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[samba4-gss.git] / source3 / smbd / smb2_ioctl_filesys.c

/*
   Unix SMB/CIFS implementation.
   Core SMB2 server

   Copyright (C) Stefan Metzmacher 2009
   Copyright (C) David Disseldorp 2013-2024

   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 "rpc_server/srv_pipe_hnd.h"
#include "include/ntioctl.h"
#include "../librpc/ndr/libndr.h"
#include "librpc/gen_ndr/ndr_ioctl.h"
#include "smb2_ioctl_private.h"
#include "lib/util/sys_rw.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_SMB2

/*
 * XXX this may reduce dup_extents->byte_count so that it's less than the
 * target file size.
 */
static NTSTATUS fsctl_dup_extents_check_lengths(struct files_struct *src_fsp,
                                                struct files_struct *dst_fsp,
                                struct fsctl_dup_extents_to_file *dup_extents)
{
        NTSTATUS status;

        if ((dup_extents->source_off + dup_extents->byte_count
                                                < dup_extents->source_off)
         || (dup_extents->target_off + dup_extents->byte_count
                                                < dup_extents->target_off)) {
                return NT_STATUS_INVALID_PARAMETER;     /* wrap */
        }

        status = vfs_stat_fsp(src_fsp);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        /*
         * XXX vfs_btrfs and vfs_default have size checks in the copychunk
         * handler, as this needs to be rechecked after the src has potentially
         * been extended by a previous chunk in the compound copychunk req.
         */
        if (src_fsp->fsp_name->st.st_ex_size
                        < dup_extents->source_off + dup_extents->byte_count) {
                DEBUG(2, ("dup_extents req exceeds src size\n"));
                return NT_STATUS_NOT_SUPPORTED;
        }

        status = vfs_stat_fsp(dst_fsp);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        if (dst_fsp->fsp_name->st.st_ex_size
                        < dup_extents->target_off + dup_extents->byte_count) {

                if (dst_fsp->fsp_name->st.st_ex_size - dup_extents->target_off
                                        > dst_fsp->fsp_name->st.st_ex_size) {
                        return NT_STATUS_INVALID_PARAMETER;     /* wrap */
                }

                /*
                 * this server behaviour is pretty hairy, but we need to match
                 * Windows, so...
                 */
                DEBUG(2, ("dup_extents req exceeds target size, capping\n"));
                dup_extents->byte_count = dst_fsp->fsp_name->st.st_ex_size
                                                - dup_extents->target_off;
        }

        return NT_STATUS_OK;
}

static NTSTATUS fsctl_dup_extents_check_overlap(struct files_struct *src_fsp,
                                                struct files_struct *dst_fsp,
                                struct fsctl_dup_extents_to_file *dup_extents)
{
        if (!file_id_equal(&src_fsp->file_id, &dst_fsp->file_id)) {
                /* src and dest refer to different files */
                return NT_STATUS_OK;
        }

        if (sys_io_ranges_overlap(dup_extents->byte_count,
                                  dup_extents->source_off,
                                  dup_extents->byte_count,
                                  dup_extents->target_off))
        {
                return NT_STATUS_NOT_SUPPORTED;
        }

        return NT_STATUS_OK;
}

static NTSTATUS fsctl_dup_extents_check_sparse(struct files_struct *src_fsp,
                                               struct files_struct *dst_fsp)
{
        /*
         * 2.3.8 FSCTL_DUPLICATE_EXTENTS_TO_FILE Reply...
         * STATUS_NOT_SUPPORTED: Target file is sparse, while source
         *                       is a non-sparse file.
         *
         * WS2016 has the following behaviour (MS are in the process of fixing
         * the spec):
         * STATUS_NOT_SUPPORTED is returned if the source is sparse, while the
         * target is non-sparse. However, if target is sparse while the source
         * is non-sparse, then FSCTL_DUPLICATE_EXTENTS_TO_FILE completes
         * successfully.
         */
        if (src_fsp->fsp_flags.is_sparse && !dst_fsp->fsp_flags.is_sparse) {
                return NT_STATUS_NOT_SUPPORTED;
        }

