packet-bootp.c

   1 /* packet-bootp.c
   2  * Routines for BOOTP/DHCP packet disassembly
   3  * Gilbert Ramirez <gram@verdict.uthscsa.edu>
   4  *
   5  * $Id: packet-bootp.c,v 1.21 1999/10/12 06:20:02 gram Exp $
   6  *
   7  * The information used comes from:
   8  * RFC 2132: DHCP Options and BOOTP Vendor Extensions
   9  * RFC 1542: Clarifications and Extensions for the Bootstrap Protocol
  10  * RFC 2131: Dynamic Host Configuration Protocol
  11  *
  12  * Ethereal - Network traffic analyzer
  13  * By Gerald Combs <gerald@unicom.net>
  14  * Copyright 1998 Gerald Combs
  15  *
  16  *
  17  * This program is free software; you can redistribute it and/or
  18  * modify it under the terms of the GNU General Public License
  19  * as published by the Free Software Foundation; either version 2
  20  * of the License, or (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program; if not, write to the Free Software
  29  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  30  */
  31
  32 #ifdef HAVE_CONFIG_H
  33 # include "config.h"
  34 #endif
  35
  36 #ifdef HAVE_SYS_TYPES_H
  37 # include <sys/types.h>
  38 #endif
  39
  40 #include <glib.h>
  41 #include "packet.h"
  42
  43 static int proto_bootp = -1;
  44 static int hf_bootp_type = -1;
  45 static int hf_bootp_hw_type = -1;
  46 static int hf_bootp_hw_len = -1;
  47 static int hf_bootp_hops = -1;
  48 static int hf_bootp_id = -1;
  49 static int hf_bootp_secs = -1;
  50 static int hf_bootp_flag = -1;
  51 static int hf_bootp_ip_client = -1;
  52 static int hf_bootp_ip_your = -1;
  53 static int hf_bootp_ip_server = -1;
  54 static int hf_bootp_ip_relay = -1;
  55 static int hf_bootp_hw_addr = -1;
  56 static int hf_bootp_server = -1;
  57 static int hf_bootp_file = -1;
  58 static int hf_bootp_cookie = -1;
  59
  60 enum field_type { none, ipv4, string, toggle, yes_no, special, opaque,
  61         time_in_secs,
  62         val_u_byte, val_u_short, val_u_long,
  63         val_s_long };
  64
  65 struct opt_info {
  66         char    *text;
  67         enum field_type ftype;
  68 };
  69
  70 #define NUM_OPT_INFOS 77
  71
  72 /* returns the number of bytes consumed by this option */
  73 static int
  74 bootp_option(const u_char *pd, proto_tree *bp_tree, int voff, int eoff)
  75 {
  76         char                    *text;
  77         enum field_type ftype;
  78         u_char                  code = pd[voff];
  79         int                             vlen = pd[voff+1];
  80         u_char                  byte;
  81         int                             i, consumed = vlen + 2;
  82         u_long                  time_secs;
  83         proto_tree              *v_tree;
  84         proto_item              *vti;
  85
  86         static const char       *opt53_text[] = {
  87                 "Unknown Message Type",
  88                 "Discover",
  89                 "Offer",
  90                 "Request",
  91                 "Decline",
  92                 "ACK",
  93                 "NAK",
  94                 "Release",
  95                 "Inform"
  96         };
  97         static const value_string nbnt_vals[] = {
  98             {0x1,   "B-node" },
  99             {0x2,   "P-node" },
 100             {0x4,   "M-node" },
 101             {0x8,   "H-node" },
 102             {0,     NULL     } };
 103
 104         static struct opt_info opt[] = {
 105                 /*   0 */ { "Padding",                                                          none },
 106                 /*   1 */ { "Subnet Mask",                                                      ipv4 },
 107                 /*   2 */ { "Time Offset",                                                      val_s_long },
 108                 /*   3 */ { "Router",                                                           ipv4 },
 109                 /*   4 */ { "Time Server",                                                      ipv4 },
 110                 /*   5 */ { "Name Server",                                                      ipv4 },
 111                 /*   6 */ { "Domain Name Server",                                       ipv4 },
 112                 /*   7 */ { "Log Server",                                                       ipv4 },
 113                 /*   8 */ { "Cookie Server",                                            ipv4 },
 114                 /*   9 */ { "LPR Server",                                                       ipv4 },
 115                 /*  10 */ { "Impress Server",                                           ipv4 },
 116                 /*  11 */ { "Resource Location Server",                         ipv4 },
 117                 /*  12 */ { "Host Name",                                                        string },
 118                 /*  13 */ { "Boot File Size",                                           val_u_short },
 119                 /*  14 */ { "Merit Dump File",                                          string },
 120                 /*  15 */ { "Domain Name",                                                      string },
 121                 /*  16 */ { "Swap Server",                                                      ipv4 },
 122                 /*  17 */ { "Root Path",                                                        string },
 123                 /*  18 */ { "Extensions Path",                                          string },
