packet-ipp.c

   1 /* packet-ipp.c
   2  * Routines for IPP packet disassembly
   3  *
   4  * Guy Harris <guy@alum.mit.edu>
   5  *
   6  * $Id: packet-ipp.c,v 1.28 2002/01/21 07:36:35 guy Exp $
   7  *
   8  * Ethereal - Network traffic analyzer
   9  * By Gerald Combs <gerald@ethereal.com>
  10  * Copyright 1998 Gerald Combs
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  25  */
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #ifdef HAVE_SYS_TYPES_H
  32 #include <sys/types.h>
  33 #endif
  34
  35 #include <string.h>
  36 #include <ctype.h>
  37
  38 #include <glib.h>
  39 #include <epan/packet.h>
  40 #include <epan/strutil.h>
  41 #include "packet-http.h"
  42
  43 static int proto_ipp = -1;
  44
  45 static gint ett_ipp = -1;
  46 static gint ett_ipp_as = -1;
  47 static gint ett_ipp_attr = -1;
  48
  49 static dissector_handle_t data_handle;
  50
  51 #define PRINT_JOB               0x0002
  52 #define PRINT_URI               0x0003
  53 #define VALIDATE_JOB            0x0004
  54 #define CREATE_JOB              0x0005
  55 #define SEND_DOCUMENT           0x0006
  56 #define SEND_URI                0x0007
  57 #define CANCEL_JOB              0x0008
  58 #define GET_JOB_ATTRIBUTES      0x0009
  59 #define GET_JOBS                0x000A
  60 #define GET_PRINTER_ATTRIBUTES  0x000B
  61
  62 static const value_string operation_vals[] = {
  63     { PRINT_JOB,              "Print-Job" },
  64     { PRINT_URI,              "Print-URI" },
  65     { VALIDATE_JOB,           "Validate-Job" },
  66     { CREATE_JOB,             "Create-Job" },
  67     { SEND_DOCUMENT,          "Send-Document" },
  68     { SEND_URI,               "Send-URI" },
  69     { CANCEL_JOB,             "Cancel-Job" },
  70     { GET_JOB_ATTRIBUTES,     "Get-Job-Attributes" },
  71     { GET_JOBS,               "Get-Jobs" },
  72     { GET_PRINTER_ATTRIBUTES, "Get-Printer-Attributes" },
  73     { 0,                      NULL }
  74 };
  75
  76 #define STATUS_SUCCESSFUL       0x0000
  77 #define STATUS_INFORMATIONAL    0x0100
  78 #define STATUS_REDIRECTION      0x0200
  79 #define STATUS_CLIENT_ERROR     0x0400
  80 #define STATUS_SERVER_ERROR     0x0500
  81
  82 #define STATUS_TYPE_MASK        0xFF00
  83
  84 #define SUCCESSFUL_OK                           0x0000
  85 #define SUCCESSFUL_OK_IGN_OR_SUB_ATTR           0x0001
  86 #define SUCCESSFUL_OK_CONFLICTING_ATTR          0x0002
  87
  88 #define CLIENT_ERROR_BAD_REQUEST                0x0400
  89 #define CLIENT_ERROR_FORBIDDEN                  0x0401
  90 #define CLIENT_ERROR_NOT_AUTHENTICATED          0x0402
  91 #define CLIENT_ERROR_NOT_AUTHORIZED             0x0403
  92 #define CLIENT_ERROR_NOT_POSSIBLE               0x0404
  93 #define CLIENT_ERROR_TIMEOUT                    0x0405
  94 #define CLIENT_ERROR_NOT_FOUND                  0x0406
  95 #define CLIENT_ERROR_GONE                       0x0407
  96 #define CLIENT_ERROR_REQ_ENTITY_TOO_LRG         0x0408
  97 #define CLIENT_ERROR_REQ_VALUE_TOO_LONG         0x0409
  98 #define CLIENT_ERROR_DOC_FMT_NOT_SUPP           0x040A
  99 #define CLIENT_ERROR_ATTR_OR_VAL_NOT_SUPP       0x040B
 100 #define CLIENT_ERROR_URI_SCHEME_NOT_SUPP        0x040C
 101 #define CLIENT_ERROR_CHARSET_NOT_SUPP           0x040D
 102 #define CLIENT_ERROR_CONFLICTING_ATTRS          0x040E
 103
 104 #define SERVER_ERROR_INTERNAL_ERROR             0x0500
 105 #define SERVER_ERROR_OPERATION_NOT_SUPP         0x0501
 106 #define SERVER_ERROR_SERVICE_UNAVAIL            0x0502
 107 #define SERVER_ERROR_VERSION_NOT_SUPP           0x0503
 108 #define SERVER_ERROR_DEVICE_ERROR               0x0504
 109 #define SERVER_ERROR_TEMPORARY_ERROR            0x0505
 110 #define SERVER_ERROR_NOT_ACCEPTING_JOBS         0x0506
 111 #define SERVER_ERROR_BUSY                       0x0507
 112 #define SERVER_ERROR_JOB_CANCELED               0x0508
 113
 114 static const value_string status_vals[] = {