        return NT_STATUS_OK;
}

struct fsctl_dup_extents_state {
        struct tevent_context *ev;
        struct connection_struct *conn;
        struct files_struct *dst_fsp;
        struct fsctl_dup_extents_to_file dup_extents;
};

static void fsctl_dup_extents_offload_read_done(struct tevent_req *subreq);
static void fsctl_dup_extents_vfs_done(struct tevent_req *subreq);

static struct tevent_req *fsctl_dup_extents_send(TALLOC_CTX *mem_ctx,
                                                 struct tevent_context *ev,
                                                 struct files_struct *dst_fsp,
                                                 DATA_BLOB *in_input,
                                                 struct smbd_smb2_request *smb2req)
{
        struct tevent_req *req = NULL;
        struct tevent_req *subreq = NULL;
        struct fsctl_dup_extents_state *state = NULL;
        uint64_t src_fid_persistent = 0;
        uint64_t src_fid_volatile = 0;
        struct files_struct *src_fsp = NULL;
        int ndr_ret;
        NTSTATUS status;

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

        if (dst_fsp == NULL) {
                tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
                return tevent_req_post(req, ev);
        }

        *state = (struct fsctl_dup_extents_state) {
                .conn = dst_fsp->conn,
                .ev = ev,
                .dst_fsp = dst_fsp,
        };

        if ((dst_fsp->conn->fs_capabilities
                                & FILE_SUPPORTS_BLOCK_REFCOUNTING) == 0) {
                DBG_INFO("FS does not advertise block refcounting support\n");
                tevent_req_nterror(req, NT_STATUS_INVALID_DEVICE_REQUEST);
                return tevent_req_post(req, ev);
        }

        ndr_ret = ndr_pull_struct_blob(in_input, state, &state->dup_extents,
                       (ndr_pull_flags_fn_t)ndr_pull_fsctl_dup_extents_to_file);
        if (ndr_ret != NDR_ERR_SUCCESS) {
                DBG_ERR("failed to unmarshall dup extents to file req\n");
                tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
                return tevent_req_post(req, ev);
        }

        src_fid_persistent = BVAL(state->dup_extents.source_fid, 0);
        src_fid_volatile = BVAL(state->dup_extents.source_fid, 8);
        src_fsp = file_fsp_get(smb2req, src_fid_persistent, src_fid_volatile);
        if ((src_fsp == NULL)
                      || (src_fsp->file_id.devid != dst_fsp->file_id.devid)) {
                /*
                 * [MS-FSCC] 2.3.8 FSCTL_DUPLICATE_EXTENTS_TO_FILE Reply
                 * STATUS_INVALID_PARAMETER:
                 * The FileHandle parameter is either invalid or does not
                 * represent a handle to an opened file on the same volume.
                 *
                 * Windows Server responds with NT_STATUS_INVALID_HANDLE instead
                 * of STATUS_INVALID_PARAMETER here, despite the above spec.
                 */
                DBG_ERR("invalid src_fsp for dup_extents\n");
                tevent_req_nterror(req, NT_STATUS_INVALID_HANDLE);
                return tevent_req_post(req, ev);
        }

        status = fsctl_dup_extents_check_lengths(src_fsp, dst_fsp,
                                                 &state->dup_extents);
        if (tevent_req_nterror(req, status)) {
                return tevent_req_post(req, ev);
        }

        if (state->dup_extents.byte_count == 0) {
                DBG_ERR("skipping zero length dup extents\n");
                tevent_req_done(req);
                return tevent_req_post(req, ev);
        }

        status = fsctl_dup_extents_check_overlap(src_fsp, dst_fsp,
                                                 &state->dup_extents);
        if (tevent_req_nterror(req, status)) {
                return tevent_req_post(req, ev);
        }

