#!/usr/bin/python

# @lint-avoid-python-3-compatibility-imports

#

# tcpsubnet Summarize TCP bytes sent to different subnets.

# For Linux, uses BCC, eBPF. Embedded C.

#

# USAGE: tcpsubnet [-h] [-v] [--ebpf] [-J] [-f FORMAT] [-i INTERVAL] [subnets]

#

# This uses dynamic tracing of kernel functions, and will need to be updated

# to match kernel changes.

#

# This is an adaptation of tcptop from written by Brendan Gregg.

#

# WARNING: This traces all send at the TCP level, and while it

# summarizes data in-kernel to reduce overhead, there may still be some

# overhead at high TCP send/receive rates (eg, ~13% of one CPU at 100k TCP

# events/sec. This is not the same as packet rate: funccount can be used to

# count the kprobes below to find out the TCP rate). Test in a lab environment

# first. If your send rate is low (eg, <1k/sec) then the overhead is

# expected to be negligible.

#

# Copyright 2017 Rodrigo Manyari

# Licensed under the Apache License, Version 2.0 (the "License")

#

# 03-Oct-2017 Rodrigo Manyari Created this based on tcptop.

# 13-Feb-2018 Rodrigo Manyari Fix pep8 errors, some refactoring.

# 05-Mar-2018 Rodrigo Manyari Add date time to output.

import argparse

import json

import logging

import struct

import socket

from bcc import BPF

from datetime import datetime as dt

from time import sleep

# arguments

examples = """examples:

"""

default_subnets = "127.0.0.1/32,10.0.0.0/8," \

"172.16.0.0/12,192.168.0.0/16,0.0.0.0/0"

parser = argparse.ArgumentParser(

description="Summarize TCP send and aggregate by subnet",

formatter_class=argparse.RawDescriptionHelpFormatter,

epilog=examples)

parser.add_argument("subnets", help="comma separated list of subnets",

type=str, nargs="?", default=default_subnets)

parser.add_argument("-v", "--verbose", action="store_true",

help="output debug statements")

parser.add_argument("-J", "--json", action="store_true",

help="format output in JSON")

parser.add_argument("--ebpf", action="store_true",

help=argparse.SUPPRESS)

parser.add_argument("-f", "--format", default="B",

help="[bkmBKM] format to report: bits, Kbits, Mbits, bytes, " +

"KBytes, MBytes (default B)", choices=["b", "k", "m", "B", "K", "M"])

parser.add_argument("-i", "--interval", default=1, type=int,

help="output interval, in seconds (default 1)")

args = parser.parse_args()

level = logging.INFO

if args.verbose:

level = logging.DEBUG

logging.basicConfig(level=level)

logging.debug("Starting with the following args:")

logging.debug(args)

# args checking

if int(args.interval) <= 0:

logging.error("Invalid interval, must be > 0. Exiting.")

exit(1)

else:

args.interval = int(args.interval)

# map of supported formats

formats = {

}

# Let's swap the string with the actual numeric value

# once here so we don't have to do it on every interval

formatFn = formats[args.format]

# define the basic structure of the BPF program

bpf_text = """

"""

# Takes in a mask and returns the integer equivalent

# e.g.

# mask_to_int(8) returns 4278190080

def mask_to_int(n):

return ((1 << n) - 1) << (32 - n)

# Takes in a list of subnets and returns a list

# of tuple-3 containing:

# - The subnet info at index 0

# - The addr portion as an int at index 1

# - The mask portion as an int at index 2

#

# e.g.

# parse_subnets([10.10.0.0/24]) returns

# [

# ['10.10.0.0/24', 168427520, 4294967040],

# ]

def parse_subnets(subnets):

return m

def generate_bpf_subnets(subnets):

return bpf

subnets = []

if args.subnets:

subnets = args.subnets.split(",")

subnets = parse_subnets(subnets)

logging.debug("Packets are going to be categorized in the following subnets:")

logging.debug(subnets)

bpf_subnets = generate_bpf_subnets(subnets)

# initialize BPF

bpf_text = bpf_text.replace("__SUBNETS__", bpf_subnets)

logging.debug("Done preprocessing the BPF program, " +

"this is what will actually get executed:")

logging.debug(bpf_text)

if args.ebpf:

print(bpf_text)

exit()

b = BPF(text=bpf_text)

ipv4_send_bytes = b["ipv4_send_bytes"]

if not args.json:

print("Tracing... Output every %d secs. Hit Ctrl-C to end" % args.interval)

# output

exiting = 0

while (1):

try:

sleep(args.interval)

except KeyboardInterrupt:

exiting = 1

# IPv4: build dict of all seen keys

keys = ipv4_send_bytes

for k, v in ipv4_send_bytes.items():

if k not in keys:

keys[k] = v

# to hold json data

data = {}

# output

now = dt.now()

data['date'] = now.strftime('%x')

data['time'] = now.strftime('%X')

data['entries'] = {}

if not args.json:

print(now.strftime('[%x %X]'))

for k, v in reversed(sorted(keys.items(), key=lambda keys: keys[1].value)):

send_bytes = 0

if k in ipv4_send_bytes:

send_bytes = int(ipv4_send_bytes[k].value)

subnet = subnets[k.index][0]

send = formatFn(send_bytes)

if args.json:

data['entries'][subnet] = send

else:

print("%-21s %6d" % (subnet, send))

if args.json:

print(json.dumps(data))

ipv4_send_bytes.clear()

if exiting:

exit(0)