nscd/nscd-client.h

   1 /* Copyright (c) 1998, 1999, 2000, 2003, 2004, 2005, 2006, 2007, 2009, 2011
   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, see
  18    <http://www.gnu.org/licenses/>.  */
  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 /* Maximum allowed length for the key.  */
  47 #define MAXKEYLEN 1024
  48
  49
  50 /* Available services.  */
  51 typedef enum
  52 {
  53   GETPWBYNAME,
  54   GETPWBYUID,
  55   GETGRBYNAME,
  56   GETGRBYGID,
  57   GETHOSTBYNAME,
  58   GETHOSTBYNAMEv6,
  59   GETHOSTBYADDR,
  60   GETHOSTBYADDRv6,
  61   SHUTDOWN,             /* Shut the server down.  */
  62   GETSTAT,              /* Get the server statistic.  */
  63   INVALIDATE,           /* Invalidate one special cache.  */
  64   GETFDPW,
  65   GETFDGR,
  66   GETFDHST,
  67   GETAI,
  68   INITGROUPS,
  69   GETSERVBYNAME,
  70   GETSERVBYPORT,
  71   GETFDSERV,
  72   GETNETGRENT,
  73   INNETGR,
  74   GETFDNETGR,
  75   LASTREQ
  76 } request_type;
  77
  78
  79 /* Header common to all requests */
  80 typedef struct
  81 {
  82   int32_t version;      /* Version number of the daemon interface.  */
  83   request_type type;    /* Service requested.  */
  84   int32_t key_len;      /* Key length.  */
  85 } request_header;
  86
  87
  88 /* Structure sent in reply to password query.  Note that this struct is
  89    sent also if the service is disabled or there is no record found.  */
  90 typedef struct
  91 {
  92   int32_t version;
  93   int32_t found;
  94   nscd_ssize_t pw_name_len;
  95   nscd_ssize_t pw_passwd_len;
  96   uid_t pw_uid;
  97   gid_t pw_gid;
  98   nscd_ssize_t pw_gecos_len;
  99   nscd_ssize_t pw_dir_len;
 100   nscd_ssize_t pw_shell_len;
 101 } pw_response_header;
 102
 103
 104 /* Structure sent in reply to group query.  Note that this struct is
 105    sent also if the service is disabled or there is no record found.  */
 106 typedef struct
 107 {
 108   int32_t version;
 109   int32_t found;
 110   nscd_ssize_t gr_name_len;
 111   nscd_ssize_t gr_passwd_len;
 112   gid_t gr_gid;
 113   nscd_ssize_t gr_mem_cnt;
 114 } gr_response_header;
 115
 116
 117 /* Structure sent in reply to host query.  Note that this struct is
 118    sent also if the service is disabled or there is no record found.  */
 119 typedef struct
 120 {
 121   int32_t version;
 122   int32_t found;
 123   nscd_ssize_t h_name_len;
 124   nscd_ssize_t h_aliases_cnt;
 125   int32_t h_addrtype;
 126   int32_t h_length;
 127   nscd_ssize_t h_addr_list_cnt;
 128   int32_t error;
 129 } hst_response_header;
 130
 131
 132 /* Structure sent in reply to addrinfo query.  Note that this struct is
 133    sent also if the service is disabled or there is no record found.  */
 134 typedef struct
 135 {
 136   int32_t version;
 137   int32_t found;
 138   nscd_ssize_t naddrs;
 139   nscd_ssize_t addrslen;
 140   nscd_ssize_t canonlen;
 141   int32_t error;
 142 } ai_response_header;
 143
 144 /* Structure filled in by __nscd_getai.  */
 145 struct nscd_ai_result
 146 {
 147   int naddrs;
 148   char *canon;
 149   uint8_t *family;
 150   char *addrs;
 151 };
 152
 153 /* Structure sent in reply to initgroups query.  Note that this struct is
 154    sent also if the service is disabled or there is no record found.  */
 155 typedef struct
 156 {
 157   int32_t version;
 158   int32_t found;
 159   nscd_ssize_t ngrps;
 160 } initgr_response_header;
 161
 162
 163 /* Structure sent in reply to services query.  Note that this struct is
 164    sent also if the service is disabled or there is no record found.  */
 165 typedef struct
 166 {
