check: add checktolerance config for lha mode

README.md

@@ -45,19 +45,17 @@ we can set up local listeners as proxy servers, and forward requests to internet
 
 |Protocol     | Listen/TCP |  Listen/UDP | Forward/TCP | Forward/UDP | Description
 |:-:          |:-:|:-:|:-:|:-:|:-
-|http         |√| |√| |client & server
-|socks4       | | |√| |client only
-|socks5       |√|√|√|√|client & server
 |mixed        |√|√| | |http+socks5 server
+|http         |√| |√| |client & server
+|socks5       |√|√|√|√|client & server
 |ss           |√|√|√|√|client & server
-|ssr          | | |√| |client only
-|ssh          | | |√| |client only
 |trojan       |√|√|√|√|client & server
-|trojanc       |√|√|√|√|trojan cleartext(without tls)
+|trojanc      |√|√|√|√|trojan cleartext(without tls)
 |vless        |√|√|√|√|client & server
 |vmess        | | |√| |client only
-|redir        |√| | | |linux only
+|ssr          | | |√| |client only
-|redir6        |√| | | |linux only(ipv6)
+|ssh          | | |√| |client only
+|socks4       | | |√| |client only
 |tls          |√| |√| |transport client & server
 |kcp          | |√|√| |transport client & server
 |unix         |√| |√| |transport client & server
@@ -66,6 +64,8 @@ we can set up local listeners as proxy servers, and forward requests to internet
 |tcptun       |√| | | |transport server only
 |udptun       | |√| | |transport server only
 |uottun       | |√| | |transport server only
+|redir        |√| | | |linux only
+|redir6       |√| | | |linux only(ipv6)
 |reject       | | |√|√|reject all requests
 
 </details>
@@ -89,15 +89,17 @@ glider -h
 <summary>click to see details</summary>
 
 ```bash
-./glider 0.12.0 usage:
+glider 0.12.0 usage:
   -checkdisabledonly
     	check disabled fowarders only
   -checkinterval int
-    	proxy check interval(seconds) (default 30)
+    	fowarder check interval(seconds) (default 30)
   -checktimeout int
-    	proxy check timeout(seconds) (default 10)
+    	fowarder check timeout(seconds) (default 10)
+  -checktolerance int
+    	fowarder check tolerance(ms), switch only when new_latency < old_latency - tolerance, only used in lha mode
   -checkwebsite string
-    	proxy check HTTP(NOT HTTPS) website address, format: HOST[:PORT], default port: 80 (default "www.apple.com")
+    	fowarder check HTTP(NOT HTTPS) website address, format: HOST[:PORT], default port: 80 (default "www.apple.com")
   -config string
     	config file path
   -dialtimeout int
@@ -285,7 +287,7 @@ Examples:
   ./glider -listen redir://:1081 -forward "ssr://method:pass@1.1.1.1:8444?protocol=a&protocol_param=b&obfs=c&obfs_param=d"
     -listen on :1081 as a transparent redirect server, forward all requests via remote ssr server.
 
-  ./glider -listen redir://:1081 -forward "tls://1.1.1.1:443,vmess://security:uuid@?alterID=10"
+  ./glider -listen redir://:1081 -forward "tls://abc.com:443,vmess://security:uuid@?alterID=10"
     -listen on :1081 as a transparent redirect server, forward all requests via remote tls+vmess server.
