/*
   Unix SMB/CIFS implementation.
   Core SMB2 server

   Copyright (C) Stefan Metzmacher 2009
   Copyright (C) David Disseldorp 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 "smbd/smbd.h"
#include "smbd/globals.h"
#include "../libcli/smb/smb_common.h"
#include "../libcli/security/security.h"
#include "../lib/util/tevent_ntstatus.h"
#include "../lib/ccan/build_assert/build_assert.h"
#include "include/ntioctl.h"
#include "../librpc/ndr/libndr.h"
#include "librpc/gen_ndr/ndr_ioctl.h"
#include "smb2_ioctl_private.h"

#define COPYCHUNK_MAX_CHUNKS	256		/* 2k8r2 & win8 = 256 */
#define COPYCHUNK_MAX_CHUNK_LEN	1048576		/* 2k8r2 & win8 = 1048576 */
#define COPYCHUNK_MAX_TOTAL_LEN	16777216	/* 2k8r2 & win8 = 16777216 */
static void copychunk_pack_limits(struct srv_copychunk_rsp *cc_rsp)
{
	cc_rsp->chunks_written = COPYCHUNK_MAX_CHUNKS;
	cc_rsp->chunk_bytes_written = COPYCHUNK_MAX_CHUNK_LEN;
	cc_rsp->total_bytes_written = COPYCHUNK_MAX_TOTAL_LEN;
}

static NTSTATUS copychunk_check_limits(struct srv_copychunk_copy *cc_copy)
{
	uint32_t i;
	uint32_t total_len = 0;

	/*
	 * [MS-SMB2] 3.3.5.15.6 Handling a Server-Side Data Copy Request
	 * Send and invalid parameter response if:
	 * - The ChunkCount value is greater than
	 *   ServerSideCopyMaxNumberofChunks
	 */
	if (cc_copy->chunk_count > COPYCHUNK_MAX_CHUNKS) {
		return NT_STATUS_INVALID_PARAMETER;
	}

	for (i = 0; i < cc_copy->chunk_count; i++) {
		/*
		 * - The Length value in a single chunk is greater than
		 *   ServerSideCopyMaxChunkSize or equal to zero.
		 */
		if ((cc_copy->chunks[i].length == 0)
		 || (cc_copy->chunks[i].length > COPYCHUNK_MAX_CHUNK_LEN)) {
			return NT_STATUS_INVALID_PARAMETER;
		}
		total_len += cc_copy->chunks[i].length;
	}
	/*
	 * - Sum of Lengths in all chunks is greater than
	 *   ServerSideCopyMaxDataSize
	 */
	if (total_len > COPYCHUNK_MAX_TOTAL_LEN) {
		return NT_STATUS_INVALID_PARAMETER;
	}

	return NT_STATUS_OK;
}

struct fsctl_srv_copychunk_state {
	struct connection_struct *conn;
	uint32_t dispatch_count;
	uint32_t recv_count;
	uint32_t bad_recv_count;
	NTSTATUS status;
	off_t total_written;
	struct files_struct *src_fsp;
	struct files_struct *dst_fsp;
	enum {
		COPYCHUNK_OUT_EMPTY = 0,
		COPYCHUNK_OUT_LIMITS,
		COPYCHUNK_OUT_RSP,
	} out_data;
};
static void fsctl_srv_copychunk_vfs_done(struct tevent_req *subreq);

static NTSTATUS copychunk_check_handles(struct files_struct *src_fsp,
					struct files_struct *dst_fsp,
					struct smb_request *smb1req)
{
	/*
	 * [MS-SMB2] 3.3.5.15.6 Handling a Server-Side Data Copy Request
	 * If Open.GrantedAccess of the destination file does not
	 * include FILE_WRITE_DATA, then the request MUST be failed with
	 * STATUS_ACCESS_DENIED. If Open.GrantedAccess of the
	 * destination file does not include FILE_READ_DATA access and
	 * the CtlCode is FSCTL_SRV_COPYCHUNK, then the request MUST be
	 * failed with STATUS_ACCESS_DENIED.
	 */
	if (!CHECK_WRITE(dst_fsp)) {
		DEBUG(5, ("copy chunk no write on dest handle (%s).\n",
			smb_fname_str_dbg(dst_fsp->fsp_name) ));
		return NT_STATUS_ACCESS_DENIED;
	}
	if (!CHECK_READ(dst_fsp, smb1req)) {
		DEBUG(5, ("copy chunk no read on dest handle (%s).\n",
			smb_fname_str_dbg(dst_fsp->fsp_name) ));
		return NT_STATUS_ACCESS_DENIED;
	}
	if (!CHECK_READ(src_fsp, smb1req)) {
		DEBUG(5, ("copy chunk no read on src handle (%s).\n",
			smb_fname_str_dbg(src_fsp->fsp_name) ));
		return NT_STATUS_ACCESS_DENIED;
	}

