Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2529 insertions, 0 deletions

diff --git a/source3/smbd/smbXsrv_session.c b/source3/smbd/smbXsrv_session.c
new file mode 100644
index 0000000..59c6b49
--- /dev/null
+++ b/source3/smbd/smbXsrv_session.c
@@ -0,0 +1,2529 @@
+/*
+   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 "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"
+
+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,
+			  0, /* hash_size */
+			  TDB_DEFAULT |
+			  TDB_CLEAR_IF_FIRST |
+			  TDB_INCOMPATIBLE_HASH,
+			  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,
+			  hex_encode_talloc(talloc_tos(), key.dptr, key.dsize));
+	}
+
+	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,
+			  hex_encode_talloc(talloc_tos(), key.dptr, key.dsize));
+	}
+
+	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);
+		DEBUG(1,("smbXsrv_session_close_loop: "
+			 "ndr_pull_struct_blob - %s\n",
+			 nt_errstr(status)));
+		goto next;
+	}
+
+	DEBUG(10,("smbXsrv_session_close_loop: MSG_SMBXSRV_SESSION_CLOSE\n"));
+	if (DEBUGLVL(10)) {
+		NDR_PRINT_DEBUG(smbXsrv_session_closeB, &close_blob);
+	}
+
+	if (close_blob.version != SMBXSRV_VERSION_0) {
+		DEBUG(0,("smbXsrv_session_close_loop: "
+			 "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) {
+		DEBUG(0,("smbXsrv_session_close_loop: "
+			 "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)) {
+		DEBUG(4,("smbXsrv_session_close_loop: "
+			 "old_session_wire_id %llu not found\n",
+			 (unsigned long long)close_info0->old_session_wire_id));
+		if (DEBUGLVL(4)) {
+			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)) {
+		DEBUG(1,("smbXsrv_session_close_loop: "
+			 "old_session_wire_id %llu - %s\n",
+			 (unsigned long long)close_info0->old_session_wire_id,
+			 nt_errstr(status)));
+		if (DEBUGLVL(1)) {
+			NDR_PRINT_DEBUG(smbXsrv_session_closeB, &close_blob);
+		}
+		goto next;
+	}
+
+	if (session->global->session_global_id != close_info0->old_session_global_id) {
+		DEBUG(1,("smbXsrv_session_close_loop: "
+			 "old_session_wire_id %llu - global %u != %u\n",
+			 (unsigned long long)close_info0->old_session_wire_id,
+			 session->global->session_global_id,
+			 close_info0->old_session_global_id));
+		if (DEBUGLVL(1)) {
+			NDR_PRINT_DEBUG(smbXsrv_session_closeB, &close_blob);
+		}
+		goto next;
+	}
+
+	if (session->global->creation_time != close_info0->old_creation_time) {
+		DEBUG(1,("smbXsrv_session_close_loop: "
+			 "old_session_wire_id %llu - "
+			 "creation %s (%llu) != %s (%llu)\n",
+			 (unsigned long long)close_info0->old_session_wire_id,
+			 nt_time_string(rec, session->global->creation_time),
+			 (unsigned long long)session->global->creation_time,
+			 nt_time_string(rec, close_info0->old_creation_time),
+			 (unsigned long long)close_info0->old_creation_time));
+		if (DEBUGLVL(1)) {
+			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;
+		DEBUG(0, ("smbXsrv_session_close_loop: "
+			  "smb2srv_session_shutdown_send(%llu) failed: %s\n",
+			  (unsigned long long)session->global->session_wire_id,
+			  nt_errstr(status)));
+		if (DEBUGLVL(1)) {
+			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)) {
+		DEBUG(0, ("smbXsrv_session_close_loop: "
+			  "smb2srv_session_shutdown_recv(%llu) failed: %s\n",
+			  (unsigned long long)session->global->session_wire_id,
+			  nt_errstr(status)));
+	}
+
+	status = smbXsrv_session_logoff(session);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("smbXsrv_session_close_loop: "
+			  "smbXsrv_session_logoff(%llu) failed: %s\n",
+			  (unsigned long long)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);
+		DEBUG(1,("smbXsrv_session_global_verify_record: "
+			 "key '%s' ndr_pull_struct_blob - %s\n",
+			 hex_encode_talloc(frame, key.dptr, key.dsize),
+			 nt_errstr(status)));
+		TALLOC_FREE(frame);
+		*is_free = true;
+		if (was_free) {
+			*was_free = true;
+		}
+		return;
+	}
+
+	DEBUG(10,("smbXsrv_session_global_verify_record\n"));
+	if (DEBUGLVL(10)) {
+		NDR_PRINT_DEBUG(smbXsrv_session_globalB, &global_blob);
+	}
+
+	if (global_blob.version != SMBXSRV_VERSION_0) {
+		DEBUG(0,("smbXsrv_session_global_verify_record: "
+			 "key '%s' use unsupported version %u\n",
+			 hex_encode_talloc(frame, key.dptr, key.dsize),
+			 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;
+		DEBUG(2,("smbXsrv_session_global_verify_record: "
+			 "key '%s' server_id %s does not exist.\n",
+			 hex_encode_talloc(frame, key.dptr, key.dsize),
+			 server_id_str_buf(global->channels[0].server_id,
+					   &idbuf)));
+		if (DEBUGLVL(2)) {
+			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.
