How can i find the TCP ips in network with the range(i.e 132.32.0.3 to 132.32.0.44) through python programming and also want to know the which ips are alive and which are dead. please send me.. thanks for the repliers...
Part 1 - "Finding IPs"
Your example range, 132.32.0.3 to 132.32.0.44 doesn't match any subnet, which is curious.
Typically applications for checking whether hosts are up and down are normally scoped within a subnet, e.g. 192.168.0.0/28 (host addresses: 192.168.0.1 to 192.168.0.14).
If you wanted to calculate the addresses within a subnet, I'd suggest you use ipaddr. E.g.:
>>> from ipaddr import IPv4Address, IPNetwork
>>> for a in IPNetwork('192.168.0.0/28').iterhosts():
... print a
...
192.168.0.1
192.168.0.2
192.168.0.3
192.168.0.4
192.168.0.5
192.168.0.6
192.168.0.7
192.168.0.8
192.168.0.9
192.168.0.10
192.168.0.11
192.168.0.12
192.168.0.13
192.168.0.14
However, if you're sure that you want an arbitrary range. You can convert an IPv4 address to an integer, increment and convert back to dotted IP. E.g.:
def aton(a):
"""
Change dotted ip address to integer
e.g. '192.168.0.1' -> 3232235521L
"""
return reduce(lambda x,y: (x<<8) + y, [ int(x) for x in a.split('.') ])
def ntoa(n):
"""
Change an integer to a dotted ip address.
e.g. 3232235522L -> '192.168.0.2'
"""
return "%d.%d.%d.%d" % (n >> 24,(n & 0xffffff) >> 16,(n & 0xffff) >> 8,(n & 0xff))
def arbitraryRange(a1,a2):
"""
Generate all IP addresses between two addresses inclusively
"""
n1, n2 = aton(a1), aton(a2)
assert n1 < n2
i = n1
while i <= n2:
yield ntoa(i)
i += 1
Providing:
>>> for a in arbitraryRange('192.168.0.10','192.168.0.20'):
... print a
...
192.168.0.10
192.168.0.11
192.168.0.12
192.168.0.13
192.168.0.14
192.168.0.15
192.168.0.16
192.168.0.17
192.168.0.18
192.168.0.19
192.168.0.20
Part 2 - "Alive or Dead"
The question of "alive" or "dead" is complex and entirely dependent on what you mean by those terms. To provide context and contrast, here's a list of testable qualities with regard to an IP address / host:
Responds to ARP request?
Responds to ICMP echo request?
Responds to TCP SYN?
Related
I am new to Networking and trying to implement a network calculator using python3 where the client's responsibility is to send operands and operators and the server will calculate the result and send it back to the client. Communication is through UDP messages and I am working on client side. Each message is comprised of a header and a payload and they are described as shown in the below figures.
UDP header:
I am familiar with sending string messages using sockets but having a hard-time with how to make a message with both header and payload and how to assign the bits for various attributes or how to generate message/client id's in the header and If there is any way to automatically generate the Id's. Any help or suggestions will be highly appreciated.
Thanks in advance
I will only do a portion of your homework.
I hope it will help you to find energy to work on missing parts.
import struct
import socket
CPROTO_ECODE_REQUEST, CPROTO_ECODE_SUCCESS, CPROTO_ECODE_FAIL = (0,1,2)
ver = 1 # version of protocol
mid = 0 # initial value
cid = 99 # client Id (arbitrary)
sock = socket.socket( ...) # to be customized
def sendRecv( num1, op, num2):
global mid
ocs = ("+", "-", "*", "/").index( op)
byte0 = ver + (ocs << 3) + (CPROTO_ECODE_REQUEST << 6)
hdr = struct.pack( "!BBH", byte0, mid, cid)
parts1 = (b'0000' + num1.encode() + b'0000').split(b'.')
parts2 = (b'0000' + num2.encode() + b'0000').split(b'.')
