Commit 0bf2eb5d authored by Jay Conrod's avatar Jay Conrod

cmd/go/internal/modfetch: switch to golang.org/x/mod/zip

zip.Create is now used to filter and translate zip files from VCS tools.

zip.Unzip is now used instead of Unzip.

Fixes #35290

Change-Id: I4aa41b2e96bf147c09db43d1d189b8393cafb06f
Reviewed-on: https://go-review.googlesource.com/c/go/+/204917
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarBryan C. Mills <bcmills@google.com>
parent 947f8504
......@@ -7,8 +7,6 @@ golang.org/x/arch v0.0.0-20190815191158-8a70ba74b3a1/go.mod h1:flIaEI6LNU6xOCD5P
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550 h1:ObdrDkeb4kJdCP557AjRjq69pTHfNouLtWZG7j9rPN8=
golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
golang.org/x/mod v0.1.1-0.20191101203923-a222b9651630 h1:QsMqsRXZFQT+jRZnwpEDIwGHWg0UY9ZrpWiplCOEK5I=
golang.org/x/mod v0.1.1-0.20191101203923-a222b9651630/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee h1:WG0RUwxtNT4qqaXX3DPA8zHFNm/D9xaBpxzHt1WcA/E=
golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
......
......@@ -6,6 +6,7 @@ package modfetch
import (
"archive/zip"
"bytes"
"errors"
"fmt"
"io"
......@@ -21,6 +22,7 @@ import (
"golang.org/x/mod/modfile"
"golang.org/x/mod/module"
"golang.org/x/mod/semver"
modzip "golang.org/x/mod/zip"
)
// A codeRepo implements modfetch.Repo using an underlying codehost.Repo.
......@@ -900,13 +902,12 @@ func (r *codeRepo) Zip(dst io.Writer, version string) error {
return err
}
zw := zip.NewWriter(dst)
var files []modzip.File
if subdir != "" {
subdir += "/"
}
haveLICENSE := false
topPrefix := ""
haveGoMod := make(map[string]bool)
for _, zf := range zr.File {
if topPrefix == "" {
i := strings.Index(zf.Name, "/")
......@@ -918,106 +919,61 @@ func (r *codeRepo) Zip(dst io.Writer, version string) error {
if !strings.HasPrefix(zf.Name, topPrefix) {
return fmt.Errorf("zip file contains more than one top-level directory")
}
dir, file := path.Split(zf.Name)
if file == "go.mod" {
haveGoMod[dir] = true
}
}
root := topPrefix + subdir
inSubmodule := func(name string) bool {
for {
dir, _ := path.Split(name)
if len(dir) <= len(root) {
return false
}
if haveGoMod[dir] {
return true
}
name = dir[:len(dir)-1]
}
}
for _, zf := range zr.File {
if !zf.FileInfo().Mode().IsRegular() {
// Skip symlinks (golang.org/issue/27093).
continue
}
if topPrefix == "" {
i := strings.Index(zf.Name, "/")
if i < 0 {
return fmt.Errorf("missing top-level directory prefix")
}
topPrefix = zf.Name[:i+1]
}
if strings.HasSuffix(zf.Name, "/") { // drop directory dummy entries
continue
}
if !strings.HasPrefix(zf.Name, topPrefix) {
return fmt.Errorf("zip file contains more than one top-level directory")
}
name := strings.TrimPrefix(zf.Name, topPrefix)
if !strings.HasPrefix(name, subdir) {
continue
}
if name == ".hg_archival.txt" {
// Inserted by hg archive.
// Not correct to drop from other version control systems, but too bad.