        status = fsctl_dup_extents_check_sparse(src_fsp, dst_fsp);
        if (tevent_req_nterror(req, status)) {
                return tevent_req_post(req, ev);
        }

        subreq = SMB_VFS_OFFLOAD_READ_SEND(state, ev, src_fsp,
                                           FSCTL_DUP_EXTENTS_TO_FILE,
                                           0, 0, 0);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }
        tevent_req_set_callback(subreq, fsctl_dup_extents_offload_read_done,
                                req);
        return req;
}

static void fsctl_dup_extents_offload_read_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct fsctl_dup_extents_state *state = tevent_req_data(
                req, struct fsctl_dup_extents_state);
        uint32_t flags;
        uint64_t xferlen;
        DATA_BLOB token;
        NTSTATUS status;

        /*
         * Note that both flags and xferlen are not used with copy-chunk.
         */

        status = SMB_VFS_OFFLOAD_READ_RECV(subreq, state->dst_fsp->conn,
                                           state, &flags, &xferlen, &token);
        if (tevent_req_nterror(req, status)) {
                return;
        }

        /* tell the VFS to ignore locks across the clone, matching ReFS */
        subreq = SMB_VFS_OFFLOAD_WRITE_SEND(state->dst_fsp->conn,
                                            state,
                                            state->ev,
                                            FSCTL_DUP_EXTENTS_TO_FILE,
                                            &token,
                                            state->dup_extents.source_off,
                                            state->dst_fsp,
                                            state->dup_extents.target_off,
                                            state->dup_extents.byte_count);
        if (tevent_req_nomem(subreq, req)) {
                return;
        }
        tevent_req_set_callback(subreq, fsctl_dup_extents_vfs_done, req);
        return;
}

static void fsctl_dup_extents_vfs_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct fsctl_dup_extents_state *state = tevent_req_data(
                req, struct fsctl_dup_extents_state);
        off_t nb_chunk;
        NTSTATUS status;

        status = SMB_VFS_OFFLOAD_WRITE_RECV(state->conn, subreq, &nb_chunk);
        TALLOC_FREE(subreq);
        if (tevent_req_nterror(req, status)) {
                return;
        }

        if (nb_chunk != state->dup_extents.byte_count) {
                tevent_req_nterror(req, NT_STATUS_IO_DEVICE_ERROR);
                return;
        }

        tevent_req_done(req);
}

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

static NTSTATUS fsctl_get_cmprn(TALLOC_CTX *mem_ctx,
                                struct tevent_context *ev,
                                struct files_struct *fsp,
                                size_t in_max_output,
                                DATA_BLOB *out_output)
{
        struct compression_state cmpr_state;
        enum ndr_err_code ndr_ret;
        DATA_BLOB output;
        NTSTATUS status;

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

        /* Windows doesn't check for SEC_FILE_READ_ATTRIBUTE permission here */

        ZERO_STRUCT(cmpr_state);
        if (fsp->conn->fs_capabilities & FILE_FILE_COMPRESSION) {
                status = SMB_VFS_FGET_COMPRESSION(fsp->conn,
                                                 mem_ctx,
                                                 fsp,
                                                 &cmpr_state.format);
                if (!NT_STATUS_IS_OK(status)) {
                        return status;
                }
        } else {
                /*
                 * bso#12144: The underlying filesystem doesn't support
                 * compression, so we should respond with "not-compressed"
                 * (like WS2016 ReFS) instead of STATUS_NOT_SUPPORTED or
                 * NT_STATUS_INVALID_DEVICE_REQUEST.
                 */
                cmpr_state.format = COMPRESSION_FORMAT_NONE;
        }

        ndr_ret = ndr_push_struct_blob(&output, mem_ctx,
                                       &cmpr_state,
                        (ndr_push_flags_fn_t)ndr_push_compression_state);
        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 compression state %ld\n",
                      (unsigned int)in_max_output, (long int)output.length));
                return NT_STATUS_INVALID_USER_BUFFER;
        }
        *out_output = output;

        return NT_STATUS_OK;
}

static NTSTATUS fsctl_set_cmprn(TALLOC_CTX *mem_ctx,
                                struct tevent_context *ev,
                                struct files_struct *fsp,
                                DATA_BLOB *in_input)
{
        struct compression_state cmpr_state;
        enum ndr_err_code ndr_ret;
        NTSTATUS status;

