Merge 6b25c7e500 into 84eeb56ae4

- Apply to random and roundrobin strategy
- Require observatory config

Co-authored-by: Mark Ma <38940419+mkmark@users.noreply.github.com>

app/router/balancing.go

@@ -4,6 +4,9 @@ import (
 	"context"
 	sync "sync"
 
+	"github.com/xtls/xray-core/app/observatory"
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/core"
 	"github.com/xtls/xray-core/features/extension"
 	"github.com/xtls/xray-core/features/outbound"
 )
@@ -17,14 +20,58 @@ type BalancingPrincipleTarget interface {
 }
 
 type RoundRobinStrategy struct {
+	FallbackTag string
+
+	ctx         context.Context
+	observatory extension.Observatory
 	mu    sync.Mutex
 	index int
 }
 
+func (s *RoundRobinStrategy) InjectContext(ctx context.Context) {
+	s.ctx = ctx
+}
+
+func (s *RoundRobinStrategy) GetPrincipleTarget(strings []string) []string {
+	return strings
+}
+
 func (s *RoundRobinStrategy) PickOutbound(tags []string) string {
+	if len(s.FallbackTag) > 0 && s.observatory == nil {
+		common.Must(core.RequireFeatures(s.ctx, func(observatory extension.Observatory) error {
+			s.observatory = observatory
+			return nil
+		}))
+	}
+	if s.observatory != nil {
+		observeReport, err := s.observatory.GetObservation(s.ctx)
+		if err == nil {
+			aliveTags := make([]string, 0)
+			if result, ok := observeReport.(*observatory.ObservationResult); ok {
+				status := result.Status
+				statusMap := make(map[string]*observatory.OutboundStatus)
+				for _, outboundStatus := range status {
+					statusMap[outboundStatus.OutboundTag] = outboundStatus
+				}
+				for _, candidate := range tags {
+					if outboundStatus, found := statusMap[candidate]; found {
+						if outboundStatus.Alive {
+							aliveTags = append(aliveTags, candidate)
+						}
+					} else {
+						// unfound candidate is considered alive
+						aliveTags = append(aliveTags, candidate)
+					}
+				}
+				tags = aliveTags
+			}
+		}
+	}
+
 	n := len(tags)
 	if n == 0 {
-		panic("0 tags")
+		// goes to fallbackTag
+		return ""
 	}
 
 	s.mu.Lock()

app/router/config.go

@@ -135,7 +135,7 @@ func (br *BalancingRule) Build(ohm outbound.Manager, dispatcher routing.Dispatch
 	case "roundrobin":
 		return &Balancer{
 			selectors:   br.OutboundSelector,
-			strategy:    &RoundRobinStrategy{},
+			strategy:    &RoundRobinStrategy{FallbackTag: br.FallbackTag},
 			fallbackTag: br.FallbackTag,
 			ohm:         ohm,
 		}, nil
@@ -162,7 +162,7 @@ func (br *BalancingRule) Build(ohm outbound.Manager, dispatcher routing.Dispatch
 			selectors:   br.OutboundSelector,
 			ohm:         ohm,
 			fallbackTag: br.FallbackTag,
-			strategy:    &RandomStrategy{},
+			strategy:    &RandomStrategy{FallbackTag: br.FallbackTag},
 		}, nil
 	default:
 		return nil, newError("unrecognized balancer type")

app/router/strategy_random.go

@@ -1,17 +1,63 @@
 package router
 
 import (
+	"context"
+
+	"github.com/xtls/xray-core/app/observatory"
+	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/dice"
+	"github.com/xtls/xray-core/core"
+	"github.com/xtls/xray-core/features/extension"
 )
 
 // RandomStrategy represents a random balancing strategy
-type RandomStrategy struct{}
+type RandomStrategy struct{
+	FallbackTag string
+
+	ctx         context.Context
+	observatory extension.Observatory
+}
+
+func (s *RandomStrategy) InjectContext(ctx context.Context) {
+	s.ctx = ctx
+}
 
 func (s *RandomStrategy) GetPrincipleTarget(strings []string) []string {
 	return strings
 }
 
