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Refactor: linux process resolving (#2305)
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@Kr328
Kr328 authored Sep 18, 2022
1 parent 4f291fa commit 6995e98
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Showing 3 changed files with 106 additions and 119 deletions.
205 changes: 86 additions & 119 deletions component/process/process_linux.go
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Original file line number Diff line number Diff line change
Expand Up @@ -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 {
Expand All @@ -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))

socket, err := syscall.Socket(syscall.AF_NETLINK, syscall.SOCK_DGRAM, syscall.NETLINK_INET_DIAG)
if err != nil {
return 0, 0, fmt.Errorf("dial netlink: %w", err)
}
defer syscall.Close(socket)

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})

if err := syscall.Connect(socket, &syscall.SockaddrNetlink{
Family: syscall.AF_NETLINK,
Pad: 0,
Pid: 0,
Groups: 0,
}); err != nil {
return 0, 0, err
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
}

if _, err := syscall.Write(socket, req); err != nil {
return 0, 0, fmt.Errorf("write request: %w", err)
if v4 := ip.To4(); v4 != nil {
copy(request.Src[:], v4)
} else {
copy(request.Src[:], ip)
}

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)
}
binary.BigEndian.PutUint16(request.SrcPort[:], uint16(srcPort))

messages, err := syscall.ParseNetlinkMessage(rb[:n])
conn, err := netlink.Dial(unix.NETLINK_INET_DIAG, nil)
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")
return 0, 0, err
}

message := messages[0]
if message.Header.Type&syscall.NLMSG_ERROR != 0 {
return 0, 0, fmt.Errorf("netlink message: NLMSG_ERROR")
defer conn.Close()

message := netlink.Message{
Header: netlink.Header{
Type: SOCK_DIAG_BY_FAMILY,
Flags: netlink.Request | netlink.Dump,
},
Data: (*(*[inetDiagRequestSize]byte)(unsafe.Pointer(request)))[:],
}

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
}

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)
messages, err := conn.Execute(message)
if err != nil {
return 0, 0, err
}

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)
for _, msg := range messages {
if len(msg.Data) < inetDiagResponseSize {
continue
}

return buf
}
response := (*inetDiagResponse)(unsafe.Pointer(&msg.Data[0]))

func unpackSocketDiagResponse(msg *syscall.NetlinkMessage) (inode, uid int32) {
if len(msg.Data) < 72 {
return 0, 0
return response.INode, response.UID, nil
}

data := msg.Data

uid = int32(nativeEndian.Uint32(data[64:68]))
inode = int32(nativeEndian.Uint32(data[68:72]))

return
return 0, 0, ErrNotFound
}

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 {
Expand All @@ -177,26 +144,26 @@ 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 {
continue
}

