The Tcpdump Group git mirrors - tcpdump/blob - print-sll.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 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: Linux cooked sockets capture printer */
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #ifdef HAVE_NET_IF_H
  29 /*
  30  * Include diag-control.h before <net/if.h>, which too defines a macro
  31  * named ND_UNREACHABLE.
  32  */
  33 #include "diag-control.h"
  34 #include <net/if.h>
  35 #endif
  36
  37 #include "netdissect-stdinc.h"
  38
  39 #define ND_LONGJMP_FROM_TCHECK
  40 #include "netdissect.h"
  41 #include "addrtoname.h"
  42 #include "ethertype.h"
  43 #include "extract.h"
  44
  45 /*
  46  * For captures on Linux cooked sockets, we construct a fake header
  47  * that includes:
  48  *
  49  *      a 2-byte "packet type" which is one of:
  50  *
  51  *              LINUX_SLL_HOST          packet was sent to us
  52  *              LINUX_SLL_BROADCAST     packet was broadcast
  53  *              LINUX_SLL_MULTICAST     packet was multicast
  54  *              LINUX_SLL_OTHERHOST     packet was sent to somebody else
  55  *              LINUX_SLL_OUTGOING      packet was sent *by* us;
  56  *
  57  *      a 2-byte Ethernet protocol field;
  58  *
  59  *      a 2-byte link-layer type;
  60  *
  61  *      a 2-byte link-layer address length;
  62  *
  63  *      an 8-byte source link-layer address, whose actual length is
  64  *      specified by the previous value.
  65  *
  66  * All fields except for the link-layer address are in network byte order.
  67  *
  68  * DO NOT change the layout of this structure, or change any of the
  69  * LINUX_SLL_ values below.  If you must change the link-layer header
  70  * for a "cooked" Linux capture, introduce a new DLT_ type (ask
  71  * "tcpdump-workers@lists.tcpdump.org" for one, so that you don't give it
  72  * a value that collides with a value already being used), and use the
  73  * new header in captures of that type, so that programs that can
  74  * handle DLT_LINUX_SLL captures will continue to handle them correctly
  75  * without any change, and so that capture files with different headers
  76  * can be told apart and programs that read them can dissect the
  77  * packets in them.
  78  *
  79  * This structure, and the #defines below, must be the same in the
  80  * libpcap and tcpdump versions of "sll.h".
  81  */
  82
  83 /*
  84  * A DLT_LINUX_SLL fake link-layer header.
  85  */
  86 #define SLL_HDR_LEN     16              /* total header length */
  87 #define SLL_ADDRLEN     8               /* length of address field */
  88
  89 struct sll_header {
  90         nd_uint16_t     sll_pkttype;    /* packet type */
  91         nd_uint16_t     sll_hatype;     /* link-layer address type */
  92         nd_uint16_t     sll_halen;      /* link-layer address length */
  93         nd_byte         sll_addr[SLL_ADDRLEN];  /* link-layer address */
  94         nd_uint16_t     sll_protocol;   /* protocol */
  95 };
  96
  97 /*
  98  * A DLT_LINUX_SLL2 fake link-layer header.
  99  */
 100 #define SLL2_HDR_LEN    20              /* total header length */
 101
 102 struct sll2_header {
 103         nd_uint16_t     sll2_protocol;          /* protocol */
 104         nd_uint16_t     sll2_reserved_mbz;      /* reserved - must be zero */
 105         nd_uint32_t     sll2_if_index;          /* 1-based interface index */
 106         nd_uint16_t     sll2_hatype;            /* link-layer address type */
 107         nd_uint8_t      sll2_pkttype;           /* packet type */
 108         nd_uint8_t      sll2_halen;             /* link-layer address length */
 109         nd_byte         sll2_addr[SLL_ADDRLEN]; /* link-layer address */
 110 };
 111
 112 /*
 113  * The LINUX_SLL_ values for "sll_pkttype"; these correspond to the
 114  * PACKET_ values on Linux, but are defined here so that they're
 115  * available even on systems other than Linux, and so that they
 116  * don't change even if the PACKET_ values change.
