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Tailscale
/
tailscale
огледало од https://github.com/tailscale/tailscale.git
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Преглед изворни кода

net/dns/resolver: add debug HTML handler to see what DNS traffic was forwarded

Change-Id: I6b790e92dcc608515ac8b178f2271adc9fd98f78
Signed-off-by: Brad Fitzpatrick <[email protected]>
Brad Fitzpatrick пре 4 година
родитељ
ae319b4636
комит
0aa4c6f147
4 измењених фајлова са 114 додато и 0 уклоњено
Један поглед Покажи статистику Diff
  1. 15 0
      health/health.go
  2. 17 0
      ipn/ipnlocal/peerapi.go
  3. 78 0
      net/dns/resolver/debug.go
  4. 4 0
      net/dns/resolver/forwarder.go

+ 15 - 0
health/health.go
Прегледај датотеку 

@@ -9,6 +9,7 @@ package health
 
 import (
 
 import (
 
 	"errors"
 
 	"errors"
 
 	"fmt"
 
 	"fmt"
 
+	"net/http"
 
 	"os"
 
 	"os"
 
 	"runtime"
 
 	"runtime"
 
 	"sort"
 
 	"sort"
 
@@ -28,6 +29,8 @@ var (
 
 	watchers = map[*watchHandle]func(Subsystem, error){} // opt func to run if error state changes
 
 	watchers = map[*watchHandle]func(Subsystem, error){} // opt func to run if error state changes
 
 	timer    *time.Timer
 
 	timer    *time.Timer
 
 
 
+	debugHandler = map[string]http.Handler{}
 
+
 
 	inMapPoll               bool
 
 	inMapPoll               bool
 
 	inMapPollSince          time.Time
 
 	inMapPollSince          time.Time
 
 	lastMapPollEndedAt      time.Time
 
 	lastMapPollEndedAt      time.Time
 
@@ -116,6 +119,18 @@ func SetNetworkCategoryHealth(err error) { set(SysNetworkCategory, err) }
 
 
 
 func NetworkCategoryHealth() error { return get(SysNetworkCategory) }
 
 func NetworkCategoryHealth() error { return get(SysNetworkCategory) }
 
 
 
+func RegisterDebugHandler(typ string, h http.Handler) {
 
+	mu.Lock()
 
+	defer mu.Unlock()
 
+	debugHandler[typ] = h
 
+}
 
+
 
+func DebugHandler(typ string) http.Handler {
 
+	mu.Lock()
 
+	defer mu.Unlock()
 
+	return debugHandler[typ]
 
+}
 
+
 
 func get(key Subsystem) error {
 
 func get(key Subsystem) error {
 
 	mu.Lock()
 
 	mu.Lock()
 
 	defer mu.Unlock()
 
 	defer mu.Unlock()

+ 17 - 0
ipn/ipnlocal/peerapi.go
Прегледај датотеку 

@@ -32,6 +32,7 @@ import (
 
 	"golang.org/x/net/dns/dnsmessage"
 
 	"golang.org/x/net/dns/dnsmessage"
 
 	"inet.af/netaddr"
 
 	"inet.af/netaddr"
 
 	"tailscale.com/client/tailscale/apitype"
 
 	"tailscale.com/client/tailscale/apitype"
 
+	"tailscale.com/health"
 
 	"tailscale.com/hostinfo"
 
 	"tailscale.com/hostinfo"
 
 	"tailscale.com/ipn"
 
 	"tailscale.com/ipn"
 
 	"tailscale.com/logtail/backoff"
 
 	"tailscale.com/logtail/backoff"
 
@@ -556,6 +557,9 @@ func (h *peerAPIHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	case "/v0/magicsock":
 
 	case "/v0/magicsock":
 
 		h.handleServeMagicsock(w, r)
 
 		h.handleServeMagicsock(w, r)
 
 		return
 
 		return
 
+	case "/v0/dnsfwd":
 
+		h.handleServeDNSFwd(w, r)
 
+		return
 
 	}
 
 	}
 
 	who := h.peerUser.DisplayName
 
 	who := h.peerUser.DisplayName
 
 	fmt.Fprintf(w, `<html>
 
 	fmt.Fprintf(w, `<html>
 
@@ -808,6 +812,19 @@ func (h *peerAPIHandler) handleServeMetrics(w http.ResponseWriter, r *http.Reque
 
 	clientmetric.WritePrometheusExpositionFormat(w)
 
 	clientmetric.WritePrometheusExpositionFormat(w)
 
