1 /* Core interface of secnet, to be used by all modules */
6 #define ADNS_FEATURE_MANYAF
19 #include <sys/types.h>
22 #include <netinet/in.h>
23 #include <arpa/inet.h>
25 #include <bsd/sys/queue.h>
27 #define MAX_PEER_ADDRS 5
28 /* send at most this many copies; honour at most that many addresses */
33 typedef char *string_t;
34 typedef const char *cstring_t;
36 #define False (_Bool)0
42 struct sockaddr_in sin;
44 struct sockaddr_in6 sin6;
48 #define ASSERT(x) do { if (!(x)) { fatal("assertion failed line %d file " \
49 __FILE__,__LINE__); } } while(0)
53 extern char version[];
56 extern uint32_t message_level;
57 extern bool_t secnet_is_daemon;
58 extern struct log_if *system_log;
61 extern void start_signal_handling(void);
64 /* Must be called before exec in every child made after
65 start_signal_handling. Safe to call in earlier children too. */
67 void childpersist_closefd_hook(void *fd_p, uint32_t newphase);
68 /* Convenience hook function for use with add_hook PHASE_CHILDPERSIST.
69 With `int fd' in your state struct, pass fd_p=&fd. The hook checks
70 whether fd>=0, so you can use it for an fd which is only sometimes
71 open. This function will set fd to -1, so it is idempotent. */
73 /***** CONFIGURATION support *****/
75 extern bool_t just_check_config; /* If True then we're going to exit after
76 reading the configuration file */
77 extern bool_t background; /* If True then we'll eventually run as a daemon */
79 typedef struct dict dict_t; /* Configuration dictionary */
80 typedef struct closure closure_t;
81 typedef struct item item_t;
82 typedef struct list list_t; /* A list of items */
84 /* Configuration file location, for error-reporting */
90 /* Modules export closures, which can be invoked from the configuration file.
91 "Invoking" a closure usually returns another closure (of a different
92 type), but can actually return any configuration object. */
93 typedef list_t *(apply_fn)(closure_t *self, struct cloc loc,
94 dict_t *context, list_t *data);
96 cstring_t description; /* For debugging */
97 uint32_t type; /* Central registry... */
99 void *interface; /* Interface for use inside secnet; depends on type */
102 enum types { t_null, t_bool, t_string, t_number, t_dict, t_closure };
115 /* Note that it is unwise to use this structure directly; use the list
116 manipulation functions instead. */
122 /* In the following two lookup functions, NULL means 'not found' */
123 /* Lookup a value in the specified dictionary, or its parents */
124 extern list_t *dict_lookup(dict_t *dict, cstring_t key);
125 /* Lookup a value in just the specified dictionary */
126 extern list_t *dict_lookup_primitive(dict_t *dict, cstring_t key);
127 /* Add a value to the specified dictionary */
128 extern void dict_add(dict_t *dict, cstring_t key, list_t *val);
129 /* Obtain an array of keys in the dictionary. malloced; caller frees */
130 extern cstring_t *dict_keys(dict_t *dict);
132 /* List-manipulation functions */
133 extern list_t *list_new(void);
134 extern int32_t list_length(const list_t *a);
135 extern list_t *list_append(list_t *a, item_t *i);
136 extern list_t *list_append_list(list_t *a, list_t *b);
137 /* Returns an item from the list (index starts at 0), or NULL */
138 extern item_t *list_elem(list_t *l, int32_t index);
140 /* Convenience functions */
141 extern list_t *new_closure(closure_t *cl);
142 extern void add_closure(dict_t *dict, cstring_t name, apply_fn apply);
143 extern void *find_cl_if(dict_t *dict, cstring_t name, uint32_t type,
144 bool_t fail_if_invalid, cstring_t desc,
146 extern item_t *dict_find_item(dict_t *dict, cstring_t key, bool_t required,
147 cstring_t desc, struct cloc loc);
148 extern string_t dict_read_string(dict_t *dict, cstring_t key, bool_t required,
149 cstring_t desc, struct cloc loc);
150 extern uint32_t dict_read_number(dict_t *dict, cstring_t key, bool_t required,
151 cstring_t desc, struct cloc loc,
153 /* return value can safely be assigned to int32_t */
154 extern bool_t dict_read_bool(dict_t *dict, cstring_t key, bool_t required,
155 cstring_t desc, struct cloc loc, bool_t def);
156 const char **dict_read_string_array(dict_t *dict, cstring_t key,
157 bool_t required, cstring_t desc,
