/src/samba/source3/smbd/smbXsrv_session.c

Source
/*
   Unix SMB/CIFS implementation.

   Copyright (C) Stefan Metzmacher 2011-2012
   Copyright (C) Michael Adam 2012

   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 "smbXsrv_session.h"
#include "system/filesys.h"
#include <tevent.h>
#include "lib/util/server_id.h"
#include "smbd/smbd.h"
#include "smbd/globals.h"
#include "dbwrap/dbwrap.h"
#include "dbwrap/dbwrap_rbt.h"
#include "dbwrap/dbwrap_open.h"
#include "dbwrap/dbwrap_watch.h"
#include "session.h"
#include "auth.h"
#include "auth/gensec/gensec.h"
#include "../lib/tsocket/tsocket.h"
#include "../libcli/security/security.h"
#include "messages.h"
#include "lib/util/util_tdb.h"
#include "librpc/gen_ndr/ndr_smbXsrv.h"
#include "serverid.h"
#include "lib/util/tevent_ntstatus.h"
#include "lib/global_contexts.h"
#include "source3/include/util_tdb.h"

struct smbXsrv_session_table {
  struct {
    struct db_context *db_ctx;
    uint32_t lowest_id;
    uint32_t highest_id;
    uint32_t max_sessions;
    uint32_t num_sessions;
  } local;
  struct {
    struct db_context *db_ctx;
  } global;
};

static struct db_context *smbXsrv_session_global_db_ctx = NULL;

NTSTATUS smbXsrv_session_global_init(struct messaging_context *msg_ctx)
{
  char *global_path = NULL;
  struct db_context *backend = NULL;
  struct db_context *db_ctx = NULL;

  if (smbXsrv_session_global_db_ctx != NULL) {
    return NT_STATUS_OK;
  }

  /*
   * This contains secret information like session keys!
   */
  global_path = lock_path(talloc_tos(), "smbXsrv_session_global.tdb");
  if (global_path == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  backend = db_open(NULL, global_path,
        SMBD_VOLATILE_TDB_HASH_SIZE,
        SMBD_VOLATILE_TDB_FLAGS,
        O_RDWR | O_CREAT, 0600,
        DBWRAP_LOCK_ORDER_1,
        DBWRAP_FLAG_NONE);
  TALLOC_FREE(global_path);
  if (backend == NULL) {
    NTSTATUS status;

    status = map_nt_error_from_unix_common(errno);

    return status;
  }

  db_ctx = db_open_watched(NULL, &backend, global_messaging_context());
  if (db_ctx == NULL) {
    TALLOC_FREE(backend);
    return NT_STATUS_NO_MEMORY;
  }

  smbXsrv_session_global_db_ctx = db_ctx;

  return NT_STATUS_OK;
}

/*
 * NOTE:
 * We need to store the keys in big endian so that dbwrap_rbt's memcmp
 * has the same result as integer comparison between the uint32_t
 * values.
 *
 * TODO: implement string based key
 */

#define SMBXSRV_SESSION_GLOBAL_TDB_KEY_SIZE sizeof(uint32_t)

static TDB_DATA smbXsrv_session_global_id_to_key(uint32_t id,
             uint8_t *key_buf)
{
  TDB_DATA key;

  RSIVAL(key_buf, 0, id);

  key = make_tdb_data(key_buf, SMBXSRV_SESSION_GLOBAL_TDB_KEY_SIZE);

  return key;
}

#if 0
static NTSTATUS smbXsrv_session_global_key_to_id(TDB_DATA key, uint32_t *id)
{
  if (id == NULL) {
    return NT_STATUS_INVALID_PARAMETER;
  }

  if (key.dsize != SMBXSRV_SESSION_GLOBAL_TDB_KEY_SIZE) {
    return NT_STATUS_INTERNAL_DB_CORRUPTION;
  }

  *id = RIVAL(key.dptr, 0);

  return NT_STATUS_OK;
}
#endif

#define SMBXSRV_SESSION_LOCAL_TDB_KEY_SIZE sizeof(uint32_t)

static TDB_DATA smbXsrv_session_local_id_to_key(uint32_t id,
            uint8_t *key_buf)
{
  TDB_DATA key;

  RSIVAL(key_buf, 0, id);

  key = make_tdb_data(key_buf, SMBXSRV_SESSION_LOCAL_TDB_KEY_SIZE);

  return key;
}

static NTSTATUS smbXsrv_session_local_key_to_id(TDB_DATA key, uint32_t *id)
{
  if (id == NULL) {
    return NT_STATUS_INVALID_PARAMETER;
  }

  if (key.dsize != SMBXSRV_SESSION_LOCAL_TDB_KEY_SIZE) {
    return NT_STATUS_INTERNAL_DB_CORRUPTION;
  }

  *id = RIVAL(key.dptr, 0);

  return NT_STATUS_OK;
}

static struct db_record *smbXsrv_session_global_fetch_locked(
      struct db_context *db,
      uint32_t id,
      TALLOC_CTX *mem_ctx)
{
  TDB_DATA key;
  uint8_t key_buf[SMBXSRV_SESSION_GLOBAL_TDB_KEY_SIZE];
  struct db_record *rec = NULL;

  key = smbXsrv_session_global_id_to_key(id, key_buf);

  rec = dbwrap_fetch_locked(db, mem_ctx, key);

  if (rec == NULL) {
    DBG_DEBUG("Failed to lock global id 0x%08x, key '%s'\n", id,
        tdb_data_dbg(key));
  }

  return rec;
}

static struct db_record *smbXsrv_session_local_fetch_locked(
      struct db_context *db,
      uint32_t id,
      TALLOC_CTX *mem_ctx)
{
  TDB_DATA key;
  uint8_t key_buf[SMBXSRV_SESSION_LOCAL_TDB_KEY_SIZE];
  struct db_record *rec = NULL;

  key = smbXsrv_session_local_id_to_key(id, key_buf);

  rec = dbwrap_fetch_locked(db, mem_ctx, key);

  if (rec == NULL) {
    DBG_DEBUG("Failed to lock local id 0x%08x, key '%s'\n", id,
        tdb_data_dbg(key));
  }

  return rec;
}

static void smbXsrv_session_close_loop(struct tevent_req *subreq);

static NTSTATUS smbXsrv_session_table_init(struct smbXsrv_connection *conn,
             uint32_t lowest_id,
             uint32_t highest_id,
             uint32_t max_sessions)
{
  struct smbXsrv_client *client = conn->client;
  struct smbXsrv_session_table *table;
  NTSTATUS status;
  struct tevent_req *subreq;
  uint64_t max_range;

  if (lowest_id > highest_id) {
    return NT_STATUS_INTERNAL_ERROR;
  }

  max_range = highest_id;
  max_range -= lowest_id;
  max_range += 1;

  if (max_sessions > max_range) {
    return NT_STATUS_INTERNAL_ERROR;
  }

  table = talloc_zero(client, struct smbXsrv_session_table);
  if (table == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  table->local.db_ctx = db_open_rbt(table);
  if (table->local.db_ctx == NULL) {
    TALLOC_FREE(table);
    return NT_STATUS_NO_MEMORY;
  }
  table->local.lowest_id = lowest_id;
  table->local.highest_id = highest_id;
  table->local.max_sessions = max_sessions;

  status = smbXsrv_session_global_init(client->msg_ctx);
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(table);
    return status;
  }

  table->global.db_ctx = smbXsrv_session_global_db_ctx;

  subreq = messaging_read_send(table,
             client->raw_ev_ctx,
             client->msg_ctx,
             MSG_SMBXSRV_SESSION_CLOSE);
  if (subreq == NULL) {
    TALLOC_FREE(table);
    return NT_STATUS_NO_MEMORY;
  }
  tevent_req_set_callback(subreq, smbXsrv_session_close_loop, client);

  client->session_table = table;
  return NT_STATUS_OK;
}

static void smbXsrv_session_close_shutdown_done(struct tevent_req *subreq);

static void smbXsrv_session_close_loop(struct tevent_req *subreq)
{
  struct smbXsrv_client *client =
    tevent_req_callback_data(subreq,
    struct smbXsrv_client);
  struct smbXsrv_session_table *table = client->session_table;
  int ret;
  struct messaging_rec *rec = NULL;
  struct smbXsrv_session_closeB close_blob;
  enum ndr_err_code ndr_err;
  struct smbXsrv_session_close0 *close_info0 = NULL;
  struct smbXsrv_session *session = NULL;
  NTSTATUS status;
  struct timeval tv = timeval_current();
  NTTIME now = timeval_to_nttime(&tv);

  ret = messaging_read_recv(subreq, talloc_tos(), &rec);
  TALLOC_FREE(subreq);
  if (ret != 0) {
    goto next;
  }

  ndr_err = ndr_pull_struct_blob(&rec->buf, rec, &close_blob,
      (ndr_pull_flags_fn_t)ndr_pull_smbXsrv_session_closeB);
  if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
    status = ndr_map_error2ntstatus(ndr_err);
    DBG_WARNING("ndr_pull_struct_blob - %s\n", nt_errstr(status));
    goto next;
  }

