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npf_impl.h revision 1.18
      1 /*	$NetBSD: npf_impl.h,v 1.18 2012/07/15 00:23:00 rmind Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2009-2012 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This material is based upon work partially supported by The
      8  * NetBSD Foundation under a contract with Mindaugas Rasiukevicius.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * Private NPF structures and interfaces.
     34  * For internal use within NPF core only.
     35  */
     36 
     37 #ifndef _NPF_IMPL_H_
     38 #define _NPF_IMPL_H_
     39 
     40 #if !defined(_KERNEL)
     41 #error "Kernel-level header only"
     42 #endif
     43 
     44 #ifdef _KERNEL_OPT
     45 /* For INET/INET6 definitions. */
     46 #include "opt_inet.h"
     47 #include "opt_inet6.h"
     48 #endif
     49 
     50 #include <sys/types.h>
     51 #include <sys/queue.h>
     52 #include <sys/hash.h>
     53 #include <sys/rbtree.h>
     54 #include <sys/ptree.h>
     55 #include <sys/rwlock.h>
     56 #include <net/if.h>
     57 
     58 #include "npf.h"
     59 #include "npf_ncode.h"
     60 
     61 #ifdef _NPF_DEBUG
     62 #define	NPF_PRINTF(x)	printf x
     63 #else
     64 #define	NPF_PRINTF(x)
     65 #endif
     66 
     67 /*
     68  * STRUCTURE DECLARATIONS.
     69  */
     70 
     71 struct npf_ruleset;
     72 struct npf_rule;
     73 struct npf_nat;
     74 struct npf_session;
     75 
     76 typedef struct npf_ruleset	npf_ruleset_t;
     77 typedef struct npf_rule		npf_rule_t;
     78 typedef struct npf_nat		npf_nat_t;
     79 typedef struct npf_alg		npf_alg_t;
     80 typedef struct npf_natpolicy	npf_natpolicy_t;
     81 typedef struct npf_session	npf_session_t;
     82 
     83 struct npf_sehash;
     84 struct npf_tblent;
     85 struct npf_table;
     86 
     87 typedef struct npf_sehash	npf_sehash_t;
     88 typedef struct npf_tblent	npf_tblent_t;
     89 typedef struct npf_table	npf_table_t;
     90 
     91 typedef npf_table_t *		npf_tableset_t;
     92 
     93 /*
     94  * DEFINITIONS.
     95  */
     96 
     97 #define	NPF_DECISION_BLOCK	0
     98 #define	NPF_DECISION_PASS	1
     99 
    100 typedef bool (*npf_algfunc_t)(npf_cache_t *, nbuf_t *, void *);
    101 
    102 #define	NPF_NCODE_LIMIT		1024
    103 #define	NPF_TABLE_SLOTS		32
    104 
    105 /*
    106  * SESSION STATE STRUCTURES
    107  */
    108 
    109 #define	NPF_FLOW_FORW		0
    110 #define	NPF_FLOW_BACK		1
    111 
    112 typedef struct {
    113 	uint32_t	nst_end;
    114 	uint32_t	nst_maxend;
    115 	uint32_t	nst_maxwin;
    116 	int		nst_wscale;
    117 } npf_tcpstate_t;
    118 
    119 typedef struct {
    120 	kmutex_t	nst_lock;
    121 	int		nst_state;
    122 	npf_tcpstate_t	nst_tcpst[2];
    123 } npf_state_t;
    124 
    125 #if defined(_NPF_TESTING)
    126 void		npf_state_sample(npf_state_t *, bool);
    127 #define	NPF_TCP_STATE_SAMPLE(n, r)	npf_state_sample(n, r)
    128 #else
    129 #define	NPF_TCP_STATE_SAMPLE(n, r)
    130 #endif
    131 
    132 /*
    133  * INTERFACES.
