resolver: Provide input name as argument to callback
[secnet] / secnet.h
1 /* Core interface of secnet, to be used by all modules */
2
3 #ifndef secnet_h
4 #define secnet_h
5
6 #define ADNS_FEATURE_MANYAF
7
8 #include "config.h"
9 #include <stdlib.h>
10 #include <stdarg.h>
11 #include <stdio.h>
12 #include <string.h>
13 #include <assert.h>
14 #include <fcntl.h>
15 #include <unistd.h>
16 #include <sys/poll.h>
17 #include <sys/types.h>
18 #include <sys/time.h>
19 #include <netinet/in.h>
20 #include <arpa/inet.h>
21
22 #define MAX_PEER_ADDRS 5
23 /* send at most this many copies; honour at most that many addresses */
24
25 struct comm_if;
26 struct comm_addr;
27
28 typedef char *string_t;
29 typedef const char *cstring_t;
30
31 #define False (_Bool)0
32 #define True (_Bool)1
33 typedef _Bool bool_t;
34
35 union iaddr {
36 struct sockaddr sa;
37 struct sockaddr_in sin;
38 #ifdef CONFIG_IPV6
39 struct sockaddr_in6 sin6;
40 #endif
41 };
42
43 #define ASSERT(x) do { if (!(x)) { fatal("assertion failed line %d file " \
44 __FILE__,__LINE__); } } while(0)
45
46 /* from version.c */
47
48 extern char version[];
49
50 /* from logmsg.c */
51 extern uint32_t message_level;
52 extern bool_t secnet_is_daemon;
53 extern struct log_if *system_log;
54
55 /* from process.c */
56 extern void start_signal_handling(void);
57
58 /***** CONFIGURATION support *****/
59
60 extern bool_t just_check_config; /* If True then we're going to exit after
61 reading the configuration file */
62 extern bool_t background; /* If True then we'll eventually run as a daemon */
63
64 typedef struct dict dict_t; /* Configuration dictionary */
65 typedef struct closure closure_t;
66 typedef struct item item_t;
67 typedef struct list list_t; /* A list of items */
68
69 /* Configuration file location, for error-reporting */
70 struct cloc {
71 cstring_t file;
72 int line;
73 };
74
75 /* Modules export closures, which can be invoked from the configuration file.
76 "Invoking" a closure usually returns another closure (of a different
77 type), but can actually return any configuration object. */
78 typedef list_t *(apply_fn)(closure_t *self, struct cloc loc,
79 dict_t *context, list_t *data);
80 struct closure {
81 cstring_t description; /* For debugging */
82 uint32_t type; /* Central registry... */
83 apply_fn *apply;
84 void *interface; /* Interface for use inside secnet; depends on type */
85 };
86
87 enum types { t_null, t_bool, t_string, t_number, t_dict, t_closure };
88 struct item {
89 enum types type;
90 union {
91 bool_t bool;
92 string_t string;
93 uint32_t number;
94 dict_t *dict;
95 closure_t *closure;
96 } data;
97 struct cloc loc;
98 };
99
100 /* Note that it is unwise to use this structure directly; use the list
101 manipulation functions instead. */
102 struct list {
103 item_t *item;
104 struct list *next;
105 };
106
107 /* In the following two lookup functions, NULL means 'not found' */
108 /* Lookup a value in the specified dictionary, or its parents */
109 extern list_t *dict_lookup(dict_t *dict, cstring_t key);
110 /* Lookup a value in just the specified dictionary */
111 extern list_t *dict_lookup_primitive(dict_t *dict, cstring_t key);
112 /* Add a value to the specified dictionary */
113 extern void dict_add(dict_t *dict, cstring_t key, list_t *val);
114 /* Obtain an array of keys in the dictionary. malloced; caller frees */
115 extern cstring_t *dict_keys(dict_t *dict);
116
117 /* List-manipulation functions */
118 extern list_t *list_new(void);
119 extern int32_t list_length(const list_t *a);
120 extern list_t *list_append(list_t *a, item_t *i);
121 extern list_t *list_append_list(list_t *a, list_t *b);
