148 lines
4.0 KiB
Go
148 lines
4.0 KiB
Go
// Copyright 2020 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 vfs2
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import (
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"gvisor.dev/gvisor/pkg/abi/linux"
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"gvisor.dev/gvisor/pkg/sentry/arch"
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"gvisor.dev/gvisor/pkg/sentry/kernel"
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slinux "gvisor.dev/gvisor/pkg/sentry/syscalls/linux"
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"gvisor.dev/gvisor/pkg/syserror"
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)
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// Close implements Linux syscall close(2).
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func Close(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
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fd := args[0].Int()
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// Note that Remove provides a reference on the file that we may use to
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// flush. It is still active until we drop the final reference below
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// (and other reference-holding operations complete).
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_, file := t.FDTable().Remove(fd)
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if file == nil {
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return 0, nil, syserror.EBADF
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}
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defer file.DecRef()
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err := file.OnClose(t)
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return 0, nil, slinux.HandleIOErrorVFS2(t, false /* partial */, err, syserror.EINTR, "close", file)
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}
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// Dup implements Linux syscall dup(2).
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func Dup(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
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fd := args[0].Int()
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file := t.GetFileVFS2(fd)
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if file == nil {
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return 0, nil, syserror.EBADF
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}
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defer file.DecRef()
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newFD, err := t.NewFDFromVFS2(0, file, kernel.FDFlags{})
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if err != nil {
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return 0, nil, syserror.EMFILE
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}
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return uintptr(newFD), nil, nil
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}
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// Dup2 implements Linux syscall dup2(2).
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func Dup2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
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oldfd := args[0].Int()
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newfd := args[1].Int()
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if oldfd == newfd {
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// As long as oldfd is valid, dup2() does nothing and returns newfd.
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file := t.GetFileVFS2(oldfd)
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if file == nil {
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return 0, nil, syserror.EBADF
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}
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file.DecRef()
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return uintptr(newfd), nil, nil
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}
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return dup3(t, oldfd, newfd, 0)
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}
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// Dup3 implements Linux syscall dup3(2).
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func Dup3(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
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oldfd := args[0].Int()
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newfd := args[1].Int()
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flags := args[2].Uint()
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if oldfd == newfd {
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return 0, nil, syserror.EINVAL
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}
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return dup3(t, oldfd, newfd, flags)
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}
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func dup3(t *kernel.Task, oldfd, newfd int32, flags uint32) (uintptr, *kernel.SyscallControl, error) {
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if flags&^linux.O_CLOEXEC != 0 {
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return 0, nil, syserror.EINVAL
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}
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file := t.GetFileVFS2(oldfd)
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if file == nil {
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return 0, nil, syserror.EBADF
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}
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defer file.DecRef()
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err := t.NewFDAtVFS2(newfd, file, kernel.FDFlags{
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CloseOnExec: flags&linux.O_CLOEXEC != 0,
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})
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if err != nil {
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return 0, nil, err
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}
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return uintptr(newfd), nil, nil
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}
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// Fcntl implements linux syscall fcntl(2).
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func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
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fd := args[0].Int()
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cmd := args[1].Int()
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file, flags := t.FDTable().GetVFS2(fd)
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if file == nil {
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return 0, nil, syserror.EBADF
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}
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defer file.DecRef()
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switch cmd {
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case linux.F_DUPFD, linux.F_DUPFD_CLOEXEC:
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minfd := args[2].Int()
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fd, err := t.NewFDFromVFS2(minfd, file, kernel.FDFlags{
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CloseOnExec: cmd == linux.F_DUPFD_CLOEXEC,
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})
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if err != nil {
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return 0, nil, err
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}
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return uintptr(fd), nil, nil
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case linux.F_GETFD:
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return uintptr(flags.ToLinuxFDFlags()), nil, nil
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case linux.F_SETFD:
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flags := args[2].Uint()
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t.FDTable().SetFlags(fd, kernel.FDFlags{
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CloseOnExec: flags&linux.FD_CLOEXEC != 0,
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})
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return 0, nil, nil
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case linux.F_GETFL:
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return uintptr(file.StatusFlags()), nil, nil
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case linux.F_SETFL:
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return 0, nil, file.SetStatusFlags(t, t.Credentials(), args[2].Uint())
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default:
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// TODO(gvisor.dev/issue/1623): Everything else is not yet supported.
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return 0, nil, syserror.EINVAL
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}
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}
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