mirror of https://github.com/k3s-io/k3s
96 lines
2.7 KiB
Go
96 lines
2.7 KiB
Go
// The UnixCredentials system call is currently only implemented on Linux
|
|
// http://golang.org/src/pkg/syscall/sockcmsg_linux.go
|
|
// https://golang.org/s/go1.4-syscall
|
|
// http://code.google.com/p/go/source/browse/unix/sockcmsg_linux.go?repo=sys
|
|
|
|
// Local implementation of the UnixCredentials system call for DragonFly BSD
|
|
|
|
package dbus
|
|
|
|
/*
|
|
#include <sys/ucred.h>
|
|
*/
|
|
import "C"
|
|
|
|
import (
|
|
"io"
|
|
"os"
|
|
"syscall"
|
|
"unsafe"
|
|
)
|
|
|
|
// http://golang.org/src/pkg/syscall/ztypes_linux_amd64.go
|
|
// http://golang.org/src/pkg/syscall/ztypes_dragonfly_amd64.go
|
|
type Ucred struct {
|
|
Pid int32
|
|
Uid uint32
|
|
Gid uint32
|
|
}
|
|
|
|
// http://golang.org/src/pkg/syscall/types_linux.go
|
|
// http://golang.org/src/pkg/syscall/types_dragonfly.go
|
|
// https://github.com/DragonFlyBSD/DragonFlyBSD/blob/master/sys/sys/ucred.h
|
|
const (
|
|
SizeofUcred = C.sizeof_struct_ucred
|
|
)
|
|
|
|
// http://golang.org/src/pkg/syscall/sockcmsg_unix.go
|
|
func cmsgAlignOf(salen int) int {
|
|
// From http://golang.org/src/pkg/syscall/sockcmsg_unix.go
|
|
//salign := sizeofPtr
|
|
// NOTE: It seems like 64-bit Darwin and DragonFly BSD kernels
|
|
// still require 32-bit aligned access to network subsystem.
|
|
//if darwin64Bit || dragonfly64Bit {
|
|
// salign = 4
|
|
//}
|
|
salign := 4
|
|
return (salen + salign - 1) & ^(salign - 1)
|
|
}
|
|
|
|
// http://golang.org/src/pkg/syscall/sockcmsg_unix.go
|
|
func cmsgData(h *syscall.Cmsghdr) unsafe.Pointer {
|
|
return unsafe.Pointer(uintptr(unsafe.Pointer(h)) + uintptr(cmsgAlignOf(syscall.SizeofCmsghdr)))
|
|
}
|
|
|
|
// http://golang.org/src/pkg/syscall/sockcmsg_linux.go
|
|
// UnixCredentials encodes credentials into a socket control message
|
|
// for sending to another process. This can be used for
|
|
// authentication.
|
|
func UnixCredentials(ucred *Ucred) []byte {
|
|
b := make([]byte, syscall.CmsgSpace(SizeofUcred))
|
|
h := (*syscall.Cmsghdr)(unsafe.Pointer(&b[0]))
|
|
h.Level = syscall.SOL_SOCKET
|
|
h.Type = syscall.SCM_CREDS
|
|
h.SetLen(syscall.CmsgLen(SizeofUcred))
|
|
*((*Ucred)(cmsgData(h))) = *ucred
|
|
return b
|
|
}
|
|
|
|
// http://golang.org/src/pkg/syscall/sockcmsg_linux.go
|
|
// ParseUnixCredentials decodes a socket control message that contains
|
|
// credentials in a Ucred structure. To receive such a message, the
|
|
// SO_PASSCRED option must be enabled on the socket.
|
|
func ParseUnixCredentials(m *syscall.SocketControlMessage) (*Ucred, error) {
|
|
if m.Header.Level != syscall.SOL_SOCKET {
|
|
return nil, syscall.EINVAL
|
|
}
|
|
if m.Header.Type != syscall.SCM_CREDS {
|
|
return nil, syscall.EINVAL
|
|
}
|
|
ucred := *(*Ucred)(unsafe.Pointer(&m.Data[0]))
|
|
return &ucred, nil
|
|
}
|
|
|
|
func (t *unixTransport) SendNullByte() error {
|
|
ucred := &Ucred{Pid: int32(os.Getpid()), Uid: uint32(os.Getuid()), Gid: uint32(os.Getgid())}
|
|
b := UnixCredentials(ucred)
|
|
_, oobn, err := t.UnixConn.WriteMsgUnix([]byte{0}, b, nil)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if oobn != len(b) {
|
|
return io.ErrShortWrite
|
|
}
|
|
return nil
|
|
}
|