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, 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 /* Maximum 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 /* Maximum timestamp.  */
 183 #define MAX_TIMEOUT_VALUE \
 184   (sizeof (time_t) == sizeof (long int) ? LONG_MAX : INT_MAX)
 185
 186 /* Alignment requirement of the beginning of the data region.  */
 187 #define ALIGN 16
 188
 189
 190 /* Head of record in data part of database.  */
 191 struct datahead
 192 {
 193   nscd_ssize_t allocsize;       /* Allocated Bytes.  */
 194   nscd_ssize_t recsize;         /* Size of the record.  */
 195   nscd_time_t timeout;          /* Time when this entry becomes invalid.  */
 196   uint8_t notfound;             /* Nonzero if data has not been found.  */
 197   uint8_t nreloads;             /* Reloads without use.  */
 198   uint8_t usable;               /* False if the entry must be ignored.  */
 199   uint8_t unused;               /* Unused.  */
 200   uint32_t ttl;                 /* TTL value used.  */
 201
 202   /* We need to have the following element aligned for the response
 203      header data types and their use in the 'struct dataset' types
 204      defined in the XXXcache.c files.  */
 205   union
 206   {
 207     pw_response_header pwdata;
 208     gr_response_header grdata;
 209     hst_response_header hstdata;
 210     ai_response_header aidata;
 211     initgr_response_header initgrdata;
 212     serv_response_header servdata;
 213     nscd_ssize_t align1;
 214     nscd_time_t align2;
 215   } data[0];
 216 };
 217
 218
 219 /* Structure for one hash table entry.  */
 220 struct hashentry
 221 {
 222   request_type type:8;          /* Which type of dataset.  */
 223   bool first;                   /* True if this was the original key.  */
 224   nscd_ssize_t len;             /* Length of key.  */
 225   ref_t key;                    /* Pointer to key.  */
 226   int32_t owner;                /* If secure table, this is the owner.  */
 227   ref_t next;                   /* Next entry in this hash bucket list.  */
 228   ref_t packet;                 /* Records for the result.  */
 229   union
 230   {
 231     struct hashentry *dellist;  /* Next record to be deleted.  This can be a
 232                                    pointer since only nscd uses this field.  */
 233     ref_t *prevp;               /* Pointer to field containing forward
 234                                    reference.  */
 235   };
 236 };
 237
 238
 239 /* Current persistent database version.  */
 240 #define DB_VERSION      1
 241
 242 /* Maximum time allowed between updates of the timestamp.  */
 243 #define MAPPING_TIMEOUT (5 * 60)
 244
 245
 246 /* Header of persistent database file.  */
 247 struct database_pers_head
 248 {
 249   int32_t version;
 250   int32_t header_size;
 251   volatile int32_t gc_cycle;
 252   volatile int32_t nscd_certainly_running;
 253   volatile nscd_time_t timestamp;
 254
 255   nscd_ssize_t module;
 256   nscd_ssize_t data_size;
 257
 258   nscd_ssize_t first_free;      /* Offset of first free byte in data area.  */
 259
 260   nscd_ssize_t nentries;
 261   nscd_ssize_t maxnentries;
 262   nscd_ssize_t maxnsearched;
 263
 264   uint64_t poshit;
 265   uint64_t neghit;
 266   uint64_t posmiss;
 267   uint64_t negmiss;
 268
 269   uint64_t rdlockdelayed;
 270   uint64_t wrlockdelayed;
 271
 272   uint64_t addfailed;
 273
 274   ref_t array[0];
 275 };
 276
 277
 278 /* Mapped database record.  */
 279 struct mapped_database
 280 {
 281   const struct database_pers_head *head;
 282   const char *data;
 283   size_t mapsize;
 284   int counter;          /* > 0 indicates it is usable.  */
 285   size_t datasize;
 286 };
 287 #define NO_MAPPING ((struct mapped_database *) -1l)
 288
 289 struct locked_map_ptr
 290 {
 291   int lock;
 292   struct mapped_database *mapped;
 293 };
 294 #define libc_locked_map_ptr(class, name) class struct locked_map_ptr name
 295
 296
 297 /* Open socket connection to nscd server.  */
 298 extern int __nscd_open_socket (const char *key, size_t keylen,
 299                                request_type type, void *response,
 300                                size_t responselen) attribute_hidden;
 301
 302 /* Get reference of mapping.  */
 303 extern struct mapped_database *__nscd_get_map_ref (request_type type,
 304                                                    const char *name,
 305                                                    volatile struct locked_map_ptr *mapptr,
 306                                                    int *gc_cyclep);
 307
 308 /* Unmap database.  */
 309 extern void __nscd_unmap (struct mapped_database *mapped);
 310
 311 /* Drop reference of mapping.  */
 312 static inline int __nscd_drop_map_ref (struct mapped_database *map,
 313                                        int *gc_cycle)
 314 {
 315   if (map != NO_MAPPING)
 316     {
 317       int now_cycle = map->head->gc_cycle;
 318       if (__builtin_expect (now_cycle != *gc_cycle, 0))
 319         {
 320           /* We might have read inconsistent data.  */
 321           *gc_cycle = now_cycle;
 322           return -1;
 323         }
 324
 325       if (atomic_decrement_val (&map->counter) == 0)
 326         __nscd_unmap (map);
 327     }
 328
 329   return 0;
 330 }
 331
 332
 333 /* Search the mapped database.  */
 334 extern struct datahead *__nscd_cache_search (request_type type,
 335                                              const char *key,
 336                                              size_t keylen,
 337                                              const struct mapped_database *mapped,
 338                                              size_t datalen);
 339
 340 /* Wrappers around read, readv and write that only read/write less than LEN
 341    bytes on error or EOF.  */
 342 extern ssize_t __readall (int fd, void *buf, size_t len)
 343   attribute_hidden;
 344 extern ssize_t __readvall (int fd, const struct iovec *iov, int iovcnt)
 345   attribute_hidden;
 346 extern ssize_t writeall (int fd, const void *buf, size_t len)
 347   attribute_hidden;
 348 extern ssize_t sendfileall (int tofd, int fromfd, off_t off, size_t len)
 349   attribute_hidden;
 350
 351 #endif /* nscd.h */