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Merge pull request #48 from kolyshkin/go111 

rebase to go-1.11's archive/tar
This commit is contained in:
Vincent Batts 2018-09-06 08:34:40 -04:00 committed by GitHub
parent e489928272 3a386a2750
commit 61b49a82bb
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38 changed files with 5820 additions and 2618 deletions
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7
.travis.yml
View File

@ -1,11 +1,8 @@
language: go
go:
- tip
- 1.x
- 1.8.x
- 1.7.x
- 1.6.x
- 1.5.x
- 1.11.x
- 1.10.x
# let us have pretty, fast Docker-based Travis workers!
sudo: false

3
README.md
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@ -67,7 +67,7 @@ Do not break the API of stdlib `archive/tar` in our fork (ideally find an upstre
## Std Version
The version of golang stdlib `archive/tar` is from go1.6
The version of golang stdlib `archive/tar` is from go1.11
It is minimally extended to expose the raw bytes of the TAR, rather than just the marshalled headers and file stream.
@ -135,4 +135,3 @@ bytes-per-file rate for the storage implications.
## License
See [LICENSE](LICENSE)

689
archive/tar/common.go
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@ -3,70 +3,528 @@
// 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
// Tape archives (tar) are a file format for storing a sequence of files that
// can be read and written in a streaming manner.
// This package aims to cover most variations of the format,
// including those produced by GNU and BSD tar tools.
package tar
import (
"bytes"
"errors"
"fmt"
"math"
"os"
"path"
"reflect"
"strconv"
"strings"
"time"
)
const (
blockSize = 512
// 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.
// Types
TypeReg = '0' // regular file
TypeRegA = '\x00' // regular file
TypeLink = '1' // hard link
TypeSymlink = '2' // symbolic link
TypeChar = '3' // character device node
TypeBlock = '4' // block device node
TypeDir = '5' // directory
TypeFifo = '6' // fifo node
TypeCont = '7' // reserved
TypeXHeader = 'x' // extended header
TypeXGlobalHeader = 'g' // global extended header
TypeGNULongName = 'L' // Next file has a long name
TypeGNULongLink = 'K' // Next file symlinks to a file w/ a long name
TypeGNUSparse = 'S' // sparse file
var (
ErrHeader = errors.New("archive/tar: invalid tar header")
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")
errMissData = errors.New("archive/tar: sparse file references non-existent data")
errUnrefData = errors.New("archive/tar: sparse file contains unreferenced data")
errWriteHole = errors.New("archive/tar: write non-NUL byte in sparse hole")
)
type headerError []string
func (he headerError) Error() string {
const prefix = "archive/tar: cannot encode header"
var ss []string
for _, s := range he {
if s != "" {
ss = append(ss, s)
}
}
if len(ss) == 0 {
return prefix
}
return fmt.Sprintf("%s: %v", prefix, strings.Join(ss, "; and "))
}
// Type flags for Header.Typeflag.
const (
// Type '0' indicates a regular file.
TypeReg = '0'
TypeRegA = '\x00' // Deprecated: Use TypeReg instead.
// Type '1' to '6' are header-only flags and may not have a data body.
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
// Type '7' is reserved.
TypeCont = '7'
// Type 'x' is used by the PAX format to store key-value records that
// are only relevant to the next file.
// This package transparently handles these types.
TypeXHeader = 'x'
// Type 'g' is used by the PAX format to store key-value records that
// are relevant to all subsequent files.
// This package only supports parsing and composing such headers,
// but does not currently support persisting the global state across files.
TypeXGlobalHeader = 'g'
// Type 'S' indicates a sparse file in the GNU format.
TypeGNUSparse = 'S'
// Types 'L' and 'K' are used by the GNU format for a meta file
// used to store the path or link name for the next file.
// This package transparently handles these types.
TypeGNULongName = 'L'
TypeGNULongLink = 'K'
)
// Keywords for PAX extended header records.
const (
paxNone = "" // Indicates that no PAX key is suitable
paxPath = "path"
paxLinkpath = "linkpath"
paxSize = "size"
paxUid = "uid"
paxGid = "gid"
paxUname = "uname"
paxGname = "gname"
paxMtime = "mtime"
paxAtime = "atime"
paxCtime = "ctime" // Removed from later revision of PAX spec, but was valid
paxCharset = "charset" // Currently unused
paxComment = "comment" // Currently unused
paxSchilyXattr = "SCHILY.xattr."
// Keywords for GNU sparse files in a PAX extended header.
paxGNUSparse = "GNU.sparse."
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"
)
// basicKeys is a set of the PAX keys for which we have built-in support.
// This does not contain "charset" or "comment", which are both PAX-specific,
// so adding them as first-class features of Header is unlikely.
// Users can use the PAXRecords field to set it themselves.
var basicKeys = map[string]bool{
paxPath: true, paxLinkpath: true, paxSize: true, paxUid: true, paxGid: true,
paxUname: true, paxGname: true, paxMtime: true, paxAtime: true, paxCtime: true,
}
// A Header represents a single header in a tar archive.
// Some fields may not be populated.
//
// For forward compatibility, users that retrieve a Header from Reader.Next,
// mutate it in some ways, and then pass it back to Writer.WriteHeader
// should do so by creating a new Header and copying the fields
// that they are interested in preserving.
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
// Typeflag is the type of header entry.
// The zero value is automatically promoted to either TypeReg or TypeDir
// depending on the presence of a trailing slash in Name.
Typeflag byte
Name string // Name of file entry
Linkname string // Target name of link (valid for TypeLink or TypeSymlink)
Size int64 // Logical file size in bytes
Mode int64 // Permission and mode bits
Uid int // User ID of owner
Gid int // Group ID of owner
Uname string // User name of owner
Gname string // Group name of owner
// If the Format is unspecified, then Writer.WriteHeader rounds ModTime
// to the nearest second and ignores the AccessTime and ChangeTime fields.
//
// To use AccessTime or ChangeTime, specify the Format as PAX or GNU.
// To use sub-second resolution, specify the Format as PAX.
ModTime time.Time // Modification time
AccessTime time.Time // Access time (requires either PAX or GNU support)
ChangeTime time.Time // Change time (requires either PAX or GNU support)
Devmajor int64 // Major device number (valid for TypeChar or TypeBlock)
Devminor int64 // Minor device number (valid for TypeChar or TypeBlock)
// Xattrs stores extended attributes as PAX records under the
// "SCHILY.xattr." namespace.
//
// The following are semantically equivalent:
// h.Xattrs[key] = value
// h.PAXRecords["SCHILY.xattr."+key] = value
//
// When Writer.WriteHeader is called, the contents of Xattrs will take
// precedence over those in PAXRecords.
//
// Deprecated: Use PAXRecords instead.
Xattrs map[string]string
// PAXRecords is a map of PAX extended header records.
//
// User-defined records should have keys of the following form:
// VENDOR.keyword
// Where VENDOR is some namespace in all uppercase, and keyword may
// not contain the '=' character (e.g., "GOLANG.pkg.version").
// The key and value should be non-empty UTF-8 strings.
//
// When Writer.WriteHeader is called, PAX records derived from the
// other fields in Header take precedence over PAXRecords.
PAXRecords map[string]string
// Format specifies the format of the tar header.
//
// This is set by Reader.Next as a best-effort guess at the format.
// Since the Reader liberally reads some non-compliant files,
// it is possible for this to be FormatUnknown.
//