msg = hdr + parts1[0][-4:] + parts1[1][:4] + parts2[0][-4:] + parts2[1][:4]
socket.send( msg) # send request
bufr = socket.recv( 512) # get answer
# to do:
# complete socket_send and socket.recv
# unpack bufr into: verr,ecr,opr,value_i, value_f
# verify that verr, ecr, opr, are appropriate
# combine value_i and value_f into answer
mid += 1
return answer
result = sendRecv( '2.47', '+', '46.234')
There are many elements that haven't be specified by your teacher:
what should be the byte-ordering on the network (bigEndian or littleEndian)? The above example suppose it's bigEndian but you can easily modify the 'pack' statement to use littleEndian.
What should the program do if the received packet header is invalid?
What should the program do if there's no answer from server?
Payload: how should we interpret "4 most significant digits of fraction"? Does that mean that the value is in ASCII? That's not specified.
Payload: assuming the fraction is in ASCII, should it be right-justified or left-justified in the packet?
Payload: same question for integer portion.
Payload: if the values are in binary, are they signed or unsigned. It will have an affect on the unpacking statement.
In the program above, I assumed that:
values are positive and in ASCII (without sign)
integer portion is right-justified
fractional portion is left justified
Have fun!
following a tutorial I coded a wifi sniffer in python using sockets (on linux) and the "struct" package. The code is splitted in two parts: the first one decodes the Ipv4 header packets getting the Ips and other information and then sends the remaining data to the second part which decodes ICMP, UDP and TCP packets. When I decode the TCP and UDP packets I can easily get source ports and destinations ports, flags etc... but I'm now looking for the host name. In other words Im trying to see which website is visited by the packet sender/receiver.
How can I get the host name? Is it in the "data" part of the tcp/udp packet, if so how to decode it? Do I have to look at the source and destination ports?
Here is the code: 2 functions for UDP/TCP packets, the data argument is the "data" part from a Ipv4 packet.
def tcp_segment(data):
(src_port, dest_port, sequence, acknowledgement, offset_reserved_flags) = struct.unpack('! H H L L H', data[:14])
offset = (offset_reserved_flags >> 12) * 4
flag_urg = (offset_reserved_flags & 32) >> 5
flag_ack = (offset_reserved_flags & 16) >> 4
flag_psh = (offset_reserved_flags & 8) >> 3
flag_rst = (offset_reserved_flags & 4) >> 2
flag_syn = (offset_reserved_flags & 2) >> 1
flag_fin = offset_reserved_flags & 1
return src_port, dest_port, sequence, acknowledgement, flag_urg, flag_ack, flag_psh, flag_rst, flag_syn, flag_fin, data[offset:]
def udp_segment(data):
src_port, dest_port, size = struct.unpack('! H H 2x H', data[:8])
return src_port, dest_port, size, data[8:]
TCP packet
I would like to send fragmented packets size of 8 bytes and a random starting offset. Also want to leave out the last fragmented packet.
So far I got everything except the fragment of
from scapy.all import *
from random import randint
dip="MY.IP.ADD.RESS"
payload="A"*250+"B"*500
packet=IP(dst=dip,id=12345,off=123)/UDP(sport=1500,dport=1501)/payload
frags=fragment(packet,fragsize=8)
print(packet.show())
for f in frags:
send(f)
What does the above code do?
It sends IP Fragment Packets size of 8 byte to a destination IP address.
I would like to send IP Fragment Packets with a random Frag Offset.
I can't find anything about fragment() and the only field, I was able to edit was in IP packet instead of each fragmented IP packet.
Does someone have an idea to accomplish this?
