File: rbldnsd_util.c

package info (click to toggle)
rbldnsd 0.998b~pre1-1
  • links: PTS, VCS
  • area: main
  • in suites: buster, stretch
  • size: 744 kB
  • ctags: 1,132
  • sloc: ansic: 8,212; python: 549; sh: 502; makefile: 249; awk: 33
file content (612 lines) | stat: -rw-r--r-- 16,161 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
/* Common utility routines for rbldnsd.
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <syslog.h>
#include <unistd.h>
#include <time.h>
#include "rbldnsd.h"

#define digit(c) ((c) >= '0' && (c) <= '9')
#define d2n(c) ((unsigned)((c) - '0'))

static char *parse_uint32_s(char *s, unsigned *np) {
  unsigned char *t = (unsigned char*)s;
  unsigned n = 0;
  if (!digit(*t))
    return NULL;
  do {
    if (n > 0xffffffffu / 10) return 0;
    if (n * 10 > 0xffffffffu - d2n(*t)) return 0;
    n = n * 10 + d2n(*t++);
  } while(digit(*t));
  *np = n;
  return (char*)t;
}

char *parse_uint32(char *s, unsigned *np) {
  if (!(s = parse_uint32_s(s, np))) return NULL;
  if (*s) {
    if (!ISSPACE(*s)) return NULL;
    ++s; SKIPSPACE(s);
  }
  return s;
}

char *parse_uint32_nb(char *s, unsigned char nb[4]) {
  unsigned n;
  if (!(s = parse_uint32(s, &n))) return NULL;
  PACK32(nb, n);
  return s;
}

char *parse_time(char *s, unsigned *tp) {
  unsigned m = 1;
  if (!(s = parse_uint32_s(s, tp))) return NULL;
  switch(*s) {
    case 'w': case 'W': m *= 7;		/* week */
    case 'd': case 'D': m *= 24;	/* day */
    case 'h': case 'H': m *= 60;	/* hours */
    case 'm': case 'M': m *= 60;	/* minues */
      if (0xffffffffu / m < *tp) return NULL;
      *tp *= m;
    case 's': case 'S':			/* secounds */
      ++s;
      break;
  }
  if (*s && *s != ':') {
    if (!ISSPACE(*s)) return NULL;
    ++s; SKIPSPACE(s);
  }
  return s;
}

char *parse_time_nb(char *s, unsigned char nb[4]) {
  unsigned t;
  if (!(s = parse_time(s, &t))) return NULL;
  PACK32(nb, t);
  return s;
}

char *parse_ttl(char *s, unsigned *ttlp, unsigned defttl) {
  s = parse_time(s, ttlp);
  if (*ttlp == 0)
    *ttlp = defttl;
  else if (min_ttl && *ttlp < min_ttl)
    *ttlp = min_ttl;
  else if (max_ttl && *ttlp > max_ttl)
    *ttlp = max_ttl;
  return s;
}

static const unsigned char mday[12] = {
  31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};

#define isleap(year) \
  ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))

static char *
parse_tsp(char *s, unsigned *np, unsigned min, unsigned max, unsigned w) {
  unsigned n = 0;
  if (!digit(*s)) return NULL;
  do n = n * 10 + d2n(*s++);
  while(digit(*s) && --w);
  if (n < min || n > max) return NULL;
  if (*s == ':' || *s == '-') ++s;
  *np = n;
  return s;
}

char *parse_timestamp(char *s, time_t *tsp) {
  unsigned year, mon, day, hour, min, sec;

  if ((*s == '0' || *s == '-' || *s == ':') &&
      (ISSPACE(s[1]) || !s[1])) {
    *tsp = 0;
    ++s;
    SKIPSPACE(s);
    return s;
  }
  if (!(s = parse_tsp(s, &year, 1970, 2038, 4))) return NULL;
  if (!(s = parse_tsp(s, &mon, 1, 12, 2))) return NULL;
  mon -= 1;
  day = mon == 1 && isleap(year) ? 29 : mday[mon];
  if (!(s = parse_tsp(s, &day, 1, day, 2))) return NULL;
  hour = min = sec = 0;
  if (*s && !ISSPACE(*s))
    if (!(s = parse_tsp(s, &hour, 0, 23, 2))) return NULL;
  if (*s && !ISSPACE(*s))
    if (!(s = parse_tsp(s, &min, 0, 59, 2))) return NULL;
  if (*s && !ISSPACE(*s))
    if (!(s = parse_tsp(s, &sec, 0, 59, 2))) return NULL;
  if (*s) {
    if (!ISSPACE(*s)) return NULL;
    ++s; SKIPSPACE(s);
  }