 124                 /*  19 */ { "IP Forwarding",                                            toggle },
 125                 /*  20 */ { "Non-Local Source Routing",                         toggle },
 126                 /*  21 */ { "Policy Filter",                                            special },
 127                 /*  22 */ { "Maximum Datagram Reassembly Size",         val_u_short },
 128                 /*  23 */ { "Default IP Time-to-Live",                          val_u_byte },
 129                 /*  24 */ { "Path MTU Aging Timeout",                           time_in_secs },
 130                 /*  25 */ { "Path MTU Plateau Table",                           val_u_short },
 131                 /*  26 */ { "Interface MTU",                                            val_u_short },
 132                 /*  27 */ { "All Subnets are Local",                            yes_no },
 133                 /*  28 */ { "Broadcast Address",                                        ipv4 },
 134                 /*  29 */ { "Perform Mask Discovery",                           toggle },
 135                 /*  30 */ { "Mask Supplier",                                            yes_no },
 136                 /*  31 */ { "Perform Router Discover",                          toggle },
 137                 /*  32 */ { "Router Solicitation Address",                      ipv4 },
 138                 /*  33 */ { "Static Route",                                                     special },
 139                 /*  34 */ { "Trailer Encapsulation",                            toggle },
 140                 /*  35 */ { "ARP Cache Timeout",                                        time_in_secs },
 141                 /*  36 */ { "Ethernet Encapsulation",                           toggle },
 142                 /*  37 */ { "TCP Default TTL",                                          val_u_byte },
 143                 /*  38 */ { "TCP Keepalive Interval",                           time_in_secs },
 144                 /*  39 */ { "TCP Keepalive Garbage",                            toggle },
 145                 /*  40 */ { "Network Information Service Domain",       string },
 146                 /*  41 */ { "Network Information Service Servers",      ipv4 },
 147                 /*  42 */ { "Network Time Protocol Servers",            ipv4 },
 148                 /*  43 */ { "Vendor-Specific Information",                      special },
 149                 /*  44 */ { "NetBIOS over TCP/IP Name Server",          ipv4 },
 150                 /*  45 */ { "NetBIOS over TCP/IP Datagram Distribution Name Server", ipv4 },
 151                 /*  46 */ { "NetBIOS over TCP/IP Node Type",            special },
 152                 /*  47 */ { "NetBIOS over TCP/IP Scope",                        string },
 153                 /*  48 */ { "X Window System Font Server",                      ipv4 },
 154                 /*  49 */ { "X Window System Display Manager",          ipv4 },
 155                 /*  50 */ { "Requested IP Address",                                     ipv4 },
 156                 /*  51 */ { "IP Address Lease Time",                            time_in_secs },
 157                 /*  52 */ { "Option Overload",                                          special },
 158                 /*  53 */ { "DHCP Message Type",                                        special },
 159                 /*  54 */ { "Server Identifier",                                        ipv4 },
 160                 /*  55 */ { "Parameter Request List",                           special },
 161                 /*  56 */ { "Message",                                                          string },
 162                 /*  57 */ { "Maximum DHCP Message Size",                        val_u_short },
 163                 /*  58 */ { "Renewal Time Value",                                       time_in_secs },
 164                 /*  59 */ { "Rebinding Time Value",                                     time_in_secs },
 165                 /*  60 */ { "Vendor class identifier",                          opaque },
 166                 /*  61 */ { "Client identifier",                                        special },
 167                 /*  64 */ { "Network Information Service+ Domain",      string },
 168                 /*  65 */ { "Network Information Service+ Servers",     ipv4 },
 169                 /*  66 */ { "TFTP Server Name",                                         string },
 170                 /*  67 */ { "Bootfile name",                                            string },
 171                 /*  68 */ { "Mobile IP Home Agent",                                     ipv4 },
 172                 /*  69 */ { "SMTP Server",                                                      ipv4 },
 173                 /*  70 */ { "POP3 Server",                                                      ipv4 },
 174                 /*  71 */ { "NNTP Server",                                                      ipv4 },
 175                 /*  72 */ { "Default WWW Server",                                       ipv4 },
 176                 /*  73 */ { "Default Finger Server",                            ipv4 },
 177                 /*  74 */ { "Default IRC Server",                                       ipv4 },
 178                 /*  75 */ { "StreetTalk Server",                                        ipv4 },
