Added new UDPBind interface

1 files changed, 176 insertions, 95 deletions

diff --git a/src/conn_linux.go b/src/conn_linux.go
index 034fb8b..8942b03 100644
--- a/src/conn_linux.go
+++ b/src/conn_linux.go
@@ -14,35 +14,158 @@ import (
 	"unsafe"
 )
 
-import "fmt"
-
 /* Supports source address caching
  *
  * Currently there is no way to achieve this within the net package:
  * See e.g. https://github.com/golang/go/issues/17930
- * So this code is platform dependent.
- *
- * It is important that the endpoint is only updated after the packet content has been authenticated!
+ * So this code is remains platform dependent.
  */
 
 type Endpoint struct {
-	// source (selected based on dst type)
-	// (could use RawSockaddrAny and unsafe)
-	// TODO: Merge
-	src6   unix.RawSockaddrInet6
-	src4   unix.RawSockaddrInet4
-	src4if int32
-
-	dst unix.RawSockaddrAny
+	src unix.RawSockaddrInet6
+	dst unix.RawSockaddrInet6
+}
+
+type IPv4Source struct {
+	src     unix.RawSockaddrInet4
+	Ifindex int32
 }
 
-type Socket int
+type Bind struct {
+	sock4 int
+	sock6 int
+}
 
-/* Returns a byte representation of the source field(s)
- * for use in "under load" cookie computations.
- */
-func (endpoint *Endpoint) Source() []byte {
-	return nil
+func CreateUDPBind(port uint16) (UDPBind, uint16, error) {
+	var err error
+	var bind Bind
+
+	bind.sock6, port, err = create6(port)
+	if err != nil {
+		return nil, port, err
+	}
+
+	bind.sock4, port, err = create4(port)
+	if err != nil {
+		unix.Close(bind.sock6)
+	}
+	return &bind, port, err
+}
+
+func (bind *Bind) SetMark(value uint32) error {
+	err := unix.SetsockoptInt(
+		bind.sock6,
+		unix.SOL_SOCKET,
+		unix.SO_MARK,
+		int(value),
+	)
+
+	if err != nil {
+		return err
+	}
+
+	return unix.SetsockoptInt(
+		bind.sock4,
+		unix.SOL_SOCKET,
+		unix.SO_MARK,
+		int(value),
+	)
+}
+
+func (bind *Bind) Close() error {
+	err1 := unix.Close(bind.sock6)
+	err2 := unix.Close(bind.sock4)
+	if err1 != nil {
+		return err1
+	}
+	return err2
+}
+
+func (bind *Bind) ReceiveIPv6(buff []byte, end *Endpoint) (int, error) {
+	return receive6(
+		bind.sock6,
+		buff,
+		end,
+	)
+}
+
+func (bind *Bind) ReceiveIPv4(buff []byte, end *Endpoint) (int, error) {
+	return receive4(
+		bind.sock4,
+		buff,
+		end,
+	)
+}
+
+func (bind *Bind) Send(buff []byte, end *Endpoint) error {
+	switch end.src.Family {
+	case unix.AF_INET6:
+		return send6(bind.sock6, end, buff)
+	case unix.AF_INET:
+		return send4(bind.sock4, end, buff)
+	default:
+		return errors.New("Unknown address family of source")
+	}
+}
+
+func sockaddrToString(addr unix.RawSockaddrInet6) string {
+	var udpAddr net.UDPAddr
+
+	switch addr.Family {
+	case unix.AF_INET6:
+		udpAddr.Port = int(addr.Port)
+		udpAddr.IP = addr.Addr[:]
+		return udpAddr.String()
+
+	case unix.AF_INET:
+		ptr := (*unix.RawSockaddrInet4)(unsafe.Pointer(&addr))
+		udpAddr.Port = int(ptr.Port)
+		udpAddr.IP = net.IPv4(
+			ptr.Addr[0],
+			ptr.Addr[1],
+			ptr.Addr[2],
+			ptr.Addr[3],
+		)
+		return udpAddr.String()
+
+	default:
+		return "<unknown address family>"
+	}
+}
+
+func (end *Endpoint) DestinationIP() net.IP {
+	switch end.dst.Family {
+	case unix.AF_INET6:
+		return end.dst.Addr[:]
+	case unix.AF_INET:
+		ptr := (*unix.RawSockaddrInet4)(unsafe.Pointer(&end.dst))
+		return net.IPv4(
+			ptr.Addr[0],
+			ptr.Addr[1],
+			ptr.Addr[2],
+			ptr.Addr[3],
+		)
+	default:
+		return nil
+	}
+}
+
+func (end *Endpoint) SourceToBytes() []byte {
+	ptr := unsafe.Pointer(&end.src)
+	arr := (*[unix.SizeofSockaddrInet6]byte)(ptr)
+	return arr[:]
+}
+
+func (end *Endpoint) SourceToString() string {
+	return sockaddrToString(end.src)
+}
+
+func (end *Endpoint) DestinationToString() string {
+	return sockaddrToString(end.dst)
+}
+
+func (end *Endpoint) ClearSrc() {
+	end.src = unix.RawSockaddrInet6{}
 }
 