122 /* Returns an item from the list (index starts at 0), or NULL */
123 extern item_t *list_elem(list_t *l, int32_t index);
124
125 /* Convenience functions */
126 extern list_t *new_closure(closure_t *cl);
127 extern void add_closure(dict_t *dict, cstring_t name, apply_fn apply);
128 extern void *find_cl_if(dict_t *dict, cstring_t name, uint32_t type,
129 bool_t fail_if_invalid, cstring_t desc,
130 struct cloc loc);
131 extern item_t *dict_find_item(dict_t *dict, cstring_t key, bool_t required,
132 cstring_t desc, struct cloc loc);
133 extern string_t dict_read_string(dict_t *dict, cstring_t key, bool_t required,
134 cstring_t desc, struct cloc loc);
135 extern uint32_t dict_read_number(dict_t *dict, cstring_t key, bool_t required,
136 cstring_t desc, struct cloc loc,
137 uint32_t def);
138 /* return value can safely be assigned to int32_t */
139 extern bool_t dict_read_bool(dict_t *dict, cstring_t key, bool_t required,
140 cstring_t desc, struct cloc loc, bool_t def);
141 struct flagstr {
142 cstring_t name;
143 uint32_t value;
144 };
145 extern uint32_t string_to_word(cstring_t s, struct cloc loc,
146 struct flagstr *f, cstring_t desc);
147 extern uint32_t string_list_to_word(list_t *l, struct flagstr *f,
148 cstring_t desc);
149
150 /***** END of configuration support *****/
151
152 /***** UTILITY functions *****/
153
154 extern char *safe_strdup(const char *string, const char *message);
155 extern void *safe_malloc(size_t size, const char *message);
156 extern void *safe_malloc_ary(size_t size, size_t count, const char *message);
157
158 void setcloexec(int fd); /* cannot fail */
159 void pipe_cloexec(int fd[2]); /* pipe(), setcloexec() twice; cannot fail */
160
161 extern int sys_cmd(const char *file, const char *argc, ...);
162
163 extern uint64_t now_global;
164 extern struct timeval tv_now_global;
165
166 static const uint64_t *const now = &now_global;
167 static const struct timeval *const tv_now = &tv_now_global;
168
169 /* "now" is current program time, in milliseconds. It is derived
170 from tv_now. Both are provided by the event loop. */
171
172 /***** END of utility functions *****/
173
174 /***** START of max_start_pad handling *****/
175
176 extern int32_t site_max_start_pad, transform_max_start_pad,
177 comm_max_start_pad;
178
179 void update_max_start_pad(int32_t *our_module_global, int32_t our_instance);
180 int32_t calculate_max_start_pad(void);
181
182 /***** END of max_start_pad handling *****/
183
184 /***** SCHEDULING support */
185
186 /* If nfds_io is insufficient for your needs, set it to the required
187 number and return ERANGE. timeout is in milliseconds; if it is too
188 high then lower it. It starts at -1 (==infinite) */
189 typedef int beforepoll_fn(void *st, struct pollfd *fds, int *nfds_io,
190 int *timeout_io);
191 typedef void afterpoll_fn(void *st, struct pollfd *fds, int nfds);
192
193 /* Register interest in the main loop of the program. Before a call
194 to poll() your supplied beforepoll function will be called. After
195 the call to poll() the supplied afterpoll function will be called.
196 max_nfds is a _hint_ about the maximum number of struct pollfd
197 structures you may require - you can always ask for more in
198 *nfds_io. */
199 extern void register_for_poll(void *st, beforepoll_fn *before,
200 afterpoll_fn *after, int32_t max_nfds,
201 cstring_t desc);
202
203 /***** END of scheduling support */
204
205 /***** PROGRAM LIFETIME support */
206
207 /* The secnet program goes through a number of phases in its lifetime.
208 Module code may arrange to be called just as various phases are
209 entered.
