+ GET /filtering/check_host: Check if host name is filtered

AGHTechDoc.md

@@ -56,6 +56,7 @@ Contents:
 	* API: Get filtering parameters
 	* API: Set filtering parameters
 	* API: Set URL parameters
+	* API: Domain Check
 * Log-in page
 	* API: Log in
 	* API: Log out
@@ -1355,6 +1356,30 @@ Response:
 	200 OK
 
 
+### API: Domain Check
+
+Check if host name is filtered.
+
+Request:
+
+	GET /control/filtering/check_host?name=hostname
+
+Response:
+
+	200 OK
+
+	{
+	"reason":"FilteredBlackList",
+	"filter_id":1,
+	"rule":"||doubleclick.net^",
+	"service_name": "...", // set if reason=FilteredBlockedService
+
+	// if reason=ReasonRewrite:
+	"cname": "...",
+	"ip_addrs": ["1.2.3.4", ...],
+	}
+
+
 ## Log-in page
 
 After user completes the steps of installation wizard, he must log in into dashboard using his name and password.  After user successfully logs in, he gets the Cookie which allows the server to authenticate him next time without password.  After the Cookie is expired, user needs to perform log-in operation again.

home/control_filtering.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"net/url"
 	"os"
@@ -11,6 +12,7 @@ import (
 	"time"
 
 	"github.com/AdguardTeam/golibs/log"
+	"github.com/miekg/dns"
 )
 
 // IsValidURL - return TRUE if URL is valid
@@ -290,15 +292,58 @@ func handleFilteringConfig(w http.ResponseWriter, r *http.Request) {
 	enableFilters(true)
 }
 
+type checkHostResp struct {
+	Reason   string `json:"reason"`
+	FilterID int64  `json:"filter_id"`
+	Rule     string `json:"rule"`
+
+	// for FilteredBlockedService:
+	SvcName string `json:"service_name"`
+
+	// for ReasonRewrite:
+	CanonName string   `json:"cname"`    // CNAME value
+	IPList    []net.IP `json:"ip_addrs"` // list of IP addresses
+}
+
+func handleCheckHost(w http.ResponseWriter, r *http.Request) {
+	q := r.URL.Query()
+	host := q.Get("name")
+
+	setts := Context.dnsFilter.GetConfig()
+	setts.FilteringEnabled = true
+	ApplyBlockedServices(&setts, config.DNS.BlockedServices)
+	result, err := Context.dnsFilter.CheckHost(host, dns.TypeA, &setts)
+	if err != nil {
+		httpError(w, http.StatusInternalServerError, "couldn't apply filtering: %s: %s", host, err)
+		return
+	}
+
+	resp := checkHostResp{}
+	resp.Reason = result.Reason.String()
+	resp.FilterID = result.FilterID
+	resp.Rule = result.Rule
+	resp.SvcName = result.ServiceName
+	resp.CanonName = result.CanonName
+	resp.IPList = result.IPList
+	js, err := json.Marshal(resp)
+	if err != nil {
+		httpError(w, http.StatusInternalServerError, "json encode: %s", err)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+	_, _ = w.Write(js)
+}
+
 // RegisterFilteringHandlers - register handlers
 func RegisterFilteringHandlers() {
-	httpRegister(http.MethodGet, "/control/filtering/status", handleFilteringStatus)
-	httpRegister(http.MethodPost, "/control/filtering/config", handleFilteringConfig)
-	httpRegister(http.MethodPost, "/control/filtering/add_url", handleFilteringAddURL)
-	httpRegister(http.MethodPost, "/control/filtering/remove_url", handleFilteringRemoveURL)
-	httpRegister(http.MethodPost, "/control/filtering/set_url", handleFilteringSetURL)
-	httpRegister(http.MethodPost, "/control/filtering/refresh", handleFilteringRefresh)
-	httpRegister(http.MethodPost, "/control/filtering/set_rules", handleFilteringSetRules)
+	httpRegister("GET", "/control/filtering/status", handleFilteringStatus)
+	httpRegister("POST", "/control/filtering/config", handleFilteringConfig)
+	httpRegister("POST", "/control/filtering/add_url", handleFilteringAddURL)
+	httpRegister("POST", "/control/filtering/remove_url", handleFilteringRemoveURL)
+	httpRegister("POST", "/control/filtering/set_url", handleFilteringSetURL)
+	httpRegister("POST", "/control/filtering/refresh", handleFilteringRefresh)
+	httpRegister("POST", "/control/filtering/set_rules", handleFilteringSetRules)
+	httpRegister("GET", "/control/filtering/check_host", handleCheckHost)
 }
 
 func checkFiltersUpdateIntervalHours(i uint32) bool {

openapi/openapi.yaml

@@ -2,7 +2,7 @@ swagger: '2.0'
 info:
     title: 'AdGuard Home'
     description: 'AdGuard Home REST API. Admin web interface is built on top of this REST API.'
-    version: '0.99.3'
+    version: '0.101'
 schemes:
     - http
 basePath: /control
@@ -594,6 +594,22 @@ paths:
                 200:
                     description: OK
 
+    /filtering/check_host:
+        get:
+            tags:
+                - filtering
+            operationId: filteringCheckHost
+            summary: 'Check if host name is filtered'
+            parameters:
+                - name: name
+                  in: query
+                  type: string
+            responses:
+                200:
+                    description: OK
+                    schema:
+                        $ref: "#/definitions/FilterCheckHostResponse"
+
     # --------------------------------------------------
     # Safebrowsing methods
     # --------------------------------------------------
@@ -1178,6 +1194,42 @@ definitions:
             enabled:
                 type: "boolean"
 
+    FilterCheckHostResponse:
+        type: "object"
+        description: "Check Host Result"
+        properties:
+            reason:
+                type: "string"
+                description: "DNS filter status"
+                enum:
+                - "NotFilteredNotFound"
+                - "NotFilteredWhiteList"
+                - "NotFilteredError"
+                - "FilteredBlackList"
+                - "FilteredSafeBrowsing"
+                - "FilteredParental"
+                - "FilteredInvalid"
+                - "FilteredSafeSearch"
+                - "FilteredBlockedService"
+                - "ReasonRewrite"
+            filter_id:
+                type: "integer"
+            rule:
+                type: "string"
+                example: "||example.org^"
+                description: "Filtering rule applied to the request (if any)"
+            service_name:
+                type: "string"
+                description: "Set if reason=FilteredBlockedService"
+            cname:
+                type: "string"
+                description: "Set if reason=ReasonRewrite"
+            ip_addrs:
+                type: "array"
+                items:
+                    type: "string"
+                description: "Set if reason=ReasonRewrite"
+
     GetVersionRequest:
         type: "object"
         description: "/version.json request data"
@@ -1471,6 +1523,7 @@ definitions:
                 - "FilteredInvalid"
                 - "FilteredSafeSearch"
                 - "FilteredBlockedService"
+                - "ReasonRewrite"
             service_name:
                 type: "string"
                 description: "Set if reason=FilteredBlockedService"