sisniff/sisniff.py

#!/usr/bin/python2

# (c) 2017 by Siegrist(SystemLoesungen) <PSS@ZweierNet.ch>

from scapy.all import *
import pwd
import os
import re
import glob
import sys
import string
import fcntl
import struct
import commands
import argparse

VERSION = "0.76"

PROC_TCP4 = "/proc/net/tcp"
PROC_UDP4 = "/proc/net/udp"
PROC_ICMP4 = "/proc/net/icmp"
PROC_TCP6 = "/proc/net/tcp6"
PROC_UDP6 = "/proc/net/udp6"
PROC_PACKET = "/proc/net/packet"

# Services
TSERV = dict((TCP_SERVICES[k], k) for k in TCP_SERVICES.keys())
USERV = dict((UDP_SERVICES[k], k) for k in UDP_SERVICES.keys())

# IP Protocol Numbers (dec)
IPPROTO_ICMP = 1
IPPROTO_TCP = 6
IPROTOP_IGP = 9
IPPROTO_UDP = 17

nostate = set(['04','05','06''07','08','09','0C','0D'])
tcp_payload_hdrs = ['GET|POST|HTTP|HEAD|PUT|PATCH|DELETE|TRACE|OPTIONS|CONNECT']
numeric = False
payloadH = False
fillter = ""

def get_conn_info(proto,hosts,ports):
    ''' returns: pid, exe, uid '''
    uid = 0
    
    line_array = _proc4load(proto,hosts,ports)
    
    if line_array == 0:
        return ['?','?','?']
    '''    
    try:
        uid = pwd.getpwuid(int(line_array[7]))[0]       # Get user from UID.
    except:
        uid = line_array[7]
    '''
        
    inode = str(line_array[9])
    if inode == "0":
        return ['.','.','.']
    
    pid = _get_pid_of_inode(inode)          # try get a pid
    
    
    if pid == "NoPid":
        #print ">>>>>>>>>>>NoPID:" + str(hosts) +" "+ str(ports) + "//" + str(line_array)
        return ['-', '-', uid]

    try:                                            # try read the process name.
        exe = os.readlink('/proc/'+pid+'/exe').split('/')[-1]
    except:
        exe = None
    
    #print str(lhost) +" "+ str(lport) +" "+ inode +" "+ pid
    return [pid, exe, uid]

    
def _proc4load(proto,hosts,ports):
    ''' Read the table of tcp/udp connections
    tcp/udp: "sl,  local_address, rem_address, st, tx_queue rx_queue, tr tm->when, retrnsmt,   uid , timeout, inode ,..."
    ---- TCP states from https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/net/tcp_states.h?id=HEAD
    enum {
	TCP_ESTABLISHED = 1,
	TCP_SYN_SENT,
	TCP_SYN_RECV,
	TCP_FIN_WAIT1,
	TCP_FIN_WAIT2,
	TCP_TIME_WAIT,
	TCP_CLOSE,
	TCP_CLOSE_WAIT,
	TCP_LAST_ACK,
	TCP_LISTEN,
	TCP_CLOSING,	/* Now a valid state */
	TCP_NEW_SYN_RECV,

	TCP_MAX_STATES	/* Leave at the end! */
    };
    ----------
    '''
    
    #xhosts = _ip_hexrev(hosts)
    xports = _dec2hex(ports)
    
    if proto == IPPROTO_UDP:
        try:
            with open(PROC_UDP4,'r') as f:
                next(f)
                for line in f:
                    line_arrayu = _remove_empty(line.split(' '))
                    l_xhost,l_xport = line_arrayu[1].split(':')
                    if l_xhost not in xMYADDRS:
                        continue
                    if l_xport == xports:
                        return line_arrayu
                        
                return 0
        except:
            print "open proc_udp4 error"
            return 0
    elif proto == IPPROTO_TCP:
        try:
            with open(PROC_TCP4,'r') as f:
                next(f)
                for line in f:
                    line_arrayt = _remove_empty(line.split(' '))
                    if line_arrayt[3] in nostate:        # not some TCP state
                        continue
                    l_xhost,l_xport = line_arrayt[1].split(':')
                    if l_xhost not in xMYADDRS:
                        continue
                    if l_xport == xports:
                        return line_arrayt
                        
                return 0
        except:
            print "open proc_tcp error"
            return 0
    
    elif proto == IPPROTO_ICMP:
        try:
            with open(PROC_ICMP4,'r') as f:
                next(f)
                for line in f:
                    line_arrayi = _remove_empty(line.split(' '))
                    l_xhost,l_xport = line_arrayi[1].split(':')
                    if l_xhost not in xMYADDRS:
                        continue
                    if l_xport == xports:
                        return line_arrayi
                        
