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Use forked archive/tar package

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Use fork of archive/tar to carry changes to tar for
all go versions.

Signed-off-by: Derek McGowan <derek@mcgstyle.net>
This commit is contained in:
Derek McGowan 2017-07-18 16:42:03 -07:00
parent 528a9d87ac
commit 23aa4910c0
No known key found for this signature in database
GPG Key ID: F58C5D0A4405ACDB
13 changed files with 2002 additions and 3 deletions
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2
archive/tar.go
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@ -1,7 +1,6 @@
package archive
import (
"archive/tar"
"context"
"fmt"
"io"
@ -16,6 +15,7 @@ import (
"github.com/containerd/containerd/fs"
"github.com/containerd/containerd/log"
"github.com/dmcgowan/go-tar"
"github.com/pkg/errors"
)

2
archive/tar_unix.go
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@ -3,12 +3,12 @@
package archive
import (
"archive/tar"
"os"
"sync"
"syscall"
"github.com/containerd/continuity/sysx"
"github.com/dmcgowan/go-tar"
"github.com/opencontainers/runc/libcontainer/system"
"github.com/pkg/errors"
)

2
archive/tar_windows.go
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@ -1,13 +1,13 @@
package archive
import (
"archive/tar"
"errors"
"fmt"
"os"
"strings"
"github.com/containerd/containerd/sys"
"github.com/dmcgowan/go-tar"
)
// tarName returns platform-specific filepath

1
vendor.conf
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@ -39,3 +39,4 @@ github.com/Microsoft/hcsshim v0.5.15
github.com/Azure/go-ansiterm fa152c58bc15761d0200cb75fe958b89a9d4888e
google.golang.org/genproto d80a6e20e776b0b17a324d0ba1ab50a39c8e8944
golang.org/x/text 19e51611da83d6be54ddafce4a4af510cb3e9ea4
github.com/dmcgowan/go-tar 2e2c51242e8993c50445dab7c03c8e7febddd0cf

27
vendor/github.com/dmcgowan/go-tar/LICENSE generated vendored Normal file
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@ -0,0 +1,27 @@
Copyright (c) 2009 The Go Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

286
vendor/github.com/dmcgowan/go-tar/common.go generated vendored Normal file
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@ -0,0 +1,286 @@
// 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 (
"errors"
"fmt"
"os"
"path"
"time"
)
// BUG: Use of the Uid and Gid fields in Header could overflow on 32-bit
// architectures. If a large value is encountered when decoding, the result
// stored in Header will be the truncated version.
// Header type flags.
const (
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
}
// 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
}
// isHeaderOnlyType checks if the given type flag is of the type that has no
// data section even if a size is specified.
func isHeaderOnlyType(flag byte) bool {
switch flag {
case TypeLink, TypeSymlink, TypeChar, TypeBlock, TypeDir, TypeFifo:
return true
default:
return false
}
}

197
vendor/github.com/dmcgowan/go-tar/format.go generated vendored Normal file
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@ -0,0 +1,197 @@
// Copyright 2016 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
// Constants to identify various tar formats.
const (
// The format is unknown.
formatUnknown = (1 << iota) / 2 // Sequence of 0, 1, 2, 4, 8, etc...
// The format of the original Unix V7 tar tool prior to standardization.
formatV7
// The old and new GNU formats, which are incompatible with USTAR.
// This does cover the old GNU sparse extension.
// This does not cover the GNU sparse extensions using PAX headers,
// versions 0.0, 0.1, and 1.0; these fall under the PAX format.
formatGNU
// Schily's tar format, which is incompatible with USTAR.
// This does not cover STAR extensions to the PAX format; these fall under
// the PAX format.
formatSTAR
// USTAR is the former standardization of tar defined in POSIX.1-1988.
// This is incompatible with the GNU and STAR formats.
formatUSTAR
// PAX is the latest standardization of tar defined in POSIX.1-2001.
// This is an extension of USTAR and is "backwards compatible" with it.
//
// Some newer formats add their own extensions to PAX, such as GNU sparse
// files and SCHILY extended attributes. Since they are backwards compatible
// with PAX, they will be labelled as "PAX".
formatPAX
)
// Magics used to identify various formats.
const (
magicGNU, versionGNU = "ustar ", " \x00"
magicUSTAR, versionUSTAR = "ustar\x00", "00"
trailerSTAR = "tar\x00"
)
// Size constants from various tar specifications.
const (
blockSize = 512 // Size of each block in a tar stream
nameSize = 100 // Max length of the name field in USTAR format
prefixSize = 155 // Max length of the prefix field in USTAR format
)
var zeroBlock block
type block [blockSize]byte
// Convert block to any number of formats.
func (b *block) V7() *headerV7 { return (*headerV7)(b) }
func (b *block) GNU() *headerGNU { return (*headerGNU)(b) }
func (b *block) STAR() *headerSTAR { return (*headerSTAR)(b) }
func (b *block) USTAR() *headerUSTAR { return (*headerUSTAR)(b) }
func (b *block) Sparse() sparseArray { return (sparseArray)(b[:]) }
// GetFormat checks that the block is a valid tar header based on the checksum.
// It then attempts to guess the specific format based on magic values.
// If the checksum fails, then formatUnknown is returned.
func (b *block) GetFormat() (format int) {
// Verify checksum.
var p parser
value := p.parseOctal(b.V7().Chksum())
chksum1, chksum2 := b.ComputeChecksum()
if p.err != nil || (value != chksum1 && value != chksum2) {
return formatUnknown
}
// Guess the magic values.
magic := string(b.USTAR().Magic())
version := string(b.USTAR().Version())
trailer := string(b.STAR().Trailer())
switch {
case magic == magicUSTAR && trailer == trailerSTAR:
return formatSTAR
case magic == magicUSTAR:
return formatUSTAR
case magic == magicGNU && version == versionGNU:
return formatGNU
default:
return formatV7
}
}
// SetFormat writes the magic values necessary for specified format
// and then updates the checksum accordingly.
func (b *block) SetFormat(format int) {
// Set the magic values.
switch format {
case formatV7:
// Do nothing.
case formatGNU:
copy(b.GNU().Magic(), magicGNU)
copy(b.GNU().Version(), versionGNU)
case formatSTAR:
copy(b.STAR().Magic(), magicUSTAR)
copy(b.STAR().Version(), versionUSTAR)
copy(b.STAR().Trailer(), trailerSTAR)
case formatUSTAR, formatPAX:
copy(b.USTAR().Magic(), magicUSTAR)
copy(b.USTAR().Version(), versionUSTAR)
default:
panic("invalid format")
}
// Update checksum.
// This field is special in that it is terminated by a NULL then space.
var f formatter
field := b.V7().Chksum()
chksum, _ := b.ComputeChecksum() // Possible values are 256..128776
f.formatOctal(field[:7], chksum) // Never fails since 128776 < 262143
field[7] = ' '
}
// ComputeChecksum computes the checksum for the header block.
// POSIX specifies a sum of the unsigned byte values, but the Sun tar used
// signed byte values.
// We compute and return both.
func (b *block) ComputeChecksum() (unsigned, signed int64) {
for i, c := range b {
if 148 <= i && i < 156 {
c = ' ' // Treat the checksum field itself as all spaces.
