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Sourcecode: samba-doc-ja version File versions

tdbutil.c

/* 
   Unix SMB/CIFS implementation.
   tdb utility functions
   Copyright (C) Andrew Tridgell 1992-1998
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

/* these are little tdb utility functions that are meant to make
   dealing with a tdb database a little less cumbersome in Samba */

static SIG_ATOMIC_T gotalarm;

/***************************************************************
 Signal function to tell us we timed out.
****************************************************************/

static void gotalarm_sig(void)
{
      gotalarm = 1;
}

/****************************************************************************
 Lock a chain with timeout (in seconds).
****************************************************************************/

int tdb_chainlock_with_timeout( TDB_CONTEXT *tdb, TDB_KEY key, unsigned int timeout)
{
      /* Allow tdb_chainlock to be interrupted by an alarm. */
      int ret;
      gotalarm = 0;
      tdb_set_lock_alarm(&gotalarm);

      if (timeout) {
            CatchSignal(SIGALRM, SIGNAL_CAST gotalarm_sig);
            alarm(timeout);
      }

      ret = tdb_chainlock(tdb, key);

      if (timeout) {
            alarm(0);
            CatchSignal(SIGALRM, SIGNAL_CAST SIG_IGN);
            if (gotalarm)
                  return -1;
      }

      return ret;
}

/****************************************************************************
 Lock a chain by string. Return -1 if timeout or lock failed.
****************************************************************************/

int tdb_lock_bystring(TDB_CONTEXT *tdb, const char *keyval, unsigned int timeout)
{
      TDB_KEY key;

      key.dptr = keyval;
      key.dsize = strlen(keyval)+1;
      
      return tdb_chainlock_with_timeout(tdb, key, timeout);
}

/****************************************************************************
 Unlock a chain by string.
****************************************************************************/

void tdb_unlock_bystring(TDB_CONTEXT *tdb, const char *keyval)
{
      TDB_KEY key;

      key.dptr = keyval;
      key.dsize = strlen(keyval)+1;
      
      tdb_chainunlock(tdb, key);
}

/****************************************************************************
 Fetch a int32 value by a arbitrary blob key, return -1 if not found.
 Output is int32 in native byte order.
****************************************************************************/

int32 tdb_fetch_int32_byblob(TDB_CONTEXT *tdb, const char *keyval, size_t len)
{
      TDB_KEY key;
      TDB_DATA data;
      int32 ret;

      key.dptr = keyval;
      key.dsize = len;
      data = tdb_fetch(tdb, key);
      if (!data.dptr || data.dsize != sizeof(int32))
            return -1;
      
      ret = IVAL(data.dptr,0);
      SAFE_FREE(data.dptr);
      return ret;
}

/****************************************************************************
 Fetch a int32 value by string key, return -1 if not found.
 Output is int32 in native byte order.
****************************************************************************/

int32 tdb_fetch_int32(TDB_CONTEXT *tdb, const char *keystr)
{
      return tdb_fetch_int32_byblob(tdb, keystr, strlen(keystr) + 1);
}

/****************************************************************************
 Store a int32 value by an arbitary blob key, return 0 on success, -1 on failure.
 Input is int32 in native byte order. Output in tdb is in little-endian.
****************************************************************************/

int tdb_store_int32_byblob(TDB_CONTEXT *tdb, const char *keystr, size_t len, int32 v)
{
      TDB_KEY key;
      TDB_DATA data;
      int32 v_store;

      key.dptr = keystr;
      key.dsize = len;
      SIVAL(&v_store,0,v);
      data.dptr = (void *)&v_store;
      data.dsize = sizeof(int32);

      return tdb_store(tdb, key, data, TDB_REPLACE);
}

/****************************************************************************
 Store a int32 value by string key, return 0 on success, -1 on failure.
 Input is int32 in native byte order. Output in tdb is in little-endian.
****************************************************************************/

int tdb_store_int32(TDB_CONTEXT *tdb, const char *keystr, int32 v)
{
      return tdb_store_int32_byblob(tdb, keystr, strlen(keystr) + 1, v);
}

