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vendor: add archive/tar

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Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
This commit is contained in:
Tonis Tiigi 2017-07-13 18:17:16 -07:00
parent f22cecf929
commit 72df48d1ad
10 changed files with 1980 additions and 0 deletions
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1
Dockerfile
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@ -107,6 +107,7 @@ RUN set -x \
# IMPORTANT: If the version of Go is updated, the Windows to Linux CI machines
# will need updating, to avoid errors. Ping #docker-maintainers on IRC
# with a heads-up.
# IMPORTANT: When updating this please note that stdlib archive/tar pkg is vendored
ENV GO_VERSION 1.8.3
RUN curl -fsSL "https://golang.org/dl/go${GO_VERSION}.linux-amd64.tar.gz" \
| tar -xzC /usr/local

8
vendor.conf
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@ -136,3 +136,11 @@ github.com/Nvveen/Gotty a8b993ba6abdb0e0c12b0125c603323a71c7790c https://github.
github.com/docker/go-metrics d466d4f6fd960e01820085bd7e1a24426ee7ef18
github.com/opencontainers/selinux v1.0.0-rc1
# archive/tar
# mkdir -p ./vendor/archive
# git clone git://github.com/tonistiigi/go-1.git ./go
# git --git-dir ./go/.git --work-tree ./go checkout revert-prefix-ignore
# cp -a go/src/archive/tar ./vendor/archive/tar
# rm -rf ./go
# vndr

286
vendor/archive/tar/common.go 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/archive/tar/format.go 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/archive/tar/reader.go vendored Normal file
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@ -0,0 +1,800 @@
// 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()
}

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// 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/archive/tar/stat_atimespec.go vendored Normal file
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// 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
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// 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
}

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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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// 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
}