}
unsigned += int64(uint8(c))
signed += int64(int8(c))
}
return unsigned, signed
}
type headerV7 [blockSize]byte
func (h *headerV7) Name() []byte { return h[000:][:100] }
func (h *headerV7) Mode() []byte { return h[100:][:8] }
func (h *headerV7) UID() []byte { return h[108:][:8] }
func (h *headerV7) GID() []byte { return h[116:][:8] }
func (h *headerV7) Size() []byte { return h[124:][:12] }
func (h *headerV7) ModTime() []byte { return h[136:][:12] }
func (h *headerV7) Chksum() []byte { return h[148:][:8] }
func (h *headerV7) TypeFlag() []byte { return h[156:][:1] }
func (h *headerV7) LinkName() []byte { return h[157:][:100] }
type headerGNU [blockSize]byte
func (h *headerGNU) V7() *headerV7 { return (*headerV7)(h) }
func (h *headerGNU) Magic() []byte { return h[257:][:6] }
func (h *headerGNU) Version() []byte { return h[263:][:2] }
func (h *headerGNU) UserName() []byte { return h[265:][:32] }
func (h *headerGNU) GroupName() []byte { return h[297:][:32] }
func (h *headerGNU) DevMajor() []byte { return h[329:][:8] }
func (h *headerGNU) DevMinor() []byte { return h[337:][:8] }
func (h *headerGNU) AccessTime() []byte { return h[345:][:12] }
func (h *headerGNU) ChangeTime() []byte { return h[357:][:12] }
func (h *headerGNU) Sparse() sparseArray { return (sparseArray)(h[386:][:24*4+1]) }
func (h *headerGNU) RealSize() []byte { return h[483:][:12] }
type headerSTAR [blockSize]byte
func (h *headerSTAR) V7() *headerV7 { return (*headerV7)(h) }
func (h *headerSTAR) Magic() []byte { return h[257:][:6] }
func (h *headerSTAR) Version() []byte { return h[263:][:2] }
func (h *headerSTAR) UserName() []byte { return h[265:][:32] }
func (h *headerSTAR) GroupName() []byte { return h[297:][:32] }
func (h *headerSTAR) DevMajor() []byte { return h[329:][:8] }
func (h *headerSTAR) DevMinor() []byte { return h[337:][:8] }
func (h *headerSTAR) Prefix() []byte { return h[345:][:131] }
func (h *headerSTAR) AccessTime() []byte { return h[476:][:12] }
func (h *headerSTAR) ChangeTime() []byte { return h[488:][:12] }
func (h *headerSTAR) Trailer() []byte { return h[508:][:4] }
type headerUSTAR [blockSize]byte
func (h *headerUSTAR) V7() *headerV7 { return (*headerV7)(h) }
func (h *headerUSTAR) Magic() []byte { return h[257:][:6] }
func (h *headerUSTAR) Version() []byte { return h[263:][:2] }
func (h *headerUSTAR) UserName() []byte { return h[265:][:32] }
func (h *headerUSTAR) GroupName() []byte { return h[297:][:32] }
func (h *headerUSTAR) DevMajor() []byte { return h[329:][:8] }
func (h *headerUSTAR) DevMinor() []byte { return h[337:][:8] }
func (h *headerUSTAR) Prefix() []byte { return h[345:][:155] }
type sparseArray []byte
func (s sparseArray) Entry(i int) sparseNode { return (sparseNode)(s[i*24:]) }
func (s sparseArray) IsExtended() []byte { return s[24*s.MaxEntries():][:1] }
func (s sparseArray) MaxEntries() int { return len(s) / 24 }
type sparseNode []byte
func (s sparseNode) Offset() []byte { return s[00:][:12] }
func (s sparseNode) NumBytes() []byte { return s[12:][:12] }

800
vendor/github.com/dmcgowan/go-tar/reader.go generated vendored Normal file
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// 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
// TODO(dsymonds):
// - pax extensions
import (
"bytes"
"errors"
"io"
"io/ioutil"
"math"
"strconv"
"strings"
"time"
)
var (
ErrHeader = errors.New("archive/tar: invalid tar header")
)
// A Reader provides sequential access to the contents of a tar archive.
// A tar archive consists of a sequence of files.
// The Next method advances to the next file in the archive (including the first),
// and then it can be treated as an io.Reader to access the file's data.
type Reader struct {
r io.Reader
pad int64 // amount of padding (ignored) after current file entry
curr numBytesReader // reader for current file entry
blk block // buffer to use as temporary local storage
// err is a persistent error.
// It is only the responsibility of every exported method of Reader to
// ensure that this error is sticky.
err error
}
// A numBytesReader is an io.Reader with a numBytes method, returning the number
// of bytes remaining in the underlying encoded data.
type numBytesReader interface {
io.Reader
numBytes() int64
}
// A regFileReader is a numBytesReader for reading file data from a tar archive.
type regFileReader struct {
r io.Reader // underlying reader
nb int64 // number of unread bytes for current file entry
}
// A sparseFileReader is a numBytesReader for reading sparse file data from a
// tar archive.
type sparseFileReader struct {
rfr numBytesReader // Reads the sparse-encoded file data
sp []sparseEntry // The sparse map for the file
pos int64 // Keeps track of file position
total int64 // Total size of the file
}
// A sparseEntry holds a single entry in a sparse file's sparse map.
//
// Sparse files are represented using a series of sparseEntrys.
// Despite the name, a sparseEntry represents an actual data fragment that
// references data found in the underlying archive stream. All regions not
// covered by a sparseEntry are logically filled with zeros.
//
// For example, if the underlying raw file contains the 10-byte data:
// var compactData = "abcdefgh"
//
// And the sparse map has the following entries:
// var sp = []sparseEntry{
// {offset: 2, numBytes: 5} // Data fragment for [2..7]
// {offset: 18, numBytes: 3} // Data fragment for [18..21]
// }
//
// Then the content of the resulting sparse file with a "real" size of 25 is:
// var sparseData = "\x00"*2 + "abcde" + "\x00"*11 + "fgh" + "\x00"*4
type sparseEntry struct {
offset int64 // Starting position of the fragment
numBytes int64 // Length of the fragment
}
// Keywords for GNU sparse files in a PAX extended header
const (
paxGNUSparseNumBlocks = "GNU.sparse.numblocks"
paxGNUSparseOffset = "GNU.sparse.offset"
paxGNUSparseNumBytes = "GNU.sparse.numbytes"
paxGNUSparseMap = "GNU.sparse.map"
paxGNUSparseName = "GNU.sparse.name"
paxGNUSparseMajor = "GNU.sparse.major"
paxGNUSparseMinor = "GNU.sparse.minor"
paxGNUSparseSize = "GNU.sparse.size"
paxGNUSparseRealSize = "GNU.sparse.realsize"
)
// NewReader creates a new Reader reading from r.
func NewReader(r io.Reader) *Reader { return &Reader{r: r} }
// Next advances to the next entry in the tar archive.
