python - Raspberry Pi Python-使用套接字多播UDP在本地网络上不起作用

Question

我当前的设置是这样的:

1 x电脑

1 x GS308v2以太网集线器

7 x树莓派的

给pi的静态ip范围为192.168.1.2到192.168.1.9。 dhcpcd.conf文件如下:



发送者的python脚本:

#!/usr/bin/python

import socket
import struct
import sys
import IN
import subprocess
import fcntl

MULTICAST_GROUP = '224.1.1.1'
MULTICAST_PORT = 12345

path = "-o /var/www/html/images-folder/pic.jpg"

SCMD = chr(1)
SEND = SCMD + path
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
dev = "eth0" + "\0"
sock.setsockopt(socket.SOL_SOCKET, IN.SO_BINDTODEVICE, dev)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 2)
sock.sendto(SEND, (MULTICAST_GROUP, MULTICAST_PORT))
sock.close()

接收者的python:

#!/usr/bin/python

import socket
import struct
import fcntl
from subprocess import call
import sys

MULTICAST_GROUP = '224.1.1.1'
MULTICAST_PORT = 12345

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)

sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('', MULTICAST_PORT))
req = struct.pack("4sl", socket.inet_aton(MULTICAST_GROUP), socket.INADDR_ANY)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, req)

while True:
   data = sock.recv(10240)

所有这些都可以与路由器上的动态IP一起使用。但是不能在带有静态IP的HUB上工作。接收方脚本给出以下错误:

Traceback (most recent call last):
  File "/home/pi/dummyPi.py", line 17, in <module>
    sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, req)
  File "/usr/lib/python2.7/socket.py", line 228, in meth
    return getattr(self._sock,name)(*args)
socket.error: [Errno 19] No such device

该Hub x pi网络如何配置为执行此多播？

Answer 1

原来的解决方案是，如果不使用路由器，则还必须为Linux设置多播路由。以下命令救了我:

sudo ip route add 224.0.0.0/4 dev eth0

如果有人想解释为什么这样做或该命令对网络确实起作用，我将很高兴学习。随时发表评论。