Merge release-20200804.0-27-g35312a95c (automated)

2 files changed, 29 insertions, 0 deletions

diff --git a/pkg/sentry/inet/inet.go b/pkg/sentry/inet/inet.go
index 2916a0644..c0b4831d1 100644
--- a/pkg/sentry/inet/inet.go
+++ b/pkg/sentry/inet/inet.go
@@ -56,6 +56,12 @@ type Stack interface {
 	// settings.
 	SetTCPSACKEnabled(enabled bool) error
 
+	// TCPRecovery returns the TCP loss detection algorithm.
+	TCPRecovery() (TCPLossRecovery, error)
+
+	// SetTCPRecovery attempts to change TCP loss detection algorithm.
+	SetTCPRecovery(recovery TCPLossRecovery) error
+
 	// Statistics reports stack statistics.
 	Statistics(stat interface{}, arg string) error
 
@@ -189,3 +195,14 @@ type StatSNMPUDP [8]uint64
 
 // StatSNMPUDPLite describes UdpLite line of /proc/net/snmp.
 type StatSNMPUDPLite [8]uint64
+
+// TCPLossRecovery indicates TCP loss detection and recovery methods to use.
+type TCPLossRecovery int32
+
+// Loss recovery constants from include/net/tcp.h which are used to set
+// /proc/sys/net/ipv4/tcp_recovery.
+const (
+	TCP_RACK_LOSS_DETECTION TCPLossRecovery = 1 << iota
+	TCP_RACK_STATIC_REO_WND
+	TCP_RACK_NO_DUPTHRESH
+)
diff --git a/pkg/sentry/inet/test_stack.go b/pkg/sentry/inet/test_stack.go
index d8961fc94..9771f01fc 100644
--- a/pkg/sentry/inet/test_stack.go
+++ b/pkg/sentry/inet/test_stack.go
@@ -25,6 +25,7 @@ type TestStack struct {
 	TCPRecvBufSize    TCPBufferSize
 	TCPSendBufSize    TCPBufferSize
 	TCPSACKFlag       bool
+	Recovery          TCPLossRecovery
 }
 
 // NewTestStack returns a TestStack with no network interfaces. The value of
@@ -91,6 +92,17 @@ func (s *TestStack) SetTCPSACKEnabled(enabled bool) error {
 	return nil
 }
 
+// TCPRecovery implements Stack.TCPRecovery.
+func (s *TestStack) TCPRecovery() (TCPLossRecovery, error) {
+	return s.Recovery, nil
+}
+
+// SetTCPRecovery implements Stack.SetTCPRecovery.
+func (s *TestStack) SetTCPRecovery(recovery TCPLossRecovery) error {
+	s.Recovery = recovery
+	return nil
+}
+
 // Statistics implements inet.Stack.Statistics.
 func (s *TestStack) Statistics(stat interface{}, arg string) error {
 	return nil