//
// io.EOF is returned at the end of the input.
func (tr *Reader) Next() (*Header, error) {
if tr.err != nil {
return nil, tr.err
}
hdr, err := tr.next()
tr.err = err
return hdr, err
}
func (tr *Reader) next() (*Header, error) {
var extHdrs map[string]string
// Externally, Next iterates through the tar archive as if it is a series of
// files. Internally, the tar format often uses fake "files" to add meta
// data that describes the next file. These meta data "files" should not
// normally be visible to the outside. As such, this loop iterates through
// one or more "header files" until it finds a "normal file".
loop:
for {
if err := tr.skipUnread(); err != nil {
return nil, err
}
hdr, rawHdr, err := tr.readHeader()
if err != nil {
return nil, err
}
if err := tr.handleRegularFile(hdr); err != nil {
return nil, err
}
// Check for PAX/GNU special headers and files.
switch hdr.Typeflag {
case TypeXHeader:
extHdrs, err = parsePAX(tr)
if err != nil {
return nil, err
}
continue loop // This is a meta header affecting the next header
case TypeGNULongName, TypeGNULongLink:
realname, err := ioutil.ReadAll(tr)
if err != nil {
return nil, err
}
// Convert GNU extensions to use PAX headers.
if extHdrs == nil {
extHdrs = make(map[string]string)
}
var p parser
switch hdr.Typeflag {
case TypeGNULongName:
extHdrs[paxPath] = p.parseString(realname)
case TypeGNULongLink:
extHdrs[paxLinkpath] = p.parseString(realname)
}
if p.err != nil {
return nil, p.err
}
continue loop // This is a meta header affecting the next header
default:
// The old GNU sparse format is handled here since it is technically
// just a regular file with additional attributes.
if err := mergePAX(hdr, extHdrs); err != nil {
return nil, err
}
// The extended headers may have updated the size.
// Thus, setup the regFileReader again after merging PAX headers.
if err := tr.handleRegularFile(hdr); err != nil {
return nil, err
}
// Sparse formats rely on being able to read from the logical data
// section; there must be a preceding call to handleRegularFile.
if err := tr.handleSparseFile(hdr, rawHdr, extHdrs); err != nil {
return nil, err
}
return hdr, nil // This is a file, so stop
}
}
}
// handleRegularFile sets up the current file reader and padding such that it
// can only read the following logical data section. It will properly handle
// special headers that contain no data section.
func (tr *Reader) handleRegularFile(hdr *Header) error {
nb := hdr.Size
if isHeaderOnlyType(hdr.Typeflag) {
nb = 0
}
if nb < 0 {
return ErrHeader
}
tr.pad = -nb & (blockSize - 1) // blockSize is a power of two
tr.curr = &regFileReader{r: tr.r, nb: nb}
return nil
}
// handleSparseFile checks if the current file is a sparse format of any type
// and sets the curr reader appropriately.
func (tr *Reader) handleSparseFile(hdr *Header, rawHdr *block, extHdrs map[string]string) error {
var sp []sparseEntry
var err error
if hdr.Typeflag == TypeGNUSparse {
sp, err = tr.readOldGNUSparseMap(hdr, rawHdr)
if err != nil {
return err
}
} else {
sp, err = tr.checkForGNUSparsePAXHeaders(hdr, extHdrs)
if err != nil {
return err
}
}
// If sp is non-nil, then this is a sparse file.
// Note that it is possible for len(sp) to be zero.
if sp != nil {
tr.curr, err = newSparseFileReader(tr.curr, sp, hdr.Size)
}
return err
}
// checkForGNUSparsePAXHeaders checks the PAX headers for GNU sparse headers. If they are found, then
// this function reads the sparse map and returns it. Unknown sparse formats are ignored, causing the file to
// be treated as a regular file.
func (tr *Reader) checkForGNUSparsePAXHeaders(hdr *Header, headers map[string]string) ([]sparseEntry, error) {
var sparseFormat string
// Check for sparse format indicators
major, majorOk := headers[paxGNUSparseMajor]
minor, minorOk := headers[paxGNUSparseMinor]
sparseName, sparseNameOk := headers[paxGNUSparseName]
_, sparseMapOk := headers[paxGNUSparseMap]
sparseSize, sparseSizeOk := headers[paxGNUSparseSize]
sparseRealSize, sparseRealSizeOk := headers[paxGNUSparseRealSize]
// Identify which, if any, sparse format applies from which PAX headers are set
if majorOk && minorOk {
sparseFormat = major + "." + minor
} else if sparseNameOk && sparseMapOk {
sparseFormat = "0.1"
} else if sparseSizeOk {
sparseFormat = "0.0"
} else {
// Not a PAX format GNU sparse file.
return nil, nil
}
// Check for unknown sparse format
if sparseFormat != "0.0" && sparseFormat != "0.1" && sparseFormat != "1.0" {
return nil, nil
}
// Update hdr from GNU sparse PAX headers
if sparseNameOk {
hdr.Name = sparseName
}
if sparseSizeOk {
realSize, err := strconv.ParseInt(sparseSize, 10, 64)
if err != nil {
return nil, ErrHeader
}
hdr.Size = realSize
} else if sparseRealSizeOk {
realSize, err := strconv.ParseInt(sparseRealSize, 10, 64)
if err != nil {
return nil, ErrHeader
}
hdr.Size = realSize
}
// Set up the sparse map, according to the particular sparse format in use
var sp []sparseEntry
var err error
switch sparseFormat {
case "0.0", "0.1":
sp, err = readGNUSparseMap0x1(headers)
case "1.0":
sp, err = readGNUSparseMap1x0(tr.curr)
}
return sp, err
}
// mergePAX merges well known headers according to PAX standard.
// In general headers with the same name as those found
// in the header struct overwrite those found in the header
// struct with higher precision or longer values. Esp. useful
// for name and linkname fields.
func mergePAX(hdr *Header, headers map[string]string) (err error) {
var id64 int64
for k, v := range headers {
switch k {
case paxPath:
hdr.Name = v
case paxLinkpath:
hdr.Linkname = v
case paxUname:
hdr.Uname = v
case paxGname:
hdr.Gname = v
case paxUid:
id64, err = strconv.ParseInt(v, 10, 64)
hdr.Uid = int(id64) // Integer overflow possible
case paxGid:
id64, err = strconv.ParseInt(v, 10, 64)
hdr.Gid = int(id64) // Integer overflow possible
case paxAtime:
hdr.AccessTime, err = parsePAXTime(v)
case paxMtime:
hdr.ModTime, err = parsePAXTime(v)
case paxCtime:
hdr.ChangeTime, err = parsePAXTime(v)
case paxSize:
hdr.Size, err = strconv.ParseInt(v, 10, 64)
default:
if strings.HasPrefix(k, paxXattr) {
if hdr.Xattrs == nil {
hdr.Xattrs = make(map[string]string)
}
hdr.Xattrs[k[len(paxXattr):]] = v
}
}
if err != nil {
return ErrHeader
}
}
return nil
}
// parsePAX parses PAX headers.
// If an extended header (type 'x') is invalid, ErrHeader is returned
func parsePAX(r io.Reader) (map[string]string, error) {
buf, err := ioutil.ReadAll(r)
if err != nil {
return nil, err
}
sbuf := string(buf)
// For GNU PAX sparse format 0.0 support.
