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      1 #ifndef _XTABLES_H
      2 #define _XTABLES_H
      3 
      4 /*
      5  * Changing any structs/functions may incur a needed change
      6  * in libxtables_vcurrent/vage too.
      7  */
      8 
      9 #include <sys/socket.h> /* PF_* */
     10 #include <sys/types.h>
     11 #include <limits.h>
     12 #include <stdbool.h>
     13 #include <stddef.h>
     14 #include <stdint.h>
     15 #include <netinet/in.h>
     16 #include <net/if.h>
     17 #include <linux/types.h>
     18 #include <linux/netfilter.h>
     19 #include <linux/netfilter/x_tables.h>
     20 
     21 #ifndef IPPROTO_SCTP
     22 #define IPPROTO_SCTP 132
     23 #endif
     24 #ifndef IPPROTO_DCCP
     25 #define IPPROTO_DCCP 33
     26 #endif
     27 #ifndef IPPROTO_MH
     28 #	define IPPROTO_MH 135
     29 #endif
     30 #ifndef IPPROTO_UDPLITE
     31 #define IPPROTO_UDPLITE	136
     32 #endif
     33 
     34 #include <xtables-version.h>
     35 
     36 struct in_addr;
     37 
     38 /*
     39  * .size is here so that there is a somewhat reasonable check
     40  * against the chosen .type.
     41  */
     42 #define XTOPT_POINTER(stype, member) \
     43 	.ptroff = offsetof(stype, member), \
     44 	.size = sizeof(((stype *)NULL)->member)
     45 #define XTOPT_TABLEEND {.name = NULL}
     46 
     47 /**
     48  * Select the format the input has to conform to, as well as the target type
     49  * (area pointed to with XTOPT_POINTER). Note that the storing is not always
     50  * uniform. @cb->val will be populated with as much as there is space, i.e.
     51  * exactly 2 items for ranges, but the target area can receive more values
     52  * (e.g. in case of ranges), or less values (e.g. %XTTYPE_HOSTMASK).
     53  *
     54  * %XTTYPE_NONE:	option takes no argument
     55  * %XTTYPE_UINT*:	standard integer
     56  * %XTTYPE_UINT*RC:	colon-separated range of standard integers
     57  * %XTTYPE_DOUBLE:	double-precision floating point number
     58  * %XTTYPE_STRING:	arbitrary string
     59  * %XTTYPE_TOSMASK:	8-bit TOS value with optional mask
     60  * %XTTYPE_MARKMASK32:	32-bit mark with optional mask
     61  * %XTTYPE_SYSLOGLEVEL:	syslog level by name or number
     62  * %XTTYPE_HOST:	one host or address (ptr: union nf_inet_addr)
     63  * %XTTYPE_HOSTMASK:	one host or address, with an optional prefix length
     64  * 			(ptr: union nf_inet_addr; only host portion is stored)
     65  * %XTTYPE_PROTOCOL:	protocol number/name from /etc/protocols (ptr: uint8_t)
     66  * %XTTYPE_PORT:	16-bit port name or number (supports %XTOPT_NBO)
     67  * %XTTYPE_PORTRC:	colon-separated port range (names acceptable),
     68  * 			(supports %XTOPT_NBO)
     69  * %XTTYPE_PLEN:	prefix length
     70  * %XTTYPE_PLENMASK:	prefix length (ptr: union nf_inet_addr)
     71  * %XTTYPE_ETHERMAC:	Ethernet MAC address in hex form
     72  */
     73 enum xt_option_type {
     74 	XTTYPE_NONE,
     75 	XTTYPE_UINT8,
     76 	XTTYPE_UINT16,
     77 	XTTYPE_UINT32,
     78 	XTTYPE_UINT64,
     79 	XTTYPE_UINT8RC,
     80 	XTTYPE_UINT16RC,
     81 	XTTYPE_UINT32RC,
     82 	XTTYPE_UINT64RC,
     83 	XTTYPE_DOUBLE,
     84 	XTTYPE_STRING,
     85 	XTTYPE_TOSMASK,
     86 	XTTYPE_MARKMASK32,
     87 	XTTYPE_SYSLOGLEVEL,
     88 	XTTYPE_HOST,
     89 	XTTYPE_HOSTMASK,
     90 	XTTYPE_PROTOCOL,
     91 	XTTYPE_PORT,
     92 	XTTYPE_PORTRC,
     93 	XTTYPE_PLEN,
     94 	XTTYPE_PLENMASK,
     95 	XTTYPE_ETHERMAC,
     96 };
     97 
     98 /**
     99  * %XTOPT_INVERT:	option is invertible (usable with !)
