/* 
   Unix SMB/CIFS implementation.
   struct samu local cache for 
   Copyright (C) Jim McDonough (jmcd@us.ibm.com) 2004.

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "system/filesys.h"
#include "passdb.h"
#include "util_tdb.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_PASSDB

#define LOGIN_CACHE_FILE "login_cache.tdb"

#define SAM_CACHE_FORMAT "dwwd"

static TDB_CONTEXT *cache;

bool login_cache_init(void)
{
	char* cache_fname = NULL;

	/* skip file open if it's already opened */
	if (cache) return True;

	cache_fname = cache_path(talloc_tos(), LOGIN_CACHE_FILE);
	if (cache_fname == NULL) {
		DEBUG(0, ("Filename allocation failed.\n"));
		return False;
	}

	DEBUG(5, ("Opening cache file at %s\n", cache_fname));

	cache = tdb_open_log(cache_fname, 0, TDB_DEFAULT,
	                     O_RDWR|O_CREAT, 0644);

	if (!cache)
		DEBUG(5, ("Attempt to open %s failed.\n", cache_fname));

	TALLOC_FREE(cache_fname);

	return (cache ? True : False);
}

bool login_cache_shutdown(void)
{
	/* tdb_close routine returns non-zero on error */
	if (!cache) return False;
	DEBUG(5, ("Closing cache file\n"));
	return tdb_close(cache) == 0;
}

/* if we can't read the cache, oh well, no need to return anything */
bool login_cache_read(struct samu *sampass, struct login_cache *entry)
{
	char *keystr;
	TDB_DATA databuf;
	uint32_t entry_timestamp = 0, bad_password_time = 0;
	uint16_t acct_ctrl;

	if (!login_cache_init()) {
		return false;
	}

	if (pdb_get_nt_username(sampass) == NULL) {
		return false;
	}

	keystr = SMB_STRDUP(pdb_get_nt_username(sampass));
	if (!keystr || !keystr[0]) {
		SAFE_FREE(keystr);
		return false;
	}

	DEBUG(7, ("Looking up login cache for user %s\n",
		  keystr));
	databuf = tdb_fetch_bystring(cache, keystr);
	SAFE_FREE(keystr);

	ZERO_STRUCTP(entry);

	if (tdb_unpack (databuf.dptr, databuf.dsize, SAM_CACHE_FORMAT,
			&entry_timestamp,
			&acct_ctrl,
			&entry->bad_password_count,
			&bad_password_time) == -1) {
		DEBUG(7, ("No cache entry found\n"));
		SAFE_FREE(databuf.dptr);
		return false;
	}

	/*
	 * Deal with 32-bit acct_ctrl. In the tdb we only store 16-bit
	 * ("w" in SAM_CACHE_FORMAT). Fixes bug 7253.
	 */
	entry->acct_ctrl = acct_ctrl;

	/* Deal with possible 64-bit time_t. */
	entry->entry_timestamp = (time_t)entry_timestamp;
	entry->bad_password_time = (time_t)bad_password_time;

	SAFE_FREE(databuf.dptr);

	DEBUG(5, ("Found login cache entry: timestamp %12u, flags 0x%x, count %d, time %12u\n",
		  (unsigned int)entry->entry_timestamp, entry->acct_ctrl, 
		  entry->bad_password_count, (unsigned int)entry->bad_password_time));
	return true;
}

bool login_cache_write(const struct samu *sampass,
		       const struct login_cache *entry)
{
	char *keystr;
	TDB_DATA databuf;
	bool ret;
	uint32_t entry_timestamp;
	uint32_t bad_password_time = entry->bad_password_time;

	if (!login_cache_init())
		return False;

	if (pdb_get_nt_username(sampass) == NULL) {
		return False;
	}

	keystr = SMB_STRDUP(pdb_get_nt_username(sampass));
	if (!keystr || !keystr[0]) {
		SAFE_FREE(keystr);
		return False;
	}

	entry_timestamp = (uint32_t)time(NULL);

	databuf.dsize = 
		tdb_pack(NULL, 0, SAM_CACHE_FORMAT,
			 entry_timestamp,
			 entry->acct_ctrl,
			 entry->bad_password_count,
			 bad_password_time);
	databuf.dptr = SMB_MALLOC_ARRAY(uint8_t, databuf.dsize);
	if (!databuf.dptr) {
		SAFE_FREE(keystr);
		return False;
	}

	if (tdb_pack(databuf.dptr, databuf.dsize, SAM_CACHE_FORMAT,
			 entry_timestamp,
			 entry->acct_ctrl,
			 entry->bad_password_count,
			 bad_password_time)
	    != databuf.dsize) {
		SAFE_FREE(keystr);
		SAFE_FREE(databuf.dptr);
		return False;
	}

	ret = tdb_store_bystring(cache, keystr, databuf, 0);
	SAFE_FREE(keystr);
	SAFE_FREE(databuf.dptr);
	return ret == 0;
}

bool login_cache_delentry(const struct samu *sampass)
{
	int ret;
	char *keystr;

	if (!login_cache_init()) 
		return False;	

	if (pdb_get_nt_username(sampass) == NULL) {
		return False;
	}

	keystr = SMB_STRDUP(pdb_get_nt_username(sampass));
	if (!keystr || !keystr[0]) {
		SAFE_FREE(keystr);
		return False;
	}

	DEBUG(9, ("About to delete entry for %s\n", keystr));
	ret = tdb_delete_bystring(cache, keystr);
	DEBUG(9, ("tdb_delete returned %d\n", ret));

	SAFE_FREE(keystr);
	return ret == 0;
}
