contrib/unbound/ldns/parse.c

   1 /*
   2  * a generic (simple) parser. Use to parse rr's, private key
   3  * information and /etc/resolv.conf files
   4  *
   5  * a Net::DNS like library for C
   6  * LibDNS Team @ NLnet Labs
   7  * (c) NLnet Labs, 2005-2006
   8  * See the file LICENSE for the license
   9  */
  10 #include "config.h"
  11 #include "ldns/parse.h"
  12 #include "ldns/parseutil.h"
  13 #include "ldns/sbuffer.h"
  14
  15 #include <limits.h>
  16 #include <strings.h>
  17
  18 sldns_lookup_table sldns_directive_types[] = {
  19         { LDNS_DIR_TTL, "$TTL" },
  20         { LDNS_DIR_ORIGIN, "$ORIGIN" },
  21         { LDNS_DIR_INCLUDE, "$INCLUDE" },
  22         { 0, NULL }
  23 };
  24
  25 /* add max_limit here? */
  26 ssize_t
  27 sldns_fget_token(FILE *f, char *token, const char *delim, size_t limit)
  28 {
  29         return sldns_fget_token_l(f, token, delim, limit, NULL);
  30 }
  31
  32 ssize_t
  33 sldns_fget_token_l(FILE *f, char *token, const char *delim, size_t limit, int *line_nr)
  34 {
  35         int c, prev_c;
  36         int p; /* 0 -> no parenthese seen, >0 nr of ( seen */
  37         int com, quoted;
  38         char *t;
  39         size_t i;
  40         const char *d;
  41         const char *del;
  42
  43         /* standard delimeters */
  44         if (!delim) {
  45                 /* from isspace(3) */
  46                 del = LDNS_PARSE_NORMAL;
  47         } else {
  48                 del = delim;
  49         }
  50
  51         p = 0;
  52         i = 0;
  53         com = 0;
  54         quoted = 0;
  55         prev_c = 0;
  56         t = token;
  57         if (del[0] == '"') {
  58                 quoted = 1;
  59         }
  60         while ((c = getc(f)) != EOF) {
  61                 if (c == '\r') /* carriage return */
  62                         c = ' ';
  63                 if (c == '(' && prev_c != '\\' && !quoted) {
  64                         /* this only counts for non-comments */
  65                         if (com == 0) {
  66                                 p++;
  67                         }
  68                         prev_c = c;
  69                         continue;
  70                 }
  71
  72                 if (c == ')' && prev_c != '\\' && !quoted) {
  73                         /* this only counts for non-comments */
  74                         if (com == 0) {
  75                                 p--;
  76                         }
  77                         prev_c = c;
  78                         continue;
  79                 }
  80
  81                 if (p < 0) {
  82                         /* more ) then ( - close off the string */
  83                         *t = '\0';
  84                         return 0;
  85                 }
  86
  87                 /* do something with comments ; */
  88                 if (c == ';' && quoted == 0) {
  89                         if (prev_c != '\\') {
  90                                 com = 1;
  91                         }
  92                 }
  93                 if (c == '\"' && com == 0 && prev_c != '\\') {
  94                         quoted = 1 - quoted;
  95                 }
  96
  97                 if (c == '\n' && com != 0) {
  98                         /* comments */
  99                         com = 0;
 100                         *t = ' ';
 101                         if (line_nr) {
 102                                 *line_nr = *line_nr + 1;
 103                         }
 104                         if (p == 0 && i > 0) {
 105                                 goto tokenread;
 106                         } else {
 107                                 prev_c = c;
 108                                 continue;
 109                         }
 110                 }
 111
 112                 if (com == 1) {
 113                         *t = ' ';
 114                         prev_c = c;
 115                         continue;
 116                 }
 117
 118                 if (c == '\n' && p != 0 && t > token) {
 119                         /* in parentheses */
 120                         if (line_nr) {
 121                                 *line_nr = *line_nr + 1;
 122                         }
 123                         *t++ = ' ';
 124                         prev_c = c;
 125                         continue;
 126                 }
 127
 128                 /* check if we hit the delim */
 129                 for (d = del; *d; d++) {
 130                         if (c == *d && i > 0 && prev_c != '\\' && p == 0) {
 131                                 if (c == '\n' && line_nr) {
 132                                         *line_nr = *line_nr + 1;
 133                                 }
 134                                 goto tokenread;
 135                         }
 136                 }
 137                 if (c != '\0' && c != '\n') {
 138                         i++;
 139                 }
 140                 if (limit > 0 && (i >= limit || (size_t)(t-token) >= limit)) {
 141                         *t = '\0';
 142                         return -1;
 143                 }
 144                 if (c != '\0' && c != '\n') {
 145                         *t++ = c;
 146                 }
 147                 if (c == '\\' && prev_c == '\\')
 148                         prev_c = 0;
 149                 else    prev_c = c;
 150         }
 151         *t = '\0';
