Optimize Darwin process finder

common/process/searcher.go

@@ -29,7 +29,7 @@ func FindProcessInfo(searcher Searcher, ctx context.Context, network string, sou
 	if err != nil {
 		return nil, err
 	}
-	if info.UserId != -1 {
+	if info.UserId != -1 && info.UserName == "" {
 		osUser, _ := user.LookupId(F.ToString(info.UserId))
 		if osUser != nil {
 			info.UserName = osUser.Username

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()))
+	return FindDarwinConnectionOwner(network, source, destination)
-	if err != nil {
-		return nil, err
-	}
-	return &adapter.ConnectionOwner{ProcessPath: processName, UserId: -1}, nil
 }
 
 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]))
-}

common/process/searcher_darwin_shared.go

@@ -0,0 +1,269 @@
+//go:build darwin
+
+package process
+
+import (
+	"encoding/binary"
+	"net/netip"
+	"os"
+	"sync"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"github.com/sagernet/sing-box/adapter"
+	N "github.com/sagernet/sing/common/network"
+
+	"golang.org/x/sys/unix"
+)
+
+const (
+	darwinSnapshotTTL = 200 * time.Millisecond
+
+	darwinXinpgenSize        = 24
+	darwinXsocketOffset      = 104
+	darwinXinpcbForeignPort  = 16
+	darwinXinpcbLocalPort    = 18
+	darwinXinpcbVFlag        = 44
+	darwinXinpcbForeignAddr  = 48
+	darwinXinpcbLocalAddr    = 64
+	darwinXinpcbIPv4Addr     = 12
+	darwinXsocketUID         = 64
+	darwinXsocketLastPID     = 68
+	darwinTCPExtraStructSize = 208
+)
+
+type darwinConnectionEntry struct {
+	localAddr  netip.Addr
+	remoteAddr netip.Addr
+	localPort  uint16
+	remotePort uint16
+	pid        uint32
+	uid        int32
+}
+
+type darwinConnectionMatchKind uint8
+
+const (
+	darwinConnectionMatchExact darwinConnectionMatchKind = iota
+	darwinConnectionMatchLocalFallback
+	darwinConnectionMatchWildcardFallback
+)
+
+type darwinSnapshot struct {
+	createdAt time.Time
+	entries   []darwinConnectionEntry
+}
+
+type darwinConnectionFinder struct {
+	access    sync.Mutex
+	ttl       time.Duration
+	snapshots map[string]darwinSnapshot
+	builder   func(string) (darwinSnapshot, error)
+}
+
+var sharedDarwinConnectionFinder = newDarwinConnectionFinder(darwinSnapshotTTL)
+
+func newDarwinConnectionFinder(ttl time.Duration) *darwinConnectionFinder {
+	return &darwinConnectionFinder{
+		ttl:       ttl,
+		snapshots: make(map[string]darwinSnapshot),
+		builder:   buildDarwinSnapshot,
+	}
+}
+
+func FindDarwinConnectionOwner(network string, source netip.AddrPort, destination netip.AddrPort) (*adapter.ConnectionOwner, error) {
+	return sharedDarwinConnectionFinder.find(network, source, destination)
+}
+
+func (f *darwinConnectionFinder) find(network string, source netip.AddrPort, destination netip.AddrPort) (*adapter.ConnectionOwner, error) {
+	networkName := N.NetworkName(network)
+	source = normalizeDarwinAddrPort(source)
+	destination = normalizeDarwinAddrPort(destination)
+	var lastOwner *adapter.ConnectionOwner
+	for attempt := 0; attempt < 2; attempt++ {
+		snapshot, fromCache, err := f.loadSnapshot(networkName, attempt > 0)
+		if err != nil {
+			return nil, err
+		}
+		entry, matchKind, err := matchDarwinConnectionEntry(snapshot.entries, networkName, source, destination)
+		if err != nil {
+			if err == ErrNotFound && fromCache {
+				continue
+			}
+			return nil, err
+		}
+		if fromCache && matchKind != darwinConnectionMatchExact {
+			continue
+		}
+		owner := &adapter.ConnectionOwner{
+			UserId: entry.uid,
+		}
+		lastOwner = owner
+		if entry.pid == 0 {
+			return owner, nil
+		}
+		processPath, err := getExecPathFromPID(entry.pid)
+		if err == nil {
+			owner.ProcessPath = processPath
+			return owner, nil
+		}
+		if fromCache {
+			continue
+		}
+		return owner, nil
+	}
+	if lastOwner != nil {
+		return lastOwner, nil
+	}
+	return nil, ErrNotFound
+}
+
+func (f *darwinConnectionFinder) loadSnapshot(network string, forceRefresh bool) (darwinSnapshot, bool, error) {
+	f.access.Lock()
+	defer f.access.Unlock()
+	if !forceRefresh {
+		if snapshot, loaded := f.snapshots[network]; loaded && time.Since(snapshot.createdAt) < f.ttl {
+			return snapshot, true, nil
+		}
+	}
+	snapshot, err := f.builder(network)
+	if err != nil {
+		return darwinSnapshot{}, false, err
+	}
+	f.snapshots[network] = snapshot
+	return snapshot, false, nil
+}
+
