use a netip.Addr instead of a net.IP in the packetInfo struct

Author: marten-seemann

send_conn.go

@@ -60,7 +60,7 @@ func (c *sconn) LocalAddr() net.Addr {
 	if c.info != nil {
 		if udpAddr, ok := addr.(*net.UDPAddr); ok {
 			addrCopy := *udpAddr
-			addrCopy.IP = c.info.addr
+			addrCopy.IP = c.info.addr.AsSlice()
 			addr = &addrCopy
 		}
 	}

sys_conn_no_oob.go

@@ -2,7 +2,10 @@
 
 package quic
 
-import "net"
+import (
+	"net"
+	"net/netip"
+)
 
 func newConn(c net.PacketConn, supportsDF bool) (*basicConn, error) {
 	return &basicConn{PacketConn: c, supportsDF: supportsDF}, nil
@@ -12,7 +15,7 @@ func inspectReadBuffer(any) (int, error)  { return 0, nil }
 func inspectWriteBuffer(any) (int, error) { return 0, nil }
 
 type packetInfo struct {
-	addr net.IP
+	addr netip.Addr
 }
 
 func (i *packetInfo) OOB() []byte { return nil }

sys_conn_oob.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"net/netip"
 	"syscall"
 	"time"
 
@@ -173,8 +174,7 @@ func (c *oobConn) ReadPacket() (receivedPacket, error) {
 
 	data := msg.OOB[:msg.NN]
 	var ecn protocol.ECN
-	var destIP net.IP
-	var ifIndex uint32
+	var info *packetInfo
 	for len(data) > 0 {
 		hdr, body, remainder, err := unix.ParseOneSocketControlMessage(data)
 		if err != nil {
@@ -191,15 +191,16 @@ func (c *oobConn) ReadPacket() (receivedPacket, error) {
 				// 	struct in_addr ipi_addr;     /* Header Destination
 				// 									address */
 				// };
-				ip := make([]byte, 4)
+				info = &packetInfo{}
+				var ip [4]byte
 				if len(body) == 12 {
-					ifIndex = binary.LittleEndian.Uint32(body)
-					copy(ip, body[8:12])
+					copy(ip[:], body[8:12])
+					info.ifIndex = binary.LittleEndian.Uint32(body)
 				} else if len(body) == 4 {
 					// FreeBSD
-					copy(ip, body)
+					copy(ip[:], body)
 				}
-				destIP = net.IP(ip)
+				info.addr = netip.AddrFrom4(ip)
 			}
 		}
 		if hdr.Level == unix.IPPROTO_IPV6 {
@@ -212,22 +213,17 @@ func (c *oobConn) ReadPacket() (receivedPacket, error) {
 				// 	unsigned int    ipi6_ifindex; /* send/recv interface index */
 				// };
 				if len(body) == 20 {
-					ip := make([]byte, 16)
-					copy(ip, body[:16])
-					destIP = net.IP(ip)
-					ifIndex = binary.LittleEndian.Uint32(body[16:])
+					var ip [16]byte
+					copy(ip[:], body[:16])
+					info = &packetInfo{
+						addr:    netip.AddrFrom16(ip),
+						ifIndex: binary.LittleEndian.Uint32(body[16:]),
+					}
 				}
 			}
 		}
 		data = remainder
 	}
-	var info *packetInfo
-	if destIP != nil {
-		info = &packetInfo{
-			addr:    destIP,
-			ifIndex: ifIndex,
-		}
-	}
 	return receivedPacket{
 		remoteAddr: msg.Addr,
 		rcvTime:    time.Now(),
@@ -265,32 +261,34 @@ func (c *oobConn) capabilities() connCapabilities {
 }
 
 type packetInfo struct {
-	addr    net.IP
+	addr    netip.Addr
 	ifIndex uint32
 }
 
