/*
   Unix SMB/CIFS implementation.
   smb2 lib
   Copyright (C) Volker Lendecke 2011

   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 "client.h"
#include "async_smb.h"
#include "smb2cli.h"
#include "../libcli/smb/smbXcli_base.h"
#include "libsmb/proto.h"
#include "lib/util/tevent_ntstatus.h"
#include "../libcli/auth/spnego.h"
#include "../auth/ntlmssp/ntlmssp.h"

struct smb2cli_session_setup_state {
	struct smbXcli_session *session;
	uint8_t fixed[24];
	uint8_t dyn_pad[1];
	struct iovec *recv_iov;
	DATA_BLOB out_security_buffer;
	NTSTATUS status;
};

static void smb2cli_session_setup_done(struct tevent_req *subreq);

struct tevent_req *smb2cli_session_setup_send(TALLOC_CTX *mem_ctx,
				struct tevent_context *ev,
				struct smbXcli_conn *conn,
				uint32_t timeout_msec,
				struct smbXcli_session *session,
				uint8_t in_flags,
				uint32_t in_capabilities,
				uint32_t in_channel,
				struct smbXcli_session *in_previous_session,
				const DATA_BLOB *in_security_buffer)
{
	struct tevent_req *req, *subreq;
	struct smb2cli_session_setup_state *state;
	uint8_t *buf;
	uint8_t *dyn;
	size_t dyn_len;
	uint8_t security_mode;
	uint16_t security_buffer_offset = 0;
	uint16_t security_buffer_length = 0;
	uint64_t previous_session_id = 0;

	req = tevent_req_create(mem_ctx, &state,
				struct smb2cli_session_setup_state);
	if (req == NULL) {
		return NULL;
	}

	if (session == NULL) {
		tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER_MIX);
		return tevent_req_post(req, ev);
	}
	state->session = session;
	security_mode = smb2cli_session_security_mode(session);

	if (in_security_buffer) {
		if (in_security_buffer->length > UINT16_MAX) {
			tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER_MIX);
			return tevent_req_post(req, ev);
		}
		security_buffer_offset = SMB2_HDR_BODY + 24;
		security_buffer_length = in_security_buffer->length;
	}

	if (in_previous_session) {
		previous_session_id =
			smb2cli_session_current_id(in_previous_session);
	}

	buf = state->fixed;

	SSVAL(buf,  0, 25);
	SCVAL(buf,  2, in_flags);
	SCVAL(buf,  3, security_mode);
	SIVAL(buf,  4, in_capabilities);
	SIVAL(buf,  8, in_channel);
	SSVAL(buf, 12, security_buffer_offset);
	SSVAL(buf, 14, security_buffer_length);
	SBVAL(buf, 16, previous_session_id);

	if (security_buffer_length > 0) {
		dyn = in_security_buffer->data;
		dyn_len = in_security_buffer->length;
	} else {
		dyn = state->dyn_pad;;
		dyn_len = sizeof(state->dyn_pad);
	}

	subreq = smb2cli_req_send(state, ev,
				  conn, SMB2_OP_SESSSETUP,
				  0, 0, /* flags */
				  timeout_msec,
				  0xFEFF,
				  0, /* tid */
				  session,
				  state->fixed, sizeof(state->fixed),
				  dyn, dyn_len);
	if (tevent_req_nomem(subreq, req)) {
		return tevent_req_post(req, ev);
	}
	tevent_req_set_callback(subreq, smb2cli_session_setup_done, req);
	return req;
}

static void smb2cli_session_setup_done(struct tevent_req *subreq)
{
	struct tevent_req *req =
		tevent_req_callback_data(subreq,
		struct tevent_req);
	struct smb2cli_session_setup_state *state =
		tevent_req_data(req,
		struct smb2cli_session_setup_state);
	NTSTATUS status;
	uint64_t current_session_id;
	uint64_t session_id;
	uint16_t session_flags;
	uint16_t expected_offset = 0;
	uint16_t security_buffer_offset;
	uint16_t security_buffer_length;
	uint8_t *security_buffer_data = NULL;
	const uint8_t *hdr;
	const uint8_t *body;
	static const struct smb2cli_req_expected_response expected[] = {
	{
		.status = NT_STATUS_MORE_PROCESSING_REQUIRED,
		.body_size = 0x09
	},
	{
		.status = NT_STATUS_OK,
		.body_size = 0x09
	}
	};