  DBG_DEBUG("MSG_SMBXSRV_SESSION_CLOSE\n");
  if (DEBUGLVL(DBGLVL_DEBUG)) {
    NDR_PRINT_DEBUG(smbXsrv_session_closeB, &close_blob);
  }

  if (close_blob.version != SMBXSRV_VERSION_0) {
    DBG_ERR("ignore invalid version %u\n", close_blob.version);
    NDR_PRINT_DEBUG(smbXsrv_session_closeB, &close_blob);
    goto next;
  }

  close_info0 = close_blob.info.info0;
  if (close_info0 == NULL) {
    DBG_ERR("ignore NULL info %u\n", close_blob.version);
    NDR_PRINT_DEBUG(smbXsrv_session_closeB, &close_blob);
    goto next;
  }

  status = smb2srv_session_lookup_client(client,
                 close_info0->old_session_wire_id,
                 now, &session);
  if (NT_STATUS_EQUAL(status, NT_STATUS_USER_SESSION_DELETED)) {
    DBG_INFO("old_session_wire_id %" PRIu64 " not found\n",
       close_info0->old_session_wire_id);
    if (DEBUGLVL(DBGLVL_INFO)) {
      NDR_PRINT_DEBUG(smbXsrv_session_closeB, &close_blob);
    }
    goto next;
  }
  if (!NT_STATUS_IS_OK(status) &&
      !NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) &&
      !NT_STATUS_EQUAL(status, NT_STATUS_NETWORK_SESSION_EXPIRED)) {
    DBG_WARNING("old_session_wire_id %" PRIu64 " - %s\n",
          close_info0->old_session_wire_id,
          nt_errstr(status));
    if (DEBUGLVL(DBGLVL_WARNING)) {
      NDR_PRINT_DEBUG(smbXsrv_session_closeB, &close_blob);
    }
    goto next;
  }

  if (session->global->session_global_id != close_info0->old_session_global_id) {
    DBG_WARNING("old_session_wire_id %" PRIu64 " - "
          "global %" PRIu32 " != %" PRIu32 "\n",
          close_info0->old_session_wire_id,
          session->global->session_global_id,
          close_info0->old_session_global_id);
    if (DEBUGLVL(DBGLVL_WARNING)) {
      NDR_PRINT_DEBUG(smbXsrv_session_closeB, &close_blob);
    }
    goto next;
  }

  if (session->global->creation_time != close_info0->old_creation_time) {
    DBG_WARNING("old_session_wire_id %" PRIu64 " - "
          "creation %s (%" PRIu64 ") != %s (%" PRIu64 ")\n",
          close_info0->old_session_wire_id,
          nt_time_string(rec,
             session->global->creation_time),
          session->global->creation_time,
          nt_time_string(rec,
             close_info0->old_creation_time),
          close_info0->old_creation_time);
    if (DEBUGLVL(DBGLVL_WARNING)) {
      NDR_PRINT_DEBUG(smbXsrv_session_closeB, &close_blob);
    }
    goto next;
  }

  subreq = smb2srv_session_shutdown_send(session, client->raw_ev_ctx,
                 session, NULL);
  if (subreq == NULL) {
    status = NT_STATUS_NO_MEMORY;
    DBG_ERR("smb2srv_session_shutdown_send(%" PRIu64
      ") failed: %s\n",
      session->global->session_wire_id,
      nt_errstr(status));
    if (DEBUGLVL(DBGLVL_WARNING)) {
      NDR_PRINT_DEBUG(smbXsrv_session_closeB, &close_blob);
    }
    goto next;
  }
  tevent_req_set_callback(subreq,
        smbXsrv_session_close_shutdown_done,
        session);

next:
  TALLOC_FREE(rec);

  subreq = messaging_read_send(table,
             client->raw_ev_ctx,
             client->msg_ctx,
             MSG_SMBXSRV_SESSION_CLOSE);
  if (subreq == NULL) {
    const char *r;
    r = "messaging_read_send(MSG_SMBXSRV_SESSION_CLOSE) failed";
    exit_server_cleanly(r);
    return;
  }
  tevent_req_set_callback(subreq, smbXsrv_session_close_loop, client);
}

static void smbXsrv_session_close_shutdown_done(struct tevent_req *subreq)
{
  struct smbXsrv_session *session =
    tevent_req_callback_data(subreq,
    struct smbXsrv_session);
  NTSTATUS status;

  status = smb2srv_session_shutdown_recv(subreq);
  TALLOC_FREE(subreq);
  if (!NT_STATUS_IS_OK(status)) {
    DBG_ERR("smb2srv_session_shutdown_recv(%" PRIu64
      ") failed: %s\n",
      session->global->session_wire_id,
      nt_errstr(status));
  }

  status = smbXsrv_session_logoff(session);
  if (!NT_STATUS_IS_OK(status)) {
    DBG_ERR("smbXsrv_session_logoff(%" PRIu64 ") failed: %s\n",
      session->global->session_wire_id,
      nt_errstr(status));
  }

  TALLOC_FREE(session);
}

struct smb1srv_session_local_allocate_state {
  const uint32_t lowest_id;
  const uint32_t highest_id;
  uint32_t last_id;
  uint32_t useable_id;
  NTSTATUS status;
};

static int smb1srv_session_local_allocate_traverse(struct db_record *rec,
               void *private_data)
{
  struct smb1srv_session_local_allocate_state *state =
    (struct smb1srv_session_local_allocate_state *)private_data;
  TDB_DATA key = dbwrap_record_get_key(rec);
  uint32_t id = 0;
  NTSTATUS status;

  status = smbXsrv_session_local_key_to_id(key, &id);
  if (!NT_STATUS_IS_OK(status)) {
    state->status = status;
    return -1;
  }

  if (id <= state->last_id) {
    state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
    return -1;
  }
  state->last_id = id;

  if (id > state->useable_id) {
    state->status = NT_STATUS_OK;
    return -1;
  }

  if (state->useable_id == state->highest_id) {
    state->status = NT_STATUS_INSUFFICIENT_RESOURCES;
    return -1;
  }

  state->useable_id +=1;
  return 0;
}

static NTSTATUS smb1srv_session_local_allocate_id(struct db_context *db,
              uint32_t lowest_id,
              uint32_t highest_id,
              TALLOC_CTX *mem_ctx,
              struct db_record **_rec,
              uint32_t *_id)
{
  struct smb1srv_session_local_allocate_state state = {
    .lowest_id = lowest_id,
    .highest_id = highest_id,
    .last_id = 0,
    .useable_id = lowest_id,
    .status = NT_STATUS_INTERNAL_ERROR,
  };
  uint32_t i;
  uint32_t range;
  NTSTATUS status;
  int count = 0;

  *_rec = NULL;
  *_id = 0;

  if (lowest_id > highest_id) {
    return NT_STATUS_INSUFFICIENT_RESOURCES;
  }

  /*
   * first we try randomly
   */
  range = (highest_id - lowest_id) + 1;

  for (i = 0; i < (range / 2); i++) {
    uint32_t id;
    TDB_DATA val;
    struct db_record *rec = NULL;

    id = generate_random() % range;
    id += lowest_id;

    if (id < lowest_id) {
      id = lowest_id;
    }
    if (id > highest_id) {
      id = highest_id;
    }

    rec = smbXsrv_session_local_fetch_locked(db, id, mem_ctx);
    if (rec == NULL) {
      return NT_STATUS_INSUFFICIENT_RESOURCES;
    }

    val = dbwrap_record_get_value(rec);
    if (val.dsize != 0) {
      TALLOC_FREE(rec);
      continue;
    }

    *_rec = rec;
    *_id = id;
    return NT_STATUS_OK;
  }

  /*
   * if the range is almost full,
   * we traverse the whole table
   * (this relies on sorted behavior of dbwrap_rbt)
   */
  status = dbwrap_traverse_read(db, smb1srv_session_local_allocate_traverse,
              &state, &count);
  if (NT_STATUS_IS_OK(status)) {
    if (NT_STATUS_IS_OK(state.status)) {
      return NT_STATUS_INTERNAL_ERROR;
    }

    if (!NT_STATUS_EQUAL(state.status, NT_STATUS_INTERNAL_ERROR)) {
      return state.status;
    }

    if (state.useable_id <= state.highest_id) {
      state.status = NT_STATUS_OK;
    } else {
      return NT_STATUS_INSUFFICIENT_RESOURCES;
    }
  } else if (!NT_STATUS_EQUAL(status, NT_STATUS_INTERNAL_DB_CORRUPTION)) {
    /*
     * Here we really expect NT_STATUS_INTERNAL_DB_CORRUPTION!
     *
     * If we get anything else it is an error, because it
     * means we did not manage to find a free slot in
     * the db.
     */
    return NT_STATUS_INSUFFICIENT_RESOURCES;
  }

  if (NT_STATUS_IS_OK(state.status)) {
    uint32_t id;
    TDB_DATA val;
    struct db_record *rec = NULL;

    id = state.useable_id;

    rec = smbXsrv_session_local_fetch_locked(db, id, mem_ctx);
    if (rec == NULL) {
      return NT_STATUS_INSUFFICIENT_RESOURCES;
    }

    val = dbwrap_record_get_value(rec);
    if (val.dsize != 0) {
      TALLOC_FREE(rec);
      return NT_STATUS_INTERNAL_DB_CORRUPTION;
    }

    *_rec = rec;
    *_id = id;
    return NT_STATUS_OK;
  }

  return state.status;
}

struct smbXsrv_session_local_fetch_state {
  struct smbXsrv_session *session;
  NTSTATUS status;
};

static void smbXsrv_session_local_fetch_parser(TDB_DATA key, TDB_DATA data,
                 void *private_data)
{
  struct smbXsrv_session_local_fetch_state *state =
    (struct smbXsrv_session_local_fetch_state *)private_data;
  void *ptr;

  if (data.dsize != sizeof(ptr)) {
    state->status = NT_STATUS_INTERNAL_DB_ERROR;
    return;
  }

  memcpy(&ptr, data.dptr, data.dsize);
  state->session = talloc_get_type_abort(ptr, struct smbXsrv_session);
  state->status = NT_STATUS_OK;
}

static NTSTATUS smbXsrv_session_local_lookup(struct smbXsrv_session_table *table,
               /* conn: optional */
               struct smbXsrv_connection *conn,
               uint32_t session_local_id,
               NTTIME now,
               struct smbXsrv_session **_session)
{
  struct smbXsrv_session_local_fetch_state state = {
    .session = NULL,
    .status = NT_STATUS_INTERNAL_ERROR,
  };
  uint8_t key_buf[SMBXSRV_SESSION_LOCAL_TDB_KEY_SIZE];
  TDB_DATA key;
  NTSTATUS status;

  *_session = NULL;

  if (session_local_id == 0) {
    return NT_STATUS_USER_SESSION_DELETED;
  }

  if (table == NULL) {
    /* this might happen before the end of negprot */
    return NT_STATUS_USER_SESSION_DELETED;
  }

  if (table->local.db_ctx == NULL) {
    return NT_STATUS_INTERNAL_ERROR;
  }

  key = smbXsrv_session_local_id_to_key(session_local_id, key_buf);

  status = dbwrap_parse_record(table->local.db_ctx, key,
             smbXsrv_session_local_fetch_parser,
             &state);
  if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
    return NT_STATUS_USER_SESSION_DELETED;
  } else if (!NT_STATUS_IS_OK(status)) {
    return status;
  }
  if (!NT_STATUS_IS_OK(state.status)) {
    return state.status;
  }

  if (NT_STATUS_EQUAL(state.session->status, NT_STATUS_USER_SESSION_DELETED)) {
    return NT_STATUS_USER_SESSION_DELETED;
  }

