diff options
Diffstat (limited to 'src/vppinfra')
| -rw-r--r-- | src/vppinfra/string.c | 369 | ||||
| -rw-r--r-- | src/vppinfra/string.h | 713 |
2 files changed, 1082 insertions, 0 deletions
diff --git a/src/vppinfra/string.c b/src/vppinfra/string.c index b90f432c0cc..feae5b9165c 100644 --- a/src/vppinfra/string.c +++ b/src/vppinfra/string.c @@ -38,6 +38,12 @@ #include <vppinfra/string.h> #include <vppinfra/error.h> +/** + * @file + * @brief String Handling routines, including a performant + * implementation of many c-11 "safe" string functions. + */ + /* Exchanges source and destination. */ void clib_memswap (void *_a, void *_b, uword bytes) @@ -91,6 +97,25 @@ clib_c11_violation (const char *s) _clib_error (CLIB_ERROR_WARNING, (char *) __FUNCTION__, 0, (char *) s); } +/** + * @brief copy src to dest, at most n bytes, up to dmax + * + * ISO/IEC 9899:2017(C11), Porgramming languages -- C + * Annex K; Bounds-checking interfaces + * + * @param *dest pointer to memory to copy to + * @param dmax maximum length of resulting dest + * @param *src pointer to memory to copy from + * @param n maximum number of characters to copy from src + * + * @constraints No null pointers + * n shall not be greater than dmax + * no memory overlap between src and dest + * + * @return EOK success + * EINVAL runtime constraint error + * + */ errno_t memcpy_s (void *__restrict__ dest, rsize_t dmax, const void *__restrict__ src, rsize_t n) @@ -98,12 +123,356 @@ memcpy_s (void *__restrict__ dest, rsize_t dmax, return memcpy_s_inline (dest, dmax, src, n); } +/** + * @brief set n bytes starting at s to the specified c value + * + * ISO/IEC 9899:2017(C11), Porgramming languages -- C + * Annex K; Bounds-checking interfaces + * + * @param *s pointer to memory to set the c value + * @param smax maximum length of resulting s + * @param c byte value + * @param n maximum number of characters to set in s + * + * @constraints No null pointers + * n shall not be greater than smax + * + * @return EOK success + * EINVAL runtime constraint error + * + */ errno_t memset_s (void *s, rsize_t smax, int c, rsize_t n) { return memset_s_inline (s, smax, c, n); } +/** + * @brief compare memory until they differ, and their difference is returned in + * diff + * + * ISO/IEC 9899:2017(C11), Porgramming languages -- C + * Annex K; Bounds-checking interfaces + * + * @param *s1 pointer to memory to compare against + * @param s1max maximum length of s1 + * @param *s2 pointer to memory to compare with s1 + * @param s2max length of s2 + * @param *diff pointer to the diff which is an integer greater than, equal to, + * or less than zero according to s1 is greater than, equal to, + * or less than s2. + * + * @constraints No null pointers + * s1max and s2max shall not be zero + * s2max shall not be greater than s1max + * + * @return EOK success + * diff when the return code is EOK + * >0 s1 greater s2 + * 0 s1 == s2 + * <0 s1 < s2 + * EINVAL runtime constraint error + * + */ +errno_t +memcmp_s (const void *s1, rsize_t s1max, const void *s2, rsize_t s2max, + int *diff) +{ + return memcmp_s_inline (s1, s1max, s2, s2max, diff); +} + +/** + * @brief compare string s2 to string s1, and their difference is returned in + * indicator + * + * ISO/IEC 9899:2017(C11), Porgramming languages -- C + * Annex K; Bounds-checking interfaces + * + * @param *s1 pointer to string to compare against + * @param s1max maximum length of s1, excluding null + * @param *s2 pointer to string to compare with s1 + * @param *indicator pointer to the comparison result, which is an integer + * greater than, equal to, or less than zero according to + * s1 is greater than, equal to, or less than s2. + * + * @constraints No null pointers + * s1max shall not be zero + * s1 shall be null terminated + * n shall not be greater than the smaller of s1max and strlen + * of s1 + * + * @return EOK success + * indicator when the return code is EOK + * >0 s1 greater s2 + * 0 s1 == s2 + * <0 s1 < s2 + * EINVAL runtime constraint error + * + */ +errno_t +strcmp_s (const char *s1, rsize_t s1max, const char *s2, int *indicator) +{ + return strcmp_s_inline (s1, s1max, s2, indicator); +} + +/** + * @brief compare string s2 to string s1, no more than n characters, and their + * difference is returned in indicator + * + * ISO/IEC 9899:2017(C11), Porgramming languages -- C + * Annex K; Bounds-checking interfaces + * + * @param *s1 pointer to string to compare against + * @param s1max maximum length of s1, excluding null + * @param *s2 pointer to string to compare with s1 + * @param n maximum number of characters to compare + * @param *indicator pointer to the comparison result, which is an integer + * greater than, equal to, or less than zero according to + * s1 is greater than, equal to, or less than s2. + * + * @constraints No null pointers + * s1max shall not be zero + * s1 shall be null terminated + * + * @return EOK success + * indicator when the return code is EOK + * >0 s1 greater s2 + * 0 s1 == s2 + * <0 s1 < s2 + * EINVAL runtime constraint error + * + */ +errno_t +strncmp_s (const char *s1, rsize_t s1max, const char *s2, rsize_t n, + int *indicator) +{ + return strncmp_s_inline (s1, s1max, s2, n, indicator); +} + +/** + * @brief copy src string to dest string + * + * ISO/IEC 9899:2017(C11), Porgramming languages -- C + * Annex K; Bounds-checking interfaces + * + * @param *dest pointer to string to copy to + * @param dmax maximum length of resulting dest string, including null + * @param *src pointer to string to copy from + * + * @constraints No null pointers + * dmax shall not be zero + * dmax shall be greater than string length of src + * no memory overlap between src and dest + * + * @return EOK success + * EINVAL runtime constraint error + * + */ +errno_t +strcpy_s (char *__restrict__ dest, rsize_t dmax, const char *__restrict__ src) +{ + return strcpy_s_inline (dest, dmax, src); +} + +/** + * @brief copy src string to dest string, no more than n characters + * + * ISO/IEC 9899:2017(C11), Porgramming languages -- C + * Annex K; Bounds-checking interfaces + * + * @param *dest pointer to string to copy to + * @param dmax maximum length of resulting dest string, including null + * @param *src pointer to string to copy from + * @param n maximum number of characters to copy from src, excluding null + * + * @constraints No null pointers + * dmax shall not be zero + * no memory overlap between src and dest + * + * @return EOK success + * EINVAL runtime constraint error + * EOVERFLOW truncated operation. dmax - 1 characters were copied. + * dest is null terminated. + * + */ +errno_t +strncpy_s (char *__restrict__ dest, rsize_t dmax, + const char *__restrict__ src, rsize_t n) +{ + return strncpy_s_inline (dest, dmax, src, n); +} + +/** + * @brief append src string to dest string, including null + * + * ISO/IEC 9899:2017(C11), Porgramming languages -- C + * Annex K; Bounds-checking interfaces + * + * @param *dest pointer to string to append to + * @param dmax maximum length of resulting dest string, including null + * @param *src pointer to string to append from + * + * @constraints No null pointers + * dmax shall not be zero + * dest shall be null terminated + * given m = dmax - strnlen (dest, dmax) + * n = strnlen (src, m) + * n shall not be >= m + * no memory overlap between src and dest + * + * @return EOK success + * EINVAL runtime constraint error + * + */ +errno_t +strcat_s (char *__restrict__ dest, rsize_t dmax, const char *__restrict__ src) +{ + return strcat_s_inline (dest, dmax, src); +} + +/** + * @brief append src string to dest string, including null, no more than n + * characters + * + * ISO/IEC 9899:2017(C11), Porgramming languages -- C + * Annex K; Bounds-checking interfaces + * + * @param *dest pointer to string to append to + * @param dmax maximum length of resulting dest string, including null + * @param *src pointer to string to append from + * @param n maximum characters to append (excluding null) + * + * @constraints No null pointers + * dmax shall not be zero + * dest