1 /* Core interface of secnet, to be used by all modules */
15 #include <sys/types.h>
17 #include <netinet/in.h>
18 #include <arpa/inet.h>
20 #define MAX_PEER_ADDRS 5
21 /* send at most this many copies; honour at most that many addresses */
26 typedef char *string_t;
27 typedef const char *cstring_t;
29 #define False (_Bool)0
35 struct sockaddr_in sin;
37 struct sockaddr_in6 sin6;
41 #define ASSERT(x) do { if (!(x)) { fatal("assertion failed line %d file " \
42 __FILE__,__LINE__); } } while(0)
46 extern char version[];
49 extern uint32_t message_level;
50 extern bool_t secnet_is_daemon;
51 extern struct log_if *system_log;
54 extern void start_signal_handling(void);
56 /***** CONFIGURATION support *****/
58 extern bool_t just_check_config; /* If True then we're going to exit after
59 reading the configuration file */
60 extern bool_t background; /* If True then we'll eventually run as a daemon */
62 typedef struct dict dict_t; /* Configuration dictionary */
63 typedef struct closure closure_t;
64 typedef struct item item_t;
65 typedef struct list list_t; /* A list of items */
67 /* Configuration file location, for error-reporting */
73 /* Modules export closures, which can be invoked from the configuration file.
74 "Invoking" a closure usually returns another closure (of a different
75 type), but can actually return any configuration object. */
76 typedef list_t *(apply_fn)(closure_t *self, struct cloc loc,
77 dict_t *context, list_t *data);
79 cstring_t description; /* For debugging */
80 uint32_t type; /* Central registry... */
82 void *interface; /* Interface for use inside secnet; depends on type */
85 enum types { t_null, t_bool, t_string, t_number, t_dict, t_closure };
98 /* Note that it is unwise to use this structure directly; use the list
99 manipulation functions instead. */
105 /* In the following two lookup functions, NULL means 'not found' */
106 /* Lookup a value in the specified dictionary, or its parents */
107 extern list_t *dict_lookup(dict_t *dict, cstring_t key);
108 /* Lookup a value in just the specified dictionary */
109 extern list_t *dict_lookup_primitive(dict_t *dict, cstring_t key);
110 /* Add a value to the specified dictionary */
111 extern void dict_add(dict_t *dict, cstring_t key, list_t *val);
112 /* Obtain an array of keys in the dictionary. malloced; caller frees */
113 extern cstring_t *dict_keys(dict_t *dict);
115 /* List-manipulation functions */
116 extern list_t *list_new(void);
117 extern int32_t list_length(list_t *a);
118 extern list_t *list_append(list_t *a, item_t *i);
119 extern list_t *list_append_list(list_t *a, list_t *b);
120 /* Returns an item from the list (index starts at 0), or NULL */
121 extern item_t *list_elem(list_t *l, int32_t index);
123 /* Convenience functions */
124 extern list_t *new_closure(closure_t *cl);
125 extern void add_closure(dict_t *dict, cstring_t name, apply_fn apply);
126 extern void *find_cl_if(dict_t *dict, cstring_t name, uint32_t type,
127 bool_t fail_if_invalid, cstring_t desc,
129 extern item_t *dict_find_item(dict_t *dict, cstring_t key, bool_t required,
130 cstring_t desc, struct cloc loc);
131 extern string_t dict_read_string(dict_t *dict, cstring_t key, bool_t required,
132 cstring_t desc, struct cloc loc);
133 extern uint32_t dict_read_number(dict_t *dict, cstring_t key, bool_t required,
134 cstring_t desc, struct cloc loc,
136 /* return value can safely be assigned to int32_t */
137 extern bool_t dict_read_bool(dict_t *dict, cstring_t key, bool_t required,
138 cstring_t desc, struct cloc loc, bool_t def);
143 extern uint32_t string_to_word(cstring_t s, struct cloc loc,
144 struct flagstr *f, cstring_t desc);
145 extern uint32_t string_list_to_word(list_t *l, struct flagstr *f,
148 /***** END of configuration support *****/
150 /***** UTILITY functions *****/
152 extern char *safe_strdup(const char *string, const char *message);
153 extern void *safe_malloc(size_t size, const char *message);
154 extern void *safe_malloc_ary(size_t size, size_t count, const char *message);
156 void setcloexec(int fd); /* cannot fail */
157 void pipe_cloexec(int fd[2]); /* pipe(), setcloexec() twice; cannot fail */
159 extern int sys_cmd(const char *file, const char *argc, ...);
161 extern uint64_t now_global;
162 extern struct timeval tv_now_global;
164 static const uint64_t *const now = &now_global;
165 static const struct timeval *const tv_now = &tv_now_global;
167 /* "now" is current program time, in milliseconds. It is derived
168 from tv_now. Both are provided by the event loop. */
170 /***** END of utility functions *****/
172 /***** START of max_start_pad handling *****/
174 extern int32_t site_max_start_pad, transform_max_start_pad,
177 void update_max_start_pad(int32_t *our_module_global, int32_t our_instance);
178 int32_t calculate_max_start_pad(void);
180 /***** END of max_start_pad handling *****/
182 /***** SCHEDULING support */
184 /* If nfds_io is insufficient for your needs, set it to the required
185 number and return ERANGE. timeout is in milliseconds; if it is too
186 high then lower it. It starts at -1 (==infinite) */
187 typedef int beforepoll_fn(void *st, struct pollfd *fds, int *nfds_io,
189 typedef void afterpoll_fn(void *st, struct pollfd *fds, int nfds);
191 /* Register interest in the main loop of the program. Before a call
192 to poll() your supplied beforepoll function will be called. After
193 the call to poll() the supplied afterpoll function will be called.
