package home import ( "context" "fmt" "net" "net/http" "net/url" "os" "os/exec" "path" "path/filepath" "runtime" "strconv" "strings" "time" "github.com/AdguardTeam/golibs/log" "github.com/joomcode/errorx" ) // ---------------------------------- // helper functions for HTTP handlers // ---------------------------------- func ensure(method string, handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) { return func(w http.ResponseWriter, r *http.Request) { log.Debug("%s %v", r.Method, r.URL) if r.Method != method { http.Error(w, "This request must be "+method, http.StatusMethodNotAllowed) return } if method == "POST" || method == "PUT" || method == "DELETE" { Context.controlLock.Lock() defer Context.controlLock.Unlock() } handler(w, r) } } func ensurePOST(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) { return ensure("POST", handler) } func ensureGET(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) { return ensure("GET", handler) } // Bridge between http.Handler object and Go function type httpHandler struct { handler func(http.ResponseWriter, *http.Request) } func (h *httpHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { h.handler(w, r) } func ensureHandler(method string, handler func(http.ResponseWriter, *http.Request)) http.Handler { h := httpHandler{} h.handler = ensure(method, handler) return &h } // ------------------- // first run / install // ------------------- func detectFirstRun() bool { configfile := Context.configFilename if !filepath.IsAbs(configfile) { configfile = filepath.Join(Context.workDir, Context.configFilename) } _, err := os.Stat(configfile) if !os.IsNotExist(err) { // do nothing, file exists return false } return true } // preInstall lets the handler run only if firstRun is true, no redirects func preInstall(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) { return func(w http.ResponseWriter, r *http.Request) { if !Context.firstRun { // if it's not first run, don't let users access it (for example /install.html when configuration is done) http.Error(w, http.StatusText(http.StatusForbidden), http.StatusForbidden) return } handler(w, r) } } // preInstallStruct wraps preInstall into a struct that can be returned as an interface where necessary type preInstallHandlerStruct struct { handler http.Handler } func (p *preInstallHandlerStruct) ServeHTTP(w http.ResponseWriter, r *http.Request) { preInstall(p.handler.ServeHTTP)(w, r) } // preInstallHandler returns http.Handler interface for preInstall wrapper func preInstallHandler(handler http.Handler) http.Handler { return &preInstallHandlerStruct{handler} } // postInstall lets the handler run only if firstRun is false, and redirects to /install.html otherwise // it also enforces HTTPS if it is enabled and configured func postInstall(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) { return func(w http.ResponseWriter, r *http.Request) { if Context.firstRun && !strings.HasPrefix(r.URL.Path, "/install.") && r.URL.Path != "/favicon.png" { http.Redirect(w, r, "/install.html", http.StatusSeeOther) // should not be cacheable return } // enforce https? if config.TLS.ForceHTTPS && r.TLS == nil && config.TLS.Enabled && config.TLS.PortHTTPS != 0 && Context.httpsServer.server != nil { // yes, and we want host from host:port host, _, err := net.SplitHostPort(r.Host) if err != nil { // no port in host host = r.Host } // construct new URL to redirect to newURL := url.URL{ Scheme: "https", Host: net.JoinHostPort(host, strconv.Itoa(config.TLS.PortHTTPS)), Path: r.URL.Path, RawQuery: r.URL.RawQuery, } http.Redirect(w, r, newURL.String(), http.StatusTemporaryRedirect) return } w.Header().Set("Access-Control-Allow-Origin", "*") handler(w, r) } } type postInstallHandlerStruct struct { handler http.Handler } func (p *postInstallHandlerStruct) ServeHTTP(w http.ResponseWriter, r *http.Request) { postInstall(p.handler.ServeHTTP)(w, r) } func postInstallHandler(handler http.Handler) http.Handler { return &postInstallHandlerStruct{handler} } // Connect to a remote server resolving hostname using our own DNS server func customDialContext(ctx context.Context, network, addr string) (net.Conn, error) { log.Tracef("network:%v addr:%v", network, addr) host, port, err := net.SplitHostPort(addr) if err != nil { return nil, err } dialer := &net.Dialer{ Timeout: time.Minute * 5, } if net.ParseIP(host) != nil || config.DNS.Port == 0 { con, err := dialer.DialContext(ctx, network, addr) return con, err } addrs, e := Context.dnsServer.Resolve(host) log.Debug("dnsServer.Resolve: %s: %v", host, addrs) if e != nil { return nil, e } if len(addrs) == 0 { return nil, fmt.Errorf("couldn't lookup host: %s", host) } var dialErrs []error for _, a := range addrs { addr = net.JoinHostPort(a.String(), port) con, err := dialer.DialContext(ctx, network, addr) if err != nil { dialErrs = append(dialErrs, err) continue } return con, err } return nil, errorx.DecorateMany(fmt.Sprintf("couldn't dial to %s", addr), dialErrs...) } // --------------------- // general helpers // --------------------- // fileExists returns TRUE if file exists func fileExists(fn string) bool { _, err := os.Stat(fn) if err != nil { return false } return true } // runCommand runs shell command func runCommand(command string, arguments ...string) (int, string, error) { cmd := exec.Command(command, arguments...) out, err := cmd.Output() if err != nil { return 1, "", fmt.Errorf("exec.Command(%s) failed: %s", command, err) } return cmd.ProcessState.ExitCode(), string(out), nil } // --------------------- // debug logging helpers // --------------------- func _Func() string { pc := make([]uintptr, 10) // at least 1 entry needed runtime.Callers(2, pc) f := runtime.FuncForPC(pc[0]) return path.Base(f.Name()) } // SplitNext - split string by a byte and return the first chunk // Whitespace is trimmed func SplitNext(str *string, splitBy byte) string { i := strings.IndexByte(*str, splitBy) s := "" if i != -1 { s = (*str)[0:i] *str = (*str)[i+1:] } else { s = *str *str = "" } return strings.TrimSpace(s) }