// This function transforms the sparse format 0.0 headers into format 0.1
// headers since 0.0 headers were not PAX compliant.
var sparseMap []string
extHdrs := make(map[string]string)
for len(sbuf) > 0 {
key, value, residual, err := parsePAXRecord(sbuf)
if err != nil {
return nil, ErrHeader
}
sbuf = residual
switch key {
case paxGNUSparseOffset, paxGNUSparseNumBytes:
// Validate sparse header order and value.
if (len(sparseMap)%2 == 0 && key != paxGNUSparseOffset) ||
(len(sparseMap)%2 == 1 && key != paxGNUSparseNumBytes) ||
strings.Contains(value, ",") {
return nil, ErrHeader
}
sparseMap = append(sparseMap, value)
default:
// According to PAX specification, a value is stored only if it is
// non-empty. Otherwise, the key is deleted.
if len(value) > 0 {
extHdrs[key] = value
} else {
delete(extHdrs, key)
}
}
}
if len(sparseMap) > 0 {
extHdrs[paxGNUSparseMap] = strings.Join(sparseMap, ",")
}
return extHdrs, nil
}
// skipUnread skips any unread bytes in the existing file entry, as well as any
// alignment padding. It returns io.ErrUnexpectedEOF if any io.EOF is
// encountered in the data portion; it is okay to hit io.EOF in the padding.
//
// Note that this function still works properly even when sparse files are being
// used since numBytes returns the bytes remaining in the underlying io.Reader.
func (tr *Reader) skipUnread() error {
dataSkip := tr.numBytes() // Number of data bytes to skip
totalSkip := dataSkip + tr.pad // Total number of bytes to skip
tr.curr, tr.pad = nil, 0
// If possible, Seek to the last byte before the end of the data section.
// Do this because Seek is often lazy about reporting errors; this will mask
// the fact that the tar stream may be truncated. We can rely on the
// io.CopyN done shortly afterwards to trigger any IO errors.
var seekSkipped int64 // Number of bytes skipped via Seek
if sr, ok := tr.r.(io.Seeker); ok && dataSkip > 1 {
// Not all io.Seeker can actually Seek. For example, os.Stdin implements
// io.Seeker, but calling Seek always returns an error and performs
// no action. Thus, we try an innocent seek to the current position
// to see if Seek is really supported.
pos1, err := sr.Seek(0, io.SeekCurrent)
if err == nil {
// Seek seems supported, so perform the real Seek.
pos2, err := sr.Seek(dataSkip-1, io.SeekCurrent)
if err != nil {
return err
}
seekSkipped = pos2 - pos1
}
}
copySkipped, err := io.CopyN(ioutil.Discard, tr.r, totalSkip-seekSkipped)
if err == io.EOF && seekSkipped+copySkipped < dataSkip {
err = io.ErrUnexpectedEOF
}
return err
}
// readHeader reads the next block header and assumes that the underlying reader
// is already aligned to a block boundary. It returns the raw block of the
// header in case further processing is required.
//
// The err will be set to io.EOF only when one of the following occurs:
// * Exactly 0 bytes are read and EOF is hit.
// * Exactly 1 block of zeros is read and EOF is hit.
// * At least 2 blocks of zeros are read.
func (tr *Reader) readHeader() (*Header, *block, error) {
// Two blocks of zero bytes marks the end of the archive.
if _, err := io.ReadFull(tr.r, tr.blk[:]); err != nil {
return nil, nil, err // EOF is okay here; exactly 0 bytes read
}
if bytes.Equal(tr.blk[:], zeroBlock[:]) {
if _, err := io.ReadFull(tr.r, tr.blk[:]); err != nil {
return nil, nil, err // EOF is okay here; exactly 1 block of zeros read
}
if bytes.Equal(tr.blk[:], zeroBlock[:]) {
return nil, nil, io.EOF // normal EOF; exactly 2 block of zeros read
}
return nil, nil, ErrHeader // Zero block and then non-zero block
}
// Verify the header matches a known format.
format := tr.blk.GetFormat()
if format == formatUnknown {
return nil, nil, ErrHeader
}
var p parser
hdr := new(Header)
// Unpack the V7 header.
v7 := tr.blk.V7()
hdr.Name = p.parseString(v7.Name())
hdr.Mode = p.parseNumeric(v7.Mode())
hdr.Uid = int(p.parseNumeric(v7.UID()))
hdr.Gid = int(p.parseNumeric(v7.GID()))
hdr.Size = p.parseNumeric(v7.Size())
hdr.ModTime = time.Unix(p.parseNumeric(v7.ModTime()), 0)
hdr.Typeflag = v7.TypeFlag()[0]
hdr.Linkname = p.parseString(v7.LinkName())
// Unpack format specific fields.
if format > formatV7 {
ustar := tr.blk.USTAR()
hdr.Uname = p.parseString(ustar.UserName())
hdr.Gname = p.parseString(ustar.GroupName())
if hdr.Typeflag == TypeChar || hdr.Typeflag == TypeBlock {
hdr.Devmajor = p.parseNumeric(ustar.DevMajor())
hdr.Devminor = p.parseNumeric(ustar.DevMinor())
}
var prefix string
switch format {
case formatUSTAR, formatGNU:
// TODO(dsnet): Do not use the prefix field for the GNU format!
// See golang.org/issues/12594
ustar := tr.blk.USTAR()
prefix = p.parseString(ustar.Prefix())
case formatSTAR:
star := tr.blk.STAR()
prefix = p.parseString(star.Prefix())
hdr.AccessTime = time.Unix(p.parseNumeric(star.AccessTime()), 0)
hdr.ChangeTime = time.Unix(p.parseNumeric(star.ChangeTime()), 0)
}
if len(prefix) > 0 {
hdr.Name = prefix + "/" + hdr.Name
}
}
return hdr, &tr.blk, p.err
}
// readOldGNUSparseMap reads the sparse map from the old GNU sparse format.
// The sparse map is stored in the tar header if it's small enough.
// If it's larger than four entries, then one or more extension headers are used
// to store the rest of the sparse map.
//
// The Header.Size does not reflect the size of any extended headers used.
// Thus, this function will read from the raw io.Reader to fetch extra headers.
// This method mutates blk in the process.
func (tr *Reader) readOldGNUSparseMap(hdr *Header, blk *block) ([]sparseEntry, error) {
// Make sure that the input format is GNU.
// Unfortunately, the STAR format also has a sparse header format that uses
// the same type flag but has a completely different layout.
if blk.GetFormat() != formatGNU {
return nil, ErrHeader
}
var p parser
hdr.Size = p.parseNumeric(blk.GNU().RealSize())
if p.err != nil {
return nil, p.err
}
var s sparseArray = blk.GNU().Sparse()
var sp = make([]sparseEntry, 0, s.MaxEntries())
for {
for i := 0; i < s.MaxEntries(); i++ {
// This termination condition is identical to GNU and BSD tar.
if s.Entry(i).Offset()[0] == 0x00 {
break // Don't return, need to process extended headers (even if empty)
}
offset := p.parseNumeric(s.Entry(i).Offset())
numBytes := p.parseNumeric(s.Entry(i).NumBytes())
if p.err != nil {
return nil, p.err
}
sp = append(sp, sparseEntry{offset: offset, numBytes: numBytes})
}
if s.IsExtended()[0] > 0 {
// There are more entries. Read an extension header and parse its entries.
if _, err := io.ReadFull(tr.r, blk[:]); err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return nil, err
}
s = blk.Sparse()
continue
}
return sp, nil // Done
}
}
// readGNUSparseMap1x0 reads the sparse map as stored in GNU's PAX sparse format
// version 1.0. The format of the sparse map consists of a series of
// newline-terminated numeric fields. The first field is the number of entries
// and is always present. Following this are the entries, consisting of two
// fields (offset, numBytes). This function must stop reading at the end
// boundary of the block containing the last newline.