	status = smb2cli_req_recv(subreq, state, &state->recv_iov,
				  expected, ARRAY_SIZE(expected));
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status) &&
	    !NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
		tevent_req_nterror(req, status);
		return;
	}

	hdr = (const uint8_t *)state->recv_iov[0].iov_base;
	body = (const uint8_t *)state->recv_iov[1].iov_base;

	session_id = BVAL(hdr, SMB2_HDR_SESSION_ID);
	session_flags = SVAL(body, 2);

	security_buffer_offset = SVAL(body, 4);
	security_buffer_length = SVAL(body, 6);

	if (security_buffer_length > 0) {
		expected_offset = SMB2_HDR_BODY + 8;
	}
	if (security_buffer_offset != 0) {
		security_buffer_data = (uint8_t *)state->recv_iov[2].iov_base;
		expected_offset = SMB2_HDR_BODY + 8;
	}

	if (security_buffer_offset != expected_offset) {
		tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
		return;
	}
	if (security_buffer_length > state->recv_iov[2].iov_len) {
		tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
		return;
	}

	state->out_security_buffer.data = security_buffer_data;
	state->out_security_buffer.length = security_buffer_length;

	current_session_id = smb2cli_session_current_id(state->session);
	if (current_session_id == 0) {
		/* A new session was requested */
		current_session_id = session_id;
	}

	if (current_session_id != session_id) {
		tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
		return;
	}

	smb2cli_session_set_id_and_flags(state->session,
					 session_id, session_flags);

	state->status = status;
	tevent_req_done(req);
}

NTSTATUS smb2cli_session_setup_recv(struct tevent_req *req,
				    TALLOC_CTX *mem_ctx,
				    struct iovec **recv_iov,
				    DATA_BLOB *out_security_buffer)
{
	struct smb2cli_session_setup_state *state =
		tevent_req_data(req,
		struct smb2cli_session_setup_state);
	NTSTATUS status;
	struct iovec *_tmp;

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

	if (recv_iov == NULL) {
		recv_iov = &_tmp;
	}

	*recv_iov = talloc_move(mem_ctx, &state->recv_iov);

	*out_security_buffer = state->out_security_buffer;

	/*
	 * Return the status from the server:
	 * NT_STATUS_MORE_PROCESSING_REQUIRED or
	 * NT_STATUS_OK.
	 */
	status = state->status;
	tevent_req_received(req);
	return status;
}

struct smb2cli_sesssetup_ntlmssp_state {
	struct tevent_context *ev;
	struct cli_state *cli;
	struct ntlmssp_state *ntlmssp;
	struct iovec iov[2];
	uint8_t fixed[24];
	DATA_BLOB msg;
	int turn;
};

static void smb2cli_sesssetup_ntlmssp_done(struct tevent_req *subreq);

struct tevent_req *smb2cli_sesssetup_ntlmssp_send(TALLOC_CTX *mem_ctx,
					  struct tevent_context *ev,
					  struct cli_state *cli,
					  const char *user,
					  const char *domain,
					  const char *pass)
{
	struct tevent_req *req, *subreq;
	struct smb2cli_sesssetup_ntlmssp_state *state;
	NTSTATUS status;
	DATA_BLOB blob_out;
	const char *OIDs_ntlm[] = {OID_NTLMSSP, NULL};

	req = tevent_req_create(mem_ctx, &state,
				struct smb2cli_sesssetup_ntlmssp_state);
	if (req == NULL) {
		return NULL;
	}
	state->ev = ev;
	state->cli = cli;