 117  */
 118 #define LINUX_SLL_HOST          0
 119 #define LINUX_SLL_BROADCAST     1
 120 #define LINUX_SLL_MULTICAST     2
 121 #define LINUX_SLL_OTHERHOST     3
 122 #define LINUX_SLL_OUTGOING      4
 123
 124 /*
 125  * The LINUX_SLL_ values for "sll_protocol"; these correspond to the
 126  * ETH_P_ values on Linux, but are defined here so that they're
 127  * available even on systems other than Linux.  We assume, for now,
 128  * that the ETH_P_ values won't change in Linux; if they do, then:
 129  *
 130  *      if we don't translate them in "pcap-linux.c", capture files
 131  *      won't necessarily be readable if captured on a system that
 132  *      defines ETH_P_ values that don't match these values;
 133  *
 134  *      if we do translate them in "pcap-linux.c", that makes life
 135  *      unpleasant for the BPF code generator, as the values you test
 136  *      for in the kernel aren't the values that you test for when
 137  *      reading a capture file, so the fixup code run on BPF programs
 138  *      handed to the kernel ends up having to do more work.
 139  *
 140  * Add other values here as necessary, for handling packet types that
 141  * might show up on non-Ethernet, non-802.x networks.  (Not all the ones
 142  * in the Linux "if_ether.h" will, I suspect, actually show up in
 143  * captures.)
 144  */
 145 #define LINUX_SLL_P_802_3       0x0001  /* Novell 802.3 frames without 802.2 LLC header */
 146 #define LINUX_SLL_P_802_2       0x0004  /* 802.2 frames (not D/I/X Ethernet) */
 147
 148 static const struct tok sll_pkttype_values[] = {
 149     { LINUX_SLL_HOST, "In" },
 150     { LINUX_SLL_BROADCAST, "B" },
 151     { LINUX_SLL_MULTICAST, "M" },
 152     { LINUX_SLL_OTHERHOST, "P" },
 153     { LINUX_SLL_OUTGOING, "Out" },
 154     { 0, NULL}
 155 };
 156
 157 static void
 158 sll_print(netdissect_options *ndo, const struct sll_header *sllp, u_int length)
 159 {
 160         u_short ether_type;
 161
 162         ndo->ndo_protocol = "sll";
 163         ND_PRINT("%3s ",
 164                  tok2str(sll_pkttype_values,"?",GET_BE_U_2(sllp->sll_pkttype)));
 165
 166         /*
 167          * XXX - check the link-layer address type value?
 168          * For now, we just assume 6 means Ethernet.
 169          * XXX - print others as strings of hex?
 170          */
 171         if (GET_BE_U_2(sllp->sll_halen) == MAC_ADDR_LEN)
 172                 ND_PRINT("%s ", GET_ETHERADDR_STRING(sllp->sll_addr));
 173
 174         if (!ndo->ndo_qflag) {
 175                 ether_type = GET_BE_U_2(sllp->sll_protocol);
 176
 177                 if (ether_type <= MAX_ETHERNET_LENGTH_VAL) {
 178                         /*
 179                          * Not an Ethernet type; what type is it?
 180                          */
 181                         switch (ether_type) {
 182
 183                         case LINUX_SLL_P_802_3:
 184                                 /*
 185                                  * Ethernet_802.3 IPX frame.
 186                                  */
 187                                 ND_PRINT("802.3");
 188                                 break;
 189
 190                         case LINUX_SLL_P_802_2:
 191                                 /*
 192                                  * 802.2.
 193                                  */
 194                                 ND_PRINT("802.2");
 195                                 break;
 196
 197                         default:
 198                                 /*
 199                                  * What is it?
 200                                  */
 201                                 ND_PRINT("ethertype Unknown (0x%04x)",
 202                                     ether_type);
 203                                 break;
 204                         }
 205                 } else {
 206                         ND_PRINT("ethertype %s (0x%04x)",
 207                             tok2str(ethertype_values, "Unknown", ether_type),
 208                             ether_type);
 209                 }
 210                 ND_PRINT(", length %u: ", length);
 211         }
 212 }
 213
 214 /*
 215  * This is the top level routine of the printer.  'p' points to the
 216  * Linux "cooked capture" header of the packet, 'h->ts' is the timestamp,
 217  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
 218  * is the number of bytes actually captured.