 152         if (c == EOF) {
 153                 return (ssize_t)i;
 154         }
 155
 156         if (i == 0) {
 157                 /* nothing read */
 158                 return -1;
 159         }
 160         if (p != 0) {
 161                 return -1;
 162         }
 163         return (ssize_t)i;
 164
 165 tokenread:
 166         if(*del == '"')
 167                 /* do not skip over quotes after the string, they are part
 168                  * of the next string.  But skip over whitespace (if needed)*/
 169                 sldns_fskipcs_l(f, del+1, line_nr);
 170         else    sldns_fskipcs_l(f, del, line_nr);
 171         *t = '\0';
 172         if (p != 0) {
 173                 return -1;
 174         }
 175
 176         return (ssize_t)i;
 177 }
 178
 179 ssize_t
 180 sldns_fget_keyword_data(FILE *f, const char *keyword, const char *k_del, char *data,
 181                const char *d_del, size_t data_limit)
 182 {
 183        return sldns_fget_keyword_data_l(f, keyword, k_del, data, d_del,
 184                        data_limit, NULL);
 185 }
 186
 187 ssize_t
 188 sldns_fget_keyword_data_l(FILE *f, const char *keyword, const char *k_del, char *data,
 189                const char *d_del, size_t data_limit, int *line_nr)
 190 {
 191        /* we assume: keyword|sep|data */
 192        char *fkeyword;
 193        ssize_t i;
 194
 195        if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
 196                return -1;
 197        fkeyword = (char*)malloc(LDNS_MAX_KEYWORDLEN);
 198        if(!fkeyword)
 199                return -1;
 200
 201        i = sldns_fget_token(f, fkeyword, k_del, LDNS_MAX_KEYWORDLEN);
 202        if(i==0 || i==-1) {
 203                free(fkeyword);
 204                return -1;
 205        }
 206
 207        /* case??? i instead of strlen? */
 208        if (strncmp(fkeyword, keyword, LDNS_MAX_KEYWORDLEN - 1) == 0) {
 209                /* whee! */
 210                /* printf("%s\n%s\n", "Matching keyword", fkeyword); */
 211                i = sldns_fget_token_l(f, data, d_del, data_limit, line_nr);
 212                free(fkeyword);
 213                return i;
 214        } else {
 215                /*printf("no match for %s (read: %s)\n", keyword, fkeyword);*/
 216                free(fkeyword);
 217                return -1;
 218        }
 219 }
 220
 221 int
 222 sldns_bgetc(sldns_buffer *buffer)
 223 {
 224         if (!sldns_buffer_available_at(buffer, buffer->_position, sizeof(uint8_t))) {
 225                 sldns_buffer_set_position(buffer, sldns_buffer_limit(buffer));
 226                 /* sldns_buffer_rewind(buffer);*/
 227                 return EOF;
 228         }
 229         return (int)sldns_buffer_read_u8(buffer);
 230 }
 231
 232 ssize_t
 233 sldns_bget_token(sldns_buffer *b, char *token, const char *delim, size_t limit)
 234 {
 235         return sldns_bget_token_par(b, token, delim, limit, NULL, NULL);
 236 }
 237
 238 ssize_t
 239 sldns_bget_token_par(sldns_buffer *b, char *token, const char *delim,
 240         size_t limit, int* par, const char* skipw)
 241 {
 242         int c, lc;
 243         int p; /* 0 -> no parenthese seen, >0 nr of ( seen */
 244         int com, quoted;
 245         char *t;
 246         size_t i;
 247         const char *d;
 248         const char *del;
 249
 250         /* standard delimiters */
 251         if (!delim) {
 252                 /* from isspace(3) */
 253                 del = LDNS_PARSE_NORMAL;
 254         } else {
 255                 del = delim;
 256         }
 257
 258         p = (par?*par:0);
 259         i = 0;
 260         com = 0;
 261         quoted = 0;
 262         t = token;
 263         lc = 0;
 264         if (del[0] == '"') {
 265                 quoted = 1;
 266         }
 267
 268         while ((c = sldns_bgetc(b)) != EOF) {
 269                 if (c == '\r') /* carriage return */
 270                         c = ' ';
 271                 if (c == '(' && lc != '\\' && !quoted) {
 272                         /* this only counts for non-comments */
 273                         if (com == 0) {
 274                                 if(par) (*par)++;
 275                                 p++;
 276                         }
 277                         lc = c;
 278                         continue;
 279                 }
 280
 281                 if (c == ')' && lc != '\\' && !quoted) {
 282                         /* this only counts for non-comments */
 283                         if (com == 0) {
 284                                 if(par) (*par)--;
 285                                 p--;
 286                         }
 287                         lc = c;
 288                         continue;
 289                 }
 290
 291                 if (p < 0) {
 292                         /* more ) then ( */
 293                         *t = '\0';
 294                         return 0;
 295                 }
 296
 297                 /* do something with comments ; */
 298                 if (c == ';' && quoted == 0) {
 299                         if (lc != '\\') {
 300                                 com = 1;
 301                         }
 302                 }
 303                 if (c == '"' && com == 0 && lc != '\\') {
 304                         quoted = 1 - quoted;
 305                 }
 306
 307                 if (c == '\n' && com != 0) {
 308                         /* comments */
 309                         com = 0;
