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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  23  */
  24
  25 #ifdef HAVE_CONFIG_H
  26 # include "config.h"
  27 #endif
  28
  29 #include <glib.h>
  30 #include <epan/arptypes.h>
  31 #include <epan/prefs.h>
  32 #include <epan/packet.h>
  33 #include "packet-sll.h"
  34 #include "packet-ipx.h"
  35 #include "packet-llc.h"
  36 #include "packet-eth.h"
  37 #include "packet-ppp.h"
  38 #include "packet-gre.h"
  39 #include <epan/addr_resolv.h>
  40 #include <epan/etypes.h>
  41
  42 static int proto_sll = -1;
  43 static int hf_sll_pkttype = -1;
  44 static int hf_sll_hatype = -1;
  45 static int hf_sll_halen = -1;
  46 static int hf_sll_src_eth = -1;
  47 static int hf_sll_src_ipv4 = -1;
  48 static int hf_sll_src_other = -1;
  49 static int hf_sll_ltype = -1;
  50 static int hf_sll_gretype = -1;
  51 static int hf_sll_etype = -1;
  52 static int hf_sll_trailer = -1;
  53
  54 static gint ett_sll = -1;
  55
  56 /*
  57  * A DLT_LINUX_SLL fake link-layer header.
  58  */
  59 #define SLL_HEADER_SIZE 16              /* total header length */
  60 #define SLL_ADDRLEN     8               /* length of address field */
  61
  62 /*
  63  * The LINUX_SLL_ values for "sll_pkttype".
  64  */
  65 #define LINUX_SLL_HOST          0
  66 #define LINUX_SLL_BROADCAST     1
  67 #define LINUX_SLL_MULTICAST     2
  68 #define LINUX_SLL_OTHERHOST     3
  69 #define LINUX_SLL_OUTGOING      4
  70
  71 static const value_string packet_type_vals[] = {
  72         { LINUX_SLL_HOST,       "Unicast to us" },
  73         { LINUX_SLL_BROADCAST,  "Broadcast" },
  74         { LINUX_SLL_MULTICAST,  "Multicast" },
  75         { LINUX_SLL_OTHERHOST,  "Unicast to another host" },
  76         { LINUX_SLL_OUTGOING,   "Sent by us" },
  77         { 0,                    NULL }
  78 };
  79
  80 static const value_string ltype_vals[] = {
  81         { LINUX_SLL_P_802_3,    "Raw 802.3" },
  82         { LINUX_SLL_P_ETHERNET, "Ethernet" },
  83         { LINUX_SLL_P_802_2,    "802.2 LLC" },
  84         { LINUX_SLL_P_PPPHDLC,  "PPP (HDLC)" },
  85         { LINUX_SLL_P_CAN,      "CAN" },
  86         { 0,                    NULL }
  87 };
  88
  89 static dissector_table_t sll_linux_dissector_table;
  90 static dissector_table_t gre_dissector_table;
  91 static dissector_handle_t data_handle;
  92
  93 void
  94 capture_sll(const guchar *pd, int len, packet_counts *ld)
  95 {
  96         guint16 protocol;
  97
  98         if (!BYTES_ARE_IN_FRAME(0, len, SLL_HEADER_SIZE)) {
  99                 ld->other++;
 100                 return;
 101         }
 102         protocol = pntohs(&pd[14]);
 103         if (protocol <= 1536) { /* yes, 1536 - that's how Linux does it */
 104                 /*
 105                  * "proto" is *not* a length field, it's a Linux internal
 106                  * protocol type.
 107                  */
 108                 switch (protocol) {
 109
 110                 case LINUX_SLL_P_802_2:
 111                         /*
 112                          * 802.2 LLC.
 113                          */
 114                         capture_llc(pd, len, SLL_HEADER_SIZE, ld);
 115                         break;
 116
 117                 case LINUX_SLL_P_ETHERNET:
 118                         /*
 119                          * Ethernet.
 120                          */
 121                         capture_eth(pd, SLL_HEADER_SIZE, len, ld);
 122                         break;
 123
 124                 case LINUX_SLL_P_802_3:
 125                         /*
 126                          * Novell IPX inside 802.3 with no 802.2 LLC
 127                          * header.
 128                          */
 129                         capture_ipx(ld);
 130                         break;
 131
 132                 case LINUX_SLL_P_PPPHDLC:
 133                         /*
 134                          * PPP HDLC.
