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   pthread_mutex_t prune_run_lock;
  73   time_t wakeup_time;
  74
  75   int enabled;
  76   int check_file;
  77   int inotify_descr;
  78   int clear_cache;
  79   int persistent;
  80   int shared;
  81   int propagate;
  82   int reset_res;
  83   const char filename[16];
  84   const char *db_filename;
  85   time_t file_mtime;
  86   size_t suggested_module;
  87   size_t max_db_size;
  88
  89   unsigned long int postimeout; /* In seconds.  */
  90   unsigned long int negtimeout; /* In seconds.  */
  91
  92   int wr_fd;                    /* Writable file descriptor.  */
  93   int ro_fd;                    /* Unwritable file descriptor.  */
  94
  95   const struct iovec *disabled_iov;
  96
  97   struct database_pers_head *head;
  98   char *data;
  99   size_t memsize;
 100   pthread_mutex_t memlock;
 101   bool mmap_used;
 102   bool last_alloc_failed;
 103 };
 104
 105
 106 /* Paths of the file for the persistent storage.  */
 107 #define _PATH_NSCD_PASSWD_DB    "/var/db/nscd/passwd"
 108 #define _PATH_NSCD_GROUP_DB     "/var/db/nscd/group"
 109 #define _PATH_NSCD_HOSTS_DB     "/var/db/nscd/hosts"
 110 #define _PATH_NSCD_SERVICES_DB  "/var/db/nscd/services"
 111
 112 /* Path used when not using persistent storage.  */
 113 #define _PATH_NSCD_XYZ_DB_TMP   "/var/run/nscd/dbXXXXXX"
 114
 115 /* Maximum alignment requirement we will encounter.  */
 116 #define BLOCK_ALIGN_LOG 3
 117 #define BLOCK_ALIGN (1 << BLOCK_ALIGN_LOG)
 118 #define BLOCK_ALIGN_M1 (BLOCK_ALIGN - 1)
 119
 120 /* Default value for the maximum size of the database files.  */
 121 #define DEFAULT_MAX_DB_SIZE     (32 * 1024 * 1024)
 122
 123 /* Number of bytes of data we initially reserve for each hash table bucket.  */
 124 #define DEFAULT_DATASIZE_PER_BUCKET 1024
 125
 126 /* Default module of hash table.  */
 127 #define DEFAULT_SUGGESTED_MODULE 211
 128
 129
 130 /* Number of seconds between two cache pruning runs if we do not have
 131    better information when it is really needed.  */
 132 #define CACHE_PRUNE_INTERVAL    15
 133
 134
 135 /* Global variables.  */
 136 extern struct database_dyn dbs[lastdb] attribute_hidden;
 137 extern const char *const dbnames[lastdb];
 138 extern const char *const serv2str[LASTREQ];
 139
 140 extern const struct iovec pwd_iov_disabled;
 141 extern const struct iovec grp_iov_disabled;
 142 extern const struct iovec hst_iov_disabled;
 143 extern const struct iovec serv_iov_disabled;
 144
 145
 146 /* Initial number of threads to run.  */
 147 extern int nthreads;
 148 /* Maximum number of threads to use.  */
 149 extern int max_nthreads;
 150
 151 /* User name to run server processes as.  */
 152 extern const char *server_user;
 153
 154 /* Name and UID of user who is allowed to request statistics.  */
 155 extern const char *stat_user;
 156 extern uid_t stat_uid;
 157
 158 /* Time the server was started.  */
 159 extern time_t start_time;
 160
 161 /* Number of times clients had to wait.  */
 162 extern unsigned long int client_queued;
 163
 164 /* Maximum needed alignment.  */
 165 extern const size_t block_align;
 166
 167 /* Number of times a value is reloaded without being used.  UINT_MAX
 168    means unlimited.  */
 169 extern unsigned int reload_count;
 170
 171 /* Pagesize minus one.  */
 172 extern uintptr_t pagesize_m1;
 173
 174 /* Nonzero if paranoia mode is enabled.  */
 175 extern int paranoia;
 176 /* Time after which the process restarts.  */
 177 extern time_t restart_time;
 178 /* How much time between restarts.  */
 179 extern time_t restart_interval;
 180 /* Old current working directory.  */
 181 extern const char *oldcwd;
 182 /* Old user and group ID.  */
 183 extern uid_t old_uid;
 184 extern gid_t old_gid;
 185
 186
 187 /* Memory allocation in flight.  Each thread can have a limited number
 188    of allocation in flight.  No need to create dynamic data
 189    structures.  We use fixed indices.  */
 190 enum in_flight
 191   {
 192     IDX_result_data = 0,
 193     /* Keep the IDX_record_data entry last at all times.  */
 194     IDX_record_data = 1,
 195     IDX_last
 196   };
 197 extern __thread struct mem_in_flight
 198 {
 199   struct
 200   {
 201     int dbidx;
 202     nscd_ssize_t blocklen;
 203     nscd_ssize_t blockoff;
 204   } block[IDX_last];
 205
 206   struct mem_in_flight *next;
 207 } mem_in_flight attribute_tls_model_ie;
 208 /* Global list of the mem_in_flight variables of all the threads.  */
 209 extern struct mem_in_flight *mem_in_flight_list;
 210
 211
 212 /* Prototypes for global functions.  */
 213
 214 /* nscd.c */
 215 extern void termination_handler (int signum) __attribute__ ((__noreturn__));
 216 extern int nscd_open_socket (void);
 217
 218 /* connections.c */
 219 extern void nscd_init (void);
 220 extern void close_sockets (void);
 221 extern void start_threads (void) __attribute__ ((__noreturn__));
 222
 223 /* nscd_conf.c */
 224 extern int nscd_parse_file (const char *fname,
 225                             struct database_dyn dbs[lastdb]);
