Pull request: 3845 hosts fatality

Merge in DNS/adguard-home from 3845-hosts-fatality to master

Updates #3845.

Squashed commit of the following:

commit 1447efcc4066e0226feaebde01fcc632cb7b7432
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Wed Nov 17 17:14:35 2021 +0300

    home: imp readability

commit e934499072e983e1111b6c976eb93e1d6017981b
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Wed Nov 17 13:35:10 2021 +0300

    aghnet: imp more

commit ed9995ee52bd9ec3fa130f3f56989619184a6669
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Wed Nov 17 13:05:56 2021 +0300

    all: imp docs, code

commit 7b0718a1a4a58a4fd5f1ba24c33792b0610c334f
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Tue Nov 16 20:32:24 2021 +0300

    all: reduce hosts container fatality
This commit is contained in:
Eugene Burkov 2021-11-17 17:21:10 +03:00
parent 4a4b4715ca
commit 9bac4b3db2
6 changed files with 171 additions and 83 deletions

View File

@ -43,6 +43,9 @@ type HostsContainer struct {
// engine serves rulesStrg.
engine *urlfilter.DNSEngine
// done is the channel to sign closing the container.
done chan struct{}
// updates is the channel for receiving updated hosts.
updates chan *netutil.IPMap
// last is the set of hosts that was cached within last detected change.
@ -57,12 +60,12 @@ type HostsContainer struct {
patterns []string
}
// errNoPaths is returned when there are no paths to watch passed to the
// HostsContainer.
const errNoPaths errors.Error = "hosts paths are empty"
// ErrNoHostsPaths is returned when there are no valid paths to watch passed to
// the HostsContainer.
const ErrNoHostsPaths errors.Error = "no valid paths to hosts files provided"
// NewHostsContainer creates a container of hosts, that watches the paths with
// w. paths shouldn't be empty and each of them should locate either a file or
// w. paths shouldn't be empty and each of paths should locate either a file or
// a directory in fsys. fsys and w must be non-nil.
func NewHostsContainer(
fsys fs.FS,
@ -72,16 +75,20 @@ func NewHostsContainer(
defer func() { err = errors.Annotate(err, "%s: %w", hostsContainerPref) }()
if len(paths) == 0 {
return nil, errNoPaths
return nil, ErrNoHostsPaths
}
patterns, err := pathsToPatterns(fsys, paths)
var patterns []string
patterns, err = pathsToPatterns(fsys, paths)
if err != nil {
return nil, err
} else if len(patterns) == 0 {
return nil, ErrNoHostsPaths
}
hc = &HostsContainer{
engLock: &sync.RWMutex{},
done: make(chan struct{}, 1),
updates: make(chan *netutil.IPMap, 1),
last: &netutil.IPMap{},
fsys: fsys,
@ -97,16 +104,13 @@ func NewHostsContainer(
}
for _, p := range paths {
err = w.Add(p)
if err == nil {
continue
} else if errors.Is(err, fs.ErrNotExist) {
log.Debug("%s: file %q expected to exist but doesn't", hostsContainerPref, p)
continue
if err = w.Add(p); err != nil {
if !errors.Is(err, fs.ErrNotExist) {
return nil, fmt.Errorf("adding path: %w", err)
}
return nil, fmt.Errorf("adding path: %w", err)
log.Debug("%s: file %q expected to exist but doesn't", hostsContainerPref, p)
}
}
go hc.handleEvents()
@ -130,16 +134,17 @@ func (hc *HostsContainer) MatchRequest(
hc.engLock.RLock()
defer hc.engLock.RUnlock()
res, ok = hc.engine.MatchRequest(req)
return res, ok
return hc.engine.MatchRequest(req)
}
// Close implements the io.Closer interface for *HostsContainer.
// Close implements the io.Closer interface for *HostsContainer. Close must
// only be called once. The returned err is always nil.
func (hc *HostsContainer) Close() (err error) {
log.Debug("%s: closing", hostsContainerPref)
return errors.Annotate(hc.w.Close(), "%s: closing: %w", hostsContainerPref)
close(hc.done)
return nil
}
// Upd returns the channel into which the updates are sent. The receivable
@ -152,8 +157,14 @@ func (hc *HostsContainer) Upd() (updates <-chan *netutil.IPMap) {
func pathsToPatterns(fsys fs.FS, paths []string) (patterns []string, err error) {
for i, p := range paths {
var fi fs.FileInfo
if fi, err = fs.Stat(fsys, p); err != nil {
return nil, fmt.Errorf("%q at index %d: %w", p, i, err)
fi, err = fs.Stat(fsys, p)
if err != nil {
if errors.Is(err, fs.ErrNotExist) {
continue
}
// Don't put a filename here since it's already added by fs.Stat.
return nil, fmt.Errorf("path at index %d: %w", i, err)
}
if fi.IsDir() {
@ -173,10 +184,22 @@ func (hc *HostsContainer) handleEvents() {
defer close(hc.updates)
for range hc.w.Events() {
ok, eventsCh := true, hc.w.Events()
for ok {
select {
case _, ok = <-eventsCh:
if !ok {
log.Debug("%s: watcher closed the events channel", hostsContainerPref)
continue
}
if err := hc.refresh(); err != nil {
log.Error("%s: %s", hostsContainerPref, err)
}
case _, ok = <-hc.done:
// Go on.
}
}
}
@ -373,6 +396,8 @@ func (hp *hostsParser) newStrg() (s *filterlist.RuleStorage, err error) {
// refresh gets the data from specified files and propagates the updates if
// needed.
//
// TODO(e.burkov): Accept a parameter to specify the files to refresh.
func (hc *HostsContainer) refresh() (err error) {
log.Debug("%s: refreshing", hostsContainerPref)