// If the format is unspecified when Writer.WriteHeader is called,
// then it uses the first format (in the order of USTAR, PAX, GNU)
// capable of encoding this Header (see Format).
Format Format
}
// File name constants from the tar spec.
const (
fileNameSize = 100 // Maximum number of bytes in a standard tar name.
fileNamePrefixSize = 155 // Maximum number of ustar extension bytes.
// sparseEntry represents a Length-sized fragment at Offset in the file.
type sparseEntry struct{ Offset, Length int64 }
func (s sparseEntry) endOffset() int64 { return s.Offset + s.Length }
// A sparse file can be represented as either a sparseDatas or a sparseHoles.
// As long as the total size is known, they are equivalent and one can be
// converted to the other form and back. The various tar formats with sparse
// file support represent sparse files in the sparseDatas form. That is, they
// specify the fragments in the file that has data, and treat everything else as
// having zero bytes. As such, the encoding and decoding logic in this package
// deals with sparseDatas.
//
// However, the external API uses sparseHoles instead of sparseDatas because the
// zero value of sparseHoles logically represents a normal file (i.e., there are
// no holes in it). On the other hand, the zero value of sparseDatas implies
// that the file has no data in it, which is rather odd.
//
// As an example, if the underlying raw file contains the 10-byte data:
// var compactFile = "abcdefgh"
//
// And the sparse map has the following entries:
// var spd sparseDatas = []sparseEntry{
// {Offset: 2, Length: 5}, // Data fragment for 2..6
// {Offset: 18, Length: 3}, // Data fragment for 18..20
// }
// var sph sparseHoles = []sparseEntry{
// {Offset: 0, Length: 2}, // Hole fragment for 0..1
// {Offset: 7, Length: 11}, // Hole fragment for 7..17
// {Offset: 21, Length: 4}, // Hole fragment for 21..24
// }
//
// Then the content of the resulting sparse file with a Header.Size of 25 is:
// var sparseFile = "\x00"*2 + "abcde" + "\x00"*11 + "fgh" + "\x00"*4
type (
sparseDatas []sparseEntry
sparseHoles []sparseEntry
)
// validateSparseEntries reports whether sp is a valid sparse map.
// It does not matter whether sp represents data fragments or hole fragments.
func validateSparseEntries(sp []sparseEntry, size int64) bool {
// Validate all sparse entries. These are the same checks as performed by
// the BSD tar utility.
if size < 0 {
return false
}
var pre sparseEntry
for _, cur := range sp {
switch {
case cur.Offset < 0 || cur.Length < 0:
return false // Negative values are never okay
case cur.Offset > math.MaxInt64-cur.Length:
return false // Integer overflow with large length
case cur.endOffset() > size:
return false // Region extends beyond the actual size
case pre.endOffset() > cur.Offset:
return false // Regions cannot overlap and must be in order
}
pre = cur
}
return true
}
// alignSparseEntries mutates src and returns dst where each fragment's
// starting offset is aligned up to the nearest block edge, and each
// ending offset is aligned down to the nearest block edge.
//
// Even though the Go tar Reader and the BSD tar utility can handle entries
// with arbitrary offsets and lengths, the GNU tar utility can only handle
// offsets and lengths that are multiples of blockSize.
func alignSparseEntries(src []sparseEntry, size int64) []sparseEntry {
dst := src[:0]
for _, s := range src {
pos, end := s.Offset, s.endOffset()
pos += blockPadding(+pos) // Round-up to nearest blockSize
if end != size {
end -= blockPadding(-end) // Round-down to nearest blockSize
}
if pos < end {
dst = append(dst, sparseEntry{Offset: pos, Length: end - pos})
}
}
return dst
}
// invertSparseEntries converts a sparse map from one form to the other.
// If the input is sparseHoles, then it will output sparseDatas and vice-versa.
// The input must have been already validated.
//
// This function mutates src and returns a normalized map where:
// * adjacent fragments are coalesced together
// * only the last fragment may be empty
// * the endOffset of the last fragment is the total size
func invertSparseEntries(src []sparseEntry, size int64) []sparseEntry {
dst := src[:0]
var pre sparseEntry
for _, cur := range src {
if cur.Length == 0 {
continue // Skip empty fragments
}
pre.Length = cur.Offset - pre.Offset
if pre.Length > 0 {
dst = append(dst, pre) // Only add non-empty fragments
}
pre.Offset = cur.endOffset()
}
pre.Length = size - pre.Offset // Possibly the only empty fragment
return append(dst, pre)
}
// fileState tracks the number of logical (includes sparse holes) and physical
// (actual in tar archive) bytes remaining for the current file.
//
// Invariant: LogicalRemaining >= PhysicalRemaining
type fileState interface {
LogicalRemaining() int64
PhysicalRemaining() int64
}
// allowedFormats determines which formats can be used.
// The value returned is the logical OR of multiple possible formats.
// If the value is FormatUnknown, then the input Header cannot be encoded
// and an error is returned explaining why.
//
// As a by-product of checking the fields, this function returns paxHdrs, which
// contain all fields that could not be directly encoded.
// A value receiver ensures that this method does not mutate the source Header.
func (h Header) allowedFormats() (format Format, paxHdrs map[string]string, err error) {
format = FormatUSTAR | FormatPAX | FormatGNU
paxHdrs = make(map[string]string)
var whyNoUSTAR, whyNoPAX, whyNoGNU string
var preferPAX bool // Prefer PAX over USTAR
verifyString := func(s string, size int, name, paxKey string) {
// NUL-terminator is optional for path and linkpath.
// Technically, it is required for uname and gname,
// but neither GNU nor BSD tar checks for it.
tooLong := len(s) > size
allowLongGNU := paxKey == paxPath || paxKey == paxLinkpath
if hasNUL(s) || (tooLong && !allowLongGNU) {
whyNoGNU = fmt.Sprintf("GNU cannot encode %s=%q", name, s)
format.mustNotBe(FormatGNU)
}
if !isASCII(s) || tooLong {
canSplitUSTAR := paxKey == paxPath
if _, _, ok := splitUSTARPath(s); !canSplitUSTAR || !ok {
whyNoUSTAR = fmt.Sprintf("USTAR cannot encode %s=%q", name, s)
format.mustNotBe(FormatUSTAR)
}
if paxKey == paxNone {
whyNoPAX = fmt.Sprintf("PAX cannot encode %s=%q", name, s)
format.mustNotBe(FormatPAX)
} else {
paxHdrs[paxKey] = s
}
}
if v, ok := h.PAXRecords[paxKey]; ok && v == s {
paxHdrs[paxKey] = v
}
}
verifyNumeric := func(n int64, size int, name, paxKey string) {
if !fitsInBase256(size, n) {
whyNoGNU = fmt.Sprintf("GNU cannot encode %s=%d", name, n)
format.mustNotBe(FormatGNU)
}
if !fitsInOctal(size, n) {
whyNoUSTAR = fmt.Sprintf("USTAR cannot encode %s=%d", name, n)
format.mustNotBe(FormatUSTAR)
if paxKey == paxNone {
whyNoPAX = fmt.Sprintf("PAX cannot encode %s=%d", name, n)
format.mustNotBe(FormatPAX)
} else {
paxHdrs[paxKey] = strconv.FormatInt(n, 10)
}
}
if v, ok := h.PAXRecords[paxKey]; ok && v == strconv.FormatInt(n, 10) {
paxHdrs[paxKey] = v
}
}
verifyTime := func(ts time.Time, size int, name, paxKey string) {
if ts.IsZero() {
return // Always okay
}
if !fitsInBase256(size, ts.Unix()) {
whyNoGNU = fmt.Sprintf("GNU cannot encode %s=%v", name, ts)
format.mustNotBe(FormatGNU)
}
isMtime := paxKey == paxMtime
fitsOctal := fitsInOctal(size, ts.Unix())
if (isMtime && !fitsOctal) || !isMtime {
whyNoUSTAR = fmt.Sprintf("USTAR cannot encode %s=%v", name, ts)
format.mustNotBe(FormatUSTAR)
}
needsNano := ts.Nanosecond() != 0
if !isMtime || !fitsOctal || needsNano {
preferPAX = true // USTAR may truncate sub-second measurements
if paxKey == paxNone {
whyNoPAX = fmt.Sprintf("PAX cannot encode %s=%v", name, ts)
format.mustNotBe(FormatPAX)
} else {
paxHdrs[paxKey] = formatPAXTime(ts)
