netdev - RE: [iproute PATCH 1/6] utils: Implement strlcpy() and strlcat()

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Message-ID: <063D6719AE5E284EB5DD2968C1650D6DD006D878@AcuExch.aculab.com>
Date:   Mon, 4 Sep 2017 14:49:20 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Phil Sutter' <phil@....cc>,
        Stephen Hemminger <stephen@...workplumber.org>
CC:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: RE: [iproute PATCH 1/6] utils: Implement strlcpy() and strlcat()

From: Phil Sutter
> Sent: 01 September 2017 17:53
> By making use of strncpy(), both implementations are really simple so
> there is no need to add libbsd as additional dependency.
> 
...
> +
> +size_t strlcpy(char *dst, const char *src, size_t size)
> +{
> +	if (size) {
> +		strncpy(dst, src, size - 1);
> +		dst[size - 1] = '\0';
> +	}
> +	return strlen(src);
> +}

Except that isn't really strlcpy().
Better would be:
	len = strlen(src) + 1;
	if (len <= size)
		memcpy(dst, src, len);
	else if (size) {
		dst[size - 1] = 0;
		memcpy(dst, src, size - 1);
	}
	return len - 1;

WTF strlcpy() has that return value I don't know.

	David