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#define XTABLES_VERSION "libxtables.so.@libxtables_vmajor@"
35#define XTABLES_VERSION_CODE @libxtables_vmajor@
36
37struct in_addr;
38
39/*
40 * .size is here so that there is a somewhat reasonable check
41 * against the chosen .type.
42 */
43#define XTOPT_POINTER(stype, member) \
44	.ptroff = offsetof(stype, member), \
45	.size = sizeof(((stype *)NULL)->member)
46#define XTOPT_TABLEEND {.name = NULL}
47
48/**
49 * Select the format the input has to conform to, as well as the target type
50 * (area pointed to with XTOPT_POINTER). Note that the storing is not always
51 * uniform. @cb->val will be populated with as much as there is space, i.e.
52 * exactly 2 items for ranges, but the target area can receive more values
53 * (e.g. in case of ranges), or less values (e.g. %XTTYPE_HOSTMASK).
54 *
55 * %XTTYPE_NONE:	option takes no argument
56 * %XTTYPE_UINT*:	standard integer
57 * %XTTYPE_UINT*RC:	colon-separated range of standard integers
58 * %XTTYPE_DOUBLE:	double-precision floating point number
59 * %XTTYPE_STRING:	arbitrary string
60 * %XTTYPE_TOSMASK:	8-bit TOS value with optional mask
61 * %XTTYPE_MARKMASK32:	32-bit mark with optional mask
62 * %XTTYPE_SYSLOGLEVEL:	syslog level by name or number
63 * %XTTYPE_HOST:	one host or address (ptr: union nf_inet_addr)
64 * %XTTYPE_HOSTMASK:	one host or address, with an optional prefix length
65 * 			(ptr: union nf_inet_addr; only host portion is stored)
66 * %XTTYPE_PROTOCOL:	protocol number/name from /etc/protocols (ptr: uint8_t)
67 * %XTTYPE_PORT:	16-bit port name or number (supports %XTOPT_NBO)
68 * %XTTYPE_PORTRC:	colon-separated port range (names acceptable),
69 * 			(supports %XTOPT_NBO)
70 * %XTTYPE_PLEN:	prefix length
71 * %XTTYPE_PLENMASK:	prefix length (ptr: union nf_inet_addr)
72 * %XTTYPE_ETHERMAC:	Ethernet MAC address in hex form
73 */
74enum xt_option_type {
75	XTTYPE_NONE,
76	XTTYPE_UINT8,
77	XTTYPE_UINT16,
78	XTTYPE_UINT32,
79	XTTYPE_UINT64,
80	XTTYPE_UINT8RC,
81	XTTYPE_UINT16RC,
82	XTTYPE_UINT32RC,
83	XTTYPE_UINT64RC,
84	XTTYPE_DOUBLE,
85	XTTYPE_STRING,
86	XTTYPE_TOSMASK,
87	XTTYPE_MARKMASK32,
88	XTTYPE_SYSLOGLEVEL,
89	XTTYPE_HOST,
90	XTTYPE_HOSTMASK,
91	XTTYPE_PROTOCOL,
92	XTTYPE_PORT,
93	XTTYPE_PORTRC,
94	XTTYPE_PLEN,
95	XTTYPE_PLENMASK,
96	XTTYPE_ETHERMAC,
97};
98
99/**
100 * %XTOPT_INVERT:	option is invertible (usable with !)
101 * %XTOPT_MAND:		option is mandatory
102 * %XTOPT_MULTI:	option may be specified multiple times
103 * %XTOPT_PUT:		store value into memory at @ptroff
104 * %XTOPT_NBO:		store value in network-byte order
105 * 			(only certain XTTYPEs recognize this)
106 */
107enum xt_option_flags {
108	XTOPT_INVERT = 1 << 0,
109	XTOPT_MAND   = 1 << 1,
110	XTOPT_MULTI  = 1 << 2,
111	XTOPT_PUT    = 1 << 3,
112	XTOPT_NBO    = 1 << 4,
113};
114
115/**
116 * @name:	name of option
117 * @type:	type of input and validation method, see %XTTYPE_*
118 * @id:		unique number (within extension) for option, 0-31
119 * @excl:	bitmask of flags that cannot be used with this option
120 * @also:	bitmask of flags that must be used with this option
121 * @flags:	bitmask of option flags, see %XTOPT_*
122 * @ptroff:	offset into private structure for member
123 * @size:	size of the item pointed to by @ptroff; this is a safeguard
124 * @min:	lowest allowed value (for singular integral types)
125 * @max:	highest allowed value (for singular integral types)
126 */
127struct xt_option_entry {
128	const char *name;
129	enum xt_option_type type;
130	unsigned int id, excl, also, flags;
131	unsigned int ptroff;
132	size_t size;
133	unsigned int min, max;
134};
135
136/**
137 * @arg:	input from command line
138 * @ext_name:	name of extension currently being processed
139 * @entry:	current option being processed
140 * @data:	per-extension kernel data block
141 * @xflags:	options of the extension that have been used
142 * @invert:	whether option was used with !
