diff options
Diffstat (limited to 'pkg/sentry/vfs/options.go')
| -rw-r--r-- | pkg/sentry/vfs/options.go | 131 |
1 files changed, 130 insertions, 1 deletions
diff --git a/pkg/sentry/vfs/options.go b/pkg/sentry/vfs/options.go index 3aa73d911..dfc8573fd 100644 --- a/pkg/sentry/vfs/options.go +++ b/pkg/sentry/vfs/options.go @@ -16,6 +16,7 @@ package vfs import ( "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/sentry/socket/unix/transport" ) // GetDentryOptions contains options to VirtualFilesystem.GetDentryAt() and @@ -32,6 +33,25 @@ type GetDentryOptions struct { type MkdirOptions struct { // Mode is the file mode bits for the created directory. Mode linux.FileMode + + // If ForSyntheticMountpoint is true, FilesystemImpl.MkdirAt() may create + // the given directory in memory only (as opposed to persistent storage). + // The created directory should be able to support the creation of + // subdirectories with ForSyntheticMountpoint == true. It does not need to + // support the creation of subdirectories with ForSyntheticMountpoint == + // false, or files of other types. + // + // FilesystemImpls are permitted to ignore the ForSyntheticMountpoint + // option. + // + // The ForSyntheticMountpoint option exists because, unlike mount(2), the + // OCI Runtime Specification permits the specification of mount points that + // do not exist, under the expectation that container runtimes will create + // them. (More accurately, the OCI Runtime Specification completely fails + // to document this feature, but it's implemented by runc.) + // ForSyntheticMountpoint allows such mount points to be created even when + // the underlying persistent filesystem is immutable. + ForSyntheticMountpoint bool } // MknodOptions contains options to VirtualFilesystem.MknodAt() and @@ -44,6 +64,48 @@ type MknodOptions struct { // DevMinor are the major and minor device numbers for the created device. DevMajor uint32 DevMinor uint32 + + // Endpoint is the endpoint to bind to the created file, if a socket file is + // being created for bind(2) on a Unix domain socket. + Endpoint transport.BoundEndpoint +} + +// MountFlags contains flags as specified for mount(2), e.g. MS_NOEXEC. +// MS_RDONLY is not part of MountFlags because it's tracked in Mount.writers. +type MountFlags struct { + // NoExec is equivalent to MS_NOEXEC. + NoExec bool + + // NoATime is equivalent to MS_NOATIME and indicates that the + // filesystem should not update access time in-place. + NoATime bool + + // NoDev is equivalent to MS_NODEV and indicates that the + // filesystem should not allow access to devices (special files). + // TODO(gVisor.dev/issue/3186): respect this flag in non FUSE + // filesystems. + NoDev bool + + // NoSUID is equivalent to MS_NOSUID and indicates that the + // filesystem should not honor set-user-ID and set-group-ID bits or + // file capabilities when executing programs. + NoSUID bool +} + +// MountOptions contains options to VirtualFilesystem.MountAt(). +type MountOptions struct { + // Flags contains flags as specified for mount(2), e.g. MS_NOEXEC. + Flags MountFlags + + // ReadOnly is equivalent to MS_RDONLY. + ReadOnly bool + + // GetFilesystemOptions contains options to FilesystemType.GetFilesystem(). + GetFilesystemOptions GetFilesystemOptions + + // If InternalMount is true, allow the use of filesystem types for which + // RegisterFilesystemTypeOptions.AllowUserMount == false. + InternalMount bool } // OpenOptions contains options to VirtualFilesystem.OpenAt() and @@ -51,7 +113,7 @@ type MknodOptions struct { type OpenOptions struct { // Flags contains access mode and flags as specified for open(2). // - // FilesystemImpls is reponsible for implementing the following flags: + // FilesystemImpls are responsible for implementing the following flags: // O_RDONLY, O_WRONLY, O_RDWR, O_APPEND, O_CREAT, O_DIRECT, O_DSYNC, // O_EXCL, O_NOATIME, O_NOCTTY, O_NONBLOCK, O_PATH, O_SYNC, O_TMPFILE, and // O_TRUNC. VFS is responsible for handling O_DIRECTORY, O_LARGEFILE, and @@ -62,6 +124,12 @@ type OpenOptions struct { // If FilesystemImpl.OpenAt() creates a file, Mode is the file mode for the // created file. Mode linux.FileMode + + // FileExec is set when the file is being opened to be executed. + // VirtualFilesystem.OpenAt() checks that the caller has execute permissions + // on the file, that the file is a regular file, and that the mount doesn't + // have MS_NOEXEC set. + FileExec bool } // ReadOptions contains options to FileDescription.PRead(), @@ -77,6 +145,9 @@ type ReadOptions struct { type RenameOptions struct { // Flags contains flags as specified for renameat2(2). Flags uint32 + + // If MustBeDir is true, the renamed file must be a directory. + MustBeDir bool } // SetStatOptions contains options to VirtualFilesystem.SetStatAt(), @@ -93,6 +164,58 @@ type SetStatOptions struct { // == UTIME_OMIT (VFS users must unset the corresponding bit in Stat.Mask // instead). Stat linux.Statx + + // NeedWritePerm indicates that write permission on the file is needed for + // this operation. This is needed for truncate(2) (note that ftruncate(2) + // does not require the same check--instead, it checks that the fd is + // writable). + NeedWritePerm bool +} + +// BoundEndpointOptions contains options to VirtualFilesystem.BoundEndpointAt() +// and FilesystemImpl.BoundEndpointAt(). +type BoundEndpointOptions struct { + // Addr is the path of the file whose socket endpoint is being retrieved. + // It is generally irrelevant: most endpoints are stored at a dentry that + // was created through a bind syscall, so the path can be stored on creation. + // However, if the endpoint was created in FilesystemImpl.BoundEndpointAt(), + // then we may not know what the original bind address was. + // + // For example, if connect(2) is called with address "foo" which corresponds + // a remote named socket in goferfs, we need to generate an endpoint wrapping + // that file. In this case, we can use Addr to set the endpoint address to + // "foo". Note that Addr is only a best-effort attempt--we still do not know + // the exact address that was used on the remote fs to bind the socket (it + // may have been "foo", "./foo", etc.). + Addr string +} + +// GetxattrOptions contains options to VirtualFilesystem.GetxattrAt(), +// FilesystemImpl.GetxattrAt(), FileDescription.Getxattr(), and +// FileDescriptionImpl.Getxattr(). +type GetxattrOptions struct { + // Name is the name of the extended attribute to retrieve. + Name string + + // Size is the maximum value size that the caller will tolerate. If the value + // is larger than size, getxattr methods may return ERANGE, but they are also + // free to ignore the hint entirely (i.e. the value returned may be larger + // than size). All size checking is done independently at the syscall layer. + Size uint64 +} + +// SetxattrOptions contains options to VirtualFilesystem.SetxattrAt(), +// FilesystemImpl.SetxattrAt(), FileDescription.Setxattr(), and +// FileDescriptionImpl.Setxattr(). +type SetxattrOptions struct { + // Name is the name of the extended attribute being mutated. + Name string + + // Value is the extended attribute's new value. + Value string + + // Flags contains flags as specified for setxattr/lsetxattr/fsetxattr(2). + Flags uint32 } // StatOptions contains options to VirtualFilesystem.StatAt(), @@ -114,6 +237,12 @@ type StatOptions struct { Sync uint32 } +// UmountOptions contains options to VirtualFilesystem.UmountAt(). +type UmountOptions struct { + // Flags contains flags as specified for umount2(2). + Flags uint32 +} + // WriteOptions contains options to FileDescription.PWrite(), // FileDescriptionImpl.PWrite(), FileDescription.Write(), and // FileDescriptionImpl.Write(). |