}
}
if v, ok := h.PAXRecords[paxKey]; ok && v == formatPAXTime(ts) {
paxHdrs[paxKey] = v
}
}
// Check basic fields.
var blk block
v7 := blk.V7()
ustar := blk.USTAR()
gnu := blk.GNU()
verifyString(h.Name, len(v7.Name()), "Name", paxPath)
verifyString(h.Linkname, len(v7.LinkName()), "Linkname", paxLinkpath)
verifyString(h.Uname, len(ustar.UserName()), "Uname", paxUname)
verifyString(h.Gname, len(ustar.GroupName()), "Gname", paxGname)
verifyNumeric(h.Mode, len(v7.Mode()), "Mode", paxNone)
verifyNumeric(int64(h.Uid), len(v7.UID()), "Uid", paxUid)
verifyNumeric(int64(h.Gid), len(v7.GID()), "Gid", paxGid)
verifyNumeric(h.Size, len(v7.Size()), "Size", paxSize)
verifyNumeric(h.Devmajor, len(ustar.DevMajor()), "Devmajor", paxNone)
verifyNumeric(h.Devminor, len(ustar.DevMinor()), "Devminor", paxNone)
verifyTime(h.ModTime, len(v7.ModTime()), "ModTime", paxMtime)
verifyTime(h.AccessTime, len(gnu.AccessTime()), "AccessTime", paxAtime)
verifyTime(h.ChangeTime, len(gnu.ChangeTime()), "ChangeTime", paxCtime)
// Check for header-only types.
var whyOnlyPAX, whyOnlyGNU string
switch h.Typeflag {
case TypeReg, TypeChar, TypeBlock, TypeFifo, TypeGNUSparse:
// Exclude TypeLink and TypeSymlink, since they may reference directories.
if strings.HasSuffix(h.Name, "/") {
return FormatUnknown, nil, headerError{"filename may not have trailing slash"}
}
case TypeXHeader, TypeGNULongName, TypeGNULongLink:
return FormatUnknown, nil, headerError{"cannot manually encode TypeXHeader, TypeGNULongName, or TypeGNULongLink headers"}
case TypeXGlobalHeader:
h2 := Header{Name: h.Name, Typeflag: h.Typeflag, Xattrs: h.Xattrs, PAXRecords: h.PAXRecords, Format: h.Format}
if !reflect.DeepEqual(h, h2) {
return FormatUnknown, nil, headerError{"only PAXRecords should be set for TypeXGlobalHeader"}
}
whyOnlyPAX = "only PAX supports TypeXGlobalHeader"
format.mayOnlyBe(FormatPAX)
}
if !isHeaderOnlyType(h.Typeflag) && h.Size < 0 {
return FormatUnknown, nil, headerError{"negative size on header-only type"}
}
// Check PAX records.
if len(h.Xattrs) > 0 {
for k, v := range h.Xattrs {
paxHdrs[paxSchilyXattr+k] = v
}
whyOnlyPAX = "only PAX supports Xattrs"
format.mayOnlyBe(FormatPAX)
}
if len(h.PAXRecords) > 0 {
for k, v := range h.PAXRecords {
switch _, exists := paxHdrs[k]; {
case exists:
continue // Do not overwrite existing records
case h.Typeflag == TypeXGlobalHeader:
paxHdrs[k] = v // Copy all records
case !basicKeys[k] && !strings.HasPrefix(k, paxGNUSparse):
paxHdrs[k] = v // Ignore local records that may conflict
}
}
whyOnlyPAX = "only PAX supports PAXRecords"
format.mayOnlyBe(FormatPAX)
}
for k, v := range paxHdrs {
if !validPAXRecord(k, v) {
return FormatUnknown, nil, headerError{fmt.Sprintf("invalid PAX record: %q", k+" = "+v)}
}
}
// TODO(dsnet): Re-enable this when adding sparse support.
// See https://golang.org/issue/22735
/*
// Check sparse files.
if len(h.SparseHoles) > 0 || h.Typeflag == TypeGNUSparse {
if isHeaderOnlyType(h.Typeflag) {
return FormatUnknown, nil, headerError{"header-only type cannot be sparse"}
}
if !validateSparseEntries(h.SparseHoles, h.Size) {
return FormatUnknown, nil, headerError{"invalid sparse holes"}
}
if h.Typeflag == TypeGNUSparse {
whyOnlyGNU = "only GNU supports TypeGNUSparse"
format.mayOnlyBe(FormatGNU)
} else {
whyNoGNU = "GNU supports sparse files only with TypeGNUSparse"
format.mustNotBe(FormatGNU)
}
whyNoUSTAR = "USTAR does not support sparse files"
format.mustNotBe(FormatUSTAR)
}
*/
// Check desired format.
if wantFormat := h.Format; wantFormat != FormatUnknown {
if wantFormat.has(FormatPAX) && !preferPAX {
wantFormat.mayBe(FormatUSTAR) // PAX implies USTAR allowed too
}
format.mayOnlyBe(wantFormat) // Set union of formats allowed and format wanted
}
if format == FormatUnknown {
switch h.Format {
case FormatUSTAR:
err = headerError{"Format specifies USTAR", whyNoUSTAR, whyOnlyPAX, whyOnlyGNU}
case FormatPAX:
err = headerError{"Format specifies PAX", whyNoPAX, whyOnlyGNU}
case FormatGNU:
err = headerError{"Format specifies GNU", whyNoGNU, whyOnlyPAX}
default:
err = headerError{whyNoUSTAR, whyNoPAX, whyNoGNU, whyOnlyPAX, whyOnlyGNU}
}
}
return format, paxHdrs, err
}
// FileInfo returns an os.FileInfo for the Header.
func (h *Header) FileInfo() os.FileInfo {
return headerFileInfo{h}
@ -97,63 +555,43 @@ func (fi headerFileInfo) Mode() (mode os.FileMode) {
// 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
// Set file mode bits; clear perm, setuid, setgid, and sticky bits.
switch m := os.FileMode(fi.h.Mode) &^ 07777; m {
case c_ISDIR:
mode |= os.ModeDir
}
if m == c_ISFIFO {
// named pipe (FIFO)
case c_ISFIFO:
mode |= os.ModeNamedPipe
}
if m == c_ISLNK {
// symbolic link
case c_ISLNK:
mode |= os.ModeSymlink
}
if m == c_ISBLK {
// device file
case c_ISBLK:
mode |= os.ModeDevice
}
if m == c_ISCHR {
// Unix character device
case c_ISCHR:
mode |= os.ModeDevice
mode |= os.ModeCharDevice
}
if m == c_ISSOCK {
// Unix domain socket
case c_ISSOCK:
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
}
@ -163,11 +601,15 @@ func (fi headerFileInfo) Mode() (mode os.FileMode) {
// 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)
// Mode constants from the USTAR spec:
// See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13_06
c_ISUID = 04000 // Set uid
c_ISGID = 02000 // Set gid
c_ISVTX = 01000 // Save text (sticky bit)
// Common Unix mode constants; these are not defined in any common tar standard.
// Header.FileInfo understands these, but FileInfoHeader will never produce these.
c_ISDIR = 040000 // Directory
c_ISFIFO = 010000 // FIFO
c_ISREG = 0100000 // Regular file
@ -177,33 +619,16 @@ const (
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.
//
// Since os.FileInfo's Name method only returns the base name of
// the file it describes, it may be necessary to modify Header.Name
// 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")
return nil, errors.New("archive/tar: FileInfo is nil")
}
fm := fi.Mode()
h := &Header{
@ -213,30 +638,24 @@ func FileInfoHeader(fi os.FileInfo, link string) (*Header, error) {
}
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
return nil, fmt.Errorf("archive/tar: sockets not supported")
default:
return nil, fmt.Errorf("archive/tar: unknown file mode %v", fm)
}
@ -272,6 +691,12 @@ func FileInfoHeader(fi os.FileInfo, link string) (*Header, error) {
h.Size = 0
h.Linkname = sys.Linkname
}
if sys.PAXRecords != nil {
h.PAXRecords = make(map[string]string)
for k, v := range sys.PAXRecords {
h.PAXRecords[k] = v
}
}
}
if sysStat != nil {
return h, sysStat(fi, h)
@ -279,55 +704,6 @@ func FileInfoHeader(fi os.FileInfo, link string) (*Header, error) {
return h, nil
}
var zeroBlock = make([]byte, blockSize)
// POSIX specifies a sum of the unsigned byte values, but the Sun tar uses signed byte values.
// We compute and return both.
func checksum(header []byte) (unsigned int64, signed int64) {
for i := 0; i < len(header); i++ {
if i == 148 {
// The chksum field (header[148:156]) is special: it should be treated as space bytes.
unsigned += ' ' * 8
signed += ' ' * 8
i += 7
continue
}
unsigned += int64(header[i])
signed += int64(int8(header[i]))
}
return
}
type slicer []byte
func (sp *slicer) next(n int) (b []byte) {
s := *sp
b, *sp = s[0:n], s[n:]
return
}
func isASCII(s string) bool {
for _, c := range s {
if c >= 0x80 {
return false
}
}
return true
}
func toASCII(s string) string {
if isASCII(s) {
return s
}
var buf bytes.Buffer
for _, c := range s {
if c < 0x80 {
buf.WriteByte(byte(c))
}
}
return buf.String()
}
// 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 {
@ -338,3 +714,10 @@ func isHeaderOnlyType(flag byte) bool {
return false
}
}
func min(a, b int64) int64 {
if a < b {
return a
}
return b
}

