optimize code, comment / log / flag

router/country.go

@@ -9,7 +9,7 @@ import (
 )
 
 func (r *Router) localSite(domain string) bool {
-
+	// parse domain to IP
 	ip := net.ParseIP(domain)
 	if ip == nil {
 		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
@@ -27,12 +27,14 @@ func (r *Router) localSite(domain string) bool {
 		ip = ips[0]
 	}
 
+	// CIDR match
 	for _, cidr := range r.country.cidrs {
 		if cidr.Contains(ip) {
 			return true
 		}
 	}
 
+	// MMDB match CN
 	if r.country.Reader != nil {
 		city, err := r.country.City(ip)
 		if err != nil {

router/dns.go

@@ -11,32 +11,32 @@ import (
 func (r *Router) ServeDNS(w dns.ResponseWriter, req *dns.Msg) {
 	// https://stackoverflow.com/questions/4082081/requesting-a-and-aaaa-records-in-single-dns-query/4083071#4083071
 	if len(req.Question) == 0 {
-		w.WriteMsg(r.dnsFail(req, dns.RcodeFormatError))
+		_ = w.WriteMsg(r.dnsFail(req, dns.RcodeFormatError))
 		return
 	}
 
 	domain := req.Question[0].Name
 	switch {
 	case r.blockRule.Match(domain):
-		w.WriteMsg(r.dnsFail(req, dns.RcodeNameError))
+		_ = w.WriteMsg(r.dnsFail(req, dns.RcodeNameError))
 		return
 
 	case r.directRule.Match(domain):
 
 	case r.proxyRule.Match(domain):
-		w.WriteMsg(r.dnsProxyA(domain, r.dns.serveIP, req))
+		_ = w.WriteMsg(r.dnsProxyA(domain, r.dns.serveIP, req))
 		return
 	}
 
 	c := &dnsCache{Router: r, Req: req}
 	if err := r.dns.cache.Remember(c, req.Question[0].String()); err != nil {
-		w.WriteMsg(r.dnsFail(req, dns.RcodeServerFailure))
+		_ = w.WriteMsg(r.dnsFail(req, dns.RcodeServerFailure))
 		return
 	}
 
 	c.Resp.SetReply(req)
 	c.Resp.Compress = true
-	w.WriteMsg(c.Resp)
+	_ = w.WriteMsg(c.Resp)
 }
 
 func (r *Router) dnsFail(req *dns.Msg, rcode int) *dns.Msg {

router/ping.go

@@ -4,6 +4,8 @@ import (
 	"net"
 	"net/http"
 	"time"
+
+	"github.com/wweir/sower/pkg/deferlog"
 )
 
 var pingClient = http.Client{
@@ -19,7 +21,7 @@ func (r *Router) isAccess(domain string, port uint16) bool {
 	}
 
 	p := &ping{}
-	r.accessCache.Remember(p, domain)
+	_ = r.accessCache.Remember(p, domain)
 	return p.isAccess
 }
 
@@ -28,7 +30,10 @@ type ping struct {
 }
 
 func (p *ping) Fulfill(key string) error {
-	_, err := http.Head(net.JoinHostPort(key, "80"))
+	_, err := pingClient.Head(net.JoinHostPort(key, "80"))
+	deferlog.Std.DebugWarn(err).
+		Str("domain", key).
+		Msg("detect if site is accessible")
 	p.isAccess = (err == nil)
 	return nil
 }

router/router.go

@@ -130,7 +130,7 @@ func (r *Router) ProxyHandle(conn net.Conn, domain string, port uint16) error {
 	start := time.Now()
 	rc, err := r.ProxyDial("tcp", domain, port)
 	if err != nil {
-		return errors.Wrapf(err, "dial proxy to (%s:%d), spend (%s)", domain, port, time.Since(start))
+		return errors.Wrapf(err, "proxy dial (%s:%d), spend (%s)", domain, port, time.Since(start))
 	}
 	defer rc.Close()