 
   ./glider -listen redir://:1081 -forward "ws://1.1.1.1:80,vmess://security:uuid@?alterID=10"
@@ -384,19 +386,19 @@ glider -config CONFIGPATH -listen :8080 -verbose
 - Chain protocols: https proxy (http over tls)
 
   ```bash
-  forward=tls://1.1.1.1:443,http://
+  forward=tls://server.com:443,http://
   ```
 
 - Chain protocols: vmess over ws over tls
 
   ```bash
-  forward=tls://1.1.1.1:443,ws://,vmess://5a146038-0b56-4e95-b1dc-5c6f5a32cd98@?alterID=2
+  forward=tls://server.com:443,ws://,vmess://5a146038-0b56-4e95-b1dc-5c6f5a32cd98@?alterID=2
   ```
 
 - Chain protocols and servers:
 
   ``` bash
-  forward=socks5://1.1.1.1:1080,tls://2.2.2.2:443,vmess://5a146038-0b56-4e95-b1dc-5c6f5a32cd98@?alterID=2
+  forward=socks5://1.1.1.1:1080,tls://server.com:443,vmess://5a146038-0b56-4e95-b1dc-5c6f5a32cd98@?alterID=2
   ```
 
 - Chain protocols in listener: https proxy server

config.go

@@ -44,9 +44,10 @@ func parseConfig() *Config {
 
 	flag.StringSliceUniqVar(&conf.Forwards, "forward", nil, "forward url, format: SCHEME://[USER|METHOD:PASSWORD@][HOST]:PORT?PARAMS[,SCHEME://[USER|METHOD:PASSWORD@][HOST]:PORT?PARAMS]")
 	flag.StringVar(&conf.StrategyConfig.Strategy, "strategy", "rr", "forward strategy, default: rr")
-	flag.StringVar(&conf.StrategyConfig.CheckWebSite, "checkwebsite", "www.apple.com", "proxy check HTTP(NOT HTTPS) website address, format: HOST[:PORT], default port: 80")
+	flag.StringVar(&conf.StrategyConfig.CheckWebSite, "checkwebsite", "www.apple.com", "fowarder check HTTP(NOT HTTPS) website address, format: HOST[:PORT], default port: 80")
-	flag.IntVar(&conf.StrategyConfig.CheckInterval, "checkinterval", 30, "proxy check interval(seconds)")
+	flag.IntVar(&conf.StrategyConfig.CheckInterval, "checkinterval", 30, "fowarder check interval(seconds)")
-	flag.IntVar(&conf.StrategyConfig.CheckTimeout, "checktimeout", 10, "proxy check timeout(seconds)")
+	flag.IntVar(&conf.StrategyConfig.CheckTimeout, "checktimeout", 10, "fowarder check timeout(seconds)")
+	flag.IntVar(&conf.StrategyConfig.CheckTolerance, "checktolerance", 0, "fowarder check tolerance(ms), switch only when new_latency < old_latency - tolerance, only used in lha mode")
 	flag.BoolVar(&conf.StrategyConfig.CheckDisabledOnly, "checkdisabledonly", false, "check disabled fowarders only")
 	flag.IntVar(&conf.StrategyConfig.MaxFailures, "maxfailures", 3, "max failures to change forwarder status to disabled")
 	flag.IntVar(&conf.StrategyConfig.DialTimeout, "dialtimeout", 3, "dial timeout(seconds)")
@@ -300,7 +301,7 @@ func usage() {
 	fmt.Fprintf(w, "  "+app+" -listen redir://:1081 -forward \"ssr://method:pass@1.1.1.1:8444?protocol=a&protocol_param=b&obfs=c&obfs_param=d\"\n")
 	fmt.Fprintf(w, "    -listen on :1081 as a transparent redirect server, forward all requests via remote ssr server.\n")
 	fmt.Fprintf(w, "\n")
-	fmt.Fprintf(w, "  "+app+" -listen redir://:1081 -forward \"tls://1.1.1.1:443,vmess://security:uuid@?alterID=10\"\n")
+	fmt.Fprintf(w, "  "+app+" -listen redir://:1081 -forward \"tls://abc.com:443,vmess://security:uuid@?alterID=10\"\n")
 	fmt.Fprintf(w, "    -listen on :1081 as a transparent redirect server, forward all requests via remote tls+vmess server.\n")
 	fmt.Fprintf(w, "\n")
 	fmt.Fprintf(w, "  "+app+" -listen redir://:1081 -forward \"ws://1.1.1.1:80,vmess://security:uuid@?alterID=10\"\n")

config/glider.conf.example

@@ -135,17 +135,17 @@ listen=socks5://:1080
