test: disable NAT port mapping, outbound dials, inbound connections

My poor network. It deserves to be treated with respect and dignity and
doesn't deserve to be spammed.

1. Disable NAT port mapping. Because no, we don't want our integration
tests nodes to be reachable.
2. Disable all but a single localhost/quic transport. No need to do more
work than necessary.
3. Set the connection manager limits to be really high. This probably
doesn't matter, but there's no need to be killing connections in our
integration tests.
4. Reject all outbound dials to non-localhost addresses.

itests/kit/ensemble.go

@@ -16,8 +16,10 @@ import (
 	"github.com/google/uuid"
 	"github.com/ipfs/go-datastore"
 	"github.com/ipfs/go-datastore/namespace"
+	"github.com/libp2p/go-libp2p"
 	libp2pcrypto "github.com/libp2p/go-libp2p/core/crypto"
 	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/libp2p/go-libp2p/p2p/net/conngater"
 	mocknet "github.com/libp2p/go-libp2p/p2p/net/mock"
 	"github.com/stretchr/testify/require"
 
@@ -57,6 +59,7 @@ import (
 	"github.com/filecoin-project/lotus/node/config"
 	"github.com/filecoin-project/lotus/node/modules"
 	"github.com/filecoin-project/lotus/node/modules/dtypes"
+	"github.com/filecoin-project/lotus/node/modules/lp2p"
 	testing2 "github.com/filecoin-project/lotus/node/modules/testing"
 	"github.com/filecoin-project/lotus/node/repo"
 	"github.com/filecoin-project/lotus/storage/paths"
@@ -438,6 +441,13 @@ func (n *Ensemble) Start() *Ensemble {
 			node.If(full.options.disableLibp2p, node.MockHost(n.mn)),
 			node.Test(),
 
+			// If we're using real libp2p, disable outbound connections to all but localhost.
+			node.If(!full.options.disableLibp2p,
+				node.Override(node.ConnGaterKey, func(gater *conngater.BasicConnectionGater) (opts lp2p.Libp2pOpts, err error) {
+					opts.Opts = append(opts.Opts, libp2p.ConnectionGater(&loopbackConnGater{gater}))
+					return
+				})),
+
 			// so that we subscribe to pubsub topics immediately
 			node.Override(new(dtypes.Bootstrapper), dtypes.Bootstrapper(true)),
 
@@ -707,6 +717,7 @@ func (n *Ensemble) Start() *Ensemble {
 			node.Repo(r),
 			node.Test(),
 
+			node.Override(node.DefaultTransportsKey, lp2p.QUIC),
 			node.If(m.options.disableLibp2p, node.MockHost(n.mn)),
 			node.Override(new(v1api.RawFullNodeAPI), m.FullNode),
 			node.Override(new(*lotusminer.Miner), lotusminer.NewTestMiner(mineBlock, m.ActorAddr)),

itests/kit/node_opts.go

@@ -2,6 +2,12 @@ package kit
 
 import (
 	"math"
+	"time"
+
+	"github.com/libp2p/go-libp2p/core/connmgr"
+	"github.com/libp2p/go-libp2p/core/peer"
+	multiaddr "github.com/multiformats/go-multiaddr"
+	manet "github.com/multiformats/go-multiaddr/net"
 
 	"github.com/filecoin-project/go-f3/manifest"
 	"github.com/filecoin-project/go-state-types/abi"
@@ -56,6 +62,23 @@ type nodeOpts struct {
 	workerName       string
 }
 
+// Libp2p connection gater that only allows outbound connections to loopback addresses.
+type loopbackConnGater struct{ connmgr.ConnectionGater }
+
+// InterceptAddrDial implements connmgr.ConnectionGater.
+func (l *loopbackConnGater) InterceptAddrDial(p peer.ID, a multiaddr.Multiaddr) (allow bool) {
+	if !l.ConnectionGater.InterceptAddrDial(p, a) {
+		return false
+	}
+	ip, err := manet.ToIP(a)
+	if err != nil {
+		return false
+	}
+	return ip.IsLoopback()
+}
+
+var _ connmgr.ConnectionGater = (*loopbackConnGater)(nil)
+
 // DefaultNodeOpts are the default options that will be applied to test nodes.
 var DefaultNodeOpts = nodeOpts{
 	balance:    big.Mul(big.NewInt(100000000), types.NewInt(buildconstants.FilecoinPrecision)),
@@ -69,6 +92,17 @@ var DefaultNodeOpts = nodeOpts{
 			cfg.Fevm.EnableEthRPC = true
 			cfg.Events.MaxFilterHeightRange = math.MaxInt64
 			cfg.Events.EnableActorEventsAPI = true
+
+			// Disable external networking ffs.
+			cfg.Libp2p.ListenAddresses = []string{
+				"/ip4/127.0.0.1/udp/0/quic-v1",
+			}
+			cfg.Libp2p.DisableNatPortMap = true
+
+			// Nerf the connection manager.
+			cfg.Libp2p.ConnMgrLow = 1024
+			cfg.Libp2p.ConnMgrHigh = 2048
+			cfg.Libp2p.ConnMgrGrace = config.Duration(time.Hour)
 			return nil
 		},
 	},