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   GETAI,
  65   INITGROUPS,
  66   LASTREQ
  67 } request_type;
  68
  69
  70 /* Header common to all requests */
  71 typedef struct
  72 {
  73   int32_t version;      /* Version number of the daemon interface.  */
  74   request_type type;    /* Service requested.  */
  75   int32_t key_len;      /* Key length.  */
  76 } request_header;
  77
  78
  79 /* Structure sent in reply to password query.  Note that this struct is
  80    sent also if the service is disabled or there is no record found.  */
  81 typedef struct
  82 {
  83   int32_t version;
  84   int32_t found;
  85   nscd_ssize_t pw_name_len;
  86   nscd_ssize_t pw_passwd_len;
  87   uid_t pw_uid;
  88   gid_t pw_gid;
  89   nscd_ssize_t pw_gecos_len;
  90   nscd_ssize_t pw_dir_len;
  91   nscd_ssize_t pw_shell_len;
  92 } pw_response_header;
  93
  94
  95 /* Structure sent in reply to group query.  Note that this struct is
  96    sent also if the service is disabled or there is no record found.  */
  97 typedef struct
  98 {
  99   int32_t version;
 100   int32_t found;
 101   nscd_ssize_t gr_name_len;
 102   nscd_ssize_t gr_passwd_len;
 103   gid_t gr_gid;
 104   nscd_ssize_t gr_mem_cnt;
 105 } gr_response_header;
 106
 107
 108 /* Structure sent in reply to host query.  Note that this struct is
 109    sent also if the service is disabled or there is no record found.  */
 110 typedef struct
 111 {
 112   int32_t version;
 113   int32_t found;
 114   nscd_ssize_t h_name_len;
 115   nscd_ssize_t h_aliases_cnt;
 116   int32_t h_addrtype;
 117   int32_t h_length;
 118   nscd_ssize_t h_addr_list_cnt;
 119   int32_t error;
 120 } hst_response_header;
 121
 122
 123 /* Structure sent in reply to addrinfo query.  Note that this struct is
 124    sent also if the service is disabled or there is no record found.  */
 125 typedef struct
 126 {
 127   int32_t version;
 128   int32_t found;
 129   nscd_ssize_t naddrs;
 130   nscd_ssize_t addrslen;
 131   nscd_ssize_t canonlen;
 132   int32_t error;
 133 } ai_response_header;
 134
 135 /* Structure filled in by __nscd_getai.  */
 136 struct nscd_ai_result
 137 {
 138   int naddrs;
 139   char *canon;
 140   uint8_t *family;
 141   char *addrs;
 142 };
 143
 144 /* Structure sent in reply to initgroups query.  Note that this struct is
 145    sent also if the service is disabled or there is no record found.  */
 146 typedef struct
 147 {
 148   int32_t version;
 149   int32_t found;
 150   nscd_ssize_t ngrps;
 151 } initgr_response_header;
 152
 153
 154 /* Type for offsets in data part of database.  */
 155 typedef uint32_t ref_t;
 156 /* Value for invalid/no reference.  */
 157 #define ENDREF  UINT32_MAX
 158
 159 /* Timestamp type.  */
 160 typedef uint64_t nscd_time_t;
 161
 162 /* Alignment requirement of the beginning of the data region.  */
 163 #define ALIGN 16
 164
 165
 166 /* Head of record in data part of database.  */
 167 struct datahead
 168 {
 169   nscd_ssize_t allocsize;       /* Allocated Bytes.  */
 170   nscd_ssize_t recsize;         /* Size of the record.  */
 171   nscd_time_t timeout;          /* Time when this entry becomes invalid.  */
 172   uint8_t notfound;             /* Nonzero if data has not been found.  */
 173   uint8_t nreloads;             /* Reloads without use.  */
 174   uint8_t usable;               /* False if the entry must be ignored.  */
 175   uint64_t :40;                 /* Alignment.  */
 176
 177   /* We need to have the following element aligned for the response
 178      header data types and their use in the 'struct dataset' types
 179      defined in the XXXcache.c files.  */
 180   union
 181   {
 182     pw_response_header pwdata;
 183     gr_response_header grdata;
 184     hst_response_header hstdata;
 185     ai_response_header aidata;
 186     initgr_response_header initgrdata;
 187     nscd_ssize_t align1;
 188     nscd_time_t align2;
 189   } data[0];
 190 };
 191
 192
 193 /* Structure for one hash table entry.  */
 194 struct hashentry