 167   int32_t version;
 168   int32_t found;
 169   nscd_ssize_t s_name_len;
 170   nscd_ssize_t s_proto_len;
 171   nscd_ssize_t s_aliases_cnt;
 172   int32_t s_port;
 173 } serv_response_header;
 174
 175
 176 /* Structure send in reply to netgroup query.  Note that this struct is
 177    sent also if the service is disabled or there is no record found.  */
 178 typedef struct
 179 {
 180   int32_t version;
 181   int32_t found;
 182   nscd_ssize_t nresults;
 183   nscd_ssize_t result_len;
 184 } netgroup_response_header;
 185
 186 typedef struct
 187 {
 188   int32_t version;
 189   int32_t found;
 190   int32_t result;
 191 } innetgroup_response_header;
 192
 193
 194 /* Type for offsets in data part of database.  */
 195 typedef uint32_t ref_t;
 196 /* Value for invalid/no reference.  */
 197 #define ENDREF  UINT32_MAX
 198
 199 /* Timestamp type.  */
 200 typedef uint64_t nscd_time_t;
 201
 202 /* Maximum timestamp.  */
 203 #define MAX_TIMEOUT_VALUE \
 204   (sizeof (time_t) == sizeof (long int) ? LONG_MAX : INT_MAX)
 205
 206 /* Alignment requirement of the beginning of the data region.  */
 207 #define ALIGN 16
 208
 209
 210 /* Head of record in data part of database.  */
 211 struct datahead
 212 {
 213   nscd_ssize_t allocsize;       /* Allocated Bytes.  */
 214   nscd_ssize_t recsize;         /* Size of the record.  */
 215   nscd_time_t timeout;          /* Time when this entry becomes invalid.  */
 216   uint8_t notfound;             /* Nonzero if data has not been found.  */
 217   uint8_t nreloads;             /* Reloads without use.  */
 218   uint8_t usable;               /* False if the entry must be ignored.  */
 219   uint8_t unused;               /* Unused.  */
 220   uint32_t ttl;                 /* TTL value used.  */
 221
 222   /* We need to have the following element aligned for the response
 223      header data types and their use in the 'struct dataset' types
 224      defined in the XXXcache.c files.  */
 225   union
 226   {
 227     pw_response_header pwdata;
 228     gr_response_header grdata;
 229     hst_response_header hstdata;
 230     ai_response_header aidata;
 231     initgr_response_header initgrdata;
 232     serv_response_header servdata;
 233     netgroup_response_header netgroupdata;
 234     innetgroup_response_header innetgroupdata;
 235     nscd_ssize_t align1;
 236     nscd_time_t align2;
 237   } data[0];
 238 };
 239
 240
 241 /* Structure for one hash table entry.  */
 242 struct hashentry
 243 {
 244   request_type type:8;          /* Which type of dataset.  */
 245   bool first;                   /* True if this was the original key.  */
 246   nscd_ssize_t len;             /* Length of key.  */
 247   ref_t key;                    /* Pointer to key.  */
 248   int32_t owner;                /* If secure table, this is the owner.  */
 249   ref_t next;                   /* Next entry in this hash bucket list.  */
 250   ref_t packet;                 /* Records for the result.  */
 251   union
 252   {
 253     struct hashentry *dellist;  /* Next record to be deleted.  This can be a
 254                                    pointer since only nscd uses this field.  */
 255     ref_t *prevp;               /* Pointer to field containing forward
 256                                    reference.  */
 257   };
 258 };
 259
 260
 261 /* Current persistent database version.  */
 262 #define DB_VERSION      2
 263
 264 /* Maximum time allowed between updates of the timestamp.  */
 265 #define MAPPING_TIMEOUT (5 * 60)
 266
 267
 268 /* Used indices for the EXTRA_DATA element of 'database_pers_head'.
