reactos/services/dhcp/options.c

   1 /*      $OpenBSD: options.c,v 1.15 2004/12/26 03:17:07 deraadt Exp $    */
   2
   3 /* DHCP options parsing and reassembly. */
   4
   5 /*
   6  * Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of The Internet Software Consortium nor the names
  19  *    of its contributors may be used to endorse or promote products derived
  20  *    from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
  23  * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  24  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  25  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  26  * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
  27  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  29  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  30  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  31  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  32  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  33  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * This software has been written for the Internet Software Consortium
  37  * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
  38  * Enterprises.  To learn more about the Internet Software Consortium,
  39  * see ``http://www.vix.com/isc''.  To learn more about Vixie
  40  * Enterprises, see ``http://www.vix.com''.
  41  */
  42
  43 #include <ctype.h>
  44
  45 #define DHCP_OPTION_DATA
  46 #include "rosdhcp.h"
  47 #include "dhcpd.h"
  48
  49 int bad_options = 0;
  50 int bad_options_max = 5;
  51
  52 void    parse_options(struct packet *);
  53 void    parse_option_buffer(struct packet *, unsigned char *, int);
  54 int     store_options(unsigned char *, int, struct tree_cache **,
  55             unsigned char *, int, int, int, int);
  56
  57
  58 /*
  59  * Parse all available options out of the specified packet.
  60  */
  61 void
  62 parse_options(struct packet *packet)
  63 {
  64         /* Initially, zero all option pointers. */
  65         memset(packet->options, 0, sizeof(packet->options));
  66
  67         /* If we don't see the magic cookie, there's nothing to parse. */
  68         if (memcmp(packet->raw->options, DHCP_OPTIONS_COOKIE, 4)) {
  69                 packet->options_valid = 0;
  70                 return;
  71         }
  72
  73         /*
  74          * Go through the options field, up to the end of the packet or
  75          * the End field.
  76          */
  77         parse_option_buffer(packet, &packet->raw->options[4],
  78             packet->packet_length - DHCP_FIXED_NON_UDP - 4);
  79
  80         /*
  81          * If we parsed a DHCP Option Overload option, parse more
  82          * options out of the buffer(s) containing them.
  83          */
  84         if (packet->options_valid &&
  85             packet->options[DHO_DHCP_OPTION_OVERLOAD].data) {
  86                 if (packet->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)
  87                         parse_option_buffer(packet,
  88                             (unsigned char *)packet->raw->file,
  89                             sizeof(packet->raw->file));
  90                 if (packet->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)
  91                         parse_option_buffer(packet,
  92                             (unsigned char *)packet->raw->sname,
  93                             sizeof(packet->raw->sname));
  94         }
  95 }
  96
  97 /*
  98  * Parse options out of the specified buffer, storing addresses of
  99  * option values in packet->options and setting packet->options_valid if
 100  * no errors are encountered.
 101  */
 102 void
 103 parse_option_buffer(struct packet *packet,
 104     unsigned char *buffer, int length)
 105 {
 106         unsigned char *s, *t, *end = buffer + length;
 107         int len, code;
 108
 109         for (s = buffer; *s != DHO_END && s < end; ) {
 110                 code = s[0];
 111
 112                 /* Pad options don't have a length - just skip them. */
 113                 if (code == DHO_PAD) {
 114                         s++;
 115                         continue;
 116                 }
 117                 if (s + 2 > end) {
 118                         len = 65536;
 119                         goto bogus;
 120                 }
 121
 122                 /*
 123                  * All other fields (except end, see above) have a
 124                  * one-byte length.
 125                  */
 126                 len = s[1];
 127
 128                 /*
 129                  * If the length is outrageous, silently skip the rest,
 130                  * and mark the packet bad. Unfortunately some crappy
 131                  * dhcp servers always seem to give us garbage on the
 132                  * end of a packet. so rather than keep refusing, give
 133                  * up and try to take one after seeing a few without
 134                  * anything good.
 135                  */
 136                 if (s + len + 2 > end) {
 137                     bogus:
 138                         bad_options++;
 139                         warning("option %s (%d) %s.",
 140                             dhcp_options[code].name, len,
 141                             "larger than buffer");
 142                         if (bad_options == bad_options_max) {
 143                                 packet->options_valid = 1;
 144                                 bad_options = 0;
 145                                 warning("Many bogus options seen in offers. "
 146                                     "Taking this offer in spite of bogus "
 147                                     "options - hope for the best!");
 148                         } else {
 149                                 warning("rejecting bogus offer.");
 150                                 packet->options_valid = 0;
 151                         }
 152                         return;
 153                 }
 154                 /*
 155                  * If we haven't seen this option before, just make
 156                  * space for it and copy it there.
