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/* Common code for DB-based databases in nss_db module.
Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <dlfcn.h>
#include <fcntl.h>
#include <bits/libc-lock.h>
#include "nsswitch.h"
#include "nss_db.h"
/* These symbols are defined by the including source file:
ENTNAME -- database name of the structure and functions (hostent, pwent).
STRUCTURE -- struct name, define only if not ENTNAME (passwd, group).
DATABASE -- database file name, ("hosts", "passwd")
NEED_H_ERRNO - defined iff an arg `int *herrnop' is used.
*/
#define ENTNAME_r CONCAT(ENTNAME,_r)
#include <paths.h>
#define DBFILE _PATH_VARDB DATABASE ".db"
#ifdef NEED_H_ERRNO
#define H_ERRNO_PROTO , int *herrnop
#define H_ERRNO_ARG , herrnop
#define H_ERRNO_SET(val) (*herrnop = (val))
#else
#define H_ERRNO_PROTO
#define H_ERRNO_ARG
#define H_ERRNO_SET(val) ((void) 0)
#endif
/* Locks the static variables in this file. */
__libc_lock_define_initialized (static, lock)
/* Maintenance of the shared handle open on the database. */
static NSS_DB *db;
static int keep_db;
static int entidx;
/* Open the database. */
enum nss_status
CONCAT(_nss_db_set,ENTNAME) (int stayopen)
{
enum nss_status status;
__libc_lock_lock (lock);
status = internal_setent (DBFILE, &db);
/* Remember STAYOPEN flag. */
if (db != NULL)
keep_db |= stayopen;
/* Reset the sequential index. */
entidx = 0;
__libc_lock_unlock (lock);
return status;
}
/* Close it again. */
enum nss_status
CONCAT(_nss_db_end,ENTNAME) (void)
{
__libc_lock_lock (lock);
internal_endent (&db);
/* Reset STAYOPEN flag. */
keep_db = 0;
__libc_lock_unlock (lock);
return NSS_STATUS_SUCCESS;
}
/* Do a database lookup for KEY. */
static enum nss_status
lookup (DBT *key, struct STRUCTURE *result,
void *buffer, size_t buflen, int *errnop H_ERRNO_PROTO EXTRA_ARGS_DECL)
{
char *p;
enum nss_status status;
int err;
DBT value;
/* Open the database. */
if (db == NULL)
{
status = internal_setent (DBFILE, &db);
if (status != NSS_STATUS_SUCCESS)
{
*errnop = errno;
H_ERRNO_SET (NETDB_INTERNAL);
return status;
}
}
/* Succeed iff it matches a value that parses correctly. */
value.flags = 0;
err = DL_CALL_FCT (db->get, (db->db, NULL, key, &value, 0));
if (err != 0)
{
if (err == db_notfound)
{
H_ERRNO_SET (HOST_NOT_FOUND);
status = NSS_STATUS_NOTFOUND;
}
else
{
*errnop = err;
H_ERRNO_SET (NETDB_INTERNAL);
status = NSS_STATUS_UNAVAIL;
}
}
else if (buflen < value.size)
{
/* No room to copy the data to. */
*errnop = ERANGE;
H_ERRNO_SET (NETDB_INTERNAL);
status = NSS_STATUS_TRYAGAIN;
}
else
{
/* Copy the result to a safe place. */
p = (char *) memcpy (buffer, value.data, value.size);
/* Skip leading blanks. */
while (isspace (*p))
++p;
err = parse_line (p, result, buffer, buflen, errnop EXTRA_ARGS);
if (err == 0)
{
/* If the key begins with '0' we are trying to get the next
entry. We want to ignore unparsable lines in this case. */
if (((char *) key->data)[0] == '0')
{
/* Super magical return value. We need to tell our caller
that it should continue looping. This value cannot
happen in other cases. */
status = NSS_STATUS_RETURN;
}
else
{
H_ERRNO_SET (HOST_NOT_FOUND);
status = NSS_STATUS_NOTFOUND;
}
}
else if (err < 0)
{
H_ERRNO_SET (NETDB_INTERNAL);
status = NSS_STATUS_TRYAGAIN;
}
else
status = NSS_STATUS_SUCCESS;
}
if (! keep_db)
internal_endent (&db);
return status;
}
/* Macro for defining lookup functions for this DB-based database.
NAME is the name of the lookup; e.g. `pwnam'.
KEYPATTERN gives `printf' args to construct a key string;
e.g. `(".%s", name)'.
KEYSIZE gives the allocation size of a buffer to construct it in;
e.g. `1 + strlen (name)'.
PROTO describes the arguments for the lookup key;
e.g. `const char *name'.
BREAK_IF_MATCH is ignored, but used by ../nss_files/files-XXX.c. */
#define DB_LOOKUP(name, keysize, keypattern, break_if_match, proto...) \
enum nss_status \
_nss_db_get##name##_r (proto, \
struct STRUCTURE *result, \
char *buffer, size_t buflen, int *errnop H_ERRNO_PROTO)\
{ \
DBT key; \
enum nss_status status; \
const size_t size = (keysize) + 1; \
key.data = __alloca (size); \
key.size = KEYPRINTF keypattern; \
key.flags = 0; \
__libc_lock_lock (lock); \
status = lookup (&key, result, buffer, buflen, errnop H_ERRNO_ARG \
EXTRA_ARGS_VALUE); \
__libc_lock_unlock (lock); \
return status; \
}
#define KEYPRINTF(pattern, args...) snprintf (key.data, size, pattern ,##args)
/* Return the next entry from the database file, doing locking. */
enum nss_status
CONCAT(_nss_db_get,ENTNAME_r) (struct STRUCTURE *result, char *buffer,
size_t buflen, int *errnop H_ERRNO_PROTO)
{
/* Return next entry in host file. */
enum nss_status status;
char buf[20];
DBT key;
__libc_lock_lock (lock);
/* Loop until we find a valid entry or hit EOF. See above for the
special meaning of the status value. */
do
{
key.size = snprintf (key.data = buf, sizeof buf, "0%u", entidx++);
key.flags = 0;
status = lookup (&key, result, buffer, buflen, errnop H_ERRNO_ARG
EXTRA_ARGS_VALUE);
if (status == NSS_STATUS_TRYAGAIN
#ifdef NEED_H_ERRNO
&& *herrnop == NETDB_INTERNAL
#endif
&& *errnop == ERANGE)
/* Give the user a chance to get the same entry with a larger
buffer. */
--entidx;
}
while (status == NSS_STATUS_RETURN);
__libc_lock_unlock (lock);
return status;
}
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