summaryrefslogtreecommitdiffstats
path: root/include/xtables.h
blob: bad11a8944fb2b4940c74c2fc8fab50ff8f6331a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
#ifndef _XTABLES_H
#define _XTABLES_H

/*
 * Changing any structs/functions may incur a needed change
 * in libxtables_vcurrent/vage too.
 */

#include <sys/socket.h> /* PF_* */
#include <sys/types.h>
#include <limits.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <netinet/in.h>
#include <net/if.h>
#include <linux/types.h>
#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>

#ifndef IPPROTO_SCTP
#define IPPROTO_SCTP 132
#endif
#ifndef IPPROTO_DCCP
#define IPPROTO_DCCP 33
#endif
#ifndef IPPROTO_MH
#	define IPPROTO_MH 135
#endif
#ifndef IPPROTO_UDPLITE
#define IPPROTO_UDPLITE	136
#endif

#include <xtables-version.h>

struct in_addr;

/*
 * .size is here so that there is a somewhat reasonable check
 * against the chosen .type.
 */
#define XTOPT_POINTER(stype, member) \
	.ptroff = offsetof(stype, member), \
	.size = sizeof(((stype *)NULL)->member)
#define XTOPT_TABLEEND {.name = NULL}

/**
 * Select the format the input has to conform to, as well as the target type
 * (area pointed to with XTOPT_POINTER). Note that the storing is not always
 * uniform. @cb->val will be populated with as much as there is space, i.e.
 * exactly 2 items for ranges, but the target area can receive more values
 * (e.g. in case of ranges), or less values (e.g. %XTTYPE_HOSTMASK).
 *
 * %XTTYPE_NONE:	option takes no argument
 * %XTTYPE_UINT*:	standard integer
 * %XTTYPE_UINT*RC:	colon-separated range of standard integers
 * %XTTYPE_DOUBLE:	double-precision floating point number
 * %XTTYPE_STRING:	arbitrary string
 * %XTTYPE_TOSMASK:	8-bit TOS value with optional mask
 * %XTTYPE_MARKMASK32:	32-bit mark with optional mask
 * %XTTYPE_SYSLOGLEVEL:	syslog level by name or number
 * %XTTYPE_HOST:	one host or address (ptr: union nf_inet_addr)
 * %XTTYPE_HOSTMASK:	one host or address, with an optional prefix length
 * 			(ptr: union nf_inet_addr; only host portion is stored)
 * %XTTYPE_PROTOCOL:	protocol number/name from /etc/protocols (ptr: uint8_t)
 * %XTTYPE_PORT:	16-bit port name or number (supports %XTOPT_NBO)
 * %XTTYPE_PORTRC:	colon-separated port range (names acceptable),
 * 			(supports %XTOPT_NBO)
 * %XTTYPE_PLEN:	prefix length
 * %XTTYPE_PLENMASK:	prefix length (ptr: union nf_inet_addr)
 * %XTTYPE_ETHERMAC:	Ethernet MAC address in hex form
 */
enum xt_option_type {
	XTTYPE_NONE,
	XTTYPE_UINT8,
	XTTYPE_UINT16,
	XTTYPE_UINT32,
	XTTYPE_UINT64,
	XTTYPE_UINT8RC,
	XTTYPE_UINT16RC,
	XTTYPE_UINT32RC,
	XTTYPE_UINT64RC,
	XTTYPE_DOUBLE,
	XTTYPE_STRING,
	XTTYPE_TOSMASK,
	XTTYPE_MARKMASK32,
	XTTYPE_SYSLOGLEVEL,
	XTTYPE_HOST,
	XTTYPE_HOSTMASK,
	XTTYPE_PROTOCOL,
	XTTYPE_PORT,
	XTTYPE_PORTRC,
	XTTYPE_PLEN,
	XTTYPE_PLENMASK,
	XTTYPE_ETHERMAC,
};

