github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/pkg/sentry/vfs/opath.go (about)

     1  // Copyright 2019 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package vfs
    16  
    17  import (
    18  	"github.com/SagerNet/gvisor/pkg/abi/linux"
    19  	"github.com/SagerNet/gvisor/pkg/context"
    20  	"github.com/SagerNet/gvisor/pkg/errors/linuxerr"
    21  	"github.com/SagerNet/gvisor/pkg/sentry/arch"
    22  	"github.com/SagerNet/gvisor/pkg/sentry/kernel/auth"
    23  	"github.com/SagerNet/gvisor/pkg/sentry/memmap"
    24  	"github.com/SagerNet/gvisor/pkg/usermem"
    25  )
    26  
    27  // opathFD implements FileDescriptionImpl for a file description opened with O_PATH.
    28  //
    29  // +stateify savable
    30  type opathFD struct {
    31  	vfsfd FileDescription
    32  	FileDescriptionDefaultImpl
    33  	BadLockFD
    34  }
    35  
    36  // Release implements FileDescriptionImpl.Release.
    37  func (fd *opathFD) Release(context.Context) {
    38  	// noop
    39  }
    40  
    41  // Allocate implements FileDescriptionImpl.Allocate.
    42  func (fd *opathFD) Allocate(ctx context.Context, mode, offset, length uint64) error {
    43  	return linuxerr.EBADF
    44  }
    45  
    46  // PRead implements FileDescriptionImpl.PRead.
    47  func (fd *opathFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts ReadOptions) (int64, error) {
    48  	return 0, linuxerr.EBADF
    49  }
    50  
    51  // Read implements FileDescriptionImpl.Read.
    52  func (fd *opathFD) Read(ctx context.Context, dst usermem.IOSequence, opts ReadOptions) (int64, error) {
    53  	return 0, linuxerr.EBADF
    54  }
    55  
    56  // PWrite implements FileDescriptionImpl.PWrite.
    57  func (fd *opathFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts WriteOptions) (int64, error) {
    58  	return 0, linuxerr.EBADF
    59  }
    60  
    61  // Write implements FileDescriptionImpl.Write.
    62  func (fd *opathFD) Write(ctx context.Context, src usermem.IOSequence, opts WriteOptions) (int64, error) {
    63  	return 0, linuxerr.EBADF
    64  }
    65  
    66  // Ioctl implements FileDescriptionImpl.Ioctl.
    67  func (fd *opathFD) Ioctl(ctx context.Context, uio usermem.IO, args arch.SyscallArguments) (uintptr, error) {
    68  	return 0, linuxerr.EBADF
    69  }
    70  
    71  // IterDirents implements FileDescriptionImpl.IterDirents.
    72  func (fd *opathFD) IterDirents(ctx context.Context, cb IterDirentsCallback) error {
    73  	return linuxerr.EBADF
    74  }
    75  
    76  // Seek implements FileDescriptionImpl.Seek.
    77  func (fd *opathFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) {
    78  	return 0, linuxerr.EBADF
    79  }
    80  
    81  // ConfigureMMap implements FileDescriptionImpl.ConfigureMMap.
    82  func (fd *opathFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpts) error {
    83  	return linuxerr.EBADF
    84  }
    85  
    86  // ListXattr implements FileDescriptionImpl.ListXattr.
    87  func (fd *opathFD) ListXattr(ctx context.Context, size uint64) ([]string, error) {
    88  	return nil, linuxerr.EBADF
    89  }
    90  
    91  // GetXattr implements FileDescriptionImpl.GetXattr.
    92  func (fd *opathFD) GetXattr(ctx context.Context, opts GetXattrOptions) (string, error) {
    93  	return "", linuxerr.EBADF
    94  }
    95  
    96  // SetXattr implements FileDescriptionImpl.SetXattr.
    97  func (fd *opathFD) SetXattr(ctx context.Context, opts SetXattrOptions) error {
    98  	return linuxerr.EBADF
    99  }
   100  
   101  // RemoveXattr implements FileDescriptionImpl.RemoveXattr.
   102  func (fd *opathFD) RemoveXattr(ctx context.Context, name string) error {
   103  	return linuxerr.EBADF
   104  }
   105  
   106  // Sync implements FileDescriptionImpl.Sync.
   107  func (fd *opathFD) Sync(ctx context.Context) error {
   108  	return linuxerr.EBADF
   109  }
   110  
   111  // SetStat implements FileDescriptionImpl.SetStat.
   112  func (fd *opathFD) SetStat(ctx context.Context, opts SetStatOptions) error {
   113  	return linuxerr.EBADF
   114  }
   115  
   116  // Stat implements FileDescriptionImpl.Stat.
   117  func (fd *opathFD) Stat(ctx context.Context, opts StatOptions) (linux.Statx, error) {
   118  	vfsObj := fd.vfsfd.vd.mount.vfs
   119  	rp := vfsObj.getResolvingPath(auth.CredentialsFromContext(ctx), &PathOperation{
   120  		Root:  fd.vfsfd.vd,
   121  		Start: fd.vfsfd.vd,
   122  	})
   123  	stat, err := fd.vfsfd.vd.mount.fs.impl.StatAt(ctx, rp, opts)
   124  	rp.Release(ctx)
   125  	return stat, err
   126  }
   127  
   128  // StatFS returns metadata for the filesystem containing the file represented
   129  // by fd.
   130  func (fd *opathFD) StatFS(ctx context.Context) (linux.Statfs, error) {
   131  	vfsObj := fd.vfsfd.vd.mount.vfs
   132  	rp := vfsObj.getResolvingPath(auth.CredentialsFromContext(ctx), &PathOperation{
   133  		Root:  fd.vfsfd.vd,
   134  		Start: fd.vfsfd.vd,
   135  	})
   136  	statfs, err := fd.vfsfd.vd.mount.fs.impl.StatFSAt(ctx, rp)
   137  	rp.Release(ctx)
   138  	return statfs, err
   139  }