nscd/nscd-client.h

   1 /* Copyright (c) 1998, 1999, 2000, 2003, 2004, 2005
   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 /* This file defines everything that client code should need to
  22    know to talk to the nscd daemon.  */
  23
  24 #ifndef _NSCD_CLIENT_H
  25 #define _NSCD_CLIENT_H  1
  26
  27 #include <stdbool.h>
  28 #include <stdint.h>
  29 #include <sys/types.h>
  30 #include <atomic.h>
  31 #include <nscd-types.h>
  32 #include <sys/uio.h>
  33
  34
  35 /* Version number of the daemon interface */
  36 #define NSCD_VERSION 2
  37
  38 /* Path of the file where the PID of the running system is stored.  */
  39 #define _PATH_NSCDPID    "/var/run/nscd/nscd.pid"
  40
  41 /* Path for the Unix domain socket.  */
  42 #define _PATH_NSCDSOCKET "/var/run/nscd/socket"
  43
  44 /* Path for the configuration file.  */
  45 #define _PATH_NSCDCONF   "/etc/nscd.conf"
  46
  47
  48 /* Available services.  */
  49 typedef enum
  50 {
  51   GETPWBYNAME,
  52   GETPWBYUID,
  53   GETGRBYNAME,
  54   GETGRBYGID,
  55   GETHOSTBYNAME,
  56   GETHOSTBYNAMEv6,
  57   GETHOSTBYADDR,
  58   GETHOSTBYADDRv6,
  59   LASTDBREQ = GETHOSTBYADDRv6,
  60   SHUTDOWN,             /* Shut the server down.  */
  61   GETSTAT,              /* Get the server statistic.  */
  62   INVALIDATE,           /* Invalidate one special cache.  */
  63   GETFDPW,
  64   GETFDGR,
  65   GETFDHST,
  66   GETAI,
  67   INITGROUPS,
  68   LASTREQ
  69 } request_type;
  70
  71
  72 /* Header common to all requests */
  73 typedef struct
  74 {
  75   int32_t version;      /* Version number of the daemon interface.  */
  76   request_type type;    /* Service requested.  */
  77   int32_t key_len;      /* Key length.  */
  78 } request_header;
  79
  80
  81 /* Structure sent in reply to password query.  Note that this struct is
  82    sent also if the service is disabled or there is no record found.  */
  83 typedef struct
  84 {
  85   int32_t version;
  86   int32_t found;
  87   nscd_ssize_t pw_name_len;
  88   nscd_ssize_t pw_passwd_len;
  89   uid_t pw_uid;
  90   gid_t pw_gid;
  91   nscd_ssize_t pw_gecos_len;
  92   nscd_ssize_t pw_dir_len;
  93   nscd_ssize_t pw_shell_len;
  94 } pw_response_header;
  95
  96
  97 /* Structure sent in reply to group query.  Note that this struct is
  98    sent also if the service is disabled or there is no record found.  */
  99 typedef struct
 100 {
 101   int32_t version;
 102   int32_t found;
 103   nscd_ssize_t gr_name_len;
 104   nscd_ssize_t gr_passwd_len;
 105   gid_t gr_gid;
 106   nscd_ssize_t gr_mem_cnt;
 107 } gr_response_header;
 108
 109
 110 /* Structure sent in reply to host query.  Note that this struct is
 111    sent also if the service is disabled or there is no record found.  */
 112 typedef struct
 113 {
 114   int32_t version;
 115   int32_t found;
 116   nscd_ssize_t h_name_len;
 117   nscd_ssize_t h_aliases_cnt;
 118   int32_t h_addrtype;
 119   int32_t h_length;
 120   nscd_ssize_t h_addr_list_cnt;
 121   int32_t error;
 122 } hst_response_header;
 123
 124
 125 /* Structure sent in reply to addrinfo query.  Note that this struct is
 126    sent also if the service is disabled or there is no record found.  */
 127 typedef struct
 128 {
 129   int32_t version;
 130   int32_t found;
 131   nscd_ssize_t naddrs;
 132   nscd_ssize_t addrslen;
 133   nscd_ssize_t canonlen;
 134   int32_t error;
 135 } ai_response_header;
 136
 137 /* Structure filled in by __nscd_getai.  */
 138 struct nscd_ai_result
 139 {
 140   int naddrs;
 141   char *canon;
 142   uint8_t *family;
 143   char *addrs;
 144 };
 145
 146 /* Structure sent in reply to initgroups query.  Note that this struct is
 147    sent also if the service is disabled or there is no record found.  */
 148 typedef struct
 149 {
 150   int32_t version;
 151   int32_t found;
 152   nscd_ssize_t ngrps;
 153 } initgr_response_header;
 154
 155
 156 /* Type for offsets in data part of database.  */
 157 typedef uint32_t ref_t;
 158 /* Value for invalid/no reference.  */
 159 #define ENDREF  UINT32_MAX
 160
 161 /* Timestamp type.  */
 162 typedef uint64_t nscd_time_t;
 163
 164 /* Alignment requirement of the beginning of the data region.  */
 165 #define ALIGN 16
 166
 167
 168 /* Head of record in data part of database.  */
 169 struct datahead
 170 {
 171   nscd_ssize_t allocsize;       /* Allocated Bytes.  */
 172   nscd_ssize_t recsize;         /* Size of the record.  */
 173   nscd_time_t timeout;          /* Time when this entry becomes invalid.  */
 174   uint8_t notfound;             /* Nonzero if data has not been found.  */
 175   uint8_t nreloads;             /* Reloads without use.  */
 176   uint8_t usable;               /* False if the entry must be ignored.  */
 177   uint64_t :40;                 /* Alignment.  */
 178
 179   /* We need to have the following element aligned for the response