	if (src_fsp->is_directory) {
		DEBUG(5, ("copy chunk no read on src directory handle (%s).\n",
			smb_fname_str_dbg(src_fsp->fsp_name) ));
		return NT_STATUS_ACCESS_DENIED;
	}

	if (dst_fsp->is_directory) {
		DEBUG(5, ("copy chunk no read on dst directory handle (%s).\n",
			smb_fname_str_dbg(dst_fsp->fsp_name) ));
		return NT_STATUS_ACCESS_DENIED;
	}

	if (IS_IPC(src_fsp->conn) || IS_IPC(dst_fsp->conn)) {
		DEBUG(5, ("copy chunk no access on IPC$ handle.\n"));
		return NT_STATUS_ACCESS_DENIED;
	}

	if (IS_PRINT(src_fsp->conn) || IS_PRINT(dst_fsp->conn)) {
		DEBUG(5, ("copy chunk no access on PRINT handle.\n"));
		return NT_STATUS_ACCESS_DENIED;
	}

	return NT_STATUS_OK;
}

static struct tevent_req *fsctl_srv_copychunk_send(TALLOC_CTX *mem_ctx,
						   struct tevent_context *ev,
						   struct files_struct *dst_fsp,
						   DATA_BLOB *in_input,
						   size_t in_max_output,
						   struct smbd_smb2_request *smb2req)
{
	struct tevent_req *req;
	struct srv_copychunk_copy cc_copy;
	enum ndr_err_code ndr_ret;
	uint64_t src_persistent_h;
	uint64_t src_volatile_h;
	int i;
	struct srv_copychunk *chunk;
	struct fsctl_srv_copychunk_state *state;

	req = tevent_req_create(mem_ctx, &state,
				struct fsctl_srv_copychunk_state);
	if (req == NULL) {
		return NULL;
	}
	state->conn = dst_fsp->conn;

	if (in_max_output < sizeof(struct srv_copychunk_rsp)) {
		DEBUG(3, ("max output %d not large enough to hold copy chunk "
			  "response %lu\n", (int)in_max_output,
			  (unsigned long)sizeof(struct srv_copychunk_rsp)));
		state->status = NT_STATUS_INVALID_PARAMETER;
		tevent_req_nterror(req, state->status);
		return tevent_req_post(req, ev);
	}

	ndr_ret = ndr_pull_struct_blob(in_input, mem_ctx, &cc_copy,
			(ndr_pull_flags_fn_t)ndr_pull_srv_copychunk_copy);
	if (ndr_ret != NDR_ERR_SUCCESS) {
		DEBUG(0, ("failed to unmarshall copy chunk req\n"));
		state->status = NT_STATUS_INVALID_PARAMETER;
		tevent_req_nterror(req, state->status);
		return tevent_req_post(req, ev);
	}

	/* persistent/volatile keys sent as the resume key */
	src_persistent_h = BVAL(cc_copy.source_key, 0);
	src_volatile_h = BVAL(cc_copy.source_key, 8);
	state->src_fsp = file_fsp_get(smb2req, src_persistent_h, src_volatile_h);
	if (state->src_fsp == NULL) {
		DEBUG(3, ("invalid resume key in copy chunk req\n"));
		state->status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
		tevent_req_nterror(req, state->status);
		return tevent_req_post(req, ev);
	}

	state->dst_fsp = dst_fsp;

	state->status = copychunk_check_handles(state->src_fsp,
						state->dst_fsp,
						smb2req->smb1req);
	if (!NT_STATUS_IS_OK(state->status)) {
		tevent_req_nterror(req, state->status);
		return tevent_req_post(req, ev);
	}

	state->status = copychunk_check_limits(&cc_copy);
	if (tevent_req_nterror(req, state->status)) {
		DEBUG(3, ("copy chunk req exceeds limits\n"));
		state->out_data = COPYCHUNK_OUT_LIMITS;
		return tevent_req_post(req, ev);
	}

