Use netip.AddrPort in PEX code and filter unusable addrs much sooner

netip-addrport.go

@@ -43,3 +43,10 @@ func addrPortFromPeerRemoteAddr(pra PeerRemoteAddr) (netip.AddrPort, error) {
 		return netip.ParseAddrPort(pra.String())
 	}
 }
+
+func krpcNodeAddrFromAddrPort(addrPort netip.AddrPort) krpc.NodeAddr {
+	return krpc.NodeAddr{
+		IP:   addrPort.Addr().AsSlice(),
+		Port: int(addrPort.Port()),
+	}
+}

peerconn.go

@@ -1072,10 +1072,15 @@ func (c *PeerConn) dialAddr() PeerRemoteAddr {
 	return netip.AddrPortFrom(addrPort.Addr(), uint16(c.PeerListenPort))
 }
 
-func (c *PeerConn) pexEvent(t pexEventType) pexEvent {
+func (c *PeerConn) pexEvent(t pexEventType) (_ pexEvent, err error) {
 	f := c.pexPeerFlags()
-	addr := c.dialAddr()
+	dialAddr := c.dialAddr()
-	return pexEvent{t, addr, f, nil}
+	addr, err := addrPortFromPeerRemoteAddr(dialAddr)
+	if err != nil || !addr.IsValid() {
+		err = fmt.Errorf("parsing dial addr %q: %w", dialAddr, err)
+		return
+	}
+	return pexEvent{t, addr, f, nil}, nil
 }
 
 func (c *PeerConn) String() string {

peerconn_test.go

@@ -181,6 +181,7 @@ func TestConnPexPeerFlags(t *testing.T) {
 }
 
 func TestConnPexEvent(t *testing.T) {
+	c := qt.New(t)
 	var (
 		udpAddr     = &net.UDPAddr{IP: net.IPv6loopback, Port: 4848}
 		tcpAddr     = &net.TCPAddr{IP: net.IPv6loopback, Port: 4848}
@@ -195,27 +196,39 @@ func TestConnPexEvent(t *testing.T) {
 		{
 			pexAdd,
 			&PeerConn{Peer: Peer{RemoteAddr: udpAddr, Network: udpAddr.Network()}},
-			pexEvent{pexAdd, udpAddr, pp.PexSupportsUtp, nil},
+			pexEvent{pexAdd, udpAddr.AddrPort(), pp.PexSupportsUtp, nil},
 		},
 		{
 			pexDrop,
-			&PeerConn{Peer: Peer{RemoteAddr: tcpAddr, Network: tcpAddr.Network(), outgoing: true}, PeerListenPort: dialTcpAddr.Port},
+			&PeerConn{
-			pexEvent{pexDrop, tcpAddr, pp.PexOutgoingConn, nil},
+				Peer:           Peer{RemoteAddr: tcpAddr, Network: tcpAddr.Network(), outgoing: true},
+				PeerListenPort: dialTcpAddr.Port,
+			},
+			pexEvent{pexDrop, tcpAddr.AddrPort(), pp.PexOutgoingConn, nil},
 		},
 		{
 			pexAdd,
-			&PeerConn{Peer: Peer{RemoteAddr: tcpAddr, Network: tcpAddr.Network()}, PeerListenPort: dialTcpAddr.Port},
+			&PeerConn{
-			pexEvent{pexAdd, dialTcpAddr, 0, nil},
+				Peer:           Peer{RemoteAddr: tcpAddr, Network: tcpAddr.Network()},
+				PeerListenPort: dialTcpAddr.Port,
+			},
+			pexEvent{pexAdd, dialTcpAddr.AddrPort(), 0, nil},
 		},
 		{
 			pexDrop,
-			&PeerConn{Peer: Peer{RemoteAddr: udpAddr, Network: udpAddr.Network()}, PeerListenPort: dialUdpAddr.Port},
+			&PeerConn{
-			pexEvent{pexDrop, dialUdpAddr, pp.PexSupportsUtp, nil},
+				Peer:           Peer{RemoteAddr: udpAddr, Network: udpAddr.Network()},
+				PeerListenPort: dialUdpAddr.Port,
+			},
+			pexEvent{pexDrop, dialUdpAddr.AddrPort(), pp.PexSupportsUtp, nil},
 		},
 	}
 	for i, tc := range testcases {
-		e := tc.c.pexEvent(tc.t)
+		c.Run(fmt.Sprintf("%v", i), func(c *qt.C) {
-		require.EqualValues(t, tc.e, e, i)
+			e, err := tc.c.pexEvent(tc.t)
+			c.Assert(err, qt.IsNil)
+			c.Check(e, qt.Equals, tc.e)
+		})
 	}
 }
 

pex.go

@@ -2,10 +2,9 @@ package torrent
 
 import (
 	"net"
+	"net/netip"
 	"sync"
 
