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/* $OpenBSD: print-enc.c,v 1.7 2002/02/19 19:39:40 millert Exp $ */
/*
* Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
* distributions including binary code include the above copyright notice and
* this paragraph in its entirety in the documentation or other materials
* provided with the distribution, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University nor the names of its contributors may be used to endorse
* or promote products derived from this software without specific prior
* written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
/* \summary: OpenBSD IPsec encapsulation BPF layer printer */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#define ND_LONGJMP_FROM_TCHECK
#include "netdissect.h"
#include "extract.h"
#include "af.h"
/* From $OpenBSD: if_enc.h,v 1.8 2001/06/25 05:14:00 angelos Exp $ */
/*
* The authors of this code are John Ioannidis (ji@tla.org),
* Angelos D. Keromytis (kermit@csd.uch.gr) and
* Niels Provos (provos@physnet.uni-hamburg.de).
*
* This code was written by John Ioannidis for BSD/OS in Athens, Greece,
* in November 1995.
*
* Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
* by Angelos D. Keromytis.
*
* Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
* and Niels Provos.
*
* Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis
* and Niels Provos.
* Copyright (c) 2001, Angelos D. Keromytis.
*
* Permission to use, copy, and modify this software with or without fee
* is hereby granted, provided that this entire notice is included in
* all copies of any software which is or includes a copy or
* modification of this software.
* You may use this code under the GNU public license if you so wish. Please
* contribute changes back to the authors under this freer than GPL license
* so that we may further the use of strong encryption without limitations to
* all.
*
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
* MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
* PURPOSE.
*/
#define ENC_HDRLEN 12
/* From $OpenBSD: mbuf.h,v 1.56 2002/01/25 15:50:23 art Exp $ */
#define M_CONF 0x0400 /* packet was encrypted (ESP-transport) */
#define M_AUTH 0x0800 /* packet was authenticated (AH) */
struct enchdr {
nd_uint32_t af;
nd_uint32_t spi;
nd_uint32_t flags;
};
#define ENC_PRINT_TYPE(wh, xf, name) \
if ((wh) & (xf)) { \
ND_PRINT("%s%s", name, (wh) == (xf) ? "): " : ","); \
(wh) &= ~(xf); \
}
/*
* Byte-swap a 32-bit number.
* ("htonl()" or "ntohl()" won't work - we want to byte-swap even on
* big-endian platforms.)
*/
#define SWAPLONG(y) \
((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
void
enc_if_print(netdissect_options *ndo,
const struct pcap_pkthdr *h, const u_char *p)
{
u_int length = h->len;
u_int af, flags;
const struct enchdr *hdr;
ndo->ndo_protocol = "enc";
ND_TCHECK_LEN(p, ENC_HDRLEN);
ndo->ndo_ll_hdr_len += ENC_HDRLEN;
hdr = (const struct enchdr *)p;
/*
* The address family and flags fields are in the byte order
* of the host that originally captured the traffic.
*
* To determine that, look at the address family. It's 32-bit,
* it is not likely ever to be > 65535 (I doubt there will
* ever be > 65535 address families and, so far, AF_ values have
* not been allocated very sparsely) so it should not have the
* upper 16 bits set, and it is not likely ever to be AF_UNSPEC,
* i.e. it's not likely ever to be 0, so if it's byte-swapped,
* it should have at least one of the upper 16 bits set.
*
* So if any of the upper 16 bits are set, we assume it, and
* the flags field, are byte-swapped.
*
* The SPI field is always in network byte order, i.e. big-
* endian.
*/
UNALIGNED_MEMCPY(&af, &hdr->af, sizeof (af));
UNALIGNED_MEMCPY(&flags, &hdr->flags, sizeof (flags));
if ((af & 0xFFFF0000) != 0) {
af = SWAPLONG(af);
flags = SWAPLONG(flags);
}
if (flags == 0)
ND_PRINT("(unprotected): ");
else
ND_PRINT("(");
ENC_PRINT_TYPE(flags, M_AUTH, "authentic");
ENC_PRINT_TYPE(flags, M_CONF, "confidential");
/* ENC_PRINT_TYPE(flags, M_TUNNEL, "tunnel"); */
ND_PRINT("SPI 0x%08x: ", GET_BE_U_4(hdr->spi));
length -= ENC_HDRLEN;
p += ENC_HDRLEN;
switch (af) {
case BSD_AFNUM_INET:
ip_print(ndo, p, length);
break;
case BSD_AFNUM_INET6_BSD:
case BSD_AFNUM_INET6_FREEBSD:
case BSD_AFNUM_INET6_DARWIN:
ip6_print(ndo, p, length);
break;
}
}
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