194 max_nfds is a _hint_ about the maximum number of struct pollfd
195 structures you may require - you can always ask for more in
197 extern void register_for_poll(void *st, beforepoll_fn *before,
198 afterpoll_fn *after, int32_t max_nfds,
201 /***** END of scheduling support */
203 /***** PROGRAM LIFETIME support */
205 /* The secnet program goes through a number of phases in its lifetime.
206 Module code may arrange to be called just as various phases are
209 Remember to update the table in util.c if changing the set of
214 PHASE_GETOPTS, /* Process command-line arguments */
215 PHASE_READCONFIG, /* Parse and process configuration file */
216 PHASE_SETUP, /* Process information in configuration */
217 PHASE_DAEMONIZE, /* Become a daemon (if necessary) */
218 PHASE_GETRESOURCES, /* Obtain all external resources */
219 PHASE_DROPPRIV, /* Last chance for privileged operations */
221 PHASE_SHUTDOWN, /* About to die; delete key material, etc. */
222 /* Keep this last: */
226 typedef void hook_fn(void *self, uint32_t newphase);
227 bool_t add_hook(uint32_t phase, hook_fn *f, void *state);
228 bool_t remove_hook(uint32_t phase, hook_fn *f, void *state);
230 extern uint32_t current_phase;
231 extern void enter_phase(uint32_t new_phase);
233 /* Some features (like netlink 'soft' routes) require that secnet
234 retain root privileges. They should indicate that here when
236 extern bool_t require_root_privileges;
237 extern cstring_t require_root_privileges_explanation;
239 /***** END of program lifetime support *****/
241 /***** MODULE support *****/
243 /* Module initialisation function type - modules export one function of
244 this type which is called to initialise them. For dynamically loaded
245 modules it's called "secnet_module". */
246 typedef void init_module(dict_t *dict);
248 extern void init_builtin_modules(dict_t *dict);
250 extern init_module resolver_module;
251 extern init_module random_module;
252 extern init_module udp_module;
253 extern init_module util_module;
254 extern init_module site_module;
255 extern init_module transform_eax_module;
256 extern init_module transform_cbcmac_module;
257 extern init_module netlink_module;
258 extern init_module rsa_module;
259 extern init_module dh_module;
260 extern init_module md5_module;
261 extern init_module slip_module;
262 extern init_module tun_module;
263 extern init_module sha1_module;
264 extern init_module log_module;
266 /***** END of module support *****/
268 /***** CLOSURE TYPES and interface definitions *****/
271 #define CL_RESOLVER 1
272 #define CL_RANDOMSRC 2
273 #define CL_RSAPUBKEY 3
274 #define CL_RSAPRIVKEY 4
279 #define CL_TRANSFORM 9
283 #define CL_NETLINK 14
287 /* PURE closure requires no interface */
289 /* RESOLVER interface */
291 /* Answers to queries are delivered to a function of this
292 type. 'address' will be NULL if there was a problem with the query. It
293 will be freed once resolve_answer_fn returns. It is in network byte
295 typedef void resolve_answer_fn(void *st, const struct comm_addr *addrs,
297 typedef bool_t resolve_request_fn(void *st, cstring_t name,
298 int remoteport, struct comm_if *comm,
299 resolve_answer_fn *cb, void *cst);
302 resolve_request_fn *request;
305 /* RANDOMSRC interface */
307 /* Return some random data. Returns TRUE for success. */
308 typedef bool_t random_fn(void *st, int32_t bytes, uint8_t *buff);
316 /* RSAPUBKEY interface */
318 typedef bool_t rsa_checksig_fn(void *st, uint8_t *data, int32_t datalen,
319 cstring_t signature);
320 struct rsapubkey_if {
322 rsa_checksig_fn *check;
325 /* RSAPRIVKEY interface */
327 typedef string_t rsa_makesig_fn(void *st, uint8_t *data, int32_t datalen);
328 struct rsaprivkey_if {
330 rsa_makesig_fn *sign;
336 /* This struct is pure data; in particular comm's clients may
338 /* Everyone is also guaranteed that all padding is set to zero, ie
339 that comm_addrs referring to semantically identical peers will