 func zoneToUint32(zone string) (uint32, error) {
@@ -56,7 +179,7 @@ func zoneToUint32(zone string) (uint32, error) {
 	return uint32(n), err
 }
 
-func CreateIPv4Socket(port uint16) (Socket, uint16, error) {
+func create4(port uint16) (int, uint16, error) {
 
 	// create socket
 
@@ -100,18 +223,10 @@ func CreateIPv4Socket(port uint16) (Socket, uint16, error) {
 		unix.Close(fd)
 	}
 
-	return Socket(fd), uint16(addr.Port), err
+	return fd, uint16(addr.Port), err
 }
 
-func CloseIPv4Socket(sock Socket) error {
-	return unix.Close(int(sock))
-}
-
-func CloseIPv6Socket(sock Socket) error {
-	return unix.Close(int(sock))
-}
-
-func CreateIPv6Socket(port uint16) (Socket, uint16, error) {
+func create6(port uint16) (int, uint16, error) {
 
 	// create socket
 
@@ -166,13 +281,7 @@ func CreateIPv6Socket(port uint16) (Socket, uint16, error) {
 		unix.Close(fd)
 	}
 
-	return Socket(fd), uint16(addr.Port), err
-}
-
-func (end *Endpoint) ClearSrc() {
-	end.src4if = 0
-	end.src4 = unix.RawSockaddrInet4{}
-	end.src6 = unix.RawSockaddrInet6{}
+	return fd, uint16(addr.Port), err
 }
 
 func (end *Endpoint) Set(s string) error {
@@ -187,23 +296,23 @@ func (end *Endpoint) Set(s string) error {
 		if err != nil {
 			return err
 		}
-		ptr := (*unix.RawSockaddrInet6)(unsafe.Pointer(&end.dst))
-		ptr.Family = unix.AF_INET6
-		ptr.Port = uint16(addr.Port)
-		ptr.Flowinfo = 0
-		ptr.Scope_id = zone
-		copy(ptr.Addr[:], ipv6[:])
+		dst := &end.dst
+		dst.Family = unix.AF_INET6
+		dst.Port = uint16(addr.Port)
+		dst.Flowinfo = 0
+		dst.Scope_id = zone
+		copy(dst.Addr[:], ipv6[:])
 		end.ClearSrc()
 		return nil
 	}
 
 	ipv4 := addr.IP.To4()
 	if ipv4 != nil {
-		ptr := (*unix.RawSockaddrInet4)(unsafe.Pointer(&end.dst))
-		ptr.Family = unix.AF_INET
-		ptr.Port = uint16(addr.Port)
-		ptr.Zero = [8]byte{}
-		copy(ptr.Addr[:], ipv4)
+		dst := (*unix.RawSockaddrInet4)(unsafe.Pointer(&end.dst))
+		dst.Family = unix.AF_INET
+		dst.Port = uint16(addr.Port)
+		dst.Zero = [8]byte{}
+		copy(dst.Addr[:], ipv4)
 		end.ClearSrc()
 		return nil
 	}
@@ -211,7 +320,7 @@ func (end *Endpoint) Set(s string) error {
 	return errors.New("Failed to recognize IP address format")
 }
 
-func send6(sock uintptr, end *Endpoint, buff []byte) error {
+func send6(sock int, end *Endpoint, buff []byte) error {
 
 	// construct message header
 
@@ -229,8 +338,8 @@ func send6(sock uintptr, end *Endpoint, buff []byte) error {
 			Len:   unix.SizeofInet6Pktinfo,
 		},
 		unix.Inet6Pktinfo{
-			Addr:    end.src6.Addr,
-			Ifindex: end.src6.Scope_id,
+			Addr:    end.src.Addr,
+			Ifindex: end.src.Scope_id,
 		},
 	}
 
@@ -248,7 +357,7 @@ func send6(sock uintptr, end *Endpoint, buff []byte) error {
 
 	_, _, errno := unix.Syscall(
 		unix.SYS_SENDMSG,
-		sock,
+		uintptr(sock),
 		uintptr(unsafe.Pointer(&msghdr)),
 		0,
 	)
@@ -258,7 +367,7 @@ func send6(sock uintptr, end *Endpoint, buff []byte) error {
 	return errno
 }
 
