232 lines
8.8 KiB
Go
232 lines
8.8 KiB
Go
// Copyright 2019 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package vfs
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import (
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"gvisor.dev/gvisor/pkg/abi/linux"
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"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
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)
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// GetDentryOptions contains options to VirtualFilesystem.GetDentryAt() and
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// FilesystemImpl.GetDentryAt().
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type GetDentryOptions struct {
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// If CheckSearchable is true, FilesystemImpl.GetDentryAt() must check that
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// the returned Dentry is a directory for which creds has search
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// permission.
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CheckSearchable bool
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}
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// MkdirOptions contains options to VirtualFilesystem.MkdirAt() and
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// FilesystemImpl.MkdirAt().
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type MkdirOptions struct {
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// Mode is the file mode bits for the created directory.
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Mode linux.FileMode
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// If ForSyntheticMountpoint is true, FilesystemImpl.MkdirAt() may create
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// the given directory in memory only (as opposed to persistent storage).
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// The created directory should be able to support the creation of
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// subdirectories with ForSyntheticMountpoint == true. It does not need to
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// support the creation of subdirectories with ForSyntheticMountpoint ==
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// false, or files of other types.
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//
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// FilesystemImpls are permitted to ignore the ForSyntheticMountpoint
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// option.
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//
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// The ForSyntheticMountpoint option exists because, unlike mount(2), the
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// OCI Runtime Specification permits the specification of mount points that
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// do not exist, under the expectation that container runtimes will create
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// them. (More accurately, the OCI Runtime Specification completely fails
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// to document this feature, but it's implemented by runc.)
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// ForSyntheticMountpoint allows such mount points to be created even when
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// the underlying persistent filesystem is immutable.
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ForSyntheticMountpoint bool
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}
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// MknodOptions contains options to VirtualFilesystem.MknodAt() and
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// FilesystemImpl.MknodAt().
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type MknodOptions struct {
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// Mode is the file type and mode bits for the created file.
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Mode linux.FileMode
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// If Mode specifies a character or block device special file, DevMajor and
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// DevMinor are the major and minor device numbers for the created device.
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DevMajor uint32
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DevMinor uint32
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// Endpoint is the endpoint to bind to the created file, if a socket file is
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// being created for bind(2) on a Unix domain socket.
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Endpoint transport.BoundEndpoint
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}
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// MountFlags contains flags as specified for mount(2), e.g. MS_NOEXEC.
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// MS_RDONLY is not part of MountFlags because it's tracked in Mount.writers.
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type MountFlags struct {
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// NoExec is equivalent to MS_NOEXEC.
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NoExec bool
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}
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// MountOptions contains options to VirtualFilesystem.MountAt().
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type MountOptions struct {
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// Flags contains flags as specified for mount(2), e.g. MS_NOEXEC.
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Flags MountFlags
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// ReadOnly is equivalent to MS_RDONLY.
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ReadOnly bool
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// GetFilesystemOptions contains options to FilesystemType.GetFilesystem().
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GetFilesystemOptions GetFilesystemOptions
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// If InternalMount is true, allow the use of filesystem types for which
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// RegisterFilesystemTypeOptions.AllowUserMount == false.
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InternalMount bool
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}
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// OpenOptions contains options to VirtualFilesystem.OpenAt() and
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// FilesystemImpl.OpenAt().
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type OpenOptions struct {
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// Flags contains access mode and flags as specified for open(2).
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//
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// FilesystemImpls are responsible for implementing the following flags:
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// O_RDONLY, O_WRONLY, O_RDWR, O_APPEND, O_CREAT, O_DIRECT, O_DSYNC,
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// O_EXCL, O_NOATIME, O_NOCTTY, O_NONBLOCK, O_PATH, O_SYNC, O_TMPFILE, and
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// O_TRUNC. VFS is responsible for handling O_DIRECTORY, O_LARGEFILE, and
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// O_NOFOLLOW. VFS users are responsible for handling O_CLOEXEC, since file
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// descriptors are mostly outside the scope of VFS.
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Flags uint32
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// If FilesystemImpl.OpenAt() creates a file, Mode is the file mode for the
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// created file.
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Mode linux.FileMode
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// FileExec is set when the file is being opened to be executed.
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// VirtualFilesystem.OpenAt() checks that the caller has execute permissions
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// on the file, that the file is a regular file, and that the mount doesn't
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// have MS_NOEXEC set.
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FileExec bool
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}
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// ReadOptions contains options to FileDescription.PRead(),
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// FileDescriptionImpl.PRead(), FileDescription.Read(), and
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// FileDescriptionImpl.Read().