 }
 
 }
 
 
 
+func (h *peerAPIHandler) handleServeDNSFwd(w http.ResponseWriter, r *http.Request) {
 
+	if !h.isSelf {
 
+		http.Error(w, "not owner", http.StatusForbidden)
 
+		return
 
+	}
 
+	dh := health.DebugHandler("dnsfwd")
 
+	if dh == nil {
 
+		http.Error(w, "not wired up", 500)
 
+		return
 
+	}
 
+	dh.ServeHTTP(w, r)
 
+}
 
+
 
 func (h *peerAPIHandler) replyToDNSQueries() bool {
 
 func (h *peerAPIHandler) replyToDNSQueries() bool {
 
 	if h.isSelf {
 
 	if h.isSelf {
 
 		// If the peer is owned by the same user, just allow it
 
 		// If the peer is owned by the same user, just allow it

+ 78 - 0
net/dns/resolver/debug.go
Прегледај датотеку 

@@ -0,0 +1,78 @@
 
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
 
+// Use of this source code is governed by a BSD-style
 
+// license that can be found in the LICENSE file.
 
+
 
+package resolver
 
+
 
+import (
 
+	"fmt"
 
+	"html"
 
+	"net/http"
 
+	"strconv"
 
+	"sync"
 
+	"sync/atomic"
 
+	"time"
 
+
 
+	"tailscale.com/health"
 
+)
 
+
 
+func init() {
 
+	health.RegisterDebugHandler("dnsfwd", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 
+		n, _ := strconv.Atoi(r.FormValue("n"))
 
+		if n <= 0 {
 
+			n = 100
 
+		} else if n > 10000 {
 
+			n = 10000
 
+		}
 
+		fl, ok := fwdLogAtomic.Load().(*fwdLog)
 
+		if !ok || n != len(fl.ent) {
 
+			fl = &fwdLog{ent: make([]fwdLogEntry, n)}
 
+			fwdLogAtomic.Store(fl)
 
+		}
 
+		fl.ServeHTTP(w, r)
 
+	}))
 
+}
 
+
 
+var fwdLogAtomic atomic.Value // of *fwdLog
 
+
 
+type fwdLog struct {
 
+	mu  sync.Mutex
 
+	pos int // ent[pos] is next entry
 
+	ent []fwdLogEntry
 
+}
 
+
 
+type fwdLogEntry struct {
 
+	Domain string
 
+	Time   time.Time
 
+}
 
+
 
+func (fl *fwdLog) addName(name string) {
 
+	if fl == nil {
 
+		return
 
+	}
 
+	fl.mu.Lock()
 
+	defer fl.mu.Unlock()
 
+	if len(fl.ent) == 0 {
 
+		return
 
+	}
 
+	fl.ent[fl.pos] = fwdLogEntry{Domain: name, Time: time.Now()}
 
+	fl.pos++
 
+	if fl.pos == len(fl.ent) {
 
+		fl.pos = 0
 
+	}
 
+}
 
+
 
+func (fl *fwdLog) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
+	fl.mu.Lock()
 
+	defer fl.mu.Unlock()
 
+
 
+	fmt.Fprintf(w, "<html><h1>DNS forwards</h1>")
 
+	now := time.Now()
 
+	for i := 0; i < len(fl.ent); i++ {
 
+		ent := fl.ent[(i+fl.pos)%len(fl.ent)]
 
+		if ent.Domain == "" {
 
+			continue
 
+		}
 
+		fmt.Fprintf(w, "%v ago: %v<br>\n", now.Sub(ent.Time).Round(time.Second), html.EscapeString(ent.Domain))
 
+	}
 
+}

+ 4 - 0
net/dns/resolver/forwarder.go
Прегледај датотеку 

@@ -611,6 +611,10 @@ func (f *forwarder) forwardWithDestChan(ctx context.Context, query packet, respo
 
 		}
 
 		}
 
 	}
 
 	}
 
 
 
+	if fl, ok := fwdLogAtomic.Load().(*fwdLog); ok {
 
+		fl.addName(string(domain))
 
+	}
 
+
 
 	clampEDNSSize(query.bs, maxResponseBytes)
 
 	clampEDNSSize(query.bs, maxResponseBytes)
 
 
 
 	if len(resolvers) == 0 {
 
 	if len(resolvers) == 0 {