 180      header data types and their use in the 'struct dataset' types
 181      defined in the XXXcache.c files.  */
 182   union
 183   {
 184     pw_response_header pwdata;
 185     gr_response_header grdata;
 186     hst_response_header hstdata;
 187     ai_response_header aidata;
 188     initgr_response_header initgrdata;
 189     nscd_ssize_t align1;
 190     nscd_time_t align2;
 191   } data[0];
 192 };
 193
 194
 195 /* Structure for one hash table entry.  */
 196 struct hashentry
 197 {
 198   request_type type:8;          /* Which type of dataset.  */
 199   bool first;                   /* True if this was the original key.  */
 200   nscd_ssize_t len;             /* Length of key.  */
 201   ref_t key;                    /* Pointer to key.  */
 202   int32_t owner;                /* If secure table, this is the owner.  */
 203   ref_t next;                   /* Next entry in this hash bucket list.  */
 204   ref_t packet;                 /* Records for the result.  */
 205   union
 206   {
 207     struct hashentry *dellist;  /* Next record to be deleted.  This can be a
 208                                    pointer since only nscd uses this field.  */
 209     ref_t *prevp;               /* Pointer to field containing forward
 210                                    reference.  */
 211   };
 212 };
 213
 214
 215 /* Current persistent database version.  */
 216 #define DB_VERSION      1
 217
 218 /* Maximum time allowed between updates of the timestamp.  */
 219 #define MAPPING_TIMEOUT (5 * 60)
 220
 221
 222 /* Header of persistent database file.  */
 223 struct database_pers_head
 224 {
 225   int32_t version;
 226   int32_t header_size;
 227   volatile int32_t gc_cycle;
 228   volatile int32_t nscd_certainly_running;
 229   volatile nscd_time_t timestamp;
 230
 231   nscd_ssize_t module;
 232   nscd_ssize_t data_size;
 233
 234   nscd_ssize_t first_free;      /* Offset of first free byte in data area.  */
 235
 236   nscd_ssize_t nentries;
 237   nscd_ssize_t maxnentries;
 238   nscd_ssize_t maxnsearched;
 239
 240   uint64_t poshit;
 241   uint64_t neghit;
 242   uint64_t posmiss;
 243   uint64_t negmiss;
 244
 245   uint64_t rdlockdelayed;
 246   uint64_t wrlockdelayed;
 247
 248   uint64_t addfailed;
 249
 250   ref_t array[0];
 251 };
 252
 253
 254 /* Mapped database record.  */
 255 struct mapped_database
 256 {
 257   const struct database_pers_head *head;
 258   const char *data;
 259   size_t mapsize;
 260   int counter;          /* > 0 indicates it is usable.  */
 261 };
 262 #define NO_MAPPING ((struct mapped_database *) -1l)
 263
 264 struct locked_map_ptr
 265 {
 266   int lock;
 267   struct mapped_database *mapped;
 268 };
 269 #define libc_locked_map_ptr(class, name) class struct locked_map_ptr name
 270
 271
 272 /* Open socket connection to nscd server.  */
 273 extern int __nscd_open_socket (const char *key, size_t keylen,
 274                                request_type type, void *response,
 275                                size_t responselen) attribute_hidden;
 276
 277 /* Get reference of mapping.  */
 278 extern struct mapped_database *__nscd_get_map_ref (request_type type,
 279                                                    const char *name,
 280                                                    struct locked_map_ptr *mapptr,
 281                                                    int *gc_cyclep);
 282
 283 /* Unmap database.  */
 284 extern void __nscd_unmap (struct mapped_database *mapped);
 285
 286 /* Drop reference of mapping.  */
 287 static inline int __nscd_drop_map_ref (struct mapped_database *map,
 288                                        int *gc_cycle)
 289 {
 290   if (map != NO_MAPPING)
 291     {
 292       int now_cycle = map->head->gc_cycle;
 293       if (__builtin_expect (now_cycle != *gc_cycle, 0))
 294         {
 295           /* We might have read inconsistent data.  */
 296           *gc_cycle = now_cycle;
 297           return -1;
 298         }
 299
 300       if (atomic_decrement_val (&map->counter) == 0)
 301         __nscd_unmap (map);
 302     }
 303
 304   return 0;
 305 }
 306
 307
 308 /* Search the mapped database.  */
 309 extern const struct datahead *__nscd_cache_search (request_type type,
 310                                                    const char *key,
 311                                                    size_t keylen,
 312                                                    const struct mapped_database *mapped);
 313
 314 /* Wrappers around read, readv and write that only read/write less than LEN
 315    bytes on error or EOF.  */
 316 extern ssize_t __readall (int fd, void *buf, size_t len)
 317   attribute_hidden;
 318 extern ssize_t __readvall (int fd, const struct iovec *iov, int iovcnt)
 319   attribute_hidden;
 320 extern ssize_t writeall (int fd, const void *buf, size_t len)
 321   attribute_hidden;
 322
 323 #endif /* nscd.h */