continue
}
name = strings.TrimPrefix(name, subdir)
if isVendoredPackage(name) {
if name == "" || strings.HasSuffix(name, "/") {
continue
}
if inSubmodule(zf.Name) {
continue
}
base := path.Base(name)
if strings.ToLower(base) == "go.mod" && base != "go.mod" {
return fmt.Errorf("zip file contains %s, want all lower-case go.mod", zf.Name)
}
files = append(files, zipFile{name: name, f: zf})
if name == "LICENSE" {
haveLICENSE = true
}
size := int64(zf.UncompressedSize64)
if size < 0 || maxSize < size {
return fmt.Errorf("module source tree too big")
}
maxSize -= size
rc, err := zf.Open()
if err != nil {
return err
}
w, err := zw.Create(r.modPrefix(version) + "/" + name)
if err != nil {
return err
}
lr := &io.LimitedReader{R: rc, N: size + 1}
if _, err := io.Copy(w, lr); err != nil {
return err
}
if lr.N <= 0 {
return fmt.Errorf("individual file too large")
}
}
if !haveLICENSE && subdir != "" {
data, err := r.code.ReadFile(rev, "LICENSE", codehost.MaxLICENSE)
if err == nil {
w, err := zw.Create(r.modPrefix(version) + "/LICENSE")
if err != nil {
return err
}
if _, err := w.Write(data); err != nil {
return err
}
files = append(files, dataFile{name: "LICENSE", data: data})
}
}
return zw.Close()
return modzip.Create(dst, module.Version{Path: r.modPath, Version: version}, files)
}
type zipFile struct {
name string
f *zip.File
}
func (f zipFile) Path() string { return f.name }
func (f zipFile) Lstat() (os.FileInfo, error) { return f.f.FileInfo(), nil }
func (f zipFile) Open() (io.ReadCloser, error) { return f.f.Open() }
type dataFile struct {
name string
data []byte
}
func (f dataFile) Path() string { return f.name }
func (f dataFile) Lstat() (os.FileInfo, error) { return dataFileInfo{f}, nil }
func (f dataFile) Open() (io.ReadCloser, error) {
return ioutil.NopCloser(bytes.NewReader(f.data)), nil
}
type dataFileInfo struct {
f dataFile
}
func (fi dataFileInfo) Name() string { return path.Base(fi.f.name) }
func (fi dataFileInfo) Size() int64 { return int64(len(fi.f.data)) }
func (fi dataFileInfo) Mode() os.FileMode { return 0644 }
func (fi dataFileInfo) ModTime() time.Time { return time.Time{} }
func (fi dataFileInfo) IsDir() bool { return false }
func (fi dataFileInfo) Sys() interface{} { return nil }
// hasPathPrefix reports whether the path s begins with the
// elements in prefix.
func hasPathPrefix(s, prefix string) bool {
......
......@@ -25,6 +25,7 @@ import (
"golang.org/x/mod/module"
"golang.org/x/mod/sumdb/dirhash"
modzip "golang.org/x/mod/zip"
)
var downloadCache par.Cache
......@@ -113,8 +114,7 @@ func download(mod module.Version, dir string) (err error) {
}
}()
modpath := mod.Path + "@" + mod.Version
if err := Unzip(tmpDir, zipfile, modpath, 0); err != nil {
if err := modzip.Unzip(tmpDir, mod, zipfile); err != nil {
fmt.Fprintf(os.Stderr, "-> %s\n", err)
return err
}
......@@ -266,6 +266,45 @@ func downloadZip(mod module.Version, zipfile string) (err error) {
return nil
}
// makeDirsReadOnly makes a best-effort attempt to remove write permissions for dir
// and its transitive contents.
func makeDirsReadOnly(dir string) {
type pathMode struct {
path string
mode os.FileMode
}
var dirs []pathMode // in lexical order
filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
if err == nil && info.Mode()&0222 != 0 {
if info.IsDir() {
dirs = append(dirs, pathMode{path, info.Mode()})
}
}
return nil
})
// Run over list backward to chmod children before parents.
for i := len(dirs) - 1; i >= 0; i-- {
os.Chmod(dirs[i].path, dirs[i].mode&^0222)
}
}
// RemoveAll removes a directory written by Download or Unzip, first applying
// any permission changes needed to do so.
func RemoveAll(dir string) error {
// Module cache has 0555 directories; make them writable in order to remove content.
filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
if err != nil {
return nil // ignore errors walking in file system
}
if info.IsDir() {
os.Chmod(path, 0777)
}
return nil
})
return os.RemoveAll(dir)
}
var GoSumFile string // path to go.sum; set by package modload
type modSum struct {
......
// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package modfetch
import (
"archive/zip"
"fmt"
"io"
"io/ioutil"
"os"
"path"
"path/filepath"
"strings"
"cmd/go/internal/modfetch/codehost"
"cmd/go/internal/str"
"golang.org/x/mod/module"
)
func Unzip(dir, zipfile, prefix string, maxSize int64) error {
// TODO(bcmills): The maxSize parameter is invariantly 0. Remove it.
if maxSize == 0 {
maxSize = codehost.MaxZipFile
}
// Directory can exist, but must be empty.
files, _ := ioutil.ReadDir(dir)
if len(files) > 0 {
return fmt.Errorf("target directory %v exists and is not empty", dir)
}
if err := os.MkdirAll(dir, 0777); err != nil {
return err
}
f, err := os.Open(zipfile)
if err != nil {
return err
}
defer f.Close()
info, err := f.Stat()
if err != nil {
return err
}
z, err := zip.NewReader(f, info.Size())
if err != nil {
return fmt.Errorf("unzip %v: %s", zipfile, err)
}
foldPath := make(map[string]string)
var checkFold func(string) error
checkFold = func(name string) error {
fold := str.ToFold(name)
if foldPath[fold] == name {
return nil
}
dir := path.Dir(name)
if dir != "." {
if err := checkFold(dir); err != nil {
return err
}
}
if foldPath[fold] == "" {
foldPath[fold] = name
return nil
}
other := foldPath[fold]
return fmt.Errorf("unzip %v: case-insensitive file name collision: %q and %q", zipfile, other, name)
}
// Check total size, valid file names.
var size int64
for _, zf := range z.File {
if !str.HasPathPrefix(zf.Name, prefix) {
return fmt.Errorf("unzip %v: unexpected file name %s", zipfile, zf.Name)
}
if zf.Name == prefix || strings.HasSuffix(zf.Name, "/") {
continue
}
name := zf.Name[len(prefix)+1:]
if err := module.CheckFilePath(name); err != nil {
return fmt.Errorf("unzip %v: %v", zipfile, err)
}
if err := checkFold(name); err != nil {
return err
}
if path.Clean(zf.Name) != zf.Name || strings.HasPrefix(zf.Name[len(prefix)+1:], "/") {
return fmt.Errorf("unzip %v: invalid file name %s", zipfile, zf.Name)
}
s := int64(zf.UncompressedSize64)
if s < 0 || maxSize-size < s {
return fmt.Errorf("unzip %v: content too large", zipfile)
}
size += s
}
// Unzip, enforcing sizes checked earlier.
for _, zf := range z.File {
if zf.Name == prefix || strings.HasSuffix(zf.Name, "/") {
continue
}
name := zf.Name[len(prefix):]
dst := filepath.Join(dir, name)
if err := os.MkdirAll(filepath.Dir(dst), 0777); err != nil {
return err
}
w, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0444)
if err != nil {
return fmt.Errorf("unzip %v: %v", zipfile, err)
}
r, err := zf.Open()
if err != nil {
w.Close()
return fmt.Errorf("unzip %v: %v", zipfile, err)
}
lr := &io.LimitedReader{R: r, N: int64(zf.UncompressedSize64) + 1}
_, err = io.Copy(w, lr)
r.Close()
if err != nil {
w.Close()
return fmt.Errorf("unzip %v: %v", zipfile, err)
}
if err := w.Close(); err != nil {
return fmt.Errorf("unzip %v: %v", zipfile, err)
}
if lr.N <= 0 {
return fmt.Errorf("unzip %v: content too large", zipfile)
}
}
return nil
}
// makeDirsReadOnly makes a best-effort attempt to remove write permissions for dir
// and its transitive contents.
func makeDirsReadOnly(dir string) {
type pathMode struct {
path string
mode os.FileMode
}
var dirs []pathMode // in lexical order
filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
if err == nil && info.Mode()&0222 != 0 {
if info.IsDir() {
dirs = append(dirs, pathMode{path, info.Mode()})
}
}
return nil
})
// Run over list backward to chmod children before parents.
for i := len(dirs) - 1; i >= 0; i-- {
os.Chmod(dirs[i].path, dirs[i].mode&^0222)
}
}
// RemoveAll removes a directory written by Download or Unzip, first applying
// any permission changes needed to do so.
func RemoveAll(dir string) error {
// Module cache has 0555 directories; make them writable in order to remove content.
filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
if err != nil {
return nil // ignore errors walking in file system
}
if info.IsDir() {
os.Chmod(path, 0777)
}
return nil
})
return os.RemoveAll(dir)
}
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package zip provides functions for creating and extracting module zip files.