33
archive/tar/example_test.go
View File

@ -13,14 +13,10 @@ import (
"os"
)
func Example() {
// Create a buffer to write our archive to.
buf := new(bytes.Buffer)
// Create a new tar archive.
tw := tar.NewWriter(buf)
// Add some files to the archive.
func Example_minimal() {
// Create and add some files to the archive.
var buf bytes.Buffer
tw := tar.NewWriter(&buf)
var files = []struct {
Name, Body string
}{
@ -35,34 +31,29 @@ func Example() {
Size: int64(len(file.Body)),
}
if err := tw.WriteHeader(hdr); err != nil {
log.Fatalln(err)
log.Fatal(err)
}
if _, err := tw.Write([]byte(file.Body)); err != nil {
log.Fatalln(err)
log.Fatal(err)
}
}
// Make sure to check the error on Close.
if err := tw.Close(); err != nil {
log.Fatalln(err)
log.Fatal(err)
}
// Open the tar archive for reading.
r := bytes.NewReader(buf.Bytes())
tr := tar.NewReader(r)
// Iterate through the files in the archive.
// Open and iterate through the files in the archive.
tr := tar.NewReader(&buf)
for {
hdr, err := tr.Next()
if err == io.EOF {
// end of tar archive
break
break // End of archive
}
if err != nil {
log.Fatalln(err)
log.Fatal(err)
}
fmt.Printf("Contents of %s:\n", hdr.Name)
if _, err := io.Copy(os.Stdout, tr); err != nil {
log.Fatalln(err)
log.Fatal(err)
}
fmt.Println()
}

