137 lines
5.0 KiB
C
137 lines
5.0 KiB
C
/*
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* Copyright (c) Huawei Technologies Co., Ltd. 2014-2018. All rights reserved.
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* Description: strncpy_s function
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* Author: lishunda
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* Create: 2014-02-25
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*/
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/*
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* [Standardize-exceptions] Use unsafe function: Performance-sensitive
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* [reason] Always used in the performance critical path,
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* and sufficient input validation is performed before calling
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*/
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#include "securecutil.h"
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#if defined(SECUREC_COMPATIBLE_WIN_FORMAT)
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#define SECUREC_STRNCPY_PARAM_OK(strDest, destMax, strSrc, count) \
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(((destMax) > 0 && (destMax) <= SECUREC_STRING_MAX_LEN && (strDest) != NULL && (strSrc) != NULL && \
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((count) <= SECUREC_STRING_MAX_LEN || (count) == ((size_t)(-1))) && (count) > 0))
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#else
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#define SECUREC_STRNCPY_PARAM_OK(strDest, destMax, strSrc, count) \
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(((destMax) > 0 && (destMax) <= SECUREC_STRING_MAX_LEN && (strDest) != NULL && (strSrc) != NULL && \
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(count) <= SECUREC_STRING_MAX_LEN && (count) > 0))
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#endif
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/*
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* Check Src Count Range
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*/
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SECUREC_INLINE errno_t CheckSrcCountRange(char *strDest, size_t destMax, const char *strSrc, size_t count)
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{
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size_t tmpDestMax = destMax;
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size_t tmpCount = count;
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const char *endPos = strSrc;
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/* Use destMax and count as boundary checker and destMax must be greater than zero */
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while (*(endPos) != '\0' && tmpDestMax > 0 && tmpCount > 0) {
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++endPos;
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--tmpCount;
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--tmpDestMax;
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}
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if (tmpDestMax == 0) {
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strDest[0] = '\0';
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SECUREC_ERROR_INVALID_RANGE("strncpy_s");
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return ERANGE_AND_RESET;
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}
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return EOK;
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}
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/*
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* Handling errors, when dest euqal src return EOK
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*/
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errno_t strncpy_error(char *strDest, size_t destMax, const char *strSrc, size_t count)
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{
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if (destMax == 0 || destMax > SECUREC_STRING_MAX_LEN) {
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SECUREC_ERROR_INVALID_RANGE("strncpy_s");
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return ERANGE;
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} else if (strDest == NULL || strSrc == NULL) {
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SECUREC_ERROR_INVALID_PARAMTER("strncpy_s");
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if (strDest != NULL) {
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strDest[0] = '\0';
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return EINVAL_AND_RESET;
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}
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return EINVAL;
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} else if (count > SECUREC_STRING_MAX_LEN) {
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strDest[0] = '\0'; /* Clear dest string */
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SECUREC_ERROR_INVALID_RANGE("strncpy_s");
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return ERANGE_AND_RESET;
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} else if (count == 0) {
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strDest[0] = '\0';
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return EOK;
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}
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return CheckSrcCountRange(strDest, destMax, strSrc, count);
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}
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/*
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* <FUNCTION DESCRIPTION>
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* The strncpy_s function copies not more than n successive characters (not including the terminating null character)
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* from the array pointed to by strSrc to the array pointed to by strDest.
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*
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* <INPUT PARAMETERS>
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* strDest Destination string.
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* destMax The size of the destination string, in characters.
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* strSrc Source string.
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* count Number of characters to be copied.
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*
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* <OUTPUT PARAMETERS>
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* strDest is updated
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*
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* <RETURN VALUE>
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* EOK Success
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* EINVAL strDest is NULL and destMax != 0 and destMax <= SECUREC_STRING_MAX_LEN
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* EINVAL_AND_RESET strDest != NULL and strSrc is NULL and destMax != 0 and destMax <= SECUREC_STRING_MAX_LEN
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* ERANGE destMax is 0 and destMax > SECUREC_STRING_MAX_LEN
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* ERANGE_AND_RESET strDest have not enough space and all other parameters are valid and not overlap
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* EOVERLAP_AND_RESET dest buffer and source buffer are overlapped and all parameters are valid
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*
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* If there is a runtime-constraint violation, strDest[0] will be set to the '\0' when strDest and destMax valid
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*/
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errno_t strncpy_s(char *strDest, size_t destMax, const char *strSrc, size_t count)
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{
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if (SECUREC_STRNCPY_PARAM_OK(strDest, destMax, strSrc, count)) {
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size_t minCpLen; /* Use it to store the maxi length limit */
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if (count < destMax) {
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SECUREC_CALC_STR_LEN(strSrc, count, &minCpLen); /* No ending terminator */
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} else {
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size_t tmpCount = destMax;
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#ifdef SECUREC_COMPATIBLE_WIN_FORMAT
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if (count == ((size_t)(-1))) {
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tmpCount = destMax - 1;
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}
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#endif
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SECUREC_CALC_STR_LEN(strSrc, tmpCount, &minCpLen); /* No ending terminator */
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if (minCpLen == destMax) {
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strDest[0] = '\0';
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SECUREC_ERROR_INVALID_RANGE("strncpy_s");
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return ERANGE_AND_RESET;
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}
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}
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if (SECUREC_STRING_NO_OVERLAP(strDest, strSrc, minCpLen) || strDest == strSrc) {
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/* Not overlap */
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SECUREC_MEMCPY_WARP_OPT(strDest, strSrc, minCpLen); /* Copy string without terminator */
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strDest[minCpLen] = '\0';
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return EOK;
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} else {
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strDest[0] = '\0';
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SECUREC_ERROR_BUFFER_OVERLAP("strncpy_s");
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return EOVERLAP_AND_RESET;
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}
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}
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return strncpy_error(strDest, destMax, strSrc, count);
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}
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#if SECUREC_IN_KERNEL
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EXPORT_SYMBOL(strncpy_s);
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#endif
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