Routing: process supports macOS as well (#6447)

#6434 (comment)

Author: yiguodev

common/net/find_process_darwin.go

@@ -0,0 +1,348 @@
+//go:build darwin
+
+package net
+
+import (
+	"bytes"
+	"net"
+	"net/netip"
+	"path/filepath"
+	"strings"
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+
+	"github.com/xtls/xray-core/common/errors"
+)
+
+const (
+	darwinProcPIDListFDs      = 1
+	darwinProcPIDFDSocketInfo = 3
+	darwinProcFDTypeSocket    = 2
+	darwinProcFDInfoSize      = 8
+	darwinSocketFDInfoSize    = 792
+	darwinSocketFDInfoPSIOff  = 24
+	darwinSocketInfoProtoOff  = darwinSocketFDInfoPSIOff + 156
+	darwinSocketInfoFamilyOff = darwinSocketFDInfoPSIOff + 160
+	darwinSocketInfoKindOff   = darwinSocketFDInfoPSIOff + 232
+	darwinSocketInfoInSockOff = darwinSocketFDInfoPSIOff + 240
+	darwinInSockInfoFPortOff  = darwinSocketInfoInSockOff
+	darwinInSockInfoLPortOff  = darwinSocketInfoInSockOff + 4
+	darwinInSockInfoVFlagOff  = darwinSocketInfoInSockOff + 24
+	darwinInSockInfoFAddrOff  = darwinSocketInfoInSockOff + 32
+	darwinInSockInfoLAddrOff  = darwinSocketInfoInSockOff + 48
+	darwinInSockInfoSize      = 80
+	darwinInSockInfoIPv4      = 0x1
+	darwinInSockInfoIPv6      = 0x2
+	darwinSockInfoIN          = 1
+	darwinSockInfoTCP         = 2
+)
+
+type darwinSocketMatchLevel int
+
+const (
+	darwinSocketNoMatch darwinSocketMatchLevel = iota
+	darwinSocketPortMatch
+	darwinSocketRemoteMatch
+	darwinSocketLocalMatch
+	darwinSocketExactMatch
+)
+
+func FindProcess(network, srcIP string, srcPort uint16, destIP string, destPort uint16) (PID int, Name string, AbsolutePath string, err error) {
+	isLocal, err := IsLocal(net.ParseIP(srcIP))
+	if err != nil {
+		return 0, "", "", errors.New("failed to determine if address is local: ", err)
+	}
+	if !isLocal {
+		return 0, "", "", ErrNotLocal
+	}
+	if network != "tcp" && network != "udp" {
+		panic("Unsupported network type for process lookup.")
+	}
+
+	srcAddr, err := netip.ParseAddr(srcIP)
+	if err != nil {
+		return 0, "", "", errors.New("invalid source IP address: ", srcIP)
+	}
+	srcAddr = srcAddr.Unmap()
+
+	var dstAddr netip.Addr
+	hasDstAddr := false
+	if destIP != "" && destPort != 0 {
+		dstAddr, err = netip.ParseAddr(destIP)
+		if err != nil {
+			return 0, "", "", errors.New("invalid destination IP address: ", destIP)
+		}
+		dstAddr = dstAddr.Unmap()
+		hasDstAddr = true
+	}
+
+	processes, err := unix.SysctlKinfoProcSlice("kern.proc.all")
+	if err != nil {
+		return 0, "", "", errors.New("failed to list processes").Base(err)
+	}
+
+	var bestPID int32
+	bestLevel := darwinSocketNoMatch
+	ambiguousBest := false
+
+	for _, process := range processes {
+		pid := process.Proc.P_pid
+		if pid <= 0 {
+			continue
+		}
+
+		matchLevel, err := darwinProcessSocketMatchLevel(pid, network, srcAddr, srcPort, dstAddr, destPort, hasDstAddr)
