Add disableFallbackIfMatch dns option

v2fly · Sep 17, 2021 · 00155ff · 00155ff
1 parent 97ef239
commit 00155ff
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Showing 4 changed files with 82 additions and 63 deletions.
diff --git a/app/dns/config.pb.go b/app/dns/config.pb.go
diff --git a/app/dns/config.proto b/app/dns/config.proto
@@ -84,4 +84,5 @@ message Config {
   QueryStrategy query_strategy = 9;
 
   bool disableFallback = 10;
+  bool disableFallbackIfMatch = 11;
 }
diff --git a/app/dns/dns.go b/app/dns/dns.go
@@ -25,15 +25,16 @@ import (
 // DNS is a DNS rely server.
 type DNS struct {
 	sync.Mutex
-	tag             string
-	disableCache    bool
-	disableFallback bool
-	ipOption        *dns.IPOption
-	hosts           *StaticHosts
-	clients         []*Client
-	ctx             context.Context
-	domainMatcher   strmatcher.IndexMatcher
-	matcherInfos    []*DomainMatcherInfo
+	tag                    string
+	disableCache           bool
+	disableFallback        bool
+	disableFallbackIfMatch bool
+	ipOption               *dns.IPOption
+	hosts                  *StaticHosts
+	clients                []*Client
+	ctx                    context.Context
+	domainMatcher          strmatcher.IndexMatcher
+	matcherInfos           []*DomainMatcherInfo
 }
 
 // DomainMatcherInfo contains information attached to index returned by Server.domainMatcher
@@ -135,15 +136,16 @@ func New(ctx context.Context, config *Config) (*DNS, error) {
 	}
 
 	return &DNS{
-		tag:             tag,
-		hosts:           hosts,
-		ipOption:        ipOption,
-		clients:         clients,
-		ctx:             ctx,
-		domainMatcher:   domainMatcher,
-		matcherInfos:    matcherInfos,
-		disableCache:    config.DisableCache,
-		disableFallback: config.DisableFallback,
+		tag:                    tag,
+		hosts:                  hosts,
+		ipOption:               ipOption,
+		clients:                clients,
+		ctx:                    ctx,
+		domainMatcher:          domainMatcher,
+		matcherInfos:           matcherInfos,
+		disableCache:           config.DisableCache,
+		disableFallback:        config.DisableFallback,
+		disableFallbackIfMatch: config.DisableFallbackIfMatch,
 	}, nil
 }
 
@@ -264,6 +266,7 @@ func (s *DNS) sortClients(domain string) []*Client {
 	domainRules := []string{}
 
 	// Priority domain matching
+	hasMatch := false
 	for _, match := range s.domainMatcher.Match(domain) {
 		info := s.matcherInfos[match]
 		client := s.clients[info.clientIdx]
@@ -275,9 +278,10 @@ func (s *DNS) sortClients(domain string) []*Client {
 		clientUsed[info.clientIdx] = true
 		clients = append(clients, client)
 		clientNames = append(clientNames, client.Name())
+		hasMatch = true
 	}
 
-	if !s.disableFallback {
+	if !(s.disableFallback || s.disableFallbackIfMatch && hasMatch) {
 		// Default round-robin query
 		for idx, client := range s.clients {
 			if clientUsed[idx] || client.skipFallback {

diff --git a/infra/conf/dns.go b/infra/conf/dns.go
@@ -133,13 +133,14 @@ var typeMap = map[router.Domain_Type]dns.DomainMatchingType{
 
 // DNSConfig is a JSON serializable object for dns.Config.
 type DNSConfig struct {
-	Servers         []*NameServerConfig     `json:"servers"`
-	Hosts           map[string]*HostAddress `json:"hosts"`
-	ClientIP        *cfgcommon.Address      `json:"clientIp"`
-	Tag             string                  `json:"tag"`
-	QueryStrategy   string                  `json:"queryStrategy"`
-	DisableCache    bool                    `json:"disableCache"`
-	DisableFallback bool                    `json:"disableFallback"`
+	Servers                []*NameServerConfig     `json:"servers"`
+	Hosts                  map[string]*HostAddress `json:"hosts"`
+	ClientIP               *cfgcommon.Address      `json:"clientIp"`
+	Tag                    string                  `json:"tag"`
+	QueryStrategy          string                  `json:"queryStrategy"`
+	DisableCache           bool                    `json:"disableCache"`
+	DisableFallback        bool                    `json:"disableFallback"`
+	DisableFallbackIfMatch bool                    `json:"disableFallbackIfMatch"`
 }
 
 type HostAddress struct {
@@ -206,9 +207,10 @@ func (c *DNSConfig) Build() (*dns.Config, error) {
 	geoLoader := cfgEnv.GetGeoLoader()
 
 	config := &dns.Config{
-		Tag:             c.Tag,
-		DisableCache:    c.DisableCache,
-		DisableFallback: c.DisableFallback,
+		Tag:                    c.Tag,
+		DisableCache:           c.DisableCache,
+		DisableFallback:        c.DisableFallback,
+		DisableFallbackIfMatch: c.DisableFallbackIfMatch,
 	}
 
 	if c.ClientIP != nil {