diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index e8d09dc028f61d581eec77f1f3886a69fae347fc..04551af2ff2309345cfae37a718cdfe4d25e1c8e 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -324,11 +324,15 @@ int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry); struct nf_conn; enum nf_nat_manip_type; struct nlattr; +enum ip_conntrack_dir; struct nf_nat_hook { int (*parse_nat_setup)(struct nf_conn *ct, enum nf_nat_manip_type manip, const struct nlattr *attr); void (*decode_session)(struct sk_buff *skb, struct flowi *fl); + unsigned int (*manip_pkt)(struct sk_buff *skb, struct nf_conn *ct, + enum nf_nat_manip_type mtype, + enum ip_conntrack_dir dir); }; extern struct nf_nat_hook __rcu *nf_nat_hook; @@ -392,6 +396,7 @@ struct nf_conn; enum ip_conntrack_info; struct nf_ct_hook { + int (*update)(struct net *net, struct sk_buff *skb); void (*destroy)(struct nf_conntrack *); }; extern struct nf_ct_hook __rcu *nf_ct_hook; diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 8d109d7500730c3d63432b44dcfba590292b0c6f..3465da2a98bd4ff68fc8e52935aad047c69855e8 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 @@ int nf_conntrack_init_start(void) } static struct nf_ct_hook nf_conntrack_hook = { + .update = nf_conntrack_update, .destroy = destroy_conntrack, }; diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index f4d264676cfe5430f8a62cf38c1e2a12b7a163e5..821f8d835f7ad7cab6cdbcba56fd4f2832dfd47d 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -493,17 +493,36 @@ nf_nat_alloc_null_binding(struct nf_conn *ct, unsigned int hooknum) } EXPORT_SYMBOL_GPL(nf_nat_alloc_null_binding); +static unsigned int nf_nat_manip_pkt(struct sk_buff *skb, struct nf_conn *ct, + enum nf_nat_manip_type mtype, + enum ip_conntrack_dir dir) +{ + const struct nf_nat_l3proto *l3proto; + const struct nf_nat_l4proto *l4proto; + struct nf_conntrack_tuple target; + + /* We are aiming to look like inverse of other direction. */ + nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); + + l3proto = __nf_nat_l3proto_find(target.src.l3num); + l4proto = __nf_nat_l4proto_find(target.src.l3num, + target.dst.protonum); + if (!l3proto->manip_pkt(skb, 0, l4proto, &target, mtype)) + return NF_DROP; + + return NF_ACCEPT; +} + /* Do packet manipulations according to nf_nat_setup_info. */ unsigned int nf_nat_packet(struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned int hooknum, struct sk_buff *skb) { - const struct nf_nat_l3proto *l3proto; - const struct nf_nat_l4proto *l4proto; + enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum); enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + unsigned int verdict = NF_ACCEPT; unsigned long statusbit; - enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum); if (mtype == NF_NAT_MANIP_SRC) statusbit = IPS_SRC_NAT; @@ -515,19 +534,10 @@ unsigned int nf_nat_packet(struct nf_conn *ct, statusbit ^= IPS_NAT_MASK; /* Non-atomic: these bits don't change. */ - if (ct->status & statusbit) { - struct nf_conntrack_tuple target; - - /* We are aiming to look like inverse of other direction. */ - nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); + if (ct->status & statusbit) + verdict = nf_nat_manip_pkt(skb, ct, mtype, dir); - l3proto = __nf_nat_l3proto_find(target.src.l3num); - l4proto = __nf_nat_l4proto_find(target.src.l3num, - target.dst.protonum); - if (!l3proto->manip_pkt(skb, 0, l4proto, &target, mtype)) - return NF_DROP; - } - return NF_ACCEPT; + return verdict; } EXPORT_SYMBOL_GPL(nf_nat_packet); @@ -1031,6 +1041,7 @@ struct nf_nat_hook nat_hook = { #ifdef CONFIG_XFRM .decode_session = __nf_nat_decode_session, #endif + .manip_pkt = nf_nat_manip_pkt, }; static int __init nf_nat_init(void) diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 74a04638ef03aedfa51d37667ad536403f890f1f..2c173042ac0e8e350ef9a38c580ea7312ea27a43 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -227,6 +227,25 @@ find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id) return entry; } +static void nfqnl_reinject(struct nf_queue_entry *entry, unsigned int verdict) +{ + struct nf_ct_hook *ct_hook; + int err; + + if (verdict == NF_ACCEPT || + verdict == NF_STOP) { + rcu_read_lock(); + ct_hook = rcu_dereference(nf_ct_hook); + if (ct_hook) { + err = ct_hook->update(entry->state.net, entry->skb); + if (err < 0) + verdict = NF_DROP; + } + rcu_read_unlock(); + } + nf_reinject(entry, verdict); +} + static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data) { @@ -237,7 +256,7 @@ nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data) if (!cmpfn || cmpfn(entry, data)) { list_del(&entry->list); queue->queue_total--; - nf_reinject(entry, NF_DROP); + nfqnl_reinject(entry, NF_DROP); } } spin_unlock_bh(&queue->lock); @@ -686,7 +705,7 @@ __nfqnl_enqueue_packet(struct net *net, struct nfqnl_instance *queue, err_out_unlock: spin_unlock_bh(&queue->lock); if (failopen) - nf_reinject(entry, NF_ACCEPT); + nfqnl_reinject(entry, NF_ACCEPT); err_out: return err; } @@ -1085,7 +1104,8 @@ static int nfqnl_recv_verdict_batch(struct net *net, struct sock *ctnl, list_for_each_entry_safe(entry, tmp, &batch_list, list) { if (nfqa[NFQA_MARK]) entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK])); - nf_reinject(entry, verdict); + + nfqnl_reinject(entry, verdict); } return 0; } @@ -1208,7 +1228,7 @@ static int nfqnl_recv_verdict(struct net *net, struct sock *ctnl, if (nfqa[NFQA_MARK]) entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK])); - nf_reinject(entry, verdict); + nfqnl_reinject(entry, verdict); return 0; }