Re: Increase some limits in git-mailinfo

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Feb 26, 2007, 19:34 UTC
Message-ID: <Pine.LNX.4.63.0702262020590.22628@wbgn013.biozentrum.uni-wuerzburg.de>
In-Reply-To: <Pine.LNX.4.64.0702261107060.12485@woody.linux-foundation.org>

Hi,

On Mon, 26 Feb 2007, Linus Torvalds wrote:

> +
> +	/* Count mbox From headers as headers */
> +	if (!memcmp(line, "From ", 5) || !memcmp(line, ">From ", 6))

I know that you copied that, but why not use the new prefixcmp() function?

Show 31 quoted lines

>  static int read_one_header_line(char *line, int sz, FILE *in)
>  {
> -	int ofs = 0;
> -	while (ofs < sz) {
> -		int peek, len;
> -		if (fgets(line + ofs, sz - ofs, in) == NULL)
> -			break;
> -		len = eatspace(line + ofs);
> -		if ((len == 0) || !is_rfc2822_header(line)) {
> -			/* Re-add the newline */
> -			line[ofs + len] = '\n';
> -			line[ofs + len + 1] = '\0';
> -			break;
> -		}
> -		ofs += len;
> -		/* Yuck, 2822 header "folding" */
> +	int len;
> +
> +	/* Get the first part of the line.. */
> +	if (!fgets(line, sz, in))
> +		return 0;
> +
> +	/*
> +	 * Is it an empty line or not a valid rfc2822 header?
> +	 * If so, stop here, and return false ("not a header")
> +	 */
> +	len = eatspace(line);
> +	if (!len || !is_rfc2822_header(line)) {
> +		/* Re-add the newline */
> +		line[len] = '\n';
> +		line[len + 1] = '\0';

Just a micro-issue: if the input ends in the middle of a header line, _and_ this line is of exactly the right size (sz), then len + 1 is not necessarily smaller than sz, right?

It's not like this can be used for a DOS or stuff, but I try to get more aware of off-by-one bugs, which I introduced all too often...

> +		addlen = eatspace(continuation);
> +		if (len < sz) {

Shouldn't this be "sz - 1"? We are setting "line[len] = 0;" later... While at it, we can always check for "addlen > 0", just in case?

But then, should it not be rather "sz - 2", because we want to _add_ something to the line?

Show 13 quoted lines

> +			if (addlen >= sz - len)
> +				addlen = sz - len - 1;
> +			memcpy(line + len, continuation, addlen);
> +			len += addlen;
> +		}
>  	}
> -	/* Count mbox From headers as headers */
> -	if (!ofs && (!memcmp(line, "From ", 5) || !memcmp(line, ">From ", 6)))
> -		ofs = 1;
> -	return ofs;
> +	line[len] = 0;
> +
> +	return 1;

Ciao, Dscho