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
33 #define ASSERT(x) do { if (!(x)) { fatal("assertion failed line %d file " \
34 __FILE__,__LINE__); } } while(0)
38 extern char version[];
41 extern uint32_t message_level;
42 extern bool_t secnet_is_daemon;
43 extern struct log_if *system_log;
46 extern void start_signal_handling(void);
48 /***** CONFIGURATION support *****/
50 extern bool_t just_check_config; /* If True then we're going to exit after
51 reading the configuration file */
52 extern bool_t background; /* If True then we'll eventually run as a daemon */
54 typedef struct dict dict_t; /* Configuration dictionary */
55 typedef struct closure closure_t;
56 typedef struct item item_t;
57 typedef struct list list_t; /* A list of items */
59 /* Configuration file location, for error-reporting */
65 /* Modules export closures, which can be invoked from the configuration file.
66 "Invoking" a closure usually returns another closure (of a different
67 type), but can actually return any configuration object. */
68 typedef list_t *(apply_fn)(closure_t *self, struct cloc loc,
69 dict_t *context, list_t *data);
71 cstring_t description; /* For debugging */
72 uint32_t type; /* Central registry... */
74 void *interface; /* Interface for use inside secnet; depends on type */
77 enum types { t_null, t_bool, t_string, t_number, t_dict, t_closure };
90 /* Note that it is unwise to use this structure directly; use the list
91 manipulation functions instead. */
97 /* In the following two lookup functions, NULL means 'not found' */
98 /* Lookup a value in the specified dictionary, or its parents */
99 extern list_t *dict_lookup(dict_t *dict, cstring_t key);
100 /* Lookup a value in just the specified dictionary */
101 extern list_t *dict_lookup_primitive(dict_t *dict, cstring_t key);
102 /* Add a value to the specified dictionary */
103 extern void dict_add(dict_t *dict, cstring_t key, list_t *val);
104 /* Obtain an array of keys in the dictionary. malloced; caller frees */
105 extern cstring_t *dict_keys(dict_t *dict);
107 /* List-manipulation functions */
108 extern list_t *list_new(void);
109 extern int32_t list_length(list_t *a);
110 extern list_t *list_append(list_t *a, item_t *i);
111 extern list_t *list_append_list(list_t *a, list_t *b);
112 /* Returns an item from the list (index starts at 0), or NULL */
113 extern item_t *list_elem(list_t *l, int32_t index);
115 /* Convenience functions */
116 extern list_t *new_closure(closure_t *cl);
117 extern void add_closure(dict_t *dict, cstring_t name, apply_fn apply);
118 extern void *find_cl_if(dict_t *dict, cstring_t name, uint32_t type,
119 bool_t fail_if_invalid, cstring_t desc,
121 extern item_t *dict_find_item(dict_t *dict, cstring_t key, bool_t required,
122 cstring_t desc, struct cloc loc);
123 extern string_t dict_read_string(dict_t *dict, cstring_t key, bool_t required,
124 cstring_t desc, struct cloc loc);
125 extern uint32_t dict_read_number(dict_t *dict, cstring_t key, bool_t required,
126 cstring_t desc, struct cloc loc,
128 /* return value can safely be assigned to int32_t */
129 extern bool_t dict_read_bool(dict_t *dict, cstring_t key, bool_t required,
130 cstring_t desc, struct cloc loc, bool_t def);
135 extern uint32_t string_to_word(cstring_t s, struct cloc loc,
136 struct flagstr *f, cstring_t desc);
137 extern uint32_t string_list_to_word(list_t *l, struct flagstr *f,
140 /***** END of configuration support *****/
142 /***** UTILITY functions *****/
144 extern char *safe_strdup(const char *string, const char *message);
145 extern void *safe_malloc(size_t size, const char *message);
146 extern void *safe_malloc_ary(size_t size, size_t count, const char *message);
148 void setcloexec(int fd); /* cannot fail */
149 void pipe_cloexec(int fd[2]); /* pipe(), setcloexec() twice; cannot fail */
151 extern int sys_cmd(const char *file, const char *argc, ...);
153 extern uint64_t now_global;
154 extern struct timeval tv_now_global;
156 static const uint64_t *const now = &now_global;
157 static const struct timeval *const tv_now = &tv_now_global;
159 /* "now" is current program time, in milliseconds. It is derived
160 from tv_now. Both are provided by the event loop. */
162 /***** END of utility functions *****/
164 /***** START of max_start_pad handling *****/
166 extern int32_t site_max_start_pad, transform_max_start_pad,
169 void update_max_start_pad(int32_t *our_module_global, int32_t our_instance);
170 int32_t calculate_max_start_pad(void);
172 /***** END of max_start_pad handling *****/
174 /***** SCHEDULING support */
176 /* If nfds_io is insufficient for your needs, set it to the required
177 number and return ERANGE. timeout is in milliseconds; if it is too
178 high then lower it. It starts at -1 (==infinite) */
179 typedef int beforepoll_fn(void *st, struct pollfd *fds, int *nfds_io,
181 typedef void afterpoll_fn(void *st, struct pollfd *fds, int nfds);
183 /* Register interest in the main loop of the program. Before a call
184 to poll() your supplied beforepoll function will be called. After
185 the call to poll() the supplied afterpoll function will be called.