303
archive/tar/format.go Normal file
View File

@ -0,0 +1,303 @@
// 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 "strings"
// Format represents the tar archive format.
//
// The original tar format was introduced in Unix V7.
// Since then, there have been multiple competing formats attempting to
// standardize or extend the V7 format to overcome its limitations.
// The most common formats are the USTAR, PAX, and GNU formats,
// each with their own advantages and limitations.
//
// The following table captures the capabilities of each format:
//
// | USTAR | PAX | GNU
// ------------------+--------+-----------+----------
// Name | 256B | unlimited | unlimited
// Linkname | 100B | unlimited | unlimited
// Size | uint33 | unlimited | uint89
// Mode | uint21 | uint21 | uint57
// Uid/Gid | uint21 | unlimited | uint57
// Uname/Gname | 32B | unlimited | 32B
// ModTime | uint33 | unlimited | int89
// AccessTime | n/a | unlimited | int89
// ChangeTime | n/a | unlimited | int89
// Devmajor/Devminor | uint21 | uint21 | uint57
// ------------------+--------+-----------+----------
// string encoding | ASCII | UTF-8 | binary
// sub-second times | no | yes | no
// sparse files | no | yes | yes
//
// The table's upper portion shows the Header fields, where each format reports
// the maximum number of bytes allowed for each string field and
// the integer type used to store each numeric field
// (where timestamps are stored as the number of seconds since the Unix epoch).
//
// The table's lower portion shows specialized features of each format,
// such as supported string encodings, support for sub-second timestamps,
// or support for sparse files.
//
// The Writer currently provides no support for sparse files.
type Format int
// Constants to identify various tar formats.
const (
// Deliberately hide the meaning of constants from public API.
_ Format = (1 << iota) / 4 // Sequence of 0, 0, 1, 2, 4, 8, etc...
// FormatUnknown indicates that the format is unknown.
FormatUnknown
// The format of the original Unix V7 tar tool prior to standardization.
formatV7
// FormatUSTAR represents the USTAR header format defined in POSIX.1-1988.
//
// While this format is compatible with most tar readers,
// the format has several limitations making it unsuitable for some usages.
// Most notably, it cannot support sparse files, files larger than 8GiB,
// filenames larger than 256 characters, and non-ASCII filenames.
//
// Reference:
// http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13_06
FormatUSTAR
// FormatPAX represents the PAX header format defined in POSIX.1-2001.
//
// PAX extends USTAR by writing a special file with Typeflag TypeXHeader
// preceding the original header. This file contains a set of key-value
// records, which are used to overcome USTAR's shortcomings, in addition to
// providing the ability to have sub-second resolution for timestamps.
//
// Some newer formats add their own extensions to PAX by defining their
// own keys and assigning certain semantic meaning to the associated values.
// For example, sparse file support in PAX is implemented using keys
// defined by the GNU manual (e.g., "GNU.sparse.map").
//
// Reference:
// http://pubs.opengroup.org/onlinepubs/009695399/utilities/pax.html
FormatPAX
// FormatGNU represents the GNU header format.
//
// The GNU header format is older than the USTAR and PAX standards and
// is not compatible with them. The GNU format supports
// arbitrary file sizes, filenames of arbitrary encoding and length,
// sparse files, and other features.
//
// It is recommended that PAX be chosen over GNU unless the target
// application can only parse GNU formatted archives.
//
// Reference:
// https://www.gnu.org/software/tar/manual/html_node/Standard.html
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
formatMax
)
func (f Format) has(f2 Format) bool { return f&f2 != 0 }
func (f *Format) mayBe(f2 Format) { *f |= f2 }
func (f *Format) mayOnlyBe(f2 Format) { *f &= f2 }
func (f *Format) mustNotBe(f2 Format) { *f &^= f2 }
var formatNames = map[Format]string{
formatV7: "V7", FormatUSTAR: "USTAR", FormatPAX: "PAX", FormatGNU: "GNU", formatSTAR: "STAR",
}
func (f Format) String() string {
var ss []string
for f2 := Format(1); f2 < formatMax; f2 <<= 1 {
if f.has(f2) {
ss = append(ss, formatNames[f2])
}
}
switch len(ss) {
case 0:
return "<unknown>"
case 1:
return ss[0]
default:
return "(" + strings.Join(ss, " | ") + ")"
}
}
// 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
)
// blockPadding computes the number of bytes needed to pad offset up to the
// nearest block edge where 0 <= n < blockSize.
func blockPadding(offset int64) (n int64) {
return -offset & (blockSize - 1)
}
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 {
// 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 | FormatPAX
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 Format) {
// Set the magic values.
switch {
case format.has(formatV7):
// Do nothing.
case format.has(FormatGNU):
copy(b.GNU().Magic(), magicGNU)
copy(b.GNU().Version(), versionGNU)
case format.has(formatSTAR):
copy(b.STAR().Magic(), magicUSTAR)
copy(b.STAR().Version(), versionUSTAR)
copy(b.STAR().Trailer(), trailerSTAR)
case format.has(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(c)
signed += int64(int8(c))
}
return unsigned, signed
}
// Reset clears the block with all zeros.
func (b *block) Reset() {
*b = block{}
}
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) sparseElem { return (sparseElem)(s[i*24:]) }
func (s sparseArray) IsExtended() []byte { return s[24*s.MaxEntries():][:1] }
func (s sparseArray) MaxEntries() int { return len(s) / 24 }
type sparseElem []byte
func (s sparseElem) Offset() []byte { return s[00:][:12] }
func (s sparseElem) Length() []byte { return s[12:][:12] }

1463
archive/tar/reader.go
View File

File diff suppressed because it is too large Load Diff

2055
archive/tar/reader_test.go
View File

File diff suppressed because it is too large Load Diff

0
archive/tar/stat_atim.go → archive/tar/stat_actime1.go
View File

0
archive/tar/stat_atimespec.go → archive/tar/stat_actime2.go
View File

72
archive/tar/stat_unix.go
View File

@ -8,6 +8,10 @@ package tar
import (
"os"
"os/user"
"runtime"
"strconv"
"sync"
"syscall"
)
@ -15,6 +19,10 @@ func init() {
sysStat = statUnix
}
// userMap and groupMap caches UID and GID lookups for performance reasons.
// The downside is that renaming uname or gname by the OS never takes effect.
var userMap, groupMap sync.Map // map[int]string
func statUnix(fi os.FileInfo, h *Header) error {
sys, ok := fi.Sys().(*syscall.Stat_t)
if !ok {
@ -22,11 +30,67 @@ func statUnix(fi os.FileInfo, h *Header) error {
}
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.
// Best effort at populating Uname and Gname.
// The os/user functions may fail for any number of reasons
// (not implemented on that platform, cgo not enabled, etc).
if u, ok := userMap.Load(h.Uid); ok {
h.Uname = u.(string)
} else if u, err := user.LookupId(strconv.Itoa(h.Uid)); err == nil {
h.Uname = u.Username
userMap.Store(h.Uid, h.Uname)
}
if g, ok := groupMap.Load(h.Gid); ok {
h.Gname = g.(string)
} else if g, err := user.LookupGroupId(strconv.Itoa(h.Gid)); err == nil {
h.Gname = g.Name
groupMap.Store(h.Gid, h.Gname)
}
h.AccessTime = statAtime(sys)
h.ChangeTime = statCtime(sys)
// TODO(bradfitz): major/minor device numbers?
// Best effort at populating Devmajor and Devminor.
if h.Typeflag == TypeChar || h.Typeflag == TypeBlock {
dev := uint64(sys.Rdev) // May be int32 or uint32
switch runtime.GOOS {
case "linux":
// Copied from golang.org/x/sys/unix/dev_linux.go.
major := uint32((dev & 0x00000000000fff00) >> 8)
major |= uint32((dev & 0xfffff00000000000) >> 32)
minor := uint32((dev & 0x00000000000000ff) >> 0)
minor |= uint32((dev & 0x00000ffffff00000) >> 12)
h.Devmajor, h.Devminor = int64(major), int64(minor)
case "darwin":
// Copied from golang.org/x/sys/unix/dev_darwin.go.
major := uint32((dev >> 24) & 0xff)
minor := uint32(dev & 0xffffff)
h.Devmajor, h.Devminor = int64(major), int64(minor)
case "dragonfly":
// Copied from golang.org/x/sys/unix/dev_dragonfly.go.
major := uint32((dev >> 8) & 0xff)
minor := uint32(dev & 0xffff00ff)
h.Devmajor, h.Devminor = int64(major), int64(minor)
case "freebsd":
// Copied from golang.org/x/sys/unix/dev_freebsd.go.
major := uint32((dev >> 8) & 0xff)
minor := uint32(dev & 0xffff00ff)
h.Devmajor, h.Devminor = int64(major), int64(minor)
case "netbsd":
// Copied from golang.org/x/sys/unix/dev_netbsd.go.
major := uint32((dev & 0x000fff00) >> 8)
minor := uint32((dev & 0x000000ff) >> 0)
minor |= uint32((dev & 0xfff00000) >> 12)
h.Devmajor, h.Devminor = int64(major), int64(minor)
case "openbsd":
// Copied from golang.org/x/sys/unix/dev_openbsd.go.
major := uint32((dev & 0x0000ff00) >> 8)
minor := uint32((dev & 0x000000ff) >> 0)
minor |= uint32((dev & 0xffff0000) >> 8)
h.Devmajor, h.Devminor = int64(major), int64(minor)
default:
// TODO: Implement solaris (see https://golang.org/issue/8106)
}
}
return nil
}

