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@@ -33,264 +33,9 @@
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#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
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#endif
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+#include <net/netfilter/nf_tproxy.h>
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#include <linux/netfilter/xt_TPROXY.h>
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-enum nf_tproxy_lookup_t {
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- NFT_LOOKUP_LISTENER,
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- NFT_LOOKUP_ESTABLISHED,
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-};
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-
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-static bool tproxy_sk_is_transparent(struct sock *sk)
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-{
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- switch (sk->sk_state) {
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- case TCP_TIME_WAIT:
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- if (inet_twsk(sk)->tw_transparent)
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- return true;
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- break;
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- case TCP_NEW_SYN_RECV:
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- if (inet_rsk(inet_reqsk(sk))->no_srccheck)
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- return true;
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- break;
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- default:
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- if (inet_sk(sk)->transparent)
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- return true;
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- }
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-
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- sock_gen_put(sk);
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- return false;
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-}
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-
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-static inline __be32
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-tproxy_laddr4(struct sk_buff *skb, __be32 user_laddr, __be32 daddr)
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-{
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- struct in_device *indev;
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- __be32 laddr;
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-
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- if (user_laddr)
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- return user_laddr;
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-
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- laddr = 0;
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- indev = __in_dev_get_rcu(skb->dev);
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- for_primary_ifa(indev) {
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- laddr = ifa->ifa_local;
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- break;
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- } endfor_ifa(indev);
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-
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- return laddr ? laddr : daddr;
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-}
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-
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-/*
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- * This is used when the user wants to intercept a connection matching
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- * an explicit iptables rule. In this case the sockets are assumed
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- * matching in preference order:
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- *
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- * - match: if there's a fully established connection matching the
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- * _packet_ tuple, it is returned, assuming the redirection
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- * already took place and we process a packet belonging to an
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- * established connection
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- *
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- * - match: if there's a listening socket matching the redirection
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- * (e.g. on-port & on-ip of the connection), it is returned,
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- * regardless if it was bound to 0.0.0.0 or an explicit
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- * address. The reasoning is that if there's an explicit rule, it
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- * does not really matter if the listener is bound to an interface
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- * or to 0. The user already stated that he wants redirection
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- * (since he added the rule).
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- *
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- * Please note that there's an overlap between what a TPROXY target
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- * and a socket match will match. Normally if you have both rules the
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- * "socket" match will be the first one, effectively all packets
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- * belonging to established connections going through that one.
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- */
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-static inline struct sock *
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-nf_tproxy_get_sock_v4(struct net *net, struct sk_buff *skb, void *hp,
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- const u8 protocol,
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- const __be32 saddr, const __be32 daddr,
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- const __be16 sport, const __be16 dport,
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- const struct net_device *in,
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- const enum nf_tproxy_lookup_t lookup_type)
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-{
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- struct sock *sk;
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- struct tcphdr *tcph;
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-
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- switch (protocol) {
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- case IPPROTO_TCP:
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- switch (lookup_type) {
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- case NFT_LOOKUP_LISTENER:
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- tcph = hp;
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- sk = inet_lookup_listener(net, &tcp_hashinfo, skb,
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- ip_hdrlen(skb) +
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- __tcp_hdrlen(tcph),
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- saddr, sport,
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- daddr, dport,
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- in->ifindex, 0);
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-
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- if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
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- sk = NULL;
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- /* NOTE: we return listeners even if bound to
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- * 0.0.0.0, those are filtered out in
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- * xt_socket, since xt_TPROXY needs 0 bound
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- * listeners too
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- */
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- break;
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- case NFT_LOOKUP_ESTABLISHED:
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- sk = inet_lookup_established(net, &tcp_hashinfo,
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- saddr, sport, daddr, dport,
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- in->ifindex);
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- break;
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- default:
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- BUG();
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- }
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- break;
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- case IPPROTO_UDP:
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- sk = udp4_lib_lookup(net, saddr, sport, daddr, dport,
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- in->ifindex);
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- if (sk) {
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- int connected = (sk->sk_state == TCP_ESTABLISHED);
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- int wildcard = (inet_sk(sk)->inet_rcv_saddr == 0);
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-
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- /* NOTE: we return listeners even if bound to
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- * 0.0.0.0, those are filtered out in
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- * xt_socket, since xt_TPROXY needs 0 bound
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- * listeners too
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- */
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- if ((lookup_type == NFT_LOOKUP_ESTABLISHED && (!connected || wildcard)) ||
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- (lookup_type == NFT_LOOKUP_LISTENER && connected)) {
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- sock_put(sk);
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- sk = NULL;
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- }
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- }
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- break;
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- default:
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- WARN_ON(1);
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- sk = NULL;
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- }
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-
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- pr_debug("tproxy socket lookup: proto %u %08x:%u -> %08x:%u, lookup type: %d, sock %p\n",
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- protocol, ntohl(saddr), ntohs(sport), ntohl(daddr), ntohs(dport), lookup_type, sk);
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-
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- return sk;
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-}
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-
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-#ifdef XT_TPROXY_HAVE_IPV6
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-static inline struct sock *
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-nf_tproxy_get_sock_v6(struct net *net, struct sk_buff *skb, int thoff, void *hp,
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- const u8 protocol,
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- const struct in6_addr *saddr, const struct in6_addr *daddr,
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- const __be16 sport, const __be16 dport,
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- const struct net_device *in,
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- const enum nf_tproxy_lookup_t lookup_type)
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-{
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- struct sock *sk;
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- struct tcphdr *tcph;
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-
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- switch (protocol) {
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- case IPPROTO_TCP:
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- switch (lookup_type) {
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- case NFT_LOOKUP_LISTENER:
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- tcph = hp;
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- sk = inet6_lookup_listener(net, &tcp_hashinfo, skb,
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- thoff + __tcp_hdrlen(tcph),
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- saddr, sport,
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- daddr, ntohs(dport),
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- in->ifindex, 0);
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-
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- if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
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- sk = NULL;
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- /* NOTE: we return listeners even if bound to
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- * 0.0.0.0, those are filtered out in
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- * xt_socket, since xt_TPROXY needs 0 bound
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- * listeners too
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- */
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- break;
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- case NFT_LOOKUP_ESTABLISHED:
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- sk = __inet6_lookup_established(net, &tcp_hashinfo,
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- saddr, sport, daddr, ntohs(dport),
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- in->ifindex, 0);
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- break;
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- default:
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- BUG();
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- }
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- break;
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- case IPPROTO_UDP:
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- sk = udp6_lib_lookup(net, saddr, sport, daddr, dport,
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- in->ifindex);
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- if (sk) {
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- int connected = (sk->sk_state == TCP_ESTABLISHED);
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- int wildcard = ipv6_addr_any(&sk->sk_v6_rcv_saddr);
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-
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- /* NOTE: we return listeners even if bound to
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- * 0.0.0.0, those are filtered out in
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- * xt_socket, since xt_TPROXY needs 0 bound
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- * listeners too
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- */
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- if ((lookup_type == NFT_LOOKUP_ESTABLISHED && (!connected || wildcard)) ||
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- (lookup_type == NFT_LOOKUP_LISTENER && connected)) {
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- sock_put(sk);
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- sk = NULL;
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- }
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- }
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- break;
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- default:
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- WARN_ON(1);
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- sk = NULL;
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- }
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-
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- pr_debug("tproxy socket lookup: proto %u %pI6:%u -> %pI6:%u, lookup type: %d, sock %p\n",
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- protocol, saddr, ntohs(sport), daddr, ntohs(dport), lookup_type, sk);
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-
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- return sk;
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-}
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-#endif
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-
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-/**
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- * tproxy_handle_time_wait4 - handle IPv4 TCP TIME_WAIT reopen redirections
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- * @skb: The skb being processed.
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- * @laddr: IPv4 address to redirect to or zero.
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- * @lport: TCP port to redirect to or zero.
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- * @sk: The TIME_WAIT TCP socket found by the lookup.
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- *
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- * We have to handle SYN packets arriving to TIME_WAIT sockets
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- * differently: instead of reopening the connection we should rather
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- * redirect the new connection to the proxy if there's a listener
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- * socket present.
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- *
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- * tproxy_handle_time_wait4() consumes the socket reference passed in.