 115     { SUCCESSFUL_OK,                     "Successful-OK" },
 116     { SUCCESSFUL_OK_IGN_OR_SUB_ATTR,     "Successful-OK-Ignored-Or-Substituted-Attributes" },
 117     { SUCCESSFUL_OK_CONFLICTING_ATTR,    "Successful-OK-Conflicting-Attributes" },
 118     { CLIENT_ERROR_BAD_REQUEST,          "Client-Error-Bad-Request" },
 119     { CLIENT_ERROR_FORBIDDEN,            "Client-Error-Forbidden" },
 120     { CLIENT_ERROR_NOT_AUTHENTICATED,    "Client-Error-Not-Authenticated" },
 121     { CLIENT_ERROR_NOT_AUTHORIZED,       "Client-Error-Not-Authorized" },
 122     { CLIENT_ERROR_NOT_POSSIBLE,         "Client-Error-Not-Possible" },
 123     { CLIENT_ERROR_TIMEOUT,              "Client-Error-Timeout" },
 124     { CLIENT_ERROR_NOT_FOUND,            "Client-Error-Not-Found" },
 125     { CLIENT_ERROR_GONE,                 "Client-Error-Gone" },
 126     { CLIENT_ERROR_REQ_ENTITY_TOO_LRG,   "Client-Error-Request-Entity-Too-Large" },
 127     { CLIENT_ERROR_REQ_VALUE_TOO_LONG,   "Client-Error-Request-Value-Too-Long" },
 128     { CLIENT_ERROR_DOC_FMT_NOT_SUPP,     "Client-Error-Document-Format-Not-Supported" },
 129     { CLIENT_ERROR_ATTR_OR_VAL_NOT_SUPP, "Client-Error-Attributes-Or-Values-Not-Supported" },
 130     { CLIENT_ERROR_URI_SCHEME_NOT_SUPP,  "Client-Error-URI-Scheme-Not-Supported" },
 131     { CLIENT_ERROR_CHARSET_NOT_SUPP,     "Client-Error-Charset-Not-Supported" },
 132     { CLIENT_ERROR_CONFLICTING_ATTRS,    "Client-Error-Conflicting-Attributes" },
 133     { SERVER_ERROR_INTERNAL_ERROR,       "Server-Error-Internal-Error" },
 134     { SERVER_ERROR_OPERATION_NOT_SUPP,   "Server-Error-Operation-Not-Supported" },
 135     { SERVER_ERROR_SERVICE_UNAVAIL,      "Server-Error-Service-Unavailable" },
 136     { SERVER_ERROR_VERSION_NOT_SUPP,     "Server-Error-Version-Not-Supported" },
 137     { SERVER_ERROR_DEVICE_ERROR,         "Server-Error-Device-Error" },
 138     { SERVER_ERROR_TEMPORARY_ERROR,      "Server-Error-Temporary-Error" },
 139     { SERVER_ERROR_NOT_ACCEPTING_JOBS,   "Server-Error-Not-Accepting-Jobs" },
 140     { SERVER_ERROR_BUSY,                 "Server-Error-Busy" },
 141     { SERVER_ERROR_JOB_CANCELED,         "Server-Error-Job-Canceled" },
 142     { 0,                                 NULL }
 143 };
 144
 145 static int parse_attributes(tvbuff_t *tvb, int offset, proto_tree *tree);
 146 static proto_tree *add_integer_tree(proto_tree *tree, tvbuff_t *tvb,
 147     int offset, int name_length, int value_length);
 148 static void add_integer_value(guint tag, gchar *tag_desc, proto_tree *tree,
 149     tvbuff_t *tvb, int offset, int name_length, int value_length);
 150 static proto_tree *add_octetstring_tree(proto_tree *tree, tvbuff_t *tvb,
 151     int offset, int name_length, int value_length);
 152 static void add_octetstring_value(guint tag, gchar *tag_desc, proto_tree *tree,
 153     tvbuff_t *tvb, int offset, int name_length, int value_length);
 154 static proto_tree *add_charstring_tree(proto_tree *tree, tvbuff_t *tvb,
 155     int offset, int name_length, int value_length);
 156 static void add_charstring_value(guint tag, gchar *tag_desc, proto_tree *tree,
 157     tvbuff_t *tvb, int offset, int name_length, int value_length);
 158 static int add_value_head(guint tag, gchar *tag_desc, proto_tree *tree,
 159     tvbuff_t *tvb, int offset, int name_length, int value_length);
 160
 161 static void
 162 dissect_ipp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 163 {
 164         proto_tree *ipp_tree;
 165         proto_item *ti;
 166         int offset = 0;
 167         gboolean is_request = (pinfo->destport == 631);
 168         guint16 status_code;
 169         gchar *status_fmt;
 170
 171         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 172                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "IPP");
 173         if (check_col(pinfo->cinfo, COL_INFO)) {
 174                 if (is_request)
