mirror of
https://github.com/vbatts/tar-split.git
synced 2024-12-23 05:46:30 +00:00
3b34dbd368
Fixes #11426 Change-Id: I77368b0e852149ed4533e139cc43887508ac7f78 Reviewed-on: https://go-review.googlesource.com/11662 Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Russ Cox <rsc@golang.org> Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>
329 lines
8.2 KiB
Go
329 lines
8.2 KiB
Go
// Copyright 2009 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 tar implements access to tar archives.
|
|
// It aims to cover most of the variations, including those produced
|
|
// by GNU and BSD tars.
|
|
//
|
|
// References:
|
|
// http://www.freebsd.org/cgi/man.cgi?query=tar&sektion=5
|
|
// http://www.gnu.org/software/tar/manual/html_node/Standard.html
|
|
// http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html
|
|
package tar
|
|
|
|
import (
|
|
"bytes"
|
|
"errors"
|
|
"fmt"
|
|
"os"
|
|
"path"
|
|
"time"
|
|
)
|
|
|
|
const (
|
|
blockSize = 512
|
|
|
|
// Types
|
|
TypeReg = '0' // regular file
|
|
TypeRegA = '\x00' // regular file
|
|
TypeLink = '1' // hard link
|
|
TypeSymlink = '2' // symbolic link
|
|
TypeChar = '3' // character device node
|
|
TypeBlock = '4' // block device node
|
|
TypeDir = '5' // directory
|
|
TypeFifo = '6' // fifo node
|
|
TypeCont = '7' // reserved
|
|
TypeXHeader = 'x' // extended header
|
|
TypeXGlobalHeader = 'g' // global extended header
|
|
TypeGNULongName = 'L' // Next file has a long name
|
|
TypeGNULongLink = 'K' // Next file symlinks to a file w/ a long name
|
|
TypeGNUSparse = 'S' // sparse file
|
|
)
|
|
|
|
// A Header represents a single header in a tar archive.
|
|
// Some fields may not be populated.
|
|
type Header struct {
|
|
Name string // name of header file entry
|
|
Mode int64 // permission and mode bits
|
|
Uid int // user id of owner
|
|
Gid int // group id of owner
|
|
Size int64 // length in bytes
|
|
ModTime time.Time // modified time
|
|
Typeflag byte // type of header entry
|
|
Linkname string // target name of link
|
|
Uname string // user name of owner
|
|
Gname string // group name of owner
|
|
Devmajor int64 // major number of character or block device
|
|
Devminor int64 // minor number of character or block device
|
|
AccessTime time.Time // access time
|
|
ChangeTime time.Time // status change time
|
|
Xattrs map[string]string
|
|
}
|
|
|
|
// File name constants from the tar spec.
|
|
const (
|
|
fileNameSize = 100 // Maximum number of bytes in a standard tar name.
|
|
fileNamePrefixSize = 155 // Maximum number of ustar extension bytes.
|
|
)
|
|
|
|
// FileInfo returns an os.FileInfo for the Header.
|
|
func (h *Header) FileInfo() os.FileInfo {
|
|
return headerFileInfo{h}
|
|
}
|
|
|
|
// headerFileInfo implements os.FileInfo.
|
|
type headerFileInfo struct {
|
|
h *Header
|
|
}
|
|
|
|
func (fi headerFileInfo) Size() int64 { return fi.h.Size }
|
|
func (fi headerFileInfo) IsDir() bool { return fi.Mode().IsDir() }
|
|
func (fi headerFileInfo) ModTime() time.Time { return fi.h.ModTime }
|
|
func (fi headerFileInfo) Sys() interface{} { return fi.h }
|
|
|
|
// Name returns the base name of the file.
|
|
func (fi headerFileInfo) Name() string {
|
|
if fi.IsDir() {
|
|
return path.Base(path.Clean(fi.h.Name))
|
|
}
|
|
return path.Base(fi.h.Name)
|
|
}
|
|
|
|
// Mode returns the permission and mode bits for the headerFileInfo.
|
|
func (fi headerFileInfo) Mode() (mode os.FileMode) {
|
|
// Set file permission bits.
|
|
mode = os.FileMode(fi.h.Mode).Perm()
|
|
|
|
// Set setuid, setgid and sticky bits.