    100  * %XTOPT_MAND:		option is mandatory
    101  * %XTOPT_MULTI:	option may be specified multiple times
    102  * %XTOPT_PUT:		store value into memory at @ptroff
    103  * %XTOPT_NBO:		store value in network-byte order
    104  * 			(only certain XTTYPEs recognize this)
    105  */
    106 enum xt_option_flags {
    107 	XTOPT_INVERT = 1 << 0,
    108 	XTOPT_MAND   = 1 << 1,
    109 	XTOPT_MULTI  = 1 << 2,
    110 	XTOPT_PUT    = 1 << 3,
    111 	XTOPT_NBO    = 1 << 4,
    112 };
    113 
    114 /**
    115  * @name:	name of option
    116  * @type:	type of input and validation method, see %XTTYPE_*
    117  * @id:		unique number (within extension) for option, 0-31
    118  * @excl:	bitmask of flags that cannot be used with this option
    119  * @also:	bitmask of flags that must be used with this option
    120  * @flags:	bitmask of option flags, see %XTOPT_*
    121  * @ptroff:	offset into private structure for member
    122  * @size:	size of the item pointed to by @ptroff; this is a safeguard
    123  * @min:	lowest allowed value (for singular integral types)
    124  * @max:	highest allowed value (for singular integral types)
    125  */
    126 struct xt_option_entry {
    127 	const char *name;
    128 	enum xt_option_type type;
    129 	unsigned int id, excl, also, flags;
    130 	unsigned int ptroff;
    131 	size_t size;
    132 	unsigned int min, max;
    133 };
    134 
    135 /**
    136  * @arg:	input from command line
    137  * @ext_name:	name of extension currently being processed
    138  * @entry:	current option being processed
    139  * @data:	per-extension kernel data block
    140  * @xflags:	options of the extension that have been used
    141  * @invert:	whether option was used with !
    142  * @nvals:	number of results in uXX_multi
    143  * @val:	parsed result
    144  * @udata:	per-extension private scratch area
    145  * 		(cf. xtables_{match,target}->udata_size)
    146  */
    147 struct xt_option_call {
    148 	const char *arg, *ext_name;
    149 	const struct xt_option_entry *entry;
    150 	void *data;
    151 	unsigned int xflags;
    152 	bool invert;
    153 	uint8_t nvals;
    154 	union {
    155 		uint8_t u8, u8_range[2], syslog_level, protocol;
    156 		uint16_t u16, u16_range[2], port, port_range[2];
    157 		uint32_t u32, u32_range[2];
    158 		uint64_t u64, u64_range[2];
    159 		double dbl;
    160 		struct {
    161 			union nf_inet_addr haddr, hmask;
    162 			uint8_t hlen;
    163 		};
    164 		struct {
    165 			uint8_t tos_value, tos_mask;
    166 		};
    167 		struct {
    168 			uint32_t mark, mask;
    169 		};
    170 		uint8_t ethermac[6];
    171 	} val;
    172 	/* Wished for a world where the ones below were gone: */
    173 	union {
    174 		struct xt_entry_match **match;
    175 		struct xt_entry_target **target;
    176 	};
    177 	void *xt_entry;
    178 	void *udata;
    179 };
    180 
    181 /**
    182  * @ext_name:	name of extension currently being processed
    183  * @data:	per-extension (kernel) data block
    184  * @udata:	per-extension private scratch area
    185  * 		(cf. xtables_{match,target}->udata_size)
    186  * @xflags:	options of the extension that have been used
    187  */
    188 struct xt_fcheck_call {
    189 	const char *ext_name;
    190 	void *data, *udata;
    191 	unsigned int xflags;
    192 };
    193 
    194 /**
    195  * A "linear"/linked-list based name<->id map, for files similar to
    196  * /etc/iproute2/.
