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Diffstat (limited to 'print-enc.c')
| -rw-r--r-- | print-enc.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/print-enc.c b/print-enc.c new file mode 100644 index 0000000..928b02c --- /dev/null +++ b/print-enc.c @@ -0,0 +1,158 @@ +/* $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; + } +} |