0️⃣ conn: permit nil sockaddr and zero value address

Author: database64128

conn/sockaddr_linuxsolaris.go

@@ -11,6 +11,9 @@ import (
 )
 
 func AddrPortToSockaddrValue(addrPort netip.AddrPort) (rsa6 unix.RawSockaddrInet6, namelen uint32) {
+	if !addrPort.IsValid() {
+		return
+	}
 	addr, port := addrPort.Addr(), addrPort.Port()
 	p := (*[2]byte)(unsafe.Pointer(&rsa6.Port))
 	p[0] = byte(port >> 8)

conn/sockaddr_notlinuxsolariswindows.go

@@ -11,6 +11,9 @@ import (
 )
 
 func AddrPortToSockaddrValue(addrPort netip.AddrPort) (rsa6 unix.RawSockaddrInet6, namelen uint32) {
+	if !addrPort.IsValid() {
+		return
+	}
 	addr, port := addrPort.Addr(), addrPort.Port()
 	p := (*[2]byte)(unsafe.Pointer(&rsa6.Port))
 	p[0] = byte(port >> 8)

conn/sockaddr_notwindows.go

@@ -12,6 +12,9 @@ import (
 )
 
 func SockaddrValueToAddrPort(rsa6 unix.RawSockaddrInet6, namelen uint32) (netip.AddrPort, error) {
+	if namelen == 0 {
+		return netip.AddrPort{}, nil
+	}
 	p := (*[2]byte)(unsafe.Pointer(&rsa6.Port))
 	port := uint16(p[0])<<8 + uint16(p[1])
 	var addr netip.Addr
@@ -27,33 +30,36 @@ func SockaddrValueToAddrPort(rsa6 unix.RawSockaddrInet6, namelen uint32) (netip.
 }
 
 func AddrPortToSockaddr(addrPort netip.AddrPort) (name *byte, namelen uint32) {
-	if addrPort.Addr().Is4() {
+	switch {
+	case !addrPort.IsValid():
+		return nil, 0
+	case addrPort.Addr().Is4():
 		rsa4 := AddrPortToSockaddrInet4(addrPort)
-		name = (*byte)(unsafe.Pointer(&rsa4))
-		namelen = unix.SizeofSockaddrInet4
-	} else {
+		return (*byte)(unsafe.Pointer(&rsa4)), unix.SizeofSockaddrInet4
+	default:
 		rsa6 := AddrPortToSockaddrInet6(addrPort)
-		name = (*byte)(unsafe.Pointer(&rsa6))
-		namelen = unix.SizeofSockaddrInet6
+		return (*byte)(unsafe.Pointer(&rsa6)), unix.SizeofSockaddrInet6
 	}
-	return
 }
 
 func AddrPortUnmappedToSockaddr(addrPort netip.AddrPort) (name *byte, namelen uint32) {
-	if addr := addrPort.Addr(); addr.Is4() || addr.Is4In6() {
+	switch {
+	case !addrPort.IsValid():
+		return nil, 0
+	case addrPort.Addr().Is4() || addrPort.Addr().Is4In6():
 		rsa4 := AddrPortToSockaddrInet4(addrPort)
-		name = (*byte)(unsafe.Pointer(&rsa4))
-		namelen = unix.SizeofSockaddrInet4
-	} else {
+		return (*byte)(unsafe.Pointer(&rsa4)), unix.SizeofSockaddrInet4
+	default:
 		rsa6 := AddrPortToSockaddrInet6(addrPort)
-		name = (*byte)(unsafe.Pointer(&rsa6))
-		namelen = unix.SizeofSockaddrInet6
+		return (*byte)(unsafe.Pointer(&rsa6)), unix.SizeofSockaddrInet6
 	}
-	return
 }
 
 func SockaddrToAddrPort(name *byte, namelen uint32) (netip.AddrPort, error) {
 	switch namelen {
+	case 0:
+		return netip.AddrPort{}, nil
+
 	case unix.SizeofSockaddrInet4:
 		rsa4 := (*unix.RawSockaddrInet4)(unsafe.Pointer(name))
 		return SockaddrInet4ToAddrPort(rsa4), nil