 157                  */
 158                 if (!packet->options[code].data) {
 159                         if (!(t = calloc(1, len + 1)))
 160                                 error("Can't allocate storage for option %s.",
 161                                     dhcp_options[code].name);
 162                         /*
 163                          * Copy and NUL-terminate the option (in case
 164                          * it's an ASCII string.
 165                          */
 166                         memcpy(t, &s[2], len);
 167                         t[len] = 0;
 168                         packet->options[code].len = len;
 169                         packet->options[code].data = t;
 170                 } else {
 171                         /*
 172                          * If it's a repeat, concatenate it to whatever
 173                          * we last saw.   This is really only required
 174                          * for clients, but what the heck...
 175                          */
 176                         t = calloc(1, len + packet->options[code].len + 1);
 177                         if (!t)
 178                                 error("Can't expand storage for option %s.",
 179                                     dhcp_options[code].name);
 180                         memcpy(t, packet->options[code].data,
 181                                 packet->options[code].len);
 182                         memcpy(t + packet->options[code].len,
 183                                 &s[2], len);
 184                         packet->options[code].len += len;
 185                         t[packet->options[code].len] = 0;
 186                         free(packet->options[code].data);
 187                         packet->options[code].data = t;
 188                 }
 189                 s += len + 2;
 190         }
 191         packet->options_valid = 1;
 192 }
 193
 194 /*
 195  * cons options into a big buffer, and then split them out into the
 196  * three separate buffers if needed.  This allows us to cons up a set of
 197  * vendor options using the same routine.
 198  */
 199 int
 200 cons_options(struct packet *inpacket, struct dhcp_packet *outpacket,
 201     int mms, struct tree_cache **options,
 202     int overload, /* Overload flags that may be set. */
 203     int terminate, int bootpp, u_int8_t *prl, int prl_len)
 204 {
 205         unsigned char priority_list[300], buffer[4096];
 206         int priority_len, main_buffer_size, mainbufix, bufix;
 207         int option_size, length;
 208
 209         /*
 210          * If the client has provided a maximum DHCP message size, use
 211          * that; otherwise, if it's BOOTP, only 64 bytes; otherwise use
 212          * up to the minimum IP MTU size (576 bytes).
 213          *
 214          * XXX if a BOOTP client specifies a max message size, we will
 215          * honor it.
 216          */
 217         if (!mms &&
 218             inpacket &&
 219             inpacket->options[DHO_DHCP_MAX_MESSAGE_SIZE].data &&
 220             (inpacket->options[DHO_DHCP_MAX_MESSAGE_SIZE].len >=
 221             sizeof(u_int16_t)))
 222                 mms = getUShort(
 223                     inpacket->options[DHO_DHCP_MAX_MESSAGE_SIZE].data);
 224
 225         if (mms)
 226                 main_buffer_size = mms - DHCP_FIXED_LEN;
 227         else if (bootpp)
 228                 main_buffer_size = 64;
 229         else
 230                 main_buffer_size = 576 - DHCP_FIXED_LEN;
 231
 232         if (main_buffer_size > sizeof(buffer))
 233                 main_buffer_size = sizeof(buffer);
 234
 235         /* Preload the option priority list with mandatory options. */
 236         priority_len = 0;
 237         priority_list[priority_len++] = DHO_DHCP_MESSAGE_TYPE;
 238         priority_list[priority_len++] = DHO_DHCP_SERVER_IDENTIFIER;
 239         priority_list[priority_len++] = DHO_DHCP_LEASE_TIME;
 240         priority_list[priority_len++] = DHO_DHCP_MESSAGE;
 241
 242         /*
 243          * If the client has provided a list of options that it wishes
 244          * returned, use it to prioritize.  Otherwise, prioritize based
 245          * on the default priority list.
