Esempio n. 1
0
// Setup creates a conf file with list of kernel modules required by given snap,
// writes it in /etc/modules-load.d/ directory and immediately loads the modules
// using /sbin/modprobe. The devMode is ignored.
//
// If the method fails it should be re-tried (with a sensible strategy) by the caller.
func (b *Backend) Setup(snapInfo *snap.Info, confinement interfaces.ConfinementOptions, repo *interfaces.Repository) error {
	snapName := snapInfo.Name()
	// Get the snippets that apply to this snap
	snippets, err := repo.SecuritySnippetsForSnap(snapInfo.Name(), interfaces.SecurityKMod)
	if err != nil {
		return fmt.Errorf("cannot obtain kmod security snippets for snap %q: %s", snapName, err)
	}

	// Get the files that this snap should have
	glob := interfaces.SecurityTagGlob(snapName)
	content, modules, err := b.combineSnippets(snapInfo, snippets)
	if err != nil {
		return fmt.Errorf("cannot obtain expected security files for snap %q: %s", snapName, err)
	}

	dir := dirs.SnapKModModulesDir
	if err := os.MkdirAll(dir, 0755); err != nil {
		return fmt.Errorf("cannot create directory for kmod files %q: %s", dir, err)
	}

	changed, _, err := osutil.EnsureDirState(dirs.SnapKModModulesDir, glob, content)
	if err != nil {
		return err
	}

	if len(changed) > 0 {
		return loadModules(modules)
	}
	return nil
}
Esempio n. 2
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// Setup creates udev rules specific to a given snap.
// If any of the rules are changed or removed then udev database is reloaded.
//
// Since udev has no concept of a complain mode, devMode is ignored.
//
// If the method fails it should be re-tried (with a sensible strategy) by the caller.
func (b *Backend) Setup(snapInfo *snap.Info, devMode bool, repo *interfaces.Repository) error {
	snapName := snapInfo.Name()
	snippets, err := repo.SecuritySnippetsForSnap(snapInfo.Name(), interfaces.SecurityUDev)
	if err != nil {
		return fmt.Errorf("cannot obtain udev security snippets for snap %q: %s", snapName, err)
	}
	content, err := b.combineSnippets(snapInfo, snippets)
	if err != nil {
		return fmt.Errorf("cannot obtain expected udev rules for snap %q: %s", snapName, err)
	}
	dir := dirs.SnapUdevRulesDir
	if err := os.MkdirAll(dir, 0755); err != nil {
		return fmt.Errorf("cannot create directory for udev rules %q: %s", dir, err)
	}

	rulesFilePath := snapRulesFilePath(snapInfo.Name())

	if len(content) == 0 {
		// Make sure that the rules file gets removed when we don't have any
		// content and exists.
		err = os.Remove(rulesFilePath)
		if err != nil && !os.IsNotExist(err) {
			return err
		} else if err == nil {
			return ReloadRules()
		}
		return nil
	}

	var buffer bytes.Buffer
	buffer.WriteString("# This file is automatically generated.\n")
	for _, snippet := range content {
		buffer.Write(snippet)
		buffer.WriteByte('\n')
	}

	rulesFileState := &osutil.FileState{
		Content: buffer.Bytes(),
		Mode:    0644,
	}

	// EnsureFileState will make sure the file will be only updated when its content
	// has changed and will otherwise return an error which prevents us from reloading
	// udev rules when not needed.
	err = osutil.EnsureFileState(rulesFilePath, rulesFileState)
	if err == osutil.ErrSameState {
		return nil
	} else if err != nil {
		return err
	}

	return ReloadRules()
}
Esempio n. 3
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func (b *Backend) Setup(snapInfo *snap.Info, confinement interfaces.ConfinementOptions, repo *interfaces.Repository) error {
	snapName := snapInfo.Name()
	rawSnippets, err := repo.SecuritySnippetsForSnap(snapInfo.Name(), interfaces.SecuritySystemd)
	if err != nil {
		return fmt.Errorf("cannot obtain systemd security snippets for snap %q: %s", snapName, err)
	}
	snippets, err := unmarshalRawSnippetMap(rawSnippets)
	if err != nil {
		return fmt.Errorf("cannot unmarshal systemd snippets for snap %q: %s", snapName, err)
	}
	snippet, err := mergeSnippetMap(snippets)
	if err != nil {
		return fmt.Errorf("cannot merge systemd snippets for snap %q: %s", snapName, err)
	}
	content, err := renderSnippet(snippet)
	if err != nil {
		return fmt.Errorf("cannot render systemd snippets for snap %q: %s", snapName, err)
	}
	dir := dirs.SnapServicesDir
	if err := os.MkdirAll(dir, 0755); err != nil {
		return fmt.Errorf("cannot create directory for systemd services %q: %s", dir, err)
	}
	glob := interfaces.InterfaceServiceName(snapName, "*")