158 struct cloc loc, const char *const *def);
159 /* Return value is a NULL-terminated array obtained from malloc;
160 * Individual string values are still owned by config file machinery
161 * and must not be modified or freed. Returns NULL if key not
168 extern uint32_t string_to_word(cstring_t s, struct cloc loc,
169 struct flagstr *f, cstring_t desc);
170 extern uint32_t string_list_to_word(list_t *l, struct flagstr *f,
173 /***** END of configuration support *****/
175 /***** UTILITY functions *****/
177 extern char *safe_strdup(const char *string, const char *message);
178 extern void *safe_malloc(size_t size, const char *message);
179 extern void *safe_malloc_ary(size_t size, size_t count, const char *message);
180 extern void *safe_realloc_ary(void *p, size_t size, size_t count,
181 const char *message);
183 void setcloexec(int fd); /* cannot fail */
184 void setnonblock(int fd); /* cannot fail */
185 void pipe_cloexec(int fd[2]); /* pipe(), setcloexec() twice; cannot fail */
187 extern int sys_cmd(const char *file, const char *argc, ...);
189 extern uint64_t now_global;
190 extern struct timeval tv_now_global;
192 static const uint64_t *const now = &now_global;
193 static const struct timeval *const tv_now = &tv_now_global;
195 /* "now" is current program time, in milliseconds. It is derived
196 from tv_now. Both are provided by the event loop. */
198 /***** END of utility functions *****/
200 /***** START of max_start_pad handling *****/
202 extern int32_t site_max_start_pad, transform_max_start_pad,
205 void update_max_start_pad(int32_t *our_module_global, int32_t our_instance);
206 int32_t calculate_max_start_pad(void);
208 /***** END of max_start_pad handling *****/
210 /***** SCHEDULING support */
212 /* If nfds_io is insufficient for your needs, set it to the required
213 number and return ERANGE. timeout is in milliseconds; if it is too
214 high then lower it. It starts at -1 (==infinite). */
215 /* Note that beforepoll_fn may NOT do anything which might change the
216 fds or timeouts wanted by other registered poll loop loopers.
217 Callers should make sure of this by not making any calls into other
218 modules from the beforepoll_fn; the easiest way to ensure this is
219 for beforepoll_fn to only retreive information and not take any
222 typedef int beforepoll_fn(void *st, struct pollfd *fds, int *nfds_io,
224 typedef void afterpoll_fn(void *st, struct pollfd *fds, int nfds);
226 /* void BEFOREPOLL_WANT_FDS(int want);
227 * Expects: int *nfds_io;
228 * Can perform non-local exit.
229 * Checks whether there is space for want fds. If so, sets *nfds_io.
230 * If not, sets *nfds_io and returns. */
231 #define BEFOREPOLL_WANT_FDS(want) do{ \
232 if (*nfds_io<(want)) { *nfds_io=(want); return ERANGE; } \
236 /* Register interest in the main loop of the program. Before a call
237 to poll() your supplied beforepoll function will be called. After
238 the call to poll() the supplied afterpoll function will be called. */
239 struct poll_interest *register_for_poll(void *st, beforepoll_fn *before,
240 afterpoll_fn *after, cstring_t desc);
241 void deregister_for_poll(struct poll_interest *i);
243 /***** END of scheduling support */
245 /***** PROGRAM LIFETIME support */
247 /* The secnet program goes through a number of phases in its lifetime.
248 Module code may arrange to be called just as various phases are
251 Remember to update the table in util.c if changing the set of
256 PHASE_GETOPTS, /* Process command-line arguments */
257 PHASE_READCONFIG, /* Parse and process configuration file */
258 PHASE_SETUP, /* Process information in configuration */
259 PHASE_DAEMONIZE, /* Become a daemon (if necessary) */
260 PHASE_GETRESOURCES, /* Obtain all external resources */
261 PHASE_DROPPRIV, /* Last chance for privileged operations */
263 PHASE_SHUTDOWN, /* About to die; delete key material, etc. */
264 PHASE_CHILDPERSIST, /* Forked long-term child: close fds, etc. */
265 /* Keep this last: */
269 /* Each module should, in its CHILDPERSIST hooks, close all fds which
270 constitute ownership of important operating system resources, or
271 which are used for IPC with other processes who want to get the
272 usual disconnection effects if the main secnet process dies.
