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  * Copyright (c) 1995, 1996, 1997 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 #include "dhcpd.h"
  46 #include "dhctoken.h"
  47
  48 int lexline;
  49 int lexchar;
  50 char *token_line;
  51 char *prev_line;
  52 char *cur_line;
  53 char *tlname;
  54 int eol_token;
  55
  56 static char line1[81];
  57 static char line2[81];
  58 static int lpos;
  59 static int line;
  60 static int tlpos;
  61 static int tline;
  62 static int token;
  63 static int ugflag;
  64 static char *tval;
  65 static char tokbuf[1500];
  66
  67 static int get_char(FILE *);
  68 static int get_token(FILE *);
  69 static void skip_to_eol(FILE *);
  70 static int read_string(FILE *);
  71 static int read_number(int, FILE *);
  72 static int read_num_or_name(int, FILE *);
  73 static int intern(char *, int);
  74
  75 void
  76 new_parse(char *name)
  77 {
  78         tlname = name;
  79         lpos = line = 1;
  80         cur_line = line1;
  81         prev_line = line2;
  82         token_line = cur_line;
  83         cur_line[0] = prev_line[0] = 0;
  84         warnings_occurred = 0;
  85 }
  86
  87 static int
  88 get_char(FILE *cfile)
  89 {
  90         int c = getc(cfile);
  91         if (!ugflag) {
  92                 if (c == '\n') {
  93                         if (cur_line == line1) {
  94                                 cur_line = line2;
  95                                 prev_line = line1;
  96                         } else {
  97                                 cur_line = line2;
  98                                 prev_line = line1;
  99                         }
 100                         line++;
 101                         lpos = 1;
 102                         cur_line[0] = 0;
 103                 } else if (c != EOF) {
 104                         if (lpos <= 81) {
 105                                 cur_line[lpos - 1] = c;
 106                                 cur_line[lpos] = 0;
 107                         }
 108                         lpos++;
 109                 }
 110         } else
 111                 ugflag = 0;
 112         return (c);
 113 }
 114
 115 static int
 116 get_token(FILE *cfile)
 117 {
 118         int             c, ttok;
 119         static char     tb[2];
 120         int             l, p;
 121
 122         do {
 123                 l = line;
 124                 p = lpos;
 125
 126                 c = get_char(cfile);
 127
 128                 if (!(c == '\n' && eol_token) && isascii(c) && isspace(c))
 129                         continue;
 130                 if (c == '#') {
 131                         skip_to_eol(cfile);
 132                         continue;
 133                 }
 134                 if (c == '"') {
 135                         lexline = l;
 136                         lexchar = p;
 137                         ttok = read_string(cfile);
 138                         break;
 139                 }
 140                 if ((isascii(c) && isdigit(c)) || c == '-') {
 141                         lexline = l;
 142                         lexchar = p;
 143                         ttok = read_number(c, cfile);
 144                         break;
 145                 } else if (isascii(c) && isalpha(c)) {
 146                         lexline = l;
 147                         lexchar = p;
 148                         ttok = read_num_or_name(c, cfile);
 149                         break;
 150                 } else {
 151                         lexline = l;
 152                         lexchar = p;
 153                         tb[0] = c;
 154                         tb[1] = 0;
 155                         tval = tb;
 156                         ttok = c;
 157                         break;
 158                 }
 159         } while (1);
 160         return (ttok);
 161 }
 162
 163 int
 164 next_token(char **rval, FILE *cfile)
 165 {
 166         int     rv;
 167
 168         if (token) {
 169                 if (lexline != tline)
 170                         token_line = cur_line;
 171                 lexchar = tlpos;
 172                 lexline = tline;
 173                 rv = token;
 174                 token = 0;
 175         } else {
 176                 rv = get_token(cfile);
 177                 token_line = cur_line;
 178         }
 179         if (rval)
 180                 *rval = tval;
 181
 182         return (rv);
 183 }
 184
 185 int
 186 peek_token(char **rval, FILE *cfile)
 187 {
 188         int     x;
 189
 190         if (!token) {
 191                 tlpos = lexchar;
 192                 tline = lexline;
 193                 token = get_token(cfile);
 194                 if (lexline != tline)
 195                         token_line = prev_line;
 196                 x = lexchar;
 197                 lexchar = tlpos;
 198                 tlpos = x;
 199                 x = lexline;
 200                 lexline = tline;
 201                 tline = x;
 202         }
 203         if (rval)
 204                 *rval = tval;
 205
 206         return (token);
 207 }
 208
 209 static void
 210 skip_to_eol(FILE *cfile)
 211 {
 212         int     c;
 213
 214         do {
 215                 c = get_char(cfile);
 216                 if (c == EOF)
 217                         return;
 218                 if (c == '\n')
 219                         return;
 220         } while (1);
 221 }
 222
 223 static int
 224 read_string(FILE *cfile)
 225 {
 226         int     i, c, bs = 0;
 227
 228         for (i = 0; i < sizeof(tokbuf); i++) {
 229                 c = get_char(cfile);
 230                 if (c == EOF) {
 231                         parse_warn("eof in string constant");
 232                         break;
 233                 }
 234                 if (bs) {
 235                         bs = 0;
 236                         tokbuf[i] = c;
 237                 } else if (c == '\\')
 238                         bs = 1;
 239                 else if (c == '"')
 240                         break;
 241                 else
 242                         tokbuf[i] = c;
 243         }
 244         /*
 245          * Normally, I'd feel guilty about this, but we're talking about
 246          * strings that'll fit in a DHCP packet here...
