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. naddrs is the actual
286 size of the array at addrs; was_naddrs is the number of addresses
287 actually found in the DNS, which may be bigger if addrs is equal
288 to MAX_PEER_ADDRS (ie there were too many). */
289 typedef void resolve_answer_fn(void *st, const struct comm_addr *addrs,
290 int naddrs, int was_naddrs);
291 typedef bool_t resolve_request_fn(void *st, cstring_t name,
292 int remoteport, struct comm_if *comm,
293 resolve_answer_fn *cb, void *cst);
296 resolve_request_fn *request;
299 /* RANDOMSRC interface */
301 /* Return some random data. Returns TRUE for success. */
302 typedef bool_t random_fn(void *st, int32_t bytes, uint8_t *buff);
310 /* RSAPUBKEY interface */
312 typedef bool_t rsa_checksig_fn(void *st, uint8_t *data, int32_t datalen,
313 cstring_t signature);
314 struct rsapubkey_if {
316 rsa_checksig_fn *check;
319 /* RSAPRIVKEY interface */
321 typedef string_t rsa_makesig_fn(void *st, uint8_t *data, int32_t datalen);
322 struct rsaprivkey_if {
324 rsa_makesig_fn *sign;
330 /* This struct is pure data; in particular comm's clients may
332 /* Everyone is also guaranteed that all padding is set to zero, ie
333 that comm_addrs referring to semantically identical peers will
334 compare equal with memcmp. Anyone who constructs a comm_addr
335 must start by memsetting it with FILLZERO, or some
337 struct comm_if *comm;
338 struct sockaddr_in sin;
341 /* Return True if the packet was processed, and shouldn't be passed to
342 any other potential receivers. */
343 typedef bool_t comm_notify_fn(void *state, struct buffer_if *buf,
344 const struct comm_addr *source);
345 typedef void comm_request_notify_fn(void *commst, void *nst,
347 typedef void comm_release_notify_fn(void *commst, void *nst,
349 typedef bool_t comm_sendmsg_fn(void *commst, struct buffer_if *buf,
350 const struct comm_addr *dest);
351 /* Only returns false if (we know that) the local network
352 * environment is such that this address cannot work; transient
353 * or unknown/unexpected failures return true. */
354 typedef const char *comm_addr_to_string_fn(void *commst,
355 const struct comm_addr *ca);
356 /* Returned string is in a static buffer. */
359 comm_request_notify_fn *request_notify;
360 comm_release_notify_fn *release_notify;
361 comm_sendmsg_fn *sendmsg;
362 comm_addr_to_string_fn *addr_to_string;
365 static inline const char *comm_addr_to_string(const struct comm_addr *ca)
367 return ca->comm->addr_to_string(ca->comm->st, ca);
372 #define LOG_MESSAGE_BUFLEN 1023
374 typedef void log_msg_fn(void *st, int class, const char *message, ...);
375 typedef void log_vmsg_fn(void *st, int class, const char *message,
379 log_vmsg_fn *vlogfn; /* printf format checking. Use [v]slilog instead */
380 char buff[LOG_MESSAGE_BUFLEN+1];
382 /* (convenience functions, defined in util.c) */
383 extern void slilog(struct log_if *lf, int class, const char *message, ...)
385 extern void vslilog(struct log_if *lf, int class, const char *message, va_list)
388 /* Versions which take (parts of) (multiple) messages, using \n to
389 * distinguish one message from another. */
390 extern void slilog_part(struct log_if *lf, int class, const char *message, ...)
392 extern void vslilog_part(struct log_if *lf, int class, const char *message,
393 va_list) FORMAT(printf,3,0);
397 /* Pretty much a placeholder; allows starting and stopping of processing,
399 typedef void site_control_fn(void *st, bool_t run);
400 typedef uint32_t site_status_fn(void *st);
403 site_control_fn *control;
404 site_status_fn *status;
407 /* TRANSFORM interface */
409 /* A reversable transformation. Transforms buffer in-place; may add
410 data to start or end. (Reverse transformations decrease
411 length, of course.) Transformations may be key-dependent, in which
412 case key material is passed in at initialisation time. They may
413 also depend on internal factors (eg. time) and keep internal
414 state. A struct transform_if only represents a particular type of
415 transformation; instances of the transformation (eg. with
416 particular key material) have a different C type. The same
417 secret key will be used in opposite directions between a pair of
418 secnets; one of these pairs will get direction==False, the other True. */
420 typedef struct transform_inst_if *transform_createinstance_fn(void *st);
421 typedef bool_t transform_setkey_fn(void *st, uint8_t *key, int32_t keylen,
423 typedef bool_t transform_valid_fn(void *st); /* 0: no key; 1: ok */
424 typedef void transform_delkey_fn(void *st);
425 typedef void transform_destroyinstance_fn(void *st);
428 * 1: for any other problem
429 * 2: message decrypted but sequence number was out of range
431 typedef uint32_t transform_apply_fn(void *st, struct buffer_if *buf,
432 const char **errmsg);
434 struct transform_inst_if {
436 transform_setkey_fn *setkey;
437 transform_valid_fn *valid;
