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2fe58dfd SE |
1 | /* Core interface of secnet, to be used by all modules */ |
2 | ||
3 | #ifndef secnet_h | |
4 | #define secnet_h | |
5 | ||
6 | #include <stdlib.h> | |
7 | #include <stdint.h> | |
8 | #include <stdarg.h> | |
9 | #include <syslog.h> | |
10 | #include <sys/poll.h> | |
11 | #include <netinet/in.h> | |
12 | #include "config.h" | |
13 | ||
14 | ||
15 | typedef char *string_t; | |
16 | typedef enum {False,True} bool_t; | |
17 | ||
18 | #define ASSERT(x) do { if (!(x)) { fatal("assertion failed line " __LINE__ \ | |
19 | " file " __FILE__ "\n"); } while(0) | |
20 | ||
21 | /***** SHARED types *****/ | |
22 | ||
23 | /* These are stored in HOST byte order */ | |
24 | struct subnet { | |
25 | uint32_t prefix; | |
26 | uint32_t mask; | |
27 | }; | |
28 | ||
29 | struct subnet_list { | |
30 | uint32_t entries; | |
31 | struct subnet *list; | |
32 | }; | |
33 | ||
34 | /* Match an address (in HOST byte order) with a subnet list. | |
35 | Returns True if matched. */ | |
36 | extern bool_t subnet_match(struct subnet_list *list, uint32_t address); | |
37 | ||
38 | /***** END of shared types *****/ | |
39 | ||
40 | /***** CONFIGURATION support *****/ | |
41 | ||
42 | typedef struct dict dict_t; /* Configuration dictionary */ | |
43 | typedef struct closure closure_t; | |
44 | typedef struct item item_t; | |
45 | typedef struct list list_t; /* A list of items */ | |
46 | ||
47 | /* Configuration file location, for error-reporting */ | |
48 | struct cloc { | |
49 | string_t file; | |
50 | uint32_t line; | |
51 | }; | |
52 | ||
53 | /* Modules export closures, which can be invoked from the configuration file. | |
54 | "Invoking" a closure usually returns another closure (of a different | |
55 | type), but can actually return any configuration object. */ | |
56 | typedef list_t *(apply_fn)(closure_t *self, struct cloc loc, | |
57 | dict_t *context, list_t *data); | |
58 | struct closure { | |
59 | string_t description; /* For debugging */ | |
60 | uint32_t type; /* Central registry... */ | |
61 | apply_fn *apply; | |
62 | void *interface; /* Interface for use inside secnet; depends on type */ | |
63 | }; | |
64 | ||
65 | enum types { t_null, t_bool, t_string, t_number, t_dict, t_closure }; | |
66 | struct item { | |
67 | enum types type; | |
68 | union { | |
69 | bool_t bool; | |
70 | string_t string; | |
71 | uint32_t number; | |
72 | dict_t *dict; | |
73 | closure_t *closure; | |
74 | } data; | |
75 | struct cloc loc; | |
76 | }; | |
77 | ||
78 | struct list { | |
79 | item_t *item; | |
80 | struct list *next; | |
81 | }; | |
82 | ||
83 | /* In the following two lookup functions, NULL means 'not found' */ | |
84 | /* Lookup a value in the specified dictionary, or its parents */ | |
85 | extern list_t *dict_lookup(dict_t *dict, string_t key); | |
86 | /* Lookup a value in just the specified dictionary */ | |
87 | extern list_t *dict_lookup_primitive(dict_t *dict, string_t key); | |
88 | /* Add a value to the specified dictionary */ | |
89 | extern void dict_add(dict_t *dict, string_t key, list_t *val); | |
90 | /* Obtain an array of keys in the dictionary. malloced; caller frees */ | |
91 | extern string_t *dict_keys(dict_t *dict); | |
92 | ||
93 | /* List-manipulation functions */ | |
94 | extern list_t *list_new(void); | |
95 | extern list_t *list_append(list_t *a, item_t *i); | |
96 | extern list_t *list_append_list(list_t *a, list_t *b); | |
97 | /* Returns an item from the list (index starts at 0), or NULL */ | |
98 | extern item_t *list_elem(list_t *l, uint32_t index); | |
99 | ||
100 | /* Convenience functions */ | |
101 | extern list_t *new_closure(closure_t *cl); | |
102 | extern void add_closure(dict_t *dict, string_t name, apply_fn apply); | |
103 | extern void *find_cl_if(dict_t *dict, string_t name, uint32_t type, | |
104 | bool_t fail_if_invalid, string_t desc, | |
105 | struct cloc loc); | |
106 | extern item_t *dict_find_item(dict_t *dict, string_t key, bool_t required, | |
