The VisAO Camera
ebtables_u.h
1 /*
2  * $Id: ebtables.c,v 1.03 2002/01/19
3  *
4  * Copyright (C) 2001-2002 Bart De Schuymer
5  *
6  * This code is stongly inspired on the iptables code which is
7  * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation; either version 2 of the
12  * License, or (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22  */
23 
24 #ifndef EBTABLES_U_H
25 #define EBTABLES_U_H
26 #include <netinet/in.h>
27 #include <linux/netfilter_bridge/ebtables.h>
28 #include <linux/netfilter/x_tables.h>
29 
30 #ifndef IPPROTO_SCTP
31 #define IPPROTO_SCTP 132
32 #endif
33 #ifndef IPPROTO_DCCP
34 #define IPPROTO_DCCP 33
35 #endif
36 
37 #define EXEC_STYLE_PRG 0
38 #define EXEC_STYLE_DAEMON 1
39 
40 #ifndef EBT_MIN_ALIGN
41 #define EBT_MIN_ALIGN (__alignof__(struct _xt_align))
42 #endif
43 #define EBT_ALIGN(s) (((s) + (EBT_MIN_ALIGN-1)) & ~(EBT_MIN_ALIGN-1))
44 #define ERRORMSG_MAXLEN 128
45 
46 struct ebt_u_entries
47 {
48  int policy;
49  unsigned int nentries;
50  /* counter offset for this chain */
51  unsigned int counter_offset;
52  /* used for udc */
53  unsigned int hook_mask;
54  char *kernel_start;
55  char name[EBT_CHAIN_MAXNAMELEN];
56  struct ebt_u_entry *entries;
57 };
58 
59 struct ebt_cntchanges
60 {
61  unsigned short type;
62  unsigned short change; /* determines incremental/decremental/change */
63  struct ebt_cntchanges *prev;
64  struct ebt_cntchanges *next;
65 };
66 
67 #define EBT_ORI_MAX_CHAINS 10
68 struct ebt_u_replace
69 {
70  char name[EBT_TABLE_MAXNAMELEN];
71  unsigned int valid_hooks;
72  /* nr of rules in the table */
73  unsigned int nentries;
74  unsigned int num_chains;
75  unsigned int max_chains;
76  struct ebt_u_entries **chains;
77  /* nr of counters userspace expects back */
78  unsigned int num_counters;
79  /* where the kernel will put the old counters */
80  struct ebt_counter *counters;
81  /*
82  * can be used e.g. to know if a standard option
83  * has been specified twice
84  */
85  unsigned int flags;
86  /* we stick the specified command (e.g. -A) in here */
87  char command;
88  /*
89  * here we stick the chain to do our thing on (can be -1 if unspecified)
90  */
91  int selected_chain;
92  /* used for the atomic option */
93  char *filename;
94  /* tells what happened to the old rules (counter changes) */
95  struct ebt_cntchanges *cc;
96 };
97 
98 struct ebt_u_table
99 {
100  char name[EBT_TABLE_MAXNAMELEN];
101  void (*check)(struct ebt_u_replace *repl);
102  void (*help)(const char **);
103  struct ebt_u_table *next;
104 };
105 
106 struct ebt_u_match_list
107 {
108  struct ebt_u_match_list *next;
109  struct ebt_entry_match *m;
110 };
111 
112 struct ebt_u_watcher_list
113 {
114  struct ebt_u_watcher_list *next;
115  struct ebt_entry_watcher *w;
116 };
117 
118 struct ebt_u_entry
119 {
120  unsigned int bitmask;
121  unsigned int invflags;
122  uint16_t ethproto;
123  char in[IFNAMSIZ];
124  char logical_in[IFNAMSIZ];
125  char out[IFNAMSIZ];
126  char logical_out[IFNAMSIZ];
127  unsigned char sourcemac[ETH_ALEN];
128  unsigned char sourcemsk[ETH_ALEN];
129  unsigned char destmac[ETH_ALEN];
130  unsigned char destmsk[ETH_ALEN];
131  struct ebt_u_match_list *m_list;
132  struct ebt_u_watcher_list *w_list;
133  struct ebt_entry_target *t;
134  struct ebt_u_entry *prev;
135  struct ebt_u_entry *next;
136  struct ebt_counter cnt;
137  struct ebt_counter cnt_surplus; /* for increasing/decreasing a counter and for option 'C' */