 175                         col_set_str(pinfo->cinfo, COL_INFO, "IPP request");
 176                 else
 177                         col_set_str(pinfo->cinfo, COL_INFO, "IPP response");
 178         }
 179
 180         if (tree) {
 181                 ti = proto_tree_add_item(tree, proto_ipp, tvb, offset,
 182                     tvb_length_remaining(tvb, offset), FALSE);
 183                 ipp_tree = proto_item_add_subtree(ti, ett_ipp);
 184
 185                 proto_tree_add_text(ipp_tree, tvb, offset, 2, "Version: %u.%u",
 186                     tvb_get_guint8(tvb, offset),
 187                     tvb_get_guint8(tvb, offset + 1));
 188                 offset += 2;
 189
 190                 if (is_request) {
 191                         proto_tree_add_text(ipp_tree, tvb, offset, 2, "Operation-id: %s",
 192                             val_to_str(tvb_get_ntohs(tvb, offset), operation_vals,
 193                                 "Unknown (0x%04x)"));
 194                 } else {
 195                         status_code = tvb_get_ntohs(tvb, offset);
 196                         switch (status_code & STATUS_TYPE_MASK) {
 197
 198                         case STATUS_SUCCESSFUL:
 199                                 status_fmt = "Successful (0x%04x)";
 200                                 break;
 201
 202                         case STATUS_INFORMATIONAL:
 203                                 status_fmt = "Informational (0x%04x)";
 204                                 break;
 205
 206                         case STATUS_REDIRECTION:
 207                                 status_fmt = "Redirection (0x%04x)";
 208                                 break;
 209
 210                         case STATUS_CLIENT_ERROR:
 211                                 status_fmt = "Client error (0x%04x)";
 212                                 break;
 213
 214                         case STATUS_SERVER_ERROR:
 215                                 status_fmt = "Server error (0x%04x)";
 216                                 break;
 217
 218                         default:
 219                                 status_fmt = "Unknown (0x%04x)";
 220                                 break;
 221                         }
 222                         proto_tree_add_text(ipp_tree, tvb, offset, 2, "Status-code: %s",
 223                             val_to_str(status_code, status_vals, status_fmt));
 224                 }
 225                 offset += 2;
 226
 227                 proto_tree_add_text(ipp_tree, tvb, offset, 4, "Request ID: %u",
 228                     tvb_get_ntohl(tvb, offset));
 229                 offset += 4;
 230
 231                 offset = parse_attributes(tvb, offset, ipp_tree);
 232
 233                 if (tvb_offset_exists(tvb, offset))
 234                         call_dissector(data_handle,tvb_new_subset(tvb, offset,-1,tvb_reported_length_remaining(tvb,offset)), pinfo, ipp_tree);
 235         }
 236 }
 237
 238 #define TAG_TYPE(tag)           ((tag) & 0xF0)
 239 #define TAG_TYPE_DELIMITER      0x00
 240 #define TAG_TYPE_INTEGER        0x20
 241 #define TAG_TYPE_OCTETSTRING    0x30
 242 #define TAG_TYPE_CHARSTRING     0x40
 243
 244 #define TAG_END_OF_ATTRIBUTES   0x03
 245
 246 #define TAG_INTEGER             0x21
 247 #define TAG_BOOLEAN             0x22
 248 #define TAG_ENUM                0x23
 249
 250 #define TAG_OCTETSTRING         0x30
 251 #define TAG_DATETIME            0x31
 252 #define TAG_RESOLUTION          0x32
 253 #define TAG_RANGEOFINTEGER      0x33
 254 #define TAG_TEXTWITHLANGUAGE    0x35
 255 #define TAG_NAMEWITHLANGUAGE    0x36
 256
 257 #define TAG_TEXTWITHOUTLANGUAGE 0x41
 258 #define TAG_NAMEWITHOUTLANGUAGE 0x42
 259 #define TAG_KEYWORD             0x44
 260 #define TAG_URI                 0x45
 261 #define TAG_URISCHEME           0x46
 262 #define TAG_CHARSET             0x47
 263 #define TAG_NATURALLANGUAGE     0x48
 264 #define TAG_MIMEMEDIATYPE       0x49
 265
