netdev - Re: [PATCH] netfilter: nft_paylaod: add base type NFT_PAYLOAD_LL_HEADER_NO

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <22ab95cb-9dca-1e48-4ca0-965d340e7d32@ucloud.cn>
Date:   Tue, 18 Jun 2019 16:26:04 +0800
From:   wenxu <wenxu@...oud.cn>
To:     Florian Westphal <fw@...len.de>,
        Pablo Neira Ayuso <pablo@...filter.org>
Cc:     netfilter-devel@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: [PATCH] netfilter: nft_paylaod: add base type
 NFT_PAYLOAD_LL_HEADER_NO_TAG


On 6/18/2019 6:42 AM, Florian Westphal wrote:
> Pablo Neira Ayuso <pablo@...filter.org> wrote:
>>> Subject: Change bridge l3 dependency to meta protocol
>>>
>>> This examines skb->protocol instead of ethernet header type, which
>>> might be different when vlan is involved.
>>>  
>>> +	if (ctx->pctx.family == NFPROTO_BRIDGE && desc == &proto_eth) {
>>> +		if (expr->payload.desc == &proto_ip ||
>>> +		    expr->payload.desc == &proto_ip6)
>>> +			desc = &proto_metaeth;
>>> +	}i
>> Is this sufficient to restrict the matching? Is this still buggy from
>> ingress?
> This is what netdev family uses as well (skb->protocol i mean).
> I'm not sure it will work for output however (haven't checked).
>
>> I wonder if an explicit NFT_PAYLOAD_CHECK_VLAN flag would be useful in
>> the kernel, if so we could rename NFTA_PAYLOAD_CSUM_FLAGS to
>> NFTA_PAYLOAD_FLAGS and place it there. Just an idea.
>
> Another unresolved issue is presence of multiple vlan tags, so we might
> have to add yet another meta key to retrieve the l3 protocol in use

Maybe add a l3proto meta key can handle the multiple vlan tags case with the l3proto dependency.  It

should travese all the vlan tags and find the real l3 proto.


>
>
>