netfilter: Libify xt_TPROXY
authorMáté Eckl <ecklm94@gmail.com>
Fri, 1 Jun 2018 18:44:56 +0000 (20:44 +0200)
committerPablo Neira Ayuso <pablo@netfilter.org>
Sat, 2 Jun 2018 22:02:05 +0000 (00:02 +0200)
The extracted functions will likely be usefull to implement tproxy
support in nf_tables.

Extrancted functions:
- nf_tproxy_sk_is_transparent
- nf_tproxy_laddr4
- nf_tproxy_handle_time_wait4
- nf_tproxy_get_sock_v4
- nf_tproxy_laddr6
- nf_tproxy_handle_time_wait6
- nf_tproxy_get_sock_v6

(nf_)tproxy_handle_time_wait6 also needed some refactor as its current
implementation was xtables-specific.

Signed-off-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
include/net/netfilter/nf_tproxy.h [new file with mode: 0644]
net/ipv4/netfilter/Kconfig
net/ipv4/netfilter/Makefile
net/ipv4/netfilter/nf_tproxy_ipv4.c [new file with mode: 0644]
net/ipv6/netfilter/Kconfig
net/ipv6/netfilter/Makefile
net/ipv6/netfilter/nf_tproxy_ipv6.c [new file with mode: 0644]
net/netfilter/Kconfig
net/netfilter/xt_TPROXY.c

diff --git a/include/net/netfilter/nf_tproxy.h b/include/net/netfilter/nf_tproxy.h
new file mode 100644 (file)
index 0000000..9754a50
--- /dev/null
@@ -0,0 +1,113 @@
+#ifndef _NF_TPROXY_H_
+#define _NF_TPROXY_H_
+
+#include <net/tcp.h>
+
+enum nf_tproxy_lookup_t {
+        NF_TPROXY_LOOKUP_LISTENER,
+        NF_TPROXY_LOOKUP_ESTABLISHED,
+};
+
+static inline bool nf_tproxy_sk_is_transparent(struct sock *sk)
+{
+       if (inet_sk_transparent(sk))
+               return true;
+
+       sock_gen_put(sk);
+       return false;
+}
+
+__be32 nf_tproxy_laddr4(struct sk_buff *skb, __be32 user_laddr, __be32 daddr);
+
+/**
+ * nf_tproxy_handle_time_wait4 - handle IPv4 TCP TIME_WAIT reopen redirections
+ * @skb:       The skb being processed.
+ * @laddr:     IPv4 address to redirect to or zero.
+ * @lport:     TCP port to redirect to or zero.
+ * @sk:                The TIME_WAIT TCP socket found by the lookup.
+ *
+ * We have to handle SYN packets arriving to TIME_WAIT sockets
+ * differently: instead of reopening the connection we should rather
+ * redirect the new connection to the proxy if there's a listener
+ * socket present.
+ *
+ * nf_tproxy_handle_time_wait4() consumes the socket reference passed in.
+ *
+ * Returns the listener socket if there's one, the TIME_WAIT socket if
+ * no such listener is found, or NULL if the TCP header is incomplete.
+ */
+struct sock *
+nf_tproxy_handle_time_wait4(struct net *net, struct sk_buff *skb,
+                           __be32 laddr, __be16 lport, struct sock *sk);
+
+/*
+ * This is used when the user wants to intercept a connection matching
+ * an explicit iptables rule. In this case the sockets are assumed
+ * matching in preference order:
+ *
+ *   - match: if there's a fully established connection matching the
+ *     _packet_ tuple, it is returned, assuming the redirection
+ *     already took place and we process a packet belonging to an
+ *     established connection
+ *
+ *   - match: if there's a listening socket matching the redirection
+ *     (e.g. on-port & on-ip of the connection), it is returned,
+ *     regardless if it was bound to 0.0.0.0 or an explicit
+ *     address. The reasoning is that if there's an explicit rule, it
+ *     does not really matter if the listener is bound to an interface
+ *     or to 0. The user already stated that he wants redirection
+ *     (since he added the rule).
+ *
+ * Please note that there's an overlap between what a TPROXY target
+ * and a socket match will match. Normally if you have both rules the
+ * "socket" match will be the first one, effectively all packets
+ * belonging to established connections going through that one.
+ */
+struct sock *
+nf_tproxy_get_sock_v4(struct net *net, struct sk_buff *skb, void *hp,
+                     const u8 protocol,
+                     const __be32 saddr, const __be32 daddr,
+                     const __be16 sport, const __be16 dport,
+                     const struct net_device *in,
+                     const enum nf_tproxy_lookup_t lookup_type);
+
+const struct in6_addr *
+nf_tproxy_laddr6(struct sk_buff *skb, const struct in6_addr *user_laddr,
+                const struct in6_addr *daddr);
+
+/**
+ * nf_tproxy_handle_time_wait6 - handle IPv6 TCP TIME_WAIT reopen redirections
+ * @skb:       The skb being processed.
+ * @tproto:    Transport protocol.
+ * @thoff:     Transport protocol header offset.
+ * @net:       Network namespace.
+ * @laddr:     IPv6 address to redirect to.
+ * @lport:     TCP port to redirect to or zero.
+ * @sk:                The TIME_WAIT TCP socket found by the lookup.
+ *
+ * We have to handle SYN packets arriving to TIME_WAIT sockets
+ * differently: instead of reopening the connection we should rather
+ * redirect the new connection to the proxy if there's a listener
+ * socket present.
+ *
+ * nf_tproxy_handle_time_wait6() consumes the socket reference passed in.
+ *
+ * Returns the listener socket if there's one, the TIME_WAIT socket if
+ * no such listener is found, or NULL if the TCP header is incomplete.
+ */
+struct sock *
+nf_tproxy_handle_time_wait6(struct sk_buff *skb, int tproto, int thoff,
+                           struct net *net,
+                           const struct in6_addr *laddr,
+                           const __be16 lport,
+                           struct sock *sk);
+
+struct sock *
+nf_tproxy_get_sock_v6(struct net *net, struct sk_buff *skb, int thoff, void *hp,
+                     const u8 protocol,
+                     const struct in6_addr *saddr, const struct in6_addr *daddr,
+                     const __be16 sport, const __be16 dport,
+                     const struct net_device *in,
+                     const enum nf_tproxy_lookup_t lookup_type);
+
+#endif /* _NF_TPROXY_H_ */
index d03bc5a01a70e4594c3dbe37f6dccb6858b36d18..bbfc356cb1b52e78d6d60a781dff531258ef9b3c 100644 (file)
@@ -29,7 +29,10 @@ config NF_SOCKET_IPV4
        tristate "IPv4 socket lookup support"
        help
          This option enables the IPv4 socket lookup infrastructure. This is
-         is required by the iptables socket match.
+         is required by the {ip,nf}tables socket match.
+
+config NF_TPROXY_IPV4
+       tristate "IPv4 tproxy support"
 