143 * @nvals:	number of results in uXX_multi
144 * @val:	parsed result
145 * @udata:	per-extension private scratch area
146 * 		(cf. xtables_{match,target}->udata_size)
147 */
148struct xt_option_call {
149	const char *arg, *ext_name;
150	const struct xt_option_entry *entry;
151	void *data;
152	unsigned int xflags;
153	bool invert;
154	uint8_t nvals;
155	union {
156		uint8_t u8, u8_range[2], syslog_level, protocol;
157		uint16_t u16, u16_range[2], port, port_range[2];
158		uint32_t u32, u32_range[2];
159		uint64_t u64, u64_range[2];
160		double dbl;
161		struct {
162			union nf_inet_addr haddr, hmask;
163			uint8_t hlen;
164		};
165		struct {
166			uint8_t tos_value, tos_mask;
167		};
168		struct {
169			uint32_t mark, mask;
170		};
171		uint8_t ethermac[6];
172	} val;
173	/* Wished for a world where the ones below were gone: */
174	union {
175		struct xt_entry_match **match;
176		struct xt_entry_target **target;
177	};
178	void *xt_entry;
179	void *udata;
180};
181
182/**
183 * @ext_name:	name of extension currently being processed
184 * @data:	per-extension (kernel) data block
185 * @udata:	per-extension private scratch area
186 * 		(cf. xtables_{match,target}->udata_size)
187 * @xflags:	options of the extension that have been used
188 */
189struct xt_fcheck_call {
190	const char *ext_name;
191	void *data, *udata;
192	unsigned int xflags;
193};
194
195/**
196 * A "linear"/linked-list based name<->id map, for files similar to
197 * /etc/iproute2/.
198 */
199struct xtables_lmap {
200	char *name;
201	int id;
202	struct xtables_lmap *next;
203};
204
205/* Include file for additions: new matches and targets. */
206struct xtables_match
207{
208	/*
209	 * ABI/API version this module requires. Must be first member,
210	 * as the rest of this struct may be subject to ABI changes.
211	 */
212	const char *version;
213
214	struct xtables_match *next;
215
216	const char *name;
217
218	/* Revision of match (0 by default). */
219	u_int8_t revision;
220
221	u_int16_t family;
222
223	/* Size of match data. */
224	size_t size;
225
226	/* Size of match data relevent for userspace comparison purposes */
227	size_t userspacesize;
228
229	/* Function which prints out usage message. */
230	void (*help)(void);
231
232	/* Initialize the match. */
233	void (*init)(struct xt_entry_match *m);
234
235	/* Function which parses command options; returns true if it
236           ate an option */
237	/* entry is struct ipt_entry for example */
238	int (*parse)(int c, char **argv, int invert, unsigned int *flags,
239		     const void *entry,
240		     struct xt_entry_match **match);
241
242	/* Final check; exit if not ok. */
243	void (*final_check)(unsigned int flags);
244
245	/* Prints out the match iff non-NULL: put space at end */
246	/* ip is struct ipt_ip * for example */
247	void (*print)(const void *ip,
248		      const struct xt_entry_match *match, int numeric);
249
250	/* Saves the match info in parsable form to stdout. */
251	/* ip is struct ipt_ip * for example */
252	void (*save)(const void *ip, const struct xt_entry_match *match);
253
254	/* Pointer to list of extra command-line options */
255	const struct option *extra_opts;
256
257	/* New parser */
258	void (*x6_parse)(struct xt_option_call *);
259	void (*x6_fcheck)(struct xt_fcheck_call *);
260	const struct xt_option_entry *x6_options;
261
262	/* Size of per-extension instance extra "global" scratch space */
263	size_t udata_size;
264
265	/* Ignore these men behind the curtain: */
266	void *udata;
267	unsigned int option_offset;
268	struct xt_entry_match *m;
269	unsigned int mflags;
270	unsigned int loaded; /* simulate loading so options are merged properly */
271};
272
273struct xtables_target
274{
275	/*
276	 * ABI/API version this module requires. Must be first member,
277	 * as the rest of this struct may be subject to ABI changes.