 247          */
 248         if (i == sizeof(tokbuf)) {
 249                 parse_warn("string constant larger than internal buffer");
 250                 i--;
 251         }
 252         tokbuf[i] = 0;
 253         tval = tokbuf;
 254         return (STRING);
 255 }
 256
 257 static int
 258 read_number(int c, FILE *cfile)
 259 {
 260         int     seenx = 0, i = 0, token = NUMBER;
 261
 262         tokbuf[i++] = c;
 263         for (; i < sizeof(tokbuf); i++) {
 264                 c = get_char(cfile);
 265                 if (!seenx && c == 'x')
 266                         seenx = 1;
 267                 else if (!isascii(c) || !isxdigit(c)) {
 268                         ungetc(c, cfile);
 269                         ugflag = 1;
 270                         break;
 271                 }
 272                 tokbuf[i] = c;
 273         }
 274         if (i == sizeof(tokbuf)) {
 275                 parse_warn("numeric token larger than internal buffer");
 276                 i--;
 277         }
 278         tokbuf[i] = 0;
 279         tval = tokbuf;
 280
 281         return (token);
 282 }
 283
 284 static int
 285 read_num_or_name(int c, FILE *cfile)
 286 {
 287         int     i = 0;
 288         int     rv = NUMBER_OR_NAME;
 289
 290         tokbuf[i++] = c;
 291         for (; i < sizeof(tokbuf); i++) {
 292                 c = get_char(cfile);
 293                 if (!isascii(c) || (c != '-' && c != '_' && !isalnum(c))) {
 294                         ungetc(c, cfile);
 295                         ugflag = 1;
 296                         break;
 297                 }
 298                 if (!isxdigit(c))
 299                         rv = NAME;
 300                 tokbuf[i] = c;
 301         }
 302         if (i == sizeof(tokbuf)) {
 303                 parse_warn("token larger than internal buffer");
 304                 i--;
 305         }
 306         tokbuf[i] = 0;
 307         tval = tokbuf;
 308
 309         return (intern(tval, rv));
 310 }
 311
 312 static int
 313 intern(char *atom, int dfv)
 314 {
 315         if (!isascii(atom[0]))
 316                 return (dfv);
 317
 318         switch (tolower(atom[0])) {
 319         case 'a':
 320                 if (!strcasecmp(atom + 1, "lways-reply-rfc1048"))
 321                         return (ALWAYS_REPLY_RFC1048);
 322                 if (!strcasecmp(atom + 1, "ppend"))
 323                         return (APPEND);
 324                 if (!strcasecmp(atom + 1, "llow"))
 325                         return (ALLOW);
 326                 if (!strcasecmp(atom + 1, "lias"))
 327                         return (ALIAS);
 328                 if (!strcasecmp(atom + 1, "bandoned"))
 329                         return (ABANDONED);
 330                 if (!strcasecmp(atom + 1, "uthoritative"))
 331                         return (AUTHORITATIVE);
 332                 break;
 333         case 'b':
 334                 if (!strcasecmp(atom + 1, "ackoff-cutoff"))
 335                         return (BACKOFF_CUTOFF);
 336                 if (!strcasecmp(atom + 1, "ootp"))
 337                         return (BOOTP);
 338                 if (!strcasecmp(atom + 1, "ooting"))
 339                         return (BOOTING);
 340                 if (!strcasecmp(atom + 1, "oot-unknown-clients"))
 341                         return (BOOT_UNKNOWN_CLIENTS);
 342         case 'c':
 343                 if (!strcasecmp(atom + 1, "lass"))
 344                         return (CLASS);
 345                 if (!strcasecmp(atom + 1, "iaddr"))
 346                         return (CIADDR);
 347                 if (!strcasecmp(atom + 1, "lient-identifier"))
 348                         return (CLIENT_IDENTIFIER);
 349                 if (!strcasecmp(atom + 1, "lient-hostname"))
 350                         return (CLIENT_HOSTNAME);
 351                 break;
 352         case 'd':
 353                 if (!strcasecmp(atom + 1, "omain"))
 354                         return (DOMAIN);
 355                 if (!strcasecmp(atom + 1, "eny"))
