/* * $Id: ebtables.c,v 1.03 2002/01/19 * * Copyright (C) 2001-2002 Bart De Schuymer * * This code is stongly inspired on the iptables code which is * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #ifndef EBTABLES_U_H #define EBTABLES_U_H #include #include #define EXEC_STYLE_PRG 0 #define EXEC_STYLE_DAEMON 1 #ifndef EBT_MIN_ALIGN #define EBT_MIN_ALIGN (__alignof__(struct ebt_entry_target)) #endif #define EBT_ALIGN(s) (((s) + (EBT_MIN_ALIGN-1)) & ~(EBT_MIN_ALIGN-1)) #define ERRORMSG_MAXLEN 128 struct ebt_u_entries { int policy; unsigned int nentries; /* counter offset for this chain */ unsigned int counter_offset; /* used for udc */ unsigned int hook_mask; char *kernel_start; char name[EBT_CHAIN_MAXNAMELEN]; struct ebt_u_entry *entries; }; struct ebt_cntchanges { unsigned short type; unsigned short change; /* determines incremental/decremental/change */ struct ebt_cntchanges *prev; struct ebt_cntchanges *next; }; #define EBT_ORI_MAX_CHAINS 10 struct ebt_u_replace { char name[EBT_TABLE_MAXNAMELEN]; unsigned int valid_hooks; /* nr of rules in the table */ unsigned int nentries; unsigned int num_chains; unsigned int max_chains; struct ebt_u_entries **chains; /* nr of counters userspace expects back */ unsigned int num_counters; /* where the kernel will put the old counters */ struct ebt_counter *counters; /* * can be used e.g. to know if a standard option * has been specified twice */ unsigned int flags; /* we stick the specified command (e.g. -A) in here */ char command; /* * here we stick the chain to do our thing on (can be -1 if unspecified) */ int selected_chain; /* used for the atomic option */ char *filename; /* tells what happened to the old rules (counter changes) */ struct ebt_cntchanges *cc; }; struct ebt_u_table { char name[EBT_TABLE_MAXNAMELEN]; void (*check)(struct ebt_u_replace *repl); void (*help)(const char **); struct ebt_u_table *next; }; struct ebt_u_match_list { struct ebt_u_match_list *next; struct ebt_entry_match *m; }; struct ebt_u_watcher_list { struct ebt_u_watcher_list *next; struct ebt_entry_watcher *w; }; struct ebt_u_entry { unsigned int bitmask; unsigned int invflags; uint16_t ethproto; char in[IFNAMSIZ]; char logical_in[IFNAMSIZ]; char out[IFNAMSIZ]; char logical_out[IFNAMSIZ]; unsigned char sourcemac[ETH_ALEN]; unsigned char sourcemsk[ETH_ALEN]; unsigned char destmac[ETH_ALEN]; unsigned char destmsk[ETH_ALEN]; struct ebt_u_match_list *m_list; struct ebt_u_watcher_list *w_list; struct ebt_entry_target *t; struct ebt_u_entry *prev; struct ebt_u_entry *next; struct ebt_counter cnt; struct ebt_counter cnt_surplus; /* for increasing/decreasing a counter and for option 'C' */ struct ebt_cntchanges *cc; /* the standard target needs this to know the name of a udc when * printing out rules. */ struct ebt_u_replace *replace; }; struct ebt_u_match { char name[EBT_FUNCTION_MAXNAMELEN]; /* size of the real match data */ unsigned int size; void (*help)(void); void (*init)(struct ebt_entry_match *m); int (*parse)(int c, char **argv, int argc, const struct ebt_u_entry *entry, unsigned int *flags, struct ebt_entry_match **match); void (*final_check)(const struct ebt_u_entry *entry, const struct ebt_entry_match *match, const char *name, unsigned int hookmask, unsigned int time); void (*print)(const struct ebt_u_entry *entry, const struct ebt_entry_match *match); int (*compare)(const struct ebt_entry_match *m1, const struct ebt_entry_match *m2); const struct option *extra_ops; /* * can be used e.g. to check for multiple occurance of the same option */ unsigned int flags; unsigned int option_offset; struct ebt_entry_match *m; /* * if used == 1 we no longer have to add it to * the match chain of the new entry * be sure to put it back on 0 when finished */ unsigned int used; struct ebt_u_match *next; }; struct ebt_u_watcher { char name[EBT_FUNCTION_MAXNAMELEN]; unsigned int size; void (*help)(void); void (*init)(struct ebt_entry_watcher *w); int (*parse)(int c, char **argv, int argc, const struct ebt_u_entry *entry, unsigned int *flags, struct ebt_entry_watcher **watcher); void (*final_check)(const struct ebt_u_entry *entry, const struct ebt_entry_watcher *watch, const char *name, unsigned int hookmask, unsigned int time); void (*print)(const struct ebt_u_entry *entry, const struct ebt_entry_watcher *watcher); int (*compare)(const struct ebt_entry_watcher *w1, const struct ebt_entry_watcher *w2); const struct option *extra_ops; unsigned int flags; unsigned int option_offset; struct ebt_entry_watcher *w; unsigned int used; struct ebt_u_watcher *next; }; struct ebt_u_target { char name[EBT_FUNCTION_MAXNAMELEN]; unsigned int size; void (*help)(void); void (*init)(struct ebt_entry_target *t); int (*parse)(int c, char **argv, int argc, const struct ebt_u_entry *entry, unsigned int *flags, struct ebt_entry_target **target); void (*final_check)(const struct ebt_u_entry *entry, const struct ebt_entry_target *target, const char *name, unsigned int hookmask, unsigned int time); void (*print)(const struct ebt_u_entry *entry, const struct ebt_entry_target *target); int (*compare)(const struct ebt_entry_target *t1, const struct ebt_entry_target *t2); const struct option *extra_ops; unsigned int option_offset; unsigned int flags; struct ebt_entry_target *t; unsigned int used; struct ebt_u_target *next; }; /* libebtc.c */ extern struct ebt_u_table *ebt_tables; extern struct ebt_u_match *ebt_matches; extern struct ebt_u_watcher *ebt_watchers; extern struct ebt_u_target *ebt_targets; void ebt_register_table(struct ebt_u_table *); void ebt_register_match(struct ebt_u_match *); void ebt_register_watcher(struct ebt_u_watcher *); void ebt_register_target(struct ebt_u_target *t); int ebt_get_kernel_table(struct ebt_u_replace *replace, int init); struct ebt_u_target *ebt_find_target(const char *name); struct ebt_u_match *ebt_find_match(const char *name); struct ebt_u_watcher *ebt_find_watcher(const char *name); struct ebt_u_table *ebt_find_table(const char *name); int ebtables_insmod(const char *modname); void ebt_list_extensions(); void ebt_initialize_entry(struct ebt_u_entry *e); void ebt_cleanup_replace(struct ebt_u_replace *replace); void ebt_reinit_extensions(); void ebt_double_chains(struct ebt_u_replace *replace); void ebt_free_u_entry(struct ebt_u_entry *e); struct ebt_u_entries *ebt_name_to_chain(const struct ebt_u_replace *replace, const char* arg); struct ebt_u_entries *ebt_name_to_chain(const struct ebt_u_replace *replace, const char* arg); int ebt_get_chainnr(const struct ebt_u_replace *replace, const char* arg); /**/ void ebt_change_policy(struct ebt_u_replace *replace, int policy); void ebt_flush_chains(struct ebt_u_replace *replace); int ebt_check_rule_exists(struct ebt_u_replace *replace, struct ebt_u_entry *new_entry); void ebt_add_rule(struct ebt_u_replace *replace, struct ebt_u_entry *new_entry, int rule_nr); void ebt_delete_rule(struct ebt_u_replace *replace, struct ebt_u_entry *new_entry, int begin, int end); void ebt_zero_counters(struct ebt_u_replace *replace); void ebt_change_counters(struct ebt_u_replace *replace, struct ebt_u_entry *new_entry, int begin, int end, struct ebt_counter *cnt, int mask); void ebt_new_chain(struct ebt_u_replace *replace, const char *name, int policy); void ebt_delete_chain(struct ebt_u_replace *replace); void ebt_rename_chain(struct ebt_u_replace *replace, const char *name); /**/ void ebt_do_final_checks(struct ebt_u_replace *replace, struct ebt_u_entry *e, struct ebt_u_entries *entries); int ebt_check_for_references(struct ebt_u_replace *replace, int print_err); int