nscd/nscd-client.h

   1 /* Copyright (c) 1998, 1999, 2000, 2003, 2004, 2005, 2006, 2007
   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 /* Maximu allowed length for the key.  */
  48 #define MAXKEYLEN 1024
  49
  50
  51 /* Available services.  */
  52 typedef enum
  53 {
  54   GETPWBYNAME,
  55   GETPWBYUID,
  56   GETGRBYNAME,
  57   GETGRBYGID,
  58   GETHOSTBYNAME,
  59   GETHOSTBYNAMEv6,
  60   GETHOSTBYADDR,
  61   GETHOSTBYADDRv6,
  62   SHUTDOWN,             /* Shut the server down.  */
  63   GETSTAT,              /* Get the server statistic.  */
  64   INVALIDATE,           /* Invalidate one special cache.  */
  65   GETFDPW,
  66   GETFDGR,
  67   GETFDHST,
  68   GETAI,
  69   INITGROUPS,
  70   GETSERVBYNAME,
  71   GETSERVBYPORT,
  72   GETFDSERV,
  73   LASTREQ
  74 } request_type;
  75
  76
  77 /* Header common to all requests */
  78 typedef struct
  79 {
  80   int32_t version;      /* Version number of the daemon interface.  */
  81   request_type type;    /* Service requested.  */
  82   int32_t key_len;      /* Key length.  */
  83 } request_header;
  84
  85
  86 /* Structure sent in reply to password query.  Note that this struct is
  87    sent also if the service is disabled or there is no record found.  */
  88 typedef struct
  89 {
  90   int32_t version;
  91   int32_t found;
  92   nscd_ssize_t pw_name_len;
  93   nscd_ssize_t pw_passwd_len;
  94   uid_t pw_uid;
  95   gid_t pw_gid;
  96   nscd_ssize_t pw_gecos_len;
  97   nscd_ssize_t pw_dir_len;
  98   nscd_ssize_t pw_shell_len;
  99 } pw_response_header;
 100
 101
 102 /* Structure sent in reply to group query.  Note that this struct is
 103    sent also if the service is disabled or there is no record found.  */
 104 typedef struct
 105 {
 106   int32_t version;
 107   int32_t found;
 108   nscd_ssize_t gr_name_len;
 109   nscd_ssize_t gr_passwd_len;
 110   gid_t gr_gid;
 111   nscd_ssize_t gr_mem_cnt;
 112 } gr_response_header;
 113
 114
 115 /* Structure sent in reply to host query.  Note that this struct is
 116    sent also if the service is disabled or there is no record found.  */
 117 typedef struct
 118 {
 119   int32_t version;
 120   int32_t found;
 121   nscd_ssize_t h_name_len;
 122   nscd_ssize_t h_aliases_cnt;
 123   int32_t h_addrtype;
 124   int32_t h_length;
 125   nscd_ssize_t h_addr_list_cnt;
 126   int32_t error;
 127 } hst_response_header;
 128
 129
 130 /* Structure sent in reply to addrinfo query.  Note that this struct is
 131    sent also if the service is disabled or there is no record found.  */
 132 typedef struct
 133 {
 134   int32_t version;
 135   int32_t found;
 136   nscd_ssize_t naddrs;
 137   nscd_ssize_t addrslen;
 138   nscd_ssize_t canonlen;
 139   int32_t error;
 140 } ai_response_header;
 141
 142 /* Structure filled in by __nscd_getai.  */
 143 struct nscd_ai_result
 144 {
 145   int naddrs;
 146   char *canon;
 147   uint8_t *family;
 148   char *addrs;
 149 };
 150
 151 /* Structure sent in reply to initgroups query.  Note that this struct is
 152    sent also if the service is disabled or there is no record found.  */
 153 typedef struct
 154 {
 155   int32_t version;
 156   int32_t found;
 157   nscd_ssize_t ngrps;
 158 } initgr_response_header;
 159
 160
 161 /* Structure sent in reply to services query.  Note that this struct is
 162    sent also if the service is disabled or there is no record found.  */
 163 typedef struct
 164 {
 165   int32_t version;
 166   int32_t found;
 167   nscd_ssize_t s_name_len;
 168   nscd_ssize_t s_proto_len;
 169   nscd_ssize_t s_aliases_cnt;
 170   int32_t s_port;
 171 } serv_response_header;
 172
 173
 174 /* Type for offsets in data part of database.  */
 175 typedef uint32_t ref_t;
 176 /* Value for invalid/no reference.  */
 177 #define ENDREF  UINT32_MAX
 178
 179 /* Timestamp type.  */
 180 typedef uint64_t nscd_time_t;
 181
 182 /* Alignment requirement of the beginning of the data region.  */
 183 #define ALIGN 16
 184
 185
 186 /* Head of record in data part of database.  */
 187 struct datahead
 188 {
 189   nscd_ssize_t allocsize;       /* Allocated Bytes.  */
 190   nscd_ssize_t recsize;         /* Size of the record.  */
 191   nscd_time_t timeout;          /* Time when this entry becomes invalid.  */
 192   uint8_t notfound;             /* Nonzero if data has not been found.  */
 193   uint8_t nreloads;             /* Reloads without use.  */
 194   uint8_t usable;               /* False if the entry must be ignored.  */
 195   uint64_t :40;                 /* Alignment.  */
 196
 197   /* We need to have the following element aligned for the response
 198      header data types and their use in the 'struct dataset' types
 199      defined in the XXXcache.c files.  */
 200   union
 201   {
 202     pw_response_header pwdata;
 203     gr_response_header grdata;