                return 0
        except:
            print "open proc_icmp4 error"
            return 0
    
    return 0

def _convert_ipv4_port(array):
    host,port = array.split(':')
    return _ip(host),_hex2dec(port)
        
def _hex2dec(s):
    return str(int(s,16))

def _dec2hex(p):
    return hex(int(p)).split('x')[-1].upper()
    
def _ip(s):
    ip = [(_hex2dec(s[6:8])),(_hex2dec(s[4:6])),(_hex2dec(s[2:4])),(_hex2dec(s[0:2]))]
    return '.'.join(ip)

def _ip6(s):
    ip = [s[6:8],s[4:6],s[2:4],s[0:2],s[12:14],s[14:16],s[10:12],s[8:10],s[22:24],s[20:22],s[18:20],s[16:18],s[30:32],s[28:30],s[26:28],s[24:26]]
    #print '66666:', ':'.join(ip), s
    return ':'.join(ip)

def _ip_hexrev(ip):
    return ''.join([hex(int(x)+256)[3:] for x in ip.split('.')][::-1]).upper()

def _remove_empty(array):
    return [x for x in array if x != '']

def _get_pid_of_inode(inode):
    s_term = r'^socket\:\['+ inode +r'\]$'
    for item in glob.iglob('/proc/[0-9]*/fd/[0-9]*'):
        try:
            if re.match(s_term,os.readlink(item)):
                return item.split('/')[2]
        except:
            pass
    return "NoPid"

def _resolve_ip(host):
    """
    resolve ip und update dictionary res_cache {'ip': 'name'}.
    If resolution for a ip failed, 'name' is n_try ... 0.
    """
    try:
        hname = socket.gethostbyaddr(host)[0]
        res_cache[host] = str(hname)
        return str(hname)
    except:
        res_cache[host] = str(host)
        return str(host)

def check_root():
   if os.getuid() == 0:
       return True
   else:
       return False
        
## Define our Custom Action function
def doPackets(packet):
    
    program = "-"
    pid = "-"    
    uid = "-"    
    o_proto = ""
    o_dport = "none"
    o_sport = "none"
    flags = ""
    
    # only local addresses
    if packet[0][1].src in MYADDRS:
        conn_addr = packet[0][1].src
        if packet.haslayer(TCP) or packet.haslayer(UDP) or packet.haslayer(ICMP):
            try:
                conn_port = packet[0][2].sport
            except:
                conn_port = 99999
        o_dir = 1
    else:
        conn_addr = packet[0][1].dst
        if packet.haslayer(TCP) or packet.haslayer(UDP) or packet.haslayer(ICMP):
            try:
                conn_port = packet[0][2].dport
            except:
                conn_port = 99999
        o_dir = 0
    
    if packet.haslayer(TCP) or packet.haslayer(UDP) or packet.haslayer(ICMP):        # grrr, no info in /proc/net/icmp so far. or packet.haslayer(ICMP):
        # logemol casch 
        c_hash = conn_addr+'=:='+str(conn_port)
        if not any(x[0] == c_hash for x in conn_cache):
            # get the connection info from packet
            spid,sexe,suid = get_conn_info(packet[0][1].proto, conn_addr, conn_port)
            if re.match("^[0-9]+$", spid):
                program = sexe
                pid = spid
                uid = suid
                
                # update cache
                if len(conn_cache) >= cc_maxlen:
                    conn_cache.pop(0)
                conn_cache.append([c_hash,program,pid])
                #print conn_cache
            else:
                program = sexe
                pid = spid
                uid = suid
        else:
            # me honds fom casch
            indx = [x[0] for x in conn_cache].index(c_hash)
            program = conn_cache[indx][1]
            pid = conn_cache[indx][2]
            uid = 0
            # cache aktualisieren
            renew = conn_cache.pop(indx)
            conn_cache.append(renew)
        