+func buildDarwinSnapshot(network string) (darwinSnapshot, error) {
+	spath, itemSize, err := darwinSnapshotSettings(network)
+	if err != nil {
+		return darwinSnapshot{}, err
+	}
+	value, err := unix.SysctlRaw(spath)
+	if err != nil {
+		return darwinSnapshot{}, err
+	}
+	return darwinSnapshot{
+		createdAt: time.Now(),
+		entries:   parseDarwinSnapshot(value, itemSize),
+	}, nil
+}
+
+func darwinSnapshotSettings(network string) (string, int, error) {
+	itemSize := structSize
+	switch network {
+	case N.NetworkTCP:
+		return "net.inet.tcp.pcblist_n", itemSize + darwinTCPExtraStructSize, nil
+	case N.NetworkUDP:
+		return "net.inet.udp.pcblist_n", itemSize, nil
+	default:
+		return "", 0, os.ErrInvalid
+	}
+}
+
+func parseDarwinSnapshot(buf []byte, itemSize int) []darwinConnectionEntry {
+	entries := make([]darwinConnectionEntry, 0, (len(buf)-darwinXinpgenSize)/itemSize)
+	for i := darwinXinpgenSize; i+itemSize <= len(buf); i += itemSize {
+		inp := i
+		so := i + darwinXsocketOffset
+		entry, ok := parseDarwinConnectionEntry(buf[inp:so], buf[so:so+structSize-darwinXsocketOffset])
+		if ok {
+			entries = append(entries, entry)
+		}
+	}
+	return entries
+}
+
+func parseDarwinConnectionEntry(inp []byte, so []byte) (darwinConnectionEntry, bool) {
+	if len(inp) < darwinXsocketOffset || len(so) < structSize-darwinXsocketOffset {
+		return darwinConnectionEntry{}, false
+	}
+	entry := darwinConnectionEntry{
+		remotePort: binary.BigEndian.Uint16(inp[darwinXinpcbForeignPort : darwinXinpcbForeignPort+2]),
+		localPort:  binary.BigEndian.Uint16(inp[darwinXinpcbLocalPort : darwinXinpcbLocalPort+2]),
+		pid:        binary.NativeEndian.Uint32(so[darwinXsocketLastPID : darwinXsocketLastPID+4]),
+		uid:        int32(binary.NativeEndian.Uint32(so[darwinXsocketUID : darwinXsocketUID+4])),
+	}
+	flag := inp[darwinXinpcbVFlag]
+	switch {
+	case flag&0x1 != 0:
+		entry.remoteAddr = netip.AddrFrom4([4]byte(inp[darwinXinpcbForeignAddr+darwinXinpcbIPv4Addr : darwinXinpcbForeignAddr+darwinXinpcbIPv4Addr+4]))
+		entry.localAddr = netip.AddrFrom4([4]byte(inp[darwinXinpcbLocalAddr+darwinXinpcbIPv4Addr : darwinXinpcbLocalAddr+darwinXinpcbIPv4Addr+4]))
+		return entry, true
+	case flag&0x2 != 0:
+		entry.remoteAddr = netip.AddrFrom16([16]byte(inp[darwinXinpcbForeignAddr : darwinXinpcbForeignAddr+16]))
+		entry.localAddr = netip.AddrFrom16([16]byte(inp[darwinXinpcbLocalAddr : darwinXinpcbLocalAddr+16]))
+		return entry, true
+	default:
+		return darwinConnectionEntry{}, false
+	}
+}
+
+func matchDarwinConnectionEntry(entries []darwinConnectionEntry, network string, source netip.AddrPort, destination netip.AddrPort) (darwinConnectionEntry, darwinConnectionMatchKind, error) {
+	sourceAddr := source.Addr()
+	if !sourceAddr.IsValid() {
+		return darwinConnectionEntry{}, darwinConnectionMatchExact, os.ErrInvalid
+	}
+	var localFallback darwinConnectionEntry
+	var hasLocalFallback bool
+	var wildcardFallback darwinConnectionEntry
+	var hasWildcardFallback bool
+	for _, entry := range entries {
+		if entry.localPort != source.Port() || sourceAddr.BitLen() != entry.localAddr.BitLen() {
+			continue
+		}
+		if entry.localAddr == sourceAddr && destination.IsValid() && entry.remotePort == destination.Port() && entry.remoteAddr == destination.Addr() {
+			return entry, darwinConnectionMatchExact, nil
+		}
+		if !destination.IsValid() && entry.localAddr == sourceAddr {
+			return entry, darwinConnectionMatchExact, nil
+		}
+		if network != N.NetworkUDP {
+			continue
+		}
+		if !hasLocalFallback && entry.localAddr == sourceAddr {
+			hasLocalFallback = true
+			localFallback = entry
+		}
+		if !hasWildcardFallback && entry.localAddr.IsUnspecified() {
+			hasWildcardFallback = true
+			wildcardFallback = entry
+		}
+	}
+	if hasLocalFallback {
+		return localFallback, darwinConnectionMatchLocalFallback, nil
+	}
+	if hasWildcardFallback {
+		return wildcardFallback, darwinConnectionMatchWildcardFallback, nil
+	}
+	return darwinConnectionEntry{}, darwinConnectionMatchExact, ErrNotFound
+}
+
+func normalizeDarwinAddrPort(addrPort netip.AddrPort) netip.AddrPort {
+	if !addrPort.IsValid() {
+		return addrPort
+	}
+	return netip.AddrPortFrom(addrPort.Addr().Unmap(), addrPort.Port())
+}
+
+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
+}

