contrib/ldns/util.c

   1 /*
   2  * util.c
   3  *
   4  * some general memory functions
   5  *
   6  * a Net::DNS like library for C
   7  *
   8  * (c) NLnet Labs, 2004-2006
   9  *
  10  * See the file LICENSE for the license
  11  */
  12
  13 #include <ldns/config.h>
  14
  15 #include <ldns/rdata.h>
  16 #include <ldns/rr.h>
  17 #include <ldns/util.h>
  18 #include <strings.h>
  19 #include <stdlib.h>
  20 #include <stdio.h>
  21 #include <sys/time.h>
  22 #include <time.h>
  23
  24 #ifdef HAVE_SSL
  25 #include <openssl/rand.h>
  26 #endif
  27
  28 /* put this here tmp. for debugging */
  29 void
  30 xprintf_rdf(ldns_rdf *rd)
  31 {
  32         /* assume printable string */
  33         fprintf(stderr, "size\t:%u\n", (unsigned int)ldns_rdf_size(rd));
  34         fprintf(stderr, "type\t:%u\n", (unsigned int)ldns_rdf_get_type(rd));
  35         fprintf(stderr, "data\t:[%.*s]\n", (int)ldns_rdf_size(rd),
  36                         (char*)ldns_rdf_data(rd));
  37 }
  38
  39 void
  40 xprintf_rr(ldns_rr *rr)
  41 {
  42         /* assume printable string */
  43         uint16_t count, i;
  44
  45         count = ldns_rr_rd_count(rr);
  46
  47         for(i = 0; i < count; i++) {
  48                 fprintf(stderr, "print rd %u\n", (unsigned int) i);
  49                 xprintf_rdf(rr->_rdata_fields[i]);
  50         }
  51 }
  52
  53 void xprintf_hex(uint8_t *data, size_t len)
  54 {
  55         size_t i;
  56         for (i = 0; i < len; i++) {
  57                 if (i > 0 && i % 20 == 0) {
  58                         printf("\t; %u - %u\n", (unsigned int) i - 19, (unsigned int) i);
  59                 }
  60                 printf("%02x ", (unsigned int) data[i]);
  61         }
  62         printf("\n");
  63 }
  64
  65 ldns_lookup_table *
  66 ldns_lookup_by_name(ldns_lookup_table *table, const char *name)
  67 {
  68         while (table->name != NULL) {
  69                 if (strcasecmp(name, table->name) == 0)
  70                         return table;
  71                 table++;
  72         }
  73         return NULL;
  74 }
  75
  76 ldns_lookup_table *
  77 ldns_lookup_by_id(ldns_lookup_table *table, int id)
  78 {
  79         while (table->name != NULL) {
  80                 if (table->id == id)
  81                         return table;
  82                 table++;
  83         }
  84         return NULL;
  85 }
  86
  87 int
  88 ldns_get_bit(uint8_t bits[], size_t index)
  89 {
  90         /*
  91          * The bits are counted from left to right, so bit #0 is the
  92          * left most bit.
  93          */
  94         return (int) (bits[index / 8] & (1 << (7 - index % 8)));
  95 }
  96
  97 int
  98 ldns_get_bit_r(uint8_t bits[], size_t index)
  99 {
 100         /*
 101          * The bits are counted from right to left, so bit #0 is the
 102          * right most bit.
 103          */
 104         return (int) bits[index / 8] & (1 << (index % 8));
 105 }
 106
 107 void
 108 ldns_set_bit(uint8_t *byte, int bit_nr, bool value)
 109 {
 110         /*
 111          * The bits are counted from right to left, so bit #0 is the
 112          * right most bit.
