1 /* Core interface of secnet, to be used by all modules */
6 #define ADNS_FEATURE_MANYAF
18 #include <sys/types.h>
21 #include <netinet/in.h>
22 #include <arpa/inet.h>
24 #include <bsd/sys/queue.h>
26 #define MAX_PEER_ADDRS 5
27 /* send at most this many copies; honour at most that many addresses */
32 typedef char *string_t;
33 typedef const char *cstring_t;
35 #define False (_Bool)0
41 struct sockaddr_in sin;
43 struct sockaddr_in6 sin6;
47 #define ASSERT(x) do { if (!(x)) { fatal("assertion failed line %d file " \
48 __FILE__,__LINE__); } } while(0)
52 extern char version[];
55 extern uint32_t message_level;
56 extern bool_t secnet_is_daemon;
57 extern struct log_if *system_log;
60 extern void start_signal_handling(void);
63 /* Must be called before exec in every child made after
64 start_signal_handling. Safe to call in earlier children too. */
66 /***** CONFIGURATION support *****/
68 extern bool_t just_check_config; /* If True then we're going to exit after
69 reading the configuration file */
70 extern bool_t background; /* If True then we'll eventually run as a daemon */
72 typedef struct dict dict_t; /* Configuration dictionary */
73 typedef struct closure closure_t;
74 typedef struct item item_t;
75 typedef struct list list_t; /* A list of items */
77 /* Configuration file location, for error-reporting */
83 /* Modules export closures, which can be invoked from the configuration file.
84 "Invoking" a closure usually returns another closure (of a different
85 type), but can actually return any configuration object. */
86 typedef list_t *(apply_fn)(closure_t *self, struct cloc loc,
87 dict_t *context, list_t *data);
89 cstring_t description; /* For debugging */
90 uint32_t type; /* Central registry... */
92 void *interface; /* Interface for use inside secnet; depends on type */
95 enum types { t_null, t_bool, t_string, t_number, t_dict, t_closure };
108 /* Note that it is unwise to use this structure directly; use the list
109 manipulation functions instead. */
115 /* In the following two lookup functions, NULL means 'not found' */
116 /* Lookup a value in the specified dictionary, or its parents */
117 extern list_t *dict_lookup(dict_t *dict, cstring_t key);
118 /* Lookup a value in just the specified dictionary */
119 extern list_t *dict_lookup_primitive(dict_t *dict, cstring_t key);
120 /* Add a value to the specified dictionary */
121 extern void dict_add(dict_t *dict, cstring_t key, list_t *val);
122 /* Obtain an array of keys in the dictionary. malloced; caller frees */
123 extern cstring_t *dict_keys(dict_t *dict);
125 /* List-manipulation functions */
126 extern list_t *list_new(void);
127 extern int32_t list_length(const list_t *a);
128 extern list_t *list_append(list_t *a, item_t *i);
129 extern list_t *list_append_list(list_t *a, list_t *b);
130 /* Returns an item from the list (index starts at 0), or NULL */
131 extern item_t *list_elem(list_t *l, int32_t index);
133 /* Convenience functions */
134 extern list_t *new_closure(closure_t *cl);
135 extern void add_closure(dict_t *dict, cstring_t name, apply_fn apply);
136 extern void *find_cl_if(dict_t *dict, cstring_t name, uint32_t type,
137 bool_t fail_if_invalid, cstring_t desc,
139 extern item_t *dict_find_item(dict_t *dict, cstring_t key, bool_t required,
140 cstring_t desc, struct cloc loc);
141 extern string_t dict_read_string(dict_t *dict, cstring_t key, bool_t required,
142 cstring_t desc, struct cloc loc);
143 extern uint32_t dict_read_number(dict_t *dict, cstring_t key, bool_t required,
144 cstring_t desc, struct cloc loc,
146 /* return value can safely be assigned to int32_t */
147 extern bool_t dict_read_bool(dict_t *dict, cstring_t key, bool_t required,