  {
    unsigned y4 = (year / 4) - !(year & 3);
    unsigned y100 = y4 / 25;
    unsigned y400 = y100 / 4;
    day =
      365 * (year - 1970) +
      (y4 - 492) - (y100 - 19) + (y400 - 4) +
      day - 1;
    if (isleap(year) && mon > 1)
      ++day;
    while(mon)
      day += mday[--mon];
    *tsp = ((day * 24 + hour) * 60 + min) * 60 + sec;
  }

  return s;
}

char *parse_dn(char *s, unsigned char *dn, unsigned *dnlenp) {
  char *n = s;
  unsigned l;
  while(*n && !ISSPACE(*n)) ++n;
  if (*n) *n++ = '\0';
  if (!*s) return NULL;
  if ((l = dns_ptodn(s, dn, DNS_MAXDN)) == 0)
    return NULL;
  if (dnlenp) *dnlenp = l;
  SKIPSPACE(n);
  return n;
}

int parse_a_txt(char *str, const char **rrp, const char *def_rr,
                struct dsctx *dsc) {
  char *rr;
  static char rrbuf[4+256];	/*XXX static buffer */
  if (*str == ':') {
    ip4addr_t a;
    int bits = ip4addr(str + 1, &a, &str);
    if (!a || bits <= 0) {
      dswarn(dsc, "invalid A RR");
      return 0;
    }
    if (bits == 8)
      a |= IP4A_LOOPBACK; /* only last digit in 127.0.0.x */
    SKIPSPACE(str);
    if (*str == ':') {	/* A+TXT */
      ++str;
      SKIPSPACE(str);
      rr = str - 4;
      PACK32(rr, a);
    }
    else if (*str) {
      dswarn(dsc, "unrecognized value for an entry");
      return 0;
    }
    else {	/* only A - take TXT from default entry */
      unsigned tlen = strlen(def_rr+4);	/* tlen is <= 255 */
      rr = rrbuf;
      PACK32(rr, a);
      memcpy(rr+4, def_rr+4, tlen+1);
      *rrp = rr;
      return tlen + 5;
    }
  }
  else {
    rr = str - 4;
    memcpy(rr, def_rr, 4);
  }
  if (*str) {
    unsigned len = strlen(str);
    if (len > 255) {
      dswarn(dsc, "TXT RR truncated to 255 bytes");
      str += 255;
    }
    else
      str += len;
    *str = '\0';
  }
  *rrp = rr;
  return 1 + (str - rr);
}

unsigned unpack32(const unsigned char p[4]) {
  unsigned n = p[0];
  n = (n << 8) | p[1];
  n = (n << 8) | p[2];
  n = (n << 8) | p[3];
  return n;
}

/* return pointer to the next word in line if first word is the same
 * as word_lc (ignoring case), or NULL if not.
 */
char *firstword_lc(char *line, const char *word_lc) {
  while(*word_lc)
    if (dns_dnlc(*line) != *word_lc)
      return NULL;
    else
      ++word_lc, ++line;
  if (!ISSPACE(*line))
    return NULL;
  SKIPSPACE(line);
 return line;
}

