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Refactor: linux process resolving (#2305)

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This commit is contained in:
Kr328
2022-09-18 12:53:51 +08:00
committed by GitHub
parent 4f291fa513
commit 6995e98181
3 changed files with 111 additions and 124 deletions
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215
component/process/process_linux.go
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@ -6,31 +6,57 @@ import (
"fmt"
"net"
"os"
"path"
"path/filepath"
"strings"
"syscall"
"unicode"
"unsafe"
"github.com/Dreamacro/clash/common/pool"
"github.com/mdlayher/netlink"
"golang.org/x/sys/unix"
)
// from https://github.com/vishvananda/netlink/blob/bca67dfc8220b44ef582c9da4e9172bf1c9ec973/nl/nl_linux.go#L52-L62
var nativeEndian = func() binary.ByteOrder {
var x uint32 = 0x01020304
if *(*byte)(unsafe.Pointer(&x)) == 0x01 {
return binary.BigEndian
}
return binary.LittleEndian
}()
const (
sizeOfSocketDiagRequest = syscall.SizeofNlMsghdr + 8 + 48
socketDiagByFamily = 20
pathProc = "/proc"
SOCK_DIAG_BY_FAMILY = 20
inetDiagRequestSize = int(unsafe.Sizeof(inetDiagRequest{}))
inetDiagResponseSize = int(unsafe.Sizeof(inetDiagResponse{}))
)
type inetDiagRequest struct {
Family byte
Protocol byte
Ext byte
Pad byte
States uint32
SrcPort [2]byte
DstPort [2]byte
Src [16]byte
Dst [16]byte
If uint32
Cookie [2]uint32
}
type inetDiagResponse struct {
Family byte
State byte
Timer byte
ReTrans byte
SrcPort [2]byte
DstPort [2]byte
Src [16]byte
Dst [16]byte
If uint32
Cookie [2]uint32
Expires uint32
RQueue uint32
WQueue uint32
UID uint32
INode uint32
}
func findProcessName(network string, ip net.IP, srcPort int) (string, error) {
inode, uid, err := resolveSocketByNetlink(network, ip, srcPort)
if err != nil {
@ -40,132 +66,73 @@ func findProcessName(network string, ip net.IP, srcPort int) (string, error) {
return resolveProcessNameByProcSearch(inode, uid)
}
func resolveSocketByNetlink(network string, ip net.IP, srcPort int) (int32, int32, error) {
var family byte
var protocol byte
switch network {
case TCP:
protocol = syscall.IPPROTO_TCP
case UDP:
protocol = syscall.IPPROTO_UDP
default:
return 0, 0, ErrInvalidNetwork
func resolveSocketByNetlink(network string, ip net.IP, srcPort int) (uint32, uint32, error) {
request := &inetDiagRequest{
States: 0xffffffff,
Cookie: [2]uint32{0xffffffff, 0xffffffff},
}
if ip.To4() != nil {
family = syscall.AF_INET
request.Family = unix.AF_INET
} else {
family = syscall.AF_INET6
request.Family = unix.AF_INET6
}
req := packSocketDiagRequest(family, protocol, ip, uint16(srcPort))
if strings.HasPrefix(network, "tcp") {
request.Protocol = unix.IPPROTO_TCP
} else if strings.HasPrefix(network, "udp") {
request.Protocol = unix.IPPROTO_UDP
} else {
return 0, 0, ErrInvalidNetwork
}
socket, err := syscall.Socket(syscall.AF_NETLINK, syscall.SOCK_DGRAM, syscall.NETLINK_INET_DIAG)
if v4 := ip.To4(); v4 != nil {
copy(request.Src[:], v4)
} else {
copy(request.Src[:], ip)
}
binary.BigEndian.PutUint16(request.SrcPort[:], uint16(srcPort))
conn, err := netlink.Dial(unix.NETLINK_INET_DIAG, nil)
if err != nil {
return 0, 0, fmt.Errorf("dial netlink: %w", err)
return 0, 0, err
}
defer syscall.Close(socket)
defer conn.Close()
syscall.SetsockoptTimeval(socket, syscall.SOL_SOCKET, syscall.SO_SNDTIMEO, &syscall.Timeval{Usec: 100})
syscall.SetsockoptTimeval(socket, syscall.SOL_SOCKET, syscall.SO_RCVTIMEO, &syscall.Timeval{Usec: 100})
message := netlink.Message{
Header: netlink.Header{
Type: SOCK_DIAG_BY_FAMILY,
Flags: netlink.Request | netlink.Dump,
},
Data: (*(*[inetDiagRequestSize]byte)(unsafe.Pointer(request)))[:],