 204     hst_response_header hstdata;
 205     ai_response_header aidata;
 206     initgr_response_header initgrdata;
 207     serv_response_header servdata;
 208     nscd_ssize_t align1;
 209     nscd_time_t align2;
 210   } data[0];
 211 };
 212
 213
 214 /* Structure for one hash table entry.  */
 215 struct hashentry
 216 {
 217   request_type type:8;          /* Which type of dataset.  */
 218   bool first;                   /* True if this was the original key.  */
 219   nscd_ssize_t len;             /* Length of key.  */
 220   ref_t key;                    /* Pointer to key.  */
 221   int32_t owner;                /* If secure table, this is the owner.  */
 222   ref_t next;                   /* Next entry in this hash bucket list.  */
 223   ref_t packet;                 /* Records for the result.  */
 224   union
 225   {
 226     struct hashentry *dellist;  /* Next record to be deleted.  This can be a
 227                                    pointer since only nscd uses this field.  */
 228     ref_t *prevp;               /* Pointer to field containing forward
 229                                    reference.  */
 230   };
 231 };
 232
 233
 234 /* Current persistent database version.  */
 235 #define DB_VERSION      1
 236
 237 /* Maximum time allowed between updates of the timestamp.  */
 238 #define MAPPING_TIMEOUT (5 * 60)
 239
 240
 241 /* Header of persistent database file.  */
 242 struct database_pers_head
 243 {
 244   int32_t version;
 245   int32_t header_size;
 246   volatile int32_t gc_cycle;
 247   volatile int32_t nscd_certainly_running;
 248   volatile nscd_time_t timestamp;
 249
 250   nscd_ssize_t module;
 251   nscd_ssize_t data_size;
 252
 253   nscd_ssize_t first_free;      /* Offset of first free byte in data area.  */
 254
 255   nscd_ssize_t nentries;
 256   nscd_ssize_t maxnentries;
 257   nscd_ssize_t maxnsearched;
 258
 259   uint64_t poshit;
 260   uint64_t neghit;
 261   uint64_t posmiss;
 262   uint64_t negmiss;
 263
 264   uint64_t rdlockdelayed;
 265   uint64_t wrlockdelayed;
 266
 267   uint64_t addfailed;
 268
 269   ref_t array[0];
 270 };
 271
 272
 273 /* Mapped database record.  */
 274 struct mapped_database
 275 {
 276   const struct database_pers_head *head;
 277   const char *data;
 278   size_t mapsize;
 279   int counter;          /* > 0 indicates it is usable.  */
 280   size_t datasize;
 281 };
 282 #define NO_MAPPING ((struct mapped_database *) -1l)
 283
 284 struct locked_map_ptr
 285 {
 286   int lock;
 287   struct mapped_database *mapped;
 288 };
 289 #define libc_locked_map_ptr(class, name) class struct locked_map_ptr name
 290
 291
 292 /* Open socket connection to nscd server.  */
 293 extern int __nscd_open_socket (const char *key, size_t keylen,
 294                                request_type type, void *response,
 295                                size_t responselen) attribute_hidden;
 296
 297 /* Get reference of mapping.  */
 298 extern struct mapped_database *__nscd_get_map_ref (request_type type,
 299                                                    const char *name,
 300                                                    volatile struct locked_map_ptr *mapptr,
 301                                                    int *gc_cyclep);
 302
 303 /* Unmap database.  */
 304 extern void __nscd_unmap (struct mapped_database *mapped);
 305
 306 /* Drop reference of mapping.  */
 307 static inline int __nscd_drop_map_ref (struct mapped_database *map,
 308                                        int *gc_cycle)
 309 {
 310   if (map != NO_MAPPING)
 311     {
 312       int now_cycle = map->head->gc_cycle;
 313       if (__builtin_expect (now_cycle != *gc_cycle, 0))
 314         {
 315           /* We might have read inconsistent data.  */
 316           *gc_cycle = now_cycle;
 317           return -1;
 318         }
 319
 320       if (atomic_decrement_val (&map->counter) == 0)
 321         __nscd_unmap (map);
 322     }
 323
 324   return 0;
 325 }
 326
 327
 328 /* Search the mapped database.  */
 329 extern struct datahead *__nscd_cache_search (request_type type,
 330                                              const char *key,
 331                                              size_t keylen,
 332                                              const struct mapped_database *mapped);
 333
 334 /* Wrappers around read, readv and write that only read/write less than LEN
 335    bytes on error or EOF.  */
 336 extern ssize_t __readall (int fd, void *buf, size_t len)
 337   attribute_hidden;
 338 extern ssize_t __readvall (int fd, const struct iovec *iov, int iovcnt)
 339   attribute_hidden;
 340 extern ssize_t writeall (int fd, const void *buf, size_t len)
 341   attribute_hidden;
 342 extern ssize_t sendfileall (int tofd, int fromfd, off_t off, size_t len)
 343   attribute_hidden;
 344
 345 #endif /* nscd.h */