badguardhome/home/control_filtering.go

390 lines
10 KiB
Go

package home
import (
"encoding/json"
"fmt"
"io/ioutil"
"net"
"net/http"
"net/url"
"os"
"strings"
"time"
"github.com/AdguardTeam/golibs/log"
"github.com/miekg/dns"
)
// IsValidURL - return TRUE if URL is valid
func IsValidURL(rawurl string) bool {
url, err := url.ParseRequestURI(rawurl)
if err != nil {
return false //Couldn't even parse the rawurl
}
if len(url.Scheme) == 0 {
return false //No Scheme found
}
return true
}
type filterAddJSON struct {
Name string `json:"name"`
URL string `json:"url"`
Whitelist bool `json:"whitelist"`
}
func (f *Filtering) handleFilteringAddURL(w http.ResponseWriter, r *http.Request) {
fj := filterAddJSON{}
err := json.NewDecoder(r.Body).Decode(&fj)
if err != nil {
httpError(w, http.StatusBadRequest, "Failed to parse request body json: %s", err)
return
}
if !IsValidURL(fj.URL) {
http.Error(w, "Invalid URL", http.StatusBadRequest)
return
}
// Check for duplicates
if filterExists(fj.URL) {
httpError(w, http.StatusBadRequest, "Filter URL already added -- %s", fj.URL)
return
}
// Set necessary properties
filt := filter{
Enabled: true,
URL: fj.URL,
Name: fj.Name,
white: fj.Whitelist,
}
filt.ID = assignUniqueFilterID()
// Download the filter contents
ok, err := f.update(&filt)
if err != nil {
httpError(w, http.StatusBadRequest, "Couldn't fetch filter from url %s: %s", filt.URL, err)
return
}
if !ok {
httpError(w, http.StatusBadRequest, "Filter at the url %s is invalid (maybe it points to blank page?)", filt.URL)
return
}
// URL is deemed valid, append it to filters, update config, write new filter file and tell dns to reload it
if !filterAdd(filt) {
httpError(w, http.StatusBadRequest, "Filter URL already added -- %s", filt.URL)
return
}
onConfigModified()
enableFilters(true)
_, err = fmt.Fprintf(w, "OK %d rules\n", filt.RulesCount)
if err != nil {
httpError(w, http.StatusInternalServerError, "Couldn't write body: %s", err)
}
}
func (f *Filtering) handleFilteringRemoveURL(w http.ResponseWriter, r *http.Request) {
type request struct {
URL string `json:"url"`
Whitelist bool `json:"whitelist"`
}
req := request{}
err := json.NewDecoder(r.Body).Decode(&req)
if err != nil {
httpError(w, http.StatusBadRequest, "Failed to parse request body json: %s", err)
return
}
if !IsValidURL(req.URL) {
http.Error(w, "URL parameter is not valid request URL", http.StatusBadRequest)
return
}
// go through each element and delete if url matches
config.Lock()
newFilters := []filter{}
filters := &config.Filters
if req.Whitelist {
filters = &config.WhitelistFilters
}
for _, filter := range *filters {
if filter.URL != req.URL {
newFilters = append(newFilters, filter)
} else {
err := os.Rename(filter.Path(), filter.Path()+".old")
if err != nil {
log.Error("os.Rename: %s: %s", filter.Path(), err)
}
}
}
// Update the configuration after removing filter files
*filters = newFilters
config.Unlock()
onConfigModified()
enableFilters(true)
// Note: the old files "filter.txt.old" aren't deleted - it's not really necessary,
// but will require the additional code to run after enableFilters() is finished: i.e. complicated
}
type filterURLJSON struct {
Name string `json:"name"`
URL string `json:"url"`
Enabled bool `json:"enabled"`
}
type filterURLReq struct {
URL string `json:"url"`
Whitelist bool `json:"whitelist"`
Data filterURLJSON `json:"data"`
}
func (f *Filtering) handleFilteringSetURL(w http.ResponseWriter, r *http.Request) {
fj := filterURLReq{}
err := json.NewDecoder(r.Body).Decode(&fj)
if err != nil {
httpError(w, http.StatusBadRequest, "json decode: %s", err)
return
}
if !IsValidURL(fj.URL) {
http.Error(w, "invalid URL", http.StatusBadRequest)
return
}
filt := filter{
Enabled: fj.Data.Enabled,
Name: fj.Data.Name,
URL: fj.Data.URL,
}
status := f.filterSetProperties(fj.URL, filt, fj.Whitelist)
if (status & statusFound) == 0 {
http.Error(w, "URL doesn't exist", http.StatusBadRequest)
return
}
if (status & statusURLExists) != 0 {
http.Error(w, "URL already exists", http.StatusBadRequest)
return
}
onConfigModified()
restart := false
if (status & statusEnabledChanged) != 0 {
// we must add or remove filter rules
restart = true
}
if (status&statusUpdateRequired) != 0 && fj.Data.Enabled {
// download new filter and apply its rules
flags := FilterRefreshBlocklists