View File

@ -24,14 +24,6 @@ const (
sp = " "
)
const closeCalled errors.Error = "close method called"
// fsWatcherOnCloseStub is a stub implementation of the Close method of
// aghos.FSWatcher.
func fsWatcherOnCloseStub() (err error) {
return closeCalled
}
func TestNewHostsContainer(t *testing.T) {
const dirname = "dir"
const filename = "file1"
@ -43,30 +35,25 @@ func TestNewHostsContainer(t *testing.T) {
}
testCases := []struct {
wantErr error
name string
paths []string
wantErr error
wantPatterns []string
}{{
wantErr: nil,
name: "one_file",
paths: []string{p},
wantErr: nil,
wantPatterns: []string{p},
}, {
wantErr: ErrNoHostsPaths,
name: "no_files",
paths: []string{},
wantErr: errNoPaths,
wantPatterns: nil,
}, {
wantErr: ErrNoHostsPaths,
name: "non-existent_file",
paths: []string{path.Join(dirname, filename+"2")},
wantErr: fs.ErrNotExist,
wantPatterns: nil,
}, {
wantErr: nil,
name: "whole_dir",
paths: []string{dirname},
wantErr: nil,
wantPatterns: []string{path.Join(dirname, "*")},
}}
for _, tc := range testCases {
@ -88,7 +75,7 @@ func TestNewHostsContainer(t *testing.T) {
hc, err := NewHostsContainer(testFS, &aghtest.FSWatcher{
OnEvents: onEvents,
OnAdd: onAdd,
OnClose: fsWatcherOnCloseStub,
OnClose: func() (err error) { panic("not implemented") },
}, tc.paths...)
if tc.wantErr != nil {
require.ErrorIs(t, err, tc.wantErr)
@ -99,13 +86,8 @@ func TestNewHostsContainer(t *testing.T) {
}
require.NoError(t, err)
t.Cleanup(func() {
require.ErrorIs(t, hc.Close(), closeCalled)
})
require.NotNil(t, hc)
assert.Equal(t, tc.wantPatterns, hc.patterns)
assert.NotNil(t, <-hc.Upd())
eventsCh <- struct{}{}
@ -178,12 +160,11 @@ func TestHostsContainer_Refresh(t *testing.T) {
return nil
},
OnClose: fsWatcherOnCloseStub,
OnClose: func() (err error) { panic("not implemented") },
}
hc, err := NewHostsContainer(testFS, w, dirname)
require.NoError(t, err)
t.Cleanup(func() { require.ErrorIs(t, hc.Close(), closeCalled) })
checkRefresh := func(t *testing.T, wantHosts *stringutil.Set) {
upd, ok := <-hc.Upd()
@ -257,10 +238,9 @@ func TestHostsContainer_MatchRequest(t *testing.T) {
return nil
},
OnClose: fsWatcherOnCloseStub,
OnClose: func() (err error) { panic("not implemented") },
}, filename)
require.NoError(t, err)
t.Cleanup(func() { require.ErrorIs(t, hc.Close(), closeCalled) })
testCase := []struct {
name string
@ -398,7 +378,7 @@ func TestHostsContainer_PathsToPatterns(t *testing.T) {
paths: []string{fp1, path.Join(dir0, dir1)},
}, {
name: "non-existing",
wantErr: fs.ErrNotExist,
wantErr: nil,
want: nil,
paths: []string{path.Join(dir0, "file_3")},
}}
@ -417,6 +397,19 @@ func TestHostsContainer_PathsToPatterns(t *testing.T) {
assert.Equal(t, tc.want, patterns)
})
}
t.Run("bad_file", func(t *testing.T) {
const errStat errors.Error = "bad file"
badFS := &aghtest.StatFS{
OnStat: func(name string) (fs.FileInfo, error) {
return nil, errStat
},
}
_, err := pathsToPatterns(badFS, []string{""})
assert.ErrorIs(t, err, errStat)
})
}
func TestUniqueRules_AddPair(t *testing.T) {

View File

@ -82,6 +82,8 @@ func (w *osWatcher) Events() (e <-chan event) {
}
// Add implements the FSWatcher interface for *osWatcher.
//
// TODO(e.burkov): Make it accept non-existing files to detect it's creating.
func (w *osWatcher) Add(name string) (err error) {
defer func() { err = errors.Annotate(err, "%s: %w", osWatcherPref) }()

