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/* Mail alias file parser in nss_db module.
Copyright (C) 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <aliases.h>
#include <alloca.h>
#include <ctype.h>
#include <db.h>
#include <errno.h>
#include <fcntl.h>
#include <bits/libc-lock.h>
#include <paths.h>
#include <string.h>
#include "nsswitch.h"
/* Locks the static variables in this file. */
__libc_lock_define_initialized (static, lock)
/* Maintenance of the shared handle open on the database. */
static DB *db;
static int keep_db;
static unsigned int entidx; /* Index for `getaliasent_r'. */
/* Open database file if not already opened. */
static enum nss_status
internal_setent (int stayopen)
{
enum nss_status status = NSS_STATUS_SUCCESS;
if (db == NULL)
{
db = __dbopen (_PATH_VARDB "aliases.db", O_RDONLY, 0, DB_BTREE, NULL);
if (db == NULL)
status = NSS_STATUS_UNAVAIL;
}
/* Remember STAYOPEN flag. */
if (db != NULL)
keep_db |= stayopen;
return status;
}
/* Thread-safe, exported version of that. */
enum nss_status
_nss_db_setaliasent (int stayopen)
{
enum nss_status status;
__libc_lock_lock (lock);
status = internal_setent (stayopen);
/* Reset the sequential index. */
entidx = 0;
__libc_lock_unlock (lock);
return status;
}
/* Close the database file. */
static void
internal_endent (void)
{
if (db != NULL)
{
(*db->close) (db);
db = NULL;
}
}
/* Thread-safe, exported version of that. */
enum nss_status
_nss_db_endaliasent (void)
{
__libc_lock_lock (lock);
internal_endent ();
/* Reset STAYOPEN flag. */
keep_db = 0;
__libc_lock_unlock (lock);
return NSS_STATUS_SUCCESS;
}
/* We provide the parse function here. The parser in libnss_files
cannot be used. The generation of the db file already resolved all
:include: statements so we simply have to parse the list and store
the result. */
static enum nss_status
lookup (const DBT *key, struct aliasent *result, char *buffer,
size_t buflen)
{
enum nss_status status;
DBT value;
/* Open the database. */
status = internal_setent (keep_db);
if (status != NSS_STATUS_SUCCESS)
return status;
if ((*db->get) (db, key, &value, 0) == 0)
{
const char *src = value.data;
result->alias_members_len = 0;
/* We now have to fill the BUFFER with all the information. */
if (buflen < key->size + 1)
{
no_more_room:
__set_errno (ERANGE);
return NSS_STATUS_TRYAGAIN;
}
if (status == NSS_STATUS_SUCCESS)
{
char *cp;
size_t cnt;
buffer = stpncpy (buffer, key->data, key->size) + 1;
buflen -= key->size + 1;
while (*src != '\0')
{
const char *end, *upto;
while (isspace (*src))
++src;
end = strchr (src, ',');
if (end == NULL)
end = strchr (src, '\0');
for (upto = end; upto > src && isspace (upto[-1]); --upto);
if (upto != src)
{
if ((upto - src) + __alignof__ (char *) > buflen)
goto no_more_room;
buffer = stpncpy (buffer, src, upto - src) + 1;
buflen -= (upto - src) + __alignof (char *);
++result->alias_members_len;
}
src = end + (*end != '\0');
}
/* Now prepare the return. Provide string pointers for the
currently selected aliases. */
/* Adjust the pointer so it is aligned for storing pointers. */
buffer += __alignof__ (char *) - 1;
buffer -= ((buffer - (char *) 0) % __alignof__ (char *));
result->alias_members = (char **) buffer;
/* Compute addresses of alias entry strings. */
cp = result->alias_name;
for (cnt = 0; cnt < result->alias_members_len; ++cnt)
{
cp = strchr (cp, '\0') + 1;
result->alias_members[cnt] = cp;
}
status = (result->alias_members_len == 0
? NSS_STATUS_RETURN : NSS_STATUS_SUCCESS);
}
}
else
status = NSS_STATUS_NOTFOUND;
if (! keep_db)
internal_endent ();
return status;
}
enum nss_status
_nss_db_getaliasent_r (struct aliasent *result, char *buffer, size_t buflen)
{
/* Return next entry in host file. */
enum nss_status status;
char buf[20];
DBT key;
__libc_lock_lock (lock);
key.size = 1 + snprintf (key.data = buf, sizeof buf, "0%u", entidx++);
status = lookup (&key, result, buffer, buflen);
__libc_lock_unlock (lock);
return status;
}
enum nss_status
_nss_db_getaliasbyname_r (const char *name, struct aliasent *result,
char *buffer, size_t buflen)
{
DBT key;
enum nss_status status;
key.size = 1 + strlen (name);
key.data = __alloca (key.size);
((char *) key.data)[0] = '.';
memcpy (&((char *) key.data)[1], name, key.size - 1);
__libc_lock_lock (lock);
status = lookup (&key, result, buffer, buflen);
__libc_lock_unlock (lock);
return status;
}
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