print-sl.c revision 1.5
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 1.5 2015/03/31 21:59:35 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 54 static const char tstr[] = "[|slip]"; 55 56 static u_int lastlen[2][256]; 57 static u_int lastconn = 255; 58 59 static void sliplink_print(netdissect_options *, const u_char *, const struct ip *, u_int); 60 static void compressed_sl_print(netdissect_options *, const u_char *, const struct ip *, u_int, int); 61 62 u_int 63 sl_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 || length < 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 case 6: 87 ip6_print(ndo, (u_char *)ip, length); 88 break; 89 default: 90 ND_PRINT((ndo, "ip v%d", IP_V(ip))); 91 } 92 93 return (SLIP_HDRLEN); 94 } 95 96 u_int 97 sl_bsdos_if_print(netdissect_options *ndo, 98 const struct pcap_pkthdr *h, const u_char *p) 99 { 100 register u_int caplen = h->caplen; 101 register u_int length = h->len; 102 register const struct ip *ip; 103 104 if (caplen < SLIP_HDRLEN) { 105 ND_PRINT((ndo, "%s", tstr)); 106 return (caplen); 107 } 108 109 length -= SLIP_HDRLEN; 110 111 ip = (struct ip *)(p + SLIP_HDRLEN); 112 113 #ifdef notdef 114 if (ndo->ndo_eflag) 115 sliplink_print(ndo, p, ip, length); 116 #endif 117 118 ip_print(ndo, (u_char *)ip, length); 119 120 return (SLIP_HDRLEN); 121 } 122 123 static void 124 sliplink_print(netdissect_options *ndo, 125 register const u_char *p, register const struct ip *ip, 126 register u_int length) 127 { 128 int dir; 129 u_int hlen; 130 131 dir = p[SLX_DIR]; 132 ND_PRINT((ndo, dir == SLIPDIR_IN ? "I " : "O ")); 133 134 if (ndo->ndo_nflag) { 135 /* XXX just dump the header */ 136 register int i; 137 138 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i) 139 ND_PRINT((ndo, "%02x.", p[i])); 140 ND_PRINT((ndo, "%02x: ", p[SLX_CHDR + CHDR_LEN - 1])); 141 return; 142 } 143 switch (p[SLX_CHDR] & 0xf0) { 144 145 case TYPE_IP: 146 ND_PRINT((ndo, "ip %d: ", length + SLIP_HDRLEN)); 147 break; 148 149 case TYPE_UNCOMPRESSED_TCP: 150 /* 151 * The connection id is stored in the IP protocol field. 152 * Get it from the link layer since sl_uncompress_tcp() 153 * has restored the IP header copy to IPPROTO_TCP. 154 */ 155 lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p; 156 hlen = IP_HL(ip); 157 hlen += TH_OFF((struct tcphdr *)&((int *)ip)[hlen]); 158 lastlen[dir][lastconn] = length - (hlen << 2); 159 ND_PRINT((ndo, "utcp %d: ", lastconn)); 160 break; 161 162 default: 163 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) { 164 compressed_sl_print(ndo, &p[SLX_CHDR], ip, 165 length, dir); 166 ND_PRINT((ndo, ": ")); 167 } else 168 ND_PRINT((ndo, "slip-%d!: ", p[SLX_CHDR])); 169 } 170 } 171 172 static const u_char * 173 print_sl_change(netdissect_options *ndo, 174 const char *str, register const u_char *cp) 175 { 176 register u_int i; 177 178 if ((i = *cp++) == 0) { 179 i = EXTRACT_16BITS(cp); 180 cp += 2; 181 } 182 ND_PRINT((ndo, " %s%d", str, i)); 183 return (cp); 184 } 185 186 static const u_char * 187 print_sl_winchange(netdissect_options *ndo, 188 register const u_char *cp) 189 { 190 register short i; 191 192 if ((i = *cp++) == 0) { 193 i = EXTRACT_16BITS(cp); 194 cp += 2; 195 } 196 if (i >= 0) 197 ND_PRINT((ndo, " W+%d", i)); 198 else 199 ND_PRINT((ndo, " W%d", i)); 200 return (cp); 201 } 202 203 static void 204 compressed_sl_print(netdissect_options *ndo, 205 const u_char *chdr, const struct ip *ip, 206 u_int length, int dir) 207 { 208 register const u_char *cp = chdr; 209 register u_int flags, hlen; 210 211 flags = *cp++; 212 if (flags & NEW_C) { 213 lastconn = *cp++; 214 ND_PRINT((ndo, "ctcp %d", lastconn)); 215 } else 216 ND_PRINT((ndo, "ctcp *")); 217 218 /* skip tcp checksum */ 219 cp += 2; 220 221 switch (flags & SPECIALS_MASK) { 222 case SPECIAL_I: 223 ND_PRINT((ndo, " *SA+%d", lastlen[dir][lastconn])); 224 break; 225 226 case SPECIAL_D: 227 ND_PRINT((ndo, " *S+%d", lastlen[dir][lastconn])); 228 break; 229 230 default: 231 if (flags & NEW_U) 232 cp = print_sl_change(ndo, "U=", cp); 233 if (flags & NEW_W) 234 cp = print_sl_winchange(ndo, cp); 235 if (flags & NEW_A) 236 cp = print_sl_change(ndo, "A+", cp); 237 if (flags & NEW_S) 238 cp = print_sl_change(ndo, "S+", cp); 239 break; 240 } 241 if (flags & NEW_I) 242 cp = print_sl_change(ndo, "I+", cp); 243 244 /* 245 * 'hlen' is the length of the uncompressed TCP/IP header (in words). 246 * 'cp - chdr' is the length of the compressed header. 247 * 'length - hlen' is the amount of data in the packet. 248 */ 249 hlen = IP_HL(ip); 250 hlen += TH_OFF((struct tcphdr *)&((int32_t *)ip)[hlen]); 251 lastlen[dir][lastconn] = length - (hlen << 2); 252 ND_PRINT((ndo, " %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr))); 253 } 254
Indexes created Thu May 14 00:25:00 UTC 2026