test: respect P2PConfig fuzzing configuration in MultiplexTransport (c…

…ometbft#1414)

As part of porting the cosmos-sdk simulator to running on top of
its testutil/network runner, we need a way to simulate adversarial
network connections between validators. This change adds the
existing fuzzing configuration of P2PConfig to MConnConfig and uses it
to conditionally create an unreliable connection in MultiplexTransport.

Co-authored-by: Elias Naur <mail@eliasnaur.com>
Co-authored-by: Sergio Mena <sergio@informal.systems>

config/config.go

@@ -735,7 +735,7 @@ type P2PConfig struct { //nolint: maligned
 	// Testing params.
 	// Force dial to fail
 	TestDialFail bool `mapstructure:"test_dial_fail"`
-	// FUzz connection
+	// Fuzz connection
 	TestFuzz       bool            `mapstructure:"test_fuzz"`
 	TestFuzzConfig *FuzzConnConfig `mapstructure:"test_fuzz_config"`
 }

p2p/conn/connection.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/cosmos/gogoproto/proto"
 
+	"github.com/cometbft/cometbft/config"
 	flow "github.com/cometbft/cometbft/libs/flowrate"
 	"github.com/cometbft/cometbft/libs/log"
 	cmtmath "github.com/cometbft/cometbft/libs/math"
@@ -136,6 +137,10 @@ type MConnConfig struct {
 
 	// Maximum wait time for pongs
 	PongTimeout time.Duration `mapstructure:"pong_timeout"`
+
+	// Fuzz connection
+	TestFuzz       bool                   `mapstructure:"test_fuzz"`
+	TestFuzzConfig *config.FuzzConnConfig `mapstructure:"test_fuzz_config"`
 }
 
 // DefaultMConnConfig returns the default config.

p2p/switch.go

@@ -39,6 +39,8 @@ func MConnConfig(cfg *config.P2PConfig) conn.MConnConfig {
 	mConfig.SendRate = cfg.SendRate
 	mConfig.RecvRate = cfg.RecvRate
 	mConfig.MaxPacketMsgPayloadSize = cfg.MaxPacketMsgPayloadSize
+	mConfig.TestFuzz = cfg.TestFuzz
+	mConfig.TestFuzzConfig = cfg.TestFuzzConfig
 	return mConfig
 }
 

p2p/transport.go

@@ -218,6 +218,11 @@ func (mt *MultiplexTransport) Dial(
 		return nil, err
 	}
 
+	if mt.mConfig.TestFuzz {
+		// so we have time to do peer handshakes and get set up.
+		c = FuzzConnAfterFromConfig(c, 10*time.Second, mt.mConfig.TestFuzzConfig)
+	}
+
 	// TODO(xla): Evaluate if we should apply filters if we explicitly dial.
 	if err := mt.filterConn(c); err != nil {
 		return nil, err