Optimize Darwin process finder

common/process/searcher_darwin.go

@@ -1,19 +1,15 @@
+//go:build darwin
+
 package process
 
 import (
 	"context"
-	"encoding/binary"
 	"net/netip"
-	"os"
 	"strconv"
 	"strings"
 	"syscall"
-	"unsafe"
 
 	"github.com/sagernet/sing-box/adapter"
-	N "github.com/sagernet/sing/common/network"
-
-	"golang.org/x/sys/unix"
 )
 
 var _ Searcher = (*darwinSearcher)(nil)
@@ -29,11 +25,7 @@ func (d *darwinSearcher) Close() error {
 }
 
 func (d *darwinSearcher) FindProcessInfo(ctx context.Context, network string, source netip.AddrPort, destination netip.AddrPort) (*adapter.ConnectionOwner, error) {
-	processName, err := findProcessName(network, source.Addr(), int(source.Port()))
-	if err != nil {
-		return nil, err
-	}
-	return &adapter.ConnectionOwner{ProcessPath: processName, UserId: -1}, nil
+	return FindDarwinConnectionOwner(network, source, destination)
 }
 
 var structSize = func() int {
@@ -51,107 +43,3 @@ var structSize = func() int {
 		return 384
 	}
 }()
-
-func findProcessName(network string, ip netip.Addr, port int) (string, error) {
-	var spath string
-	switch network {
-	case N.NetworkTCP:
-		spath = "net.inet.tcp.pcblist_n"
-	case N.NetworkUDP:
-		spath = "net.inet.udp.pcblist_n"
-	default:
-		return "", os.ErrInvalid
-	}
-
-	isIPv4 := ip.Is4()
-
-	value, err := unix.SysctlRaw(spath)
-	if err != nil {
-		return "", err
-	}
-
-	buf := value
-
-	// from darwin-xnu/bsd/netinet/in_pcblist.c:get_pcblist_n
-	// size/offset are round up (aligned) to 8 bytes in darwin
-	// rup8(sizeof(xinpcb_n)) + rup8(sizeof(xsocket_n)) +
-	// 2 * rup8(sizeof(xsockbuf_n)) + rup8(sizeof(xsockstat_n))
-	itemSize := structSize
-	if network == N.NetworkTCP {
-		// rup8(sizeof(xtcpcb_n))
-		itemSize += 208
-	}
-
-	var fallbackUDPProcess string
-	// skip the first xinpgen(24 bytes) block
-	for i := 24; i+itemSize <= len(buf); i += itemSize {
-		// offset of xinpcb_n and xsocket_n
-		inp, so := i, i+104
-
-		srcPort := binary.BigEndian.Uint16(buf[inp+18 : inp+20])
-		if uint16(port) != srcPort {
-			continue
-		}
-
-		// xinpcb_n.inp_vflag
-		flag := buf[inp+44]
-
-		var srcIP netip.Addr
-		srcIsIPv4 := false
-		switch {
-		case flag&0x1 > 0 && isIPv4:
-			// ipv4
-			srcIP = netip.AddrFrom4([4]byte(buf[inp+76 : inp+80]))
-			srcIsIPv4 = true
-		case flag&0x2 > 0 && !isIPv4:
-			// ipv6
-			srcIP = netip.AddrFrom16([16]byte(buf[inp+64 : inp+80]))
-		default:
-			continue
-		}
-
-		if ip == srcIP {
-			// xsocket_n.so_last_pid
-			pid := readNativeUint32(buf[so+68 : so+72])
-			return getExecPathFromPID(pid)
-		}
-
-		// udp packet connection may be not equal with srcIP
-		if network == N.NetworkUDP && srcIP.IsUnspecified() && isIPv4 == srcIsIPv4 {
-			pid := readNativeUint32(buf[so+68 : so+72])
-			fallbackUDPProcess, _ = getExecPathFromPID(pid)
-		}
-	}
-
-	if network == N.NetworkUDP && len(fallbackUDPProcess) > 0 {
-		return fallbackUDPProcess, nil
-	}
-
-	return "", ErrNotFound
-}
-
-func getExecPathFromPID(pid uint32) (string, error) {
-	const (
-		procpidpathinfo     = 0xb
-		procpidpathinfosize = 1024
-		proccallnumpidinfo  = 0x2
-	)
-	buf := make([]byte, procpidpathinfosize)
-	_, _, errno := syscall.Syscall6(
-		syscall.SYS_PROC_INFO,
-		proccallnumpidinfo,
-		uintptr(pid),
-		procpidpathinfo,
-		0,
-		uintptr(unsafe.Pointer(&buf[0])),
-		procpidpathinfosize)
-	if errno != 0 {
-		return "", errno
-	}
-
-	return unix.ByteSliceToString(buf), nil
-}
-
-func readNativeUint32(b []byte) uint32 {
-	return *(*uint32)(unsafe.Pointer(&b[0]))
-}