nscd/nscd.h

   1 /* Copyright (c) 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Thorsten Kukuk <kukuk@suse.de>, 1998.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #ifndef _NSCD_H
  22 #define _NSCD_H 1
  23
  24 #include <pthread.h>
  25 #include <stdbool.h>
  26 #include <time.h>
  27 #include <sys/uio.h>
  28
  29 /* The declarations for the request and response types are in the file
  30    "nscd-client.h", which should contain everything needed by client
  31    functions.  */
  32 #include "nscd-client.h"
  33
  34
  35 /* Handle databases.  */
  36 typedef enum
  37 {
  38   pwddb,
  39   grpdb,
  40   hstdb,
  41   servdb,
  42   lastdb
  43 } dbtype;
  44
  45
  46 /* Default limit on the number of times a value gets reloaded without
  47    being used in the meantime.  NSCD does not throw a value out as
  48    soon as it times out.  It tries to reload the value from the
  49    server.  Only if the value has not been used for so many rounds it
  50    is removed.  */
  51 #define DEFAULT_RELOAD_LIMIT 5
  52
  53
  54 /* Time before restarting the process in paranoia mode.  */
  55 #define RESTART_INTERVAL (60 * 60)
  56
  57
  58 /* Stack size for worker threads.  */
  59 #define NSCD_THREAD_STACKSIZE 1024 * 1024 * (sizeof (void *) / 4)
  60
  61 /* Maximum size of stack frames we allow the thread to use.  We use
  62    80% of the thread stack size.  */
  63 #define MAX_STACK_USE ((8 * NSCD_THREAD_STACKSIZE) / 10)
  64
  65
  66 /* Structure describing dynamic part of one database.  */
  67 struct database_dyn
  68 {
  69   pthread_rwlock_t lock;
  70   pthread_cond_t prune_cond;
  71   pthread_mutex_t prune_lock;
  72   time_t wakeup_time;
  73
  74   int enabled;
  75   int check_file;
  76   int persistent;
  77   int shared;
  78   int propagate;
  79   int reset_res;
  80   const char filename[16];
  81   const char *db_filename;
  82   time_t file_mtime;
  83   size_t suggested_module;
  84   size_t max_db_size;
  85
  86   unsigned long int postimeout; /* In seconds.  */
  87   unsigned long int negtimeout; /* In seconds.  */
  88
  89   int wr_fd;                    /* Writable file descriptor.  */
  90   int ro_fd;                    /* Unwritable file descriptor.  */
  91
  92   const struct iovec *disabled_iov;
  93
  94   struct database_pers_head *head;
  95   char *data;
  96   size_t memsize;
  97   pthread_mutex_t memlock;
  98   bool mmap_used;
  99   bool last_alloc_failed;
 100 };
 101
 102
 103 /* Paths of the file for the persistent storage.  */
 104 #define _PATH_NSCD_PASSWD_DB    "/var/db/nscd/passwd"
 105 #define _PATH_NSCD_GROUP_DB     "/var/db/nscd/group"
 106 #define _PATH_NSCD_HOSTS_DB     "/var/db/nscd/hosts"
 107 #define _PATH_NSCD_SERVICES_DB  "/var/db/nscd/services"
 108
 109 /* Path used when not using persistent storage.  */
 110 #define _PATH_NSCD_XYZ_DB_TMP   "/var/run/nscd/dbXXXXXX"
 111
 112 /* Maximum alignment requirement we will encounter.  */
 113 #define BLOCK_ALIGN_LOG 3
 114 #define BLOCK_ALIGN (1 << BLOCK_ALIGN_LOG)
 115 #define BLOCK_ALIGN_M1 (BLOCK_ALIGN - 1)
 116
 117 /* Default value for the maximum size of the database files.  */
 118 #define DEFAULT_MAX_DB_SIZE     (32 * 1024 * 1024)
 119
 120 /* Number of bytes of data we initially reserve for each hash table bucket.  */
 121 #define DEFAULT_DATASIZE_PER_BUCKET 1024
 122
 123 /* Default module of hash table.  */
 124 #define DEFAULT_SUGGESTED_MODULE 211
 125
 126
 127 /* Number of seconds between two cache pruning runs if we do not have
 128    better information when it is really needed.  */
 129 #define CACHE_PRUNE_INTERVAL    15
 130
 131
 132 /* Global variables.  */
 133 extern struct database_dyn dbs[lastdb] attribute_hidden;
 134 extern const char *const dbnames[lastdb];
 135 extern const char *const serv2str[LASTREQ];
 136
 137 extern const struct iovec pwd_iov_disabled;