 if NF_TABLES
 
index c4b05b1740910fbbe640106142d22332852f5e4e..8394c17c269f29c73dad644eb7e8199cc2bcffc9 100644 (file)
@@ -17,6 +17,7 @@ obj-$(CONFIG_NF_NAT_IPV4) += nf_nat_ipv4.o
 obj-$(CONFIG_NF_DEFRAG_IPV4) += nf_defrag_ipv4.o
 
 obj-$(CONFIG_NF_SOCKET_IPV4) += nf_socket_ipv4.o
+obj-$(CONFIG_NF_TPROXY_IPV4) += nf_tproxy_ipv4.o
 
 # logging
 obj-$(CONFIG_NF_LOG_ARP) += nf_log_arp.o
diff --git a/net/ipv4/netfilter/nf_tproxy_ipv4.c b/net/ipv4/netfilter/nf_tproxy_ipv4.c
new file mode 100644 (file)
index 0000000..805e83e
--- /dev/null
@@ -0,0 +1,147 @@
+/*
+ * Copyright (C) 2007-2008 BalaBit IT Ltd.
+ * Author: Krisztian Kovacs
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <net/netfilter/nf_tproxy.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/inet_sock.h>
+#include <linux/ip.h>
+#include <net/checksum.h>
+#include <net/udp.h>
+#include <net/tcp.h>
+#include <linux/inetdevice.h>
+
+struct sock *
+nf_tproxy_handle_time_wait4(struct net *net, struct sk_buff *skb,
+                        __be32 laddr, __be16 lport, struct sock *sk)
+{
+       const struct iphdr *iph = ip_hdr(skb);
+       struct tcphdr _hdr, *hp;
+
+       hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
+       if (hp == NULL) {
+               inet_twsk_put(inet_twsk(sk));
+               return NULL;
+       }
+
+       if (hp->syn && !hp->rst && !hp->ack && !hp->fin) {
+               /* SYN to a TIME_WAIT socket, we'd rather redirect it
+                * to a listener socket if there's one */
+               struct sock *sk2;
+
+               sk2 = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
+                                           iph->saddr, laddr ? laddr : iph->daddr,
+                                           hp->source, lport ? lport : hp->dest,
+                                           skb->dev, NF_TPROXY_LOOKUP_LISTENER);
+               if (sk2) {
+                       inet_twsk_deschedule_put(inet_twsk(sk));
+                       sk = sk2;
+               }
+       }
+
+       return sk;
+}
+EXPORT_SYMBOL_GPL(nf_tproxy_handle_time_wait4);
+
+__be32 nf_tproxy_laddr4(struct sk_buff *skb, __be32 user_laddr, __be32 daddr)
+{
+       struct in_device *indev;
+       __be32 laddr;
+
+       if (user_laddr)
+               return user_laddr;
+
+       laddr = 0;
+       indev = __in_dev_get_rcu(skb->dev);
+       for_primary_ifa(indev) {
+               laddr = ifa->ifa_local;
+               break;
+       } endfor_ifa(indev);
+
+       return laddr ? laddr : daddr;
+}
+EXPORT_SYMBOL_GPL(nf_tproxy_laddr4);
+
+struct sock *
+nf_tproxy_get_sock_v4(struct net *net, struct sk_buff *skb, void *hp,
+                     const u8 protocol,
+                     const __be32 saddr, const __be32 daddr,
+                     const __be16 sport, const __be16 dport,
+                     const struct net_device *in,
+                     const enum nf_tproxy_lookup_t lookup_type)
+{
+       struct sock *sk;
+       struct tcphdr *tcph;
+
+       switch (protocol) {
+       case IPPROTO_TCP:
+               switch (lookup_type) {
+               case NF_TPROXY_LOOKUP_LISTENER:
+                       tcph = hp;
+                       sk = inet_lookup_listener(net, &tcp_hashinfo, skb,
+                                                   ip_hdrlen(skb) +