	/* any errors from here onwards should carry copychunk response data */
	state->out_data = COPYCHUNK_OUT_RSP;

	for (i = 0; i < cc_copy.chunk_count; i++) {
		struct tevent_req *vfs_subreq;
		chunk = &cc_copy.chunks[i];
		vfs_subreq = SMB_VFS_COPY_CHUNK_SEND(dst_fsp->conn,
						     state, ev,
						     state->src_fsp,
						     chunk->source_off,
						     state->dst_fsp,
						     chunk->target_off,
						     chunk->length);
		if (vfs_subreq == NULL) {
			DEBUG(0, ("VFS copy chunk send failed\n"));
			state->status = NT_STATUS_NO_MEMORY;
			if (state->dispatch_count == 0) {
				/* nothing dispatched, return immediately */
				tevent_req_nterror(req, state->status);
				return tevent_req_post(req, ev);
			} else {
				/*
				 * wait for dispatched to complete before
				 * returning error.
				 */
				break;
			}
		}
		tevent_req_set_callback(vfs_subreq,
					fsctl_srv_copychunk_vfs_done, req);
		state->dispatch_count++;
	}

	return req;
}

static void fsctl_srv_copychunk_vfs_done(struct tevent_req *subreq)
{
	struct tevent_req *req = tevent_req_callback_data(
		subreq, struct tevent_req);
	struct fsctl_srv_copychunk_state *state = tevent_req_data(req,
					struct fsctl_srv_copychunk_state);
	off_t chunk_nwritten;
	NTSTATUS status;

	state->recv_count++;
	status = SMB_VFS_COPY_CHUNK_RECV(state->conn, subreq,
					 &chunk_nwritten);
	TALLOC_FREE(subreq);
	if (NT_STATUS_IS_OK(status)) {
		DEBUG(10, ("good copy chunk recv %u of %u\n",
			   (unsigned int)state->recv_count,
			   (unsigned int)state->dispatch_count));
		state->total_written += chunk_nwritten;
	} else {
		DEBUG(0, ("bad status in copy chunk recv %u of %u: %s\n",
			  (unsigned int)state->recv_count,
			  (unsigned int)state->dispatch_count,
			  nt_errstr(status)));
		state->bad_recv_count++;
		/* may overwrite previous failed status */
		state->status = status;
	}

	if (state->recv_count != state->dispatch_count) {
		/*
		 * Wait for all VFS copy_chunk requests to complete, even
		 * if an error is received for a specific chunk.
		 */
		return;
	}

	if (!tevent_req_nterror(req, state->status)) {
		tevent_req_done(req);
	}
}

static NTSTATUS fsctl_srv_copychunk_recv(struct tevent_req *req,
					 struct srv_copychunk_rsp *cc_rsp,
					 bool *pack_rsp)
{
	struct fsctl_srv_copychunk_state *state = tevent_req_data(req,
					struct fsctl_srv_copychunk_state);
	NTSTATUS status;

	switch (state->out_data) {
	case COPYCHUNK_OUT_EMPTY:
		*pack_rsp = false;
		break;
	case COPYCHUNK_OUT_LIMITS:
		/* 2.2.32.1 - send back our maximum transfer size limits */
		copychunk_pack_limits(cc_rsp);
		*pack_rsp = true;
		break;
	case COPYCHUNK_OUT_RSP:
		cc_rsp->chunks_written = state->recv_count - state->bad_recv_count;
		cc_rsp->chunk_bytes_written = 0;
		cc_rsp->total_bytes_written = state->total_written;
		*pack_rsp = true;
		break;
	default:	/* not reached */
		assert(1);
		break;
	}
	status = state->status;
	tevent_req_received(req);