//
// Note that the GNU manual says that numeric values should be encoded in octal
// format. However, the GNU tar utility itself outputs these values in decimal.
// As such, this library treats values as being encoded in decimal.
func readGNUSparseMap1x0(r io.Reader) ([]sparseEntry, error) {
var cntNewline int64
var buf bytes.Buffer
var blk = make([]byte, blockSize)
// feedTokens copies data in numBlock chunks from r into buf until there are
// at least cnt newlines in buf. It will not read more blocks than needed.
var feedTokens = func(cnt int64) error {
for cntNewline < cnt {
if _, err := io.ReadFull(r, blk); err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return err
}
buf.Write(blk)
for _, c := range blk {
if c == '\n' {
cntNewline++
}
}
}
return nil
}
// nextToken gets the next token delimited by a newline. This assumes that
// at least one newline exists in the buffer.
var nextToken = func() string {
cntNewline--
tok, _ := buf.ReadString('\n')
return tok[:len(tok)-1] // Cut off newline
}
// Parse for the number of entries.
// Use integer overflow resistant math to check this.
if err := feedTokens(1); err != nil {
return nil, err
}
numEntries, err := strconv.ParseInt(nextToken(), 10, 0) // Intentionally parse as native int
if err != nil || numEntries < 0 || int(2*numEntries) < int(numEntries) {
return nil, ErrHeader
}
// Parse for all member entries.
// numEntries is trusted after this since a potential attacker must have
// committed resources proportional to what this library used.
if err := feedTokens(2 * numEntries); err != nil {
return nil, err
}
sp := make([]sparseEntry, 0, numEntries)
for i := int64(0); i < numEntries; i++ {
offset, err := strconv.ParseInt(nextToken(), 10, 64)
if err != nil {
return nil, ErrHeader
}
numBytes, err := strconv.ParseInt(nextToken(), 10, 64)
if err != nil {
return nil, ErrHeader
}
sp = append(sp, sparseEntry{offset: offset, numBytes: numBytes})
}
return sp, nil
}
// readGNUSparseMap0x1 reads the sparse map as stored in GNU's PAX sparse format
// version 0.1. The sparse map is stored in the PAX headers.
func readGNUSparseMap0x1(extHdrs map[string]string) ([]sparseEntry, error) {
// Get number of entries.
// Use integer overflow resistant math to check this.
numEntriesStr := extHdrs[paxGNUSparseNumBlocks]
numEntries, err := strconv.ParseInt(numEntriesStr, 10, 0) // Intentionally parse as native int
if err != nil || numEntries < 0 || int(2*numEntries) < int(numEntries) {
return nil, ErrHeader
}
// There should be two numbers in sparseMap for each entry.
sparseMap := strings.Split(extHdrs[paxGNUSparseMap], ",")
if int64(len(sparseMap)) != 2*numEntries {
return nil, ErrHeader
}
// Loop through the entries in the sparse map.
// numEntries is trusted now.
sp := make([]sparseEntry, 0, numEntries)
for i := int64(0); i < numEntries; i++ {
offset, err := strconv.ParseInt(sparseMap[2*i], 10, 64)
if err != nil {
return nil, ErrHeader
}
numBytes, err := strconv.ParseInt(sparseMap[2*i+1], 10, 64)
if err != nil {
return nil, ErrHeader
}
sp = append(sp, sparseEntry{offset: offset, numBytes: numBytes})
}
return sp, nil
}
// numBytes returns the number of bytes left to read in the current file's entry
// in the tar archive, or 0 if there is no current file.
func (tr *Reader) numBytes() int64 {
if tr.curr == nil {
// No current file, so no bytes
return 0
}
return tr.curr.numBytes()
}
// Read reads from the current entry in the tar archive.
// It returns 0, io.EOF when it reaches the end of that entry,
// until Next is called to advance to the next entry.
//
// Calling Read on special types like TypeLink, TypeSymLink, TypeChar,
// TypeBlock, TypeDir, and TypeFifo returns 0, io.EOF regardless of what
// the Header.Size claims.
func (tr *Reader) Read(b []byte) (int, error) {
if tr.err != nil {
return 0, tr.err
}
if tr.curr == nil {
return 0, io.EOF
}
n, err := tr.curr.Read(b)
if err != nil && err != io.EOF {
tr.err = err
}
return n, err
}
func (rfr *regFileReader) Read(b []byte) (n int, err error) {
if rfr.nb == 0 {
// file consumed
return 0, io.EOF
}
if int64(len(b)) > rfr.nb {
b = b[0:rfr.nb]
}
n, err = rfr.r.Read(b)
rfr.nb -= int64(n)
if err == io.EOF && rfr.nb > 0 {
err = io.ErrUnexpectedEOF
}
return
}
// numBytes returns the number of bytes left to read in the file's data in the tar archive.
func (rfr *regFileReader) numBytes() int64 {
return rfr.nb
}
// newSparseFileReader creates a new sparseFileReader, but validates all of the
// sparse entries before doing so.
func newSparseFileReader(rfr numBytesReader, sp []sparseEntry, total int64) (*sparseFileReader, error) {
if total < 0 {
return nil, ErrHeader // Total size cannot be negative
}
// Validate all sparse entries. These are the same checks as performed by
// the BSD tar utility.
for i, s := range sp {
switch {
case s.offset < 0 || s.numBytes < 0:
return nil, ErrHeader // Negative values are never okay
case s.offset > math.MaxInt64-s.numBytes:
return nil, ErrHeader // Integer overflow with large length
case s.offset+s.numBytes > total:
return nil, ErrHeader // Region extends beyond the "real" size
case i > 0 && sp[i-1].offset+sp[i-1].numBytes > s.offset:
return nil, ErrHeader // Regions can't overlap and must be in order
}
}
return &sparseFileReader{rfr: rfr, sp: sp, total: total}, nil
}
// readHole reads a sparse hole ending at endOffset.
func (sfr *sparseFileReader) readHole(b []byte, endOffset int64) int {
n64 := endOffset - sfr.pos
if n64 > int64(len(b)) {
n64 = int64(len(b))
}
n := int(n64)
for i := 0; i < n; i++ {
b[i] = 0
}
sfr.pos += n64
return n
}
// Read reads the sparse file data in expanded form.
func (sfr *sparseFileReader) Read(b []byte) (n int, err error) {
// Skip past all empty fragments.
for len(sfr.sp) > 0 && sfr.sp[0].numBytes == 0 {
sfr.sp = sfr.sp[1:]
}
// If there are no more fragments, then it is possible that there
// is one last sparse hole.
if len(sfr.sp) == 0 {
// This behavior matches the BSD tar utility.
