tailscale/doctor/permissions/permissions_linux.go

63 lines
1.4 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build linux
package permissions
import (
"fmt"
"strings"
"unsafe"
"golang.org/x/sys/unix"
"tailscale.com/types/logger"
)
func permissionsImpl(logf logger.Logf) error {
// NOTE: getresuid and getresgid never fail unless passed an
// invalid address.
var ruid, euid, suid uint64
unix.Syscall(unix.SYS_GETRESUID,
uintptr(unsafe.Pointer(&ruid)),
uintptr(unsafe.Pointer(&euid)),
uintptr(unsafe.Pointer(&suid)),
)
var rgid, egid, sgid uint64
unix.Syscall(unix.SYS_GETRESGID,
uintptr(unsafe.Pointer(&rgid)),
uintptr(unsafe.Pointer(&egid)),
uintptr(unsafe.Pointer(&sgid)),
)
groups, _ := unix.Getgroups()
var buf strings.Builder
fmt.Fprintf(&buf, "ruid=%s euid=%s suid=%s rgid=%s egid=%s sgid=%s groups=%s",
formatUserID(ruid), formatUserID(euid), formatUserID(suid),
formatGroupID(rgid), formatGroupID(egid), formatGroupID(sgid),
formatGroups(groups),
)
// Get process capabilities
var (
capHeader = unix.CapUserHeader{
Version: unix.LINUX_CAPABILITY_VERSION_3,
Pid: 0, // 0 means 'ourselves'
}
capData unix.CapUserData
)
if err := unix.Capget(&capHeader, &capData); err != nil {
fmt.Fprintf(&buf, " caperr=%v", err)
} else {
fmt.Fprintf(&buf, " cap_effective=%08x cap_permitted=%08x cap_inheritable=%08x",
capData.Effective, capData.Permitted, capData.Inheritable,
)
}
logf("%s", buf.String())
return nil
}