/* implement TXT substitutions.
 * `sb' is a buffer where the result will be stored -
 * at least 255 + 3 characters long */
int txtsubst(char sb[TXTBUFSIZ], const char *txt,
	     const char *s0, const struct dataset *ds) {
  char *const *sn = ds->ds_subst;
  unsigned sl;
  char *const e = sb + 254;
  char *lp = sb;
  const char *s, *si, *sx;
  if (txt[0] == '=')
    sx = ++txt;
  else if (sn[SUBST_BASE_TEMPLATE] && *sn[SUBST_BASE_TEMPLATE]) {
    if (*txt) s0 = txt;
    sx = s0;
    txt = sn[SUBST_BASE_TEMPLATE];
  }
  else
    sx = txt;
  while(lp < e) {
    if ((s = strchr(txt, '$')) == NULL)
      s = (char*)txt + strlen(txt);
    sl = s - txt;
    if (lp + sl > e)
      sl = e - lp;
    memcpy(lp, txt, sl);
    lp += sl;
    if (!*s++) break;
    if (*s == '$') { si = s++; sl = 1; }
    else if (*s >= '0' && *s <= '9') { /* $n var */
      si = sn[*s - '0'];
      if (!si) { si = s - 1; sl = 2; }
      else sl = strlen(si);
      ++s;
    }
    else if (*s == '=') {
      si = sx;
      sl = strlen(si);
      ++s;
    }
    else
      sl = strlen(si = s0);
    if (lp + sl > e) /* silently truncate TXT RR >255 bytes */
      sl = e - lp;
    memcpy(lp, si, sl);
    lp += sl;
    txt = s;
  }
  sl = lp - sb;
  if (sl > 254) sl = 254;
  return sl;
}

#ifndef NO_MASTER_DUMP

void dump_ip4(ip4addr_t a, const char *rr, const struct dataset *ds, FILE *f) {
  char name[sizeof("255.255.254.255")];
  sprintf(name, "%u.%u.%u.%u", a&255, (a>>8)&255, (a>>16)&255, (a>>24));
  dump_a_txt(name, rr, ip4atos(a), ds, f);
}

static void
dump_ip4octets(FILE *f, unsigned idx, ip4addr_t a, unsigned cnt,
	       const char *rr, const struct dataset *ds) {
  char name[16];
  static const char * const fmt[4] = {
     "%u.%u.%u.%u", "*.%u.%u.%u", "*.%u.%u", "*.%u"
  };
  const unsigned bits = 8 * idx;
  for(;;) {
    sprintf(name, fmt[idx], a&255, (a>>8)&255, (a>>16)&255, (a>>24));
    dump_a_txt(name, rr, ip4atos(a<<bits), ds, f);
    if (!--cnt)
      break;
    ++a;
  }
}

void dump_ip4range(ip4addr_t a, ip4addr_t b, const char *rr,
		   const struct dataset *ds, FILE *f) {

#define fn(idx,start,count) \
	dump_ip4octets(f, idx, start, count, rr, ds)
#define ip4range_expand_octet(bits)               \
  if ((a | 255u) >= b) {                          \
    if (b - a == 255u)                            \
      fn((bits>>3)+1, a>>8, 1);                   \
    else                                          \
      fn(bits>>3, a, b - a + 1);                  \
    return;                                       \
  }                                               \
  if (a & 255u) {                                 \
    fn(bits>>3, a, 256u - (a & 255u));            \
    a = (a >> 8) + 1;                             \
  }                                               \
  else                                            \
    a >>= 8;                                      \
  if ((b & 255u) != 255u) {                       \
    fn((bits>>3), (b & ~255u), (b&255u)+1);       \
    b = (b >> 8) - 1;                             \
  }                                               \
  else                                            \
    b >>= 8

  ip4range_expand_octet(0);
  ip4range_expand_octet(8);
  ip4range_expand_octet(16);
  fn(3, a, b - a + 1);

#undef fn
#undef ip4range_expand_octet

}

static inline unsigned
ip6nibble(const ip6oct_t addr[IP6ADDR_FULL], unsigned i)
{
  ip6oct_t byte = addr[i / 2];
  return (i % 2) ? (byte & 0xf) : (byte >> 4);
}

/* format DNS name for ip6 address (with some nibbles possibly wild-carded) */
static const char *
ip6name(const ip6oct_t *addr, unsigned wild_nibbles)
{
  static char hexdigits[] = "0123456789abcdef";
  static char name[IP6ADDR_FULL * 4 + 2] = "*";
  char *np = name + 1;
  unsigned n = 32 - wild_nibbles;