 135                          */
 136                         capture_ppp_hdlc(pd, len, SLL_HEADER_SIZE, ld);
 137                         break;
 138
 139                 default:
 140                         ld->other++;
 141                         break;
 142                 }
 143         } else
 144                 capture_ethertype(protocol, pd, SLL_HEADER_SIZE, len, ld);
 145 }
 146
 147 static void
 148 dissect_sll(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 149 {
 150         guint16 pkttype;
 151         guint16 protocol;
 152         guint16 hatype, halen;
 153         const guint8 *src;
 154         proto_item *ti;
 155         tvbuff_t *next_tvb;
 156         proto_tree *fh_tree = NULL;
 157
 158         col_set_str(pinfo->cinfo, COL_PROTOCOL, "SLL");
 159         col_clear(pinfo->cinfo, COL_INFO);
 160
 161         pkttype = tvb_get_ntohs(tvb, 0);
 162
 163         /*
 164          * Set "pinfo->p2p_dir" if the packet wasn't received
 165          * promiscuously.
 166          */
 167         switch (pkttype) {
 168
 169         case LINUX_SLL_HOST:
 170         case LINUX_SLL_BROADCAST:
 171         case LINUX_SLL_MULTICAST:
 172                 pinfo->p2p_dir = P2P_DIR_RECV;
 173                 break;
 174
 175         case LINUX_SLL_OUTGOING:
 176                 pinfo->p2p_dir = P2P_DIR_SENT;
 177                 break;
 178         }
 179
 180         if (check_col(pinfo->cinfo, COL_INFO))
 181                 col_add_str(pinfo->cinfo, COL_INFO,
 182                     val_to_str(pkttype, packet_type_vals, "Unknown (%u)"));
 183
 184         if (tree) {
 185                 ti = proto_tree_add_protocol_format(tree, proto_sll, tvb, 0,
 186                     SLL_HEADER_SIZE, "Linux cooked capture");
 187                 fh_tree = proto_item_add_subtree(ti, ett_sll);
 188                 proto_tree_add_item(fh_tree, hf_sll_pkttype, tvb, 0, 2, FALSE);
 189         }
 190
 191         /*
 192          * XXX - check the link-layer address type value?
 193          * For now, we just assume 6 means Ethernet.
 194          */
 195         hatype = tvb_get_ntohs(tvb, 2);
 196         halen = tvb_get_ntohs(tvb, 4);
 197         if (tree) {
 198                 proto_tree_add_uint(fh_tree, hf_sll_hatype, tvb, 2, 2, hatype);
 199                 proto_tree_add_uint(fh_tree, hf_sll_halen, tvb, 4, 2, halen);
 200         }
 201         switch (halen) {
 202         case 4:
 203                 src = tvb_get_ptr(tvb, 6, 4);
 204                 SET_ADDRESS(&pinfo->dl_src, AT_IPv4, 4, src);
 205                 SET_ADDRESS(&pinfo->src, AT_IPv4, 4, src);
 206                 if (tree) {
 207                         proto_tree_add_ipv4(fh_tree, hf_sll_src_ipv4, tvb,
 208                             6, 4, FALSE);
 209                 }
 210                 break;
 211         case 6:
 212                 src = tvb_get_ptr(tvb, 6, 6);
 213                 SET_ADDRESS(&pinfo->dl_src, AT_ETHER, 6, src);
 214                 SET_ADDRESS(&pinfo->src, AT_ETHER, 6, src);
 215                 if (tree) {
 216                         proto_tree_add_ether(fh_tree, hf_sll_src_eth, tvb,
 217                             6, 6, src);
 218                 }
 219                 break;
 220         case 0:
 221                 break;
 222         default:
 223                 if (tree) {
 224                         proto_tree_add_item(fh_tree, hf_sll_src_other, tvb,
 225                             6, halen > 8 ? 8 : halen, FALSE);
 226                 }
 227                 break;
 228         }
 229
 230         protocol = tvb_get_ntohs(tvb, 14);
 231         next_tvb = tvb_new_subset_remaining(tvb, SLL_HEADER_SIZE);
 232         if (protocol <= 1536) { /* yes, 1536 - that's how Linux does it */
 233                 /*
 234                  * "proto" is *not* a length field, it's a Linux internal
 235                  * protocol type.
 236                  * We therefore cannot say how much of the packet will
 237                  * be trailer data.
 238                  * XXX - do the same thing we do for packets with Ethertypes?
