epan/dissectors/packet-dsi.c

   1 /* packet-dsi.c
   2  * Routines for dsi packet dissection
   3  * Copyright 2001, Randy McEoin <rmceoin@pe.com>
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * Copied from packet-pop.c
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #include "config.h"
  27
  28 #include <epan/packet.h>
  29 #include <epan/prefs.h>
  30
  31 #include "packet-tcp.h"
  32 #include "packet-afp.h"
  33
  34 /* The information in this module (DSI) comes from:
  35
  36   AFP 2.1 & 2.2 documentation, in PDF form, at
  37
  38 http://developer.apple.com/DOCUMENTATION/macos8/pdf/ASAppleTalkFiling2.1_2.2.pdf
  39
  40   The netatalk source code by Wesley Craig & Adrian Sun
  41
  42   The Data Stream Interface description from
  43   http://developer.apple.com/documentation/Networking/Conceptual/AFPClient/AFPClient-6.html
  44
  45 (no longer available, apparently)
  46
  47   Also, AFP 3.3 documents parts of DSI at:
  48   http://developer.apple.com/mac/library/documentation/Networking/Conceptual/AFP/Introduction/Introduction.html
  49
  50  * What a Data Stream Interface packet looks like:
  51  * 0                               32
  52  * |-------------------------------|
  53  * |flags  |command| requestID     |
  54  * |-------------------------------|
  55  * |error code/enclosed data offset|
  56  * |-------------------------------|
  57  * |total data length              |
  58  * |-------------------------------|
  59  * |reserved field                 |
  60  * |-------------------------------|
  61  */
  62
  63 void proto_register_dsi(void);
  64 void proto_reg_handoff_dsi(void);
  65
  66 static int proto_dsi = -1;
  67 static int hf_dsi_flags = -1;
  68 static int hf_dsi_command = -1;
  69 static int hf_dsi_requestid = -1;
  70 static int hf_dsi_offset = -1;
  71 static int hf_dsi_error = -1;
  72 static int hf_dsi_length = -1;
  73 static int hf_dsi_reserved = -1;
  74
  75 static gint ett_dsi = -1;
  76
  77 static int hf_dsi_open_type     = -1;
  78 static int hf_dsi_open_len      = -1;
  79 static int hf_dsi_open_quantum  = -1;
  80 static int hf_dsi_replay_cache_size = -1;
  81 static int hf_dsi_open_option   = -1;
  82
  83 static int hf_dsi_attn_flag             = -1;
  84 static int hf_dsi_attn_flag_shutdown    = -1;
  85 static int hf_dsi_attn_flag_crash       = -1;
  86 static int hf_dsi_attn_flag_msg         = -1;
  87 static int hf_dsi_attn_flag_reconnect   = -1;
  88 static int hf_dsi_attn_flag_time        = -1;
  89 static int hf_dsi_attn_flag_bitmap      = -1;
  90
  91 static gint ett_dsi_open        = -1;
  92 static gint ett_dsi_attn        = -1;
  93 static gint ett_dsi_attn_flag   = -1;
  94
  95 static const value_string dsi_attn_flag_vals[] = {
  96         {0x0, "Reserved" },                                           /* 0000 */
  97         {0x1, "Reserved" },                                           /* 0001 */
  98         {0x2, "Server message" },                                     /* 0010 */
  99         {0x3, "Server notification, cf. extended bitmap" },           /* 0011 */
 100         {0x4, "Server is shutting down, internal error" },            /* 0100 */
 101         {0x8, "Server is shutting down" },                            /* 1000 */
 102         {0x9, "Server disconnects user" },                            /* 1001 */
 103         {0x10,"Server is shutting down, message" },                   /* 1010 */
 104         {0x11,"Server is shutting down, message,no reconnect"},       /* 1011 */
 105         {0,                   NULL } };
 106 static value_string_ext dsi_attn_flag_vals_ext = VALUE_STRING_EXT_INIT(dsi_attn_flag_vals);
 107
 108 static const value_string dsi_open_type_vals[] = {
 109         {0,   "Server quantum" },
 110         {1,   "Attention quantum" },
 111         {2,   "Replay cache size" },
 112         {0,                   NULL } };
 113
 114 /* desegmentation of DSI */
 115 static gboolean dsi_desegment = TRUE;
 116
 117 static dissector_handle_t afp_handle;
 118 static dissector_handle_t afp_server_status_handle;
 119
 120 #define TCP_PORT_DSI      548 /* Not IANA registered */
 121