+                                                     __tcp_hdrlen(tcph),
+                                                   saddr, sport,
+                                                   daddr, dport,
+                                                   in->ifindex, 0);
+
+                       if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
+                               sk = NULL;
+                       /* NOTE: we return listeners even if bound to
+                        * 0.0.0.0, those are filtered out in
+                        * xt_socket, since xt_TPROXY needs 0 bound
+                        * listeners too
+                        */
+                       break;
+               case NF_TPROXY_LOOKUP_ESTABLISHED:
+                       sk = inet_lookup_established(net, &tcp_hashinfo,
+                                                   saddr, sport, daddr, dport,
+                                                   in->ifindex);
+                       break;
+               default:
+                       BUG();
+               }
+               break;
+       case IPPROTO_UDP:
+               sk = udp4_lib_lookup(net, saddr, sport, daddr, dport,
+                                    in->ifindex);
+               if (sk) {
+                       int connected = (sk->sk_state == TCP_ESTABLISHED);
+                       int wildcard = (inet_sk(sk)->inet_rcv_saddr == 0);
+
+                       /* NOTE: we return listeners even if bound to
+                        * 0.0.0.0, those are filtered out in
+                        * xt_socket, since xt_TPROXY needs 0 bound
+                        * listeners too
+                        */
+                       if ((lookup_type == NF_TPROXY_LOOKUP_ESTABLISHED &&
+                             (!connected || wildcard)) ||
+                           (lookup_type == NF_TPROXY_LOOKUP_LISTENER && connected)) {
+                               sock_put(sk);
+                               sk = NULL;
+                       }
+               }
+               break;
+       default:
+               WARN_ON(1);
+               sk = NULL;
+       }
+
+       pr_debug("tproxy socket lookup: proto %u %08x:%u -> %08x:%u, lookup type: %d, sock %p\n",
+                protocol, ntohl(saddr), ntohs(sport), ntohl(daddr), ntohs(dport), lookup_type, sk);
+
+       return sk;
+}
+EXPORT_SYMBOL_GPL(nf_tproxy_get_sock_v4);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Balazs Scheidler, Krisztian Kovacs");
+MODULE_DESCRIPTION("Netfilter IPv4 transparent proxy support");
index 9f5b00a39adfdb1cef535dcbc4da31d64205cad6..37b14dc9d86388a488f2fb39f79e0aedf03b79bd 100644 (file)
@@ -29,7 +29,10 @@ config NF_SOCKET_IPV6
        tristate "IPv6 socket lookup support"
        help
          This option enables the IPv6 socket lookup infrastructure. This
-         is used by the ip6tables socket match.
+         is used by the {ip6,nf}tables socket match.
+
+config NF_TPROXY_IPV6
+       tristate "IPv6 tproxy support"
 
 if NF_TABLES
 
index 71518f22ae3956d7ac428222a78518500c083a47..10a5a1c873208ae8aeae9bb2015d8395763a3b76 100644 (file)
@@ -26,6 +26,7 @@ nf_defrag_ipv6-y := nf_defrag_ipv6_hooks.o nf_conntrack_reasm.o
 obj-$(CONFIG_NF_DEFRAG_IPV6) += nf_defrag_ipv6.o
 
 obj-$(CONFIG_NF_SOCKET_IPV6) += nf_socket_ipv6.o
+obj-$(CONFIG_NF_TPROXY_IPV6) += nf_tproxy_ipv6.o
 
