1 /* $OpenBSD: print-sl.c,v 1.22 2021/12/01 18:28:46 deraadt 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 #include <net/if.h> 30 31 #include <netinet/in.h> 32 #include <netinet/ip.h> 33 #include <netinet/if_ether.h> 34 #include <netinet/udp.h> 35 #include <netinet/tcp.h> 36 37 #include <net/slcompress.h> 38 39 #include <ctype.h> 40 #include <netdb.h> 41 #include <pcap.h> 42 #include <stdio.h> 43 #include <limits.h> 44 45 #include "interface.h" 46 #include "addrtoname.h" 47 #include "extract.h" /* must come after interface.h */ 48 49 static u_int lastlen[2][256]; 50 static u_int lastconn = 255; 51 52 static void sliplink_print(const u_char *, const struct ip *, u_int); 53 static void compressed_sl_print(const u_char *, const struct ip *, u_int, int); 54 55 /* 56 * Definitions of the pseudo-link-level header attached to slip 57 * packets grabbed by the packet filter (bpf) traffic monitor. 58 */ 59 #define SLIP_HDRLEN 16 /* BPF SLIP header length */ 60 61 /* Offsets into BPF SLIP header. */ 62 #define SLX_DIR 0 /* direction; see below */ 63 #define SLX_CHDR 1 /* compressed header data */ 64 #define CHDR_LEN 15 /* length of compressed header data */ 65 66 #define SLIPDIR_IN 0 /* incoming */ 67 #define SLIPDIR_OUT 1 /* outgoing */ 68 69 /* XXX needs more hacking to work right */ 70 71 void 72 sl_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p) 73 { 74 u_int caplen = h->caplen; 75 u_int length = h->len; 76 const struct ip *ip; 77 78 ts_print(&h->ts); 79 80 if (caplen < SLIP_HDRLEN || length < SLIP_HDRLEN) { 81 printf("[|slip]"); 82 goto out; 83 } 84 /* 85 * Some printers want to get back at the link level addresses, 86 * and/or check that they're not walking off the end of the packet. 87 * Rather than pass them all the way down, we set these globals. 88 */ 89 packetp = p; 90 snapend = p + caplen; 91 92 length -= SLIP_HDRLEN; 93 94 ip = (struct ip *)(p + SLIP_HDRLEN); 95 96 if (eflag) 97 sliplink_print(p, ip, length); 98 99 switch (ip->ip_v) { 100 case 4: 101 ip_print((u_char *)ip, length); 102 break; 103 case 6: 104 ip6_print((u_char *)ip, length); 105 break; 106 default: 107 printf ("ip v%d", ip->ip_v); 108 } 109 110 if (xflag) 111 default_print((u_char *)ip, caplen - SLIP_HDRLEN); 112 out: 113 putchar('\n'); 114 } 115 116 117 void 118 sl_bsdos_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p) 119 { 120 u_int caplen = h->caplen; 121 u_int length = h->len; 122 const struct ip *ip; 123 124 ts_print(&h->ts); 125 126 if (caplen < SLIP_HDRLEN) { 127 printf("[|slip]"); 128 goto out; 129 } 130 /* 131 * Some printers want to get back at the link level addresses, 132 * and/or check that they're not walking off the end of the packet. 133 * Rather than pass them all the way down, we set these globals. 134 */ 135 packetp = p; 136 snapend = p + caplen; 137 138 length -= SLIP_HDRLEN; 139 140 ip = (struct ip *)(p + SLIP_HDRLEN); 141 142 #ifdef notdef 143 if (eflag) 144 sliplink_print(p, ip, length); 145 #endif 146 147 ip_print((u_char *)ip, length); 148 149 if (xflag) 150 default_print((u_char *)ip, caplen - SLIP_HDRLEN); 151 out: 152 putchar('\n'); 153 } 154 155 static void 156 sliplink_print(const u_char *p, const struct ip *ip, u_int length) 157 { 158 int dir; 159 u_int hlen; 160 161 dir = p[SLX_DIR]; 162 putchar(dir == SLIPDIR_IN ? 