//
// Module zip files have several restrictions listed below. These are necessary
// to ensure that module zip files can be extracted consistently on supported
// platforms and file systems.
//
// • All file paths within a zip file must start with "<module>@<version>/",
// where "<module>" is the module path and "<version>" is the version.
// The module path must be valid (see golang.org/x/mod/module.CheckPath).
// The version must be valid and canonical (see
// golang.org/x/mod/module.CanonicalVersion). The path must have a major
// version suffix consistent with the version (see
// golang.org/x/mod/module.Check). The part of the file path after the
// "<module>@<version>/" prefix must be valid (see
// golang.org/x/mod/module.CheckFilePath).
//
// • No two file paths may be equal under Unicode case-folding (see
// strings.EqualFold).
//
// • A go.mod file may or may not appear in the top-level directory. If present,
// it must be named "go.mod", not any other case. Files named "go.mod"
// are not allowed in any other directory.
//
// • The total size in bytes of a module zip file may be at most MaxZipFile
// bytes (500 MiB). The total uncompressed size of the files within the
// zip may also be at most MaxZipFile bytes.
//
// • Each file's uncompressed size must match its declared 64-bit uncompressed
// size in the zip file header.
//
// • If the zip contains files named "<module>@<version>/go.mod" or
// "<module>@<version>/LICENSE", their sizes in bytes may be at most
// MaxGoMod or MaxLICENSE, respectively (both are 16 MiB).
//
// • Empty directories are ignored. File permissions and timestamps are also
// ignored.
//
// • Symbolic links and other irregular files are not allowed.
//
// Note that this package does not provide hashing functionality. See
// golang.org/x/mod/sumdb/dirhash.
package zip
import (
"archive/zip"
"bytes"
"fmt"
"io"
"io/ioutil"
"os"
"path"
"path/filepath"
"strings"
"unicode"
"unicode/utf8"
"golang.org/x/mod/module"
)
const (
// MaxZipFile is the maximum size in bytes of a module zip file. The
// go command will report an error if either the zip file or its extracted
// content is larger than this.
MaxZipFile = 500 << 20
// MaxGoMod is the maximum size in bytes of a go.mod file within a
// module zip file.
MaxGoMod = 16 << 20
// MaxLICENSE is the maximum size in bytes of a LICENSE file within a
// module zip file.
MaxLICENSE = 16 << 20
)
// File provides an abstraction for a file in a directory, zip, or anything
// else that looks like a file.
type File interface {
// Path returns a clean slash-separated relative path from the module root
// directory to the file.
Path() string
// Lstat returns information about the file. If the file is a symbolic link,
// Lstat returns information about the link itself, not the file it points to.
Lstat() (os.FileInfo, error)
// Open provides access to the data within a regular file. Open may return
// an error if called on a directory or symbolic link.
Open() (io.ReadCloser, error)
}
// Create builds a zip archive for module m from an abstract list of files
// and writes it to w.
//
// Create verifies the restrictions described in the package documentation
// and should not produce an archive that Unzip cannot extract. Create does not
// include files in the output archive if they don't belong in the module zip.
// In particular, Create will not include files in modules found in
// subdirectories, most files in vendor directories, or irregular files (such
// as symbolic links) in the output archive.
func Create(w io.Writer, m module.Version, files []File) (err error) {
defer func() {
if err != nil {
err = &zipError{verb: "create zip", err: err}
}
}()
// Check that the version is canonical, the module path is well-formed, and
// the major version suffix matches the major version.
if vers := module.CanonicalVersion(m.Version); vers != m.Version {
return fmt.Errorf("version %q is not canonical (should be %q)", m.Version, vers)
}
if err := module.Check(m.Path, m.Version); err != nil {
return err
}
// Find directories containing go.mod files (other than the root).