 246          */
 247         if (inpacket &&
 248             inpacket->options[DHO_DHCP_PARAMETER_REQUEST_LIST].data) {
 249                 int prlen =
 250                     inpacket->options[DHO_DHCP_PARAMETER_REQUEST_LIST].len;
 251                 if (prlen + priority_len > sizeof(priority_list))
 252                         prlen = sizeof(priority_list) - priority_len;
 253
 254                 memcpy(&priority_list[priority_len],
 255                     inpacket->options[DHO_DHCP_PARAMETER_REQUEST_LIST].data,
 256                     prlen);
 257                 priority_len += prlen;
 258                 prl = priority_list;
 259         } else if (prl) {
 260                 if (prl_len + priority_len > sizeof(priority_list))
 261                         prl_len = sizeof(priority_list) - priority_len;
 262
 263                 memcpy(&priority_list[priority_len], prl, prl_len);
 264                 priority_len += prl_len;
 265                 prl = priority_list;
 266         } else {
 267                 memcpy(&priority_list[priority_len],
 268                     dhcp_option_default_priority_list,
 269                     sizeof_dhcp_option_default_priority_list);
 270                 priority_len += sizeof_dhcp_option_default_priority_list;
 271         }
 272
 273         /* Copy the options into the big buffer... */
 274         option_size = store_options(
 275             buffer,
 276             (main_buffer_size - 7 + ((overload & 1) ? DHCP_FILE_LEN : 0) +
 277                 ((overload & 2) ? DHCP_SNAME_LEN : 0)),
 278             options, priority_list, priority_len, main_buffer_size,
 279             (main_buffer_size + ((overload & 1) ? DHCP_FILE_LEN : 0)),
 280             terminate);
 281
 282         /* Put the cookie up front... */
 283         memcpy(outpacket->options, DHCP_OPTIONS_COOKIE, 4);
 284         mainbufix = 4;
 285
 286         /*
 287          * If we're going to have to overload, store the overload option
 288          * at the beginning.  If we can, though, just store the whole
 289          * thing in the packet's option buffer and leave it at that.
 290          */
 291         if (option_size <= main_buffer_size - mainbufix) {
 292                 memcpy(&outpacket->options[mainbufix],
 293                     buffer, option_size);
 294                 mainbufix += option_size;
 295                 if (mainbufix < main_buffer_size)
 296                         outpacket->options[mainbufix++] = DHO_END;
 297                 length = DHCP_FIXED_NON_UDP + mainbufix;
 298         } else {
 299                 outpacket->options[mainbufix++] = DHO_DHCP_OPTION_OVERLOAD;
 300                 outpacket->options[mainbufix++] = 1;
 301                 if (option_size >
 302                     main_buffer_size - mainbufix + DHCP_FILE_LEN)
 303                         outpacket->options[mainbufix++] = 3;
 304                 else
 305                         outpacket->options[mainbufix++] = 1;
 306
 307                 memcpy(&outpacket->options[mainbufix],
 308                     buffer, main_buffer_size - mainbufix);
 309                 bufix = main_buffer_size - mainbufix;
 310                 length = DHCP_FIXED_NON_UDP + mainbufix;
 311                 if (overload & 1) {
 312                         if (option_size - bufix <= DHCP_FILE_LEN) {
 313                                 memcpy(outpacket->file,
 314                                     &buffer[bufix], option_size - bufix);
 315                                 mainbufix = option_size - bufix;
 316                                 if (mainbufix < DHCP_FILE_LEN)
 317                                         outpacket->file[mainbufix++] = (char)DHO_END;
 318                                 while (mainbufix < DHCP_FILE_LEN)
 319                                         outpacket->file[mainbufix++] = (char)DHO_PAD;
 320                         } else {
 321                                 memcpy(outpacket->file,
 322                                     &buffer[bufix], DHCP_FILE_LEN);
 323                                 bufix += DHCP_FILE_LEN;
 324                         }
 325                 }
 326                 if ((overload & 2) && option_size < bufix) {
 327                         memcpy(outpacket->sname,
 328                             &buffer[bufix], option_size - bufix);
 329
 330                         mainbufix = option_size - bufix;
 331                         if (mainbufix < DHCP_SNAME_LEN)
 332                                 outpacket->file[mainbufix++] = (char)DHO_END;
 333                         while (mainbufix < DHCP_SNAME_LEN)
 334                                 outpacket->file[mainbufix++] = (char)DHO_PAD;
 335                 }
 336         }
 337         return (length);
 338 }
 339
 340 /*
 341  * Store all the requested options into the requested buffer.
