[linux-block.git] / include / net / netfilter / nf_tproxy.h

#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_ */
Commit	Line	Data
45ca4e0c ME	1	#ifndef _NF_TPROXY_H_
	2	#define _NF_TPROXY_H_
	3
	4	#include <net/tcp.h>
	5
	6	enum nf_tproxy_lookup_t {
	7	NF_TPROXY_LOOKUP_LISTENER,
	8	NF_TPROXY_LOOKUP_ESTABLISHED,
	9	};
	10
	11	static inline bool nf_tproxy_sk_is_transparent(struct sock *sk)
	12	{
	13	if (inet_sk_transparent(sk))
	14	return true;
	15
	16	sock_gen_put(sk);
	17	return false;
	18	}
	19
	20	__be32 nf_tproxy_laddr4(struct sk_buff *skb, __be32 user_laddr, __be32 daddr);
	21
	22	/**
	23	* nf_tproxy_handle_time_wait4 - handle IPv4 TCP TIME_WAIT reopen redirections
	24	* @skb: The skb being processed.
	25	* @laddr: IPv4 address to redirect to or zero.
	26	* @lport: TCP port to redirect to or zero.
	27	* @sk: The TIME_WAIT TCP socket found by the lookup.
	28	*
	29	* We have to handle SYN packets arriving to TIME_WAIT sockets
	30	* differently: instead of reopening the connection we should rather
	31	* redirect the new connection to the proxy if there's a listener
	32	* socket present.
	33	*
	34	* nf_tproxy_handle_time_wait4() consumes the socket reference passed in.
	35	*
	36	* Returns the listener socket if there's one, the TIME_WAIT socket if
	37	* no such listener is found, or NULL if the TCP header is incomplete.
	38	*/
	39	struct sock *
	40	nf_tproxy_handle_time_wait4(struct net net, struct sk_buff skb,
	41	__be32 laddr, __be16 lport, struct sock *sk);
	42
	43	/*
	44	* This is used when the user wants to intercept a connection matching
	45	* an explicit iptables rule. In this case the sockets are assumed
	46	* matching in preference order:
	47	*
	48	* - match: if there's a fully established connection matching the
	49	* _packet_ tuple, it is returned, assuming the redirection
	50	* already took place and we process a packet belonging to an
	51	* established connection
	52	*
	53	* - match: if there's a listening socket matching the redirection
	54	* (e.g. on-port & on-ip of the connection), it is returned,
	55	* regardless if it was bound to 0.0.0.0 or an explicit
	56	* address. The reasoning is that if there's an explicit rule, it
	57	* does not really matter if the listener is bound to an interface
	58	* or to 0. The user already stated that he wants redirection
	59	* (since he added the rule).
	60	*
	61	* Please note that there's an overlap between what a TPROXY target
	62	* and a socket match will match. Normally if you have both rules the
	63	* "socket" match will be the first one, effectively all packets
	64	* belonging to established connections going through that one.
65	*/
66	struct sock *
67	nf_tproxy_get_sock_v4(struct net net, struct sk_buff skb, void *hp,
68	const u8 protocol,
69	const __be32 saddr, const __be32 daddr,
70	const __be16 sport, const __be16 dport,
71	const struct net_device *in,
72	const enum nf_tproxy_lookup_t lookup_type);
73
74	const struct in6_addr *
75	nf_tproxy_laddr6(struct sk_buff skb, const struct in6_addr user_laddr,
76	const struct in6_addr *daddr);
77
78	/**
79	* nf_tproxy_handle_time_wait6 - handle IPv6 TCP TIME_WAIT reopen redirections
80	* @skb: The skb being processed.
81	* @tproto: Transport protocol.
82	* @thoff: Transport protocol header offset.
83	* @net: Network namespace.
84	* @laddr: IPv6 address to redirect to.
85	* @lport: TCP port to redirect to or zero.
86	* @sk: The TIME_WAIT TCP socket found by the lookup.
87	*
88	* We have to handle SYN packets arriving to TIME_WAIT sockets
89	* differently: instead of reopening the connection we should rather
90	* redirect the new connection to the proxy if there's a listener
91	* socket present.
92	*
93	* nf_tproxy_handle_time_wait6() consumes the socket reference passed in.
94	*
95	* Returns the listener socket if there's one, the TIME_WAIT socket if
96	* no such listener is found, or NULL if the TCP header is incomplete.
97	*/
98	struct sock *
99	nf_tproxy_handle_time_wait6(struct sk_buff *skb, int tproto, int thoff,
100	struct net *net,
101	const struct in6_addr *laddr,
102	const __be16 lport,
103	struct sock *sk);
104
105	struct sock *
106	nf_tproxy_get_sock_v6(struct net net, struct sk_buff skb, int thoff, void *hp,
107	const u8 protocol,
108	const struct in6_addr saddr, const struct in6_addr daddr,
109	const __be16 sport, const __be16 dport,
110	const struct net_device *in,
111	const enum nf_tproxy_lookup_t lookup_type);
112
113	#endif /* _NF_TPROXY_H_ */