shall be null terminated + * dmax - strnlen (dest, dmax) shall not be zero + * no memory overlap between src and dest + * + * @return EOK success + * EINVAL runtime constraint error + * EOVERFLOW truncated operation. dmax - 1 characters were appended. + * dest is null terminated. + * + */ +errno_t +strncat_s (char *__restrict__ dest, rsize_t dmax, + const char *__restrict__ src, rsize_t n) +{ + return strncat_s_inline (dest, dmax, src, n); +} + +/** + * @brief tokenize string s1 with delimiter specified in s2. This is a stateful + * API when it is iterately called, it returns the next token from s1 + * which is delimited by s2. s1max and ptr maintain the stateful + * information for the same caller and must not be altered by the + * caller during the iteration for the correct result + * + * ISO/IEC 9899:2017(C11), Porgramming languages -- C + * Annex K; Bounds-checking interfaces + * + * @param *s1 pointer to string to be searched for substring + * @param *s1max restricted maximum length of s1 + * @param *s2 pointer to substring to search (16 characters max, + * including null) + * @param **ptr in/out pointer which maintains the stateful information + * + * @constraints s2, s1max, and ptr shall not be null + * if s1 is null, contents of ptr shall not be null + * s1 and s2 shall be null terminated + * + * @return non-null pointer to the first character of a token + * s1max and ptr are modified to contain the state + * null runtime constraint error or token is not found + * + * @example + * char *str2 = " "; + * char str1[100]; + * uword len; + * char *p2str = 0; + * char *tok1, *tok2, *tok3, *tok4, *tok5, *tok6, *tok7; + * + * strncpy (str1, "brevity is the soul of wit", sizeof (str1)); + * len = strlen (str1); + * tok1 = strtok_s (str1, &len, str2, &p2str); + * tok2 = strtok_s (0, &len, str2, &p2str); + * tok3 = strtok_s (0, &len, str2, &p2str); + * tok4 = strtok_s (0, &len, str2, &p2str); + * tok5 = strtok_s (0, &len, str2, &p2str); + * tok6 = strtok_s (0, &len, str2, &p2str); + * tok7 = strtok_s (0, &len, str2, &p2str); + * + * After the above series of calls, + * tok1 = "brevity", tok2 = "is", tok3 = "the", tok4 = "soul", tok5 = "of", + * tok6 = "wit", tok7 = null + */ +char * +strtok_s (char *__restrict__ s1, rsize_t * __restrict__ s1max, + const char *__restrict__ s2, char **__restrict__ ptr) +{ + return strtok_s_inline (s1, s1max, s2, ptr); +} + +/** + * @brief compute the length in s, no more than maxsize + * + * ISO/IEC 9899:2017(C11), Porgramming languages -- C + * Annex K; Bounds-checking interfaces + * + * @param *s pointer to string + * @param maxsize restricted maximum length + * + * @constraints No null pointers + * maxsize shall not be zero + * + * @return size_t the string length in s, excluding null character, and no + * more than maxsize or 0 if there is a constraint error + * + */ +size_t +strnlen_s (const char *s, size_t maxsize) +{ + return strnlen_s_inline (s, maxsize); +} + +/** + * @brief locate the first occurrence of the substring s2 in s1 + * + * ISO/IEC 9899:2017(C11), Porgramming languages -- C + * Annex K; Bounds-checking interfaces + * + * @param *s1 pointer to string to be searched for substring + * @param s1max restricted maximum length of s1 + * @param *s2 pointer to substring to search + * @param s2max restricted maximum length of s2 + * @param **substring pointer to pointer substring to be returned + * + * @constraints No null pointers + * s1max and s2max shall not be zero + * s1 and s2 shall be null terminated + * + * @return EOK success + * substring when the return code is EOK, it contains the pointer which + * points to s1 that matches s2 + * EINVAL runtime constraint error + * ESRCH no match + * + * @example + * char *sub = 0; + * char *s1 = "success is not final, failure is not fatal."; + * + * strstr_s (s1, strlen (s1), "failure", strlen ("failure"), &sub); + * + * After the above call, + * sub = "failure is not fatal." + */ +errno_t +strstr_s (char *s1, rsize_t s1max, const char *s2, rsize_t