 func (s *RandomStrategy) PickOutbound(candidates []string) string {
+	if len(s.FallbackTag) > 0 && s.observatory == nil {
+		common.Must(core.RequireFeatures(s.ctx, func(observatory extension.Observatory) error {
+			s.observatory = observatory
+			return nil
+		}))
+	}
+	if s.observatory != nil {
+		observeReport, err := s.observatory.GetObservation(s.ctx)
+		if err == nil {
+			aliveTags := make([]string, 0)
+			if result, ok := observeReport.(*observatory.ObservationResult); ok {
+				status := result.Status
+				statusMap := make(map[string]*observatory.OutboundStatus)
+				for _, outboundStatus := range status {
+					statusMap[outboundStatus.OutboundTag] = outboundStatus
+				}
+				for _, candidate := range candidates {
+					if outboundStatus, found := statusMap[candidate]; found {
+						if outboundStatus.Alive {
+							aliveTags = append(aliveTags, candidate)
+						}
+					} else {
+						// unfound candidate is considered alive
+						aliveTags = append(aliveTags, candidate)
+					}
+				}
+				candidates = aliveTags
+			}
+		}
+	}
+
 	count := len(candidates)
 	if count == 0 {
 		// goes to fallbackTag

infra/conf/dns.go

@@ -73,8 +73,11 @@ func (c *NameServerConfig) Build() (*dns.NameServer, error) {
 	var domains []*dns.NameServer_PriorityDomain
 	var originalRules []*dns.NameServer_OriginalRule
 
+	cache := NewGeoCache()
+	defer cache.Clear()
+
 	for _, rule := range c.Domains {
-		parsedDomain, err := parseDomainRule(rule)
+		parsedDomain, err := cache.ParseDomainRule(rule)
 		if err != nil {
 			return nil, newError("invalid domain rule: ", rule).Base(err)
 		}
@@ -91,7 +94,7 @@ func (c *NameServerConfig) Build() (*dns.NameServer, error) {
 		})
 	}
 
-	geoipList, err := ToCidrList(c.ExpectIPs)
+	geoipList, err := cache.ToCidrList(c.ExpectIPs)
 	if err != nil {
 		return nil, newError("invalid IP rule: ", c.ExpectIPs).Base(err)
 	}
@@ -209,6 +212,9 @@ func (m *HostsWrapper) Build() ([]*dns.Config_HostMapping, error) {
 	}
 	sort.Strings(domains)
 
+	cache := newSiteCache()
+	defer cache.reset()
+
 	for _, domain := range domains {
 		switch {
 		case strings.HasPrefix(domain, "domain:"):
@@ -226,7 +232,7 @@ func (m *HostsWrapper) Build() ([]*dns.Config_HostMapping, error) {
 			if len(listName) == 0 {
 				return nil, newError("empty geosite rule: ", domain)
 			}
-			geositeList, err := loadGeositeWithAttr("geosite.dat", listName)
+			geositeList, err := cache.loadGeositeWithAttr("geosite.dat", listName)
 			if err != nil {
 				return nil, newError("failed to load geosite: ", listName).Base(err)
 			}
@@ -287,7 +293,7 @@ func (m *HostsWrapper) Build() ([]*dns.Config_HostMapping, error) {
 			}
 			filename := kv[0]
 			list := kv[1]
-			geositeList, err := loadGeositeWithAttr(filename, list)
+			geositeList, err := cache.loadGeositeWithAttr(filename, list)
 			if err != nil {
 				return nil, newError("failed to load domain list: ", list, " from ", filename).Base(err)
 			}

infra/conf/router.go

@@ -116,8 +116,11 @@ func (c *RouterConfig) Build() (*router.Config, error) {
 		}
 	}
 
+	cache := NewGeoCache()
+	defer cache.Clear()
+
 	for _, rawRule := range rawRuleList {
-		rule, err := ParseRule(rawRule)
+		rule, err := cache.ParseRule(rawRule)
 		if err != nil {
 			return nil, err
 		}
@@ -195,39 +198,80 @@ func ParseIP(s string) (*router.CIDR, error) {
 	}
 }
 