  /*
   * If a connection is specified check if the session is
   * valid on the channel.
   */
  if (conn != NULL) {
    struct smbXsrv_channel_global0 *c = NULL;

    status = smbXsrv_session_find_channel(state.session, conn, &c);
    if (!NT_STATUS_IS_OK(status)) {
      return status;
    }
  }

  state.session->idle_time = now;

  if (!NT_STATUS_IS_OK(state.session->status)) {
    *_session = state.session;
    return state.session->status;
  }

  if (now > state.session->global->expiration_time) {
    state.session->status = NT_STATUS_NETWORK_SESSION_EXPIRED;
  }

  *_session = state.session;
  return state.session->status;
}

static int smbXsrv_session_global_destructor(struct smbXsrv_session_global0 *global)
{
  return 0;
}

static void smbXsrv_session_global_verify_record(struct db_record *db_rec,
          bool *is_free,
          bool *was_free,
          TALLOC_CTX *mem_ctx,
          struct smbXsrv_session_global0 **_g,
          uint32_t *pseqnum);

static NTSTATUS smbXsrv_session_global_allocate(struct db_context *db,
          TALLOC_CTX *mem_ctx,
          struct smbXsrv_session_global0 **_global)
{
  uint32_t i;
  struct smbXsrv_session_global0 *global = NULL;
  uint32_t last_free = 0;
  const uint32_t min_tries = 3;

  *_global = NULL;

  global = talloc_zero(mem_ctx, struct smbXsrv_session_global0);
  if (global == NULL) {
    return NT_STATUS_NO_MEMORY;
  }
  talloc_set_destructor(global, smbXsrv_session_global_destructor);

  /*
   * Here we just randomly try the whole 32-bit space
   *
   * We use just 32-bit, because we want to reuse the
   * ID for SRVSVC.
   */
  for (i = 0; i < UINT32_MAX; i++) {
    bool is_free = false;
    bool was_free = false;
    uint32_t id;

    if (i >= min_tries && last_free != 0) {
      id = last_free;
    } else {
      id = generate_random();
    }
    if (id == 0) {
      id++;
    }
    if (id == UINT32_MAX) {
      id--;
    }

    global->db_rec = smbXsrv_session_global_fetch_locked(db, id,
                     mem_ctx);
    if (global->db_rec == NULL) {
      talloc_free(global);
      return NT_STATUS_INSUFFICIENT_RESOURCES;
    }

    smbXsrv_session_global_verify_record(global->db_rec,
                 &is_free,
                 &was_free,
                 NULL, NULL, NULL);

    if (!is_free) {
      TALLOC_FREE(global->db_rec);
      continue;
    }

    if (!was_free && i < min_tries) {
      /*
       * The session_id is free now,
       * but was not free before.
       *
       * This happens if a smbd crashed
       * and did not cleanup the record.
       *
       * If this is one of our first tries,
       * then we try to find a real free one.
       */
      if (last_free == 0) {
        last_free = id;
      }
      TALLOC_FREE(global->db_rec);
      continue;
    }

    global->session_global_id = id;

    *_global = global;
    return NT_STATUS_OK;
  }

  /* should not be reached */
  talloc_free(global);
  return NT_STATUS_INTERNAL_ERROR;
}

static void smbXsrv_session_global_verify_record(struct db_record *db_rec,
          bool *is_free,
          bool *was_free,
          TALLOC_CTX *mem_ctx,
          struct smbXsrv_session_global0 **_g,
          uint32_t *pseqnum)
{
  TDB_DATA key;
  TDB_DATA val;
  DATA_BLOB blob;
  struct smbXsrv_session_globalB global_blob;
  enum ndr_err_code ndr_err;
  struct smbXsrv_session_global0 *global = NULL;
  bool exists;
  TALLOC_CTX *frame = talloc_stackframe();

  *is_free = false;

  if (was_free) {
    *was_free = false;
  }
  if (_g) {
    *_g = NULL;
  }
  if (pseqnum) {
    *pseqnum = 0;
  }

  key = dbwrap_record_get_key(db_rec);

  val = dbwrap_record_get_value(db_rec);
  if (val.dsize == 0) {
    TALLOC_FREE(frame);
    *is_free = true;
    if (was_free) {
      *was_free = true;
    }
    return;
  }

  blob = data_blob_const(val.dptr, val.dsize);

  ndr_err = ndr_pull_struct_blob(&blob, frame, &global_blob,
      (ndr_pull_flags_fn_t)ndr_pull_smbXsrv_session_globalB);
  if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
    NTSTATUS status = ndr_map_error2ntstatus(ndr_err);
    DBG_WARNING("key '%s' ndr_pull_struct_blob - %s\n",
          tdb_data_dbg(key),
          nt_errstr(status));
    TALLOC_FREE(frame);
    *is_free = true;
    if (was_free) {
      *was_free = true;
    }
    return;
  }

  DBG_DEBUG("smbXsrv_session_global_verify_record\n");
  if (DEBUGLVL(DBGLVL_DEBUG)) {
    NDR_PRINT_DEBUG(smbXsrv_session_globalB, &global_blob);
  }

  if (global_blob.version != SMBXSRV_VERSION_0) {
    DBG_ERR("key '%s' use unsupported version %u\n",
      tdb_data_dbg(key),
      global_blob.version);
    NDR_PRINT_DEBUG(smbXsrv_session_globalB, &global_blob);
    TALLOC_FREE(frame);
    *is_free = true;
    if (was_free) {
      *was_free = true;
    }
    return;
  }

  global = global_blob.info.info0;

#define __BLOB_KEEP_SECRET(__blob) do { \
  if ((__blob).length != 0) { \
    talloc_keep_secret((__blob).data); \
  } \
} while(0)
  {
    uint32_t i;
    __BLOB_KEEP_SECRET(global->application_key_blob);
    __BLOB_KEEP_SECRET(global->signing_key_blob);
    __BLOB_KEEP_SECRET(global->encryption_key_blob);
    __BLOB_KEEP_SECRET(global->decryption_key_blob);
    for (i = 0; i < global->num_channels; i++) {
      __BLOB_KEEP_SECRET(global->channels[i].signing_key_blob);
    }
  }
#undef __BLOB_KEEP_SECRET

  exists = serverid_exists(&global->channels[0].server_id);
  if (!exists) {
    struct server_id_buf idbuf;
    DBG_NOTICE("key '%s' server_id %s does not exist.\n",
         tdb_data_dbg(key),
         server_id_str_buf(global->channels[0].server_id,
               &idbuf));
    if (DEBUGLVL(DBGLVL_NOTICE)) {
      NDR_PRINT_DEBUG(smbXsrv_session_globalB, &global_blob);
    }
    TALLOC_FREE(frame);
    dbwrap_record_delete(db_rec);
    *is_free = true;
    return;
  }

  if (_g) {
    *_g = talloc_move(mem_ctx, &global);
  }
  if (pseqnum) {
    *pseqnum = global_blob.seqnum;
  }
  TALLOC_FREE(frame);
}

static NTSTATUS smbXsrv_session_global_store(struct smbXsrv_session_global0 *global)
{
  struct smbXsrv_session_globalB global_blob;
  DATA_BLOB blob = data_blob_null;
  TDB_DATA key;
  TDB_DATA val;
  NTSTATUS status;
  enum ndr_err_code ndr_err;

  /*
   * TODO: if we use other versions than '0'
   * we would add glue code here, that would be able to
   * store the information in the old format.
   */

  key = dbwrap_record_get_key(global->db_rec);
  val = dbwrap_record_get_value(global->db_rec);

  global_blob = (struct smbXsrv_session_globalB){
    .version = smbXsrv_version_global_current(),
    .info.info0 = global,
  };

  if (val.dsize >= 8) {
    global_blob.seqnum = IVAL(val.dptr, 4);
  }
  global_blob.seqnum += 1;

  ndr_err = ndr_push_struct_blob(
    &blob,
    talloc_tos(),
    &global_blob,
    (ndr_push_flags_fn_t)ndr_push_smbXsrv_session_globalB);
  if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
    status = ndr_map_error2ntstatus(ndr_err);
    DBG_WARNING("key '%s' ndr_push - %s\n",
          tdb_data_dbg(key),
          nt_errstr(status));
    TALLOC_FREE(global->db_rec);
    return status;
  }

  val = make_tdb_data(blob.data, blob.length);
  status = dbwrap_record_store(global->db_rec, val, TDB_REPLACE);
  TALLOC_FREE(blob.data);
  if (!NT_STATUS_IS_OK(status)) {
    DBG_WARNING("key '%s' store - %s\n",
          tdb_data_dbg(key),
          nt_errstr(status));
    TALLOC_FREE(global->db_rec);
    return status;
  }

  if (DEBUGLVL(DBGLVL_DEBUG)) {
    DBG_DEBUG("key '%s' stored\n", tdb_data_dbg(key));
    NDR_PRINT_DEBUG(smbXsrv_session_globalB, &global_blob);
  }