 266 static const value_string tag_vals[] = {
 267         /* Delimiter tags */
 268         { 0x01,                    "Operation attributes" },
 269         { 0x02,                    "Job attributes" },
 270         { TAG_END_OF_ATTRIBUTES,   "End of attributes" },
 271         { 0x04,                    "Printer attributes" },
 272         { 0x05,                    "Unsupported attributes" },
 273
 274         /* Value tags */
 275         { 0x10,                    "Unsupported" },
 276         { 0x12,                    "Unknown" },
 277         { 0x13,                    "No value" },
 278         { TAG_INTEGER,             "Integer" },
 279         { TAG_BOOLEAN,             "Boolean" },
 280         { TAG_ENUM,                "Enum" },
 281         { TAG_OCTETSTRING,         "Octet string" },
 282         { TAG_DATETIME,            "Date/Time" },
 283         { TAG_RESOLUTION,          "Resolution" },
 284         { TAG_RANGEOFINTEGER,      "Range of integer" },
 285         { TAG_TEXTWITHLANGUAGE,    "Text with language" },
 286         { TAG_NAMEWITHLANGUAGE,    "Name with language" },
 287         { TAG_TEXTWITHOUTLANGUAGE, "Text without language" },
 288         { TAG_NAMEWITHOUTLANGUAGE, "Name without language" },
 289         { TAG_KEYWORD,             "Keyword" },
 290         { TAG_URI,                 "URI" },
 291         { TAG_URISCHEME,           "URI scheme" },
 292         { TAG_CHARSET,             "Character set" },
 293         { TAG_NATURALLANGUAGE,     "Natural language" },
 294         { TAG_MIMEMEDIATYPE,       "MIME media type" },
 295         { 0,                       NULL }
 296 };
 297
 298 static int
 299 parse_attributes(tvbuff_t *tvb, int offset, proto_tree *tree)
 300 {
 301         guint8 tag;
 302         gchar *tag_desc;
 303         int name_length, value_length;
 304         proto_tree *as_tree = tree;
 305         proto_item *tas = NULL;
 306         int start_offset = offset;
 307         proto_tree *attr_tree = tree;
 308
 309         while (tvb_offset_exists(tvb, offset)) {
 310                 tag = tvb_get_guint8(tvb, offset);
 311                 tag_desc = val_to_str(tag, tag_vals, "Reserved (0x%02x)");
 312                 if (TAG_TYPE(tag) == TAG_TYPE_DELIMITER) {
 313                         /*
 314                          * If we had an attribute sequence we were
 315                          * working on, we're done with it; set its
 316                          * length to the length of all the stuff
 317                          * we've done so far.
 318                          */
 319                         if (tas != NULL)
 320                                 proto_item_set_len(tas, offset - start_offset);
 321
 322                         /*
 323                          * This tag starts a new attribute sequence;
 324                          * create a new tree under this tag when we see
 325                          * a non-delimiter tag, under which to put
 326                          * those attributes.
 327                          */
 328                         as_tree = NULL;
 329                         attr_tree = tree;
 330
 331                         /*
 332                          * Remember the offset at which this attribute
 333                          * sequence started, so we can use it to compute
 334                          * its length when it's finished.
 335                          */
 336                         start_offset = offset;
 337
 338                         /*
 339                          * Now create a new item for this tag.
 340                          */
 341                         tas = proto_tree_add_text(tree, tvb, offset, 1,
 342                             "%s", tag_desc);
 343                         offset++;
 344                         if (tag == TAG_END_OF_ATTRIBUTES) {
 345                                 /*
 346                                  * No more attributes.