 # logging
 obj-$(CONFIG_NF_LOG_IPV6) += nf_log_ipv6.o
diff --git a/net/ipv6/netfilter/nf_tproxy_ipv6.c b/net/ipv6/netfilter/nf_tproxy_ipv6.c
new file mode 100644 (file)
index 0000000..bf1d6c4
--- /dev/null
@@ -0,0 +1,146 @@
+#include <net/netfilter/nf_tproxy.h>
+#include <linux/module.h>
+#include <net/inet6_hashtables.h>
+#include <net/addrconf.h>
+#include <net/udp.h>
+#include <net/tcp.h>
+
+const struct in6_addr *
+nf_tproxy_laddr6(struct sk_buff *skb, const struct in6_addr *user_laddr,
+             const struct in6_addr *daddr)
+{
+       struct inet6_dev *indev;
+       struct inet6_ifaddr *ifa;
+       struct in6_addr *laddr;
+
+       if (!ipv6_addr_any(user_laddr))
+               return user_laddr;
+       laddr = NULL;
+
+       indev = __in6_dev_get(skb->dev);
+       if (indev) {
+               read_lock_bh(&indev->lock);
+               list_for_each_entry(ifa, &indev->addr_list, if_list) {
+                       if (ifa->flags & (IFA_F_TENTATIVE | IFA_F_DEPRECATED))
+                               continue;
+
+                       laddr = &ifa->addr;
+                       break;
+               }
+               read_unlock_bh(&indev->lock);
+       }
+
+       return laddr ? laddr : daddr;
+}
+EXPORT_SYMBOL_GPL(nf_tproxy_laddr6);
+
+struct sock *
+nf_tproxy_handle_time_wait6(struct sk_buff *skb, int tproto, int thoff,
+                        struct net *net,
+                        const struct in6_addr *laddr,
+                        const __be16 lport,
+                        struct sock *sk)
+{
+       const struct ipv6hdr *iph = ipv6_hdr(skb);
+       struct tcphdr _hdr, *hp;
+
+       hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr);
+       if (hp == NULL) {
+               inet_twsk_put(inet_twsk(sk));
+               return NULL;
+       }
+
+       if (hp->syn && !hp->rst && !hp->ack && !hp->fin) {
+               /* SYN to a TIME_WAIT socket, we'd rather redirect it
+                * to a listener socket if there's one */
+               struct sock *sk2;
+
+               sk2 = nf_tproxy_get_sock_v6(net, skb, thoff, hp, tproto,
+                                           &iph->saddr,
+                                           nf_tproxy_laddr6(skb, laddr, &iph->daddr),
+                                           hp->source,
+                                           lport ? lport : hp->dest,
+                                           skb->dev, NF_TPROXY_LOOKUP_LISTENER);
+               if (sk2) {
+                       inet_twsk_deschedule_put(inet_twsk(sk));
+                       sk = sk2;
+               }
+       }
+
+       return sk;
+}
+EXPORT_SYMBOL_GPL(nf_tproxy_handle_time_wait6);
+
+struct sock *
+nf_tproxy_get_sock_v6(struct net *net, struct sk_buff *skb, int thoff, void *hp,
+                     const u8 protocol,
+                     const struct in6_addr *saddr, const struct in6_addr *daddr,
+                     const __be16 sport, const __be16 dport,
+                     const struct net_device *in,
+                     const enum nf_tproxy_lookup_t lookup_type)
+{
+       struct sock *sk;
+       struct tcphdr *tcph;
+
+       switch (protocol) {
+       case IPPROTO_TCP:
+               switch (lookup_type) {
+               case NF_TPROXY_LOOKUP_LISTENER:
+                       tcph = hp;
+                       sk = inet6_lookup_listener(net, &tcp_hashinfo, skb,
+                                                  thoff + __tcp_hdrlen(tcph),
+                                                  saddr, sport,
+                                                  daddr, ntohs(dport),
+                                                  in->ifindex, 0);
+
+                       if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
+                               sk = NULL;
+                       /* NOTE: we return listeners even if bound to
+                        * 0.0.0.0, those are filtered out in
+                        * xt_socket, since xt_TPROXY needs 0 bound
+                        * listeners too
+                        */
+                       break;
+               case NF_TPROXY_LOOKUP_ESTABLISHED:
+                       sk = __inet6_lookup_established(net, &tcp_hashinfo,
+                                                       saddr, sport, daddr, ntohs(dport),
+                                                       in->ifindex, 0);
+                       break;
+               default:
+                       BUG();
+               }
+               break;
+       case IPPROTO_UDP:
+               sk = udp6_lib_lookup(net, saddr, sport, daddr, dport,
+                                    in->ifindex);
+               if (sk) {
+                       int connected = (sk->sk_state == TCP_ESTABLISHED);
+                       int wildcard = ipv6_addr_any(&sk->sk_v6_rcv_saddr);
+
+                       /* NOTE: we return listeners even if bound to
+                        * 0.0.0.0, those are filtered out in
+                        * xt_socket, since xt_TPROXY needs 0 bound
+                        * listeners too
+                        */
+                       if ((lookup_type == NF_TPROXY_LOOKUP_ESTABLISHED && (!connected || wildcard)) ||
+                           (lookup_type == NF_TPROXY_LOOKUP_LISTENER && connected)) {
+                               sock_put(sk);
+                               sk = NULL;
+                       }
+               }
+               break;
+       default:
+               WARN_ON(1);
+               sk = NULL;
+       }
+
+       pr_debug("tproxy socket lookup: proto %u %pI6:%u -> %pI6:%u, lookup type: %d, sock %p\n",
+                protocol, saddr, ntohs(sport), daddr, ntohs(dport), lookup_type, sk);
+
+       return sk;
+}
+EXPORT_SYMBOL_GPL(nf_tproxy_get_sock_v6);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Balazs Scheidler, Krisztian Kovacs");
+MODULE_DESCRIPTION("Netfilter IPv4 transparent proxy support");
index 276e1e32f44ee6d0b584670644471627a6c127fe..41240abd755f0f072008eb09bf9a9203b46dbc1d 100644 (file)
@@ -989,6 +989,8 @@ config NETFILTER_XT_TARGET_TPROXY
        depends on IP_NF_MANGLE
        select NF_DEFRAG_IPV4
        select NF_DEFRAG_IPV6 if IP6_NF_IPTABLES != n
+       select NF_TPROXY_IPV4
+       select NF_TPROXY_IPV6 if IP6_NF_IPTABLES
        help
          This option adds a `TPROXY' target, which is somewhat similar to
          REDIRECT.  It can only be used in the mangle table and is useful
index 74df7977c17c75acfcc057488bf36869fa2646fa..58fce4e749a97deb7f50ee96cb328d45624ccc8c 100644 (file)
 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
 #endif
 
