From a6a72a5b546a2af0ed558af2975db080d393631e Mon Sep 17 00:00:00 2001
From: Dreamacro <8615343+dreamacro@users.noreply.github.com>
Date: Mon, 16 Jan 2023 15:20:39 +0800
Subject: [PATCH] Feature: add dns query json api

---
 component/resolver/resolver.go |  3 ++
 hub/route/configs.go           | 13 +++---
 hub/route/dns.go               | 76 ++++++++++++++++++++++++++++++++++
 hub/route/proxies.go           |  8 ++--
 hub/route/server.go            |  1 +
 5 files changed, 88 insertions(+), 13 deletions(-)
 create mode 100644 hub/route/dns.go

diff --git a/component/resolver/resolver.go b/component/resolver/resolver.go
index 55f98d3c..fa1e7c02 100644
--- a/component/resolver/resolver.go
+++ b/component/resolver/resolver.go
@@ -11,6 +11,8 @@ import (
 	"time"
 
 	"github.com/Dreamacro/clash/component/trie"
+
+	"github.com/miekg/dns"
 )
 
 var (
@@ -44,6 +46,7 @@ type Resolver interface {
 	ResolveIP(ctx context.Context, host string) (ip netip.Addr, err error)
 	ResolveIPv4(ctx context.Context, host string) (ip netip.Addr, err error)
 	ResolveIPv6(ctx context.Context, host string) (ip netip.Addr, err error)
+	ExchangeContext(ctx context.Context, m *dns.Msg) (msg *dns.Msg, err error)
 }
 
 // LookupIPv4WithResolver same as LookupIPv4, but with a resolver
diff --git a/hub/route/configs.go b/hub/route/configs.go
index 37acac5e..5047c6d6 100644
--- a/hub/route/configs.go
+++ b/hub/route/configs.go
@@ -104,7 +104,6 @@ func pointerOrDefault(p *int, def int) int {
 	if p != nil {
 		return *p
 	}
-
 	return def
 }
 
@@ -210,7 +209,7 @@ func pointerOrDefaultTuicServer(p *tuicServerSchema, def LC.TuicServer) LC.TuicS
 
 func patchConfigs(w http.ResponseWriter, r *http.Request) {
 	general := &configSchema{}
-	if err := render.DecodeJSON(r.Body, general); err != nil {
+	if err := render.DecodeJSON(r.Body, &general); err != nil {
 		render.Status(r, http.StatusBadRequest)
 		render.JSON(w, r, ErrBadRequest)
 		return
@@ -266,13 +265,11 @@ func patchConfigs(w http.ResponseWriter, r *http.Request) {
 	render.NoContent(w, r)
 }
 
-type updateConfigRequest struct {
-	Path    string `json:"path"`
-	Payload string `json:"payload"`
-}
-
 func updateConfigs(w http.ResponseWriter, r *http.Request) {
-	req := updateConfigRequest{}
+	req := struct {
+		Path    string `json:"path"`
+		Payload string `json:"payload"`
+	}{}
 	if err := render.DecodeJSON(r.Body, &req); err != nil {
 		render.Status(r, http.StatusBadRequest)
 		render.JSON(w, r, ErrBadRequest)
diff --git a/hub/route/dns.go b/hub/route/dns.go
new file mode 100644
index 00000000..c02db022
--- /dev/null
+++ b/hub/route/dns.go
@@ -0,0 +1,76 @@
+package route
+
+import (
+	"context"
+	"math"
+	"net/http"
+
+	"github.com/Dreamacro/clash/component/resolver"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/render"
+	"github.com/miekg/dns"
+	"github.com/samber/lo"
+)
+
+func dnsRouter() http.Handler {
+	r := chi.NewRouter()
+	r.Get("/query", queryDNS)
+	return r
+}
+
+func queryDNS(w http.ResponseWriter, r *http.Request) {
+	name := r.URL.Query().Get("name")
+	qTypeStr, _ := lo.Coalesce(r.URL.Query().Get("type"), "A")
+
+	qType, exist := dns.StringToType[qTypeStr]
+	if !exist {
+		render.Status(r, http.StatusBadRequest)
+		render.JSON(w, r, newError("invalid query type"))
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), resolver.DefaultDNSTimeout)
+	defer cancel()
+
+	msg := dns.Msg{}
+	msg.SetQuestion(dns.Fqdn(name), qType)
+	resp, err := resolver.DefaultResolver.ExchangeContext(ctx, &msg)
+	if err != nil {
+		render.Status(r, http.StatusInternalServerError)
+		render.JSON(w, r, newError(err.Error()))
+		return
+	}
+
+	responseData := render.M{
+		"Status":   resp.Rcode,
+		"Question": resp.Question,
+		"TC":       resp.Truncated,
+		"RD":       resp.RecursionDesired,
+		"RA":       resp.RecursionAvailable,
+		"AD":       resp.AuthenticatedData,
+		"CD":       resp.CheckingDisabled,
+	}
+
+	rr2Json := func(rr dns.RR, _ int) render.M {
+		header := rr.Header()
+		return render.M{
+			"name": header.Name,
+			"type": header.Rrtype,
+			"TTL":  header.Ttl,
+			"data": lo.Substring(rr.String(), len(header.String()), math.MaxUint),
+		}
+	}
+
+	if len(resp.Answer) > 0 {
+		responseData["Answer"] = lo.Map(resp.Answer, rr2Json)
+	}
+	if len(resp.Ns) > 0 {
+		responseData["Authority"] = lo.Map(resp.Ns, rr2Json)
+	}
+	if len(resp.Extra) > 0 {
+		responseData["Additional"] = lo.Map(resp.Extra, rr2Json)
+	}
+
+	render.JSON(w, r, responseData)
+}
diff --git a/hub/route/proxies.go b/hub/route/proxies.go
index baffb1f5..5bf6eb9c 100644
--- a/hub/route/proxies.go
+++ b/hub/route/proxies.go
@@ -70,12 +70,10 @@ func getProxy(w http.ResponseWriter, r *http.Request) {
 	render.JSON(w, r, proxy)
 }
 
-type UpdateProxyRequest struct {
-	Name string `json:"name"`
-}
-
 func updateProxy(w http.ResponseWriter, r *http.Request) {
-	req := UpdateProxyRequest{}
+	req := struct {
+		Name string `json:"name"`
+	}{}
 	if err := render.DecodeJSON(r.Body, &req); err != nil {
 		render.Status(r, http.StatusBadRequest)
 		render.JSON(w, r, ErrBadRequest)
diff --git a/hub/route/server.go b/hub/route/server.go
index 2bef92c1..0d6a47ac 100644
--- a/hub/route/server.go
+++ b/hub/route/server.go
@@ -73,6 +73,7 @@ func Start(addr string, tlsAddr string, secret string,
 		r.Mount("/providers/proxies", proxyProviderRouter())
 		r.Mount("/providers/rules", ruleProviderRouter())
 		r.Mount("/cache", cacheRouter())
+		r.Mount("/dns", dnsRouter())
 	})
 
 	if uiPath != "" {