138  struct ebt_cntchanges *cc;
139  /* the standard target needs this to know the name of a udc when
140  * printing out rules. */
141  struct ebt_u_replace *replace;
142 };
143 
144 struct ebt_u_match
145 {
146  char name[EBT_FUNCTION_MAXNAMELEN];
147  /* size of the real match data */
148  unsigned int size;
149  void (*help)(void);
150  void (*init)(struct ebt_entry_match *m);
151  int (*parse)(int c, char **argv, int argc,
152  const struct ebt_u_entry *entry, unsigned int *flags,
153  struct ebt_entry_match **match);
154  void (*final_check)(const struct ebt_u_entry *entry,
155  const struct ebt_entry_match *match,
156  const char *name, unsigned int hookmask, unsigned int time);
157  void (*print)(const struct ebt_u_entry *entry,
158  const struct ebt_entry_match *match);
159  int (*compare)(const struct ebt_entry_match *m1,
160  const struct ebt_entry_match *m2);
161  const struct option *extra_ops;
162  /*
163  * can be used e.g. to check for multiple occurance of the same option
164  */
165  unsigned int flags;
166  unsigned int option_offset;
167  struct ebt_entry_match *m;
168  /*
169  * if used == 1 we no longer have to add it to
170  * the match chain of the new entry
171  * be sure to put it back on 0 when finished
172  */
173  unsigned int used;
174  struct ebt_u_match *next;
175 };
176 
177 struct ebt_u_watcher
178 {
179  char name[EBT_FUNCTION_MAXNAMELEN];
180  unsigned int size;
181  void (*help)(void);
182  void (*init)(struct ebt_entry_watcher *w);
183  int (*parse)(int c, char **argv, int argc,
184  const struct ebt_u_entry *entry, unsigned int *flags,
185  struct ebt_entry_watcher **watcher);
186  void (*final_check)(const struct ebt_u_entry *entry,
187  const struct ebt_entry_watcher *watch, const char *name,
188  unsigned int hookmask, unsigned int time);
189  void (*print)(const struct ebt_u_entry *entry,
190  const struct ebt_entry_watcher *watcher);
191  int (*compare)(const struct ebt_entry_watcher *w1,
192  const struct ebt_entry_watcher *w2);
193  const struct option *extra_ops;
194  unsigned int flags;
195  unsigned int option_offset;
196  struct ebt_entry_watcher *w;
197  unsigned int used;
198  struct ebt_u_watcher *next;
199 };
200 
201 struct ebt_u_target
202 {
203  char name[EBT_FUNCTION_MAXNAMELEN];
204  unsigned int size;
205  void (*help)(void);
206  void (*init)(struct ebt_entry_target *t);
207  int (*parse)(int c, char **argv, int argc,
208  const struct ebt_u_entry *entry, unsigned int *flags,
209  struct ebt_entry_target **target);
210  void (*final_check)(const struct ebt_u_entry *entry,
211  const struct ebt_entry_target *target, const char *name,
212  unsigned int hookmask, unsigned int time);
213  void (*print)(const struct ebt_u_entry *entry,
214  const struct ebt_entry_target *target);
215  int (*compare)(const struct ebt_entry_target *t1,
216  const struct ebt_entry_target *t2);
217  const struct option *extra_ops;
218  unsigned int option_offset;
219  unsigned int flags;
220  struct ebt_entry_target *t;
221  unsigned int used;
222  struct ebt_u_target *next;
223 };
224 
225 /* libebtc.c */
226 
227 extern struct ebt_u_table *ebt_tables;
228 extern struct ebt_u_match *ebt_matches;
229 extern struct ebt_u_watcher *ebt_watchers;
230 extern struct ebt_u_target *ebt_targets;
231 
232 void ebt_register_table(struct ebt_u_table *);
233 void ebt_register_match(struct ebt_u_match *);
234 void ebt_register_watcher(struct ebt_u_watcher *);
235 void ebt_register_target(struct ebt_u_target *t);
