Add fakedns+others sniffing mode

"fakedns+others" means if the request IP is in the range of fakes, when fakeDNS cache missed (most likely due to reboot), "tls" and "http" sniffer will be used to identify domain
v2fly · Feb 21, 2021 · b17dbd5 · b17dbd5
1 parent efb9632
commit b17dbd5
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Showing 6 changed files with 29 additions and 5 deletions.
diff --git a/app/dispatcher/default.go b/app/dispatcher/default.go
@@ -17,6 +17,7 @@ import (
 	"github.com/v2fly/v2ray-core/v4/common/net"
 	"github.com/v2fly/v2ray-core/v4/common/protocol"
 	"github.com/v2fly/v2ray-core/v4/common/session"
+	"github.com/v2fly/v2ray-core/v4/features/dns"
 	"github.com/v2fly/v2ray-core/v4/features/outbound"
 	"github.com/v2fly/v2ray-core/v4/features/policy"
 	"github.com/v2fly/v2ray-core/v4/features/routing"
@@ -177,7 +178,11 @@ func (d *DefaultDispatcher) getLink(ctx context.Context) (*transport.Link, *tran
 	return inboundLink, outboundLink
 }
 
-func shouldOverride(result SniffResult, domainOverride []string) bool {
+func shouldOverride(ctx context.Context, result SniffResult, domainOverride []string, destination net.Destination) bool {
+	var fakeDNSEngine dns.FakeDNSEngine
+	core.RequireFeatures(ctx, func(fdns dns.FakeDNSEngine) {
+		fakeDNSEngine = fdns
+	})
 	protocolString := result.Protocol()
 	if resComp, ok := result.(SnifferResultComposite); ok {
 		protocolString = resComp.ProtocolForDomainResult()
@@ -186,6 +191,14 @@ func shouldOverride(result SniffResult, domainOverride []string) bool {
 		if strings.HasPrefix(protocolString, p) {
 			return true
 		}
+		if protocolString == "fakedns" && p == "fakedns+others" {
+			return true
+		}
+		if fakeDNSEngine != nil && protocolString != "bittorrent" && p == "fakedns+others" &&
+			fakeDNSEngine.GetFakeIPRange().Contains(destination.Address.IP()) {
+			newError("Using sniffer ", protocolString, " since the fake DNS missed").WriteToLog(session.ExportIDToError(ctx))
+			return true
+		}
 	}
 	return false
 }
@@ -215,7 +228,7 @@ func (d *DefaultDispatcher) Dispatch(ctx context.Context, destination net.Destin
 		result, err := sniffer(ctx, nil, true)
 		if err == nil {
 			content.Protocol = result.Protocol()
-			if shouldOverride(result, sniffingRequest.OverrideDestinationForProtocol) {
+			if shouldOverride(ctx, result, sniffingRequest.OverrideDestinationForProtocol, destination) {
 				domain := result.Domain()
 				newError("sniffed domain: ", domain).WriteToLog(session.ExportIDToError(ctx))
 				destination.Address = net.ParseAddress(domain)
@@ -233,7 +246,7 @@ func (d *DefaultDispatcher) Dispatch(ctx context.Context, destination net.Destin
 			if err == nil {
 				content.Protocol = result.Protocol()
 			}
-			if err == nil && shouldOverride(result, sniffingRequest.OverrideDestinationForProtocol) {
+			if err == nil && shouldOverride(ctx, result, sniffingRequest.OverrideDestinationForProtocol, destination) {
 				domain := result.Domain()
 				newError("sniffed domain: ", domain).WriteToLog(session.ExportIDToError(ctx))
 				destination.Address = net.ParseAddress(domain)

diff --git a/app/dns/fakedns/fake.go b/app/dns/fakedns/fake.go
@@ -117,9 +117,15 @@ func (fkdns *Holder) GetDomainFromFakeDNS(ip net.Address) string {
 	if k, ok := fkdns.domainToIP.GetKeyFromValue(ip); ok {
 		return k.(string)
 	}
+	newError("A fake ip request to ", ip, ", however there is no matching domain name in fake DNS").AtInfo().WriteToLog()
 	return ""
 }
 
+// GetFakeIPRange return fake IP range from configuration
+func (fkdns *Holder) GetFakeIPRange() *gonet.IPNet {
+	return fkdns.ipRange
+}
+
 func init() {
 	common.Must(common.RegisterConfig((*FakeDnsPool)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
 		var f *Holder

diff --git a/app/proxyman/config.proto b/app/proxyman/config.proto
@@ -54,7 +54,7 @@ message SniffingConfig {
   bool enabled = 1;
 
   // Override target destination if sniff'ed protocol is in the given list.
-  // Supported values are "http", "tls", "fakedns".
+  // Supported values are "http", "tls", "fakedns", "fakedns+others".
   repeated string destination_override = 2;
 
   // Whether should only try to sniff metadata without waiting for client input.

diff --git a/features/dns/fakedns.go b/features/dns/fakedns.go
@@ -1,6 +1,8 @@
 package dns
 
 import (
+	gonet "net"
+
 	"github.com/v2fly/v2ray-core/v4/common/net"
 	"github.com/v2fly/v2ray-core/v4/features"
 )
@@ -9,4 +11,5 @@ type FakeDNSEngine interface {
 	features.Feature
 	GetFakeIPForDomain(domain string) []net.Address
 	GetDomainFromFakeDNS(ip net.Address) string
+	GetFakeIPRange() *gonet.IPNet
 }
diff --git a/infra/conf/fakedns.go b/infra/conf/fakedns.go
@@ -51,7 +51,7 @@ func (FakeDNSPostProcessingStage) Process(conf *Config) error {
 		for _, v := range inbounds {
 			if v.SniffingConfig != nil && v.SniffingConfig.Enabled && v.SniffingConfig.DestOverride != nil {
 				for _, dov := range *v.SniffingConfig.DestOverride {
-					if dov == "fakedns" {
+					if dov == "fakedns" || dov == "fakedns+others" {
 						found = true
 					}
 				}

diff --git a/infra/conf/v2ray.go b/infra/conf/v2ray.go
@@ -74,6 +74,8 @@ func (c *SniffingConfig) Build() (*proxyman.SniffingConfig, error) {
 				p = append(p, "tls")
 			case "fakedns":
 				p = append(p, "fakedns")
+			case "fakedns+others":
+				p = append(p, "fakedns+others")
 			default:
 				return nil, newError("unknown protocol: ", domainOverride)
 			}