 # forward=vmess://aes-128-gcm:5a146038-0b56-4e95-b1dc-5c6f5a32cd98@1.1.1.1:443?alterID=2
 
 # vmess over tls
-# forward=tls://1.1.1.1:443,vmess://5a146038-0b56-4e95-b1dc-5c6f5a32cd98@?alterID=2
+# forward=tls://server.com:443,vmess://5a146038-0b56-4e95-b1dc-5c6f5a32cd98@?alterID=2
 
 # vmess over websocket
-# forward=ws://1.1.1.1:80/path,vmess://chacha20-poly1305:5a146038-0b56-4e95-b1dc-5c6f5a32cd98@?alterID=2
+# forward=ws://server.com:80/path,vmess://chacha20-poly1305:5a146038-0b56-4e95-b1dc-5c6f5a32cd98@?alterID=2
 
 # vmess over ws over tls
-# forward=tls://1.1.1.1:443,ws://,vmess://5a146038-0b56-4e95-b1dc-5c6f5a32cd98@?alterID=2
+# forward=tls://server.com:443,ws://,vmess://5a146038-0b56-4e95-b1dc-5c6f5a32cd98@?alterID=2
-# forward=tls://1.1.1.1:443,ws://@/path,vmess://5a146038-0b56-4e95-b1dc-5c6f5a32cd98@?alterID=2
+# forward=tls://server.com:443,ws://@/path,vmess://5a146038-0b56-4e95-b1dc-5c6f5a32cd98@?alterID=2
 
 # ss over tls
-# forward=tls://1.1.1.1:443,ss://AEAD_CHACHA20_POLY1305:pass@
+# forward=tls://server.com:443,ss://AEAD_CHACHA20_POLY1305:pass@
 
 # ss over kcp
 # forward=kcp://aes:key@127.0.0.1:8444?dataShards=10&parityShards=3,ss://AEAD_CHACHA20_POLY1305:pass@
@@ -203,6 +203,9 @@ checkinterval=30
 # timeout to set a forwarder to be disabled(seconds)
 checktimeout=10
 
+# switch forwarder only when new_latency < old_latency - tolerance, used in lha mode
+checktolerance=100
+
 # check disabled fowarders only
 checkdisabledonly=false
 

dns/cache.go

@@ -62,7 +62,7 @@ func (c *LruCache) Get(k string) (v []byte, expired bool) {
 // Set sets an item with key, value, and ttl(seconds).
 // if the ttl is zero, this item will be set and never be deleted.
 // if the key exists, update it with value and exp and move it to head.
-// if the key does not exist, put an item to the cache's head.
+// if the key does not exist, put a new item to the cache's head.
 // finally, remove the tail if the cache is full.
 func (c *LruCache) Set(k string, v []byte, ttl int) {
 	c.mu.Lock()

go.mod

@@ -13,7 +13,7 @@ require (
 	golang.org/x/crypto v0.0.0-20201002170205-7f63de1d35b0
 	golang.org/x/net v0.0.0-20201010224723-4f7140c49acb // indirect
 	golang.org/x/sys v0.0.0-20201009025420-dfb3f7c4e634 // indirect
-	golang.org/x/tools v0.0.0-20201010145503-6e5c6d77ddcc // indirect
+	golang.org/x/tools v0.0.0-20201011145850-ed2f50202694 // indirect
 	gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b // indirect
 )
 

go.sum

@@ -177,8 +177,8 @@ golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtn
 golang.org/x/tools v0.0.0-20200425043458-8463f397d07c h1:iHhCR0b26amDCiiO+kBguKZom9aMF+NrFxh9zeKR/XU=
 golang.org/x/tools v0.0.0-20200425043458-8463f397d07c/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
 golang.org/x/tools v0.0.0-20200808161706-5bf02b21f123/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
-golang.org/x/tools v0.0.0-20201010145503-6e5c6d77ddcc h1:NJuVOHii6+cOLWV2ofkVwU7frODgrUFHcjHCxyQ4DqI=
+golang.org/x/tools v0.0.0-20201011145850-ed2f50202694 h1:BANdcOVw3KTuUiyfDp7wrzCpkCe8UP3lowugJngxBTg=
-golang.org/x/tools v0.0.0-20201010145503-6e5c6d77ddcc/go.mod h1:z6u4i615ZeAfBE4XtMziQW1fSVJXACjjbWkB/mvPzlU=
+golang.org/x/tools v0.0.0-20201011145850-ed2f50202694/go.mod h1:z6u4i615ZeAfBE4XtMziQW1fSVJXACjjbWkB/mvPzlU=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=

proxy/trojan/server.go

@@ -136,6 +136,7 @@ func (s *Trojan) Serve(c net.Conn) {
 }
 
 func (s *Trojan) serveFallback(c net.Conn, tgt string, headBuf *bytes.Buffer) {
+	// TODO: should we access fallback directly or via proxy?
