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npf_impl.h revision 1.72
      1 /*	$NetBSD: npf_impl.h,v 1.72 2018/09/12 21:58:38 christos 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) && !defined(_NPF_STANDALONE)
     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 #ifdef _KERNEL
     51 #include <sys/types.h>
     52 #include <sys/queue.h>
     53 #include <sys/rbtree.h>
     54 
     55 #include <net/bpf.h>
     56 #include <net/bpfjit.h>
     57 #include <net/if.h>
     58 #endif
     59 
     60 #include "npf.h"
     61 #include "npfkern.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_conn;
     78 struct npf_config;
     79 
     80 typedef struct npf_ruleset	npf_ruleset_t;
     81 typedef struct npf_rule		npf_rule_t;
     82 typedef struct npf_nat		npf_nat_t;
     83 typedef struct npf_rprocset	npf_rprocset_t;
     84 typedef struct npf_alg		npf_alg_t;
     85 typedef struct npf_natpolicy	npf_natpolicy_t;
     86 typedef struct npf_conn		npf_conn_t;
     87 typedef struct npf_config	npf_config_t;
     88 
     89 struct npf_conndb;
     90 struct npf_table;
     91 struct npf_tableset;
     92 struct npf_algset;
     93 struct npf_ifmap;
     94 
     95 typedef struct npf_conndb	npf_conndb_t;
     96 typedef struct npf_table	npf_table_t;
     97 typedef struct npf_tableset	npf_tableset_t;
     98 typedef struct npf_algset	npf_algset_t;
     99 
    100 /*
    101  * DEFINITIONS.
    102  */
    103 
    104 typedef void (*npf_workfunc_t)(npf_t *);
    105 
    106 /*
    107  * Some artificial limits.
    108  * Note: very unlikely to have many ALGs.
    109  */
    110 #define	NPF_MAX_RULES		(1024 * 1024)
    111 #define	NPF_MAX_TABLES		128
    112 #define	NPF_MAX_RPROCS		128
    113 #define	NPF_MAX_IFMAP		64
    114 #define	NPF_MAX_ALGS		4
    115 #define	NPF_MAX_WORKS		4
    116 
    117 /*
    118  * CONNECTION STATE STRUCTURES
    119  */
    120 
    121 #define	NPF_FLOW_FORW		0
    122 #define	NPF_FLOW_BACK		1
    123 
    124 typedef struct {
    125 	uint32_t	nst_end;
    126 	uint32_t	nst_maxend;
    127 	uint32_t	nst_maxwin;
    128 	int		nst_wscale;
    129 } npf_tcpstate_t;
    130 
    131 typedef struct {
    132 	u_int		nst_state;
    133 	npf_tcpstate_t	nst_tcpst[2];
    134 } npf_state_t;
    135 
    136 /*
    137  * ALG FUNCTIONS.
    138  */
    139 
    140 typedef struct {
    141 	bool		(*match)(npf_cache_t *, npf_nat_t *, int);
    142 	bool		(*translate)(npf_cache_t *, npf_nat_t *, bool);
    143 	npf_conn_t *	(*inspect)(npf_cache_t *, int);
    144 } npfa_funcs_t;
    145 
    146 /*
    147  * NBUF STRUCTURE.
    148  */
    149 
    150 struct nbuf {
    151 	struct mbuf *	nb_mbuf0;
    152 	struct mbuf *	nb_mbuf;
    153 	void *		nb_nptr;
    154 	const ifnet_t *	nb_ifp;
    155 	unsigned	nb_ifid;
    156 	int		nb_flags;
    157 	const npf_mbufops_t *nb_mops;
    158 };
    159 
    160 /*
    161  * NPF INSTANCE (CONTEXT) STRUCTURE AND AUXILIARY OPERATIONS.