  TALLOC_FREE(global->db_rec);

  return NT_STATUS_OK;
}

struct smb2srv_session_close_previous_state {
  struct tevent_context *ev;
  struct smbXsrv_connection *connection;
  struct dom_sid *current_sid;
  uint64_t previous_session_id;
  uint64_t current_session_id;
  struct db_record *db_rec;
  uint64_t watch_instance;
  uint32_t last_seqnum;
};

static void smb2srv_session_close_previous_cleanup(struct tevent_req *req,
               enum tevent_req_state req_state)
{
  struct smb2srv_session_close_previous_state *state =
    tevent_req_data(req,
    struct smb2srv_session_close_previous_state);

  if (state->db_rec != NULL) {
    dbwrap_watched_watch_remove_instance(state->db_rec,
                 state->watch_instance);
    state->watch_instance = 0;
    TALLOC_FREE(state->db_rec);
  }
}

static void smb2srv_session_close_previous_check(struct tevent_req *req);
static void smb2srv_session_close_previous_modified(struct tevent_req *subreq);

struct tevent_req *smb2srv_session_close_previous_send(TALLOC_CTX *mem_ctx,
          struct tevent_context *ev,
          struct smbXsrv_connection *conn,
          struct auth_session_info *session_info,
          uint64_t previous_session_id,
          uint64_t current_session_id)
{
  struct tevent_req *req = NULL;
  struct smb2srv_session_close_previous_state *state = NULL;
  uint32_t global_id = previous_session_id & UINT32_MAX;
  uint64_t global_zeros = previous_session_id & 0xFFFFFFFF00000000LLU;
  struct smbXsrv_session_table *table = conn->client->session_table;
  struct security_token *current_token = NULL;

  req = tevent_req_create(mem_ctx, &state,
        struct smb2srv_session_close_previous_state);
  if (req == NULL) {
    return NULL;
  }
  state->ev = ev;
  state->connection = conn;
  state->previous_session_id = previous_session_id;
  state->current_session_id = current_session_id;

  tevent_req_set_cleanup_fn(req, smb2srv_session_close_previous_cleanup);

  if (global_zeros != 0) {
    tevent_req_done(req);
    return tevent_req_post(req, ev);
  }

  if (session_info == NULL) {
    tevent_req_done(req);
    return tevent_req_post(req, ev);
  }
  current_token = session_info->security_token;

  if (current_token->num_sids <= PRIMARY_USER_SID_INDEX) {
    tevent_req_done(req);
    return tevent_req_post(req, ev);
  }
  state->current_sid = &current_token->sids[PRIMARY_USER_SID_INDEX];

  if (!security_token_has_nt_authenticated_users(current_token)) {
    /* TODO */
    tevent_req_done(req);
    return tevent_req_post(req, ev);
  }

  state->db_rec = smbXsrv_session_global_fetch_locked(
              table->global.db_ctx,
              global_id,
              state /* TALLOC_CTX */);
  if (state->db_rec == NULL) {
    tevent_req_nterror(req, NT_STATUS_UNSUCCESSFUL);
    return tevent_req_post(req, ev);
  }

  smb2srv_session_close_previous_check(req);
  if (!tevent_req_is_in_progress(req)) {
    return tevent_req_post(req, ev);
  }

  return req;
}

static void smb2srv_session_close_previous_check(struct tevent_req *req)
{
  struct smb2srv_session_close_previous_state *state =
    tevent_req_data(req,
    struct smb2srv_session_close_previous_state);
  struct smbXsrv_connection *conn = state->connection;
  DATA_BLOB blob;
  struct security_token *previous_token = NULL;
  struct smbXsrv_session_global0 *global = NULL;
  enum ndr_err_code ndr_err;
  struct smbXsrv_session_close0 close_info0;
  struct smbXsrv_session_closeB close_blob;
  struct tevent_req *subreq = NULL;
  NTSTATUS status;
  bool is_free = false;
  uint32_t seqnum = 0;

  smbXsrv_session_global_verify_record(state->db_rec,
               &is_free,
               NULL,
               state,
               &global,
               &seqnum);

  if (is_free) {
    tevent_req_done(req);
    return;
  }

  if (global->auth_session_info == NULL) {
    tevent_req_done(req);
    return;
  }

  previous_token = global->auth_session_info->security_token;

  if (!security_token_is_sid(previous_token, state->current_sid)) {
    tevent_req_done(req);
    return;
  }

  /*
   * If the record changed, but we are not happy with the change yet,
   * we better remove ourself from the waiter list
   * (most likely the first position)
   * and re-add us at the end of the list.
   *
   * This gives other waiters a change
   * to make progress.
   *
   * Otherwise we'll keep our waiter instance alive,
   * keep waiting (most likely at first position).
   * It means the order of watchers stays fair.
   */
  if (state->last_seqnum != seqnum) {
    state->last_seqnum = seqnum;
    dbwrap_watched_watch_remove_instance(state->db_rec,
                 state->watch_instance);
    state->watch_instance =
      dbwrap_watched_watch_add_instance(state->db_rec);
  }

  subreq = dbwrap_watched_watch_send(state, state->ev, state->db_rec,
             state->watch_instance,
             (struct server_id){0});
  if (tevent_req_nomem(subreq, req)) {
    return;
  }
  tevent_req_set_callback(subreq,
        smb2srv_session_close_previous_modified,
        req);

  close_info0 = (struct smbXsrv_session_close0){
    .old_session_global_id = global->session_global_id,
    .old_session_wire_id = global->session_wire_id,
    .old_creation_time = global->creation_time,
    .new_session_wire_id = state->current_session_id,
  };

  close_blob = (struct smbXsrv_session_closeB){
    .version = smbXsrv_version_global_current(),
    .info.info0 = &close_info0,
  };

  ndr_err = ndr_push_struct_blob(&blob, state, &close_blob,
      (ndr_push_flags_fn_t)ndr_push_smbXsrv_session_closeB);
  if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
    status = ndr_map_error2ntstatus(ndr_err);
    DBG_WARNING("old_session[%" PRIu64 "] "
          "new_session[%" PRIu64 "] ndr_push - %s\n",
          close_info0.old_session_wire_id,
          close_info0.new_session_wire_id,
          nt_errstr(status));
    tevent_req_nterror(req, status);
    return;
  }

  status = messaging_send(conn->client->msg_ctx,
        global->channels[0].server_id,
        MSG_SMBXSRV_SESSION_CLOSE, &blob);
  TALLOC_FREE(global);
  if (tevent_req_nterror(req, status)) {
    return;
  }

  TALLOC_FREE(state->db_rec);
  return;
}

static void smb2srv_session_close_previous_modified(struct tevent_req *subreq)
{
  struct tevent_req *req =
    tevent_req_callback_data(subreq,
    struct tevent_req);
  struct smb2srv_session_close_previous_state *state =
    tevent_req_data(req,
    struct smb2srv_session_close_previous_state);
  uint32_t global_id;
  NTSTATUS status;
  uint64_t instance = 0;

  status = dbwrap_watched_watch_recv(subreq, &instance, NULL, NULL);
  TALLOC_FREE(subreq);
  if (tevent_req_nterror(req, status)) {
    return;
  }

  state->watch_instance = instance;

  global_id = state->previous_session_id & UINT32_MAX;

  state->db_rec = smbXsrv_session_global_fetch_locked(
    state->connection->client->session_table->global.db_ctx,
    global_id, state /* TALLOC_CTX */);
  if (state->db_rec == NULL) {
    tevent_req_nterror(req, NT_STATUS_UNSUCCESSFUL);
    return;
  }

  smb2srv_session_close_previous_check(req);
}

NTSTATUS smb2srv_session_close_previous_recv(struct tevent_req *req)
{
  NTSTATUS status;

  if (tevent_req_is_nterror(req, &status)) {
    tevent_req_received(req);
    return status;
  }

  tevent_req_received(req);
  return NT_STATUS_OK;
}

static NTSTATUS smbXsrv_session_clear_and_logoff(struct smbXsrv_session *session)
{
  NTSTATUS status;
  struct smbXsrv_connection *xconn = NULL;

  if (session->client != NULL) {
    xconn = session->client->connections;
  }

  for (; xconn != NULL; xconn = xconn->next) {
    struct smbd_smb2_request *preq;

    for (preq = xconn->smb2.requests; preq != NULL; preq = preq->next) {
      if (preq->session != session) {
        continue;
      }

      preq->session = NULL;
      /*
       * If we no longer have a session we can't
       * sign or encrypt replies.
       */
      preq->do_signing = false;
      preq->do_encryption = false;
      preq->preauth = NULL;
    }
  }

  status = smbXsrv_session_logoff(session);
  return status;
}

static int smbXsrv_session_destructor(struct smbXsrv_session *session)
{
  NTSTATUS status;

  DBG_DEBUG("destructing session(%" PRIu64 ")\n",
      session->global->session_wire_id);

  status = smbXsrv_session_clear_and_logoff(session);
  if (!NT_STATUS_IS_OK(status)) {
    DBG_ERR("smbXsrv_session_logoff() failed: %s\n",
      nt_errstr(status));
  }

  TALLOC_FREE(session->global);

  return 0;
}

NTSTATUS smbXsrv_session_create(struct smbXsrv_connection *conn,
        NTTIME now,
        struct smbXsrv_session **_session)
{
  struct smbXsrv_session_table *table = conn->client->session_table;
  struct db_record *local_rec = NULL;
  struct smbXsrv_session *session = NULL;
  void *ptr = NULL;
  TDB_DATA val;
  struct smbXsrv_session_global0 *global = NULL;
  struct smbXsrv_channel_global0 *channel = NULL;
  NTSTATUS status;

  if (table->local.num_sessions >= table->local.max_sessions) {
    return NT_STATUS_INSUFFICIENT_RESOURCES;
  }

  session = talloc_zero(table, struct smbXsrv_session);
  if (session == NULL) {
    return NT_STATUS_NO_MEMORY;
  }
  session->table = table;
  session->idle_time = now;
  session->status = NT_STATUS_MORE_PROCESSING_REQUIRED;
  session->client = conn->client;
  session->homes_snum = -1;

  status = smbXsrv_session_global_allocate(table->global.db_ctx,
             session,
             &global);
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(session);
    return status;
  }
  session->global = global;

  if (conn->protocol >= PROTOCOL_SMB2_02) {
    uint64_t id = global->session_global_id;

    global->connection_dialect = conn->smb2.server.dialect;
    global->client_guid = conn->smb2.client.guid;

    global->session_wire_id = id;

    status = smb2srv_tcon_table_init(session);
    if (!NT_STATUS_IS_OK(status)) {
      TALLOC_FREE(session);
      return status;
    }

    session->local_id = global->session_global_id;

    local_rec = smbXsrv_session_local_fetch_locked(
            table->local.db_ctx,
            session->local_id,
            session /* TALLOC_CTX */);
    if (local_rec == NULL) {
      TALLOC_FREE(session);
      return NT_STATUS_NO_MEMORY;
    }

    val = dbwrap_record_get_value(local_rec);
    if (val.dsize != 0) {
      TALLOC_FREE(session);
      return NT_STATUS_INTERNAL_DB_CORRUPTION;
    }
  } else {

    status = smb1srv_session_local_allocate_id(table->local.db_ctx,
              table->local.lowest_id,
              table->local.highest_id,
              session,
              &local_rec,
              &session->local_id);
    if (!NT_STATUS_IS_OK(status)) {
      TALLOC_FREE(session);
      return status;
    }

    global->session_wire_id = session->local_id;
  }

  global->creation_time = now;
  global->expiration_time = GENSEC_EXPIRE_TIME_INFINITY;

  status = smbXsrv_session_add_channel(session, conn, now, &channel);
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(session);
    return status;
  }

  ptr = session;
  val = make_tdb_data((uint8_t const *)&ptr, sizeof(ptr));
  status = dbwrap_record_store(local_rec, val, TDB_REPLACE);
  TALLOC_FREE(local_rec);
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(session);
    return status;
  }
  table->local.num_sessions += 1;

  talloc_set_destructor(session, smbXsrv_session_destructor);

  status = smbXsrv_session_global_store(global);
  if (!NT_STATUS_IS_OK(status)) {
    DBG_ERR("global_id (0x%08x) store failed - %s\n",
      session->global->session_global_id,
      nt_errstr(status));
    TALLOC_FREE(session);
    return status;
  }

  if (DEBUGLVL(DBGLVL_DEBUG)) {
    struct smbXsrv_sessionB session_blob = {
      .version = SMBXSRV_VERSION_0,
      .info.info0 = session,
    };

