summaryrefslogtreecommitdiffstats
path: root/net/netfilter/xt_TPROXY.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/netfilter/xt_TPROXY.c')
-rw-r--r--net/netfilter/xt_TPROXY.c366
1 files changed, 18 insertions, 348 deletions
diff --git a/net/netfilter/xt_TPROXY.c b/net/netfilter/xt_TPROXY.c
index 8c89323c06afe..58fce4e749a97 100644
--- a/net/netfilter/xt_TPROXY.c
+++ b/net/netfilter/xt_TPROXY.c
@@ -33,264 +33,9 @@
#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)
-{
- switch (sk->sk_state) {
- case TCP_TIME_WAIT:
- if (inet_twsk(sk)->tw_transparent)
- return true;
- break;
- case TCP_NEW_SYN_RECV:
- if (inet_rsk(inet_reqsk(sk))->no_srccheck)
- return true;
- break;
- default:
- if (inet_sk(sk)->transparent)
- 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)
@@ -319,26 +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;
@@ -377,87 +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)
{
@@ -489,25 +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;