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npf_impl.h revision 1.50
      1 /*	$NetBSD: npf_impl.h,v 1.50 2014/03/14 11:29:44 rmind Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2009-2014 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 
     57 #include <net/bpf.h>
     58 #include <net/bpfjit.h>
     59 #include <net/if.h>
     60 
     61 #include "npf.h"
     62 
     63 #ifdef _NPF_DEBUG
     64 #define	NPF_PRINTF(x)	printf x
     65 #else
     66 #define	NPF_PRINTF(x)
     67 #endif
     68 
     69 /*
     70  * STRUCTURE DECLARATIONS.
     71  */
     72 
     73 struct npf_ruleset;
     74 struct npf_rule;
     75 struct npf_rprocset;
     76 struct npf_nat;
     77 struct npf_session;
     78 
     79 typedef struct npf_ruleset	npf_ruleset_t;
     80 typedef struct npf_rule		npf_rule_t;
     81 typedef struct npf_nat		npf_nat_t;
     82 typedef struct npf_rprocset	npf_rprocset_t;
     83 typedef struct npf_alg		npf_alg_t;
     84 typedef struct npf_natpolicy	npf_natpolicy_t;
     85 typedef struct npf_session	npf_session_t;
     86 
     87 struct npf_sehash;
     88 struct npf_table;
     89 struct npf_tableset;
     90 
     91 typedef struct npf_sehash	npf_sehash_t;
     92 typedef struct npf_table	npf_table_t;
     93 typedef struct npf_tableset	npf_tableset_t;
     94 
     95 /*
     96  * DEFINITIONS.
     97  */
     98 
     99 typedef void (*npf_workfunc_t)(void);
    100 
    101 /*
    102  * Some artificial limits.
    103  * Note: very unlikely to have many ALGs.
    104  */
    105 #define	NPF_MAX_RULES		(1024 * 1024)
    106 #define	NPF_MAX_ALGS		4
    107 #define	NPF_MAX_TABLES		128
    108 #define	NPF_MAX_RPROCS		128
    109 #define	NPF_MAX_IFMAP		64
    110 
    111 /*
    112  * SESSION STATE STRUCTURES
    113  */
    114 
    115 #define	NPF_FLOW_FORW		0
    116 #define	NPF_FLOW_BACK		1
    117 
    118 typedef struct {
    119 	uint32_t	nst_end;
    120 	uint32_t	nst_maxend;
    121 	uint32_t	nst_maxwin;
    122 	int		nst_wscale;
    123 } npf_tcpstate_t;
    124 
    125 typedef struct {
    126 	kmutex_t	nst_lock;
    127 	u_int		nst_state;
    128 	npf_tcpstate_t	nst_tcpst[2];
    129 } npf_state_t;
    130 
    131 /*
    132  * ALG FUNCTIONS.
    133  */
    134 
    135 typedef struct {
    136 	bool		(*match)(npf_cache_t *, nbuf_t *, npf_nat_t *, int);
    137 	bool		(*translate)(npf_cache_t *, nbuf_t *, npf_nat_t *, bool);
    138 	npf_session_t * (*inspect)(npf_cache_t *, nbuf_t *, int);
    139 } npfa_funcs_t;
    140 
    141 /*
    142  * INTERFACES.