 func (info *packetInfo) OOB() []byte {
 	if info == nil {
 		return nil
 	}
-	if ip4 := info.addr.To4(); ip4 != nil {
+	if info.addr.Is4() {
+		ip := info.addr.As4()
 		// struct in_pktinfo {
 		// 	unsigned int   ipi_ifindex;  /* Interface index */
 		// 	struct in_addr ipi_spec_dst; /* Local address */
 		// 	struct in_addr ipi_addr;     /* Header Destination address */
 		// };
 		cm := ipv4.ControlMessage{
-			Src:     ip4,
+			Src:     ip[:],
 			IfIndex: int(info.ifIndex),
 		}
 		return cm.Marshal()
-	} else if len(info.addr) == 16 {
+	} else if info.addr.Is6() {
+		ip := info.addr.As16()
 		// struct in6_pktinfo {
 		// 	struct in6_addr ipi6_addr;    /* src/dst IPv6 address */
 		// 	unsigned int    ipi6_ifindex; /* send/recv interface index */
 		// };
 		cm := ipv6.ControlMessage{
-			Src:     info.addr,
+			Src:     ip[:],
 			IfIndex: int(info.ifIndex),
 		}
 		return cm.Marshal()

sys_conn_oob_test.go

@@ -155,7 +155,7 @@ var _ = Describe("OOB Conn Test", func() {
 			Expect(p.data).To(Equal([]byte("foobar")))
 			Expect(p.remoteAddr).To(Equal(sentFrom))
 			Expect(p.info).To(Not(BeNil()))
-			Expect(p.info.addr.To4()).To(Equal(ip))
+			Expect(net.IP(p.info.addr.AsSlice())).To(Equal(ip))
 		})
 
 		It("reads packet info on IPv6", func() {
@@ -173,7 +173,7 @@ var _ = Describe("OOB Conn Test", func() {
 			Expect(p.data).To(Equal([]byte("foobar")))
 			Expect(p.remoteAddr).To(Equal(sentFrom))
 			Expect(p.info).To(Not(BeNil()))
-			Expect(p.info.addr).To(Equal(ip))
+			Expect(net.IP(p.info.addr.AsSlice())).To(Equal(ip))
 		})
 
 		It("reads packet info on a connection that supports both IPv4 and IPv6", func() {
@@ -182,14 +182,16 @@ var _ = Describe("OOB Conn Test", func() {
 			port := conn.LocalAddr().(*net.UDPAddr).Port
 
 			// IPv4
-			ip4 := net.ParseIP("127.0.0.1").To4()
+			ip4 := net.ParseIP("127.0.0.1")
 			sendPacket("udp4", &net.UDPAddr{IP: ip4, Port: port})
 
 			var p receivedPacket
 			Eventually(packetChan).Should(Receive(&p))
 			Expect(utils.IsIPv4(p.remoteAddr.(*net.UDPAddr).IP)).To(BeTrue())
 			Expect(p.info).To(Not(BeNil()))
-			Expect(p.info.addr.To4()).To(Equal(ip4))
+			Expect(p.info.addr.Is4In6() || p.info.addr.Is4()).To(BeTrue())
+			ip := p.info.addr.As4()
+			Expect(net.IP(ip[:])).To(Equal(ip4.To4()))
 
 			// IPv6
 			ip6 := net.ParseIP("::1")
@@ -198,7 +200,7 @@ var _ = Describe("OOB Conn Test", func() {
 			Eventually(packetChan).Should(Receive(&p))
 			Expect(utils.IsIPv4(p.remoteAddr.(*net.UDPAddr).IP)).To(BeFalse())
 			Expect(p.info).To(Not(BeNil()))
-			Expect(p.info.addr).To(Equal(ip6))
+			Expect(net.IP(p.info.addr.AsSlice())).To(Equal(ip6))
 		})
 	})
 

sys_conn_windows.go

@@ -3,7 +3,7 @@
 package quic
 
 import (
-	"net"
+	"net/netip"
 	"syscall"
 
 	"golang.org/x/sys/windows"
@@ -36,7 +36,7 @@ func inspectWriteBuffer(c syscall.RawConn) (int, error) {
 }
 
 type packetInfo struct {
-	addr net.IP
+	addr netip.Addr
 }
 
 func (i *packetInfo) OOB() []byte { return nil }