107 | string_t desc, struct cloc loc); | |
108 | extern string_t dict_read_string(dict_t *dict, string_t key, bool_t required, | |
109 | string_t desc, struct cloc loc); | |
110 | extern uint32_t dict_read_number(dict_t *dict, string_t key, bool_t required, | |
111 | string_t desc, struct cloc loc, uint32_t def); | |
112 | extern bool_t dict_read_bool(dict_t *dict, string_t key, bool_t required, | |
113 | string_t desc, struct cloc loc, bool_t def); | |
114 | extern void dict_read_subnet_list(dict_t *dict, string_t key, bool_t required, | |
115 | string_t desc, struct cloc loc, | |
116 | struct subnet_list *sl); | |
117 | extern uint32_t string_to_ipaddr(item_t *i, string_t desc); | |
118 | ||
119 | /***** END of configuration support *****/ | |
120 | ||
121 | /***** UTILITY functions *****/ | |
122 | ||
123 | #define M_WARNING 1 | |
124 | #define M_ERROR 2 | |
125 | #define M_FATAL 4 | |
126 | #define M_INFO 8 | |
127 | #define M_DEBUG_CONFIG 16 | |
128 | #define M_DEBUG_PHASE 32 | |
129 | ||
130 | extern void fatal(char *message, ...); | |
131 | extern void fatal_perror(char *message, ...); | |
132 | extern void fatal_status(int status, char *message, ...); | |
133 | extern void fatal_perror_status(int status, char *message, ...); | |
134 | extern void cfgfatal(struct cloc loc, string_t facility, char *message, ...); | |
135 | ||
136 | extern char *safe_strdup(char *string, char *message); | |
137 | extern void *safe_malloc(size_t size, char *message); | |
138 | ||
139 | extern void Message(uint32_t class, char *message, ...); | |
140 | ||
141 | extern string_t ipaddr_to_string(uint32_t addr); | |
142 | extern string_t subnet_to_string(struct subnet *sn); | |
143 | ||
144 | /***** END of utility functions *****/ | |
145 | ||
146 | /***** SCHEDULING support */ | |
147 | ||
148 | /* "now" is current program time, in milliseconds. It is derived | |
149 | (once) from tv_now. If nfds_io is insufficient for your needs, set | |
150 | it to the required number and return ERANGE. timeout is in milliseconds; | |
151 | if it is too high then lower it. It starts at -1 (==infinite) */ | |
152 | typedef int beforepoll_fn(void *st, struct pollfd *fds, int *nfds_io, | |
153 | int *timeout_io, const struct timeval *tv_now, | |
154 | uint64_t *now); | |
155 | typedef void afterpoll_fn(void *st, struct pollfd *fds, int nfds, | |
156 | const struct timeval *tv_now, uint64_t *now); | |
157 | ||
158 | /* Register interest in the main loop of the program. Before a call | |
159 | to poll() your supplied beforepoll function will be called. After | |
160 | the call to poll() the supplied afterpoll function will be called. | |
161 | max_nfds is a _hint_ about the maximum number of struct pollfd | |
162 | structures you may require - you can always ask for more in | |
163 | *nfds_io. */ | |
164 | extern void register_for_poll(void *st, beforepoll_fn *before, | |
165 | afterpoll_fn *after, uint32_t max_nfds, | |
166 | string_t desc); | |
167 | ||
168 | /***** END of scheduling support */ | |
169 | ||
170 | /***** PROGRAM LIFETIME support */ | |
171 | ||
172 | /* The secnet program goes through a number of phases in its lifetime. | |
173 | Module code may arrange to be called just as various phases are | |
174 | entered. */ | |
175 | ||
176 | #define PHASE_INIT 0 | |
177 | #define PHASE_GETOPTS 1 /* Process command-line arguments */ | |
178 | #define PHASE_READCONFIG 2 /* Parse and process configuration file */ | |
179 | #define PHASE_SETUP 3 /* Process information in configuration */ | |
180 | #define PHASE_DROPPRIV 4 /* Last chance for privileged operations */ | |
181 | #define PHASE_RUN 5 | |
182 | #define PHASE_SHUTDOWN 6 /* About to die; delete key material, etc. */ | |
183 | #define NR_PHASES 7 | |
184 | ||
185 | typedef void hook_fn(void *self, uint32_t newphase); | |
186 | bool_t add_hook(uint32_t phase, hook_fn *f, void *state); | |
187 | bool_t remove_hook(uint32_t phase, hook_fn *f, void *state); | |
188 | ||
189 | /***** END of program lifetime support *****/ | |
190 | ||
