util-strptime.c

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/*  $NetBSD: strptime.c,v 1.36 2012/03/13 21:13:48 christos Exp $   */
 
/*-
 * Copyright (c) 1997, 1998, 2005, 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code was contributed to The NetBSD Foundation by Klaus Klein.
 * Heavily optimised by David Laight
 *
 * 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 <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: strptime.c,v 1.36 2012/03/13 21:13:48 christos Exp $");
#endif
 
#include "namespace.h"
#include <sys/localedef.h>
*/
#include "suricata-common.h"
#ifndef HAVE_STRPTIME
#include <ctype.h>
#include <locale.h>
#include <string.h>
#include <time.h>
#include <stdint.h>
/*
#include <tzfile.h>
#include "private.h"
 
#ifdef __weak_alias
__weak_alias(strptime,_strptime)
#endif
*/
 
#define _ctloc(x)       (_CurrentTimeLocale->x)
 
/*
 * 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 NULL; }
 
static int TM_YEAR_BASE = 1900;
static char gmt[] = { "GMT" };
static char utc[] = { "UTC" };
/* RFC-822/RFC-2822 */
static const char * const nast[5] = {
       "EST",    "CST",    "MST",    "PST",    "\0\0\0"
};
static const char * const nadt[5] = {
       "EDT",    "CDT",    "MDT",    "PDT",    "\0\0\0"
};
static const char * const am_pm[2] = {
       "am", "pm"
};
static const char * const day[7] = {
    "sunday", "monday", "tuesday", "wednesday", "thursday", "friday", "saturday"
};
static const char * const abday[7] = {
    "sun", "mon", "tue", "wed", "thu", "fri", "sat"
};
static const char * const mon[12] = {
    "january", "february", "march", "april", "may", "june", "july", "august", "september", "october", "november", "december"
};
static const char * const abmon[12] = {
    "jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec"
};
 
static const u_char *conv_num(const unsigned char *, int *, unsigned int, unsigned int);
static const u_char *find_string(const u_char *, int *, const char * const *,
    const char * const *, int);
 
char *
strptime(const char *buf, const char *fmt, struct tm *tm)
{
    unsigned char c;
    const unsigned char *bp, *ep;
    int alt_format, i, split_year = 0, neg = 0, offs;
    const char *new_fmt;
 
    bp = (const u_char *)buf;
 
    while (bp != NULL && (c = *fmt++) != '\0') {
        /* Clear `alternate' modifier prior to new conversion. */
        alt_format = 0;
        i = 0;
 
        /* Eat up white-space. */
        if (isspace(c)) {
            while (isspace(*bp))
                bp++;
            continue;
        }
 
        if (c != '%')
            goto literal;
 
 
again:      switch (c = *fmt++) {
        case '%':   /* "%%" is converted to "%". */
literal:
            if (c != *bp++)
                return NULL;
            LEGAL_ALT(0);
            continue;
 
        /*
         * "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.
         */
        /* we do not need 'c'
      case 'c': Date and time, using the locale's format.
            new_fmt = _ctloc(d_t_fmt);
            goto recurse;
      */
 
        case 'D':   /* The date as "%m/%d/%y". */
            new_fmt = "%m/%d/%y";
            LEGAL_ALT(0);
            goto recurse;
 
        case 'F':   /* The date as "%Y-%m-%d". */
            new_fmt = "%Y-%m-%d";
            LEGAL_ALT(0);
            goto recurse;
 
        case 'R':   /* The time as "%H:%M". */
            new_fmt = "%H:%M";
            LEGAL_ALT(0);
            goto recurse;
 
        case 'r':   /* The time in 12-hour clock representation. */
            new_fmt = "%I:%M:S %p";//_ctloc(t_fmt_ampm);
            LEGAL_ALT(0);
            goto recurse;
 
        case 'T':   /* The time as "%H:%M:%S". */
            new_fmt = "%H:%M:%S";
            LEGAL_ALT(0);
            goto recurse;
 