273 CHILDPERSIST hooks are not run if the child is going to exec;
274 so fds such as described above should be CLOEXEC too. */
276 typedef void hook_fn(void *self, uint32_t newphase);
277 bool_t add_hook(uint32_t phase, hook_fn *f, void *state);
278 bool_t remove_hook(uint32_t phase, hook_fn *f, void *state);
280 extern uint32_t current_phase;
281 extern void enter_phase(uint32_t new_phase);
283 void phase_hooks_init(void); /* for main() only */
284 void clear_phase_hooks(uint32_t phase); /* for afterfork() */
286 /* Some features (like netlink 'soft' routes) require that secnet
287 retain root privileges. They should indicate that here when
289 extern bool_t require_root_privileges;
290 extern cstring_t require_root_privileges_explanation;
292 /* Some modules may want to know whether secnet is going to drop
293 privilege, so that they know whether to do privsep. Call only
294 in phases SETUP and later. */
295 bool_t will_droppriv(void);
297 /***** END of program lifetime support *****/
299 /***** MODULE support *****/
301 /* Module initialisation function type - modules export one function of
302 this type which is called to initialise them. For dynamically loaded
303 modules it's called "secnet_module". */
304 typedef void init_module(dict_t *dict);
306 extern void init_builtin_modules(dict_t *dict);
308 extern init_module resolver_module;
309 extern init_module random_module;
310 extern init_module udp_module;
311 extern init_module polypath_module;
312 extern init_module util_module;
313 extern init_module site_module;
314 extern init_module transform_eax_module;
315 extern init_module transform_cbcmac_module;
316 extern init_module netlink_module;
317 extern init_module rsa_module;
318 extern init_module dh_module;
319 extern init_module md5_module;
320 extern init_module slip_module;
321 extern init_module tun_module;
322 extern init_module sha1_module;
323 extern init_module log_module;
325 /***** END of module support *****/
327 /***** CLOSURE TYPES and interface definitions *****/
330 #define CL_RESOLVER 1
331 #define CL_RANDOMSRC 2
332 #define CL_RSAPUBKEY 3
333 #define CL_RSAPRIVKEY 4
338 #define CL_TRANSFORM 9
342 #define CL_NETLINK 14
346 /* PURE closure requires no interface */
348 /* RESOLVER interface */
350 /* Answers to queries are delivered to a function of this
351 type. 'address' will be NULL if there was a problem with the query. It
352 will be freed once resolve_answer_fn returns. It is in network byte
354 typedef void resolve_answer_fn(void *st, const struct comm_addr *addrs,
355 int naddrs, const char *name,
356 const char *failwhy);
357 /* name is the same ptr as passed to request, so its lifetime must
359 typedef bool_t resolve_request_fn(void *st, cstring_t name,
360 int remoteport, struct comm_if *comm,
361 resolve_answer_fn *cb, void *cst);
364 resolve_request_fn *request;
367 /* RANDOMSRC interface */
369 /* Return some random data. Returns TRUE for success. */
370 typedef bool_t random_fn(void *st, int32_t bytes, uint8_t *buff);
378 /* RSAPUBKEY interface */
380 typedef bool_t rsa_checksig_fn(void *st, uint8_t *data, int32_t datalen,
381 cstring_t signature);
382 struct rsapubkey_if {
384 rsa_checksig_fn *check;
387 /* RSAPRIVKEY interface */
389 typedef string_t rsa_makesig_fn(void *st, uint8_t *data, int32_t datalen);
390 struct rsaprivkey_if {
392 rsa_makesig_fn *sign;
398 /* This struct is pure data; in particular comm's clients may
400 /* Everyone is also guaranteed that all padding is set to zero, ie
401 that comm_addrs referring to semantically identical peers will
402 compare equal with memcmp. Anyone who constructs a comm_addr
403 must start by memsetting it with FILLZERO, or some
405 struct comm_if *comm;
410 /* Return True if the packet was processed, and shouldn't be passed to
411 any other potential receivers. (buf is freed iff True returned.) */
412 typedef bool_t comm_notify_fn(void *state, struct buffer_if *buf,
413 const struct comm_addr *source);
414 typedef void comm_request_notify_fn(void *commst, void *nst,
416 typedef void comm_release_notify_fn(void *commst, void *nst,
418 typedef bool_t comm_sendmsg_fn(void *commst, struct buffer_if *buf,
419 const struct comm_addr *dest);
420 /* Only returns false if (we know that) the local network
421 * environment is such that this address cannot work; transient
422 * or unknown/unexpected failures return true. */
423 typedef const char *comm_addr_to_string_fn(void *commst,
424 const struct comm_addr *ca);
425 /* Returned string is in a static buffer. */
428 comm_request_notify_fn *request_notify;
429 comm_release_notify_fn *release_notify;
430 comm_sendmsg_fn *sendmsg;
431 comm_addr_to_string_fn *addr_to_string;
434 static inline const char *comm_addr_to_string(const struct comm_addr *ca)
436 return ca->comm->addr_to_string(ca->comm->st, ca);
441 #define LOG_MESSAGE_BUFLEN 1023
443 typedef void log_msg_fn(void *st, int class, const char *message, ...);
444 typedef void log_vmsg_fn(void *st, int class, const char *message,
448 log_vmsg_fn *vlogfn; /* printf format checking. Use [v]slilog instead */
449 char buff[LOG_MESSAGE_BUFLEN+1];
451 /* (convenience functions, defined in util.c) */
452 extern void slilog(struct log_if *lf, int class, const char *message, ...)
