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;
38 #define ASSERT(x) do { if (!(x)) { fatal("assertion failed line %d file " \
39 __FILE__,__LINE__); } } while(0)
43 extern char version[];
46 extern uint32_t message_level;
47 extern bool_t secnet_is_daemon;
48 extern struct log_if *system_log;
51 extern void start_signal_handling(void);
53 /***** CONFIGURATION support *****/
55 extern bool_t just_check_config; /* If True then we're going to exit after
56 reading the configuration file */
57 extern bool_t background; /* If True then we'll eventually run as a daemon */
59 typedef struct dict dict_t; /* Configuration dictionary */
60 typedef struct closure closure_t;
61 typedef struct item item_t;
62 typedef struct list list_t; /* A list of items */
64 /* Configuration file location, for error-reporting */
70 /* Modules export closures, which can be invoked from the configuration file.
71 "Invoking" a closure usually returns another closure (of a different
72 type), but can actually return any configuration object. */
73 typedef list_t *(apply_fn)(closure_t *self, struct cloc loc,
74 dict_t *context, list_t *data);
76 cstring_t description; /* For debugging */
77 uint32_t type; /* Central registry... */
79 void *interface; /* Interface for use inside secnet; depends on type */
82 enum types { t_null, t_bool, t_string, t_number, t_dict, t_closure };
95 /* Note that it is unwise to use this structure directly; use the list
96 manipulation functions instead. */
102 /* In the following two lookup functions, NULL means 'not found' */
103 /* Lookup a value in the specified dictionary, or its parents */
104 extern list_t *dict_lookup(dict_t *dict, cstring_t key);
105 /* Lookup a value in just the specified dictionary */
106 extern list_t *dict_lookup_primitive(dict_t *dict, cstring_t key);
107 /* Add a value to the specified dictionary */
108 extern void dict_add(dict_t *dict, cstring_t key, list_t *val);
109 /* Obtain an array of keys in the dictionary. malloced; caller frees */
110 extern cstring_t *dict_keys(dict_t *dict);
112 /* List-manipulation functions */
113 extern list_t *list_new(void);
114 extern int32_t list_length(list_t *a);
115 extern list_t *list_append(list_t *a, item_t *i);
116 extern list_t *list_append_list(list_t *a, list_t *b);
117 /* Returns an item from the list (index starts at 0), or NULL */
118 extern item_t *list_elem(list_t *l, int32_t index);
120 /* Convenience functions */
121 extern list_t *new_closure(closure_t *cl);
122 extern void add_closure(dict_t *dict, cstring_t name, apply_fn apply);
123 extern void *find_cl_if(dict_t *dict, cstring_t name, uint32_t type,
124 bool_t fail_if_invalid, cstring_t desc,
126 extern item_t *dict_find_item(dict_t *dict, cstring_t key, bool_t required,
127 cstring_t desc, struct cloc loc);
128 extern string_t dict_read_string(dict_t *dict, cstring_t key, bool_t required,
129 cstring_t desc, struct cloc loc);
130 extern uint32_t dict_read_number(dict_t *dict, cstring_t key, bool_t required,
131 cstring_t desc, struct cloc loc,
133 /* return value can safely be assigned to int32_t */
134 extern bool_t dict_read_bool(dict_t *dict, cstring_t key, bool_t required,
135 cstring_t desc, struct cloc loc, bool_t def);
140 extern uint32_t string_to_word(cstring_t s, struct cloc loc,
141 struct flagstr *f, cstring_t desc);
142 extern uint32_t string_list_to_word(list_t *l, struct flagstr *f,
145 /***** END of configuration support *****/
147 /***** UTILITY functions *****/
149 extern char *safe_strdup(const char *string, const char *message);
150 extern void *safe_malloc(size_t size, const char *message);
151 extern void *safe_malloc_ary(size_t size, size_t count, const char *message);
153 void setcloexec(int fd); /* cannot fail */
154 void pipe_cloexec(int fd[2]); /* pipe(), setcloexec() twice; cannot fail */
156 extern int sys_cmd(const char *file, const char *argc, ...);
158 extern uint64_t now_global;
159 extern struct timeval tv_now_global;
161 static const uint64_t *const now = &now_global;
162 static const struct timeval *const tv_now = &tv_now_global;
164 /* "now" is current program time, in milliseconds. It is derived
165 from tv_now. Both are provided by the event loop. */
167 /***** END of utility functions *****/
169 /***** START of max_start_pad handling *****/
171 extern int32_t site_max_start_pad, transform_max_start_pad,
174 void update_max_start_pad(int32_t *our_module_global, int32_t our_instance);
175 int32_t calculate_max_start_pad(void);
177 /***** END of max_start_pad handling *****/
179 /***** SCHEDULING support */
181 /* If nfds_io is insufficient for your needs, set it to the required
182 number and return ERANGE. timeout is in milliseconds; if it is too
183 high then lower it. It starts at -1 (==infinite) */
184 typedef int beforepoll_fn(void *st, struct pollfd *fds, int *nfds_io,
186 typedef void afterpoll_fn(void *st, struct pollfd *fds, int nfds);
188 /* Register interest in the main loop of the program. Before a call
189 to poll() your supplied beforepoll function will be called. After
190 the call to poll() the supplied afterpoll function will be called.
