Add urltest outbound

common/urltest/urltest.go

@@ -0,0 +1,107 @@
+package urltest
+
+import (
+	"context"
+	"net"
+	"net/http"
+	"net/url"
+	"sync"
+	"time"
+
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+type History struct {
+	Time  time.Time `json:"time"`
+	Delay uint16    `json:"delay"`
+}
+
+type HistoryStorage struct {
+	access       sync.RWMutex
+	delayHistory map[string]*History
+}
+
+func NewHistoryStorage() *HistoryStorage {
+	return &HistoryStorage{
+		delayHistory: make(map[string]*History),
+	}
+}
+
+func (s *HistoryStorage) LoadURLTestHistory(tag string) *History {
+	if s == nil {
+		return nil
+	}
+	s.access.RLock()
+	defer s.access.RUnlock()
+	return s.delayHistory[tag]
+}
+
+func (s *HistoryStorage) DeleteURLTestHistory(tag string) {
+	s.access.Lock()
+	defer s.access.Unlock()
+	delete(s.delayHistory, tag)
+}
+
+func (s *HistoryStorage) StoreURLTestHistory(tag string, history *History) {
+	s.access.Lock()
+	defer s.access.Unlock()
+	s.delayHistory[tag] = history
+}
+
+func URLTest(ctx context.Context, link string, detour N.Dialer) (t uint16, err error) {
+	linkURL, err := url.Parse(link)
+	if err != nil {
+		return
+	}
+	hostname := linkURL.Hostname()
+	port := linkURL.Port()
+	if port == "" {
+		switch linkURL.Scheme {
+		case "http":
+			port = "80"
+		case "https":
+			port = "443"
+		}
+	}
+
+	start := time.Now()
+	instance, err := detour.DialContext(ctx, "tcp", M.ParseSocksaddrHostPortStr(hostname, port))
+	if err != nil {
+		return
+	}
+	defer instance.Close()
+
+	req, err := http.NewRequest(http.MethodHead, link, nil)
+	if err != nil {
+		return
+	}
+	req = req.WithContext(ctx)
+
+	transport := &http.Transport{
+		Dial: func(string, string) (net.Conn, error) {
+			return instance, nil
+		},
+		// from http.DefaultTransport
+		MaxIdleConns:          100,
+		IdleConnTimeout:       90 * time.Second,
+		TLSHandshakeTimeout:   10 * time.Second,
+		ExpectContinueTimeout: 1 * time.Second,
+	}
+
+	client := http.Client{
+		Transport: transport,
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			return http.ErrUseLastResponse
+		},
+	}
+	defer client.CloseIdleConnections()
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return
+	}
+	resp.Body.Close()
+	t = uint16(time.Since(start) / time.Millisecond)
+	return
+}