-	"github.com/anacrolix/dht/v2/krpc"
-
 	pp "github.com/anacrolix/torrent/peer_protocol"
 )
 
@@ -26,7 +25,7 @@ const (
 // represents a single connection (t=pexAdd) or disconnection (t=pexDrop) event
 type pexEvent struct {
 	t    pexEventType
-	addr PeerRemoteAddr
+	addr netip.AddrPort
 	f    pp.PexPeerFlags
 	next *pexEvent // event feed list
 }
@@ -34,8 +33,8 @@ type pexEvent struct {
 // facilitates efficient de-duplication while generating PEX messages
 type pexMsgFactory struct {
 	msg     pp.PexMsg
-	added   map[addrKey]struct{}
+	added   map[netip.AddrPort]struct{}
-	dropped map[addrKey]struct{}
+	dropped map[netip.AddrPort]struct{}
 }
 
 func (me *pexMsgFactory) DeltaLen() int {
@@ -44,11 +43,11 @@ func (me *pexMsgFactory) DeltaLen() int {
 		int64(len(me.dropped))))
 }
 
-type addrKey string
+type addrKey = netip.AddrPort
 
 // Returns the key to use to identify a given addr in the factory.
-func (me *pexMsgFactory) addrKey(addr PeerRemoteAddr) addrKey {
+func (me *pexMsgFactory) addrKey(addr netip.AddrPort) addrKey {
-	return addrKey(addr.String())
+	return addr
 }
 
 // Returns whether the entry was added (we can check if we're cancelling out another entry and so
@@ -61,10 +60,7 @@ func (me *pexMsgFactory) add(e pexEvent) {
 	if me.added == nil {
 		me.added = make(map[addrKey]struct{}, pexMaxDelta)
 	}
-	addr, ok := nodeAddr(e.addr)
+	addr := krpcNodeAddrFromAddrPort(e.addr)
-	if !ok {
-		return
-	}
 	m := &me.msg
 	switch {
 	case addr.IP.To4() != nil:
@@ -96,10 +92,7 @@ func (me *pexMsgFactory) add(e pexEvent) {
 // Returns whether the entry was added (we can check if we're cancelling out another entry and so
 // won't hit the limit consuming this event).
 func (me *pexMsgFactory) drop(e pexEvent) {
-	addr, ok := nodeAddr(e.addr)
+	addr := krpcNodeAddrFromAddrPort(e.addr)
-	if !ok {
-		return
-	}
 	key := me.addrKey(e.addr)
 	if me.dropped == nil {
 		me.dropped = make(map[addrKey]struct{}, pexMaxDelta)
@@ -148,14 +141,6 @@ func (me *pexMsgFactory) PexMsg() *pp.PexMsg {
 	return &me.msg
 }
 
-// Convert an arbitrary torrent peer Addr into one that can be represented by the compact addr
-// format.
-func nodeAddr(addr PeerRemoteAddr) (krpc.NodeAddr, bool) {
-	ipport, _ := tryIpPortFromNetAddr(addr)
-	ok := ipport.IP != nil
-	return krpc.NodeAddr{IP: ipport.IP, Port: ipport.Port}, ok
-}
-
 // Per-torrent PEX state
 type pexState struct {
 	sync.RWMutex
@@ -184,6 +169,10 @@ func (s *pexState) append(e *pexEvent) {
 }
 
 func (s *pexState) Add(c *PeerConn) {
+	e, err := c.pexEvent(pexAdd)
+	if err != nil {
+		return
+	}
 	s.Lock()
 	defer s.Unlock()
 	s.nc++
@@ -194,7 +183,6 @@ func (s *pexState) Add(c *PeerConn) {
 		}
 		s.hold = s.hold[:0]
 	}
-	e := c.pexEvent(pexAdd)
 	c.pex.Listed = true
 	s.append(&e)
 }
@@ -204,9 +192,12 @@ func (s *pexState) Drop(c *PeerConn) {
 		// skip connections which were not previously Added
 		return
 	}
+	e, err := c.pexEvent(pexDrop)
+	if err != nil {
+		return
+	}
 	s.Lock()
 	defer s.Unlock()
-	e := c.pexEvent(pexDrop)
 	s.nc--
 	if s.nc < pexTargAdded && len(s.hold) < pexMaxHold {
 		s.hold = append(s.hold, e)

pex_test.go

@@ -47,12 +47,12 @@ func TestPexReset(t *testing.T) {
 	require.EqualValues(t, targ, s)
 }
 