191 max_nfds is a _hint_ about the maximum number of struct pollfd
192 structures you may require - you can always ask for more in
194 extern void register_for_poll(void *st, beforepoll_fn *before,
195 afterpoll_fn *after, int32_t max_nfds,
198 /***** END of scheduling support */
200 /***** PROGRAM LIFETIME support */
202 /* The secnet program goes through a number of phases in its lifetime.
203 Module code may arrange to be called just as various phases are
206 Remember to update the table in util.c if changing the set of
211 PHASE_GETOPTS, /* Process command-line arguments */
212 PHASE_READCONFIG, /* Parse and process configuration file */
213 PHASE_SETUP, /* Process information in configuration */
214 PHASE_DAEMONIZE, /* Become a daemon (if necessary) */
215 PHASE_GETRESOURCES, /* Obtain all external resources */
216 PHASE_DROPPRIV, /* Last chance for privileged operations */
218 PHASE_SHUTDOWN, /* About to die; delete key material, etc. */
219 /* Keep this last: */
223 typedef void hook_fn(void *self, uint32_t newphase);
224 bool_t add_hook(uint32_t phase, hook_fn *f, void *state);
225 bool_t remove_hook(uint32_t phase, hook_fn *f, void *state);
227 extern uint32_t current_phase;
228 extern void enter_phase(uint32_t new_phase);
230 /* Some features (like netlink 'soft' routes) require that secnet
231 retain root privileges. They should indicate that here when
233 extern bool_t require_root_privileges;
234 extern cstring_t require_root_privileges_explanation;
236 /***** END of program lifetime support *****/
238 /***** MODULE support *****/
240 /* Module initialisation function type - modules export one function of
241 this type which is called to initialise them. For dynamically loaded
242 modules it's called "secnet_module". */
243 typedef void init_module(dict_t *dict);
245 extern void init_builtin_modules(dict_t *dict);
247 extern init_module resolver_module;
248 extern init_module random_module;
249 extern init_module udp_module;
250 extern init_module util_module;
251 extern init_module site_module;
252 extern init_module transform_eax_module;
253 extern init_module transform_cbcmac_module;
254 extern init_module netlink_module;
255 extern init_module rsa_module;
256 extern init_module dh_module;
257 extern init_module md5_module;
258 extern init_module slip_module;
259 extern init_module tun_module;
260 extern init_module sha1_module;
261 extern init_module log_module;
263 /***** END of module support *****/
265 /***** CLOSURE TYPES and interface definitions *****/
268 #define CL_RESOLVER 1
269 #define CL_RANDOMSRC 2
270 #define CL_RSAPUBKEY 3
271 #define CL_RSAPRIVKEY 4
276 #define CL_TRANSFORM 9
280 #define CL_NETLINK 14
284 /* PURE closure requires no interface */
286 /* RESOLVER interface */
288 /* Answers to queries are delivered to a function of this
289 type. 'address' will be NULL if there was a problem with the query. It
290 will be freed once resolve_answer_fn returns. naddrs is the actual
291 size of the array at addrs; was_naddrs is the number of addresses
292 actually found in the DNS, which may be bigger if addrs is equal
293 to MAX_PEER_ADDRS (ie there were too many). */
294 typedef void resolve_answer_fn(void *st, const struct comm_addr *addrs,
295 int naddrs, int was_naddrs);
296 typedef bool_t resolve_request_fn(void *st, cstring_t name,
297 int remoteport, struct comm_if *comm,
298 resolve_answer_fn *cb, void *cst);
301 resolve_request_fn *request;
304 /* RANDOMSRC interface */
306 /* Return some random data. Returns TRUE for success. */
307 typedef bool_t random_fn(void *st, int32_t bytes, uint8_t *buff);
315 /* RSAPUBKEY interface */
317 typedef bool_t rsa_checksig_fn(void *st, uint8_t *data, int32_t datalen,
318 cstring_t signature);
319 struct rsapubkey_if {
321 rsa_checksig_fn *check;
324 /* RSAPRIVKEY interface */
326 typedef string_t rsa_makesig_fn(void *st, uint8_t *data, int32_t datalen);
327 struct rsaprivkey_if {
329 rsa_makesig_fn *sign;
335 /* This struct is pure data; in particular comm's clients may
337 /* Everyone is also guaranteed that all padding is set to zero, ie
338 that comm_addrs referring to semantically identical peers will
339 compare equal with memcmp. Anyone who constructs a comm_addr