210
211 Remember to update the table in util.c if changing the set of
212 phases. */
213
214 enum phase {
215 PHASE_INIT,
216 PHASE_GETOPTS, /* Process command-line arguments */
217 PHASE_READCONFIG, /* Parse and process configuration file */
218 PHASE_SETUP, /* Process information in configuration */
219 PHASE_DAEMONIZE, /* Become a daemon (if necessary) */
220 PHASE_GETRESOURCES, /* Obtain all external resources */
221 PHASE_DROPPRIV, /* Last chance for privileged operations */
222 PHASE_RUN,
223 PHASE_SHUTDOWN, /* About to die; delete key material, etc. */
224 /* Keep this last: */
225 NR_PHASES,
226 };
227
228 typedef void hook_fn(void *self, uint32_t newphase);
229 bool_t add_hook(uint32_t phase, hook_fn *f, void *state);
230 bool_t remove_hook(uint32_t phase, hook_fn *f, void *state);
231
232 extern uint32_t current_phase;
233 extern void enter_phase(uint32_t new_phase);
234
235 /* Some features (like netlink 'soft' routes) require that secnet
236 retain root privileges. They should indicate that here when
237 appropriate. */
238 extern bool_t require_root_privileges;
239 extern cstring_t require_root_privileges_explanation;
240
241 /***** END of program lifetime support *****/
242
243 /***** MODULE support *****/
244
245 /* Module initialisation function type - modules export one function of
246 this type which is called to initialise them. For dynamically loaded
247 modules it's called "secnet_module". */
248 typedef void init_module(dict_t *dict);
249
250 extern void init_builtin_modules(dict_t *dict);
251
252 extern init_module resolver_module;
253 extern init_module random_module;
254 extern init_module udp_module;
255 extern init_module util_module;
256 extern init_module site_module;
257 extern init_module transform_eax_module;
258 extern init_module transform_cbcmac_module;
259 extern init_module netlink_module;
260 extern init_module rsa_module;
261 extern init_module dh_module;
262 extern init_module md5_module;
263 extern init_module slip_module;
264 extern init_module tun_module;
265 extern init_module sha1_module;
266 extern init_module log_module;
267
268 /***** END of module support *****/
269
270 /***** CLOSURE TYPES and interface definitions *****/
271
272 #define CL_PURE 0
273 #define CL_RESOLVER 1
274 #define CL_RANDOMSRC 2
275 #define CL_RSAPUBKEY 3
276 #define CL_RSAPRIVKEY 4
277 #define CL_COMM 5
278 #define CL_IPIF 6
279 #define CL_LOG 7
280 #define CL_SITE 8
281 #define CL_TRANSFORM 9
282 #define CL_DH 11
283 #define CL_HASH 12
284 #define CL_BUFFER 13
285 #define CL_NETLINK 14
286
287 struct buffer_if;
288
289 /* PURE closure requires no interface */
290
291 /* RESOLVER interface */
292
293 /* Answers to queries are delivered to a function of this
294 type. 'address' will be NULL if there was a problem with the query. It
295 will be freed once resolve_answer_fn returns. naddrs is the actual
296 size of the array at addrs; was_naddrs is the number of addresses
297 actually found in the DNS, which may be bigger if addrs is equal
298 to MAX_PEER_ADDRS (ie there were too many). */
299 typedef void resolve_answer_fn(void *st, const struct comm_addr *addrs,
300 int naddrs, int was_naddrs,
301 const char *name, const char *failwhy);
302 /* name is the same ptr as passed to request, so its lifetime must
303 * be suitable*/
304 typedef bool_t resolve_request_fn(void *st, cstring_t name,
