netdev - Re: [PATCH net] openvswitch: update checksum in {push,pop}

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] [day] [month] [year] [list]

Date:	Sun, 29 May 2016 09:16:09 -0700
From:	pravin shelar <pshelar@....org>
To:	Simon Horman <simon.horman@...ronome.com>
Cc:	Pravin Shelar <pshelar@...ira.com>,
	Linux Kernel Network Developers <netdev@...r.kernel.org>
Subject: Re: [PATCH net] openvswitch: update checksum in {push,pop}_mpls

On Thu, May 26, 2016 at 11:58 PM, Simon Horman
<simon.horman@...ronome.com> wrote:
> In the case of CHECKSUM_COMPLETE the skb checksum should be updated in
> {push,pop}_mpls() as they the type in the ethernet header.
>
> As suggested by Pravin Shelar.
>
> Cc: Pravin Shelar <pshelar@...ira.com>
> Fixes: 25cd9ba0abc0 ("openvswitch: Add basic MPLS support to kernel")
> Signed-off-by: Simon Horman <simon.horman@...ronome.com>
> ---
>  net/openvswitch/actions.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
> index 879185fe183f..d6010b44d423 100644
> --- a/net/openvswitch/actions.c
> +++ b/net/openvswitch/actions.c
> @@ -161,6 +161,12 @@ static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
>         skb_postpush_rcsum(skb, new_mpls_lse, MPLS_HLEN);
>
>         hdr = eth_hdr(skb);
> +       if (skb->ip_summed == CHECKSUM_COMPLETE) {
> +               __be16 diff[] = { ~(hdr->h_proto), mpls->mpls_ethertype };
> +
> +               skb->csum = ~csum_partial((char *)diff, sizeof(diff),
> +                                       ~skb->csum);
> +       }
>         hdr->h_proto = mpls->mpls_ethertype;
>
This looks correct. But same code is now replicated three times in
this file. can you add helper function to update checksum for such
case?

>         if (!skb->inner_protocol)
> @@ -193,6 +199,12 @@ static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
>          * field correctly in the presence of VLAN tags.
>          */
>         hdr = (struct ethhdr *)(skb_mpls_header(skb) - ETH_HLEN);
> +       if (skb->ip_summed == CHECKSUM_COMPLETE) {
> +               __be16 diff[] = { ~(hdr->h_proto), ethertype };
> +
> +               skb->csum = ~csum_partial((char *)diff, sizeof(diff),
> +                                       ~skb->csum);
> +       }
>         hdr->h_proto = ethertype;
>         if (eth_p_mpls(skb->protocol))
>                 skb->protocol = ethertype;
> --
> 2.1.4
>