|
|
if fi.h.Mode&c_ISUID != 0 {
|
|
// setuid
|
|
mode |= os.ModeSetuid
|
|
}
|
|
if fi.h.Mode&c_ISGID != 0 {
|
|
// setgid
|
|
mode |= os.ModeSetgid
|
|
}
|
|
if fi.h.Mode&c_ISVTX != 0 {
|
|
// sticky
|
|
mode |= os.ModeSticky
|
|
}
|
|
|
|
// Set file mode bits.
|
|
// clear perm, setuid, setgid and sticky bits.
|
|
m := os.FileMode(fi.h.Mode) &^ 07777
|
|
if m == c_ISDIR {
|
|
// directory
|
|
mode |= os.ModeDir
|
|
}
|
|
if m == c_ISFIFO {
|
|
// named pipe (FIFO)
|
|
mode |= os.ModeNamedPipe
|
|
}
|
|
if m == c_ISLNK {
|
|
// symbolic link
|
|
mode |= os.ModeSymlink
|
|
}
|
|
if m == c_ISBLK {
|
|
// device file
|
|
mode |= os.ModeDevice
|
|
}
|
|
if m == c_ISCHR {
|
|
// Unix character device
|
|
mode |= os.ModeDevice
|
|
mode |= os.ModeCharDevice
|
|
}
|
|
if m == c_ISSOCK {
|
|
// Unix domain socket
|
|
mode |= os.ModeSocket
|
|
}
|
|
|
|
switch fi.h.Typeflag {
|
|
case TypeSymlink:
|
|
// symbolic link
|
|
mode |= os.ModeSymlink
|
|
case TypeChar:
|
|
// character device node
|
|
mode |= os.ModeDevice
|
|
mode |= os.ModeCharDevice
|
|
case TypeBlock:
|
|
// block device node
|
|
mode |= os.ModeDevice
|
|
case TypeDir:
|
|
// directory
|
|
mode |= os.ModeDir
|
|
case TypeFifo:
|
|
// fifo node
|
|
mode |= os.ModeNamedPipe
|
|
}
|
|
|
|
return mode
|
|
}
|
|
|
|
// sysStat, if non-nil, populates h from system-dependent fields of fi.
|
|
var sysStat func(fi os.FileInfo, h *Header) error
|
|
|
|
// Mode constants from the tar spec.
|
|
const (
|
|
c_ISUID = 04000 // Set uid
|
|
c_ISGID = 02000 // Set gid
|
|
c_ISVTX = 01000 // Save text (sticky bit)
|
|
c_ISDIR = 040000 // Directory
|
|
c_ISFIFO = 010000 // FIFO
|
|
c_ISREG = 0100000 // Regular file
|
|
c_ISLNK = 0120000 // Symbolic link
|
|
c_ISBLK = 060000 // Block special file
|
|
c_ISCHR = 020000 // Character special file
|
|
c_ISSOCK = 0140000 // Socket
|
|
)
|
|
|
|
// Keywords for the PAX Extended Header
|
|
const (
|
|
paxAtime = "atime"
|
|
paxCharset = "charset"
|
|
paxComment = "comment"
|
|
paxCtime = "ctime" // please note that ctime is not a valid pax header.
|
|
paxGid = "gid"
|
|
paxGname = "gname"
|
|
paxLinkpath = "linkpath"
|
|
paxMtime = "mtime"
|
|
paxPath = "path"
|
|
paxSize = "size"
|
|
paxUid = "uid"
|
|
paxUname = "uname"
|
|
paxXattr = "SCHILY.xattr."
|
|
paxNone = ""
|
|
)
|
|
|
|
// FileInfoHeader creates a partially-populated Header from fi.
|
|
// If fi describes a symlink, FileInfoHeader records link as the link target.
|
|
// If fi describes a directory, a slash is appended to the name.
|
|
// Because os.FileInfo's Name method returns only the base name of
|
|
// the file it describes, it may be necessary to modify the Name field
|
|
// of the returned header to provide the full path name of the file.
