Fix: process resolving for udp (#2806)

component/process/process_freebsd.go

@@ -23,32 +23,32 @@ type InEndpoints12 struct {
 
 type XTcpcb12 struct {
 	Len         uint32        // offset 0
-	Padding1    [20]byte      // offset 4
+	_           [20]byte      // offset 4
 	SocketAddr  uint64        // offset 24
-	Padding2    [84]byte      // offset 32
+	_           [84]byte      // offset 32
 	Family      uint32        // offset 116
-	Padding3    [140]byte     // offset 120
+	_           [140]byte     // offset 120
 	InEndpoints InEndpoints12 // offset 260
-	Padding4    [444]byte     // offset 300
+	_           [444]byte     // offset 300
 } // size 744
 
 type XInpcb12 struct {
 	Len         uint32        // offset 0
-	Padding1    [12]byte      // offset 4
+	_           [12]byte      // offset 4
 	SocketAddr  uint64        // offset 16
-	Padding2    [84]byte      // offset 24
+	_           [84]byte      // offset 24
 	Family      uint32        // offset 108
-	Padding3    [140]byte     // offset 112
+	_           [140]byte     // offset 112
 	InEndpoints InEndpoints12 // offset 252
-	Padding4    [108]byte     // offset 292
+	_           [108]byte     // offset 292
 } // size 400
 
 type XFile12 struct {
 	Size     uint64   // offset 0
 	Pid      uint32   // offset 8
-	Padding1 [44]byte // offset 12
+	_        [44]byte // offset 12
 	DataAddr uint64   // offset 56
-	Padding2 [64]byte // offset 64
+	_        [64]byte // offset 64
 } // size 128
 
 var majorVersion = func() int {
@@ -144,7 +144,6 @@ func findProcessPath12(network string, from netip.AddrPort, to netip.AddrPort) (
 			data = data[icb.Len:]
 
 			var connFromAddr netip.Addr
-
 			if icb.Family == unix.AF_INET {
 				connFromAddr = netip.AddrFrom4([4]byte(icb.InEndpoints.LAddr[12:16]))
 			} else if icb.Family == unix.AF_INET6 {
@@ -153,9 +152,9 @@ func findProcessPath12(network string, from netip.AddrPort, to netip.AddrPort) (
 				continue
 			}
 
-			connFrom := netip.AddrPortFrom(connFromAddr, binary.BigEndian.Uint16(icb.InEndpoints.LPort[:]))
+			connFromPort := binary.BigEndian.Uint16(icb.InEndpoints.LPort[:])
 
-			if connFrom == from {
+			if (connFromAddr == from.Addr() || connFromAddr.IsUnspecified()) && connFromPort == from.Port() {
 				pid, err := findPidBySocketAddr12(icb.SocketAddr)
 				if err != nil {
 					return "", err
@@ -208,7 +207,8 @@ func findExecutableByPid(pid uint32) (string, error) {
 		uintptr(unsafe.Pointer(&buf[0])),
 		uintptr(unsafe.Pointer(&size)),
 		0,
-		0)
+		0,
+	)
 	if errno != 0 || size == 0 {
 		return "", fmt.Errorf("sysctl: get proc name: %w", errno)
 	}

component/process/process_linux.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
+	"net"
 	"net/netip"
 	"os"
 	"unsafe"
@@ -59,40 +60,65 @@ func findProcessPath(network string, from netip.AddrPort, to netip.AddrPort) (st
 }
 
 func resolveSocketByNetlink(network string, from netip.AddrPort, to netip.AddrPort) (inode uint32, uid uint32, err error) {
-	request := &inetDiagRequest{
+	var families []byte
-		States: 0xffffffff,
+	if from.Addr().Unmap().Is4() {
-		Cookie: [2]uint32{0xffffffff, 0xffffffff},
+		families = []byte{unix.AF_INET, unix.AF_INET6}
-	}
-
-	if from.Addr().Is4() {
-		request.Family = unix.AF_INET
 	} else {
-		request.Family = unix.AF_INET6
+		families = []byte{unix.AF_INET6, unix.AF_INET}
 	}
 
-	// Swap src & dst for udp
+	var protocol byte
-	// See also https://www.mail-archive.com/netdev@vger.kernel.org/msg248638.html
 	switch network {
 	case TCP:
-		request.Protocol = unix.IPPROTO_TCP
+		protocol = unix.IPPROTO_TCP
-
-		copy(request.Src[:], from.Addr().AsSlice())
-		copy(request.Dst[:], to.Addr().AsSlice())
-
-		binary.BigEndian.PutUint16(request.SrcPort[:], from.Port())
-		binary.BigEndian.PutUint16(request.DstPort[:], to.Port())
 	case UDP:
-		request.Protocol = unix.IPPROTO_UDP
+		protocol = unix.IPPROTO_UDP
-
-		copy(request.Dst[:], from.Addr().AsSlice())
-		copy(request.Src[:], to.Addr().AsSlice())
-
-		binary.BigEndian.PutUint16(request.DstPort[:], from.Port())
-		binary.BigEndian.PutUint16(request.SrcPort[:], to.Port())
 	default:
 		return 0, 0, ErrInvalidNetwork
 	}
 
