nscd/nscd-client.h

   1 /* Copyright (c) 1998, 1999, 2000, 2003, 2004 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@suse.de>, 1998.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 /* This file defines everything that client code should need to
  21    know to talk to the nscd daemon.  */
  22
  23 #ifndef _NSCD_CLIENT_H
  24 #define _NSCD_CLIENT_H  1
  25
  26 #include <stdbool.h>
  27 #include <stdint.h>
  28 #include <sys/types.h>
  29 #include <atomic.h>
  30 #include <nscd-types.h>
  31
  32
  33 /* Version number of the daemon interface */
  34 #define NSCD_VERSION 2
  35
  36 /* Path of the file where the PID of the running system is stored.  */
  37 #define _PATH_NSCDPID    "/var/run/nscd/nscd.pid"
  38
  39 /* Path for the Unix domain socket.  */
  40 #define _PATH_NSCDSOCKET "/var/run/nscd/socket"
  41
  42 /* Path for the configuration file.  */
  43 #define _PATH_NSCDCONF   "/etc/nscd.conf"
  44
  45
  46 /* Available services.  */
  47 typedef enum
  48 {
  49   GETPWBYNAME,
  50   GETPWBYUID,
  51   GETGRBYNAME,
  52   GETGRBYGID,
  53   GETHOSTBYNAME,
  54   GETHOSTBYNAMEv6,
  55   GETHOSTBYADDR,
  56   GETHOSTBYADDRv6,
  57   LASTDBREQ = GETHOSTBYADDRv6,
  58   SHUTDOWN,             /* Shut the server down.  */
  59   GETSTAT,              /* Get the server statistic.  */
  60   INVALIDATE,           /* Invalidate one special cache.  */
  61   GETFDPW,
  62   GETFDGR,
  63   GETFDHST,
  64   LASTREQ
  65 } request_type;
  66
  67
  68 /* Header common to all requests */
  69 typedef struct
  70 {
  71   int32_t version;      /* Version number of the daemon interface.  */
  72   request_type type;    /* Service requested.  */
  73   int32_t key_len;      /* Key length.  */
  74 } request_header;
  75
  76
  77 /* Structure sent in reply to password query.  Note that this struct is
  78    sent also if the service is disabled or there is no record found.  */
  79 typedef struct
  80 {
  81   int32_t version;
  82   int32_t found;
  83   nscd_ssize_t pw_name_len;
  84   nscd_ssize_t pw_passwd_len;
  85   uid_t pw_uid;
  86   gid_t pw_gid;
  87   nscd_ssize_t pw_gecos_len;
  88   nscd_ssize_t pw_dir_len;
  89   nscd_ssize_t pw_shell_len;
  90 } pw_response_header;
  91
  92
  93 /* Structure sent in reply to group query.  Note that this struct is
  94    sent also if the service is disabled or there is no record found.  */
  95 typedef struct
  96 {
  97   int32_t version;
  98   int32_t found;
  99   nscd_ssize_t gr_name_len;
 100   nscd_ssize_t gr_passwd_len;
 101   gid_t gr_gid;
 102   nscd_ssize_t gr_mem_cnt;
 103 } gr_response_header;
 104
 105
 106 /* Structure sent in reply to host query.  Note that this struct is
 107    sent also if the service is disabled or there is no record found.  */
 108 typedef struct
 109 {
 110   int32_t version;
 111   int32_t found;
 112   nscd_ssize_t h_name_len;
 113   nscd_ssize_t h_aliases_cnt;
 114   int32_t h_addrtype;
 115   int32_t h_length;
 116   nscd_ssize_t h_addr_list_cnt;
 117   int32_t error;
 118 } hst_response_header;
 119
 120
 121 /* Type for offsets in data part of database.  */
 122 typedef uint32_t ref_t;
 123 /* Value for invalid/no reference.  */
 124 #define ENDREF  UINT32_MAX
 125
 126 /* Alignment requirement of the beginning of the data region.  */
 127 #define ALIGN 16
 128
 129
 130 /* Head of record in data part of database.  */
 131 struct datahead
 132 {
 133   size_t allocsize;     /* Allocated Bytes.  */
 134   size_t recsize;       /* Size of the record.  */
 135   time_t timeout;       /* Time when this entry becomes invalid.  */
 136   bool notfound;        /* Nonzero if data for key has not been found.  */
 137   uint8_t nreloads;     /* Reloads without use.  */
 138   bool usable;          /* False if the entry must be ignored.  */
 139
 140   /* We need to have the following element aligned for the response
 141      header data types and their use in the 'struct dataset' types
 142      defined in the XXXcache.c files.  */
 143   union
 144   {
 145     pw_response_header pwdata;
 146     gr_response_header grdata;