-func send4(sock uintptr, end *Endpoint, buff []byte) error {
+func send4(sock int, end *Endpoint, buff []byte) error {
 
 	// construct message header
 
@@ -266,6 +375,8 @@ func send4(sock uintptr, end *Endpoint, buff []byte) error {
 	iovec.Base = (*byte)(unsafe.Pointer(&buff[0]))
 	iovec.SetLen(len(buff))
 
+	src4 := (*IPv4Source)(unsafe.Pointer(&end.src))
+
 	cmsg := struct {
 		cmsghdr unix.Cmsghdr
 		pktinfo unix.Inet4Pktinfo
@@ -276,8 +387,8 @@ func send4(sock uintptr, end *Endpoint, buff []byte) error {
 			Len:   unix.SizeofInet4Pktinfo,
 		},
 		unix.Inet4Pktinfo{
-			Spec_dst: end.src4.Addr,
-			Ifindex:  end.src4if,
+			Spec_dst: src4.src.Addr,
+			Ifindex:  src4.Ifindex,
 		},
 	}
 
@@ -295,7 +406,7 @@ func send4(sock uintptr, end *Endpoint, buff []byte) error {
 
 	_, _, errno := unix.Syscall(
 		unix.SYS_SENDMSG,
-		sock,
+		uintptr(sock),
 		uintptr(unsafe.Pointer(&msghdr)),
 		0,
 	)
@@ -305,28 +416,7 @@ func send4(sock uintptr, end *Endpoint, buff []byte) error {
 	return errno
 }
 
-func (end *Endpoint) Send(c *net.UDPConn, buff []byte) error {
-
-	// extract underlying file descriptor
-
-	file, err := c.File()
-	if err != nil {
-		return err
-	}
-	sock := file.Fd()
-
-	// send depending on address family of dst
-
-	family := *((*uint16)(unsafe.Pointer(&end.dst)))
-	if family == unix.AF_INET {
-		return send4(sock, end, buff)
-	} else if family == unix.AF_INET6 {
-		return send6(sock, end, buff)
-	}
-	return errors.New("Unknown address family of source")
-}
-
-func (end *Endpoint) ReceiveIPv4(sock Socket, buff []byte) (int, error) {
+func receive4(sock int, buff []byte, end *Endpoint) (int, error) {
 
 	// contruct message header
 
@@ -360,22 +450,21 @@ func (end *Endpoint) ReceiveIPv4(sock Socket, buff []byte) (int, error) {
 		return 0, errno
 	}
 
-	fmt.Println(msghdr)
-	fmt.Println(cmsg)
-
 	// update source cache
 
 	if cmsg.cmsghdr.Level == unix.IPPROTO_IP &&
 		cmsg.cmsghdr.Type == unix.IP_PKTINFO &&
 		cmsg.cmsghdr.Len >= unix.SizeofInet4Pktinfo {
-		end.src4.Addr = cmsg.pktinfo.Spec_dst
-		end.src4if = cmsg.pktinfo.Ifindex
+		src4 := (*IPv4Source)(unsafe.Pointer(&end.src))
+		src4.src.Family = unix.AF_INET
+		src4.src.Addr = cmsg.pktinfo.Spec_dst
+		src4.Ifindex = cmsg.pktinfo.Ifindex
 	}
 
 	return int(size), nil
 }
 
-func (end *Endpoint) ReceiveIPv6(sock Socket, buff []byte) (int, error) {
+func receive6(sock int, buff []byte, end *Endpoint) (int, error) {
 
 	// contruct message header
 
@@ -414,18 +503,10 @@ func (end *Endpoint) ReceiveIPv6(sock Socket, buff []byte) (int, error) {
 	if cmsg.cmsghdr.Level == unix.IPPROTO_IPV6 &&
 		cmsg.cmsghdr.Type == unix.IPV6_PKTINFO &&
 		cmsg.cmsghdr.Len >= unix.SizeofInet6Pktinfo {
-		end.src6.Addr = cmsg.pktinfo.Addr
-		end.src6.Scope_id = cmsg.pktinfo.Ifindex
+		end.src.Family = unix.AF_INET6
+		end.src.Addr = cmsg.pktinfo.Addr
+		end.src.Scope_id = cmsg.pktinfo.Ifindex
 	}
 
 	return int(size), nil
 }
-
-func SetMark(sock Socket, value uint32) error {
-	return unix.SetsockoptInt(
-		int(sock),
-		unix.SOL_SOCKET,
-		unix.SO_MARK,
-		int(value),
-	)
-}