// However, GNU tar stops returning data even if sfr.total is unmet.
if sfr.pos < sfr.total {
return sfr.readHole(b, sfr.total), nil
}
return 0, io.EOF
}
// In front of a data fragment, so read a hole.
if sfr.pos < sfr.sp[0].offset {
return sfr.readHole(b, sfr.sp[0].offset), nil
}
// In a data fragment, so read from it.
// This math is overflow free since we verify that offset and numBytes can
// be safely added when creating the sparseFileReader.
endPos := sfr.sp[0].offset + sfr.sp[0].numBytes // End offset of fragment
bytesLeft := endPos - sfr.pos // Bytes left in fragment
if int64(len(b)) > bytesLeft {
b = b[:bytesLeft]
}
n, err = sfr.rfr.Read(b)
sfr.pos += int64(n)
if err == io.EOF {
if sfr.pos < endPos {
err = io.ErrUnexpectedEOF // There was supposed to be more data
} else if sfr.pos < sfr.total {
err = nil // There is still an implicit sparse hole at the end
}
}
if sfr.pos == endPos {
sfr.sp = sfr.sp[1:] // We are done with this fragment, so pop it
}
return n, err
}
// numBytes returns the number of bytes left to read in the sparse file's
// sparse-encoded data in the tar archive.
func (sfr *sparseFileReader) numBytes() int64 {
return sfr.rfr.numBytes()
}

20
vendor/github.com/dmcgowan/go-tar/stat_atim.go generated vendored Normal file
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@ -0,0 +1,20 @@
// Copyright 2012 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.
// +build linux dragonfly openbsd solaris
package tar
import (
"syscall"
"time"
)
func statAtime(st *syscall.Stat_t) time.Time {
return time.Unix(st.Atim.Unix())
}
func statCtime(st *syscall.Stat_t) time.Time {
return time.Unix(st.Ctim.Unix())
}

20
vendor/github.com/dmcgowan/go-tar/stat_atimespec.go generated vendored Normal file
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@ -0,0 +1,20 @@
// Copyright 2012 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.
// +build darwin freebsd netbsd
package tar
import (
"syscall"
"time"
)
func statAtime(st *syscall.Stat_t) time.Time {
return time.Unix(st.Atimespec.Unix())
}
func statCtime(st *syscall.Stat_t) time.Time {
return time.Unix(st.Ctimespec.Unix())
}

32
vendor/github.com/dmcgowan/go-tar/stat_unix.go generated vendored Normal file
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@ -0,0 +1,32 @@
// Copyright 2012 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.
// +build linux darwin dragonfly freebsd openbsd netbsd solaris
package tar
import (
"os"
"syscall"
)
func init() {
sysStat = statUnix
}
func statUnix(fi os.FileInfo, h *Header) error {
sys, ok := fi.Sys().(*syscall.Stat_t)
if !ok {
return nil
}
h.Uid = int(sys.Uid)
h.Gid = int(sys.Gid)
// TODO(bradfitz): populate username & group. os/user
// doesn't cache LookupId lookups, and lacks group
// lookup functions.
h.AccessTime = statAtime(sys)
h.ChangeTime = statCtime(sys)
// TODO(bradfitz): major/minor device numbers?
return nil
}

252
vendor/github.com/dmcgowan/go-tar/strconv.go generated vendored Normal file
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// Copyright 2016 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
import (
"bytes"
"fmt"
"strconv"
"strings"
"time"
)
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()
}
type parser struct {
err error // Last error seen
}
type formatter struct {
err error // Last error seen
}
// parseString parses bytes as a NUL-terminated C-style string.
// If a NUL byte is not found then the whole slice is returned as a string.
func (*parser) parseString(b []byte) string {
n := 0
for n < len(b) && b[n] != 0 {
n++
}
return string(b[0:n])
}
// Write s into b, terminating it with a NUL if there is room.
func (f *formatter) formatString(b []byte, s string) {
if len(s) > len(b) {
f.err = ErrFieldTooLong
return
}
ascii := toASCII(s)
copy(b, ascii)
if len(ascii) < len(b) {
b[len(ascii)] = 0
}
}
// fitsInBase256 reports whether x can be encoded into n bytes using base-256
// encoding. Unlike octal encoding, base-256 encoding does not require that the
// string ends with a NUL character. Thus, all n bytes are available for output.
//
// If operating in binary mode, this assumes strict GNU binary mode; which means
// that the first byte can only be either 0x80 or 0xff. Thus, the first byte is
// equivalent to the sign bit in two's complement form.
func fitsInBase256(n int, x int64) bool {
var binBits = uint(n-1) * 8
return n >= 9 || (x >= -1<<binBits && x < 1<<binBits)
}
// parseNumeric parses the input as being encoded in either base-256 or octal.
// This function may return negative numbers.
// If parsing fails or an integer overflow occurs, err will be set.
func (p *parser) parseNumeric(b []byte) int64 {
// Check for base-256 (binary) format first.
// If the first bit is set, then all following bits constitute a two's
// complement encoded number in big-endian byte order.
if len(b) > 0 && b[0]&0x80 != 0 {
// Handling negative numbers relies on the following identity:
// -a-1 == ^a
//
// If the number is negative, we use an inversion mask to invert the
// data bytes and treat the value as an unsigned number.
var inv byte // 0x00 if positive or zero, 0xff if negative
if b[0]&0x40 != 0 {
inv = 0xff
}
var x uint64
for i, c := range b {
c ^= inv // Inverts c only if inv is 0xff, otherwise does nothing
if i == 0 {
c &= 0x7f // Ignore signal bit in first byte
}
if (x >> 56) > 0 {
p.err = ErrHeader // Integer overflow
return 0
}
x = x<<8 | uint64(c)
}
if (x >> 63) > 0 {
p.err = ErrHeader // Integer overflow
return 0
}
if inv == 0xff {
return ^int64(x)
}
return int64(x)
}
// Normal case is base-8 (octal) format.
return p.parseOctal(b)
}
// Write x into b, as binary (GNUtar/star extension).
func (f *formatter) formatNumeric(b []byte, x int64) {
if fitsInBase256(len(b), x) {
for i := len(b) - 1; i >= 0; i-- {
b[i] = byte(x)
x >>= 8
}
b[0] |= 0x80 // Highest bit indicates binary format
return
}
f.formatOctal(b, 0) // Last resort, just write zero
f.err = ErrFieldTooLong
}
func (p *parser) parseOctal(b []byte) int64 {
// Because unused fields are filled with NULs, we need
// to skip leading NULs. Fields may also be padded with
// spaces or NULs.