 179                 /*  76 */ { "StreetTalk Directory Assistance Server", ipv4 }
 180         };
 181
 182         text = opt[code].text;
 183         /* Special cases */
 184         switch (code) {
 185                 /* Padding */
 186                 case 0:
 187                         /* check how much padding we have */
 188                         for (i = voff + 1; i < eoff; i++ ) {
 189                                 if (pd[i] != 0) {
 190                                         break;
 191                                 }
 192                         }
 193                         i = i - voff;
 194                         proto_tree_add_text(bp_tree, voff, i, "Padding");
 195                         consumed = i;
 196                         return consumed;
 197
 198                 /* Policy Filter */
 199                 case 21:
 200                         /* one IP address pair */
 201                         if (vlen == 8) {
 202                                 proto_tree_add_text(bp_tree, voff, consumed,
 203                                         "Option %d: %s = %s/%s", code, text,
 204                                         ip_to_str((guint8*)&pd[voff+2]),
 205                                         ip_to_str((guint8*)&pd[voff+6]));
 206                         }
 207                         /* > 1 IP address pair. Let's make a sub-tree */
 208                         else {
 209
 210                                 vti = proto_tree_add_text(bp_tree, voff,
 211                                         consumed, "Option %d: %s", code, text);
 212                                 v_tree = proto_item_add_subtree(vti, ETT_BOOTP_OPTION);
 213                                 for (i = voff + 2; i < voff + consumed; i += 8) {
 214                                         proto_tree_add_text(v_tree, i, 8, "IP Address/Mask: %s/%s",
 215                                                 ip_to_str((guint8*)&pd[i]),
 216                                                 ip_to_str((guint8*)&pd[i+4]));
 217                                 }
 218                         }
 219                         break;
 220
 221                 /* Static Route */
 222                 case 33:
 223                         /* one IP address pair */
 224                         if (vlen == 8) {
 225                                 proto_tree_add_text(bp_tree, voff, consumed,
 226                                         "Option %d: %s = %s/%s", code, text,
 227                                         ip_to_str((guint8*)&pd[voff+2]),
 228                                         ip_to_str((guint8*)&pd[voff+6]));
 229                         }
 230                         /* > 1 IP address pair. Let's make a sub-tree */
 231                         else {
 232
 233                                 vti = proto_tree_add_text(bp_tree, voff,
 234                                         consumed, "Option %d: %s", code, text);
 235                                 v_tree = proto_item_add_subtree(vti, ETT_BOOTP_OPTION);
 236                                 for (i = voff + 2; i < voff + consumed; i += 8) {
 237                                         proto_tree_add_text(v_tree, i, 8,
 238                                                 "Destination IP Address/Router: %s/%s",
 239                                                 ip_to_str((guint8*)&pd[i]),
 240                                                 ip_to_str((guint8*)&pd[i+4]));
 241                                 }
 242                         }
 243                         break;
 244
 245                 /* Vendor-Specific Info */
 246                 case 43:
 247                         proto_tree_add_text(bp_tree, voff, consumed,
 248                                         "Option %d: %s", code, text);
 249                         break;
 250
 251                 /* NetBIOS-over-TCP/IP Node Type */
 252                 case 46:
 253                         byte = pd[voff+2];
 254                         proto_tree_add_text(bp_tree, voff, consumed,
 255                                         "Option %d: %s = %s", code, text,
 256                                         val_to_str(byte, nbnt_vals,
 257                                             "Unknown (0x%02x)"));
 258                         break;
 259
 260                 /* DHCP Message Type */
 261                 case 53:
 262                         byte = pd[voff+2];
 263                         if (byte > 0 && byte < 9) {
 264                                 i = byte;
 265                         }
 266                         else {
 267                                 i = 0;
 268                         }
 269                         proto_tree_add_text(bp_tree, voff, 3, "Option %d: %s = DHCP %s",
 270                                 code, text, opt53_text[i]);
 271                         break;
 272
 273                 /* Parameter Request List */
 274                 case 55:
 275                         vti = proto_tree_add_text(bp_tree, voff,
 276                                 vlen + 2, "Option %d: %s", code, text);
 277                         v_tree = proto_item_add_subtree(vti, ETT_BOOTP_OPTION);
 278                         for (i = 0; i < vlen; i++) {
 279                                 byte = pd[voff+2+i];
 280                                 if (byte < NUM_OPT_INFOS) {
 281                                         proto_tree_add_text(v_tree, voff+2+i, 1, "%d = %s",