 113          */
 114         if (bit_nr >= 0 && bit_nr < 8) {
 115                 if (value) {
 116                         *byte = *byte | (0x01 << bit_nr);
 117                 } else {
 118                         *byte = *byte & ~(0x01 << bit_nr);
 119                 }
 120         }
 121 }
 122
 123 int
 124 ldns_hexdigit_to_int(char ch)
 125 {
 126         switch (ch) {
 127         case '0': return 0;
 128         case '1': return 1;
 129         case '2': return 2;
 130         case '3': return 3;
 131         case '4': return 4;
 132         case '5': return 5;
 133         case '6': return 6;
 134         case '7': return 7;
 135         case '8': return 8;
 136         case '9': return 9;
 137         case 'a': case 'A': return 10;
 138         case 'b': case 'B': return 11;
 139         case 'c': case 'C': return 12;
 140         case 'd': case 'D': return 13;
 141         case 'e': case 'E': return 14;
 142         case 'f': case 'F': return 15;
 143         default:
 144                 return -1;
 145         }
 146 }
 147
 148 char
 149 ldns_int_to_hexdigit(int i)
 150 {
 151         switch (i) {
 152         case 0: return '0';
 153         case 1: return '1';
 154         case 2: return '2';
 155         case 3: return '3';
 156         case 4: return '4';
 157         case 5: return '5';
 158         case 6: return '6';
 159         case 7: return '7';
 160         case 8: return '8';
 161         case 9: return '9';
 162         case 10: return 'a';
 163         case 11: return 'b';
 164         case 12: return 'c';
 165         case 13: return 'd';
 166         case 14: return 'e';
 167         case 15: return 'f';
 168         default:
 169                 abort();
 170         }
 171 }
 172
 173 int
 174 ldns_hexstring_to_data(uint8_t *data, const char *str)
 175 {
 176         size_t i;
 177
 178         if (!str || !data) {
 179                 return -1;
 180         }
 181
 182         if (strlen(str) % 2 != 0) {
 183                 return -2;
 184         }
 185
 186         for (i = 0; i < strlen(str) / 2; i++) {
 187                 data[i] =
 188                         16 * (uint8_t) ldns_hexdigit_to_int(str[i*2]) +
 189                         (uint8_t) ldns_hexdigit_to_int(str[i*2 + 1]);
 190         }
 191
 192         return (int) i;
 193 }
 194
 195 const char *
 196 ldns_version(void)
 197 {
 198         return (char*)LDNS_VERSION;
 199 }
 200
 201 /* Number of days per month (except for February in leap years). */
 202 static const int mdays[] = {
 203         31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
 204 };
 205
 206 #define LDNS_MOD(x,y) (((x) % (y) < 0) ? ((x) % (y) + (y)) : ((x) % (y)))
 207 #define LDNS_DIV(x,y) (((x) % (y) < 0) ? ((x) / (y) -  1 ) : ((x) / (y)))
 208
 209 static int
 210 is_leap_year(int year)
 211 {
 212         return LDNS_MOD(year,   4) == 0 && (LDNS_MOD(year, 100) != 0
 213             || LDNS_MOD(year, 400) == 0);
 214 }
 215
 216 static int
 217 leap_days(int y1, int y2)
 218 {
 219         --y1;
 220         --y2;
 221         return (LDNS_DIV(y2,   4) - LDNS_DIV(y1,   4)) -
 222                (LDNS_DIV(y2, 100) - LDNS_DIV(y1, 100)) +
 223                (LDNS_DIV(y2, 400) - LDNS_DIV(y1, 400));
 224 }
 225
 226 /*
 227  * Code adapted from Python 2.4.1 sources (Lib/calendar.py).
 228  */
 229 time_t
 230 ldns_mktime_from_utc(const struct tm *tm)
 231 {
 232         int year = 1900 + tm->tm_year;
 233         time_t days = 365 * ((time_t) year - 1970) + leap_days(1970, year);
 234         time_t hours;
 235         time_t minutes;
 236         time_t seconds;
 237         int i;
 238
 239         for (i = 0; i < tm->tm_mon; ++i) {
 240                 days += mdays[i];
 241         }
 242         if (tm->tm_mon > 1 && is_leap_year(year)) {
 243                 ++days;
 244         }
 245         days += tm->tm_mday - 1;
 246
 247         hours = days * 24 + tm->tm_hour;
 248         minutes = hours * 60 + tm->tm_min;
 249         seconds = minutes * 60 + tm->tm_sec;
 250
 251         return seconds;
 252 }
 253
 254 time_t
 255 mktime_from_utc(const struct tm *tm)
 256 {
 257         return ldns_mktime_from_utc(tm);
 258 }
 259
 260 #if SIZEOF_TIME_T <= 4
 261
 262 static void
 263 ldns_year_and_yday_from_days_since_epoch(int64_t days, struct tm *result)
 264 {
 265         int year = 1970;
 266         int new_year;
 267
 268         while (days < 0 || days >= (int64_t) (is_leap_year(year) ? 366 : 365)) {
 269                 new_year = year + (int) LDNS_DIV(days, 365);
 270                 days -= (new_year - year) * 365;
 271                 days -= leap_days(year, new_year);
 272                 year  = new_year;
 273         }
 274         result->tm_year = year;
 275         result->tm_yday = (int) days;
 276 }
 277
 278 /* Number of days per month in a leap year. */
 279 static const int leap_year_mdays[] = {
 280         31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
 281 };
 282
 283 static void
 284 ldns_mon_and_mday_from_year_and_yday(struct tm *result)
 285 {
 286         int idays = result->tm_yday;
 287         const int *mon_lengths = is_leap_year(result->tm_year) ?