  /* don't write past end of buffer, even if passed invalid args */
  if (n > 32) n = 32;
  while (n-- > 0) {
    *np++ = '.';
    *np++ = hexdigits[ip6nibble(addr, n)];
  }
  *np = '\0';

  return wild_nibbles ? name : name + 2;
}

/* dump an ip6 address, with some nibbles possible wild-carded */
void
dump_ip6(const ip6oct_t *addr, unsigned wild_nibbles, const char *rr,
         const struct dataset *ds, FILE *f)
{
  const char *dns_name = ip6name(addr, wild_nibbles);
  const char *ipsubst = NULL;

  if (rr) {
    /* careful: addr may point to a short array (e.g. IP6ADDR_HALF) */
    ipsubst = ip6atos(addr, IP6ADDR_FULL - wild_nibbles / 2);
  }
  dump_a_txt(dns_name, rr, ipsubst, ds, f);
}

/* dump an ip6 address range.
 *
 * BEG is the first address in the range, END is one past the last
 * address included in the range.  END = NULL means no end limit.
 *
 * NB: The semantics of END are different than for dump_ip4range!
 */
void
dump_ip6range(const ip6oct_t *beg, const ip6oct_t *end, const char *rr,
              const struct dataset *ds, FILE *f)
{
  ip6oct_t addr[IP6ADDR_FULL];

  memcpy(addr, beg, IP6ADDR_FULL);
  while (1) {
    unsigned nwild, i;
    unsigned maxwild = 32;
    if (end) {
      /* find first nibble of end which is greater than addr */
      for (i = 0; i < 32; i++) {
        if (ip6nibble(end, i) != ip6nibble(addr, i))
          break;
      }
      if (i == 32 || ip6nibble(end, i) < ip6nibble(addr, i))
        return;                   /* end <= addr */
      /* we can only wildcard after this nibble */
      maxwild = 31 - i;
    }
    /* can only wildcard nibbles where we're starting from zero */
    for (nwild = 0; nwild < maxwild; nwild++)
      if (ip6nibble(addr, 31 - nwild) != 0)
        break;

    dump_ip6(addr, nwild, rr, ds, f);

    /* advance address to one past end of wildcarded range */
    /* Increment right-most non-wildcarded nibble */
    i = 15 -  nwild / 2;
    addr[i] += (nwild % 2) ? 0x10 : 0x01;
    while (addr[i] == 0) {      /* propagate carry */
      if (i == 0) return;       /* wrapped */
      addr[--i]++;
    }
  }
}

void
dump_a_txt(const char *name, const char *rr,
           const char *subst, const struct dataset *ds, FILE *f) {
  if (!rr)
    fprintf(f, "%s\tCNAME\texcluded\n", name);
  else {
    const unsigned char *a = (const unsigned char*)rr;
    char sb[TXTBUFSIZ];
    unsigned sl = txtsubst(sb, rr + 4, subst, ds);
    fprintf(f, "%s\tA\t%u.%u.%u.%u\n", name, a[0], a[1], a[2], a[3]);
    if (sl) {
      char *p, *n;
      sb[sl] = '\0';
      fprintf(f, "\tTXT\t\"");
      for(p = sb; (n = strchr(p, '"')) != NULL; p = n + 1) {
        fwrite(p, 1, n - p, f);
        putc('\\', f); putc('"', f);
      }
      fprintf(f, "%s\"\n", p);
    }
  }
}

#endif

char *emalloc(size_t size) {
  void *ptr = malloc(size);
  if (!ptr)
    oom();
  return ptr;
}

char *ezalloc(size_t size) {
  void *ptr = calloc(1, size);
  if (!ptr)
    oom();
  return ptr;
}

char *erealloc(void *ptr, size_t size) {
  void *nptr = realloc(ptr, size);
  if (!nptr)
    oom();
  return nptr;
}

char *ememdup(const void *buf, unsigned len) {
  char *b = emalloc(len);
  if (b)
    memcpy(b, buf, len);
  return b;
}

char *estrdup(const char *str) {
  return ememdup(str, strlen(str) + 1);
}

/* what a mess... this routine is to work around various snprintf
 * implementations.  It never return <1 or value greather than
 * size of buffer: i.e. it returns number of chars _actually written_
 * to a buffer.
 * Maybe replace this with an alternative (simplistic) implementation,
 * only %d/%u/%s, with additional %S to print untrusted data replacing
 * control chars with something sane, and to print `...' for arguments
 * that aren't fit (e.g. "%.5s", "1234567" will print `12...') ?
 */

int vssprintf(char *buf, int bufsz, const char *fmt, va_list ap) {
  int r = vsnprintf(buf, bufsz, fmt, ap);
  return r < 0 ? 0 : r >= bufsz ? buf[bufsz-1] = '\0', bufsz - 1 : r;
}

int ssprintf(char *buf, int bufsz, const char *fmt, ...) {
  va_list ap;
  va_start(ap, fmt);
  bufsz = vssprintf(buf, bufsz, fmt, ap);
  va_end(ap);
  return bufsz;
}