148 cstring_t desc, struct cloc loc, bool_t def);
149 const char **dict_read_string_array(dict_t *dict, cstring_t key,
150 bool_t required, cstring_t desc,
151 struct cloc loc, const char *const *def);
152 /* Return value is a NULL-terminated array obtained from malloc;
153 * Individual string values are still owned by config file machinery
154 * and must not be modified or freed. Returns NULL if key not
161 extern uint32_t string_to_word(cstring_t s, struct cloc loc,
162 struct flagstr *f, cstring_t desc);
163 extern uint32_t string_list_to_word(list_t *l, struct flagstr *f,
166 /***** END of configuration support *****/
168 /***** UTILITY functions *****/
170 extern char *safe_strdup(const char *string, const char *message);
171 extern void *safe_malloc(size_t size, const char *message);
172 extern void *safe_malloc_ary(size_t size, size_t count, const char *message);
173 extern void *safe_realloc_ary(void *p, size_t size, size_t count,
174 const char *message);
176 void setcloexec(int fd); /* cannot fail */
177 void setnonblock(int fd); /* cannot fail */
178 void pipe_cloexec(int fd[2]); /* pipe(), setcloexec() twice; cannot fail */
180 extern int sys_cmd(const char *file, const char *argc, ...);
182 extern uint64_t now_global;
183 extern struct timeval tv_now_global;
185 static const uint64_t *const now = &now_global;
186 static const struct timeval *const tv_now = &tv_now_global;
188 /* "now" is current program time, in milliseconds. It is derived
189 from tv_now. Both are provided by the event loop. */
191 /***** END of utility functions *****/
193 /***** START of max_start_pad handling *****/
195 extern int32_t site_max_start_pad, transform_max_start_pad,
198 void update_max_start_pad(int32_t *our_module_global, int32_t our_instance);
199 int32_t calculate_max_start_pad(void);
201 /***** END of max_start_pad handling *****/
203 /***** SCHEDULING support */
205 /* If nfds_io is insufficient for your needs, set it to the required
206 number and return ERANGE. timeout is in milliseconds; if it is too
207 high then lower it. It starts at -1 (==infinite). */
208 /* Note that beforepoll_fn may NOT do anything which might change the
209 fds or timeouts wanted by other registered poll loop loopers.
210 Callers should make sure of this by not making any calls into other
211 modules from the beforepoll_fn; the easiest way to ensure this is
212 for beforepoll_fn to only retreive information and not take any
215 typedef int beforepoll_fn(void *st, struct pollfd *fds, int *nfds_io,
217 typedef void afterpoll_fn(void *st, struct pollfd *fds, int nfds);
218 /* If beforepoll_fn returned ERANGE, afterpoll_fn gets nfds==0.
219 afterpoll_fn never gets !!(fds[].revents & POLLNVAL) - such
220 a report is detected as a fatal error by the event loop. */
222 /* void BEFOREPOLL_WANT_FDS(int want);
223 * Expects: int *nfds_io;
224 * Can perform non-local exit.
225 * Checks whether there is space for want fds. If so, sets *nfds_io.
226 * If not, sets *nfds_io and returns. */
227 #define BEFOREPOLL_WANT_FDS(want) do{ \
228 if (*nfds_io<(want)) { *nfds_io=(want); return ERANGE; } \
232 /* Register interest in the main loop of the program. Before a call
233 to poll() your supplied beforepoll function will be called. After
234 the call to poll() the supplied afterpoll function will be called. */
235 struct poll_interest *register_for_poll(void *st, beforepoll_fn *before,
236 afterpoll_fn *after, cstring_t desc);
237 void deregister_for_poll(struct poll_interest *i);
239 /***** END of scheduling support */
241 /***** PROGRAM LIFETIME support */
243 /* The secnet program goes through a number of phases in its lifetime.
