[PATCH] udev - safer string handling all over the place

On Tue, Feb 24, 2004 at 11:50:52PM +0100, Kay Sievers wrote:
> Here is the first step towards a safer string handling.
> More will follow, but for now only the easy ones :)
>
> Thanks to all who pointed this out. strncat() isn't a nice function. We
> all should remember that the destination string is not terminated if the
> given lenght is shorter than the strlen of the source string.
>
> And shame on the various implementers of strfieldcat() I found in the
> unapplied patches on this list, it's not really better than strncpy()
> and hides the real problem.

Hmm, bk didn't checked in one file, maybe I edited it again as root.
Nevermind, here is the more complete version.

1 files changed, 6 insertions, 0 deletions

diff --git a/udev.h b/udev.h
index b5088b90c..fc44a9847 100644
--- a/udev.h
+++ b/udev.h
@@ -61,6 +61,12 @@ do { \
 	strncpy(to, from, sizeof(to)-1); \
 } while (0)
 
+#define strfieldcat(to, from) \
+do { \
+	to[sizeof(to)-1] = '\0'; \
+	strncat(to, from, sizeof(to) - strlen(to) -1); \
+} while (0)
+
 extern int udev_add_device(char *path, char *subsystem, int fake);
 extern int udev_remove_device(char *path, char *subsystem);
 extern void udev_init_config(void);