* SB/PC: use 4-character hash in request

* use hash prefix as the cache key Squashed commit of the following: commit d719a84ee9b9cf43aaab4f53d07451645ea836db Merge: d9d6d443 97df1989 Author: Simon Zolin <s.zolin@adguard.com> Date: Thu Aug 13 11:41:28 2020 +0300 Merge remote-tracking branch 'origin/master' into sbpc commit d9d6d44376c44959f2216b08e577d8e5c5f65bff Merge: 0a8b2483 de92c852 Author: Simon Zolin <s.zolin@adguard.com> Date: Thu Aug 13 11:23:14 2020 +0300 Merge remote-tracking branch 'origin/master' into sbpc commit 0a8b24839683683a9d327ecf57a7d182b3996b1d Merge: 0255a24a 9b9902f0 Author: Simon Zolin <s.zolin@adguard.com> Date: Wed Aug 12 20:21:22 2020 +0300 Merge remote-tracking branch 'origin/master' into sbpc commit 0255a24a191efd2e4ef23d6a00a7a9fed8831730 Author: Simon Zolin <s.zolin@adguard.com> Date: Wed Aug 12 17:16:57 2020 +0300 - TestServerCustomClientUpstream(): fix commit d2311902f887be9621a9d9312c73f899dd269440 Author: Simon Zolin <s.zolin@adguard.com> Date: Wed Aug 12 17:07:12 2020 +0300 * SB/PC: hard-code Family server IP addresses to prevent from requesting them at runtime commit ee340108f11f98d49a7af2a7e8a228c25ab1537a Author: Simon Zolin <s.zolin@adguard.com> Date: Wed Aug 12 17:05:57 2020 +0300 * dnsproxy v0.30.1 commit f5f53ba7116ad525204d00b80352202eee88b78c Author: Simon Zolin <s.zolin@adguard.com> Date: Wed Aug 12 14:53:23 2020 +0300 minor commit fb4631e2cd570b0fd5ae26ec2b1890361275a5a8 Author: Simon Zolin <s.zolin@adguard.com> Date: Mon Aug 10 20:07:27 2020 +0300 * SB/PC: implement new cache commit f9f58461a6efbcfacd798f7640a4645cf1971cb2 Author: Simon Zolin <s.zolin@adguard.com> Date: Fri Aug 7 19:31:05 2020 +0300 doc commit ed69626a6c119ab1a3b187f5afbd4cef708c3159 Author: Simon Zolin <s.zolin@adguard.com> Date: Fri Aug 7 18:25:57 2020 +0300 * SB/PC: use hostname prefix for cache commit afa8040c8c0836c7e59e6fb9aaf1caccd132ea8f Author: Simon Zolin <s.zolin@adguard.com> Date: Fri Jul 31 11:19:49 2020 +0300 * SB/PC: use 4-character hash in request
2020-08-13 11:49:42 +03:00
parent 97df19898f
commit 705a9d909d
9 changed files with 469 additions and 185 deletions
--- a/dnsfilter/safe_search.go
+++ b/dnsfilter/safe_search.go
@@ -0,0 +1,149 @@
+package dnsfilter
+
+import (
+	"bytes"
+	"encoding/binary"
+	"encoding/gob"
+	"encoding/json"
+	"fmt"
+	"net"
+	"net/http"
+	"time"
+
+	"github.com/AdguardTeam/golibs/cache"
+	"github.com/AdguardTeam/golibs/log"
+)
+
+/*
+expire byte[4]
+res Result
+*/
+func (d *Dnsfilter) setCacheResult(cache cache.Cache, host string, res Result) int {
+	var buf bytes.Buffer
+
+	expire := uint(time.Now().Unix()) + d.Config.CacheTime*60
+	var exp []byte
+	exp = make([]byte, 4)
+	binary.BigEndian.PutUint32(exp, uint32(expire))
+	_, _ = buf.Write(exp)
+
+	enc := gob.NewEncoder(&buf)
+	err := enc.Encode(res)
+	if err != nil {
+		log.Error("gob.Encode(): %s", err)
+		return 0
+	}
+	val := buf.Bytes()
+	_ = cache.Set([]byte(host), val)
+	return len(val)
+}
+
+func getCachedResult(cache cache.Cache, host string) (Result, bool) {
