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authorFlorian Westphal <fw@strlen.de>2013-07-29 15:41:53 +0200
committerPablo Neira Ayuso <pablo@netfilter.org>2013-07-31 18:43:45 +0200
commit93742cf8af9dd3b053242b273040aa35fcbf93b3 (patch)
tree997b49b70262b88edf3560108c280b42ed7970a4 /net
parentfd158d79d33d3c8b693e3e2d8c0e3068d529c2dc (diff)
downloadlinux-stericsson-93742cf8af9dd3b053242b273040aa35fcbf93b3.tar.gz
netfilter: tproxy: remove nf_tproxy_core.h
We've removed nf_tproxy_core.ko, so also remove its header. The lookup helpers are split and then moved to tproxy target/socket match. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/xt_TPROXY.c160
-rw-r--r--net/netfilter/xt_socket.c66
2 files changed, 220 insertions, 6 deletions
diff --git a/net/netfilter/xt_TPROXY.c b/net/netfilter/xt_TPROXY.c
index 17c40deafa4f..851383a7f461 100644
--- a/net/netfilter/xt_TPROXY.c
+++ b/net/netfilter/xt_TPROXY.c
@@ -15,7 +15,9 @@
#include <linux/ip.h>
#include <net/checksum.h>
#include <net/udp.h>
+#include <net/tcp.h>
#include <net/inet_sock.h>
+#include <net/inet_hashtables.h>
#include <linux/inetdevice.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv4/ip_tables.h>
@@ -26,13 +28,18 @@
#define XT_TPROXY_HAVE_IPV6 1
#include <net/if_inet6.h>
#include <net/addrconf.h>
+#include <net/inet6_hashtables.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
#endif
-#include <net/netfilter/nf_tproxy_core.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 (sk->sk_state != TCP_TIME_WAIT) {
@@ -68,6 +75,157 @@ tproxy_laddr4(struct sk_buff *skb, __be32 user_laddr, __be32 daddr)
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, 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;
+
+ switch (protocol) {
+ case IPPROTO_TCP:
+ switch (lookup_type) {
+ case NFT_LOOKUP_LISTENER:
+ sk = inet_lookup_listener(net, &tcp_hashinfo,
+ saddr, sport,
+ daddr, dport,
+ in->ifindex);
+
+ /* 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;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static inline struct sock *
+nf_tproxy_get_sock_v6(struct net *net, 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;
+
+ switch (protocol) {
+ case IPPROTO_TCP:
+ switch (lookup_type) {
+ case NFT_LOOKUP_LISTENER:
+ sk = inet6_lookup_listener(net, &tcp_hashinfo,
+ saddr, sport,
+ daddr, ntohs(dport),
+ in->ifindex);
+
+ /* 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);
+ 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(&inet6_sk(sk)->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.
diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c
index f8b71911037a..a7dd108d4063 100644
--- a/net/netfilter/xt_socket.c
+++ b/net/netfilter/xt_socket.c
@@ -19,12 +19,12 @@
#include <net/icmp.h>
#include <net/sock.h>
#include <net/inet_sock.h>
-#include <net/netfilter/nf_tproxy_core.h>
#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
#define XT_SOCKET_HAVE_IPV6 1
#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <net/inet6_hashtables.h>
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
#endif
@@ -101,6 +101,43 @@ extract_icmp4_fields(const struct sk_buff *skb,
return 0;
}
+/* "socket" match based redirection (no specific rule)
+ * ===================================================
+ *
+ * There are connections with dynamic endpoints (e.g. FTP data
+ * connection) that the user is unable to add explicit rules
+ * for. These are taken care of by a generic "socket" rule. It is
+ * assumed that the proxy application is trusted to open such
+ * connections without explicit iptables rule (except of course the
+ * generic 'socket' rule). In this case the following sockets are
+ * matched in preference order:
+ *
+ * - match: if there's a fully established connection matching the
+ * _packet_ tuple
+ *
+ * - match: if there's a non-zero bound listener (possibly with a
+ * non-local address) We don't accept zero-bound listeners, since
+ * then local services could intercept traffic going through the
+ * box.
+ */
+static struct sock *
+xt_socket_get_sock_v4(struct net *net, const u8 protocol,
+ const __be32 saddr, const __be32 daddr,
+ const __be16 sport, const __be16 dport,
+ const struct net_device *in)
+{
+ switch (protocol) {
+ case IPPROTO_TCP:
+ return __inet_lookup(net, &tcp_hashinfo,
+ saddr, sport, daddr, dport,
+ in->ifindex);
+ case IPPROTO_UDP:
+ return udp4_lib_lookup(net, saddr, sport, daddr, dport,
+ in->ifindex);
+ }
+ return NULL;
+}
+
static bool
socket_match(const struct sk_buff *skb, struct xt_action_param *par,
const struct xt_socket_mtinfo1 *info)
@@ -156,9 +193,9 @@ socket_match(const struct sk_buff *skb, struct xt_action_param *par,
#endif
if (!sk)
- sk = nf_tproxy_get_sock_v4(dev_net(skb->dev), protocol,
+ sk = xt_socket_get_sock_v4(dev_net(skb->dev), protocol,
saddr, daddr, sport, dport,
- par->in, NFT_LOOKUP_ANY);
+ par->in);
if (sk) {
bool wildcard;
bool transparent = true;
@@ -261,6 +298,25 @@ extract_icmp6_fields(const struct sk_buff *skb,
return 0;
}
+static struct sock *
+xt_socket_get_sock_v6(struct net *net, const u8 protocol,
+ const struct in6_addr *saddr, const struct in6_addr *daddr,
+ const __be16 sport, const __be16 dport,
+ const struct net_device *in)
+{
+ switch (protocol) {
+ case IPPROTO_TCP:
+ return inet6_lookup(net, &tcp_hashinfo,
+ saddr, sport, daddr, dport,
+ in->ifindex);
+ case IPPROTO_UDP:
+ return udp6_lib_lookup(net, saddr, sport, daddr, dport,
+ in->ifindex);
+ }
+
+ return NULL;
+}
+
static bool
socket_mt6_v1_v2(const struct sk_buff *skb, struct xt_action_param *par)
{
@@ -298,9 +354,9 @@ socket_mt6_v1_v2(const struct sk_buff *skb, struct xt_action_param *par)
}
if (!sk)
- sk = nf_tproxy_get_sock_v6(dev_net(skb->dev), tproto,
+ sk = xt_socket_get_sock_v6(dev_net(skb->dev), tproto,
saddr, daddr, sport, dport,
- par->in, NFT_LOOKUP_ANY);
+ par->in);
if (sk) {
bool wildcard;
bool transparent = true;