/****************************************************************************
 Fetch a uint32 value by a arbitrary blob key, return -1 if not found.
 Output is uint32 in native byte order.
****************************************************************************/

BOOL tdb_fetch_uint32_byblob(TDB_CONTEXT *tdb, const char *keyval, size_t len, uint32 *value)
{
      TDB_KEY key;
      TDB_DATA data;

      key.dptr = keyval;
      key.dsize = len;
      data = tdb_fetch(tdb, key);
      if (!data.dptr || data.dsize != sizeof(uint32))
            return False;
      
      *value = IVAL(data.dptr,0);
      SAFE_FREE(data.dptr);
      return True;
}

/****************************************************************************
 Fetch a uint32 value by string key, return -1 if not found.
 Output is uint32 in native byte order.
****************************************************************************/

BOOL tdb_fetch_uint32(TDB_CONTEXT *tdb, const char *keystr, uint32 *value)
{
      return tdb_fetch_uint32_byblob(tdb, keystr, strlen(keystr) + 1, value);
}

/****************************************************************************
 Store a uint32 value by an arbitary blob key, return 0 on success, -1 on failure.
 Input is uint32 in native byte order. Output in tdb is in little-endian.
****************************************************************************/

BOOL tdb_store_uint32_byblob(TDB_CONTEXT *tdb, const char *keystr, size_t len, uint32 value)
{
      TDB_KEY key;
      TDB_DATA data;
      uint32 v_store;
      BOOL ret = True;

      key.dptr = keystr;
      key.dsize = len;
      SIVAL(&v_store, 0, value);
      data.dptr = (void *)&v_store;
      data.dsize = sizeof(uint32);

      if (tdb_store(tdb, key, data, TDB_REPLACE) == -1)
            ret = False;

      return ret;
}

/****************************************************************************
 Store a uint32 value by string key, return 0 on success, -1 on failure.
 Input is uint32 in native byte order. Output in tdb is in little-endian.
****************************************************************************/

BOOL tdb_store_uint32(TDB_CONTEXT *tdb, const char *keystr, uint32 value)
{
      return tdb_store_uint32_byblob(tdb, keystr, strlen(keystr) + 1, value);
}
/****************************************************************************
 Store a buffer by a null terminated string key.  Return 0 on success, -1
 on failure.
****************************************************************************/

int tdb_store_by_string(TDB_CONTEXT *tdb, const char *keystr, void *buffer, int len)
{
    TDB_KEY key;
    TDB_DATA data;

    key.dptr = keystr;
    key.dsize = strlen(keystr) + 1;

    data.dptr = buffer;
    data.dsize = len;

    return tdb_store(tdb, key, data, TDB_REPLACE);
}

/****************************************************************************
 Fetch a buffer using a null terminated string key.  Don't forget to call
 free() on the result dptr.
****************************************************************************/

TDB_DATA tdb_fetch_by_string(TDB_CONTEXT *tdb, const char *keystr)
{
    TDB_KEY key;

    key.dptr = keystr;
    key.dsize = strlen(keystr) + 1;

    return tdb_fetch(tdb, key);
}

/****************************************************************************
 Atomic integer change. Returns old value. To create, set initial value in *oldval. 
****************************************************************************/

int32 tdb_change_int32_atomic(TDB_CONTEXT *tdb, const char *keystr, int32 *oldval, int32 change_val)
{
      int32 val;
      int32 ret = -1;

      if (tdb_lock_bystring(tdb, keystr,0) == -1)
            return -1;

      if ((val = tdb_fetch_int32(tdb, keystr)) == -1) {
            /* The lookup failed */
            if (tdb_error(tdb) != TDB_ERR_NOEXIST) {
                  /* but not becouse it didn't exist */
                  goto err_out;
            }