 195 {
 196   request_type type:8;          /* Which type of dataset.  */
 197   bool first;                   /* True if this was the original key.  */
 198   nscd_ssize_t len;             /* Length of key.  */
 199   ref_t key;                    /* Pointer to key.  */
 200   int32_t owner;                /* If secure table, this is the owner.  */
 201   ref_t next;                   /* Next entry in this hash bucket list.  */
 202   ref_t packet;                 /* Records for the result.  */
 203   union
 204   {
 205     struct hashentry *dellist;  /* Next record to be deleted.  This can be a
 206                                    pointer since only nscd uses this field.  */
 207     ref_t *prevp;               /* Pointer to field containing forward
 208                                    reference.  */
 209   };
 210 };
 211
 212
 213 /* Current persistent database version.  */
 214 #define DB_VERSION      1
 215
 216 /* Maximum time allowed between updates of the timestamp.  */
 217 #define MAPPING_TIMEOUT (5 * 60)
 218
 219
 220 /* Header of persistent database file.  */
 221 struct database_pers_head
 222 {
 223   int32_t version;
 224   int32_t header_size;
 225   volatile int32_t gc_cycle;
 226   volatile int32_t nscd_certainly_running;
 227   volatile nscd_time_t timestamp;
 228
 229   nscd_ssize_t module;
 230   nscd_ssize_t data_size;
 231
 232   nscd_ssize_t first_free;      /* Offset of first free byte in data area.  */
 233
 234   nscd_ssize_t nentries;
 235   nscd_ssize_t maxnentries;
 236   nscd_ssize_t maxnsearched;
 237
 238   uint64_t poshit;
 239   uint64_t neghit;
 240   uint64_t posmiss;
 241   uint64_t negmiss;
 242
 243   uint64_t rdlockdelayed;
 244   uint64_t wrlockdelayed;
 245
 246   uint64_t addfailed;
 247
 248   ref_t array[0];
 249 };
 250
 251
 252 /* Mapped database record.  */
 253 struct mapped_database
 254 {
 255   const struct database_pers_head *head;
 256   const char *data;
 257   size_t mapsize;
 258   int counter;          /* > 0 indicates it is usable.  */
 259 };
 260 #define NO_MAPPING ((struct mapped_database *) -1l)
 261
 262 struct locked_map_ptr
 263 {
 264   int lock;
 265   struct mapped_database *mapped;
 266 };
 267 #define libc_locked_map_ptr(name) static struct locked_map_ptr name
 268
 269
 270 /* Open socket connection to nscd server.  */
 271 extern int __nscd_open_socket (const char *key, size_t keylen,
 272                                request_type type, void *response,
 273                                size_t responselen) attribute_hidden;
 274
 275 /* Get reference of mapping.  */
 276 extern struct mapped_database *__nscd_get_map_ref (request_type type,
 277                                                    const char *name,
 278                                                    struct locked_map_ptr *mapptr,
 279                                                    int *gc_cyclep);
 280
 281 /* Unmap database.  */
 282 extern void __nscd_unmap (struct mapped_database *mapped);
 283
 284 /* Drop reference of mapping.  */
 285 static inline int __nscd_drop_map_ref (struct mapped_database *map,
 286                                        int *gc_cycle)
 287 {
 288   if (map != NO_MAPPING)
 289     {
 290       int now_cycle = map->head->gc_cycle;
 291       if (__builtin_expect (now_cycle != *gc_cycle, 0))
 292         {
 293           /* We might have read inconsistent data.  */
 294           *gc_cycle = now_cycle;
 295           return -1;
 296         }
 297
 298       if (atomic_decrement_val (&map->counter) == 0)
 299         __nscd_unmap (map);
 300     }
 301
 302   return 0;
 303 }
 304
 305
 306 /* Search the mapped database.  */
 307 extern const struct datahead *__nscd_cache_search (request_type type,
 308                                                    const char *key,
 309                                                    size_t keylen,
 310                                                    const struct mapped_database *mapped);
 311
 312 #endif /* nscd.h */