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 #include <sys/uio.h>
  32
  33
  34 /* Version number of the daemon interface */
  35 #define NSCD_VERSION 2
  36
  37 /* Path of the file where the PID of the running system is stored.  */
  38 #define _PATH_NSCDPID    "/var/run/nscd/nscd.pid"
  39
  40 /* Path for the Unix domain socket.  */
  41 #define _PATH_NSCDSOCKET "/var/run/nscd/socket"
  42
  43 /* Path for the configuration file.  */
  44 #define _PATH_NSCDCONF   "/etc/nscd.conf"
  45
  46
  47 /* Available services.  */
  48 typedef enum
  49 {
  50   GETPWBYNAME,
  51   GETPWBYUID,
  52   GETGRBYNAME,
  53   GETGRBYGID,
  54   GETHOSTBYNAME,
  55   GETHOSTBYNAMEv6,
  56   GETHOSTBYADDR,
  57   GETHOSTBYADDRv6,
  58   LASTDBREQ = GETHOSTBYADDRv6,
  59   SHUTDOWN,             /* Shut the server down.  */
  60   GETSTAT,              /* Get the server statistic.  */
  61   INVALIDATE,           /* Invalidate one special cache.  */
  62   GETFDPW,
  63   GETFDGR,
  64   GETFDHST,
  65   GETAI,
  66   INITGROUPS,
  67   LASTREQ
  68 } request_type;
  69
  70
  71 /* Header common to all requests */
  72 typedef struct
  73 {
  74   int32_t version;      /* Version number of the daemon interface.  */
  75   request_type type;    /* Service requested.  */
  76   int32_t key_len;      /* Key length.  */
  77 } request_header;
  78
  79
  80 /* Structure sent in reply to password query.  Note that this struct is
  81    sent also if the service is disabled or there is no record found.  */
  82 typedef struct
  83 {
  84   int32_t version;
  85   int32_t found;
  86   nscd_ssize_t pw_name_len;
  87   nscd_ssize_t pw_passwd_len;
  88   uid_t pw_uid;
  89   gid_t pw_gid;
  90   nscd_ssize_t pw_gecos_len;
  91   nscd_ssize_t pw_dir_len;
  92   nscd_ssize_t pw_shell_len;
  93 } pw_response_header;
  94
  95
  96 /* Structure sent in reply to group query.  Note that this struct is
  97    sent also if the service is disabled or there is no record found.  */
  98 typedef struct
  99 {
 100   int32_t version;
 101   int32_t found;
 102   nscd_ssize_t gr_name_len;
 103   nscd_ssize_t gr_passwd_len;
 104   gid_t gr_gid;
 105   nscd_ssize_t gr_mem_cnt;
 106 } gr_response_header;
 107
 108
 109 /* Structure sent in reply to host query.  Note that this struct is
 110    sent also if the service is disabled or there is no record found.  */
 111 typedef struct
 112 {
 113   int32_t version;
 114   int32_t found;
 115   nscd_ssize_t h_name_len;
 116   nscd_ssize_t h_aliases_cnt;
 117   int32_t h_addrtype;
 118   int32_t h_length;
 119   nscd_ssize_t h_addr_list_cnt;
 120   int32_t error;
 121 } hst_response_header;
 122
 123
 124 /* Structure sent in reply to addrinfo query.  Note that this struct is
 125    sent also if the service is disabled or there is no record found.  */
 126 typedef struct
 127 {
 128   int32_t version;
 129   int32_t found;
 130   nscd_ssize_t naddrs;
 131   nscd_ssize_t addrslen;
 132   nscd_ssize_t canonlen;
 133   int32_t error;
 134 } ai_response_header;
 135
 136 /* Structure filled in by __nscd_getai.  */
 137 struct nscd_ai_result
 138 {
 139   int naddrs;
 140   char *canon;
 141   uint8_t *family;
 142   char *addrs;
 143 };
 144
 145 /* Structure sent in reply to initgroups query.  Note that this struct is
 146    sent also if the service is disabled or there is no record found.  */
 147 typedef struct
 148 {
 149   int32_t version;
 150   int32_t found;
 151   nscd_ssize_t ngrps;
 152 } initgr_response_header;
 153
 154
 155 /* Type for offsets in data part of database.  */
 156 typedef uint32_t ref_t;
 157 /* Value for invalid/no reference.  */
 158 #define ENDREF  UINT32_MAX
 159
 160 /* Timestamp type.  */
 161 typedef uint64_t nscd_time_t;
 162
 163 /* Alignment requirement of the beginning of the data region.  */
 164 #define ALIGN 16
 165
 166
 167 /* Head of record in data part of database.  */
 168 struct datahead
 169 {
 170   nscd_ssize_t allocsize;       /* Allocated Bytes.  */
 171   nscd_ssize_t recsize;         /* Size of the record.  */
 172   nscd_time_t timeout;          /* Time when this entry becomes invalid.  */
 173   uint8_t notfound;             /* Nonzero if data has not been found.  */
 174   uint8_t nreloads;             /* Reloads without use.  */
 175   uint8_t usable;               /* False if the entry must be ignored.  */
 176   uint64_t :40;                 /* Alignment.  */
 177
 178   /* We need to have the following element aligned for the response
 179      header data types and their use in the 'struct dataset' types
 180      defined in the XXXcache.c files.  */
 181   union
 182   {
 183     pw_response_header pwdata;
 184     gr_response_header grdata;
