resolv/ns_ttl.c

   1 /*
   2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (c) 1996,1999 by Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  10  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  11  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  12  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  13  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  14  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  15  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  16  * SOFTWARE.
  17  */
  18
  19 /* Import. */
  20
  21 #include <arpa/nameser.h>
  22
  23 #include <ctype.h>
  24 #include <errno.h>
  25 #include <stdio.h>
  26 #include <string.h>
  27
  28 #ifdef SPRINTF_CHAR
  29 # define SPRINTF(x) strlen(sprintf/**/x)
  30 #else
  31 # define SPRINTF(x) ((size_t)sprintf x)
  32 #endif
  33
  34 /* Forward. */
  35
  36 static int      fmt1(int t, char s, char **buf, size_t *buflen);
  37
  38 /* Macros. */
  39
  40 #define T(x) if ((x) < 0) return (-1); else (void)NULL
  41
  42 /* Public. */
  43
  44 int
  45 ns_format_ttl(u_long src, char *dst, size_t dstlen) {
  46         char *odst = dst;
  47         int secs, mins, hours, days, weeks, x;
  48         char *p;
  49
  50         secs = src % 60;   src /= 60;
  51         mins = src % 60;   src /= 60;
  52         hours = src % 24;  src /= 24;
  53         days = src % 7;    src /= 7;
  54         weeks = src;       src = 0;
  55
  56         x = 0;
  57         if (weeks) {
  58                 T(fmt1(weeks, 'W', &dst, &dstlen));
  59                 x++;
  60         }
  61         if (days) {
  62                 T(fmt1(days, 'D', &dst, &dstlen));
  63                 x++;
  64         }
  65         if (hours) {
  66                 T(fmt1(hours, 'H', &dst, &dstlen));
  67                 x++;
  68         }
  69         if (mins) {
  70                 T(fmt1(mins, 'M', &dst, &dstlen));
  71                 x++;
  72         }
  73         if (secs || !(weeks || days || hours || mins)) {
  74                 T(fmt1(secs, 'S', &dst, &dstlen));
  75                 x++;
  76         }
  77
  78         if (x > 1) {
  79                 int ch;
  80
  81                 for (p = odst; (ch = *p) != '\0'; p++)
  82                         if (isascii(ch) && isupper(ch))
  83                                 *p = tolower(ch);
  84         }
  85
  86         return (dst - odst);
  87 }
  88 libresolv_hidden_def (ns_format_ttl)
  89
  90 // Seems not to be needed.  It's not exported from the DSO.  Some libresolv.a
  91 // might depend on it so we let it in.
  92 int
  93 ns_parse_ttl(const char *src, u_long *dst) {
  94         u_long ttl, tmp;
  95         int ch, digits, dirty;
  96
  97         ttl = 0;
  98         tmp = 0;
  99         digits = 0;
 100         dirty = 0;
 101         while ((ch = *src++) != '\0') {
 102                 if (!isascii(ch) || !isprint(ch))
 103                         goto einval;
 104                 if (isdigit(ch)) {
 105                         tmp *= 10;
 106                         tmp += (ch - '0');
 107                         digits++;
 108                         continue;
 109                 }
 110                 if (digits == 0)
 111                         goto einval;
 112                 if (islower(ch))
 113                         ch = toupper(ch);
 114                 switch (ch) {
 115                 case 'W':  tmp *= 7;
 116                 case 'D':  tmp *= 24;
 117                 case 'H':  tmp *= 60;
 118                 case 'M':  tmp *= 60;
 119                 case 'S':  break;
 120                 default:   goto einval;
 121                 }
 122                 ttl += tmp;
 123                 tmp = 0;
 124                 digits = 0;
 125                 dirty = 1;
 126         }
 127         if (digits > 0) {
 128                 if (dirty)
 129                         goto einval;
 130                 else
 131                         ttl += tmp;
 132         } else if (!dirty)
 133                 goto einval;
 134         *dst = ttl;
 135         return (0);
 136
 137  einval:
 138         __set_errno (EINVAL);
 139         return (-1);
 140 }
 141
 142 /* Private. */
 143
 144 static int
 145 fmt1(int t, char s, char **buf, size_t *buflen) {
 146         char tmp[50];
 147         size_t len;
 148
 149         len = SPRINTF((tmp, "%d%c", t, s));
 150         if (len + 1 > *buflen)
 151                 return (-1);
 152         strcpy(*buf, tmp);
 153         *buf += len;
 154         *buflen -= len;
 155         return (0);
 156 }
 157
 158 /*! \file */