diff --git a/include/linux/netfilter_ipv4.h b/include/linux/netfilter_ipv4.h index 9a10092e358cacead0c968e694eb2b0f426d4cbf..650318b0c405b2669fcfe413eb7a73f9b4628240 100644 --- a/include/linux/netfilter_ipv4.h +++ b/include/linux/netfilter_ipv4.h @@ -62,8 +62,6 @@ enum nf_ip_hook_priorities { NF_IP_PRI_FILTER = 0, NF_IP_PRI_NAT_SRC = 100, NF_IP_PRI_SELINUX_LAST = 225, - NF_IP_PRI_CONNTRACK_HELPER = INT_MAX - 2, - NF_IP_PRI_NAT_SEQ_ADJUST = INT_MAX - 1, NF_IP_PRI_CONNTRACK_CONFIRM = INT_MAX, NF_IP_PRI_LAST = INT_MAX, }; diff --git a/include/net/netfilter/nf_nat_helper.h b/include/net/netfilter/nf_nat_helper.h index 58dd22687949ca807a89e8bd9c913636cdc248bf..237a961f40e1fb23a20951ea166dacd8053790fc 100644 --- a/include/net/netfilter/nf_nat_helper.h +++ b/include/net/netfilter/nf_nat_helper.h @@ -24,6 +24,9 @@ extern int nf_nat_mangle_udp_packet(struct sk_buff *skb, extern int nf_nat_seq_adjust(struct sk_buff *skb, struct nf_conn *ct, enum ip_conntrack_info ctinfo); +extern int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb, + struct nf_conn *ct, + enum ip_conntrack_info ctinfo); /* Setup NAT on this expected conntrack so it follows master, but goes * to port ct->master->saved_proto. */ diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c index a65b845c5f1596ec5d7732b6d84508f1133eef3f..41e79613eb0a211fa370d2650fac5e691d95ea37 100644 --- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c +++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c @@ -23,6 +23,12 @@ #include #include #include +#include + +int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb, + struct nf_conn *ct, + enum ip_conntrack_info ctinfo); +EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook); static int ipv4_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff, struct nf_conntrack_tuple *tuple) @@ -100,36 +106,42 @@ static unsigned int ipv4_confirm(unsigned int hooknum, const struct net_device *in, const struct net_device *out, int (*okfn)(struct sk_buff *)) -{ - /* We've seen it coming out the other side: confirm it */ - return nf_conntrack_confirm(skb); -} - -static unsigned int ipv4_conntrack_help(unsigned int hooknum, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) { struct nf_conn *ct; enum ip_conntrack_info ctinfo; const struct nf_conn_help *help; const struct nf_conntrack_helper *helper; + unsigned int ret; /* This is where we call the helper: as the packet goes out. */ ct = nf_ct_get(skb, &ctinfo); if (!ct || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY) - return NF_ACCEPT; + goto out; help = nfct_help(ct); if (!help) - return NF_ACCEPT; + goto out; + /* rcu_read_lock()ed by nf_hook_slow */ helper = rcu_dereference(help->helper); if (!helper) - return NF_ACCEPT; - return helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb), - ct, ctinfo); + goto out; + + ret = helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb), + ct, ctinfo); + if (ret != NF_ACCEPT) + return ret; + + if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status)) { + typeof(nf_nat_seq_adjust_hook) seq_adjust; + + seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook); + if (!seq_adjust || !seq_adjust(skb, ct, ctinfo)) + return NF_DROP; + } +out: + /* We've seen it coming out the other side: confirm it */ + return nf_conntrack_confirm(skb); } static unsigned int ipv4_conntrack_defrag(unsigned int hooknum, @@ -210,20 +222,6 @@ static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = { .hooknum = NF_INET_LOCAL_OUT, .priority = NF_IP_PRI_CONNTRACK, }, - { - .hook = ipv4_conntrack_help, - .owner = THIS_MODULE, - .pf = PF_INET, - .hooknum = NF_INET_POST_ROUTING, - .priority = NF_IP_PRI_CONNTRACK_HELPER, - }, - { - .hook = ipv4_conntrack_help, - .owner = THIS_MODULE, - .pf = PF_INET, - .hooknum = NF_INET_LOCAL_IN, - .priority = NF_IP_PRI_CONNTRACK_HELPER, - }, { .hook = ipv4_confirm, .owner = THIS_MODULE, diff --git a/net/ipv4/netfilter/nf_nat_core.c b/net/ipv4/netfilter/nf_nat_core.c index 9320c7ac5729b3e43c72e8fed574d7510b096221..25c3efe4207e221bc0a9a1c9a3f7b75ef5599816 100644 --- a/net/ipv4/netfilter/nf_nat_core.c +++ b/net/ipv4/netfilter/nf_nat_core.c @@ -618,6 +618,9 @@ static int __init nf_nat_init(void) nf_conntrack_untracked.status |= IPS_NAT_DONE_MASK; l3proto = nf_ct_l3proto_find_get((u_int16_t)AF_INET); + + BUG_ON(nf_nat_seq_adjust_hook != NULL); + rcu_assign_pointer(nf_nat_seq_adjust_hook, nf_nat_seq_adjust); return 0; cleanup_extend: @@ -644,6 +647,8 @@ static void __exit nf_nat_cleanup(void) nf_ct_free_hashtable(bysource, nf_nat_vmalloced, nf_nat_htable_size); nf_ct_l3proto_put(l3proto); nf_ct_extend_unregister(&nat_extend); + rcu_assign_pointer(nf_nat_seq_adjust_hook, NULL); + synchronize_net(); } MODULE_LICENSE("GPL"); diff --git a/net/ipv4/netfilter/nf_nat_helper.c b/net/ipv4/netfilter/nf_nat_helper.c index 2fca727aa8ba1b9ff7bcdee6978b36a64be3c387..11976ea2988493eee1b108aceb677da3d5637250 100644 --- a/net/ipv4/netfilter/nf_nat_helper.c +++ b/net/ipv4/netfilter/nf_nat_helper.c @@ -416,7 +416,6 @@ nf_nat_seq_adjust(struct sk_buff *skb, return 1; } -EXPORT_SYMBOL(nf_nat_seq_adjust); /* Setup NAT on this expected conntrack so it follows master. */ /* If we fail to get a free NAT slot, we'll get dropped on confirm */ diff --git a/net/ipv4/netfilter/nf_nat_standalone.c b/net/ipv4/netfilter/nf_nat_standalone.c index a366b5865b9c3c3b0556a5ebb772097b64299ac4..b7dd695691a0858bf20bda8b4f756e05f585ab1f 100644 --- a/net/ipv4/netfilter/nf_nat_standalone.c +++ b/net/ipv4/netfilter/nf_nat_standalone.c @@ -245,25 +245,6 @@ nf_nat_local_fn(unsigned int hooknum, return ret; } -static unsigned int -nf_nat_adjust(unsigned int hooknum, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) -{ - struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - - ct = nf_ct_get(skb, &ctinfo); - if (ct && test_bit(IPS_SEQ_ADJUST_BIT, &ct->status)) { - pr_debug("nf_nat_standalone: adjusting sequence number\n"); - if (!nf_nat_seq_adjust(skb, ct, ctinfo)) - return NF_DROP; - } - return NF_ACCEPT; -} - /* We must be after connection tracking and before packet filtering. */ static struct nf_hook_ops nf_nat_ops[] __read_mostly = { @@ -283,14 +264,6 @@ static struct nf_hook_ops nf_nat_ops[] __read_mostly = { .hooknum = NF_INET_POST_ROUTING, .priority = NF_IP_PRI_NAT_SRC, }, - /* After conntrack, adjust sequence number */ - { - .hook = nf_nat_adjust, - .owner = THIS_MODULE, - .pf = PF_INET, - .hooknum = NF_INET_POST_ROUTING, - .priority = NF_IP_PRI_NAT_SEQ_ADJUST, - }, /* Before packet filtering, change destination */ { .hook = nf_nat_local_fn, @@ -307,14 +280,6 @@ static struct nf_hook_ops nf_nat_ops[] __read_mostly = { .hooknum = NF_INET_LOCAL_IN, .priority = NF_IP_PRI_NAT_SRC, }, - /* After conntrack, adjust sequence number */ - { - .hook = nf_nat_adjust, - .owner = THIS_MODULE, - .pf = PF_INET, - .hooknum = NF_INET_LOCAL_IN, - .priority = NF_IP_PRI_NAT_SEQ_ADJUST, - }, }; static int __init nf_nat_standalone_init(void)