}
if err := syscall.Connect(socket, &syscall.SockaddrNetlink{
Family: syscall.AF_NETLINK,
Pad: 0,
Pid: 0,
Groups: 0,
}); err != nil {
messages, err := conn.Execute(message)
if err != nil {
return 0, 0, err
}
if _, err := syscall.Write(socket, req); err != nil {
return 0, 0, fmt.Errorf("write request: %w", err)
for _, msg := range messages {
if len(msg.Data) < inetDiagResponseSize {
continue
}
response := (*inetDiagResponse)(unsafe.Pointer(&msg.Data[0]))
return response.INode, response.UID, nil
}
rb := pool.Get(pool.RelayBufferSize)
defer pool.Put(rb)
n, err := syscall.Read(socket, rb)
if err != nil {
return 0, 0, fmt.Errorf("read response: %w", err)
}
messages, err := syscall.ParseNetlinkMessage(rb[:n])
if err != nil {
return 0, 0, fmt.Errorf("parse netlink message: %w", err)
} else if len(messages) == 0 {
return 0, 0, fmt.Errorf("unexcepted netlink response")
}
message := messages[0]
if message.Header.Type&syscall.NLMSG_ERROR != 0 {
return 0, 0, fmt.Errorf("netlink message: NLMSG_ERROR")
}
inode, uid := unpackSocketDiagResponse(&messages[0])
if inode < 0 || uid < 0 {
return 0, 0, fmt.Errorf("invalid inode(%d) or uid(%d)", inode, uid)
}
return inode, uid, nil
return 0, 0, ErrNotFound
}
func packSocketDiagRequest(family, protocol byte, source net.IP, sourcePort uint16) []byte {
s := make([]byte, 16)
if v4 := source.To4(); v4 != nil {
copy(s, v4)
} else {
copy(s, source)
}
buf := make([]byte, sizeOfSocketDiagRequest)
nativeEndian.PutUint32(buf[0:4], sizeOfSocketDiagRequest)
nativeEndian.PutUint16(buf[4:6], socketDiagByFamily)
nativeEndian.PutUint16(buf[6:8], syscall.NLM_F_REQUEST|syscall.NLM_F_DUMP)
nativeEndian.PutUint32(buf[8:12], 0)
nativeEndian.PutUint32(buf[12:16], 0)
buf[16] = family
buf[17] = protocol
buf[18] = 0
buf[19] = 0
nativeEndian.PutUint32(buf[20:24], 0xFFFFFFFF)
binary.BigEndian.PutUint16(buf[24:26], sourcePort)
binary.BigEndian.PutUint16(buf[26:28], 0)
copy(buf[28:44], s)
copy(buf[44:60], net.IPv6zero)
nativeEndian.PutUint32(buf[60:64], 0)
nativeEndian.PutUint64(buf[64:72], 0xFFFFFFFFFFFFFFFF)
return buf
}
func unpackSocketDiagResponse(msg *syscall.NetlinkMessage) (inode, uid int32) {
if len(msg.Data) < 72 {
return 0, 0
}
data := msg.Data
uid = int32(nativeEndian.Uint32(data[64:68]))
inode = int32(nativeEndian.Uint32(data[68:72]))
return
}
func resolveProcessNameByProcSearch(inode, uid int32) (string, error) {
files, err := os.ReadDir(pathProc)
func resolveProcessNameByProcSearch(inode, uid uint32) (string, error) {
files, err := os.ReadDir("/proc")
if err != nil {
return "", err
}
buffer := make([]byte, syscall.PathMax)
buffer := make([]byte, unix.PathMax)
socket := fmt.Appendf(nil, "socket:[%d]", inode)
for _, f := range files {
@ -177,12 +144,12 @@ func resolveProcessNameByProcSearch(inode, uid int32) (string, error) {
if err != nil {
return "", err
}
if info.Sys().(*syscall.Stat_t).Uid != uint32(uid) {
if info.Sys().(*syscall.Stat_t).Uid != uid {
continue
}
processPath := path.Join(pathProc, f.Name())
fdPath := path.Join(processPath, "fd")
processPath := filepath.Join("/proc", f.Name())
fdPath := filepath.Join(processPath, "fd")
fds, err := os.ReadDir(fdPath)
if err != nil {
@ -190,13 +157,13 @@ func resolveProcessNameByProcSearch(inode, uid int32) (string, error) {
}
for _, fd := range fds {
n, err := syscall.Readlink(path.Join(fdPath, fd.Name()), buffer)
n, err := unix.Readlink(filepath.Join(fdPath, fd.Name()), buffer)
if err != nil {
continue
}
if bytes.Equal(buffer[:n], socket) {
return os.Readlink(path.Join(processPath, "exe"))
return os.Readlink(filepath.Join(processPath, "exe"))
}
}
}