	status = ntlmssp_client_start(state,
				      lp_netbios_name(),
				      lp_workgroup(),
				      lp_client_ntlmv2_auth(),
				      &state->ntlmssp);
	if (!NT_STATUS_IS_OK(status)) {
		goto post_status;
	}
	ntlmssp_want_feature(state->ntlmssp,
			     NTLMSSP_FEATURE_SESSION_KEY);
	status = ntlmssp_set_username(state->ntlmssp, user);
	if (!NT_STATUS_IS_OK(status)) {
		goto post_status;
	}
	status = ntlmssp_set_domain(state->ntlmssp, domain);
	if (!NT_STATUS_IS_OK(status)) {
		goto post_status;
	}
	status = ntlmssp_set_password(state->ntlmssp, pass);
	if (!NT_STATUS_IS_OK(status)) {
		goto post_status;
	}

	status = ntlmssp_update(state->ntlmssp, data_blob_null, &blob_out);
	if (!NT_STATUS_IS_OK(status)
	    && !NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
		goto post_status;
	}

	blob_out = spnego_gen_negTokenInit(state, OIDs_ntlm, &blob_out, NULL);
	state->turn = 1;

	state->cli->smb2.session = smbXcli_session_create(cli, cli->conn);
	if (tevent_req_nomem(state->cli->smb2.session, req)) {
		return tevent_req_post(req, ev);
	}

	subreq = smb2cli_session_setup_send(state, state->ev,
					    state->cli->conn,
					    state->cli->timeout,
					    state->cli->smb2.session,
					    0, /* in_flags */
					    SMB2_CAP_DFS, /* in_capabilities */
					    0, /* in_channel */
					    NULL, /* in_previous_session */
					    &blob_out);
	if (tevent_req_nomem(subreq, req)) {
		return tevent_req_post(req, ev);
	}
	tevent_req_set_callback(subreq, smb2cli_sesssetup_ntlmssp_done, req);
	return req;
post_status:
	tevent_req_nterror(req, status);
	return tevent_req_post(req, ev);
}

static void smb2cli_sesssetup_ntlmssp_done(struct tevent_req *subreq)
{
	struct tevent_req *req =
		tevent_req_callback_data(subreq,
		struct tevent_req);
	struct smb2cli_sesssetup_ntlmssp_state *state =
		tevent_req_data(req,
		struct smb2cli_sesssetup_ntlmssp_state);
	NTSTATUS status;
	DATA_BLOB blob, blob_in, blob_out, spnego_blob;
	bool ret;
	struct iovec *recv_iov;

	status = smb2cli_session_setup_recv(subreq, state, &recv_iov, &blob);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)
	    && !NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
		tevent_req_nterror(req, status);
		return;
	}

	if (NT_STATUS_IS_OK(status)) {
		status = smb2cli_session_update_session_key(state->cli->smb2.session,
							state->ntlmssp->session_key,
							recv_iov);
		if (tevent_req_nterror(req, status)) {
			return;
		}

		tevent_req_done(req);
		return;
	}

	if (state->turn == 1) {
		DATA_BLOB tmp_blob = data_blob_null;
		ret = spnego_parse_challenge(state, blob, &blob_in, &tmp_blob);
		data_blob_free(&tmp_blob);
	} else {
		ret = spnego_parse_auth_response(state, blob, status,
						 OID_NTLMSSP, &blob_in);
	}
	TALLOC_FREE(subreq);
	if (!ret) {
		tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
		return;
	}

	status = ntlmssp_update(state->ntlmssp, blob_in, &blob_out);
	data_blob_free(&blob_in);
	state->turn += 1;

	if (!NT_STATUS_IS_OK(status)) {
		tevent_req_nterror(req, status);
		return;
	}

	spnego_blob = spnego_gen_auth(state, blob_out);
	TALLOC_FREE(subreq);
	if (tevent_req_nomem(spnego_blob.data, req)) {
		return;
	}

	subreq = smb2cli_session_setup_send(state, state->ev,
					    state->cli->conn,
					    state->cli->timeout,
					    state->cli->smb2.session,
					    0, /* in_flags */
					    SMB2_CAP_DFS, /* in_capabilities */
					    0, /* in_channel */
					    NULL, /* in_previous_session */
					    &spnego_blob);
	if (tevent_req_nomem(subreq, req)) {
		return;
	}
	tevent_req_set_callback(subreq, smb2cli_sesssetup_ntlmssp_done, req);
}