278	 */
279	const char *version;
280
281	struct xtables_target *next;
282
283
284	const char *name;
285
286	/* Revision of target (0 by default). */
287	u_int8_t revision;
288
289	u_int16_t family;
290
291
292	/* Size of target data. */
293	size_t size;
294
295	/* Size of target data relevent for userspace comparison purposes */
296	size_t userspacesize;
297
298	/* Function which prints out usage message. */
299	void (*help)(void);
300
301	/* Initialize the target. */
302	void (*init)(struct xt_entry_target *t);
303
304	/* Function which parses command options; returns true if it
305           ate an option */
306	/* entry is struct ipt_entry for example */
307	int (*parse)(int c, char **argv, int invert, unsigned int *flags,
308		     const void *entry,
309		     struct xt_entry_target **targetinfo);
310
311	/* Final check; exit if not ok. */
312	void (*final_check)(unsigned int flags);
313
314	/* Prints out the target iff non-NULL: put space at end */
315	void (*print)(const void *ip,
316		      const struct xt_entry_target *target, int numeric);
317
318	/* Saves the targinfo in parsable form to stdout. */
319	void (*save)(const void *ip,
320		     const struct xt_entry_target *target);
321
322	/* Pointer to list of extra command-line options */
323	const struct option *extra_opts;
324
325	/* New parser */
326	void (*x6_parse)(struct xt_option_call *);
327	void (*x6_fcheck)(struct xt_fcheck_call *);
328	const struct xt_option_entry *x6_options;
329
330	size_t udata_size;
331
332	/* Ignore these men behind the curtain: */
333	void *udata;
334	unsigned int option_offset;
335	struct xt_entry_target *t;
336	unsigned int tflags;
337	unsigned int used;
338	unsigned int loaded; /* simulate loading so options are merged properly */
339};
340
341struct xtables_rule_match {
342	struct xtables_rule_match *next;
343	struct xtables_match *match;
344	/* Multiple matches of the same type: the ones before
345	   the current one are completed from parsing point of view */
346	bool completed;
347};
348
349/**
350 * struct xtables_pprot -
351 *
352 * A few hardcoded protocols for 'all' and in case the user has no
353 * /etc/protocols.
354 */
355struct xtables_pprot {
356	const char *name;
357	u_int8_t num;
358};
359
360enum xtables_tryload {
361	XTF_DONT_LOAD,
362	XTF_DURING_LOAD,
363	XTF_TRY_LOAD,
364	XTF_LOAD_MUST_SUCCEED,
365};
366
367enum xtables_exittype {
368	OTHER_PROBLEM = 1,
369	PARAMETER_PROBLEM,
370	VERSION_PROBLEM,
371	RESOURCE_PROBLEM,
372	XTF_ONLY_ONCE,
373	XTF_NO_INVERT,
374	XTF_BAD_VALUE,
375	XTF_ONE_ACTION,
376};
377
378struct xtables_globals
379{
380	unsigned int option_offset;
381	const char *program_name, *program_version;
382	struct option *orig_opts;
383	struct option *opts;
384	void (*exit_err)(enum xtables_exittype status, const char *msg, ...) __attribute__((noreturn, format(printf,2,3)));
385};
386
387#define XT_GETOPT_TABLEEND {.name = NULL, .has_arg = false}
388
389#ifdef __cplusplus
390extern "C" {
391#endif
392
393extern const char *xtables_modprobe_program;
394extern struct xtables_match *xtables_matches;
395extern struct xtables_target *xtables_targets;
396
397extern void xtables_init(void);
398extern void xtables_set_nfproto(uint8_t);
399extern void *xtables_calloc(size_t, size_t);
400extern void *xtables_malloc(size_t);
401extern void *xtables_realloc(void *, size_t);
402
403extern int xtables_insmod(const char *, const char *, bool);
404extern int xtables_load_ko(const char *, bool);
405extern int xtables_set_params(struct xtables_globals *xtp);
406extern void xtables_free_opts(int reset_offset);
407extern struct option *xtables_merge_options(struct option *origopts,
408	struct option *oldopts, const struct option *newopts,
409	unsigned int *option_offset);
410
411extern int xtables_init_all(struct xtables_globals *xtp, uint8_t nfproto);
412extern struct xtables_match *xtables_find_match(const char *name,
413	enum xtables_tryload, struct xtables_rule_match **match);
414extern struct xtables_target *xtables_find_target(const char *name,
415	enum xtables_tryload);
416
417/* Your shared library should call one of these. */