    162  */
    163 
    164 struct npf {
    165 	/* Active NPF configuration. */
    166 	kmutex_t		config_lock;
    167 	pserialize_t		qsbr;
    168 	npf_config_t *		config;
    169 
    170 	/* BPF byte-code context. */
    171 	bpf_ctx_t *		bpfctx;
    172 	const npf_mbufops_t *	mbufops;
    173 
    174 	/*
    175 	 * Connection tracking state: disabled (off) or enabled (on).
    176 	 * Connection tracking database, connection cache and the lock.
    177 	 */
    178 	volatile int		conn_tracking;
    179 	kmutex_t		conn_lock;
    180 	npf_conndb_t *		conn_db;
    181 	pool_cache_t		conn_cache;
    182 
    183 	/* ALGs. */
    184 	npf_algset_t *		algset;
    185 
    186 	/* Interface mapping. */
    187 	const npf_ifops_t *	ifops;
    188 	struct npf_ifmap *	ifmap;
    189 	unsigned		ifmap_cnt;
    190 
    191 	/* Associated worker thread. */
    192 	unsigned		worker_id;
    193 	void *			worker_entry;
    194 
    195 	/* List of extensions and its lock. */
    196 	LIST_HEAD(, npf_ext)	ext_list;
    197 	kmutex_t		ext_lock;
    198 
    199 	/* Statistics. */
    200 	percpu_t *		stats_percpu;
    201 };
    202 
    203 /*
    204  * INTERFACES.
    205  */
    206 
    207 /* NPF config, statistics, etc. */
    208 void		npf_config_init(npf_t *);
    209 void		npf_config_fini(npf_t *);
    210 
    211 void		npf_config_enter(npf_t *);
    212 void		npf_config_exit(npf_t *);
    213 void		npf_config_sync(npf_t *);
    214 bool		npf_config_locked_p(npf_t *);
    215 int		npf_config_read_enter(void);
    216 void		npf_config_read_exit(int s);
    217 
    218 void		npf_config_load(npf_t *, npf_ruleset_t *, npf_tableset_t *,
    219 		    npf_ruleset_t *, npf_rprocset_t *, npf_conndb_t *, bool);
    220 npf_ruleset_t *	npf_config_ruleset(npf_t *npf);
    221 npf_ruleset_t *	npf_config_natset(npf_t *npf);
    222 npf_tableset_t *npf_config_tableset(npf_t *npf);
    223 npf_rprocset_t *npf_config_rprocs(npf_t *);
    224 bool		npf_default_pass(npf_t *);
    225 
    226 int		npf_worker_sysinit(unsigned);
    227 void		npf_worker_sysfini(void);
    228 void		npf_worker_signal(npf_t *);
    229 void		npf_worker_register(npf_t *, npf_workfunc_t);
    230 void		npf_worker_unregister(npf_t *, npf_workfunc_t);
    231 
    232 int		npfctl_switch(void *);
    233 int		npfctl_reload(u_long, void *);
    234 int		npfctl_save(npf_t *, u_long, void *);
    235 int		npfctl_load(npf_t *, u_long, void *);
    236 int		npfctl_rule(npf_t *, u_long, void *);
    237 int		npfctl_conn_lookup(npf_t *, u_long, void *);
    238 int		npfctl_table(npf_t *, void *);
    239 
    240 void		npf_stats_inc(npf_t *, npf_stats_t);
    241 void		npf_stats_dec(npf_t *, npf_stats_t);
    242 
    243 void		npf_ifmap_init(npf_t *, const npf_ifops_t *);
    244 void		npf_ifmap_fini(npf_t *);
    245 u_int		npf_ifmap_register(npf_t *, const char *);
    246 void		npf_ifmap_flush(npf_t *);
    247 u_int		npf_ifmap_getid(npf_t *, const ifnet_t *);
    248 const char *	npf_ifmap_getname(npf_t *, const u_int);
