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 #include <sys/cdefs.h> 25 #ifndef lint 26 __RCSID("$NetBSD: print-enc.c,v 1.8 2023/08/17 20:19:40 christos Exp $"); 27 #endif 28 29 /* \summary: OpenBSD IPsec encapsulation BPF layer printer */ 30 31 #ifdef HAVE_CONFIG_H 32 #include <config.h> 33 #endif 34 35 #include "netdissect-stdinc.h" 36 37 #define ND_LONGJMP_FROM_TCHECK 38 #include "netdissect.h" 39 #include "extract.h" 40 #include "af.h" 41 42 /* From $OpenBSD: if_enc.h,v 1.8 2001/06/25 05:14:00 angelos Exp $ */ 43 /* 44 * The authors of this code are John Ioannidis (ji@tla.org), 45 * Angelos D. Keromytis (kermit@csd.uch.gr) and 46 * Niels Provos (provos@physnet.uni-hamburg.de). 47 * 48 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 49 * in November 1995. 50 * 51 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 52 * by Angelos D. Keromytis. 53 * 54 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 55 * and Niels Provos. 56 * 57 * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis 58 * and Niels Provos. 59 * Copyright (c) 2001, Angelos D. Keromytis. 60 * 61 * Permission to use, copy, and modify this software with or without fee 62 * is hereby granted, provided that this entire notice is included in 63 * all copies of any software which is or includes a copy or 64 * modification of this software. 65 * You may use this code under the GNU public license if you so wish. Please 66 * contribute changes back to the authors under this freer than GPL license 67 * so that we may further the use of strong encryption without limitations to 68 * all. 69 * 70 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 71 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 72 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 73 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 74 * PURPOSE. 75 */ 76 77 #define ENC_HDRLEN 12 78 79 /* From $OpenBSD: mbuf.h,v 1.56 2002/01/25 15:50:23 art Exp $ */ 80 #define M_CONF 0x0400 /* packet was encrypted (ESP-transport) */ 81 #define M_AUTH 0x0800 /* packet was authenticated (AH) */ 82 83 struct enchdr { 84 nd_uint32_t af; 85 nd_uint32_t spi; 86 nd_uint32_t flags; 87 }; 88 89 #define ENC_PRINT_TYPE(wh, xf, name) \ 90 if ((wh) & (xf)) { \ 91 ND_PRINT("%s%s", name, (wh) == (xf) ? "): " : ","); \ 92 (wh) &= ~(xf); \ 93 } 94 95 /* 96 * Byte-swap a 32-bit number. 97 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on 98 * big-endian platforms.) 99 */ 100 #define SWAPLONG(y) \ 101 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff)) 102 103 void 104 enc_if_print(netdissect_options *ndo, 105 const struct pcap_pkthdr *h, const u_char *p) 106 { 107 u_int length = h->len; 108 u_int af, flags; 109 const struct enchdr *hdr; 110 111 ndo->ndo_protocol = "enc"; 112 ND_TCHECK_LEN(p, ENC_HDRLEN); 113 ndo->ndo_ll_hdr_len += ENC_HDRLEN; 114 115 hdr = (const struct enchdr *)p; 116 /* 117 * The address family and flags fields are in the byte order 118 * of the host that originally captured the traffic. 119 * 120 * To determine that, look at the address family. It's 32-bit, 121 * it is not likely ever to be > 65535 (I doubt there will 122 * ever be > 65535 address families and, so far, AF_ values have 123 * not been allocated very sparsely) so it should not have the 124 * upper 16 bits set, and it is not likely ever to be AF_UNSPEC, 125 * i.e. it's not likely ever to be 0, so if it's byte-swapped, 126 * it should have at least one of the upper 16 bits set. 127 * 128 * So if any of the upper 16 bits are set, we assume it, and 129 * the flags field, are byte-swapped. 130 * 131 * The SPI field is always in network byte order, i.e. big- 132 * endian. 133 */ 134 UNALIGNED_MEMCPY(&af, &hdr->af, sizeof (af)); 135 UNALIGNED_MEMCPY(&flags, &hdr->flags, sizeof (flags)); 136 if ((af & 0xFFFF0000) != 0) { 137 af = SWAPLONG(af); 138 flags = SWAPLONG(flags); 139 } 140 141 if (flags == 0) 142 ND_PRINT("(unprotected): "); 143 else 144 ND_PRINT("("); 145 ENC_PRINT_TYPE(flags, M_AUTH, "authentic"); 146 ENC_PRINT_TYPE(flags, M_CONF, "confidential"); 147 /* ENC_PRINT_TYPE(flags, M_TUNNEL, "tunnel"); */ 148 ND_PRINT("SPI 0x%08x: ", GET_BE_U_4(hdr->spi)); 149 150 length -= ENC_HDRLEN; 151 p += ENC_HDRLEN; 152 153 switch (af) { 154 case BSD_AFNUM_INET: 155 ip_print(ndo, p, length); 156 break; 157 case BSD_AFNUM_INET6_BSD: 158 case BSD_AFNUM_INET6_FREEBSD: 159 case BSD_AFNUM_INET6_DARWIN: 160 ip6_print(ndo, p, length); 161 break; 162 } 163 } 164