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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 /* Include file for additions: new matches and targets. */
    209 struct xtables_match
    210 {
    211 	/*
    212 	 * ABI/API version this module requires. Must be first member,
    213 	 * as the rest of this struct may be subject to ABI changes.
    214 	 */
    215 	const char *version;
    216 
    217 	struct xtables_match *next;
    218 
    219 	const char *name;
    220 	const char *real_name;
    221 
    222 	/* Revision of match (0 by default). */
    223 	u_int8_t revision;
    224 
    225 	/* Extension flags */
    226 	u_int8_t ext_flags;
    227 
    228 	u_int16_t family;
    229 
    230 	/* Size of match data. */
    231 	size_t size;
    232 
    233 	/* Size of match data relevent for userspace comparison purposes */
    234 	size_t userspacesize;
    235 
    236 	/* Function which prints out usage message. */
    237 	void (*help)(void);
    238 
    239 	/* Initialize the match. */
    240 	void (*init)(struct xt_entry_match *m);
    241 
    242 	/* Function which parses command options; returns true if it
    243            ate an option */
    244 	/* entry is struct ipt_entry for example */
    245 	int (*parse)(int c, char **argv, int invert, unsigned int *flags,
    246 		     const void *entry,
    247 		     struct xt_entry_match **match);
    248 
    249 	/* Final check; exit if not ok. */
    250 	void (*final_check)(unsigned int flags);
    251 
    252 	/* Prints out the match iff non-NULL: put space at end */
    253 	/* ip is struct ipt_ip * for example */
    254 	void (*print)(const void *ip,
    255 		      const struct xt_entry_match *match, int numeric);
    256 
    257 	/* Saves the match info in parsable form to stdout. */
    258 	/* ip is struct ipt_ip * for example */
    259 	void (*save)(const void *ip, const struct xt_entry_match *match);
    260 
    261 	/* Print match name or alias */
    262 	const char *(*alias)(const struct xt_entry_match *match);
    263 
    264 	/* Pointer to list of extra command-line options */
    265 	const struct option *extra_opts;
    266 
    267 	/* New parser */
    268 	void (*x6_parse)(struct xt_option_call *);
    269 	void (*x6_fcheck)(struct xt_fcheck_call *);
    270 	const struct xt_option_entry *x6_options;
    271 
    272 	/* Size of per-extension instance extra "global" scratch space */
    273 	size_t udata_size;
    274 
    275 	/* Ignore these men behind the curtain: */
    276 	void *udata;
    277 	unsigned int option_offset;
    278 	struct xt_entry_match *m;
    279 	unsigned int mflags;
    280 	unsigned int loaded; /* simulate loading so options are merged properly */
    281 };
    282 
    283 struct xtables_target
    284 {
    285 	/*
    286 	 * ABI/API version this module requires. Must be first member,
    287 	 * as the rest of this struct may be subject to ABI changes.
    288 	 */
    289 	const char *version;
    290 
    291 	struct xtables_target *next;
    292 
    293 
    294 	const char *name;
    295 
    296 	/* Real target behind this, if any. */
    297 	const char *real_name;
    298 
    299 	/* Revision of target (0 by default). */
    300 	u_int8_t revision;
    301 
    302 	/* Extension flags */
    303 	u_int8_t ext_flags;
    304 
    305 	u_int16_t family;
    306 
    307 
    308 	/* Size of target data. */
    309 	size_t size;
    310 
    311 	/* Size of target data relevent for userspace comparison purposes */
    312 	size_t userspacesize;
    313 
    314 	/* Function which prints out usage message. */
    315 	void (*help)(void);
    316 
    317 	/* Initialize the target. */
    318 	void (*init)(struct xt_entry_target *t);
    319 
    320 	/* Function which parses command options; returns true if it
    321            ate an option */
    322 	/* entry is struct ipt_entry for example */
    323 	int (*parse)(int c, char **argv, int invert, unsigned int *flags,
    324 		     const void *entry,
    325 		     struct xt_entry_target **targetinfo);
    326 
    327 	/* Final check; exit if not ok. */
    328 	void (*final_check)(unsigned int flags);
    329 
    330 	/* Prints out the target iff non-NULL: put space at end */
    331 	void (*print)(const void *ip,
    332 		      const struct xt_entry_target *target, int numeric);
    333 
    334 	/* Saves the targinfo in parsable form to stdout. */
    335 	void (*save)(const void *ip,
    336 		     const struct xt_entry_target *target);
    337 
    338 	/* Print target name or alias */
    339 	const char *(*alias)(const struct xt_entry_target *target);
    340 
    341 	/* Pointer to list of extra command-line options */
    342 	const struct option *extra_opts;
    343 
    344 	/* New parser */
    345 	void (*x6_parse)(struct xt_option_call *);
    346 	void (*x6_fcheck)(struct xt_fcheck_call *);
    347 	const struct xt_option_entry *x6_options;
    348 
    349 	size_t udata_size;
    350 
    351 	/* Ignore these men behind the curtain: */
    352 	void *udata;
    353 	unsigned int option_offset;
    354 	struct xt_entry_target *t;
    355 	unsigned int tflags;
    356 	unsigned int used;
    357 	unsigned int loaded; /* simulate loading so options are merged properly */
    358 };
    359 
    360 struct xtables_rule_match {
    361 	struct xtables_rule_match *next;
    362 	struct xtables_match *match;
    363 	/* Multiple matches of the same type: the ones before
    364 	   the current one are completed from parsing point of view */
    365 	bool completed;
    366 };
    367 
    368 /**
    369  * struct xtables_pprot -
    370  *
    371  * A few hardcoded protocols for 'all' and in case the user has no
    372  * /etc/protocols.
