Reduce flakiness in tcp_test.

Tests now use a MinRTO of 3s instead of default 200ms. This reduced flakiness in
a lot of the congestion control/recovery tests which were flaky due to
retransmit timer firing too early in case the test executors were overloaded.

This change also bumps some of the timeouts in tests which were too sensitive to
timer variations and reduces the number of slow start iterations which can
make the tests run for too long and also trigger retansmit timeouts etc if
the executor is overloaded.

PiperOrigin-RevId: 306562645

1 files changed, 17 insertions, 0 deletions

diff --git a/pkg/tcpip/transport/tcp/protocol.go b/pkg/tcpip/transport/tcp/protocol.go
index dce9a1652..91f25c132 100644
--- a/pkg/tcpip/transport/tcp/protocol.go
+++ b/pkg/tcpip/transport/tcp/protocol.go
@@ -105,6 +105,7 @@ type protocol struct {
 	moderateReceiveBuffer      bool
 	tcpLingerTimeout           time.Duration
 	tcpTimeWaitTimeout         time.Duration
+	minRTO                     time.Duration
 	dispatcher                 *dispatcher
 }
 
@@ -272,6 +273,15 @@ func (p *protocol) SetOption(option interface{}) *tcpip.Error {
 		p.mu.Unlock()
 		return nil
 
+	case tcpip.TCPMinRTOOption:
+		if v < 0 {
+			v = tcpip.TCPMinRTOOption(MinRTO)
+		}
+		p.mu.Lock()
+		p.minRTO = time.Duration(v)
+		p.mu.Unlock()
+		return nil
+
 	default:
 		return tcpip.ErrUnknownProtocolOption
 	}
@@ -334,6 +344,12 @@ func (p *protocol) Option(option interface{}) *tcpip.Error {
 		p.mu.RUnlock()
 		return nil
 
+	case *tcpip.TCPMinRTOOption:
+		p.mu.RLock()
+		*v = tcpip.TCPMinRTOOption(p.minRTO)
+		p.mu.RUnlock()
+		return nil
+
 	default:
 		return tcpip.ErrUnknownProtocolOption
 	}
@@ -359,5 +375,6 @@ func NewProtocol() stack.TransportProtocol {
 		tcpLingerTimeout:           DefaultTCPLingerTimeout,
 		tcpTimeWaitTimeout:         DefaultTCPTimeWaitTimeout,
 		dispatcher:                 newDispatcher(runtime.GOMAXPROCS(0)),
+		minRTO:                     MinRTO,
 	}
 }