 347                                  */
 348                                 break;
 349                         }
 350                 } else {
 351                         /*
 352                          * Value tag - get the name length.
 353                          */
 354                         name_length = tvb_get_ntohs(tvb, offset + 1);
 355
 356                         /*
 357                          * OK, get the value length.
 358                          */
 359                         value_length = tvb_get_ntohs(tvb, offset + 1 + 2 + name_length);
 360
 361                         /*
 362                          * OK, does the value run past the end of the
 363                          * frame?
 364                          */
 365                         if (as_tree == NULL) {
 366                                 /*
 367                                  * OK, there's an attribute to hang
 368                                  * under a delimiter tag, but we don't
 369                                  * have a tree for that tag yet; create
 370                                  * a tree.
 371                                  */
 372                                 as_tree = proto_item_add_subtree(tas,
 373                                     ett_ipp_as);
 374                                 attr_tree = as_tree;
 375                         }
 376
 377                         switch (TAG_TYPE(tag)) {
 378
 379                         case TAG_TYPE_INTEGER:
 380                                 if (name_length != 0) {
 381                                         /*
 382                                          * This is an attribute, not
 383                                          * an additional value, so
 384                                          * start a tree for it.
 385                                          */
 386                                         attr_tree = add_integer_tree(as_tree,
 387                                             tvb, offset, name_length,
 388                                             value_length);
 389                                 }
 390                                 add_integer_value(tag, tag_desc, attr_tree, tvb,
 391                                     offset, name_length, value_length);
 392                                 break;
 393
 394                         case TAG_TYPE_OCTETSTRING:
 395                                 if (name_length != 0) {
 396                                         /*
 397                                          * This is an attribute, not
 398                                          * an additional value, so
 399                                          * start a tree for it.
 400                                          */
 401                                         attr_tree = add_octetstring_tree(as_tree,
 402                                             tvb, offset, name_length,
 403                                             value_length);
 404                                 }
 405                                 add_octetstring_value(tag, tag_desc,
 406                                     attr_tree, tvb, offset, name_length,
 407                                     value_length);
 408                                 break;
 409
 410                         case TAG_TYPE_CHARSTRING:
 411                                 if (name_length != 0) {
 412                                         /*
 413                                          * This is an attribute, not
 414                                          * an additional value, so
 415                                          * start a tree for it.
 416                                          */
 417                                         attr_tree = add_charstring_tree(as_tree,
 418                                             tvb, offset, name_length,
 419                                             value_length);
 420                                 }
 421                                 add_charstring_value(tag, tag_desc,
 422                                     attr_tree, tvb, offset, name_length,
 423                                     value_length);
 424                                 break;
 425                         }
 426                         offset += 1 + 2 + name_length + 2 + value_length;
 427                 }
 428         }
 429
 430         return offset;
 431 }
 432
 433 static proto_tree *
 434 add_integer_tree(proto_tree *tree, tvbuff_t *tvb, int offset,
 435     int name_length, int value_length)
 436 {
 437         proto_item *ti;
 438
 439         if (value_length != 4) {
 440                 ti = proto_tree_add_text(tree, tvb, offset,
 441                     1 + 2 + name_length + 2 + value_length,
 442                     "%.*s: Invalid integer (length is %u, should be 4)",
 443                     name_length,
 444                     tvb_get_ptr(tvb, offset + 1 + 2, name_length),
