package main import ( "bytes" "encoding/json" "fmt" "io/ioutil" "log" "net" "net/http" "os" "os/exec" "path/filepath" "regexp" "strconv" "strings" "syscall" "time" "github.com/AdguardTeam/AdguardDNS/dnsfilter" "github.com/miekg/dns" "gopkg.in/asaskevich/govalidator.v4" ) const updatePeriod = time.Minute * 30 var coreDNSCommand *exec.Cmd var filterTitle = regexp.MustCompile(`^! Title: +(.*)$`) // cached version.json to avoid hammering github.io for each page reload var versionCheckJSON []byte var versionCheckLastTime time.Time const versionCheckURL = "https://adguardteam.github.io/AdguardDNS/version.json" const versionCheckPeriod = time.Hour * 8 var client = &http.Client{ Timeout: time.Second * 30, } // ------------------- // coredns run control // ------------------- func tellCoreDNSToReload() { // not running -- cheap check if coreDNSCommand == nil && coreDNSCommand.Process == nil { return } // not running -- more expensive check if !isRunning() { return } pid := coreDNSCommand.Process.Pid process, err := os.FindProcess(pid) if err != nil { log.Printf("os.FindProcess(%d) returned err: %v\n", pid, err) return } err = process.Signal(syscall.SIGUSR1) if err != nil { log.Printf("process.Signal on pid %d returned: %v\n", pid, err) return } } func writeAllConfigsAndReloadCoreDNS() error { err := writeAllConfigs() if err != nil { log.Printf("Couldn't write all configs: %s", err) return err } tellCoreDNSToReload() return nil } func isRunning() bool { if coreDNSCommand != nil && coreDNSCommand.Process != nil { pid := coreDNSCommand.Process.Pid process, err := os.FindProcess(pid) if err != nil { log.Printf("os.FindProcess(%d) returned err: %v\n", pid, err) } else { err := process.Signal(syscall.Signal(0)) if err != nil { log.Printf("process.Signal on pid %d returned: %v\n", pid, err) } if err == nil { return true } } } return false } func startDNSServer() error { if isRunning() { return fmt.Errorf("Unable to start coreDNS: Already running") } err := writeCoreDNSConfig() if err != nil { errortext := fmt.Errorf("Unable to write coredns config: %s", err) log.Println(errortext) return errortext } err = writeFilterFile() if err != nil { errortext := fmt.Errorf("Couldn't write filter file: %s", err) log.Println(errortext) return errortext } binarypath := filepath.Join(config.ourBinaryDir, config.CoreDNS.binaryFile) configpath := filepath.Join(config.ourBinaryDir, config.CoreDNS.coreFile) coreDNSCommand = exec.Command(binarypath, "-conf", configpath, "-dns.port", fmt.Sprintf("%d", config.CoreDNS.Port)) coreDNSCommand.Stdout = os.Stdout coreDNSCommand.Stderr = os.Stderr err = coreDNSCommand.Start() if err != nil { errortext := fmt.Errorf("Unable to start coreDNS: %s", err) log.Println(errortext) return errortext } log.Printf("coredns PID: %v\n", coreDNSCommand.Process.Pid) go childwaiter() return nil } func handleStart(w http.ResponseWriter, r *http.Request) { if isRunning() { http.Error(w, fmt.Sprintf("Unable to start coreDNS: Already running"), 400) return } err := startDNSServer() if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } _, err = fmt.Fprintf(w, "OK, PID %d\n", coreDNSCommand.Process.Pid) if err != nil { log.Printf("Couldn't write body in %s(): %s", _Func(), err) return } } func childwaiter() { err := coreDNSCommand.Wait() log.Printf("coredns unexpectedly died: %s\n", err) coreDNSCommand.Process.Release() log.Printf("restarting coredns") err = startDNSServer() if err != nil { log.Printf("Couldn't restart DNS server: %s\n", err) return } } func handleStop(w http.ResponseWriter, r *http.Request) { if coreDNSCommand == nil || coreDNSCommand.Process == nil { http.Error(w, fmt.Sprintf("Unable to start coreDNS: Not running"), 400) return } if isRunning() { http.Error(w, fmt.Sprintf("Unable to start coreDNS: Not running"), 400) return } cmd := coreDNSCommand // TODO: send SIGTERM first, then SIGKILL err := cmd.Process.Kill() if err != nil { errortext := fmt.Sprintf("Unable to stop coreDNS:\nGot error %T\n%v\n%s", err, err, err) log.Println(errortext) http.Error(w, errortext, 500) return } exitstatus := cmd.Wait() err = cmd.Process.Release() if err != nil { errortext := fmt.Sprintf("Unable to release process resources: %s", err) log.Println(errortext) http.Error(w, errortext, 500) return } _, err = fmt.Fprintf(w, "OK\n%s\n", exitstatus) if err != nil { log.Printf("Couldn't write body in %s(): %s", _Func(), err) return } } func handleRestart(w http.ResponseWriter, r *http.Request) { handleStop(w, r) handleStart(w, r) } func handleStatus(w http.ResponseWriter, r *http.Request) { data := map[string]interface{}{ "running": isRunning(), "version": VersionString, "dns_address": config.BindHost, "dns_port": config.CoreDNS.Port, "querylog_enabled": config.CoreDNS.QueryLogEnabled, "upstream_dns": config.CoreDNS.UpstreamDNS, } json, err := json.Marshal(data) if err != nil { errortext := fmt.Sprintf("Unable to marshal status json: %s", err) log.Println(errortext) http.Error(w, errortext, 500) return } w.Header().Set("Content-Type", "application/json") _, err = w.Write(json) if err != nil { errortext := fmt.Sprintf("Unable to write response json: %s", err) log.Println(errortext) http.Error(w, errortext, 500) return } } // ----- // stats // ----- func handleStats(w http.ResponseWriter, r *http.Request) { resp, err := client.Get("http://127.0.0.1:8618/stats") if err != nil { 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 } if resp != nil && resp.Body != nil { defer resp.Body.Close() } // read the body entirely body, err := ioutil.ReadAll(resp.Body) if err != nil { errortext := fmt.Sprintf("Couldn't read response body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusBadGateway) return } // forward body entirely with status code w.Header().Set("Content-Type", "application/json") 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) http.Error(w, errortext, http.StatusInternalServerError) } } func handleStatsHistory(w http.ResponseWriter, r *http.Request) { resp, err := client.Get("http://127.0.0.1:8618/stats_history?" + r.URL.RawQuery) if err != nil { 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 } if resp != nil && resp.Body != nil { defer resp.Body.Close() } // read the body entirely body, err := ioutil.ReadAll(resp.Body) if err != nil { errortext := fmt.Sprintf("Couldn't read response body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusBadGateway) return } // forward body entirely with status code w.Header().Set("Content-Type", "application/json") 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) http.Error(w, errortext, http.StatusInternalServerError) } } func handleQueryLog(w http.ResponseWriter, r *http.Request) { isDownload := r.URL.Query().Get("download") != "" resp, err := client.Get("http://127.0.0.1:8618/querylog") if err != nil { errortext := fmt.Sprintf("Couldn't get querylog from coredns: %T %s\n", err, err) log.Println(errortext) http.Error(w, errortext, http.StatusBadGateway) return } if resp != nil && resp.Body != nil { defer resp.Body.Close() } // read the body entirely body, err := ioutil.ReadAll(resp.Body) if err != nil { errortext := fmt.Sprintf("Couldn't read response body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusBadGateway) return } // forward body entirely with status code w.Header().Set("Content-Type", "application/json") w.Header().Set("Content-Length", strconv.Itoa(len(body))) if isDownload { w.Header().Set("Content-Disposition", "attachment; filename=querylog.json") } w.WriteHeader(resp.StatusCode) _, err = w.Write(body) if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleQueryLogEnable(w http.ResponseWriter, r *http.Request) { config.CoreDNS.QueryLogEnabled = true err := writeAllConfigsAndReloadCoreDNS() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleQueryLogDisable(w http.ResponseWriter, r *http.Request) { config.CoreDNS.QueryLogEnabled = false err := writeAllConfigsAndReloadCoreDNS() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleStatsReset(w