/* logging */

static void
vdslog(int level, struct dsctx *dsc, const char *fmt, va_list ap) {
  char buf[1024];
  int pl, l;
  if ((logto & LOGTO_STDOUT) ||
      (level <= LOG_WARNING && (logto & LOGTO_STDERR)))
    l = pl = ssprintf(buf, sizeof(buf), "%.30s: ", progname);
  else if (logto & LOGTO_SYSLOG)
    l = pl = 0;
  else
    return;
  if (dsc) {
    if (dsc->dsc_fname) {
      l += ssprintf(buf + l, sizeof(buf) - l, "file %.60s", dsc->dsc_fname);
      l += ssprintf(buf + l, sizeof(buf) - l,
                    dsc->dsc_lineno ? "(%d): " : ": ", dsc->dsc_lineno);
    }
    else {
      l += ssprintf(buf + l, sizeof(buf) - l, "%s:%.60s:",
                    dsc->dsc_ds->ds_type->dst_name, dsc->dsc_ds->ds_spec);
      if (dsc->dsc_subset) {
        l += ssprintf(buf + l, sizeof(buf) - l, "%s:",
                      dsc->dsc_subset->ds_type->dst_name);
	if (dsc->dsc_subset->ds_spec)
          l += ssprintf(buf + l, sizeof(buf) - l, "%s:",
                        dsc->dsc_subset->ds_spec);
      }
      l += ssprintf(buf + l, sizeof(buf) - l, " ");
    }
  }
  l += vssprintf(buf + l, sizeof(buf) - l, fmt, ap);
  if (logto & LOGTO_SYSLOG) {
    fmt = buf + pl;
    syslog(level, strchr(fmt, '%') ? "%s" : fmt, fmt);
  }
  buf[l++] = '\n';
  if (level <= LOG_WARNING) {
    if (logto & (LOGTO_STDERR|LOGTO_STDOUT))
      write(2, buf, l);
  }
  else if (logto & LOGTO_STDOUT)
    write(1, buf, l);
}

void dslog(int level, struct dsctx *dsc, const char *fmt, ...) {
  va_list ap;
  va_start(ap, fmt);
  vdslog(level, dsc, fmt, ap);
  va_end(ap);
}

#define MAXWARN 5

void dswarn(struct dsctx *dsc, const char *fmt, ...) {
  if (++dsc->dsc_warns <= MAXWARN) { /* prevent syslog flood */
    va_list ap;
    va_start(ap, fmt);
    vdslog(LOG_WARNING, dsc, fmt, ap);
    va_end(ap);
  }
}

void dsloaded(struct dsctx *dsc, const char *fmt, ...) {
  va_list ap;
  if (dsc->dsc_warns > MAXWARN)
    dslog(LOG_WARNING, dsc, "%d more warnings suppressed",
          dsc->dsc_warns - MAXWARN);
  va_start(ap, fmt);
  if (dsc->dsc_subset)
     vdslog(LOG_INFO, dsc, fmt, ap);
  else {
    struct tm *tm = gmtime(&dsc->dsc_ds->ds_stamp);
    char buf[128];
    vssprintf(buf, sizeof(buf), fmt, ap);
    dslog(LOG_INFO, dsc, "%04d%02d%02d %02d%02d%02d: %s",
          tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
          tm->tm_hour, tm->tm_min, tm->tm_sec,
          buf);
  }
  va_end(ap);
}

void zlog(int level, const struct zone *zone, const char *fmt, ...) {
  va_list ap;
  char buf[128];
  char name[DNS_MAXDOMAIN+1];

  va_start(ap, fmt);
  vssprintf(buf, sizeof(buf), fmt, ap);
  va_end(ap);
  dns_dntop(zone->z_dn, name, sizeof(name));
  dslog(level, 0, "zone %.70s: %s", name, buf);
}