326
archive/tar/strconv.go Normal file
View File

@ -0,0 +1,326 @@
// 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"
)
// hasNUL reports whether the NUL character exists within s.
func hasNUL(s string) bool {
return strings.IndexByte(s, 0) >= 0
}
// isASCII reports whether the input is an ASCII C-style string.
func isASCII(s string) bool {
for _, c := range s {
if c >= 0x80 || c == 0x00 {
return false
}
}
return true
}
// toASCII converts the input to an ASCII C-style string.
// This a best effort conversion, so invalid characters are dropped.
func toASCII(s string) string {
if isASCII(s) {
return s
}
b := make([]byte, 0, len(s))
for _, c := range s {
if c < 0x80 && c != 0x00 {
b = append(b, byte(c))
}
}
return string(b)
}
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 {
if i := bytes.IndexByte(b, 0); i >= 0 {
return string(b[:i])
}
return string(b)
}
// formatString copies s into b, NUL-terminating if possible.
func (f *formatter) formatString(b []byte, s string) {
if len(s) > len(b) {
f.err = ErrFieldTooLong
}
copy(b, s)
if len(s) < len(b) {
b[len(s)] = 0
}
// Some buggy readers treat regular files with a trailing slash
// in the V7 path field as a directory even though the full path
// recorded elsewhere (e.g., via PAX record) contains no trailing slash.
if len(s) > len(b) && b[len(b)-1] == '/' {
n := len(strings.TrimRight(s[:len(b)], "/"))
b[n] = 0 // Replace trailing slash with NUL terminator
}
}
// 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 {
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)
}
// formatNumeric encodes x into b using base-8 (octal) encoding if possible.
// Otherwise it will attempt to use base-256 (binary) encoding.
func (f *formatter) formatNumeric(b []byte, x int64) {
if fitsInOctal(len(b), x) {
f.formatOctal(b, x)
return
}
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) {
if !fitsInOctal(len(b), x) {
x = 0 // Last resort, just write zero
f.err = ErrFieldTooLong
}
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)
}
// fitsInOctal reports whether the integer x fits in a field n-bytes long
// using octal encoding with the appropriate NUL terminator.
func fitsInOctal(n int, x int64) bool {
octBits := uint(n-1) * 3
return x >= 0 && (n >= 22 || x < 1<<octBits)
}
// 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*nsecs), nil // Negative correction
}
return time.Unix(secs, nsecs), nil
}
// formatPAXTime converts ts into a time of the form %d.%d as described in the
// PAX specification. This function is capable of negative timestamps.
func formatPAXTime(ts time.Time) (s string) {
secs, nsecs := ts.Unix(), ts.Nanosecond()
if nsecs == 0 {
return strconv.FormatInt(secs, 10)
}
// If seconds is negative, then perform correction.
sign := ""
if secs < 0 {
sign = "-" // Remember sign
secs = -(secs + 1) // Add a second to secs
nsecs = -(nsecs - 1E9) // Take that second away from nsecs
}
return strings.TrimRight(fmt.Sprintf("%s%d.%09d", sign, secs, nsecs), "0")
}
// 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.
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
}
k, v = rec[:eq], rec[eq+1:]
if !validPAXRecord(k, v) {
return "", "", s, ErrHeader
}
return k, v, rem, nil
}
// formatPAXRecord formats a single PAX record, prefixing it with the
// appropriate length.
func formatPAXRecord(k, v string) (string, error) {
if !validPAXRecord(k, v) {
return "", ErrHeader
}
const padding = 3 // Extra padding for ' ', '=', and '\n'
size := len(k) + len(v) + padding
size += len(strconv.Itoa(size))
record := strconv.Itoa(size) + " " + k + "=" + v + "\n"
// Final adjustment if adding size field increased the record size.
if len(record) != size {
size = len(record)
record = strconv.Itoa(size) + " " + k + "=" + v + "\n"
}
return record, nil
}
// validPAXRecord reports whether the key-value pair is valid where each
// record is formatted as:
// "%d %s=%s\n" % (size, key, value)
//
// Keys and values should be UTF-8, but the number of bad writers out there
// forces us to be a more liberal.
// Thus, we only reject all keys with NUL, and only reject NULs in values
// for the PAX version of the USTAR string fields.
// The key must not contain an '=' character.
func validPAXRecord(k, v string) bool {
if k == "" || strings.IndexByte(k, '=') >= 0 {
return false
}
switch k {
case paxPath, paxLinkpath, paxUname, paxGname:
return !hasNUL(v)
default:
return !hasNUL(k)
}
}

