/*------------------------------------------------------------------ * asctime_s.c * * September 2017, Reini Urban * * Copyright (c) 2017 by Reini Urban * All rights reserved. * * Permission is hereby granted, free of charge, to any person * obtaining a copy of this software and associated documentation * files (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, * copy, modify, merge, publish, distribute, sublicense, and/or * sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following * conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. *------------------------------------------------------------------ */ #define _GNU_SOURCE #ifdef FOR_DOXYGEN #include "safe_lib.h" #else #include "safeclib_private.h" #include #endif /* conflicting API */ #if (defined(TEST_MSVCRT) && defined(HAVE_ASCTIME_S)) || \ (defined(MINGW_HAS_SECURE_API) && __MINGW64_VERSION_MAJOR < 7) #else /*#if defined(HAVE_ASCTIME_R) char *asctime_r(const struct tm * __restrict, char * __restrict); #endif */ /** * @def asctime_s(dest,dmax,tm) * @brief * The \c asctime_s function converts the given calendar time \c tm to a * textual representation of the following fixed 25-character form: * \c "Www Mmm dd hh:mm:ss yyyy\n", as with asctime. The message is copied * into user-provided \c dest buffer, which is guaranteed to be * null-terminated. * * @details * No more than dmax-1 bytes are written, the buffer is always * null-terminated. * Uses the re-entrant \c asctime_r() if available. * * @remark SPECIFIED IN * * C11 standard (ISO/IEC 9899:2011): * K.3.8.2.1 The asctime_s function (p: 624-625) * http://en.cppreference.com/w/c/chrono/asctime * * ISO/IEC TR 24731, Programming languages, environments * and system software interfaces, Extensions to the C Library, * Part I: Bounds-checking interfaces * * @param[out] dest pointer to a user-provided buffer. * @param[in] dmax restricted maximum length of dest * @param[in] tm pointer to a tm object specifying the time to print * * @pre dest and tm shall not be a null pointer. * @pre dmax shall not be less than 26 and greater than RSIZE_MAX_STR. * @pre not all members of *tm are within their normal ranges, * the year indicated by tm->tm_year is between 0-8099. * * @return Zero if the entire message was successfully stored in dest, * non-zero otherwise. * @retval EOK on success * @retval ESNULLP when dest or tm is a NULL pointer * @retval ESLEMIN when dmax < 26 or a tm member is too small * @retval ESLEMAX when dmax > RSIZE_MAX_STR or a tm member is too large * @retval EOVERFLOW when dmax > size of dest (optionally, when the compiler * knows the object_size statically) * @retval ESLEWRNG when dmax != size of dest and --enable-error-dmax * @retval ESNOSPC when dmax is too small for the result buffer * @retval -1 when asctime_r or asctime returned NULL * * @note * This function returns a pointer to static data and is not * thread-safe. POSIX marks this function obsolete and recommends strftime * instead. The C standard also recommends strftime instead of asctime and * asctime_s because strftime is more flexible and locale-sensitive. POSIX * limits undefined behaviors only to when the output string would be * longer than 25 characters, when tm->tm_wday or tm->tm_mon are * not within the expected ranges, or when tm->tm_year exceeds * INT_MAX-1990. Some implementations handle tm->tm_mday==0 as * meaning the last day of the preceding month. * * @see * ctime_s() */ #ifdef FOR_DOXYGEN errno_t asctime_s(char *dest, rsize_t dmax, const struct tm *tm) #else EXPORT errno_t _asctime_s_chk(char *dest, rsize_t dmax, const struct tm *tm, const size_t destbos) #endif { const char *buf; size_t len; CHK_DEST_NULL("asctime_s") if (unlikely(dmax < 26)) { invoke_safe_str_constraint_handler("asctime_s: dmax is too small", NULL, ESLEMIN); return ESLEMIN; } if (destbos == BOS_UNKNOWN) { CHK_DMAX_MAX("asctime_s", RSIZE_MAX_STR) BND_CHK_PTR_BOUNDS(dest, dmax); } else { CHK_DEST_OVR("asctime_s", destbos) if (unlikely(destbos < 26)) { invoke_safe_str_constraint_handler("ctime_s: dmax is too small", dest, ESLEMIN); return ESLEMIN; } } if (unlikely(tm == NULL)) { invoke_safe_str_constraint_handler("asctime_s: tm is null", NULL, ESNULLP); return ESNULLP; } if (tm->tm_year < 0 || tm->tm_mon < 0 || tm->tm_yday < 0 || tm->tm_mday < 1 || tm->tm_wday < 0 || tm->tm_hour < 0 || tm->tm_min < 0 || tm->tm_sec < 0 || tm->tm_isdst < 0 #ifdef HAVE_TM_GMTOFF || tm->tm_gmtoff < -1036800 /* 12*86400 */ #endif ) { invoke_safe_str_constraint_handler( "asctime_s: a tm member is too small", NULL, ESLEMIN); return ESLEMIN; } if (tm->tm_year > 8099 || tm->tm_mon > 11 || tm->tm_yday > 365 || tm->tm_mday > 31 || tm->tm_wday > 6 || tm->tm_hour > 23 || tm->tm_min > 59 || tm->tm_sec > 60 || tm->tm_isdst > 1 #ifdef HAVE_TM_GMTOFF || tm->tm_gmtoff > 1036800 /* 12*86400 */ #endif ) { /* does EOVERFLOW in asctime() */ invoke_safe_str_constraint_handler( "asctime_s: a tm member is too large", NULL, ESLEMAX); return ESLEMAX; } #if defined(HAVE_ASCTIME_R) if (dmax >= 120) { /* glibc reserves 114 */ buf = asctime_r(tm, dest); if (!buf) { #ifdef SAFECLIB_STR_NULL_SLACK memset(dest, 0, dmax); #else *dest = '\0'; #endif return -1; } } else { static char tmp[120]; buf = asctime_r(tm, (char *)&tmp); if (!buf) return -1; len = strlen(buf); if (likely(len < dmax)) { strcpy_s(dest, dmax, buf); return EOK; } else { goto esnospc; } } #else buf = asctime(tm); if (0) goto esnospc; #endif if (!buf) return -1; len = strlen(buf); if (likely(len < dmax)) { strcpy_s(dest, dmax, buf); } else { esnospc: invoke_safe_str_constraint_handler("asctime_s: dmax is too small", dest, ESNOSPC); return ESNOSPC; } return EOK; } #endif /* MINGW_HAS_SECURE_API */