    143  */
    144 
    145 /* NPF config, statistics, etc. */
    146 void		npf_config_init(void);
    147 void		npf_config_fini(void);
    148 
    149 void		npf_config_enter(void);
    150 void		npf_config_exit(void);
    151 void		npf_config_sync(void);
    152 bool		npf_config_locked_p(void);
    153 int		npf_config_read_enter(void);
    154 void		npf_config_read_exit(int);
    155 
    156 void		npf_config_reload(prop_dictionary_t, npf_ruleset_t *,
    157 		    npf_tableset_t *, npf_ruleset_t *, npf_rprocset_t *, bool);
    158 npf_ruleset_t *	npf_config_ruleset(void);
    159 npf_ruleset_t *	npf_config_natset(void);
    160 npf_tableset_t *npf_config_tableset(void);
    161 prop_dictionary_t npf_config_dict(void);
    162 bool		npf_default_pass(void);
    163 
    164 int		npf_worker_sysinit(void);
    165 void		npf_worker_sysfini(void);
    166 void		npf_worker_signal(void);
    167 void		npf_worker_register(npf_workfunc_t);
    168 void		npf_worker_unregister(npf_workfunc_t);
    169 
    170 void		npflogattach(int);
    171 void		npflogdetach(void);
    172 int		npfctl_switch(void *);
    173 int		npfctl_reload(u_long, void *);
    174 int		npfctl_getconf(u_long, void *);
    175 int		npfctl_sessions_save(u_long, void *);
    176 int		npfctl_sessions_load(u_long, void *);
    177 int		npfctl_rule(u_long, void *);
    178 int		npfctl_table(void *);
    179 
    180 void		npf_stats_inc(npf_stats_t);
    181 void		npf_stats_dec(npf_stats_t);
    182 
    183 u_int		npf_ifmap_register(const char *);
    184 void		npf_ifmap_flush(void);
    185 void		npf_ifmap_attach(ifnet_t *);
    186 void		npf_ifmap_detach(ifnet_t *);
    187 u_int		npf_ifmap_id(const ifnet_t *);
    188 
    189 /* Packet filter hooks. */
    190 int		npf_pfil_register(bool);
    191 void		npf_pfil_unregister(bool);
    192 bool		npf_pfil_registered_p(void);
    193 int		npf_packet_handler(void *, struct mbuf **, ifnet_t *, int);
    194 
    195 /* Protocol helpers. */
    196 int		npf_cache_all(npf_cache_t *, nbuf_t *);
    197 void		npf_recache(npf_cache_t *, nbuf_t *);
    198 
    199 bool		npf_rwrip(const npf_cache_t *, u_int, const npf_addr_t *);
    200 bool		npf_rwrport(const npf_cache_t *, u_int, const in_port_t);
    201 bool		npf_rwrcksum(const npf_cache_t *, u_int,
    202 		    const npf_addr_t *, const in_port_t);
    203 int		npf_napt_rwr(const npf_cache_t *, u_int, const npf_addr_t *,
    204 		    const in_addr_t);
    205 int		npf_npt66_rwr(const npf_cache_t *, u_int, const npf_addr_t *,
    206 		    npf_netmask_t, uint16_t);
    207 
    208 uint16_t	npf_fixup16_cksum(uint16_t, uint16_t, uint16_t);
    209 uint16_t	npf_fixup32_cksum(uint16_t, uint32_t, uint32_t);
    210 uint16_t	npf_addr_cksum(uint16_t, int, const npf_addr_t *,
    211 		    const npf_addr_t *);
    212 uint32_t	npf_addr_mix(const int, const npf_addr_t *, const npf_addr_t *);
    213 int		npf_addr_cmp(const npf_addr_t *, const npf_netmask_t,
    214 		    const npf_addr_t *, const npf_netmask_t, const int);
    215 void		npf_addr_mask(const npf_addr_t *, const npf_netmask_t,
    216 		    const int, npf_addr_t *);
    217 
    218 int		npf_tcpsaw(const npf_cache_t *, tcp_seq *, tcp_seq *,
    219 		    uint32_t *);
    220 bool		npf_fetch_tcpopts(npf_cache_t *, nbuf_t *, uint16_t *, int *);
    221 bool		npf_return_block(npf_cache_t *, nbuf_t *, const int);
    222 
    223 /* BPF interface. */
    224 void		npf_bpf_sysinit(void);
    225 void		npf_bpf_sysfini(void);
    226 int		npf_bpf_filter(bpf_args_t *, const void *, bpfjit_func_t);