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

        /* WRITE_DATA permission is required, WRITE_ATTRIBUTES is not */
        status = check_any_access_fsp(fsp, FILE_WRITE_DATA);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        ndr_ret = ndr_pull_struct_blob(in_input, mem_ctx, &cmpr_state,
                        (ndr_pull_flags_fn_t)ndr_pull_compression_state);
        if (ndr_ret != NDR_ERR_SUCCESS) {
                DEBUG(0, ("failed to unmarshall set compression req\n"));
                return NT_STATUS_INVALID_PARAMETER;
        }

        status = NT_STATUS_NOT_SUPPORTED;
        if (fsp->conn->fs_capabilities & FILE_FILE_COMPRESSION) {
                status = SMB_VFS_SET_COMPRESSION(fsp->conn,
                                                 mem_ctx,
                                                 fsp,
                                                 cmpr_state.format);
        } else if (cmpr_state.format == COMPRESSION_FORMAT_NONE) {
                /*
                 * bso#12144: The underlying filesystem doesn't support
                 * compression. We should still accept set(FORMAT_NONE) requests
                 * (like WS2016 ReFS).
                 */
                status = NT_STATUS_OK;
        }

        return status;
}

static NTSTATUS fsctl_zero_data(TALLOC_CTX *mem_ctx,
                                struct tevent_context *ev,
                                struct files_struct *fsp,
                                DATA_BLOB *in_input)
{
        struct file_zero_data_info zdata_info;
        enum ndr_err_code ndr_ret;
        struct lock_struct lck;
        int mode;
        uint64_t len;
        int ret;
        NTSTATUS status;

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

        /* WRITE_DATA permission is required */
        status = check_any_access_fsp(fsp, FILE_WRITE_DATA);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        /* allow regardless of whether FS supports sparse or not */

        ndr_ret = ndr_pull_struct_blob(in_input, mem_ctx, &zdata_info,
                        (ndr_pull_flags_fn_t)ndr_pull_file_zero_data_info);
        if (ndr_ret != NDR_ERR_SUCCESS) {
                DEBUG(0, ("failed to unmarshall zero data request\n"));
                return NT_STATUS_INVALID_PARAMETER;
        }

        if (zdata_info.beyond_final_zero < zdata_info.file_off) {
                DEBUG(0, ("invalid zero data params: off %lu, bfz, %lu\n",
                          (unsigned long)zdata_info.file_off,
                          (unsigned long)zdata_info.beyond_final_zero));
                return NT_STATUS_INVALID_PARAMETER;
        }

        /* convert strange "beyond final zero" param into length */
        len = zdata_info.beyond_final_zero - zdata_info.file_off;

        if (len == 0) {
                DEBUG(2, ("zero data called with zero length range\n"));
                return NT_STATUS_OK;
        }

        init_strict_lock_struct(fsp,
                                fsp->op->global->open_persistent_id,
                                zdata_info.file_off,
                                len,
                                WRITE_LOCK,
                                lp_posix_cifsu_locktype(fsp),
                                &lck);

        if (!SMB_VFS_STRICT_LOCK_CHECK(fsp->conn, fsp, &lck)) {
                DEBUG(2, ("failed to lock range for zero-data\n"));
                return NT_STATUS_FILE_LOCK_CONFLICT;
        }