+#include <net/netfilter/nf_tproxy.h>
 #include <linux/netfilter/xt_TPROXY.h>
 
-enum nf_tproxy_lookup_t {
-        NFT_LOOKUP_LISTENER,
-        NFT_LOOKUP_ESTABLISHED,
-};
-
-static bool tproxy_sk_is_transparent(struct sock *sk)
-{
-       if (inet_sk_transparent(sk))
-               return true;
-
-       sock_gen_put(sk);
-       return false;
-}
-
-static inline __be32
-tproxy_laddr4(struct sk_buff *skb, __be32 user_laddr, __be32 daddr)
-{
-       struct in_device *indev;
-       __be32 laddr;
-
-       if (user_laddr)
-               return user_laddr;
-
-       laddr = 0;
-       indev = __in_dev_get_rcu(skb->dev);
-       for_primary_ifa(indev) {
-               laddr = ifa->ifa_local;
-               break;
-       } endfor_ifa(indev);
-
-       return laddr ? laddr : daddr;
-}
-
-/*
- * This is used when the user wants to intercept a connection matching
- * an explicit iptables rule. In this case the sockets are assumed
- * matching in preference order:
- *
- *   - match: if there's a fully established connection matching the
- *     _packet_ tuple, it is returned, assuming the redirection
- *     already took place and we process a packet belonging to an
- *     established connection
- *
- *   - match: if there's a listening socket matching the redirection
- *     (e.g. on-port & on-ip of the connection), it is returned,
- *     regardless if it was bound to 0.0.0.0 or an explicit
- *     address. The reasoning is that if there's an explicit rule, it
- *     does not really matter if the listener is bound to an interface
- *     or to 0. The user already stated that he wants redirection
- *     (since he added the rule).
- *
- * Please note that there's an overlap between what a TPROXY target
- * and a socket match will match. Normally if you have both rules the
- * "socket" match will be the first one, effectively all packets
- * belonging to established connections going through that one.
- */
-static inline struct sock *
-nf_tproxy_get_sock_v4(struct net *net, struct sk_buff *skb, void *hp,
-                     const u8 protocol,
-                     const __be32 saddr, const __be32 daddr,
-                     const __be16 sport, const __be16 dport,
-                     const struct net_device *in,
-                     const enum nf_tproxy_lookup_t lookup_type)
-{
-       struct sock *sk;
-       struct tcphdr *tcph;
-
-       switch (protocol) {
-       case IPPROTO_TCP:
-               switch (lookup_type) {
-               case NFT_LOOKUP_LISTENER:
-                       tcph = hp;
-                       sk = inet_lookup_listener(net, &tcp_hashinfo, skb,
-                                                   ip_hdrlen(skb) +
-                                                     __tcp_hdrlen(tcph),
-                                                   saddr, sport,
-                                                   daddr, dport,
-                                                   in->ifindex, 0);
-
-                       if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
-                               sk = NULL;
-                       /* NOTE: we return listeners even if bound to
-                        * 0.0.0.0, those are filtered out in
-                        * xt_socket, since xt_TPROXY needs 0 bound
-                        * listeners too
-                        */
-                       break;
-               case NFT_LOOKUP_ESTABLISHED:
-                       sk = inet_lookup_established(net, &tcp_hashinfo,
-                                                   saddr, sport, daddr, dport,
-                                                   in->ifindex);
-                       break;
-               default:
-                       BUG();
-               }
-               break;
-       case IPPROTO_UDP:
-               sk = udp4_lib_lookup(net, saddr, sport, daddr, dport,
-                                    in->ifindex);
-               if (sk) {
-                       int connected = (sk->sk_state == TCP_ESTABLISHED);
-                       int wildcard = (inet_sk(sk)->inet_rcv_saddr == 0);
-
-                       /* NOTE: we return listeners even if bound to
-                        * 0.0.0.0, those are filtered out in
-                        * xt_socket, since xt_TPROXY needs 0 bound
-                        * listeners too
-                        */
-                       if ((lookup_type == NFT_LOOKUP_ESTABLISHED && (!connected || wildcard)) ||
-                           (lookup_type == NFT_LOOKUP_LISTENER && connected)) {
-                               sock_put(sk);
-                               sk = NULL;
-                       }
-               }
-               break;
-       default:
-               WARN_ON(1);
-               sk = NULL;
-       }
-
-       pr_debug("tproxy socket lookup: proto %u %08x:%u -> %08x:%u, lookup type: %d, sock %p\n",
-                protocol, ntohl(saddr), ntohs(sport), ntohl(daddr), ntohs(dport), lookup_type, sk);
-
-       return sk;
-}
-
-#ifdef XT_TPROXY_HAVE_IPV6
-static inline struct sock *
-nf_tproxy_get_sock_v6(struct net *net, struct sk_buff *skb, int thoff, void *hp,
-                     const u8 protocol,
-                     const struct in6_addr *saddr, const struct in6_addr *daddr,