    DBG_DEBUG("global_id (0x%08x) stored\n",
        session->global->session_global_id);
    NDR_PRINT_DEBUG(smbXsrv_sessionB, &session_blob);
  }

  *_session = session;
  return NT_STATUS_OK;
}

NTSTATUS smbXsrv_session_add_channel(struct smbXsrv_session *session,
             struct smbXsrv_connection *conn,
             NTTIME now,
             struct smbXsrv_channel_global0 **_c)
{
  struct smbXsrv_session_global0 *global = session->global;
  struct smbXsrv_channel_global0 *c = NULL;

  if (global->num_channels > 31) {
    /*
     * Windows allow up to 32 channels
     */
    return NT_STATUS_INSUFFICIENT_RESOURCES;
  }

  c = talloc_realloc(global,
         global->channels,
         struct smbXsrv_channel_global0,
         global->num_channels + 1);
  if (c == NULL) {
    return NT_STATUS_NO_MEMORY;
  }
  global->channels = c;

  c = &global->channels[global->num_channels];

  *c = (struct smbXsrv_channel_global0){
    .server_id = messaging_server_id(conn->client->msg_ctx),
    .channel_id = conn->channel_id,
    .creation_time = now,
    .connection = conn,
    .transport_type = conn->transport.type,
  };

  c->local_address = tsocket_address_string(conn->local_address,
              global->channels);
  if (c->local_address == NULL) {
    return NT_STATUS_NO_MEMORY;
  }
  c->remote_address = tsocket_address_string(conn->remote_address,
               global->channels);
  if (c->remote_address == NULL) {
    return NT_STATUS_NO_MEMORY;
  }
  c->remote_name = talloc_strdup(global->channels,
               conn->remote_hostname);
  if (c->remote_name == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  global->num_channels += 1;

  *_c = c;
  return NT_STATUS_OK;
}

NTSTATUS smbXsrv_session_update(struct smbXsrv_session *session)
{
  struct smbXsrv_session_table *table = session->table;
  NTSTATUS status;

  if (session->global->db_rec != NULL) {
    DBG_ERR("smbXsrv_session_update(0x%08x): "
        "Called with db_rec != NULL'\n",
        session->global->session_global_id);
    return NT_STATUS_INTERNAL_ERROR;
  }

  if (table == NULL) {
    DBG_ERR("smbXsrv_session_update(0x%08x): "
        "Called with table == NULL'\n",
        session->global->session_global_id);
    return NT_STATUS_INTERNAL_ERROR;
  }

  session->global->db_rec = smbXsrv_session_global_fetch_locked(
          table->global.db_ctx,
          session->global->session_global_id,
          session->global /* TALLOC_CTX */);
  if (session->global->db_rec == NULL) {
    return NT_STATUS_INTERNAL_DB_ERROR;
  }

  status = smbXsrv_session_global_store(session->global);
  if (!NT_STATUS_IS_OK(status)) {
    DBG_ERR("global_id (0x%08x) store failed - %s\n",
      session->global->session_global_id,
      nt_errstr(status));
    return status;
  }

  if (DEBUGLVL(DBGLVL_DEBUG)) {
    struct smbXsrv_sessionB session_blob = {
      .version = SMBXSRV_VERSION_0,
      .info.info0 = session,
    };

    DBG_DEBUG("global_id (0x%08x) stored\n",
        session->global->session_global_id);
    NDR_PRINT_DEBUG(smbXsrv_sessionB, &session_blob);
  }

  return NT_STATUS_OK;
}

NTSTATUS smbXsrv_session_find_channel(const struct smbXsrv_session *session,
              const struct smbXsrv_connection *conn,
              struct smbXsrv_channel_global0 **_c)
{
  uint32_t i;

  for (i=0; i < session->global->num_channels; i++) {
    struct smbXsrv_channel_global0 *c = &session->global->channels[i];

    if (c->channel_id != conn->channel_id) {
      continue;
    }

    if (c->connection != conn) {
      continue;
    }

    *_c = c;
    return NT_STATUS_OK;
  }

  return NT_STATUS_USER_SESSION_DELETED;
}

NTSTATUS smbXsrv_session_find_auth(const struct smbXsrv_session *session,
           const struct smbXsrv_connection *conn,
           NTTIME now,
           struct smbXsrv_session_auth0 **_a)
{
  struct smbXsrv_session_auth0 *a;

  for (a = session->pending_auth; a != NULL; a = a->next) {
    if (a->channel_id != conn->channel_id) {
      continue;
    }

    if (a->connection == conn) {
      if (now != 0) {
        a->idle_time = now;
      }
      *_a = a;
      return NT_STATUS_OK;
    }
  }

  return NT_STATUS_USER_SESSION_DELETED;
}

static int smbXsrv_session_auth0_destructor(struct smbXsrv_session_auth0 *a)
{
  if (a->session == NULL) {
    return 0;
  }

  DLIST_REMOVE(a->session->pending_auth, a);
  a->session = NULL;
  return 0;
}

NTSTATUS smbXsrv_session_create_auth(struct smbXsrv_session *session,
             struct smbXsrv_connection *conn,
             NTTIME now,
             uint8_t in_flags,
             uint8_t in_security_mode,
             struct smbXsrv_session_auth0 **_a)
{
  struct smbXsrv_session_auth0 *a;
  NTSTATUS status;

  status = smbXsrv_session_find_auth(session, conn, 0, &a);
  if (NT_STATUS_IS_OK(status)) {
    return NT_STATUS_INTERNAL_ERROR;
  }

  a = talloc(session, struct smbXsrv_session_auth0);
  if (a == NULL) {
    return NT_STATUS_NO_MEMORY;
  }

  *a = (struct smbXsrv_session_auth0){
    .session = session,
    .connection = conn,
    .in_flags = in_flags,
    .in_security_mode = in_security_mode,
    .creation_time = now,
    .idle_time = now,
    .channel_id = conn->channel_id,
  };

  if (conn->protocol >= PROTOCOL_SMB3_11) {
    a->preauth = talloc(a, struct smbXsrv_preauth);
    if (a->preauth == NULL) {
      TALLOC_FREE(session);
      return NT_STATUS_NO_MEMORY;
    }
    *a->preauth = conn->smb2.preauth;
  }

  talloc_set_destructor(a, smbXsrv_session_auth0_destructor);
  DLIST_ADD_END(session->pending_auth, a);

  *_a = a;
  return NT_STATUS_OK;
}

static void smbXsrv_session_remove_channel_done(struct tevent_req *subreq);

NTSTATUS smbXsrv_session_remove_channel(struct smbXsrv_session *session,
          struct smbXsrv_connection *xconn)
{
  struct smbXsrv_session_auth0 *a = NULL;
  struct smbXsrv_channel_global0 *c = NULL;
  NTSTATUS status;
  bool need_update = false;

  status = smbXsrv_session_find_auth(session, xconn, 0, &a);
  if (!NT_STATUS_IS_OK(status)) {
    a = NULL;
  }
  status = smbXsrv_session_find_channel(session, xconn, &c);
  if (!NT_STATUS_IS_OK(status)) {
    c = NULL;
  }

  if (a != NULL) {
    smbXsrv_session_auth0_destructor(a);
    a->connection = NULL;
    need_update = true;
  }

  if (c != NULL) {
    struct smbXsrv_session_global0 *global = session->global;
    ptrdiff_t n;

    n = (c - global->channels);
    if (n >= global->num_channels || n < 0) {
      return NT_STATUS_INTERNAL_ERROR;
    }
    ARRAY_DEL_ELEMENT(global->channels, n, global->num_channels);
    global->num_channels--;
    if (global->num_channels == 0) {
      struct smbXsrv_client *client = session->client;
      struct tevent_queue *xconn_wait_queue =
        xconn->transport.shutdown_wait_queue;
      struct tevent_req *subreq = NULL;

      /*
       * Let the connection wait until the session is
       * destroyed.
       *
       * We don't set a callback, as we just want to block the
       * wait queue and the talloc_free() of the session will
       * remove the item from the wait queue in order
       * to remove allow the connection to disappear.
       */
      if (xconn_wait_queue != NULL) {
        subreq = tevent_queue_wait_send(session,
                client->raw_ev_ctx,
                xconn_wait_queue);
        if (subreq == NULL) {
          status = NT_STATUS_NO_MEMORY;
          DBG_ERR("tevent_queue_wait_send() "
            "session(%" PRIu64
            ") failed: %s\n",
            session->global
              ->session_wire_id,
            nt_errstr(status));
          return status;
        }
      }