    227 void *		npf_bpf_compile(void *, size_t);
    228 bool		npf_bpf_validate(const void *, size_t);
    229 
    230 /* Tableset interface. */
    231 void		npf_tableset_sysinit(void);
    232 void		npf_tableset_sysfini(void);
    233 
    234 extern const pt_tree_ops_t npf_table_ptree_ops;
    235 
    236 npf_tableset_t *npf_tableset_create(u_int);
    237 void		npf_tableset_destroy(npf_tableset_t *);
    238 int		npf_tableset_insert(npf_tableset_t *, npf_table_t *);
    239 npf_table_t *	npf_tableset_getbyname(npf_tableset_t *, const char *);
    240 npf_table_t *	npf_tableset_getbyid(npf_tableset_t *, u_int);
    241 void		npf_tableset_reload(npf_tableset_t *, npf_tableset_t *);
    242 void		npf_tableset_syncdict(const npf_tableset_t *, prop_dictionary_t);
    243 
    244 npf_table_t *	npf_table_create(const char *, u_int, int, void *, size_t);
    245 void		npf_table_destroy(npf_table_t *);
    246 
    247 int		npf_table_check(npf_tableset_t *, const char *, u_int, int);
    248 int		npf_table_insert(npf_table_t *, const int,
    249 		    const npf_addr_t *, const npf_netmask_t);
    250 int		npf_table_remove(npf_table_t *, const int,
    251 		    const npf_addr_t *, const npf_netmask_t);
    252 int		npf_table_lookup(npf_table_t *, const int, const npf_addr_t *);
    253 int		npf_table_list(npf_table_t *, void *, size_t);
    254 int		npf_table_flush(npf_table_t *);
    255 
    256 /* Ruleset interface. */
    257 npf_ruleset_t *	npf_ruleset_create(size_t);
    258 void		npf_ruleset_destroy(npf_ruleset_t *);
    259 void		npf_ruleset_insert(npf_ruleset_t *, npf_rule_t *);
    260 void		npf_ruleset_reload(npf_ruleset_t *, npf_ruleset_t *);
    261 void		npf_ruleset_natreload(npf_ruleset_t *, npf_ruleset_t *);
    262 npf_rule_t *	npf_ruleset_matchnat(npf_ruleset_t *, npf_natpolicy_t *);
    263 npf_rule_t *	npf_ruleset_sharepm(npf_ruleset_t *, npf_natpolicy_t *);
    264 void		npf_ruleset_freealg(npf_ruleset_t *, npf_alg_t *);
    265 
    266 int		npf_ruleset_add(npf_ruleset_t *, const char *, npf_rule_t *);
    267 int		npf_ruleset_remove(npf_ruleset_t *, const char *, uint64_t);
    268 int		npf_ruleset_remkey(npf_ruleset_t *, const char *,
    269 		    const void *, size_t);
    270 prop_dictionary_t npf_ruleset_list(npf_ruleset_t *, const char *);
    271 int		npf_ruleset_flush(npf_ruleset_t *, const char *);
    272 void		npf_ruleset_gc(npf_ruleset_t *);
    273 
    274 npf_rule_t *	npf_ruleset_inspect(npf_cache_t *, nbuf_t *,
    275 		    const npf_ruleset_t *, const int, const int);
    276 int		npf_rule_conclude(const npf_rule_t *, int *);
    277 
    278 /* Rule interface. */
    279 npf_rule_t *	npf_rule_alloc(prop_dictionary_t);
    280 void		npf_rule_setcode(npf_rule_t *, int, void *, size_t);
    281 void		npf_rule_setrproc(npf_rule_t *, npf_rproc_t *);
    282 void		npf_rule_free(npf_rule_t *);
    283 uint64_t	npf_rule_getid(const npf_rule_t *);
    284 npf_natpolicy_t *npf_rule_getnat(const npf_rule_t *);
    285 void		npf_rule_setnat(npf_rule_t *, npf_natpolicy_t *);
    286 npf_rproc_t *	npf_rule_getrproc(const npf_rule_t *);
    287 
    288 void		npf_ext_sysinit(void);
    289 void		npf_ext_sysfini(void);
    290 int		npf_ext_construct(const char *,
    291 		    npf_rproc_t *, prop_dictionary_t);
    292 
    293 npf_rprocset_t *npf_rprocset_create(void);
    294 void		npf_rprocset_destroy(npf_rprocset_t *);
    295 npf_rproc_t *	npf_rprocset_lookup(npf_rprocset_t *, const char *);
    296 void		npf_rprocset_insert(npf_rprocset_t *, npf_rproc_t *);
    297 
    298 npf_rproc_t *	npf_rproc_create(prop_dictionary_t);
