resolv/ns_ttl.c

   1 /*
   2  * Copyright (c) 1996,1999 by Internet Software Consortium.
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
   9  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  10  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  11  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  12  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  13  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  14  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  15  * SOFTWARE.
  16  */
  17
  18 #if !defined(_LIBC) && !defined(lint)
  19 static const char rcsid[] = "$BINDId: ns_ttl.c,v 8.8 1999/10/13 16:39:36 vixie Exp $";
  20 #endif
  21
  22 /* Import. */
  23
  24 #include <arpa/nameser.h>
  25
  26 #include <ctype.h>
  27 #include <errno.h>
  28 #include <stdio.h>
  29 #include <string.h>
  30
  31 #ifdef SPRINTF_CHAR
  32 # define SPRINTF(x) strlen(sprintf/**/x)
  33 #else
  34 # define SPRINTF(x) ((size_t)sprintf x)
  35 #endif
  36
  37 /* Forward. */
  38
  39 static int      fmt1(int t, char s, char **buf, size_t *buflen);
  40
  41 /* Macros. */
  42
  43 #define T(x) if ((x) < 0) return (-1); else (void)NULL
  44
  45 /* Public. */
  46
  47 int
  48 ns_format_ttl(u_long src, char *dst, size_t dstlen) {
  49         char *odst = dst;
  50         int secs, mins, hours, days, weeks, x;
  51         char *p;
  52
  53         secs = src % 60;   src /= 60;
  54         mins = src % 60;   src /= 60;
  55         hours = src % 24;  src /= 24;
  56         days = src % 7;    src /= 7;
  57         weeks = src;       src = 0;
  58
  59         x = 0;
  60         if (weeks) {
  61                 T(fmt1(weeks, 'W', &dst, &dstlen));
  62                 x++;
  63         }
  64         if (days) {
  65                 T(fmt1(days, 'D', &dst, &dstlen));
  66                 x++;
  67         }
  68         if (hours) {
  69                 T(fmt1(hours, 'H', &dst, &dstlen));
  70                 x++;
  71         }
  72         if (mins) {
  73                 T(fmt1(mins, 'M', &dst, &dstlen));
  74                 x++;
  75         }
  76         if (secs || !(weeks || days || hours || mins)) {
  77                 T(fmt1(secs, 'S', &dst, &dstlen));
  78                 x++;
  79         }
  80
  81         if (x > 1) {
  82                 int ch;
  83
  84                 for (p = odst; (ch = *p) != '\0'; p++)
  85                         if (isascii(ch) && isupper(ch))
  86                                 *p = tolower(ch);
  87         }
  88
  89         return (dst - odst);
  90 }
  91
  92 #ifndef SHARED
  93 // Seems not to be needed.  It's not exported from the DSO.  Some libresolv.a
  94 // might depend on it so we let it in.
  95 int
  96 ns_parse_ttl(const char *src, u_long *dst) {
  97         u_long ttl, tmp;
  98         int ch, digits, dirty;
  99
 100         ttl = 0;
 101         tmp = 0;
 102         digits = 0;
 103         dirty = 0;
 104         while ((ch = *src++) != '\0') {
 105                 if (!isascii(ch) || !isprint(ch))
 106                         goto einval;
 107                 if (isdigit(ch)) {
 108                         tmp *= 10;
 109                         tmp += (ch - '0');
 110                         digits++;
 111                         continue;
 112                 }
 113                 if (digits == 0)
 114                         goto einval;
 115                 if (islower(ch))
 116                         ch = toupper(ch);
 117                 switch (ch) {
 118                 case 'W':  tmp *= 7;
 119                 case 'D':  tmp *= 24;
 120                 case 'H':  tmp *= 60;
 121                 case 'M':  tmp *= 60;
 122                 case 'S':  break;
 123                 default:   goto einval;
 124                 }
 125                 ttl += tmp;
 126                 tmp = 0;
 127                 digits = 0;
 128                 dirty = 1;
 129         }
 130         if (digits > 0) {
 131                 if (dirty)
 132                         goto einval;
 133                 else
 134                         ttl += tmp;
 135         }
 136         *dst = ttl;
 137         return (0);
 138
 139  einval:
 140         __set_errno (EINVAL);
 141         return (-1);
 142 }
 143 #endif
 144
 145 /* Private. */
 146
 147 static int
 148 fmt1(int t, char s, char **buf, size_t *buflen) {
 149         char tmp[50];
 150         size_t len;
 151
 152         len = SPRINTF((tmp, "%d%c", t, s));
 153         if (len + 1 > *buflen)
 154                 return (-1);
 155         strcpy(*buf, tmp);
 156         *buf += len;
 157         *buflen -= len;
 158         return (0);
 159 }