        /*
         * MS-FSCC <58> Section 2.3.67
         * This FSCTL sets the range of bytes to zero (0) without extending the
         * file size.
         *
         * The VFS_FALLOCATE_FL_KEEP_SIZE flag is used to satisfy this
         * constraint.
         */

        mode = VFS_FALLOCATE_FL_PUNCH_HOLE | VFS_FALLOCATE_FL_KEEP_SIZE;
        ret = SMB_VFS_FALLOCATE(fsp, mode, zdata_info.file_off, len);
        if (ret == -1)  {
                status = map_nt_error_from_unix_common(errno);
                DEBUG(2, ("zero-data fallocate(0x%x) failed: %s\n", mode,
                      strerror(errno)));
                return status;
        }

        if (!fsp->fsp_flags.is_sparse && lp_strict_allocate(SNUM(fsp->conn))) {
                /*
                 * File marked non-sparse and "strict allocate" is enabled -
                 * allocate the range that we just punched out.
                 * In future FALLOC_FL_ZERO_RANGE could be used exclusively for
                 * this, but it's currently only supported on XFS and ext4.
                 *
                 * The newly allocated range still won't be found by SEEK_DATA
                 * for QAR, but stat.st_blocks will reflect it.
                 */
                ret = SMB_VFS_FALLOCATE(fsp, VFS_FALLOCATE_FL_KEEP_SIZE,
                                        zdata_info.file_off, len);
                if (ret == -1)  {
                        status = map_nt_error_from_unix_common(errno);
                        DEBUG(0, ("fallocate failed: %s\n", strerror(errno)));
                        return status;
                }
        }

        return NT_STATUS_OK;
}

static NTSTATUS fsctl_qar_buf_push(TALLOC_CTX *mem_ctx,
                                   struct file_alloced_range_buf *qar_buf,
                                   DATA_BLOB *qar_array_blob)
{
        DATA_BLOB new_slot;
        enum ndr_err_code ndr_ret;
        bool ok;

        ndr_ret = ndr_push_struct_blob(&new_slot, mem_ctx, qar_buf,
                        (ndr_push_flags_fn_t)ndr_push_file_alloced_range_buf);
        if (ndr_ret != NDR_ERR_SUCCESS) {
                DEBUG(0, ("failed to marshall QAR buf\n"));
                return NT_STATUS_INVALID_PARAMETER;
        }

        /* TODO should be able to avoid copy by pushing into prealloced buf */
        ok = data_blob_append(mem_ctx, qar_array_blob, new_slot.data,
                              new_slot.length);
        data_blob_free(&new_slot);
        if (!ok) {
                return NT_STATUS_NO_MEMORY;
        }

        return NT_STATUS_OK;
}

static NTSTATUS fsctl_qar_seek_fill(TALLOC_CTX *mem_ctx,
                                    struct files_struct *fsp,
                                    off_t curr_off,
                                    off_t max_off,
                                    size_t in_max_output,
                                    DATA_BLOB *qar_array_blob)
{
        NTSTATUS status = NT_STATUS_NOT_SUPPORTED;

#ifdef HAVE_LSEEK_HOLE_DATA
        while (curr_off <= max_off) {
                off_t data_off;
                off_t hole_off;
                struct file_alloced_range_buf qar_buf;

                /* seek next data */
                data_off = SMB_VFS_LSEEK(fsp, curr_off, SEEK_DATA);
                if ((data_off == -1) && (errno == ENXIO)) {
                        /* no data from curr_off to EOF */
                        break;
                } else if (data_off == -1) {
                        status = map_nt_error_from_unix_common(errno);
                        DEBUG(1, ("lseek data failed: %s\n", strerror(errno)));
                        return status;
                }

                if (data_off > max_off) {
                        /* found something, but passed range of interest */
                        break;
                }

                hole_off = SMB_VFS_LSEEK(fsp, data_off, SEEK_HOLE);
                if (hole_off == -1) {
                        status = map_nt_error_from_unix_common(errno);
                        DEBUG(1, ("lseek hole failed: %s\n", strerror(errno)));
                        return status;
                }

