Question

I’m trying to work with sockets and I have such problem

In code example:

setsockopt(socket.SOL_SOCKET,IN.SO_BINDTODEVICE,self.listen_address+'\0')

I have error

AttributeError: 'module' object has no attribute 'SO_BINDTODEVICE'

On Linux machine this attribute is OK but on FreeBSD trere are no any SO_* attributes in module IN. What port should I install to resolve this problem on FreeBDS machine?

Python versions on Linux tested:
2.5.4 and 2.6.4;
on FreeBSD:
2.5.5

I can’t find anything about this module in my book, and googling keyword IN looks like seamless …

update:

I can only bind to address, not to device.

>>> import socket
>>> s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
>>> s.bind(("eth0",3040))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1, in bind
socket.gaierror: [Errno -2] Name or service not known
>>> s.bind(("192.168.33.152",3040))
>>> s.close()

update 2:

… but I’m working with broadcast packets. I’m trying to write daemon which acts like DHCP server.
If I bind to address would I catch broadcast packets? And if I’ll set promiscuous mode on?

Answer 1

SO_BINDTODEVICE socket option is not standard and is not supported on FreeBSD. Why can’t you just use regular bind(2) for assigning local address/interface?

Edit:

Take a look at the socket object docs.
Here’s an example.

Edit 2:

You didn’t say what exactly you are trying to achieve, so assuming regular TCP/IP client-server.

IP, being a network-layer protocol (vs. for example, Ethernet, which is a data-link protocol), is not concerned with devices, but addresses. The idea is that you don’t need to bind to a device – the OS takes care of mapping addresses to devices, and maintains a routing table. The only time you need explicit relationship between a socket and a device is when working with broadcast and multicast, where mapping between addresses and interfaces is not obvious.

Each network interface known to TCP/IP stack is assigned an IP address (see ifconfig(8)). Bind your socket to that IP address and you’ll be all set.

Hope this helps.

Edit 3:

Have you looked into SO_BROADCAST option? Also check out this SO question about raw sockets.