 342  */
 343 int
 344 store_options(unsigned char *buffer, int buflen, struct tree_cache **options,
 345     unsigned char *priority_list, int priority_len, int first_cutoff,
 346     int second_cutoff, int terminate)
 347 {
 348         int bufix = 0, option_stored[256], i, ix, tto;
 349
 350         /* Zero out the stored-lengths array. */
 351         memset(option_stored, 0, sizeof(option_stored));
 352
 353         /*
 354          * Copy out the options in the order that they appear in the
 355          * priority list...
 356          */
 357         for (i = 0; i < priority_len; i++) {
 358                 /* Code for next option to try to store. */
 359                 int code = priority_list[i];
 360                 int optstart;
 361
 362                 /*
 363                  * Number of bytes left to store (some may already have
 364                  * been stored by a previous pass).
 365                  */
 366                 int length;
 367
 368                 /* If no data is available for this option, skip it. */
 369                 if (!options[code]) {
 370                         continue;
 371                 }
 372
 373                 /*
 374                  * The client could ask for things that are mandatory,
 375                  * in which case we should avoid storing them twice...
 376                  */
 377                 if (option_stored[code])
 378                         continue;
 379                 option_stored[code] = 1;
 380
 381                 /* We should now have a constant length for the option. */
 382                 length = options[code]->len;
 383
 384                 /* Do we add a NUL? */
 385                 if (terminate && dhcp_options[code].format[0] == 't') {
 386                         length++;
 387                         tto = 1;
 388                 } else
 389                         tto = 0;
 390
 391                 /* Try to store the option. */
 392
 393                 /*
 394                  * If the option's length is more than 255, we must
 395                  * store it in multiple hunks.   Store 255-byte hunks
 396                  * first.  However, in any case, if the option data will
 397                  * cross a buffer boundary, split it across that
 398                  * boundary.
 399                  */
 400                 ix = 0;
 401
 402                 optstart = bufix;
 403                 while (length) {
 404                         unsigned char incr = length > 255 ? 255 : length;
 405
 406                         /*
 407                          * If this hunk of the buffer will cross a
 408                          * boundary, only go up to the boundary in this
 409                          * pass.
 410                          */
 411                         if (bufix < first_cutoff &&
 412                             bufix + incr > first_cutoff)
 413                                 incr = first_cutoff - bufix;
 414                         else if (bufix < second_cutoff &&
 415                             bufix + incr > second_cutoff)
 416                                 incr = second_cutoff - bufix;
 417
 418                         /*
 419                          * If this option is going to overflow the
 420                          * buffer, skip it.
 421                          */
 422                         if (bufix + 2 + incr > buflen) {
 423                                 bufix = optstart;
 424                                 break;
 425                         }
 426
 427                         /* Everything looks good - copy it in! */
 428                         buffer[bufix] = code;
 429                         buffer[bufix + 1] = incr;
 430                         if (tto && incr == length) {
 431                                 memcpy(buffer + bufix + 2,
 432                                     options[code]->value + ix, incr - 1);
 433                                 buffer[bufix + 2 + incr - 1] = 0;
 434                         } else
 435                                 memcpy(buffer + bufix + 2,
 436                                     options[code]->value + ix, incr);
 437                         length -= incr;
 438                         ix += incr;
 439                         bufix += 2 + incr;
 440                 }
 441         }
 442         return (bufix);
 443 }
 444
 445 /*
 446  * Format the specified option so that a human can easily read it.