    197  */
    198 struct xtables_lmap {
    199 	char *name;
    200 	int id;
    201 	struct xtables_lmap *next;
    202 };
    203 
    204 enum xtables_ext_flags {
    205 	XTABLES_EXT_ALIAS = 1 << 0,
    206 };
    207 
    208 struct xt_xlate;
    209 
    210 struct xt_xlate_mt_params {
    211 	const void			*ip;
    212 	const struct xt_entry_match	*match;
    213 	int				numeric;
    214 	bool				escape_quotes;
    215 };
    216 
    217 struct xt_xlate_tg_params {
    218 	const void			*ip;
    219 	const struct xt_entry_target	*target;
    220 	int				numeric;
    221 	bool				escape_quotes;
    222 };
    223 
    224 /* Include file for additions: new matches and targets. */
    225 struct xtables_match {
    226 	/*
    227 	 * ABI/API version this module requires. Must be first member,
    228 	 * as the rest of this struct may be subject to ABI changes.
    229 	 */
    230 	const char *version;
    231 
    232 	struct xtables_match *next;
    233 
    234 	const char *name;
    235 	const char *real_name;
    236 
    237 	/* Revision of match (0 by default). */
    238 	uint8_t revision;
    239 
    240 	/* Extension flags */
    241 	uint8_t ext_flags;
    242 
    243 	uint16_t family;
    244 
    245 	/* Size of match data. */
    246 	size_t size;
    247 
    248 	/* Size of match data relevant for userspace comparison purposes */
    249 	size_t userspacesize;
    250 
    251 	/* Function which prints out usage message. */
    252 	void (*help)(void);
    253 
    254 	/* Initialize the match. */
    255 	void (*init)(struct xt_entry_match *m);
    256 
    257 	/* Function which parses command options; returns true if it
    258            ate an option */
    259 	/* entry is struct ipt_entry for example */
    260 	int (*parse)(int c, char **argv, int invert, unsigned int *flags,
    261 		     const void *entry,
    262 		     struct xt_entry_match **match);
    263 
    264 	/* Final check; exit if not ok. */
    265 	void (*final_check)(unsigned int flags);
    266 
    267 	/* Prints out the match iff non-NULL: put space at end */
    268 	/* ip is struct ipt_ip * for example */
    269 	void (*print)(const void *ip,
    270 		      const struct xt_entry_match *match, int numeric);
    271 
    272 	/* Saves the match info in parsable form to stdout. */
    273 	/* ip is struct ipt_ip * for example */
    274 	void (*save)(const void *ip, const struct xt_entry_match *match);
    275 
    276 	/* Print match name or alias */
    277 	const char *(*alias)(const struct xt_entry_match *match);
    278 
    279 	/* Pointer to list of extra command-line options */
    280 	const struct option *extra_opts;
    281 
    282 	/* New parser */
    283 	void (*x6_parse)(struct xt_option_call *);
    284 	void (*x6_fcheck)(struct xt_fcheck_call *);
    285 	const struct xt_option_entry *x6_options;
    286 
    287 	/* Translate iptables to nft */
    288 	int (*xlate)(struct xt_xlate *xl,
    289 		     const struct xt_xlate_mt_params *params);
    290 
    291 	/* Size of per-extension instance extra "global" scratch space */
    292 	size_t udata_size;
    293 
    294 	/* Ignore these men behind the curtain: */
    295 	void *udata;
    296 	unsigned int option_offset;
    297 	struct xt_entry_match *m;
    298 	unsigned int mflags;
    299 	unsigned int loaded; /* simulate loading so options are merged properly */
    300 };
    301 
    302 struct xtables_target {
    303 	/*
    304 	 * ABI/API version this module requires. Must be first member,
    305 	 * as the rest of this struct may be subject to ABI changes.