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- *
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- * Returns the listener socket if there's one, the TIME_WAIT socket if
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- * no such listener is found, or NULL if the TCP header is incomplete.
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- */
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-static struct sock *
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-tproxy_handle_time_wait4(struct net *net, struct sk_buff *skb,
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- __be32 laddr, __be16 lport, struct sock *sk)
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-{
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- const struct iphdr *iph = ip_hdr(skb);
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- struct tcphdr _hdr, *hp;
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-
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- hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
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- if (hp == NULL) {
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- inet_twsk_put(inet_twsk(sk));
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- return NULL;
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- }
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-
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- if (hp->syn && !hp->rst && !hp->ack && !hp->fin) {
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- /* SYN to a TIME_WAIT socket, we'd rather redirect it
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- * to a listener socket if there's one */
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- struct sock *sk2;
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-
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- sk2 = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
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- iph->saddr, laddr ? laddr : iph->daddr,
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- hp->source, lport ? lport : hp->dest,
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- skb->dev, NFT_LOOKUP_LISTENER);
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- if (sk2) {
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- inet_twsk_deschedule_put(inet_twsk(sk));
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- sk = sk2;
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- }
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- }
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-
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- return sk;
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-}
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-
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/* assign a socket to the skb -- consumes sk */
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static void
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nf_tproxy_assign_sock(struct sk_buff *skb, struct sock *sk)
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@@ -319,26 +64,26 @@ tproxy_tg4(struct net *net, struct sk_buff *skb, __be32 laddr, __be16 lport,
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sk = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
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iph->saddr, iph->daddr,
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hp->source, hp->dest,
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- skb->dev, NFT_LOOKUP_ESTABLISHED);
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+ skb->dev, NF_TPROXY_LOOKUP_ESTABLISHED);
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- laddr = tproxy_laddr4(skb, laddr, iph->daddr);
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+ laddr = nf_tproxy_laddr4(skb, laddr, iph->daddr);
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if (!lport)
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lport = hp->dest;
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/* UDP has no TCP_TIME_WAIT state, so we never enter here */
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if (sk && sk->sk_state == TCP_TIME_WAIT)
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/* reopening a TIME_WAIT connection needs special handling */
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- sk = tproxy_handle_time_wait4(net, skb, laddr, lport, sk);
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+ sk = nf_tproxy_handle_time_wait4(net, skb, laddr, lport, sk);
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else if (!sk)
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/* no, there's no established connection, check if
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* there's a listener on the redirected addr/port */
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sk = nf_tproxy_get_sock_v4(net, skb, hp, iph->protocol,
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iph->saddr, laddr,
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hp->source, lport,
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- skb->dev, NFT_LOOKUP_LISTENER);
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+ skb->dev, NF_TPROXY_LOOKUP_LISTENER);
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/* NOTE: assign_sock consumes our sk reference */
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- if (sk && tproxy_sk_is_transparent(sk)) {
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+ if (sk && nf_tproxy_sk_is_transparent(sk)) {
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/* This should be in a separate target, but we don't do multiple
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targets on the same rule yet */
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skb->mark = (skb->mark & ~mark_mask) ^ mark_value;
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@@ -377,87 +122,6 @@ tproxy_tg4_v1(struct sk_buff *skb, const struct xt_action_param *par)
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#ifdef XT_TPROXY_HAVE_IPV6
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-static inline const struct in6_addr *
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-tproxy_laddr6(struct sk_buff *skb, const struct in6_addr *user_laddr,
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- const struct in6_addr *daddr)
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-{
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- struct inet6_dev *indev;
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- struct inet6_ifaddr *ifa;
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- struct in6_addr *laddr;
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-
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- if (!ipv6_addr_any(user_laddr))
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- return user_laddr;
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- laddr = NULL;
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-
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- indev = __in6_dev_get(skb->dev);
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- if (indev) {
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- read_lock_bh(&indev->lock);
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- list_for_each_entry(ifa, &indev->addr_list, if_list) {
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- if (ifa->flags & (IFA_F_TENTATIVE | IFA_F_DEPRECATED))
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- continue;
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-
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- laddr = &ifa->addr;
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- break;
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- }
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- read_unlock_bh(&indev->lock);
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- }
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-
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- return laddr ? laddr : daddr;
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-}
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-
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-/**
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- * tproxy_handle_time_wait6 - handle IPv6 TCP TIME_WAIT reopen redirections
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- * @skb: The skb being processed.