http.ResponseWriter, r *http.Request) { resp, err := client.Post("http://127.0.0.1:8618/stats_reset", "text/plain", nil) if err != nil { 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 } if resp != nil && resp.Body != nil { defer resp.Body.Close() } // read the body entirely body, err := ioutil.ReadAll(resp.Body) if err != nil { errortext := fmt.Sprintf("Couldn't read response body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusBadGateway) return } // forward body entirely with status code w.Header().Set("Content-Type", "application/json") 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) http.Error(w, errortext, http.StatusInternalServerError) } } func handleStatsTop(w http.ResponseWriter, r *http.Request) { resp, err := client.Get("http://127.0.0.1:8618/stats_top") if err != nil { 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 } if resp != nil && resp.Body != nil { defer resp.Body.Close() } // read the body entirely body, err := ioutil.ReadAll(resp.Body) if err != nil { errortext := fmt.Sprintf("Couldn't read response body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusBadGateway) return } // forward body entirely with status code w.Header().Set("Content-Type", "application/json") 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) http.Error(w, errortext, http.StatusInternalServerError) } } func httpError(w http.ResponseWriter, code int, format string, args ...interface{}) { text := fmt.Sprintf(format, args...) http.Error(w, text, code) } func handleSetUpstreamDNS(w http.ResponseWriter, r *http.Request) { body, err := ioutil.ReadAll(r.Body) if err != nil { errortext := fmt.Sprintf("Failed to read request body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusBadRequest) return } // if empty body -- user is asking for default servers hosts, err := sanitiseDNSServers(string(body)) if err != nil { httpError(w, http.StatusBadRequest, "Invalid DNS servers were given: %s", err) return } if len(hosts) == 0 { config.CoreDNS.UpstreamDNS = defaultDNS } else { config.CoreDNS.UpstreamDNS = hosts } err = writeAllConfigs() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } tellCoreDNSToReload() _, err = fmt.Fprintf(w, "OK %d servers\n", len(hosts)) if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleTestUpstreamDNS(w http.ResponseWriter, r *http.Request) { body, err := ioutil.ReadAll(r.Body) if err != nil { errortext := fmt.Sprintf("Failed to read request body: %s", err) log.Println(errortext) http.Error(w, errortext, 400) return } hosts := strings.Fields(string(body)) if len(hosts) == 0 { errortext := fmt.Sprintf("No servers specified") log.Println(errortext) http.Error(w, errortext, http.StatusBadRequest) return } result := map[string]string{} for _, host := range hosts { err = checkDNS(host) if err != nil { log.Println(err) result[host] = err.Error() } else { result[host] = "OK" } } json, err := json.Marshal(result) if err != nil { errortext := fmt.Sprintf("Unable to marshal status json: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } w.Header().Set("Content-Type", "application/json") _, err = w.Write(json) if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func checkDNS(input string) error { input, err := sanitizeDNSServer(input) if err != nil { return err } req := dns.Msg{} req.Id = dns.Id() req.RecursionDesired = true req.Question = []dns.Question{ {"google-public-dns-a.google.com.", dns.TypeA, dns.ClassINET}, } prefix, host := splitDNSServerPrefixServer(input) c := dns.Client{ Timeout: time.Minute, } switch prefix { case "tls://": c.Net = "tcp-tls" } resp, rtt, err := c.Exchange(&req, host) if err != nil { return fmt.Errorf("Couldn't communicate with DNS server %s: %s", input, err) } trace("exchange with %s took %v", input, rtt) if len(resp.Answer) != 1 { return fmt.Errorf("DNS server %s returned wrong answer", input) } if t, ok := resp.Answer[0].