186 max_nfds is a _hint_ about the maximum number of struct pollfd
187 structures you may require - you can always ask for more in
189 extern void register_for_poll(void *st, beforepoll_fn *before,
190 afterpoll_fn *after, int32_t max_nfds,
193 /***** END of scheduling support */
195 /***** PROGRAM LIFETIME support */
197 /* The secnet program goes through a number of phases in its lifetime.
198 Module code may arrange to be called just as various phases are
201 Remember to update the table in util.c if changing the set of
206 PHASE_GETOPTS, /* Process command-line arguments */
207 PHASE_READCONFIG, /* Parse and process configuration file */
208 PHASE_SETUP, /* Process information in configuration */
209 PHASE_DAEMONIZE, /* Become a daemon (if necessary) */
210 PHASE_GETRESOURCES, /* Obtain all external resources */
211 PHASE_DROPPRIV, /* Last chance for privileged operations */
213 PHASE_SHUTDOWN, /* About to die; delete key material, etc. */
214 /* Keep this last: */
218 typedef void hook_fn(void *self, uint32_t newphase);
219 bool_t add_hook(uint32_t phase, hook_fn *f, void *state);
220 bool_t remove_hook(uint32_t phase, hook_fn *f, void *state);
222 extern uint32_t current_phase;
223 extern void enter_phase(uint32_t new_phase);
225 /* Some features (like netlink 'soft' routes) require that secnet
226 retain root privileges. They should indicate that here when
228 extern bool_t require_root_privileges;
229 extern cstring_t require_root_privileges_explanation;
231 /***** END of program lifetime support *****/
233 /***** MODULE support *****/
235 /* Module initialisation function type - modules export one function of
236 this type which is called to initialise them. For dynamically loaded
237 modules it's called "secnet_module". */
238 typedef void init_module(dict_t *dict);
240 extern void init_builtin_modules(dict_t *dict);
242 extern init_module resolver_module;
243 extern init_module random_module;
244 extern init_module udp_module;
245 extern init_module util_module;
246 extern init_module site_module;
247 extern init_module transform_eax_module;
248 extern init_module transform_cbcmac_module;
249 extern init_module netlink_module;
250 extern init_module rsa_module;
251 extern init_module dh_module;
252 extern init_module md5_module;
253 extern init_module slip_module;
254 extern init_module tun_module;
255 extern init_module sha1_module;
256 extern init_module log_module;
258 /***** END of module support *****/
260 /***** CLOSURE TYPES and interface definitions *****/
263 #define CL_RESOLVER 1
264 #define CL_RANDOMSRC 2
265 #define CL_RSAPUBKEY 3
266 #define CL_RSAPRIVKEY 4
271 #define CL_TRANSFORM 9
275 #define CL_NETLINK 14
279 /* PURE closure requires no interface */
281 /* RESOLVER interface */
283 /* Answers to queries are delivered to a function of this
284 type. 'address' will be NULL if there was a problem with the query. It
285 will be freed once resolve_answer_fn returns. It is in network byte
287 typedef void resolve_answer_fn(void *st, const struct comm_addr *addrs,
289 typedef bool_t resolve_request_fn(void *st, cstring_t name,
290 int remoteport, struct comm_if *comm,
291 resolve_answer_fn *cb, void *cst);
294 resolve_request_fn *request;
297 /* RANDOMSRC interface */
299 /* Return some random data. Returns TRUE for success. */
300 typedef bool_t random_fn(void *st, int32_t bytes, uint8_t *buff);
308 /* RSAPUBKEY interface */
310 typedef bool_t rsa_checksig_fn(void *st, uint8_t *data, int32_t datalen,
311 cstring_t signature);
312 struct rsapubkey_if {
314 rsa_checksig_fn *check;
317 /* RSAPRIVKEY interface */
319 typedef string_t rsa_makesig_fn(void *st, uint8_t *data, int32_t datalen);
320 struct rsaprivkey_if {
322 rsa_makesig_fn *sign;
328 /* This struct is pure data; in particular comm's clients may
330 /* Everyone is also guaranteed that all padding is set to zero, ie
331 that comm_addrs referring to semantically identical peers will
332 compare equal with memcmp. Anyone who constructs a comm_addr
333 must start by memsetting it with FILLZERO, or some
335 struct comm_if *comm;
336 struct sockaddr_in sin;
339 /* Return True if the packet was processed, and shouldn't be passed to