/**
 * %XTOPT_INVERT:	option is invertible (usable with !)
 * %XTOPT_MAND:		option is mandatory
 * %XTOPT_MULTI:	option may be specified multiple times
 * %XTOPT_PUT:		store value into memory at @ptroff
 * %XTOPT_NBO:		store value in network-byte order
 * 			(only certain XTTYPEs recognize this)
 */
enum xt_option_flags {
	XTOPT_INVERT = 1 << 0,
	XTOPT_MAND   = 1 << 1,
	XTOPT_MULTI  = 1 << 2,
	XTOPT_PUT    = 1 << 3,
	XTOPT_NBO    = 1 << 4,
};

/**
 * @name:	name of option
 * @type:	type of input and validation method, see %XTTYPE_*
 * @id:		unique number (within extension) for option, 0-31
 * @excl:	bitmask of flags that cannot be used with this option
 * @also:	bitmask of flags that must be used with this option
 * @flags:	bitmask of option flags, see %XTOPT_*
 * @ptroff:	offset into private structure for member
 * @size:	size of the item pointed to by @ptroff; this is a safeguard
 * @min:	lowest allowed value (for singular integral types)
 * @max:	highest allowed value (for singular integral types)
 */
struct xt_option_entry {
	const char *name;
	enum xt_option_type type;
	unsigned int id, excl, also, flags;
	unsigned int ptroff;
	size_t size;
	unsigned int min, max;
};

/**
 * @arg:	input from command line
 * @ext_name:	name of extension currently being processed
 * @entry:	current option being processed
 * @data:	per-extension kernel data block
 * @xflags:	options of the extension that have been used
 * @invert:	whether option was used with !
 * @nvals:	number of results in uXX_multi
 * @val:	parsed result
 * @udata:	per-extension private scratch area
 * 		(cf. xtables_{match,target}->udata_size)
 */
struct xt_option_call {
	const char *arg, *ext_name;
	const struct xt_option_entry *entry;
	void *data;
	unsigned int xflags;
	bool invert;
	uint8_t nvals;
	union {
		uint8_t u8, u8_range[2], syslog_level, protocol;
		uint16_t u16, u16_range[2], port, port_range[2];
		uint32_t u32, u32_range[2];
		uint64_t u64, u64_range[2];
		double dbl;
		struct {
			union nf_inet_addr haddr, hmask;
			uint8_t hlen;
		};
		struct {
			uint8_t tos_value, tos_mask;
		};
		struct {
			uint32_t mark, mask;
		};
		uint8_t ethermac[6];
	} val;
	/* Wished for a world where the ones below were gone: */
	union {
		struct xt_entry_match **match;
		struct xt_entry_target **target;
	};
	void *xt_entry;
	void *udata;
};

/**
 * @ext_name:	name of extension currently being processed
 * @data:	per-extension (kernel) data block
 * @udata:	per-extension private scratch area
 * 		(cf. xtables_{match,target}->udata_size)
 * @xflags:	options of the extension that have been used
 */
struct xt_fcheck_call {
	const char *ext_name;
	void *data, *udata;
	unsigned int xflags;
};

/**
 * A "linear"/linked-list based name<->id map, for files similar to
 * /etc/iproute2/.
 */
struct xtables_lmap {
	char *name;
	int id;
	struct xtables_lmap *next;
};

enum xtables_ext_flags {
	XTABLES_EXT_ALIAS = 1 << 0,
};

/* Include file for additions: new matches and targets. */
struct xtables_match
{
	/*
	 * ABI/API version this module requires. Must be first member,
	 * as the rest of this struct may be subject to ABI changes.
	 */
	const char *version;

	struct xtables_match *next;

	const char *name;
	const char *real_name;

	/* Revision of match (0 by default). */
	u_int8_t revision;

	/* Extension flags */
	u_int8_t ext_flags;

	u_int16_t family;

	/* Size of match data. */
	size_t size;