-                     const __be16 sport, const __be16 dport,
-                     const struct net_device *in,
-                     const enum nf_tproxy_lookup_t lookup_type)
-{
-       struct sock *sk;
-       struct tcphdr *tcph;
-
-       switch (protocol) {
-       case IPPROTO_TCP:
-               switch (lookup_type) {
-               case NFT_LOOKUP_LISTENER:
-                       tcph = hp;
-                       sk = inet6_lookup_listener(net, &tcp_hashinfo, skb,
-                                                  thoff + __tcp_hdrlen(tcph),
-                                                  saddr, sport,
-                                                  daddr, ntohs(dport),
-                                                  in->ifindex, 0);
-
-                       if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
-                               sk = NULL;
-                       /* NOTE: we return listeners even if bound to
-                        * 0.0.0.0, those are filtered out in
-                        * xt_socket, since xt_TPROXY needs 0 bound
-                        * listeners too
-                        */
-                       break;
-               case NFT_LOOKUP_ESTABLISHED:
-                       sk = __inet6_lookup_established(net, &tcp_hashinfo,
-                                                       saddr, sport, daddr, ntohs(dport),
-                                                       in->ifindex, 0);
-                       break;
-               default:
-                       BUG();
-               }
-               break;
-       case IPPROTO_UDP:
-               sk = udp6_lib_lookup(net, saddr, sport, daddr, dport,
-                                    in->ifindex);
-               if (sk) {
-                       int connected = (sk->sk_state == TCP_ESTABLISHED);
-                       int wildcard = ipv6_addr_any(&sk->sk_v6_rcv_saddr);
-
-                       /* NOTE: we return listeners even if bound to
-                        * 0.0.0.0, those are filtered out in
-                        * xt_socket, since xt_TPROXY needs 0 bound
-                        * listeners too
-                        */
-                       if ((lookup_type == NFT_LOOKUP_ESTABLISHED && (!connected || wildcard)) ||
-                           (lookup_type == NFT_LOOKUP_LISTENER && connected)) {
-                               sock_put(sk);
-                               sk = NULL;
-                       }
-               }
-               break;
-       default:
-               WARN_ON(1);
-               sk = NULL;
-       }
-
-       pr_debug("tproxy socket lookup: proto %u %pI6:%u -> %pI6:%u, lookup type: %d, sock %p\n",
-                protocol, saddr, ntohs(sport), daddr, ntohs(dport), lookup_type, sk);
-
-       return sk;
-}
-#endif
-
-/**
- * tproxy_handle_time_wait4 - handle IPv4 TCP TIME_WAIT reopen redirections
- * @skb:       The skb being processed.
- * @laddr:     IPv4 address to redirect to or zero.
- * @lport:     TCP port to redirect to or zero.
- * @sk:                The TIME_WAIT TCP socket found by the lookup.
- *
- * We have to handle SYN packets arriving to TIME_WAIT sockets
- * differently: instead of reopening the connection we should rather
- * redirect the new connection to the proxy if there's a listener
- * socket present.
- *
- * tproxy_handle_time_wait4() consumes the socket reference passed in.
- *
- * Returns the listener socket if there's one, the TIME_WAIT socket if
- * no such listener is found, or NULL if the TCP header is incomplete.
- */
-static struct sock *
-tproxy_handle_time_wait4(struct net *net, struct sk_buff *skb,
-                        __be32 laddr, __be16 lport, struct sock *sk)
-{
-       const struct iphdr *iph = ip_hdr(skb);
-       struct tcphdr _hdr, *hp;
-
-       hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
-       if (hp == NULL) {
-               inet_twsk_put(inet_twsk(sk));
-               return NULL;
-       }
-
-       if (hp->syn && !hp->rst && !hp->ack && !hp->fin) {
-               /* SYN to a TIME_WAIT socket, we'd rather redirect it
-                * to a listener socket if there's one */
-               struct sock *sk2;
-
-               sk2 = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
-                                           iph->saddr, laddr ? laddr : iph->daddr,
-                                           hp->source, lport ? lport : hp->dest,
-                                           skb->dev, NFT_LOOKUP_LISTENER);
-               if (sk2) {
-                       inet_twsk_deschedule_put(inet_twsk(sk));
-                       sk = sk2;
-               }
-       }
-
-       return sk;
-}
-
 /* assign a socket to the skb -- consumes sk */
 static void
 nf_tproxy_assign_sock(struct sk_buff *skb, struct sock *sk)
@@ -308,26 +64,26 @@ tproxy_tg4(struct net *net, struct sk_buff *skb, __be32 laddr, __be16 lport,
        sk = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
                                   iph->saddr, iph->daddr,
                                   hp->source, hp->dest,
-                                  skb->dev, NFT_LOOKUP_ESTABLISHED);
+                                  skb->dev, NF_TPROXY_LOOKUP_ESTABLISHED);
 