    249 void		npf_ifmap_copyname(npf_t *, u_int, char *, size_t);
    250 
    251 void		npf_ifaddr_sync(npf_t *, ifnet_t *);
    252 void		npf_ifaddr_flush(npf_t *, ifnet_t *);
    253 void		npf_ifaddr_syncall(npf_t *);
    254 
    255 /* Packet filter hooks. */
    256 int		npf_pfil_register(bool);
    257 void		npf_pfil_unregister(bool);
    258 bool		npf_pfil_registered_p(void);
    259 
    260 /* Protocol helpers. */
    261 int		npf_cache_all(npf_cache_t *);
    262 void		npf_recache(npf_cache_t *);
    263 
    264 bool		npf_rwrip(const npf_cache_t *, u_int, const npf_addr_t *);
    265 bool		npf_rwrport(const npf_cache_t *, u_int, const in_port_t);
    266 bool		npf_rwrcksum(const npf_cache_t *, u_int,
    267 		    const npf_addr_t *, const in_port_t);
    268 int		npf_napt_rwr(const npf_cache_t *, u_int, const npf_addr_t *,
    269 		    const in_addr_t);
    270 int		npf_npt66_rwr(const npf_cache_t *, u_int, const npf_addr_t *,
    271 		    npf_netmask_t, uint16_t);
    272 
    273 uint16_t	npf_fixup16_cksum(uint16_t, uint16_t, uint16_t);
    274 uint16_t	npf_fixup32_cksum(uint16_t, uint32_t, uint32_t);
    275 uint16_t	npf_addr_cksum(uint16_t, int, const npf_addr_t *,
    276 		    const npf_addr_t *);
    277 uint32_t	npf_addr_mix(const int, const npf_addr_t *, const npf_addr_t *);
    278 int		npf_addr_cmp(const npf_addr_t *, const npf_netmask_t,
    279 		    const npf_addr_t *, const npf_netmask_t, const int);
    280 void		npf_addr_mask(const npf_addr_t *, const npf_netmask_t,
    281 		    const int, npf_addr_t *);
    282 
    283 int		npf_tcpsaw(const npf_cache_t *, tcp_seq *, tcp_seq *,
    284 		    uint32_t *);
    285 bool		npf_fetch_tcpopts(npf_cache_t *, uint16_t *, int *);
    286 bool		npf_set_mss(npf_cache_t *, uint16_t, uint16_t *, uint16_t *,
    287 		    bool *);
    288 bool		npf_return_block(npf_cache_t *, const int);
    289 
    290 /* BPF interface. */
    291 void		npf_bpf_sysinit(void);
    292 void		npf_bpf_sysfini(void);
    293 void		npf_bpf_prepare(npf_cache_t *, bpf_args_t *, uint32_t *);
    294 int		npf_bpf_filter(bpf_args_t *, const void *, bpfjit_func_t);
    295 void *		npf_bpf_compile(void *, size_t);
    296 bool		npf_bpf_validate(const void *, size_t);
    297 
    298 /* Tableset interface. */
    299 void		npf_tableset_sysinit(void);
    300 void		npf_tableset_sysfini(void);
    301 
    302 npf_tableset_t *npf_tableset_create(u_int);
    303 void		npf_tableset_destroy(npf_tableset_t *);
    304 int		npf_tableset_insert(npf_tableset_t *, npf_table_t *);
    305 npf_table_t *	npf_tableset_getbyname(npf_tableset_t *, const char *);
    306 npf_table_t *	npf_tableset_getbyid(npf_tableset_t *, u_int);
    307 npf_table_t *	npf_tableset_swap(npf_tableset_t *, npf_table_t *);
    308 void		npf_tableset_reload(npf_t *, npf_tableset_t *, npf_tableset_t *);
    309 int		npf_tableset_export(npf_t *, const npf_tableset_t *, prop_array_t);
    310 
    311 npf_table_t *	npf_table_create(const char *, u_int, int, void *, size_t);
