sbin/dhclient/conflex.c

   1 /*      $OpenBSD: conflex.c,v 1.7 2004/09/15 19:02:38 deraadt Exp $     */
   2
   3 /* Lexical scanner for dhcpd config file... */
   4
   5 /*-
   6  * SPDX-License-Identifier: BSD-3-Clause
   7  *
   8  * Copyright (c) 1995, 1996, 1997 The Internet Software Consortium.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  *
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. Neither the name of The Internet Software Consortium nor the names
  21  *    of its contributors may be used to endorse or promote products derived
  22  *    from this software without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
  25  * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  26  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
  29  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  32  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  33  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  34  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  35  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  *
  38  * This software has been written for the Internet Software Consortium
  39  * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
  40  * Enterprises.  To learn more about the Internet Software Consortium,
  41  * see ``http://www.vix.com/isc''.  To learn more about Vixie
  42  * Enterprises, see ``http://www.vix.com''.
  43  */
  44
  45 #include <sys/cdefs.h>
  46 __FBSDID("$FreeBSD$");
  47
  48 #include <ctype.h>
  49
  50 #include "dhcpd.h"
  51 #include "dhctoken.h"
  52
  53 int lexline;
  54 int lexchar;
  55 char *token_line;
  56 static char *prev_line;
  57 static char *cur_line;
  58 const char *tlname;
  59 int eol_token;
  60
  61 static char line1[81];
  62 static char line2[81];
  63 static unsigned lpos;
  64 static unsigned line;
  65 static int tlpos;
  66 static int tline;
  67 static int token;
  68 static int ugflag;
  69 static char *tval;
  70 static char tokbuf[1500];
  71
  72 static int get_char(FILE *);
  73 static int get_token(FILE *);
  74 static void skip_to_eol(FILE *);
  75 static int read_string(FILE *);
  76 static int read_number(int, FILE *);
  77 static int read_num_or_name(int, FILE *);
  78 static int intern(char *, int);
  79
  80 void
  81 new_parse(const char *name)
  82 {
  83         tlname = name;
  84         lpos = line = 1;
  85         cur_line = line1;
  86         prev_line = line2;
  87         token_line = cur_line;
  88         cur_line[0] = prev_line[0] = 0;
  89         warnings_occurred = 0;
  90 }
  91
  92 static int
  93 get_char(FILE *cfile)
  94 {
  95         int c = getc(cfile);
  96         if (!ugflag) {
  97                 if (c == '\n') {
  98                         if (cur_line == line1) {
  99                                 cur_line = line2;
 100                                 prev_line = line1;
 101                         } else {
 102                                 cur_line = line1;
 103                                 prev_line = line2;
 104                         }
 105                         line++;
 106                         lpos = 1;
 107                         cur_line[0] = 0;
 108                 } else if (c != EOF) {
 109                         if (lpos < sizeof(line1)) {
 110                                 cur_line[lpos - 1] = c;
 111                                 cur_line[lpos] = 0;
 112                         }
 113                         lpos++;
 114                 }
 115         } else
 116                 ugflag = 0;
 117         return (c);
 118 }
 119
 120 static int
 121 get_token(FILE *cfile)
 122 {
 123         int             c, ttok;
 124         static char     tb[2];
 125         int             l, p;
 126
 127         do {
 128                 l = line;
 129                 p = lpos;
 130
 131                 c = get_char(cfile);
 132
 133                 if (!(c == '\n' && eol_token) && isascii(c) && isspace(c))
 134                         continue;
 135                 if (c == '#') {
 136                         skip_to_eol(cfile);
 137                         continue;
 138                 }
 139                 if (c == '"') {
 140                         lexline = l;
 141                         lexchar = p;
 142                         ttok = read_string(cfile);
 143                         break;
 144                 }
 145                 if ((isascii(c) && isdigit(c)) || c == '-') {
 146                         lexline = l;
 147                         lexchar = p;
 148                         ttok = read_number(c, cfile);
 149                         break;
 150                 } else if (isascii(c) && isalpha(c)) {
 151                         lexline = l;
 152                         lexchar = p;
 153                         ttok = read_num_or_name(c, cfile);
 154                         break;
 155                 } else {
 156                         lexline = l;
 157                         lexchar = p;