 122 #define DSI_BLOCKSIZ       16
 123
 124 /* DSI flags */
 125 #define DSIFL_REQUEST    0x00
 126 #define DSIFL_REPLY      0x01
 127 #define DSIFL_MAX        0x01
 128
 129 /* DSI Commands */
 130 #define DSIFUNC_CLOSE   1       /* DSICloseSession */
 131 #define DSIFUNC_CMD     2       /* DSICommand */
 132 #define DSIFUNC_STAT    3       /* DSIGetStatus */
 133 #define DSIFUNC_OPEN    4       /* DSIOpenSession */
 134 #define DSIFUNC_TICKLE  5       /* DSITickle */
 135 #define DSIFUNC_WRITE   6       /* DSIWrite */
 136 #define DSIFUNC_ATTN    8       /* DSIAttention */
 137 #define DSIFUNC_MAX     8       /* largest command */
 138
 139 static const value_string flag_vals[] = {
 140         {DSIFL_REQUEST,       "Request" },
 141         {DSIFL_REPLY,         "Reply" },
 142         {0,                   NULL } };
 143
 144 static const value_string func_vals[] = {
 145         {DSIFUNC_CLOSE,       "CloseSession" },
 146         {DSIFUNC_CMD,         "Command" },
 147         {DSIFUNC_STAT,        "GetStatus" },
 148         {DSIFUNC_OPEN,        "OpenSession" },
 149         {DSIFUNC_TICKLE,      "Tickle" },
 150         {DSIFUNC_WRITE,       "Write" },
 151         { 7,                  "Unknown" },
 152         {DSIFUNC_ATTN,        "Attention" },
 153         {0,                   NULL } };
 154 static value_string_ext func_vals_ext = VALUE_STRING_EXT_INIT(func_vals);
 155
 156 static gint
 157 dissect_dsi_open_session(tvbuff_t *tvb, proto_tree *dsi_tree, gint offset, gint dsi_length)
 158 {
 159         proto_tree      *tree;
 160         guint8          type;
 161         guint8          len;
 162
 163         tree = proto_tree_add_subtree(dsi_tree, tvb, offset, -1, ett_dsi_open, NULL, "Open Session");
 164
 165         while( dsi_length >2 ) {
 166
 167                 type = tvb_get_guint8(tvb, offset);
 168                 proto_tree_add_item(tree, hf_dsi_open_type, tvb, offset, 1, ENC_BIG_ENDIAN);
 169                 offset++;
 170                 len = tvb_get_guint8(tvb, offset);
 171                 proto_tree_add_item(tree, hf_dsi_open_len, tvb, offset, 1, ENC_BIG_ENDIAN);
 172                 offset++;
 173                 switch (type) {
 174                         case 0:
 175                                 proto_tree_add_item(tree, hf_dsi_open_quantum, tvb, offset, 4, ENC_BIG_ENDIAN);
 176                                 break;
 177                         case 1:
 178                                 proto_tree_add_item(tree, hf_dsi_open_quantum, tvb, offset, 4, ENC_BIG_ENDIAN);
 179                                 break;
 180                         case 2:
 181                                 proto_tree_add_item(tree, hf_dsi_replay_cache_size, tvb, offset, 4, ENC_BIG_ENDIAN);
 182                                 break;
 183                         default:
 184                                 proto_tree_add_item(tree, hf_dsi_open_option, tvb, offset, len, ENC_NA);
 185                 }
 186
 187                 dsi_length -= len + 2;
 188
 189                 offset += len;
 190         }
 191         return offset;
 192 }
 193
 194 static gint
 195 dissect_dsi_attention(tvbuff_t *tvb, proto_tree *dsi_tree, gint offset)
 196 {
 197         proto_tree      *tree;
 198         proto_item      *ti;
 199         guint16         flag;
 200
 201         if (!tvb_reported_length_remaining(tvb,offset))
 202                 return offset;
 203
 204         flag = tvb_get_ntohs(tvb, offset);
 205         tree = proto_tree_add_subtree(dsi_tree, tvb, offset, -1, ett_dsi_attn, NULL, "Attention");
 206
 207         ti = proto_tree_add_item(tree, hf_dsi_attn_flag, tvb, offset, 2, ENC_BIG_ENDIAN);
 208         tree = proto_item_add_subtree(ti, ett_dsi_attn_flag);
 209         proto_tree_add_item(tree, hf_dsi_attn_flag_shutdown, tvb, offset, 2, ENC_BIG_ENDIAN);
 210         proto_tree_add_item(tree, hf_dsi_attn_flag_crash, tvb, offset, 2, ENC_BIG_ENDIAN);
 211         proto_tree_add_item(tree, hf_dsi_attn_flag_msg, tvb, offset, 2, ENC_BIG_ENDIAN);
 212         proto_tree_add_item(tree, hf_dsi_attn_flag_reconnect, tvb, offset, 2, ENC_BIG_ENDIAN);
 213         /* FIXME */
