backports: add strtobool()

This was added in the following upstream commit:
commit d0f1fed29e6e73d9d17f4c91a5896a4ce3938d45
Author: Jonathan Cameron <jic23@cam.ac.uk>
Date:   Tue Apr 19 12:43:45 2011 +0100

    Add a strtobool function matching semantics of existing in kernel equivalents

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

diff --git a/backport/backport-include/linux/string.h b/backport/backport-include/linux/string.h
index 819d1414413e8e9ec5299bf2c71b1ad7ff923831..f9f175059f85aa6bb0ce9654cd5d9ac91b59b833 100644 (file)
--- a/backport/backport-include/linux/string.h
+++ b/backport/backport-include/linux/string.h
@@ -8,4 +8,9 @@
 extern size_t memweight(const void *ptr, size_t bytes);
 #endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,0,0)
+#define strtobool LINUX_BACKPORT(strtobool)
+extern int strtobool(const char *s, bool *res);
+#endif
+
 #endif /* __BACKPORT_LINUX_STRING_H */

diff --git a/backport/compat/compat-3.0.c b/backport/compat/compat-3.0.c
index 9841019feffaabb0bc89160ffbf41a228a6f2af6..1bed6a6afab6a5cd4b9d4d15c923b309fe0b6ece 100644 (file)
--- a/backport/compat/compat-3.0.c
+++ b/backport/compat/compat-3.0.c
@@ -60,3 +60,32 @@ kstrto_from_user(kstrtou16_from_user,        kstrtou16,      u16);
 kstrto_from_user(kstrtos16_from_user,  kstrtos16,      s16);
 kstrto_from_user(kstrtou8_from_user,   kstrtou8,       u8);
 kstrto_from_user(kstrtos8_from_user,   kstrtos8,       s8);
+
+/**
+ * strtobool - convert common user inputs into boolean values
+ * @s: input string
+ * @res: result
+ *
+ * This routine returns 0 iff the first character is one of 'Yy1Nn0'.
+ * Otherwise it will return -EINVAL.  Value pointed to by res is
+ * updated upon finding a match.
+ */
+int strtobool(const char *s, bool *res)
+{
+       switch (s[0]) {
+       case 'y':
+       case 'Y':
+       case '1':
+               *res = true;
+               break;
+       case 'n':
+       case 'N':
+       case '0':
+               *res = false;
+               break;
+       default:
+               return -EINVAL;
+       }
+       return 0;
+}
+EXPORT_SYMBOL_GPL(strtobool);