340 must start by memsetting it with FILLZERO, or some
342 struct comm_if *comm;
346 /* Return True if the packet was processed, and shouldn't be passed to
347 any other potential receivers. */
348 typedef bool_t comm_notify_fn(void *state, struct buffer_if *buf,
349 const struct comm_addr *source);
350 typedef void comm_request_notify_fn(void *commst, void *nst,
352 typedef void comm_release_notify_fn(void *commst, void *nst,
354 typedef bool_t comm_sendmsg_fn(void *commst, struct buffer_if *buf,
355 const struct comm_addr *dest);
356 /* Only returns false if (we know that) the local network
357 * environment is such that this address cannot work; transient
358 * or unknown/unexpected failures return true. */
359 typedef const char *comm_addr_to_string_fn(void *commst,
360 const struct comm_addr *ca);
361 /* Returned string is in a static buffer. */
364 comm_request_notify_fn *request_notify;
365 comm_release_notify_fn *release_notify;
366 comm_sendmsg_fn *sendmsg;
367 comm_addr_to_string_fn *addr_to_string;
370 static inline const char *comm_addr_to_string(const struct comm_addr *ca)
372 return ca->comm->addr_to_string(ca->comm->st, ca);
377 #define LOG_MESSAGE_BUFLEN 1023
379 typedef void log_msg_fn(void *st, int class, const char *message, ...);
380 typedef void log_vmsg_fn(void *st, int class, const char *message,
384 log_vmsg_fn *vlogfn; /* printf format checking. Use [v]slilog instead */
385 char buff[LOG_MESSAGE_BUFLEN+1];
387 /* (convenience functions, defined in util.c) */
388 extern void slilog(struct log_if *lf, int class, const char *message, ...)
390 extern void vslilog(struct log_if *lf, int class, const char *message, va_list)
393 /* Versions which take (parts of) (multiple) messages, using \n to
394 * distinguish one message from another. */
395 extern void slilog_part(struct log_if *lf, int class, const char *message, ...)
397 extern void vslilog_part(struct log_if *lf, int class, const char *message,
398 va_list) FORMAT(printf,3,0);
402 /* Pretty much a placeholder; allows starting and stopping of processing,
404 typedef void site_control_fn(void *st, bool_t run);
405 typedef uint32_t site_status_fn(void *st);
408 site_control_fn *control;
409 site_status_fn *status;
412 /* TRANSFORM interface */
414 /* A reversable transformation. Transforms buffer in-place; may add
415 data to start or end. (Reverse transformations decrease
416 length, of course.) Transformations may be key-dependent, in which
417 case key material is passed in at initialisation time. They may
418 also depend on internal factors (eg. time) and keep internal
419 state. A struct transform_if only represents a particular type of
420 transformation; instances of the transformation (eg. with
421 particular key material) have a different C type. The same
422 secret key will be used in opposite directions between a pair of
423 secnets; one of these pairs will get direction==False, the other True. */
425 typedef struct transform_inst_if *transform_createinstance_fn(void *st);
426 typedef bool_t transform_setkey_fn(void *st, uint8_t *key, int32_t keylen,
428 typedef bool_t transform_valid_fn(void *st); /* 0: no key; 1: ok */
429 typedef void transform_delkey_fn(void *st);
430 typedef void transform_destroyinstance_fn(void *st);
433 * 1: for any other problem
434 * 2: message decrypted but sequence number was out of range
436 typedef uint32_t transform_apply_fn(void *st, struct buffer_if *buf,
437 const char **errmsg);
439 struct transform_inst_if {
441 transform_setkey_fn *setkey;
442 transform_valid_fn *valid;
443 transform_delkey_fn *delkey;
444 transform_apply_fn *forwards;
445 transform_apply_fn *reverse;
446 transform_destroyinstance_fn *destroy;
449 struct transform_if {
451 int capab_transformnum;
452 int32_t keylen; /* <<< INT_MAX */
453 transform_createinstance_fn *create;
456 /* NETLINK interface */
458 /* Used by netlink to deliver to site, and by site to deliver to
459 netlink. cid is the client identifier returned by
460 netlink_regnets_fn. If buf has size 0 then the function is just
461 being called for its site-effects (eg. making the site code attempt
462 to bring up a network link) */
463 typedef void netlink_deliver_fn(void *st, struct buffer_if *buf);