 158                         tb[0] = c;
 159                         tb[1] = 0;
 160                         tval = tb;
 161                         ttok = c;
 162                         break;
 163                 }
 164         } while (1);
 165         return (ttok);
 166 }
 167
 168 int
 169 next_token(char **rval, FILE *cfile)
 170 {
 171         int     rv;
 172
 173         if (token) {
 174                 if (lexline != tline)
 175                         token_line = cur_line;
 176                 lexchar = tlpos;
 177                 lexline = tline;
 178                 rv = token;
 179                 token = 0;
 180         } else {
 181                 rv = get_token(cfile);
 182                 token_line = cur_line;
 183         }
 184         if (rval)
 185                 *rval = tval;
 186
 187         return (rv);
 188 }
 189
 190 int
 191 peek_token(char **rval, FILE *cfile)
 192 {
 193         int     x;
 194
 195         if (!token) {
 196                 tlpos = lexchar;
 197                 tline = lexline;
 198                 token = get_token(cfile);
 199                 if (lexline != tline)
 200                         token_line = prev_line;
 201                 x = lexchar;
 202                 lexchar = tlpos;
 203                 tlpos = x;
 204                 x = lexline;
 205                 lexline = tline;
 206                 tline = x;
 207         }
 208         if (rval)
 209                 *rval = tval;
 210
 211         return (token);
 212 }
 213
 214 static void
 215 skip_to_eol(FILE *cfile)
 216 {
 217         int     c;
 218
 219         do {
 220                 c = get_char(cfile);
 221                 if (c == EOF)
 222                         return;
 223                 if (c == '\n')
 224                         return;
 225         } while (1);
 226 }
 227
 228 static int
 229 read_string(FILE *cfile)
 230 {
 231         int     c, bs = 0;
 232         unsigned i;
 233
 234         for (i = 0; i < sizeof(tokbuf); i++) {
 235                 c = get_char(cfile);
 236                 if (c == EOF) {
 237                         parse_warn("eof in string constant");
 238                         break;
 239                 }
 240                 if (bs) {
 241                         bs = 0;
 242                         i--;
 243                         tokbuf[i] = c;
 244                 } else if (c == '\\')
 245                         bs = 1;
 246                 else if (c == '"')
 247                         break;
 248                 else
 249                         tokbuf[i] = c;
 250         }
 251         /*
 252          * Normally, I'd feel guilty about this, but we're talking about
 253          * strings that'll fit in a DHCP packet here...
 254          */
 255         if (i == sizeof(tokbuf)) {
 256                 parse_warn("string constant larger than internal buffer");
 257                 i--;
 258         }
 259         tokbuf[i] = 0;
 260         tval = tokbuf;
 261         return (STRING);
 262 }
 263
 264 static int
 265 read_number(int c, FILE *cfile)
 266 {
 267         int     seenx = 0, _token = NUMBER;
 268         unsigned i = 0;
 269
 270         tokbuf[i++] = c;
 271         for (; i < sizeof(tokbuf); i++) {
 272                 c = get_char(cfile);
 273                 if (!seenx && c == 'x')
 274                         seenx = 1;
 275                 else if (!isascii(c) || !isxdigit(c)) {
 276                         ungetc(c, cfile);
 277                         ugflag = 1;
 278                         break;
 279                 }
 280                 tokbuf[i] = c;
 281         }
 282         if (i == sizeof(tokbuf)) {
 283                 parse_warn("numeric token larger than internal buffer");
 284                 i--;
 285         }
 286         tokbuf[i] = 0;
 287         tval = tokbuf;
 288
 289         return (_token);
 290 }
 291
 292 static int
 293 read_num_or_name(int c, FILE *cfile)
 294 {
 295         unsigned i = 0;
 296         int     rv = NUMBER_OR_NAME;
 297
 298         tokbuf[i++] = c;
 299         for (; i < sizeof(tokbuf); i++) {
 300                 c = get_char(cfile);
 301                 if (!isascii(c) || (c != '-' && c != '_' && !isalnum(c))) {
 302                         ungetc(c, cfile);
 303                         ugflag = 1;
 304                         break;
 305                 }
 306                 if (!isxdigit(c))
 307                         rv = NAME;
 308                 tokbuf[i] = c;
 309         }
 310         if (i == sizeof(tokbuf)) {
 311                 parse_warn("token larger than internal buffer");
 312                 i--;
 313         }
 314         tokbuf[i] = 0;
 315         tval = tokbuf;
 316
 317         return (intern(tval, rv));
 318 }
 319
 320 static int
 321 intern(char *atom, int dfv)
 322 {
 323         if (!isascii(atom[0]))
 324                 return (dfv);
 325
 326         switch (tolower(atom[0])) {
 327         case 'a':