|
|
func FileInfoHeader(fi os.FileInfo, link string) (*Header, error) {
|
|
if fi == nil {
|
|
return nil, errors.New("tar: FileInfo is nil")
|
|
}
|
|
fm := fi.Mode()
|
|
h := &Header{
|
|
Name: fi.Name(),
|
|
ModTime: fi.ModTime(),
|
|
Mode: int64(fm.Perm()), // or'd with c_IS* constants later
|
|
}
|
|
switch {
|
|
case fm.IsRegular():
|
|
h.Mode |= c_ISREG
|
|
h.Typeflag = TypeReg
|
|
h.Size = fi.Size()
|
|
case fi.IsDir():
|
|
h.Typeflag = TypeDir
|
|
h.Mode |= c_ISDIR
|
|
h.Name += "/"
|
|
case fm&os.ModeSymlink != 0:
|
|
h.Typeflag = TypeSymlink
|
|
h.Mode |= c_ISLNK
|
|
h.Linkname = link
|
|
case fm&os.ModeDevice != 0:
|
|
if fm&os.ModeCharDevice != 0 {
|
|
h.Mode |= c_ISCHR
|
|
h.Typeflag = TypeChar
|
|
} else {
|
|
h.Mode |= c_ISBLK
|
|
h.Typeflag = TypeBlock
|
|
}
|
|
case fm&os.ModeNamedPipe != 0:
|
|
h.Typeflag = TypeFifo
|
|
h.Mode |= c_ISFIFO
|
|
case fm&os.ModeSocket != 0:
|
|
h.Mode |= c_ISSOCK
|
|
default:
|
|
return nil, fmt.Errorf("archive/tar: unknown file mode %v", fm)
|
|
}
|
|
if fm&os.ModeSetuid != 0 {
|
|
h.Mode |= c_ISUID
|
|
}
|
|
if fm&os.ModeSetgid != 0 {
|
|
h.Mode |= c_ISGID
|
|
}
|
|
if fm&os.ModeSticky != 0 {
|
|
h.Mode |= c_ISVTX
|
|
}
|
|
// If possible, populate additional fields from OS-specific
|
|
// FileInfo fields.
|
|
if sys, ok := fi.Sys().(*Header); ok {
|
|
// This FileInfo came from a Header (not the OS). Use the
|
|
// original Header to populate all remaining fields.
|
|
h.Uid = sys.Uid
|
|
h.Gid = sys.Gid
|
|
h.Uname = sys.Uname
|
|
h.Gname = sys.Gname
|
|
h.AccessTime = sys.AccessTime
|
|
h.ChangeTime = sys.ChangeTime
|
|
if sys.Xattrs != nil {
|
|
h.Xattrs = make(map[string]string)
|
|
for k, v := range sys.Xattrs {
|
|
h.Xattrs[k] = v
|
|
}
|
|
}
|
|
if sys.Typeflag == TypeLink {
|
|
// hard link
|
|
h.Typeflag = TypeLink
|
|
h.Size = 0
|
|
h.Linkname = sys.Linkname
|
|
}
|
|
}
|
|
if sysStat != nil {
|
|
return h, sysStat(fi, h)
|
|
}
|
|
return h, nil
|
|
}
|
|
|
|
var zeroBlock = make([]byte, blockSize)
|
|
|
|
// POSIX specifies a sum of the unsigned byte values, but the Sun tar uses signed byte values.
|
|
// We compute and return both.
|
|
func checksum(header []byte) (unsigned int64, signed int64) {
|
|
for i := 0; i < len(header); i++ {
|
|
if i == 148 {
|
|
// The chksum field (header[148:156]) is special: it should be treated as space bytes.
|
|
unsigned += ' ' * 8
|
|
signed += ' ' * 8
|
|
i += 7
|
|
continue
|
|
}
|
|
unsigned += int64(header[i])
|
|
signed += int64(int8(header[i]))
|
|
}
|
|
return
|
|
}
|
|
|
|
type slicer []byte
|
|
|
|
func (sp *slicer) next(n int) (b []byte) {
|
|
s := *sp
|
|
b, *sp = s[0:n], s[n:]
|
|
return
|
|
}
|
|
|
|
func isASCII(s string) bool {
|
|
for _, c := range s {
|
|
if c >= 0x80 {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
func toASCII(s string) string {
|
|
if isASCII(s) {
|
|
return s
|
|
}
|
|
var buf bytes.Buffer
|
|
for _, c := range s {
|
|
if c < 0x80 {
|
|
buf.WriteByte(byte(c))
|
|
}
|
|
}
|
|
return buf.String()
|
|
}
|