python raw socket: Protocol not supported

Question

I am trying to open a raw socket with Python under linux.

My simple code:

s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_IP)
s.bind((HOST, 5454))

And I got this error:

[ERROR] Protocol not supported

By the way, I am using python 2.7.3 under linux 12.04, and I used root to run the code.

Does anyone have a clue?

Update: The solution given by dstromberg is correct. If you want the whole packet, then use his solution. However, there is another combination:

s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_TCP)

that also works.

In this case, you will receive a whole TCP packet with IP and TCP headers on it. If your use dstromberg's solution, you will also see the ethernet header. So it depends on how 'raw' you want your packet to be.

• pts: FYI I get the same error when running it as root.
• Anthony: Try AF_UNIX, instead of AF_INET.
• Jerry Meng: @Anthony, It seems work. I got new error, though. Let me do some test and see whether it works. Thanks for advice~~~
• Robᵩ: Are you trying to receive all IP packets? All packets? Or all packets of a specific IP protocol?
• Jerry Meng: @Robφ,All Packets. We have conversation in another post. And this is the way for me to bypass the TCP part. If I can receive all the packet then I can acheive the goal: one socket send, one socket receive.

Answer 1

Try socket.AF_PACKET instead of socket.AF_INET.

• Jerry Meng: I tried, and I got "[ERROR] No such device". It confused me, actually.
• Robφ: @JerryMeng - What OS are you running on? On Ubuntu 12.04, with root privileges, socket.socket(socket.AF_PACKET, socket.SOCK_RAW) worked for me.
• Jerry Meng: @Robφ then how do you bind your socket to a host? like s.bind((HOST, 5454))? I got "[ERROR] No such device". And by the way, If I use AF_PACKET, why I don't need to specify the proto argument?
• Robφ: @JerryMeng 1) You don't bind raw sockets to hosts. You are bypassing IP, so you don't get any of its features. 2) I didn't specify a protocol because you said "All Packets".
• Robφ: @JerryMeng - You can bind raw sockets to a specific device & protocol. So, you might try s.bind(("eth0", 0x0800)).

Answer 2

This runs without error as root:

#!/usr/local/cpython-3.3/bin/python
import socket as socket_mod
#s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_IP)
socket = socket_mod.socket(socket_mod.AF_PACKET, socket_mod.SOCK_RAW, socket_mod.IPPROTO_IP)
#socket.bind(('localhost', 5454))
socket.bind(('lo', 5454))

• Jerry Meng: In fact, I have figured it out. And the second line is not right. 5454 won't give your error, neither any packet. 0x0800 is the correct port to use. Thanks for answering~~
• Josiah Yoder: Why two answers? Wouldn't it be clearer to merge this into your first answer?

Answer 3

Try socket.AF_UNIX, it can solve your problem, good luck.