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Diffstat (limited to '')
-rw-r--r-- | lib/isc/tm.c | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/lib/isc/tm.c b/lib/isc/tm.c new file mode 100644 index 0000000..c390396 --- /dev/null +++ b/lib/isc/tm.c @@ -0,0 +1,439 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +/*- + * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc. + * All rights reserved. + * + * This code was contributed to The NetBSD Foundation by Klaus Klein. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <ctype.h> + +#include <isc/tm.h> +#include <isc/util.h> + +/* + * Portable conversion routines for struct tm, replacing + * timegm() and strptime(), which are not available on all + * platforms and don't always behave the same way when they + * are. + */ + +/* + * We do not implement alternate representations. However, we always + * check whether a given modifier is allowed for a certain conversion. + */ +#define ALT_E 0x01 +#define ALT_O 0x02 +#define LEGAL_ALT(x) { if (alt_format & ~(x)) return (0); } + +#ifndef TM_YEAR_BASE +#define TM_YEAR_BASE 1900 +#endif + +static const char *day[7] = { + "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", + "Friday", "Saturday" +}; +static const char *abday[7] = { + "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" +}; +static const char *mon[12] = { + "January", "February", "March", "April", "May", "June", "July", + "August", "September", "October", "November", "December" +}; +static const char *abmon[12] = { + "Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" +}; +static const char *am_pm[2] = { + "AM", "PM" +}; + +static int +conv_num(const char **buf, int *dest, int llim, int ulim) { + int result = 0; + + /* The limit also determines the number of valid digits. */ + int rulim = ulim; + + if (**buf < '0' || **buf > '9') + return (0); + + do { + result *= 10; + result += *(*buf)++ - '0'; + rulim /= 10; + } while ((result * 10 <= ulim) && + rulim && **buf >= '0' && **buf <= '9'); + + if (result < llim || result > ulim) + return (0); + + *dest = result; + return (1); +} + +time_t +isc_tm_timegm(struct tm *tm) { + time_t ret; + int i, yday = 0, leapday; + int mdays[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30 }; + + leapday = ((((tm->tm_year + 1900 ) % 4) == 0 && + ((tm->tm_year + 1900 ) % 100) != 0) || + ((tm->tm_year + 1900 ) % 400) == 0) ? 1 : 0; + mdays[1] += leapday; + + yday = tm->tm_mday - 1; + for (i = 1; i <= tm->tm_mon; i++) + yday += mdays[i - 1]; + ret = tm->tm_sec + + (60 * tm->tm_min) + + (3600 * tm->tm_hour) + + (86400 * (yday + + ((tm->tm_year - 70) * 365) + + ((tm->tm_year - 69) / 4) - + ((tm->tm_year - 1) / 100) + + ((tm->tm_year + 299) / 400))); + return (ret); +} + +char * +isc_tm_strptime(const char *buf, const char *fmt, struct tm *tm) { + char c, *ret; + const char *bp; + size_t len = 0; + int alt_format, i, split_year = 0; + + REQUIRE(buf != NULL); + REQUIRE(fmt != NULL); + REQUIRE(tm != NULL); + + memset(tm, 0, sizeof(struct tm)); + + bp = buf; + + while ((c = *fmt) != '\0') { + /* Clear `alternate' modifier prior to new conversion. */ + alt_format = 0; + + /* Eat up white-space. */ + if (isspace((unsigned char) c)) { + while (isspace((unsigned char) *bp)) + bp++; + + fmt++; + continue; + } + + if ((c = *fmt++) != '%') + goto literal; + + +again: switch (c = *fmt++) { + case '%': /* "%%" is converted to "%". */ +literal: + if (c != *bp++) + return (0); + break; + + /* + * "Alternative" modifiers. Just set the appropriate flag + * and start over again. + */ + case 'E': /* "%E?" alternative conversion modifier. */ + LEGAL_ALT(0); + alt_format |= ALT_E; + goto again; + + case 'O': /* "%O?" alternative conversion modifier. */ + LEGAL_ALT(0); + alt_format |= ALT_O; + goto again; + + /* + * "Complex" conversion rules, implemented through recursion. + */ + case 'c': /* Date and time, using the locale's format. */ + LEGAL_ALT(ALT_E); + if (!(bp = isc_tm_strptime(bp, "%x %X", tm))) + return (0); + break; + + case 'D': /* The date as "%m/%d/%y". */ + LEGAL_ALT(0); + if (!(bp = isc_tm_strptime(bp, "%m/%d/%y", tm))) + return (0); + break; + + case 'R': /* The time as "%H:%M". */ + LEGAL_ALT(0); + if (!(bp = isc_tm_strptime(bp, "%H:%M", tm))) + return (0); + break; + + case 'r': /* The time in 12-hour clock representation. */ + LEGAL_ALT(0); + if (!