VXLAN

And custom from bf-switch (some of them are in the WIP):

• DTEL_report_header
• fabric_cpu_header
• fabric_cpu_timestamp_header
• fabric_header
• fabric_payload_header
• mod_header
• postcard_header

Available commands

command name	command description
send	Send packet at layer 3
sendp	Send packet at layer 2
sr	Send and receive packet at layer 3
sr1	Send and receive packet at layer 3. Return only 1st answer
srp	Send and receive packet at layer 2
srp1	Send and receive packet at layer 3. Return only 1st answer
srloop	Send and receive packets in loop at layer 2
srploop	Send and receive packets in loop at layer 3
sniff
bridge_and_sniff

Additional functionality

This section stores information about additional features and similarities to the Scapy.

load_bytes pkt.__class__(packet_bytes)

Load bytes allows to load a received bytes into a structure (If we know the packets that made up the frame).

Example:

pkt = Ether() / IP() / TCP()
new_packet = pkt.load_bytes(bytes(pkt))  # value: bytes array 
# new_packet:  New Packet (Base) Object

Regarding p4-tests, tna_timestamp. Let's define a simple udp packet.

ipkt_payload = struct.pack("I", 0) * 10
ipkt = testutils.simple_udp_packet(eth_dst='11:11:11:11:11:11',
                                   eth_src='22:22:22:22:22:22',
                                   ip_src='1.2.3.4',
                                   ip_dst='100.99.98.97',
                                   ip_id=101,
                                   ip_ttl=64,
                                   udp_sport=0x1234,
                                   udp_dport=0xabcd,
                                   with_udp_chksum=False,
                                   udp_payload=ipkt_payload)

testutils.send_packet(self, swports[0], ipkt)

When we receive packet:

(_, _, rcv_pkt, _) = testutils.dp_poll(self, 0, swports[1], timeout=2)

# previous implementation
nrcv = ipkt.__class__(rcv_pkt)

# new implementation 
nrcv = ipkt.load_bytes(rcv_pkt)

New Packet class

To create a new version of packet you need to inherit from the Packet class (similar to other popular python's solution -- Scapy). The basic structure is similar to the Scapy packet implementation standards and simple packages should be cross-compatible.

Example of Ethernet class:

from bf_pktpy.library.specs.packet import Packet
from bf_pktpy.library.helpers.ether_types import ETYPES
from bf_pktpy.library.fields import (
    DestMACField,
    SourceMACField,
    XShortEnumField,
)


class Ether(Packet):
    name = "Ethernet"
    fields_desc = [
        DestMACField("dst"),
        SourceMACField("src"),
        XShortEnumField("type", 0x9000, types=ETYPES),
    ]

Test profiling

To view files created by cProfile you need for example cprofilev library. Files are being stored as artifacts from Jenkins pipeline. To view them execute command python -m cprofilev -f combined.prof and go to local server for a html preview of results.