	return status;
}

static NTSTATUS fsctl_validate_neg_info(TALLOC_CTX *mem_ctx,
				        struct tevent_context *ev,
				        struct smbXsrv_connection *conn,
				        DATA_BLOB *in_input,
				        uint32_t in_max_output,
				        DATA_BLOB *out_output,
					bool *disconnect)
{
	uint32_t in_capabilities;
	DATA_BLOB in_guid_blob;
	struct GUID in_guid;
	uint16_t in_security_mode;
	uint16_t in_num_dialects;
	uint16_t i;
	DATA_BLOB out_guid_blob;
	NTSTATUS status;

	if (in_input->length < 0x18) {
		return NT_STATUS_INVALID_PARAMETER;
	}

	in_capabilities = IVAL(in_input->data, 0x00);
	in_guid_blob = data_blob_const(in_input->data + 0x04, 16);
	in_security_mode = SVAL(in_input->data, 0x14);
	in_num_dialects = SVAL(in_input->data, 0x16);

	if (in_input->length < (0x18 + in_num_dialects*2)) {
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (in_max_output < 0x18) {
		return NT_STATUS_BUFFER_TOO_SMALL;
	}

	status = GUID_from_ndr_blob(&in_guid_blob, &in_guid);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	if (in_num_dialects != conn->smb2.client.num_dialects) {
		*disconnect = true;
		return NT_STATUS_ACCESS_DENIED;
	}

	for (i=0; i < in_num_dialects; i++) {
		uint16_t v = SVAL(in_input->data, 0x18 + i*2);

		if (conn->smb2.client.dialects[i] != v) {
			*disconnect = true;
			return NT_STATUS_ACCESS_DENIED;
		}
	}

	if (GUID_compare(&in_guid, &conn->smb2.client.guid) != 0) {
		*disconnect = true;
		return NT_STATUS_ACCESS_DENIED;
	}

	if (in_security_mode != conn->smb2.client.security_mode) {
		*disconnect = true;
		return NT_STATUS_ACCESS_DENIED;
	}

	if (in_capabilities != conn->smb2.client.capabilities) {
		*disconnect = true;
		return NT_STATUS_ACCESS_DENIED;
	}

	status = GUID_to_ndr_blob(&conn->smb2.server.guid, mem_ctx,
				  &out_guid_blob);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	*out_output = data_blob_talloc(mem_ctx, NULL, 0x18);
	if (out_output->data == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	SIVAL(out_output->data, 0x00, conn->smb2.server.capabilities);
	memcpy(out_output->data+0x04, out_guid_blob.data, 16);
	SSVAL(out_output->data, 0x14, conn->smb2.server.security_mode);
	SSVAL(out_output->data, 0x16, conn->smb2.server.dialect);

	return NT_STATUS_OK;
}

static NTSTATUS fsctl_srv_req_resume_key(TALLOC_CTX *mem_ctx,
					 struct tevent_context *ev,
					 struct files_struct *fsp,
					 uint32_t in_max_output,
					 DATA_BLOB *out_output)
{
	struct req_resume_key_rsp rkey_rsp;
	enum ndr_err_code ndr_ret;
	DATA_BLOB output;

	if (fsp == NULL) {
		return NT_STATUS_FILE_CLOSED;
	}

	ZERO_STRUCT(rkey_rsp);
	/* combine persistent and volatile handles for the resume key */
	SBVAL(rkey_rsp.resume_key, 0, fsp->op->global->open_persistent_id);
	SBVAL(rkey_rsp.resume_key, 8, fsp->op->global->open_volatile_id);

	ndr_ret = ndr_push_struct_blob(&output, mem_ctx, &rkey_rsp,
			(ndr_push_flags_fn_t)ndr_push_req_resume_key_rsp);
	if (ndr_ret != NDR_ERR_SUCCESS) {
		return NT_STATUS_INTERNAL_ERROR;
	}