      /*
       * This is guaranteed to set
       * session->status = NT_STATUS_USER_SESSION_DELETED
       * even if NULL is returned.
       */
      subreq = smb2srv_session_shutdown_send(session,
                     client->raw_ev_ctx,
                     session,
                     NULL);
      if (subreq == NULL) {
        status = NT_STATUS_NO_MEMORY;
        DBG_ERR("smb2srv_session_shutdown_send("
          "%" PRIu64 " failed: %s\n",
          session->global->session_wire_id,
          nt_errstr(status));
        return status;
      }
      tevent_req_set_callback(subreq,
            smbXsrv_session_remove_channel_done,
            session);
    }
    need_update = true;
  }

  if (!need_update) {
    return NT_STATUS_OK;
  }

  return smbXsrv_session_update(session);
}

static void smbXsrv_session_remove_channel_done(struct tevent_req *subreq)
{
  struct smbXsrv_session *session =
    tevent_req_callback_data(subreq,
    struct smbXsrv_session);
  NTSTATUS status;

  status = smb2srv_session_shutdown_recv(subreq);
  TALLOC_FREE(subreq);
  if (!NT_STATUS_IS_OK(status)) {
    DBG_ERR("smb2srv_session_shutdown_recv(%" PRIu64
      ") failed: %s\n",
      session->global->session_wire_id,
      nt_errstr(status));
  }

  status = smbXsrv_session_logoff(session);
  if (!NT_STATUS_IS_OK(status)) {
    DBG_ERR("smbXsrv_session_logoff(%" PRIu64 ") failed: %s\n",
      session->global->session_wire_id,
      nt_errstr(status));
  }

  TALLOC_FREE(session);
}

struct smb2srv_session_shutdown_state {
  struct tevent_queue *wait_queue;
};

static void smb2srv_session_shutdown_wait_done(struct tevent_req *subreq);

struct check_for_lease_break_fsp_cmp_state {
  struct smbXsrv_session *session;
};

static bool check_for_lease_break_fsp_cmp_fn(struct files_struct *fsp,
               void *private_data)
{
  struct check_for_lease_break_fsp_cmp_state *state =
    (struct check_for_lease_break_fsp_cmp_state *)private_data;

  return (fsp->vuid == state->session->global->session_wire_id);
}

struct tevent_req *smb2srv_session_shutdown_send(TALLOC_CTX *mem_ctx,
          struct tevent_context *ev,
          struct smbXsrv_session *session,
          struct smbd_smb2_request *current_req)
{
  struct tevent_req *req = NULL;
  struct smb2srv_session_shutdown_state *state = NULL;
  struct tevent_req *subreq = NULL;
  struct smbXsrv_connection *xconn = NULL;
  struct check_for_lease_break_fsp_cmp_state fsp_cmp_state;
  size_t len = 0;

  /*
   * Make sure that no new request will be able to use this session.
   */
  session->status = NT_STATUS_USER_SESSION_DELETED;

  req = tevent_req_create(mem_ctx, &state,
        struct smb2srv_session_shutdown_state);
  if (req == NULL) {
    return NULL;
  }

  state->wait_queue = tevent_queue_create(state, "smb2srv_session_shutdown_queue");
  if (tevent_req_nomem(state->wait_queue, req)) {
    return tevent_req_post(req, ev);
  }

  for (xconn = session->client->connections; xconn != NULL; xconn = xconn->next) {
    struct smbd_smb2_request *preq;

    for (preq = xconn->smb2.requests; preq != NULL; preq = preq->next) {
      if (preq == current_req) {
        /* Can't cancel current request. */
        continue;
      }
      if (preq->session != session) {
        /* Request on different session. */
        continue;
      }

      if (preq->subreq != NULL) {
        tevent_req_cancel(preq->subreq);
      }

      /*
       * Now wait until the request is finished.
       *
       * We don't set a callback, as we just want to block the
       * wait queue and the talloc_free() of the request will
       * remove the item from the wait queue.
       */
      subreq = tevent_queue_wait_send(preq, ev, state->wait_queue);
      if (tevent_req_nomem(subreq, req)) {
        return tevent_req_post(req, ev);
      }
    }
  }

  fsp_cmp_state = (struct check_for_lease_break_fsp_cmp_state) {
    .session = session,
  };

  smbXsrv_wait_for_handle_lease_break(
    req,
    ev,
    session->client,
    state->wait_queue,
    check_for_lease_break_fsp_cmp_fn,
    &fsp_cmp_state);
  if (!tevent_req_is_in_progress(req)) {
    return tevent_req_post(req, ev);
  }

  len = tevent_queue_length(state->wait_queue);
  if (len == 0) {
    tevent_req_done(req);
    return tevent_req_post(req, ev);
  }

  /*
   * Now we add our own waiter to the end of the queue,
   * this way we get notified when all pending requests are finished
   * and send to the socket.
   */
  subreq = tevent_queue_wait_send(state, ev, state->wait_queue);
  if (tevent_req_nomem(subreq, req)) {
    return tevent_req_post(req, ev);
  }
  tevent_req_set_callback(subreq, smb2srv_session_shutdown_wait_done, req);

  return req;
}

static void smb2srv_session_shutdown_wait_done(struct tevent_req *subreq)
{
  struct tevent_req *req =
    tevent_req_callback_data(subreq,
    struct tevent_req);

  tevent_queue_wait_recv(subreq);
  TALLOC_FREE(subreq);

  tevent_req_done(req);
}

NTSTATUS smb2srv_session_shutdown_recv(struct tevent_req *req)
{
  return tevent_req_simple_recv_ntstatus(req);
}

NTSTATUS smbXsrv_session_logoff(struct smbXsrv_session *session)
{
  struct smbXsrv_session_table *table;
  struct db_record *local_rec = NULL;
  struct db_record *global_rec = NULL;
  struct smbd_server_connection *sconn = NULL;
  NTSTATUS status;
  NTSTATUS error = NT_STATUS_OK;

  if (session->table == NULL) {
    return NT_STATUS_OK;
  }

  table = session->table;
  session->table = NULL;

  sconn = session->client->sconn;
  session->client = NULL;
  session->status = NT_STATUS_USER_SESSION_DELETED;

  /*
   * For SMB2 this is a bit redundant as files are also close
   * below via smb2srv_tcon_disconnect_all() -> ... ->
   * smbXsrv_tcon_disconnect() -> close_cnum() ->
   * file_close_conn().
   */
  file_close_user(sconn, session->global->session_wire_id);

  if (session->tcon_table != NULL) {
    /*
     * Note: We only have a tcon_table for SMB2.
     */
    status = smb2srv_tcon_disconnect_all(session);
    if (!NT_STATUS_IS_OK(status)) {
      DBG_ERR("smbXsrv_session_logoff(0x%08x): "
          "smb2srv_tcon_disconnect_all() failed: %s\n",
          session->global->session_global_id,
          nt_errstr(status));
      error = status;
    }
  }

  invalidate_vuid(sconn, session->global->session_wire_id);

  global_rec = session->global->db_rec;
  session->global->db_rec = NULL;
  if (global_rec == NULL) {
    global_rec = smbXsrv_session_global_fetch_locked(
          table->global.db_ctx,
          session->global->session_global_id,
          session->global /* TALLOC_CTX */);
    if (global_rec == NULL) {
      error = NT_STATUS_INTERNAL_ERROR;
    }
  }

  if (global_rec != NULL) {
    status = dbwrap_record_delete(global_rec);
    if (!NT_STATUS_IS_OK(status)) {
      TDB_DATA key = dbwrap_record_get_key(global_rec);

      DBG_ERR("smbXsrv_session_logoff(0x%08x): "
          "failed to delete global key '%s': %s\n",
          session->global->session_global_id,
          tdb_data_dbg(key),
          nt_errstr(status));
      error = status;
    }
  }
  TALLOC_FREE(global_rec);

  local_rec = session->db_rec;
  if (local_rec == NULL) {
    local_rec = smbXsrv_session_local_fetch_locked(
            table->local.db_ctx,
            session->local_id,
            session /* TALLOC_CTX */);
    if (local_rec == NULL) {
      error = NT_STATUS_INTERNAL_ERROR;
    }
  }

  if (local_rec != NULL) {
    status = dbwrap_record_delete(local_rec);
    if (!NT_STATUS_IS_OK(status)) {
      TDB_DATA key = dbwrap_record_get_key(local_rec);

      DBG_ERR("smbXsrv_session_logoff(0x%08x): "
          "failed to delete local key '%s': %s\n",
          session->global->session_global_id,
          tdb_data_dbg(key),
          nt_errstr(status));
      error = status;
    }
    table->local.num_sessions -= 1;
  }
  if (session->db_rec == NULL) {
    TALLOC_FREE(local_rec);
  }
  session->db_rec = NULL;

  return error;
}

struct smbXsrv_session_logoff_all_state {
  NTSTATUS first_status;
  int errors;
};

static int smbXsrv_session_logoff_all_callback(struct db_record *local_rec,
                 void *private_data);

NTSTATUS smbXsrv_session_logoff_all(struct smbXsrv_client *client)
{
  struct smbXsrv_session_table *table = client->session_table;
  struct smbXsrv_session_logoff_all_state state = {};
  NTSTATUS status;
  int count = 0;

  if (table == NULL) {
    DBG_DEBUG("empty session_table, nothing to do.\n");
    return NT_STATUS_OK;
  }

  status = dbwrap_traverse(table->local.db_ctx,
         smbXsrv_session_logoff_all_callback,
         &state, &count);
  if (!NT_STATUS_IS_OK(status)) {
    DBG_ERR("dbwrap_traverse() failed: %s\n", nt_errstr(status));
    return status;
  }

  if (!NT_STATUS_IS_OK(state.first_status)) {
    DBG_ERR("count[%d] errors[%d] first[%s]\n",
      count,
      state.errors,
      nt_errstr(state.first_status));
    return state.first_status;
  }

  return NT_STATUS_OK;
}

static int smbXsrv_session_logoff_all_callback(struct db_record *local_rec,
                 void *private_data)
{
  struct smbXsrv_session_logoff_all_state *state =
    (struct smbXsrv_session_logoff_all_state *)private_data;
  TDB_DATA val;
  void *ptr = NULL;
  struct smbXsrv_session *session = NULL;
  NTSTATUS status;

  val = dbwrap_record_get_value(local_rec);
  if (val.dsize != sizeof(ptr)) {
    status = NT_STATUS_INTERNAL_ERROR;
    if (NT_STATUS_IS_OK(state->first_status)) {
      state->first_status = status;
    }
    state->errors++;
    return 0;
  }

  memcpy(&ptr, val.dptr, val.dsize);
  session = talloc_get_type_abort(ptr, struct smbXsrv_session);

  session->db_rec = local_rec;
  status = smbXsrv_session_clear_and_logoff(session);
  session->db_rec = NULL;
  if (!NT_STATUS_IS_OK(status)) {
    if (NT_STATUS_IS_OK(state->first_status)) {
      state->first_status = status;
    }
    state->errors++;
    return 0;
  }

  return 0;
}

struct smbXsrv_session_local_trav_state {
  NTSTATUS status;
  int (*caller_cb)(struct smbXsrv_session *session,
       void *caller_data);
  void *caller_data;
};

static int smbXsrv_session_local_traverse_cb(struct db_record *local_rec,
               void *private_data);