    
    o_payload = ""
    if packet.haslayer(UDP):
        o_proto = "UDP"
        try:
            o_dport = "\033[1m"+USERV[packet[0][2].dport]+"\033[0m"
        except:
            o_dport = str(packet[0][2].dport)
        try:
            o_sport = "\033[1m"+USERV[packet[0][2].sport]+"\033[0m"
        except:
            o_sport = str(packet[0][2].sport)
        flags = ""
        #o_payload = packet[0].sprintf('%10s,UDP.payload%')
    elif packet.haslayer(TCP):
        o_proto = "TCP"
        try:
            o_dport = "\033[1m"+TSERV[packet[0][2].dport]+"\033[0m"
        except:
            o_dport = str(packet[0][2].dport)
        try:
            o_sport = "\033[1m"+TSERV[packet[0][2].sport]+"\033[0m"
        except:
            o_sport = str(packet[0][2].sport)
        flags = packet[0].sprintf('%3s,TCP.flags%')
        if payloadH == True:
            if packet.haslayer(Raw):
                tpld = packet[0].sprintf('%TCP.payload%')
                if re.match("^GET|POST|HTTP|HEAD|PUT|PATCH|DELETE|TRACE|OPTIONS|CONNECT.*", tpld[0:8]):
                    request_line, gaga = tpld.split('\r\n', 1)
                    o_payload = str(request_line)
                    #o_payload = tpld[0:20]
    elif packet.haslayer(ICMP):
        o_proto = "ICMP"
        if conn_port == 99999:
            o_dport = "-"
            o_sport = "-"
        else:
            try:
                o_dport = "\033[1m"+USERV[packet[0][2].sport]+"\033[0m"
            except:
                o_dport = str(packet[0][2].sport)
            try:
                o_sport = "\033[1m"+USERV[packet[0][2].dport]+"\033[0m"
            except:
                o_sport = str(packet[0][2].dport)
        flags = "["+packet[0].sprintf('%ICMP.type%') + "/" + packet[0].sprintf('%ICMP.code%')+"]"
    else:
        o_proto = "UNKNOWN"
        
    if o_dir == 1:
        if numeric == False:
            if res_cache.has_key(packet[0][1].dst):
                rem_name = res_cache[packet[0][1].dst]
            else:
                rem_name = _resolve_ip(packet[0][1].dst)
        else:
            rem_name = packet[0][1].dst
            
        return "\033[1m"+str(program)+"\033[0m" +"/"+ str(pid) + " - " + o_proto + ": " + packet[0][1].src + ":" + o_sport + "\033[1m\033[31m  ->>>  \033[0m" + rem_name + ":" + o_dport + " " + flags + " Len:" + str(packet[0][1].len) + " : " + o_payload
    else:
        if numeric == False:
            if res_cache.has_key(packet[0][1].src):
                rem_name = res_cache[packet[0][1].src]
            else:
                rem_name = _resolve_ip(packet[0][1].src)
        else:
            rem_name = packet[0][1].src
            
        return "\033[1m"+str(program)+"\033[0m" +"/"+ str(pid) + " - " + o_proto + ": " + packet[0][1].dst + ":" + o_dport + "\033[1m\033[36m  <<<-  \033[0m" + rem_name + ":" + o_sport + " " + flags + " Len:" + str(packet[0][1].len) + " : " + o_payload



## -- Ond denn s'Hooptprogramm

# root check
if not check_root():
    print("This program needs root privileges !\nThats because of reading the /proc filesystem and using libpcap functions.\nSo I give up\n")
    conf.sniff_promisc=0
    conf.sniff_promisc=0
    #print conf
    sys.exit()

# get the interfaces
ifaces = commands.getoutput("ls /sys/class/net")
iface_list = ifaces.split('\n')

print
# commandline params
parser = argparse.ArgumentParser(description='sisniff V'+VERSION)
parser.add_argument('-i', help="Interface (mandatory)", choices=iface_list, required=True)
parser.add_argument('-n', help="Do not resolve IP-Addresses", action="store_true")
parser.add_argument('-pH', help="Show HTTP Payload", action="store_true")
parser.add_argument('filter', nargs='?', help="Filter (BPF syntax) on top of IP (in dbl-quotes \"...\")", type=str)
args = parser.parse_args()
iface = args.i
if args.n:
    numeric = True
if args.pH:
    payloadH = True
if args.filter:
    fillter = " and (" + args.filter + ")"
    print "> Applying Filter: \"ip" + fillter + "\"" 

# local addresses 
MYADDRS = _remove_empty([os.popen('ip addr show '+iface).read().split("inet ")[1].split("/")[0]])
MYADDRS.append('0.0.0.0')
MYADDRS.append('127.0.0.1')
xMYADDRS = [_ip_hexrev(x) for x in MYADDRS]
print "> My IP-Addresses: " + str(MYADDRS)

# confirmed connections cache (ringboffer)
conn_cache = []
cc_maxlen = 20

# resolver cache
res_cache = {}
n_try = 3
print
print "Prog/PID mavericks: ?/? = No entry in /proc/net/xxx; -/- = No PID for Inode found; ./. = Inode=0;"
print
print "Program/PID: Local addr:port <<->> Remote addr:port [Flags] Len:length : [Payload]"
print "-------------------------------------------------------------------------------"

# sniff, filtering for IP traffic
sniff(filter="ip"+fillter,iface=iface,prn=doPackets, store=0)

## -- oond denn isch schloss