236 int ebt_get_kernel_table(struct ebt_u_replace *replace, int init);
237 struct ebt_u_target *ebt_find_target(const char *name);
238 struct ebt_u_match *ebt_find_match(const char *name);
239 struct ebt_u_watcher *ebt_find_watcher(const char *name);
240 struct ebt_u_table *ebt_find_table(const char *name);
241 int ebtables_insmod(const char *modname);
242 void ebt_list_extensions();
243 void ebt_initialize_entry(struct ebt_u_entry *e);
244 void ebt_cleanup_replace(struct ebt_u_replace *replace);
245 void ebt_reinit_extensions();
246 void ebt_double_chains(struct ebt_u_replace *replace);
247 void ebt_free_u_entry(struct ebt_u_entry *e);
248 struct ebt_u_entries *ebt_name_to_chain(const struct ebt_u_replace *replace,
249  const char* arg);
250 struct ebt_u_entries *ebt_name_to_chain(const struct ebt_u_replace *replace,
251  const char* arg);
252 int ebt_get_chainnr(const struct ebt_u_replace *replace, const char* arg);
253 /**/
254 void ebt_change_policy(struct ebt_u_replace *replace, int policy);
255 void ebt_flush_chains(struct ebt_u_replace *replace);
256 int ebt_check_rule_exists(struct ebt_u_replace *replace,
257  struct ebt_u_entry *new_entry);
258 void ebt_add_rule(struct ebt_u_replace *replace, struct ebt_u_entry *new_entry,
259  int rule_nr);
260 void ebt_delete_rule(struct ebt_u_replace *replace,
261  struct ebt_u_entry *new_entry, int begin, int end);
262 void ebt_zero_counters(struct ebt_u_replace *replace);
263 void ebt_change_counters(struct ebt_u_replace *replace,
264  struct ebt_u_entry *new_entry, int begin, int end,
265  struct ebt_counter *cnt, int mask);
266 void ebt_new_chain(struct ebt_u_replace *replace, const char *name, int policy);
267 void ebt_delete_chain(struct ebt_u_replace *replace);
268 void ebt_rename_chain(struct ebt_u_replace *replace, const char *name);
269 /**/
270 void ebt_do_final_checks(struct ebt_u_replace *replace, struct ebt_u_entry *e,
271  struct ebt_u_entries *entries);
272 int ebt_check_for_references(struct ebt_u_replace *replace, int print_err);
273 int ebt_check_for_references2(struct ebt_u_replace *replace, int chain_nr,
274  int print_err);
275 void ebt_check_for_loops(struct ebt_u_replace *replace);
276 void ebt_add_match(struct ebt_u_entry *new_entry, struct ebt_u_match *m);
277 void ebt_add_watcher(struct ebt_u_entry *new_entry, struct ebt_u_watcher *w);
278 void ebt_iterate_matches(void (*f)(struct ebt_u_match *));
279 void ebt_iterate_watchers(void (*f)(struct ebt_u_watcher *));
280 void ebt_iterate_targets(void (*f)(struct ebt_u_target *));
281 void __ebt_print_bug(char *file, int line, char *format, ...);
282 void __ebt_print_error(char *format, ...);
283 
284 /* communication.c */
285 
286 int ebt_get_table(struct ebt_u_replace *repl, int init);
287 void ebt_deliver_counters(struct ebt_u_replace *repl);
288 void ebt_deliver_table(struct ebt_u_replace *repl);
289 
290 /* useful_functions.c */
291 
292 extern int ebt_invert;
293 void ebt_check_option(unsigned int *flags, unsigned int mask);
294 #define ebt_check_inverse(arg) _ebt_check_inverse(arg, argc, argv)
295 int _ebt_check_inverse(const char option[], int argc, char **argv);
296 void ebt_print_mac(const unsigned char *mac);
297 void ebt_print_mac_and_mask(const unsigned char *mac, const unsigned char *mask);
298 int ebt_get_mac_and_mask(const char *from, unsigned char *to, unsigned char *mask);
299 void ebt_parse_ip_address(char *address, uint32_t *addr, uint32_t *msk);
