From 694a0055f039bc1d73aba10606ea74e798d2d759 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Sat, 15 Apr 2017 19:26:10 +0200 Subject: [PATCH] netfilter: nft_ct: allow to set ctnetlink event types of a connection By default the kernel emits all ctnetlink events for a connection. This allows to select the types of events to generate. This can be used to e.g. only send DESTROY events but no NEW/UPDATE ones and will work even if sysctl net.netfilter.nf_conntrack_events is set to 0. This was already possible via iptables' CT target, but the nft version has the advantage that it can also be used with already-established conntracks. The added nf_ct_is_template() check isn't a bug fix as we only support mark and labels (and unlike ecache the conntrack core doesn't copy those). Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/uapi/linux/netfilter/nf_tables.h | 2 ++ net/netfilter/nft_ct.c | 25 +++++++++++++++++++++++- 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 8f3842690d17..683f6f88fcac 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -901,6 +901,7 @@ enum nft_rt_attributes { * @NFT_CT_BYTES: conntrack bytes * @NFT_CT_AVGPKT: conntrack average bytes per packet * @NFT_CT_ZONE: conntrack zone + * @NFT_CT_EVENTMASK: ctnetlink events to be generated for this conntrack */ enum nft_ct_keys { NFT_CT_STATE, @@ -921,6 +922,7 @@ enum nft_ct_keys { NFT_CT_BYTES, NFT_CT_AVGPKT, NFT_CT_ZONE, + NFT_CT_EVENTMASK, }; /** diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c index 6c6fd48b024c..a34ceb38fc55 100644 --- a/net/netfilter/nft_ct.c +++ b/net/netfilter/nft_ct.c @@ -264,7 +264,7 @@ static void nft_ct_set_eval(const struct nft_expr *expr, struct nf_conn *ct; ct = nf_ct_get(skb, &ctinfo); - if (ct == NULL) + if (ct == NULL || nf_ct_is_template(ct)) return; switch (priv->key) { @@ -283,6 +283,22 @@ static void nft_ct_set_eval(const struct nft_expr *expr, ®s->data[priv->sreg], NF_CT_LABELS_MAX_SIZE / sizeof(u32)); break; +#endif +#ifdef CONFIG_NF_CONNTRACK_EVENTS + case NFT_CT_EVENTMASK: { + struct nf_conntrack_ecache *e = nf_ct_ecache_find(ct); + u32 ctmask = regs->data[priv->sreg]; + + if (e) { + if (e->ctmask != ctmask) + e->ctmask = ctmask; + break; + } + + if (ctmask && !nf_ct_is_confirmed(ct)) + nf_ct_ecache_ext_add(ct, ctmask, 0, GFP_ATOMIC); + break; + } #endif default: break; @@ -538,6 +554,13 @@ static int nft_ct_set_init(const struct nft_ctx *ctx, nft_ct_pcpu_template_refcnt++; len = sizeof(u16); break; +#endif +#ifdef CONFIG_NF_CONNTRACK_EVENTS + case NFT_CT_EVENTMASK: + if (tb[NFTA_CT_DIRECTION]) + return -EINVAL; + len = sizeof(u32); + break; #endif default: return -EOPNOTSUPP; -- 2.20.1