View File

@ -0,0 +1,46 @@
package aghtest
import "io/fs"
// type check
var _ fs.FS = &FS{}
// FS is a mock fs.FS implementation to use in tests.
type FS struct {
OnOpen func(name string) (fs.File, error)
}
// Open implements the fs.FS interface for *FS.
func (fsys *FS) Open(name string) (fs.File, error) {
return fsys.OnOpen(name)
}
// type check
var _ fs.StatFS = &StatFS{}
// StatFS is a mock fs.StatFS implementation to use in tests.
type StatFS struct {
// FS is embedded here to avoid implementing all it's methods.
FS
OnStat func(name string) (fs.FileInfo, error)
}
// Stat implements the fs.StatFS interface for *StatFS.
func (fsys *StatFS) Stat(name string) (fs.FileInfo, error) {
return fsys.OnStat(name)
}
// type check
var _ fs.GlobFS = &GlobFS{}
// GlobFS is a mock fs.GlobFS implementation to use in tests.
type GlobFS struct {
// FS is embedded here to avoid implementing all it's methods.
FS
OnGlob func(pattern string) ([]string, error)
}
// Glob implements the fs.GlobFS interface for *GlobFS.
func (fsys *GlobFS) Glob(pattern string) ([]string, error) {
return fsys.OnGlob(pattern)
}

View File

@ -1077,8 +1077,6 @@ func TestPTRResponseFromHosts(t *testing.T) {
`)},
}
const closeCalled errors.Error = "close method called"
var eventsCalledCounter uint32
hc, err := aghnet.NewHostsContainer(testFS, &aghtest.FSWatcher{
OnEvents: func() (e <-chan struct{}) {
@ -1091,13 +1089,11 @@ func TestPTRResponseFromHosts(t *testing.T) {
return nil
},
OnClose: func() (err error) { return closeCalled },
OnClose: func() (err error) { panic("not implemented") },
}, hostsFilename)
require.NoError(t, err)
t.Cleanup(func() {
assert.Equal(t, uint32(1), atomic.LoadUint32(&eventsCalledCounter))
require.ErrorIs(t, hc.Close(), closeCalled)
})
flt := filtering.New(&filtering.Config{

View File

@ -59,6 +59,9 @@ type homeContext struct {
// etcHosts is an IP-hostname pairs set taken from system configuration
// (e.g. /etc/hosts) files.
etcHosts *aghnet.HostsContainer
// hostsWatcher is the watcher to detect changes in the hosts files.
hostsWatcher aghos.FSWatcher
updater *updater.Updater
subnetDetector *aghnet.SubnetDetector
@ -232,6 +235,33 @@ func configureOS(conf *configuration) (err error) {
return nil
}
// setupHostsContainer initializes the structures to keep up-to-date the hosts
// provided by the OS.
func setupHostsContainer() (err error) {
Context.hostsWatcher, err = aghos.NewOSWritesWatcher()
if err != nil {
return fmt.Errorf("initing hosts watcher: %w", err)
}
Context.etcHosts, err = aghnet.NewHostsContainer(
aghos.RootDirFS(),
Context.hostsWatcher,
aghnet.DefaultHostsPaths()...,
)
if err != nil {
cerr := Context.hostsWatcher.Close()
if errors.Is(err, aghnet.ErrNoHostsPaths) && cerr == nil {
log.Info("warning: initing hosts container: %s", err)
return nil
}
return errors.WithDeferred(fmt.Errorf("initing hosts container: %w", err), cerr)
}
return nil
}
func setupConfig(args options) (err error) {
config.DHCP.WorkDir = Context.workDir
config.DHCP.HTTPRegister = httpRegister
@ -259,19 +289,8 @@ func setupConfig(args options) (err error) {
})
if !args.noEtcHosts {
var osWritesWatcher aghos.FSWatcher
osWritesWatcher, err = aghos.NewOSWritesWatcher()
if err != nil {
return fmt.Errorf("initing os watcher: %w", err)
}
Context.etcHosts, err = aghnet.NewHostsContainer(
aghos.RootDirFS(),
osWritesWatcher,
aghnet.DefaultHostsPaths()...,
)
if err != nil {
return fmt.Errorf("initing hosts container: %w", err)
if err = setupHostsContainer(); err != nil {
return err
}
}
Context.clients.Init(config.Clients, Context.dhcpServer, Context.etcHosts)
@ -661,8 +680,15 @@ func cleanup(ctx context.Context) {
}
if Context.etcHosts != nil {
// Currently Context.hostsWatcher is only used in Context.etcHosts and
// needs closing only in case of the successful initialization of
// Context.etcHosts.
if err = Context.hostsWatcher.Close(); err != nil {
log.Error("closing hosts watcher: %s", err)
}
if err = Context.etcHosts.Close(); err != nil {
log.Error("stopping hosts container: %s", err)
log.Error("closing hosts container: %s", err)
}
}