// So we remove leading and trailing NULs and spaces to
// be sure.
b = bytes.Trim(b, " \x00")
if len(b) == 0 {
return 0
}
x, perr := strconv.ParseUint(p.parseString(b), 8, 64)
if perr != nil {
p.err = ErrHeader
}
return int64(x)
}
func (f *formatter) formatOctal(b []byte, x int64) {
s := strconv.FormatInt(x, 8)
// Add leading zeros, but leave room for a NUL.
if n := len(b) - len(s) - 1; n > 0 {
s = strings.Repeat("0", n) + s
}
f.formatString(b, s)
}
// parsePAXTime takes a string of the form %d.%d as described in the PAX
// specification. Note that this implementation allows for negative timestamps,
// which is allowed for by the PAX specification, but not always portable.
func parsePAXTime(s string) (time.Time, error) {
const maxNanoSecondDigits = 9
// Split string into seconds and sub-seconds parts.
ss, sn := s, ""
if pos := strings.IndexByte(s, '.'); pos >= 0 {
ss, sn = s[:pos], s[pos+1:]
}
// Parse the seconds.
secs, err := strconv.ParseInt(ss, 10, 64)
if err != nil {
return time.Time{}, ErrHeader
}
if len(sn) == 0 {
return time.Unix(secs, 0), nil // No sub-second values
}
// Parse the nanoseconds.
if strings.Trim(sn, "0123456789") != "" {
return time.Time{}, ErrHeader
}
if len(sn) < maxNanoSecondDigits {
sn += strings.Repeat("0", maxNanoSecondDigits-len(sn)) // Right pad
} else {
sn = sn[:maxNanoSecondDigits] // Right truncate
}
nsecs, _ := strconv.ParseInt(sn, 10, 64) // Must succeed
if len(ss) > 0 && ss[0] == '-' {
return time.Unix(secs, -1*int64(nsecs)), nil // Negative correction
}
return time.Unix(secs, int64(nsecs)), nil
}
// TODO(dsnet): Implement formatPAXTime.
// parsePAXRecord parses the input PAX record string into a key-value pair.
// If parsing is successful, it will slice off the currently read record and
// return the remainder as r.
//
// A PAX record is of the following form:
// "%d %s=%s\n" % (size, key, value)
func parsePAXRecord(s string) (k, v, r string, err error) {
// The size field ends at the first space.
sp := strings.IndexByte(s, ' ')
if sp == -1 {
return "", "", s, ErrHeader
}
// Parse the first token as a decimal integer.
n, perr := strconv.ParseInt(s[:sp], 10, 0) // Intentionally parse as native int
if perr != nil || n < 5 || int64(len(s)) < n {
return "", "", s, ErrHeader
}
// Extract everything between the space and the final newline.
rec, nl, rem := s[sp+1:n-1], s[n-1:n], s[n:]
if nl != "\n" {
return "", "", s, ErrHeader
}
// The first equals separates the key from the value.
eq := strings.IndexByte(rec, '=')
if eq == -1 {
return "", "", s, ErrHeader
}
return rec[:eq], rec[eq+1:], rem, nil
}
// formatPAXRecord formats a single PAX record, prefixing it with the
// appropriate length.
func formatPAXRecord(k, v string) string {
const padding = 3 // Extra padding for ' ', '=', and '\n'
size := len(k) + len(v) + padding
size += len(strconv.Itoa(size))
record := fmt.Sprintf("%d %s=%s\n", size, k, v)
// Final adjustment if adding size field increased the record size.
if len(record) != size {
size = len(record)
record = fmt.Sprintf("%d %s=%s\n", size, k, v)
}
return record
}

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vendor/github.com/dmcgowan/go-tar/writer.go generated vendored Normal file
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@ -0,0 +1,364 @@
// 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
// TODO(dsymonds):
// - catch more errors (no first header, etc.)
import (
"bytes"
"errors"
"fmt"
"io"
"path"
"sort"
"strconv"
"strings"
"time"
)
var (
ErrWriteTooLong = errors.New("archive/tar: write too long")
ErrFieldTooLong = errors.New("archive/tar: header field too long")
ErrWriteAfterClose = errors.New("archive/tar: write after close")
errInvalidHeader = errors.New("archive/tar: header field too long or contains invalid values")
)
// A Writer provides sequential writing of a tar archive in POSIX.1 format.
// A tar archive consists of a sequence of files.
// Call WriteHeader to begin a new file, and then call Write to supply that file's data,
// writing at most hdr.Size bytes in total.
type Writer struct {
w io.Writer
err error
nb int64 // number of unwritten bytes for current file entry
pad int64 // amount of padding to write after current file entry
closed bool
usedBinary bool // whether the binary numeric field extension was used
preferPax bool // use PAX header instead of binary numeric header
hdrBuff block // buffer to use in writeHeader when writing a regular header
paxHdrBuff block // buffer to use in writeHeader when writing a PAX header
}
// NewWriter creates a new Writer writing to w.
func NewWriter(w io.Writer) *Writer { return &Writer{w: w} }
// Flush finishes writing the current file (optional).
func (tw *Writer) Flush() error {
if tw.nb > 0 {
tw.err = fmt.Errorf("archive/tar: missed writing %d bytes", tw.nb)
return tw.err
}
n := tw.nb + tw.pad
for n > 0 && tw.err == nil {
nr := n
if nr > blockSize {
nr = blockSize
}
var nw int
nw, tw.err = tw.w.Write(zeroBlock[0:nr])
n -= int64(nw)
}
tw.nb = 0
tw.pad = 0
return tw.err
}
var (
minTime = time.Unix(0, 0)
// There is room for 11 octal digits (33 bits) of mtime.
maxTime = minTime.Add((1<<33 - 1) * time.Second)
)
// WriteHeader writes hdr and prepares to accept the file's contents.
// WriteHeader calls Flush if it is not the first header.
// Calling after a Close will return ErrWriteAfterClose.
func (tw *Writer) WriteHeader(hdr *Header) error {
return tw.writeHeader(hdr, true)
}
// WriteHeader writes hdr and prepares to accept the file's contents.
// WriteHeader calls Flush if it is not the first header.
// Calling after a Close will return ErrWriteAfterClose.
// As this method is called internally by writePax header to allow it to
// suppress writing the pax header.
func (tw *Writer) writeHeader(hdr *Header, allowPax bool) error {
if tw.closed {
return ErrWriteAfterClose
}
if tw.err == nil {
tw.Flush()
}
if tw.err != nil {
return tw.err
}
// a map to hold pax header records, if any are needed
paxHeaders := make(map[string]string)
// TODO(dsnet): we might want to use PAX headers for
// subsecond time resolution, but for now let's just capture
// too long fields or non ascii characters
// We need to select which scratch buffer to use carefully,
// since this method is called recursively to write PAX headers.
// If allowPax is true, this is the non-recursive call, and we will use hdrBuff.