 310                         *t = ' ';
 311                         lc = c;
 312                         continue;
 313                 }
 314
 315                 if (com == 1) {
 316                         *t = ' ';
 317                         lc = c;
 318                         continue;
 319                 }
 320
 321                 if (c == '\n' && p != 0) {
 322                         /* in parentheses */
 323                         /* do not write ' ' if we want to skip spaces */
 324                         if(!(skipw && (strchr(skipw, c)||strchr(skipw, ' '))))
 325                                 *t++ = ' ';
 326                         lc = c;
 327                         continue;
 328                 }
 329
 330                 /* check to skip whitespace at start, but also after ( */
 331                 if(skipw && i==0 && !com && !quoted && lc != '\\') {
 332                         if(strchr(skipw, c)) {
 333                                 lc = c;
 334                                 continue;
 335                         }
 336                 }
 337
 338                 /* check if we hit the delim */
 339                 for (d = del; *d; d++) {
 340                         /* we can only exit if no parens or user tracks them */
 341                         if (c == *d && lc != '\\' && (p == 0 || par)) {
 342                                 goto tokenread;
 343                         }
 344                 }
 345
 346                 i++;
 347                 if (limit > 0 && (i >= limit || (size_t)(t-token) >= limit)) {
 348                         *t = '\0';
 349                         return -1;
 350                 }
 351                 *t++ = c;
 352
 353                 if (c == '\\' && lc == '\\') {
 354                         lc = 0;
 355                 } else {
 356                         lc = c;
 357                 }
 358         }
 359         *t = '\0';
 360         if (i == 0) {
 361                 /* nothing read */
 362                 return -1;
 363         }
 364         if (!par && p != 0) {
 365                 return -1;
 366         }
 367         return (ssize_t)i;
 368
 369 tokenread:
 370         if(*del == '"')
 371                 /* do not skip over quotes after the string, they are part
 372                  * of the next string.  But skip over whitespace (if needed)*/
 373                 sldns_bskipcs(b, del+1);
 374         else    sldns_bskipcs(b, del);
 375         *t = '\0';
 376
 377         if (!par && p != 0) {
 378                 return -1;
 379         }
 380         return (ssize_t)i;
 381 }
 382
 383
 384 void
 385 sldns_bskipcs(sldns_buffer *buffer, const char *s)
 386 {
 387         int found;
 388         char c;
 389         const char *d;
 390
 391         while(sldns_buffer_available_at(buffer, buffer->_position, sizeof(char))) {
 392                 c = (char) sldns_buffer_read_u8_at(buffer, buffer->_position);
 393                 found = 0;
 394                 for (d = s; *d; d++) {
 395                         if (*d == c) {
 396                                 found = 1;
 397                         }
 398                 }
 399                 if (found && buffer->_limit > buffer->_position) {
 400                         buffer->_position += sizeof(char);
 401                 } else {
 402                         return;
 403                 }
 404         }
 405 }
 406
 407 void
 408 sldns_fskipcs(FILE *fp, const char *s)
 409 {
 410         sldns_fskipcs_l(fp, s, NULL);
 411 }
 412
 413 void
 414 sldns_fskipcs_l(FILE *fp, const char *s, int *line_nr)
 415 {
 416         int found;
 417         int c;
 418         const char *d;
 419
 420         while ((c = fgetc(fp)) != EOF) {
 421                 if (line_nr && c == '\n') {
 422                         *line_nr = *line_nr + 1;
 423                 }
 424                 found = 0;
 425                 for (d = s; *d; d++) {
 426                         if (*d == c) {
 427                                 found = 1;
 428                         }
 429                 }
 430                 if (!found) {
 431                         /* with getc, we've read too far */
 432                         ungetc(c, fp);
 433                         return;
 434                 }
 435         }
 436 }
 437
 438 ssize_t
 439 sldns_bget_keyword_data(sldns_buffer *b, const char *keyword, const char *k_del, char
 440 *data, const char *d_del, size_t data_limit)
 441 {
 442        /* we assume: keyword|sep|data */
 443        char *fkeyword;
 444        ssize_t i;
 445
 446        if(strlen(keyword) >= LDNS_MAX_KEYWORDLEN)
 447                return -1;
 448        fkeyword = (char*)malloc(LDNS_MAX_KEYWORDLEN);
 449        if(!fkeyword)
 450                return -1; /* out of memory */
 451
 452        i = sldns_bget_token(b, fkeyword, k_del, data_limit);
 453        if(i==0 || i==-1) {
 454                free(fkeyword);
 455                return -1; /* nothing read */
 456        }
 457
 458        /* case??? */
 459        if (strncmp(fkeyword, keyword, strlen(keyword)) == 0) {
 460                free(fkeyword);
 461                /* whee, the match! */
 462                /* retrieve it's data */
 463                i = sldns_bget_token(b, data, d_del, 0);
 464                return i;
 465        } else {
 466                free(fkeyword);
 467                return -1;
 468        }
 469 }
 470