+	if protocol == unix.IPPROTO_UDP {
+		// Swap from & to for udp
+		// See also https://www.mail-archive.com/netdev@vger.kernel.org/msg248638.html
+		from, to = to, from
+	}
+
+	for _, family := range families {
+		inode, uid, err = resolveSocketByNetlinkExact(family, protocol, from, to, netlink.Request)
+		if err == nil {
+			return inode, uid, err
+		}
+	}
+
+	return 0, 0, ErrNotFound
+}
+
+func resolveSocketByNetlinkExact(family byte, protocol byte, from netip.AddrPort, to netip.AddrPort, flags netlink.HeaderFlags) (inode uint32, uid uint32, err error) {
+	request := &inetDiagRequest{
+		Family:   family,
+		Protocol: protocol,
+		States:   0xffffffff,
+		Cookie:   [2]uint32{0xffffffff, 0xffffffff},
+	}
+
+	var (
+		fromAddr []byte
+		toAddr   []byte
+	)
+	if family == unix.AF_INET {
+		fromAddr = net.IP(from.Addr().AsSlice()).To4()
+		toAddr = net.IP(to.Addr().AsSlice()).To4()
+	} else {
+		fromAddr = net.IP(from.Addr().AsSlice()).To16()
+		toAddr = net.IP(to.Addr().AsSlice()).To16()
+	}
+
+	copy(request.Src[:], fromAddr)
+	copy(request.Dst[:], toAddr)
+
+	binary.BigEndian.PutUint16(request.SrcPort[:], from.Port())
+	binary.BigEndian.PutUint16(request.DstPort[:], to.Port())
+
 	conn, err := netlink.Dial(unix.NETLINK_INET_DIAG, nil)
 	if err != nil {
 		return 0, 0, err
@@ -102,7 +128,7 @@ func resolveSocketByNetlink(network string, from netip.AddrPort, to netip.AddrPo
 	message := netlink.Message{
 		Header: netlink.Header{
 			Type:  20, // SOCK_DIAG_BY_FAMILY
-			Flags: netlink.Request,
+			Flags: flags,
 		},
 		Data: (*(*[unsafe.Sizeof(*request)]byte)(unsafe.Pointer(request)))[:],
 	}

component/process/process_test.go

@@ -28,7 +28,7 @@ func testConn(t *testing.T, network, address string) {
 	}
 	defer rConn.Close()
 
-	path, err := FindProcessPath(TCP, netip.MustParseAddrPort(conn.LocalAddr().String()), netip.MustParseAddrPort(conn.RemoteAddr().String()))
+	path, err := FindProcessPath(TCP, conn.LocalAddr().(*net.TCPAddr).AddrPort(), conn.RemoteAddr().(*net.TCPAddr).AddrPort())
 	if err != nil {
 		assert.FailNow(t, "Find process path failed", err)
 	}
@@ -68,7 +68,12 @@ func testPacketConn(t *testing.T, network, lAddress, rAddress string) {
 		assert.FailNow(t, "Send message failed", err)
 	}
 
-	path, err := FindProcessPath(UDP, netip.MustParseAddrPort(lConn.LocalAddr().String()), netip.MustParseAddrPort(rConn.LocalAddr().String()))
+	_, lAddr, err := rConn.ReadFrom([]byte{0})
+	if err != nil {
+		assert.FailNow(t, "Receive message failed", err)
+	}
+
+	path, err := FindProcessPath(UDP, lAddr.(*net.UDPAddr).AddrPort(), rConn.LocalAddr().(*net.UDPAddr).AddrPort())
 	if err != nil {
 		assert.FailNow(t, "Find process path", err)
 	}
@@ -88,6 +93,12 @@ func TestFindProcessPathUDP(t *testing.T) {
 	t.Run("v6", func(t *testing.T) {
 		testPacketConn(t, "udp6", "[::1]:0", "[::1]:0")
 	})
+	t.Run("v4AnyLocal", func(t *testing.T) {
+		testPacketConn(t, "udp4", "0.0.0.0:0", "127.0.0.1:0")
+	})
+	t.Run("v6AnyLocal", func(t *testing.T) {
+		testPacketConn(t, "udp6", "[::]:0", "[::1]:0")
+	})
 }
 
 func BenchmarkFindProcessName(b *testing.B) {

component/process/process_windows.go

@@ -168,7 +168,7 @@ loop:
 				localAddr := netip.AddrFrom4(entry.LocalAddr)
 				localPort := windows.Ntohs(uint16(entry.LocalPort))
 
-				if localAddr == from.Addr() && localPort == from.Port() {
+				if (localAddr == from.Addr() || localAddr.IsUnspecified()) && localPort == from.Port() {
 					return entry.OwningPid, nil
 				}
 			}
@@ -189,7 +189,7 @@ loop:
 				localAddr := netip.AddrFrom16(entry.LocalAddr)
 				localPort := windows.Ntohs(uint16(entry.LocalPort))
 
-				if localAddr == from.Addr() && localPort == from.Port() {
+				if (localAddr == from.Addr() || localAddr.IsUnspecified()) && localPort == from.Port() {
 					return entry.OwningPid, nil
 				}
 			}