(bp = isc_tm_strptime(bp, "%I:%M:%S %p", tm))) + return (0); + break; + + case 'T': /* The time as "%H:%M:%S". */ + LEGAL_ALT(0); + if (!(bp = isc_tm_strptime(bp, "%H:%M:%S", tm))) + return (0); + break; + + case 'X': /* The time, using the locale's format. */ + LEGAL_ALT(ALT_E); + if (!(bp = isc_tm_strptime(bp, "%H:%M:%S", tm))) + return (0); + break; + + case 'x': /* The date, using the locale's format. */ + LEGAL_ALT(ALT_E); + if (!(bp = isc_tm_strptime(bp, "%m/%d/%y", tm))) + return (0); + break; + + /* + * "Elementary" conversion rules. + */ + case 'A': /* The day of week, using the locale's form. */ + case 'a': + LEGAL_ALT(0); + for (i = 0; i < 7; i++) { + /* Full name. */ + len = strlen(day[i]); + if (strncasecmp(day[i], bp, len) == 0) + break; + + /* Abbreviated name. */ + len = strlen(abday[i]); + if (strncasecmp(abday[i], bp, len) == 0) + break; + } + + /* Nothing matched. */ + if (i == 7) + return (0); + + tm->tm_wday = i; + bp += len; + break; + + case 'B': /* The month, using the locale's form. */ + case 'b': + case 'h': + LEGAL_ALT(0); + for (i = 0; i < 12; i++) { + /* Full name. */ + len = strlen(mon[i]); + if (strncasecmp(mon[i], bp, len) == 0) + break; + + /* Abbreviated name. */ + len = strlen(abmon[i]); + if (strncasecmp(abmon[i], bp, len) == 0) + break; + } + + /* Nothing matched. */ + if (i == 12) + return (0); + + tm->tm_mon = i; + bp += len; + break; + + case 'C': /* The century number. */ + LEGAL_ALT(ALT_E); + if (!(conv_num(&bp, &i, 0, 99))) + return (0); + + if (split_year) { + tm->tm_year = (tm->tm_year % 100) + (i * 100); + } else { + tm->tm_year = i * 100; + split_year = 1; + } + break; + + case 'd': /* The day of month. */ + case 'e': + LEGAL_ALT(ALT_O); + if (!(conv_num(&bp, &tm->tm_mday, 1, 31))) + return (0); + break; + + case 'k': /* The hour (24-hour clock representation). */ + LEGAL_ALT(0); + /* FALLTHROUGH */ + case 'H': + LEGAL_ALT(ALT_O); + if (!(conv_num(&bp, &tm->tm_hour, 0, 23))) + return (0); + break; + + case 'l': /* The hour (12-hour clock representation). */ + LEGAL_ALT(0); + /* FALLTHROUGH */ + case 'I': + LEGAL_ALT(ALT_O); + if (!(conv_num(&bp, &tm->tm_hour, 1, 12))) + return (0); + if (tm->tm_hour == 12) + tm->tm_hour = 0; + break; + + case 'j': /* The day of year. */ + LEGAL_ALT(0); + if (!(conv_num(&bp, &i, 1, 366))) + return (0); + tm->tm_yday = i - 1; + break; + + case 'M': /* The minute. */ + LEGAL_ALT(ALT_O); + if (!(conv_num(&bp, &tm->tm_min, 0, 59))) + return (0); + break; + + case 'm': /* The month. */ + LEGAL_ALT(ALT_O); + if (!(conv_num(&bp, &i, 1, 12))) + return (0); + tm->tm_mon = i - 1; + break; + + case 'p': /* The locale's equivalent of AM/PM. */ + LEGAL_ALT(0); + /* AM? */ + if (strcasecmp(am_pm[0], bp) == 0) { + if (tm->tm_hour > 11) + return (0); + + bp += strlen(am_pm[0]); + break; + } + /* PM? */ + else if (strcasecmp(am_pm[1], bp) == 0) { + if (tm->tm_hour > 11) + return (0); + + tm->tm_hour += 12; + bp += strlen(am_pm[1]); + break; + } + + /* Nothing matched. */ + return (0); + + case 'S': /* The seconds. */ + LEGAL_ALT(ALT_O); + if (!(conv_num(&bp, &tm->tm_sec, 0, 61))) + return (0); + break; + + case 'U': /* The week of year, beginning on sunday. */ + case 'W': /* The week of year, beginning on monday. */ + LEGAL_ALT(ALT_O); + /* + * XXX This is bogus, as we can not assume any valid + * information present in the tm structure at this + * point to calculate a real value, so just check the + * range for now. + */ + if (!(conv_num(&bp, &i, 0, 53))) + return (0); + break; + + case 'w': /* The day of week, beginning on sunday. */ + LEGAL_ALT(ALT_O); + if (!(conv_num(&bp, &tm->tm_wday, 0, 6))) + return (0); + break; + + case 'Y': /* The year. */ + LEGAL_ALT(ALT_E); + if (!(conv_num(&bp, &i, 0, 9999))) + return (0); + + tm->tm_year = i - TM_YEAR_BASE; + break; + + case 'y': /* The year within 100 years of the epoch. */ + LEGAL_ALT(ALT_E | ALT_O); + if (!(conv_num(&bp, &i, 0, 99))) + return (0); + + if (split_year) { + tm->tm_year = ((tm->tm_year / 100) * 100) + i; + break; + } + split_year = 1; + if (i <= 68) + tm->tm_year = i + 2000 - TM_YEAR_BASE; + else + tm->tm_year = i + 1900 - TM_YEAR_BASE; + break; + + /* + * Miscellaneous conversions. + */ + case 'n': /* Any kind of white-space. */ + case 't': + LEGAL_ALT(0); + while (isspace((unsigned char) *bp)) + bp++; + break; + + + default: /* Unknown/unsupported conversion. */ + return (0); + } + + + } + + /* LINTED functional specification */ + DE_CONST(bp, ret); + return (ret); +} |