 282                                                         byte, opt[byte].text);
 283                                 }
 284                                 else {
 285                                         proto_tree_add_text(vti, voff+2+i, 1,
 286                                                 "Unknown Option Code: %d", byte);
 287                                 }
 288                         }
 289                         break;
 290
 291                 /* Client Identifier */
 292                 case 61:
 293                         /* We *MAY* use hwtype/hwaddr. If we have 7 bytes, I'll
 294                                 guess that the first is the hwtype, and the last 6 are
 295                                 the hw addr */
 296                         if (vlen == 7) {
 297                                 vti = proto_tree_add_text(bp_tree, voff,
 298                                         consumed, "Option %d: %s", code, text);
 299                                 v_tree = proto_item_add_subtree(vti, ETT_BOOTP_OPTION);
 300                                 proto_tree_add_text(v_tree, voff+2, 1,
 301                                         "Hardware type: %s",
 302                                         arphrdtype_to_str(pd[voff+2],
 303                                                 "Unknown (0x%02x)"));
 304                                 proto_tree_add_text(v_tree, voff+3, 6,
 305                                         "Client hardware address: %s",
 306                                         arphrdaddr_to_str((guint8*)&pd[voff+3],
 307                                                 6, pd[voff+2]));
 308                         }
 309                         /* otherwise, it's opaque data */
 310                         else {
 311                                 proto_tree_add_text(bp_tree, voff, consumed,
 312                                         "Option %d: %s (%d bytes)", code, text, vlen);
 313                         }
 314                         break;
 315
 316                 /* End Option */
 317                 case 255:
 318                         proto_tree_add_text(bp_tree, voff, 1, "End Option");
 319                         consumed = 1;
 320                         return consumed;
 321
 322                 default:
 323                         /* nothing */
 324                         break;
 325         }
 326
 327         /* Normal cases */
 328         if (code < NUM_OPT_INFOS) {
 329                 text = opt[code].text;
 330                 ftype = opt[code].ftype;
 331
 332                 switch (ftype) {
 333                         case special:
 334                                 return consumed;
 335
 336                         case ipv4:
 337                                 /* one IP address */
 338                                 if (vlen == 4) {
 339                                         proto_tree_add_text(bp_tree, voff, consumed,
 340                                                 "Option %d: %s = %s", code, text,
 341                                                 ip_to_str((guint8*)&pd[voff+2]));
 342                                 }
 343                                 /* > 1 IP addresses. Let's make a sub-tree */
 344                                 else {
 345
 346                                         vti = proto_tree_add_text(bp_tree, voff,
 347                                                 consumed, "Option %d: %s", code, text);
 348                                         v_tree = proto_item_add_subtree(vti, ETT_BOOTP_OPTION);
 349                                         for (i = voff + 2; i < voff + consumed; i += 4) {
 350                                                 proto_tree_add_text(v_tree, i, 4, "IP Address: %s",
 351                                                         ip_to_str((guint8*)&pd[i]));
 352                                         }
 353                                 }
 354                                 break;
 355
 356                         case string:
 357                                 /* Fix for non null-terminated string supplied by
 358                                  * John Lines <John.Lines@aeat.co.uk>
 359                                  */
 360                                 proto_tree_add_text(bp_tree, voff, consumed,
 361                                                 "Option %d: %s = %.*s", code, text, vlen, &pd[voff+2]);
 362                                 break;
 363
 364                         case opaque:
 365                                 proto_tree_add_text(bp_tree, voff, consumed,
 366                                                 "Option %d: %s (%d bytes)",
 367                                                 code, text, vlen);
 368                                 break;
 369
 370                         case val_u_short:
 371                                 /* one IP address */
 372                                 if (vlen == 2) {
 373                                         proto_tree_add_text(bp_tree, voff, consumed,
 374                                                         "Option %d: %s = %d", code, text,
 375                                                         pntohs(&pd[voff+2]));
 376                                 }
 377                                 /* > 1 u_short */
 378                                 else {
