linux - Python socket.error: [Errno 13] Permission denied

Question

Using Linux and Python, I want to send some data with broadcast:

d = b'109u433279423423423'    

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

s.sendto(d, 0, ('192.168.0.255', 9))

I launch this script under root and get this error:

s.sendto(d, 0, ('192.168.0.255', 9)) socket.error: [Errno 13]
Permission denied

What is wrong?

Answer 1

You are trying to send to a broadcast address. It is not allowed, see manpage for sendto(2):

EACCES (For UDP sockets) An attempt was made to send to a network/broadcast address as though it was a unicast address.

Set the SO_BROADCAST option, if you actually mean to send to a broadcast address:

s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)