-       laddr = tproxy_laddr4(skb, laddr, iph->daddr);
+       laddr = nf_tproxy_laddr4(skb, laddr, iph->daddr);
        if (!lport)
                lport = hp->dest;
 
        /* UDP has no TCP_TIME_WAIT state, so we never enter here */
        if (sk && sk->sk_state == TCP_TIME_WAIT)
                /* reopening a TIME_WAIT connection needs special handling */
-               sk = tproxy_handle_time_wait4(net, skb, laddr, lport, sk);
+               sk = nf_tproxy_handle_time_wait4(net, skb, laddr, lport, sk);
        else if (!sk)
                /* no, there's no established connection, check if
                 * there's a listener on the redirected addr/port */
                sk = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
                                           iph->saddr, laddr,
                                           hp->source, lport,
-                                          skb->dev, NFT_LOOKUP_LISTENER);
+                                          skb->dev, NF_TPROXY_LOOKUP_LISTENER);
 
        /* NOTE: assign_sock consumes our sk reference */
-       if (sk && tproxy_sk_is_transparent(sk)) {
+       if (sk && nf_tproxy_sk_is_transparent(sk)) {
                /* This should be in a separate target, but we don't do multiple
                   targets on the same rule yet */
                skb->mark = (skb->mark & ~mark_mask) ^ mark_value;
@@ -366,87 +122,6 @@ tproxy_tg4_v1(struct sk_buff *skb, const struct xt_action_param *par)
 