 328                 if (!strcasecmp(atom + 1, "lways-reply-rfc1048"))
 329                         return (ALWAYS_REPLY_RFC1048);
 330                 if (!strcasecmp(atom + 1, "ppend"))
 331                         return (APPEND);
 332                 if (!strcasecmp(atom + 1, "llow"))
 333                         return (ALLOW);
 334                 if (!strcasecmp(atom + 1, "lias"))
 335                         return (ALIAS);
 336                 if (!strcasecmp(atom + 1, "bandoned"))
 337                         return (ABANDONED);
 338                 if (!strcasecmp(atom + 1, "uthoritative"))
 339                         return (AUTHORITATIVE);
 340                 break;
 341         case 'b':
 342                 if (!strcasecmp(atom + 1, "ackoff-cutoff"))
 343                         return (BACKOFF_CUTOFF);
 344                 if (!strcasecmp(atom + 1, "ootp"))
 345                         return (BOOTP);
 346                 if (!strcasecmp(atom + 1, "ooting"))
 347                         return (BOOTING);
 348                 if (!strcasecmp(atom + 1, "oot-unknown-clients"))
 349                         return (BOOT_UNKNOWN_CLIENTS);
 350                 break;
 351         case 'c':
 352                 if (!strcasecmp(atom + 1, "lass"))
 353                         return (CLASS);
 354                 if (!strcasecmp(atom + 1, "iaddr"))
 355                         return (CIADDR);
 356                 if (!strcasecmp(atom + 1, "lient-identifier"))
 357                         return (CLIENT_IDENTIFIER);
 358                 if (!strcasecmp(atom + 1, "lient-hostname"))
 359                         return (CLIENT_HOSTNAME);
 360                 break;
 361         case 'd':
 362                 if (!strcasecmp(atom + 1, "omain"))
 363                         return (DOMAIN);
 364                 if (!strcasecmp(atom + 1, "eny"))
 365                         return (DENY);
 366                 if (!strncasecmp(atom + 1, "efault", 6)) {
 367                         if (!atom[7])
 368                                 return (DEFAULT);
 369                         if (!strcasecmp(atom + 7, "-lease-time"))
 370                                 return (DEFAULT_LEASE_TIME);
 371                         break;
 372                 }
 373                 if (!strncasecmp(atom + 1, "ynamic-bootp", 12)) {
 374                         if (!atom[13])
 375                                 return (DYNAMIC_BOOTP);
 376                         if (!strcasecmp(atom + 13, "-lease-cutoff"))
 377                                 return (DYNAMIC_BOOTP_LEASE_CUTOFF);
 378                         if (!strcasecmp(atom + 13, "-lease-length"))
 379                                 return (DYNAMIC_BOOTP_LEASE_LENGTH);
 380                         break;
 381                 }
 382                 break;
 383         case 'e':
 384                 if (!strcasecmp(atom + 1, "thernet"))
 385                         return (ETHERNET);
 386                 if (!strcasecmp(atom + 1, "nds"))
 387                         return (ENDS);
 388                 if (!strcasecmp(atom + 1, "xpire"))
 389                         return (EXPIRE);
 390                 break;
 391         case 'f':
 392                 if (!strcasecmp(atom + 1, "ilename"))
 393                         return (FILENAME);
 394                 if (!strcasecmp(atom + 1, "ixed-address"))
 395                         return (FIXED_ADDR);
 396                 if (!strcasecmp(atom + 1, "ddi"))
 397                         return (FDDI);
 398                 break;
 399         case 'g':
 400                 if (!strcasecmp(atom + 1, "iaddr"))
 401                         return (GIADDR);
 402                 if (!strcasecmp(atom + 1, "roup"))
 403                         return (GROUP);
 404                 if (!strcasecmp(atom + 1, "et-lease-hostnames"))
 405                         return (GET_LEASE_HOSTNAMES);
 406                 break;
 407         case 'h':
 408                 if (!strcasecmp(atom + 1, "ost"))
 409                         return (HOST);
 410                 if (!strcasecmp(atom + 1, "ardware"))
 411                         return (HARDWARE);
 412                 if (!strcasecmp(atom + 1, "ostname"))
 413                         return (HOSTNAME);
 414                 break;
 415         case 'i':
 416                 if (!strcasecmp(atom + 1, "nitial-interval"))
 417                         return (INITIAL_INTERVAL);
 418                 if (!strcasecmp(atom + 1, "nterface"))
 419                         return (INTERFACE);
 420                 break;
 421         case 'l':
 422                 if (!strcasecmp(atom + 1, "ease"))
 423                         return (LEASE);
 424                 break;
 425         case 'm':
 426                 if (!strcasecmp(atom + 1, "ax-lease-time"))
 427                         return (MAX_LEASE_TIME);
 428                 if (!strncasecmp(atom + 1, "edi", 3)) {
 429                         if (!strcasecmp(atom + 4, "a"))
