epan/dissectors/packet-sll.c

   1 /* packet-sll.c
   2  * Routines for disassembly of packets from Linux "cooked mode" captures
   3  *
   4  * $Id$
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version 2
  13  * of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  23  */
  24
  25 #include "config.h"
  26
  27 #include <glib.h>
  28 #include <epan/arptypes.h>
  29 #include <epan/prefs.h>
  30 #include <epan/packet.h>
  31 #include "packet-sll.h"
  32 #include "packet-ipx.h"
  33 #include "packet-llc.h"
  34 #include "packet-eth.h"
  35 #include "packet-ppp.h"
  36 #include "packet-gre.h"
  37 #include <epan/addr_resolv.h>
  38 #include <epan/etypes.h>
  39
  40 static int proto_sll = -1;
  41 static int hf_sll_pkttype = -1;
  42 static int hf_sll_hatype = -1;
  43 static int hf_sll_halen = -1;
  44 static int hf_sll_src_eth = -1;
  45 static int hf_sll_src_ipv4 = -1;
  46 static int hf_sll_src_other = -1;
  47 static int hf_sll_ltype = -1;
  48 static int hf_sll_gretype = -1;
  49 static int hf_sll_etype = -1;
  50 static int hf_sll_trailer = -1;
  51
  52 static gint ett_sll = -1;
  53
  54 /*
  55  * A DLT_LINUX_SLL fake link-layer header.
  56  */
  57 #define SLL_HEADER_SIZE 16              /* total header length */
  58 #define SLL_ADDRLEN     8               /* length of address field */
  59
  60 /*
  61  * The LINUX_SLL_ values for "sll_pkttype".
  62  */
  63 #define LINUX_SLL_HOST          0
  64 #define LINUX_SLL_BROADCAST     1
  65 #define LINUX_SLL_MULTICAST     2
  66 #define LINUX_SLL_OTHERHOST     3
  67 #define LINUX_SLL_OUTGOING      4
  68
  69 static const value_string packet_type_vals[] = {
  70         { LINUX_SLL_HOST,       "Unicast to us" },
  71         { LINUX_SLL_BROADCAST,  "Broadcast" },
  72         { LINUX_SLL_MULTICAST,  "Multicast" },
  73         { LINUX_SLL_OTHERHOST,  "Unicast to another host" },
  74         { LINUX_SLL_OUTGOING,   "Sent by us" },
  75         { 0,                    NULL }
  76 };
  77
  78 static const value_string ltype_vals[] = {
  79         { LINUX_SLL_P_802_3,    "Raw 802.3" },
  80         { LINUX_SLL_P_ETHERNET, "Ethernet" },
  81         { LINUX_SLL_P_802_2,    "802.2 LLC" },
  82         { LINUX_SLL_P_PPPHDLC,  "PPP (HDLC)" },
  83         { LINUX_SLL_P_CAN,      "CAN" },
  84         { LINUX_SLL_P_IRDA_LAP, "IrDA LAP" },
  85         { 0,                    NULL }
  86 };
  87
  88 static dissector_table_t sll_linux_dissector_table;
  89 static dissector_table_t gre_dissector_table;
  90 static dissector_handle_t data_handle;
  91
  92 void
  93 capture_sll(const guchar *pd, int len, packet_counts *ld)
  94 {
  95         guint16 protocol;
  96
  97         if (!BYTES_ARE_IN_FRAME(0, len, SLL_HEADER_SIZE)) {
  98                 ld->other++;
  99                 return;
 100         }
 101         protocol = pntohs(&pd[14]);
 102         if (protocol <= 1536) { /* yes, 1536 - that's how Linux does it */
 103                 /*
 104                  * "proto" is *not* a length field, it's a Linux internal
 105                  * protocol type.
 106                  */
 107                 switch (protocol) {
 108
 109                 case LINUX_SLL_P_802_2:
 110                         /*
 111                          * 802.2 LLC.
 112                          */
 113                         capture_llc(pd, len, SLL_HEADER_SIZE, ld);
 114                         break;
 115
 116                 case LINUX_SLL_P_ETHERNET:
 117                         /*
 118                          * Ethernet.
 119                          */
 120                         capture_eth(pd, SLL_HEADER_SIZE, len, ld);
 121                         break;
 122
 123                 case LINUX_SLL_P_802_3:
 124                         /*
 125                          * Novell IPX inside 802.3 with no 802.2 LLC
 126                          * header.
 127                          */
 128                         capture_ipx(ld);
 129                         break;
 130
 131                 case LINUX_SLL_P_PPPHDLC:
 132                         /*
 133                          * PPP HDLC.