 239                  */
 240                 proto_tree_add_uint(fh_tree, hf_sll_ltype, tvb, 14, 2,
 241                     protocol);
 242
 243                 if(!dissector_try_port(sll_linux_dissector_table, protocol,
 244                         next_tvb, pinfo, tree)) {
 245                         call_dissector(data_handle, next_tvb, pinfo, tree);
 246                 }
 247         } else {
 248                 switch (hatype) {
 249                 case ARPHRD_IPGRE:
 250                         proto_tree_add_uint(fh_tree, hf_sll_gretype, tvb, 14, 2,
 251                             protocol);
 252                         dissector_try_port(gre_dissector_table,
 253                                            protocol, next_tvb, pinfo, tree);
 254                         break;
 255                 default:
 256                         ethertype(protocol, tvb, SLL_HEADER_SIZE, pinfo, tree,
 257                                   fh_tree, hf_sll_etype, hf_sll_trailer, 0);
 258                         break;
 259                 }
 260         }
 261 }
 262
 263 void
 264 proto_register_sll(void)
 265 {
 266         static hf_register_info hf[] = {
 267                 { &hf_sll_pkttype,
 268                 { "Packet type",        "sll.pkttype", FT_UINT16, BASE_DEC,
 269                   VALS(packet_type_vals), 0x0, NULL, HFILL }},
 270
 271                 /* ARP hardware type?  With Linux extensions? */
 272                 { &hf_sll_hatype,
 273                 { "Link-layer address type",    "sll.hatype", FT_UINT16, BASE_DEC,
 274                   NULL, 0x0, NULL, HFILL }},
 275
 276                 { &hf_sll_halen,
 277                 { "Link-layer address length",  "sll.halen", FT_UINT16, BASE_DEC,
 278                   NULL, 0x0, NULL, HFILL }},
 279
 280                 /* Source address if it's an Ethernet-type address */
 281                 { &hf_sll_src_eth,
 282                 { "Source",     "sll.src.eth", FT_ETHER, BASE_NONE, NULL, 0x0,
 283                         "Source link-layer address", HFILL }},
 284
 285                 /* Source address if it's an IPv4 address */
 286                 { &hf_sll_src_ipv4,
 287                 { "Source",     "sll.src.ipv4", FT_IPv4, BASE_NONE, NULL, 0x0,
 288                         "Source link-layer address", HFILL }},
 289
 290                 /* Source address if it's not an Ethernet-type address */
 291                 { &hf_sll_src_other,
 292                 { "Source",     "sll.src.other", FT_BYTES, BASE_NONE, NULL, 0x0,
 293                         "Source link-layer address", HFILL }},
 294
 295                 /* if the protocol field is an internal Linux protocol type */
 296                 { &hf_sll_ltype,
 297                 { "Protocol",   "sll.ltype", FT_UINT16, BASE_HEX,
 298                    VALS(ltype_vals), 0x0, "Linux protocol type", HFILL }},
 299
 300                 /* if the protocol field is a GRE protocol type */
 301                 { &hf_sll_gretype,
 302                 { "Protocol",   "sll.gretype", FT_UINT16, BASE_HEX,
 303                    VALS(gre_typevals), 0x0, "GRE protocol type", HFILL }},
 304
 305                 /* registered here but handled in ethertype.c */
 306                 { &hf_sll_etype,
 307                 { "Protocol",   "sll.etype", FT_UINT16, BASE_HEX,
 308                    VALS(etype_vals), 0x0, "Ethernet protocol type", HFILL }},
 309
 310                 { &hf_sll_trailer,
 311                 { "Trailer", "sll.trailer", FT_BYTES, BASE_NONE, NULL, 0x0,
 312                         NULL, HFILL }}
 313         };
 314         static gint *ett[] = {
 315                 &ett_sll
 316         };
 317
 318         proto_sll = proto_register_protocol("Linux cooked-mode capture",
 319             "SLL", "sll" );
 320         proto_register_field_array(proto_sll, hf, array_length(hf));
 321         proto_register_subtree_array(ett, array_length(ett));
 322
 323         sll_linux_dissector_table = register_dissector_table (
 324                 "sll.ltype",
 325                 "Linux protocol type",
 326                 FT_UINT16,
 327                 BASE_HEX
 328         );
 329 }
 330
 331 void
 332 proto_reg_handoff_sll(void)
 333 {
 334         dissector_handle_t sll_handle;
 335
 336         /*
 337          * Get handles for the IPX and LLC dissectors.
 338          */
 339         gre_dissector_table = find_dissector_table("gre.proto");
 340         data_handle = find_dissector("data");
 341
 342         sll_handle = create_dissector_handle(dissect_sll, proto_sll);
 343         dissector_add("wtap_encap", WTAP_ENCAP_SLL, sll_handle);
 344 }