 138 extern const struct iovec grp_iov_disabled;
 139 extern const struct iovec hst_iov_disabled;
 140 extern const struct iovec serv_iov_disabled;
 141
 142
 143 /* Initial number of threads to run.  */
 144 extern int nthreads;
 145 /* Maximum number of threads to use.  */
 146 extern int max_nthreads;
 147
 148 /* User name to run server processes as.  */
 149 extern const char *server_user;
 150
 151 /* Name and UID of user who is allowed to request statistics.  */
 152 extern const char *stat_user;
 153 extern uid_t stat_uid;
 154
 155 /* Time the server was started.  */
 156 extern time_t start_time;
 157
 158 /* Number of times clients had to wait.  */
 159 extern unsigned long int client_queued;
 160
 161 /* Maximum needed alignment.  */
 162 extern const size_t block_align;
 163
 164 /* Number of times a value is reloaded without being used.  UINT_MAX
 165    means unlimited.  */
 166 extern unsigned int reload_count;
 167
 168 /* Pagesize minus one.  */
 169 extern uintptr_t pagesize_m1;
 170
 171 /* Nonzero if paranoia mode is enabled.  */
 172 extern int paranoia;
 173 /* Time after which the process restarts.  */
 174 extern time_t restart_time;
 175 /* How much time between restarts.  */
 176 extern time_t restart_interval;
 177 /* Old current working directory.  */
 178 extern const char *oldcwd;
 179 /* Old user and group ID.  */
 180 extern uid_t old_uid;
 181 extern gid_t old_gid;
 182
 183
 184 /* Memory allocation in flight.  Each thread can have a limited number
 185    of allocation in flight.  No need to create dynamic data
 186    structures.  We use fixed indices.  */
 187 enum in_flight
 188   {
 189     IDX_result_data = 0,
 190     /* Keep the IDX_record_data entry last at all times.  */
 191     IDX_record_data = 1,
 192     IDX_last
 193   };
 194 extern __thread struct mem_in_flight
 195 {
 196   struct
 197   {
 198     int dbidx;
 199     nscd_ssize_t blocklen;
 200     nscd_ssize_t blockoff;
 201   } block[IDX_last];
 202
 203   struct mem_in_flight *next;
 204 } mem_in_flight attribute_tls_model_ie;
 205 /* Global list of the mem_in_flight variables of all the threads.  */
 206 extern struct mem_in_flight *mem_in_flight_list;
 207
 208
 209 /* Prototypes for global functions.  */
 210
 211 /* nscd.c */
 212 extern void termination_handler (int signum) __attribute__ ((__noreturn__));
 213 extern int nscd_open_socket (void);
 214
 215 /* connections.c */
 216 extern void nscd_init (void);
 217 extern void close_sockets (void);
 218 extern void start_threads (void) __attribute__ ((__noreturn__));
 219
 220 /* nscd_conf.c */
 221 extern int nscd_parse_file (const char *fname,
 222                             struct database_dyn dbs[lastdb]);
 223
 224 /* nscd_stat.c */
 225 extern void send_stats (int fd, struct database_dyn dbs[lastdb]);
 226 extern int receive_print_stats (void) __attribute__ ((__noreturn__));
 227
 228 /* cache.c */
 229 extern struct datahead *cache_search (request_type, void *key, size_t len,
 230                                       struct database_dyn *table,
 231                                       uid_t owner);
 232 extern int cache_add (int type, const void *key, size_t len,
 233                       struct datahead *packet, bool first,
 234                       struct database_dyn *table, uid_t owner,
 235                       bool prune_wakeup);
 236 extern time_t prune_cache (struct database_dyn *table, time_t now, int fd);
 237
 238 /* pwdcache.c */
 239 extern void addpwbyname (struct database_dyn *db, int fd, request_header *req,
 240                          void *key, uid_t uid);
 241 extern void addpwbyuid (struct database_dyn *db, int fd, request_header *req,
 242                         void *key, uid_t uid);
 243 extern void readdpwbyname (struct database_dyn *db, struct hashentry *he,
 244                            struct datahead *dh);
