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