 226
 227 /* nscd_stat.c */
 228 extern void send_stats (int fd, struct database_dyn dbs[lastdb]);
 229 extern int receive_print_stats (void) __attribute__ ((__noreturn__));
 230
 231 /* cache.c */
 232 extern struct datahead *cache_search (request_type, void *key, size_t len,
 233                                       struct database_dyn *table,
 234                                       uid_t owner);
 235 extern int cache_add (int type, const void *key, size_t len,
 236                       struct datahead *packet, bool first,
 237                       struct database_dyn *table, uid_t owner,
 238                       bool prune_wakeup);
 239 extern time_t prune_cache (struct database_dyn *table, time_t now, int fd);
 240
 241 /* pwdcache.c */
 242 extern void addpwbyname (struct database_dyn *db, int fd, request_header *req,
 243                          void *key, uid_t uid);
 244 extern void addpwbyuid (struct database_dyn *db, int fd, request_header *req,
 245                         void *key, uid_t uid);
 246 extern void readdpwbyname (struct database_dyn *db, struct hashentry *he,
 247                            struct datahead *dh);
 248 extern void readdpwbyuid (struct database_dyn *db, struct hashentry *he,
 249                           struct datahead *dh);
 250
 251 /* grpcache.c */
 252 extern void addgrbyname (struct database_dyn *db, int fd, request_header *req,
 253                          void *key, uid_t uid);
 254 extern void addgrbygid (struct database_dyn *db, int fd, request_header *req,
 255                         void *key, uid_t uid);
 256 extern void readdgrbyname (struct database_dyn *db, struct hashentry *he,
 257                            struct datahead *dh);
 258 extern void readdgrbygid (struct database_dyn *db, struct hashentry *he,
 259                           struct datahead *dh);
 260
 261 /* hstcache.c */
 262 extern void addhstbyname (struct database_dyn *db, int fd, request_header *req,
 263                           void *key, uid_t uid);
 264 extern void addhstbyaddr (struct database_dyn *db, int fd, request_header *req,
 265                           void *key, uid_t uid);
 266 extern void addhstbynamev6 (struct database_dyn *db, int fd,
 267                             request_header *req, void *key, uid_t uid);
 268 extern void addhstbyaddrv6 (struct database_dyn *db, int fd,
 269                             request_header *req, void *key, uid_t uid);
 270 extern void readdhstbyname (struct database_dyn *db, struct hashentry *he,
 271                             struct datahead *dh);
 272 extern void readdhstbyaddr (struct database_dyn *db, struct hashentry *he,
 273                             struct datahead *dh);
 274 extern void readdhstbynamev6 (struct database_dyn *db, struct hashentry *he,
 275                               struct datahead *dh);
 276 extern void readdhstbyaddrv6 (struct database_dyn *db, struct hashentry *he,
 277                               struct datahead *dh);
 278
 279 /* aicache.c */
 280 extern void addhstai (struct database_dyn *db, int fd, request_header *req,
 281                       void *key, uid_t uid);
 282 extern void readdhstai (struct database_dyn *db, struct hashentry *he,
 283                         struct datahead *dh);
 284
 285
 286 /* initgrcache.c */
 287 extern void addinitgroups (struct database_dyn *db, int fd,
 288                            request_header *req, void *key, uid_t uid);
 289 extern void readdinitgroups (struct database_dyn *db, struct hashentry *he,
 290                              struct datahead *dh);
 291
 292 /* servicecache.c */
 293 extern void addservbyname (struct database_dyn *db, int fd,
 294                            request_header *req, void *key, uid_t uid);
 295 extern void readdservbyname (struct database_dyn *db, struct hashentry *he,
 296                              struct datahead *dh);
 297 extern void addservbyport (struct database_dyn *db, int fd,
 298                            request_header *req, void *key, uid_t uid);
 299 extern void readdservbyport (struct database_dyn *db, struct hashentry *he,
 300                              struct datahead *dh);
 301
 302 /* mem.c */
 303 extern void *mempool_alloc (struct database_dyn *db, size_t len,
 304                             enum in_flight idx);
 305 extern void gc (struct database_dyn *db);
 306
 307
 308 /* nscd_setup_thread.c */
 309 extern int setup_thread (struct database_dyn *db);
 310
 311
 312 /* Special version of TEMP_FAILURE_RETRY for functions returning error
 313    values.  */
 314 #define TEMP_FAILURE_RETRY_VAL(expression) \
 315   (__extension__                                                              \
 316     ({ long int __result;                                                     \
 317        do __result = (long int) (expression);                                 \
 318        while (__result == EINTR);                                             \
 319        __result; }))
 320
 321 #endif /* nscd.h */