340 compare equal with memcmp. Anyone who constructs a comm_addr
341 must start by memsetting it with FILLZERO, or some
343 struct comm_if *comm;
347 /* Return True if the packet was processed, and shouldn't be passed to
348 any other potential receivers. */
349 typedef bool_t comm_notify_fn(void *state, struct buffer_if *buf,
350 const struct comm_addr *source);
351 typedef void comm_request_notify_fn(void *commst, void *nst,
353 typedef void comm_release_notify_fn(void *commst, void *nst,
355 typedef bool_t comm_sendmsg_fn(void *commst, struct buffer_if *buf,
356 const struct comm_addr *dest);
357 /* Only returns false if (we know that) the local network
358 * environment is such that this address cannot work; transient
359 * or unknown/unexpected failures return true. */
360 typedef const char *comm_addr_to_string_fn(void *commst,
361 const struct comm_addr *ca);
362 /* Returned string is in a static buffer. */
365 comm_request_notify_fn *request_notify;
366 comm_release_notify_fn *release_notify;
367 comm_sendmsg_fn *sendmsg;
368 comm_addr_to_string_fn *addr_to_string;
371 static inline const char *comm_addr_to_string(const struct comm_addr *ca)
373 return ca->comm->addr_to_string(ca->comm->st, ca);
378 #define LOG_MESSAGE_BUFLEN 1023
380 typedef void log_msg_fn(void *st, int class, const char *message, ...);
381 typedef void log_vmsg_fn(void *st, int class, const char *message,
385 log_vmsg_fn *vlogfn; /* printf format checking. Use [v]slilog instead */
386 char buff[LOG_MESSAGE_BUFLEN+1];
388 /* (convenience functions, defined in util.c) */
389 extern void slilog(struct log_if *lf, int class, const char *message, ...)
391 extern void vslilog(struct log_if *lf, int class, const char *message, va_list)
394 /* Versions which take (parts of) (multiple) messages, using \n to
395 * distinguish one message from another. */
396 extern void slilog_part(struct log_if *lf, int class, const char *message, ...)
398 extern void vslilog_part(struct log_if *lf, int class, const char *message,
399 va_list) FORMAT(printf,3,0);
403 /* Pretty much a placeholder; allows starting and stopping of processing,
405 typedef void site_control_fn(void *st, bool_t run);
406 typedef uint32_t site_status_fn(void *st);
409 site_control_fn *control;
410 site_status_fn *status;
413 /* TRANSFORM interface */
415 /* A reversable transformation. Transforms buffer in-place; may add
416 data to start or end. (Reverse transformations decrease
417 length, of course.) Transformations may be key-dependent, in which
418 case key material is passed in at initialisation time. They may
419 also depend on internal factors (eg. time) and keep internal
420 state. A struct transform_if only represents a particular type of
421 transformation; instances of the transformation (eg. with
422 particular key material) have a different C type. The same
423 secret key will be used in opposite directions between a pair of
424 secnets; one of these pairs will get direction==False, the other True. */
426 typedef struct transform_inst_if *transform_createinstance_fn(void *st);
427 typedef bool_t transform_setkey_fn(void *st, uint8_t *key, int32_t keylen,
429 typedef bool_t transform_valid_fn(void *st); /* 0: no key; 1: ok */
430 typedef void transform_delkey_fn(void *st);
431 typedef void transform_destroyinstance_fn(void *st);
434 * 1: for any other problem
435 * 2: message decrypted but sequence number was out of range
437 typedef uint32_t transform_apply_fn(void *st, struct buffer_if *buf,
438 const char **errmsg);
440 struct transform_inst_if {
442 transform_setkey_fn *setkey;
443 transform_valid_fn *valid;
444 transform_delkey_fn *delkey;
445 transform_apply_fn *forwards;
446 transform_apply_fn *reverse;
447 transform_destroyinstance_fn *destroy;
450 struct transform_if {
452 int capab_transformnum;
453 int32_t keylen; /* <<< INT_MAX */
454 transform_createinstance_fn *create;
457 /* NETLINK interface */
459 /* Used by netlink to deliver to site, and by site to deliver to