	if (in_max_output < output.length) {
		DEBUG(1, ("max output %u too small for resume key rsp %ld\n",
			  (unsigned int)in_max_output, (long int)output.length));
		return NT_STATUS_INVALID_PARAMETER;
	}
	*out_output = output;

	return NT_STATUS_OK;
}

static void smb2_ioctl_network_fs_copychunk_done(struct tevent_req *subreq);

struct tevent_req *smb2_ioctl_network_fs(uint32_t ctl_code,
					 struct tevent_context *ev,
					 struct tevent_req *req,
					 struct smbd_smb2_ioctl_state *state)
{
	struct tevent_req *subreq;
	NTSTATUS status;

	switch (ctl_code) {
	case FSCTL_SRV_COPYCHUNK:
		subreq = fsctl_srv_copychunk_send(state, ev, state->fsp,
						  &state->in_input,
						  state->in_max_output,
						  state->smb2req);
		if (tevent_req_nomem(subreq, req)) {
			return tevent_req_post(req, ev);
		}
		tevent_req_set_callback(subreq,
					smb2_ioctl_network_fs_copychunk_done,
					req);
		return req;
		break;
	case FSCTL_VALIDATE_NEGOTIATE_INFO:
		status = fsctl_validate_neg_info(state, ev,
						 state->smbreq->sconn->conn,
						 &state->in_input,
						 state->in_max_output,
						 &state->out_output,
						 &state->disconnect);
		if (!tevent_req_nterror(req, status)) {
			tevent_req_done(req);
		}
		return tevent_req_post(req, ev);
		break;
	case FSCTL_SRV_REQUEST_RESUME_KEY:
		status = fsctl_srv_req_resume_key(state, ev, state->fsp,
						  state->in_max_output,
						  &state->out_output);
		if (!tevent_req_nterror(req, status)) {
			tevent_req_done(req);
		}
		return tevent_req_post(req, ev);
		break;
	default: {
		uint8_t *out_data = NULL;
		uint32_t out_data_len = 0;

		if (state->fsp == NULL) {
			status = NT_STATUS_NOT_SUPPORTED;
		} else {
			status = SMB_VFS_FSCTL(state->fsp,
					       state,
					       ctl_code,
					       state->smbreq->flags2,
					       state->in_input.data,
					       state->in_input.length,
					       &out_data,
					       state->in_max_output,
					       &out_data_len);
			state->out_output = data_blob_const(out_data, out_data_len);
			if (NT_STATUS_IS_OK(status)) {
				tevent_req_done(req);
				return tevent_req_post(req, ev);
			}
		}

		if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_SUPPORTED)) {
			if (IS_IPC(state->smbreq->conn)) {
				status = NT_STATUS_FS_DRIVER_REQUIRED;
			} else {
				status = NT_STATUS_INVALID_DEVICE_REQUEST;
			}
		}

		tevent_req_nterror(req, status);
		return tevent_req_post(req, ev);
		break;
	}
	}

	tevent_req_nterror(req, NT_STATUS_INTERNAL_ERROR);
	return tevent_req_post(req, ev);
}

static void smb2_ioctl_network_fs_copychunk_done(struct tevent_req *subreq)
{
	struct tevent_req *req = tevent_req_callback_data(subreq,
							  struct tevent_req);
	struct smbd_smb2_ioctl_state *ioctl_state = tevent_req_data(req,
						struct smbd_smb2_ioctl_state);
	struct srv_copychunk_rsp cc_rsp;
	NTSTATUS status;
	bool pack_rsp = false;

	ZERO_STRUCT(cc_rsp);
	status = fsctl_srv_copychunk_recv(subreq, &cc_rsp, &pack_rsp);
	TALLOC_FREE(subreq);
	if (pack_rsp == true) {
		enum ndr_err_code ndr_ret;
		ndr_ret = ndr_push_struct_blob(&ioctl_state->out_output,
					       ioctl_state,
					       &cc_rsp,
				(ndr_push_flags_fn_t)ndr_push_srv_copychunk_rsp);
		if (ndr_ret != NDR_ERR_SUCCESS) {
			status = NT_STATUS_INTERNAL_ERROR;
		}
	}

	if (!tevent_req_nterror(req, status)) {
		tevent_req_done(req);
	}
}