 134                          */
 135                         capture_ppp_hdlc(pd, len, SLL_HEADER_SIZE, ld);
 136                         break;
 137
 138                 default:
 139                         ld->other++;
 140                         break;
 141                 }
 142         } else
 143                 capture_ethertype(protocol, pd, SLL_HEADER_SIZE, len, ld);
 144 }
 145
 146 static void
 147 dissect_sll(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 148 {
 149         guint16 pkttype;
 150         guint16 protocol;
 151         guint16 hatype, halen;
 152         const guint8 *src;
 153         proto_item *ti;
 154         tvbuff_t *next_tvb;
 155         proto_tree *fh_tree = NULL;
 156
 157         col_set_str(pinfo->cinfo, COL_PROTOCOL, "SLL");
 158         col_clear(pinfo->cinfo, COL_INFO);
 159
 160         pkttype = tvb_get_ntohs(tvb, 0);
 161
 162         /*
 163          * Set "pinfo->p2p_dir" if the packet wasn't received
 164          * promiscuously.
 165          */
 166         switch (pkttype) {
 167
 168         case LINUX_SLL_HOST:
 169         case LINUX_SLL_BROADCAST:
 170         case LINUX_SLL_MULTICAST:
 171                 pinfo->p2p_dir = P2P_DIR_RECV;
 172                 break;
 173
 174         case LINUX_SLL_OUTGOING:
 175                 pinfo->p2p_dir = P2P_DIR_SENT;
 176                 break;
 177         }
 178
 179         if (check_col(pinfo->cinfo, COL_INFO))
 180                 col_add_str(pinfo->cinfo, COL_INFO,
 181                     val_to_str(pkttype, packet_type_vals, "Unknown (%u)"));
 182
 183         if (tree) {
 184                 ti = proto_tree_add_protocol_format(tree, proto_sll, tvb, 0,
 185                     SLL_HEADER_SIZE, "Linux cooked capture");
 186                 fh_tree = proto_item_add_subtree(ti, ett_sll);
 187                 proto_tree_add_item(fh_tree, hf_sll_pkttype, tvb, 0, 2, ENC_BIG_ENDIAN);
 188         }
 189
 190         /*
 191          * XXX - check the link-layer address type value?
 192          * For now, we just assume 6 means Ethernet.
 193          */
 194         hatype = tvb_get_ntohs(tvb, 2);
 195         halen = tvb_get_ntohs(tvb, 4);
 196         if (tree) {
 197                 proto_tree_add_uint(fh_tree, hf_sll_hatype, tvb, 2, 2, hatype);
 198                 proto_tree_add_uint(fh_tree, hf_sll_halen, tvb, 4, 2, halen);
 199         }
 200         switch (halen) {
 201         case 4:
 202                 src = tvb_get_ptr(tvb, 6, 4);
 203                 SET_ADDRESS(&pinfo->dl_src, AT_IPv4, 4, src);
 204                 SET_ADDRESS(&pinfo->src, AT_IPv4, 4, src);
 205                 if (tree) {
 206                         proto_tree_add_item(fh_tree, hf_sll_src_ipv4, tvb,
 207                             6, 4, ENC_BIG_ENDIAN);
 208                 }
 209                 break;
 210         case 6:
 211                 src = tvb_get_ptr(tvb, 6, 6);
 212                 SET_ADDRESS(&pinfo->dl_src, AT_ETHER, 6, src);
 213                 SET_ADDRESS(&pinfo->src, AT_ETHER, 6, src);
 214                 if (tree) {
 215                         proto_tree_add_ether(fh_tree, hf_sll_src_eth, tvb,
 216                             6, 6, src);
 217                 }
 218                 break;
 219         case 0:
 220                 break;
 221         default:
 222                 if (tree) {
 223                         proto_tree_add_item(fh_tree, hf_sll_src_other, tvb,
 224                             6, halen > 8 ? 8 : halen, ENC_NA);
 225                 }
 226                 break;
 227         }
 228
 229         protocol = tvb_get_ntohs(tvb, 14);
 230         next_tvb = tvb_new_subset_remaining(tvb, SLL_HEADER_SIZE);
 231         if (protocol <= 1536) { /* yes, 1536 - that's how Linux does it */
 232                 /*
 233                  * "proto" is *not* a length field, it's a Linux internal
 234                  * protocol type.
 235                  * We therefore cannot say how much of the packet will
 236                  * be trailer data.
 237                  * XXX - do the same thing we do for packets with Ethertypes?
