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 /* \summary: Compressed Serial Line Internet Protocol printer */ 23 24 #ifdef HAVE_CONFIG_H 25 #include "config.h" 26 #endif 27 28 #include <netdissect-stdinc.h> 29 30 #include "netdissect.h" 31 #include "extract.h" 32 33 #include "ip.h" 34 #include "tcp.h" 35 #include "slcompress.h" 36 37 /* 38 * definitions of the pseudo- link-level header attached to slip 39 * packets grabbed by the packet filter (bpf) traffic monitor. 40 */ 41 #define SLIP_HDRLEN 16 42 43 #define SLX_DIR 0 44 #define SLX_CHDR 1 45 #define CHDR_LEN 15 46 47 #define SLIPDIR_IN 0 48 #define SLIPDIR_OUT 1 49 50 static const char tstr[] = "[|slip]"; 51 52 static u_int lastlen[2][256]; 53 static u_int lastconn = 255; 54 55 static void sliplink_print(netdissect_options *, const u_char *, const struct ip *, u_int); 56 static void compressed_sl_print(netdissect_options *, const u_char *, const struct ip *, u_int, int); 57 58 u_int 59 sl_if_print(netdissect_options *ndo, 60 const struct pcap_pkthdr *h, const u_char *p) 61 { 62 register u_int caplen = h->caplen; 63 register u_int length = h->len; 64 register const struct ip *ip; 65 66 if (caplen < SLIP_HDRLEN || length < SLIP_HDRLEN) { 67 ND_PRINT((ndo, "%s", tstr)); 68 return (caplen); 69 } 70 71 caplen -= SLIP_HDRLEN; 72 length -= SLIP_HDRLEN; 73 74 ip = (const struct ip *)(p + SLIP_HDRLEN); 75 76 if (ndo->ndo_eflag) 77 sliplink_print(ndo, p, ip, length); 78 79 if (caplen < 1 || length < 1) { 80 ND_PRINT((ndo, "%s", tstr)); 81 return (caplen + SLIP_HDRLEN); 82 } 83 84 switch (IP_V(ip)) { 85 case 4: 86 ip_print(ndo, (const u_char *)ip, length); 87 break; 88 case 6: 89 ip6_print(ndo, (const u_char *)ip, length); 90 break; 91 default: 92 ND_PRINT((ndo, "ip v%d", IP_V(ip))); 93 } 94 95 return (SLIP_HDRLEN); 96 } 97 98 u_int 99 sl_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 = (const 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, (const u_char *)ip, length); 121 122 return (SLIP_HDRLEN); 123 } 124 125 static void 126 sliplink_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 = ((const struct ip *)&p[SLX_CHDR])->ip_p; 158 hlen = IP_HL(ip); 159 hlen += TH_OFF((const struct tcphdr *)&((const 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 } 173 174 static const u_char * 175 print_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 } 187 188 static const u_char * 189 print_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 } 204 205 static void 206 compressed_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((const struct tcphdr *)&((const 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