cifs: add passthrough for smb2 setinfo

Add support to send smb2 set-info commands from userspace.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
 fs/cifs/cifs_ioctl.h |  1 +
 fs/cifs/smb2ops.c    | 29 +++++++++++++++++++++++++----
 2 files changed, 26 insertions(+), 4 deletions(-)

tentatively merged into cifs-2.6.git for-next pending more testing

On Wed, Jul 24, 2019 at 10:09 PM Ronnie Sahlberg <lsahlber@redhat.com> wrote:
>
> Add support to send smb2 set-info commands from userspace.
>
> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
> ---
>  fs/cifs/cifs_ioctl.h |  1 +
>  fs/cifs/smb2ops.c    | 29 +++++++++++++++++++++++++----
>  2 files changed, 26 insertions(+), 4 deletions(-)
>
> diff --git a/fs/cifs/cifs_ioctl.h b/fs/cifs/cifs_ioctl.h
> index 086ddc5108af..6c3bd07868d7 100644
> --- a/fs/cifs/cifs_ioctl.h
> +++ b/fs/cifs/cifs_ioctl.h
> @@ -46,6 +46,7 @@ struct smb_snapshot_array {
>  /* query_info flags */
>  #define PASSTHRU_QUERY_INFO    0x00000000
>  #define PASSTHRU_FSCTL         0x00000001
> +#define PASSTHRU_SET_INFO      0x00000002
>  struct smb_query_info {
>         __u32   info_type;
>         __u32   file_info_class;
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index 592aa11aaf57..fc464dc20b30 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -1369,7 +1369,10 @@ smb2_ioctl_query_info(const unsigned int xid,
>         struct cifs_fid fid;
>         struct kvec qi_iov[1];
>         struct kvec io_iov[SMB2_IOCTL_IOV_SIZE];
> +       struct kvec si_iov[SMB2_SET_INFO_IOV_SIZE];
>         struct kvec close_iov[1];
> +       unsigned int size[2];
> +       void *data[2];
>
>         memset(rqst, 0, sizeof(rqst));
>         resp_buftype[0] = resp_buftype[1] = resp_buftype[2] = CIFS_NO_BUFFER;
> @@ -1404,7 +1407,6 @@ smb2_ioctl_query_info(const unsigned int xid,
>
>         memset(&oparms, 0, sizeof(oparms));
>         oparms.tcon = tcon;
> -       oparms.desired_access = FILE_READ_ATTRIBUTES | READ_CONTROL;
>         oparms.disposition = FILE_OPEN;
>         if (is_dir)
>                 oparms.create_options = CREATE_NOT_FILE;
> @@ -1413,9 +1415,6 @@ smb2_ioctl_query_info(const unsigned int xid,
>         oparms.fid = &fid;
>         oparms.reconnect = false;
>
> -       /*
> -        * FSCTL codes encode the special access they need in the fsctl code.
> -        */
>         if (qi.flags & PASSTHRU_FSCTL) {
>                 switch (qi.info_type & FSCTL_DEVICE_ACCESS_MASK) {
>                 case FSCTL_DEVICE_ACCESS_FILE_READ_WRITE_ACCESS:
> @@ -1431,6 +1430,10 @@ smb2_ioctl_query_info(const unsigned int xid,
>                         oparms.desired_access = GENERIC_WRITE;
>                         break;
>                 }
> +       } else if (qi.flags & PASSTHRU_SET_INFO) {
> +               oparms.desired_access = GENERIC_WRITE;
> +       } else {
> +               oparms.desired_access = FILE_READ_ATTRIBUTES | READ_CONTROL;
>         }
>
>         rc = SMB2_open_init(tcon, &rqst[0], &oplock, &oparms, path);
> @@ -1454,6 +1457,24 @@ smb2_ioctl_query_info(const unsigned int xid,
>                                              qi.output_buffer_length,
>                                              CIFSMaxBufSize);
>                 }
> +       } else if (qi.flags == PASSTHRU_SET_INFO) {
> +               /* Can eventually relax perm check since server enforces too */
> +               if (!capable(CAP_SYS_ADMIN))
> +                       rc = -EPERM;
> +               else  {
> +                       memset(&si_iov, 0, sizeof(si_iov));
> +                       rqst[1].rq_iov = si_iov;
> +                       rqst[1].rq_nvec = 1;
> +
> +                       size[0] = 8;
> +                       data[0] = buffer;
> +
> +                       rc = SMB2_set_info_init(tcon, &rqst[1],
> +                                       COMPOUND_FID, COMPOUND_FID,
> +                                       current->tgid,
> +                                       FILE_END_OF_FILE_INFORMATION,
> +                                       SMB2_O_INFO_FILE, 0, data, size);
> +               }
>         } else if (qi.flags == PASSTHRU_QUERY_INFO) {
>                 memset(&qi_iov, 0, sizeof(qi_iov));
>                 rqst[1].rq_iov = qi_iov;
> --
> 2.13.6
>