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"))
}
}
}
Expand Down
4 changes: 4 additions & 0 deletions go.mod
View file
Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,7 @@ require (
github.com/gofrs/uuid v4.2.0+incompatible
github.com/gorilla/websocket v1.5.0
github.com/insomniacslk/dhcp v0.0.0-20220822114210-de18a9d48e84
github.com/mdlayher/netlink v1.6.0
github.com/miekg/dns v1.1.50
github.com/oschwald/geoip2-golang v1.8.0
github.com/sirupsen/logrus v1.9.0
Expand All @@ -26,7 +27,10 @@ require (
require (
github.com/ajg/form v1.5.1 // indirect
github.com/davecgh/go-spew v1.1.1 // indirect
github.com/google/go-cmp v0.5.7 // indirect
github.com/josharian/native v1.0.0 // indirect
github.com/kr/text v0.2.0 // indirect
github.com/mdlayher/socket v0.1.1 // indirect
github.com/oschwald/maxminddb-golang v1.10.0 // indirect
github.com/pmezard/go-difflib v1.0.0 // indirect
github.com/u-root/uio v0.0.0-20210528114334-82958018845c // indirect
Expand Down
16 changes: 16 additions & 0 deletions go.sum
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,12 +18,17 @@ github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMyw
github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
github.com/google/go-cmp v0.5.7 h1:81/ik6ipDQS2aGcBfIN5dHDB36BwrStyeAQquSYCV4o=
github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
github.com/gorilla/websocket v1.5.0 h1:PPwGk2jz7EePpoHN/+ClbZu8SPxiqlu12wZP/3sWmnc=
github.com/gorilla/websocket v1.5.0/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
github.com/hugelgupf/socketpair v0.0.0-20190730060125-05d35a94e714/go.mod h1:2Goc3h8EklBH5mspfHFxBnEoURQCGzQQH1ga9Myjvis=
github.com/insomniacslk/dhcp v0.0.0-20220822114210-de18a9d48e84 h1:MJTy6H+EpXLeAn0P5WAWeLk6dJA3V0ik6S3VJfUyQuI=
github.com/insomniacslk/dhcp v0.0.0-20220822114210-de18a9d48e84/go.mod h1:h+MxyHxRg9NH3terB1nfRIUaQEcI0XOVkdR9LNBlp8E=
github.com/josharian/native v1.0.0 h1:Ts/E8zCSEsG17dUqv7joXJFybuMLjQfWE04tsBODTxk=
github.com/josharian/native v1.0.0/go.mod h1:7X/raswPFr05uY3HiLlYeyQntB6OO7E/d2Cu7qoaN2w=
github.com/jsimonetti/rtnetlink v0.0.0-20190606172950-9527aa82566a/go.mod h1:Oz+70psSo5OFh8DBl0Zv2ACw7Esh6pPUphlvZG9x7uw=
github.com/jsimonetti/rtnetlink v0.0.0-20200117123717-f846d4f6c1f4/go.mod h1:WGuG/smIU4J/54PblvSbh+xvCZmpJnFgr3ds6Z55XMQ=
github.com/jsimonetti/rtnetlink v0.0.0-20201009170750-9c6f07d100c1/go.mod h1:hqoO/u39cqLeBLebZ8fWdE96O7FxrAsRYhnVOdgHxok=
Expand All @@ -37,8 +42,12 @@ github.com/mdlayher/netlink v0.0.0-20190409211403-11939a169225/go.mod h1:eQB3mZE
github.com/mdlayher/netlink v1.0.0/go.mod h1:KxeJAFOFLG6AjpyDkQ/iIhxygIUKD+vcwqcnu43w/+M=
github.com/mdlayher/netlink v1.1.0/go.mod h1:H4WCitaheIsdF9yOYu8CFmCgQthAPIWZmcKp9uZHgmY=
github.com/mdlayher/netlink v1.1.1/go.mod h1:WTYpFb/WTvlRJAyKhZL5/uy69TDDpHHu2VZmb2XgV7o=
github.com/mdlayher/netlink v1.6.0 h1:rOHX5yl7qnlpiVkFWoqccueppMtXzeziFjWAjLg6sz0=
github.com/mdlayher/netlink v1.6.0/go.mod h1:0o3PlBmGst1xve7wQ7j/hwpNaFaH4qCRyWCdcZk8/vA=
github.com/mdlayher/raw v0.0.0-20190606142536-fef19f00fc18/go.mod h1:7EpbotpCmVZcu+KCX4g9WaRNuu11uyhiW7+Le1dKawg=
github.com/mdlayher/raw v0.0.0-20191009151244-50f2db8cc065/go.mod h1:7EpbotpCmVZcu+KCX4g9WaRNuu11uyhiW7+Le1dKawg=
github.com/mdlayher/socket v0.1.1 h1:q3uOGirUPfAV2MUoaC7BavjQ154J7+JOkTWyiV+intI=
github.com/mdlayher/socket v0.1.1/go.mod h1:mYV5YIZAfHh4dzDVzI8x8tWLWCliuX8Mon5Awbj+qDs=
github.com/miekg/dns v1.1.50 h1:DQUfb9uc6smULcREF09Uc+/Gd46YWqJd5DbpPE9xkcA=
github.com/miekg/dns v1.1.50/go.mod h1:e3IlAVfNqAllflbibAZEWOXOQ+Ynzk/dDozDxY7XnME=
github.com/oschwald/geoip2-golang v1.8.0 h1:KfjYB8ojCEn/QLqsDU0AzrJ3R5Qa9vFlx3z6SLNcKTs=
Expand Down Expand Up @@ -87,6 +96,8 @@ golang.org/x/net v0.0.0-20201010224723-4f7140c49acb/go.mod h1:sp8m0HH+o8qH0wwXwY
golang.org/x/net v0.0.0-20201110031124-69a78807bb2b/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
golang.org/x/net v0.0.0-20210726213435-c6fcb2dbf985/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
golang.org/x/net v0.0.0-20210928044308-7d9f5e0b762b/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
golang.org/x/net v0.0.0-20220127200216-cd36cc0744dd/go.mod h1:CfG3xpIq0wQ8r1q4Su4UZFWDARRcnwPjda9FqA0JpMk=
golang.org/x/net v0.0.0-20220822230855-b0a4917ee28c h1:JVAXQ10yGGVbSyoer5VILysz6YKjdNT2bsvlayjqhes=
golang.org/x/net v0.0.0-20220822230855-b0a4917ee28c/go.mod h1:YDH+HFinaLZZlnHAfSS6ZXJJ9M9t4Dl22yv3iI2vPwk=
golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
Expand All @@ -111,11 +122,16 @@ golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7w
golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.0.0-20210525143221-35b2ab0089ea/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.0.0-20220128215802-99c3d69c2c27/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.0.0-20220825204002-c680a09ffe64 h1:UiNENfZ8gDvpiWw7IpOMQ27spWmThO1RwwdQVbJahJM=
golang.org/x/sys v0.0.0-20220825204002-c680a09ffe64/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
Expand Down

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