[patch] abuse of strncpy

[Peter Kjellerstedt]

> -----Original Message-----
> From: busybox-bounces at busybox.net 
> [mailto:busybox-bounces at busybox.net] On Behalf Of Tito
> Sent: Friday, June 02, 2006 14:20
> To: busybox at busybox.net; wharms at bfs.de
> Subject: Re: [patch] abuse of strncpy
> 
> On Friday 2 June 2006 10:07, walter harms wrote:
> > Hi Erik good catch,
> > if you are concerned about security why not use strlcpy() or a bb 
> > supplied bb_strlcpy() if its not available ?.
> 
> Hi,
> In libbb we have it ;-)
> 
> /* Like strncpy but make sure the resulting string is always 
> 0 terminated. */
> char * safe_strncpy(char *dst, const char *src, size_t size)
> {
> 	dst[size-1] = '\0';
> 	return strncpy(dst, src, size-1);
> }

Is it just me that find the name safe_strncpy() somewhat misleading
when looking at its implementation? What if size == 0?

I would suggest it is changed to the following:

char * safe_strncpy(char *dst, const char *src, size_t size)
{
	if (!size) {
		return dst;
	} else {
		dst[size-1] = '\0';
		return strncpy(dst, src, size-1);
	}
}

And on the related subject of renaming the above function to
bb_strlcpy(), that would be totally misleading, as strlcpy() has
totally different semantics and functionality.

//Peter