305 int remoteport, struct comm_if *comm,
306 resolve_answer_fn *cb, void *cst);
307 struct resolver_if {
308 void *st;
309 resolve_request_fn *request;
310 };
311
312 /* RANDOMSRC interface */
313
314 /* Return some random data. Returns TRUE for success. */
315 typedef bool_t random_fn(void *st, int32_t bytes, uint8_t *buff);
316
317 struct random_if {
318 void *st;
319 bool_t blocking;
320 random_fn *generate;
321 };
322
323 /* RSAPUBKEY interface */
324
325 typedef bool_t rsa_checksig_fn(void *st, uint8_t *data, int32_t datalen,
326 cstring_t signature);
327 struct rsapubkey_if {
328 void *st;
329 rsa_checksig_fn *check;
330 };
331
332 /* RSAPRIVKEY interface */
333
334 typedef string_t rsa_makesig_fn(void *st, uint8_t *data, int32_t datalen);
335 struct rsaprivkey_if {
336 void *st;
337 rsa_makesig_fn *sign;
338 };
339
340 /* COMM interface */
341
342 struct comm_addr {
343 /* This struct is pure data; in particular comm's clients may
344 freely copy it. */
345 struct comm_if *comm;
346 union iaddr ia;
347 int ix; /* see comment `Re comm_addr.ix' in udp.c */
348 };
349
350 /* Return True if the packet was processed, and shouldn't be passed to
351 any other potential receivers. */
352 typedef bool_t comm_notify_fn(void *state, struct buffer_if *buf,
353 const struct comm_addr *source);
354 typedef void comm_request_notify_fn(void *commst, void *nst,
355 comm_notify_fn *fn);
356 typedef void comm_release_notify_fn(void *commst, void *nst,
357 comm_notify_fn *fn);
358 typedef bool_t comm_sendmsg_fn(void *commst, struct buffer_if *buf,
359 const struct comm_addr *dest);
360 /* Only returns false if (we know that) the local network
361 * environment is such that this address cannot work; transient
362 * or unknown/unexpected failures return true. */
363 typedef const char *comm_addr_to_string_fn(void *commst,
364 const struct comm_addr *ca);
365 /* Returned string is in a static buffer. */
366 struct comm_if {
367 void *st;
368 comm_request_notify_fn *request_notify;
369 comm_release_notify_fn *release_notify;
370 comm_sendmsg_fn *sendmsg;
371 comm_addr_to_string_fn *addr_to_string;
372 };
373
374 bool_t iaddr_equal(const union iaddr *ia, const union iaddr *ib);
375
376 static inline const char *comm_addr_to_string(const struct comm_addr *ca)
377 {
378 return ca->comm->addr_to_string(ca->comm->st, ca);
379 }
380
381 static inline bool_t comm_addr_equal(const struct comm_addr *a,
382 const struct comm_addr *b)
383 {
384 return a->comm==b->comm && iaddr_equal(&a->ia,&b->ia);
385 }
386
387 /* LOG interface */
388
389 #define LOG_MESSAGE_BUFLEN 1023
390
391 typedef void log_msg_fn(void *st, int class, const char *message, ...);
392 typedef void log_vmsg_fn(void *st, int class, const char *message,
393 va_list args);
394 struct log_if {
395 void *st;
396 log_vmsg_fn *vlogfn; /* printf format checking. Use [v]slilog instead */
397 char buff[LOG_MESSAGE_BUFLEN+1];
398 };
399 /* (convenience functions, defined in util.c) */
400 extern void slilog(struct log_if *lf, int class, const char *message, ...)
401 FORMAT(printf,3,4);
402 extern void vslilog(struct log_if *lf, int class, const char *message, va_list)
403 FORMAT(printf,3,0);
404
405 /* Versions which take (parts of) (multiple) messages, using \n to
406 * distinguish one message from another. */
407 extern void slilog_part(struct log_if *lf, int class, const char *message, ...)