(*dns.A); ok { if !net.IPv4(8, 8, 8, 8).Equal(t.A) { return fmt.Errorf("DNS server %s returned wrong answer: %v", input, t.A) } } return nil } func sanitiseDNSServers(input string) ([]string, error) { fields := strings.Fields(input) hosts := []string{} for _, field := range fields { sanitized, err := sanitizeDNSServer(field) if err != nil { return hosts, err } hosts = append(hosts, sanitized) } return hosts, nil } func getDNSServerPrefix(input string) string { prefix := "" switch { case strings.HasPrefix(input, "dns://"): prefix = "dns://" case strings.HasPrefix(input, "tls://"): prefix = "tls://" } return prefix } func splitDNSServerPrefixServer(input string) (string, string) { prefix := getDNSServerPrefix(input) host := strings.TrimPrefix(input, prefix) return prefix, host } func sanitizeDNSServer(input string) (string, error) { prefix, host := splitDNSServerPrefixServer(input) host = appendPortIfMissing(prefix, host) { h, _, err := net.SplitHostPort(host) if err != nil { return "", err } ip := net.ParseIP(h) if ip == nil { return "", fmt.Errorf("Invalid DNS server field: %s", h) } } return prefix + host, nil } func appendPortIfMissing(prefix, input string) string { port := "53" switch prefix { case "tls://": port = "853" } _, _, err := net.SplitHostPort(input) if err == nil { return input } return net.JoinHostPort(input, port) } func handleGetVersionJSON(w http.ResponseWriter, r *http.Request) { now := time.Now() if now.Sub(versionCheckLastTime) <= versionCheckPeriod && len(versionCheckJSON) != 0 { // return cached copy w.Header().Set("Content-Type", "application/json") w.Write(versionCheckJSON) return } resp, err := client.Get(versionCheckURL) if err != nil { errortext := fmt.Sprintf("Couldn't get querylog from coredns: %T %s\n", err, err) log.Println(errortext) http.Error(w, errortext, http.StatusBadGateway) return } if resp != nil && resp.Body != nil { defer resp.Body.Close() } // read the body entirely body, err := ioutil.ReadAll(resp.Body) if err != nil { errortext := fmt.Sprintf("Couldn't read response body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusBadGateway) return } w.Header().Set("Content-Type", "application/json") _, err = w.Write(body) if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } versionCheckLastTime = now versionCheckJSON = body } // --------- // filtering // --------- func handleFilteringEnable(w http.ResponseWriter, r *http.Request) { config.CoreDNS.FilteringEnabled = true err := writeAllConfigsAndReloadCoreDNS() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleFilteringDisable(w http.ResponseWriter, r *http.Request) { config.CoreDNS.FilteringEnabled = false err := writeAllConfigsAndReloadCoreDNS() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleFilteringStatus(w http.ResponseWriter, r *http.Request) { data := map[string]interface{}{ "enabled": config.CoreDNS.FilteringEnabled, } config.RLock() data["filters"] = config.Filters data["user_rules"] = config.UserRules json, err := json.Marshal(data) config.RUnlock() if err != nil { errortext := fmt.Sprintf("Unable to marshal status json: %s", err) log.Println(errortext) http.Error(w, errortext, 500) return } w.Header().Set("Content-Type", "application/json") _, err = w.Write(json) if err != nil { errortext := fmt.Sprintf("Unable to write response json: %s", err) log.Println(errortext) http.Error(w, errortext, 500) return } } func handleFilteringAddURL(w http.ResponseWriter, r *http.Request) { parameters, err := parseParametersFromBody(r.Body) if err != nil { errortext := fmt.Sprintf("failed to parse parameters from body: %s", err) log.Println(errortext) http.Error(w, errortext, 400) return } url, ok := parameters["url"] if !ok { http.Error(w, "URL parameter was not specified", 400) return } if valid := govalidator.IsRequestURL(url); !valid { http.Error(w, "URL parameter is not valid request URL", 400) return } // check for duplicates for i := range config.Filters { filter := &config.Filters[i] if filter.URL == url { errortext := fmt.Sprintf("Filter URL already