无法在python中接收UDP广播

Question

这里是广播服务器

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)

请注意，您需要将'<broadcast>' 更改为您网络的实际广播地址。请看Python can't send a broadcast package with address

这里是广播接收器

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

但问题是我的接收器只停留在s.recvfrom(1024) 虽然通过 tcpdump 我可以看到数据包，但为什么这个 python 客户端无法捕获它？ 命令是sudo tcpdump -i wlan0 ip -X dst host 255.255.255.255

Answer 1

我将您的代码更改为 Python 3 并更正了 2 个错误：

• 将s 更改为client
• 仅当有来自recvfrom() 的数据时才打印该语句

希望对你有帮助。

from socket import socket, AF_INET, SOCK_DGRAM
PORT = 50000
client = socket(AF_INET, SOCK_DGRAM)
client.bind(('0.0.0.0', PORT))

while True:
  data, addr = client.recvfrom(1024) #sticks here forever!
  if data:
    print("Found Broadcast server at : ", addr)

Answer 2

绑定前需要设置socket选项，并且需要绑定到INADDR_BROADCAST。