util.c
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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
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
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 
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 
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
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
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 *
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 
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 
435 uint16_t
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 }
void xprintf_rdf(ldns_rdf *rd)
Definition: util.c:30
time_t mktime_from_utc(const struct tm *tm)
Definition: util.c:255
void ldns_set_bit(uint8_t *byte, int bit_nr, bool value)
Definition: util.c:108
Defines ldns_rdf and functions to manipulate those.
char * ldns_bubblebabble(uint8_t *data, size_t len)
Encode data as BubbleBabble.
Definition: util.c:454
char ldns_int_to_hexdigit(int i)
Returns the char (hex) representation of the given int.
Definition: util.c:149
int ldns_get_bit_r(uint8_t bits[], size_t index)
Returns the value of the specified bit The bits are counted from right to left, so bit #0 is the righ...
Definition: util.c:98
time_t ldns_mktime_from_utc(const struct tm *tm)
Convert TM to seconds since epoch (midnight, January 1st, 1970).
Definition: util.c:230
struct tm * ldns_serial_arithmitics_gmtime_r(int32_t time, time_t now, struct tm *result)
The function interprets time as the number of seconds since epoch with respect to now using serial ar...
Definition: util.c:340
#define LDNS_XMALLOC(type, count)
Definition: util.h:51
size_t ldns_rdf_size(const ldns_rdf *rd)
returns the size of the rdf.
Definition: rdata.c:24
size_t ldns_rr_rd_count(const ldns_rr *rr)
returns the rd_count of an rr structure.
Definition: rr.c:876
Contains the definition of ldns_rr and functions to manipulate those.
void xprintf_rr(ldns_rr *rr)
Definition: util.c:40
Resource Record.
Definition: rr.h:278
uint16_t ldns_get_random(void)
Get random number.
Definition: util.c:436
uint8_t * ldns_rdf_data(const ldns_rdf *rd)
returns the data of the rdf.
Definition: rdata.c:38
const char * ldns_version(void)
Show the internal library version.
Definition: util.c:196
#define LDNS_VERSION
Definition: util.h:30
int ldns_init_random(FILE *fd, unsigned int size)
Init the random source applications should call this if they need entropy data within ldns If openSSL...
Definition: util.c:363
return NULL
Definition: keys.c:738
ldns_lookup_table * ldns_lookup_by_id(ldns_lookup_table *table, int id)
Definition: util.c:77
#define LDNS_MOD(x, y)
Definition: util.c:206
ldns_rdf_type ldns_rdf_get_type(const ldns_rdf *rd)
returns the type of the rdf.
Definition: rdata.c:31
#define LDNS_DIV(x, y)
Definition: util.c:207
const char * name
Definition: util.h:158
A general purpose lookup table.
Definition: util.h:156
int ldns_hexstring_to_data(uint8_t *data, const char *str)
Converts a hex string to binary data.
Definition: util.c:174
int ldns_hexdigit_to_int(char ch)
Returns the int value of the given (hex) digit.
Definition: util.c:124
Resource record data field.
Definition: rdata.h:138
ldns_lookup_table * ldns_lookup_by_name(ldns_lookup_table *table, const char *name)
Definition: util.c:66
int ldns_get_bit(uint8_t bits[], size_t index)
Returns the value of the specified bit The bits are counted from left to right, so bit #0 is the left...
Definition: util.c:88
#define LDNS_FREE(ptr)
Definition: util.h:60
void xprintf_hex(uint8_t *data, size_t len)
Definition: util.c:53
ldns_rdf ** _rdata_fields
The array of rdata&#39;s.
Definition: rr.h:292
int
Definition: dnssec.c:1575
i
Definition: keys.c:681