NTSTATUS smb2cli_sesssetup_ntlmssp_recv(struct tevent_req *req)
{
	return tevent_req_simple_recv_ntstatus(req);
}

NTSTATUS smb2cli_sesssetup_ntlmssp(struct cli_state *cli, const char *user,
			   const char *domain, const char *pass)
{
	TALLOC_CTX *frame = talloc_stackframe();
	struct event_context *ev;
	struct tevent_req *req;
	NTSTATUS status = NT_STATUS_NO_MEMORY;

	if (cli_has_async_calls(cli)) {
		/*
		 * Can't use sync call while an async call is in flight
		 */
		status = NT_STATUS_INVALID_PARAMETER;
		goto fail;
	}
	ev = event_context_init(frame);
	if (ev == NULL) {
		goto fail;
	}
	req = smb2cli_sesssetup_ntlmssp_send(frame, ev, cli, user, domain, pass);
	if (req == NULL) {
		goto fail;
	}
	if (!tevent_req_poll_ntstatus(req, ev, &status)) {
		goto fail;
	}
	status = smb2cli_sesssetup_ntlmssp_recv(req);
 fail:
	TALLOC_FREE(frame);
	return status;
}

struct smb2cli_logoff_state {
	uint8_t fixed[4];
};

static void smb2cli_logoff_done(struct tevent_req *subreq);

struct tevent_req *smb2cli_logoff_send(TALLOC_CTX *mem_ctx,
				       struct tevent_context *ev,
				       struct cli_state *cli)
{
	struct tevent_req *req, *subreq;
	struct smb2cli_logoff_state *state;

	req = tevent_req_create(mem_ctx, &state,
				struct smb2cli_logoff_state);
	if (req == NULL) {
		return NULL;
	}
	SSVAL(state->fixed, 0, 4);

	subreq = smb2cli_req_send(state, ev,
				  cli->conn, SMB2_OP_LOGOFF,
				  0, 0, /* flags */
				  cli->timeout,
				  cli->smb2.pid,
				  0, /* tid */
				  cli->smb2.session,
				  state->fixed, sizeof(state->fixed),
				  NULL, 0);
	if (tevent_req_nomem(subreq, req)) {
		return tevent_req_post(req, ev);
	}
	tevent_req_set_callback(subreq, smb2cli_logoff_done, req);
	return req;
}

static void smb2cli_logoff_done(struct tevent_req *subreq)
{
	struct tevent_req *req =
		tevent_req_callback_data(subreq,
		struct tevent_req);
	NTSTATUS status;
	struct iovec *iov;
	static const struct smb2cli_req_expected_response expected[] = {
	{
		.status = NT_STATUS_OK,
		.body_size = 0x04
	}
	};

	status = smb2cli_req_recv(subreq, talloc_tos(), &iov,
				  expected, ARRAY_SIZE(expected));
	TALLOC_FREE(subreq);
	if (tevent_req_nterror(req, status)) {
		return;
	}
	tevent_req_done(req);
}

NTSTATUS smb2cli_logoff_recv(struct tevent_req *req)
{
	return tevent_req_simple_recv_ntstatus(req);
}

NTSTATUS smb2cli_logoff(struct cli_state *cli)
{
	TALLOC_CTX *frame = talloc_stackframe();
	struct event_context *ev;
	struct tevent_req *req;
	NTSTATUS status = NT_STATUS_NO_MEMORY;

	if (cli_has_async_calls(cli)) {
		/*
		 * Can't use sync call while an async call is in flight
		 */
		status = NT_STATUS_INVALID_PARAMETER;
		goto fail;
	}
	ev = event_context_init(frame);
	if (ev == NULL) {
		goto fail;
	}
	req = smb2cli_logoff_send(frame, ev, cli);
	if (req == NULL) {
		goto fail;
	}
	if (!tevent_req_poll_ntstatus(req, ev, &status)) {
		goto fail;
	}
	status = smb2cli_logoff_recv(req);
 fail:
	TALLOC_FREE(frame);
	return status;
}