| 1 | /* $OpenBSD: src/sbin/dhclient/conflex.c,v 1.14 2011/12/10 17:36:40 krw Exp $ */ |
| 2 | |
| 3 | /* Lexical scanner for dhclient 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 | |
| 55 | static char line1[81]; |
| 56 | static char line2[81]; |
| 57 | static uint lpos; |
| 58 | static int line; |
| 59 | static int tlpos; |
| 60 | static int tline; |
| 61 | static int token; |
| 62 | static int ugflag; |
| 63 | static char *tval; |
| 64 | static char tokbuf[1500]; |
| 65 | |
| 66 | static int get_char(FILE *); |
| 67 | static int get_token(FILE *); |
| 68 | static void skip_to_eol(FILE *); |
| 69 | static int read_string(FILE *); |
| 70 | static int read_number(int, FILE *); |
| 71 | static int read_num_or_name(int, FILE *); |
| 72 | int kw_cmp(const void *, const void *); |
| 73 | static int intern(char *, int); |
| 74 | |
| 75 | void |
| 76 | new_parse(char *name) |
| 77 | { |
| 78 | /* |
| 79 | * Initialize all parsing state, as we are starting to parse a |
| 80 | * new file, 'name'. |
| 81 | */ |
| 82 | |
| 83 | bzero(line1, sizeof(line1)); |
| 84 | bzero(line2, sizeof(line2)); |
| 85 | bzero(tokbuf, sizeof(tokbuf)); |
| 86 | |
| 87 | lpos = line = 1; |
| 88 | tlpos = tline = token = ugflag = 0; |
| 89 | tval = NULL; |
| 90 | |
| 91 | lexline = lexchar = 0; |
| 92 | cur_line = line1; |
| 93 | prev_line = line2; |
| 94 | token_line = cur_line; |
| 95 | tlname = name; |
| 96 | |
| 97 | warnings_occurred = 0; |
| 98 | } |
| 99 | |
| 100 | static int |
| 101 | get_char(FILE *cfile) |
| 102 | { |
| 103 | int c = getc(cfile); |
| 104 | if (!ugflag) { |
| 105 | if (c == '\n') { |
| 106 | if (cur_line == line1) { |
| 107 | cur_line = line2; |
| 108 | prev_line = line1; |
| 109 | } else { |
| 110 | cur_line = line2; |
| 111 | prev_line = line1; |
| 112 | } |
| 113 | line++; |
| 114 | lpos = 1; |
| 115 | cur_line[0] = 0; |
| 116 | } else if (c != EOF) { |
| 117 | if (lpos < sizeof(line1)) { |
| 118 | cur_line[lpos - 1] = c; |
| 119 | cur_line[lpos] = 0; |
| 120 | } |
| 121 | lpos++; |
| 122 | } |
| 123 | } else |
| 124 | ugflag = 0; |
| 125 | return (c); |
| 126 | } |
| 127 | |
| 128 | static int |
| 129 | get_token(FILE *cfile) |
| 130 | { |
| 131 | int c, ttok; |
| 132 | static char tb[2]; |
| 133 | int l, p; |
| 134 | |
| 135 | do { |
| 136 | l = line; |
| 137 | p = lpos; |
| 138 | |
| 139 | c = get_char(cfile); |
| 140 | |
| 141 | if (isascii(c) && isspace(c)) |
| 142 | continue; |
| 143 | if (c == '#') { |
| 144 | skip_to_eol(cfile); |
| 145 | continue; |
| 146 | } |
| 147 | if (c == '"') { |
| 148 | lexline = l; |
| 149 | lexchar = p; |
| 150 | ttok = read_string(cfile); |
| 151 | break; |
| 152 | } |
| 153 | if ((isascii(c) && isdigit(c)) || c == '-') { |
| 154 | lexline = l; |
| 155 | lexchar = p; |
| 156 | ttok = read_number(c, cfile); |
| 157 | break; |
| 158 | } else if (isascii(c) && isalpha(c)) { |
| 159 | lexline = l; |
| 160 | lexchar = p; |
| 161 | ttok = read_num_or_name(c, cfile); |
