Parsing IP address and port in python - python

Using python, I'd like to accomplish two things:
Need to split an ipv6 address and port combination in the format [fec2::10]:80 to fec2::10 and 80.
Given an IP address and port combination, I need to determine if the IP is a v4 or v6 address. Eg: 1.2.3.4:80 and [fec2::10]:80
Please suggest a way to do it.
Thanks!
Sample code:
#!/usr/bin/env python
def main():
server = "[fec1::1]:80"
if server.find("[", 0, 2) == -1:
print "IPv4"
ip, port = server.split(':')
else:
print "IPv6"
new_ip, port = server.rsplit(':', 1)
print new_ip
ip = new_ip.strip('[]')
print ip
print port
if __name__ == '__main__':
main()
This works for all cases except when the input is specified without a port. Eg: 10.78.49.50 and [fec2::10]
Any suggestions to address this?

Assuming your_input is like "[fec2::10]:80" or "1.2.3.4:80", it is easy to split the port and find out the ip address:
#!/usr/bin/env python3
from ipaddress import ip_address
ip, separator, port = your_input.rpartition(':')
assert separator # separator (`:`) must be present
port = int(port) # convert to integer
ip = ip_address(ip.strip("[]")) # convert to `IPv4Address` or `IPv6Address`
print(ip.version) # print ip version: `4` or `6`

You can use urlparse (called urllib.parse in 3.x) to separate the URL into each of its components:
>>> from urlparse import urlparse
>>> ipv4address = urlparse("http://1.2.3.4:80")
>>> ipv4address
ParseResult(scheme='http', netloc='1.2.3.4:80', path='', params='', query='', fragment='')
>>> ipv6address = urlparse("http://[fec2::10]:80")
>>> ipv6address
ParseResult(scheme='http', netloc='[fec2::10]:80', path='', params='', query='', fragment='')
Then you can split the port off by finding the index of the last colon using rfind:
>>> ipv4address.netloc.rfind(':')
7
>>> ipv4address.netloc[:7], ipv4address.netloc[8:]
('1.2.3.4', '80')
>>> ipv6address.netloc.rfind(':')
10
>>> ipv6address.netloc[:10], ipv6address.netloc[11:]
('[fec2::10]', '80')
Identifying which type it is should then be as simple as if ':' in that_split_tuple[0], right? (Not 100% sure because it's been a while since I learned about how to write IPv6 addresses in URLs.)
Finally, removing the brackets from your IPv6 address is simple, there are many ways to do it:
>>> ipv6address.netloc[:10].replace('[', '').replace(']', '')
'fec2::10'
>>> ipv6address.netloc[:10].strip('[]')
'fec2::10'
Edit: since you expressed concern about not always having port numbers, you could simplify significantly by using a regular expression:
>>> import re
>>> f = lambda(n): re.split(r"(?<=\]):" if n.startswith('[') else r"(?<=\d):", n)
>>> f(ipv4address.netloc)
['1.2.3.4', '80']
>>> f(ipv6address.netloc)
['[fec2::10]', '80']
>>> f("1.2.3.4")
['1.2.3.4']
>>> f("[fec2::10]")
['[fec2::10]']
(I'm having trouble being more clever with my regular expression, hence the inline ternary.)

This is the code I came up with. It looks lengthy and laborious, but it addresses all possible input scenarios. Any suggestion to condense/better it is most welcome :)
#!/usr/bin/env python
import optparse
def main():
server = "[fec1::1]:80"
if server.find("[", 0, 2) == -1:
print "IPv4"
if server.find(":", 0, len(server)) == -1:
ip = server
port = ""
else:
ip, port = server.split(':')
else:
print "IPv6"
index = server.find("]", 0, len(server))
if index == -1:
print "Something wrong"
new_ip = ""
port = ""
else:
if server.find(":", index, len(server)) == -1:
new_ip = server
port = ""
else:
new_ip, port = server.rsplit(':', 1)
print new_ip
ip = new_ip.strip('[]')
print ip
print port
if __name__ == '__main__':
main()

Related

I want to convert bytes to IP and PORT

I want to convert a hexadecimal byte variable that comes in through the network into IP and Port.
For example, the format is :
value = (b'\xd3[\xdf\x94:\x98\xd5\xe6J\x9f\xb2\xfb\xd8\x18\xbdDsa')
# Size is random but multiples of 6 all.
type(value) # bytes
I want to print the variable named value above as follows.
>>> func(value)
"211.91.223.148:15000"
"213.230.74.159:45819"
Even if I searched, I could not find a module that changes bytes to IP and Port.
Any help would be appreciated.
test.py:
import ipaddress
import struct
from itertools import islice
N = 6
def func(value):
it = iter(value)
while chunk := bytes(islice(it, N)):
ip, port = struct.unpack("!IH", chunk)
ip = ipaddress.ip_address(ip)
print(f"{ip}:{port}")
def main():
value = b"\xd3[\xdf\x94:\x98\xd5\xe6J\x9f\xb2\xfb\xd8\x18\xbdDsa"
func(value)
if __name__ == "__main__":
main()
Test:
$ python test.py
211.91.223.148:15000
213.230.74.159:45819
216.24.189.68:29537