                if (hole_off <= data_off) {
                        DEBUG(1, ("lseek inconsistent: hole %lu at or before "
                                  "data %lu\n", (unsigned long)hole_off,
                                  (unsigned long)data_off));
                        return NT_STATUS_INTERNAL_ERROR;
                }

                if (qar_array_blob->length + sizeof(qar_buf) > in_max_output) {
                        /*
                         * Earlier check ensures space for one range or more.
                         * Subsequent overflow results in a truncated response.
                         */
                        DBG_NOTICE("truncated QAR output: need > %zu, max %zu\n",
                                qar_array_blob->length + sizeof(qar_buf),
                                in_max_output);
                        return STATUS_BUFFER_OVERFLOW;
                }

                qar_buf.file_off = data_off;
                /* + 1 to convert maximum offset to length */
                qar_buf.len = MIN(hole_off, max_off + 1) - data_off;

                status = fsctl_qar_buf_push(mem_ctx, &qar_buf, qar_array_blob);
                if (!NT_STATUS_IS_OK(status)) {
                        return NT_STATUS_NO_MEMORY;
                }

                curr_off = hole_off;
        }
        status = NT_STATUS_OK;
#endif

        return status;
}

static NTSTATUS fsctl_qar(TALLOC_CTX *mem_ctx,
                          struct tevent_context *ev,
                          struct files_struct *fsp,
                          DATA_BLOB *in_input,
                          size_t in_max_output,
                          DATA_BLOB *out_output)
{
        struct fsctl_query_alloced_ranges_req qar_req;
        struct fsctl_query_alloced_ranges_rsp qar_rsp;
        DATA_BLOB qar_array_blob = data_blob_null;
        uint64_t max_off;
        enum ndr_err_code ndr_ret;
        int ret;
        NTSTATUS status;
        SMB_STRUCT_STAT sbuf;

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

        /* READ_DATA permission is required */
        status = check_any_access_fsp(fsp, FILE_READ_DATA);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        ndr_ret = ndr_pull_struct_blob(in_input, mem_ctx, &qar_req,
                (ndr_pull_flags_fn_t)ndr_pull_fsctl_query_alloced_ranges_req);
        if (ndr_ret != NDR_ERR_SUCCESS) {
                DEBUG(0, ("failed to unmarshall QAR req\n"));
                return NT_STATUS_INVALID_PARAMETER;
        }

        /*
         * XXX Windows Server 2008 & 2012 servers don't return lock-conflict
         * for QAR requests over an exclusively locked range!
         */

        ret = SMB_VFS_FSTAT(fsp, &sbuf);
        if (ret == -1) {
                status = map_nt_error_from_unix_common(errno);
                DEBUG(2, ("fstat failed: %s\n", strerror(errno)));
                return status;
        }

        if ((qar_req.buf.len == 0)
         || (sbuf.st_ex_size == 0)
         || (qar_req.buf.file_off >= sbuf.st_ex_size)) {
                /* zero length range or after EOF, no ranges to return */
                return NT_STATUS_OK;
        }

        /* check for integer overflow */
        if (qar_req.buf.file_off + qar_req.buf.len < qar_req.buf.file_off) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        /* must have enough space for at least one range */
        if (in_max_output < sizeof(struct file_alloced_range_buf)) {
                DEBUG(2, ("QAR max %lu insufficient for one range\n",
                          (unsigned long)in_max_output));
                return NT_STATUS_BUFFER_TOO_SMALL;
        }

        /*
         * Maximum offset is either the last valid offset _before_ EOF, or the
         * last byte offset within the requested range. -1 converts length to
         * offset, which is easier to work with for SEEK_DATA/SEEK_HOLE, E.g.:
         *
         * /off=0             /off=512K          /st_ex_size=1M
         * |-------------------------------------|
         * | File data                           |
         * |-------------------------------------|
         *                                                   QAR end\
         *                    |=====================================|
         *                    |    QAR off=512K, len=1M             |
         *                    |=================^===================|
         *                                   max_off=1M - 1
         *             QAR end\
         * |==================|
         * |QAR off=0 len=512K|
         * |==================|
         *                   ^
         *                max_off=512K - 1
         */
        max_off = MIN(sbuf.st_ex_size,
                      qar_req.buf.file_off + qar_req.buf.len) - 1;

        if (!fsp->fsp_flags.is_sparse) {
                struct file_alloced_range_buf qar_buf;