+	data := cache.Get([]byte(host))
+	if data == nil {
+		return Result{}, false
+	}
+
+	exp := int(binary.BigEndian.Uint32(data[:4]))
+	if exp <= int(time.Now().Unix()) {
+		cache.Del([]byte(host))
+		return Result{}, false
+	}
+
+	var buf bytes.Buffer
+	buf.Write(data[4:])
+	dec := gob.NewDecoder(&buf)
+	r := Result{}
+	err := dec.Decode(&r)
+	if err != nil {
+		log.Debug("gob.Decode(): %s", err)
+		return Result{}, false
+	}
+
+	return r, true
+}
+
+// SafeSearchDomain returns replacement address for search engine
+func (d *Dnsfilter) SafeSearchDomain(host string) (string, bool) {
+	val, ok := safeSearchDomains[host]
+	return val, ok
+}
+
+func (d *Dnsfilter) checkSafeSearch(host string) (Result, error) {
+	if log.GetLevel() >= log.DEBUG {
+		timer := log.StartTimer()
+		defer timer.LogElapsed("SafeSearch: lookup for %s", host)
+	}
+
+	// Check cache. Return cached result if it was found
+	cachedValue, isFound := getCachedResult(gctx.safeSearchCache, host)
+	if isFound {
+		// atomic.AddUint64(&gctx.stats.Safesearch.CacheHits, 1)
+		log.Tracef("SafeSearch: found in cache: %s", host)
+		return cachedValue, nil
+	}
+
+	safeHost, ok := d.SafeSearchDomain(host)
+	if !ok {
+		return Result{}, nil
+	}
+
+	res := Result{IsFiltered: true, Reason: FilteredSafeSearch}
+	if ip := net.ParseIP(safeHost); ip != nil {
+		res.IP = ip
+		valLen := d.setCacheResult(gctx.safeSearchCache, host, res)
+		log.Debug("SafeSearch: stored in cache: %s (%d bytes)", host, valLen)
+		return res, nil
+	}
+
+	// TODO this address should be resolved with upstream that was configured in dnsforward
+	addrs, err := net.LookupIP(safeHost)
+	if err != nil {
+		log.Tracef("SafeSearchDomain for %s was found but failed to lookup for %s cause %s", host, safeHost, err)
+		return Result{}, err
+	}
+
+	for _, i := range addrs {
+		if ipv4 := i.To4(); ipv4 != nil {
+			res.IP = ipv4
+			break
+		}
+	}
+
+	if len(res.IP) == 0 {
+		return Result{}, fmt.Errorf("no ipv4 addresses in safe search response for %s", safeHost)
+	}
+
+	// Cache result
+	valLen := d.setCacheResult(gctx.safeSearchCache, host, res)
+	log.Debug("SafeSearch: stored in cache: %s (%d bytes)", host, valLen)
+	return res, nil
+}
+
+func (d *Dnsfilter) handleSafeSearchEnable(w http.ResponseWriter, r *http.Request) {
+	d.Config.SafeSearchEnabled = true
+	d.Config.ConfigModified()
+}
+
+func (d *Dnsfilter) handleSafeSearchDisable(w http.ResponseWriter, r *http.Request) {
+	d.Config.SafeSearchEnabled = false
+	d.Config.ConfigModified()
+}
+
+func (d *Dnsfilter) handleSafeSearchStatus(w http.ResponseWriter, r *http.Request) {
+	data := map[string]interface{}{
+		"enabled": d.Config.SafeSearchEnabled,
+	}
+	jsonVal, err := json.Marshal(data)
+	if err != nil {
+		httpError(r, w, http.StatusInternalServerError, "Unable to marshal status json: %s", err)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	_, err = w.Write(jsonVal)
+	if err != nil {
+		httpError(r, w, http.StatusInternalServerError, "Unable to write response json: %s", err)
+		return
+	}
+}