244 Module code may arrange to be called just as various phases are
247 Remember to update the table in util.c if changing the set of
252 PHASE_GETOPTS, /* Process command-line arguments */
253 PHASE_READCONFIG, /* Parse and process configuration file */
254 PHASE_SETUP, /* Process information in configuration */
255 PHASE_DAEMONIZE, /* Become a daemon (if necessary) */
256 PHASE_GETRESOURCES, /* Obtain all external resources */
257 PHASE_DROPPRIV, /* Last chance for privileged operations */
259 PHASE_SHUTDOWN, /* About to die; delete key material, etc. */
260 /* Keep this last: */
264 typedef void hook_fn(void *self, uint32_t newphase);
265 bool_t add_hook(uint32_t phase, hook_fn *f, void *state);
266 bool_t remove_hook(uint32_t phase, hook_fn *f, void *state);
268 extern uint32_t current_phase;
269 extern void enter_phase(uint32_t new_phase);
271 /* Some features (like netlink 'soft' routes) require that secnet
272 retain root privileges. They should indicate that here when
274 extern bool_t require_root_privileges;
275 extern cstring_t require_root_privileges_explanation;
277 /***** END of program lifetime support *****/
279 /***** MODULE support *****/
281 /* Module initialisation function type - modules export one function of
282 this type which is called to initialise them. For dynamically loaded
283 modules it's called "secnet_module". */
284 typedef void init_module(dict_t *dict);
286 extern void init_builtin_modules(dict_t *dict);
288 extern init_module resolver_module;
289 extern init_module random_module;
290 extern init_module udp_module;
291 extern init_module util_module;
292 extern init_module site_module;
293 extern init_module transform_eax_module;
294 extern init_module transform_cbcmac_module;
295 extern init_module netlink_module;
296 extern init_module rsa_module;
297 extern init_module dh_module;
298 extern init_module md5_module;
299 extern init_module slip_module;
300 extern init_module tun_module;
301 extern init_module sha1_module;
302 extern init_module log_module;
304 /***** END of module support *****/
306 /***** CLOSURE TYPES and interface definitions *****/
309 #define CL_RESOLVER 1
310 #define CL_RANDOMSRC 2
311 #define CL_RSAPUBKEY 3
312 #define CL_RSAPRIVKEY 4
317 #define CL_TRANSFORM 9
321 #define CL_NETLINK 14
325 /* PURE closure requires no interface */
327 /* RESOLVER interface */
329 /* Answers to queries are delivered to a function of this
330 type. 'address' will be NULL if there was a problem with the query. It
331 will be freed once resolve_answer_fn returns. naddrs is the actual
332 size of the array at addrs; was_naddrs is the number of addresses
333 actually found in the DNS, which may be bigger if addrs is equal
334 to MAX_PEER_ADDRS (ie there were too many). */
335 typedef void resolve_answer_fn(void *st, const struct comm_addr *addrs,
336 int naddrs, int was_naddrs,
337 const char *name, const char *failwhy);
338 /* name is the same ptr as passed to request, so its lifetime must
340 typedef bool_t resolve_request_fn(void *st, cstring_t name,
341 int remoteport, struct comm_if *comm,
342 resolve_answer_fn *cb, void *cst);
345 resolve_request_fn *request;
348 /* RANDOMSRC interface */
350 /* Return some random data. Returns TRUE for success. */
351 typedef bool_t random_fn(void *st, int32_t bytes, uint8_t *buff);
359 /* RSAPUBKEY interface */
361 typedef bool_t rsa_checksig_fn(void *st, uint8_t *data, int32_t datalen,
362 cstring_t signature);
363 struct rsapubkey_if {
365 rsa_checksig_fn *check;
368 /* RSAPRIVKEY interface */
370 typedef string_t rsa_makesig_fn(void *st, uint8_t *data, int32_t datalen);
371 struct rsaprivkey_if {
373 rsa_makesig_fn *sign;
379 /* This struct is pure data; in particular comm's clients may
381 struct comm_if *comm;
383 int ix; /* see comment `Re comm_addr.ix' in udp.c */
386 /* Return True if the packet was processed, and shouldn't be passed to
387 any other potential receivers. (buf is freed iff True returned.) */
388 typedef bool_t comm_notify_fn(void *state, struct buffer_if *buf,
389 const struct comm_addr *source);
390 typedef void comm_request_notify_fn(void *commst, void *nst,
392 typedef void comm_release_notify_fn(void *commst, void *nst,
394 typedef bool_t comm_sendmsg_fn(void *commst, struct buffer_if *buf,
395 const struct comm_addr *dest);
396 /* Only returns false if (we know that) the local network
397 * environment is such that this address cannot work; transient
398 * or unknown/unexpected failures return true. */
399 typedef const char *comm_addr_to_string_fn(void *commst,
400 const struct comm_addr *ca);
401 /* Returned string is in a static buffer. */
404 comm_request_notify_fn *request_notify;
405 comm_release_notify_fn *release_notify;
406 comm_sendmsg_fn *sendmsg;
407 comm_addr_to_string_fn *addr_to_string;
410 bool_t iaddr_equal(const union iaddr *ia, const union iaddr *ib);
412 static inline const char *comm_addr_to_string(const struct comm_addr *ca)
414 return ca->comm->addr_to_string(ca->comm->st, ca);
417 static inline bool_t comm_addr_equal(const struct comm_addr *a,
418 const struct comm_addr *b)
420 return a->comm==b->comm && iaddr_equal(&a->ia,&b->ia);
425 #define LOG_MESSAGE_BUFLEN 1023
427 typedef void log_msg_fn(void *st, int class, const char *message, ...);
428 typedef void log_vmsg_fn(void *st, int class, const char *message,
432 log_vmsg_fn *vlogfn; /* printf format checking. Use [v]slilog instead */
433 char buff[LOG_MESSAGE_BUFLEN+1];
435 /* (convenience functions, defined in util.c) */
436 extern void slilog(struct log_if *lf, int class, const char *message, ...)
