1 /* $OpenBSD: print-sl.c,v 1.20 2017/10/30 10:07:44 mpi Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1990, 1991, 1993, 1994, 1995, 1996, 1997 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that: (1) source code distributions 9 * retain the above copyright notice and this paragraph in its entirety, (2) 10 * distributions including binary code include the above copyright notice and 11 * this paragraph in its entirety in the documentation or other materials 12 * provided with the distribution, and (3) all advertising materials mentioning 13 * features or use of this software display the following acknowledgement: 14 * ``This product includes software developed by the University of California, 15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 16 * the University nor the names of its contributors may be used to endorse 17 * or promote products derived from this software without specific prior 18 * written permission. 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 22 */ 23 24 #include <sys/time.h> 25 #include <sys/file.h> 26 #include <sys/ioctl.h> 27 #include <sys/socket.h> 28 29 struct rtentry; 30 #include <net/if.h> 31 32 #include <netinet/in.h> 33 #include <netinet/ip.h> 34 #include <netinet/if_ether.h> 35 #include <netinet/udp.h> 36 #include <netinet/tcp.h> 37 38 #include <net/slcompress.h> 39 40 #include <ctype.h> 41 #include <netdb.h> 42 #include <pcap.h> 43 #include <stdio.h> 44 #include <limits.h> 45 46 #include "interface.h" 47 #include "addrtoname.h" 48 #include "extract.h" /* must come after interface.h */ 49 50 static u_int lastlen[2][256]; 51 static u_int lastconn = 255; 52 53 static void sliplink_print(const u_char *, const struct ip *, u_int); 54 static void compressed_sl_print(const u_char *, const struct ip *, u_int, int); 55 56 /* 57 * Definitions of the pseudo-link-level header attached to slip 58 * packets grabbed by the packet filter (bpf) traffic monitor. 59 */ 60 #define SLIP_HDRLEN 16 /* BPF SLIP header length */ 61 62 /* Offsets into BPF SLIP header. */ 63 #define SLX_DIR 0 /* direction; see below */ 64 #define SLX_CHDR 1 /* compressed header data */ 65 #define CHDR_LEN 15 /* length of compressed header data */ 66 67 #define SLIPDIR_IN 0 /* incoming */ 68 #define SLIPDIR_OUT 1 /* outgoing */ 69 70 /* XXX needs more hacking to work right */ 71 72 void 73 sl_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p) 74 { 75 u_int caplen = h->caplen; 76 u_int length = h->len; 77 const struct ip *ip; 78 79 ts_print(&h->ts); 80 81 if (caplen < SLIP_HDRLEN || length < SLIP_HDRLEN) { 82 printf("[|slip]"); 83 goto out; 84 } 85 /* 86 * Some printers want to get back at the link level addresses, 87 * and/or check that they're not walking off the end of the packet. 88 * Rather than pass them all the way down, we set these globals. 89 */ 90 packetp = p; 91 snapend = p + caplen; 92 93 length -= SLIP_HDRLEN; 94 95 ip = (struct ip *)(p + SLIP_HDRLEN); 96 97 if (eflag) 98 sliplink_print(p, ip, length); 99 100 switch (ip->ip_v) { 101 case 4: 102 ip_print((u_char *)ip, length); 103 break; 104 #ifdef INET6 105 case 6: 106 ip6_print((u_char *)ip, length); 107 break; 108 #endif 109 default: 110 printf ("ip v%d", ip->ip_v); 111 } 112 113 if (xflag) 114 default_print((u_char *)ip, caplen - SLIP_HDRLEN); 115 out: 116 putchar('\n'); 117 } 118 119 120 void 121 sl_bsdos_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p) 122 { 123 u_int caplen = h->caplen; 124 u_int length = h->len; 125 const struct ip *ip; 126 127 ts_print(&h->ts); 128 129 if (caplen < SLIP_HDRLEN) { 130 printf("[|slip]"); 131 goto out; 132 } 133 /* 134 * Some printers want to get back at the link level addresses, 135 * and/or check that they're not walking off the end of the packet. 