 379                                         vti = proto_tree_add_text(bp_tree, voff,
 380                                                 consumed, "Option %d: %s", code, text);
 381                                         v_tree = proto_item_add_subtree(vti, ETT_BOOTP_OPTION);
 382                                         for (i = voff + 2; i < voff + consumed; i += 2) {
 383                                                 proto_tree_add_text(v_tree, i, 4, "Value: %d",
 384                                                         pntohs(&pd[i]));
 385                                         }
 386                                 }
 387                                 break;
 388
 389                         case val_u_long:
 390                                 proto_tree_add_text(bp_tree, voff, consumed,
 391                                                 "Option %d: %s = %d", code, text,
 392                                                 pntohl(&pd[voff+2]));
 393                                 break;
 394
 395                         case val_u_byte:
 396                                 proto_tree_add_text(bp_tree, voff, consumed,
 397                                                 "Option %d: %s = %d", code, text, pd[voff+2]);
 398                                 break;
 399
 400                         case toggle:
 401                                 i = pd[voff+2];
 402                                 if (i != 0 && i != 1) {
 403                                         proto_tree_add_text(bp_tree, voff, consumed,
 404                                                         "Option %d: %s = Invalid Value %d", code, text,
 405                                                         pd[voff+2]);
 406                                 }
 407                                 else {
 408                                         proto_tree_add_text(bp_tree, voff, consumed,
 409                                                         "Option %d: %s = %s", code, text,
 410                                                         pd[voff+2] == 0 ? "Disabled" : "Enabled");
 411                                 }
 412                                 break;
 413
 414                         case yes_no:
 415                                 i = pd[voff+2];
 416                                 if (i != 0 && i != 1) {
 417                                         proto_tree_add_text(bp_tree, voff, consumed,
 418                                                         "Option %d: %s = Invalid Value %d", code, text,
 419                                                         pd[voff+2]);
 420                                 }
 421                                 else {
 422                                         proto_tree_add_text(bp_tree, voff, consumed,
 423                                                         "Option %d: %s = %s", code, text,
 424                                                         pd[voff+2] == 0 ? "No" : "Yes");
 425                                 }
 426                                 break;
 427
 428                         case time_in_secs:
 429                                 time_secs = pntohl(&pd[voff+2]);
 430                                 proto_tree_add_text(bp_tree, voff, consumed,
 431                                         "Option %d: %s = %s", code, text,
 432                                         ((time_secs == 0xffffffff) ?
 433                                             "infinity" :
 434                                             time_secs_to_str(time_secs)));
 435                                 break;
 436
 437                         default:
 438                                 proto_tree_add_text(bp_tree, voff, consumed,
 439                                                 "Option %d: %s (%d bytes)", code, text, vlen);
 440                 }
 441         }
 442         else {
 443                 proto_tree_add_text(bp_tree, voff, consumed,
 444                                 "Unknown Option Code: %d (%d bytes)", code, vlen);
 445         }
 446
 447         return consumed;
 448 }
 449
 450 void
 451 dissect_bootp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 452 {
 453         proto_tree      *bp_tree;
 454         proto_item      *ti;
 455         int                     voff, eoff; /* vender offset, end offset */
 456         guint32         ip_addr;
 457
 458         if (check_col(fd, COL_PROTOCOL))
 459                 col_add_str(fd, COL_PROTOCOL, "BOOTP");
 460
 461         if (check_col(fd, COL_INFO)) {
 462                 if (pd[offset] == 1) {
 463                         col_add_fstr(fd, COL_INFO, "Boot Request from %s",
 464                                 arphrdaddr_to_str((guint8*)&pd[offset+28],
 465                                         pd[offset+2], pd[offset+1]));
 466                 }
 467                 else {
 468                         col_add_str(fd, COL_INFO, "Boot Reply");
 469                 }
 470         }
 471
 472         if (tree) {
 473                 ti = proto_tree_add_item(tree, proto_bootp, offset, END_OF_FRAME, NULL);
 474                 bp_tree = proto_item_add_subtree(ti, ETT_BOOTP);
 475
 476                 proto_tree_add_item_format(bp_tree, hf_bootp_type,
 477                                            offset, 1,
 478                                            pd[offset],
 479                                            pd[offset] == 1 ?