 288                                         leap_year_mdays : mdays;
 289
 290         result->tm_mon = 0;
 291         while  (idays >= mon_lengths[result->tm_mon]) {
 292                 idays -= mon_lengths[result->tm_mon++];
 293         }
 294         result->tm_mday = idays + 1;
 295 }
 296
 297 static void
 298 ldns_wday_from_year_and_yday(struct tm *result)
 299 {
 300         result->tm_wday = 4 /* 1-1-1970 was a thursday */
 301                         + LDNS_MOD((result->tm_year - 1970), 7) * LDNS_MOD(365, 7)
 302                         + leap_days(1970, result->tm_year)
 303                         + result->tm_yday;
 304         result->tm_wday = LDNS_MOD(result->tm_wday, 7);
 305         if (result->tm_wday < 0) {
 306                 result->tm_wday += 7;
 307         }
 308 }
 309
 310 static struct tm *
 311 ldns_gmtime64_r(int64_t clock, struct tm *result)
 312 {
 313         result->tm_isdst = 0;
 314         result->tm_sec   = (int) LDNS_MOD(clock, 60);
 315         clock            =       LDNS_DIV(clock, 60);
 316         result->tm_min   = (int) LDNS_MOD(clock, 60);
 317         clock            =       LDNS_DIV(clock, 60);
 318         result->tm_hour  = (int) LDNS_MOD(clock, 24);
 319         clock            =       LDNS_DIV(clock, 24);
 320
 321         ldns_year_and_yday_from_days_since_epoch(clock, result);
 322         ldns_mon_and_mday_from_year_and_yday(result);
 323         ldns_wday_from_year_and_yday(result);
 324         result->tm_year -= 1900;
 325
 326         return result;
 327 }
 328
 329 #endif /* SIZEOF_TIME_T <= 4 */
 330
 331 static int64_t
 332 ldns_serial_arithmitics_time(int32_t time, time_t now)
 333 {
 334         int32_t offset = time - (int32_t) now;
 335         return (int64_t) now + offset;
 336 }
 337
 338
 339 struct tm *
 340 ldns_serial_arithmitics_gmtime_r(int32_t time, time_t now, struct tm *result)
 341 {
 342 #if SIZEOF_TIME_T <= 4
 343         int64_t secs_since_epoch = ldns_serial_arithmitics_time(time, now);
 344         return  ldns_gmtime64_r(secs_since_epoch, result);
 345 #else
 346         time_t  secs_since_epoch = ldns_serial_arithmitics_time(time, now);
 347         return  gmtime_r(&secs_since_epoch, result);
 348 #endif
 349 }
 350
 351 /**
 352  * Init the random source
 353  * applications should call this if they need entropy data within ldns
 354  * If openSSL is available, it is automatically seeded from /dev/urandom
 355  * or /dev/random
 356  *
 357  * If you need more entropy, or have no openssl available, this function
 358  * MUST be called at the start of the program
 359  *
 360  * If openssl *is* available, this function just adds more entropy
 361  **/
 362 int
 363 ldns_init_random(FILE *fd, unsigned int size)
 364 {
 365         /* if fp is given, seed srandom with data from file
 366            otherwise use /dev/urandom */
 367         FILE *rand_f;
 368         uint8_t *seed;
 369         size_t read = 0;
 370         unsigned int seed_i;
 371         struct timeval tv;
 372
 373         /* we'll need at least sizeof(unsigned int) bytes for the
 374            standard prng seed */
 375         if (size < (unsigned int) sizeof(seed_i)){
 376                 size = (unsigned int) sizeof(seed_i);
 377         }
 378
 379         seed = LDNS_XMALLOC(uint8_t, size);
 380         if(!seed) {
 381                 return 1;
 382         }
 383
 384         if (!fd) {
 385                 if ((rand_f = fopen("/dev/urandom", "r")) == NULL) {
 386                         /* no readable /dev/urandom, try /dev/random */
 387                         if ((rand_f = fopen("/dev/random", "r")) == NULL) {
 388                                 /* no readable /dev/random either, and no entropy
 389                                    source given. we'll have to improvise */
 390                                 for (read = 0; read < size; read++) {
 391                                         gettimeofday(&tv, NULL);
 392                                         seed[read] = (uint8_t) (tv.tv_usec % 256);
 393                                 }