// These directories will not be included in the output zip.
haveGoMod := make(map[string]bool)
for _, f := range files {
dir, base := path.Split(f.Path())
if strings.EqualFold(base, "go.mod") {
info, err := f.Lstat()
if err != nil {
return err
}
if info.Mode().IsRegular() {
haveGoMod[dir] = true
}
}
}
inSubmodule := func(p string) bool {
for {
dir, _ := path.Split(p)
if dir == "" {
return false
}
if haveGoMod[dir] {
return true
}
p = dir[:len(dir)-1]
}
}
// Create the module zip file.
zw := zip.NewWriter(w)
prefix := fmt.Sprintf("%s@%s/", m.Path, m.Version)
addFile := func(f File, path string, size int64) error {
rc, err := f.Open()
if err != nil {
return err
}
defer rc.Close()
w, err := zw.Create(prefix + path)
if err != nil {
return err
}
lr := &io.LimitedReader{R: rc, N: size + 1}
if _, err := io.Copy(w, lr); err != nil {
return err
}
if lr.N <= 0 {
return fmt.Errorf("file %q is larger than declared size", path)
}
return nil
}
collisions := make(collisionChecker)
maxSize := int64(MaxZipFile)
for _, f := range files {
p := f.Path()
if p != path.Clean(p) {
return fmt.Errorf("file path %s is not clean", p)
}
if path.IsAbs(p) {
return fmt.Errorf("file path %s is not relative", p)
}
if isVendoredPackage(p) || inSubmodule(p) {
continue
}
if p == ".hg_archival.txt" {
// Inserted by hg archive.
// The go command drops this regardless of the VCS being used.
continue
}
if err := module.CheckFilePath(p); err != nil {
return err
}
if strings.ToLower(p) == "go.mod" && p != "go.mod" {
return fmt.Errorf("found file named %s, want all lower-case go.mod", p)
}
info, err := f.Lstat()
if err != nil {
return err
}
if err := collisions.check(p, info.IsDir()); err != nil {
return err
}
if !info.Mode().IsRegular() {
// Skip symbolic links (golang.org/issue/27093).
continue
}
size := info.Size()
if size < 0 || maxSize < size {
return fmt.Errorf("module source tree too large (max size is %d bytes)", MaxZipFile)
}
maxSize -= size
if p == "go.mod" && size > MaxGoMod {
return fmt.Errorf("go.mod file too large (max size is %d bytes)", MaxGoMod)
}
if p == "LICENSE" && size > MaxLICENSE {
return fmt.Errorf("LICENSE file too large (max size is %d bytes)", MaxLICENSE)
}
if err := addFile(f, p, size); err != nil {
return err
}
}
return zw.Close()
}
// CreateFromDir creates a module zip file for module m from the contents of
// a directory, dir. The zip content is written to w.
//
// CreateFromDir verifies the restrictions described in the package
// documentation and should not produce an archive that Unzip cannot extract.
// CreateFromDir does not include files in the output archive if they don't
// belong in the module zip. In particular, CreateFromDir will not include
// files in modules found in subdirectories, most files in vendor directories,
// or irregular files (such as symbolic links) in the output archive.
func CreateFromDir(w io.Writer, m module.Version, dir string) (err error) {
defer func() {
if zerr, ok := err.(*zipError); ok {
zerr.path = dir
} else if err != nil {
err = &zipError{verb: "create zip", path: dir, err: err}
}
}()
var files []File
err = filepath.Walk(dir, func(filePath string, info os.FileInfo, err error) error {
relPath, err := filepath.Rel(dir, filePath)
if err != nil {
return err
}
slashPath := filepath.ToSlash(relPath)
if info.IsDir() {
if filePath == dir {
// Don't skip the top-level directory.
return nil
}
// Skip some subdirectories inside vendor, but maintain bug
// golang.org/issue/31562, described in isVendoredPackage.
// We would like Create and CreateFromDir to produce the same result
// for a set of files, whether expressed as a directory tree or zip.
if isVendoredPackage(slashPath) {
return filepath.SkipDir
}
// Skip submodules (directories containing go.mod files).
if goModInfo, err := os.Lstat(filepath.Join(filePath, "go.mod")); err == nil && !goModInfo.IsDir() {
return filepath.SkipDir
}
return nil
}
if info.Mode().IsRegular() {
if !isVendoredPackage(slashPath) {
files = append(files, dirFile{
filePath: filePath,
slashPath: slashPath,
info: info,
})
}
return nil
}
// Not a regular file or a directory. Probably a symbolic link.
