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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