 447  */
 448 char *
 449 pretty_print_option(unsigned int code, unsigned char *data, int len,
 450     int emit_commas, int emit_quotes)
 451 {
 452         static char optbuf[32768]; /* XXX */
 453         int hunksize = 0, numhunk = -1, numelem = 0;
 454         char fmtbuf[32], *op = optbuf;
 455         int i, j, k, opleft = sizeof(optbuf);
 456         unsigned char *dp = data;
 457         struct in_addr foo;
 458         char comma;
 459
 460         /* Code should be between 0 and 255. */
 461         if (code > 255)
 462                 error("pretty_print_option: bad code %d", code);
 463
 464         if (emit_commas)
 465                 comma = ',';
 466         else
 467                 comma = ' ';
 468
 469         /* Figure out the size of the data. */
 470         for (i = 0; dhcp_options[code].format[i]; i++) {
 471                 if (!numhunk) {
 472                         warning("%s: Excess information in format string: %s",
 473                             dhcp_options[code].name,
 474                             &(dhcp_options[code].format[i]));
 475                         break;
 476                 }
 477                 numelem++;
 478                 fmtbuf[i] = dhcp_options[code].format[i];
 479                 switch (dhcp_options[code].format[i]) {
 480                 case 'A':
 481                         --numelem;
 482                         fmtbuf[i] = 0;
 483                         numhunk = 0;
 484                         break;
 485                 case 'X':
 486                         for (k = 0; k < len; k++)
 487                                 if (!isascii(data[k]) ||
 488                                     !isprint(data[k]))
 489                                         break;
 490                         if (k == len) {
 491                                 fmtbuf[i] = 't';
 492                                 numhunk = -2;
 493                         } else {
 494                                 fmtbuf[i] = 'x';
 495                                 hunksize++;
 496                                 comma = ':';
 497                                 numhunk = 0;
 498                         }
 499                         fmtbuf[i + 1] = 0;
 500                         break;
 501                 case 't':
 502                         fmtbuf[i] = 't';
 503                         fmtbuf[i + 1] = 0;
 504                         numhunk = -2;
 505                         break;
 506                 case 'I':
 507                 case 'l':
 508                 case 'L':
 509                         hunksize += 4;
 510                         break;
 511                 case 's':
 512                 case 'S':
 513                         hunksize += 2;
 514                         break;
 515                 case 'b':
 516                 case 'B':
 517                 case 'f':
 518                         hunksize++;
 519                         break;
 520                 case 'e':
 521                         break;
 522                 default:
 523                         warning("%s: garbage in format string: %s",
 524                             dhcp_options[code].name,
 525                             &(dhcp_options[code].format[i]));
 526                         break;
 527                 }
 528         }
 529
 530         /* Check for too few bytes... */
 531         if (hunksize > len) {
 532                 warning("%s: expecting at least %d bytes; got %d",
 533                     dhcp_options[code].name, hunksize, len);
 534                 return ("<error>");
 535         }
 536         /* Check for too many bytes... */
 537         if (numhunk == -1 && hunksize < len)
 538                 warning("%s: %d extra bytes",
 539                     dhcp_options[code].name, len - hunksize);
 540
 541         /* If this is an array, compute its size. */
 542         if (!numhunk)
 543                 numhunk = len / hunksize;
 544         /* See if we got an exact number of hunks. */
 545         if (numhunk > 0 && numhunk * hunksize < len)
 546                 warning("%s: %d extra bytes at end of array",
 547                     dhcp_options[code].name, len - numhunk * hunksize);
 548
 549         /* A one-hunk array prints the same as a single hunk. */
 550         if (numhunk < 0)
 551                 numhunk = 1;
 552
 553         /* Cycle through the array (or hunk) printing the data. */
 554         for (i = 0; i < numhunk; i++) {
 555                 for (j = 0; j < numelem; j++) {
 556                         int opcount;
 557                         switch (fmtbuf[j]) {
 558                         case 't':
 559                                 if (emit_quotes) {
 560                                         *op++ = '"';
 561                                         opleft--;
 562                                 }
 563                                 for (; dp < data + len; dp++) {
 564                                         if (!isascii(*dp) ||
 565                                             !isprint(*dp)) {
 566                                                 if (dp + 1 != data + len ||
 567                                                     *dp != 0) {
 568                                                         snprintf(op, opleft,
 569                                                             "\\%03o", *dp);
 570                                                         op += 4;
 571                                                         opleft -= 4;
 572                                                 }
 573                                         } else if (*dp == '"' ||
 574                                             *dp == '\'' ||
 575                                             *dp == '$' ||
 576                                             *dp == '`' ||
 577                                             *dp == '\\') {
 578                                                 *op++ = '\\';
 579                                                 *op++ = *dp;
 580                                                 opleft -= 2;
 581                                         } else {
 582                                                 *op++ = *dp;
 583                                                 opleft--;
 584                                         }