 430                                 return (MEDIA);
 431                         if (!strcasecmp(atom + 4, "um"))
 432                                 return (MEDIUM);
 433                         break;
 434                 }
 435                 break;
 436         case 'n':
 437                 if (!strcasecmp(atom + 1, "ameserver"))
 438                         return (NAMESERVER);
 439                 if (!strcasecmp(atom + 1, "etmask"))
 440                         return (NETMASK);
 441                 if (!strcasecmp(atom + 1, "ext-server"))
 442                         return (NEXT_SERVER);
 443                 if (!strcasecmp(atom + 1, "ot"))
 444                         return (TOKEN_NOT);
 445                 break;
 446         case 'o':
 447                 if (!strcasecmp(atom + 1, "ption"))
 448                         return (OPTION);
 449                 if (!strcasecmp(atom + 1, "ne-lease-per-client"))
 450                         return (ONE_LEASE_PER_CLIENT);
 451                 break;
 452         case 'p':
 453                 if (!strcasecmp(atom + 1, "repend"))
 454                         return (PREPEND);
 455                 if (!strcasecmp(atom + 1, "acket"))
 456                         return (PACKET);
 457                 break;
 458         case 'r':
 459                 if (!strcasecmp(atom + 1, "ange"))
 460                         return (RANGE);
 461                 if (!strcasecmp(atom + 1, "equest"))
 462                         return (REQUEST);
 463                 if (!strcasecmp(atom + 1, "equire"))
 464                         return (REQUIRE);
 465                 if (!strcasecmp(atom + 1, "etry"))
 466                         return (RETRY);
 467                 if (!strcasecmp(atom + 1, "enew"))
 468                         return (RENEW);
 469                 if (!strcasecmp(atom + 1, "ebind"))
 470                         return (REBIND);
 471                 if (!strcasecmp(atom + 1, "eboot"))
 472                         return (REBOOT);
 473                 if (!strcasecmp(atom + 1, "eject"))
 474                         return (REJECT);
 475                 break;
 476         case 's':
 477                 if (!strcasecmp(atom + 1, "earch"))
 478                         return (SEARCH);
 479                 if (!strcasecmp(atom + 1, "tarts"))
 480                         return (STARTS);
 481                 if (!strcasecmp(atom + 1, "iaddr"))
 482                         return (SIADDR);
 483                 if (!strcasecmp(atom + 1, "ubnet"))
 484                         return (SUBNET);
 485                 if (!strcasecmp(atom + 1, "hared-network"))
 486                         return (SHARED_NETWORK);
 487                 if (!strcasecmp(atom + 1, "erver-name"))
 488                         return (SERVER_NAME);
 489                 if (!strcasecmp(atom + 1, "erver-identifier"))
 490                         return (SERVER_IDENTIFIER);
 491                 if (!strcasecmp(atom + 1, "elect-timeout"))
 492                         return (SELECT_TIMEOUT);
 493                 if (!strcasecmp(atom + 1, "end"))
 494                         return (SEND);
 495                 if (!strcasecmp(atom + 1, "cript"))
 496                         return (SCRIPT);
 497                 if (!strcasecmp(atom + 1, "upersede"))
 498                         return (SUPERSEDE);
 499                 break;
 500         case 't':
 501                 if (!strcasecmp(atom + 1, "imestamp"))
 502                         return (TIMESTAMP);
 503                 if (!strcasecmp(atom + 1, "imeout"))
 504                         return (TIMEOUT);
 505                 if (!strcasecmp(atom + 1, "oken-ring"))
 506                         return (TOKEN_RING);
 507                 break;
 508         case 'u':
 509                 if (!strncasecmp(atom + 1, "se", 2)) {
 510                         if (!strcasecmp(atom + 3, "r-class"))
 511                                 return (USER_CLASS);
 512                         if (!strcasecmp(atom + 3, "-host-decl-names"))
 513                                 return (USE_HOST_DECL_NAMES);
 514                         if (!strcasecmp(atom + 3,
 515                                          "-lease-addr-for-default-route"))
 516                                 return (USE_LEASE_ADDR_FOR_DEFAULT_ROUTE);
 517                         break;
 518                 }
 519                 if (!strcasecmp(atom + 1, "id"))
 520                         return (UID);
 521                 if (!strcasecmp(atom + 1, "nknown-clients"))
 522                         return (UNKNOWN_CLIENTS);
 523                 break;
 524         case 'v':
 525                 if (!strcasecmp(atom + 1, "endor-class"))
 526                         return (VENDOR_CLASS);
 527                 break;
 528         case 'y':
 529                 if (!strcasecmp(atom + 1, "iaddr"))
 530                         return (YIADDR);
 531                 break;
 532         }
 533         return (dfv);
 534 }