-func loadGeoIP(code string) ([]*router.CIDR, error) {
-	return loadIP("geoip.dat", code)
-}
-
-var (
-	FileCache = make(map[string][]byte)
-	IPCache   = make(map[string]*router.GeoIP)
-	SiteCache = make(map[string]*router.GeoSite)
-)
-
 func loadFile(file string) ([]byte, error) {
-	if FileCache[file] == nil {
-		bs, err := filesystem.ReadAsset(file)
-		if err != nil {
-			return nil, newError("failed to open file: ", file).Base(err)
-		}
-		if len(bs) == 0 {
-			return nil, newError("empty file: ", file)
-		}
-		// Do not cache file, may save RAM when there
-		// are many files, but consume CPU each time.
-		return bs, nil
-		FileCache[file] = bs
+	bs, err := filesystem.ReadAsset(file)
+	if err != nil {
+		return nil, newError("failed to open file: ", file).Base(err)
 	}
-	return FileCache[file], nil
+	if len(bs) == 0 {
+		return nil, newError("empty file: ", file)
+	}
+	return bs, nil
 }
 
-func loadIP(file, code string) ([]*router.CIDR, error) {
+type ipCache struct {
+	fileContent map[string][]byte
+	geoIPs      map[string]*router.GeoIP
+}
+
+type siteCache struct {
+	fileContent map[string][]byte
+	geoSites    map[string]*router.GeoSite
+}
+
+// GeoCache is a cache for GeoIP and GeoSite.
+type GeoCache struct {
+	ipCache   *ipCache
+	siteCache *siteCache
+}
+
+// NewGeoCache creates a new GeoCache.
+func NewGeoCache() *GeoCache {
+	return &GeoCache{
+		ipCache:   newIPCache(),
+		siteCache: newSiteCache(),
+	}
+}
+
+// Clear clears the cache.
+func (c *GeoCache) Clear() {
+	if c.ipCache.reset() || c.siteCache.reset() {
+		// only trigger GC if there is something to release
+		runtime.GC()
+	}
+}
+
+// newIPCache creates a new ipCache.
+// after use, call close() to release memory.
+func newIPCache() *ipCache {
+	return &ipCache{
+		fileContent: make(map[string][]byte),
+		geoIPs:      make(map[string]*router.GeoIP),
+	}
+}
+
+// reset remove the content of ipCache.
+// returns true if the cache is not empty.
+func (c *ipCache) reset() bool {
+	if len(c.fileContent) == 0 && len(c.geoIPs) == 0 {
+		return false
+	}
+	c.fileContent = make(map[string][]byte)
+	c.geoIPs = make(map[string]*router.GeoIP)
+	return true
+}
+
+func (c *ipCache) loadIP(file, code string) ([]*router.CIDR, error) {
 	index := file + ":" + code
-	if IPCache[index] == nil {
-		bs, err := loadFile(file)
-		if err != nil {
-			return nil, newError("failed to load file: ", file).Base(err)
+	if c.geoIPs[index] == nil {
+		bs := c.fileContent[file]
+		if bs == nil {
+			var err error
+			bs, err = loadFile(file)
+			if err != nil {
+				return nil, newError("failed to load file: ", file).Base(err)
+			}
+			c.fileContent[file] = bs
 		}
 		bs = find(bs, []byte(code))
 		if bs == nil {
@@ -237,19 +281,43 @@ func loadIP(file, code string) ([]*router.CIDR, error) {
 		if err := proto.Unmarshal(bs, &geoip); err != nil {
 			return nil, newError("error unmarshal IP in ", file, ": ", code).Base(err)
 		}
-		defer runtime.GC()     // or debug.FreeOSMemory()
-		return geoip.Cidr, nil // do not cache geoip
-		IPCache[index] = &geoip
+		c.geoIPs[index] = &geoip
+		return geoip.Cidr, nil
 	}
-	return IPCache[index].Cidr, nil
+	return c.geoIPs[index].Cidr, nil
 }
 