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- * @tproto: Transport protocol.
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- * @thoff: Transport protocol header offset.
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- * @par: Iptables target parameters.
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- * @sk: The TIME_WAIT TCP socket found by the lookup.
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- *
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- * We have to handle SYN packets arriving to TIME_WAIT sockets
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- * differently: instead of reopening the connection we should rather
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- * redirect the new connection to the proxy if there's a listener
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- * socket present.
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- *
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- * tproxy_handle_time_wait6() consumes the socket reference passed in.
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- *
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- * Returns the listener socket if there's one, the TIME_WAIT socket if
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- * no such listener is found, or NULL if the TCP header is incomplete.
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- */
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-static struct sock *
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-tproxy_handle_time_wait6(struct sk_buff *skb, int tproto, int thoff,
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- const struct xt_action_param *par,
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- struct sock *sk)
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-{
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- const struct ipv6hdr *iph = ipv6_hdr(skb);
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- struct tcphdr _hdr, *hp;
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- const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
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-
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- hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr);
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- if (hp == NULL) {
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- inet_twsk_put(inet_twsk(sk));
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- return NULL;
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- }
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-
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- if (hp->syn && !hp->rst && !hp->ack && !hp->fin) {
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- /* SYN to a TIME_WAIT socket, we'd rather redirect it
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- * to a listener socket if there's one */
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- struct sock *sk2;
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-
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- sk2 = nf_tproxy_get_sock_v6(xt_net(par), skb, thoff, hp, tproto,
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- &iph->saddr,
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- tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr),
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- hp->source,
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- tgi->lport ? tgi->lport : hp->dest,
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- skb->dev, NFT_LOOKUP_LISTENER);
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- if (sk2) {
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- inet_twsk_deschedule_put(inet_twsk(sk));
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- sk = sk2;
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- }
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- }
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-
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- return sk;
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-}
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-
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static unsigned int
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tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par)
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{
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@@ -489,25 +153,31 @@ tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par)
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sk = nf_tproxy_get_sock_v6(xt_net(par), skb, thoff, hp, tproto,
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&iph->saddr, &iph->daddr,
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hp->source, hp->dest,
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- xt_in(par), NFT_LOOKUP_ESTABLISHED);
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+ xt_in(par), NF_TPROXY_LOOKUP_ESTABLISHED);
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- laddr = tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr);
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+ laddr = nf_tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr);
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lport = tgi->lport ? tgi->lport : hp->dest;
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/* UDP has no TCP_TIME_WAIT state, so we never enter here */
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- if (sk && sk->sk_state == TCP_TIME_WAIT)
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+ if (sk && sk->sk_state == TCP_TIME_WAIT) {
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+ const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
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/* reopening a TIME_WAIT connection needs special handling */
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- sk = tproxy_handle_time_wait6(skb, tproto, thoff, par, sk);
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+ sk = nf_tproxy_handle_time_wait6(skb, tproto, thoff,
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+ xt_net(par),
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+ &tgi->laddr.in6,
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+ tgi->lport,
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+ sk);
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+ }
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else if (!sk)
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/* no there's no established connection, check if
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* there's a listener on the redirected addr/port */
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sk = nf_tproxy_get_sock_v6(xt_net(par), skb, thoff, hp,
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tproto, &iph->saddr, laddr,
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hp->source, lport,
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- xt_in(par), NFT_LOOKUP_LISTENER);
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+ xt_in(par), NF_TPROXY_LOOKUP_LISTENER);
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/* NOTE: assign_sock consumes our sk reference */
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- if (sk && tproxy_sk_is_transparent(sk)) {
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+ if (sk && nf_tproxy_sk_is_transparent(sk)) {
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/* This should be in a separate target, but we don't do multiple
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targets on the same rule yet */
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skb->mark = (skb->mark & ~tgi->mark_mask) ^ tgi->mark_value;
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