print-sl.c revision 1.4
1/* 2 * Copyright (c) 1989, 1990, 1991, 1993, 1994, 1995, 1996, 1997 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that: (1) source code distributions 7 * retain the above copyright notice and this paragraph in its entirety, (2) 8 * distributions including binary code include the above copyright notice and 9 * this paragraph in its entirety in the documentation or other materials 10 * provided with the distribution, and (3) all advertising materials mentioning 11 * features or use of this software display the following acknowledgement: 12 * ``This product includes software developed by the University of California, 13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 14 * the University nor the names of its contributors may be used to endorse 15 * or promote products derived from this software without specific prior 16 * written permission. 17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 20 */ 21 22#include <sys/cdefs.h> 23#ifndef lint 24__RCSID("$NetBSD: print-sl.c,v 1.4 2014/11/20 03:05:03 christos Exp $"); 25#endif 26 27#define NETDISSECT_REWORKED 28#ifdef HAVE_CONFIG_H 29#include "config.h" 30#endif 31 32#include <tcpdump-stdinc.h> 33 34#include "interface.h" 35#include "extract.h" /* must come after interface.h */ 36 37#include "ip.h" 38#include "tcp.h" 39#include "slcompress.h" 40 41/* 42 * definitions of the pseudo- link-level header attached to slip 43 * packets grabbed by the packet filter (bpf) traffic monitor. 44 */ 45#define SLIP_HDRLEN 16 46 47#define SLX_DIR 0 48#define SLX_CHDR 1 49#define CHDR_LEN 15 50 51#define SLIPDIR_IN 0 52#define SLIPDIR_OUT 1 53 54static const char tstr[] = "[|slip]"; 55 56static u_int lastlen[2][256]; 57static u_int lastconn = 255; 58 59static void sliplink_print(netdissect_options *, const u_char *, const struct ip *, u_int); 60static void compressed_sl_print(netdissect_options *, const u_char *, const struct ip *, u_int, int); 61 62u_int 63sl_if_print(netdissect_options *ndo, 64 const struct pcap_pkthdr *h, const u_char *p) 65{ 66 register u_int caplen = h->caplen; 67 register u_int length = h->len; 68 register const struct ip *ip; 69 70 if (caplen < SLIP_HDRLEN) { 71 ND_PRINT((ndo, "%s", tstr)); 72 return (caplen); 73 } 74 75 length -= SLIP_HDRLEN; 76 77 ip = (struct ip *)(p + SLIP_HDRLEN); 78 79 if (ndo->ndo_eflag) 80 sliplink_print(ndo, p, ip, length); 81 82 switch (IP_V(ip)) { 83 case 4: 84 ip_print(ndo, (u_char *)ip, length); 85 break; 86#ifdef INET6 87 case 6: 88 ip6_print(ndo, (u_char *)ip, length); 89 break; 90#endif 91 default: 92 ND_PRINT((ndo, "ip v%d", IP_V(ip))); 93 } 94 95 return (SLIP_HDRLEN); 96} 97 98u_int 99sl_bsdos_if_print(netdissect_options *ndo, 100 const struct pcap_pkthdr *h, const u_char *p) 101{ 102 register u_int caplen = h->caplen; 103 register u_int length = h->len; 104 register const struct ip *ip; 105 106 if (caplen < SLIP_HDRLEN) { 107 ND_PRINT((ndo, "%s", tstr)); 108 return (caplen); 109 } 110 111 length -= SLIP_HDRLEN; 112 113 ip = (struct ip *)(p + SLIP_HDRLEN); 114 115#ifdef notdef 116 if (ndo->ndo_eflag) 117 sliplink_print(ndo, p, ip, length); 118#endif 119 120 ip_print(ndo, (u_char *)ip, length); 121 122 return (SLIP_HDRLEN); 123} 124 125static void 126sliplink_print(netdissect_options *ndo, 127 register const u_char *p, register const struct ip *ip, 128 register u_int length) 129{ 130 int dir; 131 u_int hlen; 132 133 dir = p[SLX_DIR]; 134 ND_PRINT((ndo, dir == SLIPDIR_IN ? "I " : "O ")); 135 136 if (ndo->ndo_nflag) { 137 /* XXX just dump the header */ 138 register int i; 139 140 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i) 141 ND_PRINT((ndo, "%02x.", p[i])); 142 ND_PRINT((ndo, "%02x: ", p[SLX_CHDR + CHDR_LEN - 1])); 143 return; 144 } 145 switch (p[SLX_CHDR] & 0xf0) { 146 147 case TYPE_IP: 148 ND_PRINT((ndo, "ip %d: ", length + SLIP_HDRLEN)); 149 break; 150 151 case TYPE_UNCOMPRESSED_TCP: 152 /* 153 * The connection id is stored in the IP protocol field. 154 * Get it from the link layer since sl_uncompress_tcp() 155 * has restored the IP header copy to IPPROTO_TCP. 156 */ 157 lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p; 158 hlen = IP_HL(ip); 159 hlen += TH_OFF((struct tcphdr *)&((int *)ip)[hlen]); 160 lastlen[dir][lastconn] = length - (hlen << 2); 161 ND_PRINT((ndo, "utcp %d: ", lastconn)); 162 break; 163 164 default: 165 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) { 166 compressed_sl_print(ndo, &p[SLX_CHDR], ip, 167 length, dir); 168 ND_PRINT((ndo, ": ")); 169 } else 170 ND_PRINT((ndo, "slip-%d!: ", p[SLX_CHDR])); 171 } 172} 173 174static const u_char * 175print_sl_change(netdissect_options *ndo, 176 const char *str, register const u_char *cp) 177{ 178 register u_int i; 179 180 if ((i = *cp++) == 0) { 181 i = EXTRACT_16BITS(cp); 182 cp += 2; 183 } 184 ND_PRINT((ndo, " %s%d", str, i)); 185 return (cp); 186} 187 188static const u_char * 189print_sl_winchange(netdissect_options *ndo, 190 register const u_char *cp) 191{ 192 register short i; 193 194 if ((i = *cp++) == 0) { 195 i = EXTRACT_16BITS(cp); 196 cp += 2; 197 } 198 if (i >= 0) 199 ND_PRINT((ndo, " W+%d", i)); 200 else 201 ND_PRINT((ndo, " W%d", i)); 202 return (cp); 203} 204 205static void 206compressed_sl_print(netdissect_options *ndo, 207 const u_char *chdr, const struct ip *ip, 208 u_int length, int dir) 209{ 210 register const u_char *cp = chdr; 211 register u_int flags, hlen; 212 213 flags = *cp++; 214 if (flags & NEW_C) { 215 lastconn = *cp++; 216 ND_PRINT((ndo, "ctcp %d", lastconn)); 217 } else 218 ND_PRINT((ndo, "ctcp *")); 219 220 /* skip tcp checksum */ 221 cp += 2; 222 223 switch (flags & SPECIALS_MASK) { 224 case SPECIAL_I: 225 ND_PRINT((ndo, " *SA+%d", lastlen[dir][lastconn])); 226 break; 227 228 case SPECIAL_D: 229 ND_PRINT((ndo, " *S+%d", lastlen[dir][lastconn])); 230 break; 231 232 default: 233 if (flags & NEW_U) 234 cp = print_sl_change(ndo, "U=", cp); 235 if (flags & NEW_W) 236 cp = print_sl_winchange(ndo, cp); 237 if (flags & NEW_A) 238 cp = print_sl_change(ndo, "A+", cp); 239 if (flags & NEW_S) 240 cp = print_sl_change(ndo, "S+", cp); 241 break; 242 } 243 if (flags & NEW_I) 244 cp = print_sl_change(ndo, "I+", cp); 245 246 /* 247 * 'hlen' is the length of the uncompressed TCP/IP header (in words). 248 * 'cp - chdr' is the length of the compressed header. 249 * 'length - hlen' is the amount of data in the packet. 250 */ 251 hlen = IP_HL(ip); 252 hlen += TH_OFF((struct tcphdr *)&((int32_t *)ip)[hlen]); 253 lastlen[dir][lastconn] = length - (hlen << 2); 254 ND_PRINT((ndo, " %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr))); 255} 256