experimental/libbox/connection_owner_darwin.go

@@ -0,0 +1,57 @@
+package libbox
+
+import (
+	"net/netip"
+	"os/user"
+	"syscall"
+
+	"github.com/sagernet/sing-box/common/process"
+	E "github.com/sagernet/sing/common/exceptions"
+	F "github.com/sagernet/sing/common/format"
+)
+
+func FindConnectionOwner(ipProtocol int32, sourceAddress string, sourcePort int32, destinationAddress string, destinationPort int32) (*ConnectionOwner, error) {
+	source, err := parseConnectionOwnerAddrPort(sourceAddress, sourcePort)
+	if err != nil {
+		return nil, E.Cause(err, "parse source")
+	}
+	destination, err := parseConnectionOwnerAddrPort(destinationAddress, destinationPort)
+	if err != nil {
+		return nil, E.Cause(err, "parse destination")
+	}
+	var network string
+	switch ipProtocol {
+	case syscall.IPPROTO_TCP:
+		network = "tcp"
+	case syscall.IPPROTO_UDP:
+		network = "udp"
+	default:
+		return nil, E.New("unknown protocol: ", ipProtocol)
+	}
+	owner, err := process.FindDarwinConnectionOwner(network, source, destination)
+	if err != nil {
+		return nil, err
+	}
+	result := &ConnectionOwner{
+		UserId:      owner.UserId,
+		ProcessPath: owner.ProcessPath,
+	}
+	if owner.UserId != -1 && owner.UserName == "" {
+		osUser, _ := user.LookupId(F.ToString(owner.UserId))
+		if osUser != nil {
+			result.UserName = osUser.Username
+		}
+	}
+	return result, nil
+}
+
+func parseConnectionOwnerAddrPort(address string, port int32) (netip.AddrPort, error) {
+	if port < 0 || port > 65535 {
+		return netip.AddrPort{}, E.New("invalid port: ", port)
+	}
+	addr, err := netip.ParseAddr(address)
+	if err != nil {
+		return netip.AddrPort{}, err
+	}
+	return netip.AddrPortFrom(addr.Unmap(), uint16(port)), nil
+}