/*------------------------------------------------------------------ * wcsncpy_s.c * * September 2017, Reini Urban * January 2018, Reini Urban * * Copyright (c) 2017, 2018 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. *------------------------------------------------------------------ */ #ifdef FOR_DOXYGEN #include "safe_str_lib.h" #else #include "safeclib_private.h" #endif #if (defined(TEST_MSVCRT) && defined(HAVE_WCSNCPY_S)) || !defined(HAVE_WCHAR_H) #else /** * @def wcsncpy_s(dest,dmax,src,slen) * @brief * The \b wcsncpy_s function copies the wide string pointed to by src * (including the terminating null character) into the wide string * pointed to by dest. * With SAFECLIB_STR_NULL_SLACK defined all elements following the * terminating null character (if any) written by wcsncpy_s in the * array of dmax characters pointed to by dest are nulled when * wcsncpy_s returns. * * @remark SPECIFIED IN * * C11 standard (ISO/IEC 9899:2011): * K.3.9.2.1.2 The wcsncpy_s function (p: 639) * http://en.cppreference.com/w/c/string/wide/wcsncpy * * 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 wide string that will be replaced by src. * @param[in] dmax restricted maximum length of dest * @param[in] src pointer to the wide string that will be copied to dest * @param[in] slen maximum number of wide characters to copy * * @pre Neither dest nor src shall be a null pointer. * @pre dmax shall not be greater than RSIZE_MAX_WSTR. * @pre dmax shall not equal zero. * @pre If slen is either greater than or equal to dmax, then dmax should * be more than wcsnlen_s(src,dmax) to avoid truncation. * @pre Copying shall not take place between objects that overlap. * * @note C11 uses RSIZE_MAX, not RSIZE_MAX_WSTR. * * @return If there is a runtime-constraint violation, then if dest and * dmax are valid, then wcsncpy_s nulls dest. * @retval EOK successful operation, when slen == 0 or the wide * characters in src were copied into dest and the result is null terminated. * @retval ESNULLP when dest/src is a NULL pointer * @retval ESZEROL when dmax = 0 * @retval ESLEMAX when dmax > RSIZE_MAX_WSTR * @retval EOVERFLOW when dmax/slen > size of dest/src (optionally, when the * compiler knows the object_size statically) * @retval ESLEWRNG when dmax != size of dest and --enable-error-dmax * @retval ESOVRLP when buffers overlap * @retval ESNOSPC when src > dest * * @see * wcscpy_s(), strncpy_s(), wmemcpy_s(), wmemmove_s() */ #ifdef FOR_DOXYGEN errno_t wcsncpy_s(wchar_t *restrict dest, rsize_t dmax, const wchar_t *restrict src, rsize_t slen) #else EXPORT errno_t _wcsncpy_s_chk(wchar_t *restrict dest, rsize_t dmax, const wchar_t *restrict src, rsize_t slen, const size_t destbos, const size_t srcbos) #endif { rsize_t orig_dmax; wchar_t *orig_dest; const wchar_t *overlap_bumper; const size_t destsz = dmax * sizeof(wchar_t); if (unlikely(slen == 0 && dest && dmax)) { *dest = L'\0'; return EOK; } CHK_DEST_NULL("wcsncpy_s") CHK_DMAX_ZERO("wcsncpy_s") if (destbos == BOS_UNKNOWN) { CHK_DMAX_MAX("wcsncpy_s", RSIZE_MAX_WSTR) BND_CHK_PTR_BOUNDS(dest, destsz); } else { CHK_DESTW_OVR_CLEAR("wcsncpy_s", destsz, destbos) } CHK_SRCW_NULL_CLEAR("wcsncpy_s", src) if (unlikely(slen > RSIZE_MAX_WSTR)) { handle_werror(dest, wcslen(dest), "wcsncpy_s: slen exceeds max", ESLEMAX); return RCNEGATE(ESLEMAX); } if (srcbos == BOS_UNKNOWN) { BND_CHK_PTR_BOUNDS(src, slen * sizeof(wchar_t)); } else { if (unlikely(slen * sizeof(wchar_t) > srcbos)) { handle_werror(dest, wcsnlen_s(dest, dmax), "wcsncpy_s: slen exceeds src", EOVERFLOW); return RCNEGATE(EOVERFLOW); } } /* hold base in case src was not copied */ orig_dmax = dmax; orig_dest = dest; if (dest < src) { overlap_bumper = src; while (dmax > 0) { if (unlikely(dest == overlap_bumper)) { handle_werror(orig_dest, orig_dmax, "wcsncpy_s: " "overlapping objects", ESOVRLP); return RCNEGATE(ESOVRLP); } if (unlikely(slen == 0)) { /* Copying truncated to slen chars. Note that the TR says to * copy slen chars plus the null char. We null the slack. */ #ifdef SAFECLIB_STR_NULL_SLACK if (dmax > 0x20) memset(dest, 0, dmax * sizeof(wchar_t)); else { while (dmax) { *dest = L'\0'; dmax--; dest++; } } #else *dest = L'\0'; #endif return RCNEGATE(EOK); } *dest = *src; if (*dest == L'\0') { #ifdef SAFECLIB_STR_NULL_SLACK /* null slack to clear any data */ if (dmax > 0x20) memset(dest, 0, dmax * sizeof(wchar_t)); else { while (dmax) { *dest = L'\0'; dmax--; dest++; } } #endif return RCNEGATE(EOK); } dmax--; slen--; dest++; src++; } } else { overlap_bumper = dest; while (dmax > 0) { if (unlikely(src == overlap_bumper)) { handle_werror(orig_dest, orig_dmax, "wcsncpy_s: " "overlapping objects", ESOVRLP); return RCNEGATE(ESOVRLP); } if (unlikely(slen == 0)) { /* Copying truncated to slen chars. Note that the TR says to * copy slen chars plus the null char. We null the slack. */ #ifdef SAFECLIB_STR_NULL_SLACK if (dmax > 0x20) memset(dest, 0, dmax * sizeof(wchar_t)); else { while (dmax) { *dest = L'\0'; dmax--; dest++; } } #else *dest = L'\0'; #endif return RCNEGATE(EOK); } *dest = *src; if (*dest == L'\0') { #ifdef SAFECLIB_STR_NULL_SLACK /* null slack to clear any data */ if (dmax > 0x20) memset(dest, 0, dmax * sizeof(wchar_t)); else { while (dmax) { *dest = L'\0'; dmax--; dest++; } } #endif return RCNEGATE(EOK); } dmax--; slen--; dest++; src++; } } /* * the entire src must have been copied, if not reset dest * to null the string. (only with SAFECLIB_STR_NULL_SLACK) */ handle_werror(orig_dest, orig_dmax, "wcsncpy_s: not " "enough space for src", ESNOSPC); return RCNEGATE(ESNOSPC); } #endif /* HAVE_WCHAR_H or !TEST_MSVCRT */