runc/libcontainer/apparmor/apparmor.go

61 lines
1.4 KiB
Go

// +build apparmor,linux
package apparmor
import (
"fmt"
"io/ioutil"
"os"
"github.com/opencontainers/runc/libcontainer/utils"
)
// IsEnabled returns true if apparmor is enabled for the host.
func IsEnabled() bool {
if _, err := os.Stat("/sys/kernel/security/apparmor"); err == nil && os.Getenv("container") == "" {
if _, err = os.Stat("/sbin/apparmor_parser"); err == nil {
buf, err := ioutil.ReadFile("/sys/module/apparmor/parameters/enabled")
return err == nil && len(buf) > 1 && buf[0] == 'Y'
}
}
return false
}
func setProcAttr(attr, value string) error {
// Under AppArmor you can only change your own attr, so use /proc/self/
// instead of /proc/<tid>/ like libapparmor does
path := fmt.Sprintf("/proc/self/attr/%s", attr)
f, err := os.OpenFile(path, os.O_WRONLY, 0)
if err != nil {
return err
}
defer f.Close()
if err := utils.EnsureProcHandle(f); err != nil {
return err
}
_, err = fmt.Fprintf(f, "%s", value)
return err
}
// changeOnExec reimplements aa_change_onexec from libapparmor in Go
func changeOnExec(name string) error {
value := "exec " + name
if err := setProcAttr("exec", value); err != nil {
return fmt.Errorf("apparmor failed to apply profile: %s", err)
}
return nil
}
// ApplyProfile will apply the profile with the specified name to the process after
// the next exec.
func ApplyProfile(name string) error {
if name == "" {
return nil
}
return changeOnExec(name)
}