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      1 /*-
      2  * Copyright (c) 2009-2020 The NetBSD Foundation, Inc.
      3  * All rights reserved.
      4  *
      5  * This material is based upon work partially supported by The
      6  * NetBSD Foundation under a contract with Mindaugas Rasiukevicius.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     27  * POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 #ifndef _NPF_CONN_H_
     31 #define _NPF_CONN_H_
     32 
     33 #if !defined(_KERNEL) && !defined(_NPF_STANDALONE)
     34 #error "kernel-level header only"
     35 #endif
     36 
     37 #include <sys/types.h>
     38 
     39 #include "npf_impl.h"
     40 
     41 #if defined(__NPF_CONN_PRIVATE)
     42 
     43 /*
     44  * The main connection tracking structure.
     45  */
     46 struct npf_conn {
     47 	/*
     48 	 * Protocol, address length, the interface ID (if zero,
     49 	 * then the state is global) and connection flags.
     50 	 */
     51 	uint16_t		c_proto;
     52 	uint16_t		c_alen;
     53 	unsigned		c_ifid;
     54 	unsigned		c_flags;
     55 
     56 	/* Matching rule flags and ID. */
     57 	unsigned		c_retfl;
     58 	uint64_t		c_rid;
     59 
     60 	/*
     61 	 * Entry in the connection database/list.  The entry is
     62 	 * protected by npf_t::conn_lock.
     63 	 */
     64 	union {
     65 		npf_conn_t *		c_next;
     66 		LIST_ENTRY(npf_conn)	c_entry;
     67 	};
     68 
     69 	/* Associated rule procedure or NAT (if any). */
     70 	npf_rproc_t *		c_rproc;
     71 	npf_nat_t *		c_nat;
     72 
     73 	/*
     74 	 * The Reference count and the last activity time (used to
     75 	 * calculate expiration time).  Note: *unsigned* 32-bit integer
     76 	 * as a timestamp is sufficient for us.
     77 	 */
     78 	unsigned		c_refcnt;
     79 	uint32_t		c_atime;
     80 
     81 	/* The protocol state and lock. */
     82 	kmutex_t		c_lock;
     83 	npf_state_t		c_state;
     84 
     85 	/*
     86 	 * Connection "forwards" and "backwards" keys.  They are accessed
     87 	 * as npf_connkey_t, see below and npf_conn_getkey().
     88 	 */
     89 	uint32_t		c_keys[];
     90 };
     91 
     92 typedef struct {
     93 	int	connkey_interface;
     94 	int	connkey_direction;
     95 } npf_conn_params_t;
     96 
     97 #endif
     98 
     99 /*
    100  * Connection key interface.
    101  *
    102  * See the key layout description in the npf_connkey.c source file.
    103  */
    104 
    105 #define	NPF_CONNKEY_V4WORDS	(2 + ((sizeof(struct in_addr) * 2) >> 2))
    106 #define	NPF_CONNKEY_V6WORDS	(2 + ((sizeof(struct in6_addr) * 2) >> 2))
    107 #define	NPF_CONNKEY_MAXWORDS	(NPF_CONNKEY_V6WORDS)
    108 
    109 #define	NPF_CONNKEY_ALEN(key)	(((key)->ck_key[0] >> 28) << 2)
    110 #define	NPF_CONNKEY_LEN(key)	(8 + (NPF_CONNKEY_ALEN(key) * 2))
    111 
    112 typedef struct npf_connkey {
    113 	/* Warning: ck_key has a variable length -- see above. */
    114 	uint32_t		ck_key[NPF_CONNKEY_MAXWORDS];
    115 } npf_connkey_t;
    116 
    117 unsigned	npf_conn_conkey(const npf_cache_t *, npf_connkey_t *,
    118 		    const unsigned, const npf_flow_t);
    119 npf_connkey_t *	npf_conn_getforwkey(npf_conn_t *);
    120 npf_connkey_t *	npf_conn_getbackkey(npf_conn_t *, unsigned);
    121 void		npf_conn_adjkey(npf_connkey_t *, const npf_addr_t *,
    122 		    const uint16_t, const unsigned);
    123 unsigned	npf_connkey_setkey(npf_connkey_t *, unsigned, unsigned,
    124 		    const void *, const uint16_t *, const npf_flow_t);
    125 void		npf_connkey_getkey(const npf_connkey_t *, unsigned *,
    126 		    unsigned *, npf_addr_t *, uint16_t *);
    127 unsigned	npf_connkey_import(npf_t *, const nvlist_t *, npf_connkey_t *);
    128 nvlist_t *	npf_connkey_export(npf_t *, const npf_connkey_t *);
    129 void		npf_connkey_print(const npf_connkey_t *);
    130 
    131 /*
    132  * Connection tracking interface.
