/* 
   Unix SMB/CIFS implementation.
   Manage smbsrv_tcon structures
   Copyright (C) Andrew Tridgell 1998
   Copyright (C) Alexander Bokovoy 2002
   Copyright (C) Stefan Metzmacher 2005-2006
   
   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 "smb_server/smb_server.h"
#include "samba/service_stream.h"
#include "lib/tsocket/tsocket.h"
#include "ntvfs/ntvfs.h"

/****************************************************************************
init the tcon structures
****************************************************************************/
static NTSTATUS smbsrv_init_tcons(struct smbsrv_tcons_context *tcons_ctx, TALLOC_CTX *mem_ctx, uint32_t limit)
{
	/* 
	 * the idr_* functions take 'int' as limit,
	 * and only work with a max limit 0x00FFFFFF
	 */
	limit &= 0x00FFFFFF;

	tcons_ctx->idtree_tid	= idr_init(mem_ctx);
	NT_STATUS_HAVE_NO_MEMORY(tcons_ctx->idtree_tid);
	tcons_ctx->idtree_limit	= limit;
	tcons_ctx->list		= NULL;

	return NT_STATUS_OK;
}

NTSTATUS smbsrv_smb_init_tcons(struct smbsrv_connection *smb_conn)
{
	return smbsrv_init_tcons(&smb_conn->smb_tcons, smb_conn, UINT16_MAX);
}

NTSTATUS smbsrv_smb2_init_tcons(struct smbsrv_session *smb_sess)
{
	return smbsrv_init_tcons(&smb_sess->smb2_tcons, smb_sess, UINT32_MAX);
}

/****************************************************************************
find a tcon given a tid for SMB
****************************************************************************/
static struct smbsrv_tcon *smbsrv_tcon_find(struct smbsrv_tcons_context *tcons_ctx,
					    uint32_t tid, struct timeval request_time)
{
	void *p;
	struct smbsrv_tcon *tcon;

	if (tid == 0) return NULL;

	if (tid > tcons_ctx->idtree_limit) return NULL;

	p = idr_find(tcons_ctx->idtree_tid, tid);
	if (!p) return NULL;

	tcon = talloc_get_type(p, struct smbsrv_tcon);
	if (!tcon) return NULL;

	tcon->statistics.last_request_time = request_time;

	return tcon;
}

struct smbsrv_tcon *smbsrv_smb_tcon_find(struct smbsrv_connection *smb_conn,
					 uint32_t tid, struct timeval request_time)
{
	return smbsrv_tcon_find(&smb_conn->smb_tcons, tid, request_time);
}

struct smbsrv_tcon *smbsrv_smb2_tcon_find(struct smbsrv_session *smb_sess,
					  uint32_t tid, struct timeval request_time)
{
	if (!smb_sess) return NULL;
	return smbsrv_tcon_find(&smb_sess->smb2_tcons, tid, request_time);
}

/*
  destroy a connection structure
*/
static int smbsrv_tcon_destructor(struct smbsrv_tcon *tcon)
{
	struct smbsrv_tcons_context *tcons_ctx;
	struct tsocket_address *client_addr;

	client_addr = tcon->smb_conn->connection->remote_address;

	DEBUG(3,("%s closed connection to service %s\n",
		 tsocket_address_string(client_addr, tcon),
		 tcon->share_name));

	/* tell the ntvfs backend that we are disconnecting */
	if (tcon->ntvfs) {
		ntvfs_disconnect(tcon->ntvfs);
		tcon->ntvfs = NULL;
	}

	if (tcon->smb2.session) {
		tcons_ctx = &tcon->smb2.session->smb2_tcons;
	} else {
		tcons_ctx = &tcon->smb_conn->smb_tcons;
	}

	idr_remove(tcons_ctx->idtree_tid, tcon->tid);
	DLIST_REMOVE(tcons_ctx->list, tcon);
	return 0;
}

/*
  find first available connection slot
*/
static struct smbsrv_tcon *smbsrv_tcon_new(struct smbsrv_connection *smb_conn,
					   struct smbsrv_session *smb_sess,
					   const char *share_name)
{
	TALLOC_CTX *mem_ctx;
	struct smbsrv_tcons_context *tcons_ctx;
	uint32_t handle_uint_max;
	struct smbsrv_tcon *tcon;
	NTSTATUS status;
	int i;

	if (smb_sess) {
		mem_ctx = smb_sess;
		tcons_ctx = &smb_sess->smb2_tcons;
		handle_uint_max = UINT32_MAX;
	} else {
		mem_ctx = smb_conn;
		tcons_ctx = &smb_conn->smb_tcons;
		handle_uint_max = UINT16_MAX;
	}

	tcon = talloc_zero(mem_ctx, struct smbsrv_tcon);
	if (!tcon) return NULL;
	tcon->smb_conn		= smb_conn;
	tcon->smb2.session	= smb_sess;
	tcon->share_name	= talloc_strdup(tcon, share_name);
	if (!tcon->share_name) goto failed;

	/*
	 * the use -1 here, because we don't want to give away the wildcard
	 * fnum used in SMBflush
	 */
	status = smbsrv_init_handles(tcon, handle_uint_max - 1);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1,("ERROR! failed to init handles: %s\n", nt_errstr(status)));
		goto failed;
	}

	i = idr_get_new_random(tcons_ctx->idtree_tid, tcon, tcons_ctx->idtree_limit);
	if (i == -1) {
		DEBUG(1,("ERROR! Out of connection structures\n"));
		goto failed;
	}
	tcon->tid = i;

	DLIST_ADD(tcons_ctx->list, tcon);
	talloc_set_destructor(tcon, smbsrv_tcon_destructor);

	/* now fill in some statistics */
	tcon->statistics.connect_time = timeval_current();

	return tcon;

failed:
	talloc_free(tcon);
	return NULL;
}

struct smbsrv_tcon *smbsrv_smb_tcon_new(struct smbsrv_connection *smb_conn, const char *share_name)
{
	return smbsrv_tcon_new(smb_conn, NULL, share_name);
}

struct smbsrv_tcon *smbsrv_smb2_tcon_new(struct smbsrv_session *smb_sess, const char *share_name)
{
	return smbsrv_tcon_new(smb_sess->smb_conn, smb_sess, share_name);
}