coredns plugin -- Calculate top for domains, clients and blocked both from querylog and running requests.

This moves the functionality from frontend to coredns plugin.

control.go

@@ -417,9 +417,9 @@ func handleStatsReset(w http.ResponseWriter, r *http.Request) {
 }
 
 func handleStatsTop(w http.ResponseWriter, r *http.Request) {
-	resp, err := client.Get("http://127.0.0.1:8618/querylog")
+	resp, err := client.Get("http://127.0.0.1:8618/stats_top")
 	if err != nil {
-		errortext := fmt.Sprintf("Couldn't get querylog from coredns: %T %s\n", err, err)
+		errortext := fmt.Sprintf("Couldn't get stats_top from coredns: %T %s\n", err, err)
 		log.Println(errortext)
 		http.Error(w, errortext, http.StatusBadGateway)
 		return
@@ -428,7 +428,7 @@ func handleStatsTop(w http.ResponseWriter, r *http.Request) {
 		defer resp.Body.Close()
 	}
 
-	// read body
+	// read the body entirely
 	body, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
 		errortext := fmt.Sprintf("Couldn't read response body: %s", err)
@@ -436,85 +436,12 @@ func handleStatsTop(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, errortext, http.StatusBadGateway)
 		return
 	}
-	// empty body
-	if len(body) == 0 {
-		return
-	}
-
-	values := []interface{}{}
-	err = json.Unmarshal(body, &values)
-	if err != nil {
-		errortext := fmt.Sprintf("Couldn't parse response body: %s", err)
-		log.Println(errortext)
-		http.Error(w, errortext, http.StatusBadGateway)
-		return
-	}
-
-	domains := map[string]int{}
-	blocked := map[string]int{}
-	clients := map[string]int{}
-	now := time.Now()
-	timeWindow := time.Hour * 24
-	notBefore := now.Add(timeWindow * -1)
-
-	for _, value := range values {
-		entry, ok := value.(map[string]interface{})
-		if !ok {
-			// ignore anything else
-			continue
-		}
-		host := getHost(entry)
-		reason := getReason(entry)
-		client := getClient(entry)
-		time := getTime(entry)
-		if time.Before(notBefore) {
-			// skip if the entry is before specified cutoff
-			continue
-		}
-		if len(host) > 0 {
-			domains[host]++
-		}
-		if len(host) > 0 && strings.HasPrefix(reason, "Filtered") {
-			blocked[host]++
-		}
-		if len(client) > 0 {
-			clients[client]++
-		}
-	}
-
-	// use manual json marshalling because we want maps to be sorted by value
-	json := bytes.Buffer{}
-	json.WriteString("{\n")
-
-	gen := func(json *bytes.Buffer, name string, top map[string]int, addComma bool) {
-		json.WriteString("  \"")
-		json.WriteString(name)
-		json.WriteString("\": {\n")
-		sorted := sortByValue(top)
-		for i, key := range sorted {
-			json.WriteString("    \"")
-			json.WriteString(key)
-			json.WriteString("\": ")
-			json.WriteString(strconv.Itoa(top[key]))
-			if i+1 != len(sorted) {
-				json.WriteByte(',')
-			}
-			json.WriteByte('\n')
-		}
-		json.WriteString("  }")
-		if addComma {
-			json.WriteByte(',')
-		}
-		json.WriteByte('\n')
-	}
-	gen(&json, "top_queried_domains", domains, true)
-	gen(&json, "top_blocked_domains", blocked, true)
-	gen(&json, "top_clients", clients, true)
-	json.WriteString("  \"stats_period\": \"24 hours\"\n")
-	json.WriteString("}\n")
 
+	// forward body entirely with status code
 	w.Header().Set("Content-Type", "application/json")
-	_, err = w.Write(json.Bytes())
+	w.Header().Set("Content-Length", strconv.Itoa(len(body)))
+	w.WriteHeader(resp.StatusCode)
+	_, err = w.Write(body)
 	if err != nil {
 		errortext := fmt.Sprintf("Couldn't write body: %s", err)
 		log.Println(errortext)

coredns_plugin/coredns_plugin.go

@@ -147,9 +147,6 @@ func setupPlugin(c *caddy.Controller) (*plug, error) {
 				p.settings.BlockedTTL = uint32(blockttl)
 			case "querylog":
 				p.settings.QueryLogEnabled = true
-				onceQueryLog.Do(func() {
-					go startQueryLogServer() // TODO: how to handle errors?
-				})
 			}
 		}
 	}
@@ -186,7 +183,19 @@ func setupPlugin(c *caddy.Controller) (*plug, error) {
 		}
 	}
 