 238                  */
 239                 proto_tree_add_uint(fh_tree, hf_sll_ltype, tvb, 14, 2,
 240                     protocol);
 241
 242                 if(!dissector_try_uint(sll_linux_dissector_table, protocol,
 243                         next_tvb, pinfo, tree)) {
 244                         call_dissector(data_handle, next_tvb, pinfo, tree);
 245                 }
 246         } else {
 247                 switch (hatype) {
 248                 case ARPHRD_IPGRE:
 249                         proto_tree_add_uint(fh_tree, hf_sll_gretype, tvb, 14, 2,
 250                             protocol);
 251                         dissector_try_uint(gre_dissector_table,
 252                                            protocol, next_tvb, pinfo, tree);
 253                         break;
 254                 default:
 255                         ethertype(protocol, tvb, SLL_HEADER_SIZE, pinfo, tree,
 256                                   fh_tree, hf_sll_etype, hf_sll_trailer, 0);
 257                         break;
 258                 }
 259         }
 260 }
 261
 262 void
 263 proto_register_sll(void)
 264 {
 265         static hf_register_info hf[] = {
 266                 { &hf_sll_pkttype,
 267                 { "Packet type",        "sll.pkttype", FT_UINT16, BASE_DEC,
 268                   VALS(packet_type_vals), 0x0, NULL, HFILL }},
 269
 270                 /* ARP hardware type?  With Linux extensions? */
 271                 { &hf_sll_hatype,
 272                 { "Link-layer address type",    "sll.hatype", FT_UINT16, BASE_DEC,
 273                   NULL, 0x0, NULL, HFILL }},
 274
 275                 { &hf_sll_halen,
 276                 { "Link-layer address length",  "sll.halen", FT_UINT16, BASE_DEC,
 277                   NULL, 0x0, NULL, HFILL }},
 278
 279                 /* Source address if it's an Ethernet-type address */
 280                 { &hf_sll_src_eth,
 281                 { "Source",     "sll.src.eth", FT_ETHER, BASE_NONE, NULL, 0x0,
 282                         "Source link-layer address", HFILL }},
 283
 284                 /* Source address if it's an IPv4 address */
 285                 { &hf_sll_src_ipv4,
 286                 { "Source",     "sll.src.ipv4", FT_IPv4, BASE_NONE, NULL, 0x0,
 287                         "Source link-layer address", HFILL }},
 288
 289                 /* Source address if it's not an Ethernet-type address */
 290                 { &hf_sll_src_other,
 291                 { "Source",     "sll.src.other", FT_BYTES, BASE_NONE, NULL, 0x0,
 292                         "Source link-layer address", HFILL }},
 293
 294                 /* if the protocol field is an internal Linux protocol type */
 295                 { &hf_sll_ltype,
 296                 { "Protocol",   "sll.ltype", FT_UINT16, BASE_HEX,
 297                    VALS(ltype_vals), 0x0, "Linux protocol type", HFILL }},
 298
 299                 /* if the protocol field is a GRE protocol type */
 300                 { &hf_sll_gretype,
 301                 { "Protocol",   "sll.gretype", FT_UINT16, BASE_HEX,
 302                    VALS(gre_typevals), 0x0, "GRE protocol type", HFILL }},
 303
 304                 /* registered here but handled in ethertype.c */
 305                 { &hf_sll_etype,
 306                 { "Protocol",   "sll.etype", FT_UINT16, BASE_HEX,
 307                    VALS(etype_vals), 0x0, "Ethernet protocol type", HFILL }},
 308
 309                 { &hf_sll_trailer,
 310                 { "Trailer", "sll.trailer", FT_BYTES, BASE_NONE, NULL, 0x0,
 311                         NULL, HFILL }}
 312         };
 313         static gint *ett[] = {
 314                 &ett_sll
 315         };
 316
 317         proto_sll = proto_register_protocol("Linux cooked-mode capture",
 318             "SLL", "sll" );
 319         proto_register_field_array(proto_sll, hf, array_length(hf));
 320         proto_register_subtree_array(ett, array_length(ett));
 321
 322         sll_linux_dissector_table = register_dissector_table (
 323                 "sll.ltype",
 324                 "Linux protocol type",
 325                 FT_UINT16,
 326                 BASE_HEX
 327         );
 328 }
 329
 330 void
 331 proto_reg_handoff_sll(void)
 332 {
 333         dissector_handle_t sll_handle;
 334
 335         /*
 336          * Get handles for the IPX and LLC dissectors.
 337          */
 338         gre_dissector_table = find_dissector_table("gre.proto");
 339         data_handle = find_dissector("data");
 340
 341         sll_handle = create_dissector_handle(dissect_sll, proto_sll);
 342         dissector_add_uint("wtap_encap", WTAP_ENCAP_SLL, sll_handle);
 343 }