On Tue, Apr 09, 2019 at 02:23:46PM +0000, Kevin 'ldir' Darbyshire-Bryant wrote:
> diff --git a/include/uapi/linux/netfilter/xt_connmark.h b/include/uapi/linux/netfilter/xt_connmark.h
> index 1aa5c955ee1e..24272cac2d37 100644
> --- a/include/uapi/linux/netfilter/xt_connmark.h
> +++ b/include/uapi/linux/netfilter/xt_connmark.h
> @@ -16,7 +16,8 @@
> enum {
> XT_CONNMARK_SET = 0,
> XT_CONNMARK_SAVE,
> - XT_CONNMARK_RESTORE
> + XT_CONNMARK_RESTORE,
> + XT_CONNMARK_SAVEDSCP
I'd prefer you implement this in nftables, more comments below.
> };
>
> enum {
> diff --git a/net/netfilter/xt_connmark.c b/net/netfilter/xt_connmark.c
> index 29c38aa7f726..6c63cf476342 100644
> --- a/net/netfilter/xt_connmark.c
> +++ b/net/netfilter/xt_connmark.c
> @@ -42,6 +42,7 @@ connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
> u_int32_t new_targetmark;
> struct nf_conn *ct;
> u_int32_t newmark;
> + u8 dscp;
>
> ct = nf_ct_get(skb, &ctinfo);
> if (ct == NULL)
> @@ -74,6 +75,34 @@ connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
> nf_conntrack_event_cache(IPCT_MARK, ct);
> }
> break;
> + case XT_CONNMARK_SAVEDSCP:
Could you add a new revision and a new flag field for this? so it just
adds the dscp to the mark as you need.
> + if (!info->ctmark)
> + goto out;
> +
> + if (skb->protocol == htons(ETH_P_IP)) {
> + if (skb->len < sizeof(struct iphdr))
> + goto out;
> +
> + dscp = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
> +
> + } else if (skb->protocol == htons(ETH_P_IPV6)) {
> + if (skb->len < sizeof(struct ipv6hdr))
> + goto out;
This is already guaranteed to have a valid IP header in place, no need
for this check.
> +
> + dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
> +
> + } else { /* protocol doesn't have diffserv - get out! */
> + goto out;
> + }
> +
> + newmark = (ct->mark & ~info->ctmark) ^
> + (info->ctmask | (dscp << info->shift_bits));
> +
> + if (ct->mark != newmark) {
> + ct->mark = newmark;
> + nf_conntrack_event_cache(IPCT_MARK, ct);
> + }
> + break;
> case XT_CONNMARK_RESTORE:
> new_targetmark = (ct->mark & info->ctmask);
> if (info->shift_dir == D_SHIFT_RIGHT)
> @@ -86,6 +115,7 @@ connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
> skb->mark = newmark;
> break;
> }
> +out:
> return XT_CONTINUE;
> }
>
> --
> 2.20.1 (Apple Git-117)
>