-	var err error
+	log.Printf("Loading top from querylog")
+	err := loadTopFromFiles()
+	if err != nil {
+		log.Printf("Failed to load top from querylog: %s", err)
+		return nil, err
+	}
+
+	if p.settings.QueryLogEnabled {
+		onceQueryLog.Do(func() {
+			go startQueryLogServer() // TODO: how to handle errors?
+		})
+	}
+
 	p.upstream, err = upstream.New(nil)
 	if err != nil {
 		return nil, err

coredns_plugin/querylog.go

@@ -57,11 +57,12 @@ func logRequest(question *dns.Msg, answer *dns.Msg, result dnsfilter.Result, ela
 		}
 	}
 
+	now := time.Now()
 	entry := logEntry{
 		Question: q,
 		Answer:   a,
 		Result:   result,
-		Time:     time.Now(),
+		Time:     now,
 		Elapsed:  elapsed,
 		IP:       ip,
 	}
@@ -74,6 +75,15 @@ func logRequest(question *dns.Msg, answer *dns.Msg, result dnsfilter.Result, ela
 		logBuffer = nil
 	}
 	logBufferLock.Unlock()
+
+	// add it to running top
+	err = runningTop.addEntry(&entry, now)
+	if err != nil {
+		log.Printf("Failed to add entry to running top: %s", err)
+		// don't do failure, just log
+	}
+
+	// if buffer needs to be flushed to disk, do it now
 	if len(flushBuffer) > 0 {
 		// write to file
 		// do it in separate goroutine -- we are stalling DNS response this whole time
@@ -204,8 +214,10 @@ func startQueryLogServer() {
 	listenAddr := "127.0.0.1:8618" // 8618 is sha512sum of "querylog" then each byte summed
 
 	go periodicQueryLogRotate(queryLogRotationPeriod)
+	go periodicHourlyTopRotate()
 
 	http.HandleFunc("/querylog", handleQueryLog)
+	http.HandleFunc("/stats_top", handleStatsTop)
 	if err := http.ListenAndServe(listenAddr, nil); err != nil {
 		log.Fatalf("error in ListenAndServe: %s", err)
 	}

coredns_plugin/querylog_file.go

@@ -145,7 +145,7 @@ func periodicQueryLogRotate(t time.Duration) {
 	}
 }
 
-func appendFromLogFile(values []logEntry, maxLen int, timeWindow time.Duration) []logEntry {
+func genericLoader(onEntry func(entry *logEntry) error, needMore func() bool, timeWindow time.Duration) error {
 	now := time.Now()
 	// read from querylog files, try newest file first
 	files := []string{
@@ -153,12 +153,9 @@ func appendFromLogFile(values []logEntry, maxLen int, timeWindow time.Duration)
 		queryLogFileName + ".gz.1",
 	}
 
-	a := []logEntry{}
-
 	// read from all files
 	for _, file := range files {
-		if len(a) >= maxLen {
-			// previous file filled us with enough fresh entries
+		if !needMore() {
 			break
 		}
 		if _, err := os.Stat(file); os.IsNotExist(err) {
@@ -181,6 +178,7 @@ func appendFromLogFile(values []logEntry, maxLen int, timeWindow time.Duration)
 			log.Printf("Failed to create gzip reader: %s", err)
 			continue
 		}
+		defer zr.Close()
 
 		trace("Creating json decoder")
 		d := json.NewDecoder(zr)
@@ -189,6 +187,9 @@ func appendFromLogFile(values []logEntry, maxLen int, timeWindow time.Duration)
 		// entries on file are in oldest->newest order
 		// we want maxLen newest
 		for d.More() {
+			if !needMore() {
+				break
+			}
 			var entry logEntry
 			err := d.Decode(&entry)
 			if err != nil {
@@ -203,18 +204,40 @@ func appendFromLogFile(values []logEntry, maxLen int, timeWindow time.Duration)
 			}
 
