On 3/11/21 12:15 AM, Sean Anderson wrote:
strlcpy should always return the number of bytes copied. We were
accidentally missing the nul-terminator. We also always used to return a
It looks like I was a bit bullish in assuming a mistake. After reviewing
the man page, it looks like the nul-terminator is intentionally
excluded.
The strlcpy() and strlcat() functions return the total length of the
string they tried to create. For strlcpy() that means the length of
src. For strlcat() that means the initial length of dst plus the
length of src. While this may seem somewhat confusing, it was done to
make truncation detection simple.
In particular, we should return the length of the string, which may be
different from the amount of bytes copied. However, the non-zero return
value should be fixed.
non-zero value, even if we did not actually copy anything.
Fixes: 23cd138503 ("Integrate USB gadget layer and USB CDC driver layer")
Signed-off-by: Sean Anderson <sean...@gmail.com>
---
Changes in v2:
- New
lib/string.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/lib/string.c b/lib/string.c
index 73b984123d..1b867ac09d 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -114,17 +114,21 @@ char * strncpy(char * dest,const char *src,size_t count)
* NUL-terminated string that fits in the buffer (unless,
* of course, the buffer size is zero). It does not pad
* out the result like strncpy() does.
+ *
+ * Return: the number of bytes copied
*/
size_t strlcpy(char *dest, const char *src, size_t size)
{
- size_t ret = strlen(src);
-
if (size) {
- size_t len = (ret >= size) ? size - 1 : ret;
+ size_t srclen = strlen(src);
+ size_t len = (srclen >= size) ? size - 1 : srclen;
+
memcpy(dest, src, len);
dest[len] = '\0';
+ return len + 1;
}
- return ret;
+
+ return 0;
}
#endif
