/*

   Unix SMB/CIFS implementation.

   Manage connections_struct structures

   Copyright (C) Andrew Tridgell 1998

   Copyright (C) Alexander Bokovoy 2002

   Copyright (C) Jeremy Allison 2010

   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 "smbd/smbd.h"

#include "smbd/globals.h"

#include "lib/util/bitmap.h"

static void conn_free_internal(connection_struct *conn);

/****************************************************************************

 * Remove a conn struct from conn->sconn->connections

 * if not already done.

****************************************************************************/

static int conn_struct_destructor(connection_struct *conn)

{

        if (conn->sconn != NULL) {

    DLIST_REMOVE(conn->sconn->connections, conn);

    SMB_ASSERT(conn->sconn->num_connections > 0);

    conn->sconn->num_connections--;

    conn->sconn = NULL;

  }

  conn_free_internal(conn);

  return 0;

}

/****************************************************************************

 Return the number of open connections.

****************************************************************************/

int conn_num_open(struct smbd_server_connection *sconn)

{

  return sconn->num_connections;

}

/****************************************************************************

 Check if a snum is in use.

****************************************************************************/

bool conn_snum_used(struct smbd_server_connection *sconn,

        int snum)

{

  struct connection_struct *conn;

  for (conn=sconn->connections; conn; conn=conn->next) {

    if (conn->params->service == snum) {

      return true;

    }

  }

  return false;

}

enum protocol_types conn_protocol(struct smbd_server_connection *sconn)

{

  if ((sconn != NULL) &&

      (sconn->client != NULL) &&

      (sconn->client->connections != NULL)) {

    return sconn->client->connections->protocol;

  }

  /*

   * Default to what source3/lib/util.c has as default for the

   * static Protocol variable to not change behaviour.

   */

  return PROTOCOL_COREPLUS;

}

bool conn_using_smb2(struct smbd_server_connection *sconn)

{

  enum protocol_types proto = conn_protocol(sconn);

  return (proto >= PROTOCOL_SMB2_02);

}

/****************************************************************************

 Find first available connection slot, starting from a random position.

 The randomisation stops problems with the server dying and clients

 thinking the server is still available.

****************************************************************************/

connection_struct *conn_new(struct smbd_server_connection *sconn)

{

  connection_struct *conn = NULL;

  conn = talloc_zero(NULL, connection_struct);

  if (conn == NULL) {

    DBG_ERR("talloc_zero failed\n");

    return NULL;

  }

  conn->params = talloc(conn, struct share_params);

  if (conn->params == NULL) {

    DBG_ERR("talloc_zero failed\n");

    TALLOC_FREE(conn);

    return NULL;

  }

  conn->vuid_cache = talloc_zero(conn, struct vuid_cache);

  if (conn->vuid_cache == NULL) {

    DBG_ERR("talloc_zero failed\n");

    TALLOC_FREE(conn);

    return NULL;

  }

  conn->connectpath = talloc_strdup(conn, "");

  if (conn->connectpath == NULL) {

    DBG_ERR("talloc_zero failed\n");

    TALLOC_FREE(conn);

    return NULL;

  }

  conn->cwd_fsp = talloc_zero(conn, struct files_struct);

  if (conn->cwd_fsp == NULL) {

    DBG_ERR("talloc_zero failed\n");

    TALLOC_FREE(conn);

    return NULL;

  }

  conn->cwd_fsp->fsp_name = synthetic_smb_fname(conn->cwd_fsp,

                  ".",

                  NULL,

                  NULL,

                  0,

                  0);

  if (conn->cwd_fsp->fsp_name == NULL) {

    TALLOC_FREE(conn);

    return NULL;

  }

  conn->cwd_fsp->fh = fd_handle_create(conn->cwd_fsp);

  if (conn->cwd_fsp->fh == NULL) {

    DBG_ERR("talloc_zero failed\n");

    TALLOC_FREE(conn);

    return NULL;

  }

  conn->sconn = sconn;

  conn->force_group_gid = (gid_t)-1;

  fsp_set_fd(conn->cwd_fsp, -1);

  conn->cwd_fsp->fnum = FNUM_FIELD_INVALID;

  conn->cwd_fsp->conn = conn;

  DLIST_ADD(sconn->connections, conn);

  sconn->num_connections++;

  /*

   * Catches the case where someone forgets to call

   * conn_free().