s2max, + char **substring) +{ + return strstr_s_inline (s1, s1max, s2, s2max, substring); +} + /* * fd.io coding-style-patch-verification: ON * diff --git a/src/vppinfra/string.h b/src/vppinfra/string.h index b00c0cfbcc2..a25d461868b 100644 --- a/src/vppinfra/string.h +++ b/src/vppinfra/string.h @@ -92,6 +92,23 @@ void clib_memswap (void *_a, void *_b, uword bytes); #ifndef EINVAL #define EINVAL 22 #endif +#ifndef ESRCH +#define ESRCH 3 +#endif +#ifndef EOVERFLOW +#define EOVERFLOW 75 +#endif + +/* + * In order to provide smooth mapping from unsafe string API to the clib string + * macro, we often have to improvise s1max and s2max due to the additional + * arguments are required for implementing the safe API. This macro is used + * to provide the s1max/s2max. It is not perfect becuase the actual + * s1max/s2max may be greater than 4k and the mapping from the unsafe API to + * the macro would cause a regression. However, it is not terribly likely. + * So I bet against the odds. + */ +#define CLIB_STRING_MACRO_MAX 4096 typedef int errno_t; typedef uword rsize_t; @@ -693,6 +710,702 @@ clib_count_equal_u8 (u8 * data, uword max_count) return count; } +/* + * This macro is to provide smooth mapping from memcmp to memcmp_s. + * memcmp has fewer parameters and fewer returns than memcmp_s. + * This macro is somewhat a crutch. When err != EOK is returned from memcmp_s, + * we return 0 and spit out a message in the console because there is + * no way to return the error code to the memcmp callers. + * This condition happens when s1 or s2 is null. Please note + * in the extant memcmp calls, if s1, s2, or both are null, memcmp returns 0 + * anyway. So we are consistent in this case for the comparison return + * although we also spit out a C11 violation message in the console to + * warn that they pass null pointers for both s1 and s2. + * Applications are encouraged to use the cool C11 memcmp_s API to get the + * maximum benefit out of it. + */ +#define clib_memcmp(s1,s2,m1) \ + ({ int __diff = 0; \ + memcmp_s_inline (s1, m1, s2, m1, &__diff); \ + __diff; \ + }) + +errno_t memcmp_s (const void *s1, rsize_t s1max, const void *s2, + rsize_t s2max, int *diff); + +always_inline errno_t +memcmp_s_inline (const void *s1, rsize_t s1max, const void *s2, rsize_t s2max, + int *diff) +{ + u8 bad; + + bad = (s1 == 0) + (s2 == 0) + (diff == 0) + (s2max > s1max) + (s2max == 0) + + (s1max == 0); + + if (PREDICT_FALSE (bad != 0)) + { + if (s1 == NULL) + clib_c11_violation ("s1 NULL"); + if (s2 == NULL) + clib_c11_violation ("s2 NULL"); + if (diff == NULL) + clib_c11_violation ("diff NULL"); + if (s2max > s1max) + clib_c11_violation ("s2max > s1max"); + if (s2max == 0) + clib_c11_violation ("s2max 0"); + if (s1max == 0) + clib_c11_violation ("s1max 0"); + return EINVAL; + } + + if (PREDICT_FALSE (s1 == s2)) + { + *diff = 0; + return EOK; + } + + *diff = memcmp (s1, s2, s2max); + return EOK; +} + +/* + * This macro is to provide smooth mapping from strnlen to strnlen_s + */ +#define clib_strnlen(s,m) strnlen_s_inline(s,m) + +size_t strnlen_s (const char *s, size_t maxsize); + +always_inline size_t +strnlen_s_inline (const char *s, size_t maxsize) +{ + u8 bad; + + bad = (s == 0) + (maxsize == 0); + if (PREDICT_FALSE (bad != 0)) + { + if (s == 0) + clib_c11_violation ("s NULL"); + if (maxsize == 0) + clib_c11_violation ("maxsize 0"); + return 0; + } + return strnlen (s, maxsize); +} + +/* + * This macro is to provide smooth mapping from strcmp to strcmp_s. + * strcmp has fewer parameters and fewer returns than strcmp_s. + * This macro is somewhat a crutch. When err != EOK is returned from strcmp_s, + * we return 0 and spit out a message in the console because + * there is no way to return the error to the strcmp callers. + * This condition happens when s1 or s2 is null. Please note in the extant + * strcmp call, they would end up crashing if one of them is null. + * So the new behavior is no crash, but an error is displayed in the + * console which I think is more user