438 extern void vslilog(struct log_if *lf, int class, const char *message, va_list)
441 /* Versions which take (parts of) (multiple) messages, using \n to
442 * distinguish one message from another. */
443 extern void slilog_part(struct log_if *lf, int class, const char *message, ...)
445 extern void vslilog_part(struct log_if *lf, int class, const char *message,
446 va_list) FORMAT(printf,3,0);
450 /* Pretty much a placeholder; allows starting and stopping of processing,
452 typedef void site_control_fn(void *st, bool_t run);
453 typedef uint32_t site_status_fn(void *st);
456 site_control_fn *control;
457 site_status_fn *status;
460 /* TRANSFORM interface */
462 /* A reversable transformation. Transforms buffer in-place; may add
463 data to start or end. (Reverse transformations decrease
464 length, of course.) Transformations may be key-dependent, in which
465 case key material is passed in at initialisation time. They may
466 also depend on internal factors (eg. time) and keep internal
467 state. A struct transform_if only represents a particular type of
468 transformation; instances of the transformation (eg. with
469 particular key material) have a different C type. The same
470 secret key will be used in opposite directions between a pair of
471 secnets; one of these pairs will get direction==False, the other True. */
473 typedef struct transform_inst_if *transform_createinstance_fn(void *st);
474 typedef bool_t transform_setkey_fn(void *st, uint8_t *key, int32_t keylen,
476 typedef bool_t transform_valid_fn(void *st); /* 0: no key; 1: ok */
477 typedef void transform_delkey_fn(void *st);
478 typedef void transform_destroyinstance_fn(void *st);
481 * 1: for any other problem
482 * 2: message decrypted but sequence number was out of range
484 typedef uint32_t transform_apply_fn(void *st, struct buffer_if *buf,
485 const char **errmsg);
487 struct transform_inst_if {
489 transform_setkey_fn *setkey;
490 transform_valid_fn *valid;
491 transform_delkey_fn *delkey;
492 transform_apply_fn *forwards;
493 transform_apply_fn *reverse;
494 transform_destroyinstance_fn *destroy;
497 struct transform_if {
499 int capab_transformnum;
500 int32_t keylen; /* <<< INT_MAX */
501 transform_createinstance_fn *create;
504 /* NETLINK interface */
506 /* Used by netlink to deliver to site, and by site to deliver to
507 netlink. cid is the client identifier returned by
508 netlink_regnets_fn. If buf has size 0 then the function is just
509 being called for its site-effects (eg. making the site code attempt
510 to bring up a network link) */
511 typedef void netlink_deliver_fn(void *st, struct buffer_if *buf);
512 /* site code can tell netlink when outgoing packets will be dropped,
513 so netlink can generate appropriate ICMP and make routing decisions */
514 #define LINK_QUALITY_UNUSED 0 /* This link is unused, do not make this netlink */
515 #define LINK_QUALITY_DOWN 1 /* No chance of a packet being delivered right away*/
516 #define LINK_QUALITY_DOWN_STALE_ADDRESS 2 /* Link down, old address information */
517 #define LINK_QUALITY_DOWN_CURRENT_ADDRESS 3 /* Link down, current address information */
518 #define LINK_QUALITY_UP 4 /* Link active */
519 #define MAXIMUM_LINK_QUALITY 3
520 typedef void netlink_link_quality_fn(void *st, uint32_t quality);
521 typedef void netlink_register_fn(void *st, netlink_deliver_fn *deliver,
522 void *dst, uint32_t *localmtu_r /* NULL ok */);
523 typedef void netlink_output_config_fn(void *st, struct buffer_if *buf);
524 typedef bool_t netlink_check_config_fn(void *st, struct buffer_if *buf);
525 typedef void netlink_set_mtu_fn(void *st, int32_t new_mtu);
528 netlink_register_fn *reg;
529 netlink_deliver_fn *deliver;
530 netlink_link_quality_fn *set_quality;
531 netlink_set_mtu_fn *set_mtu;
