the protocol like tcp and udp is all represented by a number.
import socket
socket.getprotocobyname('tcp')
the above code will return 6.
How I can get the protocol name if I know the protocol number?
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3See bugs.python.org/issue24809cdarke– cdarke2016-05-03 13:23:47 +00:00Commented May 3, 2016 at 13:23
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Python 2 or Python 3?cdarke– cdarke2016-05-03 13:25:21 +00:00Commented May 3, 2016 at 13:25
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2 Answers
I'm going to say there is almost definitely a better way then this, but all the protocol names (and values) are stored as constants prefixed by "IPPROTO_" so you can create a lookup table by iterating over the values in the module:
import socket
prefix = "IPPROTO_"
table = {num:name[len(prefix):]
for name,num in vars(socket).items()
if name.startswith(prefix)}
assert table[6] == 'TCP'
assert table[0x11] == 'UDP'
print(len(table)) # in python 3.10.0 this has 30 entries
from pprint import pprint
pprint(table) # if you want to see what is available to you
answered May 3, 2016 at 13:16
Tadhg McDonald-Jensen
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3 Comments
RatDon
While it gives protocols up to
6 that's tcp (except 3 and 5), it is unable to give beyond that. Say 11 is for UDP for which the above script gives a key-error.
Tadhg McDonald-Jensen
@RatDon
table[17] == 'UDP' and according to microsoft's protocol numbers UDP is associated with 17. Not sure where 11 is coming from but I frankly don't know much about this area, sorry I can't be more help to you.RatDon
sorry, My mistake, I took the hexadecimel number which is '11'. But still 132 is not available which is for SCTP. Yeah I agree. few fields are available but not all. Anyway, Thanks.
Python's socket module will do that:
import socket
socket.getservbyport(80)
Results in
>>> import socket
>>> socket.getservbyport(6)
'zip'
>>> socket.getservbyport(80)
'http'
As the documentation mentioned for socket.getservbyname(servicename[, protocolname]) and socket.getservbyport(port[, protocolname]). The second optional protocol name, if given, should be 'tcp' or 'udp', otherwise any protocol will match.
3 Comments
Alex K.
is socket.getservbyport(6) "tcp" ?
Tadhg McDonald-Jensen
nope, it's 'zip', I don't think this is the right thing
Tadhg McDonald-Jensen
@salomonderossi, are you able to use
getservbyport in any way to associate 6 with tcp? The OP is asking "given 6 how can I get back 'tcp'" which you do not do in your answer.