+	 */
+
+	if (global->db_rec == NULL) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	key = dbwrap_record_get_key(global->db_rec);
+	val = dbwrap_record_get_value(global->db_rec);
+
+	ZERO_STRUCT(global_blob);
+	global_blob.version = smbXsrv_version_global_current();
+	if (val.dsize >= 8) {
+		global_blob.seqnum = IVAL(val.dptr, 4);
+	}
+	global_blob.seqnum += 1;
+	global_blob.info.info0 = global;
+
+	ndr_err = ndr_push_struct_blob(&blob, global->db_rec, &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);
+		DEBUG(1,("smbXsrv_session_global_store: key '%s' ndr_push - %s\n",
+			 hex_encode_talloc(global->db_rec, key.dptr, key.dsize),
+			 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);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1,("smbXsrv_session_global_store: key '%s' store - %s\n",
+			 hex_encode_talloc(global->db_rec, key.dptr, key.dsize),
+			 nt_errstr(status)));
+		TALLOC_FREE(global->db_rec);
+		return status;
+	}
+
+	if (DEBUGLVL(10)) {
+		DEBUG(10,("smbXsrv_session_global_store: key '%s' stored\n",
+			 hex_encode_talloc(global->db_rec, key.dptr, key.dsize)));
+		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;
+	struct smb2srv_session_close_previous_state *state;
+	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) {
+		state->current_sid = &current_token->sids[PRIMARY_USER_SID_INDEX];
+	}
+
+	if (state->current_sid == NULL) {
+		tevent_req_done(req);
+		return tevent_req_post(req, ev);
+	}
+
+	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.old_session_global_id = global->session_global_id;
+	close_info0.old_session_wire_id = global->session_wire_id;
+	close_info0.old_creation_time = global->creation_time;
+	close_info0.new_session_wire_id = state->current_session_id;
+
+	ZERO_STRUCT(close_blob);
+	close_blob.version = smbXsrv_version_global_current();
+	close_blob.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);
+		DEBUG(1,("smb2srv_session_close_previous_check: "
+			 "old_session[%llu] new_session[%llu] ndr_push - %s\n",
+			 (unsigned long long)close_info0.old_session_wire_id,
+			 (unsigned long long)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(%llu)\n",
+		  (unsigned long long)session->global->session_wire_id);
+
+	status = smbXsrv_session_clear_and_logoff(session);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("smbXsrv_session_destructor: "
+			  "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->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)) {
+		DEBUG(0,("smbXsrv_session_create: "
+			 "global_id (0x%08x) store failed - %s\n",
+			 session->global->session_global_id,
+			 nt_errstr(status)));
+		TALLOC_FREE(session);
+		return status;
+	}
+
+	if (DEBUGLVL(10)) {
+		struct smbXsrv_sessionB session_blob = {
+			.version = SMBXSRV_VERSION_0,
+			.info.info0 = session,
+		};
+
+		DEBUG(10,("smbXsrv_session_create: 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];
+	ZERO_STRUCTP(c);
+
+	c->server_id = messaging_server_id(conn->client->msg_ctx);
+	c->channel_id = conn->channel_id;
+	c->creation_time = now;
+	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;
+	}
+	c->connection = conn;
+
+	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) {
+		DEBUG(0, ("smbXsrv_session_update(0x%08x): "
+			  "Called with db_rec != NULL'\n",
+			  session->global->session_global_id));
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	if (table == NULL) {
+		DEBUG(0, ("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)) {
+		DEBUG(0,("smbXsrv_session_update: "
+			 "global_id (0x%08x) store failed - %s\n",
+			 session->global->session_global_id,
+			 nt_errstr(status)));
+		return status;
+	}
+
+	if (DEBUGLVL(10)) {
+		struct smbXsrv_sessionB session_blob = {
+			.version = SMBXSRV_VERSION_0,
+			.info.info0 = session,
+		};
+
+		DEBUG(10,("smbXsrv_session_update: 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_zero(session, struct smbXsrv_session_auth0);
+	if (a == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+	a->session = session;
+	a->connection = conn;
+	a->in_flags = in_flags;
+	a->in_security_mode = in_security_mode;
+	a->creation_time = now;
+	a->idle_time = now;
+	a->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 disapear.