 356                         return (DENY);
 357                 if (!strncasecmp(atom + 1, "efault", 6)) {
 358                         if (!atom[7])
 359                                 return (DEFAULT);
 360                         if (!strcasecmp(atom + 7, "-lease-time"))
 361                                 return (DEFAULT_LEASE_TIME);
 362                         break;
 363                 }
 364                 if (!strncasecmp(atom + 1, "ynamic-bootp", 12)) {
 365                         if (!atom[13])
 366                                 return (DYNAMIC_BOOTP);
 367                         if (!strcasecmp(atom + 13, "-lease-cutoff"))
 368                                 return (DYNAMIC_BOOTP_LEASE_CUTOFF);
 369                         if (!strcasecmp(atom + 13, "-lease-length"))
 370                                 return (DYNAMIC_BOOTP_LEASE_LENGTH);
 371                         break;
 372                 }
 373                 break;
 374         case 'e':
 375                 if (!strcasecmp(atom + 1, "thernet"))
 376                         return (ETHERNET);
 377                 if (!strcasecmp(atom + 1, "nds"))
 378                         return (ENDS);
 379                 if (!strcasecmp(atom + 1, "xpire"))
 380                         return (EXPIRE);
 381                 break;
 382         case 'f':
 383                 if (!strcasecmp(atom + 1, "ilename"))
 384                         return (FILENAME);
 385                 if (!strcasecmp(atom + 1, "ixed-address"))
 386                         return (FIXED_ADDR);
 387                 if (!strcasecmp(atom + 1, "ddi"))
 388                         return (FDDI);
 389                 break;
 390         case 'g':
 391                 if (!strcasecmp(atom + 1, "iaddr"))
 392                         return (GIADDR);
 393                 if (!strcasecmp(atom + 1, "roup"))
 394                         return (GROUP);
 395                 if (!strcasecmp(atom + 1, "et-lease-hostnames"))
 396                         return (GET_LEASE_HOSTNAMES);
 397                 break;
 398         case 'h':
 399                 if (!strcasecmp(atom + 1, "ost"))
 400                         return (HOST);
 401                 if (!strcasecmp(atom + 1, "ardware"))
 402                         return (HARDWARE);
 403                 if (!strcasecmp(atom + 1, "ostname"))
 404                         return (HOSTNAME);
 405                 break;
 406         case 'i':
 407                 if (!strcasecmp(atom + 1, "nitial-interval"))
 408                         return (INITIAL_INTERVAL);
 409                 if (!strcasecmp(atom + 1, "nterface"))
 410                         return (INTERFACE);
 411                 break;
 412         case 'l':
 413                 if (!strcasecmp(atom + 1, "ease"))
 414                         return (LEASE);
 415                 break;
 416         case 'm':
 417                 if (!strcasecmp(atom + 1, "ax-lease-time"))
 418                         return (MAX_LEASE_TIME);
 419                 if (!strncasecmp(atom + 1, "edi", 3)) {
 420                         if (!strcasecmp(atom + 4, "a"))
 421                                 return (MEDIA);
 422                         if (!strcasecmp(atom + 4, "um"))
 423                                 return (MEDIUM);
 424                         break;
 425                 }
 426                 break;
 427         case 'n':
 428                 if (!strcasecmp(atom + 1, "ameserver"))
 429                         return (NAMESERVER);
 430                 if (!strcasecmp(atom + 1, "etmask"))
 431                         return (NETMASK);
 432                 if (!strcasecmp(atom + 1, "ext-server"))
 433                         return (NEXT_SERVER);
 434                 if (!strcasecmp(atom + 1, "ot"))
 435                         return (TOKEN_NOT);
 436                 break;
 437         case 'o':
 438                 if (!strcasecmp(atom + 1, "ption"))
 439                         return (OPTION);
 440                 if (!strcasecmp(atom + 1, "ne-lease-per-client"))