 219  */
 220 void
 221 sll_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
 222 {
 223         u_int caplen = h->caplen;
 224         u_int length = h->len;
 225         const struct sll_header *sllp;
 226         u_short hatype;
 227         u_short ether_type;
 228         int llc_hdrlen;
 229         u_int hdrlen;
 230
 231         ndo->ndo_protocol = "sll";
 232         ND_TCHECK_LEN(p, SLL_HDR_LEN);
 233
 234         sllp = (const struct sll_header *)p;
 235
 236         if (ndo->ndo_eflag)
 237                 sll_print(ndo, sllp, length);
 238
 239         /*
 240          * Go past the cooked-mode header.
 241          */
 242         length -= SLL_HDR_LEN;
 243         caplen -= SLL_HDR_LEN;
 244         p += SLL_HDR_LEN;
 245         hdrlen = SLL_HDR_LEN;
 246
 247         hatype = GET_BE_U_2(sllp->sll_hatype);
 248         switch (hatype) {
 249
 250         case 803:
 251                 /*
 252                  * This is an packet with a radiotap header;
 253                  * just dissect the payload as such.
 254                  */
 255                 ndo->ndo_ll_hdr_len += SLL_HDR_LEN;
 256                 ndo->ndo_ll_hdr_len += ieee802_11_radio_print(ndo, p, length, caplen);
 257                 return;
 258         }
 259         ether_type = GET_BE_U_2(sllp->sll_protocol);
 260
 261 recurse:
 262         /*
 263          * Is it (gag) an 802.3 encapsulation, or some non-Ethernet
 264          * packet type?
 265          */
 266         if (ether_type <= MAX_ETHERNET_LENGTH_VAL) {
 267                 /*
 268                  * Yes - what type is it?
 269                  */
 270                 switch (ether_type) {
 271
 272                 case LINUX_SLL_P_802_3:
 273                         /*
 274                          * Ethernet_802.3 IPX frame.
 275                          */
 276                         ipx_print(ndo, p, length);
 277                         break;
 278
 279                 case LINUX_SLL_P_802_2:
 280                         /*
 281                          * 802.2.
 282                          * Try to print the LLC-layer header & higher layers.
 283                          */
 284                         llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL);
 285                         if (llc_hdrlen < 0)
 286                                 goto unknown;   /* unknown LLC type */
 287                         hdrlen += llc_hdrlen;
 288                         break;
 289
 290                 default:
 291                         /*FALLTHROUGH*/
 292
 293                 unknown:
 294                         /* packet type not known, print raw packet */
 295                         if (!ndo->ndo_suppress_default_print)
 296                                 ND_DEFAULTPRINT(p, caplen);
 297                         break;
 298                 }
 299         } else if (ether_type == ETHERTYPE_8021Q) {
 300                 /*
 301                  * Print VLAN information, and then go back and process
 302                  * the enclosed type field.
