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