	/* Size of match data relevant for userspace comparison purposes */
	size_t userspacesize;

	/* Function which prints out usage message. */
	void (*help)(void);

	/* Initialize the match. */
	void (*init)(struct xt_entry_match *m);

	/* Function which parses command options; returns true if it
           ate an option */
	/* entry is struct ipt_entry for example */
	int (*parse)(int c, char **argv, int invert, unsigned int *flags,
		     const void *entry,
		     struct xt_entry_match **match);

	/* Final check; exit if not ok. */
	void (*final_check)(unsigned int flags);

	/* Prints out the match iff non-NULL: put space at end */
	/* ip is struct ipt_ip * for example */
	void (*print)(const void *ip,
		      const struct xt_entry_match *match, int numeric);

	/* Saves the match info in parsable form to stdout. */
	/* ip is struct ipt_ip * for example */
	void (*save)(const void *ip, const struct xt_entry_match *match);

	/* Print match name or alias */
	const char *(*alias)(const struct xt_entry_match *match);

	/* Pointer to list of extra command-line options */
	const struct option *extra_opts;

	/* New parser */
	void (*x6_parse)(struct xt_option_call *);
	void (*x6_fcheck)(struct xt_fcheck_call *);
	const struct xt_option_entry *x6_options;

	/* Size of per-extension instance extra "global" scratch space */
	size_t udata_size;

	/* Ignore these men behind the curtain: */
	void *udata;
	unsigned int option_offset;
	struct xt_entry_match *m;
	unsigned int mflags;
	unsigned int loaded; /* simulate loading so options are merged properly */
};

struct xtables_target
{
	/*
	 * ABI/API version this module requires. Must be first member,
	 * as the rest of this struct may be subject to ABI changes.
	 */
	const char *version;

	struct xtables_target *next;


	const char *name;

	/* Real target behind this, if any. */
	const char *real_name;

	/* Revision of target (0 by default). */
	u_int8_t revision;

	/* Extension flags */
	u_int8_t ext_flags;

	u_int16_t family;


	/* Size of target data. */
	size_t size;

	/* Size of target data relevant for userspace comparison purposes */
	size_t userspacesize;

	/* Function which prints out usage message. */
	void (*help)(void);

	/* Initialize the target. */
	void (*init)(struct xt_entry_target *t);

	/* Function which parses command options; returns true if it
           ate an option */
	/* entry is struct ipt_entry for example */
	int (*parse)(int c, char **argv, int invert, unsigned int *flags,
		     const void *entry,
		     struct xt_entry_target **targetinfo);

	/* Final check; exit if not ok. */
	void (*final_check)(unsigned int flags);

	/* Prints out the target iff non-NULL: put space at end */
	void (*print)(const void *ip,
		      const struct xt_entry_target *target, int numeric);

	/* Saves the targinfo in parsable form to stdout. */
	void (*save)(const void *ip,
		     const struct xt_entry_target *target);

	/* Print target name or alias */
	const char *(*alias)(const struct xt_entry_target *target);

	/* Pointer to list of extra command-line options */
	const struct option *extra_opts;

	/* New parser */
	void (*x6_parse)(struct xt_option_call *);
	void (*x6_fcheck)(struct xt_fcheck_call *);
	const struct xt_option_entry *x6_options;

	size_t udata_size;

	/* Ignore these men behind the curtain: */
	void *udata;
	unsigned int option_offset;
	struct xt_entry_target *t;
	unsigned int tflags;
	unsigned int used;
	unsigned int loaded; /* simulate loading so options are merged properly */
};

struct xtables_rule_match {
	struct xtables_rule_match *next;
	struct xtables_match *match;
	/* Multiple matches of the same type: the ones before
	   the current one are completed from parsing point of view */
	bool completed;
};