    134  */
    135 
    136 /* NPF control, statistics, etc. */
    137 void		npf_core_enter(void);
    138 npf_ruleset_t *	npf_core_ruleset(void);
    139 npf_ruleset_t *	npf_core_natset(void);
    140 npf_tableset_t *npf_core_tableset(void);
    141 void		npf_core_exit(void);
    142 bool		npf_core_locked(void);
    143 bool		npf_default_pass(void);
    144 prop_dictionary_t npf_core_dict(void);
    145 
    146 void		npf_reload(prop_dictionary_t, npf_ruleset_t *,
    147 		    npf_tableset_t *, npf_ruleset_t *, bool);
    148 
    149 void		npflogattach(int);
    150 void		npflogdetach(void);
    151 int		npfctl_switch(void *);
    152 int		npfctl_reload(u_long, void *);
    153 int		npfctl_getconf(u_long, void *);
    154 int		npfctl_sessions_save(u_long, void *);
    155 int		npfctl_sessions_load(u_long, void *);
    156 int		npfctl_update_rule(u_long, void *);
    157 int		npfctl_table(void *);
    158 
    159 void		npf_stats_inc(npf_stats_t);
    160 void		npf_stats_dec(npf_stats_t);
    161 
    162 /* Packet filter hooks. */
    163 int		npf_pfil_register(void);
    164 void		npf_pfil_unregister(void);
    165 bool		npf_pfil_registered_p(void);
    166 int		npf_packet_handler(void *, struct mbuf **, ifnet_t *, int);
    167 void		npf_log_packet(npf_cache_t *, nbuf_t *, int);
    168 
    169 /* Protocol helpers. */
    170 bool		npf_fetch_ip(npf_cache_t *, nbuf_t *, void *);
    171 bool		npf_fetch_tcp(npf_cache_t *, nbuf_t *, void *);
    172 bool		npf_fetch_udp(npf_cache_t *, nbuf_t *, void *);
    173 bool		npf_fetch_icmp(npf_cache_t *, nbuf_t *, void *);
    174 int		npf_cache_all(npf_cache_t *, nbuf_t *);
    175 
    176 bool		npf_rwrip(npf_cache_t *, nbuf_t *, void *, const int,
    177 		    npf_addr_t *);
    178 bool		npf_rwrport(npf_cache_t *, nbuf_t *, void *, const int,
    179 		    in_port_t);
    180 bool		npf_rwrcksum(npf_cache_t *, nbuf_t *, void *, const int,
    181 		    npf_addr_t *, in_port_t);
    182 
    183 uint16_t	npf_fixup16_cksum(uint16_t, uint16_t, uint16_t);
    184 uint16_t	npf_fixup32_cksum(uint16_t, uint32_t, uint32_t);
    185 uint16_t	npf_addr_cksum(uint16_t, int, npf_addr_t *, npf_addr_t *);
    186 uint32_t	npf_addr_sum(const int, const npf_addr_t *, const npf_addr_t *);
    187 int		npf_addr_cmp(const npf_addr_t *, const npf_netmask_t,
    188 		    const npf_addr_t *, const npf_netmask_t, const int);
    189 void		npf_addr_mask(const npf_addr_t *, const npf_netmask_t,
    190 		    const int, npf_addr_t *);
    191 
    192 int		npf_tcpsaw(const npf_cache_t *, tcp_seq *, tcp_seq *,
    193 		    uint32_t *);
    194 bool		npf_fetch_tcpopts(const npf_cache_t *, nbuf_t *,
    195 		    uint16_t *, int *);
    196 bool		npf_normalize(npf_cache_t *, nbuf_t *, bool, bool, u_int, u_int);
    197 bool		npf_return_block(npf_cache_t *, nbuf_t *, const int);
    198 
    199 /* Complex instructions. */
    200 int		npf_match_ether(nbuf_t *, int, int, uint16_t, uint32_t *);
    201 int		npf_match_proto(npf_cache_t *, nbuf_t *, void *, uint32_t);
    202 int		npf_match_table(npf_cache_t *, nbuf_t *, void *,
    203 		    const int, const u_int);
    204 int		npf_match_ipmask(npf_cache_t *, nbuf_t *, void *,