added -- %s", url) log.Println(errortext) http.Error(w, errortext, http.StatusBadRequest) return } } var filter = filter{ Enabled: true, URL: url, } ok, err = filter.update(time.Now()) if err != nil { errortext := fmt.Sprintf("Couldn't fetch filter from url %s: %s", url, err) log.Println(errortext) http.Error(w, errortext, http.StatusBadRequest) return } if filter.RulesCount == 0 { errortext := fmt.Sprintf("Filter at url %s has no rules (maybe it points to blank page?)", url) log.Println(errortext) http.Error(w, errortext, http.StatusBadRequest) return } if !ok { errortext := fmt.Sprintf("Filter at url %s is invalid (maybe it points to blank page?)", url) log.Println(errortext) http.Error(w, errortext, http.StatusBadRequest) return } // URL is deemed valid, append it to filters, update config, write new filter file and tell coredns to reload it config.Filters = append(config.Filters, filter) err = writeAllConfigs() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } err = writeFilterFile() if err != nil { errortext := fmt.Sprintf("Couldn't write filter file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } tellCoreDNSToReload() _, err = fmt.Fprintf(w, "OK %d rules\n", filter.RulesCount) if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleFilteringRemoveURL(w http.ResponseWriter, r *http.Request) { parameters, err := parseParametersFromBody(r.Body) if err != nil { errortext := fmt.Sprintf("failed to parse parameters from body: %s", err) log.Println(errortext) http.Error(w, errortext, 400) return } url, ok := parameters["url"] if !ok { http.Error(w, "URL parameter was not specified", 400) return } if valid := govalidator.IsRequestURL(url); !valid { http.Error(w, "URL parameter is not valid request URL", 400) return } // go through each element and delete if url matches newFilters := config.Filters[:0] for _, filter := range config.Filters { if filter.URL != url { newFilters = append(newFilters, filter) } } config.Filters = newFilters err = writeAllConfigs() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } err = writeFilterFile() if err != nil { errortext := fmt.Sprintf("Couldn't write filter file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } tellCoreDNSToReload() _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleFilteringEnableURL(w http.ResponseWriter, r *http.Request) { parameters, err := parseParametersFromBody(r.Body) if err != nil { errortext := fmt.Sprintf("failed to parse parameters from body: %s", err) log.Println(errortext) http.Error(w, errortext, 400) return } url, ok := parameters["url"] if !ok { http.Error(w, "URL parameter was not specified", 400) return } if valid := govalidator.IsRequestURL(url); !valid { http.Error(w, "URL parameter is not valid request URL", http.StatusBadRequest) return } found := false for i := range config.Filters { filter := &config.Filters[i] // otherwise we will be operating on a copy if filter.URL == url { filter.Enabled = true found = true } } if !found { http.Error(w, "URL parameter was not previously added", http.StatusBadRequest) return } err = writeAllConfigs() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } // kick off refresh of rules from new URLs refreshFiltersIfNeccessary() err = writeFilterFile() if err != nil { errortext := fmt.Sprintf("Couldn't write filter file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } tellCoreDNSToReload() _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleFilteringDisableURL(w http.ResponseWriter, r *http.Request) { parameters, err := parseParametersFromBody(r.Body) if err != nil { errortext := fmt.Sprintf("failed to parse parameters from body: %s", err) log.Println(errortext) http.Error(w, errortext, 400) return } url, ok := parameters["url"] if !ok { http.Error(w, "URL parameter was not specified", 400) return } if valid := govalidator.IsRequestURL(url); !valid { http.Error(w, "URL parameter is not valid request URL", http.StatusBadRequest) return } found := false for