diff options
Diffstat (limited to 'pkg/sentry/fsimpl/host')
| -rw-r--r-- | pkg/sentry/fsimpl/host/host.go | 41 |
1 files changed, 32 insertions, 9 deletions
diff --git a/pkg/sentry/fsimpl/host/host.go b/pkg/sentry/fsimpl/host/host.go index 36bceeaa4..8caf55a1b 100644 --- a/pkg/sentry/fsimpl/host/host.go +++ b/pkg/sentry/fsimpl/host/host.go @@ -40,8 +40,20 @@ import ( "gvisor.dev/gvisor/pkg/waiter" ) -// ImportFD sets up and returns a vfs.FileDescription from a donated fd. -func ImportFD(ctx context.Context, mnt *vfs.Mount, hostFD int, isTTY bool) (*vfs.FileDescription, error) { +// NewFDOptions contains options to NewFD. +type NewFDOptions struct { + // If IsTTY is true, the file descriptor is a TTY. + IsTTY bool + + // If HaveFlags is true, use Flags for the new file description. Otherwise, + // the new file description will inherit flags from hostFD. + HaveFlags bool + Flags uint32 +} + +// NewFD returns a vfs.FileDescription representing the given host file +// descriptor. mnt must be Kernel.HostMount(). +func NewFD(ctx context.Context, mnt *vfs.Mount, hostFD int, opts *NewFDOptions) (*vfs.FileDescription, error) { fs, ok := mnt.Filesystem().Impl().(*filesystem) if !ok { return nil, fmt.Errorf("can't import host FDs into filesystems of type %T", mnt.Filesystem().Impl()) @@ -53,10 +65,14 @@ func ImportFD(ctx context.Context, mnt *vfs.Mount, hostFD int, isTTY bool) (*vfs return nil, err } - // Get flags for the imported FD. - flags, err := unix.FcntlInt(uintptr(hostFD), syscall.F_GETFL, 0) - if err != nil { - return nil, err + flags := opts.Flags + if !opts.HaveFlags { + // Get flags for the imported FD. + flagsInt, err := unix.FcntlInt(uintptr(hostFD), syscall.F_GETFL, 0) + if err != nil { + return nil, err + } + flags = uint32(flagsInt) } fileMode := linux.FileMode(s.Mode) @@ -65,13 +81,13 @@ func ImportFD(ctx context.Context, mnt *vfs.Mount, hostFD int, isTTY bool) (*vfs // Determine if hostFD is seekable. If not, this syscall will return ESPIPE // (see fs/read_write.c:llseek), e.g. for pipes, sockets, and some character // devices. - _, err = unix.Seek(hostFD, 0, linux.SEEK_CUR) + _, err := unix.Seek(hostFD, 0, linux.SEEK_CUR) seekable := err != syserror.ESPIPE i := &inode{ hostFD: hostFD, seekable: seekable, - isTTY: isTTY, + isTTY: opts.IsTTY, canMap: canMap(uint32(fileType)), wouldBlock: wouldBlock(uint32(fileType)), ino: fs.NextIno(), @@ -101,7 +117,14 @@ func ImportFD(ctx context.Context, mnt *vfs.Mount, hostFD int, isTTY bool) (*vfs // i.open will take a reference on d. defer d.DecRef() - return i.open(ctx, d.VFSDentry(), mnt, uint32(flags)) + return i.open(ctx, d.VFSDentry(), mnt, flags) +} + +// ImportFD sets up and returns a vfs.FileDescription from a donated fd. +func ImportFD(ctx context.Context, mnt *vfs.Mount, hostFD int, isTTY bool) (*vfs.FileDescription, error) { + return NewFD(ctx, mnt, hostFD, &NewFDOptions{ + IsTTY: isTTY, + }) } // filesystemType implements vfs.FilesystemType. |