ebt_check_for_references2(struct ebt_u_replace *replace, int chain_nr, int print_err); void ebt_check_for_loops(struct ebt_u_replace *replace); void ebt_add_match(struct ebt_u_entry *new_entry, struct ebt_u_match *m); void ebt_add_watcher(struct ebt_u_entry *new_entry, struct ebt_u_watcher *w); void ebt_iterate_matches(void (*f)(struct ebt_u_match *)); void ebt_iterate_watchers(void (*f)(struct ebt_u_watcher *)); void ebt_iterate_targets(void (*f)(struct ebt_u_target *)); void __ebt_print_bug(char *file, int line, char *format, ...); void __ebt_print_error(char *format, ...); /* communication.c */ int ebt_get_table(struct ebt_u_replace *repl, int init); void ebt_deliver_counters(struct ebt_u_replace *repl); void ebt_deliver_table(struct ebt_u_replace *repl); /* useful_functions.c */ extern int ebt_invert; void ebt_check_option(unsigned int *flags, unsigned int mask); #define ebt_check_inverse(arg) _ebt_check_inverse(arg, argc, argv) int _ebt_check_inverse(const char option[], int argc, char **argv); void ebt_print_mac(const char *mac); void ebt_print_mac_and_mask(const char *mac, const char *mask); int ebt_get_mac_and_mask(char *from, char *to, char *mask); void ebt_parse_ip_address(char *address, uint32_t *addr, uint32_t *msk); char *ebt_mask_to_dotted(uint32_t mask); int do_command(int argc, char *argv[], int exec_style, struct ebt_u_replace *replace_); struct ethertypeent *parseethertypebynumber(int type); #define ebt_to_chain(repl) \ ({struct ebt_u_entries *_ch = NULL; \ if (repl->selected_chain != -1) \ _ch = repl->chains[repl->selected_chain]; \ _ch;}) #define ebt_print_bug(format, args...) \ __ebt_print_bug(__FILE__, __LINE__, format, ##args) #define ebt_print_error(format,args...) __ebt_print_error(format, ##args); #define ebt_print_error2(format, args...) do {__ebt_print_error(format, ##args); \ return -1;} while (0) #define ebt_check_option2(flags,mask) \ ({ebt_check_option(flags,mask); \ if (ebt_errormsg[0] != '\0') \ return -1;}) #define ebt_check_inverse2(option) \ ({int __ret = ebt_check_inverse(option); \ if (ebt_errormsg[0] != '\0') \ return -1; \ if (!optarg) { \ __ebt_print_error("Option without (mandatory) argument"); \ return -1; \ } \ __ret;}) #define ebt_print_memory() do {printf("Ebtables: " __FILE__ \ " %s %d :Out of memory.\n", __FUNCTION__, __LINE__); exit(-1);} while (0) /* used for keeping the rule counters right during rule adds or deletes */ #define CNT_NORM 0 #define CNT_DEL 1 #define CNT_ADD 2 #define CNT_CHANGE 3 extern const char *ebt_hooknames[NF_BR_NUMHOOKS]; extern const char *ebt_standard_targets[NUM_STANDARD_TARGETS]; extern char ebt_errormsg[ERRORMSG_MAXLEN]; extern char *ebt_modprobe; extern int ebt_silent; extern int ebt_printstyle_mac; /* * Transforms a target string into the right integer, * returns 0 on success. */ #define FILL_TARGET(_str, _pos) ({ \ int _i, _ret = 0; \ for (_i = 0; _i < NUM_STANDARD_TARGETS; _i++) \ if (!strcmp(_str, ebt_standard_targets[_i])) {\ _pos = -_i - 1; \ break; \ } \ if (_i == NUM_STANDARD_TARGETS) \ _ret = 1; \ _ret; \ }) /* Transforms the target value to an index into standard_targets[] */ #define TARGET_INDEX(_value) (-_value - 1) /* Returns a target string corresponding to the value */ #define TARGET_NAME(_value) (ebt_standard_targets[TARGET_INDEX(_value)]) /* True if the hook mask denotes that the rule is in a base chain */ #define BASE_CHAIN (hookmask & (1 << NF_BR_NUMHOOKS)) /* Clear the bit in the hook_mask that tells if the rule is on a base chain */ #define CLEAR_BASE_CHAIN_BIT (hookmask &= ~(1 << NF_BR_NUMHOOKS)) #define PRINT_VERSION printf(PROGNAME" v"PROGVERSION" ("PROGDATE")\n") #ifndef PROC_SYS_MODPROBE #define PROC_SYS_MODPROBE "/proc/sys/kernel/modprobe" #endif #define ATOMIC_ENV_VARIABLE "EBTABLES_ATOMIC_FILE" #endif /* EBTABLES_U_H */