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|
//go:build linux && cgo && !agent
package sys
import (
"os"
"os/exec"
"strconv"
"strings"
"golang.org/x/sys/unix"
"github.com/lxc/incus/v6/internal/server/db/cluster"
"github.com/lxc/incus/v6/internal/server/db/warningtype"
localUtil "github.com/lxc/incus/v6/internal/server/util"
internalUtil "github.com/lxc/incus/v6/internal/util"
"github.com/lxc/incus/v6/shared/logger"
"github.com/lxc/incus/v6/shared/util"
)
// Initialize AppArmor-specific attributes.
func (s *OS) initAppArmor() []cluster.Warning {
var dbWarnings []cluster.Warning
/* Detect AppArmor availability */
_, err := exec.LookPath("apparmor_parser")
if util.IsFalse(os.Getenv("INCUS_SECURITY_APPARMOR")) {
logger.Warnf("AppArmor support has been manually disabled")
dbWarnings = append(dbWarnings, cluster.Warning{
TypeCode: warningtype.AppArmorNotAvailable,
LastMessage: "Manually disabled",
})
} else if !internalUtil.IsDir("/sys/kernel/security/apparmor") {
logger.Warnf("AppArmor support has been disabled because of lack of kernel support")
dbWarnings = append(dbWarnings, cluster.Warning{
TypeCode: warningtype.AppArmorNotAvailable,
LastMessage: "Disabled because of lack of kernel support",
})
} else if err != nil {
logger.Warnf("AppArmor support has been disabled because 'apparmor_parser' couldn't be found")
dbWarnings = append(dbWarnings, cluster.Warning{
TypeCode: warningtype.AppArmorNotAvailable,
LastMessage: "Disabled because 'apparmor_parser' couldn't be found",
})
} else {
s.AppArmorAvailable = true
}
/* Detect AppArmor stacking support */
s.AppArmorStacking = appArmorCanStack()
/* Detect existing AppArmor stack */
if util.PathExists("/sys/kernel/security/apparmor/.ns_stacked") {
contentBytes, err := os.ReadFile("/sys/kernel/security/apparmor/.ns_stacked")
if err == nil && string(contentBytes) == "yes\n" {
s.AppArmorStacked = true
}
}
/* Detect AppArmor admin support */
if !haveMacAdmin() {
if s.AppArmorAvailable {
logger.Warnf("Per-container AppArmor profiles are disabled because the mac_admin capability is missing")
}
} else if s.RunningInUserNS && !s.AppArmorStacked {
if s.AppArmorAvailable {
logger.Warnf("Per-container AppArmor profiles are disabled because Incus is running in an unprivileged container without stacking")
}
} else {
s.AppArmorAdmin = true
}
/* Detect AppArmor confinment */
profile := localUtil.AppArmorProfile()
if profile != "unconfined" && profile != "" {
if s.AppArmorAvailable {
logger.Warnf("Per-container AppArmor profiles are disabled because Incus is already protected by AppArmor")
}
s.AppArmorConfined = true
}
return dbWarnings
}
func haveMacAdmin() bool {
hdr := unix.CapUserHeader{Pid: 0}
// Get hdr version to check.
err := unix.Capget(&hdr, nil)
if err != nil {
return false
}
// Return false if not version 3.
if hdr.Version != unix.LINUX_CAPABILITY_VERSION_3 {
return false
}
var data [2]unix.CapUserData
err = unix.Capget(&hdr, &data[0])
if err != nil {
return false
}
idx := unix.CAP_MAC_ADMIN / 32
bit := uint(unix.CAP_MAC_ADMIN % 32)
return ((1 << bit) & data[idx].Effective) != 0
}
// Returns true if AppArmor stacking support is available.
func appArmorCanStack() bool {
contentBytes, err := os.ReadFile("/sys/kernel/security/apparmor/features/domain/stack")
if err != nil {
return false
}
if string(contentBytes) != "yes\n" {
return false
}
contentBytes, err = os.ReadFile("/sys/kernel/security/apparmor/features/domain/version")
if err != nil {
return false
}
content := string(contentBytes)
parts := strings.Split(strings.TrimSpace(content), ".")
if len(parts) == 0 {
logger.Warn("Unknown apparmor domain version", logger.Ctx{"version": content})
return false
}
major, err := strconv.Atoi(parts[0])
if err != nil {
logger.Warn("Unknown apparmor domain version", logger.Ctx{"version": content})
return false
}
minor := 0
if len(parts) == 2 {
minor, err = strconv.Atoi(parts[1])
if err != nil {
logger.Warn("Unknown apparmor domain version", logger.Ctx{"version": content})
return false
}
}
return major >= 1 && minor >= 2
}
|