-func loadSite(file, code string) ([]*router.Domain, error) {
+// newSiteCache creates a new siteCache.
+// after use, call close() to release memory.
+func newSiteCache() *siteCache {
+	return &siteCache{
+		fileContent: make(map[string][]byte),
+		geoSites:    make(map[string]*router.GeoSite),
+	}
+}
+
+// reset remove the content of siteCache.
+// returns true if the cache is not empty.
+func (c *siteCache) reset() bool {
+	if len(c.fileContent) == 0 && len(c.geoSites) == 0 {
+		return false
+	}
+	c.fileContent = make(map[string][]byte)
+	c.geoSites = make(map[string]*router.GeoSite)
+	return true
+}
+
+func (c *siteCache) loadSite(file, code string) ([]*router.Domain, error) {
 	index := file + ":" + code
-	if SiteCache[index] == nil {
-		bs, err := loadFile(file)
-		if err != nil {
-			return nil, newError("failed to load file: ", file).Base(err)
+	if c.geoSites[index] == nil {
+		bs := c.fileContent[file]
+		if bs == nil {
+			var err error
+			bs, err = loadFile(file)
+			if err != nil {
+				return nil, newError("failed to load file: ", file).Base(err)
+			}
+			c.fileContent[file] = bs
 		}
 		bs = find(bs, []byte(code))
 		if bs == nil {
@@ -259,11 +327,10 @@ func loadSite(file, code string) ([]*router.Domain, error) {
 		if err := proto.Unmarshal(bs, &geosite); err != nil {
 			return nil, newError("error unmarshal Site in ", file, ": ", code).Base(err)
 		}
-		defer runtime.GC()         // or debug.FreeOSMemory()
-		return geosite.Domain, nil // do not cache geosite
-		SiteCache[index] = &geosite
+		c.geoSites[index] = &geosite
+		return geosite.Domain, nil
 	}
-	return SiteCache[index].Domain, nil
+	return c.geoSites[index].Domain, nil
 }
 
 func DecodeVarint(buf []byte) (x uint64, n int) {
@@ -358,14 +425,14 @@ func parseAttrs(attrs []string) *AttributeList {
 	return al
 }
 
-func loadGeositeWithAttr(file string, siteWithAttr string) ([]*router.Domain, error) {
+func (c *siteCache) loadGeositeWithAttr(file string, siteWithAttr string) ([]*router.Domain, error) {
 	parts := strings.Split(siteWithAttr, "@")
 	if len(parts) == 0 {
 		return nil, newError("empty site")
 	}
 	country := strings.ToUpper(parts[0])
 	attrs := parseAttrs(parts[1:])
-	domains, err := loadSite(file, country)
+	domains, err := c.loadSite(file, country)
 	if err != nil {
 		return nil, err
 	}
@@ -384,10 +451,10 @@ func loadGeositeWithAttr(file string, siteWithAttr string) ([]*router.Domain, er
 	return filteredDomains, nil
 }
 
-func parseDomainRule(domain string) ([]*router.Domain, error) {
+func (c *GeoCache) ParseDomainRule(domain string) ([]*router.Domain, error) {
 	if strings.HasPrefix(domain, "geosite:") {
 		country := strings.ToUpper(domain[8:])
-		domains, err := loadGeositeWithAttr("geosite.dat", country)
+		domains, err := c.siteCache.loadGeositeWithAttr("geosite.dat", country)
 		if err != nil {
 			return nil, newError("failed to load geosite: ", country).Base(err)
 		}
@@ -411,7 +478,7 @@ func parseDomainRule(domain string) ([]*router.Domain, error) {
 		}
 		filename := kv[0]
 		country := kv[1]
-		domains, err := loadGeositeWithAttr(filename, country)
+		domains, err := c.siteCache.loadGeositeWithAttr(filename, country)
 		if err != nil {
 			return nil, newError("failed to load external sites: ", country, " from ", filename).Base(err)
 		}
@@ -454,7 +521,7 @@ func parseDomainRule(domain string) ([]*router.Domain, error) {
 	return []*router.Domain{domainRule}, nil
 }
 
-func ToCidrList(ips StringList) ([]*router.GeoIP, error) {
+func (c *GeoCache) ToCidrList(ips StringList) ([]*router.GeoIP, error) {
 	var geoipList []*router.GeoIP
 	var customCidrs []*router.CIDR
 
@@ -469,7 +536,7 @@ func ToCidrList(ips StringList) ([]*router.GeoIP, error) {
 			if len(country) == 0 {
 				return nil, newError("empty country name in rule")
 			}
-			geoip, err := loadGeoIP(strings.ToUpper(country))
+			geoip, err := c.ipCache.loadIP("geoip.dat", strings.ToUpper(country))
 			if err != nil {
 				return nil, newError("failed to load GeoIP: ", country).Base(err)
 			}
@@ -509,7 +576,7 @@ func ToCidrList(ips StringList) ([]*router.GeoIP, error) {
 				country = country[1:]
 				isReverseMatch = true
 			}
-			geoip, err := loadIP(filename, strings.ToUpper(country))
+			geoip, err := c.ipCache.loadIP(filename, strings.ToUpper(country))
 			if err != nil {
 				return nil, newError("failed to load IPs: ", country, " from ", filename).Base(err)
 			}
@@ -539,7 +606,7 @@ func ToCidrList(ips StringList) ([]*router.GeoIP, error) {
 	return geoipList, nil
 }
 
