0de7b04927
A small C program is added to make a special socket (UDP_ENCAP_ESPINUDP) and keep it to handle UDP-encapsulated ESP packets.
109 lines
3.0 KiB
C
109 lines
3.0 KiB
C
/* $NetBSD: natt_terminator.c,v 1.1 2017/10/30 15:59:23 ozaki-r Exp $ */
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/*-
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* Copyright (c) 2017 Internet Initiative Japan Inc.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <sys/wait.h>
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#include <sys/time.h>
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#include <netinet/in.h>
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#include <netinet/udp.h>
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#include <stdio.h>
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#include <err.h>
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#include <netdb.h>
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#include <string.h>
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#include <stdlib.h>
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#include <unistd.h>
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int
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main(int argc, char **argv)
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{
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struct addrinfo hints;
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struct addrinfo *res;
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int s, e;
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const char *addr, *port;
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int option;
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if (argc != 3) {
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fprintf(stderr, "Usage: %s <addr> <port>\n", argv[0]);
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return 1;
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}
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addr = argv[1];
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port = argv[2];
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memset(&hints, 0, sizeof(hints));
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hints.ai_family = AF_INET;
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hints.ai_socktype = SOCK_DGRAM;
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hints.ai_protocol = IPPROTO_UDP;
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hints.ai_flags = 0;
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e = getaddrinfo(addr, port, &hints, &res);
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if (e != 0)
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errx(EXIT_FAILURE, "getaddrinfo failed: %s", gai_strerror(e));
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s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
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if (s == -1)
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err(EXIT_FAILURE, "socket");
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/*
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* Set the option to tell the kernel that the socket can handle
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* UDP-encapsulated ESP packets for NAT-T.
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*/
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option = UDP_ENCAP_ESPINUDP;
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e = setsockopt(s, IPPROTO_UDP, UDP_ENCAP, &option, sizeof(option));
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if (e == -1)
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err(EXIT_FAILURE, "setsockopt(UDP_ENCAP)");
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e = bind(s, res->ai_addr, res->ai_addrlen);
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if (e == -1)
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err(EXIT_FAILURE, "bind");
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/* Receiving a packet make the NAPT create a mapping. */
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{
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char buf[64];
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struct sockaddr_storage z;
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socklen_t len = sizeof(z);
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e = recvfrom(s, buf, 64, MSG_PEEK,
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(struct sockaddr *)&z, &len);
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if (e == -1)
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err(EXIT_FAILURE, "recvfrom");
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}
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/*
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* Keep the socket in the kernel to handle UDP-encapsulated ESP packets.
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*/
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pause();
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close(s);
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return 0;
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}
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