Fix: new file missing in commit b6d1b32b9cdc0c68b094e0379c33e5a8b3d587df

psiphon/upgradeDownload.go

@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2015, Psiphon Inc.
+ * All rights reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package psiphon
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"os"
+)
+
+// DownloadUpgrade performs a tunneled, resumable download of client upgrade files.
+// While downloading/resuming, a temporary file is used. Once the download is complete,
+// a notice is issued and the upgrade is available at the destination specified in
+// config.UpgradeDownloadFilename.
+// NOTE: this code does not check that any existing file at config.UpgradeDownloadFilename
+// is actually the version specified in clientUpgradeVersion.
+func DownloadUpgrade(config *Config, clientUpgradeVersion string, tunnel *Tunnel) error {
+
+	// Check if complete file already downloaded
+	if _, err := os.Stat(config.UpgradeDownloadFilename); err == nil {
+		NoticeClientUpgradeDownloaded(config.UpgradeDownloadFilename)
+		return nil
+	}
+
+	partialFilename := fmt.Sprintf(
+		"%s.%s.part", config.UpgradeDownloadFilename, clientUpgradeVersion)
+
+	file, err := os.OpenFile(partialFilename, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0600)
+	if err != nil {
+		return ContextError(err)
+	}
+	defer file.Close()
+
+	fileInfo, err := file.Stat()
+	if err != nil {
+		return ContextError(err)
+	}
+
+	request, err := http.NewRequest("GET", config.UpgradeDownloadUrl, nil)
+	if err != nil {
+		return ContextError(err)
+	}
+	request.Header.Add("Range", fmt.Sprintf("bytes=%d-", fileInfo.Size()))
+
+	tunneledDialer := func(_, addr string) (conn net.Conn, err error) {
+		return tunnel.sshClient.Dial("tcp", addr)
+	}
+	transport := &http.Transport{
+		Dial: tunneledDialer,
+		ResponseHeaderTimeout: DOWNLOAD_UPGRADE_TIMEOUT,
+	}
+	httpClient := &http.Client{
+		Transport: transport,
+		Timeout:   DOWNLOAD_UPGRADE_TIMEOUT,
+	}
+
+	response, err := httpClient.Do(request)
+	if err != nil {
+		return ContextError(err)
+	}
+	defer response.Body.Close()
+
+	n, err := io.Copy(NewSyncFileWriter(file), response.Body)
+	if err != nil {
+		return ContextError(err)
+	}
+
+	NoticeInfo("client upgrade downloaded bytes: %d", n)
+
+	// Ensure the file is flushed to disk. The deferred close
+	// will be a noop when this succeeds.
+	err = file.Close()
+	if err != nil {
+		return ContextError(err)
+	}
+
+	err = os.Rename(partialFilename, config.UpgradeDownloadFilename)
+	if err != nil {
+		return ContextError(err)
+	}
+
+	NoticeClientUpgradeDownloaded(config.UpgradeDownloadFilename)
+
+	return nil
+}