 585                                 }
 586                                 if (emit_quotes) {
 587                                         *op++ = '"';
 588                                         opleft--;
 589                                 }
 590
 591                                 *op = 0;
 592                                 break;
 593                         case 'I':
 594                                 foo.s_addr = htonl(getULong(dp));
 595                                 opcount = strlcpy(op, inet_ntoa(foo), opleft);
 596                                 if (opcount >= opleft)
 597                                         goto toobig;
 598                                 opleft -= opcount;
 599                                 dp += 4;
 600                                 break;
 601                         case 'l':
 602                                 opcount = snprintf(op, opleft, "%ld",
 603                                     (long)getLong(dp));
 604                                 if (opcount >= opleft || opcount == -1)
 605                                         goto toobig;
 606                                 opleft -= opcount;
 607                                 dp += 4;
 608                                 break;
 609                         case 'L':
 610                                 opcount = snprintf(op, opleft, "%ld",
 611                                     (unsigned long)getULong(dp));
 612                                 if (opcount >= opleft || opcount == -1)
 613                                         goto toobig;
 614                                 opleft -= opcount;
 615                                 dp += 4;
 616                                 break;
 617                         case 's':
 618                                 opcount = snprintf(op, opleft, "%d",
 619                                     getShort(dp));
 620                                 if (opcount >= opleft || opcount == -1)
 621                                         goto toobig;
 622                                 opleft -= opcount;
 623                                 dp += 2;
 624                                 break;
 625                         case 'S':
 626                                 opcount = snprintf(op, opleft, "%d",
 627                                     getUShort(dp));
 628                                 if (opcount >= opleft || opcount == -1)
 629                                         goto toobig;
 630                                 opleft -= opcount;
 631                                 dp += 2;
 632                                 break;
 633                         case 'b':
 634                                 opcount = snprintf(op, opleft, "%d",
 635                                     *(char *)dp++);
 636                                 if (opcount >= opleft || opcount == -1)
 637                                         goto toobig;
 638                                 opleft -= opcount;
 639                                 break;
 640                         case 'B':
 641                                 opcount = snprintf(op, opleft, "%d", *dp++);
 642                                 if (opcount >= opleft || opcount == -1)
 643                                         goto toobig;
 644                                 opleft -= opcount;
 645                                 break;
 646                         case 'x':
 647                                 opcount = snprintf(op, opleft, "%x", *dp++);
 648                                 if (opcount >= opleft || opcount == -1)
 649                                         goto toobig;
 650                                 opleft -= opcount;
 651                                 break;
 652                         case 'f':
 653                                 opcount = strlcpy(op,
 654                                     *dp++ ? "true" : "false", opleft);
 655                                 if (opcount >= opleft)
 656                                         goto toobig;
 657                                 opleft -= opcount;
 658                                 break;
 659                         default:
 660                                 warning("Unexpected format code %c", fmtbuf[j]);
 661                         }
 662                         op += strlen(op);
 663                         opleft -= strlen(op);
 664                         if (opleft < 1)
 665                                 goto toobig;
 666                         if (j + 1 < numelem && comma != ':') {
 667                                 *op++ = ' ';
 668                                 opleft--;
 669                         }
 670                 }
 671                 if (i + 1 < numhunk) {
 672                         *op++ = comma;
 673                         opleft--;
 674                 }
 675                 if (opleft < 1)
 676                         goto toobig;
 677
 678         }
 679         return (optbuf);
 680  toobig:
 681         warning("dhcp option too large");
 682         return ("<error>");
 683 }
 684
 685 void
 686 do_packet(struct interface_info *interface, struct dhcp_packet *packet,
 687     int len, unsigned int from_port, struct iaddr from, struct hardware *hfrom)
 688 {
 689         struct packet tp;
 690         int i;
 691
 692         if (packet->hlen > sizeof(packet->chaddr)) {
 693                 note("Discarding packet with invalid hlen.");
 694                 return;
 695         }
 696
 697         memset(&tp, 0, sizeof(tp));
 698         tp.raw = packet;
 699         tp.packet_length = len;
 700         tp.client_port = from_port;
 701         tp.client_addr = from;
 702         tp.interface = interface;
 703         tp.haddr = hfrom;
 704
 705         parse_options(&tp);
 706         if (tp.options_valid &&
 707             tp.options[DHO_DHCP_MESSAGE_TYPE].data)
 708                 tp.packet_type = tp.options[DHO_DHCP_MESSAGE_TYPE].data[0];
 709         if (tp.packet_type)
 710                 dhcp(&tp);
 711         else
 712                 bootp(&tp);
 713
 714         /* Free the data associated with the options. */
 715         for (i = 0; i < 256; i++)
 716                 if (tp.options[i].len && tp.options[i].data)
 717                         free(tp.options[i].data);
 718 }