1 /* $OpenBSD: print-enc.c,v 1.7 2002/02/19 19:39:40 millert Exp $ */ 2 3 /* 4 * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that: (1) source code distributions 9 * retain the above copyright notice and this paragraph in its entirety, (2) 10 * distributions including binary code include the above copyright notice and 11 * this paragraph in its entirety in the documentation or other materials 12 * provided with the distribution, and (3) all advertising materials mentioning 13 * features or use of this software display the following acknowledgement: 14 * ``This product includes software developed by the University of California, 15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 16 * the University nor the names of its contributors may be used to endorse 17 * or promote products derived from this software without specific prior 18 * written permission. 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 22 */ 23 24 /* \summary: OpenBSD IPsec encapsulation BPF layer printer */ 25 26 #ifdef HAVE_CONFIG_H 27 #include <config.h> 28 #endif 29 30 #include "netdissect-stdinc.h" 31 32 #define ND_LONGJMP_FROM_TCHECK 33 #include "netdissect.h" 34 #include "extract.h" 35 #include "af.h" 36 37 /* From $OpenBSD: if_enc.h,v 1.8 2001/06/25 05:14:00 angelos Exp $ */ 38 /* 39 * The authors of this code are John Ioannidis (ji@tla.org), 40 * Angelos D. Keromytis (kermit@csd.uch.gr) and 41 * Niels Provos (provos@physnet.uni-hamburg.de). 42 * 43 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 44 * in November 1995. 45 * 46 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 47 * by Angelos D. Keromytis. 48 * 49 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 50 * and Niels Provos. 51 * 52 * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis 53 * and Niels Provos. 54 * Copyright (c) 2001, Angelos D. Keromytis. 55 * 56 * Permission to use, copy, and modify this software with or without fee 57 * is hereby granted, provided that this entire notice is included in 58 * all copies of any software which is or includes a copy or 59 * modification of this software. 60 * You may use this code under the GNU public license if you so wish. Please 61 * contribute changes back to the authors under this freer than GPL license 62 * so that we may further the use of strong encryption without limitations to 63 * all. 64 * 65 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 66 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 67 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 68 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 69 * PURPOSE. 70 */ 71 72 #define ENC_HDRLEN 12 73 74 /* From $OpenBSD: mbuf.h,v 1.56 2002/01/25 15:50:23 art Exp $ */ 75 #define M_CONF 0x0400 /* packet was encrypted (ESP-transport) */ 76 #define M_AUTH 0x0800 /* packet was authenticated (AH) */ 77 78 struct enchdr { 79 nd_uint32_t af; 80 nd_uint32_t spi; 81 nd_uint32_t flags; 82 }; 83 84 #define ENC_PRINT_TYPE(wh, xf, name) \ 85 if ((wh) & (xf)) { \ 86 ND_PRINT("%s%s", name, (wh) == (xf) ? "): " : ","); \ 87 (wh) &= ~(xf); \ 88 } 89 90 /* 91 * Byte-swap a 32-bit number. 92 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on 93 * big-endian platforms.) 94 */ 95 #define SWAPLONG(y) \ 96 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff)) 97 98 void 99 enc_if_print(netdissect_options *ndo, 100 const struct pcap_pkthdr *h, const u_char *p) 101 { 102 u_int length = h->len; 103 u_int caplen = h->caplen; 104 u_int af, flags; 105 const struct enchdr *hdr; 106 107 ndo->ndo_protocol = "enc"; 108 ND_TCHECK_LEN(p, ENC_HDRLEN); 109 ndo->ndo_ll_hdr_len += ENC_HDRLEN; 110 111 hdr = (const struct enchdr *)p; 112 /* 113 * The address family and flags fields are in the byte order 114 * of the host that originally captured the traffic. 115 * 116 * To determine that, look at the address family. It's 32-bit, 117 * it is not likely ever to be > 65535 (I doubt there will 118 * ever be > 65535 address families and, so far, AF_ values have 119 * not been allocated very sparsely) so it should not have the 120 * upper 16 bits set, and it is not likely ever to be AF_UNSPEC, 121 * i.e. it's not likely ever to be 0, so if it's byte-swapped, 122 * it should have at least one of the upper 16 bits set. 123 * 124 * So if any of the upper 16 bits are set, we assume it, and 125 * the flags field, are byte-swapped. 126 * 127 * The SPI field is always in network byte order, i.e. big- 128 * endian. 129 */ 130 UNALIGNED_MEMCPY(&af, &hdr->af, sizeof (af)); 131 UNALIGNED_MEMCPY(&flags, &hdr->flags, sizeof (flags)); 132 if ((af & 0xFFFF0000) != 0) { 133 af = SWAPLONG(af); 134 flags = SWAPLONG(flags); 135 } 136 137 if (flags == 0) 138 ND_PRINT("(unprotected): "); 139 else 140 ND_PRINT("("); 141 ENC_PRINT_TYPE(flags, M_AUTH, "authentic"); 142 ENC_PRINT_TYPE(flags, M_CONF, "confidential"); 143 /* ENC_PRINT_TYPE(flags, M_TUNNEL, "tunnel"); */ 144 ND_PRINT("SPI 0x%08x: ", GET_BE_U_4(hdr->spi)); 145 146 length -= ENC_HDRLEN; 147 caplen -= ENC_HDRLEN; 148 p += ENC_HDRLEN; 149 150 switch (af) { 151 case BSD_AFNUM_INET: 152 ip_print(ndo, p, length); 153 break; 154 case BSD_AFNUM_INET6_BSD: 155 case BSD_AFNUM_INET6_FREEBSD: 156 case BSD_AFNUM_INET6_DARWIN: 157 ip6_print(ndo, p, length); 158 break; 159 } 160 } 161