    373  */
    374 struct xtables_pprot {
    375 	const char *name;
    376 	u_int8_t num;
    377 };
    378 
    379 enum xtables_tryload {
    380 	XTF_DONT_LOAD,
    381 	XTF_DURING_LOAD,
    382 	XTF_TRY_LOAD,
    383 	XTF_LOAD_MUST_SUCCEED,
    384 };
    385 
    386 enum xtables_exittype {
    387 	OTHER_PROBLEM = 1,
    388 	PARAMETER_PROBLEM,
    389 	VERSION_PROBLEM,
    390 	RESOURCE_PROBLEM,
    391 	XTF_ONLY_ONCE,
    392 	XTF_NO_INVERT,
    393 	XTF_BAD_VALUE,
    394 	XTF_ONE_ACTION,
    395 };
    396 
    397 struct xtables_globals
    398 {
    399 	unsigned int option_offset;
    400 	const char *program_name, *program_version;
    401 	struct option *orig_opts;
    402 	struct option *opts;
    403 	void (*exit_err)(enum xtables_exittype status, const char *msg, ...) __attribute__((noreturn, format(printf,2,3)));
    404 };
    405 
    406 #define XT_GETOPT_TABLEEND {.name = NULL, .has_arg = false}
    407 
    408 #ifdef __cplusplus
    409 extern "C" {
    410 #endif
    411 
    412 extern const char *xtables_modprobe_program;
    413 extern struct xtables_match *xtables_matches;
    414 extern struct xtables_target *xtables_targets;
    415 
    416 extern void xtables_init(void);
    417 extern void xtables_set_nfproto(uint8_t);
    418 extern void *xtables_calloc(size_t, size_t);
    419 extern void *xtables_malloc(size_t);
    420 extern void *xtables_realloc(void *, size_t);
    421 
    422 extern int xtables_insmod(const char *, const char *, bool);
    423 extern int xtables_load_ko(const char *, bool);
    424 extern int xtables_set_params(struct xtables_globals *xtp);
    425 extern void xtables_free_opts(int reset_offset);
    426 extern struct option *xtables_merge_options(struct option *origopts,
    427 	struct option *oldopts, const struct option *newopts,
    428 	unsigned int *option_offset);
    429 
    430 extern int xtables_init_all(struct xtables_globals *xtp, uint8_t nfproto);
    431 extern struct xtables_match *xtables_find_match(const char *name,
    432 	enum xtables_tryload, struct xtables_rule_match **match);
    433 extern struct xtables_target *xtables_find_target(const char *name,
    434 	enum xtables_tryload);
    435 
    436 extern void xtables_rule_matches_free(struct xtables_rule_match **matches);
    437 
    438 /* Your shared library should call one of these. */
    439 extern void xtables_register_match(struct xtables_match *me);
    440 extern void xtables_register_matches(struct xtables_match *, unsigned int);
    441 extern void xtables_register_target(struct xtables_target *me);
    442 extern void xtables_register_targets(struct xtables_target *, unsigned int);
    443 
    444 extern bool xtables_strtoul(const char *, char **, uintmax_t *,
    445 	uintmax_t, uintmax_t);
    446 extern bool xtables_strtoui(const char *, char **, unsigned int *,
    447 	unsigned int, unsigned int);
    448 extern int xtables_service_to_port(const char *name, const char *proto);
    449 extern u_int16_t xtables_parse_port(const char *port, const char *proto);
    450 extern void
    451 xtables_parse_interface(const char *arg, char *vianame, unsigned char *mask);
    452 
    453 /* this is a special 64bit data type that is 8-byte aligned */
    454 #define aligned_u64 u_int64_t __attribute__((aligned(8)))
    455 
    456 extern struct xtables_globals *xt_params;
    457 #define xtables_error (xt_params->exit_err)
    458 
    459 extern void xtables_param_act(unsigned int, const char *, ...);
    460 
    461 extern const char *xtables_ipaddr_to_numeric(const struct in_addr *);
    462 extern const char *xtables_ipaddr_to_anyname(const struct in_addr *);
    463 extern const char *xtables_ipmask_to_numeric(const struct in_addr *);
    464 extern struct in_addr *xtables_numeric_to_ipaddr(const char *);
    465 extern struct in_addr *xtables_numeric_to_ipmask(const char *);
    466 extern int xtables_ipmask_to_cidr(const struct in_addr *);
    467 extern void xtables_ipparse_any(const char *, struct in_addr **,
    468 	struct in_addr *, unsigned int *);
    469 extern void xtables_ipparse_multiple(const char *, struct in_addr **,
    470 	struct in_addr **, unsigned int *);
    471 
    472 extern struct in6_addr *xtables_numeric_to_ip6addr(const char *);
    473 extern const char *xtables_ip6addr_to_numeric(const struct in6_addr *);
    474 extern const char *xtables_ip6addr_to_anyname(const struct in6_addr *);
    475 extern const char *xtables_ip6mask_to_numeric(const struct in6_addr *);
    476 extern int xtables_ip6mask_to_cidr(const struct in6_addr *);
    477 extern void xtables_ip6parse_any(const char *, struct in6_addr **,
    478 	struct in6_addr *, unsigned int *);
    479 extern void xtables_ip6parse_multiple(const char *, struct in6_addr **,
    480 	struct in6_addr **, unsigned int *);
    481 
    482 /**
    483  * Print the specified value to standard output, quoting dangerous
    484  * characters if required.