 			i++
-			a = append(a, entry)
-			if len(a) > maxLen {
-				toskip := len(a) - maxLen
-				a = a[toskip:]
+			err = onEntry(&entry)
+			if err != nil {
+				return err
 			}
 		}
-		err = zr.Close()
-		if err != nil {
-			log.Printf("Encountered error while closing gzip reader: %s", err)
-		}
 		log.Printf("file \"%s\": read %d entries", file, i)
 	}
+	return nil
+}
+
+func appendFromLogFile(values []logEntry, maxLen int, timeWindow time.Duration) []logEntry {
+	a := []logEntry{}
+
+	onEntry := func(entry *logEntry) error {
+		a = append(a, *entry)
+		if len(a) > maxLen {
+			toskip := len(a) - maxLen
+			a = a[toskip:]
+		}
+		return nil
+	}
+
+	needMore := func() bool {
+		if len(a) >= maxLen {
+			return false
+		}
+		return true
+	}
+
+	err := genericLoader(onEntry, needMore, timeWindow)
+	if err != nil {
+		log.Printf("Failed to load entries from querylog: %s", err)
+		return values
+	}
 
 	// now that we've read all eligible entries, reverse the slice to make it go from newest->oldest
 	for left, right := 0, len(a)-1; left < right; left, right = left+1, right-1 {