 185     hst_response_header hstdata;
 186     ai_response_header aidata;
 187     initgr_response_header initgrdata;
 188     nscd_ssize_t align1;
 189     nscd_time_t align2;
 190   } data[0];
 191 };
 192
 193
 194 /* Structure for one hash table entry.  */
 195 struct hashentry
 196 {
 197   request_type type:8;          /* Which type of dataset.  */
 198   bool first;                   /* True if this was the original key.  */
 199   nscd_ssize_t len;             /* Length of key.  */
 200   ref_t key;                    /* Pointer to key.  */
 201   int32_t owner;                /* If secure table, this is the owner.  */
 202   ref_t next;                   /* Next entry in this hash bucket list.  */
 203   ref_t packet;                 /* Records for the result.  */
 204   union
 205   {
 206     struct hashentry *dellist;  /* Next record to be deleted.  This can be a
 207                                    pointer since only nscd uses this field.  */
 208     ref_t *prevp;               /* Pointer to field containing forward
 209                                    reference.  */
 210   };
 211 };
 212
 213
 214 /* Current persistent database version.  */
 215 #define DB_VERSION      1
 216
 217 /* Maximum time allowed between updates of the timestamp.  */
 218 #define MAPPING_TIMEOUT (5 * 60)
 219
 220
 221 /* Header of persistent database file.  */
 222 struct database_pers_head
 223 {
 224   int32_t version;
 225   int32_t header_size;
 226   volatile int32_t gc_cycle;
 227   volatile int32_t nscd_certainly_running;
 228   volatile nscd_time_t timestamp;
 229
 230   nscd_ssize_t module;
 231   nscd_ssize_t data_size;
 232
 233   nscd_ssize_t first_free;      /* Offset of first free byte in data area.  */
 234
 235   nscd_ssize_t nentries;
 236   nscd_ssize_t maxnentries;
 237   nscd_ssize_t maxnsearched;
 238
 239   uint64_t poshit;
 240   uint64_t neghit;
 241   uint64_t posmiss;
 242   uint64_t negmiss;
 243
 244   uint64_t rdlockdelayed;
 245   uint64_t wrlockdelayed;
 246
 247   uint64_t addfailed;
 248
 249   ref_t array[0];
 250 };
 251
 252
 253 /* Mapped database record.  */
 254 struct mapped_database
 255 {
 256   const struct database_pers_head *head;
 257   const char *data;
 258   size_t mapsize;
 259   int counter;          /* > 0 indicates it is usable.  */
 260 };
 261 #define NO_MAPPING ((struct mapped_database *) -1l)
 262
 263 struct locked_map_ptr
 264 {
 265   int lock;
 266   struct mapped_database *mapped;
 267 };
 268 #define libc_locked_map_ptr(class, name) class struct locked_map_ptr name
 269
 270
 271 /* Open socket connection to nscd server.  */
 272 extern int __nscd_open_socket (const char *key, size_t keylen,
 273                                request_type type, void *response,
 274                                size_t responselen) attribute_hidden;
 275
 276 /* Get reference of mapping.  */
 277 extern struct mapped_database *__nscd_get_map_ref (request_type type,
 278                                                    const char *name,
 279                                                    struct locked_map_ptr *mapptr,
 280                                                    int *gc_cyclep);
 281
 282 /* Unmap database.  */
 283 extern void __nscd_unmap (struct mapped_database *mapped);
 284
 285 /* Drop reference of mapping.  */
 286 static inline int __nscd_drop_map_ref (struct mapped_database *map,
 287                                        int *gc_cycle)
 288 {
 289   if (map != NO_MAPPING)
 290     {
 291       int now_cycle = map->head->gc_cycle;
 292       if (__builtin_expect (now_cycle != *gc_cycle, 0))
 293         {
 294           /* We might have read inconsistent data.  */
 295           *gc_cycle = now_cycle;
 296           return -1;
 297         }
 298
 299       if (atomic_decrement_val (&map->counter) == 0)
 300         __nscd_unmap (map);
 301     }
 302
 303   return 0;
 304 }
 305
 306
 307 /* Search the mapped database.  */
 308 extern const struct datahead *__nscd_cache_search (request_type type,
 309                                                    const char *key,
 310                                                    size_t keylen,
 311                                                    const struct mapped_database *mapped);
 312
 313 /* Wrappers around read, readv and write that only read/write less than LEN
 314    bytes on error or EOF.  */
 315 extern ssize_t __readall (int fd, void *buf, size_t len)
 316   attribute_hidden;
 317 extern ssize_t __readvall (int fd, const struct iovec *iov, int iovcnt)
 318   attribute_hidden;
 319 extern ssize_t writeall (int fd, const void *buf, size_t len)
 320   attribute_hidden;
 321
 322 #endif /* nscd.h */