 480                                            "Boot Request" : "Boot Reply");
 481                 proto_tree_add_item_format(bp_tree, hf_bootp_hw_type,
 482                                            offset + 1, 1,
 483                                            pd[offset+1],
 484                                            "Hardware type: %s",
 485                                            arphrdtype_to_str(pd[offset+1],
 486                                                              "Unknown (0x%02x)"));
 487                 proto_tree_add_item(bp_tree, hf_bootp_hw_len,
 488                                     offset + 2, 1, pd[offset+2]);
 489                 proto_tree_add_item(bp_tree, hf_bootp_hops,
 490                                     offset + 3, 1, pd[offset+3]);
 491                 proto_tree_add_item(bp_tree, hf_bootp_id,
 492                                    offset + 4, 4, pntohl(&pd[offset+4]));
 493                 proto_tree_add_item(bp_tree, hf_bootp_secs,
 494                                     offset + 8, 2, pntohs(&pd[offset+8]));
 495                 proto_tree_add_item(bp_tree, hf_bootp_flag,
 496                                     offset + 10, 2, pd[offset+10] & 1);
 497
 498                 memcpy(&ip_addr, &pd[offset+12], sizeof(ip_addr));
 499                 proto_tree_add_item(bp_tree, hf_bootp_ip_client,
 500                                     offset + 12, 4, ip_addr);
 501                 memcpy(&ip_addr, &pd[offset+16], sizeof(ip_addr));
 502                 proto_tree_add_item(bp_tree, hf_bootp_ip_your,
 503                                     offset + 16, 4, ip_addr);
 504                 memcpy(&ip_addr, &pd[offset+20], sizeof(ip_addr));
 505                 proto_tree_add_item(bp_tree, hf_bootp_ip_server,
 506                                     offset + 20, 4, ip_addr);
 507                 memcpy(&ip_addr, &pd[offset+24], sizeof(ip_addr));
 508                 proto_tree_add_item(bp_tree, hf_bootp_ip_relay,
 509                                     offset + 24, 4, ip_addr);
 510
 511                 proto_tree_add_item_format(bp_tree, hf_bootp_hw_addr,
 512                                            offset + 28, pd[offset+2],
 513                                            &pd[offset+28],
 514                                            "Client hardware address: %s",
 515                                            arphrdaddr_to_str((guint8*)&pd[offset+28],
 516                                                              pd[offset+2], pd[offset+1]));
 517
 518                 /* The server host name is optional */
 519                 if (pd[offset+44]) {
 520                         proto_tree_add_item_format(bp_tree, hf_bootp_server,
 521                                                    offset + 44, 64,
 522                                                    &pd[offset+44],
 523                                                    "Server host name: %s",
 524                                                    &pd[offset+44]);
 525                 }
 526                 else {
 527                         proto_tree_add_item_format(bp_tree, hf_bootp_server,
 528                                                    offset + 44, 64,
 529                                                    &pd[offset+44],
 530                                                    "Server host name not given");
 531                 }
 532
 533                 /* Boot file */
 534                 if (pd[offset+108]) {
 535                         proto_tree_add_item_format(bp_tree, hf_bootp_file,
 536                                                    offset + 108, 128,
 537                                                    &pd[offset+108],
 538                                                    "Boot file name: %s",
 539                                                    &pd[offset+108]);