friendly. If both s1 and s2 are null, + * strcmp returns 0. Obviously, strcmp did the pointers comparison prior + * to actually accessing the pointer contents. We are still consistent + * in this case for the comparison return although we also spit out a + * C11 violation message in the console to warn that they pass null pointers + * for both s1 and s2. The other problem is strcmp does not provide s1max, + * we use CLIB_STRING_MACRO_MAX and hopefully, s1 is null terminated. + * If not, we may be accessing memory beyonf what is intended. + * Applications are encouraged to use the cool C11 strcmp_s API to get the + * maximum benefit out of it. + */ +#define clib_strcmp(s1,s2) \ + ({ int __indicator = 0; \ + strcmp_s_inline (s1, CLIB_STRING_MACRO_MAX, s2, &__indicator); \ + __indicator; \ + }) + +errno_t strcmp_s (const char *s1, rsize_t s1max, const char *s2, + int *indicator); + +always_inline errno_t +strcmp_s_inline (const char *s1, rsize_t s1max, const char *s2, + int *indicator) +{ + u8 bad; + + bad = (indicator == 0) + (s1 == 0) + (s2 == 0) + (s1max == 0) + + (s1 && s1max && s1[clib_strnlen (s1, s1max)] != '\0'); + + if (PREDICT_FALSE (bad != 0)) + { + if (indicator == NULL) + clib_c11_violation ("indicator NULL"); + if (s1 == NULL) + clib_c11_violation ("s1 NULL"); + if (s2 == NULL) + clib_c11_violation ("s2 NULL"); + if (s1max == 0) + clib_c11_violation ("s1max 0"); + if (s1 && s1max && s1[clib_strnlen (s1, s1max)] != '\0') + clib_c11_violation ("s1 unterminated"); + return EINVAL; + } + + *indicator = strcmp (s1, s2); + return EOK; +} + +/* + * This macro is to provide smooth mapping from strncmp to strncmp_s. + * strncmp has fewer parameters and fewer returns than strncmp_s. That said, + * this macro is somewhat a crutch. When we get err != EOK from strncmp_s, + * we return 0 and spit out a message in the console because there is no + * means to return the error to the strncmp caller. + * This condition happens when s1 or s2 is null. In the extant strncmp call, + * they would end up crashing if one of them is null. So the new behavior is + * no crash, but error is displayed in the console which is more + * user friendly. If s1 and s2 are null, strncmp returns 0. Obviously, + * strncmp did the pointers comparison prior to actually accessing the + * pointer contents. We are still consistent in this case for the comparison + * return although we also spit out a C11 violation message in the console to + * warn that they pass null pointers for both s1 and s2. + * Applications are encouraged to use the cool C11 strncmp_s API to get the + * maximum benefit out of it. + */ +#define clib_strncmp(s1,s2,n) \ + ({ int __indicator = 0; \ + strncmp_s_inline (s1, CLIB_STRING_MACRO_MAX, s2, n, &__indicator); \ + __indicator; \ + }) + +errno_t strncmp_s (const char *s1, rsize_t s1max, const char *s2, rsize_t n, + int *indicator); + +always_inline errno_t +strncmp_s_inline (const char *s1, rsize_t s1max, const char *s2, rsize_t n, + int *indicator) +{ + u8 bad; + u8 s1_greater_s1max = (s1 && s1max && n > clib_strnlen (s1, s1max)); + + if (PREDICT_FALSE (s1_greater_s1max && indicator)) + { + /* + * strcmp allows n > s1max. If indicator is non null, we can still + * do the compare without any harm and return EINVAL as well as the + * result in indicator. + */ + clib_c11_violation ("n exceeds s1 length"); + *indicator = strncmp (s1, s2, n); + return EINVAL; + } + + bad = (s1 == 0) + (s2 == 0) + (indicator == 0) + (s1max == 0) + + (s1 && s1max && s1[clib_strnlen (s1, s1max)] != '\0') + s1_greater_s1max; + + if (PREDICT_FALSE (bad != 0)) + { + if (indicator == NULL) + clib_c11_violation ("indicator NULL"); + if (s1 == NULL) + clib_c11_violation ("s1 NULL"); + if (s2 == NULL) + clib_c11_violation ("s2 NULL"); + if (s1max == 0) + clib_c11_violation ("s1max 0"); + if (s1 && s1max && s1[clib_strnlen (s1, s1max)] != '\0') + clib_c11_violation ("s1 unterminated"); + if (s1_greater_s1max) + clib_c11_violation ("n exceeds s1 length"); + return EINVAL; + } + + *indicator = strncmp (s1, s2, n); + return EOK; +} + +/* + * This macro is provided for smooth migration from strcpy. It is not perfect + * because we don't know the size of the destination buffer to pass to strcpy_s. + * We improvise dmax with CLIB_STRING_MACRO_MAX. + * Applications are encouraged to move to the C11 strcpy_s API. + */ +#define clib_strcpy(d,s) strcpy_s_inline(d,CLIB_STRING_MACRO_MAX,s) + +errno_t strcpy_s (char *__restrict__ dest, rsize_t dmax, + const char *__restrict__ src); + +always_inline errno_t +strcpy_s_inline (char *__restrict__ dest, rsize_t dmax, + const char *__restrict__ src) +{ + u8 bad; + uword low, hi; + size_t n; + + bad = (dest == 0) + (dmax == 0) + (src == 0); + if (PREDICT_FALSE (bad != 0)) + { + if (dest == 0) + clib_c11_violation ("dest NULL"); + if (src == 0) + clib_c11_violation ("src NULL"); + if (dmax == 0) + clib_c11_violation ("dmax 0"); + return EINVAL; + } + + n = clib_strnlen (src, dmax); + if (PREDICT_FALSE (n >= dmax)) + { + clib_c11_violation ("not enough space for dest"); + return (EINVAL); + } + /* Not actually trying to copy anything is OK */ + if (PREDICT_FALSE (n == 0)) + return EOK; + + /* Check for src/dst overlap, which is not allowed */ + low = (uword) (src < dest ? src : dest); + hi = (uword) (src < dest ? dest : src); + + if (PREDICT_FALSE (low + (n - 1) >= hi)) + { + clib_c11_violation ("src/dest overlap"); + return EINVAL; + } + + clib_memcpy_fast (dest, src, n); + dest[n] = '\0'; + return EOK; +} + +/* + * This macro is provided for smooth migration from strncpy. It is not perfect + * because we don't know the size of the destination buffer to pass to + * strncpy_s. We improvise dmax with CLIB_STRING_MACRO_MAX. + * Applications are encouraged to move to the C11 strncpy_s API and provide + * the correct dmax for better error checking. + */ +#define clib_strncpy(d,s,n) strncpy_s_inline(d,CLIB_STRING_MACRO_MAX,s,n) + +errno_t +strncpy_s (char *__restrict__ dest, rsize_t dmax, + const char *__restrict__ src, rsize_t n); + +always_inline errno_t +strncpy_s_inline (char *__restrict__ dest, rsize_t dmax, + const char *__restrict__ src, rsize_t n) +{ + u8 bad; + uword low, hi; + rsize_t m; + errno_t status = EOK; + + bad = (dest == 0) + (dmax == 0) + (src == 0) + (n == 0); + if (PREDICT_FALSE (bad != 0)) + { + /* Not actually trying to copy anything is OK */ + if (n == 0) + return EOK; + if (dest == 0) + clib_c11_violation ("dest NULL"); + if (src == 0) + clib_c11_violation ("src NULL"); + if (dmax == 0) + clib_c11_violation ("dmax 0"); + return EINVAL; + } + + if (PREDICT_FALSE (n >= dmax)) + { + /* Relax and use strnlen of src */ + clib_c11_violation ("n >= dmax"); + m = clib_strnlen (src, dmax); + if (m >= dmax) + { + /* Truncate, adjust copy length to fit dest */ + m = dmax - 1; + status = EOVERFLOW; + } + } + else + m = n; + + /* Check for src/dst overlap, which is not allowed */ + low = (uword) (src < dest ? src : dest); + hi = (uword) (src < dest ? dest : src); + + if (PREDICT_FALSE (low + (m - 1) >= hi)) + { + clib_c11_violation ("src/dest overlap"); + return EINVAL; + } + + clib_memcpy_fast (dest, src, m); + dest[m] = '\0'; + return status; +} + +/* + * This macro is to provide smooth migration from strcat to strcat_s. + * Because there is no dmax in strcat, we improvise it with + * CLIB_STRING_MACRO_MAX. Please note there may be a chance to overwrite dest + * with too many bytes from src. + * Applications are encouraged to use C11 API to provide the actual dmax + * for proper checking and protection. + */ +#define clib_strcat(d,s) strcat_s_inline(d,CLIB_STRING_MACRO_MAX,s) + +errno_t strcat_s (char *__restrict__ dest, rsize_t dmax, + const char *__restrict__ src); + +always_inline errno_t +strcat_s_inline (char *__restrict__ dest, rsize_t dmax, + const char *__restrict__ src) +{ + u8 bad; + uword low, hi; + size_t m, n, dest_size; + + bad = (dest == 0) + (dmax == 0) + (src == 0); + if (PREDICT_FALSE (bad != 0)) + { + if (dest == 0) + clib_c11_violation ("dest NULL"); + if (src == 0) + clib_c11_violation ("src NULL"); + if (dmax == 0) + clib_c11_violation ("dmax 0"); + return EINVAL; + } + + dest_size = clib_strnlen (dest, dmax); + m = dmax - dest_size; + n = clib_strnlen (src, m); + if (PREDICT_FALSE (n >= m)) + { + clib_c11_violation ("not enough space for dest"); + return EINVAL; + } + + /* Not actually trying to concatenate anything is OK */ + if (PREDICT_FALSE (n == 0)) + return EOK; + + /* Check for src/dst overlap, which is not allowed */ + low = (uword) (src < dest ? src : dest); + hi = (uword) (src < dest ? dest : src); + + if (PREDICT_FALSE (low + (n - 1) >= hi)) + { + clib_c11_violation ("src/dest overlap"); + return EINVAL; + } + + clib_memcpy_fast (dest + dest_size, src, n); + dest[dest_size + n] = '\0'; + return EOK; +} + +/* + * This macro is to provide smooth migration from strncat to strncat_s. + * The unsafe strncat does not have s1max. We improvise it with + * CLIB_STRING_MACRO_MAX. Please note there may be a chance to overwrite + * dest with too many bytes from src. + * Applications are encouraged to move to C11 strncat_s which requires dmax + * from the caller and provides checking to safeguard the memory corruption. + */ +#define clib_strncat(d,s,n) strncat_s_inline(d,CLIB_STRING_MACRO_MAX,s,n) + +errno_t strncat_s (char *__restrict__ dest, rsize_t dmax, + const char *__restrict__ src, rsize_t n); + +always_inline errno_t +strncat_s_inline (char *__restrict__ dest, rsize_t dmax, + const char *__restrict__ src, rsize_t n) +{ + u8 bad; + uword low, hi; + size_t m, dest_size, allowed_size; + errno_t status = EOK; + + bad = (dest == 0) + (src == 0) + (dmax == 0) + (n == 0); + if (PREDICT_FALSE (bad != 0)) + { + /* Not actually trying to concatenate anything is OK */ + if (n == 0) + return EOK; + if (dest == 0) + clib_c11_violation ("dest NULL"); + if (src == 0) + clib_c11_violation ("src NULL"); + if (dmax == 0) + clib_c11_violation ("dmax 0"); + return EINVAL; + } + + /* Check for src/dst overlap, which is not allowed */ + low = (uword) (src < dest ? src : dest); + hi = (uword) (src < dest ? dest : src); + + if (PREDICT_FALSE (low + (n - 1) >= hi)) + { + clib_c11_violation ("src/dest overlap"); + return EINVAL; + } + + dest_size = clib_strnlen (dest, dmax); + allowed_size = dmax - dest_size; + + if (PREDICT_FALSE (allowed_size == 0)) + { + clib_c11_violation ("no space left in dest"); + return (EINVAL); + } + + if (PREDICT_FALSE (n >= allowed_size)) + { + /* + * unlike strcat_s, strncat_s will do the concatenation anyway when + * there is not enough space in dest. But it will do the truncation and + * null terminate dest + */ + m = clib_strnlen (src, allowed_size); + if (m >= allowed_size) + { + m = allowed_size - 1; + status = EOVERFLOW; + } + } + else + m = clib_strnlen (src, n); + + clib_memcpy_fast (dest + dest_size, src, m); + dest[dest_size + m] = '\0'; + return status; +} + +/* + * This macro is to provide smooth mapping from strtok_r to strtok_s. + * To map strtok to this macro, the caller would have to supply an additional + * argument. strtokr_s requires s1max which the unsafe API does not have. So + * we have to improvise it with CLIB_STRING_MACRO_MAX. Unlike strtok_s, + * this macro cannot catch unterminated s1 and s2. + * Applications are encouraged to use the cool C11 strtok_s API to avoid + * these problems. + */ +#define clib_strtok(s1,s2,p) \ + ({ rsize_t __s1max = CLIB_STRING_MACRO_MAX; \ + strtok_s_inline (s1, &__s1max, s2, p); \ + }) + +char *strtok_s (char *__restrict__ s1, rsize_t * __restrict__ s1max, + const char *__restrict__ s2, char **__restrict__ ptr); + +always_inline char * +strtok_s_inline (char *__restrict__ s1, rsize_t * __restrict__ s1max, + const char *__restrict__ s2, char **__restrict__ ptr) +{ +#define STRTOK_DELIM_MAX_LEN 16 + u8 bad; + const char *pt; + char *ptoken; + uword dlen, slen; + + bad = (s1max == 0) + (s2 == 0) + (ptr == 0) + + ((s1 == 0) && ptr && (*ptr == 0)); + if (PREDICT_FALSE (bad != 0)) + { + if (s2 == NULL) + clib_c11_violation ("s2 NULL"); + if (s1max == NULL) + clib_c11_violation ("s1max is NULL"); + if (ptr == NULL) + clib_c11_violation ("ptr is NULL"); + /* s1 == 0 and *ptr == null is no good */ + if ((s1 == 0) && ptr && (*ptr == 0)) + clib_c11_violation ("s1 and ptr contents are NULL"); + return 0; + } + + if (s1 == 0) + s1 = *ptr; + + /* + * scan s1 for a delimiter + */ + dlen = *s1max; + ptoken = 0; + while (*s1 != '\0' && !ptoken) + { + if (PREDICT_FALSE (dlen == 0)) + { + *ptr = 0; + clib_c11_violation ("s1 unterminated"); + return 0; + } + + /* + * must scan the entire delimiter list + * ISO should have included a delimiter string limit!! + */ + slen = STRTOK_DELIM_MAX_LEN; + pt = s2; + while (*pt != '\0') + { + if (PREDICT_FALSE (slen == 0)) + { + *ptr = 0; + clib_c11_violation ("s2 unterminated"); + return 0; + } + slen--; + if (*s1 == *pt) + { + ptoken = 0; + break; + } + else + { + pt++; + ptoken = s1; + } + } + s1++; + dlen--; + } + + /* + * if the beginning of a token was not found, then no + * need to continue the scan. + */ + if (ptoken == 0) + { + *s1max = dlen; + return (ptoken); + } + + /* + * Now we need to locate the end of the token + */ + while (*s1 != '\0') + { + if (dlen == 0) + { + *ptr = 0; + clib_c11_violation ("s1 unterminated"); + return 0; + } + + slen = STRTOK_DELIM_MAX_LEN; + pt = s2; + while (*pt != '\0') + { + if (slen == 0) + { + *ptr = 0; + clib_c11_violation ("s2 unterminated"); + return 0; + } + slen--; + if (*s1 == *pt) + { + /* + * found a delimiter, set to null + * and return context ptr to next char + */ + *s1 = '\0'; + *ptr = (s1 + 1); /* return pointer for next scan */ + *s1max = dlen - 1; /* account for the nulled delimiter */ + return (ptoken); + } + else + { + /* + * simply scanning through the delimiter string + */ + pt++; + } + } + s1++; + dlen--; + } + + *ptr = s1; + *s1max = dlen; + return (ptoken); +} + +/* + * This macro is to provide smooth mapping from strstr to strstr_s. + * strstr_s requires s1max and s2max which the unsafe API does not have. So + * we have to improvise them with CLIB_STRING_MACRO_MAX which may cause us + * to access memory beyond it is intended if s1 or s2 is unterminated. + * For the record, strstr crashes if s1 or s2 is unterminated. But this macro + * does not. + * Applications are encouraged to use the cool C11 strstr_s API to avoid + * this problem. + */ +#define clib_strstr(s1,s2) \ + ({ char * __substring = 0; \ + strstr_s_inline (s1, CLIB_STRING_MACRO_MAX, s2, CLIB_STRING_MACRO_MAX, \ + &__substring); \ + __substring; \ + }) + +errno_t strstr_s (char *s1, rsize_t s1max, const char *s2, rsize_t s2max, + char **substring); + +always_inline errno_t +strstr_s_inline (char *s1, rsize_t s1max, const char *s2, rsize_t s2max, + char **substring) +{ + u8 bad; + size_t s1_size, s2_size; + + bad = + (s1 == 0) + (s2 == 0) + (substring == 0) + (s1max == 0) + (s2max == 0) + + (s1 && s1max && (s1[clib_strnlen (s1, s1max)] != '\0')) + + (s2 && s2max && (s2[clib_strnlen (s2, s2max)] != '\0')); + if (PREDICT_FALSE (bad != 0)) + { + if (s1 == 0) + clib_c11_violation ("s1 NULL"); + if (s2 == 0) + clib_c11_violation ("s2 NULL"); + if (s1max == 0) + clib_c11_violation ("s1max 0"); + if (s2max == 0) + clib_c11_violation ("s2max 0"); + if (substring == 0) + clib_c11_violation ("substring NULL"); + if (s1 && s1max && (s1[clib_strnlen (s1, s1max)] != '\0')) + clib_c11_violation ("s1 unterminated"); + if (s2 && s2max && (s2[clib_strnlen (s2, s1max)] != '\0')) + clib_c11_violation ("s2 unterminated"); + return EINVAL; + } + + /* + * s2 points to a string with zero length, or s2 equals s1, return s1 + */ + if (PREDICT_FALSE (*s2 == '\0' || s1 == s2)) + { + *substring = s1; + return EOK; + } + + /* + * s2_size > s1_size, it won't find match. + */ + s1_size = clib_strnlen (s1, s1max); + s2_size = clib_strnlen (s2, s2max); + if (PREDICT_FALSE (s2_size > s1_size)) + return ESRCH; + + *substring = strstr (s1, s2); + if (*substring == 0) + return ESRCH; + + return EOK; +} + #endif /* included_clib_string_h */ /* |