300 char *ebt_mask_to_dotted(uint32_t mask);
301 void ebt_parse_ip6_address(char *address, struct in6_addr *addr,
302  struct in6_addr *msk);
303 char *ebt_ip6_to_numeric(const struct in6_addr *addrp);
304 
305 
306 int do_command(int argc, char *argv[], int exec_style,
307  struct ebt_u_replace *replace_);
308 
309 struct ethertypeent *parseethertypebynumber(int type);
310 
311 #define ebt_to_chain(repl) \
312 ({struct ebt_u_entries *_ch = NULL; \
313 if (repl->selected_chain != -1) \
314  _ch = repl->chains[repl->selected_chain]; \
315 _ch;})
316 #define ebt_print_bug(format, args...) \
317  __ebt_print_bug(__FILE__, __LINE__, format, ##args)
318 #define ebt_print_error(format,args...) __ebt_print_error(format, ##args);
319 #define ebt_print_error2(format, args...) do {__ebt_print_error(format, ##args); \
320  return -1;} while (0)
321 #define ebt_check_option2(flags,mask) \
322 ({ebt_check_option(flags,mask); \
323  if (ebt_errormsg[0] != '\0') \
324  return -1;})
325 #define ebt_check_inverse2(option) \
326 ({int __ret = ebt_check_inverse(option); \
327 if (ebt_errormsg[0] != '\0') \
328  return -1; \
329 if (!optarg) { \
330  __ebt_print_error("Option without (mandatory) argument"); \
331  return -1; \
332 } \
333 __ret;})
334 #define ebt_print_memory() do {printf("Ebtables: " __FILE__ \
335  " %s %d :Out of memory.\n", __FUNCTION__, __LINE__); exit(-1);} while (0)
336 
337 /* used for keeping the rule counters right during rule adds or deletes */
338 #define CNT_NORM 0
339 #define CNT_DEL 1
340 #define CNT_ADD 2
341 #define CNT_CHANGE 3
342 
343 extern const char *ebt_hooknames[NF_BR_NUMHOOKS];
344 extern const char *ebt_standard_targets[NUM_STANDARD_TARGETS];
345 extern char ebt_errormsg[ERRORMSG_MAXLEN];
346 extern char *ebt_modprobe;
347 extern int ebt_silent;
348 extern int ebt_printstyle_mac;
349 
350 /*
351  * Transforms a target string into the right integer,
352  * returns 0 on success.
353  */
354 #define FILL_TARGET(_str, _pos) ({ \
355  int _i, _ret = 0; \
356  for (_i = 0; _i < NUM_STANDARD_TARGETS; _i++) \
357  if (!strcmp(_str, ebt_standard_targets[_i])) {\
358  _pos = -_i - 1; \
359  break; \
360  } \
361  if (_i == NUM_STANDARD_TARGETS) \
362  _ret = 1; \
363  _ret; \
364 })
365 
366 /* Transforms the target value to an index into standard_targets[] */
367 #define TARGET_INDEX(_value) (-_value - 1)
368 /* Returns a target string corresponding to the value */
369 #define TARGET_NAME(_value) (ebt_standard_targets[TARGET_INDEX(_value)])
370 /* True if the hook mask denotes that the rule is in a base chain */
371 #define BASE_CHAIN (hookmask & (1 << NF_BR_NUMHOOKS))
372 /* Clear the bit in the hook_mask that tells if the rule is on a base chain */
373 #define CLEAR_BASE_CHAIN_BIT (hookmask &= ~(1 << NF_BR_NUMHOOKS))
374 #define PRINT_VERSION printf(PROGNAME" v"PROGVERSION" ("PROGDATE")\n")
375 #ifndef PROC_SYS_MODPROBE
376 #define PROC_SYS_MODPROBE "/proc/sys/kernel/modprobe"
377 #endif
378 #define ATOMIC_ENV_VARIABLE "EBTABLES_ATOMIC_FILE"
379 #endif /* EBTABLES_U_H */
ebt_cntchanges
Definition: ebtables_u.h:59
ebt_u_entry
Definition: ebtables_u.h:118
ebt_u_watcher_list
Definition: ebtables_u.h:112
ebt_u_match_list
Definition: ebtables_u.h:106
ebt_u_table
Definition: ebtables_u.h:98
ebt_u_replace
Definition: ebtables_u.h:68
ebt_u_watcher
Definition: ebtables_u.h:177
ebt_u_target
Definition: ebtables_u.h:201
ebt_u_match
Definition: ebtables_u.h:144
ebt_u_entries
Definition: ebtables_u.h:46