+		if err != nil || matchLevel == darwinSocketNoMatch {
+			continue
+		}
+		if matchLevel == darwinSocketExactMatch {
+			bestPID = pid
+			bestLevel = matchLevel
+			ambiguousBest = false
+			break
+		}
+		if matchLevel > bestLevel {
+			bestPID = pid
+			bestLevel = matchLevel
+			ambiguousBest = false
+			continue
+		}
+		if matchLevel == bestLevel {
+			ambiguousBest = true
+		}
+	}
+
+	if bestLevel == darwinSocketNoMatch {
+		return 0, "", "", errors.New("process not found for ", network, " connection from ", srcIP, ":", srcPort, " to ", destIP, ":", destPort)
+	}
+	if ambiguousBest {
+		return 0, "", "", errors.New("ambiguous process match for ", network, " connection from ", srcIP, ":", srcPort, " to ", destIP, ":", destPort)
+	}
+
+	absPath, err := darwinProcessPath(bestPID)
+	if err != nil {
+		return 0, "", "", errors.New("could not get process path for PID ", bestPID, ": ", err)
+	}
+
+	absPath = filepath.ToSlash(absPath)
+	return int(bestPID), filepath.Base(absPath), absPath, nil
+}
+
+func darwinProcessSocketMatchLevel(pid int32, network string, srcAddr netip.Addr, srcPort uint16, dstAddr netip.Addr, dstPort uint16, hasDstAddr bool) (darwinSocketMatchLevel, error) {
+	fds, err := darwinProcessFDs(pid)
+	if err != nil {
+		return darwinSocketNoMatch, err
+	}
+
+	bestLevel := darwinSocketNoMatch
+	info := make([]byte, darwinSocketFDInfoSize)
+	for fd := 0; fd+darwinProcFDInfoSize <= len(fds); fd += darwinProcFDInfoSize {
+		fdNumber := int32(darwinReadNativeUint32(fds[fd : fd+4]))
+		fdType := darwinReadNativeUint32(fds[fd+4 : fd+8])
+		if fdType != darwinProcFDTypeSocket {
+			continue
+		}
+
+		n, err := darwinProcPIDFDInfo(pid, fdNumber, darwinProcPIDFDSocketInfo, info)
+		if err != nil || n < darwinSocketInfoInSockOff+darwinInSockInfoSize {
+			continue
+		}
+		level := darwinSocketInfoMatchLevel(info[:n], network, srcAddr, srcPort, dstAddr, dstPort, hasDstAddr)
+		if level == darwinSocketExactMatch {
+			return level, nil
+		}
+		if level > bestLevel {
+			bestLevel = level
+		}
+	}
+
+	return bestLevel, nil
+}
+
+func darwinProcessFDs(pid int32) ([]byte, error) {
+	n, err := darwinProcPIDInfo(pid, darwinProcPIDListFDs, 0, nil)
+	if err != nil {
+		return nil, err
+	}
+	if n <= 0 {
+		return nil, nil
+	}
+
+	buf := make([]byte, n)
+	n, err = darwinProcPIDInfo(pid, darwinProcPIDListFDs, 0, buf)
+	if err != nil {
+		return nil, err
+	}
+	return buf[:n], nil
+}
+
+func darwinSocketInfoMatchLevel(info []byte, network string, srcAddr netip.Addr, srcPort uint16, dstAddr netip.Addr, dstPort uint16, hasDstAddr bool) darwinSocketMatchLevel {
+	protocol := int(darwinReadNativeUint32(info[darwinSocketInfoProtoOff : darwinSocketInfoProtoOff+4]))
+	family := int(darwinReadNativeUint32(info[darwinSocketInfoFamilyOff : darwinSocketInfoFamilyOff+4]))
