無法接收UDP廣播在Python

Question

這裏是廣播服務器

from time import sleep 
from socket import * 

PORT = 50000 
s = socket(AF_INET, SOCK_DGRAM) 
s.bind(('', 0)) 
s.setsockopt(SOL_SOCKET, SO_BROADCAST, 1) 

data = "I am server" 
while 1: 
    s.sendto(data, ('<broadcast>', PORT)) 
    print "sent data" 
    sleep(5) 

這裏是廣播接收器

from socket import socket, AF_INET, SOCK_DGRAM 
PORT = 50000 
client = socket(AF_INET, SOCK_DGRAM) 
client.bind(('0.0.0.0', PORT)) 
data, addr = s.recvfrom(1024) #sticks here forever! 

if data: 
    print "Found Broadcast server at : " + addr 

但問題是，我只接收在s.recvfrom(1024) 堅持，同時通過tcpdump的，我能夠看到數據包，那麼爲什麼這個python客戶端無法捕捉它呢？ 命令是sudo tcpdump -i wlan0 ip -X dst host 255.255.255.255

Answer 1

您需要在綁定它之前設置套接字選項，並且您需要將它綁定到INADDR_BROADCAST。