 441                         return (ONE_LEASE_PER_CLIENT);
 442                 break;
 443         case 'p':
 444                 if (!strcasecmp(atom + 1, "repend"))
 445                         return (PREPEND);
 446                 if (!strcasecmp(atom + 1, "acket"))
 447                         return (PACKET);
 448                 break;
 449         case 'r':
 450                 if (!strcasecmp(atom + 1, "ange"))
 451                         return (RANGE);
 452                 if (!strcasecmp(atom + 1, "equest"))
 453                         return (REQUEST);
 454                 if (!strcasecmp(atom + 1, "equire"))
 455                         return (REQUIRE);
 456                 if (!strcasecmp(atom + 1, "etry"))
 457                         return (RETRY);
 458                 if (!strcasecmp(atom + 1, "enew"))
 459                         return (RENEW);
 460                 if (!strcasecmp(atom + 1, "ebind"))
 461                         return (REBIND);
 462                 if (!strcasecmp(atom + 1, "eboot"))
 463                         return (REBOOT);
 464                 if (!strcasecmp(atom + 1, "eject"))
 465                         return (REJECT);
 466                 break;
 467         case 's':
 468                 if (!strcasecmp(atom + 1, "earch"))
 469                         return (SEARCH);
 470                 if (!strcasecmp(atom + 1, "tarts"))
 471                         return (STARTS);
 472                 if (!strcasecmp(atom + 1, "iaddr"))
 473                         return (SIADDR);
 474                 if (!strcasecmp(atom + 1, "ubnet"))
 475                         return (SUBNET);
 476                 if (!strcasecmp(atom + 1, "hared-network"))
 477                         return (SHARED_NETWORK);
 478                 if (!strcasecmp(atom + 1, "erver-name"))
 479                         return (SERVER_NAME);
 480                 if (!strcasecmp(atom + 1, "erver-identifier"))
 481                         return (SERVER_IDENTIFIER);
 482                 if (!strcasecmp(atom + 1, "elect-timeout"))
 483                         return (SELECT_TIMEOUT);
 484                 if (!strcasecmp(atom + 1, "end"))
 485                         return (SEND);
 486                 if (!strcasecmp(atom + 1, "cript"))
 487                         return (SCRIPT);
 488                 if (!strcasecmp(atom + 1, "upersede"))
 489                         return (SUPERSEDE);
 490                 break;
 491         case 't':
 492                 if (!strcasecmp(atom + 1, "imestamp"))
 493                         return (TIMESTAMP);
 494                 if (!strcasecmp(atom + 1, "imeout"))
 495                         return (TIMEOUT);
 496                 if (!strcasecmp(atom + 1, "oken-ring"))
 497                         return (TOKEN_RING);
 498                 break;
 499         case 'u':
 500                 if (!strncasecmp(atom + 1, "se", 2)) {
 501                         if (!strcasecmp(atom + 3, "r-class"))
 502                                 return (USER_CLASS);
 503                         if (!strcasecmp(atom + 3, "-host-decl-names"))
 504                                 return (USE_HOST_DECL_NAMES);
 505                         if (!strcasecmp(atom + 3,
 506                                          "-lease-addr-for-default-route"))
 507                                 return (USE_LEASE_ADDR_FOR_DEFAULT_ROUTE);
 508                         break;
 509                 }
 510                 if (!strcasecmp(atom + 1, "id"))
 511                         return (UID);
 512                 if (!strcasecmp(atom + 1, "nknown-clients"))
 513                         return (UNKNOWN_CLIENTS);
 514                 break;
 515         case 'v':
 516                 if (!strcasecmp(atom + 1, "endor-class"))
 517                         return (VENDOR_CLASS);
 518                 break;
 519         case 'y':
 520                 if (!strcasecmp(atom + 1, "iaddr"))
 521                         return (YIADDR);
 522                 break;
 523         }
 524         return (dfv);
 525 }