 #ifdef XT_TPROXY_HAVE_IPV6
 
-static inline const struct in6_addr *
-tproxy_laddr6(struct sk_buff *skb, const struct in6_addr *user_laddr,
-             const struct in6_addr *daddr)
-{
-       struct inet6_dev *indev;
-       struct inet6_ifaddr *ifa;
-       struct in6_addr *laddr;
-
-       if (!ipv6_addr_any(user_laddr))
-               return user_laddr;
-       laddr = NULL;
-
-       indev = __in6_dev_get(skb->dev);
-       if (indev) {
-               read_lock_bh(&indev->lock);
-               list_for_each_entry(ifa, &indev->addr_list, if_list) {
-                       if (ifa->flags & (IFA_F_TENTATIVE | IFA_F_DEPRECATED))
-                               continue;
-
-                       laddr = &ifa->addr;
-                       break;
-               }
-               read_unlock_bh(&indev->lock);
-       }
-
-       return laddr ? laddr : daddr;
-}
-
-/**
- * tproxy_handle_time_wait6 - handle IPv6 TCP TIME_WAIT reopen redirections
- * @skb:       The skb being processed.
- * @tproto:    Transport protocol.
- * @thoff:     Transport protocol header offset.
- * @par:       Iptables target parameters.
- * @sk:                The TIME_WAIT TCP socket found by the lookup.
- *
- * We have to handle SYN packets arriving to TIME_WAIT sockets
- * differently: instead of reopening the connection we should rather
- * redirect the new connection to the proxy if there's a listener
- * socket present.
- *
- * tproxy_handle_time_wait6() consumes the socket reference passed in.
- *
- * Returns the listener socket if there's one, the TIME_WAIT socket if
- * no such listener is found, or NULL if the TCP header is incomplete.
- */
-static struct sock *
-tproxy_handle_time_wait6(struct sk_buff *skb, int tproto, int thoff,
-                        const struct xt_action_param *par,
-                        struct sock *sk)
-{
-       const struct ipv6hdr *iph = ipv6_hdr(skb);
-       struct tcphdr _hdr, *hp;
-       const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
-
-       hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr);
-       if (hp == NULL) {
-               inet_twsk_put(inet_twsk(sk));
-               return NULL;
-       }
-
-       if (hp->syn && !hp->rst && !hp->ack && !hp->fin) {
-               /* SYN to a TIME_WAIT socket, we'd rather redirect it
-                * to a listener socket if there's one */
-               struct sock *sk2;
-
-               sk2 = nf_tproxy_get_sock_v6(xt_net(par), skb, thoff, hp, tproto,
-                                           &iph->saddr,
-                                           tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr),
-                                           hp->source,
-                                           tgi->lport ? tgi->lport : hp->dest,
-                                           skb->dev, NFT_LOOKUP_LISTENER);
-               if (sk2) {
-                       inet_twsk_deschedule_put(inet_twsk(sk));
-                       sk = sk2;
-               }
-       }
-
-       return sk;
-}
-
 static unsigned int
 tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par)
 {
@@ -478,25 +153,31 @@ tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par)
        sk = nf_tproxy_get_sock_v6(xt_net(par), skb, thoff, hp, tproto,
                                   &iph->saddr, &iph->daddr,
                                   hp->source, hp->dest,
-                                  xt_in(par), NFT_LOOKUP_ESTABLISHED);
+                                  xt_in(par), NF_TPROXY_LOOKUP_ESTABLISHED);
 
-       laddr = tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr);
+       laddr = nf_tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr);
        lport = tgi->lport ? tgi->lport : hp->dest;
 
        /* UDP has no TCP_TIME_WAIT state, so we never enter here */
-       if (sk && sk->sk_state == TCP_TIME_WAIT)
+       if (sk && sk->sk_state == TCP_TIME_WAIT) {
+               const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
                /* reopening a TIME_WAIT connection needs special handling */
-               sk = tproxy_handle_time_wait6(skb, tproto, thoff, par, sk);
+               sk = nf_tproxy_handle_time_wait6(skb, tproto, thoff,
+                                             xt_net(par),
+                                             &tgi->laddr.in6,
+                                             tgi->lport,
+                                             sk);
+       }
        else if (!sk)
                /* no there's no established connection, check if
                 * there's a listener on the redirected addr/port */
                sk = nf_tproxy_get_sock_v6(xt_net(par), skb, thoff, hp,
                                           tproto, &iph->saddr, laddr,
                                           hp->source, lport,
-                                          xt_in(par), NFT_LOOKUP_LISTENER);
+                                          xt_in(par), NF_TPROXY_LOOKUP_LISTENER);
 
        /* NOTE: assign_sock consumes our sk reference */
-       if (sk && tproxy_sk_is_transparent(sk)) {
+       if (sk && nf_tproxy_sk_is_transparent(sk)) {
                /* This should be in a separate target, but we don't do multiple
                   targets on the same rule yet */
                skb->mark = (skb->mark & ~tgi->mark_mask) ^ tgi->mark_value;