340 any other potential receivers. */
341 typedef bool_t comm_notify_fn(void *state, struct buffer_if *buf,
342 const struct comm_addr *source);
343 typedef void comm_request_notify_fn(void *commst, void *nst,
345 typedef void comm_release_notify_fn(void *commst, void *nst,
347 typedef bool_t comm_sendmsg_fn(void *commst, struct buffer_if *buf,
348 const struct comm_addr *dest);
349 /* Only returns false if (we know that) the local network
350 * environment is such that this address cannot work; transient
351 * or unknown/unexpected failures return true. */
352 typedef const char *comm_addr_to_string_fn(void *commst,
353 const struct comm_addr *ca);
354 /* Returned string is in a static buffer. */
357 comm_request_notify_fn *request_notify;
358 comm_release_notify_fn *release_notify;
359 comm_sendmsg_fn *sendmsg;
360 comm_addr_to_string_fn *addr_to_string;
363 static inline const char *comm_addr_to_string(const struct comm_addr *ca)
365 return ca->comm->addr_to_string(ca->comm->st, ca);
370 #define LOG_MESSAGE_BUFLEN 1023
372 typedef void log_msg_fn(void *st, int class, const char *message, ...);
373 typedef void log_vmsg_fn(void *st, int class, const char *message,
377 log_vmsg_fn *vlogfn; /* printf format checking. Use [v]slilog instead */
378 char buff[LOG_MESSAGE_BUFLEN+1];
380 /* (convenience functions, defined in util.c) */
381 extern void slilog(struct log_if *lf, int class, const char *message, ...)
383 extern void vslilog(struct log_if *lf, int class, const char *message, va_list)
386 /* Versions which take (parts of) (multiple) messages, using \n to
387 * distinguish one message from another. */
388 extern void slilog_part(struct log_if *lf, int class, const char *message, ...)
390 extern void vslilog_part(struct log_if *lf, int class, const char *message,
391 va_list) FORMAT(printf,3,0);
395 /* Pretty much a placeholder; allows starting and stopping of processing,
397 typedef void site_control_fn(void *st, bool_t run);
398 typedef uint32_t site_status_fn(void *st);
401 site_control_fn *control;
402 site_status_fn *status;
405 /* TRANSFORM interface */
407 /* A reversable transformation. Transforms buffer in-place; may add
408 data to start or end. (Reverse transformations decrease
409 length, of course.) Transformations may be key-dependent, in which
410 case key material is passed in at initialisation time. They may
411 also depend on internal factors (eg. time) and keep internal
412 state. A struct transform_if only represents a particular type of
413 transformation; instances of the transformation (eg. with
414 particular key material) have a different C type. The same
415 secret key will be used in opposite directions between a pair of
416 secnets; one of these pairs will get direction==False, the other True. */
418 typedef struct transform_inst_if *transform_createinstance_fn(void *st);
419 typedef bool_t transform_setkey_fn(void *st, uint8_t *key, int32_t keylen,
421 typedef bool_t transform_valid_fn(void *st); /* 0: no key; 1: ok */
422 typedef void transform_delkey_fn(void *st);
423 typedef void transform_destroyinstance_fn(void *st);
426 * 1: for any other problem
427 * 2: message decrypted but sequence number was out of range
429 typedef uint32_t transform_apply_fn(void *st, struct buffer_if *buf,
430 const char **errmsg);
432 struct transform_inst_if {
434 transform_setkey_fn *setkey;
435 transform_valid_fn *valid;
436 transform_delkey_fn *delkey;
437 transform_apply_fn *forwards;
438 transform_apply_fn *reverse;
439 transform_destroyinstance_fn *destroy;
442 struct transform_if {
444 int capab_transformnum;
445 int32_t keylen; /* <<< INT_MAX */
446 transform_createinstance_fn *create;
449 /* NETLINK interface */
451 /* Used by netlink to deliver to site, and by site to deliver to
452 netlink. cid is the client identifier returned by
453 netlink_regnets_fn. If buf has size 0 then the function is just
454 being called for its site-effects (eg. making the site code attempt
455 to bring up a network link) */
456 typedef void netlink_deliver_fn(void *st, struct buffer_if *buf);
457 /* site code can tell netlink when outgoing packets will be dropped,