 214         if ((flag & 0xf000) != 0x3000)
 215                 proto_tree_add_item(tree, hf_dsi_attn_flag_time, tvb, offset, 2, ENC_BIG_ENDIAN);
 216         else
 217                 proto_tree_add_item(tree, hf_dsi_attn_flag_bitmap, tvb, offset, 2, ENC_BIG_ENDIAN);
 218         offset += 2;
 219         return offset;
 220 }
 221
 222 static int
 223 dissect_dsi_packet(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 224 {
 225         proto_tree      *dsi_tree;
 226         proto_item      *dsi_ti;
 227         guint8          dsi_flags,dsi_command;
 228         guint16         dsi_requestid;
 229         gint32          dsi_code;
 230         guint32         dsi_length;
 231         guint32         dsi_reserved;
 232         struct          aspinfo aspinfo;
 233
 234
 235         col_set_str(pinfo->cinfo, COL_PROTOCOL, "DSI");
 236         col_clear(pinfo->cinfo, COL_INFO);
 237
 238         dsi_flags = tvb_get_guint8(tvb, 0);
 239         dsi_command = tvb_get_guint8(tvb, 1);
 240         dsi_requestid = tvb_get_ntohs(tvb, 2);
 241         dsi_code = tvb_get_ntohl(tvb, 4);
 242         dsi_length = tvb_get_ntohl(tvb, 8);
 243         dsi_reserved = tvb_get_ntohl(tvb, 12);
 244
 245         col_add_fstr(pinfo->cinfo, COL_INFO, "%s %s (%u)",
 246                         val_to_str(dsi_flags, flag_vals,
 247                                    "Unknown flag (0x%02x)"),
 248                         val_to_str_ext(dsi_command, &func_vals_ext,
 249                                    "Unknown function (0x%02x)"),
 250                         dsi_requestid);
 251
 252         dsi_ti = proto_tree_add_item(tree, proto_dsi, tvb, 0, -1, ENC_NA);
 253         dsi_tree = proto_item_add_subtree(dsi_ti, ett_dsi);
 254
 255         if (tree) {
 256                 proto_tree_add_uint(dsi_tree, hf_dsi_flags, tvb,
 257                         0, 1, dsi_flags);
 258                 proto_tree_add_uint(dsi_tree, hf_dsi_command, tvb,
 259                         1, 1, dsi_command);
 260                 proto_tree_add_uint(dsi_tree, hf_dsi_requestid, tvb,
 261                         2, 2, dsi_requestid);
 262                 switch (dsi_flags) {
 263
 264                 case DSIFL_REQUEST:
 265                         proto_tree_add_int(dsi_tree, hf_dsi_offset, tvb,
 266                                 4, 4, dsi_code);
 267                         break;
 268
 269                 case DSIFL_REPLY:
 270                         proto_tree_add_int(dsi_tree, hf_dsi_error, tvb,
 271                                 4, 4, dsi_code);
 272                         break;
 273                 }
 274                 proto_tree_add_uint_format_value(dsi_tree, hf_dsi_length, tvb,
 275                         8, 4, dsi_length,
 276                         "%u bytes", dsi_length);
 277                 proto_tree_add_uint(dsi_tree, hf_dsi_reserved, tvb,
 278                         12, 4, dsi_reserved);
 279         }
 280
 281         switch (dsi_command) {
 282         case DSIFUNC_OPEN:
 283                 if (tree) {
 284                         dissect_dsi_open_session(tvb, dsi_tree, DSI_BLOCKSIZ, dsi_length);
 285                 }
 286                 break;
 287         case DSIFUNC_ATTN:
 288                 if (tree) {
 289                         dissect_dsi_attention(tvb, dsi_tree, DSI_BLOCKSIZ);
 290                 }
 291                 break;
 292         case DSIFUNC_STAT:
 293                 if (tree && (dsi_flags == DSIFL_REPLY)) {
 294                         tvbuff_t   *new_tvb;
 295
 296                         /* XXX - assumes only AFP runs atop DSI */
 297                         new_tvb = tvb_new_subset_remaining(tvb, DSI_BLOCKSIZ);
 298                         call_dissector(afp_server_status_handle, new_tvb, pinfo, dsi_tree);
 299                 }
 300                 break;
 301         case DSIFUNC_CMD:
 302         case DSIFUNC_WRITE:
 303                 {
 304                         tvbuff_t   *new_tvb;
 305
 306                         aspinfo.reply = (dsi_flags == DSIFL_REPLY);
 307                         aspinfo.command = dsi_command;
 308                         aspinfo.seq = dsi_requestid;
