sbin/dhclient/conflex.c

   1 /*      $OpenBSD: conflex.c,v 1.13 2006/12/17 17:41:56 stevesk Exp $    */
   2 /*      $DragonFly: src/sbin/dhclient/conflex.c,v 1.1 2008/08/30 16:07:58 hasso Exp $   */
   3
   4 /* Lexical scanner for dhclient config file... */
   5
   6 /*
   7  * Copyright (c) 1995, 1996, 1997 The Internet Software Consortium.
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  *
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. Neither the name of The Internet Software Consortium nor the names
  20  *    of its contributors may be used to endorse or promote products derived
  21  *    from this software without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
  24  * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  25  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  27  * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
  28  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  29  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  30  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  31  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  32  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  33  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  34  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  *
  37  * This software has been written for the Internet Software Consortium
  38  * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
  39  * Enterprises.  To learn more about the Internet Software Consortium,
  40  * see ``http://www.vix.com/isc''.  To learn more about Vixie
  41  * Enterprises, see ``http://www.vix.com''.
  42  */
  43
  44 #include <ctype.h>
  45
  46 #include "dhcpd.h"
  47 #include "dhctoken.h"
  48
  49 int lexline;
  50 int lexchar;
  51 char *token_line;
  52 char *prev_line;
  53 char *cur_line;
  54 char *tlname;
  55
  56 static char line1[81];
  57 static char line2[81];
  58 static uint 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 int kw_cmp(const void *, const void *);
  74 static int intern(char *, int);
  75
  76 void
  77 new_parse(char *name)
  78 {
  79         tlname = name;
  80         lpos = line = 1;
  81         cur_line = line1;
  82         prev_line = line2;
  83         token_line = cur_line;
  84         cur_line[0] = prev_line[0] = 0;
  85         warnings_occurred = 0;
  86 }
  87
  88 static int
  89 get_char(FILE *cfile)
  90 {
  91         int c = getc(cfile);
  92         if (!ugflag) {
  93                 if (c == '\n') {
  94                         if (cur_line == line1) {
  95                                 cur_line = line2;
  96                                 prev_line = line1;
  97                         } else {
  98                                 cur_line = line2;
  99                                 prev_line = line1;
 100                         }
 101                         line++;
 102                         lpos = 1;
 103                         cur_line[0] = 0;
 104                 } else if (c != EOF) {
 105                         if (lpos < sizeof(line1)) {
 106                                 cur_line[lpos - 1] = c;
 107                                 cur_line[lpos] = 0;
 108                         }
 109                         lpos++;
 110                 }
 111         } else
 112                 ugflag = 0;
 113         return (c);
 114 }
 115
 116 static int
 117 get_token(FILE *cfile)
 118 {
 119         int             c, ttok;
 120         static char     tb[2];
 121         int             l, p;
 122
 123         do {
 124                 l = line;
 125                 p = lpos;
 126
 127                 c = get_char(cfile);
 128
 129                 if (isascii(c) && isspace(c))
 130                         continue;
 131                 if (c == '#') {
 132                         skip_to_eol(cfile);
 133                         continue;
 134                 }
 135                 if (c == '"') {
 136                         lexline = l;
 137                         lexchar = p;
 138                         ttok = read_string(cfile);
 139                         break;
 140                 }
 141                 if ((isascii(c) && isdigit(c)) || c == '-') {
 142                         lexline = l;
 143                         lexchar = p;
 144                         ttok = read_number(c, cfile);
 145                         break;
 146                 } else if (isascii(c) && isalpha(c)) {
 147                         lexline = l;
 148                         lexchar = p;
 149                         ttok = read_num_or_name(c, cfile);
 150                         break;
 151                 } else {
 152                         lexline = l;
 153                         lexchar = p;
 154                         tb[0] = c;
 155                         tb[1] = 0;
 156                         tval = tb;
 157                         ttok = c;
 158                         break;
 159                 }
 160         } while (1);
 161         return (ttok);
 162 }
 163
 164 int
 165 next_token(char **rval, FILE *cfile)
 166 {
 167         int     rv;
 168
 169         if (token) {
 170                 if (lexline != tline)
 171                         token_line = cur_line;
 172                 lexchar = tlpos;
 173                 lexline = tline;
 174                 rv = token;
 175                 token = 0;
 176         } else {
 177                 rv = get_token(cfile);
 178                 token_line = cur_line;
 179         }
 180         if (rval)
 181                 *rval = tval;
 182
 183         return (rv);
 184 }
 185
 186 int
 187 peek_token(char **rval, FILE *cfile)
 188 {
 189         int     x;
 190
 191         if (!token) {
 192                 tlpos = lexchar;
 193                 tline = lexline;
 194                 token = get_token(cfile);
 195                 if (lexline != tline)
 196                         token_line = prev_line;
 197                 x = lexchar;
 198                 lexchar = tlpos;
 199                 tlpos = x;
 200                 x = lexline;
 201                 lexline = tline;
 202                 tline = x;
 203         }
 204         if (rval)
 205                 *rval = tval;
 206
 207         return (token);
 208 }
 209
 210 static void
 211 skip_to_eol(FILE *cfile)
 212 {
 213         int     c;
 214
 215         do {
 216                 c = get_char(cfile);
 217                 if (c == EOF)
 218                         return;
 219                 if (c == '\n')
 220                         return;
 221         } while (1);
 222 }
 223
 224 static int
 225 read_string(FILE *cfile)
 226 {
 227         uint    i;
 228         int     c, bs = 0;
 229
 230         for (i = 0; i < sizeof(tokbuf); i++) {
 231                 c = get_char(cfile);
 232                 if (c == EOF) {
 233                         parse_warn("eof in string constant");
 234                         break;
 235                 }
 236                 if (bs) {
 237                         bs = 0;
 238                         tokbuf[i] = c;
 239                 } else if (c == '\\')
 240                         bs = 1;
 241                 else if (c == '"')
 242                         break;
 243                 else
 244                         tokbuf[i] = c;
 245         }
 246         /*
 247          * Normally, I'd feel guilty about this, but we're talking about
 248          * strings that'll fit in a DHCP packet here...
