1 files changed, 123 insertions, 0 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 7b481cea54ae..419993f58c6b 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -126,6 +126,129 @@ long long simple_strtoll(const char *cp,char **endp,unsigned int base)
         return simple_strtoull(cp,endp,base);
 }
 
+
+/**
+ * strict_strtoul - convert a string to an unsigned long strictly
+ * @cp: The string to be converted
+ * @base: The number base to use
+ * @res: The converted result value
+ *
+ * strict_strtoul converts a string to an unsigned long only if the
+ * string is really an unsigned long string, any string containing
+ * any invalid char at the tail will be rejected and -EINVAL is returned,
+ * only a newline char at the tail is acceptible because people generally
+ * change a module parameter in the following way:
+ *
+ *      echo 1024 > /sys/module/e1000/parameters/copybreak
+ *
+ * echo will append a newline to the tail.
+ *
+ * It returns 0 if conversion is successful and *res is set to the converted
+ * value, otherwise it returns -EINVAL and *res is set to 0.
+ *
+ * simple_strtoul just ignores the successive invalid characters and
+ * return the converted value of prefix part of the string.
+ */
+int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);
+
+/**
+ * strict_strtol - convert a string to a long strictly
+ * @cp: The string to be converted
+ * @base: The number base to use
+ * @res: The converted result value
+ *
+ * strict_strtol is similiar to strict_strtoul, but it allows the first
+ * character of a string is '-'.
+ *
+ * It returns 0 if conversion is successful and *res is set to the converted
+ * value, otherwise it returns -EINVAL and *res is set to 0.
+ */
+int strict_strtol(const char *cp, unsigned int base, long *res);
+
+/**
+ * strict_strtoull - convert a string to an unsigned long long strictly
+ * @cp: The string to be converted
+ * @base: The number base to use
+ * @res: The converted result value
+ *
+ * strict_strtoull converts a string to an unsigned long long only if the
+ * string is really an unsigned long long string, any string containing
+ * any invalid char at the tail will be rejected and -EINVAL is returned,
+ * only a newline char at the tail is acceptible because people generally
+ * change a module parameter in the following way:
+ *
+ *      echo 1024 > /sys/module/e1000/parameters/copybreak
+ *
+ * echo will append a newline to the tail of the string.
+ *
+ * It returns 0 if conversion is successful and *res is set to the converted
+ * value, otherwise it returns -EINVAL and *res is set to 0.
+ *
+ * simple_strtoull just ignores the successive invalid characters and
+ * return the converted value of prefix part of the string.
+ */
+int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res);
+
+/**
+ * strict_strtoll - convert a string to a long long strictly
+ * @cp: The string to be converted
+ * @base: The number base to use
+ * @res: The converted result value
+ *
+ * strict_strtoll is similiar to strict_strtoull, but it allows the first
+ * character of a string is '-'.
+ *
+ * It returns 0 if conversion is successful and *res is set to the converted
+ * value, otherwise it returns -EINVAL and *res is set to 0.
+ */
+int strict_strtoll(const char *cp, unsigned int base, long long *res);
+
+#define define_strict_strtoux(type, valtype)                            \
+int strict_strtou##type(const char *cp, unsigned int base, valtype *res)\
+{                                                                       \
+        char *tail;                                                     \
+        valtype val;                                                    \
+        size_t len;                                                     \
+                                                                        \
+        *res = 0;                                                       \
+        len = strlen(cp);                                               \
+        if (len == 0)                                                   \
+                return -EINVAL;                                         \
+                                                                        \
+        val = simple_strtoul(cp, &tail, base);                          \
+        if ((*tail == '\0') ||                                          \
+                ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {\
+                *res = val;                                             \
+                return 0;                                               \
+        }                                                               \
+                                                                        \
+        return -EINVAL;                                                 \
+}                                                                       \
+
+#define define_strict_strtox(type, valtype)                             \
+int strict_strto##type(const char *cp, unsigned int base, valtype *res) \
+{                                                                       \
+        int ret;                                                        \
+        if (*cp == '-') {                                               \
+                ret = strict_strtou##type(cp+1, base, res);             \
+                if (ret != 0)                                           \
+                        *res = -(*res);                                 \
+        } else                                                          \
+                ret = strict_strtou##type(cp, base, res);               \
+                                                                        \
+        return ret;                                                     \
+}                                                                       \
+
+define_strict_strtoux(l, unsigned long)
+define_strict_strtox(l, long)
+define_strict_strtoux(ll, unsigned long long)
+define_strict_strtox(ll, long long)
+
+EXPORT_SYMBOL(strict_strtoul);
+EXPORT_SYMBOL(strict_strtol);
+EXPORT_SYMBOL(strict_strtoll);
+EXPORT_SYMBOL(strict_strtoull);
+
 static int skip_atoi(const char **s)
 {
         int i=0;