    312 void		npf_table_destroy(npf_table_t *);
    313 
    314 u_int		npf_table_getid(npf_table_t *);
    315 int		npf_table_check(npf_tableset_t *, const char *, u_int, int);
    316 int		npf_table_insert(npf_table_t *, const int,
    317 		    const npf_addr_t *, const npf_netmask_t);
    318 int		npf_table_remove(npf_table_t *, const int,
    319 		    const npf_addr_t *, const npf_netmask_t);
    320 int		npf_table_lookup(npf_table_t *, const int, const npf_addr_t *);
    321 int		npf_table_list(npf_table_t *, void *, size_t);
    322 int		npf_table_flush(npf_table_t *);
    323 
    324 /* Ruleset interface. */
    325 npf_ruleset_t *	npf_ruleset_create(size_t);
    326 void		npf_ruleset_destroy(npf_ruleset_t *);
    327 void		npf_ruleset_insert(npf_ruleset_t *, npf_rule_t *);
    328 void		npf_ruleset_reload(npf_t *, npf_ruleset_t *,
    329 		    npf_ruleset_t *, bool);
    330 npf_rule_t *	npf_ruleset_sharepm(npf_ruleset_t *, npf_natpolicy_t *);
    331 npf_natpolicy_t *npf_ruleset_findnat(npf_ruleset_t *, uint64_t);
    332 void		npf_ruleset_freealg(npf_ruleset_t *, npf_alg_t *);
    333 int		npf_ruleset_export(npf_t *, const npf_ruleset_t *, prop_array_t);
    334 
    335 npf_rule_t *	npf_ruleset_lookup(npf_ruleset_t *, const char *);
    336 int		npf_ruleset_add(npf_ruleset_t *, const char *, npf_rule_t *);
    337 int		npf_ruleset_remove(npf_ruleset_t *, const char *, uint64_t);
    338 int		npf_ruleset_remkey(npf_ruleset_t *, const char *,
    339 		    const void *, size_t);
    340 prop_dictionary_t npf_ruleset_list(npf_t *, npf_ruleset_t *, const char *);
    341 int		npf_ruleset_flush(npf_ruleset_t *, const char *);
    342 void		npf_ruleset_gc(npf_ruleset_t *);
    343 
    344 npf_rule_t *	npf_ruleset_inspect(npf_cache_t *, const npf_ruleset_t *,
    345 		    const int, const int);
    346 int		npf_rule_conclude(const npf_rule_t *, npf_match_info_t *);
    347 
    348 /* Rule interface. */
    349 npf_rule_t *	npf_rule_alloc(npf_t *, prop_dictionary_t);
    350 void		npf_rule_setcode(npf_rule_t *, int, void *, size_t);
    351 void		npf_rule_setrproc(npf_rule_t *, npf_rproc_t *);
    352 void		npf_rule_free(npf_rule_t *);
    353 uint64_t	npf_rule_getid(const npf_rule_t *);
    354 npf_natpolicy_t *npf_rule_getnat(const npf_rule_t *);
    355 void		npf_rule_setnat(npf_rule_t *, npf_natpolicy_t *);
    356 npf_rproc_t *	npf_rule_getrproc(const npf_rule_t *);
    357 
    358 void		npf_ext_init(npf_t *);
    359 void		npf_ext_fini(npf_t *);
    360 int		npf_ext_construct(npf_t *, const char *,
    361 		    npf_rproc_t *, prop_dictionary_t);
    362 
    363 npf_rprocset_t *npf_rprocset_create(void);
    364 void		npf_rprocset_destroy(npf_rprocset_t *);
    365 npf_rproc_t *	npf_rprocset_lookup(npf_rprocset_t *, const char *);
    366 void		npf_rprocset_insert(npf_rprocset_t *, npf_rproc_t *);
    367 int		npf_rprocset_export(const npf_rprocset_t *, prop_array_t);
    368 
    369 npf_rproc_t *	npf_rproc_create(prop_dictionary_t);
    370 void		npf_rproc_acquire(npf_rproc_t *);