Python DNS Server IP Address Query

I am trying to get the DNS Server IP Addresses using python. To do this in Windows command prompt, I would use
ipconfig -all
As shown below:
I want to do the exact same thing using a python script. Is there any way to extract these values?
I was successful in extracting the IP address of my device, but DNS Server IP is proving to be more challenging.
I recently had to get the IP addresses of the DNS servers that a set of cross platform hosts were using (linux, macOS, windows), this is how I ended up doing it and I hope it's helpful:
#!/usr/bin/env python
import platform
import socket
import subprocess
def is_valid_ipv4_address(address):
try:
socket.inet_pton(socket.AF_INET, address)
except AttributeError: # no inet_pton here, sorry
try:
socket.inet_aton(address)
except socket.error:
return False
return address.count('.') == 3
except socket.error: # not a valid address
return False
return True
def get_unix_dns_ips():
dns_ips = []
with open('/etc/resolv.conf') as fp:
for cnt, line in enumerate(fp):
columns = line.split()
if columns[0] == 'nameserver':
ip = columns[1:][0]
if is_valid_ipv4_address(ip):
dns_ips.append(ip)
return dns_ips
def get_windows_dns_ips():
output = subprocess.check_output(["ipconfig", "-all"])
ipconfig_all_list = output.split('\n')
dns_ips = []
for i in range(0, len(ipconfig_all_list)):
if "DNS Servers" in ipconfig_all_list[i]:
# get the first dns server ip
first_ip = ipconfig_all_list[i].split(":")[1].strip()
if not is_valid_ipv4_address(first_ip):
continue
dns_ips.append(first_ip)
# get all other dns server ips if they exist
k = i+1
while k < len(ipconfig_all_list) and ":" not in ipconfig_all_list[k]:
ip = ipconfig_all_list[k].strip()
if is_valid_ipv4_address(ip):
dns_ips.append(ip)
k += 1
# at this point we're done
break
return dns_ips
def main():
dns_ips = []
if platform.system() == 'Windows':
dns_ips = get_windows_dns_ips()
elif platform.system() == 'Darwin':
dns_ips = get_unix_dns_ips()
elif platform.system() == 'Linux':
dns_ips = get_unix_dns_ips()
else:
print("unsupported platform: {0}".format(platform.system()))
print(dns_ips)
return
if __name__ == "__main__":
main()
Resources I used to make this script:
https://stackoverflow.com/a/1325603
https://stackoverflow.com/a/4017219
Edit: If anyone has a better way of doing this please share :)
DNS Python (dnspython) might be helpful. You can get the DNS server address with:
import dns.resolver
dns_resolver = dns.resolver.Resolver()
dns_resolver.nameservers[0]

How to receive data from a socket, process, and send back data in python?

i have the following code:
import socket # Import socket module
import sys
s = socket.socket() # Create a socket object
host = '' # Get local machine name
port = 1234 # Reserve a port for your service.
s.connect((host, port))
while 1:
data = s.recv(1024)
print ' data ' , data
d = data.split('?') # parsing values from server
if len(d) < 2:
# if does not contain ?, do nothing
continue
else:
a = d[0]
b = d[1].replace('\n', '')
# check how a compares to b, and send response accordingly
if (a > b):
s.send('1')
elif (a == b):
s.send('2')
else:
s.send('3')
s.close() # Close the socket when done
Without the processing code I have, it works fine if I just send a random value. But with the code above, I can only parse the first set of line, and then it stops. (I assume it closes the socket or something?)
The data coming from the socket looks like '1 ? 23' or '23 ? 1' , etc. it expects a response that determines how the two numbers relate.
In comparison, if I have this code:
import socket # Import socket module
import sys
s = socket.socket() # Create a socket object
host = '' # Get local machine name
port = 1234 # Reserve a port for your service.
s.connect((host, port))
backlog = ''
while 1:
data = s.recv(1024)
sp = data.split('\n')
if len(sp) < 2:
backlog += data
continue
line = backlog + sp[0]
backlog = sp[1]
data = line
print ' data ' , data
if not data:
break
s.send ('2')
s.close() # Close the socket when done
This code will yield a server response of either 'Correct!' or 'Incorrect...try again!' depending on whether it's right or wrong.
You seem to assume that you always get a full line with each read() call. That is wrong.
You should split your input into lines, and only if you have a full line, you proceed.
backlog = ''
while 1:
data = s.recv(1024)
# do we have a line break?
sp = data.split('\n')
if len(sp) < 2:
# no, we haven't...
backlog += data
continue
# yes, we have.
line = backlog + sp[0] # first part is the now complete line.
backlog = sp[1] # 2nd part is the start of the new line.
print ' line ' , line
d = line.split('?') # parsing values from server
if len(d) < 2:
# if does not contain ?, do nothing
continue
else:
a = int(d[0]) # we want to compare numbers, not strings.
b = int(d[1])
# check how a compares to b, and send response accordingly
if (a > b):
s.send('1')
elif (a == b):
s.send('2')
else:
s.send('3')
Try out what happens now.
Another question which occurs to me is what exactly does the server expect? Really only one byte? Or rather '1\n', '2\n', '3\n'?