    485  */
    486 extern void xtables_save_string(const char *value);
    487 
    488 #define FMT_NUMERIC		0x0001
    489 #define FMT_NOCOUNTS		0x0002
    490 #define FMT_KILOMEGAGIGA	0x0004
    491 #define FMT_OPTIONS		0x0008
    492 #define FMT_NOTABLE		0x0010
    493 #define FMT_NOTARGET		0x0020
    494 #define FMT_VIA			0x0040
    495 #define FMT_NONEWLINE		0x0080
    496 #define FMT_LINENUMBERS		0x0100
    497 
    498 #define FMT_PRINT_RULE (FMT_NOCOUNTS | FMT_OPTIONS | FMT_VIA \
    499                         | FMT_NUMERIC | FMT_NOTABLE)
    500 #define FMT(tab,notab) ((format) & FMT_NOTABLE ? (notab) : (tab))
    501 
    502 extern void xtables_print_num(uint64_t number, unsigned int format);
    503 
    504 #if defined(ALL_INCLUSIVE) || defined(NO_SHARED_LIBS)
    505 #	ifdef _INIT
    506 #		undef _init
    507 #		define _init _INIT
    508 #	endif
    509 	extern void init_extensions(void);
    510 	extern void init_extensions4(void);
    511 	extern void init_extensions6(void);
    512 #else
    513 #	define _init __attribute__((constructor)) _INIT
    514 #endif
    515 
    516 extern const struct xtables_pprot xtables_chain_protos[];
    517 extern u_int16_t xtables_parse_protocol(const char *s);
    518 
    519 /* kernel revision handling */
    520 extern int kernel_version;
    521 extern void get_kernel_version(void);
    522 #define LINUX_VERSION(x,y,z)	(0x10000*(x) + 0x100*(y) + z)
    523 #define LINUX_VERSION_MAJOR(x)	(((x)>>16) & 0xFF)
    524 #define LINUX_VERSION_MINOR(x)	(((x)>> 8) & 0xFF)
    525 #define LINUX_VERSION_PATCH(x)	( (x)      & 0xFF)
    526 
    527 /* xtoptions.c */
    528 extern void xtables_option_metavalidate(const char *,
    529 					const struct xt_option_entry *);
    530 extern struct option *xtables_options_xfrm(struct option *, struct option *,
    531 					   const struct xt_option_entry *,
    532 					   unsigned int *);
    533 extern void xtables_option_parse(struct xt_option_call *);
    534 extern void xtables_option_tpcall(unsigned int, char **, bool,
    535 				  struct xtables_target *, void *);
    536 extern void xtables_option_mpcall(unsigned int, char **, bool,
    537 				  struct xtables_match *, void *);
    538 extern void xtables_option_tfcall(struct xtables_target *);
    539 extern void xtables_option_mfcall(struct xtables_match *);
    540 extern void xtables_options_fcheck(const char *, unsigned int,
    541 				   const struct xt_option_entry *);
    542 
    543 extern struct xtables_lmap *xtables_lmap_init(const char *);
    544 extern void xtables_lmap_free(struct xtables_lmap *);
    545 extern int xtables_lmap_name2id(const struct xtables_lmap *, const char *);
    546 extern const char *xtables_lmap_id2name(const struct xtables_lmap *, int);
    547 
    548 #ifdef XTABLES_INTERNAL
    549 
    550 /* Shipped modules rely on this... */
    551 
    552 #	ifndef ARRAY_SIZE
    553 #		define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
    554 #	endif
    555 
    556 extern void _init(void);
    557 
    558 #endif
    559 
    560 #ifdef __cplusplus
    561 } /* extern "C" */
    562 #endif
    563 
    564 #endif /* _XTABLES_H */
    565