                /* file is non-sparse, claim file_off->max_off is allocated */
                qar_buf.file_off = qar_req.buf.file_off;
                /* + 1 to convert maximum offset back to length */
                qar_buf.len = max_off - qar_req.buf.file_off + 1;

                status = fsctl_qar_buf_push(mem_ctx, &qar_buf, &qar_array_blob);
        } else {
                status = fsctl_qar_seek_fill(mem_ctx, fsp, qar_req.buf.file_off,
                                             max_off, in_max_output,
                                             &qar_array_blob);
        }

        if (NT_STATUS_IS_OK(status)
         || NT_STATUS_EQUAL(status, STATUS_BUFFER_OVERFLOW)) {
                /* marshall response. STATUS_BUFFER_OVERFLOW=truncated */
                qar_rsp.far_buf_array = qar_array_blob;

                ndr_ret = ndr_push_struct_blob(out_output, mem_ctx, &qar_rsp,
                 (ndr_push_flags_fn_t)ndr_push_fsctl_query_alloced_ranges_rsp);
                if (ndr_ret != NDR_ERR_SUCCESS) {
                        DEBUG(0, ("failed to marshall QAR rsp\n"));
                        return NT_STATUS_INVALID_PARAMETER;
                }
        }

        return status;
}

static void smb2_ioctl_filesys_dup_extents_done(struct tevent_req *subreq);

struct tevent_req *smb2_ioctl_filesys(uint32_t ctl_code,
                                      struct tevent_context *ev,
                                      struct tevent_req *req,
                                      struct smbd_smb2_ioctl_state *state)
{
        NTSTATUS status;

        switch (ctl_code) {
        case FSCTL_GET_COMPRESSION:
                status = fsctl_get_cmprn(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;
        case FSCTL_SET_COMPRESSION:
                status = fsctl_set_cmprn(state, ev, state->fsp,
                                         &state->in_input);
                if (!tevent_req_nterror(req, status)) {
                        tevent_req_done(req);
                }
                return tevent_req_post(req, ev);
                break;
        case FSCTL_SET_ZERO_DATA:
                status = fsctl_zero_data(state, ev, state->fsp,
                                         &state->in_input);
                if (!tevent_req_nterror(req, status)) {
                        tevent_req_done(req);
                }
                return tevent_req_post(req, ev);
                break;
        case FSCTL_QUERY_ALLOCATED_RANGES:
                status = fsctl_qar(state, ev, state->fsp,
                                   &state->in_input,
                                   state->in_max_output,
                                   &state->out_output);
                if (!tevent_req_nterror(req, status)) {
                        tevent_req_done(req);
                }
                return tevent_req_post(req, ev);
                break;
        case FSCTL_DUP_EXTENTS_TO_FILE: {
                struct tevent_req *subreq = NULL;

                subreq = fsctl_dup_extents_send(state, ev,
                                                state->fsp,
                                                &state->in_input,
                                                state->smb2req);
                if (tevent_req_nomem(subreq, req)) {
                        return tevent_req_post(req, ev);
                }
                tevent_req_set_callback(subreq,
                                        smb2_ioctl_filesys_dup_extents_done,
                                        req);
                return req;
                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_filesys_dup_extents_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(subreq,
                                                          struct tevent_req);
        NTSTATUS status;

        status = fsctl_dup_extents_recv(subreq);
        TALLOC_FREE(subreq);
        if (!tevent_req_nterror(req, status)) {
                tevent_req_done(req);
        }
}