1 | /* Copyright (c) 1998-2024 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #ifndef _NSCD_H |
19 | #define _NSCD_H 1 |
20 | |
21 | #include <pthread.h> |
22 | #include <stdbool.h> |
23 | #include <time.h> |
24 | #include <sys/uio.h> |
25 | |
26 | /* The declarations for the request and response types are in the file |
27 | "nscd-client.h", which should contain everything needed by client |
28 | functions. */ |
29 | #include "nscd-client.h" |
30 | |
31 | |
32 | /* Handle databases. */ |
33 | typedef enum |
34 | { |
35 | pwddb, |
36 | grpdb, |
37 | hstdb, |
38 | servdb, |
39 | netgrdb, |
40 | lastdb |
41 | } dbtype; |
42 | |
43 | |
44 | /* Default limit on the number of times a value gets reloaded without |
45 | being used in the meantime. NSCD does not throw a value out as |
46 | soon as it times out. It tries to reload the value from the |
47 | server. Only if the value has not been used for so many rounds it |
48 | is removed. */ |
49 | #define DEFAULT_RELOAD_LIMIT 5 |
50 | |
51 | |
52 | /* Time before restarting the process in paranoia mode. */ |
53 | #define RESTART_INTERVAL (60 * 60) |
54 | |
55 | |
56 | /* Stack size for worker threads. */ |
57 | #define NSCD_THREAD_STACKSIZE 1024 * 1024 * (sizeof (void *) / 4) |
58 | |
59 | /* Maximum size of stack frames we allow the thread to use. We use |
60 | 80% of the thread stack size. */ |
61 | #define MAX_STACK_USE ((8 * NSCD_THREAD_STACKSIZE) / 10) |
62 | |
63 | /* Records the file registered per database that when changed |
64 | or modified requires invalidating the database. */ |
65 | struct traced_file |
66 | { |
67 | /* Tracks the last modified time of the traced file. */ |
68 | __time64_t mtime; |
69 | /* Support multiple registered files per database. */ |
70 | struct traced_file *next; |
71 | int call_res_init; |
72 | /* Requires Inotify support to do anything useful. */ |
73 | #define TRACED_FILE 0 |
74 | #define TRACED_DIR 1 |
75 | int inotify_descr[2]; |
76 | # ifndef PATH_MAX |
77 | # define PATH_MAX 1024 |
78 | # endif |
79 | /* The parent directory is used to scan for creation/deletion. */ |
80 | char dname[PATH_MAX]; |
81 | /* Just the name of the file with no directory component. */ |
82 | char *sfname; |
83 | /* The full-path name of the registered file. */ |
84 | char fname[]; |
85 | }; |
86 | |
87 | /* Initialize a `struct traced_file`. As input we need the name |
88 | of the file, and if invalidation requires calling res_init. |
89 | If CRINIT is 1 then res_init will be called after invalidation |
90 | or if the traced file is changed in any way, otherwise it will |
91 | not. */ |
92 | static inline void |
93 | init_traced_file(struct traced_file *file, const char *fname, int crinit) |
94 | { |
95 | char *dname; |
96 | file->mtime = 0; |
97 | file->inotify_descr[TRACED_FILE] = -1; |
98 | file->inotify_descr[TRACED_DIR] = -1; |
99 | strcpy (dest: file->fname, src: fname); |
100 | /* Compute the parent directory name and store a copy. The copy makes |
101 | it much faster to add/remove watches while nscd is running instead |
102 | of computing this over and over again in a temp buffer. */ |
103 | file->dname[0] = '\0'; |
104 | dname = strrchr (s: fname, c: '/'); |
105 | if (dname != NULL) |
106 | { |
107 | size_t len = (size_t)(dname - fname); |
108 | if (len > sizeof (file->dname)) |
109 | abort (); |
110 | memcpy (dest: file->dname, src: file->fname, n: len); |
111 | file->dname[len] = '\0'; |
112 | } |
113 | /* The basename is the name just after the last forward slash. */ |