// If allowPax is false, we are being called by writePAXHeader, and hdrBuff is
// already being used by the non-recursive call, so we must use paxHdrBuff.
header := &tw.hdrBuff
if !allowPax {
header = &tw.paxHdrBuff
}
copy(header[:], zeroBlock[:])
// Wrappers around formatter that automatically sets paxHeaders if the
// argument extends beyond the capacity of the input byte slice.
var f formatter
var formatString = func(b []byte, s string, paxKeyword string) {
needsPaxHeader := paxKeyword != paxNone && len(s) > len(b) || !isASCII(s)
if needsPaxHeader {
paxHeaders[paxKeyword] = s
return
}
f.formatString(b, s)
}
var formatNumeric = func(b []byte, x int64, paxKeyword string) {
// Try octal first.
s := strconv.FormatInt(x, 8)
if len(s) < len(b) {
f.formatOctal(b, x)
return
}
// If it is too long for octal, and PAX is preferred, use a PAX header.
if paxKeyword != paxNone && tw.preferPax {
f.formatOctal(b, 0)
s := strconv.FormatInt(x, 10)
paxHeaders[paxKeyword] = s
return
}
tw.usedBinary = true
f.formatNumeric(b, x)
}
// Handle out of range ModTime carefully.
var modTime int64
if !hdr.ModTime.Before(minTime) && !hdr.ModTime.After(maxTime) {
modTime = hdr.ModTime.Unix()
}
v7 := header.V7()
formatString(v7.Name(), hdr.Name, paxPath)
// TODO(dsnet): The GNU format permits the mode field to be encoded in
// base-256 format. Thus, we can use formatNumeric instead of formatOctal.
f.formatOctal(v7.Mode(), hdr.Mode)
formatNumeric(v7.UID(), int64(hdr.Uid), paxUid)
formatNumeric(v7.GID(), int64(hdr.Gid), paxGid)
formatNumeric(v7.Size(), hdr.Size, paxSize)
// TODO(dsnet): Consider using PAX for finer time granularity.
formatNumeric(v7.ModTime(), modTime, paxNone)
v7.TypeFlag()[0] = hdr.Typeflag
formatString(v7.LinkName(), hdr.Linkname, paxLinkpath)
ustar := header.USTAR()
formatString(ustar.UserName(), hdr.Uname, paxUname)
formatString(ustar.GroupName(), hdr.Gname, paxGname)
formatNumeric(ustar.DevMajor(), hdr.Devmajor, paxNone)
formatNumeric(ustar.DevMinor(), hdr.Devminor, paxNone)
// TODO(dsnet): The logic surrounding the prefix field is broken when trying
// to encode the header as GNU format. The challenge with the current logic
// is that we are unsure what format we are using at any given moment until
// we have processed *all* of the fields. The problem is that by the time
// all fields have been processed, some work has already been done to handle
// each field under the assumption that it is for one given format or
// another. In some situations, this causes the Writer to be confused and
// encode a prefix field when the format being used is GNU. Thus, producing
// an invalid tar file.
//
// As a short-term fix, we disable the logic to use the prefix field, which
// will force the badly generated GNU files to become encoded as being
// the PAX format.
//
// As an alternative fix, we could hard-code preferPax to be true. However,
// this is problematic for the following reasons:
// * The preferPax functionality is not tested at all.
// * This can result in headers that try to use both the GNU and PAX
// features at the same time, which is also wrong.
//
// The proper fix for this is to use a two-pass method:
// * The first pass simply determines what set of formats can possibly
// encode the given header.
// * The second pass actually encodes the header as that given format
// without worrying about violating the format.
//
// See the following:
// https://golang.org/issue/12594
// https://golang.org/issue/17630
// https://golang.org/issue/9683
const usePrefix = false
// try to use a ustar header when only the name is too long
_, paxPathUsed := paxHeaders[paxPath]
if usePrefix && !tw.preferPax && len(paxHeaders) == 1 && paxPathUsed {
prefix, suffix, ok := splitUSTARPath(hdr.Name)
if ok {
// Since we can encode in USTAR format, disable PAX header.
delete(paxHeaders, paxPath)
// Update the path fields
formatString(v7.Name(), suffix, paxNone)
formatString(ustar.Prefix(), prefix, paxNone)
}
}
if tw.usedBinary {
header.SetFormat(formatGNU)
} else {
header.SetFormat(formatUSTAR)
}
// Check if there were any formatting errors.
if f.err != nil {
tw.err = f.err
return tw.err
}
if allowPax {
for k, v := range hdr.Xattrs {
paxHeaders[paxXattr+k] = v
}
}
if len(paxHeaders) > 0 {
if !allowPax {
return errInvalidHeader
}
if err := tw.writePAXHeader(hdr, paxHeaders); err != nil {
return err
}
}
tw.nb = hdr.Size
tw.pad = (blockSize - (tw.nb % blockSize)) % blockSize
_, tw.err = tw.w.Write(header[:])
return tw.err
}
// splitUSTARPath splits a path according to USTAR prefix and suffix rules.
// If the path is not splittable, then it will return ("", "", false).
func splitUSTARPath(name string) (prefix, suffix string, ok bool) {
length := len(name)
if length <= nameSize || !isASCII(name) {
return "", "", false
} else if length > prefixSize+1 {
length = prefixSize + 1
} else if name[length-1] == '/' {
length--
}
i := strings.LastIndex(name[:length], "/")
nlen := len(name) - i - 1 // nlen is length of suffix
plen := i // plen is length of prefix
if i <= 0 || nlen > nameSize || nlen == 0 || plen > prefixSize {
return "", "", false
}
return name[:i], name[i+1:], true
}
// writePaxHeader writes an extended pax header to the
// archive.
func (tw *Writer) writePAXHeader(hdr *Header, paxHeaders map[string]string) error {
// Prepare extended header
ext := new(Header)
ext.Typeflag = TypeXHeader
// Setting ModTime is required for reader parsing to
// succeed, and seems harmless enough.
ext.ModTime = hdr.ModTime
// The spec asks that we namespace our pseudo files
// with the current pid. However, this results in differing outputs
// for identical inputs. As such, the constant 0 is now used instead.
// golang.org/issue/12358
dir, file := path.Split(hdr.Name)
fullName := path.Join(dir, "PaxHeaders.0", file)
ascii := toASCII(fullName)
if len(ascii) > nameSize {
ascii = ascii[:nameSize]
}
ext.Name = ascii
// Construct the body
var buf bytes.Buffer
// Keys are sorted before writing to body to allow deterministic output.
keys := make([]string, 0, len(paxHeaders))
for k := range paxHeaders {
keys = append(keys, k)
}
sort.Strings(keys)
for _, k := range keys {
fmt.Fprint(&buf, formatPAXRecord(k, paxHeaders[k]))
}
ext.Size = int64(len(buf.Bytes()))
if err := tw.writeHeader(ext, false); err != nil {
return err
}
if _, err := tw.Write(buf.Bytes()); err != nil {
return err
}
if err := tw.Flush(); err != nil {
return err
}
return nil
}
// Write writes to the current entry in the tar archive.
// Write returns the error ErrWriteTooLong if more than
// hdr.Size bytes are written after WriteHeader.
func (tw *Writer) Write(b []byte) (n int, err error) {
if tw.closed {
err = ErrWriteAfterClose
return
}
overwrite := false
if int64(len(b)) > tw.nb {
b = b[0:tw.nb]
overwrite = true
}
n, err = tw.w.Write(b)
tw.nb -= int64(n)
if err == nil && overwrite {
err = ErrWriteTooLong
return
}
tw.err = err
return
}
// Close closes the tar archive, flushing any unwritten
// data to the underlying writer.
func (tw *Writer) Close() error {
if tw.err != nil || tw.closed {
return tw.err
}
tw.Flush()
tw.closed = true
if tw.err != nil {
return tw.err
}
// trailer: two zero blocks
for i := 0; i < 2; i++ {
_, tw.err = tw.w.Write(zeroBlock[:])
if tw.err != nil {
break
}
}
return tw.err
}