conn/sockaddr_windows.go

@@ -15,6 +15,9 @@ const (
 )
 
 func AddrPortToSockaddrValue(addrPort netip.AddrPort) (rsa6 windows.RawSockaddrInet6, namelen uint32) {
+	if !addrPort.IsValid() {
+		return
+	}
 	addr, port := addrPort.Addr(), addrPort.Port()
 	p := (*[2]byte)(unsafe.Pointer(&rsa6.Port))
 	p[0] = byte(port >> 8)
@@ -34,6 +37,9 @@ func AddrPortToSockaddrValue(addrPort netip.AddrPort) (rsa6 windows.RawSockaddrI
 }
 
 func SockaddrValueToAddrPort(rsa6 windows.RawSockaddrInet6, namelen uint32) (netip.AddrPort, error) {
+	if namelen == 0 {
+		return netip.AddrPort{}, nil
+	}
 	p := (*[2]byte)(unsafe.Pointer(&rsa6.Port))
 	port := uint16(p[0])<<8 + uint16(p[1])
 	var addr netip.Addr
@@ -49,29 +55,29 @@ func SockaddrValueToAddrPort(rsa6 windows.RawSockaddrInet6, namelen uint32) (net
 }
 
 func AddrPortToSockaddr(addrPort netip.AddrPort) (name *byte, namelen uint32) {
-	if addrPort.Addr().Is4() {
+	switch {
+	case !addrPort.IsValid():
+		return nil, 0
+	case addrPort.Addr().Is4():
 		rsa4 := AddrPortToSockaddrInet4(addrPort)
-		name = (*byte)(unsafe.Pointer(&rsa4))
-		namelen = SizeofSockaddrInet4
-	} else {
+		return (*byte)(unsafe.Pointer(&rsa4)), SizeofSockaddrInet4
+	default:
 		rsa6 := AddrPortToSockaddrInet6(addrPort)
-		name = (*byte)(unsafe.Pointer(&rsa6))
-		namelen = SizeofSockaddrInet6
+		return (*byte)(unsafe.Pointer(&rsa6)), SizeofSockaddrInet6
 	}
-	return
 }
 
 func AddrPortUnmappedToSockaddr(addrPort netip.AddrPort) (name *byte, namelen uint32) {
-	if addr := addrPort.Addr(); addr.Is4() || addr.Is4In6() {
+	switch {
+	case !addrPort.IsValid():
+		return nil, 0
+	case addrPort.Addr().Is4() || addrPort.Addr().Is4In6():
 		rsa4 := AddrPortToSockaddrInet4(addrPort)
-		name = (*byte)(unsafe.Pointer(&rsa4))
-		namelen = SizeofSockaddrInet4
-	} else {
+		return (*byte)(unsafe.Pointer(&rsa4)), SizeofSockaddrInet4
+	default:
 		rsa6 := AddrPortToSockaddrInet6(addrPort)
-		name = (*byte)(unsafe.Pointer(&rsa6))
-		namelen = SizeofSockaddrInet6
+		return (*byte)(unsafe.Pointer(&rsa6)), SizeofSockaddrInet6
 	}
-	return
 }
 
 func AddrPortToSockaddrInet4(addrPort netip.AddrPort) windows.RawSockaddrInet4 {
@@ -103,6 +109,9 @@ func AddrPortToSockaddrInet6(addrPort netip.AddrPort) windows.RawSockaddrInet6 {
 
 func SockaddrToAddrPort(name *byte, namelen uint32) (netip.AddrPort, error) {
 	switch namelen {
+	case 0:
+		return netip.AddrPort{}, nil
+
 	case SizeofSockaddrInet4:
 		rsa4 := (*windows.RawSockaddrInet4)(unsafe.Pointer(name))
 		return SockaddrInet4ToAddrPort(rsa4), nil