'I' : 'O'); 163 putchar(' '); 164 165 if (nflag) { 166 /* XXX just dump the header */ 167 int i; 168 169 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i) 170 printf("%02x.", p[i]); 171 printf("%02x: ", p[SLX_CHDR + CHDR_LEN - 1]); 172 return; 173 } 174 switch (p[SLX_CHDR] & 0xf0) { 175 176 case TYPE_IP: 177 printf("ip %d: ", length + SLIP_HDRLEN); 178 break; 179 180 case TYPE_UNCOMPRESSED_TCP: 181 /* 182 * The connection id is stored in the IP protocol field. 183 * Get it from the link layer since sl_uncompress_tcp() 184 * has restored the IP header copy to IPPROTO_TCP. 185 */ 186 lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p; 187 hlen = ip->ip_hl; 188 hlen += ((struct tcphdr *)&((int *)ip)[hlen])->th_off; 189 lastlen[dir][lastconn] = length - (hlen << 2); 190 printf("utcp %d: ", lastconn); 191 break; 192 193 default: 194 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) { 195 compressed_sl_print(&p[SLX_CHDR], ip, 196 length, dir); 197 printf(": "); 198 } else 199 printf("slip-%d!: ", p[SLX_CHDR]); 200 } 201 } 202 203 static const u_char * 204 print_sl_change(const char *str, const u_char *cp) 205 { 206 u_int i; 207 208 if ((i = *cp++) == 0) { 209 i = EXTRACT_16BITS(cp); 210 cp += 2; 211 } 212 printf(" %s%d", str, i); 213 return (cp); 214 } 215 216 static const u_char * 217 print_sl_winchange(const u_char *cp) 218 { 219 short i; 220 221 if ((i = *cp++) == 0) { 222 i = EXTRACT_16BITS(cp); 223 cp += 2; 224 } 225 if (i >= 0) 226 printf(" W+%d", i); 227 else 228 printf(" W%d", i); 229 return (cp); 230 } 231 232 static void 233 compressed_sl_print(const u_char *chdr, const struct ip *ip, 234 u_int length, int dir) 235 { 236 const u_char *cp = chdr; 237 u_int flags, hlen; 238 239 flags = *cp++; 240 if (flags & NEW_C) { 241 lastconn = *cp++; 242 printf("ctcp %d", lastconn); 243 } else 244 printf("ctcp *"); 245 246 /* skip tcp checksum */ 247 cp += 2; 248 249 switch (flags & SPECIALS_MASK) { 250 case SPECIAL_I: 251 printf(" *SA+%d", lastlen[dir][lastconn]); 252 break; 253 254 case SPECIAL_D: 255 printf(" *S+%d", lastlen[dir][lastconn]); 256 break; 257 258 default: 259 if (flags & NEW_U) 260 cp = print_sl_change("U=", cp); 261 if (flags & NEW_W) 262 cp = print_sl_winchange(cp); 263 if (flags & NEW_A) 264 cp = print_sl_change("A+", cp); 265 if (flags & NEW_S) 266 cp = print_sl_change("S+", cp); 267 break; 268 } 269 if (flags & NEW_I) 270 cp = print_sl_change("I+", cp); 271 272 /* 273 * 'hlen' is the length of the uncompressed TCP/IP header (in words). 274 * 'cp - chdr' is the length of the compressed header. 275 * 'length - hlen' is the amount of data in the packet. 276 */ 277 hlen = ip->ip_hl; 278 hlen += ((struct tcphdr *)&((int32_t *)ip)[hlen])->th_off; 279 lastlen[dir][lastconn] = length - (hlen << 2); 280 printf(" %d (%d)", lastlen[dir][lastconn], (int)(cp - chdr)); 281 } 282