glibc/resolv/ns_date.c
2016-04-28 12:53:49 +02:00

118 lines
3.5 KiB
C

/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1999 by Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* Import. */
#include <arpa/nameser.h>
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#define SPRINTF(x) ((size_t)sprintf x)
/* Forward. */
static int datepart(const char *, int, int, int, int *);
/* Public. */
/*%
* Convert a date in ASCII into the number of seconds since
* 1 January 1970 (GMT assumed). Format is yyyymmddhhmmss, all
* digits required, no spaces allowed.
*/
u_int32_t
ns_datetosecs(const char *cp, int *errp) {
struct tm time;
u_int32_t result;
int mdays, i;
static const int days_per_month[12] =
{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
if (strlen(cp) != 14U) {
*errp = 1;
return (0);
}
*errp = 0;
memset(&time, 0, sizeof time);
time.tm_year = datepart(cp + 0, 4, 1990, 9999, errp) - 1900;
time.tm_mon = datepart(cp + 4, 2, 01, 12, errp) - 1;
time.tm_mday = datepart(cp + 6, 2, 01, 31, errp);
time.tm_hour = datepart(cp + 8, 2, 00, 23, errp);
time.tm_min = datepart(cp + 10, 2, 00, 59, errp);
time.tm_sec = datepart(cp + 12, 2, 00, 59, errp);
if (*errp) /*%< Any parse errors? */
return (0);
/*
* OK, now because timegm() is not available in all environments,
* we will do it by hand. Roll up sleeves, curse the gods, begin!
*/
#define SECS_PER_DAY ((u_int32_t)24*60*60)
#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
result = time.tm_sec; /*%< Seconds */
result += time.tm_min * 60; /*%< Minutes */
result += time.tm_hour * (60*60); /*%< Hours */
result += (time.tm_mday - 1) * SECS_PER_DAY; /*%< Days */
/* Months are trickier. Look without leaping, then leap */
mdays = 0;
for (i = 0; i < time.tm_mon; i++)
mdays += days_per_month[i];
result += mdays * SECS_PER_DAY; /*%< Months */
if (time.tm_mon > 1 && isleap(1900+time.tm_year))
result += SECS_PER_DAY; /*%< Add leapday for this year */
/* First figure years without leapdays, then add them in. */
/* The loop is slow, FIXME, but simple and accurate. */
result += (time.tm_year - 70) * (SECS_PER_DAY*365); /*%< Years */
for (i = 70; i < time.tm_year; i++)
if (isleap(1900+i))
result += SECS_PER_DAY; /*%< Add leapday for prev year */
return (result);
}
/* Private. */
/*%
* Parse part of a date. Set error flag if any error.
* Don't reset the flag if there is no error.
*/
static int
datepart(const char *buf, int size, int min, int max, int *errp) {
int result = 0;
int i;
for (i = 0; i < size; i++) {
if (!isdigit((unsigned char)(buf[i])))
*errp = 1;
result = (result * 10) + buf[i] - '0';
}
if (result < min)
*errp = 1;
if (result > max)
*errp = 1;
return (result);
}
/*! \file */