| 162 | break; |
| 163 | } else { |
| 164 | lexline = l; |
| 165 | lexchar = p; |
| 166 | tb[0] = c; |
| 167 | tb[1] = 0; |
| 168 | tval = tb; |
| 169 | ttok = c; |
| 170 | break; |
| 171 | } |
| 172 | } while (1); |
| 173 | return (ttok); |
| 174 | } |
| 175 | |
| 176 | int |
| 177 | next_token(char **rval, FILE *cfile) |
| 178 | { |
| 179 | int rv; |
| 180 | |
| 181 | if (token) { |
| 182 | if (lexline != tline) |
| 183 | token_line = cur_line; |
| 184 | lexchar = tlpos; |
| 185 | lexline = tline; |
| 186 | rv = token; |
| 187 | token = 0; |
| 188 | } else { |
| 189 | rv = get_token(cfile); |
| 190 | token_line = cur_line; |
| 191 | } |
| 192 | if (rval) |
| 193 | *rval = tval; |
| 194 | |
| 195 | return (rv); |
| 196 | } |
| 197 | |
| 198 | int |
| 199 | peek_token(char **rval, FILE *cfile) |
| 200 | { |
| 201 | int x; |
| 202 | |
| 203 | if (!token) { |
| 204 | tlpos = lexchar; |
| 205 | tline = lexline; |
| 206 | token = get_token(cfile); |
| 207 | if (lexline != tline) |
| 208 | token_line = prev_line; |
| 209 | x = lexchar; |
| 210 | lexchar = tlpos; |
| 211 | tlpos = x; |
| 212 | x = lexline; |
| 213 | lexline = tline; |
| 214 | tline = x; |
| 215 | } |
| 216 | if (rval) |
| 217 | *rval = tval; |
| 218 | |
| 219 | return (token); |
| 220 | } |
| 221 | |
| 222 | static void |
| 223 | skip_to_eol(FILE *cfile) |
| 224 | { |
| 225 | int c; |
| 226 | |
| 227 | do { |
| 228 | c = get_char(cfile); |
| 229 | if (c == EOF) |
| 230 | return; |
| 231 | if (c == '\n') |
| 232 | return; |
| 233 | } while (1); |
| 234 | } |
| 235 | |
| 236 | static int |
| 237 | read_string(FILE *cfile) |
| 238 | { |
| 239 | uint i; |
| 240 | int c, bs = 0; |
| 241 | |
| 242 | for (i = 0; i < sizeof(tokbuf); i++) { |
| 243 | c = get_char(cfile); |
| 244 | if (c == EOF) { |
| 245 | parse_warn("eof in string constant"); |
| 246 | break; |
| 247 | } |
| 248 | if (bs) { |
| 249 | bs = 0; |
| 250 | tokbuf[i] = c; |
| 251 | } else if (c == '\\') |
| 252 | bs = 1; |
| 253 | else if (c == '"') |
| 254 | break; |
| 255 | else |
| 256 | tokbuf[i] = c; |
| 257 | } |
| 258 | /* |
| 259 | * Normally, I'd feel guilty about this, but we're talking about |
| 260 | * strings that'll fit in a DHCP packet here... |
| 261 | */ |
| 262 | if (i == sizeof(tokbuf)) { |
| 263 | parse_warn("string constant larger than internal buffer"); |
| 264 | i--; |
| 265 | } |
| 266 | tokbuf[i] = 0; |
| 267 | tval = tokbuf; |
| 268 | return (TOK_STRING); |
| 269 | } |
| 270 | |
| 271 | static int |
| 272 | read_number(int c, FILE *cfile) |
| 273 | { |
| 274 | uint i = 0; |
| 275 | int seenx = 0, token = TOK_NUMBER; |
| 276 | |
| 277 | tokbuf[i++] = c; |
| 278 | for (; i < sizeof(tokbuf); i++) { |
| 279 | c = get_char(cfile); |
| 280 | if (!seenx && c == 'x') |
| 281 | seenx = 1; |
| 282 | else if (!isascii(c) || !isxdigit(c)) { |
| 283 | ungetc(c, cfile); |
| 284 | ugflag = 1; |
| 285 | break; |
| 286 | } |
| 287 | tokbuf[i] = c; |