454 extern void vslilog(struct log_if *lf, int class, const char *message, va_list)
457 /* Versions which take (parts of) (multiple) messages, using \n to
458 * distinguish one message from another. */
459 extern void slilog_part(struct log_if *lf, int class, const char *message, ...)
461 extern void vslilog_part(struct log_if *lf, int class, const char *message,
462 va_list) FORMAT(printf,3,0);
466 /* Pretty much a placeholder; allows starting and stopping of processing,
468 typedef void site_control_fn(void *st, bool_t run);
469 typedef uint32_t site_status_fn(void *st);
472 site_control_fn *control;
473 site_status_fn *status;
476 /* TRANSFORM interface */
478 /* A reversable transformation. Transforms buffer in-place; may add
479 data to start or end. (Reverse transformations decrease
480 length, of course.) Transformations may be key-dependent, in which
481 case key material is passed in at initialisation time. They may
482 also depend on internal factors (eg. time) and keep internal
483 state. A struct transform_if only represents a particular type of
484 transformation; instances of the transformation (eg. with
485 particular key material) have a different C type. The same
486 secret key will be used in opposite directions between a pair of
487 secnets; one of these pairs will get direction==False, the other True. */
489 typedef struct transform_inst_if *transform_createinstance_fn(void *st);
490 typedef bool_t transform_setkey_fn(void *st, uint8_t *key, int32_t keylen,
492 typedef bool_t transform_valid_fn(void *st); /* 0: no key; 1: ok */
493 typedef void transform_delkey_fn(void *st);
494 typedef void transform_destroyinstance_fn(void *st);
497 * 1: for any other problem
498 * 2: message decrypted but sequence number was out of range
500 typedef uint32_t transform_apply_fn(void *st, struct buffer_if *buf,
501 const char **errmsg);
503 struct transform_inst_if {
505 transform_setkey_fn *setkey;
506 transform_valid_fn *valid;
507 transform_delkey_fn *delkey;
508 transform_apply_fn *forwards;
509 transform_apply_fn *reverse;
510 transform_destroyinstance_fn *destroy;
513 struct transform_if {
515 int capab_transformnum;
516 int32_t keylen; /* <<< INT_MAX */
517 transform_createinstance_fn *create;
520 /* NETLINK interface */
522 /* Used by netlink to deliver to site, and by site to deliver to
523 netlink. cid is the client identifier returned by
524 netlink_regnets_fn. If buf has size 0 then the function is just
525 being called for its site-effects (eg. making the site code attempt
526 to bring up a network link) */
527 typedef void netlink_deliver_fn(void *st, struct buffer_if *buf);
528 /* site code can tell netlink when outgoing packets will be dropped,
529 so netlink can generate appropriate ICMP and make routing decisions */
530 #define LINK_QUALITY_UNUSED 0 /* This link is unused, do not make this netlink */
531 #define LINK_QUALITY_DOWN 1 /* No chance of a packet being delivered right away*/
532 #define LINK_QUALITY_DOWN_STALE_ADDRESS 2 /* Link down, old address information */
533 #define LINK_QUALITY_DOWN_CURRENT_ADDRESS 3 /* Link down, current address information */
534 #define LINK_QUALITY_UP 4 /* Link active */
535 #define MAXIMUM_LINK_QUALITY 3
536 typedef void netlink_link_quality_fn(void *st, uint32_t quality);
537 typedef void netlink_register_fn(void *st, netlink_deliver_fn *deliver,
538 void *dst, uint32_t *localmtu_r /* NULL ok */);
539 typedef void netlink_output_config_fn(void *st, struct buffer_if *buf);
540 typedef bool_t netlink_check_config_fn(void *st, struct buffer_if *buf);
541 typedef void netlink_set_mtu_fn(void *st, int32_t new_mtu);
544 netlink_register_fn *reg;
545 netlink_deliver_fn *deliver;
546 netlink_link_quality_fn *set_quality;
547 netlink_set_mtu_fn *set_mtu;