 147     hst_response_header hstdata;
 148     ssize_t align1;
 149     time_t align2;
 150   } data[0];
 151 };
 152
 153
 154 /* Structure for one hash table entry.  */
 155 struct hashentry
 156 {
 157   request_type type:8;          /* Which type of dataset.  */
 158   bool first;                   /* True if this was the original key.  */
 159   size_t len;                   /* Length of key.  */
 160   ref_t key;                    /* Pointer to key.  */
 161   uid_t owner;                  /* If secure table, this is the owner.  */
 162   ref_t next;                   /* Next entry in this hash bucket list.  */
 163   ref_t packet;                 /* Records for the result.  */
 164   union
 165   {
 166     struct hashentry *dellist;  /* Next record to be deleted.  This can be a
 167                                    pointer since only nscd uses this field.  */
 168     ref_t *prevp;               /* Pointer to field containing forward
 169                                    reference.  */
 170   };
 171 };
 172
 173
 174 /* Current persistent database version.  */
 175 #define DB_VERSION      1
 176
 177 /* Maximum time allowed between updates of the timestamp.  */
 178 #define MAPPING_TIMEOUT (5 * 60)
 179
 180
 181 /* Header of persistent database file.  */
 182 struct database_pers_head
 183 {
 184   int version;
 185   int header_size;
 186   volatile int gc_cycle;
 187   volatile int nscd_certainly_running;
 188   volatile time_t timestamp;
 189
 190   size_t module;
 191   size_t data_size;
 192
 193   size_t first_free;            /* Offset of first free byte in data area.  */
 194
 195   size_t nentries;
 196   size_t maxnentries;
 197   size_t maxnsearched;
 198
 199   uintmax_t poshit;
 200   uintmax_t neghit;
 201   uintmax_t posmiss;
 202   uintmax_t negmiss;
 203
 204   uintmax_t rdlockdelayed;
 205   uintmax_t wrlockdelayed;
 206
 207   uintmax_t addfailed;
 208
 209   ref_t array[0];
 210 };
 211
 212
 213 /* Mapped database record.  */
 214 struct mapped_database
 215 {
 216   const struct database_pers_head *head;
 217   const char *data;
 218   size_t mapsize;
 219   int counter;          /* > 0 indicates it isusable.  */
 220 };
 221 #define NO_MAPPING ((struct mapped_database *) -1l)
 222
 223 struct locked_map_ptr
 224 {
 225   int lock;
 226   struct mapped_database *mapped;
 227 };
 228 #define libc_locked_map_ptr(name) static struct locked_map_ptr name
 229
 230
 231 /* Open socket connection to nscd server.  */
 232 extern int __nscd_open_socket (const char *key, size_t keylen,
 233                                request_type type, void *response,
 234                                size_t responselen) attribute_hidden;
 235
 236 /* Get reference of mapping.  */
 237 extern struct mapped_database *__nscd_get_map_ref (request_type type,
 238                                                    const char *name,
 239                                                    struct locked_map_ptr *mapptr,
 240                                                    volatile int *gc_cyclep);
 241
 242 /* Unmap database.  */
 243 extern void __nscd_unmap (struct mapped_database *mapped);
 244
 245 /* Drop reference of mapping.  */
 246 static inline int __nscd_drop_map_ref (struct mapped_database *map,
 247                                        int gc_cycle)
 248 {
 249   if (map != NO_MAPPING)
 250     {
 251       if (__builtin_expect (map->head->gc_cycle != gc_cycle, 0))
 252         /* We might have read inconsistent data.  */
 253         return -1;
 254
 255       if (atomic_decrement_val (&map->counter) == 0)
 256         __nscd_unmap (map);
 257     }
 258
 259   return 0;
 260 }
 261
 262
 263 /* Search the mapped database.  */
 264 extern const struct datahead *__nscd_cache_search (request_type type,
 265                                                    const char *key,
 266                                                    size_t keylen,
 267                                                    const struct mapped_database *mapped);
 268
 269 #endif /* nscd.h */