 249          */
 250         if (i == sizeof(tokbuf)) {
 251                 parse_warn("string constant larger than internal buffer");
 252                 i--;
 253         }
 254         tokbuf[i] = 0;
 255         tval = tokbuf;
 256         return (TOK_STRING);
 257 }
 258
 259 static int
 260 read_number(int c, FILE *cfile)
 261 {
 262         uint    i = 0;
 263         int     seenx = 0, token = TOK_NUMBER;
 264
 265         tokbuf[i++] = c;
 266         for (; i < sizeof(tokbuf); i++) {
 267                 c = get_char(cfile);
 268                 if (!seenx && c == 'x')
 269                         seenx = 1;
 270                 else if (!isascii(c) || !isxdigit(c)) {
 271                         ungetc(c, cfile);
 272                         ugflag = 1;
 273                         break;
 274                 }
 275                 tokbuf[i] = c;
 276         }
 277         if (i == sizeof(tokbuf)) {
 278                 parse_warn("numeric token larger than internal buffer");
 279                 i--;
 280         }
 281         tokbuf[i] = 0;
 282         tval = tokbuf;
 283
 284         return (token);
 285 }
 286
 287 static int
 288 read_num_or_name(int c, FILE *cfile)
 289 {
 290         uint    i = 0;
 291         int     rv = TOK_NUMBER_OR_NAME;
 292
 293         tokbuf[i++] = c;
 294         for (; i < sizeof(tokbuf); i++) {
 295                 c = get_char(cfile);
 296                 if (!isascii(c) || (c != '-' && c != '_' && !isalnum(c))) {
 297                         ungetc(c, cfile);
 298                         ugflag = 1;
 299                         break;
 300                 }
 301                 if (!isxdigit(c))
 302                         rv = TOK_NAME;
 303                 tokbuf[i] = c;
 304         }
 305         if (i == sizeof(tokbuf)) {
 306                 parse_warn("token larger than internal buffer");
 307                 i--;
 308         }
 309         tokbuf[i] = 0;
 310         tval = tokbuf;
 311
 312         return (intern(tval, rv));
 313 }
 314
 315 static const struct keywords {
 316         const char      *k_name;
 317         int             k_val;
 318 } keywords[] = {
 319         { "alias",                              TOK_ALIAS },
 320         { "append",                             TOK_APPEND },
 321         { "backoff-cutoff",                     TOK_BACKOFF_CUTOFF },
 322         { "bootp",                              TOK_BOOTP },
 323         { "default",                            TOK_DEFAULT },
 324         { "deny",                               TOK_DENY },
 325         { "ethernet",                           TOK_ETHERNET },
 326         { "expire",                             TOK_EXPIRE },
 327         { "fddi",                               TOK_FDDI },
 328         { "filename",                           TOK_FILENAME },
 329         { "fixed-address",                      TOK_FIXED_ADDR },
 330         { "hardware",                           TOK_HARDWARE },
 331         { "initial-interval",                   TOK_INITIAL_INTERVAL },
 332         { "interface",                          TOK_INTERFACE },
 333         { "lease",                              TOK_LEASE },
 334         { "link-timeout",                       TOK_LINK_TIMEOUT },
 335         { "media",                              TOK_MEDIA },
 336         { "medium",                             TOK_MEDIUM },
 337         { "option",                             TOK_OPTION },
 338         { "prepend",                            TOK_PREPEND },
 339         { "rebind",                             TOK_REBIND },
 340         { "reboot",                             TOK_REBOOT },
 341         { "reject",                             TOK_REJECT },
 342         { "renew",                              TOK_RENEW },
 343         { "request",                            TOK_REQUEST },
 344         { "require",                            TOK_REQUIRE },
 345         { "retry",                              TOK_RETRY },
 346         { "script",                             TOK_SCRIPT },
 347         { "select-timeout",                     TOK_SELECT_TIMEOUT },
 348         { "send",                               TOK_SEND },
 349         { "server-name",                        TOK_SERVER_NAME },
 350         { "supersede",                          TOK_SUPERSEDE },
 351         { "timeout",                            TOK_TIMEOUT },
 352         { "token-ring",                         TOK_TOKEN_RING }
 353 };
 354
 355 int
 356 kw_cmp(const void *k, const void *e)
 357 {
 358         return (strcasecmp(k, ((const struct keywords *)e)->k_name));
 359 }
 360
 361 static int
 362 intern(char *atom, int dfv)
 363 {
 364         const struct keywords *p;
 365
 366         p = bsearch(atom, keywords, sizeof(keywords)/sizeof(keywords[0]),
 367             sizeof(keywords[0]), kw_cmp);
 368         if (p)
 369                 return (p->k_val);
 370         return (dfv);
 371 }