coredns_plugin/querylog_top.go

@@ -0,0 +1,325 @@
+package dnsfilter
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"net/http"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/bluele/gcache"
+	"github.com/miekg/dns"
+)
+
+// top domains/clients/blocked stats in the last 24 hours
+
+// on start we read the saved stats from the last 24 hours and add them to the stats
+
+// stats are counted using hourly LRU, rotating hourly and keeping last 24 hours
+
+type hourTop struct {
+	domains gcache.Cache
+	blocked gcache.Cache
+	clients gcache.Cache
+	sync.RWMutex
+}
+
+func (top *hourTop) init() {
+	top.domains = gcache.New(500).LRU().Build()
+	top.blocked = gcache.New(500).LRU().Build()
+	top.clients = gcache.New(500).LRU().Build()
+}
+
+type dayTop struct {
+	hours        []*hourTop
+	sync.RWMutex // write -- rotating hourTop, read -- anything else
+}
+
+var runningTop dayTop
+
+func init() {
+	runningTop.Lock()
+	for i := 0; i < 24; i++ {
+		hour := hourTop{}
+		hour.init()
+		runningTop.hours = append(runningTop.hours, &hour)
+	}
+	runningTop.Unlock()
+}
+
+func rotateHourlyTop() {
+	log.Printf("Rotating hourly top")
+	hour := &hourTop{}
+	hour.init()
+	runningTop.Lock()
+	runningTop.hours = append([]*hourTop{hour}, runningTop.hours...)
+	runningTop.hours = runningTop.hours[:24]
+	runningTop.Unlock()
+}
+
+func periodicHourlyTopRotate() {
+	t := time.Hour
+	for range time.Tick(t) {
+		rotateHourlyTop()
+	}
+}
+
+func (top *hourTop) incrementValue(key string, cache gcache.Cache) error {
+	top.Lock()
+	defer top.Unlock()
+	ivalue, err := cache.Get(key)
+	if err == gcache.KeyNotFoundError {
+		// we just set it and we're done
+		err = cache.Set(key, 1)
+		if err != nil {
+			log.Printf("Failed to set hourly top value: %s", err)
+			return err
+		}
+		return nil
+	}
+
+	if err != nil {
+		log.Printf("gcache encountered an error during get: %s", err)
+		return err
+	}
+
+	cachedValue, ok := ivalue.(int)
+	if !ok {
+		err = fmt.Errorf("SHOULD NOT HAPPEN: gcache has non-int as value: %v", ivalue)
+		log.Println(err)
+		return err
+	}
+
+	err = cache.Set(key, cachedValue+1)
+	if err != nil {
+		log.Printf("Failed to set hourly top value: %s", err)
+		return err
+	}
+	return nil
+}
+
+func (top *hourTop) incrementDomains(key string) error {
+	return top.incrementValue(key, top.domains)
+}
+
+func (top *hourTop) incrementBlocked(key string) error {
+	return top.incrementValue(key, top.blocked)
+}
+
+func (top *hourTop) incrementClients(key string) error {
+	return top.incrementValue(key, top.clients)
+}
+
+// if does not exist -- return 0
+func (top *hourTop) lockedGetValue(key string, cache gcache.Cache) (int, error) {
+	ivalue, err := cache.Get(key)
+	if err == gcache.KeyNotFoundError {
+		return 0, nil
+	}
+
+	if err != nil {
+		log.Printf("gcache encountered an error during get: %s", err)
+		return 0, err
+	}
+
+	value, ok := ivalue.(int)
+	if !ok {
+		err := fmt.Errorf("SHOULD NOT HAPPEN: gcache has non-int as value: %v", ivalue)
+		log.Println(err)
+		return 0, err
+	}
+
+	return value, nil
+}
+
+func (top *hourTop) lockedGetDomains(key string) (int, error) {
+	return top.lockedGetValue(key, top.domains)
+}
+
+func (top *hourTop) lockedGetBlocked(key string) (int, error) {
+	return top.lockedGetValue(key, top.blocked)
+}
+
+func (top *hourTop) lockedGetClients(key string) (int, error) {
+	return top.lockedGetValue(key, top.clients)
+}
+
+func (r *dayTop) addEntry(entry *logEntry, now time.Time) error {
+	if len(entry.Question) == 0 {
+		log.Printf("entry question is absent, skipping")
+		return nil
+	}
+
+	if entry.Time.After(now) {
+		log.Printf("t %v vs %v is in the future, ignoring", entry.Time, now)
+		return nil
+	}
+	// figure out which hour bucket it belongs to
+	hour := int(now.Sub(entry.Time).Hours())
+	if hour >= 24 {
+		log.Printf("t %v is >24 hours ago, ignoring", entry.Time)
+		return nil
+	}
+
+	q := new(dns.Msg)
+	if err := q.Unpack(entry.Question); err != nil {
+		log.Printf("failed to unpack dns message question: %s", err)
+		return err
+	}
+
+	if len(q.Question) != 1 {
+		log.Printf("malformed dns message, has no questions, skipping")
+		return nil
+	}
+
+	hostname := strings.ToLower(strings.TrimSuffix(q.Question[0].Name, "."))
+
+	// get value, if not set, crate one
+	runningTop.RLock()
+	defer runningTop.RUnlock()
+	err := runningTop.hours[hour].incrementDomains(hostname)
+	if err != nil {
+		log.Printf("Failed to increment value: %s", err)
+		return err
+	}
+
+	if entry.Result.IsFiltered {
+		err := runningTop.hours[hour].incrementBlocked(hostname)
+		if err != nil {
+			log.Printf("Failed to increment value: %s", err)
+			return err
+		}
+	}
+
+	if len(entry.IP) > 0 {
+		err := runningTop.hours[hour].incrementClients(entry.IP)
+		if err != nil {
+			log.Printf("Failed to increment value: %s", err)
+			return err
+		}
+	}
+
+	return nil
+}
+
+func loadTopFromFiles() error {
+	now := time.Now()
+	runningTop.RLock()
+	defer runningTop.RUnlock()
+	onEntry := func(entry *logEntry) error {
+		err := runningTop.addEntry(entry, now)
+		if err != nil {
+			log.Printf("Failed to add entry to running top: %s", err)
+			return err
+		}
+		return nil
+	}
+
+	needMore := func() bool { return true }
+	err := genericLoader(onEntry, needMore, time.Hour*24)
+	if err != nil {
+		log.Printf("Failed to load entries from querylog: %s", err)
+		return err
+	}
+
+	return nil
+}
+
+func handleStatsTop(w http.ResponseWriter, r *http.Request) {
+	domains := map[string]int{}
+	blocked := map[string]int{}
+	clients := map[string]int{}
+
+	do := func(keys []interface{}, getter func(key string) (int, error), result map[string]int) {
+		for _, ikey := range keys {
+			key, ok := ikey.(string)
+			if !ok {
+				continue
+			}
+			value, err := getter(key)
+			if err != nil {
+				log.Printf("Failed to get top domains value for %v: %s", key, err)
+				return
+			}
+			result[key] += value
+		}
+	}
+
+	runningTop.RLock()
+	for hour := 0; hour < 24; hour++ {
+		runningTop.hours[hour].RLock()
+		do(runningTop.hours[hour].domains.Keys(), runningTop.hours[hour].lockedGetDomains, domains)
+		do(runningTop.hours[hour].blocked.Keys(), runningTop.hours[hour].lockedGetBlocked, blocked)
+		do(runningTop.hours[hour].clients.Keys(), runningTop.hours[hour].lockedGetClients, clients)
+		runningTop.hours[hour].RUnlock()
+	}
+	runningTop.RUnlock()
+
+	// use manual json marshalling because we want maps to be sorted by value
+	json := bytes.Buffer{}
+	json.WriteString("{\n")
+
+	gen := func(json *bytes.Buffer, name string, top map[string]int, addComma bool) {
+		json.WriteString("  \"")
+		json.WriteString(name)
+		json.WriteString("\": {\n")
+		sorted := sortByValue(top)
+		for i, key := range sorted {
+			// no more than 50 entries
+			if i >= 50 {
+				break
+			}
+			json.WriteString("    \"")
+			json.WriteString(key)
+			json.WriteString("\": ")
+			json.WriteString(strconv.Itoa(top[key]))
+			if i+1 != len(sorted) {
+				json.WriteByte(',')
+			}
+			json.WriteByte('\n')
+		}
+		json.WriteString("  }")
+		if addComma {
+			json.WriteByte(',')
+		}
+		json.WriteByte('\n')
+	}
+	gen(&json, "top_queried_domains", domains, true)
+	gen(&json, "top_blocked_domains", blocked, true)
+	gen(&json, "top_clients", clients, true)
+	json.WriteString("  \"stats_period\": \"24 hours\"\n")
+	json.WriteString("}\n")
+
+	w.Header().Set("Content-Type", "application/json")
+	_, err := w.Write(json.Bytes())
+	if err != nil {
+		errortext := fmt.Sprintf("Couldn't write body: %s", err)
+		log.Println(errortext)
+		http.Error(w, errortext, http.StatusInternalServerError)
+	}
+}
+
+// helper function for querylog API
+func sortByValue(m map[string]int) []string {
+	type kv struct {
+		k string
+		v int
+	}
+	var ss []kv
+	for k, v := range m {
+		ss = append(ss, kv{k, v})
+	}
+	sort.Slice(ss, func(l, r int) bool {
+		return ss[l].v > ss[r].v
+	})
+
+	sorted := []string{}
+	for _, v := range ss {
+		sorted = append(sorted, v.k)
+	}
+	return sorted
+}