    133  */
    134 void		npf_conn_init(npf_t *);
    135 void		npf_conn_fini(npf_t *);
    136 void		npf_conn_tracking(npf_t *, bool);
    137 void		npf_conn_load(npf_t *, npf_conndb_t *, bool);
    138 
    139 npf_conn_t *	npf_conn_lookup(const npf_cache_t *, const unsigned, npf_flow_t *);
    140 npf_conn_t *	npf_conn_inspect(npf_cache_t *, const unsigned, int *);
    141 npf_conn_t *	npf_conn_establish(npf_cache_t *, const unsigned, bool);
    142 void		npf_conn_release(npf_conn_t *);
    143 void		npf_conn_destroy(npf_t *, npf_conn_t *);
    144 void		npf_conn_expire(npf_conn_t *);
    145 bool		npf_conn_pass(const npf_conn_t *, npf_match_info_t *,
    146 		    npf_rproc_t **);
    147 void		npf_conn_setpass(npf_conn_t *, const npf_match_info_t *,
    148 		    npf_rproc_t *);
    149 int		npf_conn_setnat(const npf_cache_t *, npf_conn_t *,
    150 		    npf_nat_t *, unsigned);
    151 npf_nat_t *	npf_conn_getnat(const npf_conn_t *);
    152 bool		npf_conn_expired(npf_t *, const npf_conn_t *, uint64_t);
    153 void		npf_conn_remove(npf_conndb_t *, npf_conn_t *);
    154 void		npf_conn_worker(npf_t *);
    155 int		npf_conn_import(npf_t *, npf_conndb_t *, const nvlist_t *,
    156 		    npf_ruleset_t *);
    157 int		npf_conn_find(npf_t *, const nvlist_t *, nvlist_t *);
    158 void		npf_conn_print(npf_conn_t *);
    159 
    160 /*
    161  * Connection database (aka state table) interface.
    162  */
    163 void		npf_conndb_sysinit(npf_t *);
    164 void		npf_conndb_sysfini(npf_t *);
    165 
    166 npf_conndb_t *	npf_conndb_create(void);
    167 void		npf_conndb_destroy(npf_conndb_t *);
    168 
    169 npf_conn_t *	npf_conndb_lookup(npf_t *, const npf_connkey_t *, npf_flow_t *);
    170 bool		npf_conndb_insert(npf_conndb_t *, const npf_connkey_t *,
    171 		    npf_conn_t *, npf_flow_t);
    172 npf_conn_t *	npf_conndb_remove(npf_conndb_t *, npf_connkey_t *);
    173 
    174 void		npf_conndb_enqueue(npf_conndb_t *, npf_conn_t *);
    175 npf_conn_t *	npf_conndb_getlist(npf_conndb_t *);
    176 npf_conn_t *	npf_conndb_getnext(npf_conndb_t *, npf_conn_t *);
    177 int		npf_conndb_export(npf_t *, nvlist_t *);
    178 void		npf_conndb_gc(npf_t *, npf_conndb_t *, bool, bool);
    179 
    180 #endif	/* _NPF_CONN_H_ */
    181