    299 void		npf_rproc_acquire(npf_rproc_t *);
    300 void		npf_rproc_release(npf_rproc_t *);
    301 void		npf_rproc_run(npf_cache_t *, nbuf_t *, npf_rproc_t *, int *);
    302 
    303 /* Session handling interface. */
    304 void		npf_session_sysinit(void);
    305 void		npf_session_sysfini(void);
    306 void		npf_session_tracking(bool);
    307 
    308 npf_sehash_t *	sess_htable_create(void);
    309 void		sess_htable_destroy(npf_sehash_t *);
    310 
    311 npf_session_t *	npf_session_lookup(const npf_cache_t *, const nbuf_t *,
    312 		    const int, bool *);
    313 npf_session_t *	npf_session_inspect(npf_cache_t *, nbuf_t *, const int, int *);
    314 npf_session_t *	npf_session_establish(npf_cache_t *, nbuf_t *, int, bool);
    315 void		npf_session_release(npf_session_t *);
    316 void		npf_session_expire(npf_session_t *);
    317 bool		npf_session_pass(const npf_session_t *, npf_rproc_t **);
    318 void		npf_session_setpass(npf_session_t *, npf_rproc_t *);
    319 int		npf_session_setnat(npf_session_t *, npf_nat_t *, u_int);
    320 npf_nat_t *	npf_session_retnat(npf_session_t *, const int, bool *);
    321 
    322 void		npf_session_load(npf_sehash_t *);
    323 int		npf_session_save(prop_array_t, prop_array_t);
    324 int		npf_session_restore(npf_sehash_t *, prop_dictionary_t);
    325 
    326 /* State handling. */
    327 bool		npf_state_init(npf_cache_t *, nbuf_t *, npf_state_t *);
    328 bool		npf_state_inspect(npf_cache_t *, nbuf_t *, npf_state_t *,
    329 		    const bool);
    330 int		npf_state_etime(const npf_state_t *, const int);
    331 void		npf_state_destroy(npf_state_t *);
    332 
    333 bool		npf_state_tcp(npf_cache_t *, nbuf_t *, npf_state_t *, int);
    334 int		npf_state_tcp_timeout(const npf_state_t *);
    335 
    336 /* NAT. */
    337 void		npf_nat_sysinit(void);
    338 void		npf_nat_sysfini(void);
    339 npf_natpolicy_t *npf_nat_newpolicy(prop_dictionary_t, npf_ruleset_t *);
    340 void		npf_nat_freepolicy(npf_natpolicy_t *);
    341 bool		npf_nat_matchpolicy(npf_natpolicy_t *, npf_natpolicy_t *);
    342 bool		npf_nat_sharepm(npf_natpolicy_t *, npf_natpolicy_t *);
    343 void		npf_nat_freealg(npf_natpolicy_t *, npf_alg_t *);
    344 
    345 int		npf_do_nat(npf_cache_t *, npf_session_t *, nbuf_t *, const int);
    346 void		npf_nat_destroy(npf_nat_t *);
    347 void		npf_nat_getorig(npf_nat_t *, npf_addr_t **, in_port_t *);
    348 void		npf_nat_gettrans(npf_nat_t *, npf_addr_t **, in_port_t *);
    349 void		npf_nat_setalg(npf_nat_t *, npf_alg_t *, uintptr_t);
    350 
    351 int		npf_nat_save(prop_dictionary_t, prop_array_t, npf_nat_t *);
    352 npf_nat_t *	npf_nat_restore(prop_dictionary_t, npf_session_t *);
    353 
    354 /* ALG interface. */
    355 void		npf_alg_sysinit(void);
    356 void		npf_alg_sysfini(void);
    357 npf_alg_t *	npf_alg_register(const char *, const npfa_funcs_t *);
    358 int		npf_alg_unregister(npf_alg_t *);
    359 npf_alg_t *	npf_alg_construct(const char *);
    360 bool		npf_alg_match(npf_cache_t *, nbuf_t *, npf_nat_t *, int);
    361 void		npf_alg_exec(npf_cache_t *, nbuf_t *, npf_nat_t *, bool);
    362 npf_session_t *	npf_alg_session(npf_cache_t *, nbuf_t *, int);
    363 
    364 /* Debugging routines. */
    365 void		npf_addr_dump(const npf_addr_t *);
    366 void		npf_sessions_dump(void);
    367 void		npf_state_dump(const npf_state_t *);
    368 void		npf_nat_dump(const npf_nat_t *);
    369 void		npf_state_setsampler(void (*)(npf_state_t *, bool));
    370 
    371 #endif	/* _NPF_IMPL_H_ */
    372