69 lines
1.9 KiB
Python
Executable File
69 lines
1.9 KiB
Python
Executable File
#!/usr/bin/env python3
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#
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# @RDE_HEADER@
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# $Id$
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# $HeadURL$
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# $Author$
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# Created by Christian Fröbel, NLE, 2019-08-08
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#
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import socket
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import struct
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from contextlib import contextmanager
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from argparse import ArgumentParser, RawDescriptionHelpFormatter
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import sys
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# struct in_addr
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# {
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# uint32_t s_addr; /* address in network byte order */
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# };
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# struct ip_mreqn
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# {
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# struct in_addr imr_multiaddr; /* IP multicast group address */
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# struct in_addr imr_address; /* IP address of local interface */
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# int imr_ifindex; /* interface index */
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# };
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def _createBoundSocket(multicastGroup, multicastPort, interface):
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s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
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s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
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s.bind((multicastGroup, multicastPort))
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mreqn = struct.pack('4s4si', socket.inet_aton(multicastGroup), socket.inet_aton(interface), 0)
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s.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreqn)
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return s
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def _receive(s):
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while True:
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buf, address = s.recvfrom(4096)
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print('received {} bytes from {}'.format(len(buf), address))
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def _main():
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args = _parseCmdLine()
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with autoClose(_createBoundSocket(args.group, args.port, args.interface)) as s:
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_receive(s)
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@contextmanager
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def autoClose(resource):
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try:
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yield resource
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finally:
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resource.close()
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def _parseCmdLine():
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parser = ArgumentParser(description='Tool to receive multicast traffic', formatter_class=RawDescriptionHelpFormatter)
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parser.add_argument('--group', '-g', required=True, help='multicast group')
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parser.add_argument('--port', '-p', type=int, required=True, help='port')
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parser.add_argument('--interface', '-i', default='0.0.0.0', help='address of interface to listen on; default 0.0.0.0')
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return parser.parse_args()
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if __name__ == '__main__':
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_main()
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