460 netlink. cid is the client identifier returned by
461 netlink_regnets_fn. If buf has size 0 then the function is just
462 being called for its site-effects (eg. making the site code attempt
463 to bring up a network link) */
464 typedef void netlink_deliver_fn(void *st, struct buffer_if *buf);
465 /* site code can tell netlink when outgoing packets will be dropped,
466 so netlink can generate appropriate ICMP and make routing decisions */
467 #define LINK_QUALITY_UNUSED 0 /* This link is unused, do not make this netlink */
468 #define LINK_QUALITY_DOWN 1 /* No chance of a packet being delivered right away*/
469 #define LINK_QUALITY_DOWN_STALE_ADDRESS 2 /* Link down, old address information */
470 #define LINK_QUALITY_DOWN_CURRENT_ADDRESS 3 /* Link down, current address information */
471 #define LINK_QUALITY_UP 4 /* Link active */
472 #define MAXIMUM_LINK_QUALITY 3
473 typedef void netlink_link_quality_fn(void *st, uint32_t quality);
474 typedef void netlink_register_fn(void *st, netlink_deliver_fn *deliver,
475 void *dst, uint32_t *localmtu_r /* NULL ok */);
476 typedef void netlink_output_config_fn(void *st, struct buffer_if *buf);
477 typedef bool_t netlink_check_config_fn(void *st, struct buffer_if *buf);
478 typedef void netlink_set_mtu_fn(void *st, int32_t new_mtu);
481 netlink_register_fn *reg;
482 netlink_deliver_fn *deliver;
483 netlink_link_quality_fn *set_quality;
484 netlink_set_mtu_fn *set_mtu;
489 /* Returns public key as a malloced hex string */
490 typedef string_t dh_makepublic_fn(void *st, uint8_t *secret,
492 /* Fills buffer (up to buflen) with shared secret */
493 typedef void dh_makeshared_fn(void *st, uint8_t *secret,
494 int32_t secretlen, cstring_t rempublic,
495 uint8_t *sharedsecret, int32_t buflen);
498 int32_t len; /* Approximate size of modulus in bytes */
499 int32_t ceil_len; /* Number of bytes just sufficient to contain modulus */
500 dh_makepublic_fn *makepublic;
501 dh_makeshared_fn *makeshared;
506 typedef void *hash_init_fn(void);
507 typedef void hash_update_fn(void *st, const void *buf, int32_t len);
508 typedef void hash_final_fn(void *st, uint8_t *digest);
510 int32_t len; /* Hash output length in bytes */
512 hash_update_fn *update;
513 hash_final_fn *final;
516 /* BUFFER interface */
520 cstring_t owner; /* Set to constant string */
521 uint32_t flags; /* How paranoid should we be? */
522 struct cloc loc; /* Where we were defined */
525 int32_t size; /* Size of buffer contents */
526 int32_t alloclen; /* Total length allocated at base */
529 /***** LOG functions *****/
531 #define M_DEBUG_CONFIG 0x001
532 #define M_DEBUG_PHASE 0x002
533 #define M_DEBUG 0x004
535 #define M_NOTICE 0x010
536 #define M_WARNING 0x020
538 #define M_SECURITY 0x080
539 #define M_FATAL 0x100
541 /* The fatal() family of functions require messages that do not end in '\n' */
542 extern NORETURN(fatal(const char *message, ...)) FORMAT(printf,1,2);
543 extern NORETURN(fatal_perror(const char *message, ...)) FORMAT(printf,1,2);
544 extern NORETURN(fatal_status(int status, const char *message, ...))
546 extern NORETURN(fatal_perror_status(int status, const char *message, ...))
549 /* The cfgfatal() family of functions require messages that end in '\n' */
550 extern NORETURN(cfgfatal(struct cloc loc, cstring_t facility,
551 const char *message, ...)) FORMAT(printf,3,4);
552 extern void cfgfile_postreadcheck(struct cloc loc, FILE *f);
553 extern NORETURN(vcfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
554 cstring_t facility, const char *message,
557 extern NORETURN(cfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
559 const char *message, ...))
562 extern void Message(uint32_t class, const char *message, ...)
564 extern void log_from_fd(int fd, cstring_t prefix, struct log_if *log);
566 /***** END of log functions *****/
568 #define STRING2(x) #x
569 #define STRING(x) STRING2(x)
571 #define FILLZERO(obj) (memset(&(obj),0,sizeof((obj))))
573 #endif /* secnet_h */