// Irregular files are ignored, so skip it.
return nil
})
if err != nil {
return err
}
return Create(w, m, files)
}
type dirFile struct {
filePath, slashPath string
info os.FileInfo
}
func (f dirFile) Path() string { return f.slashPath }
func (f dirFile) Lstat() (os.FileInfo, error) { return f.info, nil }
func (f dirFile) Open() (io.ReadCloser, error) { return os.Open(f.filePath) }
func isVendoredPackage(name string) bool {
var i int
if strings.HasPrefix(name, "vendor/") {
i += len("vendor/")
} else if j := strings.Index(name, "/vendor/"); j >= 0 {
// This offset looks incorrect; this should probably be
//
// i = j + len("/vendor/")
//
// (See https://golang.org/issue/31562.)
//
// Unfortunately, we can't fix it without invalidating checksums.
// Fortunately, the error appears to be strictly conservative: we'll retain
// vendored packages that we should have pruned, but we won't prune
// non-vendored packages that we should have retained.
//
// Since this defect doesn't seem to break anything, it's not worth fixing
// for now.
i += len("/vendor/")
} else {
return false
}
return strings.Contains(name[i:], "/")
}
// Unzip extracts the contents of a module zip file to a directory.
//
// Unzip checks all restrictions listed in the package documentation and returns
// an error if the zip archive is not valid. In some cases, files may be written
// to dir before an error is returned (for example, if a file's uncompressed
// size does not match its declared size).
//
// dir may or may not exist: Unzip will create it and any missing parent
// directories if it doesn't exist. If dir exists, it must be empty.
func Unzip(dir string, m module.Version, zipFile string) (err error) {
defer func() {
if err != nil {
err = &zipError{verb: "unzip", path: zipFile, err: err}
}
}()
if vers := module.CanonicalVersion(m.Version); vers != m.Version {
return fmt.Errorf("version %q is not canonical (should be %q)", m.Version, vers)
}
if err := module.Check(m.Path, m.Version); err != nil {
return err
}
// Check that the directory is empty. Don't create it yet in case there's
// an error reading the zip.
files, _ := ioutil.ReadDir(dir)
if len(files) > 0 {
return fmt.Errorf("target directory %v exists and is not empty", dir)
}
// Open the zip file and ensure it's under the size limit.
f, err := os.Open(zipFile)
if err != nil {
return err
}
defer f.Close()
info, err := f.Stat()
if err != nil {
return err
}
zipSize := info.Size()
if zipSize > MaxZipFile {
return fmt.Errorf("module zip file is too large (%d bytes; limit is %d bytes)", zipSize, MaxZipFile)
}
z, err := zip.NewReader(f, zipSize)
if err != nil {
return err
}
// Check total size, valid file names.
collisions := make(collisionChecker)
prefix := fmt.Sprintf("%s@%s/", m.Path, m.Version)
var size int64
for _, zf := range z.File {
if !strings.HasPrefix(zf.Name, prefix) {
return fmt.Errorf("unexpected file name %s", zf.Name)
}
name := zf.Name[len(prefix):]
if name == "" {
continue
}
isDir := strings.HasSuffix(name, "/")
if isDir {
name = name[:len(name)-1]
}
if path.Clean(name) != name {
return fmt.Errorf("invalid file name %s", zf.Name)
}
if err := module.CheckFilePath(name); err != nil {
return err
}
if err := collisions.check(name, isDir); err != nil {
return err
}
if isDir {
continue
}
if base := path.Base(name); strings.EqualFold(base, "go.mod") {
if base != name {
return fmt.Errorf("found go.mod file not in module root directory (%s)", zf.Name)
} else if name != "go.mod" {
return fmt.Errorf("found file named %s, want all lower-case go.mod", zf.Name)
}
}
s := int64(zf.UncompressedSize64)
if s < 0 || MaxZipFile-size < s {
return fmt.Errorf("total uncompressed size of module contents too large (max size is %d bytes)", MaxZipFile)
}
size += s
if name == "go.mod" && s > MaxGoMod {
return fmt.Errorf("go.mod file too large (max size is %d bytes)", MaxGoMod)
}
if name == "LICENSE" && s > MaxLICENSE {
return fmt.Errorf("LICENSE file too large (max size is %d bytes)", MaxLICENSE)
}
}
// Unzip, enforcing sizes checked earlier.
