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 	uint8_t revision;
224 
225 	/* Extension flags */
226 	uint8_t ext_flags;
227 
228 	uint16_t family;
229 
230 	/* Size of match data. */
231 	size_t size;
232 
233 	/* Size of match data relevant 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 	uint8_t revision;
301 
302 	/* Extension flags */
303 	uint8_t ext_flags;
304 
305 	uint16_t family;
306 
307 
308 	/* Size of target data. */
309 	size_t size;
310 
311 	/* Size of target data relevant 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 	uint8_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 	int (*compat_rev)(const char *name, uint8_t rev, int opt);
405 };
406 
407 #define XT_GETOPT_TABLEEND {.name = NULL, .has_arg = false}
408 
409 #ifdef __cplusplus
410 extern "C" {
411 #endif
412 
413 extern const char *xtables_modprobe_program;
414 extern struct xtables_match *xtables_matches;
415 extern struct xtables_target *xtables_targets;
416 
417 extern void xtables_init(void);
418 extern void xtables_set_nfproto(uint8_t);
419 extern void *xtables_calloc(size_t, size_t);
420 extern void *xtables_malloc(size_t);
421 extern void *xtables_realloc(void *, size_t);
422 
423 extern int xtables_insmod(const char *, const char *, bool);
424 extern int xtables_load_ko(const char *, bool);
425 extern int xtables_set_params(struct xtables_globals *xtp);
426 extern void xtables_free_opts(int reset_offset);
427 extern struct option *xtables_merge_options(struct option *origopts,
428 	struct option *oldopts, const struct option *newopts,
429 	unsigned int *option_offset);
430 
431 extern int xtables_init_all(struct xtables_globals *xtp, uint8_t nfproto);
432 extern struct xtables_match *xtables_find_match(const char *name,
433 	enum xtables_tryload, struct xtables_rule_match **match);
434 extern struct xtables_target *xtables_find_target(const char *name,
435 	enum xtables_tryload);
436 extern int xtables_compatible_revision(const char *name, uint8_t revision,
437 				       int opt);
438 
439 extern void xtables_rule_matches_free(struct xtables_rule_match **matches);
440 
441 /* Your shared library should call one of these. */
442 extern void xtables_register_match(struct xtables_match *me);
443 extern void xtables_register_matches(struct xtables_match *, unsigned int);
444 extern void xtables_register_target(struct xtables_target *me);
445 extern void xtables_register_targets(struct xtables_target *, unsigned int);
446 
447 extern bool xtables_strtoul(const char *, char **, uintmax_t *,
448 	uintmax_t, uintmax_t);
449 extern bool xtables_strtoui(const char *, char **, unsigned int *,
450 	unsigned int, unsigned int);
451 extern int xtables_service_to_port(const char *name, const char *proto);
452 extern uint16_t xtables_parse_port(const char *port, const char *proto);
453 extern void
454 xtables_parse_interface(const char *arg, char *vianame, unsigned char *mask);
455 
456 /* this is a special 64bit data type that is 8-byte aligned */
457 #define aligned_u64 uint64_t __attribute__((aligned(8)))
458 
459 extern struct xtables_globals *xt_params;
460 #define xtables_error (xt_params->exit_err)
461 
462 extern void xtables_param_act(unsigned int, const char *, ...);
463 
464 extern const char *xtables_ipaddr_to_numeric(const struct in_addr *);
465 extern const char *xtables_ipaddr_to_anyname(const struct in_addr *);
466 extern const char *xtables_ipmask_to_numeric(const struct in_addr *);
467 extern struct in_addr *xtables_numeric_to_ipaddr(const char *);
468 extern struct in_addr *xtables_numeric_to_ipmask(const char *);
469 extern int xtables_ipmask_to_cidr(const struct in_addr *);
470 extern void xtables_ipparse_any(const char *, struct in_addr **,
471 	struct in_addr *, unsigned int *);
472 extern void xtables_ipparse_multiple(const char *, struct in_addr **,
473 	struct in_addr **, unsigned int *);
474 
475 extern struct in6_addr *xtables_numeric_to_ip6addr(const char *);
476 extern const char *xtables_ip6addr_to_numeric(const struct in6_addr *);
477 extern const char *xtables_ip6addr_to_anyname(const struct in6_addr *);
478 extern const char *xtables_ip6mask_to_numeric(const struct in6_addr *);
479 extern int xtables_ip6mask_to_cidr(const struct in6_addr *);
480 extern void xtables_ip6parse_any(const char *, struct in6_addr **,
481 	struct in6_addr *, unsigned int *);
482 extern void xtables_ip6parse_multiple(const char *, struct in6_addr **,
483 	struct in6_addr **, unsigned int *);
484 
485 /**
486  * Print the specified value to standard output, quoting dangerous
487  * characters if required.