i := range config.Filters { filter := &config.Filters[i] // otherwise we will be operating on a copy if filter.URL == url { filter.Enabled = false found = true } } if !found { http.Error(w, "URL parameter was not previously added", http.StatusBadRequest) return } err = writeAllConfigs() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } err = writeFilterFile() if err != nil { errortext := fmt.Sprintf("Couldn't write filter file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } tellCoreDNSToReload() _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } // TODO: regenerate coredns config and tell coredns to reload it if it's running } func handleFilteringSetRules(w http.ResponseWriter, r *http.Request) { body, err := ioutil.ReadAll(r.Body) if err != nil { errortext := fmt.Sprintf("Failed to read request body: %s", err) log.Println(errortext) http.Error(w, errortext, 400) return } config.UserRules = strings.Split(string(body), "\n") err = writeAllConfigs() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } err = writeFilterFile() if err != nil { errortext := fmt.Sprintf("Couldn't write filter file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } tellCoreDNSToReload() _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleFilteringRefresh(w http.ResponseWriter, r *http.Request) { force := r.URL.Query().Get("force") if force != "" { config.Lock() for i := range config.Filters { filter := &config.Filters[i] // otherwise we will be operating on a copy filter.LastUpdated = time.Unix(0, 0) } config.Unlock() // not defer because refreshFiltersIfNeccessary locks it too } updated := refreshFiltersIfNeccessary() fmt.Fprintf(w, "OK %d filters updated\n", updated) } func runFilterRefreshers() { go func() { for range time.Tick(time.Second) { refreshFiltersIfNeccessary() } }() } func refreshFiltersIfNeccessary() int { now := time.Now() config.Lock() // deduplicate // TODO: move it somewhere else { i := 0 // output index, used for deletion later urls := map[string]bool{} for _, filter := range config.Filters { if _, ok := urls[filter.URL]; !ok { // we didn't see it before, keep it urls[filter.URL] = true // remember the URL config.Filters[i] = filter i++ } } // all entries we want to keep are at front, delete the rest config.Filters = config.Filters[:i] } // fetch URLs updateCount := 0 for i := range config.Filters { filter := &config.Filters[i] // otherwise we will be operating on a copy updated, err := filter.update(now) if err != nil { log.Printf("Failed to update filter %s: %s\n", filter.URL, err) continue } if updated { updateCount++ } } config.Unlock() if updateCount > 0 { err := writeFilterFile() if err != nil { errortext := fmt.Sprintf("Couldn't write filter file: %s", err) log.Println(errortext) } tellCoreDNSToReload() } return updateCount } func (filter *filter) update(now time.Time) (bool, error) { if !filter.Enabled { return false, nil } elapsed := time.Since(filter.LastUpdated) if elapsed <= updatePeriod { return false, nil } // use same update period for failed filter downloads to avoid flooding with requests filter.LastUpdated = now resp, err := client.Get(filter.URL) if resp != nil && resp.Body != nil { defer resp.Body.Close() } if err != nil { log.Printf("Couldn't request filter from URL %s, skipping: %s", filter.URL, err) return false, err } if resp.StatusCode >= 400 { log.Printf("Got status code %d from URL %s, skipping", resp.StatusCode, filter.URL) return false, fmt.Errorf("Got status code >= 400: %d", resp.StatusCode) } body, err := ioutil.ReadAll(resp.Body) if err != nil { log.Printf("Couldn't fetch filter contents from URL %s, skipping: %s", filter.URL, err) return false, err } // extract filter name and count number of rules lines := strings.Split(string(body), "\n") rulesCount := 0 seenTitle := false d := dnsfilter.New() for _, line := range lines { line = strings.TrimSpace(line) if len(line) > 0 && line[0] == '!' { if m := filterTitle.FindAllStringSubmatch(line, -1); len(m) > 