136 * Rather than pass them all the way down, we set these globals. 137 */ 138 packetp = p; 139 snapend = p + caplen; 140 141 length -= SLIP_HDRLEN; 142 143 ip = (struct ip *)(p + SLIP_HDRLEN); 144 145 #ifdef notdef 146 if (eflag) 147 sliplink_print(p, ip, length); 148 #endif 149 150 ip_print((u_char *)ip, length); 151 152 if (xflag) 153 default_print((u_char *)ip, caplen - SLIP_HDRLEN); 154 out: 155 putchar('\n'); 156 } 157 158 static void 159 sliplink_print(const u_char *p, const struct ip *ip, u_int length) 160 { 161 int dir; 162 u_int hlen; 163 164 dir = p[SLX_DIR]; 165 putchar(dir == SLIPDIR_IN ? 'I' : 'O'); 166 putchar(' '); 167 168 if (nflag) { 169 /* XXX just dump the header */ 170 int i; 171 172 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i) 173 printf("%02x.", p[i]); 174 printf("%02x: ", p[SLX_CHDR + CHDR_LEN - 1]); 175 return; 176 } 177 switch (p[SLX_CHDR] & 0xf0) { 178 179 case TYPE_IP: 180 printf("ip %d: ", length + SLIP_HDRLEN); 181 break; 182 183 case TYPE_UNCOMPRESSED_TCP: 184 /* 185 * The connection id is stored in the IP protocol field. 186 * Get it from the link layer since sl_uncompress_tcp() 187 * has restored the IP header copy to IPPROTO_TCP. 188 */ 189 lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p; 190 hlen = ip->ip_hl; 191 hlen += ((struct tcphdr *)&((int *)ip)[hlen])->th_off; 192 lastlen[dir][lastconn] = length - (hlen << 2); 193 printf("utcp %d: ", lastconn); 194 break; 195 196 default: 197 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) { 198 compressed_sl_print(&p[SLX_CHDR], ip, 199 length, dir); 200 printf(": "); 201 } else 202 printf("slip-%d!: ", p[SLX_CHDR]); 203 } 204 } 205 206 static const u_char * 207 print_sl_change(const char *str, const u_char *cp) 208 { 209 u_int i; 210 211 if ((i = *cp++) == 0) { 212 i = EXTRACT_16BITS(cp); 213 cp += 2; 214 } 215 printf(" %s%d", str, i); 216 return (cp); 217 } 218 219 static const u_char * 220 print_sl_winchange(const u_char *cp) 221 { 222 short i; 223 224 if ((i = *cp++) == 0) { 225 i = EXTRACT_16BITS(cp); 226 cp += 2; 227 } 228 if (i >= 0) 229 printf(" W+%d", i); 230 else 231 printf(" W%d", i); 232 return (cp); 233 } 234 235 static void 236 compressed_sl_print(const u_char *chdr, const struct ip *ip, 237 u_int length, int dir) 238 { 239 const u_char *cp = chdr; 240 u_int flags, hlen; 241 242 flags = *cp++; 243 if (flags & NEW_C) { 244 lastconn = *cp++; 245 printf("ctcp %d", lastconn); 246 } else 247 printf("ctcp *"); 248 249 /* skip tcp checksum */ 250 cp += 2; 251 252 switch (flags & SPECIALS_MASK) { 253 case SPECIAL_I: 254 printf(" *SA+%d", lastlen[dir][lastconn]); 255 break; 256 257 case SPECIAL_D: 258 printf(" *S+%d", lastlen[dir][lastconn]); 259 break; 260 261 default: 262 if (flags & NEW_U) 263 cp = print_sl_change("U=", cp); 264 if (flags & NEW_W) 265 cp = print_sl_winchange(cp); 266 if (flags & NEW_A) 267 cp = print_sl_change("A+", cp); 268 if (flags & NEW_S) 269 cp = print_sl_change("S+", cp); 270 break; 271 } 272 if (flags & NEW_I) 273 cp = print_sl_change("I+", cp); 274 275 /* 276 * 'hlen' is the length of the uncompressed TCP/IP header (in words). 277 * 'cp - chdr' is the length of the compressed header. 278 * 'length - hlen' is the amount of data in the packet. 279 */ 280 hlen = ip->ip_hl; 281 hlen += ((struct tcphdr *)&((int32_t *)ip)[hlen])->th_off; 282 lastlen[dir][lastconn] = length - (hlen << 2); 283 printf(" %d (%d)", lastlen[dir][lastconn], (int)(cp - chdr)); 284 } 285