Converting IPv4 Address to a Hex IPv6 Address in Python

Q: Write a program that prompts the user for an IP address then converts this to a base 10, binary and hex value. The program then converts the hex value to an RFC3056 IPv6 6to4 address.
I have the base 10 and binary parts working but I can't seem to get my head around the hex part. Can the format string method be used somehow to accomplish the same thing? Or would I need to import the ipaddress module in this case?
#!/usr/bin/python3
ip_address = input("Please enter a dot decimal IP Address: ")
"""This part converts to base 10"""
ListA = ip_address.split(".")
ListA = list(map(int, ListA))
ListA = ListA[0]*(256**3) + ListA[1]*(256**2) + ListA[2]*(256**1) + ListA[3]
print("The IP Address in base 10 is: " , ListA)
"""This part converts to base 2"""
base2 = [format(int(x), '08b') for x in ip_address.split('.')]
print("The IP Address in base 2 is: ", base2)
"""This part converts to hex"""
hexIP = []
[hexIP.append(hex(int(x))[2:].zfill(2)) for x in ip_address.split('.')]
hexIP = "".join(hexIP)
print("The IP Address in hex is: " , hexIP)
EDIT: Managed to convert the IP Address to hex value. Now how do I convert this hex value into IPv6 address?
>>> ip_address = '123.45.67.89'
>>> numbers = list(map(int, ip_address.split('.')))
>>> '2002:{:02x}{:02x}:{:02x}{:02x}::'.format(*numbers)
'2002:7b2d:4359::'
In Python 3.3 you could use ipaddress module to manipulate IPv4, IPv6 addresses:
#!/usr/bin/env python3
import ipaddress
# get ip address
while True:
ip4str = input("Enter IPv4 (e.g., 9.254.253.252):")
try:
ip4 = ipaddress.IPv4Address(ip4str)
except ValueError:
print("invalid ip address. Try, again")
else:
break # got ip address
# convert ip4 to rfc 3056 IPv6 6to4 address
# http://tools.ietf.org/html/rfc3056#section-2
prefix6to4 = int(ipaddress.IPv6Address("2002::"))
ip6 = ipaddress.IPv6Address(prefix6to4 | (int(ip4) << 80))
print(ip6)
assert ip6.sixtofour == ip4
# convert ip4 to a base 10
print(int(ip4))
# convert ip4 to binary (0b)
print(bin(int(ip4)))
# convert ip4 to hex (0x)
print(hex(int(ip4)))
If you just want to use the IPv4 addresses in an IPv6 context (e.g. by passing to socket.connect() created using the socket.AF_INET6 address family), you can just use the syntax described in RFC4291, Section 2.2:
>>> import socket
>>> a = '10.20.30.40'
>>> s = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
>>> s.connect(('2002::' + a, 9))
I.e. just prepend ::ffff: to the IPv4 address and you get a valid 6to4 address. If you instead want to convert this address to the more common hexadecimal form, I suggest using the standard library ipaddress module you mentioned:
>>> import ipaddress
>>> a = '10.20.30.40'
>>> print(ipaddress.IPv6Address('2002::' + a).compressed)
'2002::a14:1e28'
Before referring to the solution, have a look at this doc for conversion and convention of ipv6 representation.
def ipconversion4to6(ipv4_address):
hex_number = ["{:02x}".format(int(_)) for _ in address.split(".")]
ipv4 = "".join(hex_number)
ipv6 = "2002:"+ipv4[:4]+":"+ipv4[4:]+"::"
return ipv6

Python - why is it not reading my variables?

I'm a python newbie and I don't understand why it won't read my IP and ADDR variables in the function dns.zone.query(IP, ADDR)???
import dns.query
import dns.zone
import sys
IP = sys.stdin.readline()
ADDR = sys.stdin.readline()
z = dns.zone.from_xfr(dns.query.xfr(IP , ADDR))
names = z.nodes.keys()
names.sort()
for n in names:
print z[n].to_text(n)
It works when I pass an actual IP and Domain, but not with the variables... I don't get what's wrong?
readline() will include a trailing newline. You can use sys.stdin.readline().strip()
I would try with:
IP = sys.stdin.readline().strip()
ADDR = sys.stdin.readline().strip()
Add some prints after the variables to debug it:
print '_%s_' % IP
print '_%s_' % ADDR
Try sys.stdin.readline().strip(). You need to remove the newlines.

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