 269    Each database has its own indices.  */
 270 #define NSCD_HST_IDX_CONF_TIMESTAMP     0
 271
 272
 273 /* Header of persistent database file.  */
 274 struct database_pers_head
 275 {
 276   int32_t version;
 277   int32_t header_size;
 278   volatile int32_t gc_cycle;
 279   volatile int32_t nscd_certainly_running;
 280   volatile nscd_time_t timestamp;
 281   /* Room for extensions.  */
 282   volatile uint32_t extra_data[4];
 283
 284   nscd_ssize_t module;
 285   nscd_ssize_t data_size;
 286
 287   nscd_ssize_t first_free;      /* Offset of first free byte in data area.  */
 288
 289   nscd_ssize_t nentries;
 290   nscd_ssize_t maxnentries;
 291   nscd_ssize_t maxnsearched;
 292
 293   uint64_t poshit;
 294   uint64_t neghit;
 295   uint64_t posmiss;
 296   uint64_t negmiss;
 297
 298   uint64_t rdlockdelayed;
 299   uint64_t wrlockdelayed;
 300
 301   uint64_t addfailed;
 302
 303   ref_t array[0];
 304 };
 305
 306
 307 /* Mapped database record.  */
 308 struct mapped_database
 309 {
 310   const struct database_pers_head *head;
 311   const char *data;
 312   size_t mapsize;
 313   int counter;          /* > 0 indicates it is usable.  */
 314   size_t datasize;
 315 };
 316 #define NO_MAPPING ((struct mapped_database *) -1l)
 317
 318 struct locked_map_ptr
 319 {
 320   int lock;
 321   struct mapped_database *mapped;
 322 };
 323 #define libc_locked_map_ptr(class, name) class struct locked_map_ptr name
 324
 325
 326 /* Open socket connection to nscd server.  */
 327 extern int __nscd_open_socket (const char *key, size_t keylen,
 328                                request_type type, void *response,
 329                                size_t responselen) attribute_hidden;
 330
 331 /* Try to get a file descriptor for the shared meory segment
 332    containing the database.  */
 333 extern struct mapped_database *__nscd_get_mapping (request_type type,
 334                                                    const char *key,
 335                                                    struct mapped_database **mappedp) attribute_hidden;
 336
 337 /* Get reference of mapping.  */
 338 extern struct mapped_database *__nscd_get_map_ref (request_type type,
 339                                                    const char *name,
 340                                                    volatile struct locked_map_ptr *mapptr,
 341                                                    int *gc_cyclep);
 342
 343 /* Unmap database.  */
 344 extern void __nscd_unmap (struct mapped_database *mapped);
 345
 346 /* Drop reference of mapping.  */
 347 static inline int __nscd_drop_map_ref (struct mapped_database *map,
 348                                        int *gc_cycle)
 349 {
 350   if (map != NO_MAPPING)
 351     {
 352       int now_cycle = map->head->gc_cycle;
 353       if (__builtin_expect (now_cycle != *gc_cycle, 0))
 354         {
 355           /* We might have read inconsistent data.  */
 356           *gc_cycle = now_cycle;
 357           return -1;
 358         }
 359
 360       if (atomic_decrement_val (&map->counter) == 0)
 361         __nscd_unmap (map);
 362     }
 363
 364   return 0;
 365 }
 366
 367
 368 /* Search the mapped database.  */
 369 extern struct datahead *__nscd_cache_search (request_type type,
 370                                              const char *key,
 371                                              size_t keylen,
 372                                              const struct mapped_database *mapped,
 373                                              size_t datalen);
 374
 375 /* Wrappers around read, readv and write that only read/write less than LEN
 376    bytes on error or EOF.  */
 377 extern ssize_t __readall (int fd, void *buf, size_t len)
 378   attribute_hidden;
 379 extern ssize_t __readvall (int fd, const struct iovec *iov, int iovcnt)
 380   attribute_hidden;
 381 extern ssize_t writeall (int fd, const void *buf, size_t len)
 382   attribute_hidden;
 383 extern ssize_t sendfileall (int tofd, int fromfd, off_t off, size_t len)
 384   attribute_hidden;
 385
 386 /* Get netlink timestamp counter from mapped area or zero.  */
 387 extern uint32_t __nscd_get_nl_timestamp (void);
 388
 389 #endif /* nscd.h */