 394                         } else {
 395                                 read = fread(seed, 1, size, rand_f);
 396                         }
 397                 } else {
 398                         read = fread(seed, 1, size, rand_f);
 399                 }
 400         } else {
 401                 rand_f = fd;
 402                 read = fread(seed, 1, size, rand_f);
 403         }
 404
 405         if (read < size) {
 406                 LDNS_FREE(seed);
 407                 if (!fd) fclose(rand_f);
 408                 return 1;
 409         } else {
 410 #ifdef HAVE_SSL
 411                 /* Seed the OpenSSL prng (most systems have it seeded
 412                    automatically, in that case this call just adds entropy */
 413                 RAND_seed(seed, (int) size);
 414 #else
 415                 /* Seed the standard prng, only uses the first
 416                  * unsigned sizeof(unsiged int) bytes found in the entropy pool
 417                  */
 418                 memcpy(&seed_i, seed, sizeof(seed_i));
 419                 srandom(seed_i);
 420 #endif
 421                 LDNS_FREE(seed);
 422         }
 423
 424         if (!fd) {
 425                 if (rand_f) fclose(rand_f);
 426         }
 427
 428         return 0;
 429 }
 430
 431 /**
 432  * Get random number.
 433  *
 434  */
 435 uint16_t
 436 ldns_get_random(void)
 437 {
 438         uint16_t rid = 0;
 439 #ifdef HAVE_SSL
 440         if (RAND_bytes((unsigned char*)&rid, 2) != 1) {
 441                 rid = (uint16_t) random();
 442         }
 443 #else
 444         rid = (uint16_t) random();
 445 #endif
 446         return rid;
 447 }
 448
 449 /*
 450  * BubbleBabble code taken from OpenSSH
 451  * Copyright (c) 2001 Carsten Raskgaard.  All rights reserved.
 452  */
 453 char *
 454 ldns_bubblebabble(uint8_t *data, size_t len)
 455 {
 456         char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' };
 457         char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm',
 458             'n', 'p', 'r', 's', 't', 'v', 'z', 'x' };
 459         size_t i, j = 0, rounds, seed = 1;
 460         char *retval;
 461
 462         rounds = (len / 2) + 1;
 463         retval = LDNS_XMALLOC(char, rounds * 6);
 464         if(!retval) return NULL;
 465         retval[j++] = 'x';
 466         for (i = 0; i < rounds; i++) {
 467                 size_t idx0, idx1, idx2, idx3, idx4;
 468                 if ((i + 1 < rounds) || (len % 2 != 0)) {
 469                         idx0 = (((((size_t)(data[2 * i])) >> 6) & 3) +
 470                             seed) % 6;
 471                         idx1 = (((size_t)(data[2 * i])) >> 2) & 15;
 472                         idx2 = ((((size_t)(data[2 * i])) & 3) +
 473                             (seed / 6)) % 6;
 474                         retval[j++] = vowels[idx0];
 475                         retval[j++] = consonants[idx1];
 476                         retval[j++] = vowels[idx2];
 477                         if ((i + 1) < rounds) {
 478                                 idx3 = (((size_t)(data[(2 * i) + 1])) >> 4) & 15;
 479                                 idx4 = (((size_t)(data[(2 * i) + 1]))) & 15;
 480                                 retval[j++] = consonants[idx3];
 481                                 retval[j++] = '-';
 482                                 retval[j++] = consonants[idx4];
 483                                 seed = ((seed * 5) +
 484                                     ((((size_t)(data[2 * i])) * 7) +
 485                                     ((size_t)(data[(2 * i) + 1])))) % 36;
 486                         }
 487                 } else {
 488                         idx0 = seed % 6;
 489                         idx1 = 16;
 490                         idx2 = seed / 6;
 491                         retval[j++] = vowels[idx0];
 492                         retval[j++] = consonants[idx1];
 493                         retval[j++] = vowels[idx2];
 494                 }
 495         }
 496         retval[j++] = 'x';
 497         retval[j++] = '\0';
 498         return retval;
 499 }