Merge branch 'master' into doc-deprecated

AdguardTeam · Dec 25, 2020 · c189404 · c189404
2 parents 108097c + 1191a9a
commit c189404
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diff --git a/README.md b/README.md
@@ -123,20 +123,22 @@ AdGuard Home provides a lot of features out-of-the-box with no need to install a
 
 > Disclaimer: some of the listed features can be added to Pi-Hole by installing additional software or by manually using SSH terminal and reconfiguring one of the utilities Pi-Hole consists of. However, in our opinion, this cannot be legitimately counted as a Pi-Hole's feature.
 
-| Feature                                                                 | AdGuard&nbsp;Home | Pi-Hole                                                |
-|-------------------------------------------------------------------------|--------------|--------------------------------------------------------|
-| Blocking ads and trackers                                               | ✅            | ✅                                                      |
-| Customizing blocklists                                                  | ✅            | ✅                                                      |
-| Built-in DHCP server                                                    | ✅            | ✅                                                      |
-| HTTPS for the Admin interface                                           | ✅            | Kind of, but you'll need to manually configure lighthttpd |
-| Encrypted DNS upstream servers (DNS-over-HTTPS, DNS-over-TLS, DNSCrypt) | ✅            | ❌ (requires additional software)                       |
-| Cross-platform                                                          | ✅            | ❌ (not natively, only via Docker)                      |
-| Running as a DNS-over-HTTPS or DNS-over-TLS server                      | ✅            | ❌ (requires additional software)                       |
-| Blocking phishing and malware domains                                   | ✅            | ❌ (requires non-default blocklists)                    |
-| Parental control (blocking adult domains)                               | ✅            | ❌                                                      |
-| Force Safe search on search engines                                     | ✅            | ❌                                                      |
-| Per-client (device) configuration                                       | ✅            | ✅                                                      |
-| Access settings (choose who can use AGH DNS)                            | ✅            | ❌                                                      |
+| Feature                                                                 | AdGuard&nbsp;Home | Pi-Hole                                                   |
+|-------------------------------------------------------------------------|-------------------|-----------------------------------------------------------|
+| Blocking ads and trackers                                               | ✅                | ✅                                                        |
+| Customizing blocklists                                                  | ✅                | ✅                                                        |
+| Built-in DHCP server                                                    | ✅                | ✅                                                        |
+| HTTPS for the Admin interface                                           | ✅                | Kind of, but you'll need to manually configure lighthttpd |
+| Encrypted DNS upstream servers (DNS-over-HTTPS, DNS-over-TLS, DNSCrypt) | ✅                | ❌ (requires additional software)                         |
+| Cross-platform                                                          | ✅                | ❌ (not natively, only via Docker)                        |
+| Running as a DNS-over-HTTPS or DNS-over-TLS server                      | ✅                | ❌ (requires additional software)                         |
+| Blocking phishing and malware domains                                   | ✅                | ❌ (requires non-default blocklists)                      |
+| Parental control (blocking adult domains)                               | ✅                | ❌                                                        |
+| Force Safe search on search engines                                     | ✅                | ❌                                                        |
+| Per-client (device) configuration                                       | ✅                | ✅                                                        |
+| Access settings (choose who can use AGH DNS)                            | ✅                | ❌                                                        |
+| Written in a memory-safe language                                       | ✅                | ❌                                                        |
+| Running without root privileges                                         | ✅                | ❌                                                        |
 
 <a id="comparison-adblock"></a>
 ### How does AdGuard Home compare to traditional ad blockers

diff --git a/internal/home/controlupdate.go b/internal/home/controlupdate.go
@@ -2,13 +2,14 @@ package home
 
 import (
 	"encoding/json"
+	"errors"
 	"net/http"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"runtime"
-	"strings"
 	"syscall"
+	"time"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/sysutil"
 	"github.com/AdguardTeam/AdGuardHome/internal/update"
@@ -19,6 +20,13 @@ type getVersionJSONRequest struct {
 	RecheckNow bool `json:"recheck_now"`
 }
 
+// temporaryError is the interface for temporary errors from the Go standard
+// library.
+type temporaryError interface {
+	error
+	Temporary() (ok bool)
+}
+
 // Get the latest available version from the Internet
 func handleGetVersionJSON(w http.ResponseWriter, r *http.Request) {
 	if Context.disableUpdate {
@@ -41,14 +49,29 @@ func handleGetVersionJSON(w http.ResponseWriter, r *http.Request) {
 
 	var info update.VersionInfo
 	for i := 0; i != 3; i++ {
-		Context.controlLock.Lock()
-		info, err = Context.updater.GetVersionResponse(req.RecheckNow)
-		Context.controlLock.Unlock()
-		if err != nil && strings.HasSuffix(err.Error(), "i/o timeout") {
-			// This case may happen while we're restarting DNS server
-			// https://github.com/AdguardTeam/AdGuardHome/internal/issues/934
-			continue
+		func() {
+			Context.controlLock.Lock()
+			defer Context.controlLock.Unlock()
+
+			info, err = Context.updater.GetVersionResponse(req.RecheckNow)
+		}()
+
+		if err != nil {
+			var terr temporaryError
+			if errors.As(err, &terr) && terr.Temporary() {
+				// Temporary network error.  This case may happen while
+				// we're restarting our DNS server.  Log and sleep for
+				// some time.
+				//
+				// See https://github.com/AdguardTeam/AdGuardHome/issues/934.
+				d := time.Duration(i) * time.Second
+				log.Info("temp net error: %q; sleeping for %s and retrying", err, d)
+				time.Sleep(d)
+
+				continue
+			}
 		}
+
 		break
 	}
 	if err != nil {