        /* we don't use 'X'
      case 'X': The time, using the locale's format.
            new_fmt =_ctloc(t_fmt);
            goto recurse;
      */
 
        /* we do not need 'x'
      case 'x': The date, using the locale's format.
            new_fmt =_ctloc(d_fmt);*/
recurse:
            bp = (const u_char *)strptime((const char *)bp,
                                new_fmt, tm);
            LEGAL_ALT(ALT_E);
            continue;
 
        /*
         * "Elementary" conversion rules.
         */
        case 'A':   /* The day of week, using the locale's form. */
        case 'a':
            bp = find_string(bp, &tm->tm_wday, day, abday, 7);
            LEGAL_ALT(0);
            continue;
 
        case 'B':   /* The month, using the locale's form. */
        case 'b':
        case 'h':
            bp = find_string(bp, &tm->tm_mon, mon, abmon, 12);
            LEGAL_ALT(0);
            continue;
 
        case 'C':   /* The century number. */
            i = 20;
            bp = conv_num(bp, &i, 0, 99);
 
            i = i * 100 - TM_YEAR_BASE;
            if (split_year)
                i += tm->tm_year % 100;
            split_year = 1;
            tm->tm_year = i;
            LEGAL_ALT(ALT_E);
            continue;
 
        case 'd':   /* The day of month. */
        case 'e':
            bp = conv_num(bp, &tm->tm_mday, 1, 31);
            LEGAL_ALT(ALT_O);
            continue;
 
        case 'k':   /* The hour (24-hour clock representation). */
            LEGAL_ALT(0);
            /* FALLTHROUGH */
        case 'H':
            bp = conv_num(bp, &tm->tm_hour, 0, 23);
            LEGAL_ALT(ALT_O);
            continue;
 
        case 'l':   /* The hour (12-hour clock representation). */
            LEGAL_ALT(0);
            /* FALLTHROUGH */
        case 'I':
            bp = conv_num(bp, &tm->tm_hour, 1, 12);
            if (tm->tm_hour == 12)
                tm->tm_hour = 0;
            LEGAL_ALT(ALT_O);
            continue;
 
        case 'j':   /* The day of year. */
            i = 1;
            bp = conv_num(bp, &i, 1, 366);
            tm->tm_yday = i - 1;
            LEGAL_ALT(0);
            continue;
 
        case 'M':   /* The minute. */
            bp = conv_num(bp, &tm->tm_min, 0, 59);
            LEGAL_ALT(ALT_O);
            continue;
 
        case 'm':   /* The month. */
            i = 1;
            bp = conv_num(bp, &i, 1, 12);
            tm->tm_mon = i - 1;
            LEGAL_ALT(ALT_O);
            continue;
 
        case 'p':   /* The locale's equivalent of AM/PM. */
            bp = find_string(bp, &i, am_pm, NULL, 2);
            if (tm->tm_hour > 11)
                return NULL;
            tm->tm_hour += i * 12;
            LEGAL_ALT(0);
            continue;
 
        case 'S':   /* The seconds. */
            bp = conv_num(bp, &tm->tm_sec, 0, 61);
            LEGAL_ALT(ALT_O);
            continue;
 
#ifndef TIME_MAX
#define TIME_MAX    INT64_MAX
#endif
        case 's':   /* seconds since the epoch */
            {
                time_t sse = 0;
                uint64_t rulim = TIME_MAX;
 
                if (*bp < '0' || *bp > '9') {
                    bp = NULL;
                    continue;
                }
 
                do {
                    sse *= 10;
                    sse += *bp++ - '0';
                    rulim /= 10;
                } while (((uint64_t)sse * 10 <= TIME_MAX) &&
                     rulim && *bp >= '0' && *bp <= '9');
 
                if (sse < 0 || (uint64_t)sse > TIME_MAX) {
                    bp = NULL;
                    continue;
                }
 
                tm = localtime(&sse);
            if (tm == NULL)
                    bp = NULL;
            }
            continue;
 