408 FORMAT(printf,3,4);
409 extern void vslilog_part(struct log_if *lf, int class, const char *message,
410 va_list) FORMAT(printf,3,0);
411
412 /* SITE interface */
413
414 /* Pretty much a placeholder; allows starting and stopping of processing,
415 key expiry, etc. */
416 typedef void site_control_fn(void *st, bool_t run);
417 typedef uint32_t site_status_fn(void *st);
418 struct site_if {
419 void *st;
420 site_control_fn *control;
421 site_status_fn *status;
422 };
423
424 /* TRANSFORM interface */
425
426 /* A reversable transformation. Transforms buffer in-place; may add
427 data to start or end. (Reverse transformations decrease
428 length, of course.) Transformations may be key-dependent, in which
429 case key material is passed in at initialisation time. They may
430 also depend on internal factors (eg. time) and keep internal
431 state. A struct transform_if only represents a particular type of
432 transformation; instances of the transformation (eg. with
433 particular key material) have a different C type. The same
434 secret key will be used in opposite directions between a pair of
435 secnets; one of these pairs will get direction==False, the other True. */
436
437 typedef struct transform_inst_if *transform_createinstance_fn(void *st);
438 typedef bool_t transform_setkey_fn(void *st, uint8_t *key, int32_t keylen,
439 bool_t direction);
440 typedef bool_t transform_valid_fn(void *st); /* 0: no key; 1: ok */
441 typedef void transform_delkey_fn(void *st);
442 typedef void transform_destroyinstance_fn(void *st);
443 /* Returns:
444 * 0: all is well
445 * 1: for any other problem
446 * 2: message decrypted but sequence number was out of range
447 */
448 typedef uint32_t transform_apply_fn(void *st, struct buffer_if *buf,
449 const char **errmsg);
450
451 struct transform_inst_if {
452 void *st;
453 transform_setkey_fn *setkey;
454 transform_valid_fn *valid;
455 transform_delkey_fn *delkey;
456 transform_apply_fn *forwards;
457 transform_apply_fn *reverse;
458 transform_destroyinstance_fn *destroy;
459 };
460
461 struct transform_if {
462 void *st;
463 int capab_transformnum;
464 int32_t keylen; /* <<< INT_MAX */
465 transform_createinstance_fn *create;
466 };
467
468 /* NETLINK interface */
469
470 /* Used by netlink to deliver to site, and by site to deliver to
471 netlink. cid is the client identifier returned by
472 netlink_regnets_fn. If buf has size 0 then the function is just
473 being called for its site-effects (eg. making the site code attempt
474 to bring up a network link) */
475 typedef void netlink_deliver_fn(void *st, struct buffer_if *buf);
476 /* site code can tell netlink when outgoing packets will be dropped,
477 so netlink can generate appropriate ICMP and make routing decisions */
478 #define LINK_QUALITY_UNUSED 0 /* This link is unused, do not make this netlink */
479 #define LINK_QUALITY_DOWN 1 /* No chance of a packet being delivered right away*/
480 #define LINK_QUALITY_DOWN_STALE_ADDRESS 2 /* Link down, old address information */
481 #define LINK_QUALITY_DOWN_CURRENT_ADDRESS 3 /* Link down, current address information */
482 #define LINK_QUALITY_UP 4 /* Link active */
483 #define MAXIMUM_LINK_QUALITY 3
484 typedef void netlink_link_quality_fn(void *st, uint32_t quality);
485 typedef void netlink_register_fn(void *st, netlink_deliver_fn *deliver,
486 void *dst, uint32_t *localmtu_r /* NULL ok */);
487 typedef void netlink_output_config_fn(void *st, struct buffer_if *buf);
488 typedef bool_t netlink_check_config_fn(void *st, struct buffer_if *buf);
489 typedef void netlink_set_mtu_fn(void *st, int32_t new_mtu);
490 struct netlink_if {
491 void *st;
492 netlink_register_fn *reg;
493 netlink_deliver_fn *deliver;
494 netlink_link_quality_fn *set_quality;
