Implement library function strnstr(). Implement strstr() using strnstr(). Sort the includes.
Signed-off-by: Heinrich Schuchardt heinrich.schuchardt@canonical.com --- include/linux/string.h | 3 +++ lib/string.c | 49 +++++++++++++++++++++++++++++------------- 2 files changed, 37 insertions(+), 15 deletions(-)
diff --git a/include/linux/string.h b/include/linux/string.h index 27b2beb9ddb..8a377a8176a 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -72,6 +72,9 @@ extern char * strrchr(const char *,int); #ifndef __HAVE_ARCH_STRSTR extern char * strstr(const char *,const char *); #endif +#ifndef __HAVE_ARCH_STRNSTR +extern char *strnstr(const char *, const char *, size_t); +#endif #ifndef __HAVE_ARCH_STRLEN extern __kernel_size_t strlen(const char *); #endif diff --git a/lib/string.c b/lib/string.c index feae9519f2f..d5a486fb89d 100644 --- a/lib/string.c +++ b/lib/string.c @@ -16,11 +16,12 @@ */
#include <config.h> +#include <malloc.h> +#include <stdint.h> #include <linux/compiler.h> +#include <linux/ctype.h> #include <linux/types.h> #include <linux/string.h> -#include <linux/ctype.h> -#include <malloc.h>
/** * strncasecmp - Case insensitive, length-limited string comparison @@ -678,30 +679,48 @@ char *memdup(const void *src, size_t len) return p; }
-#ifndef __HAVE_ARCH_STRSTR +#ifndef __HAVE_ARCH_STRNSTR /** - * strstr - Find the first substring in a %NUL terminated string - * @s1: The string to be searched - * @s2: The string to search for + * strnstr() - find the first substring occurrence in a NUL terminated string + * + * @s1: string to be searched + * @s2: string to search for + * @len: maximum number of characters in s2 to consider + * + * Return: pointer to the first occurrence or NULL */ -char * strstr(const char * s1,const char * s2) +char *strnstr(const char *s1, const char *s2, size_t len) { - int l1, l2; + size_t l1, l2;
+ l1 = strnlen(s1, len); l2 = strlen(s2); - if (!l2) - return (char *) s1; - l1 = strlen(s1); - while (l1 >= l2) { - l1--; - if (!memcmp(s1,s2,l2)) + + for (; l1 >= l2; --l1, ++s1) { + if (!memcmp(s1, s2, l2)) return (char *) s1; - s1++; } + return NULL; } #endif
+#ifndef __HAVE_ARCH_STRSTR +/** + * strstr() - find the first substring occurrence in a NUL terminated string + * + * @s1: string to be searched + * @s2: string to search for + * @len: maximum number of characters in s2 to consider + * + * Return: pointer to the first occurrence or NULL + */ +char *strstr(const char *s1, const char *s2) +{ + return strnstr(s1, s2, SIZE_MAX); +} +#endif + #ifndef __HAVE_ARCH_MEMCHR /** * memchr - Find a character in an area of memory.