Pull request: * all: move internal Go packages to internal/

Merge in DNS/adguard-home from 2234-move-to-internal to master

Squashed commit of the following:

commit d26a288cabeac86f9483fab307677b1027c78524
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Fri Oct 30 12:44:18 2020 +0300

    * all: move internal Go packages to internal/

    Closes #2234.

internal/home/control.go

@@ -0,0 +1,234 @@
+package home
+
+import (
+	"encoding/json"
+	"fmt"
+	"net"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
+	"github.com/AdguardTeam/golibs/log"
+	"github.com/NYTimes/gziphandler"
+)
+
+// ----------------
+// helper functions
+// ----------------
+
+func returnOK(w http.ResponseWriter) {
+	_, err := fmt.Fprintf(w, "OK\n")
+	if err != nil {
+		httpError(w, http.StatusInternalServerError, "Couldn't write body: %s", err)
+	}
+}
+
+func httpError(w http.ResponseWriter, code int, format string, args ...interface{}) {
+	text := fmt.Sprintf(format, args...)
+	log.Info(text)
+	http.Error(w, text, code)
+}
+
+// ---------------
+// dns run control
+// ---------------
+func addDNSAddress(dnsAddresses *[]string, addr string) {
+	if config.DNS.Port != 53 {
+		addr = fmt.Sprintf("%s:%d", addr, config.DNS.Port)
+	}
+	*dnsAddresses = append(*dnsAddresses, addr)
+}
+
+func handleStatus(w http.ResponseWriter, r *http.Request) {
+	c := dnsforward.FilteringConfig{}
+	if Context.dnsServer != nil {
+		Context.dnsServer.WriteDiskConfig(&c)
+	}
+	data := map[string]interface{}{
+		"dns_addresses": getDNSAddresses(),
+		"http_port":     config.BindPort,
+		"dns_port":      config.DNS.Port,
+		"running":       isRunning(),
+		"version":       versionString,
+		"language":      config.Language,
+
+		"protection_enabled": c.ProtectionEnabled,
+	}
+	data["dhcp_available"] = (Context.dhcpServer != nil)
+
+	jsonVal, err := json.Marshal(data)
+	if err != nil {
+		httpError(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(w, http.StatusInternalServerError, "Unable to write response json: %s", err)
+		return
+	}
+}
+
+type profileJSON struct {
+	Name string `json:"name"`
+}
+
+func handleGetProfile(w http.ResponseWriter, r *http.Request) {
+	pj := profileJSON{}
+	u := Context.auth.GetCurrentUser(r)
+	pj.Name = u.Name
+
+	data, err := json.Marshal(pj)
+	if err != nil {
+		httpError(w, http.StatusInternalServerError, "json.Marshal: %s", err)
+		return
+	}
+	_, _ = w.Write(data)
+}
+
+// ------------------------
+// registration of handlers
+// ------------------------
+func registerControlHandlers() {
+	httpRegister(http.MethodGet, "/control/status", handleStatus)
+	httpRegister(http.MethodPost, "/control/i18n/change_language", handleI18nChangeLanguage)
+	httpRegister(http.MethodGet, "/control/i18n/current_language", handleI18nCurrentLanguage)
+	http.HandleFunc("/control/version.json", postInstall(optionalAuth(handleGetVersionJSON)))
+	httpRegister(http.MethodPost, "/control/update", handleUpdate)
+	httpRegister(http.MethodGet, "/control/profile", handleGetProfile)
+
+	// No auth is necessary for DOH/DOT configurations
+	http.HandleFunc("/apple/doh.mobileconfig", postInstall(handleMobileConfigDoh))
+	http.HandleFunc("/apple/dot.mobileconfig", postInstall(handleMobileConfigDot))
+	RegisterAuthHandlers()
+}
+
+func httpRegister(method string, url string, handler func(http.ResponseWriter, *http.Request)) {
+	if len(method) == 0 {
+		// "/dns-query" handler doesn't need auth, gzip and isn't restricted by 1 HTTP method
+		http.HandleFunc(url, postInstall(handler))
+		return
+	}
+
+	http.Handle(url, postInstallHandler(optionalAuthHandler(gziphandler.GzipHandler(ensureHandler(method, handler)))))
+}
+
+// ----------------------------------
+// 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
+}
+
+// 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.") &&
+			!strings.HasPrefix(r.URL.Path, "/assets/") {
+			http.Redirect(w, r, "/install.html", http.StatusFound)
+			return
+		}
+
+		// enforce https?
+		if r.TLS == nil && Context.web.forceHTTPS && Context.web.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(Context.web.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}
+}