	systemd := sysd.New(dirs.GlobalRootDir, &dummyReporter{})
	// We need to be carefully here and stop all removed service units before
	// we remove their files as otherwise systemd is not able to disable/stop
	// them anymore.
	if err := disableRemovedServices(systemd, dir, glob, content); err != nil {
		logger.Noticef("cannot stop removed services: %s", err)
	}
	changed, removed, errEnsure := osutil.EnsureDirState(dir, glob, content)
	// Reload systemd whenever something is added or removed
	if len(changed) > 0 || len(removed) > 0 {
		err := systemd.DaemonReload()
		if err != nil {
			logger.Noticef("cannot reload systemd state: %s", err)
		}
	}
	// Ensure the service is running right now and on reboots
	for _, service := range changed {
		if err := systemd.Enable(service); err != nil {
			logger.Noticef("cannot enable service %q: %s", service, err)
		}
		// If we have a new service here which isn't started yet the restart
		// operation will start it.
		if err := systemd.Restart(service, 10*time.Second); err != nil {
			logger.Noticef("cannot restart service %q: %s", service, err)
		}
	}
	return errEnsure
}
Esempio n. 4
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func (b *Backend) Setup(snapInfo *snap.Info, devMode bool, repo *interfaces.Repository) error {
	snapName := snapInfo.Name()
	rawSnippets, err := repo.SecuritySnippetsForSnap(snapInfo.Name(), interfaces.SecuritySystemd)
	if err != nil {
		return fmt.Errorf("cannot obtain systemd security snippets for snap %q: %s", snapName, err)
	}
	snippets, err := unmarshalRawSnippetMap(rawSnippets)
	if err != nil {
		return fmt.Errorf("cannot unmarshal systemd snippets for snap %q: %s", snapName, err)
	}
	snippet, err := mergeSnippetMap(snippets)
	if err != nil {
		return fmt.Errorf("cannot merge systemd snippets for snap %q: %s", snapName, err)
	}
	content, err := renderSnippet(snippet)
	if err != nil {
		return fmt.Errorf("cannot render systemd snippets for snap %q: %s", snapName, err)
	}
	dir := dirs.SnapServicesDir
	if err := os.MkdirAll(dir, 0755); err != nil {
		return fmt.Errorf("cannot create directory for systemd services %q: %s", dir, err)
	}
	glob := interfaces.InterfaceServiceName(snapName, "*")
	changed, removed, errEnsure := osutil.EnsureDirState(dir, glob, content)
	systemd := sysd.New(dirs.GlobalRootDir, &dummyReporter{})
	// Reload systemd whenever something is added or removed
	if len(changed) > 0 || len(removed) > 0 {
		err := systemd.DaemonReload()
		if err != nil {
			logger.Noticef("cannot reload systemd state: %s", err)
		}
	}
	// Start any new services
	for _, service := range changed {
		err := systemd.Start(service)
		if err != nil {
			logger.Noticef("cannot start service %q: %s", service, err)
		}
	}
	// Stop any removed services
	for _, service := range removed {
		err := systemd.Stop(service, 10*time.Second)
		if err != nil {
			logger.Noticef("cannot stop service %q: %s", service, err)
		}
	}
	return errEnsure
}
Esempio n. 5
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// Setup creates seccomp profiles specific to a given snap.
// The snap can be in developer mode to make security violations non-fatal to
// the offending application process.
//
// This method should be called after changing plug, slots, connections between
// them or application present in the snap.
func (b *Backend) Setup(snapInfo *snap.Info, devMode bool, repo *interfaces.Repository) error {
	snapName := snapInfo.Name()
	// Get the snippets that apply to this snap
	snippets, err := repo.SecuritySnippetsForSnap(snapInfo.Name(), interfaces.SecuritySecComp)
	if err != nil {
		return fmt.Errorf("cannot obtain security snippets for snap %q: %s", snapName, err)
	}