    306 	 */
    307 	const char *version;
    308 
    309 	struct xtables_target *next;
    310 
    311 
    312 	const char *name;
    313 
    314 	/* Real target behind this, if any. */
    315 	const char *real_name;
    316 
    317 	/* Revision of target (0 by default). */
    318 	uint8_t revision;
    319 
    320 	/* Extension flags */
    321 	uint8_t ext_flags;
    322 
    323 	uint16_t family;
    324 
    325 
    326 	/* Size of target data. */
    327 	size_t size;
    328 
    329 	/* Size of target data relevant for userspace comparison purposes */
    330 	size_t userspacesize;
    331 
    332 	/* Function which prints out usage message. */
    333 	void (*help)(void);
    334 
    335 	/* Initialize the target. */
    336 	void (*init)(struct xt_entry_target *t);
    337 
    338 	/* Function which parses command options; returns true if it
    339            ate an option */
    340 	/* entry is struct ipt_entry for example */
    341 	int (*parse)(int c, char **argv, int invert, unsigned int *flags,
    342 		     const void *entry,
    343 		     struct xt_entry_target **targetinfo);
    344 
    345 	/* Final check; exit if not ok. */
    346 	void (*final_check)(unsigned int flags);
    347 
    348 	/* Prints out the target iff non-NULL: put space at end */
    349 	void (*print)(const void *ip,
    350 		      const struct xt_entry_target *target, int numeric);
    351 
    352 	/* Saves the targinfo in parsable form to stdout. */
    353 	void (*save)(const void *ip,
    354 		     const struct xt_entry_target *target);
    355 
    356 	/* Print target name or alias */
    357 	const char *(*alias)(const struct xt_entry_target *target);
    358 
    359 	/* Pointer to list of extra command-line options */
    360 	const struct option *extra_opts;
    361 
    362 	/* New parser */
    363 	void (*x6_parse)(struct xt_option_call *);
    364 	void (*x6_fcheck)(struct xt_fcheck_call *);
    365 	const struct xt_option_entry *x6_options;
    366 
    367 	/* Translate iptables to nft */
    368 	int (*xlate)(struct xt_xlate *xl,
    369 		     const struct xt_xlate_tg_params *params);
    370 
    371 	size_t udata_size;
    372 
    373 	/* Ignore these men behind the curtain: */
    374 	void *udata;
    375 	unsigned int option_offset;
    376 	struct xt_entry_target *t;
    377 	unsigned int tflags;
    378 	unsigned int used;
    379 	unsigned int loaded; /* simulate loading so options are merged properly */
    380 };
    381 
    382 struct xtables_rule_match {
    383 	struct xtables_rule_match *next;
    384 	struct xtables_match *match;
    385 	/* Multiple matches of the same type: the ones before
    386 	   the current one are completed from parsing point of view */
    387 	bool completed;
    388 };
    389 
    390 /**
    391  * struct xtables_pprot -
    392  *
    393  * A few hardcoded protocols for 'all' and in case the user has no
    394  * /etc/protocols.
    395  */
    396 struct xtables_pprot {
    397 	const char *name;
    398 	uint8_t num;
    399 };
    400 
    401 enum xtables_tryload {
    402 	XTF_DONT_LOAD,
    403 	XTF_DURING_LOAD,
    404 	XTF_TRY_LOAD,
    405 	XTF_LOAD_MUST_SUCCEED,
    406 };
    407 
    408 enum xtables_exittype {
    409 	OTHER_PROBLEM = 1,
    410 	PARAMETER_PROBLEM,
    411 	VERSION_PROBLEM,
    412 	RESOURCE_PROBLEM,
    413 	XTF_ONLY_ONCE,
    414 	XTF_NO_INVERT,
    415 	XTF_BAD_VALUE,
    416 	XTF_ONE_ACTION,
    417 };
    418 
    419 struct xtables_globals
    420 {
    421 	unsigned int option_offset;
    422 	const char *program_name, *program_version;
    423 	struct option *orig_opts;
    424 	struct option *opts;
    425 	void (*exit_err)(enum xtables_exittype status, const char *msg, ...) __attribute__((noreturn, format(printf,2,3)));
    426 	int (*compat_rev)(const char *name, uint8_t rev, int opt);
    427 };
    428 
    429 #define XT_GETOPT_TABLEEND {.name = NULL, .has_arg = false}
    430 
    431 /*
    432  * enum op-
    433  *
    434  * For writing clean nftables translations code
    435  */
    436 enum xt_op {
    437 	XT_OP_EQ,
    438 	XT_OP_NEQ,
    439 	XT_OP_MAX,