+	kind := int(darwinReadNativeUint32(info[darwinSocketInfoKindOff : darwinSocketInfoKindOff+4]))
+
+	switch network {
+	case "tcp":
+		if protocol != unix.IPPROTO_TCP || kind != darwinSockInfoTCP {
+			return darwinSocketNoMatch
+		}
+	case "udp":
+		if protocol != unix.IPPROTO_UDP || kind != darwinSockInfoIN {
+			return darwinSocketNoMatch
+		}
+	default:
+		return darwinSocketNoMatch
+	}
+
+	vflag := info[darwinInSockInfoVFlagOff]
+	if srcAddr.Is4() {
+		if family != unix.AF_INET || vflag&darwinInSockInfoIPv4 == 0 {
+			return darwinSocketNoMatch
+		}
+	} else {
+		if family != unix.AF_INET6 || vflag&darwinInSockInfoIPv6 == 0 {
+			return darwinSocketNoMatch
+		}
+	}
+
+	localPort := int32(darwinReadNativeUint32(info[darwinInSockInfoLPortOff : darwinInSockInfoLPortOff+4]))
+	if !darwinPortMatches(localPort, srcPort) {
+		return darwinSocketNoMatch
+	}
+	localAddrMatches := darwinAddrMatchesOrUnspecified(info[darwinInSockInfoLAddrOff:darwinInSockInfoLAddrOff+16], srcAddr)
+
+	foreignAddrRaw := info[darwinInSockInfoFAddrOff : darwinInSockInfoFAddrOff+16]
+	foreignPort := int32(darwinReadNativeUint32(info[darwinInSockInfoFPortOff : darwinInSockInfoFPortOff+4]))
+
+	if !hasDstAddr {
+		if localAddrMatches {
+			return darwinSocketExactMatch
+		}
+		return darwinSocketNoMatch
+	}
+
+	remoteMatches := darwinPortMatches(foreignPort, dstPort) && darwinAddrMatches(foreignAddrRaw, dstAddr)
+	if network == "udp" && darwinEndpointIsZero(foreignAddrRaw, foreignPort) && localAddrMatches {
+		return darwinSocketExactMatch
+	}
+	switch {
+	case localAddrMatches && remoteMatches:
+		return darwinSocketExactMatch
+	case localAddrMatches:
+		return darwinSocketLocalMatch
+	case remoteMatches:
+		return darwinSocketRemoteMatch
+	default:
+		return darwinSocketPortMatch
+	}
+}
+
+func darwinPortMatches(value int32, port uint16) bool {
+	raw := uint16(value)
+	return raw == port || darwinNtohs(raw) == port
+}
+
+func darwinNtohs(value uint16) uint16 {
+	return value<<8 | value>>8
+}
+
+func darwinAddrMatches(raw []byte, addr netip.Addr) bool {
+	if addr.Is4() {
+		ip := addr.As4()
+		return bytes.Equal(raw[12:16], ip[:])
+	}
+	ip := addr.As16()
+	return bytes.Equal(raw, ip[:])
+}
+
+func darwinAddrMatchesOrUnspecified(raw []byte, addr netip.Addr) bool {
+	if darwinAddrMatches(raw, addr) {
+		return true
+	}
+	if addr.Is4() {
+		return darwinBytesAreZero(raw[12:16])
+	}
+	return darwinBytesAreZero(raw)
+}
+
+func darwinEndpointIsZero(rawAddr []byte, port int32) bool {
+	return uint32(port) == 0 && darwinBytesAreZero(rawAddr)
+}
+
+func darwinBytesAreZero(raw []byte) bool {
+	for _, value := range raw {
+		if value != 0 {
+			return false
+		}
+	}
+	return true
+}
+
+func darwinReadNativeUint32(b []byte) uint32 {