    371 void		npf_rproc_release(npf_rproc_t *);
    372 const char *	npf_rproc_getname(const npf_rproc_t *);
    373 bool		npf_rproc_run(npf_cache_t *, npf_rproc_t *,
    374 		    const npf_match_info_t *, int *);
    375 
    376 /* State handling. */
    377 bool		npf_state_init(npf_cache_t *, npf_state_t *);
    378 bool		npf_state_inspect(npf_cache_t *, npf_state_t *, const bool);
    379 int		npf_state_etime(const npf_state_t *, const int);
    380 void		npf_state_destroy(npf_state_t *);
    381 
    382 bool		npf_state_tcp(npf_cache_t *, npf_state_t *, int);
    383 int		npf_state_tcp_timeout(const npf_state_t *);
    384 
    385 /* NAT. */
    386 void		npf_nat_sysinit(void);
    387 void		npf_nat_sysfini(void);
    388 npf_natpolicy_t *npf_nat_newpolicy(npf_t *, prop_dictionary_t, npf_ruleset_t *);
    389 int		npf_nat_policyexport(const npf_natpolicy_t *, prop_dictionary_t);
    390 void		npf_nat_freepolicy(npf_natpolicy_t *);
    391 bool		npf_nat_cmppolicy(npf_natpolicy_t *, npf_natpolicy_t *);
    392 bool		npf_nat_sharepm(npf_natpolicy_t *, npf_natpolicy_t *);
    393 void		npf_nat_setid(npf_natpolicy_t *, uint64_t);
    394 uint64_t	npf_nat_getid(const npf_natpolicy_t *);
    395 void		npf_nat_freealg(npf_natpolicy_t *, npf_alg_t *);
    396 
    397 int		npf_do_nat(npf_cache_t *, npf_conn_t *, const int);
    398 void		npf_nat_destroy(npf_nat_t *);
    399 void		npf_nat_getorig(npf_nat_t *, npf_addr_t **, in_port_t *);
    400 void		npf_nat_gettrans(npf_nat_t *, npf_addr_t **, in_port_t *);
    401 void		npf_nat_setalg(npf_nat_t *, npf_alg_t *, uintptr_t);
    402 
    403 void		npf_nat_export(prop_dictionary_t, npf_nat_t *);
    404 npf_nat_t *	npf_nat_import(npf_t *, prop_dictionary_t, npf_ruleset_t *,
    405 		    npf_conn_t *);
    406 
    407 /* ALG interface. */
    408 void		npf_alg_sysinit(void);
    409 void		npf_alg_sysfini(void);
    410 void		npf_alg_init(npf_t *);
    411 void		npf_alg_fini(npf_t *);
    412 npf_alg_t *	npf_alg_register(npf_t *, const char *, const npfa_funcs_t *);
    413 int		npf_alg_unregister(npf_t *, npf_alg_t *);
    414 npf_alg_t *	npf_alg_construct(npf_t *, const char *);
    415 bool		npf_alg_match(npf_cache_t *, npf_nat_t *, int);
    416 void		npf_alg_exec(npf_cache_t *, npf_nat_t *, bool);
    417 npf_conn_t *	npf_alg_conn(npf_cache_t *, int);
    418 prop_array_t	npf_alg_export(npf_t *);
    419 
    420 /* Debugging routines. */
    421 const char *	npf_addr_dump(const npf_addr_t *, int);
    422 void		npf_state_dump(const npf_state_t *);
    423 void		npf_nat_dump(const npf_nat_t *);
    424 void		npf_ruleset_dump(npf_t *, const char *);
    425 void		npf_state_setsampler(void (*)(npf_state_t *, bool));
    426 
    427 /* In-kernel routines. */
    428 void		npf_setkernctx(npf_t *);
    429 npf_t *		npf_getkernctx(void);
    430 
    431 #ifdef __NetBSD__
    432 #define	pserialize_register(x)
    433 #define	pserialize_checkpoint(x)
    434 #endif
    435 
    436 #endif	/* _NPF_IMPL_H_ */
    437