    440 };
    441 
    442 #ifdef __cplusplus
    443 extern "C" {
    444 #endif
    445 
    446 extern const char *xtables_modprobe_program;
    447 extern struct xtables_match *xtables_matches;
    448 extern struct xtables_target *xtables_targets;
    449 
    450 extern void xtables_init(void);
    451 extern void xtables_set_nfproto(uint8_t);
    452 extern void *xtables_calloc(size_t, size_t);
    453 extern void *xtables_malloc(size_t);
    454 extern void *xtables_realloc(void *, size_t);
    455 
    456 extern int xtables_insmod(const char *, const char *, bool);
    457 extern int xtables_load_ko(const char *, bool);
    458 extern int xtables_set_params(struct xtables_globals *xtp);
    459 extern void xtables_free_opts(int reset_offset);
    460 extern struct option *xtables_merge_options(struct option *origopts,
    461 	struct option *oldopts, const struct option *newopts,
    462 	unsigned int *option_offset);
    463 
    464 extern int xtables_init_all(struct xtables_globals *xtp, uint8_t nfproto);
    465 extern struct xtables_match *xtables_find_match(const char *name,
    466 	enum xtables_tryload, struct xtables_rule_match **match);
    467 extern struct xtables_target *xtables_find_target(const char *name,
    468 	enum xtables_tryload);
    469 extern int xtables_compatible_revision(const char *name, uint8_t revision,
    470 				       int opt);
    471 
    472 extern void xtables_rule_matches_free(struct xtables_rule_match **matches);
    473 
    474 /* Your shared library should call one of these. */
    475 extern void xtables_register_match(struct xtables_match *me);
    476 extern void xtables_register_matches(struct xtables_match *, unsigned int);
    477 extern void xtables_register_target(struct xtables_target *me);
    478 extern void xtables_register_targets(struct xtables_target *, unsigned int);
    479 
    480 extern bool xtables_strtoul(const char *, char **, uintmax_t *,
    481 	uintmax_t, uintmax_t);
    482 extern bool xtables_strtoui(const char *, char **, unsigned int *,
    483 	unsigned int, unsigned int);
    484 extern int xtables_service_to_port(const char *name, const char *proto);
    485 extern uint16_t xtables_parse_port(const char *port, const char *proto);
    486 extern void
    487 xtables_parse_interface(const char *arg, char *vianame, unsigned char *mask);
    488 
    489 /* this is a special 64bit data type that is 8-byte aligned */
    490 #define aligned_u64 uint64_t __attribute__((aligned(8)))
    491 
    492 extern struct xtables_globals *xt_params;
    493 #define xtables_error (xt_params->exit_err)
    494 
    495 extern void xtables_param_act(unsigned int, const char *, ...);
    496 
    497 extern const char *xtables_ipaddr_to_numeric(const struct in_addr *);
    498 extern const char *xtables_ipaddr_to_anyname(const struct in_addr *);
    499 extern const char *xtables_ipmask_to_numeric(const struct in_addr *);
    500 extern struct in_addr *xtables_numeric_to_ipaddr(const char *);
    501 extern struct in_addr *xtables_numeric_to_ipmask(const char *);
    502 extern int xtables_ipmask_to_cidr(const struct in_addr *);
    503 extern void xtables_ipparse_any(const char *, struct in_addr **,
    504 	struct in_addr *, unsigned int *);
    505 extern void xtables_ipparse_multiple(const char *, struct in_addr **,
    506 	struct in_addr **, unsigned int *);
    507 
    508 extern struct in6_addr *xtables_numeric_to_ip6addr(const char *);
    509 extern const char *xtables_ip6addr_to_numeric(const struct in6_addr *);
    510 extern const char *xtables_ip6addr_to_anyname(const struct in6_addr *);
    511 extern const char *xtables_ip6mask_to_numeric(const struct in6_addr *);
    512 extern int xtables_ip6mask_to_cidr(const struct in6_addr *);
    513 extern void xtables_ip6parse_any(const char *, struct in6_addr **,
    514 	struct in6_addr *, unsigned int *);
    515 extern void xtables_ip6parse_multiple(const char *, struct in6_addr **,
    516 	struct in6_addr **, unsigned int *);
    517 
    518 /**
    519  * Print the specified value to standard output, quoting dangerous
    520  * characters if required.