/**
 * struct xtables_pprot -
 *
 * A few hardcoded protocols for 'all' and in case the user has no
 * /etc/protocols.
 */
struct xtables_pprot {
	const char *name;
	u_int8_t num;
};

enum xtables_tryload {
	XTF_DONT_LOAD,
	XTF_DURING_LOAD,
	XTF_TRY_LOAD,
	XTF_LOAD_MUST_SUCCEED,
};

enum xtables_exittype {
	OTHER_PROBLEM = 1,
	PARAMETER_PROBLEM,
	VERSION_PROBLEM,
	RESOURCE_PROBLEM,
	XTF_ONLY_ONCE,
	XTF_NO_INVERT,
	XTF_BAD_VALUE,
	XTF_ONE_ACTION,
};

struct xtables_globals
{
	unsigned int option_offset;
	const char *program_name, *program_version;
	struct option *orig_opts;
	struct option *opts;
	void (*exit_err)(enum xtables_exittype status, const char *msg, ...) __attribute__((noreturn, format(printf,2,3)));
	int (*compat_rev)(const char *name, uint8_t rev, int opt);
};

#define XT_GETOPT_TABLEEND {.name = NULL, .has_arg = false}

#ifdef __cplusplus
extern "C" {
#endif

extern const char *xtables_modprobe_program;
extern struct xtables_match *xtables_matches;
extern struct xtables_target *xtables_targets;

extern void xtables_init(void);
extern void xtables_set_nfproto(uint8_t);
extern void *xtables_calloc(size_t, size_t);
extern void *xtables_malloc(size_t);
extern void *xtables_realloc(void *, size_t);

extern int xtables_insmod(const char *, const char *, bool);
extern int xtables_load_ko(const char *, bool);
extern int xtables_set_params(struct xtables_globals *xtp);
extern void xtables_free_opts(int reset_offset);
extern struct option *xtables_merge_options(struct option *origopts,
	struct option *oldopts, const struct option *newopts,
	unsigned int *option_offset);

extern int xtables_init_all(struct xtables_globals *xtp, uint8_t nfproto);
extern struct xtables_match *xtables_find_match(const char *name,
	enum xtables_tryload, struct xtables_rule_match **match);
extern struct xtables_target *xtables_find_target(const char *name,
	enum xtables_tryload);
extern int xtables_compatible_revision(const char *name, uint8_t revision,
				       int opt);

extern void xtables_rule_matches_free(struct xtables_rule_match **matches);

/* Your shared library should call one of these. */
extern void xtables_register_match(struct xtables_match *me);
extern void xtables_register_matches(struct xtables_match *, unsigned int);
extern void xtables_register_target(struct xtables_target *me);
extern void xtables_register_targets(struct xtables_target *, unsigned int);

extern bool xtables_strtoul(const char *, char **, uintmax_t *,
	uintmax_t, uintmax_t);
extern bool xtables_strtoui(const char *, char **, unsigned int *,
	unsigned int, unsigned int);
extern int xtables_service_to_port(const char *name, const char *proto);
extern u_int16_t xtables_parse_port(const char *port, const char *proto);
extern void
xtables_parse_interface(const char *arg, char *vianame, unsigned char *mask);

/* this is a special 64bit data type that is 8-byte aligned */
#define aligned_u64 u_int64_t __attribute__((aligned(8)))

extern struct xtables_globals *xt_params;
#define xtables_error (xt_params->exit_err)

extern void xtables_param_act(unsigned int, const char *, ...);

extern const char *xtables_ipaddr_to_numeric(const struct in_addr *);
extern const char *xtables_ipaddr_to_anyname(const struct in_addr *);
extern const char *xtables_ipmask_to_numeric(const struct in_addr *);
extern struct in_addr *xtables_numeric_to_ipaddr(const char *);
extern struct in_addr *xtables_numeric_to_ipmask(const char *);
extern int xtables_ipmask_to_cidr(const struct in_addr *);
extern void xtables_ipparse_any(const char *, struct in_addr **,
	struct in_addr *, unsigned int *);
extern void xtables_ipparse_multiple(const char *, struct in_addr **,
	struct in_addr **, unsigned int *);

