mirror of https://github.com/python/cpython
60 lines
1.5 KiB
Python
Executable File
60 lines
1.5 KiB
Python
Executable File
# Send/receive UDP multicast packets (SGI)
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# After /usr/people/4Dgifts/examples/network/mcast.c
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# Usage:
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# mcast -s (sender)
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# mcast -b (sender, using broadcast instead multicast)
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# mcast (receivers)
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MYPORT = 8123
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MYGROUP = '225.0.0.250'
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import sys
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import time
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import struct
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import regsub
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from socket import *
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from SOCKET import *
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from IN import * # Local module, SGI specific!!!
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sender = sys.argv[1:]
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s = socket(AF_INET, SOCK_DGRAM)
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if sender:
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if sys.argv[1] == '-b':
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s.setsockopt(SOL_SOCKET, SO_BROADCAST, 1)
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mygroup = '<broadcast>'
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else:
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mygroup = MYGROUP
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ttl = struct.pack('b', 1) # Time-to-live
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s.setsockopt(IPPROTO_IP, IP_MULTICAST_TTL, ttl)
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while 1:
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data = `time.time()`
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## data = data + (1400 - len(data)) * '\0'
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s.sendto(data, (mygroup, MYPORT))
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time.sleep(1)
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else:
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# Bind the socket to my port
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s.bind('', MYPORT)
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# Allow multiple copies of this program on one machine
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s.setsockopt(SOL_SOCKET, SO_REUSEPORT, 1) # (Not strictly needed)
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# Ugly: construct binary group address from MYGROUP converted to bytes
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bytes = eval(regsub.gsub('\.', ',', MYGROUP))
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grpaddr = 0
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for byte in bytes: grpaddr = (grpaddr << 8) | byte
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# Construct struct mreq from grpaddr and ifaddr
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ifaddr = INADDR_ANY
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mreq = struct.pack('ll', grpaddr, ifaddr)
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# Add group membership
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s.setsockopt(IPPROTO_IP, IP_ADD_MEMBERSHIP, mreq)
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# Loop, printing any data we receive
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while 1:
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data, sender = s.recvfrom(1500)
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while data[-1:] == '\0': data = data[:-1] # Strip trailing \0's
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print sender, ':', `data`
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