* dnsfilter: major refactoring

* dnsfilter is controlled by package home, not dnsforward
* move HTTP handlers to dnsfilter/
* apply filtering settings without DNS server restart
* use only 1 goroutine for filters update
* apply new filters quickly (after they are ready to be used)

dnsfilter/security.go

@@ -0,0 +1,179 @@
+// Parental Control, Safe Browsing, Safe Search
+
+package dnsfilter
+
+import (
+	"bufio"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/AdguardTeam/golibs/log"
+)
+
+func httpError(r *http.Request, w http.ResponseWriter, code int, format string, args ...interface{}) {
+	text := fmt.Sprintf(format, args...)
+	log.Info("DNSFilter: %s %s: %s", r.Method, r.URL, text)
+	http.Error(w, text, code)
+}
+
+func (d *Dnsfilter) handleSafeBrowsingEnable(w http.ResponseWriter, r *http.Request) {
+	d.Config.SafeBrowsingEnabled = true
+	d.Config.ConfigModified()
+}
+
+func (d *Dnsfilter) handleSafeBrowsingDisable(w http.ResponseWriter, r *http.Request) {
+	d.Config.SafeBrowsingEnabled = false
+	d.Config.ConfigModified()
+}
+
+func (d *Dnsfilter) handleSafeBrowsingStatus(w http.ResponseWriter, r *http.Request) {
+	data := map[string]interface{}{
+		"enabled": d.Config.SafeBrowsingEnabled,
+	}
+	jsonVal, err := json.Marshal(data)
+	if err != nil {
+		httpError(r, w, http.StatusInternalServerError, "Unable to marshal status json: %s", err)
+	}
+
+	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
+	}
+}
+
+func parseParametersFromBody(r io.Reader) (map[string]string, error) {
+	parameters := map[string]string{}
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if len(line) == 0 {
+			// skip empty lines
+			continue
+		}
+		parts := strings.SplitN(line, "=", 2)
+		if len(parts) != 2 {
+			return parameters, errors.New("Got invalid request body")
+		}
+		parameters[strings.TrimSpace(parts[0])] = strings.TrimSpace(parts[1])
+	}
+
+	return parameters, nil
+}
+
+func (d *Dnsfilter) handleParentalEnable(w http.ResponseWriter, r *http.Request) {
+	parameters, err := parseParametersFromBody(r.Body)
+	if err != nil {
+		httpError(r, w, http.StatusBadRequest, "failed to parse parameters from body: %s", err)
+		return
+	}
+
+	sensitivity, ok := parameters["sensitivity"]
+	if !ok {
+		http.Error(w, "Sensitivity parameter was not specified", 400)
+		return
+	}
+
+	switch sensitivity {
+	case "3":
+		break
+	case "EARLY_CHILDHOOD":
+		sensitivity = "3"
+	case "10":
+		break
+	case "YOUNG":
+		sensitivity = "10"
+	case "13":
+		break
+	case "TEEN":
+		sensitivity = "13"
+	case "17":
+		break
+	case "MATURE":
+		sensitivity = "17"
+	default:
+		http.Error(w, "Sensitivity must be set to valid value", 400)
+		return
+	}
+	i, err := strconv.Atoi(sensitivity)
+	if err != nil {
+		http.Error(w, "Sensitivity must be set to valid value", 400)
+		return
+	}
+	d.Config.ParentalSensitivity = i
+	d.Config.ParentalEnabled = true
+	d.Config.ConfigModified()
+}
+
+func (d *Dnsfilter) handleParentalDisable(w http.ResponseWriter, r *http.Request) {
+	d.Config.ParentalEnabled = false
+	d.Config.ConfigModified()
+}
+
+func (d *Dnsfilter) handleParentalStatus(w http.ResponseWriter, r *http.Request) {
+	data := map[string]interface{}{
+		"enabled": d.Config.ParentalEnabled,
+	}
+	if d.Config.ParentalEnabled {
+		data["sensitivity"] = d.Config.ParentalSensitivity
+	}
+	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
+	}
+}
+
+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
+	}
+}
+
+func (d *Dnsfilter) registerSecurityHandlers() {
+	d.Config.HTTPRegister("POST", "/control/safebrowsing/enable", d.handleSafeBrowsingEnable)
+	d.Config.HTTPRegister("POST", "/control/safebrowsing/disable", d.handleSafeBrowsingDisable)
+	d.Config.HTTPRegister("GET", "/control/safebrowsing/status", d.handleSafeBrowsingStatus)
+	d.Config.HTTPRegister("POST", "/control/parental/enable", d.handleParentalEnable)
+	d.Config.HTTPRegister("POST", "/control/parental/disable", d.handleParentalDisable)
+	d.Config.HTTPRegister("GET", "/control/parental/status", d.handleParentalStatus)
+	d.Config.HTTPRegister("POST", "/control/safesearch/enable", d.handleSafeSearchEnable)
+	d.Config.HTTPRegister("POST", "/control/safesearch/disable", d.handleSafeSearchDisable)
+	d.Config.HTTPRegister("GET", "/control/safesearch/status", d.handleSafeSearchStatus)
+}