 309                         aspinfo.code = dsi_code;
 310                         proto_item_set_len(dsi_ti, DSI_BLOCKSIZ);
 311
 312                         new_tvb = tvb_new_subset_remaining(tvb, DSI_BLOCKSIZ);
 313                         call_dissector_with_data(afp_handle, new_tvb, pinfo, tree, &aspinfo);
 314                 }
 315                 break;
 316         default:
 317                 call_data_dissector(tvb_new_subset_remaining(tvb, DSI_BLOCKSIZ),
 318                                                 pinfo, dsi_tree);
 319                 break;
 320         }
 321
 322         return tvb_captured_length(tvb);
 323 }
 324
 325 static guint
 326 get_dsi_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_)
 327 {
 328         guint32 plen;
 329         guint8  dsi_flags,dsi_command;
 330
 331         dsi_flags = tvb_get_guint8(tvb, offset);
 332         dsi_command = tvb_get_guint8(tvb, offset+ 1);
 333         if ( dsi_flags > DSIFL_MAX || !dsi_command || dsi_command > DSIFUNC_MAX)
 334         {
 335             /* it's not a known dsi pdu start sequence */
 336             return tvb_captured_length_remaining(tvb, offset);
 337         }
 338
 339         /*
 340          * Get the length of the DSI packet.
 341          */
 342         plen = tvb_get_ntohl(tvb, offset+8);
 343
 344         /*
 345          * That length doesn't include the length of the header itself;
 346          * add that in.
 347          */
 348         return plen + 16;
 349 }
 350
 351 static int
 352 dissect_dsi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
 353 {
 354         tcp_dissect_pdus(tvb, pinfo, tree, dsi_desegment, 12,
 355             get_dsi_pdu_len, dissect_dsi_packet, data);
 356
 357         return tvb_captured_length(tvb);
 358 }
 359
 360 void
 361 proto_register_dsi(void)
 362 {
 363
 364         static hf_register_info hf[] = {
 365                 { &hf_dsi_flags,
 366                   { "Flags",            "dsi.flags",
 367                     FT_UINT8, BASE_HEX, VALS(flag_vals), 0x0,
 368                     "Indicates request or reply.", HFILL }},
 369
 370                 { &hf_dsi_command,
 371                   { "Command",          "dsi.command",
 372                     FT_UINT8, BASE_DEC|BASE_EXT_STRING, &func_vals_ext, 0x0,
 373                     "Represents a DSI command.", HFILL }},
 374
 375                 { &hf_dsi_requestid,
 376                   { "Request ID",       "dsi.requestid",
 377                     FT_UINT16, BASE_DEC, NULL, 0x0,
 378                     "Keeps track of which request this is.  Replies must match a Request.  IDs must be generated in sequential order.", HFILL }},
 379
 380                 { &hf_dsi_offset,
 381                   { "Data offset",      "dsi.data_offset",
 382                     FT_INT32, BASE_DEC, NULL, 0x0,
 383                     NULL, HFILL }},
 384
 385                 { &hf_dsi_error,
 386                   { "Error code",       "dsi.error_code",
 387                     FT_INT32, BASE_DEC|BASE_EXT_STRING, &asp_error_vals_ext, 0x0,
 388                     NULL, HFILL }},
 389
 390                 { &hf_dsi_length,
 391                   { "Length",           "dsi.length",
 392                     FT_UINT32, BASE_DEC, NULL, 0x0,
 393                     "Total length of the data that follows the DSI header.", HFILL }},
 394
 395                 { &hf_dsi_reserved,
 396                   { "Reserved",         "dsi.reserved",
 397                     FT_UINT32, BASE_HEX, NULL, 0x0,
 398                     "Reserved for future use.  Should be set to zero.", HFILL }},
 399
 400                 { &hf_dsi_open_type,
 401                   { "Option",          "dsi.open_type",
 402                     FT_UINT8, BASE_DEC, VALS(dsi_open_type_vals), 0x0,
 403                     "Open session option type.", HFILL }},
 404
 405                 { &hf_dsi_open_len,
 406                   { "Length",          "dsi.open_len",
 407                     FT_UINT8, BASE_DEC, NULL, 0x0,
 408                     "Open session option len", HFILL }},
 409
 410                 { &hf_dsi_open_quantum,