if err := os.MkdirAll(dir, 0777); err != nil {
return err
}
for _, zf := range z.File {
name := zf.Name[len(prefix):]
if name == "" || strings.HasSuffix(name, "/") {
continue
}
dst := filepath.Join(dir, name)
if err := os.MkdirAll(filepath.Dir(dst), 0777); err != nil {
return err
}
w, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0444)
if err != nil {
return err
}
r, err := zf.Open()
if err != nil {
w.Close()
return err
}
lr := &io.LimitedReader{R: r, N: int64(zf.UncompressedSize64) + 1}
_, err = io.Copy(w, lr)
r.Close()
if err != nil {
w.Close()
return err
}
if err := w.Close(); err != nil {
return err
}
if lr.N <= 0 {
return fmt.Errorf("uncompressed size of file %s is larger than declared size (%d bytes)", zf.Name, zf.UncompressedSize64)
}
}
return nil
}
// collisionChecker finds case-insensitive name collisions and paths that
// are listed as both files and directories.
//
// The keys of this map are processed with strToFold. pathInfo has the original
// path for each folded path.
type collisionChecker map[string]pathInfo
type pathInfo struct {
path string
isDir bool
}
func (cc collisionChecker) check(p string, isDir bool) error {
fold := strToFold(p)
if other, ok := cc[fold]; ok {
if p != other.path {
return fmt.Errorf("case-insensitive file name collision: %q and %q", other.path, p)
}
if isDir != other.isDir {
return fmt.Errorf("entry %q is both a file and a directory", p)
}
if !isDir {
return fmt.Errorf("multiple entries for file %q", p)
}
// It's not an error if check is called with the same directory multiple
// times. check is called recursively on parent directories, so check
// may be called on the same directory many times.
} else {
cc[fold] = pathInfo{path: p, isDir: isDir}
}
if parent := path.Dir(p); parent != "." {
return cc.check(parent, true)
}
return nil
}
type zipError struct {
verb, path string
err error
}
func (e *zipError) Error() string {
if e.path == "" {
return fmt.Sprintf("%s: %v", e.verb, e.err)
} else {
return fmt.Sprintf("%s %s: %v", e.verb, e.path, e.err)
}
}
func (e *zipError) Unwrap() error {
return e.err
}
// strToFold returns a string with the property that
// strings.EqualFold(s, t) iff strToFold(s) == strToFold(t)
// This lets us test a large set of strings for fold-equivalent
// duplicates without making a quadratic number of calls
// to EqualFold. Note that strings.ToUpper and strings.ToLower
// do not have the desired property in some corner cases.
func strToFold(s string) string {
// Fast path: all ASCII, no upper case.
// Most paths look like this already.
for i := 0; i < len(s); i++ {
c := s[i]
if c >= utf8.RuneSelf || 'A' <= c && c <= 'Z' {
goto Slow
}
}
return s
Slow:
var buf bytes.Buffer
for _, r := range s {
// SimpleFold(x) cycles to the next equivalent rune > x
// or wraps around to smaller values. Iterate until it wraps,
// and we've found the minimum value.
for {
r0 := r
r = unicode.SimpleFold(r0)
if r <= r0 {
break
}
}
// Exception to allow fast path above: A-Z => a-z
if 'A' <= r && r <= 'Z' {
r += 'a' - 'A'
}
buf.WriteRune(r)
}
return buf.String()
}
......@@ -39,6 +39,7 @@ golang.org/x/mod/sumdb
golang.org/x/mod/sumdb/dirhash
golang.org/x/mod/sumdb/note
golang.org/x/mod/sumdb/tlog
golang.org/x/mod/zip
# golang.org/x/sys v0.0.0-20190502175342-a43fa875dd82
## explicit
golang.org/x/sys/unix
......
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