            /* Start with 'old' value */
            val = *oldval;

      } else {
            /* It worked, set return value (oldval) to tdb data */
            *oldval = val;
      }
            
      /* Increment value for storage and return next time */
      val += change_val;

      if (tdb_store_int32(tdb, keystr, val) == -1)
            goto err_out;

      ret = 0;

  err_out:

      tdb_unlock_bystring(tdb, keystr);
      return ret;
}

/****************************************************************************
 Atomic unsigned integer change. Returns old value. To create, set initial value in *oldval. 
****************************************************************************/

BOOL tdb_change_uint32_atomic(TDB_CONTEXT *tdb, char *keystr, uint32 *oldval, uint32 change_val)
{
      uint32 val;
      BOOL ret = False;
 
      if (tdb_lock_bystring(tdb, keystr,0) == -1)
            return False;
 
      if (!tdb_fetch_uint32(tdb, keystr, &val)) {
            /* It failed */
            if (tdb_error(tdb) != TDB_ERR_NOEXIST) {
                  /* and not becouse it didn't exist */
                  goto err_out;
            }
 
            /* Start with 'old' value */
            val = *oldval;
 
      } else {
            /* it worked, set return value (oldval) to tdb data */
            *oldval = val;
 
      }
 
      /* get a new value to store */
      val += change_val;
 
      if (!tdb_store_uint32(tdb, keystr, val))
            goto err_out;
 
      ret = True;
 
  err_out:
 
      tdb_unlock_bystring(tdb, keystr);
      return ret;
}

/****************************************************************************
 Useful pair of routines for packing/unpacking data consisting of
 integers and strings.
****************************************************************************/

size_t tdb_pack(char *buf, int bufsize, const char *fmt, ...)
{
      va_list ap;
      uint16 w;
      uint32 d;
      int i;
      void *p;
      int len;
      char *s;
      char c;
      char *buf0 = buf;
      const char *fmt0 = fmt;
      int bufsize0 = bufsize;

      va_start(ap, fmt);

      while (*fmt) {
            switch ((c = *fmt++)) {
            case 'w':
                  len = 2;
                  w = (uint16)va_arg(ap, int);
                  if (bufsize >= len)
                        SSVAL(buf, 0, w);
                  break;
            case 'd':
                  len = 4;
                  d = va_arg(ap, uint32);
                  if (bufsize >= len)
                        SIVAL(buf, 0, d);
                  break;
            case 'p':
                  len = 4;
                  p = va_arg(ap, void *);
                  d = p?1:0;
                  if (bufsize >= len)
                        SIVAL(buf, 0, d);
                  break;
            case 'P':
                  s = va_arg(ap,char *);
                  w = strlen(s);
                  len = w + 1;
                  if (bufsize >= len)
                        memcpy(buf, s, len);
                  break;
            case 'f':
                  s = va_arg(ap,char *);
                  w = strlen(s);
                  len = w + 1;
                  if (bufsize >= len)
                        memcpy(buf, s, len);
                  break;
            case 'B':
                  i = va_arg(ap, int);
                  s = va_arg(ap, char *);
                  len = 4+i;
                  if (bufsize >= len) {
                        SIVAL(buf, 0, i);
                        memcpy(buf+4, s, i);
                  }
                  break;
            default:
                  DEBUG(0,("Unknown tdb_pack format %c in %s\n", 
                         c, fmt));
                  len = 0;
                  break;
            }

            buf += len;
            bufsize -= len;
      }

      va_end(ap);