| 288 | } |
| 289 | if (i == sizeof(tokbuf)) { |
| 290 | parse_warn("numeric token larger than internal buffer"); |
| 291 | i--; |
| 292 | } |
| 293 | tokbuf[i] = 0; |
| 294 | tval = tokbuf; |
| 295 | |
| 296 | return (token); |
| 297 | } |
| 298 | |
| 299 | static int |
| 300 | read_num_or_name(int c, FILE *cfile) |
| 301 | { |
| 302 | uint i = 0; |
| 303 | int rv = TOK_NUMBER_OR_NAME; |
| 304 | |
| 305 | tokbuf[i++] = c; |
| 306 | for (; i < sizeof(tokbuf); i++) { |
| 307 | c = get_char(cfile); |
| 308 | if (!isascii(c) || (c != '-' && c != '_' && !isalnum(c))) { |
| 309 | ungetc(c, cfile); |
| 310 | ugflag = 1; |
| 311 | break; |
| 312 | } |
| 313 | if (!isxdigit(c)) |
| 314 | rv = TOK_NAME; |
| 315 | tokbuf[i] = c; |
| 316 | } |
| 317 | if (i == sizeof(tokbuf)) { |
| 318 | parse_warn("token larger than internal buffer"); |
| 319 | i--; |
| 320 | } |
| 321 | tokbuf[i] = 0; |
| 322 | tval = tokbuf; |
| 323 | |
| 324 | return (intern(tval, rv)); |
| 325 | } |
| 326 | |
| 327 | static const struct keywords { |
| 328 | const char *k_name; |
| 329 | int k_val; |
| 330 | } keywords[] = { |
| 331 | { "alias", TOK_ALIAS }, |
| 332 | { "append", TOK_APPEND }, |
| 333 | { "backoff-cutoff", TOK_BACKOFF_CUTOFF }, |
| 334 | { "bootp", TOK_BOOTP }, |
| 335 | { "default", TOK_DEFAULT }, |
| 336 | { "deny", TOK_DENY }, |
| 337 | { "ethernet", TOK_ETHERNET }, |
| 338 | { "expire", TOK_EXPIRE }, |
| 339 | { "fddi", TOK_FDDI }, |
| 340 | { "filename", TOK_FILENAME }, |
| 341 | { "fixed-address", TOK_FIXED_ADDR }, |
| 342 | { "hardware", TOK_HARDWARE }, |
| 343 | { "initial-interval", TOK_INITIAL_INTERVAL }, |
| 344 | { "interface", TOK_INTERFACE }, |
| 345 | { "lease", TOK_LEASE }, |
| 346 | { "link-timeout", TOK_LINK_TIMEOUT }, |
| 347 | { "media", TOK_MEDIA }, |
| 348 | { "medium", TOK_MEDIUM }, |
| 349 | { "option", TOK_OPTION }, |
| 350 | { "prepend", TOK_PREPEND }, |
| 351 | { "rebind", TOK_REBIND }, |
| 352 | { "reboot", TOK_REBOOT }, |
| 353 | { "reject", TOK_REJECT }, |
| 354 | { "renew", TOK_RENEW }, |
| 355 | { "request", TOK_REQUEST }, |
| 356 | { "require", TOK_REQUIRE }, |
| 357 | { "retry", TOK_RETRY }, |
| 358 | { "script", TOK_SCRIPT }, |
| 359 | { "select-timeout", TOK_SELECT_TIMEOUT }, |
| 360 | { "send", TOK_SEND }, |
| 361 | { "server-name", TOK_SERVER_NAME }, |
| 362 | { "supersede", TOK_SUPERSEDE }, |
| 363 | { "timeout", TOK_TIMEOUT }, |
| 364 | { "token-ring", TOK_TOKEN_RING } |
| 365 | }; |
| 366 | |
| 367 | int |
| 368 | kw_cmp(const void *k, const void *e) |
| 369 | { |
| 370 | return (strcasecmp(k, ((const struct keywords *)e)->k_name)); |
| 371 | } |
| 372 | |
| 373 | static int |
| 374 | intern(char *atom, int dfv) |
| 375 | { |
| 376 | const struct keywords *p; |
| 377 | |
| 378 | p = bsearch(atom, keywords, sizeof(keywords)/sizeof(keywords[0]), |
| 379 | sizeof(keywords[0]), kw_cmp); |
| 380 | if (p) |
| 381 | return (p->k_val); |
| 382 | return (dfv); |
| 383 | } |