 411                   { "Quantum",       "dsi.open_quantum",
 412                     FT_UINT32, BASE_DEC, NULL, 0x0,
 413                     "Server/Attention quantum", HFILL }},
 414
 415                 { &hf_dsi_replay_cache_size,
 416                   { "Replay",       "dsi.replay_cache",
 417                     FT_UINT32, BASE_DEC, NULL, 0x0,
 418                     "Replay cache size", HFILL }},
 419
 420                 { &hf_dsi_open_option,
 421                   { "Option",          "dsi.open_option",
 422                     FT_BYTES, BASE_NONE, NULL, 0x0,
 423                     "Open session options (undecoded)", HFILL }},
 424
 425                 { &hf_dsi_attn_flag,
 426                   { "Flags",          "dsi.attn_flag",
 427                     FT_UINT16, BASE_HEX|BASE_EXT_STRING, &dsi_attn_flag_vals_ext, 0xf000,
 428                     "Server attention flag", HFILL }},
 429                 { &hf_dsi_attn_flag_shutdown,
 430                   { "Shutdown",      "dsi.attn_flag.shutdown",
 431                     FT_BOOLEAN, 16, NULL, 1<<15,
 432                     "Attention flag, server is shutting down", HFILL }},
 433                 { &hf_dsi_attn_flag_crash,
 434                   { "Crash",      "dsi.attn_flag.crash",
 435                     FT_BOOLEAN, 16, NULL, 1<<14,
 436                     "Attention flag, server crash bit", HFILL }},
 437                 { &hf_dsi_attn_flag_msg,
 438                   { "Message",      "dsi.attn_flag.msg",
 439                     FT_BOOLEAN, 16, NULL, 1<<13,
 440                     "Attention flag, server message bit", HFILL }},
 441                 { &hf_dsi_attn_flag_reconnect,
 442                   { "Don't reconnect",      "dsi.attn_flag.reconnect",
 443                     FT_BOOLEAN, 16, NULL, 1<<12,
 444                     "Attention flag, don't reconnect bit", HFILL }},
 445                 { &hf_dsi_attn_flag_time,
 446                   { "Minutes",          "dsi.attn_flag.time",
 447                     FT_UINT16, BASE_DEC, NULL, 0xfff,
 448                     "Number of minutes", HFILL }},
 449                 { &hf_dsi_attn_flag_bitmap,
 450                   { "Bitmap",          "dsi.attn_flag.bitmap",
 451                     FT_UINT16, BASE_HEX, NULL, 0xfff,
 452                     "Attention extended bitmap", HFILL }},
 453         };
 454
 455         static gint *ett[] = {
 456                 &ett_dsi,
 457                 &ett_dsi_open,
 458                 &ett_dsi_attn,
 459                 &ett_dsi_attn_flag
 460         };
 461         module_t *dsi_module;
 462
 463         proto_dsi = proto_register_protocol("Data Stream Interface", "DSI", "dsi");
 464         proto_register_field_array(proto_dsi, hf, array_length(hf));
 465         proto_register_subtree_array(ett, array_length(ett));
 466
 467         dsi_module = prefs_register_protocol(proto_dsi, NULL);
 468         prefs_register_bool_preference(dsi_module, "desegment",
 469                                        "Reassemble DSI messages spanning multiple TCP segments",
 470                                        "Whether the DSI dissector should reassemble messages spanning multiple TCP segments."
 471                                        " To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
 472                                        &dsi_desegment);
 473 }
 474
 475 void
 476 proto_reg_handoff_dsi(void)
 477 {
 478         dissector_handle_t dsi_handle;
 479
 480         dsi_handle = create_dissector_handle(dissect_dsi, proto_dsi);
 481         dissector_add_uint_with_preference("tcp.port", TCP_PORT_DSI, dsi_handle);
 482
 483         afp_handle = find_dissector_add_dependency("afp", proto_dsi);
 484         afp_server_status_handle = find_dissector_add_dependency("afp_server_status", proto_dsi);
 485 }
 486
 487 /*
 488  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 489  *
 490  * Local variables:
 491  * c-basic-offset: 8
 492  * tab-width: 8
 493  * indent-tabs-mode: t
 494  * End:
 495  *
 496  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 497  * :indentSize=8:tabSize=8:noTabs=false:
 498  */