 303                  */
 304                 if (caplen < 4) {
 305                         ndo->ndo_protocol = "vlan";
 306                         nd_print_trunc(ndo);
 307                         ndo->ndo_ll_hdr_len += hdrlen + caplen;
 308                         return;
 309                 }
 310                 if (ndo->ndo_eflag) {
 311                         uint16_t tag = GET_BE_U_2(p);
 312
 313                         ND_PRINT("%s, ", ieee8021q_tci_string(tag));
 314                 }
 315
 316                 ether_type = GET_BE_U_2(p + 2);
 317                 if (ether_type <= MAX_ETHERNET_LENGTH_VAL)
 318                         ether_type = LINUX_SLL_P_802_2;
 319                 if (!ndo->ndo_qflag) {
 320                         ND_PRINT("ethertype %s, ",
 321                             tok2str(ethertype_values, "Unknown", ether_type));
 322                 }
 323                 p += 4;
 324                 length -= 4;
 325                 caplen -= 4;
 326                 hdrlen += 4;
 327                 goto recurse;
 328         } else {
 329                 if (ethertype_print(ndo, ether_type, p, length, caplen, NULL, NULL) == 0) {
 330                         /* ether_type not known, print raw packet */
 331                         if (!ndo->ndo_eflag)
 332                                 sll_print(ndo, sllp, length + SLL_HDR_LEN);
 333                         if (!ndo->ndo_suppress_default_print)
 334                                 ND_DEFAULTPRINT(p, caplen);
 335                 }
 336         }
 337
 338         ndo->ndo_ll_hdr_len += hdrlen;
 339 }
 340
 341 static void
 342 sll2_print(netdissect_options *ndo, const struct sll2_header *sllp, u_int length)
 343 {
 344         u_short ether_type;
 345
 346         ndo->ndo_protocol = "sll2";
 347         ND_PRINT("ifindex %u ", GET_BE_U_4(sllp->sll2_if_index));
 348
 349         /*
 350          * XXX - check the link-layer address type value?
 351          * For now, we just assume 6 means Ethernet.
 352          * XXX - print others as strings of hex?
 353          */
 354         if (GET_U_1(sllp->sll2_halen) == MAC_ADDR_LEN)
 355                 ND_PRINT("%s ", GET_ETHERADDR_STRING(sllp->sll2_addr));
 356
 357         if (!ndo->ndo_qflag) {
 358                 ether_type = GET_BE_U_2(sllp->sll2_protocol);
 359
 360                 if (ether_type <= MAX_ETHERNET_LENGTH_VAL) {
 361                         /*
 362                          * Not an Ethernet type; what type is it?
 363                          */
 364                         switch (ether_type) {
 365
 366                         case LINUX_SLL_P_802_3:
 367                                 /*
 368                                  * Ethernet_802.3 IPX frame.
 369                                  */
 370                                 ND_PRINT("802.3");
 371                                 break;
 372
 373                         case LINUX_SLL_P_802_2:
 374                                 /*
 375                                  * 802.2.
 376                                  */
 377                                 ND_PRINT("802.2");
 378                                 break;
 379
 380                         default:
 381                                 /*
 382                                  * What is it?
 383                                  */
 384                                 ND_PRINT("ethertype Unknown (0x%04x)",
 385                                     ether_type);
 386                                 break;
 387                         }
 388                 } else {
 389                         ND_PRINT("ethertype %s (0x%04x)",
 390                             tok2str(ethertype_values, "Unknown", ether_type),
 391                             ether_type);
 392                 }
 393                 ND_PRINT(", length %u: ", length);
 394         }
 395 }
 396
 397 /*
 398  * This is the top level routine of the printer.  'p' points to the
 399  * Linux "cooked capture" header of the packet, 'h->ts' is the timestamp,
 400  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
 401  * is the number of bytes actually captured.
 402  */
 403 void
 404 sll2_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
 405 {
 406         u_int caplen = h->caplen;
 407         u_int length = h->len;
 408         const struct sll2_header *sllp;
 409         u_short hatype;
 410         u_short ether_type;
 411         int llc_hdrlen;
 412         u_int hdrlen;
 413 #ifdef HAVE_NET_IF_H
 414         uint32_t if_index;
 415         char ifname[IF_NAMESIZE];
 416 #endif
 417
 418         ndo->ndo_protocol = "sll2";
 419         ND_TCHECK_LEN(p, SLL2_HDR_LEN);
 420
 421         sllp = (const struct sll2_header *)p;
 422 #ifdef HAVE_NET_IF_H
 423         if_index = GET_BE_U_4(sllp->sll2_if_index);
 424         if (!if_indextoname(if_index, ifname))
 425                 strncpy(ifname, "?", 2);
 426         ND_PRINT("%-5s ", ifname);
 427 #endif
 428
 429         ND_PRINT("%-3s ",
 430                  tok2str(sll_pkttype_values, "?", GET_U_1(sllp->sll2_pkttype)));
 431
 432         if (ndo->ndo_eflag)
 433                 sll2_print(ndo, sllp, length);
 434
 435         /*
 436          * Go past the cooked-mode header.