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type ReadOptions struct {
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// Flags contains flags as specified for preadv2(2).
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Flags uint32
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}
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// RenameOptions contains options to VirtualFilesystem.RenameAt() and
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// FilesystemImpl.RenameAt().
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type RenameOptions struct {
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// Flags contains flags as specified for renameat2(2).
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Flags uint32
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// If MustBeDir is true, the renamed file must be a directory.
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MustBeDir bool
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}
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// SetStatOptions contains options to VirtualFilesystem.SetStatAt(),
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// FilesystemImpl.SetStatAt(), FileDescription.SetStat(), and
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// FileDescriptionImpl.SetStat().
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type SetStatOptions struct {
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// Stat is the metadata that should be set. Only fields indicated by
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// Stat.Mask should be set.
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//
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// If Stat specifies that a timestamp should be set,
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// FilesystemImpl.SetStatAt() and FileDescriptionImpl.SetStat() must
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// special-case StatxTimestamp.Nsec == UTIME_NOW as described by
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// utimensat(2); however, they do not need to check for StatxTimestamp.Nsec
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// == UTIME_OMIT (VFS users must unset the corresponding bit in Stat.Mask
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// instead).
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Stat linux.Statx
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}
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// BoundEndpointOptions contains options to VirtualFilesystem.BoundEndpointAt()
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// and FilesystemImpl.BoundEndpointAt().
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type BoundEndpointOptions struct {
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// Addr is the path of the file whose socket endpoint is being retrieved.
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// It is generally irrelevant: most endpoints are stored at a dentry that
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// was created through a bind syscall, so the path can be stored on creation.
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// However, if the endpoint was created in FilesystemImpl.BoundEndpointAt(),
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// then we may not know what the original bind address was.
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//
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// For example, if connect(2) is called with address "foo" which corresponds
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// a remote named socket in goferfs, we need to generate an endpoint wrapping
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// that file. In this case, we can use Addr to set the endpoint address to
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// "foo". Note that Addr is only a best-effort attempt--we still do not know
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// the exact address that was used on the remote fs to bind the socket (it
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// may have been "foo", "./foo", etc.).
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Addr string
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}
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// GetxattrOptions contains options to VirtualFilesystem.GetxattrAt(),
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// FilesystemImpl.GetxattrAt(), FileDescription.Getxattr(), and
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// FileDescriptionImpl.Getxattr().
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type GetxattrOptions struct {
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// Name is the name of the extended attribute to retrieve.
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Name string
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// Size is the maximum value size that the caller will tolerate. If the value
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// is larger than size, getxattr methods may return ERANGE, but they are also
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// free to ignore the hint entirely (i.e. the value returned may be larger
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// than size). All size checking is done independently at the syscall layer.
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Size uint64
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}
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// SetxattrOptions contains options to VirtualFilesystem.SetxattrAt(),
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// FilesystemImpl.SetxattrAt(), FileDescription.Setxattr(), and
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// FileDescriptionImpl.Setxattr().
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type SetxattrOptions struct {
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// Name is the name of the extended attribute being mutated.
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Name string
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// Value is the extended attribute's new value.
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Value string
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// Flags contains flags as specified for setxattr/lsetxattr/fsetxattr(2).
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Flags uint32
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}
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// StatOptions contains options to VirtualFilesystem.StatAt(),
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// FilesystemImpl.StatAt(), FileDescription.Stat(), and
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// FileDescriptionImpl.Stat().
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type StatOptions struct {
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// Mask is the set of fields in the returned Statx that the FilesystemImpl
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// or FileDescriptionImpl should provide. Bits are as in linux.Statx.Mask.
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//
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// The FilesystemImpl or FileDescriptionImpl may return fields not
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// requested in Mask, and may fail to return fields requested in Mask that
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// are not supported by the underlying filesystem implementation, without
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// returning an error.
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Mask uint32
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// Sync specifies the synchronization required, and is one of
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// linux.AT_STATX_SYNC_AS_STAT (which is 0, and therefore the default),
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// linux.AT_STATX_SYNC_FORCE_SYNC, or linux.AT_STATX_SYNC_DONT_SYNC.
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Sync uint32
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}
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// UmountOptions contains options to VirtualFilesystem.UmountAt().
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type UmountOptions struct {
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// Flags contains flags as specified for umount2(2).
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Flags uint32
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}
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// WriteOptions contains options to FileDescription.PWrite(),
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// FileDescriptionImpl.PWrite(), FileDescription.Write(), and
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// FileDescriptionImpl.Write().
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type WriteOptions struct {
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// Flags contains flags as specified for pwritev2(2).
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Flags uint32
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}
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