add multiple error checks

dnscrypt-proxy/config.go

@@ -708,7 +708,11 @@ func cdLocal() {
 		dlog.Warnf("Unable to determine the executable directory: [%s] -- You will need to specify absolute paths in the configuration file", err)
 		return
 	}
-	os.Chdir(filepath.Dir(exeFileName))
+
+	err = os.Chdir(filepath.Dir(exeFileName))
+	if err != nil {
+		dlog.Warnf("Unable to change working directory: %s", err)
+	}
 }
 
 func isIPAndPort(addrStr string) error {

dnscrypt-proxy/dnscrypt_certs.go

@@ -226,8 +226,14 @@ func _dnsExchange(proxy *Proxy, proto string, query *dns.Msg, serverAddress stri
 			return nil, 0, err
 		}
 		defer pc.Close()
-		pc.SetDeadline(time.Now().Add(proxy.timeout))
-		pc.Write(binQuery)
+		err = pc.SetDeadline(time.Now().Add(proxy.timeout))
+		if err != nil {
+			return nil, 0, err
+		}
+		_, err = pc.Write(binQuery)
+		if err != nil {
+			return nil, 0, err
+		}
 		packet = make([]byte, MaxDNSPacketSize)
 		length, err := pc.Read(packet)
 		if err != nil {
@@ -261,12 +267,18 @@ func _dnsExchange(proxy *Proxy, proto string, query *dns.Msg, serverAddress stri
 			return nil, 0, err
 		}
 		defer pc.Close()
-		pc.SetDeadline(time.Now().Add(proxy.timeout))
+		err = pc.SetDeadline(time.Now().Add(proxy.timeout))
+		if err != nil {
+			return nil, 0, err
+		}
 		binQuery, err = PrefixWithSize(binQuery)
 		if err != nil {
 			return nil, 0, err
 		}
-		pc.Write(binQuery)
+		_, err = pc.Write(binQuery)
+		if err != nil {
+			return nil, 0, err
+		}
 		packet, err = ReadPrefixed(&pc)
 		if err != nil {
 			return nil, 0, err

dnscrypt-proxy/main.go

@@ -126,7 +126,9 @@ func (app *App) AppMain() {
 	}
 	app.quit = make(chan struct{})
 	app.wg.Add(1)
-	pidfile.Write()
+	if err := pidfile.Write(); err != nil {
+		dlog.Fatal(err)
+	}
 	app.proxy.StartProxy()
 	<-app.quit
 	dlog.Notice("Quit signal received...")

dnscrypt-proxy/plugin_block_ip.go

@@ -151,7 +151,10 @@ func (plugin *PluginBlockIP) Eval(pluginsState *PluginsState, msg *dns.Msg) erro
 			if plugin.logger == nil {
 				return errors.New("Log file not initialized")
 			}
-			plugin.logger.Write([]byte(line))
+			_, err := plugin.logger.Write([]byte(line))
+			if err != nil {
+				return err
+			}
 		}
 	}
 	return nil

dnscrypt-proxy/plugin_block_name.go

@@ -66,7 +66,10 @@ func (blockedNames *BlockedNames) check(pluginsState *PluginsState, qName string
 		if blockedNames.logger == nil {
 			return false, errors.New("Log file not initialized")
 		}
-		blockedNames.logger.Write([]byte(line))
+		_, err := blockedNames.logger.Write([]byte(line))
+		if err != nil {
+			return false, err
+		}
 	}
 	return true, nil
 }

dnscrypt-proxy/plugin_cloak.go

@@ -84,7 +84,10 @@ func (plugin *PluginCloak) Init(proxy *Proxy) error {
 		cloakedNames[line] = cloakedName
 	}
 	for line, cloakedName := range cloakedNames {
-		plugin.patternMatcher.Add(line, cloakedName, cloakedName.lineNo)
+		err = plugin.patternMatcher.Add(line, cloakedName, cloakedName.lineNo)
+		if err != nil {
+			return err
+		}
 	}
 	return nil
 }

dnscrypt-proxy/service_windows.go

@@ -7,7 +7,10 @@ func ServiceManagerStartNotify() error {
 	if err != nil {
 		return err
 	}
-	mgr.Disconnect()
+
+	if err = mgr.Disconnect(); err != nil {
+		return err
+	}
 	return nil
 }