191 | /***** MODULE support *****/ | |
192 | ||
193 | /* Module initialisation function type - modules export one function of | |
194 | this type which is called to initialise them. For dynamically loaded | |
195 | modules it's called "secnet_module". */ | |
196 | typedef void (init_module)(dict_t *dict); | |
197 | ||
198 | /***** END of module support *****/ | |
199 | ||
200 | /***** CLOSURE TYPES and interface definitions *****/ | |
201 | ||
202 | #define CL_PURE 0 | |
203 | #define CL_RESOLVER 1 | |
204 | #define CL_RANDOMSRC 2 | |
205 | #define CL_RSAPUBKEY 3 | |
206 | #define CL_RSAPRIVKEY 4 | |
207 | #define CL_COMM 5 | |
208 | #define CL_IPIF 6 | |
209 | #define CL_LOG 7 | |
210 | #define CL_SITE 8 | |
211 | #define CL_TRANSFORM 9 | |
212 | #define CL_NETLINK 10 | |
213 | #define CL_DH 11 | |
214 | #define CL_HASH 12 | |
215 | #define CL_BUFFER 13 | |
216 | ||
217 | struct buffer_if; | |
218 | ||
219 | /* PURE closure requires no interface */ | |
220 | ||
221 | /* RESOLVER interface */ | |
222 | ||
223 | /* Answers to queries are delivered to a function of this | |
224 | type. 'address' will be NULL if there was a problem with the query. It | |
225 | will be freed once resolve_answer_fn returns. It is in network byte | |
226 | order. */ | |
227 | typedef void resolve_answer_fn(void *st, struct in_addr *addr); | |
228 | typedef bool_t resolve_request_fn(void *st, string_t name, | |
229 | resolve_answer_fn *cb, void *cst); | |
230 | struct resolver_if { | |
231 | void *st; | |
232 | resolve_request_fn *request; | |
233 | }; | |
234 | ||
235 | /* RANDOMSRC interface */ | |
236 | ||
237 | /* Return some random data. Returns TRUE for success. */ | |
238 | typedef bool_t random_fn(void *st, uint32_t bytes, uint8_t *buff); | |
239 | ||
240 | struct random_if { | |
241 | void *st; | |
242 | bool_t blocking; | |
243 | random_fn *generate; | |
244 | }; | |
245 | ||
246 | /* RSAPUBKEY interface */ | |
247 | ||
248 | typedef bool_t rsa_checksig_fn(void *st, uint8_t *data, uint32_t datalen, | |
249 | string_t signature); | |
250 | struct rsapubkey_if { | |
251 | void *st; | |
252 | rsa_checksig_fn *check; | |
253 | }; | |
254 | ||
255 | /* RSAPRIVKEY interface */ | |
256 | ||
257 | typedef string_t rsa_makesig_fn(void *st, uint8_t *data, uint32_t datalen); | |
258 | struct rsaprivkey_if { | |
259 | void *st; | |
260 | rsa_makesig_fn *sign; | |
261 | }; | |
262 | ||
263 | /* COMM interface */ | |
264 | ||
265 | /* Return True if the packet was processed, and shouldn't be passed to | |
266 | any other potential receivers. */ | |
267 | typedef bool_t comm_notify_fn(void *state, struct buffer_if *buf, | |
268 | struct sockaddr_in *source); | |
269 | typedef void comm_request_notify_fn(void *commst, void *nst, | |
270 | comm_notify_fn *fn); | |
271 | typedef void comm_release_notify_fn(void *commst, void *nst, | |
272 | comm_notify_fn *fn); | |
273 | typedef bool_t comm_sendmsg_fn(void *commst, struct buffer_if *buf, | |
274 | struct sockaddr_in *dest); | |
275 | struct comm_if { | |
276 | void *st; | |
277 | comm_request_notify_fn *request_notify; | |
278 | comm_release_notify_fn *release_notify; | |
279 | comm_sendmsg_fn *sendmsg; | |
280 | }; | |
281 | ||
282 | /* LOG interface */ | |
283 | ||
284 | typedef void log_msg_fn(void *st, int priority, char *message, ...); | |
285 | typedef void log_vmsg_fn(void *st, int priority, char *message, va_list args); | |
286 | struct log_if { | |
287 | void *st; | |
288 | log_msg_fn *log; | |
289 | log_vmsg_fn *vlog; | |
290 | }; | |
291 | /* (convenience function, defined in util.c) */ | |
292 | extern void log(struct log_if *lf, int priority, char *message, ...); | |
293 | ||
294 | /* SITE interface */ | |
295 | ||
296 | /* Pretty much a placeholder; allows starting and stopping of processing, | |
297 | key expiry, etc. */ | |
298 | typedef void site_control_fn(void *st, bool_t run); | |
299 | typedef uint32_t site_status_fn(void *st); | |
300 | struct site_if { | |
301 | void *st; | |
302 | site_control_fn *control; | |
303 | site_status_fn *status; | |