458 so netlink can generate appropriate ICMP and make routing decisions */
459 #define LINK_QUALITY_UNUSED 0 /* This link is unused, do not make this netlink */
460 #define LINK_QUALITY_DOWN 1 /* No chance of a packet being delivered right away*/
461 #define LINK_QUALITY_DOWN_STALE_ADDRESS 2 /* Link down, old address information */
462 #define LINK_QUALITY_DOWN_CURRENT_ADDRESS 3 /* Link down, current address information */
463 #define LINK_QUALITY_UP 4 /* Link active */
464 #define MAXIMUM_LINK_QUALITY 3
465 typedef void netlink_link_quality_fn(void *st, uint32_t quality);
466 typedef void netlink_register_fn(void *st, netlink_deliver_fn *deliver,
467 void *dst, uint32_t *localmtu_r /* NULL ok */);
468 typedef void netlink_output_config_fn(void *st, struct buffer_if *buf);
469 typedef bool_t netlink_check_config_fn(void *st, struct buffer_if *buf);
470 typedef void netlink_set_mtu_fn(void *st, int32_t new_mtu);
473 netlink_register_fn *reg;
474 netlink_deliver_fn *deliver;
475 netlink_link_quality_fn *set_quality;
476 netlink_set_mtu_fn *set_mtu;
481 /* Returns public key as a malloced hex string */
482 typedef string_t dh_makepublic_fn(void *st, uint8_t *secret,
484 /* Fills buffer (up to buflen) with shared secret */
485 typedef void dh_makeshared_fn(void *st, uint8_t *secret,
486 int32_t secretlen, cstring_t rempublic,
487 uint8_t *sharedsecret, int32_t buflen);
490 int32_t len; /* Approximate size of modulus in bytes */
491 int32_t ceil_len; /* Number of bytes just sufficient to contain modulus */
492 dh_makepublic_fn *makepublic;
493 dh_makeshared_fn *makeshared;
498 typedef void *hash_init_fn(void);
499 typedef void hash_update_fn(void *st, const void *buf, int32_t len);
500 typedef void hash_final_fn(void *st, uint8_t *digest);
502 int32_t len; /* Hash output length in bytes */
504 hash_update_fn *update;
505 hash_final_fn *final;
508 /* BUFFER interface */
512 cstring_t owner; /* Set to constant string */
513 uint32_t flags; /* How paranoid should we be? */
514 struct cloc loc; /* Where we were defined */
517 int32_t size; /* Size of buffer contents */
518 int32_t alloclen; /* Total length allocated at base */
521 /***** LOG functions *****/
523 #define M_DEBUG_CONFIG 0x001
524 #define M_DEBUG_PHASE 0x002
525 #define M_DEBUG 0x004
527 #define M_NOTICE 0x010
528 #define M_WARNING 0x020
530 #define M_SECURITY 0x080
531 #define M_FATAL 0x100
533 /* The fatal() family of functions require messages that do not end in '\n' */
534 extern NORETURN(fatal(const char *message, ...)) FORMAT(printf,1,2);
535 extern NORETURN(fatal_perror(const char *message, ...)) FORMAT(printf,1,2);
536 extern NORETURN(fatal_status(int status, const char *message, ...))
538 extern NORETURN(fatal_perror_status(int status, const char *message, ...))
541 /* The cfgfatal() family of functions require messages that end in '\n' */
542 extern NORETURN(cfgfatal(struct cloc loc, cstring_t facility,
543 const char *message, ...)) FORMAT(printf,3,4);
544 extern void cfgfile_postreadcheck(struct cloc loc, FILE *f);
545 extern NORETURN(vcfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
546 cstring_t facility, const char *message,
549 extern NORETURN(cfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
551 const char *message, ...))
554 extern void Message(uint32_t class, const char *message, ...)
556 extern void log_from_fd(int fd, cstring_t prefix, struct log_if *log);
558 /***** END of log functions *****/
560 #define STRING2(x) #x
561 #define STRING(x) STRING2(x)
563 #define FILLZERO(obj) (memset(&(obj),0,sizeof((obj))))
566 * void COPY_OBJ( OBJECT& dst, const OBJECT& src);
567 * void COPY_ARRAY(OBJECT *dst, const OBJECT *src, INTEGER count);
568 * // Typesafe: we check that the type OBJECT is the same in both cases.
569 * // It is OK to use COPY_OBJ on an array object, proviced it's
570 * // _actually_ the whole array object and not decayed into a
571 * // pointer (e.g. a formal parameter).
573 #define COPY_OBJ(dst,src) \
574 (&(dst)==&(src), memcpy(&(dst),&(src),sizeof((dst))))
575 #define COPY_ARRAY(dst,src,count) \
576 (&(dst)[0]==&(src)[0], memcpy((dst),(src),sizeof((dst)[0])*(count)))
578 #endif /* secnet_h */