Merge release-20200422.0-16-gcbc5bef (automated)

1 files changed, 124 insertions, 0 deletions

diff --git a/pkg/sentry/fsimpl/devpts/terminal.go b/pkg/sentry/fsimpl/devpts/terminal.go
new file mode 100755
index 000000000..b44e673d8
--- /dev/null
+++ b/pkg/sentry/fsimpl/devpts/terminal.go
@@ -0,0 +1,124 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package devpts
+
+import (
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/usermem"
+)
+
+// LINT.IfChanges
+
+// Terminal is a pseudoterminal.
+//
+// +stateify savable
+type Terminal struct {
+	// n is the terminal index. It is immutable.
+	n uint32
+
+	// ld is the line discipline of the terminal. It is immutable.
+	ld *lineDiscipline
+
+	// masterKTTY contains the controlling process of the master end of
+	// this terminal. This field is immutable.
+	masterKTTY *kernel.TTY
+
+	// slaveKTTY contains the controlling process of the slave end of this
+	// terminal. This field is immutable.
+	slaveKTTY *kernel.TTY
+}
+
+func newTerminal(n uint32) *Terminal {
+	termios := linux.DefaultSlaveTermios
+	t := Terminal{
+		n:          n,
+		ld:         newLineDiscipline(termios),
+		masterKTTY: &kernel.TTY{Index: n},
+		slaveKTTY:  &kernel.TTY{Index: n},
+	}
+	return &t
+}
+
+// setControllingTTY makes tm the controlling terminal of the calling thread
+// group.
+func (tm *Terminal) setControllingTTY(ctx context.Context, io usermem.IO, args arch.SyscallArguments, isMaster bool) error {
+	task := kernel.TaskFromContext(ctx)
+	if task == nil {
+		panic("setControllingTTY must be called from a task context")
+	}
+
+	return task.ThreadGroup().SetControllingTTY(tm.tty(isMaster), args[2].Int())
+}
+
+// releaseControllingTTY removes tm as the controlling terminal of the calling
+// thread group.
+func (tm *Terminal) releaseControllingTTY(ctx context.Context, io usermem.IO, args arch.SyscallArguments, isMaster bool) error {
+	task := kernel.TaskFromContext(ctx)
+	if task == nil {
+		panic("releaseControllingTTY must be called from a task context")
+	}
+
+	return task.ThreadGroup().ReleaseControllingTTY(tm.tty(isMaster))
+}
+
+// foregroundProcessGroup gets the process group ID of tm's foreground process.
+func (tm *Terminal) foregroundProcessGroup(ctx context.Context, io usermem.IO, args arch.SyscallArguments, isMaster bool) (uintptr, error) {
+	task := kernel.TaskFromContext(ctx)
+	if task == nil {
+		panic("foregroundProcessGroup must be called from a task context")
+	}
+
+	ret, err := task.ThreadGroup().ForegroundProcessGroup(tm.tty(isMaster))
+	if err != nil {
+		return 0, err
+	}
+
+	// Write it out to *arg.
+	_, err = usermem.CopyObjectOut(ctx, io, args[2].Pointer(), int32(ret), usermem.IOOpts{
+		AddressSpaceActive: true,
+	})
+	return 0, err
+}
+
+// foregroundProcessGroup sets tm's foreground process.
+func (tm *Terminal) setForegroundProcessGroup(ctx context.Context, io usermem.IO, args arch.SyscallArguments, isMaster bool) (uintptr, error) {
+	task := kernel.TaskFromContext(ctx)
+	if task == nil {
+		panic("setForegroundProcessGroup must be called from a task context")
+	}
+
+	// Read in the process group ID.
+	var pgid int32
+	if _, err := usermem.CopyObjectIn(ctx, io, args[2].Pointer(), &pgid, usermem.IOOpts{
+		AddressSpaceActive: true,
+	}); err != nil {
+		return 0, err
+	}
+
+	ret, err := task.ThreadGroup().SetForegroundProcessGroup(tm.tty(isMaster), kernel.ProcessGroupID(pgid))
+	return uintptr(ret), err
+}
+
+func (tm *Terminal) tty(isMaster bool) *kernel.TTY {
+	if isMaster {
+		return tm.masterKTTY
+	}
+	return tm.slaveKTTY
+}
+
+// LINT.ThenChange(../../fs/tty/terminal.go)