   */

  talloc_set_destructor(conn, conn_struct_destructor);

  return conn;

}

/****************************************************************************

 Clear a vuid out of the connection's vuid cache

****************************************************************************/

static void conn_clear_vuid_cache(connection_struct *conn, uint64_t vuid)

{

  struct vuid_cache_entry *ent = NULL;

  int i;

  for (i=0; i<VUID_CACHE_SIZE; i++) {

    ent = &conn->vuid_cache->array[i];

    if (ent->vuid == vuid) {

      break;

    }

  }

  if (i == VUID_CACHE_SIZE) {

    return;

  }

  ent->vuid = UID_FIELD_INVALID;

  /*

   * We need to keep conn->session_info around

   * if it's equal to ent->session_info as a SMBulogoff

   * is often followed by a SMBtdis (with an invalid

   * vuid). The debug code (or regular code in

   * vfs_full_audit) wants to refer to the

   * conn->session_info pointer to print debug

   * statements. Theoretically this is a bug,

   * as once the vuid is gone the session_info

   * on the conn struct isn't valid any more,

   * but there's enough code that assumes

   * conn->session_info is never null that

   * it's easier to hold onto the old pointer

   * until we get a new sessionsetupX.

   * As everything is hung off the

   * conn pointer as a talloc context we're not

   * leaking memory here. See bug #6315. JRA.

   */

  if (conn->session_info == ent->session_info) {

    ent->session_info = NULL;

  } else {

    TALLOC_FREE(ent->session_info);

  }

  ent->read_only = False;

  ent->share_access = 0;

  TALLOC_FREE(ent->veto_list);

  TALLOC_FREE(ent->hide_list);

}

/****************************************************************************

 Clear a vuid out of the validity cache, and as the 'owner' of a connection.

 Called from invalidate_vuid()

****************************************************************************/

void conn_clear_vuid_caches(struct smbd_server_connection *sconn, uint64_t vuid)

{

  connection_struct *conn;

  for (conn=sconn->connections; conn;conn=conn->next) {

    if (conn->vuid == vuid) {

      conn->vuid = UID_FIELD_INVALID;

    }

    conn_clear_vuid_cache(conn, vuid);

  }

}

/****************************************************************************

 Free a conn structure - internal part.

****************************************************************************/

static void conn_free_internal(connection_struct *conn)

{

  vfs_handle_struct *handle = NULL, *thandle = NULL;

  struct trans_state *state = NULL;

  /* Free vfs_connection_struct */

  handle = conn->vfs_handles;

  while(handle) {

    thandle = handle->next;

    DLIST_REMOVE(conn->vfs_handles, handle);

    if (handle->free_data)

      handle->free_data(&handle->data);

    handle = thandle;

  }

  /* Free any pending transactions stored on this conn. */

  for (state = conn->pending_trans; state; state = state->next) {

    /* state->setup is a talloc child of state. */

    SAFE_FREE(state->param);

    SAFE_FREE(state->data);

  }

  ZERO_STRUCTP(conn);

}

/****************************************************************************

 Free a conn structure.

****************************************************************************/

void conn_free(connection_struct *conn)

{

  TALLOC_FREE(conn);

}

/*

 * Correctly initialize a share with case options.

 */

void conn_setup_case_options(connection_struct *conn)

{

  int snum = conn->params->service;

  if (lp_case_sensitive(snum) == Auto) {

    /* We will be setting this per packet. Set to be case

    * insensitive for now. */

    conn->case_sensitive = false;

  } else {

    conn->case_sensitive = (bool)lp_case_sensitive(snum);

  }

  conn->case_preserve = lp_preserve_case(snum);

  conn->short_case_preserve = lp_short_preserve_case(snum);

}