 437          */
 438         length -= SLL2_HDR_LEN;
 439         caplen -= SLL2_HDR_LEN;
 440         p += SLL2_HDR_LEN;
 441         hdrlen = SLL2_HDR_LEN;
 442
 443         hatype = GET_BE_U_2(sllp->sll2_hatype);
 444         switch (hatype) {
 445
 446         case 803:
 447                 /*
 448                  * This is an packet with a radiotap header;
 449                  * just dissect the payload as such.
 450                  */
 451                 ndo->ndo_ll_hdr_len += SLL2_HDR_LEN;
 452                 ndo->ndo_ll_hdr_len += ieee802_11_radio_print(ndo, p, length, caplen);
 453                 return;
 454         }
 455         ether_type = GET_BE_U_2(sllp->sll2_protocol);
 456
 457 recurse:
 458         /*
 459          * Is it (gag) an 802.3 encapsulation, or some non-Ethernet
 460          * packet type?
 461          */
 462         if (ether_type <= MAX_ETHERNET_LENGTH_VAL) {
 463                 /*
 464                  * Yes - what type is it?
 465                  */
 466                 switch (ether_type) {
 467
 468                 case LINUX_SLL_P_802_3:
 469                         /*
 470                          * Ethernet_802.3 IPX frame.
 471                          */
 472                         ipx_print(ndo, p, length);
 473                         break;
 474
 475                 case LINUX_SLL_P_802_2:
 476                         /*
 477                          * 802.2.
 478                          * Try to print the LLC-layer header & higher layers.
 479                          */
 480                         llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL);
 481                         if (llc_hdrlen < 0)
 482                                 goto unknown;   /* unknown LLC type */
 483                         hdrlen += llc_hdrlen;
 484                         break;
 485
 486                 default:
 487                         /*FALLTHROUGH*/
 488
 489                 unknown:
 490                         /* packet type not known, print raw packet */
 491                         if (!ndo->ndo_suppress_default_print)
 492                                 ND_DEFAULTPRINT(p, caplen);
 493                         break;
 494                 }
 495         } else if (ether_type == ETHERTYPE_8021Q) {
 496                 /*
 497                  * Print VLAN information, and then go back and process
 498                  * the enclosed type field.
 499                  */
 500                 if (caplen < 4) {
 501                         ndo->ndo_protocol = "vlan";
 502                         nd_print_trunc(ndo);
 503                         ndo->ndo_ll_hdr_len += hdrlen + caplen;
 504                         return;
 505                 }
 506                 if (ndo->ndo_eflag) {
 507                         uint16_t tag = GET_BE_U_2(p);
 508
 509                         ND_PRINT("%s, ", ieee8021q_tci_string(tag));
 510                 }
 511
 512                 ether_type = GET_BE_U_2(p + 2);
 513                 if (ether_type <= MAX_ETHERNET_LENGTH_VAL)
 514                         ether_type = LINUX_SLL_P_802_2;
 515                 if (!ndo->ndo_qflag) {
 516                         ND_PRINT("ethertype %s, ",
 517                             tok2str(ethertype_values, "Unknown", ether_type));
 518                 }
 519                 p += 4;
 520                 length -= 4;
 521                 caplen -= 4;
 522                 hdrlen += 4;
 523                 goto recurse;
 524         } else {
 525                 if (ethertype_print(ndo, ether_type, p, length, caplen, NULL, NULL) == 0) {
 526                         /* ether_type not known, print raw packet */
 527                         if (!ndo->ndo_eflag)
 528                                 sll2_print(ndo, sllp, length + SLL2_HDR_LEN);
 529                         if (!ndo->ndo_suppress_default_print)
 530                                 ND_DEFAULTPRINT(p, caplen);
 531                 }
 532         }
 533
 534         ndo->ndo_ll_hdr_len += hdrlen;
 535 }