304 | }; | |
305 | ||
306 | /* TRANSFORM interface */ | |
307 | ||
308 | /* A reversable transformation. Transforms buffer in-place; may add | |
309 | data to start or end. Maximum amount of data to be added specified | |
310 | in max_start_pad and max_end_pad. (Reverse transformations decrease | |
311 | length, of course.) Transformations may be key-dependent, in which | |
312 | case key material is passed in at initialisation time. They may | |
313 | also depend on internal factors (eg. time) and keep internal | |
314 | state. A struct transform_if only represents a particular type of | |
315 | transformation; instances of the transformation (eg. with | |
316 | particular key material) have a different C type. */ | |
317 | ||
318 | typedef struct transform_inst_if *transform_createinstance_fn(void *st); | |
319 | typedef bool_t transform_setkey_fn(void *st, uint8_t *key, uint32_t keylen); | |
320 | typedef void transform_delkey_fn(void *st); | |
321 | typedef void transform_destroyinstance_fn(void *st); | |
322 | /* Returns 0 for 'all is well', any other value for a problem */ | |
323 | typedef uint32_t transform_apply_fn(void *st, struct buffer_if *buf, | |
324 | char **errmsg); | |
325 | ||
326 | struct transform_inst_if { | |
327 | void *st; | |
328 | transform_setkey_fn *setkey; | |
329 | transform_delkey_fn *delkey; | |
330 | transform_apply_fn *forwards; | |
331 | transform_apply_fn *reverse; | |
332 | transform_destroyinstance_fn *destroy; | |
333 | }; | |
334 | ||
335 | struct transform_if { | |
336 | void *st; | |
337 | uint32_t max_start_pad; | |
338 | uint32_t max_end_pad; | |
339 | uint32_t keylen; | |
340 | transform_createinstance_fn *create; | |
341 | }; | |
342 | ||
343 | /* NETLINK interface */ | |
344 | ||
345 | /* Used by netlink to deliver to site, and by site to deliver to netlink. | |
346 | cid is the client identifier returned by netlink_regnets_fn */ | |
347 | typedef void netlink_deliver_fn(void *st, void *cid, struct buffer_if *buf); | |
348 | /* Register for packets from specified networks. Return value is client | |
349 | identifier. */ | |
350 | typedef void *netlink_regnets_fn(void *st, struct subnet_list *networks, | |
351 | netlink_deliver_fn *deliver, void *dst, | |
352 | uint32_t max_start_pad, uint32_t max_end_pad); | |
353 | ||
354 | struct netlink_if { | |
355 | void *st; | |
356 | netlink_regnets_fn *regnets; | |
357 | netlink_deliver_fn *deliver; | |
358 | }; | |
359 | ||
360 | /* DH interface */ | |
361 | ||
362 | /* Returns public key as a malloced hex string */ | |
363 | typedef string_t dh_makepublic_fn(void *st, uint8_t *secret, | |
364 | uint32_t secretlen); | |
365 | /* Fills buffer (up to buflen) with shared secret */ | |
366 | typedef void dh_makeshared_fn(void *st, uint8_t *secret, | |
367 | uint32_t secretlen, string_t rempublic, | |
368 | uint8_t *sharedsecret, uint32_t buflen); | |
369 | struct dh_if { | |
370 | void *st; | |
371 | uint32_t len; /* Approximate size of modulus in bytes */ | |
372 | dh_makepublic_fn *makepublic; | |
373 | dh_makeshared_fn *makeshared; | |
374 | }; | |
375 | ||
376 | /* HASH interface */ | |
377 | ||
378 | typedef void *hash_init_fn(void); | |
379 | typedef void hash_update_fn(void *st, uint8_t const *buf, uint32_t len); | |
380 | typedef void hash_final_fn(void *st, uint8_t *digest); | |
381 | struct hash_if { | |
382 | uint32_t len; /* Hash output length in bytes */ | |
383 | hash_init_fn *init; | |
384 | hash_update_fn *update; | |
385 | hash_final_fn *final; | |
386 | }; | |
387 | ||
388 | /* BUFFER interface */ | |
389 | ||
390 | struct buffer_if { | |
391 | bool_t free; | |
392 | string_t owner; /* Set to constant string */ | |
393 | uint32_t flags; /* How paranoid should we be? */ | |
394 | struct cloc loc; /* Where we were defined */ | |
395 | uint8_t *base; | |
396 | uint8_t *start; | |
397 | uint32_t size; /* Size of buffer contents */ | |
398 | uint32_t len; /* Total length allocated at base */ | |
399 | }; | |
400 | ||
401 | #endif /* secnet_h */ |