diff options
Diffstat (limited to 'net/netfilter/nf_conntrack_core.c')
-rw-r--r-- | net/netfilter/nf_conntrack_core.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 8d109d750073..3465da2a98bd 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1607,6 +1607,82 @@ static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb) nf_conntrack_get(skb_nfct(nskb)); } +static int nf_conntrack_update(struct net *net, struct sk_buff *skb) +{ + const struct nf_conntrack_l3proto *l3proto; + const struct nf_conntrack_l4proto *l4proto; + struct nf_conntrack_tuple_hash *h; + struct nf_conntrack_tuple tuple; + enum ip_conntrack_info ctinfo; + struct nf_nat_hook *nat_hook; + unsigned int dataoff, status; + struct nf_conn *ct; + u16 l3num; + u8 l4num; + + ct = nf_ct_get(skb, &ctinfo); + if (!ct || nf_ct_is_confirmed(ct)) + return 0; + + l3num = nf_ct_l3num(ct); + l3proto = nf_ct_l3proto_find_get(l3num); + + if (l3proto->get_l4proto(skb, skb_network_offset(skb), &dataoff, + &l4num) <= 0) + return -1; + + l4proto = nf_ct_l4proto_find_get(l3num, l4num); + + if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num, + l4num, net, &tuple, l3proto, l4proto)) + return -1; + + if (ct->status & IPS_SRC_NAT) { + memcpy(tuple.src.u3.all, + ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.all, + sizeof(tuple.src.u3.all)); + tuple.src.u.all = + ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.all; + } + + if (ct->status & IPS_DST_NAT) { + memcpy(tuple.dst.u3.all, + ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.all, + sizeof(tuple.dst.u3.all)); + tuple.dst.u.all = + ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.all; + } + + h = nf_conntrack_find_get(net, nf_ct_zone(ct), &tuple); + if (!h) + return 0; + + /* Store status bits of the conntrack that is clashing to re-do NAT + * mangling according to what it has been done already to this packet. + */ + status = ct->status; + + nf_ct_put(ct); + ct = nf_ct_tuplehash_to_ctrack(h); + nf_ct_set(skb, ct, ctinfo); + + nat_hook = rcu_dereference(nf_nat_hook); + if (!nat_hook) + return 0; + + if (status & IPS_SRC_NAT && + nat_hook->manip_pkt(skb, ct, NF_NAT_MANIP_SRC, + IP_CT_DIR_ORIGINAL) == NF_DROP) + return -1; + + if (status & IPS_DST_NAT && + nat_hook->manip_pkt(skb, ct, NF_NAT_MANIP_DST, + IP_CT_DIR_ORIGINAL) == NF_DROP) + return -1; + + return 0; +} + /* Bring out ya dead! */ static struct nf_conn * get_next_corpse(int (*iter)(struct nf_conn *i, void *data), @@ -2126,6 +2202,7 @@ err_cachep: } static struct nf_ct_hook nf_conntrack_hook = { + .update = nf_conntrack_update, .destroy = destroy_conntrack, }; |