114 | file->sfname = &dname[1]; |
115 | file->call_res_init = crinit; |
116 | } |
117 | |
118 | #define define_traced_file(id, filename) \ |
119 | static union \ |
120 | { \ |
121 | struct traced_file file; \ |
122 | char buf[sizeof (struct traced_file) + sizeof (filename)]; \ |
123 | } id##_traced_file; |
124 | |
125 | /* Structure describing dynamic part of one database. */ |
126 | struct database_dyn |
127 | { |
128 | pthread_rwlock_t lock; |
129 | pthread_cond_t prune_cond; |
130 | pthread_mutex_t prune_lock; |
131 | pthread_mutex_t prune_run_lock; |
132 | time_t wakeup_time; |
133 | |
134 | int enabled; |
135 | int check_file; |
136 | int clear_cache; |
137 | int persistent; |
138 | int shared; |
139 | int propagate; |
140 | struct traced_file *traced_files; |
141 | const char *db_filename; |
142 | size_t suggested_module; |
143 | size_t max_db_size; |
144 | |
145 | unsigned long int postimeout; /* In seconds. */ |
146 | unsigned long int negtimeout; /* In seconds. */ |
147 | |
148 | int wr_fd; /* Writable file descriptor. */ |
149 | int ro_fd; /* Unwritable file descriptor. */ |
150 | |
151 | const struct iovec *disabled_iov; |
152 | |
153 | struct database_pers_head *head; |
154 | char *data; |
155 | size_t memsize; |
156 | pthread_mutex_t memlock; |
157 | bool mmap_used; |
158 | bool last_alloc_failed; |
159 | }; |
160 | |
161 | |
162 | /* Paths of the file for the persistent storage. */ |
163 | #define _PATH_NSCD_PASSWD_DB "/var/db/nscd/passwd" |
164 | #define _PATH_NSCD_GROUP_DB "/var/db/nscd/group" |
165 | #define _PATH_NSCD_HOSTS_DB "/var/db/nscd/hosts" |
166 | #define _PATH_NSCD_SERVICES_DB "/var/db/nscd/services" |
167 | #define _PATH_NSCD_NETGROUP_DB "/var/db/nscd/netgroup" |
168 | |
169 | /* Path used when not using persistent storage. */ |
170 | #define _PATH_NSCD_XYZ_DB_TMP "/var/run/nscd/dbXXXXXX" |
171 | |
172 | /* Maximum alignment requirement we will encounter. */ |
173 | #define BLOCK_ALIGN_LOG 3 |
174 | #define BLOCK_ALIGN (1 << BLOCK_ALIGN_LOG) |
175 | #define BLOCK_ALIGN_M1 (BLOCK_ALIGN - 1) |
176 | |
177 | /* Default value for the maximum size of the database files. */ |
178 | #define DEFAULT_MAX_DB_SIZE (32 * 1024 * 1024) |
179 | |
180 | /* Number of bytes of data we initially reserve for each hash table bucket. */ |
181 | #define DEFAULT_DATASIZE_PER_BUCKET 1024 |
182 | |
183 | /* Default module of hash table. */ |
184 | #define DEFAULT_SUGGESTED_MODULE 211 |
185 | |
186 | |
187 | /* Number of seconds between two cache pruning runs if we do not have |
188 | better information when it is really needed. */ |
189 | #define CACHE_PRUNE_INTERVAL 15 |
190 | |
191 | |
192 | /* Global variables. */ |
193 | extern struct database_dyn dbs[lastdb] attribute_hidden; |
194 | extern const char *const dbnames[lastdb]; |
195 | extern const char *const serv2str[LASTREQ]; |
196 | |
197 | extern const struct iovec pwd_iov_disabled; |
198 | extern const struct iovec grp_iov_disabled; |
199 | extern const struct iovec hst_iov_disabled; |
200 | extern const struct iovec serv_iov_disabled; |
201 | extern const struct iovec netgroup_iov_disabled; |
202 | |
203 | |
204 | /* Initial number of threads to run. */ |
205 | extern int nthreads; |
206 | /* Maximum number of threads to use. */ |
207 | extern int max_nthreads; |
208 | |
209 | /* Inotify descriptor. */ |
210 | extern int inotify_fd; |
211 | |
212 | /* User name to run server processes as. */ |
213 | extern const char *server_user; |
214 | |
