Add rule set

route/rule_set_remote.go

@@ -0,0 +1,218 @@
+package route
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"net"
+	"net/http"
+	"time"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/json"
+	"github.com/sagernet/sing-box/common/srs"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/logger"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+	"github.com/sagernet/sing/service"
+)
+
+var _ adapter.RuleSet = (*RemoteRuleSet)(nil)
+
+type RemoteRuleSet struct {
+	ctx            context.Context
+	cancel         context.CancelFunc
+	router         adapter.Router
+	logger         logger.ContextLogger
+	options        option.RuleSet
+	updateInterval time.Duration
+	dialer         N.Dialer
+	rules          []adapter.HeadlessRule
+	lastUpdated    time.Time
+	lastEtag       string
+	updateTicker   *time.Ticker
+}
+
+func NewRemoteRuleSet(ctx context.Context, router adapter.Router, logger logger.ContextLogger, options option.RuleSet) *RemoteRuleSet {
+	ctx, cancel := context.WithCancel(ctx)
+	var updateInterval time.Duration
+	if options.RemoteOptions.UpdateInterval > 0 {
+		updateInterval = time.Duration(options.RemoteOptions.UpdateInterval)
+	} else {
+		updateInterval = 12 * time.Hour
+	}
+	return &RemoteRuleSet{
+		ctx:            ctx,
+		cancel:         cancel,
+		router:         router,
+		logger:         logger,
+		options:        options,
+		updateInterval: updateInterval,
+	}
+}
+
+func (s *RemoteRuleSet) Match(metadata *adapter.InboundContext) bool {
+	for _, rule := range s.rules {
+		if rule.Match(metadata) {
+			return true
+		}
+	}
+	return false
+}
+
+func (s *RemoteRuleSet) Start() error {
+	var dialer N.Dialer
+	if s.options.RemoteOptions.DownloadDetour != "" {
+		outbound, loaded := s.router.Outbound(s.options.RemoteOptions.DownloadDetour)
+		if !loaded {
+			return E.New("download_detour not found: ", s.options.RemoteOptions.DownloadDetour)
+		}
+		dialer = outbound
+	} else {
+		outbound, err := s.router.DefaultOutbound(N.NetworkTCP)
+		if err != nil {
+			return err
+		}
+		dialer = outbound
+	}
+	s.dialer = dialer
+	cacheFile := service.FromContext[adapter.CacheFile](s.ctx)
+	if cacheFile != nil {
+		if savedSet := cacheFile.LoadRuleSet(s.options.Tag); savedSet != nil {
+			err := s.loadBytes(savedSet.Content)
+			if err != nil {
+				return E.Cause(err, "restore cached rule-set")
+			}
+			s.lastUpdated = savedSet.LastUpdated
+			s.lastEtag = savedSet.LastEtag
+		}
+	}
+	if s.lastUpdated.IsZero() || time.Since(s.lastUpdated) > s.updateInterval {
+		err := s.fetchOnce()
+		if err != nil {
+			return E.Cause(err, "fetch rule-set ", s.options.Tag)
+		}
+	}
+	s.updateTicker = time.NewTicker(s.updateInterval)
+	go s.loopUpdate()
+	return nil
+}
+
+func (s *RemoteRuleSet) loadBytes(content []byte) error {
+	var (
+		plainRuleSet option.PlainRuleSet
+		err          error
+	)
+	switch s.options.Format {
+	case C.RuleSetFormatSource, "":
+		var compat option.PlainRuleSetCompat
+		decoder := json.NewDecoder(json.NewCommentFilter(bytes.NewReader(content)))
+		decoder.DisallowUnknownFields()
+		err = decoder.Decode(&compat)
+		if err != nil {
+			return err
+		}
+		plainRuleSet = compat.Upgrade()
+	case C.RuleSetFormatBinary:
+		plainRuleSet, err = srs.Read(bytes.NewReader(content), false)
+		if err != nil {
+			return err
+		}
+	default:
+		return E.New("unknown rule set format: ", s.options.Format)
+	}
+	rules := make([]adapter.HeadlessRule, len(plainRuleSet.Rules))
+	for i, ruleOptions := range plainRuleSet.Rules {
+		rules[i], err = NewHeadlessRule(s.router, ruleOptions)
+		if err != nil {
+			return E.Cause(err, "parse rule_set.rules.[", i, "]")
+		}
+	}
+	s.rules = rules
+	return nil
+}
+
+func (s *RemoteRuleSet) loopUpdate() {
+	for {
+		select {
+		case <-s.ctx.Done():
+			return
+		case <-s.updateTicker.C:
+			err := s.fetchOnce()
+			if err != nil {
+				s.logger.Error("fetch rule-set ", s.options.Tag, ": ", err)
+			}
+		}
+	}
+}
+
+func (s *RemoteRuleSet) fetchOnce() error {
+	s.logger.Debug("updating rule-set ", s.options.Tag, " from URL: ", s.options.RemoteOptions.URL)
+	httpClient := &http.Client{
+		Transport: &http.Transport{
+			ForceAttemptHTTP2:   true,
+			TLSHandshakeTimeout: C.TCPTimeout,
+			DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+				return s.dialer.DialContext(ctx, network, M.ParseSocksaddr(addr))
+			},
+		},
+	}
+	defer httpClient.CloseIdleConnections()
+	request, err := http.NewRequest("GET", s.options.RemoteOptions.URL, nil)
+	if err != nil {
+		return err
+	}
+	if s.lastEtag != "" {
+		request.Header.Set("If-None-Match", s.lastEtag)
+	}
+	response, err := httpClient.Do(request.WithContext(s.ctx))
+	if err != nil {
+		return err
+	}
+	switch response.StatusCode {
+	case http.StatusOK:
+	case http.StatusNotModified:
+		s.logger.Info("update rule-set ", s.options.Tag, ": not modified")
+		return nil
+	default:
+		return E.New("unexpected status: ", response.Status)
+	}
+	content, err := io.ReadAll(response.Body)
+	if err != nil {
+		response.Body.Close()
+		return err
+	}
+	err = s.loadBytes(content)
+	if err != nil {
+		response.Body.Close()
+		return err
+	}
+	response.Body.Close()
+	eTagHeader := response.Header.Get("Etag")
+	if eTagHeader != "" {
+		s.lastEtag = eTagHeader
+	}
+	s.lastUpdated = time.Now()
+	cacheFile := service.FromContext[adapter.CacheFile](s.ctx)
+	if cacheFile != nil {
+		err = cacheFile.SaveRuleSet(s.options.Tag, &adapter.SavedRuleSet{
+			LastUpdated: s.lastUpdated,
+			Content:     content,
+			LastEtag:    s.lastEtag,
+		})
+		if err != nil {
+			s.logger.Error("save rule-set cache: ", err)
+		}
+	}
+	s.logger.Info("updated rule-set ", s.options.Tag)
+	return nil
+}
+
+func (s *RemoteRuleSet) Close() error {
+	s.updateTicker.Stop()
+	s.cancel()
+	return nil
+}