diff options
| author | Florian Westphal <fw@strlen.de> | 2017-04-14 21:31:08 +0300 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-04-15 12:47:57 +0300 |
| commit | cc41c84b7e7f2d7f6698bccc84890943fd021265 (patch) | |
| tree | 08c09a05f63c6d146e0baf3f8f5f4752092c7622 /net/ipv6 | |
| parent | 6e354a5e565110c3a0eb7da3788340d4809a42b6 (diff) | |
| download | linux-cc41c84b7e7f2d7f6698bccc84890943fd021265.tar.xz | |
netfilter: kill the fake untracked conntrack objects
resurrect an old patch from Pablo Neira to remove the untracked objects.
Currently, there are four possible states of an skb wrt. conntrack.
1. No conntrack attached, ct is NULL.
2. Normal (kmem cache allocated) ct attached.
3. a template (kmalloc'd), not in any hash tables at any point in time
4. the 'untracked' conntrack, a percpu nf_conn object, tagged via
IPS_UNTRACKED_BIT in ct->status.
Untracked is supposed to be identical to case 1. It exists only
so users can check
-m conntrack --ctstate UNTRACKED vs.
-m conntrack --ctstate INVALID
e.g. attempts to set connmark on INVALID or UNTRACKED conntracks is
supposed to be a no-op.
Thus currently we need to check
ct == NULL || nf_ct_is_untracked(ct)
in a lot of places in order to avoid altering untracked objects.
The other consequence of the percpu untracked object is that all
-j NOTRACK (and, later, kfree_skb of such skbs) result in an atomic op
(inc/dec the untracked conntracks refcount).
This adds a new kernel-private ctinfo state, IP_CT_UNTRACKED, to
make the distinction instead.
The (few) places that care about packet invalid (ct is NULL) vs.
packet untracked now need to test ct == NULL vs. ctinfo == IP_CT_UNTRACKED,
but all other places can omit the nf_ct_is_untracked() check.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c | 3 | ||||
| -rw-r--r-- | net/ipv6/netfilter/nf_dup_ipv6.c | 3 |
2 files changed, 2 insertions, 4 deletions
diff --git a/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c b/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c index d2c2ccbfbe72..d5f028e33f65 100644 --- a/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c +++ b/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c @@ -221,8 +221,7 @@ icmpv6_error(struct net *net, struct nf_conn *tmpl, type = icmp6h->icmp6_type - 130; if (type >= 0 && type < sizeof(noct_valid_new) && noct_valid_new[type]) { - nf_ct_set(skb, nf_ct_untracked_get(), IP_CT_NEW); - nf_conntrack_get(skb_nfct(skb)); + nf_ct_set(skb, NULL, IP_CT_UNTRACKED); return NF_ACCEPT; } diff --git a/net/ipv6/netfilter/nf_dup_ipv6.c b/net/ipv6/netfilter/nf_dup_ipv6.c index 888ecd106e5f..4a7ddeddbaab 100644 --- a/net/ipv6/netfilter/nf_dup_ipv6.c +++ b/net/ipv6/netfilter/nf_dup_ipv6.c @@ -58,8 +58,7 @@ void nf_dup_ipv6(struct net *net, struct sk_buff *skb, unsigned int hooknum, #if IS_ENABLED(CONFIG_NF_CONNTRACK) nf_reset(skb); - nf_ct_set(skb, nf_ct_untracked_get(), IP_CT_NEW); - nf_conntrack_get(skb_nfct(skb)); + nf_ct_set(skb, NULL, IP_CT_UNTRACKED); #endif if (hooknum == NF_INET_PRE_ROUTING || hooknum == NF_INET_LOCAL_IN) { |