552 /* Returns public key as a malloced hex string */
553 typedef string_t dh_makepublic_fn(void *st, uint8_t *secret,
555 /* Fills buffer (up to buflen) with shared secret */
556 typedef void dh_makeshared_fn(void *st, uint8_t *secret,
557 int32_t secretlen, cstring_t rempublic,
558 uint8_t *sharedsecret, int32_t buflen);
561 int32_t len; /* Approximate size of modulus in bytes */
562 int32_t ceil_len; /* Number of bytes just sufficient to contain modulus */
563 dh_makepublic_fn *makepublic;
564 dh_makeshared_fn *makeshared;
569 typedef void *hash_init_fn(void);
570 typedef void hash_update_fn(void *st, const void *buf, int32_t len);
571 typedef void hash_final_fn(void *st, uint8_t *digest);
573 int32_t len; /* Hash output length in bytes */
575 hash_update_fn *update;
576 hash_final_fn *final;
579 /* BUFFER interface */
583 cstring_t owner; /* Set to constant string */
584 uint32_t flags; /* How paranoid should we be? */
585 struct cloc loc; /* Where we were defined */
588 int32_t size; /* Size of buffer contents */
589 int32_t alloclen; /* Total length allocated at base */
592 /***** LOG functions *****/
594 #define M_DEBUG_CONFIG 0x001
595 #define M_DEBUG_PHASE 0x002
596 #define M_DEBUG 0x004
598 #define M_NOTICE 0x010
599 #define M_WARNING 0x020
601 #define M_SECURITY 0x080
602 #define M_FATAL 0x100
604 /* The fatal() family of functions require messages that do not end in '\n' */
605 extern NORETURN(fatal(const char *message, ...)) FORMAT(printf,1,2);
606 extern NORETURN(fatal_perror(const char *message, ...)) FORMAT(printf,1,2);
607 extern NORETURN(fatal_status(int status, const char *message, ...))
609 extern NORETURN(fatal_perror_status(int status, const char *message, ...))
612 /* Convenient nonfatal logging. Requires message that does not end in '\n'.
613 * If class contains M_FATAL, exits (after entering PHASE_SHUTDOWN).
614 * lg, errnoval and loc may sensibly be 0. desc must NOT be 0.
615 * lg_[v]perror save and restore errno. */
616 void lg_vperror(struct log_if *lg, const char *desc, struct cloc *loc,
617 int class, int errnoval, const char *fmt, va_list al)
619 void lg_perror(struct log_if *lg, const char *desc, struct cloc *loc,
620 int class, int errnoval, const char *fmt, ...)
622 void lg_exitstatus(struct log_if *lg, const char *desc, struct cloc *loc,
623 int class, int status, const char *progname);
625 /* The cfgfatal() family of functions require messages that end in '\n' */
626 extern NORETURN(cfgfatal(struct cloc loc, cstring_t facility,
627 const char *message, ...)) FORMAT(printf,3,4);
628 extern void cfgfile_postreadcheck(struct cloc loc, FILE *f);
629 extern NORETURN(vcfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
630 cstring_t facility, const char *message,
633 extern NORETURN(cfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
635 const char *message, ...))
638 extern void Message(uint32_t class, const char *message, ...)
640 extern void log_from_fd(int fd, cstring_t prefix, struct log_if *log);
642 /***** END of log functions *****/
644 #define STRING2(x) #x
645 #define STRING(x) STRING2(x)
647 #define FILLZERO(obj) (memset(&(obj),0,sizeof((obj))))
648 #define ARRAY_SIZE(ary) (sizeof(ary)/sizeof(ary[0]))
651 * void COPY_OBJ( OBJECT& dst, const OBJECT& src);
652 * void COPY_ARRAY(OBJECT *dst, const OBJECT *src, INTEGER count);
653 * // Typesafe: we check that the type OBJECT is the same in both cases.
654 * // It is OK to use COPY_OBJ on an array object, proviced it's
655 * // _actually_ the whole array object and not decayed into a
656 * // pointer (e.g. a formal parameter).
658 #define COPY_OBJ(dst,src) \
659 (&(dst)==&(src), memcpy(&(dst),&(src),sizeof((dst))))
660 #define COPY_ARRAY(dst,src,count) \
661 (&(dst)[0]==&(src)[0], memcpy((dst),(src),sizeof((dst)[0])*(count)))
663 #endif /* secnet_h */