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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 (
"math"
"strings"
"testing"
"time"
)
func TestFitsInBase256(t *testing.T) {
vectors := []struct {
in int64
width int
ok bool
}{
{+1, 8, true},
{0, 8, true},
{-1, 8, true},
{1 << 56, 8, false},
{(1 << 56) - 1, 8, true},
{-1 << 56, 8, true},
{(-1 << 56) - 1, 8, false},
{121654, 8, true},
{-9849849, 8, true},
{math.MaxInt64, 9, true},
{0, 9, true},
{math.MinInt64, 9, true},
{math.MaxInt64, 12, true},
{0, 12, true},
{math.MinInt64, 12, true},
}
for _, v := range vectors {
ok := fitsInBase256(v.width, v.in)
if ok != v.ok {
t.Errorf("fitsInBase256(%d, %d): got %v, want %v", v.in, v.width, ok, v.ok)
}
}
}
func TestParseNumeric(t *testing.T) {
vectors := []struct {
in string
want int64
ok bool
}{
// Test base-256 (binary) encoded values.
{"", 0, true},
{"\x80", 0, true},
{"\x80\x00", 0, true},
{"\x80\x00\x00", 0, true},
{"\xbf", (1 << 6) - 1, true},
{"\xbf\xff", (1 << 14) - 1, true},
{"\xbf\xff\xff", (1 << 22) - 1, true},
{"\xff", -1, true},
{"\xff\xff", -1, true},
{"\xff\xff\xff", -1, true},
{"\xc0", -1 * (1 << 6), true},
{"\xc0\x00", -1 * (1 << 14), true},
{"\xc0\x00\x00", -1 * (1 << 22), true},
{"\x87\x76\xa2\x22\xeb\x8a\x72\x61", 537795476381659745, true},
{"\x80\x00\x00\x00\x07\x76\xa2\x22\xeb\x8a\x72\x61", 537795476381659745, true},
{"\xf7\x76\xa2\x22\xeb\x8a\x72\x61", -615126028225187231, true},
{"\xff\xff\xff\xff\xf7\x76\xa2\x22\xeb\x8a\x72\x61", -615126028225187231, true},
{"\x80\x7f\xff\xff\xff\xff\xff\xff\xff", math.MaxInt64, true},
{"\x80\x80\x00\x00\x00\x00\x00\x00\x00", 0, false},
{"\xff\x80\x00\x00\x00\x00\x00\x00\x00", math.MinInt64, true},
{"\xff\x7f\xff\xff\xff\xff\xff\xff\xff", 0, false},
{"\xf5\xec\xd1\xc7\x7e\x5f\x26\x48\x81\x9f\x8f\x9b", 0, false},
// Test base-8 (octal) encoded values.
{"0000000\x00", 0, true},
{" \x0000000\x00", 0, true},
{" \x0000003\x00", 3, true},
{"00000000227\x00", 0227, true},
{"032033\x00 ", 032033, true},
{"320330\x00 ", 0320330, true},
{"0000660\x00 ", 0660, true},
{"\x00 0000660\x00 ", 0660, true},
{"0123456789abcdef", 0, false},
{"0123456789\x00abcdef", 0, false},
{"01234567\x0089abcdef", 342391, true},
{"0123\x7e\x5f\x264123", 0, false},
}
for _, v := range vectors {
var p parser
got := p.parseNumeric([]byte(v.in))
ok := (p.err == nil)
if ok != v.ok {
if v.ok {
t.Errorf("parseNumeric(%q): got parsing failure, want success", v.in)
} else {
t.Errorf("parseNumeric(%q): got parsing success, want failure", v.in)
}
}
if ok && got != v.want {
t.Errorf("parseNumeric(%q): got %d, want %d", v.in, got, v.want)
}
}
}
func TestFormatNumeric(t *testing.T) {
vectors := []struct {
in int64
want string
ok bool
}{
// Test base-8 (octal) encoded values.
{0, "0\x00", true},
{7, "7\x00", true},
{8, "\x80\x08", true},
{077, "77\x00", true},
{0100, "\x80\x00\x40", true},
{0, "0000000\x00", true},
{0123, "0000123\x00", true},
{07654321, "7654321\x00", true},
{07777777, "7777777\x00", true},
{010000000, "\x80\x00\x00\x00\x00\x20\x00\x00", true},
{0, "00000000000\x00", true},
{000001234567, "00001234567\x00", true},
{076543210321, "76543210321\x00", true},
{012345670123, "12345670123\x00", true},
{077777777777, "77777777777\x00", true},
{0100000000000, "\x80\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00", true},
{math.MaxInt64, "777777777777777777777\x00", true},
// Test base-256 (binary) encoded values.
{-1, "\xff", true},
{-1, "\xff\xff", true},
{-1, "\xff\xff\xff", true},
{(1 << 0), "0", false},
{(1 << 8) - 1, "\x80\xff", true},
{(1 << 8), "0\x00", false},
{(1 << 16) - 1, "\x80\xff\xff", true},
{(1 << 16), "00\x00", false},
{-1 * (1 << 0), "\xff", true},
{-1*(1<<0) - 1, "0", false},
{-1 * (1 << 8), "\xff\x00", true},
{-1*(1<<8) - 1, "0\x00", false},
{-1 * (1 << 16), "\xff\x00\x00", true},
{-1*(1<<16) - 1, "00\x00", false},
{537795476381659745, "0000000\x00", false},
{537795476381659745, "\x80\x00\x00\x00\x07\x76\xa2\x22\xeb\x8a\x72\x61", true},
{-615126028225187231, "0000000\x00", false},
{-615126028225187231, "\xff\xff\xff\xff\xf7\x76\xa2\x22\xeb\x8a\x72\x61", true},
{math.MaxInt64, "0000000\x00", false},
{math.MaxInt64, "\x80\x00\x00\x00\x7f\xff\xff\xff\xff\xff\xff\xff", true},
{math.MinInt64, "0000000\x00", false},
{math.MinInt64, "\xff\xff\xff\xff\x80\x00\x00\x00\x00\x00\x00\x00", true},
{math.MaxInt64, "\x80\x7f\xff\xff\xff\xff\xff\xff\xff", true},
{math.MinInt64, "\xff\x80\x00\x00\x00\x00\x00\x00\x00", true},
}
for _, v := range vectors {
var f formatter
got := make([]byte, len(v.want))
f.formatNumeric(got, v.in)
ok := (f.err == nil)
if ok != v.ok {
if v.ok {
t.Errorf("formatNumeric(%d): got formatting failure, want success", v.in)
} else {
t.Errorf("formatNumeric(%d): got formatting success, want failure", v.in)
}
}
if string(got) != v.want {
t.Errorf("formatNumeric(%d): got %q, want %q", v.in, got, v.want)
}
}
}
func TestFitsInOctal(t *testing.T) {
vectors := []struct {
input int64
width int
ok bool
}{
{-1, 1, false},
{-1, 2, false},
{-1, 3, false},
{0, 1, true},
{0 + 1, 1, false},
{0, 2, true},
{07, 2, true},
{07 + 1, 2, false},
{0, 4, true},
{0777, 4, true},
{0777 + 1, 4, false},
{0, 8, true},
{07777777, 8, true},
{07777777 + 1, 8, false},
{0, 12, true},
{077777777777, 12, true},
{077777777777 + 1, 12, false},
{math.MaxInt64, 22, true},
{012345670123, 12, true},
{01564164, 12, true},
{-012345670123, 12, false},
{-01564164, 12, false},
{-1564164, 30, false},
}
for _, v := range vectors {
ok := fitsInOctal(v.width, v.input)
if ok != v.ok {
t.Errorf("checkOctal(%d, %d): got %v, want %v", v.input, v.width, ok, v.ok)
}
}
}
func TestParsePAXTime(t *testing.T) {
vectors := []struct {
in string
want time.Time
ok bool
}{
{"1350244992.023960108", time.Unix(1350244992, 23960108), true},
{"1350244992.02396010", time.Unix(1350244992, 23960100), true},
{"1350244992.0239601089", time.Unix(1350244992, 23960108), true},
{"1350244992.3", time.Unix(1350244992, 300000000), true},