extern struct in6_addr *xtables_numeric_to_ip6addr(const char *);
extern const char *xtables_ip6addr_to_numeric(const struct in6_addr *);
extern const char *xtables_ip6addr_to_anyname(const struct in6_addr *);
extern const char *xtables_ip6mask_to_numeric(const struct in6_addr *);
extern int xtables_ip6mask_to_cidr(const struct in6_addr *);
extern void xtables_ip6parse_any(const char *, struct in6_addr **,
	struct in6_addr *, unsigned int *);
extern void xtables_ip6parse_multiple(const char *, struct in6_addr **,
	struct in6_addr **, unsigned int *);

/**
 * Print the specified value to standard output, quoting dangerous
 * characters if required.
 */
extern void xtables_save_string(const char *value);

#define FMT_NUMERIC		0x0001
#define FMT_NOCOUNTS		0x0002
#define FMT_KILOMEGAGIGA	0x0004
#define FMT_OPTIONS		0x0008
#define FMT_NOTABLE		0x0010
#define FMT_NOTARGET		0x0020
#define FMT_VIA			0x0040
#define FMT_NONEWLINE		0x0080
#define FMT_LINENUMBERS		0x0100

#define FMT_PRINT_RULE (FMT_NOCOUNTS | FMT_OPTIONS | FMT_VIA \
                        | FMT_NUMERIC | FMT_NOTABLE)
#define FMT(tab,notab) ((format) & FMT_NOTABLE ? (notab) : (tab))

extern void xtables_print_num(uint64_t number, unsigned int format);

#if defined(ALL_INCLUSIVE) || defined(NO_SHARED_LIBS)
#	ifdef _INIT
#		undef _init
#		define _init _INIT
#	endif
	extern void init_extensions(void);
	extern void init_extensions4(void);
	extern void init_extensions6(void);
#else
#	define _init __attribute__((constructor)) _INIT
#endif

extern const struct xtables_pprot xtables_chain_protos[];
extern u_int16_t xtables_parse_protocol(const char *s);

/* kernel revision handling */
extern int kernel_version;
extern void get_kernel_version(void);
#define LINUX_VERSION(x,y,z)	(0x10000*(x) + 0x100*(y) + z)
#define LINUX_VERSION_MAJOR(x)	(((x)>>16) & 0xFF)
#define LINUX_VERSION_MINOR(x)	(((x)>> 8) & 0xFF)
#define LINUX_VERSION_PATCH(x)	( (x)      & 0xFF)

/* xtoptions.c */
extern void xtables_option_metavalidate(const char *,
					const struct xt_option_entry *);
extern struct option *xtables_options_xfrm(struct option *, struct option *,
					   const struct xt_option_entry *,
					   unsigned int *);
extern void xtables_option_parse(struct xt_option_call *);
extern void xtables_option_tpcall(unsigned int, char **, bool,
				  struct xtables_target *, void *);
extern void xtables_option_mpcall(unsigned int, char **, bool,
				  struct xtables_match *, void *);
extern void xtables_option_tfcall(struct xtables_target *);
extern void xtables_option_mfcall(struct xtables_match *);
extern void xtables_options_fcheck(const char *, unsigned int,
				   const struct xt_option_entry *);

extern struct xtables_lmap *xtables_lmap_init(const char *);
extern void xtables_lmap_free(struct xtables_lmap *);
extern int xtables_lmap_name2id(const struct xtables_lmap *, const char *);
extern const char *xtables_lmap_id2name(const struct xtables_lmap *, int);

#ifdef XTABLES_INTERNAL

/* Shipped modules rely on this... */

#	ifndef ARRAY_SIZE
#		define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
#	endif

extern void _init(void);

#endif

#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /* _XTABLES_H */