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 * $FreeBSD$ 22 */ 23 24 #define NETDISSECT_REWORKED 25 #ifdef HAVE_CONFIG_H 26 #include "config.h" 27 #endif 28 29 #include <tcpdump-stdinc.h> 30 31 #include "interface.h" 32 #include "extract.h" /* must come after interface.h */ 33 34 #include "ip.h" 35 #include "tcp.h" 36 #include "slcompress.h" 37 38 /* 39 * definitions of the pseudo- link-level header attached to slip 40 * packets grabbed by the packet filter (bpf) traffic monitor. 41 */ 42 #define SLIP_HDRLEN 16 43 44 #define SLX_DIR 0 45 #define SLX_CHDR 1 46 #define CHDR_LEN 15 47 48 #define SLIPDIR_IN 0 49 #define SLIPDIR_OUT 1 50 51 static const char tstr[] = "[|slip]"; 52 53 static u_int lastlen[2][256]; 54 static u_int lastconn = 255; 55 56 static void sliplink_print(netdissect_options *, const u_char *, const struct ip *, u_int); 57 static void compressed_sl_print(netdissect_options *, const u_char *, const struct ip *, u_int, int); 58 59 u_int 60 sl_if_print(netdissect_options *ndo, 61 const struct pcap_pkthdr *h, const u_char *p) 62 { 63 register u_int caplen = h->caplen; 64 register u_int length = h->len; 65 register const struct ip *ip; 66 67 if (caplen < SLIP_HDRLEN || length < SLIP_HDRLEN) { 68 ND_PRINT((ndo, "%s", tstr)); 69 return (caplen); 70 } 71 72 length -= SLIP_HDRLEN; 73 74 ip = (struct ip *)(p + SLIP_HDRLEN); 75 76 if (ndo->ndo_eflag) 77 sliplink_print(ndo, p, ip, length); 78 79 switch (IP_V(ip)) { 80 case 4: 81 ip_print(ndo, (u_char *)ip, length); 82 break; 83 case 6: 84 ip6_print(ndo, (u_char *)ip, length); 85 break; 86 default: 87 ND_PRINT((ndo, "ip v%d", IP_V(ip))); 88 } 89 90 return (SLIP_HDRLEN); 91 } 92 93 u_int 94 sl_bsdos_if_print(netdissect_options *ndo, 95 const struct pcap_pkthdr *h, const u_char *p) 96 { 97 register u_int caplen = h->caplen; 98 register u_int length = h->len; 99 register const struct ip *ip; 100 101 if (caplen < SLIP_HDRLEN) { 102 ND_PRINT((ndo, "%s", tstr)); 103 return (caplen); 104 } 105 106 length -= SLIP_HDRLEN; 107 108 ip = (struct ip *)(p + SLIP_HDRLEN); 109 110 #ifdef notdef 111 if (ndo->ndo_eflag) 112 sliplink_print(ndo, p, ip, length); 113 #endif 114 115 ip_print(ndo, (u_char *)ip, length); 116 117 return (SLIP_HDRLEN); 118 } 119 120 static void 121 sliplink_print(netdissect_options *ndo, 122 register const u_char *p, register const struct ip *ip, 123 register u_int length) 124 { 125 int dir; 126 u_int hlen; 127 128 dir = p[SLX_DIR]; 129 ND_PRINT((ndo, dir == SLIPDIR_IN ? "I " : "O ")); 130 131 if (ndo->ndo_nflag) { 132 /* XXX just dump the header */ 133 register int i; 134 135 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i) 136 ND_PRINT((ndo, "%02x.", p[i])); 137 ND_PRINT((ndo, "%02x: ", p[SLX_CHDR + CHDR_LEN - 1])); 138 return; 139 } 140 switch (p[SLX_CHDR] & 0xf0) { 141 142 case TYPE_IP: 143 ND_PRINT((ndo, "ip %d: ", length + SLIP_HDRLEN)); 144 break; 145 146 case TYPE_UNCOMPRESSED_TCP: 147 /* 148 * The connection id is stored in the IP protocol field. 149 * Get it from the link layer since sl_uncompress_tcp() 150 * has restored the IP header copy to IPPROTO_TCP. 151 */ 152 lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p; 153 hlen = IP_HL(ip); 154 hlen += TH_OFF((struct tcphdr *)&((int *)ip)[hlen]); 155 lastlen[dir][lastconn] = length - (hlen << 2); 156 ND_PRINT((ndo, "utcp %d: ", lastconn)); 157 break; 158 159 default: 160 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) { 161 compressed_sl_print(ndo, &p[SLX_CHDR], ip, 162 length, dir); 163 ND_PRINT((ndo, ": ")); 164 } else 165 ND_PRINT((ndo, "slip-%d!: ", p[SLX_CHDR])); 166 } 167 } 168 169 static const u_char * 170 print_sl_change(netdissect_options *ndo, 171 const char *str, register const u_char *cp) 172 { 173 register u_int i; 174 175 if ((i = *cp++) == 0) { 176 i = EXTRACT_16BITS(cp); 177 cp += 2; 178 } 179 ND_PRINT((ndo, " %s%d", str, i)); 180 return (cp); 181 } 182 183 static const u_char * 184 print_sl_winchange(netdissect_options *ndo, 185 register const u_char *cp) 186 { 187 register short i; 188 189 if ((i = *cp++) == 0) { 190 i = EXTRACT_16BITS(cp); 191 cp += 2; 192 } 193 if (i >= 0) 194 ND_PRINT((ndo, " W+%d", i)); 195 else 196 ND_PRINT((ndo, " W%d", i)); 197 return (cp); 198 } 199 200 static void 201 compressed_sl_print(netdissect_options *ndo, 202 const u_char *chdr, const struct ip *ip, 203 u_int length, int dir) 204 { 205 register const u_char *cp = chdr; 206 register u_int flags, hlen; 207 208 flags = *cp++; 209 if (flags & NEW_C) { 210 lastconn = *cp++; 211 ND_PRINT((ndo, "ctcp %d", lastconn)); 212 } else 213 ND_PRINT((ndo, "ctcp *")); 214 215 /* skip tcp checksum */ 216 cp += 2; 217 218 switch (flags & SPECIALS_MASK) { 219 case SPECIAL_I: 220 ND_PRINT((ndo, " *SA+%d", lastlen[dir][lastconn])); 221 break; 222 223 case SPECIAL_D: 224 ND_PRINT((ndo, " *S+%d", lastlen[dir][lastconn])); 225 break; 226 227 default: 228 if (flags & NEW_U) 229 cp = print_sl_change(ndo, "U=", cp); 230 if (flags & NEW_W) 231 cp = print_sl_winchange(ndo, cp); 232 if (flags & NEW_A) 233 cp = print_sl_change(ndo, "A+", cp); 234 if (flags & NEW_S) 235 cp = print_sl_change(ndo, "S+", cp); 236 break; 237 } 238 if (flags & NEW_I) 239 cp = print_sl_change(ndo, "I+", cp); 240 241 /* 242 * 'hlen' is the length of the uncompressed TCP/IP header (in words). 243 * 'cp - chdr' is the length of the compressed header. 244 * 'length - hlen' is the amount of data in the packet. 245 */ 246 hlen = IP_HL(ip); 247 hlen += TH_OFF((struct tcphdr *)&((int32_t *)ip)[hlen]); 248 lastlen[dir][lastconn] = length - (hlen << 2); 249 ND_PRINT((ndo, " %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr))); 250 } 251