 540                 }
 541                 else {
 542                         proto_tree_add_item_format(bp_tree, hf_bootp_file,
 543                                                    offset + 108, 128,
 544                                                    &pd[offset+108],
 545                                                    "Boot file name not given");
 546                 }
 547
 548                 if (pntohl(&pd[offset+236]) == 0x63825363) {
 549                         proto_tree_add_item_format(bp_tree, hf_bootp_cookie,
 550                                                    offset + 236, 4,
 551                                                    pd[offset+236],
 552                                                    "Magic cookie: (OK)");
 553                 }
 554                 else {
 555                         memcpy(&ip_addr, &pd[offset + 236], sizeof(ip_addr));
 556                         proto_tree_add_item(bp_tree, hf_bootp_cookie,
 557                                             offset + 236, 4, ip_addr);
 558                 }
 559
 560                 voff = offset+240;
 561                 eoff = pi.captured_len;
 562
 563                 while (voff < eoff) {
 564                         voff += bootp_option(pd, bp_tree, voff, eoff);
 565                 }
 566         }
 567 }
 568
 569 void
 570 proto_register_bootp(void)
 571 {
 572   static hf_register_info hf[] = {
 573     { &hf_bootp_type,
 574       { "Message type",                 "bootp.type",    FT_UINT8,  BASE_NONE, NULL, 0x0,
 575         "" }},
 576
 577     { &hf_bootp_hw_type,
 578       { "Hardware type",                "bootp.hw.type", FT_UINT8,  BASE_HEX, NULL, 0x0,
 579         "" }},
 580
 581     { &hf_bootp_hw_len,
 582       { "Hardware address length",      "bootp.hw.len",  FT_UINT8,  BASE_DEC, NULL, 0x0,
 583         "" }},
 584
 585     { &hf_bootp_hops,
 586       { "Hops",                         "bootp.hops",    FT_UINT8,  BASE_DEC, NULL, 0x0,
 587         "" }},
 588
 589     { &hf_bootp_id,
 590       { "Transaction ID",               "bootp.id",      FT_UINT32, BASE_HEX, NULL, 0x0,
 591         "" }},
 592
 593     { &hf_bootp_secs,
 594       { "Seconds elapsed",              "bootp.secs",    FT_UINT16, BASE_DEC, NULL, 0x0,
 595         "" }},
 596
 597     { &hf_bootp_flag,
 598       { "Broadcast flag",               "bootp.flag",    FT_UINT16, BASE_DEC, NULL, 0x0,
 599         "" }},
 600
 601     { &hf_bootp_ip_client,
 602       { "Client IP address",            "bootp.ip.client",FT_IPv4,  BASE_NONE, NULL, 0x0,
 603         "" }},
 604
 605     { &hf_bootp_ip_your,
 606       { "Your (client) IP address",     "bootp.ip.your",  FT_IPv4,  BASE_NONE, NULL, 0x0,
 607         "" }},
 608
 609     { &hf_bootp_ip_server,
 610       { "Next server IP address",       "bootp.ip.server",FT_IPv4,  BASE_NONE, NULL, 0x0,
 611         "" }},
 612
 613     { &hf_bootp_ip_relay,
 614       { "Relay agent IP address",       "bootp.ip.relay", FT_IPv4,  BASE_NONE, NULL, 0x0,
 615         "" }},
 616
 617     { &hf_bootp_hw_addr,
 618       { "Client hardware address",      "bootp.hw.addr", FT_BYTES,  BASE_NONE, NULL, 0x0,
 619         "" }},
 620
 621     { &hf_bootp_server,
 622       { "Server host name",             "bootp.server",  FT_STRING, BASE_NONE, NULL, 0x0,
 623         "" }},
 624
 625     { &hf_bootp_file,
 626       { "Boot file name",               "bootp.file",    FT_STRING, BASE_NONE, NULL, 0x0,
 627         "" }},
 628
 629     { &hf_bootp_cookie,
 630       { "Magic cookie",                 "bootp.cookie",  FT_IPv4,   BASE_NONE, NULL, 0x0,
 631         "" }},
 632   };
 633
 634   proto_bootp = proto_register_protocol("Bootstrap Protocol", "bootp");
 635   proto_register_field_array(proto_bootp, hf, array_length(hf));
 636 }