+			 */
+			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(%llu) failed: %s\n",
+						(unsigned long long)session->global->session_wire_id,
+						nt_errstr(status));
+					return status;
+				}
+			}
+
+			/*
+			 * This is garanteed 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(%llu) failed: %s\n",
+					(unsigned long long)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(%llu) failed: %s\n",
+			(unsigned long long)session->global->session_wire_id,
+			nt_errstr(status));
+	}
+
+	status = smbXsrv_session_logoff(session);
+	if (!NT_STATUS_IS_OK(status)) {
+		DBG_ERR("smbXsrv_session_logoff(%llu) failed: %s\n",
+			(unsigned long long)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 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;
+	struct smb2srv_session_shutdown_state *state;
+	struct tevent_req *subreq;
+	struct smbXsrv_connection *xconn = NULL;
+	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);
+			}
+		}
+	}
+
+	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)) {
+			DEBUG(0, ("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);
+
+			DEBUG(0, ("smbXsrv_session_logoff(0x%08x): "
+				  "failed to delete global key '%s': %s\n",
+				  session->global->session_global_id,
+				  hex_encode_talloc(global_rec, key.dptr,
+						    key.dsize),
+				  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);
+
+			DEBUG(0, ("smbXsrv_session_logoff(0x%08x): "
+				  "failed to delete local key '%s': %s\n",
+				  session->global->session_global_id,
+				  hex_encode_talloc(local_rec, key.dptr,
+						    key.dsize),
+				  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) {
+		DEBUG(10, ("smbXsrv_session_logoff_all: "
+			   "empty session_table, nothing to do.\n"));
+		return NT_STATUS_OK;
+	}
+
+	ZERO_STRUCT(state);
+
+	status = dbwrap_traverse(table->local.db_ctx,
+				 smbXsrv_session_logoff_all_callback,
+				 &state, &count);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("smbXsrv_session_logoff_all: "
+			  "dbwrap_traverse() failed: %s\n",
+			  nt_errstr(status)));
+		return status;
+	}
+
+	if (!NT_STATUS_IS_OK(state.first_status)) {
+		DEBUG(0, ("smbXsrv_session_logoff_all: "
+			  "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;
+	NTSTATUS status;
+	int count = 0;
+
+	if (table == NULL) {
+		DBG_ERR("empty session_table, nothing to do.\n");
+		return NT_STATUS_OK;
+	}
+
+	ZERO_STRUCT(state);
+	state.xconn = xconn;
+
+	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 = {
+		.session = NULL,
+		.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 = {
+		.session = NULL,
+		.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 intialize 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)) {
+		DEBUG(1,("Invalid record in smbXsrv_session_global.tdb:"
+			 "key '%s' ndr_pull_struct_blob - %s\n",
+			 hex_encode_talloc(frame, key.dptr, key.dsize),
+			 ndr_errstr(ndr_err)));
+		goto done;
+	}
+
+	if (global_blob.version != SMBXSRV_VERSION_0) {
+		DEBUG(1,("Invalid record in smbXsrv_session_global.tdb:"
+			 "key '%s' unsupported version - %d\n",
+			 hex_encode_talloc(frame, key.dptr, key.dsize),
+			 (int)global_blob.version));
+		goto done;
+	}
+
+	if (global_blob.info.info0 == NULL) {
+		DEBUG(1,("Invalid record in smbXsrv_tcon_global.tdb:"
+			 "key '%s' info0 NULL pointer\n",
+			 hex_encode_talloc(frame, key.dptr, key.dsize)));
+		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();
+		DEBUG(0, ("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;
+}