From 460d206f309fc0884c666bd191a1b6a4b63462fc Mon Sep 17 00:00:00 2001 From: lash Date: Wed, 20 Feb 2019 14:46:00 +0100 Subject: [PATCH] swarm/network: Use actual remote peer ip in underlay (#19137) * swarm/network: Logline to see handshake addr * swarm/network: Replace remote ip in handshake uaddr * swarm/network: Add test for enode uaddr rewrite method * swarm/network: Remove redundance pointer return from sanitize * swarm/network: Obeying the linting machine * swarm/network: Add panic comment (travis trigger take 1) --- swarm/network/protocol.go | 21 ++++++++++++++++++++- swarm/network/protocol_test.go | 26 ++++++++++++++++++++++++++ 2 files changed, 46 insertions(+), 1 deletion(-) diff --git a/swarm/network/protocol.go b/swarm/network/protocol.go index 6f8eadad2a..ba2a7e5fa5 100644 --- a/swarm/network/protocol.go +++ b/swarm/network/protocol.go @@ -21,6 +21,7 @@ import ( "errors" "fmt" "net" + "regexp" "sync" "time" @@ -39,6 +40,8 @@ const ( bzzHandshakeTimeout = 3000 * time.Millisecond ) +var regexpEnodeIP = regexp.MustCompile("@(.+):([0-9]+)") + // BzzSpec is the spec of the generic swarm handshake var BzzSpec = &protocols.Spec{ Name: "bzz", @@ -214,10 +217,26 @@ func (b *Bzz) performHandshake(p *protocols.Peer, handshake *HandshakeMsg) error return err } handshake.peerAddr = rsh.(*HandshakeMsg).Addr + sanitizeEnodeRemote(p.RemoteAddr(), handshake.peerAddr) handshake.LightNode = rsh.(*HandshakeMsg).LightNode return nil } +// the remote enode string may advertise arbitrary host information (e.g. localhost) +// this method ensures that the addr of the peer will be the one +// applicable on the interface the connection came in on +// it modifies the passed bzzaddr in place, and returns the same pointer +func sanitizeEnodeRemote(paddr net.Addr, baddr *BzzAddr) { + hsSubmatch := regexpEnodeIP.FindSubmatch(baddr.UAddr) + ip, _, err := net.SplitHostPort(paddr.String()) + // since we expect nothing else than ipv4 here, a panic on missing submatch is desired + if err == nil && string(hsSubmatch[1]) != ip { + remoteStr := fmt.Sprintf("@%s:%s", ip, string(hsSubmatch[2])) + log.Debug("rewrote peer uaddr host/port", "addr", baddr) + baddr.UAddr = regexpEnodeIP.ReplaceAll(baddr.UAddr, []byte(remoteStr)) + } +} + // runBzz is the p2p protocol run function for the bzz base protocol // that negotiates the bzz handshake func (b *Bzz) runBzz(p *p2p.Peer, rw p2p.MsgReadWriter) error { @@ -324,7 +343,7 @@ func (b *Bzz) GetOrCreateHandshake(peerID enode.ID) (*HandshakeMsg, bool) { init: make(chan bool, 1), done: make(chan struct{}), } - // when handhsake is first created for a remote peer + // when handshake is first created for a remote peer // it is initialised with the init handshake.init <- true b.handshakes[peerID] = handshake diff --git a/swarm/network/protocol_test.go b/swarm/network/protocol_test.go index 64ce7ba4ab..97cb4b97ba 100644 --- a/swarm/network/protocol_test.go +++ b/swarm/network/protocol_test.go @@ -17,12 +17,15 @@ package network import ( + "bytes" "flag" "fmt" + "net" "os" "testing" "time" + "github.com/ethereum/go-ethereum/crypto" "github.com/ethereum/go-ethereum/log" "github.com/ethereum/go-ethereum/p2p" "github.com/ethereum/go-ethereum/p2p/enode" @@ -251,3 +254,26 @@ func TestBzzHandshakeLightNode(t *testing.T) { }) } } + +// Tests the overwriting of localhost enode in handshake if actual remote ip is known +// (swarm.network/protocol.go:sanitizeEnodeRemote) +func TestSanitizeEnodeRemote(t *testing.T) { + pk, err := crypto.GenerateKey() + if err != nil { + t.Fatal(err) + } + remoteIP := net.IPv4(0x80, 0x40, 0x20, 0x10) + remoteAddr := net.TCPAddr{ + IP: remoteIP, + Port: 30399, + } + nodLocal := enode.NewV4(&pk.PublicKey, net.IPv4(0x7f, 0x00, 0x00, 0x01), 30341, 30341) + nodRemote := enode.NewV4(&pk.PublicKey, remoteIP, 30341, 30341) + baddr := RandomAddr() + oldUAddr := []byte(nodLocal.String()) + baddr.UAddr = oldUAddr + sanitizeEnodeRemote(&remoteAddr, baddr) + if !bytes.Equal(baddr.UAddr, []byte(nodRemote.String())) { + t.Fatalf("insane address. expected %v, got %v", nodRemote.String(), string(baddr.UAddr)) + } +}