0 && len(m[0]) >= 2 && !seenTitle { filter.Name = m[0][1] seenTitle = true } } else if len(line) != 0 { err = d.AddRule(line, 0) if err == dnsfilter.ErrInvalidSyntax { continue } if err != nil { log.Printf("Couldn't add rule %s: %s", filter.URL, err) return false, err } rulesCount++ } } if bytes.Equal(filter.contents, body) { return false, nil } log.Printf("Filter %s updated: %d bytes, %d rules", filter.URL, len(body), rulesCount) filter.RulesCount = rulesCount filter.contents = body return true, nil } // write filter file func writeFilterFile() error { filterpath := filepath.Join(config.ourBinaryDir, config.CoreDNS.FilterFile) log.Printf("Writing filter file: %s", filterpath) // TODO: check if file contents have modified data := []byte{} config.RLock() filters := config.Filters for _, filter := range filters { if !filter.Enabled { continue } data = append(data, filter.contents...) data = append(data, '\n') } for _, rule := range config.UserRules { data = append(data, []byte(rule)...) data = append(data, '\n') } config.RUnlock() err := ioutil.WriteFile(filterpath+".tmp", data, 0644) if err != nil { log.Printf("Couldn't write filter file: %s", err) return err } err = os.Rename(filterpath+".tmp", filterpath) if err != nil { log.Printf("Couldn't rename filter file: %s", err) return err } return nil } // ------------ // safebrowsing // ------------ func handleSafeBrowsingEnable(w http.ResponseWriter, r *http.Request) { config.CoreDNS.SafeBrowsingEnabled = true err := writeAllConfigsAndReloadCoreDNS() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleSafeBrowsingDisable(w http.ResponseWriter, r *http.Request) { config.CoreDNS.SafeBrowsingEnabled = false err := writeAllConfigsAndReloadCoreDNS() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleSafeBrowsingStatus(w http.ResponseWriter, r *http.Request) { data := map[string]interface{}{ "enabled": config.CoreDNS.SafeBrowsingEnabled, } json, err := json.Marshal(data) if err != nil { errortext := fmt.Sprintf("Unable to marshal status json: %s", err) log.Println(errortext) http.Error(w, errortext, 500) } w.Header().Set("Content-Type", "application/json") _, err = w.Write(json) if err != nil { errortext := fmt.Sprintf("Unable to write response json: %s", err) log.Println(errortext) http.Error(w, errortext, 500) return } } // -------- // parental // -------- func handleParentalEnable(w http.ResponseWriter, r *http.Request) { parameters, err := parseParametersFromBody(r.Body) if err != nil { errortext := fmt.Sprintf("failed to parse parameters from body: %s", err) log.Println(errortext) http.Error(w, errortext, 400) return } sensitivity, ok := parameters["sensitivity"] if !ok { http.Error(w, "URL 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 } config.CoreDNS.ParentalSensitivity = i config.CoreDNS.ParentalEnabled = true err = writeAllConfigsAndReloadCoreDNS() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleParentalDisable(w http.ResponseWriter, r *http.Request) { config.CoreDNS.ParentalEnabled = false err := writeAllConfigsAndReloadCoreDNS() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleParentalStatus(w http.ResponseWriter, r *http.Request) { data := map[string]interface{}{ "enabled": config.CoreDNS.ParentalEnabled, } if config.CoreDNS.ParentalEnabled { data["sensitivity"] = config.CoreDNS.ParentalSensitivity } json, err := json.Marshal(data) if err != nil { errortext := fmt.Sprintf("Unable to marshal status json: %s", err) log.Println(errortext) http.Error(w, errortext, 500) return } w.Header().Set("Content-Type", "application/json") _, err = w.Write(json) if err != nil { errortext := fmt.Sprintf("Unable to write response json: %s", err) log.Println(errortext) http.Error(w, errortext, 500) return } } // ------------ // safebrowsing // ------------ func handleSafeSearchEnable(w http.ResponseWriter, r *http.Request) { config.CoreDNS.SafeSearchEnabled = true err := writeAllConfigsAndReloadCoreDNS() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleSafeSearchDisable(w