/* $NetBSD: tm.c,v 1.1.4.2 2024/02/29 11:39:02 martin Exp $ */ /* * Copyright (C) Internet Systems Consortium, Inc. ("ISC") * * SPDX-License-Identifier: MPL-2.0 AND BSD-2-Clause * * 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 https://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 #include #include #include #include #include #include /* * 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)) != 0) \ return ((0)); \ } #ifndef TM_YEAR_BASE #define TM_YEAR_BASE 1900 #endif /* ifndef TM_YEAR_BASE */ 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 (!isdigit((unsigned char)**buf)) { 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); }