464 /* site code can tell netlink when outgoing packets will be dropped,
465 so netlink can generate appropriate ICMP and make routing decisions */
466 #define LINK_QUALITY_UNUSED 0 /* This link is unused, do not make this netlink */
467 #define LINK_QUALITY_DOWN 1 /* No chance of a packet being delivered right away*/
468 #define LINK_QUALITY_DOWN_STALE_ADDRESS 2 /* Link down, old address information */
469 #define LINK_QUALITY_DOWN_CURRENT_ADDRESS 3 /* Link down, current address information */
470 #define LINK_QUALITY_UP 4 /* Link active */
471 #define MAXIMUM_LINK_QUALITY 3
472 typedef void netlink_link_quality_fn(void *st, uint32_t quality);
473 typedef void netlink_register_fn(void *st, netlink_deliver_fn *deliver,
474 void *dst, uint32_t *localmtu_r /* NULL ok */);
475 typedef void netlink_output_config_fn(void *st, struct buffer_if *buf);
476 typedef bool_t netlink_check_config_fn(void *st, struct buffer_if *buf);
477 typedef void netlink_set_mtu_fn(void *st, int32_t new_mtu);
480 netlink_register_fn *reg;
481 netlink_deliver_fn *deliver;
482 netlink_link_quality_fn *set_quality;
483 netlink_set_mtu_fn *set_mtu;
488 /* Returns public key as a malloced hex string */
489 typedef string_t dh_makepublic_fn(void *st, uint8_t *secret,
491 /* Fills buffer (up to buflen) with shared secret */
492 typedef void dh_makeshared_fn(void *st, uint8_t *secret,
493 int32_t secretlen, cstring_t rempublic,
494 uint8_t *sharedsecret, int32_t buflen);
497 int32_t len; /* Approximate size of modulus in bytes */
498 int32_t ceil_len; /* Number of bytes just sufficient to contain modulus */
499 dh_makepublic_fn *makepublic;
500 dh_makeshared_fn *makeshared;
505 typedef void *hash_init_fn(void);
506 typedef void hash_update_fn(void *st, const void *buf, int32_t len);
507 typedef void hash_final_fn(void *st, uint8_t *digest);
509 int32_t len; /* Hash output length in bytes */
511 hash_update_fn *update;
512 hash_final_fn *final;
515 /* BUFFER interface */
519 cstring_t owner; /* Set to constant string */
520 uint32_t flags; /* How paranoid should we be? */
521 struct cloc loc; /* Where we were defined */
524 int32_t size; /* Size of buffer contents */
525 int32_t alloclen; /* Total length allocated at base */
528 /***** LOG functions *****/
530 #define M_DEBUG_CONFIG 0x001
531 #define M_DEBUG_PHASE 0x002
532 #define M_DEBUG 0x004
534 #define M_NOTICE 0x010
535 #define M_WARNING 0x020
537 #define M_SECURITY 0x080
538 #define M_FATAL 0x100
540 /* The fatal() family of functions require messages that do not end in '\n' */
541 extern NORETURN(fatal(const char *message, ...)) FORMAT(printf,1,2);
542 extern NORETURN(fatal_perror(const char *message, ...)) FORMAT(printf,1,2);
543 extern NORETURN(fatal_status(int status, const char *message, ...))
545 extern NORETURN(fatal_perror_status(int status, const char *message, ...))
548 /* The cfgfatal() family of functions require messages that end in '\n' */
549 extern NORETURN(cfgfatal(struct cloc loc, cstring_t facility,
550 const char *message, ...)) FORMAT(printf,3,4);
551 extern void cfgfile_postreadcheck(struct cloc loc, FILE *f);
552 extern NORETURN(vcfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
553 cstring_t facility, const char *message,
556 extern NORETURN(cfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
558 const char *message, ...))
561 extern void Message(uint32_t class, const char *message, ...)
563 extern void log_from_fd(int fd, cstring_t prefix, struct log_if *log);
565 /***** END of log functions *****/
567 #define STRING2(x) #x
568 #define STRING(x) STRING2(x)
570 #define FILLZERO(obj) (memset(&(obj),0,sizeof((obj))))
573 * void COPY_OBJ( OBJECT& dst, const OBJECT& src);
574 * void COPY_ARRAY(OBJECT *dst, const OBJECT *src, INTEGER count);
575 * // Typesafe: we check that the type OBJECT is the same in both cases.
576 * // It is OK to use COPY_OBJ on an array object, provided it's
577 * // _actually_ the whole array object and not decayed into a
578 * // pointer (e.g. a formal parameter).
580 #define COPY_OBJ(dst,src) \
581 (&(dst)==&(src), memcpy(&(dst),&(src),sizeof((dst))))
582 #define COPY_ARRAY(dst,src,count) \
583 (&(dst)[0]==&(src)[0], memcpy((dst),(src),sizeof((dst)[0])*(count)))
585 #endif /* secnet_h */