    205 		    const int, const npf_addr_t *, const npf_netmask_t);
    206 int		npf_match_tcp_ports(npf_cache_t *, nbuf_t *, void *,
    207 		    const int, const uint32_t);
    208 int		npf_match_udp_ports(npf_cache_t *, nbuf_t *, void *,
    209 		    const int, const uint32_t);
    210 int		npf_match_icmp4(npf_cache_t *, nbuf_t *, void *, uint32_t);
    211 int		npf_match_tcpfl(npf_cache_t *, nbuf_t *, void *, uint32_t);
    212 
    213 /* Tableset interface. */
    214 void		npf_tableset_sysinit(void);
    215 void		npf_tableset_sysfini(void);
    216 
    217 const pt_tree_ops_t npf_table_ptree_ops;
    218 
    219 npf_tableset_t *npf_tableset_create(void);
    220 void		npf_tableset_destroy(npf_tableset_t *);
    221 int		npf_tableset_insert(npf_tableset_t *, npf_table_t *);
    222 npf_tableset_t *npf_tableset_reload(npf_tableset_t *);
    223 
    224 npf_table_t *	npf_table_create(u_int, int, size_t);
    225 void		npf_table_destroy(npf_table_t *);
    226 void		npf_table_ref(npf_table_t *);
    227 void		npf_table_unref(npf_table_t *);
    228 
    229 npf_table_t *	npf_table_get(npf_tableset_t *, u_int);
    230 void		npf_table_put(npf_table_t *);
    231 int		npf_table_check(const npf_tableset_t *, u_int, int);
    232 int		npf_table_insert(npf_tableset_t *, u_int,
    233 		    const int, const npf_addr_t *, const npf_netmask_t);
    234 int		npf_table_remove(npf_tableset_t *, u_int,
    235 		    const int, const npf_addr_t *, const npf_netmask_t);
    236 int		npf_table_lookup(npf_tableset_t *, u_int,
    237 		    const int, const npf_addr_t *);
    238 
    239 /* Ruleset interface. */
    240 npf_ruleset_t *	npf_ruleset_create(void);
    241 void		npf_ruleset_destroy(npf_ruleset_t *);
    242 void		npf_ruleset_insert(npf_ruleset_t *, npf_rule_t *);
    243 void		npf_ruleset_natreload(npf_ruleset_t *, npf_ruleset_t *);
    244 npf_rule_t *	npf_ruleset_matchnat(npf_ruleset_t *, npf_natpolicy_t *);
    245 npf_rule_t *	npf_ruleset_sharepm(npf_ruleset_t *, npf_natpolicy_t *);
    246 npf_rule_t *	npf_ruleset_replace(const char *, npf_ruleset_t *);
    247 void		npf_ruleset_freealg(npf_ruleset_t *, npf_alg_t *);
    248 
    249 npf_rule_t *	npf_ruleset_inspect(npf_cache_t *, nbuf_t *, npf_ruleset_t *,
    250 		    ifnet_t *, const int, const int);
    251 int		npf_rule_apply(npf_cache_t *, nbuf_t *, npf_rule_t *, int *);
    252 
    253 /* Rule interface. */
    254 npf_rule_t *	npf_rule_alloc(prop_dictionary_t, npf_rproc_t *, void *, size_t);
    255 void		npf_rule_free(npf_rule_t *);
    256 npf_ruleset_t *	npf_rule_subset(npf_rule_t *);
    257 npf_natpolicy_t *npf_rule_getnat(const npf_rule_t *);
    258 void		npf_rule_setnat(npf_rule_t *, npf_natpolicy_t *);
    259 npf_rproc_t *	npf_rule_getrproc(npf_rule_t *);
    260 
    261 npf_rproc_t *	npf_rproc_create(prop_dictionary_t);
    262 void		npf_rproc_acquire(npf_rproc_t *);
    263 void		npf_rproc_release(npf_rproc_t *);
    264 void		npf_rproc_run(npf_cache_t *, nbuf_t *, npf_rproc_t *, int);
    265 
    266 /* Session handling interface. */
    267 void		npf_session_sysinit(void);
    268 void		npf_session_sysfini(void);