Infos: Python2.7, latest version of scapy (pip)
If you want to generate "broken" fragment offset fields, you have to do that yourself. The scapy fragment() function is simple enough:
def fragment(pkt, fragsize=1480):
"""Fragment a big IP datagram"""
fragsize = (fragsize + 7) // 8 * 8
lst = []
for p in pkt:
s = raw(p[IP].payload)
nb = (len(s) + fragsize - 1) // fragsize
for i in range(nb):
q = p.copy()
del(q[IP].payload)
del(q[IP].chksum)
del(q[IP].len)
if i != nb - 1:
q[IP].flags |= 1
q[IP].frag += i * fragsize // 8 # <---- CHANGE THIS
r = conf.raw_layer(load=s[i * fragsize:(i + 1) * fragsize])
r.overload_fields = p[IP].payload.overload_fields.copy()
q.add_payload(r)
lst.append(q)
return lst
Source: https://github.com/secdev/scapy/blob/652b77bf12499451b47609b89abc663aa0f69c55/scapy/layers/inet.py#L891
If you change the marked code line above, you can set the fragment offset to whatever you want.
I am interested in being able to detect specific parameters using the loading time it took a request from when I send it to when it got to the server.
The request I am talking about is the SYN packet in a three way hand shake.
How can I do this?
Looking forward to your answer!
Of course also what language should I use...I am testing with Python + Scapy right now.
If you want to use Scapy (which seems a reasonable choice for what you want to do), you need to use the Packet.time attribute. Here is a simple example:
>>> def measure_delay(packet):
... ans, _ = sr(packet, verbose=False)
... if ans:
... return reduce(lambda x, y: y.time - x.time, ans[0])
...
>>> measure_delay(IP(dst='192.168.1.254')/TCP(dport=80))
0.07259798049926758
From a Unix command line, you can also use hping3, and look for the rtt= value:
# sudo hping3 --syn 192.168.1.254 -p 80 -c 1
HPING 192.168.1.254 (wlan0 192.168.1.254): S set, 40 headers + 0 data bytes
len=44 ip=192.168.1.254 ttl=64 DF id=0 sport=80 flags=SA seq=0 win=14600 rtt=3.1 ms
--- 192.168.1.254 hping statistic ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 3.1/3.1/3.1 ms
i am trying to unpack data i receive from a packet dynamically, the main reason for this is i do not know the length of the ip addresses or the number of ip addresses in a packet, so need to unpack all
if our_or_addr_len == 4:
our_op_ip = struct.unpack(">BBBB", payload[6:10])
num_their_ips = struct.unpack(">B", payload[10])[0]
len_their_ips = struct.unpack(">B", payload[12])[0]
# Much better way to unpack the packet, does unpacking dynamically rather than set values
byte_string = '>{}'.format('b'*len_their_ips)
their_ips = []
for count in range(num_their_ips):
start = 13 + (count*len_their_ips)
end = start + len_their_ips
ip = struct.unpack(byte_string, payload[start:end])
print 'IP #{}: {}'.format(count+1, ip)
their_ips.append(ip)
return { 'tm': tm, 'our_or_ip_version': our_or_ip_version, 'our_or_addr_len': our_or_addr_len, 'our_op_ip': our_op_ip, 'num_their_ips': num_their_ips, 'len_their_ips': len_their_ips, 'their_ips': their_ips }
above is currently my code
what it should do is if my ip address is that of an ip v4 for, the for all of their ip address to unpack them for the packet starting at 13 in the payload for the length of their ip address for the number of ip addresses contained
currently it is only outputting one ip address although there is 2 ip address in the payload
shown in this output
{'our_or_addr_len': 4, 'len_their_ips': 4, 'our_op_ip': (00, 00, 00, 00), 'their_ips': [(0, 00, 00, 0)], 'tm': 1402265584, 'our_or_ip_version': 4, 'num_their_ips': 2}
how can i get both of the ip addresses returned, is there an issue with the loop as i think it should work so am confused as to why only one ip is returned
Managed to fix it it seemed my indenting was out on the their_ips.append(ip) so it was not getting assigned properly, weird how i had no errors however on complie, anyone got a good IDE program for linux and python ?