	// Get the files that this snap should have
	content, err := b.combineSnippets(snapInfo, devMode, snippets)
	if err != nil {
		return fmt.Errorf("cannot obtain expected security files for snap %q: %s", snapName, err)
	}
	glob := interfaces.SecurityTagGlob(snapName)
	dir := dirs.SnapSeccompDir
	if err := os.MkdirAll(dir, 0755); err != nil {
		return fmt.Errorf("cannot create directory for seccomp profiles %q: %s", dir, err)
	}
	_, _, err = osutil.EnsureDirState(dir, glob, content)
	if err != nil {
		return fmt.Errorf("cannot synchronize security files for snap %q: %s", snapName, err)
	}
	return nil
}
Esempio n. 6
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// Setup creates dbus configuration files specific to a given snap.
//
// DBus has no concept of a complain mode so confinment type is ignored.
func (b *Backend) Setup(snapInfo *snap.Info, opts interfaces.ConfinementOptions, repo *interfaces.Repository) error {
	snapName := snapInfo.Name()
	// Get the snippets that apply to this snap
	snippets, err := repo.SecuritySnippetsForSnap(snapInfo.Name(), interfaces.SecurityDBus)
	if err != nil {
		return fmt.Errorf("cannot obtain DBus security snippets for snap %q: %s", snapName, err)
	}
	// Get the files that this snap should have
	content, err := b.combineSnippets(snapInfo, snippets)
	if err != nil {
		return fmt.Errorf("cannot obtain expected DBus configuration files for snap %q: %s", snapName, err)
	}
	glob := fmt.Sprintf("%s.conf", interfaces.SecurityTagGlob(snapName))
	dir := dirs.SnapBusPolicyDir
	if err := os.MkdirAll(dir, 0755); err != nil {
		return fmt.Errorf("cannot create directory for DBus configuration files %q: %s", dir, err)
	}
	_, _, err = osutil.EnsureDirState(dir, glob, content)
	if err != nil {
		return fmt.Errorf("cannot synchronize DBus configuration files for snap %q: %s", snapName, err)
	}
	return nil
}
Esempio n. 7
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// Setup creates and loads apparmor profiles specific to a given snap.
// The snap can be in developer mode to make security violations non-fatal to
// the offending application process.
//
// This method should be called after changing plug, slots, connections between
// them or application present in the snap.
func (b *Backend) Setup(snapInfo *snap.Info, opts interfaces.ConfinementOptions, repo *interfaces.Repository) error {
	snapName := snapInfo.Name()
	// Get the snippets that apply to this snap
	snippets, err := repo.SecuritySnippetsForSnap(snapName, interfaces.SecurityAppArmor)
	if err != nil {
		return fmt.Errorf("cannot obtain security snippets for snap %q: %s", snapName, err)
	}
	// Get the files that this snap should have
	content, err := b.combineSnippets(snapInfo, opts, snippets)
	if err != nil {
		return fmt.Errorf("cannot obtain expected security files for snap %q: %s", snapName, err)
	}
	glob := interfaces.SecurityTagGlob(snapInfo.Name())
	dir := dirs.SnapAppArmorDir
	if err := os.MkdirAll(dir, 0755); err != nil {
		return fmt.Errorf("cannot create directory for apparmor profiles %q: %s", dir, err)
	}
	_, removed, errEnsure := osutil.EnsureDirState(dir, glob, content)
	// NOTE: load all profiles instead of just the changed profiles.  We're
	// relying on apparmor cache to make this efficient. This gives us
	// certainty that each call to Setup ends up with working profiles.
	all := make([]string, 0, len(content))
	for name := range content {
		all = append(all, name)
	}
	sort.Strings(all)
	errReload := reloadProfiles(all)
	errUnload := unloadProfiles(removed)
	if errEnsure != nil {
		return fmt.Errorf("cannot synchronize security files for snap %q: %s", snapName, errEnsure)
	}
	if errReload != nil {
		return errReload
	}
	return errUnload
}