NTSTATUS smbXsrv_session_local_traverse(
  struct smbXsrv_client *client,
  int (*caller_cb)(struct smbXsrv_session *session,
       void *caller_data),
  void *caller_data)
{
  struct smbXsrv_session_table *table = client->session_table;
  struct smbXsrv_session_local_trav_state state;
  NTSTATUS status;
  int count = 0;

  state = (struct smbXsrv_session_local_trav_state) {
    .status = NT_STATUS_OK,
    .caller_cb = caller_cb,
    .caller_data = caller_data,
  };

  if (table == NULL) {
    DBG_DEBUG("empty session_table, nothing to do.\n");
    return NT_STATUS_OK;
  }

  status = dbwrap_traverse(table->local.db_ctx,
         smbXsrv_session_local_traverse_cb,
         &state,
         &count);
  if (!NT_STATUS_IS_OK(status)) {
    DBG_ERR("dbwrap_traverse() failed: %s\n", nt_errstr(status));
    return status;
  }
  if (!NT_STATUS_IS_OK(state.status)) {
    DBG_ERR("count[%d] status[%s]\n",
      count, nt_errstr(state.status));
    return state.status;
  }

  return NT_STATUS_OK;
}

static int smbXsrv_session_local_traverse_cb(struct db_record *local_rec,
               void *private_data)
{
  struct smbXsrv_session_local_trav_state *state =
    (struct smbXsrv_session_local_trav_state *)private_data;
  TDB_DATA val;
  void *ptr = NULL;
  struct smbXsrv_session *session = NULL;
  int ret;

  val = dbwrap_record_get_value(local_rec);
  if (val.dsize != sizeof(ptr)) {
    state->status = NT_STATUS_INTERNAL_ERROR;
    return -1;
  }

  memcpy(&ptr, val.dptr, val.dsize);
  session = talloc_get_type_abort(ptr, struct smbXsrv_session);

  session->db_rec = local_rec;
  ret = state->caller_cb(session, state->caller_data);
  session->db_rec = NULL;

  return ret;
}

struct smbXsrv_session_disconnect_xconn_state {
  struct smbXsrv_connection *xconn;
  NTSTATUS first_status;
  int errors;
};

static int smbXsrv_session_disconnect_xconn_callback(struct db_record *local_rec,
                 void *private_data);

NTSTATUS smbXsrv_session_disconnect_xconn(struct smbXsrv_connection *xconn)
{
  struct smbXsrv_client *client = xconn->client;
  struct smbXsrv_session_table *table = client->session_table;
  struct smbXsrv_session_disconnect_xconn_state state = {
    .xconn = xconn,
  };
  NTSTATUS status;
  int count = 0;

  if (table == NULL) {
    DBG_ERR("empty session_table, nothing to do.\n");
    return NT_STATUS_OK;
  }

  status = dbwrap_traverse(table->local.db_ctx,
         smbXsrv_session_disconnect_xconn_callback,
         &state, &count);
  if (!NT_STATUS_IS_OK(status)) {
    DBG_ERR("dbwrap_traverse() failed: %s\n",
      nt_errstr(status));
    return status;
  }

  if (!NT_STATUS_IS_OK(state.first_status)) {
    DBG_ERR("count[%d] errors[%d] first[%s]\n",
      count, state.errors,
      nt_errstr(state.first_status));
    return state.first_status;
  }

  return NT_STATUS_OK;
}

static int smbXsrv_session_disconnect_xconn_callback(struct db_record *local_rec,
                 void *private_data)
{
  struct smbXsrv_session_disconnect_xconn_state *state =
    (struct smbXsrv_session_disconnect_xconn_state *)private_data;
  TDB_DATA val;
  void *ptr = NULL;
  struct smbXsrv_session *session = NULL;
  NTSTATUS status;

  val = dbwrap_record_get_value(local_rec);
  if (val.dsize != sizeof(ptr)) {
    status = NT_STATUS_INTERNAL_ERROR;
    if (NT_STATUS_IS_OK(state->first_status)) {
      state->first_status = status;
    }
    state->errors++;
    return 0;
  }

  memcpy(&ptr, val.dptr, val.dsize);
  session = talloc_get_type_abort(ptr, struct smbXsrv_session);

  session->db_rec = local_rec;
  status = smbXsrv_session_remove_channel(session, state->xconn);
  session->db_rec = NULL;
  if (!NT_STATUS_IS_OK(status)) {
    if (NT_STATUS_IS_OK(state->first_status)) {
      state->first_status = status;
    }
    state->errors++;
  }

  return 0;
}

NTSTATUS smb1srv_session_table_init(struct smbXsrv_connection *conn)
{
  /*
   * Allow a range from 1..65534 with 65534 values.
   */
  return smbXsrv_session_table_init(conn, 1, UINT16_MAX - 1,
            UINT16_MAX - 1);
}

NTSTATUS smb1srv_session_lookup(struct smbXsrv_connection *conn,
        uint16_t vuid, NTTIME now,
        struct smbXsrv_session **session)
{
  struct smbXsrv_session_table *table = conn->client->session_table;
  uint32_t local_id = vuid;

  return smbXsrv_session_local_lookup(table, conn, local_id, now,
              session);
}

NTSTATUS smbXsrv_session_info_lookup(struct smbXsrv_client *client,
             uint64_t session_wire_id,
             struct auth_session_info **si)
{
  struct smbXsrv_session_table *table = client->session_table;
  uint8_t key_buf[SMBXSRV_SESSION_LOCAL_TDB_KEY_SIZE];
  struct smbXsrv_session_local_fetch_state state = {
    .status = NT_STATUS_INTERNAL_ERROR,
  };
  TDB_DATA key;
  NTSTATUS status;

  if (session_wire_id == 0) {
    return NT_STATUS_USER_SESSION_DELETED;
  }

  if (table == NULL) {
    /* this might happen before the end of negprot */
    return NT_STATUS_USER_SESSION_DELETED;
  }

  if (table->local.db_ctx == NULL) {
    return NT_STATUS_INTERNAL_ERROR;
  }

  key = smbXsrv_session_local_id_to_key(session_wire_id, key_buf);

  status = dbwrap_parse_record(table->local.db_ctx, key,
             smbXsrv_session_local_fetch_parser,
             &state);
  if (!NT_STATUS_IS_OK(status)) {
    return status;
  }
  if (!NT_STATUS_IS_OK(state.status)) {
    return state.status;
  }
  if (state.session->global->auth_session_info == NULL) {
    return NT_STATUS_USER_SESSION_DELETED;
  }

  *si = state.session->global->auth_session_info;
  return NT_STATUS_OK;
}

/*
 * In memory of get_valid_user_struct()
 *
 * This function is similar to smbXsrv_session_local_lookup() and it's wrappers,
 * but it doesn't implement the state checks of
 * those. get_valid_smbXsrv_session() is NOT meant to be called to validate the
 * session wire-id of incoming SMB requests, it MUST only be used in later
 * internal processing where the session wire-id has already been validated.
 */
NTSTATUS get_valid_smbXsrv_session(struct smbXsrv_client *client,
           uint64_t session_wire_id,
           struct smbXsrv_session **session)
{
  struct smbXsrv_session_table *table = client->session_table;
  uint8_t key_buf[SMBXSRV_SESSION_LOCAL_TDB_KEY_SIZE];
  struct smbXsrv_session_local_fetch_state state = {
    .status = NT_STATUS_INTERNAL_ERROR,
  };
  TDB_DATA key;
  NTSTATUS status;

  if (session_wire_id == 0) {
    return NT_STATUS_USER_SESSION_DELETED;
  }

  if (table == NULL) {
    /* this might happen before the end of negprot */
    return NT_STATUS_USER_SESSION_DELETED;
  }

  if (table->local.db_ctx == NULL) {
    return NT_STATUS_INTERNAL_ERROR;
  }

  key = smbXsrv_session_local_id_to_key(session_wire_id, key_buf);

  status = dbwrap_parse_record(table->local.db_ctx, key,
             smbXsrv_session_local_fetch_parser,
             &state);
  if (!NT_STATUS_IS_OK(status)) {
    return status;
  }
  if (!NT_STATUS_IS_OK(state.status)) {
    return state.status;
  }
  if (state.session->global->auth_session_info == NULL) {
    return NT_STATUS_USER_SESSION_DELETED;
  }

  *session = state.session;
  return NT_STATUS_OK;
}

NTSTATUS smb2srv_session_lookup_global(struct smbXsrv_client *client,
               uint64_t session_wire_id,
               TALLOC_CTX *mem_ctx,
               struct smbXsrv_session **_session)
{
  TALLOC_CTX *frame = talloc_stackframe();
  struct smbXsrv_session_table *table = client->session_table;
  uint32_t global_id = session_wire_id & UINT32_MAX;
  uint64_t global_zeros = session_wire_id & 0xFFFFFFFF00000000LLU;
  struct smbXsrv_session *session = NULL;
  struct db_record *global_rec = NULL;
  bool is_free = false;
  NTSTATUS status;

  if (global_id == 0) {
    TALLOC_FREE(frame);
    return NT_STATUS_USER_SESSION_DELETED;
  }
  if (global_zeros != 0) {
    TALLOC_FREE(frame);
    return NT_STATUS_USER_SESSION_DELETED;
  }

  if (table == NULL) {
    /* this might happen before the end of negprot */
    TALLOC_FREE(frame);
    return NT_STATUS_USER_SESSION_DELETED;
  }

  if (table->global.db_ctx == NULL) {
    TALLOC_FREE(frame);
    return NT_STATUS_INTERNAL_ERROR;
  }

  session = talloc_zero(mem_ctx, struct smbXsrv_session);
  if (session == NULL) {
    TALLOC_FREE(frame);
    return NT_STATUS_NO_MEMORY;
  }
  talloc_steal(frame, session);

  session->client = client;
  session->status = NT_STATUS_BAD_LOGON_SESSION_STATE;
  session->local_id = global_id;