488  */
489 extern void xtables_save_string(const char *value);
490 
491 #define FMT_NUMERIC		0x0001
492 #define FMT_NOCOUNTS		0x0002
493 #define FMT_KILOMEGAGIGA	0x0004
494 #define FMT_OPTIONS		0x0008
495 #define FMT_NOTABLE		0x0010
496 #define FMT_NOTARGET		0x0020
497 #define FMT_VIA			0x0040
498 #define FMT_NONEWLINE		0x0080
499 #define FMT_LINENUMBERS		0x0100
500 
501 #define FMT_PRINT_RULE (FMT_NOCOUNTS | FMT_OPTIONS | FMT_VIA \
502                         | FMT_NUMERIC | FMT_NOTABLE)
503 #define FMT(tab,notab) ((format) & FMT_NOTABLE ? (notab) : (tab))
504 
505 extern void xtables_print_num(uint64_t number, unsigned int format);
506 
507 #if defined(ALL_INCLUSIVE) || defined(NO_SHARED_LIBS)
508 #	ifdef _INIT
509 #		undef _init
510 #		define _init _INIT
511 #	endif
512 	extern void init_extensions(void);
513 	extern void init_extensions4(void);
514 	extern void init_extensions6(void);
515 #else
516 #	define _init __attribute__((constructor)) _INIT
517 #endif
518 
519 extern const struct xtables_pprot xtables_chain_protos[];
520 extern uint16_t xtables_parse_protocol(const char *s);
521 
522 /* kernel revision handling */
523 extern int kernel_version;
524 extern void get_kernel_version(void);
525 #define LINUX_VERSION(x,y,z)	(0x10000*(x) + 0x100*(y) + z)
526 #define LINUX_VERSION_MAJOR(x)	(((x)>>16) & 0xFF)
527 #define LINUX_VERSION_MINOR(x)	(((x)>> 8) & 0xFF)
528 #define LINUX_VERSION_PATCH(x)	( (x)      & 0xFF)
529 
530 /* xtoptions.c */
531 extern void xtables_option_metavalidate(const char *,
532 					const struct xt_option_entry *);
533 extern struct option *xtables_options_xfrm(struct option *, struct option *,
534 					   const struct xt_option_entry *,
535 					   unsigned int *);
536 extern void xtables_option_parse(struct xt_option_call *);
537 extern void xtables_option_tpcall(unsigned int, char **, bool,
538 				  struct xtables_target *, void *);
539 extern void xtables_option_mpcall(unsigned int, char **, bool,
540 				  struct xtables_match *, void *);
541 extern void xtables_option_tfcall(struct xtables_target *);
542 extern void xtables_option_mfcall(struct xtables_match *);
543 extern void xtables_options_fcheck(const char *, unsigned int,
544 				   const struct xt_option_entry *);
545 
546 extern struct xtables_lmap *xtables_lmap_init(const char *);
547 extern void xtables_lmap_free(struct xtables_lmap *);
548 extern int xtables_lmap_name2id(const struct xtables_lmap *, const char *);
549 extern const char *xtables_lmap_id2name(const struct xtables_lmap *, int);
550 
551 #ifdef XTABLES_INTERNAL
552 
553 /* Shipped modules rely on this... */
554 
555 #	ifndef ARRAY_SIZE
556 #		define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
557 #	endif
558 
559 extern void _init(void);
560 
561 #endif
562 
563 #ifdef __cplusplus
564 } /* extern "C" */
565 #endif
566 
567 #endif /* _XTABLES_H */
568