215 | /* Name and UID of user who is allowed to request statistics. */ |
216 | extern const char *stat_user; |
217 | extern uid_t stat_uid; |
218 | |
219 | /* Time the server was started. */ |
220 | extern time_t start_time; |
221 | |
222 | /* Number of times clients had to wait. */ |
223 | extern unsigned long int client_queued; |
224 | |
225 | /* Maximum needed alignment. */ |
226 | extern const size_t block_align; |
227 | |
228 | /* Number of times a value is reloaded without being used. UINT_MAX |
229 | means unlimited. */ |
230 | extern unsigned int reload_count; |
231 | |
232 | /* Pagesize minus one. */ |
233 | extern uintptr_t pagesize_m1; |
234 | |
235 | /* Nonzero if paranoia mode is enabled. */ |
236 | extern int paranoia; |
237 | /* Time after which the process restarts. */ |
238 | extern time_t restart_time; |
239 | /* How much time between restarts. */ |
240 | extern time_t restart_interval; |
241 | /* Old current working directory. */ |
242 | extern const char *oldcwd; |
243 | /* Old user and group ID. */ |
244 | extern uid_t old_uid; |
245 | extern gid_t old_gid; |
246 | |
247 | |
248 | /* Prototypes for global functions. */ |
249 | |
250 | /* Wrapper functions with error checking for standard functions. */ |
251 | #include <programs/xmalloc.h> |
252 | |
253 | /* nscd.c */ |
254 | extern void termination_handler (int signum) __attribute__ ((__noreturn__)); |
255 | extern int nscd_open_socket (void); |
256 | void notify_parent (int child_ret); |
257 | void do_exit (int child_ret, int errnum, const char *format, ...); |
258 | |
259 | /* connections.c */ |
260 | extern void nscd_init (void); |
261 | extern void register_traced_file (size_t dbidx, struct traced_file *finfo); |
262 | #ifdef HAVE_INOTIFY |
263 | extern void install_watches (struct traced_file *finfo); |
264 | #endif |
265 | extern void close_sockets (void); |
266 | extern void start_threads (void) __attribute__ ((__noreturn__)); |
267 | |
268 | /* nscd_conf.c */ |
269 | extern int nscd_parse_file (const char *fname, |
270 | struct database_dyn dbs[lastdb]); |
271 | |
272 | /* nscd_stat.c */ |
273 | extern void send_stats (int fd, struct database_dyn dbs[lastdb]); |
274 | extern int receive_print_stats (void) __attribute__ ((__noreturn__)); |
275 | |
276 | /* cache.c */ |
277 | extern struct datahead *cache_search (request_type, const void *key, |
278 | size_t len, struct database_dyn *table, |
279 | uid_t owner); |
280 | extern int cache_add (int type, const void *key, size_t len, |
281 | struct datahead *packet, bool first, |
282 | struct database_dyn *table, uid_t owner, |
283 | bool prune_wakeup); |
284 | extern time_t prune_cache (struct database_dyn *table, time_t now, int fd); |
285 | |
286 | /* pwdcache.c */ |
287 | extern void addpwbyname (struct database_dyn *db, int fd, request_header *req, |
288 | void *key, uid_t uid); |
289 | extern void addpwbyuid (struct database_dyn *db, int fd, request_header *req, |
290 | void *key, uid_t uid); |
291 | extern time_t readdpwbyname (struct database_dyn *db, struct hashentry *he, |
292 | struct datahead *dh); |
293 | extern time_t readdpwbyuid (struct database_dyn *db, struct hashentry *he, |
294 | struct datahead *dh); |
295 | |
296 | /* grpcache.c */ |
297 | extern void addgrbyname (struct database_dyn *db, int fd, request_header *req, |
298 | void *key, uid_t uid); |
299 | extern void addgrbygid (struct database_dyn *db, int fd, request_header *req, |
300 | void *key, uid_t uid); |