-func mustNodeAddr(addr net.Addr) krpc.NodeAddr {
+func krpcNodeAddrFromNetAddr(addr net.Addr) krpc.NodeAddr {
-	ret, ok := nodeAddr(addr)
+	addrPort, err := addrPortFromPeerRemoteAddr(addr)
-	if !ok {
+	if err != nil {
-		panic(addr)
+		panic(err)
 	}
-	return ret
+	return krpcNodeAddrFromAddrPort(addrPort)
 }
 
 var testcases = []struct {
@@ -99,13 +99,13 @@ var testcases = []struct {
 		}(),
 		targ: pp.PexMsg{
 			Added: krpc.CompactIPv4NodeAddrs{
-				mustNodeAddr(addrs[2]),
+				krpcNodeAddrFromNetAddr(addrs[2]),
-				mustNodeAddr(addrs[3]),
+				krpcNodeAddrFromNetAddr(addrs[3]),
 			},
 			AddedFlags: []pp.PexPeerFlags{pp.PexOutgoingConn, 0},
 			Added6: krpc.CompactIPv6NodeAddrs{
-				mustNodeAddr(addrs[0]),
+				krpcNodeAddrFromNetAddr(addrs[0]),
-				mustNodeAddr(addrs[1]),
+				krpcNodeAddrFromNetAddr(addrs[1]),
 			},
 			Added6Flags: []pp.PexPeerFlags{0, pp.PexOutgoingConn},
 		},
@@ -120,10 +120,10 @@ var testcases = []struct {
 		}(),
 		targ: pp.PexMsg{
 			Dropped: krpc.CompactIPv4NodeAddrs{
-				mustNodeAddr(addrs[2]),
+				krpcNodeAddrFromNetAddr(addrs[2]),
 			},
 			Dropped6: krpc.CompactIPv6NodeAddrs{
-				mustNodeAddr(addrs[0]),
+				krpcNodeAddrFromNetAddr(addrs[0]),
 			},
 		},
 	},
@@ -144,7 +144,7 @@ var testcases = []struct {
 		}(),
 		targ: pp.PexMsg{
 			Added6: krpc.CompactIPv6NodeAddrs{
-				mustNodeAddr(addrs[1]),
+				krpcNodeAddrFromNetAddr(addrs[1]),
 			},
 			Added6Flags: []pp.PexPeerFlags{0},
 		},
@@ -168,12 +168,12 @@ var testcases = []struct {
 		}(),
 		targ: pp.PexMsg{
 			Added: krpc.CompactIPv4NodeAddrs{
-				mustNodeAddr(addrs[2]),
+				krpcNodeAddrFromNetAddr(addrs[2]),
 			},
 			AddedFlags: []pp.PexPeerFlags{0},
 			Added6: krpc.CompactIPv6NodeAddrs{
-				mustNodeAddr(addrs[0]),
+				krpcNodeAddrFromNetAddr(addrs[0]),
-				mustNodeAddr(addrs[1]),
+				krpcNodeAddrFromNetAddr(addrs[1]),
 			},
 			Added6Flags: []pp.PexPeerFlags{0, 0},
 		},
@@ -193,7 +193,7 @@ var testcases = []struct {
 		}(),
 		targ: pp.PexMsg{
 			Added6: krpc.CompactIPv6NodeAddrs{
-				mustNodeAddr(addrs[1]),
+				krpcNodeAddrFromNetAddr(addrs[1]),
 			},
 			Added6Flags: []pp.PexPeerFlags{0},
 		},
@@ -207,7 +207,7 @@ var testcases = []struct {
 		}(),
 		targ: pp.PexMsg{
 			Added6: krpc.CompactIPv6NodeAddrs{
-				mustNodeAddr(addrs[0]),
+				krpcNodeAddrFromNetAddr(addrs[0]),
 			},
 			Added6Flags: []pp.PexPeerFlags{0},
 		},
@@ -216,7 +216,7 @@ var testcases = []struct {
 		},
 		targ1: pp.PexMsg{
 			Added6: krpc.CompactIPv6NodeAddrs{
-				mustNodeAddr(addrs[1]),
+				krpcNodeAddrFromNetAddr(addrs[1]),
 			},
 			Added6Flags: []pp.PexPeerFlags{0},
 		},

pexconn_test.go

@@ -53,7 +53,7 @@ func TestPexConnState(t *testing.T) {
 		Added:      krpc.CompactIPv4NodeAddrs(nil),
 		AddedFlags: []pp.PexPeerFlags{},
 		Added6: krpc.CompactIPv6NodeAddrs{
-			mustNodeAddr(addr),
+			krpcNodeAddrFromNetAddr(addr),
 		},
 		Added6Flags: []pp.PexPeerFlags{0},
 	}