115 lines
3.6 KiB
C
115 lines
3.6 KiB
C
/* $NetBSD: npf.c,v 1.2 2016/12/10 22:09:18 christos Exp $ */
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/*-
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* Copyright (c) 2016 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Christos Zoulas.
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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/cdefs.h>
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__RCSID("$NetBSD: npf.c,v 1.2 2016/12/10 22:09:18 christos Exp $");
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <sys/ioctl.h>
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#include <sys/fcntl.h>
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#include <net/if.h>
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#include <netinet/in.h>
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#include <npf.h>
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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#include <syslog.h>
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#include <unistd.h>
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#include "identd.h"
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int
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npf_natlookup(const struct sockaddr_storage *ss,
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struct sockaddr_storage *nat_addr, in_port_t *nat_lport)
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{
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npf_addr_t *addr[2];
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in_port_t port[2];
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int dev, af;
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/* copy the source into nat_addr so it is writable */
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memcpy(nat_addr, &ss[0], sizeof(ss[0]));
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switch (af = ss[0].ss_family) {
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case AF_INET:
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addr[0] = (void *)&satosin(nat_addr)->sin_addr;
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addr[1] = __UNCONST(&csatosin(&ss[1])->sin_addr);
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port[0] = csatosin(&ss[0])->sin_port;
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port[1] = csatosin(&ss[1])->sin_port;
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break;
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case AF_INET6:
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addr[0] = (void *)&satosin6(&nat_addr)->sin6_addr;
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addr[1] = __UNCONST(&csatosin6(&ss[0])->sin6_addr);
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port[0] = csatosin6(&ss[0])->sin6_port;
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port[1] = csatosin6(&ss[1])->sin6_port;
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break;
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default:
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errno = EAFNOSUPPORT;
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maybe_syslog(LOG_ERR, "NAT lookup for %d: %m" , af);
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return 0;
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}
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/* Open the /dev/pf device and do the lookup. */
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if ((dev = open("/dev/npf", O_RDWR)) == -1) {
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maybe_syslog(LOG_ERR, "Cannot open /dev/npf: %m");
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return 0;
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}
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if (npf_nat_lookup(dev, af, addr, port, IPPROTO_TCP, PFIL_OUT) == -1) {
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maybe_syslog(LOG_ERR, "NAT lookup failure: %m");
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(void)close(dev);
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return 0;
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}
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(void)close(dev);
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/*
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* The originating address is already set into nat_addr so fill
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* in the rest, family, port (ident), len....
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*/
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switch (af) {
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case AF_INET:
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satosin(nat_addr)->sin_port = htons(113);
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satosin(nat_addr)->sin_len = sizeof(struct sockaddr_in);
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satosin(nat_addr)->sin_family = AF_INET;
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break;
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case AF_INET6:
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satosin6(nat_addr)->sin6_port = htons(113);
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satosin6(nat_addr)->sin6_len = sizeof(struct sockaddr_in6);
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satosin6(nat_addr)->sin6_family = AF_INET6;
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break;
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}
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/* Put the originating port into nat_lport. */
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*nat_lport = ntohs(port[0]);
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return 1;
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}
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