        case 'U':   /* The week of year, beginning on sunday. */
        case 'W':   /* The week of year, beginning on monday. */
            /*
             * 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.
             */
             bp = conv_num(bp, &i, 0, 53);
             LEGAL_ALT(ALT_O);
             continue;
 
        case 'w':   /* The day of week, beginning on sunday. */
            bp = conv_num(bp, &tm->tm_wday, 0, 6);
            LEGAL_ALT(ALT_O);
            continue;
 
        case 'u':   /* The day of week, monday = 1. */
            bp = conv_num(bp, &i, 1, 7);
            tm->tm_wday = i % 7;
            LEGAL_ALT(ALT_O);
            continue;
 
        case 'g':   /* The year corresponding to the ISO week
                 * number but without the century.
                 */
            bp = conv_num(bp, &i, 0, 99);
            continue;
 
        case 'G':   /* The year corresponding to the ISO week
                 * number with century.
                 */
            do
                bp++;
            while (isdigit(*bp));
            continue;
 
        case 'V':   /* The ISO 8601:1988 week number as decimal */
            bp = conv_num(bp, &i, 0, 53);
            continue;
 
        case 'Y':   /* The year. */
            i = TM_YEAR_BASE;   /* just for data sanity... */
            bp = conv_num(bp, &i, 0, 9999);
            tm->tm_year = i - TM_YEAR_BASE;
            LEGAL_ALT(ALT_E);
            continue;
 
        case 'y':   /* The year within 100 years of the epoch. */
            /* LEGAL_ALT(ALT_E | ALT_O); */
            bp = conv_num(bp, &i, 0, 99);
 
            if (split_year)
                /* preserve century */
                i += (tm->tm_year / 100) * 100;
            else {
                split_year = 1;
                if (i <= 68)
                    i = i + 2000 - TM_YEAR_BASE;
                else
                    i = i + 1900 - TM_YEAR_BASE;
            }
            tm->tm_year = i;
            continue;
 
        case 'Z':
            tzset();
            if (strncasecmp((const char *)bp, gmt, 3) == 0
          || strncasecmp((const char *)bp, utc, 3) == 0) {
                tm->tm_isdst = 0;
#ifdef TM_GMTOFF
                tm->TM_GMTOFF = 0;
#endif
#ifdef TM_ZONE
                tm->TM_ZONE = gmt;
#endif
                bp += 3;
            } else {
                ep = find_string(bp, &i,
                         (const char * const *)tzname,
                          NULL, 2);
                if (ep != NULL) {
                    tm->tm_isdst = i;
#ifdef TM_GMTOFF
                    tm->TM_GMTOFF = -(timezone);
#endif
#ifdef TM_ZONE
                    tm->TM_ZONE = tzname[i];
#endif
                }
                bp = ep;
            }
            continue;
 
        case 'z':
            /*
             * We recognize all ISO 8601 formats:
             * Z    = Zulu time/UTC
             * [+-]hhmm
             * [+-]hh:mm
             * [+-]hh
             * We recognize all RFC-822/RFC-2822 formats:
             * UT|GMT
             *          North American : UTC offsets
             * E[DS]T = Eastern : -4 | -5
             * C[DS]T = Central : -5 | -6
             * M[DS]T = Mountain: -6 | -7
             * P[DS]T = Pacific : -7 | -8
             *          Military
             * [A-IL-M] = -1 ... -9 (J not used)
             * [N-Y]  = +1 ... +12
             */
            while (isspace(*bp))
                bp++;
 