438 transform_delkey_fn *delkey;
439 transform_apply_fn *forwards;
440 transform_apply_fn *reverse;
441 transform_destroyinstance_fn *destroy;
444 struct transform_if {
446 int capab_transformnum;
447 int32_t keylen; /* <<< INT_MAX */
448 transform_createinstance_fn *create;
451 /* NETLINK interface */
453 /* Used by netlink to deliver to site, and by site to deliver to
454 netlink. cid is the client identifier returned by
455 netlink_regnets_fn. If buf has size 0 then the function is just
456 being called for its site-effects (eg. making the site code attempt
457 to bring up a network link) */
458 typedef void netlink_deliver_fn(void *st, struct buffer_if *buf);
459 /* site code can tell netlink when outgoing packets will be dropped,
460 so netlink can generate appropriate ICMP and make routing decisions */
461 #define LINK_QUALITY_UNUSED 0 /* This link is unused, do not make this netlink */
462 #define LINK_QUALITY_DOWN 1 /* No chance of a packet being delivered right away*/
463 #define LINK_QUALITY_DOWN_STALE_ADDRESS 2 /* Link down, old address information */
464 #define LINK_QUALITY_DOWN_CURRENT_ADDRESS 3 /* Link down, current address information */
465 #define LINK_QUALITY_UP 4 /* Link active */
466 #define MAXIMUM_LINK_QUALITY 3
467 typedef void netlink_link_quality_fn(void *st, uint32_t quality);
468 typedef void netlink_register_fn(void *st, netlink_deliver_fn *deliver,
469 void *dst, uint32_t *localmtu_r /* NULL ok */);
470 typedef void netlink_output_config_fn(void *st, struct buffer_if *buf);
471 typedef bool_t netlink_check_config_fn(void *st, struct buffer_if *buf);
472 typedef void netlink_set_mtu_fn(void *st, int32_t new_mtu);
475 netlink_register_fn *reg;
476 netlink_deliver_fn *deliver;
477 netlink_link_quality_fn *set_quality;
478 netlink_set_mtu_fn *set_mtu;
483 /* Returns public key as a malloced hex string */
484 typedef string_t dh_makepublic_fn(void *st, uint8_t *secret,
486 /* Fills buffer (up to buflen) with shared secret */
487 typedef void dh_makeshared_fn(void *st, uint8_t *secret,
488 int32_t secretlen, cstring_t rempublic,
489 uint8_t *sharedsecret, int32_t buflen);
492 int32_t len; /* Approximate size of modulus in bytes */
493 int32_t ceil_len; /* Number of bytes just sufficient to contain modulus */
494 dh_makepublic_fn *makepublic;
495 dh_makeshared_fn *makeshared;
500 typedef void *hash_init_fn(void);
501 typedef void hash_update_fn(void *st, const void *buf, int32_t len);
502 typedef void hash_final_fn(void *st, uint8_t *digest);
504 int32_t len; /* Hash output length in bytes */
506 hash_update_fn *update;
507 hash_final_fn *final;
510 /* BUFFER interface */
514 cstring_t owner; /* Set to constant string */
515 uint32_t flags; /* How paranoid should we be? */
516 struct cloc loc; /* Where we were defined */
519 int32_t size; /* Size of buffer contents */
520 int32_t alloclen; /* Total length allocated at base */
523 /***** LOG functions *****/
525 #define M_DEBUG_CONFIG 0x001
526 #define M_DEBUG_PHASE 0x002
527 #define M_DEBUG 0x004
529 #define M_NOTICE 0x010
530 #define M_WARNING 0x020
532 #define M_SECURITY 0x080
533 #define M_FATAL 0x100
535 /* The fatal() family of functions require messages that do not end in '\n' */
536 extern NORETURN(fatal(const char *message, ...)) FORMAT(printf,1,2);
537 extern NORETURN(fatal_perror(const char *message, ...)) FORMAT(printf,1,2);
538 extern NORETURN(fatal_status(int status, const char *message, ...))
540 extern NORETURN(fatal_perror_status(int status, const char *message, ...))
543 /* The cfgfatal() family of functions require messages that end in '\n' */
544 extern NORETURN(cfgfatal(struct cloc loc, cstring_t facility,
545 const char *message, ...)) FORMAT(printf,3,4);
546 extern void cfgfile_postreadcheck(struct cloc loc, FILE *f);
547 extern NORETURN(vcfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
548 cstring_t facility, const char *message,
551 extern NORETURN(cfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
553 const char *message, ...))
556 extern void Message(uint32_t class, const char *message, ...)
558 extern void log_from_fd(int fd, cstring_t prefix, struct log_if *log);
560 /***** END of log functions *****/
562 #define STRING2(x) #x
563 #define STRING(x) STRING2(x)
565 #define FILLZERO(obj) (memset(&(obj),0,sizeof((obj))))
568 * void COPY_OBJ( OBJECT& dst, const OBJECT& src);
569 * void COPY_ARRAY(OBJECT *dst, const OBJECT *src, INTEGER count);
570 * // Typesafe: we check that the type OBJECT is the same in both cases.
571 * // It is OK to use COPY_OBJ on an array object, provided it's
572 * // _actually_ the whole array object and not decayed into a
573 * // pointer (e.g. a formal parameter).
575 #define COPY_OBJ(dst,src) \
576 (&(dst)==&(src), memcpy(&(dst),&(src),sizeof((dst))))
577 #define COPY_ARRAY(dst,src,count) \
578 (&(dst)[0]==&(src)[0], memcpy((dst),(src),sizeof((dst)[0])*(count)))
580 #endif /* secnet_h */