syncthing/internal/upgrade/upgrade_supported.go
2015-01-04 18:19:00 +00:00

330 lines
6.9 KiB
Go

// Copyright (C) 2014 The Syncthing Authors.
//
// 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/>.
// +build !noupgrade
package upgrade
import (
"archive/tar"
"archive/zip"
"bytes"
"compress/gzip"
"crypto/md5"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"net/http"
"os"
"path"
"path/filepath"
"runtime"
"strings"
)
// Returns the latest release, including prereleases or not depending on the argument
func LatestRelease(prerelease bool) (Release, error) {
resp, err := http.Get("https://api.github.com/repos/syncthing/syncthing/releases?per_page=10")
if err != nil {
return Release{}, err
}
if resp.StatusCode > 299 {
return Release{}, fmt.Errorf("API call returned HTTP error: %s", resp.Status)
}
var rels []Release
json.NewDecoder(resp.Body).Decode(&rels)
resp.Body.Close()
if len(rels) == 0 {
return Release{}, ErrVersionUnknown
}
if prerelease {
// We are a beta version. Use the latest.
return rels[0], nil
}
// We are a regular release. Only consider non-prerelease versions for upgrade.
for _, rel := range rels {
if !rel.Prerelease {
return rel, nil
}
}
return Release{}, ErrVersionUnknown
}
// Upgrade to the given release, saving the previous binary with a ".old" extension.
func upgradeTo(binary string, rel Release) error {
expectedRelease := releaseName(rel.Tag)
if debug {
l.Debugf("expected release asset %q", expectedRelease)
}
for _, asset := range rel.Assets {
assetName := path.Base(asset.Name)
if debug {
l.Debugln("considering release", assetName)
}
if strings.HasPrefix(assetName, expectedRelease) {
return upgradeToURL(binary, asset.URL)
}
}
return ErrVersionUnknown
}
// Upgrade to the given release, saving the previous binary with a ".old" extension.
func upgradeToURL(binary string, url string) error {
fname, err := readRelease(filepath.Dir(binary), url)
if err != nil {
return err
}
old := binary + ".old"
_ = os.Remove(old)
err = os.Rename(binary, old)
if err != nil {
return err
}
err = os.Rename(fname, binary)
if err != nil {
return err
}
return nil
}
func readRelease(dir, url string) (string, error) {
if debug {
l.Debugf("loading %q", url)
}
req, err := http.NewRequest("GET", url, nil)
if err != nil {
return "", err
}
req.Header.Add("Accept", "application/octet-stream")
resp, err := http.DefaultClient.Do(req)
if err != nil {
return "", err
}
defer resp.Body.Close()
switch runtime.GOOS {
case "windows":
return readZip(dir, resp.Body)
default:
return readTarGz(dir, resp.Body)
}
}
func readTarGz(dir string, r io.Reader) (string, error) {
gr, err := gzip.NewReader(r)
if err != nil {
return "", err
}
tr := tar.NewReader(gr)
var tempName, actualMD5, expectedMD5 string
// Iterate through the files in the archive.
fileLoop:
for {
hdr, err := tr.Next()
if err == io.EOF {
// end of tar archive
break
}
if err != nil {
return "", err
}
shortName := path.Base(hdr.Name)
if debug {
l.Debugf("considering file %q", shortName)
}
switch shortName {
case "syncthing":
if debug {
l.Debugln("writing and hashing binary")
}
tempName, actualMD5, err = writeBinary(dir, tr)
if err != nil {
return "", err
}
if expectedMD5 != "" {
// We're done
break fileLoop
}
case "syncthing.md5":
bs, err := ioutil.ReadAll(tr)
if err != nil {
return "", err
}
expectedMD5 = strings.TrimSpace(string(bs))
if debug {
l.Debugln("expected md5 is", actualMD5)
}
if actualMD5 != "" {
// We're done
break fileLoop
}
}
}
if tempName != "" && actualMD5 != "" {
// We found and saved something to disk.
if expectedMD5 == "" {
if debug {
l.Debugln("there is no md5 to compare with")
}
} else if actualMD5 != expectedMD5 {
// There was an md5 file included in the archive, and it doesn't
// match what we just wrote to disk.
return "", fmt.Errorf("incorrect MD5 checksum")
}
return tempName, nil
}
return "", fmt.Errorf("no upgrade found")
}
func readZip(dir string, r io.Reader) (string, error) {
body, err := ioutil.ReadAll(r)
if err != nil {
return "", err
}
archive, err := zip.NewReader(bytes.NewReader(body), int64(len(body)))
if err != nil {
return "", err
}
var tempName, actualMD5, expectedMD5 string
// Iterate through the files in the archive.
fileLoop:
for _, file := range archive.File {
shortName := path.Base(file.Name)
if debug {
l.Debugf("considering file %q", shortName)
}
switch shortName {
case "syncthing.exe":
if debug {
l.Debugln("writing and hashing binary")
}
inFile, err := file.Open()
if err != nil {
return "", err
}
tempName, actualMD5, err = writeBinary(dir, inFile)
if err != nil {
return "", err
}
if expectedMD5 != "" {
// We're done
break fileLoop
}
case "syncthing.exe.md5":
inFile, err := file.Open()
if err != nil {
return "", err
}
bs, err := ioutil.ReadAll(inFile)
if err != nil {
return "", err
}
expectedMD5 = strings.TrimSpace(string(bs))
if debug {
l.Debugln("expected md5 is", actualMD5)
}
if actualMD5 != "" {
// We're done
break fileLoop
}
}
}
if tempName != "" && actualMD5 != "" {
// We found and saved something to disk.
if expectedMD5 == "" {
if debug {
l.Debugln("there is no md5 to compare with")
}
} else if actualMD5 != expectedMD5 {
// There was an md5 file included in the archive, and it doesn't
// match what we just wrote to disk.
return "", fmt.Errorf("incorrect MD5 checksum")
}
return tempName, nil
}
return "", fmt.Errorf("No upgrade found")
}
func writeBinary(dir string, inFile io.Reader) (filename, md5sum string, err error) {
outFile, err := ioutil.TempFile(dir, "syncthing")
if err != nil {
return "", "", err
}
// Write the binary both a temporary file and to the MD5 hasher.
h := md5.New()
mw := io.MultiWriter(h, outFile)
_, err = io.Copy(mw, inFile)
if err != nil {
os.Remove(outFile.Name())
return "", "", err
}
err = outFile.Close()
if err != nil {
os.Remove(outFile.Name())
return "", "", err
}
err = os.Chmod(outFile.Name(), os.FileMode(0755))
if err != nil {
os.Remove(outFile.Name())
return "", "", err
}
actualMD5 := fmt.Sprintf("%x", h.Sum(nil))
if debug {
l.Debugln("actual md5 is", actualMD5)
}
return outFile.Name(), actualMD5, nil
}