 445                     value_length);
 446         } else {
 447                 ti = proto_tree_add_text(tree, tvb, offset,
 448                     1 + 2 + name_length + 2 + value_length,
 449                     "%.*s: %u",
 450                     name_length,
 451                     tvb_get_ptr(tvb, offset + 1 + 2, name_length),
 452                     tvb_get_ntohl(tvb, offset + 1 + 2 + name_length + 2));
 453         }
 454         return proto_item_add_subtree(ti, ett_ipp_attr);
 455 }
 456
 457 static void
 458 add_integer_value(guint tag, gchar *tag_desc, proto_tree *tree,
 459     tvbuff_t *tvb, int offset, int name_length, int value_length)
 460 {
 461         offset = add_value_head(tag, tag_desc, tree, tvb, offset,
 462             name_length, value_length);
 463         if (value_length == 4) {
 464                 proto_tree_add_text(tree, tvb, offset, value_length,
 465                     "Value: %u", tvb_get_ntohl(tvb, offset));
 466         }
 467 }
 468
 469 static proto_tree *
 470 add_octetstring_tree(proto_tree *tree, tvbuff_t *tvb, int offset,
 471     int name_length, int value_length)
 472 {
 473         proto_item *ti;
 474
 475         ti = proto_tree_add_text(tree, tvb, offset,
 476             1 + 2 + name_length + 2 + value_length,
 477             "%.*s: %s",
 478             name_length,
 479             tvb_get_ptr(tvb, offset + 1 + 2, name_length),
 480             tvb_bytes_to_str(tvb, offset + 1 + 2 + name_length + 2, value_length));
 481         return proto_item_add_subtree(ti, ett_ipp_attr);
 482 }
 483
 484 static void
 485 add_octetstring_value(guint tag, gchar *tag_desc, proto_tree *tree,
 486     tvbuff_t *tvb, int offset, int name_length, int value_length)
 487 {
 488         offset = add_value_head(tag, tag_desc, tree, tvb, offset,
 489             name_length, value_length);
 490         proto_tree_add_text(tree, tvb, offset, value_length,
 491             "Value: %s", tvb_bytes_to_str(tvb, offset, value_length));
 492 }
 493
 494 static proto_tree *
 495 add_charstring_tree(proto_tree *tree, tvbuff_t *tvb, int offset,
 496     int name_length, int value_length)
 497 {
 498         proto_item *ti;
 499
 500         ti = proto_tree_add_text(tree, tvb, offset,
 501             1 + 2 + name_length + 2 + value_length,
 502             "%.*s: %.*s",
 503             name_length,
 504             tvb_get_ptr(tvb, offset + 1 + 2, name_length),
 505             value_length,
 506             tvb_get_ptr(tvb, offset + 1 + 2 + name_length + 2, value_length));
 507         return proto_item_add_subtree(ti, ett_ipp_attr);
 508 }
 509
 510 static void
 511 add_charstring_value(guint tag, gchar *tag_desc, proto_tree *tree,
 512     tvbuff_t *tvb, int offset, int name_length, int value_length)
 513 {
 514         offset = add_value_head(tag, tag_desc, tree, tvb, offset,
 515             name_length, value_length);
 516         proto_tree_add_text(tree, tvb, offset, value_length,
 517             "Value: %.*s", value_length, tvb_get_ptr(tvb, offset, value_length));
 518 }
 519
 520 static int
 521 add_value_head(guint tag, gchar *tag_desc, proto_tree *tree,
 522     tvbuff_t *tvb, int offset, int name_length, int value_length)
 523 {
 524         proto_tree_add_text(tree, tvb, offset, 1, "Tag: %s", tag_desc);
 525         offset += 1;
 526         proto_tree_add_text(tree, tvb, offset, 2, "Name length: %u",
 527             name_length);
 528         offset += 2;
 529         if (name_length != 0) {
 530                 proto_tree_add_text(tree, tvb, offset, name_length,
 531                     "Name: %.*s", name_length,
 532                     tvb_get_ptr(tvb, offset, name_length));
 533         }
 534         offset += name_length;
 535         proto_tree_add_text(tree, tvb, offset, 2, "Value length: %u",
 536             value_length);
 537         offset += 2;
 538         return offset;
 539 }
 540
 541 void
 542 proto_register_ipp(void)
 543 {
 544 /*        static hf_register_info hf[] = {
 545                 { &variable,
 546                 { "Name",           "ipp.abbreviation", TYPE, VALS_POINTER }},
 547         };*/
 548         static gint *ett[] = {
 549                 &ett_ipp,
 550                 &ett_ipp_as,
 551                 &ett_ipp_attr,
 552         };
 553
 554         proto_ipp = proto_register_protocol("Internet Printing Protocol",
 555             "IPP", "ipp");
 556  /*       proto_register_field_array(proto_ipp, hf, array_length(hf));*/
 557         proto_register_subtree_array(ett, array_length(ett));
 558 }
 559
 560 void
 561 proto_reg_handoff_ipp(void)
 562 {
 563         dissector_handle_t ipp_handle;
 564
 565         /*
 566          * Register ourselves as running atop HTTP and using port 631.
 567          */
 568         ipp_handle = create_dissector_handle(dissect_ipp, proto_ipp);
 569         http_dissector_add(631, ipp_handle);
 570         data_handle = find_dissector("data");
 571 }