http.ResponseWriter, r *http.Request) { config.CoreDNS.SafeSearchEnabled = false err := writeAllConfigsAndReloadCoreDNS() if err != nil { errortext := fmt.Sprintf("Couldn't write config file: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) return } _, err = fmt.Fprintf(w, "OK\n") if err != nil { errortext := fmt.Sprintf("Couldn't write body: %s", err) log.Println(errortext) http.Error(w, errortext, http.StatusInternalServerError) } } func handleSafeSearchStatus(w http.ResponseWriter, r *http.Request) { data := map[string]interface{}{ "enabled": config.CoreDNS.SafeSearchEnabled, } json, err := json.Marshal(data) if err != nil { errortext := fmt.Sprintf("Unable to marshal status json: %s", err) log.Println(errortext) http.Error(w, errortext, 500) return } w.Header().Set("Content-Type", "application/json") _, err = w.Write(json) if err != nil { errortext := fmt.Sprintf("Unable to write response json: %s", err) log.Println(errortext) http.Error(w, errortext, 500) return } } func registerControlHandlers() { http.HandleFunc("/control/start", optionalAuth(ensurePOST(handleStart))) http.HandleFunc("/control/stop", optionalAuth(ensurePOST(handleStop))) http.HandleFunc("/control/restart", optionalAuth(ensurePOST(handleRestart))) http.HandleFunc("/control/status", optionalAuth(ensureGET(handleStatus))) http.HandleFunc("/control/stats", optionalAuth(ensureGET(handleStats))) http.HandleFunc("/control/stats_history", optionalAuth(ensureGET(handleStatsHistory))) http.HandleFunc("/control/stats_top", optionalAuth(ensureGET(handleStatsTop))) http.HandleFunc("/control/stats_reset", optionalAuth(ensurePOST(handleStatsReset))) http.HandleFunc("/control/querylog", optionalAuth(ensureGET(handleQueryLog))) http.HandleFunc("/control/querylog_enable", optionalAuth(ensurePOST(handleQueryLogEnable))) http.HandleFunc("/control/querylog_disable", optionalAuth(ensurePOST(handleQueryLogDisable))) http.HandleFunc("/control/set_upstream_dns", optionalAuth(ensurePOST(handleSetUpstreamDNS))) http.HandleFunc("/control/test_upstream_dns", optionalAuth(ensurePOST(handleTestUpstreamDNS))) http.HandleFunc("/control/version.json", optionalAuth(handleGetVersionJSON)) http.HandleFunc("/control/filtering/enable", optionalAuth(ensurePOST(handleFilteringEnable))) http.HandleFunc("/control/filtering/disable", optionalAuth(ensurePOST(handleFilteringDisable))) http.HandleFunc("/control/filtering/status", optionalAuth(ensureGET(handleFilteringStatus))) http.HandleFunc("/control/filtering/add_url", optionalAuth(ensurePUT(handleFilteringAddURL))) http.HandleFunc("/control/filtering/remove_url", optionalAuth(ensureDELETE(handleFilteringRemoveURL))) http.HandleFunc("/control/filtering/enable_url", optionalAuth(ensurePOST(handleFilteringEnableURL))) http.HandleFunc("/control/filtering/disable_url", optionalAuth(ensurePOST(handleFilteringDisableURL))) http.HandleFunc("/control/filtering/set_rules", optionalAuth(ensurePUT(handleFilteringSetRules))) http.HandleFunc("/control/filtering/refresh", optionalAuth(ensurePOST(handleFilteringRefresh))) http.HandleFunc("/control/safebrowsing/enable", optionalAuth(ensurePOST(handleSafeBrowsingEnable))) http.HandleFunc("/control/safebrowsing/disable", optionalAuth(ensurePOST(handleSafeBrowsingDisable))) http.HandleFunc("/control/safebrowsing/status", optionalAuth(ensureGET(handleSafeBrowsingStatus))) http.HandleFunc("/control/parental/enable", optionalAuth(ensurePOST(handleParentalEnable))) http.HandleFunc("/control/parental/disable", optionalAuth(ensurePOST(handleParentalDisable))) http.HandleFunc("/control/parental/status", optionalAuth(ensureGET(handleParentalStatus))) http.HandleFunc("/control/safesearch/enable", optionalAuth(ensurePOST(handleSafeSearchEnable))) http.HandleFunc("/control/safesearch/disable", optionalAuth(ensurePOST(handleSafeSearchDisable))) http.HandleFunc("/control/safesearch/status", optionalAuth(ensureGET(handleSafeSearchStatus))) }