  /*
   * This means smb2_get_new_nonce() will return
   * NT_STATUS_ENCRYPTION_FAILED.
   *
   * But we initialize some random parts just in case...
   */
  session->nonce_high_max = session->nonce_high = 0;
  generate_nonce_buffer((uint8_t *)&session->nonce_high_random,
            sizeof(session->nonce_high_random));
  generate_nonce_buffer((uint8_t *)&session->nonce_low,
            sizeof(session->nonce_low));

  global_rec = smbXsrv_session_global_fetch_locked(table->global.db_ctx,
               global_id,
               frame);
  if (global_rec == NULL) {
    TALLOC_FREE(frame);
    return NT_STATUS_INTERNAL_DB_ERROR;
  }

  smbXsrv_session_global_verify_record(global_rec,
               &is_free,
               NULL,
               session,
               &session->global,
               NULL);
  if (is_free) {
    TALLOC_FREE(frame);
    return NT_STATUS_USER_SESSION_DELETED;
  }

  /*
   * We don't have channels on this session
   * and only the main signing key
   */
  session->global->num_channels = 0;
  status = smb2_signing_key_sign_create(session->global,
                session->global->signing_algo,
                NULL, /* no master key */
                NULL, /* derivations */
                &session->global->signing_key);
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(frame);
    return NT_STATUS_NO_MEMORY;
  }
  session->global->signing_key->blob = session->global->signing_key_blob;
  session->global->signing_flags = 0;

  status = smb2_signing_key_cipher_create(session->global,
            session->global->encryption_cipher,
            NULL, /* no master key */
            NULL, /* derivations */
            &session->global->decryption_key);
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(frame);
    return NT_STATUS_NO_MEMORY;
  }
  session->global->decryption_key->blob = session->global->decryption_key_blob;
  session->global->encryption_flags = 0;

  *_session = talloc_move(mem_ctx, &session);
  TALLOC_FREE(frame);
  return NT_STATUS_OK;
}

NTSTATUS smb2srv_session_table_init(struct smbXsrv_connection *conn)
{
  /*
   * Allow a range from 1..4294967294 with 65534 (same as SMB1) values.
   */
  return smbXsrv_session_table_init(conn, 1, UINT32_MAX - 1,
            UINT16_MAX - 1);
}

static NTSTATUS smb2srv_session_lookup_raw(struct smbXsrv_session_table *table,
             /* conn: optional */
             struct smbXsrv_connection *conn,
             uint64_t session_id, NTTIME now,
             struct smbXsrv_session **session)
{
  uint32_t local_id = session_id & UINT32_MAX;
  uint64_t local_zeros = session_id & 0xFFFFFFFF00000000LLU;

  if (local_zeros != 0) {
    return NT_STATUS_USER_SESSION_DELETED;
  }

  return smbXsrv_session_local_lookup(table, conn, local_id, now,
              session);
}

NTSTATUS smb2srv_session_lookup_conn(struct smbXsrv_connection *conn,
             uint64_t session_id, NTTIME now,
             struct smbXsrv_session **session)
{
  struct smbXsrv_session_table *table = conn->client->session_table;
  return smb2srv_session_lookup_raw(table, conn, session_id, now,
            session);
}

NTSTATUS smb2srv_session_lookup_client(struct smbXsrv_client *client,
               uint64_t session_id, NTTIME now,
               struct smbXsrv_session **session)
{
  struct smbXsrv_session_table *table = client->session_table;
  return smb2srv_session_lookup_raw(table, NULL, session_id, now,
            session);
}

struct smbXsrv_session_global_traverse_state {
  int (*fn)(struct smbXsrv_session_global0 *, void *);
  void *private_data;
};

static int smbXsrv_session_global_traverse_fn(struct db_record *rec, void *data)
{
  int ret = -1;
  struct smbXsrv_session_global_traverse_state *state =
    (struct smbXsrv_session_global_traverse_state*)data;
  TDB_DATA key = dbwrap_record_get_key(rec);
  TDB_DATA val = dbwrap_record_get_value(rec);
  DATA_BLOB blob = data_blob_const(val.dptr, val.dsize);
  struct smbXsrv_session_globalB global_blob;
  enum ndr_err_code ndr_err;
  TALLOC_CTX *frame = talloc_stackframe();

  ndr_err = ndr_pull_struct_blob(&blob, frame, &global_blob,
      (ndr_pull_flags_fn_t)ndr_pull_smbXsrv_session_globalB);
  if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
    DBG_WARNING("Invalid record in smbXsrv_session_global.tdb:"
       "key '%s' ndr_pull_struct_blob - %s\n",
       tdb_data_dbg(key),
       ndr_errstr(ndr_err));
    goto done;
  }

  if (global_blob.version != SMBXSRV_VERSION_0) {
    DBG_WARNING("Invalid record in smbXsrv_session_global.tdb:"
       "key '%s' unsupported version - %d\n",
       tdb_data_dbg(key),
       (int)global_blob.version);
    goto done;
  }

  if (global_blob.info.info0 == NULL) {
    DBG_WARNING("Invalid record in smbXsrv_tcon_global.tdb:"
       "key '%s' info0 NULL pointer\n",
       tdb_data_dbg(key));
    goto done;
  }

  global_blob.info.info0->db_rec = rec;
  ret = state->fn(global_blob.info.info0, state->private_data);
done:
  TALLOC_FREE(frame);
  return ret;
}

NTSTATUS smbXsrv_session_global_traverse(
      int (*fn)(struct smbXsrv_session_global0 *, void *),
      void *private_data)
{

  NTSTATUS status;
  int count = 0;
  struct smbXsrv_session_global_traverse_state state = {
    .fn = fn,
    .private_data = private_data,
  };

  become_root();
  status = smbXsrv_session_global_init(NULL);
  if (!NT_STATUS_IS_OK(status)) {
    unbecome_root();
    DBG_ERR("Failed to initialize session_global: %s\n",
        nt_errstr(status));
    return status;
  }

  status = dbwrap_traverse_read(smbXsrv_session_global_db_ctx,
              smbXsrv_session_global_traverse_fn,
              &state,
              &count);
  unbecome_root();

  return status;
}

static struct files_struct *smbXsrv_wait_for_handle_lease_break_fn(
            struct files_struct *fsp,
            void *private_data);
static void smbXsrv_wait_for_handle_lease_break_done(
            struct tevent_req *subreq);

struct delay_for_handle_lease_break_state {
  struct tevent_req *req;
  struct tevent_context *ev;
  struct smbXsrv_client *client;
  struct tevent_queue *wait_queue;
  bool (*fsp_cmp_fn)(struct files_struct *fsp,
         void *private_data);
  void *fsp_cmp_private_data;
};

void smbXsrv_wait_for_handle_lease_break(
        struct tevent_req *req,
        struct tevent_context *ev,
        struct smbXsrv_client *client,
        struct tevent_queue *wait_queue,
        bool (*fsp_cmp_fn)(struct files_struct *fsp,
               void *private_data),
        void *fsp_cmp_private_data)
{
  struct delay_for_handle_lease_break_state state;

  state = (struct delay_for_handle_lease_break_state) {
    .req = req,
    .ev = ev,
    .client = client,
    .wait_queue = wait_queue,
    .fsp_cmp_fn = fsp_cmp_fn,
    .fsp_cmp_private_data = fsp_cmp_private_data,
  };

  files_forall(client->sconn,
         smbXsrv_wait_for_handle_lease_break_fn,
         &state);
}

static struct files_struct *smbXsrv_wait_for_handle_lease_break_fn(
            struct files_struct *fsp,
            void *private_data)
{
  struct delay_for_handle_lease_break_state *state = private_data;
  struct tevent_req *subreq = NULL;
  struct share_mode_lock *lck = NULL;
  struct timeval timeout = timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0);
  bool match;
  NTSTATUS status;

  match = state->fsp_cmp_fn(fsp, state->fsp_cmp_private_data);
  if (!match) {
    return NULL;
  }

  if (!fsp->fsp_flags.initial_delete_on_close) {
    return NULL;
  }

  lck = get_existing_share_mode_lock(fsp, fsp->file_id);
  if (lck == NULL) {
    /* No opens on this file */
    return NULL;
  }

  subreq = delay_for_handle_lease_break_send(fsp,
               state->ev,
               timeout,
               fsp,
               SEC_RIGHTS_DIR_ALL,
               false,
               &lck);
  if (tevent_req_nomem(subreq, state->req)) {
    TALLOC_FREE(lck);
    /* Reminder: returning != NULL means STOP traverse */
    return fsp;
  }
  if (tevent_req_is_in_progress(subreq)) {
    struct tevent_req *wait_subreq = NULL;

    tevent_req_set_callback(
      subreq,
      smbXsrv_wait_for_handle_lease_break_done,
      state->req);

    /*
     * This just adds a blocker that unblocks when subreq is
     * completed and goes away.
     */
    wait_subreq = tevent_queue_wait_send(subreq,
                 state->ev,
                 state->wait_queue);
    if (wait_subreq == NULL) {
      exit_server("tevent_queue_wait_send failed");
    }
    return NULL;
  }

  status = delay_for_handle_lease_break_recv(subreq, state->req, &lck);
  TALLOC_FREE(subreq);
  TALLOC_FREE(lck);
  if (tevent_req_nterror(state->req, status)) {
    DBG_ERR("delay_for_handle_lease_break_recv failed %s\n",
      nt_errstr(status));
    return fsp;
  }
  return NULL;
}

static void smbXsrv_wait_for_handle_lease_break_done(
            struct tevent_req *subreq)
{
  struct tevent_req *req = tevent_req_callback_data(
    subreq, struct tevent_req);
  struct share_mode_lock *lck = NULL;
  NTSTATUS status;

  status = delay_for_handle_lease_break_recv(subreq,
               req,
               &lck);
  TALLOC_FREE(subreq);
  TALLOC_FREE(lck);
  if (tevent_req_nterror(req, status)) {
    DBG_ERR("delay_for_handle_lease_break_recv failed %s\n",
      nt_errstr(status));
    return;
  }
}

Coverage Report

Created: 2025-12-31 06:20