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