418extern void xtables_register_match(struct xtables_match *me);
419extern void xtables_register_matches(struct xtables_match *, unsigned int);
420extern void xtables_register_target(struct xtables_target *me);
421extern void xtables_register_targets(struct xtables_target *, unsigned int);
422
423extern bool xtables_strtoul(const char *, char **, uintmax_t *,
424	uintmax_t, uintmax_t);
425extern bool xtables_strtoui(const char *, char **, unsigned int *,
426	unsigned int, unsigned int);
427extern int xtables_service_to_port(const char *name, const char *proto);
428extern u_int16_t xtables_parse_port(const char *port, const char *proto);
429extern void
430xtables_parse_interface(const char *arg, char *vianame, unsigned char *mask);
431
432/* this is a special 64bit data type that is 8-byte aligned */
433#define aligned_u64 u_int64_t __attribute__((aligned(8)))
434
435extern struct xtables_globals *xt_params;
436#define xtables_error (xt_params->exit_err)
437
438extern void xtables_param_act(unsigned int, const char *, ...);
439
440extern const char *xtables_ipaddr_to_numeric(const struct in_addr *);
441extern const char *xtables_ipaddr_to_anyname(const struct in_addr *);
442extern const char *xtables_ipmask_to_numeric(const struct in_addr *);
443extern struct in_addr *xtables_numeric_to_ipaddr(const char *);
444extern struct in_addr *xtables_numeric_to_ipmask(const char *);
445extern void xtables_ipparse_any(const char *, struct in_addr **,
446	struct in_addr *, unsigned int *);
447extern void xtables_ipparse_multiple(const char *, struct in_addr **,
448	struct in_addr **, unsigned int *);
449
450extern struct in6_addr *xtables_numeric_to_ip6addr(const char *);
451extern const char *xtables_ip6addr_to_numeric(const struct in6_addr *);
452extern const char *xtables_ip6addr_to_anyname(const struct in6_addr *);
453extern const char *xtables_ip6mask_to_numeric(const struct in6_addr *);
454extern void xtables_ip6parse_any(const char *, struct in6_addr **,
455	struct in6_addr *, unsigned int *);
456extern void xtables_ip6parse_multiple(const char *, struct in6_addr **,
457	struct in6_addr **, unsigned int *);
458
459/**
460 * Print the specified value to standard output, quoting dangerous
461 * characters if required.
462 */
463extern void xtables_save_string(const char *value);
464
465#if defined(ALL_INCLUSIVE) || defined(NO_SHARED_LIBS)
466#	ifdef _INIT
467#		undef _init
468#		define _init _INIT
469#	endif
470	extern void init_extensions(void);
471	extern void init_extensions4(void);
472	extern void init_extensions6(void);
473#else
474#	define _init __attribute__((constructor)) _INIT
475#endif
476
477extern const struct xtables_pprot xtables_chain_protos[];
478extern u_int16_t xtables_parse_protocol(const char *s);
479
480/* xtoptions.c */
481extern void xtables_option_metavalidate(const char *,
482					const struct xt_option_entry *);
483extern struct option *xtables_options_xfrm(struct option *, struct option *,
484					   const struct xt_option_entry *,
485					   unsigned int *);
486extern void xtables_option_parse(struct xt_option_call *);
487extern void xtables_option_tpcall(unsigned int, char **, bool,
488				  struct xtables_target *, void *);
489extern void xtables_option_mpcall(unsigned int, char **, bool,
490				  struct xtables_match *, void *);
491extern void xtables_option_tfcall(struct xtables_target *);
492extern void xtables_option_mfcall(struct xtables_match *);
493extern void xtables_options_fcheck(const char *, unsigned int,
494				   const struct xt_option_entry *);
495
496extern struct xtables_lmap *xtables_lmap_init(const char *);
497extern void xtables_lmap_free(struct xtables_lmap *);
498extern int xtables_lmap_name2id(const struct xtables_lmap *, const char *);
499extern const char *xtables_lmap_id2name(const struct xtables_lmap *, int);
500
501#ifdef XTABLES_INTERNAL
502
503/* Shipped modules rely on this... */
504
505#	ifndef ARRAY_SIZE
506#		define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
507#	endif
508
509extern void _init(void);
510
511#endif
512
513#ifdef __cplusplus
514} /* extern "C" */
515#endif
516
517#endif /* _XTABLES_H */
518