      DEBUG(18,("tdb_pack(%s, %d) -> %d\n", 
             fmt0, bufsize0, (int)PTR_DIFF(buf, buf0)));
      
      return PTR_DIFF(buf, buf0);
}

/****************************************************************************
 Useful pair of routines for packing/unpacking data consisting of
 integers and strings.
****************************************************************************/

int tdb_unpack(char *buf, int bufsize, const char *fmt, ...)
{
      va_list ap;
      uint16 *w;
      uint32 *d;
      int len;
      int *i;
      void **p;
      char *s, **b;
      char c;
      char *buf0 = buf;
      const char *fmt0 = fmt;
      int bufsize0 = bufsize;

      va_start(ap, fmt);
      
      while (*fmt) {
            switch ((c = *fmt++)) {
            case 'w':
                  len = 2;
                  w = va_arg(ap, uint16 *);
                  if (bufsize < len)
                        goto no_space;
                  *w = SVAL(buf, 0);
                  break;
            case 'd':
                  len = 4;
                  d = va_arg(ap, uint32 *);
                  if (bufsize < len)
                        goto no_space;
                  *d = IVAL(buf, 0);
                  break;
            case 'p':
                  len = 4;
                  p = va_arg(ap, void **);
                  if (bufsize < len)
                        goto no_space;
                  *p = (void *)IVAL(buf, 0);
                  break;
            case 'P':
                  s = va_arg(ap,char *);
                  len = strlen(buf) + 1;
                  if (bufsize < len || len > sizeof(pstring))
                        goto no_space;
                  memcpy(s, buf, len);
                  break;
            case 'f':
                  s = va_arg(ap,char *);
                  len = strlen(buf) + 1;
                  if (bufsize < len || len > sizeof(fstring))
                        goto no_space;
                  memcpy(s, buf, len);
                  break;
            case 'B':
                  i = va_arg(ap, int *);
                  b = va_arg(ap, char **);
                  len = 4;
                  if (bufsize < len)
                        goto no_space;
                  *i = IVAL(buf, 0);
                  if (! *i) {
                        *b = NULL;
                        break;
                  }
                  len += *i;
                  if (bufsize < len)
                        goto no_space;
                  *b = (char *)malloc(*i);
                  if (! *b)
                        goto no_space;
                  memcpy(*b, buf+4, *i);
                  break;
            default:
                  DEBUG(0,("Unknown tdb_unpack format %c in %s\n", 
                         c, fmt));

                  len = 0;
                  break;
            }

            buf += len;
            bufsize -= len;
      }

      va_end(ap);

      DEBUG(18,("tdb_unpack(%s, %d) -> %d\n", 
             fmt0, bufsize0, (int)PTR_DIFF(buf, buf0)));

      return PTR_DIFF(buf, buf0);

 no_space:
      return -1;
}

/****************************************************************************
 Log tdb messages via DEBUG().
****************************************************************************/

static void tdb_log(TDB_CONTEXT *tdb, int level, const char *format, ...)
{
      va_list ap;
      char *ptr = NULL;

      va_start(ap, format);
      vasprintf(&ptr, format, ap);
      va_end(ap);
      
      if (!ptr || !*ptr)
            return;

      DEBUG(level, ("tdb(%s): %s", tdb->name ? tdb->name : "unknown", ptr));
      SAFE_FREE(ptr);
}

/****************************************************************************
 Like tdb_open() but also setup a logging function that redirects to
 the samba DEBUG() system.
****************************************************************************/

TDB_CONTEXT *tdb_open_log(const char *name, int hash_size, int tdb_flags,
                    int open_flags, mode_t mode)
{
      TDB_CONTEXT *tdb;

      if (!lp_use_mmap())
            tdb_flags |= TDB_NOMMAP;

      tdb = tdb_open_ex(name, hash_size, tdb_flags, 
                            open_flags, mode, tdb_log);
      if (!tdb)
            return NULL;

      return tdb;
}


/****************************************************************************
 Allow tdb_delete to be used as a tdb_traversal_fn.
****************************************************************************/

int tdb_traverse_delete_fn(TDB_CONTEXT *the_tdb, TDB_KEY key, TDB_DATA dbuf,
                     void *state)
{
    return tdb_delete(the_tdb, key);
}

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