+	return *(*uint32)(unsafe.Pointer(&b[0]))
+}
+
+func darwinProcessPath(pid int32) (string, error) {
+	buf := make([]byte, unix.PathMax)
+	n, err := darwinProcPIDPath(pid, buf)
+	if err != nil {
+		return "", err
+	}
+	if n <= 0 {
+		return "", errors.New("empty process path")
+	}
+	return strings.TrimRight(string(buf[:n]), "\x00"), nil
+}
+
+func darwinProcPIDInfo(pid int32, flavor int, arg uint64, buf []byte) (int, error) {
+	var ptr unsafe.Pointer
+	if len(buf) > 0 {
+		ptr = unsafe.Pointer(&buf[0])
+	}
+
+	r0, _, errno := syscall_syscall6(libc_proc_pidinfo_trampoline_addr, uintptr(pid), uintptr(flavor), uintptr(arg), uintptr(ptr), uintptr(len(buf)), 0)
+	if errno != 0 {
+		return 0, errno
+	}
+	return int(r0), nil
+}
+
+func darwinProcPIDFDInfo(pid int32, fd int32, flavor int, buf []byte) (int, error) {
+	var ptr unsafe.Pointer
+	if len(buf) > 0 {
+		ptr = unsafe.Pointer(&buf[0])
+	}
+
+	r0, _, errno := syscall_syscall6(libc_proc_pidfdinfo_trampoline_addr, uintptr(pid), uintptr(fd), uintptr(flavor), uintptr(ptr), uintptr(len(buf)), 0)
+	if errno != 0 {
+		return 0, errno
+	}
+	return int(r0), nil
+}
+
+func darwinProcPIDPath(pid int32, buf []byte) (int, error) {
+	r0, _, errno := syscall_syscall6(libc_proc_pidpath_trampoline_addr, uintptr(pid), uintptr(unsafe.Pointer(&buf[0])), uintptr(len(buf)), 0, 0, 0)
+	if errno != 0 {
+		return 0, errno
+	}
+	return int(r0), nil
+}
+
+var libc_proc_pidinfo_trampoline_addr uintptr
+
+//go:cgo_import_dynamic libc_proc_pidinfo proc_pidinfo "/usr/lib/libproc.dylib"
+
+var libc_proc_pidfdinfo_trampoline_addr uintptr
+
+//go:cgo_import_dynamic libc_proc_pidfdinfo proc_pidfdinfo "/usr/lib/libproc.dylib"
+
+var libc_proc_pidpath_trampoline_addr uintptr
+
+//go:cgo_import_dynamic libc_proc_pidpath proc_pidpath "/usr/lib/libproc.dylib"
+
+// Implemented in the runtime package (runtime/sys_darwin.go).
+func syscall_syscall6(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err syscall.Errno)
+
+//go:linkname syscall_syscall6 syscall.syscall6

common/net/find_process_darwin.s

@@ -0,0 +1,18 @@
+//go:build darwin
+
+#include "textflag.h"
+
+TEXT libc_proc_pidinfo_trampoline<>(SB),NOSPLIT,$0-0
+	JMP	libc_proc_pidinfo(SB)
+GLOBL	·libc_proc_pidinfo_trampoline_addr(SB), RODATA, $8
+DATA	·libc_proc_pidinfo_trampoline_addr(SB)/8, $libc_proc_pidinfo_trampoline<>(SB)
+
+TEXT libc_proc_pidfdinfo_trampoline<>(SB),NOSPLIT,$0-0
+	JMP	libc_proc_pidfdinfo(SB)
+GLOBL	·libc_proc_pidfdinfo_trampoline_addr(SB), RODATA, $8
+DATA	·libc_proc_pidfdinfo_trampoline_addr(SB)/8, $libc_proc_pidfdinfo_trampoline<>(SB)
+
+TEXT libc_proc_pidpath_trampoline<>(SB),NOSPLIT,$0-0
+	JMP	libc_proc_pidpath(SB)
+GLOBL	·libc_proc_pidpath_trampoline_addr(SB), RODATA, $8
+DATA	·libc_proc_pidpath_trampoline_addr(SB)/8, $libc_proc_pidpath_trampoline<>(SB)