536 /* Returns public key as a malloced hex string */
537 typedef string_t dh_makepublic_fn(void *st, uint8_t *secret,
539 /* Fills buffer (up to buflen) with shared secret */
540 typedef void dh_makeshared_fn(void *st, uint8_t *secret,
541 int32_t secretlen, cstring_t rempublic,
542 uint8_t *sharedsecret, int32_t buflen);
545 int32_t len; /* Approximate size of modulus in bytes */
546 int32_t ceil_len; /* Number of bytes just sufficient to contain modulus */
547 dh_makepublic_fn *makepublic;
548 dh_makeshared_fn *makeshared;
553 typedef void *hash_init_fn(void);
554 typedef void hash_update_fn(void *st, const void *buf, int32_t len);
555 typedef void hash_final_fn(void *st, uint8_t *digest);
557 int32_t len; /* Hash output length in bytes */
559 hash_update_fn *update;
560 hash_final_fn *final;
563 /* BUFFER interface */
567 cstring_t owner; /* Set to constant string */
568 uint32_t flags; /* How paranoid should we be? */
569 struct cloc loc; /* Where we were defined */
572 int32_t size; /* Size of buffer contents */
573 int32_t alloclen; /* Total length allocated at base */
576 /***** LOG functions *****/
578 #define M_DEBUG_CONFIG 0x001
579 #define M_DEBUG_PHASE 0x002
580 #define M_DEBUG 0x004
582 #define M_NOTICE 0x010
583 #define M_WARNING 0x020
585 #define M_SECURITY 0x080
586 #define M_FATAL 0x100
588 /* The fatal() family of functions require messages that do not end in '\n' */
589 extern NORETURN(fatal(const char *message, ...)) FORMAT(printf,1,2);
590 extern NORETURN(fatal_perror(const char *message, ...)) FORMAT(printf,1,2);
591 extern NORETURN(fatal_status(int status, const char *message, ...))
593 extern NORETURN(fatal_perror_status(int status, const char *message, ...))
596 /* Convenient nonfatal logging. Requires message that does not end in '\n'.
597 * If class contains M_FATAL, exits (after entering PHASE_SHUTDOWN).
598 * lg, errnoval and loc may sensibly be 0. desc must NOT be 0.
599 * lg_[v]perror save and restore errno. */
600 void lg_vperror(struct log_if *lg, const char *desc, struct cloc *loc,
601 int class, int errnoval, const char *fmt, va_list al)
603 void lg_perror(struct log_if *lg, const char *desc, struct cloc *loc,
604 int class, int errnoval, const char *fmt, ...)
606 void lg_exitstatus(struct log_if *lg, const char *desc, struct cloc *loc,
607 int class, int status, const char *progname);
609 /* The cfgfatal() family of functions require messages that end in '\n' */
610 extern NORETURN(cfgfatal(struct cloc loc, cstring_t facility,
611 const char *message, ...)) FORMAT(printf,3,4);
612 extern void cfgfile_postreadcheck(struct cloc loc, FILE *f);
613 extern NORETURN(vcfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
614 cstring_t facility, const char *message,
617 extern NORETURN(cfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
619 const char *message, ...))
622 extern void Message(uint32_t class, const char *message, ...)
624 extern void log_from_fd(int fd, cstring_t prefix, struct log_if *log);
626 /***** END of log functions *****/
628 #define STRING2(x) #x
629 #define STRING(x) STRING2(x)
631 #define FILLZERO(obj) (memset(&(obj),0,sizeof((obj))))
632 #define ARRAY_SIZE(ary) (sizeof((ary))/sizeof((ary)[0]))
635 * void COPY_OBJ( OBJECT& dst, const OBJECT& src);
636 * void COPY_ARRAY(OBJECT *dst, const OBJECT *src, INTEGER count);
637 * // Typesafe: we check that the type OBJECT is the same in both cases.
638 * // It is OK to use COPY_OBJ on an array object, provided it's
639 * // _actually_ the whole array object and not decayed into a
640 * // pointer (e.g. a formal parameter).
642 #define COPY_OBJ(dst,src) \
643 (&(dst)==&(src), memcpy(&(dst),&(src),sizeof((dst))))
644 #define COPY_ARRAY(dst,src,count) \
645 (&(dst)[0]==&(src)[0], memcpy((dst),(src),sizeof((dst)[0])*(count)))
647 #endif /* secnet_h */