Snoopy(8) patch

Snoopy(8) patch

[Alex Musolino]

Hello,

I've made some changes [1] to snoopy(8) in order to help with some
work I'm doing on dhcpd(8) to support the static route options.

Any objections to committing/pushing these?

[1] http://musolino.id.au/up/2019/06/05/snoopy.dhcp.patch

--
Cheers,
Alex Musolino

Re: [9front] Snoopy(8) patch

[Ori Bernstein]

On Fri, 7 Jun 2019 00:51:52 +0930
Alex Musolino <alex@musolino.id.au> wrote:

> Hello,
> 
> I've made some changes [1] to snoopy(8) in order to help with some
> work I'm doing on dhcpd(8) to support the static route options.
> 
> Any objections to committing/pushing these?
> 
> [1] http://musolino.id.au/up/2019/06/05/snoopy.dhcp.patch
> 
> --
> Cheers,
> Alex Musolino
> 

If you inline the patch in the mail, it's easier for me to comment on it.

It mostly looks good to me, just noticed one thing:

> +	uchar addr[4];
> ...
> +		nbits = *o++;

Nbits is a uchar, so if we get a junk message, the maximum value here is 255.

> +		n--;
> +		nocts = (nbits+7)/8;

(255 + 7)/8 == 32

> +		memset(addr, 0, 4);
> +		if(n < nocts+4)
> +			break;
> +		memmove(addr, o, nocts);

And because addr is only 4 bytes, we overwrite random memory.
I think a check on nocts here is neeeded.

-- 
Ori Bernstein <ori@eigenstate.org>