python中原始套接字的网络接口？

Question

I'm writing a small configuration utility for a wireless bridge in Python, using raw sockets with Ethernet II proto 0x8888. There are several tutorials on raw sockets for python, but all of them seem to hardcode the network interface ("eth0", "eth1", etc.), which I don't want to, because each computer might have a different network interface (on my laptop its "wlan0").

My current working code is (unfortunatly with hardcoded "wlan0"):

# Create an Ethernet II broadcast of ethertype 0x8888:
s = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, 0x8888)
s.bind(("wlan0",0x8888))
ifName,ifProto,pktType,hwType,hwAddr = s.getsockname()
txFrame = struct.pack("!6s6sH","\xFF\xFF\xFF\xFF\xFF\xFF",hwAddr,0x8888) + "\x00"*0x32
# Send and wait for response
s.send(txFrame)

Is there any way to get the network interface name on the current system instead of having to hardcode it?

I have tried INADDR_ANY, but that doesn't work either.

Answer 1

You can use subprocess and re to get a list of the network interfaces:

import subprocess, re

config = subprocess.check_output("ifconfig")
expr = re.compile("([a-zA-Z0-9]+)\s+Link")
interfaces = expr.findall(config)

ifconfig also has options that allow you to see 'down' interfaces although I don't think you'll need them if you want to broadcast. See man ifconfig for more details.