495 netlink_set_mtu_fn *set_mtu;
496 };
497
498 /* DH interface */
499
500 /* Returns public key as a malloced hex string */
501 typedef string_t dh_makepublic_fn(void *st, uint8_t *secret,
502 int32_t secretlen);
503 /* Fills buffer (up to buflen) with shared secret */
504 typedef void dh_makeshared_fn(void *st, uint8_t *secret,
505 int32_t secretlen, cstring_t rempublic,
506 uint8_t *sharedsecret, int32_t buflen);
507 struct dh_if {
508 void *st;
509 int32_t len; /* Approximate size of modulus in bytes */
510 int32_t ceil_len; /* Number of bytes just sufficient to contain modulus */
511 dh_makepublic_fn *makepublic;
512 dh_makeshared_fn *makeshared;
513 };
514
515 /* HASH interface */
516
517 typedef void *hash_init_fn(void);
518 typedef void hash_update_fn(void *st, const void *buf, int32_t len);
519 typedef void hash_final_fn(void *st, uint8_t *digest);
520 struct hash_if {
521 int32_t len; /* Hash output length in bytes */
522 hash_init_fn *init;
523 hash_update_fn *update;
524 hash_final_fn *final;
525 };
526
527 /* BUFFER interface */
528
529 struct buffer_if {
530 bool_t free;
531 cstring_t owner; /* Set to constant string */
532 uint32_t flags; /* How paranoid should we be? */
533 struct cloc loc; /* Where we were defined */
534 uint8_t *base;
535 uint8_t *start;
536 int32_t size; /* Size of buffer contents */
537 int32_t alloclen; /* Total length allocated at base */
538 };
539
540 /***** LOG functions *****/
541
542 #define M_DEBUG_CONFIG 0x001
543 #define M_DEBUG_PHASE 0x002
544 #define M_DEBUG 0x004
545 #define M_INFO 0x008
546 #define M_NOTICE 0x010
547 #define M_WARNING 0x020
548 #define M_ERR 0x040
549 #define M_SECURITY 0x080
550 #define M_FATAL 0x100
551
552 /* The fatal() family of functions require messages that do not end in '\n' */
553 extern NORETURN(fatal(const char *message, ...)) FORMAT(printf,1,2);
554 extern NORETURN(fatal_perror(const char *message, ...)) FORMAT(printf,1,2);
555 extern NORETURN(fatal_status(int status, const char *message, ...))
556 FORMAT(printf,2,3);
557 extern NORETURN(fatal_perror_status(int status, const char *message, ...))
558 FORMAT(printf,2,3);
559
560 /* The cfgfatal() family of functions require messages that end in '\n' */
561 extern NORETURN(cfgfatal(struct cloc loc, cstring_t facility,
562 const char *message, ...)) FORMAT(printf,3,4);
563 extern void cfgfile_postreadcheck(struct cloc loc, FILE *f);
564 extern NORETURN(vcfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
565 cstring_t facility, const char *message,
566 va_list))
567 FORMAT(printf,4,0);
568 extern NORETURN(cfgfatal_maybefile(FILE *maybe_f, struct cloc loc,
569 cstring_t facility,
570 const char *message, ...))
571 FORMAT(printf,4,5);
572
573 extern void Message(uint32_t class, const char *message, ...)
574 FORMAT(printf,2,3);
575 extern void log_from_fd(int fd, cstring_t prefix, struct log_if *log);
576
577 /***** END of log functions *****/
578
579 #define STRING2(x) #x
580 #define STRING(x) STRING2(x)
581
582 #define FILLZERO(obj) (memset(&(obj),0,sizeof((obj))))
583 #define ARRAY_SIZE(ary) (sizeof((ary))/sizeof((ary)[0]))
584
585 /*
586 * void COPY_OBJ( OBJECT& dst, const OBJECT& src);
587 * void COPY_ARRAY(OBJECT *dst, const OBJECT *src, INTEGER count);
588 * // Typesafe: we check that the type OBJECT is the same in both cases.
589 * // It is OK to use COPY_OBJ on an array object, provided it's
590 * // _actually_ the whole array object and not decayed into a
591 * // pointer (e.g. a formal parameter).
592 */
593 #define COPY_OBJ(dst,src) \
594 (&(dst)==&(src), memcpy(&(dst),&(src),sizeof((dst))))
595 #define COPY_ARRAY(dst,src,count) \
596 (&(dst)[0]==&(src)[0], memcpy((dst),(src),sizeof((dst)[0])*(count)))
597
598 #endif /* secnet_h */