    269 int		npf_session_tracking(bool);
    270 
    271 npf_sehash_t *	sess_htable_create(void);
    272 void		sess_htable_destroy(npf_sehash_t *);
    273 void		sess_htable_reload(npf_sehash_t *);
    274 
    275 npf_session_t *	npf_session_inspect(npf_cache_t *, nbuf_t *, const int, int *);
    276 npf_session_t *	npf_session_establish(const npf_cache_t *, nbuf_t *, const int);
    277 void		npf_session_release(npf_session_t *);
    278 void		npf_session_expire(npf_session_t *);
    279 bool		npf_session_pass(const npf_session_t *, npf_rproc_t **);
    280 void		npf_session_setpass(npf_session_t *, npf_rproc_t *);
    281 int		npf_session_setnat(npf_session_t *, npf_nat_t *, const int);
    282 npf_nat_t *	npf_session_retnat(npf_session_t *, const int, bool *);
    283 
    284 int		npf_session_save(prop_array_t, prop_array_t);
    285 int		npf_session_restore(npf_sehash_t *, prop_dictionary_t);
    286 
    287 /* State handling. */
    288 bool		npf_state_init(const npf_cache_t *, nbuf_t *, npf_state_t *);
    289 bool		npf_state_inspect(const npf_cache_t *, nbuf_t *, npf_state_t *,
    290 		    const bool);
    291 int		npf_state_etime(const npf_state_t *, const int);
    292 void		npf_state_destroy(npf_state_t *);
    293 
    294 bool		npf_state_tcp(const npf_cache_t *, nbuf_t *, npf_state_t *, int);
    295 int		npf_state_tcp_timeout(const npf_state_t *);
    296 
    297 /* NAT. */
    298 void		npf_nat_sysinit(void);
    299 void		npf_nat_sysfini(void);
    300 npf_natpolicy_t *npf_nat_newpolicy(prop_dictionary_t, npf_ruleset_t *);
    301 void		npf_nat_freepolicy(npf_natpolicy_t *);
    302 bool		npf_nat_matchpolicy(npf_natpolicy_t *, npf_natpolicy_t *);
    303 bool		npf_nat_sharepm(npf_natpolicy_t *, npf_natpolicy_t *);
    304 void		npf_nat_freealg(npf_natpolicy_t *, npf_alg_t *);
    305 
    306 int		npf_do_nat(npf_cache_t *, npf_session_t *, nbuf_t *,
    307 		    ifnet_t *, const int);
    308 void		npf_nat_expire(npf_nat_t *);
    309 void		npf_nat_getorig(npf_nat_t *, npf_addr_t **, in_port_t *);
    310 void		npf_nat_gettrans(npf_nat_t *, npf_addr_t **, in_port_t *);
    311 void		npf_nat_setalg(npf_nat_t *, npf_alg_t *, uintptr_t);
    312 
    313 int		npf_nat_save(prop_dictionary_t, prop_array_t, npf_nat_t *);
    314 npf_nat_t *	npf_nat_restore(prop_dictionary_t, npf_session_t *);
    315 
    316 /* ALG interface. */
    317 void		npf_alg_sysinit(void);
    318 void		npf_alg_sysfini(void);
    319 npf_alg_t *	npf_alg_register(npf_algfunc_t, npf_algfunc_t,
    320 		    npf_algfunc_t, npf_algfunc_t);
    321 int		npf_alg_unregister(npf_alg_t *);
    322 bool		npf_alg_match(npf_cache_t *, nbuf_t *, npf_nat_t *);
    323 void		npf_alg_exec(npf_cache_t *, nbuf_t *, npf_nat_t *, const int );
    324 bool		npf_alg_sessionid(npf_cache_t *, nbuf_t *, npf_cache_t *);
    325 
    326 /* Debugging routines. */
    327 void		npf_addr_dump(const npf_addr_t *);
    328 void		npf_rulenc_dump(const npf_rule_t *);
    329 void		npf_sessions_dump(void);
    330 void		npf_state_dump(const npf_state_t *);
    331 void		npf_nat_dump(const npf_nat_t *);
    332 
    333 #endif	/* _NPF_IMPL_H_ */
    334