helpers.go

@@ -9,9 +9,7 @@ import (
 	"os"
 	"path"
 	"runtime"
-	"sort"
 	"strings"
-	"time"
 )
 
 func clamp(value, low, high int) int {
@@ -133,89 +131,6 @@ func generateMapFromStats(stats *periodicStats, start int, end int) map[string]i
 	return result
 }
 
-// -------------------------------------
-// helper functions for querylog parsing
-// -------------------------------------
-func sortByValue(m map[string]int) []string {
-	type kv struct {
-		k string
-		v int
-	}
-	var ss []kv
-	for k, v := range m {
-		ss = append(ss, kv{k, v})
-	}
-	sort.Slice(ss, func(l, r int) bool {
-		return ss[l].v > ss[r].v
-	})
-
-	sorted := []string{}
-	for _, v := range ss {
-		sorted = append(sorted, v.k)
-	}
-	return sorted
-}
-
-func getHost(entry map[string]interface{}) string {
-	q, ok := entry["question"]
-	if !ok {
-		return ""
-	}
-	question, ok := q.(map[string]interface{})
-	if !ok {
-		return ""
-	}
-	h, ok := question["host"]
-	if !ok {
-		return ""
-	}
-	host, ok := h.(string)
-	if !ok {
-		return ""
-	}
-	return host
-}
-
-func getReason(entry map[string]interface{}) string {
-	r, ok := entry["reason"]
-	if !ok {
-		return ""
-	}
-	reason, ok := r.(string)
-	if !ok {
-		return ""
-	}
-	return reason
-}
-
-func getClient(entry map[string]interface{}) string {
-	c, ok := entry["client"]
-	if !ok {
-		return ""
-	}
-	client, ok := c.(string)
-	if !ok {
-		return ""
-	}
-	return client
-}
-
-func getTime(entry map[string]interface{}) time.Time {
-	t, ok := entry["time"]
-	if !ok {
-		return time.Time{}
-	}
-	tstr, ok := t.(string)
-	if !ok {
-		return time.Time{}
-	}
-	value, err := time.Parse(time.RFC3339, tstr)
-	if err != nil {
-		return time.Time{}
-	}
-	return value
-}
-
 // -------------------------------------------------
 // helper functions for parsing parameters from body
 // -------------------------------------------------