if fj.Whitelist {
flags = FilterRefreshAllowlists
}
nUpdated, _ := f.refreshFilters(flags, true)
// if at least 1 filter has been updated, refreshFilters() restarts the filtering automatically
// if not - we restart the filtering ourselves
restart = false
if nUpdated == 0 {
restart = true
}
}
if restart {
enableFilters(true)
}
}
func (f *Filtering) handleFilteringSetRules(w http.ResponseWriter, r *http.Request) {
body, err := ioutil.ReadAll(r.Body)
if err != nil {
httpError(w, http.StatusBadRequest, "Failed to read request body: %s", err)
return
}
config.UserRules = strings.Split(string(body), "\n")
onConfigModified()
enableFilters(true)
}
func (f *Filtering) handleFilteringRefresh(w http.ResponseWriter, r *http.Request) {
type Req struct {
White bool `json:"whitelist"`
}
type Resp struct {
Updated int `json:"updated"`
}
resp := Resp{}
var err error
req := Req{}
err = json.NewDecoder(r.Body).Decode(&req)
if err != nil {
httpError(w, http.StatusBadRequest, "json decode: %s", err)
return
}
Context.controlLock.Unlock()
flags := FilterRefreshBlocklists
if req.White {
flags = FilterRefreshAllowlists
}
resp.Updated, err = f.refreshFilters(flags|FilterRefreshForce, false)
Context.controlLock.Lock()
if err != nil {
httpError(w, http.StatusInternalServerError, "%s", err)
return
}
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)
}
type filterJSON struct {
ID int64 `json:"id"`
Enabled bool `json:"enabled"`
URL string `json:"url"`
Name string `json:"name"`
RulesCount uint32 `json:"rules_count"`
LastUpdated string `json:"last_updated"`
}
type filteringConfig struct {
Enabled bool `json:"enabled"`
Interval uint32 `json:"interval"` // in hours
Filters []filterJSON `json:"filters"`
WhitelistFilters []filterJSON `json:"whitelist_filters"`
UserRules []string `json:"user_rules"`
}
func filterToJSON(f filter) filterJSON {
fj := filterJSON{
ID: f.ID,
Enabled: f.Enabled,
URL: f.URL,
Name: f.Name,
RulesCount: uint32(f.RulesCount),
}
if !f.LastUpdated.IsZero() {
fj.LastUpdated = f.LastUpdated.Format(time.RFC3339)
}
return fj
}
// Get filtering configuration
func (f *Filtering) handleFilteringStatus(w http.ResponseWriter, r *http.Request) {
resp := filteringConfig{}
config.RLock()
resp.Enabled = config.DNS.FilteringEnabled
resp.Interval = config.DNS.FiltersUpdateIntervalHours
for _, f := range config.Filters {
fj := filterToJSON(f)
resp.Filters = append(resp.Filters, fj)
}
for _, f := range config.WhitelistFilters {
fj := filterToJSON(f)
resp.WhitelistFilters = append(resp.WhitelistFilters, fj)
}
resp.UserRules = config.UserRules
config.RUnlock()
jsonVal, err := json.Marshal(resp)
if err != nil {
httpError(w, http.StatusInternalServerError, "json encode: %s", err)
return
}
w.Header().Set("Content-Type", "application/json")
_, err = w.Write(jsonVal)
if err != nil {
httpError(w, http.StatusInternalServerError, "http write: %s", err)
}
}
// Set filtering configuration
func (f *Filtering) handleFilteringConfig(w http.ResponseWriter, r *http.Request) {
req := filteringConfig{}
err := json.NewDecoder(r.Body).Decode(&req)
if err != nil {
httpError(w, http.StatusBadRequest, "json decode: %s", err)
return
}
if !checkFiltersUpdateIntervalHours(req.Interval) {
httpError(w, http.StatusBadRequest, "Unsupported interval")
return
}
config.DNS.FilteringEnabled = req.Enabled
config.DNS.FiltersUpdateIntervalHours = req.Interval
onConfigModified()
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 (f *Filtering) 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 (f *Filtering) RegisterFilteringHandlers() {
httpRegister("GET", "/control/filtering/status", f.handleFilteringStatus)
httpRegister("POST", "/control/filtering/config", f.handleFilteringConfig)
httpRegister("POST", "/control/filtering/add_url", f.handleFilteringAddURL)
httpRegister("POST", "/control/filtering/remove_url", f.handleFilteringRemoveURL)
httpRegister("POST", "/control/filtering/set_url", f.handleFilteringSetURL)
httpRegister("POST", "/control/filtering/refresh", f.handleFilteringRefresh)
httpRegister("POST", "/control/filtering/set_rules", f.handleFilteringSetRules)
httpRegister("GET", "/control/filtering/check_host", f.handleCheckHost)
}
func checkFiltersUpdateIntervalHours(i uint32) bool {
return i == 0 || i == 1 || i == 12 || i == 1*24 || i == 3*24 || i == 7*24
}