print-sl.c revision 1.6
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 1.6 2017/01/24 23:29:14 christos Exp $"); 25 #endif 26 27 #ifdef HAVE_CONFIG_H 28 #include "config.h" 29 #endif 30 31 #include <netdissect-stdinc.h> 32 33 #include "netdissect.h" 34 #include "extract.h" 35 36 #include "ip.h" 37 #include "tcp.h" 38 #include "slcompress.h" 39 40 /* 41 * definitions of the pseudo- link-level header attached to slip 42 * packets grabbed by the packet filter (bpf) traffic monitor. 43 */ 44 #define SLIP_HDRLEN 16 45 46 #define SLX_DIR 0 47 #define SLX_CHDR 1 48 #define CHDR_LEN 15 49 50 #define SLIPDIR_IN 0 51 #define SLIPDIR_OUT 1 52 53 static const char tstr[] = "[|slip]"; 54 55 static u_int lastlen[2][256]; 56 static u_int lastconn = 255; 57 58 static void sliplink_print(netdissect_options *, const u_char *, const struct ip *, u_int); 59 static void compressed_sl_print(netdissect_options *, const u_char *, const struct ip *, u_int, int); 60 61 u_int 62 sl_if_print(netdissect_options *ndo, 63 const struct pcap_pkthdr *h, const u_char *p) 64 { 65 register u_int caplen = h->caplen; 66 register u_int length = h->len; 67 register const struct ip *ip; 68 69 if (caplen < SLIP_HDRLEN || length < SLIP_HDRLEN) { 70 ND_PRINT((ndo, "%s", tstr)); 71 return (caplen); 72 } 73 74 length -= SLIP_HDRLEN; 75 76 ip = (const struct ip *)(p + SLIP_HDRLEN); 77 78 if (ndo->ndo_eflag) 79 sliplink_print(ndo, p, ip, length); 80 81 switch (IP_V(ip)) { 82 case 4: 83 ip_print(ndo, (const u_char *)ip, length); 84 break; 85 case 6: 86 ip6_print(ndo, (const u_char *)ip, length); 87 break; 88 default: 89 ND_PRINT((ndo, "ip v%d", IP_V(ip))); 90 } 91 92 return (SLIP_HDRLEN); 93 } 94 95 u_int 96 sl_bsdos_if_print(netdissect_options *ndo, 97 const struct pcap_pkthdr *h, const u_char *p) 98 { 99 register u_int caplen = h->caplen; 100 register u_int length = h->len; 101 register const struct ip *ip; 102 103 if (caplen < SLIP_HDRLEN) { 104 ND_PRINT((ndo, "%s", tstr)); 105 return (caplen); 106 } 107 108 length -= SLIP_HDRLEN; 109 110 ip = (const struct ip *)(p + SLIP_HDRLEN); 111 112 #ifdef notdef 113 if (ndo->ndo_eflag) 114 sliplink_print(ndo, p, ip, length); 115 #endif 116 117 ip_print(ndo, (const u_char *)ip, length); 118 119 return (SLIP_HDRLEN); 120 } 121 122 static void 123 sliplink_print(netdissect_options *ndo, 124 register const u_char *p, register const struct ip *ip, 125 register u_int length) 126 { 127 int dir; 128 u_int hlen; 129 130 dir = p[SLX_DIR]; 131 ND_PRINT((ndo, dir == SLIPDIR_IN ? "I " : "O ")); 132 133 if (ndo->ndo_nflag) { 134 /* XXX just dump the header */ 135 register int i; 136 137 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i) 138 ND_PRINT((ndo, "%02x.", p[i])); 139 ND_PRINT((ndo, "%02x: ", p[SLX_CHDR + CHDR_LEN - 1])); 140 return; 141 } 142 switch (p[SLX_CHDR] & 0xf0) { 143 144 case TYPE_IP: 145 ND_PRINT((ndo, "ip %d: ", length + SLIP_HDRLEN)); 146 break; 147 148 case TYPE_UNCOMPRESSED_TCP: 149 /* 150 * The connection id is stored in the IP protocol field. 151 * Get it from the link layer since sl_uncompress_tcp() 152 * has restored the IP header copy to IPPROTO_TCP. 153 */ 154 lastconn = ((const struct ip *)&p[SLX_CHDR])->ip_p; 155 hlen = IP_HL(ip); 156 hlen += TH_OFF((const struct tcphdr *)&((const int *)ip)[hlen]); 157 lastlen[dir][lastconn] = length - (hlen << 2); 158 ND_PRINT((ndo, "utcp %d: ", lastconn)); 159 break; 160 161 default: 162 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) { 163 compressed_sl_print(ndo, &p[SLX_CHDR], ip, 164 length, dir); 165 ND_PRINT((ndo, ": ")); 166 } else 167 ND_PRINT((ndo, "slip-%d!: ", p[SLX_CHDR])); 168 } 169 } 170 171 static const u_char * 172 print_sl_change(netdissect_options *ndo, 173 const char *str, register const u_char *cp) 174 { 175 register u_int i; 176 177 if ((i = *cp++) == 0) { 178 i = EXTRACT_16BITS(cp); 179 cp += 2; 180 } 181 ND_PRINT((ndo, " %s%d", str, i)); 182 return (cp); 183 } 184 185 static const u_char * 186 print_sl_winchange(netdissect_options *ndo, 187 register const u_char *cp) 188 { 189 register short i; 190 191 if ((i = *cp++) == 0) { 192 i = EXTRACT_16BITS(cp); 193 cp += 2; 194 } 195 if (i >= 0) 196 ND_PRINT((ndo, " W+%d", i)); 197 else 198 ND_PRINT((ndo, " W%d", i)); 199 return (cp); 200 } 201 202 static void 203 compressed_sl_print(netdissect_options *ndo, 204 const u_char *chdr, const struct ip *ip, 205 u_int length, int dir) 206 { 207 register const u_char *cp = chdr; 208 register u_int flags, hlen; 209 210 flags = *cp++; 211 if (flags & NEW_C) { 212 lastconn = *cp++; 213 ND_PRINT((ndo, "ctcp %d", lastconn)); 214 } else 215 ND_PRINT((ndo, "ctcp *")); 216 217 /* skip tcp checksum */ 218 cp += 2; 219 220 switch (flags & SPECIALS_MASK) { 221 case SPECIAL_I: 222 ND_PRINT((ndo, " *SA+%d", lastlen[dir][lastconn])); 223 break; 224 225 case SPECIAL_D: 226 ND_PRINT((ndo, " *S+%d", lastlen[dir][lastconn])); 227 break; 228 229 default: 230 if (flags & NEW_U) 231 cp = print_sl_change(ndo, "U=", cp); 232 if (flags & NEW_W) 233 cp = print_sl_winchange(ndo, cp); 234 if (flags & NEW_A) 235 cp = print_sl_change(ndo, "A+", cp); 236 if (flags & NEW_S) 237 cp = print_sl_change(ndo, "S+", cp); 238 break; 239 } 240 if (flags & NEW_I) 241 cp = print_sl_change(ndo, "I+", cp); 242 243 /* 244 * 'hlen' is the length of the uncompressed TCP/IP header (in words). 245 * 'cp - chdr' is the length of the compressed header. 246 * 'length - hlen' is the amount of data in the packet. 247 */ 248 hlen = IP_HL(ip); 249 hlen += TH_OFF((const struct tcphdr *)&((const int32_t *)ip)[hlen]); 250 lastlen[dir][lastconn] = length - (hlen << 2); 251 ND_PRINT((ndo, " %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr))); 252 } 253
Indexes created Thu May 14 00:25:00 UTC 2026