    521  */
    522 extern void xtables_save_string(const char *value);
    523 
    524 #define FMT_NUMERIC		0x0001
    525 #define FMT_NOCOUNTS		0x0002
    526 #define FMT_KILOMEGAGIGA	0x0004
    527 #define FMT_OPTIONS		0x0008
    528 #define FMT_NOTABLE		0x0010
    529 #define FMT_NOTARGET		0x0020
    530 #define FMT_VIA			0x0040
    531 #define FMT_NONEWLINE		0x0080
    532 #define FMT_LINENUMBERS		0x0100
    533 
    534 #define FMT_PRINT_RULE (FMT_NOCOUNTS | FMT_OPTIONS | FMT_VIA \
    535                         | FMT_NUMERIC | FMT_NOTABLE)
    536 #define FMT(tab,notab) ((format) & FMT_NOTABLE ? (notab) : (tab))
    537 
    538 extern void xtables_print_num(uint64_t number, unsigned int format);
    539 
    540 #if defined(ALL_INCLUSIVE) || defined(NO_SHARED_LIBS)
    541 #	ifdef _INIT
    542 #		undef _init
    543 #		define _init _INIT
    544 #	endif
    545 	extern void init_extensions(void);
    546 	extern void init_extensions4(void);
    547 	extern void init_extensions6(void);
    548 #else
    549 #	define _init __attribute__((constructor)) _INIT
    550 #endif
    551 
    552 extern const struct xtables_pprot xtables_chain_protos[];
    553 extern uint16_t xtables_parse_protocol(const char *s);
    554 
    555 /* kernel revision handling */
    556 extern int kernel_version;
    557 extern void get_kernel_version(void);
    558 #define LINUX_VERSION(x,y,z)	(0x10000*(x) + 0x100*(y) + z)
    559 #define LINUX_VERSION_MAJOR(x)	(((x)>>16) & 0xFF)
    560 #define LINUX_VERSION_MINOR(x)	(((x)>> 8) & 0xFF)
    561 #define LINUX_VERSION_PATCH(x)	( (x)      & 0xFF)
    562 
    563 /* xtoptions.c */
    564 extern void xtables_option_metavalidate(const char *,
    565 					const struct xt_option_entry *);
    566 extern struct option *xtables_options_xfrm(struct option *, struct option *,
    567 					   const struct xt_option_entry *,
    568 					   unsigned int *);
    569 extern void xtables_option_parse(struct xt_option_call *);
    570 extern void xtables_option_tpcall(unsigned int, char **, bool,
    571 				  struct xtables_target *, void *);
    572 extern void xtables_option_mpcall(unsigned int, char **, bool,
    573 				  struct xtables_match *, void *);
    574 extern void xtables_option_tfcall(struct xtables_target *);
    575 extern void xtables_option_mfcall(struct xtables_match *);
    576 extern void xtables_options_fcheck(const char *, unsigned int,
    577 				   const struct xt_option_entry *);
    578 
    579 extern struct xtables_lmap *xtables_lmap_init(const char *);
    580 extern void xtables_lmap_free(struct xtables_lmap *);
    581 extern int xtables_lmap_name2id(const struct xtables_lmap *, const char *);
    582 extern const char *xtables_lmap_id2name(const struct xtables_lmap *, int);
    583 
    584 /* xlate infrastructure */
    585 struct xt_xlate *xt_xlate_alloc(int size);
    586 void xt_xlate_free(struct xt_xlate *xl);
    587 void xt_xlate_add(struct xt_xlate *xl, const char *fmt, ...);
    588 void xt_xlate_add_comment(struct xt_xlate *xl, const char *comment);
    589 const char *xt_xlate_get_comment(struct xt_xlate *xl);
    590 const char *xt_xlate_get(struct xt_xlate *xl);
    591 
    592 #ifdef XTABLES_INTERNAL
    593 
    594 /* Shipped modules rely on this... */
    595 
    596 #	ifndef ARRAY_SIZE
    597 #		define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
    598 #	endif
    599 
    600 extern void _init(void);
    601 
    602 #endif
    603 
    604 #ifdef __cplusplus
    605 } /* extern "C" */
    606 #endif
    607 
    608 #endif /* _XTABLES_H */
    609