Merge pull request #8562 from 42wim:signals

PiperOrigin-RevId: 511907546

pkg/sentry/fsimpl/devpts/line_discipline.go

@@ -111,6 +111,9 @@ type lineDiscipline struct {
 
 	// replicaWaiter is used to wait on the replica end of the TTY.
 	replicaWaiter waiter.Queue
+
+	// terminal is the terminal linked to this lineDiscipline.
+	terminal *Terminal
 }
 
 func newLineDiscipline(termios linux.KernelTermios) *lineDiscipline {
@@ -393,6 +396,12 @@ func (*inputQueueTransformer) transform(l *lineDiscipline, q *queue, buf []byte)
 			if l.termios.IEnabled(linux.INLCR) {
 				cBytes[0] = '\r'
 			}
+		case l.termios.ControlCharacters[linux.VINTR]: // ctrl-c
+			l.terminal.fgProcessGroup.SendSignal(kernel.SignalInfoPriv(linux.SIGINT))
+		case l.termios.ControlCharacters[linux.VSUSP]: // ctrl-z
+			l.terminal.fgProcessGroup.SendSignal(kernel.SignalInfoPriv(linux.SIGTSTP))
+		case l.termios.ControlCharacters[linux.VQUIT]: // ctrl-\
+			l.terminal.fgProcessGroup.SendSignal(kernel.SignalInfoPriv(linux.SIGQUIT))
 		}
 
 		// In canonical mode, we discard non-terminating characters

pkg/sentry/fsimpl/devpts/terminal.go

@@ -39,6 +39,10 @@ type Terminal struct {
 	// replicaKTTY contains the controlling process of the replica end of this
 	// terminal. This field is immutable.
 	replicaKTTY *kernel.TTY
+
+	// fgProcessGroup is the foreground process group that is currently
+	// connected to this TTY.
+	fgProcessGroup *kernel.ProcessGroup
 }
 
 func newTerminal(n uint32) *Terminal {
@@ -49,6 +53,9 @@ func newTerminal(n uint32) *Terminal {
 		masterKTTY:  &kernel.TTY{Index: n},
 		replicaKTTY: &kernel.TTY{Index: n},
 	}
+
+	t.ld.terminal = &t
+
 	return &t
 }
 
@@ -106,6 +113,9 @@ func (tm *Terminal) setForegroundProcessGroup(ctx context.Context, args arch.Sys
 	}
 
 	ret, err := task.ThreadGroup().SetForegroundProcessGroup(tm.tty(isMaster), kernel.ProcessGroupID(pgid))
+	if err == nil {
+		tm.fgProcessGroup = task.PIDNamespace().ProcessGroupWithID(kernel.ProcessGroupID(pgid))
+	}
 	return uintptr(ret), err
 }