            switch (*bp++) {
            case 'G':
                if (*bp++ != 'M')
                    return NULL;
                /*FALLTHROUGH*/
            case 'U':
                if (*bp++ != 'T')
                    return NULL;
                /*FALLTHROUGH*/
            case 'Z':
                tm->tm_isdst = 0;
#ifdef TM_GMTOFF
                tm->TM_GMTOFF = 0;
#endif
#ifdef TM_ZONE
                tm->TM_ZONE = utc;
#endif
                continue;
            case '+':
                neg = 0;
                break;
            case '-':
                neg = 1;
                break;
            default:
                --bp;
                ep = find_string(bp, &i, nast, NULL, 4);
                if (ep != NULL) {
#ifdef TM_GMTOFF
                    tm->TM_GMTOFF = -5 - i;
#endif
#ifdef TM_ZONE
                    tm->TM_ZONE = __UNCONST(nast[i]);
#endif
                    bp = ep;
                    continue;
                }
                ep = find_string(bp, &i, nadt, NULL, 4);
                if (ep != NULL) {
                    tm->tm_isdst = 1;
#ifdef TM_GMTOFF
                    tm->TM_GMTOFF = -4 - i;
#endif
#ifdef TM_ZONE
                    tm->TM_ZONE = __UNCONST(nadt[i]);
#endif
                    bp = ep;
                    continue;
                }
 
                if ((*bp >= 'A' && *bp <= 'I') ||
                    (*bp >= 'L' && *bp <= 'Y')) {
#ifdef TM_GMTOFF
                    /* Argh! No 'J'! */
                    if (*bp >= 'A' && *bp <= 'I')
                        tm->TM_GMTOFF =
                            ('A' - 1) - (int)*bp;
                    else if (*bp >= 'L' && *bp <= 'M')
                        tm->TM_GMTOFF = 'A' - (int)*bp;
                    else if (*bp >= 'N' && *bp <= 'Y')
                        tm->TM_GMTOFF = (int)*bp - 'M';
#endif
#ifdef TM_ZONE
                    tm->TM_ZONE = NULL; /* XXX */
#endif
                    bp++;
                    continue;
                }
                return NULL;
            }
            offs = 0;
            for (i = 0; i < 4; ) {
                if (isdigit(*bp)) {
                    offs = offs * 10 + (*bp++ - '0');
                    i++;
                    continue;
                }
                if (i == 2 && *bp == ':') {
                    bp++;
                    continue;
                }
                break;
            }
            switch (i) {
            case 2:
                offs *= 100;
                break;
            case 4:
                i = offs % 100;
                if (i >= 60)
                    return NULL;
                /* Convert minutes into decimal */
                offs = (offs / 100) * 100 + (i * 50) / 30;
                break;
            default:
                return NULL;
            }
            if (neg)
                offs = -offs;
            tm->tm_isdst = 0;   /* XXX */
#ifdef TM_GMTOFF
            tm->TM_GMTOFF = offs;
#endif
#ifdef TM_ZONE
            tm->TM_ZONE = NULL; /* XXX */
#endif
            continue;
 
        /*
         * Miscellaneous conversions.
         */
        case 'n':   /* Any kind of white-space. */
        case 't':
            while (isspace(*bp))
                bp++;
            LEGAL_ALT(0);
            continue;
 
 
        default:    /* Unknown/unsupported conversion. */
            return NULL;
        }
    }
 
    return (char *)(bp);
}
 
 
static const u_char *
conv_num(const unsigned char *buf, int *dest, unsigned int llim, unsigned int ulim)
{
    unsigned int result = 0;
    unsigned char ch;
 
    /* The limit also determines the number of valid digits. */
    unsigned int rulim = ulim;
 
    ch = *buf;
    if (ch < '0' || ch > '9')
        return NULL;
 
    do {
        result *= 10;
        result += ch - '0';
        rulim /= 10;
        ch = *++buf;
    } while ((result * 10 <= ulim) && rulim && ch >= '0' && ch <= '9');
 
    if (result < llim || result > ulim)
        return NULL;
 
    *dest = result;
    return buf;
}
 
static const u_char *
find_string(const u_char *bp, int *tgt, const char * const *n1,
        const char * const *n2, int c)
{
    int i;
    size_t len;
 
    /* check full name - then abbreviated ones */
    for (; n1 != NULL; n1 = n2, n2 = NULL) {
        for (i = 0; i < c; i++, n1++) {
            len = strlen(*n1);
            if (strncasecmp(*n1, (const char *)bp, len) == 0) {
                *tgt = i;
                return bp + len;
            }
        }
    }
 
    /* Nothing matched */
    return NULL;
}
#endif /* HAVE_STRPTIME */