 	dialer := s.proxy.NextDialer(tgt)
 	rc, err := dialer.Dial("tcp", tgt)
 	if err != nil {

proxy/vless/server.go

@@ -92,6 +92,7 @@ func (s *VLess) Serve(c net.Conn) {
 }
 
 func (s *VLess) serveFallback(c net.Conn, tgt string, headBuf *bytes.Buffer) {
+	// TODO: should we access fallback directly or via proxy?
 	dialer := s.proxy.NextDialer(tgt)
 	rc, err := dialer.Dial("tcp", tgt)
 	if err != nil {

rule/config.go

@@ -29,6 +29,7 @@ type StrategyConfig struct {
 	CheckWebSite      string
 	CheckInterval     int
 	CheckTimeout      int
+	CheckTolerance    int
 	CheckDisabledOnly bool
 	MaxFailures       int
 	DialTimeout       int
@@ -43,9 +44,10 @@ func NewConfFromFile(ruleFile string) (*Config, error) {
 	f := conflag.NewFromFile("rule", ruleFile)
 	f.StringSliceUniqVar(&p.Forward, "forward", nil, "forward url, format: SCHEME://[USER|METHOD:PASSWORD@][HOST]:PORT?PARAMS[,SCHEME://[USER|METHOD:PASSWORD@][HOST]:PORT?PARAMS]")
 	f.StringVar(&p.StrategyConfig.Strategy, "strategy", "rr", "forward strategy, default: rr")
-	f.StringVar(&p.StrategyConfig.CheckWebSite, "checkwebsite", "www.apple.com", "proxy check HTTP(NOT HTTPS) website address, format: HOST[:PORT], default port: 80")
+	f.StringVar(&p.StrategyConfig.CheckWebSite, "checkwebsite", "www.apple.com", "fowarder check HTTP(NOT HTTPS) website address, format: HOST[:PORT], default port: 80")
-	f.IntVar(&p.StrategyConfig.CheckInterval, "checkinterval", 30, "proxy check interval(seconds)")
+	f.IntVar(&p.StrategyConfig.CheckInterval, "checkinterval", 30, "fowarder check interval(seconds)")
-	f.IntVar(&p.StrategyConfig.CheckTimeout, "checktimeout", 10, "proxy check timeout(seconds)")
+	f.IntVar(&p.StrategyConfig.CheckTimeout, "checktimeout", 10, "fowarder check timeout(seconds)")
+	f.IntVar(&p.StrategyConfig.CheckTolerance, "checktolerance", 0, "fowarder check tolerance(ms), switch only when new_latency < old_latency - tolerance, only used in lha mode")
 	f.BoolVar(&p.StrategyConfig.CheckDisabledOnly, "checkdisabledonly", false, "check disabled fowarders only")
 	f.IntVar(&p.StrategyConfig.MaxFailures, "maxfailures", 3, "max failures to change forwarder status to disabled")
 	f.IntVar(&p.StrategyConfig.DialTimeout, "dialtimeout", 3, "dial timeout(seconds)")

rule/group.go

@@ -283,15 +283,19 @@ func (p *FwdrGroup) scheduleHA(dstAddr string) *Forwarder {
 
 // Latency based High Availability.
 func (p *FwdrGroup) scheduleLHA(dstAddr string) *Forwarder {
-	fwdr := p.avail[0]
+	oldfwdr, newfwdr := p.avail[0], p.avail[0]
-	lowest := fwdr.Latency()
+	lowest := oldfwdr.Latency()
 	for _, f := range p.avail {
 		if f.Latency() < lowest {
 			lowest = f.Latency()
-			fwdr = f
+			newfwdr = f
 		}
 	}
-	return fwdr
+	tolerance := int64(p.config.CheckTolerance) * int64(time.Millisecond)
+	if newfwdr.Latency() < (oldfwdr.Latency() - tolerance) {
+		return newfwdr
+	}
+	return oldfwdr
 }
 
 // Destination Hashing.