 245 extern void readdpwbyuid (struct database_dyn *db, struct hashentry *he,
 246                           struct datahead *dh);
 247
 248 /* grpcache.c */
 249 extern void addgrbyname (struct database_dyn *db, int fd, request_header *req,
 250                          void *key, uid_t uid);
 251 extern void addgrbygid (struct database_dyn *db, int fd, request_header *req,
 252                         void *key, uid_t uid);
 253 extern void readdgrbyname (struct database_dyn *db, struct hashentry *he,
 254                            struct datahead *dh);
 255 extern void readdgrbygid (struct database_dyn *db, struct hashentry *he,
 256                           struct datahead *dh);
 257
 258 /* hstcache.c */
 259 extern void addhstbyname (struct database_dyn *db, int fd, request_header *req,
 260                           void *key, uid_t uid);
 261 extern void addhstbyaddr (struct database_dyn *db, int fd, request_header *req,
 262                           void *key, uid_t uid);
 263 extern void addhstbynamev6 (struct database_dyn *db, int fd,
 264                             request_header *req, void *key, uid_t uid);
 265 extern void addhstbyaddrv6 (struct database_dyn *db, int fd,
 266                             request_header *req, void *key, uid_t uid);
 267 extern void readdhstbyname (struct database_dyn *db, struct hashentry *he,
 268                             struct datahead *dh);
 269 extern void readdhstbyaddr (struct database_dyn *db, struct hashentry *he,
 270                             struct datahead *dh);
 271 extern void readdhstbynamev6 (struct database_dyn *db, struct hashentry *he,
 272                               struct datahead *dh);
 273 extern void readdhstbyaddrv6 (struct database_dyn *db, struct hashentry *he,
 274                               struct datahead *dh);
 275
 276 /* aicache.c */
 277 extern void addhstai (struct database_dyn *db, int fd, request_header *req,
 278                       void *key, uid_t uid);
 279 extern void readdhstai (struct database_dyn *db, struct hashentry *he,
 280                         struct datahead *dh);
 281
 282
 283 /* initgrcache.c */
 284 extern void addinitgroups (struct database_dyn *db, int fd,
 285                            request_header *req, void *key, uid_t uid);
 286 extern void readdinitgroups (struct database_dyn *db, struct hashentry *he,
 287                              struct datahead *dh);
 288
 289 /* servicecache.c */
 290 extern void addservbyname (struct database_dyn *db, int fd,
 291                            request_header *req, void *key, uid_t uid);
 292 extern void readdservbyname (struct database_dyn *db, struct hashentry *he,
 293                              struct datahead *dh);
 294 extern void addservbyport (struct database_dyn *db, int fd,
 295                            request_header *req, void *key, uid_t uid);
 296 extern void readdservbyport (struct database_dyn *db, struct hashentry *he,
 297                              struct datahead *dh);
 298
 299 /* mem.c */
 300 extern void *mempool_alloc (struct database_dyn *db, size_t len,
 301                             enum in_flight idx);
 302 extern void gc (struct database_dyn *db);
 303
 304
 305 /* nscd_setup_thread.c */
 306 extern int setup_thread (struct database_dyn *db);
 307
 308
 309 /* Special version of TEMP_FAILURE_RETRY for functions returning error
 310    values.  */
 311 #define TEMP_FAILURE_RETRY_VAL(expression) \
 312   (__extension__                                                              \
 313     ({ long int __result;                                                     \
 314        do __result = (long int) (expression);                                 \
 315        while (__result == EINTR);                                             \
 316        __result; }))
 317
 318 #endif /* nscd.h */