301 | extern time_t readdgrbyname (struct database_dyn *db, struct hashentry *he, |
302 | struct datahead *dh); |
303 | extern time_t readdgrbygid (struct database_dyn *db, struct hashentry *he, |
304 | struct datahead *dh); |
305 | |
306 | /* hstcache.c */ |
307 | extern void addhstbyname (struct database_dyn *db, int fd, request_header *req, |
308 | void *key, uid_t uid); |
309 | extern void addhstbyaddr (struct database_dyn *db, int fd, request_header *req, |
310 | void *key, uid_t uid); |
311 | extern void addhstbynamev6 (struct database_dyn *db, int fd, |
312 | request_header *req, void *key, uid_t uid); |
313 | extern void addhstbyaddrv6 (struct database_dyn *db, int fd, |
314 | request_header *req, void *key, uid_t uid); |
315 | extern time_t readdhstbyname (struct database_dyn *db, struct hashentry *he, |
316 | struct datahead *dh); |
317 | extern time_t readdhstbyaddr (struct database_dyn *db, struct hashentry *he, |
318 | struct datahead *dh); |
319 | extern time_t readdhstbynamev6 (struct database_dyn *db, struct hashentry *he, |
320 | struct datahead *dh); |
321 | extern time_t readdhstbyaddrv6 (struct database_dyn *db, struct hashentry *he, |
322 | struct datahead *dh); |
323 | |
324 | /* aicache.c */ |
325 | extern void addhstai (struct database_dyn *db, int fd, request_header *req, |
326 | void *key, uid_t uid); |
327 | extern time_t readdhstai (struct database_dyn *db, struct hashentry *he, |
328 | struct datahead *dh); |
329 | |
330 | |
331 | /* initgrcache.c */ |
332 | extern void addinitgroups (struct database_dyn *db, int fd, |
333 | request_header *req, void *key, uid_t uid); |
334 | extern time_t readdinitgroups (struct database_dyn *db, struct hashentry *he, |
335 | struct datahead *dh); |
336 | |
337 | /* servicecache.c */ |
338 | extern void addservbyname (struct database_dyn *db, int fd, |
339 | request_header *req, void *key, uid_t uid); |
340 | extern time_t readdservbyname (struct database_dyn *db, struct hashentry *he, |
341 | struct datahead *dh); |
342 | extern void addservbyport (struct database_dyn *db, int fd, |
343 | request_header *req, void *key, uid_t uid); |
344 | extern time_t readdservbyport (struct database_dyn *db, struct hashentry *he, |
345 | struct datahead *dh); |
346 | |
347 | /* netgroupcache.c */ |
348 | extern void addinnetgr (struct database_dyn *db, int fd, request_header *req, |
349 | void *key, uid_t uid); |
350 | extern time_t readdinnetgr (struct database_dyn *db, struct hashentry *he, |
351 | struct datahead *dh); |
352 | extern void addgetnetgrent (struct database_dyn *db, int fd, |
353 | request_header *req, void *key, uid_t uid); |
354 | extern time_t readdgetnetgrent (struct database_dyn *db, struct hashentry *he, |
355 | struct datahead *dh); |
356 | |
357 | /* mem.c */ |
358 | extern void *mempool_alloc (struct database_dyn *db, size_t len, |
359 | int data_alloc); |
360 | extern void gc (struct database_dyn *db); |
361 | |
362 | |
363 | /* nscd_setup_thread.c */ |
364 | extern int setup_thread (struct database_dyn *db); |
365 | |
366 | /* cachedumper.c */ |
367 | extern void nscd_print_cache (const char *name); |
368 | |
369 | /* Special version of TEMP_FAILURE_RETRY for functions returning error |
370 | values. */ |
371 | #define TEMP_FAILURE_RETRY_VAL(expression) \ |
372 | (__extension__ \ |
373 | ({ long int __result; \ |
374 | do __result = (long int) (expression); \ |
375 | while (__result == EINTR); \ |
376 | __result; })) |
377 | |
378 | #endif /* nscd.h */ |
379 | |