-func parseFieldRule(msg json.RawMessage) (*router.RoutingRule, error) {
+func (c *GeoCache) parseFieldRule(msg json.RawMessage) (*router.RoutingRule, error) {
 	type RawFieldRule struct {
 		RouterRule
 		Domain     *StringList       `json:"domain"`
@@ -581,7 +648,7 @@ func parseFieldRule(msg json.RawMessage) (*router.RoutingRule, error) {
 
 	if rawFieldRule.Domain != nil {
 		for _, domain := range *rawFieldRule.Domain {
-			rules, err := parseDomainRule(domain)
+			rules, err := c.ParseDomainRule(domain)
 			if err != nil {
 				return nil, newError("failed to parse domain rule: ", domain).Base(err)
 			}
@@ -591,7 +658,7 @@ func parseFieldRule(msg json.RawMessage) (*router.RoutingRule, error) {
 
 	if rawFieldRule.Domains != nil {
 		for _, domain := range *rawFieldRule.Domains {
-			rules, err := parseDomainRule(domain)
+			rules, err := c.ParseDomainRule(domain)
 			if err != nil {
 				return nil, newError("failed to parse domain rule: ", domain).Base(err)
 			}
@@ -600,7 +667,7 @@ func parseFieldRule(msg json.RawMessage) (*router.RoutingRule, error) {
 	}
 
 	if rawFieldRule.IP != nil {
-		geoipList, err := ToCidrList(*rawFieldRule.IP)
+		geoipList, err := c.ToCidrList(*rawFieldRule.IP)
 		if err != nil {
 			return nil, err
 		}
@@ -616,7 +683,7 @@ func parseFieldRule(msg json.RawMessage) (*router.RoutingRule, error) {
 	}
 
 	if rawFieldRule.SourceIP != nil {
-		geoipList, err := ToCidrList(*rawFieldRule.SourceIP)
+		geoipList, err := c.ToCidrList(*rawFieldRule.SourceIP)
 		if err != nil {
 			return nil, err
 		}
@@ -652,14 +719,14 @@ func parseFieldRule(msg json.RawMessage) (*router.RoutingRule, error) {
 	return rule, nil
 }
 
-func ParseRule(msg json.RawMessage) (*router.RoutingRule, error) {
+func (c *GeoCache) ParseRule(msg json.RawMessage) (*router.RoutingRule, error) {
 	rawRule := new(RouterRule)
 	err := json.Unmarshal(msg, rawRule)
 	if err != nil {
 		return nil, newError("invalid router rule").Base(err)
 	}
 	if rawRule.Type == "" || strings.EqualFold(rawRule.Type, "field") {
-		fieldrule, err := parseFieldRule(msg)
+		fieldrule, err := c.parseFieldRule(msg)
 		if err != nil {
 			return nil, newError("invalid field rule").Base(err)
 		}

infra/conf/router_test.go

@@ -44,7 +44,10 @@ func TestToCidrList(t *testing.T) {
 		"ext-ip:geoiptestrouter.dat:!ca",
 	})
 
-	_, err := ToCidrList(ips)
+	cache := NewGeoCache()
+	defer cache.Clear()
+
+	_, err := cache.ToCidrList(ips)
 	if err != nil {
 		t.Fatalf("Failed to parse geoip list, got %s", err)
 	}
@@ -97,7 +100,8 @@ func TestRouterConfig(t *testing.T) {
 				"balancers": [
 					{
 						"tag": "b1",
-						"selector": ["test"]
+						"selector": ["test"],
+						"fallbackTag": "fall"
 					},
 					{
 						"tag": "b2",
@@ -137,6 +141,7 @@ func TestRouterConfig(t *testing.T) {
 						Tag:              "b1",
 						OutboundSelector: []string{"test"},
 						Strategy:         "random",
+						FallbackTag:      "fall",
 					},
 					{
 						Tag:              "b2",