{"1350244992", time.Unix(1350244992, 0), true},
{"-1.000000001", time.Unix(-1, -1e0+0e0), true},
{"-1.000001", time.Unix(-1, -1e3+0e0), true},
{"-1.001000", time.Unix(-1, -1e6+0e0), true},
{"-1", time.Unix(-1, -0e0+0e0), true},
{"-1.999000", time.Unix(-1, -1e9+1e6), true},
{"-1.999999", time.Unix(-1, -1e9+1e3), true},
{"-1.999999999", time.Unix(-1, -1e9+1e0), true},
{"0.000000001", time.Unix(0, 1e0+0e0), true},
{"0.000001", time.Unix(0, 1e3+0e0), true},
{"0.001000", time.Unix(0, 1e6+0e0), true},
{"0", time.Unix(0, 0e0), true},
{"0.999000", time.Unix(0, 1e9-1e6), true},
{"0.999999", time.Unix(0, 1e9-1e3), true},
{"0.999999999", time.Unix(0, 1e9-1e0), true},
{"1.000000001", time.Unix(+1, +1e0-0e0), true},
{"1.000001", time.Unix(+1, +1e3-0e0), true},
{"1.001000", time.Unix(+1, +1e6-0e0), true},
{"1", time.Unix(+1, +0e0-0e0), true},
{"1.999000", time.Unix(+1, +1e9-1e6), true},
{"1.999999", time.Unix(+1, +1e9-1e3), true},
{"1.999999999", time.Unix(+1, +1e9-1e0), true},
{"-1350244992.023960108", time.Unix(-1350244992, -23960108), true},
{"-1350244992.02396010", time.Unix(-1350244992, -23960100), true},
{"-1350244992.0239601089", time.Unix(-1350244992, -23960108), true},
{"-1350244992.3", time.Unix(-1350244992, -300000000), true},
{"-1350244992", time.Unix(-1350244992, 0), true},
{"", time.Time{}, false},
{"0", time.Unix(0, 0), true},
{"1.", time.Unix(1, 0), true},
{"0.0", time.Unix(0, 0), true},
{".5", time.Time{}, false},
{"-1.3", time.Unix(-1, -3e8), true},
{"-1.0", time.Unix(-1, -0e0), true},
{"-0.0", time.Unix(-0, -0e0), true},
{"-0.1", time.Unix(-0, -1e8), true},
{"-0.01", time.Unix(-0, -1e7), true},
{"-0.99", time.Unix(-0, -99e7), true},
{"-0.98", time.Unix(-0, -98e7), true},
{"-1.1", time.Unix(-1, -1e8), true},
{"-1.01", time.Unix(-1, -1e7), true},
{"-2.99", time.Unix(-2, -99e7), true},
{"-5.98", time.Unix(-5, -98e7), true},
{"-", time.Time{}, false},
{"+", time.Time{}, false},
{"-1.-1", time.Time{}, false},
{"99999999999999999999999999999999999999999999999", time.Time{}, false},
{"0.123456789abcdef", time.Time{}, false},
{"foo", time.Time{}, false},
{"\x00", time.Time{}, false},
{"𝟵𝟴𝟳𝟲𝟱.𝟰𝟯𝟮𝟭𝟬", time.Time{}, false}, // Unicode numbers (U+1D7EC to U+1D7F5)
{"98765﹒43210", time.Time{}, false}, // Unicode period (U+FE52)
}
for _, v := range vectors {
ts, err := parsePAXTime(v.in)
ok := (err == nil)
if v.ok != ok {
if v.ok {
t.Errorf("parsePAXTime(%q): got parsing failure, want success", v.in)
} else {
t.Errorf("parsePAXTime(%q): got parsing success, want failure", v.in)
}
}
if ok && !ts.Equal(v.want) {
t.Errorf("parsePAXTime(%q): got (%ds %dns), want (%ds %dns)",
v.in, ts.Unix(), ts.Nanosecond(), v.want.Unix(), v.want.Nanosecond())
}
}
}
func TestFormatPAXTime(t *testing.T) {
vectors := []struct {
sec, nsec int64
want string
}{
{1350244992, 0, "1350244992"},
{1350244992, 300000000, "1350244992.3"},
{1350244992, 23960100, "1350244992.0239601"},
{1350244992, 23960108, "1350244992.023960108"},
{+1, +1E9 - 1E0, "1.999999999"},
{+1, +1E9 - 1E3, "1.999999"},
{+1, +1E9 - 1E6, "1.999"},
{+1, +0E0 - 0E0, "1"},
{+1, +1E6 - 0E0, "1.001"},
{+1, +1E3 - 0E0, "1.000001"},
{+1, +1E0 - 0E0, "1.000000001"},
{0, 1E9 - 1E0, "0.999999999"},
{0, 1E9 - 1E3, "0.999999"},
{0, 1E9 - 1E6, "0.999"},
{0, 0E0, "0"},
{0, 1E6 + 0E0, "0.001"},
{0, 1E3 + 0E0, "0.000001"},
{0, 1E0 + 0E0, "0.000000001"},
{-1, -1E9 + 1E0, "-1.999999999"},
{-1, -1E9 + 1E3, "-1.999999"},
{-1, -1E9 + 1E6, "-1.999"},
{-1, -0E0 + 0E0, "-1"},
{-1, -1E6 + 0E0, "-1.001"},
{-1, -1E3 + 0E0, "-1.000001"},
{-1, -1E0 + 0E0, "-1.000000001"},
{-1350244992, 0, "-1350244992"},
{-1350244992, -300000000, "-1350244992.3"},
{-1350244992, -23960100, "-1350244992.0239601"},
{-1350244992, -23960108, "-1350244992.023960108"},
}
for _, v := range vectors {
got := formatPAXTime(time.Unix(v.sec, v.nsec))
if got != v.want {
t.Errorf("formatPAXTime(%ds, %dns): got %q, want %q",
v.sec, v.nsec, got, v.want)
}
}
}
func TestParsePAXRecord(t *testing.T) {
medName := strings.Repeat("CD", 50)
longName := strings.Repeat("AB", 100)
vectors := []struct {
in string
wantRes string
wantKey string
wantVal string
ok bool
}{
{"6 k=v\n\n", "\n", "k", "v", true},
{"19 path=/etc/hosts\n", "", "path", "/etc/hosts", true},
{"210 path=" + longName + "\nabc", "abc", "path", longName, true},
{"110 path=" + medName + "\n", "", "path", medName, true},
{"9 foo=ba\n", "", "foo", "ba", true},
{"11 foo=bar\n\x00", "\x00", "foo", "bar", true},
{"18 foo=b=\nar=\n==\x00\n", "", "foo", "b=\nar=\n==\x00", true},
{"27 foo=hello9 foo=ba\nworld\n", "", "foo", "hello9 foo=ba\nworld", true},
{"27 ☺☻☹=日a本b語ç\nmeow mix", "meow mix", "☺☻☹", "日a本b語ç", true},
{"17 \x00hello=\x00world\n", "17 \x00hello=\x00world\n", "", "", false},
{"1 k=1\n", "1 k=1\n", "", "", false},
{"6 k~1\n", "6 k~1\n", "", "", false},
{"6_k=1\n", "6_k=1\n", "", "", false},
{"6 k=1 ", "6 k=1 ", "", "", false},
{"632 k=1\n", "632 k=1\n", "", "", false},
{"16 longkeyname=hahaha\n", "16 longkeyname=hahaha\n", "", "", false},
{"3 somelongkey=\n", "3 somelongkey=\n", "", "", false},
{"50 tooshort=\n", "50 tooshort=\n", "", "", false},
}
for _, v := range vectors {
key, val, res, err := parsePAXRecord(v.in)
ok := (err == nil)
if ok != v.ok {
if v.ok {
t.Errorf("parsePAXRecord(%q): got parsing failure, want success", v.in)
} else {
t.Errorf("parsePAXRecord(%q): got parsing success, want failure", v.in)
}
}
if v.ok && (key != v.wantKey || val != v.wantVal) {
t.Errorf("parsePAXRecord(%q): got (%q: %q), want (%q: %q)",
v.in, key, val, v.wantKey, v.wantVal)
}
if res != v.wantRes {
t.Errorf("parsePAXRecord(%q): got residual %q, want residual %q",
v.in, res, v.wantRes)
}
}
}
func TestFormatPAXRecord(t *testing.T) {
medName := strings.Repeat("CD", 50)
longName := strings.Repeat("AB", 100)
vectors := []struct {
inKey string
inVal string
want string
ok bool
}{
{"k", "v", "6 k=v\n", true},
{"path", "/etc/hosts", "19 path=/etc/hosts\n", true},
{"path", longName, "210 path=" + longName + "\n", true},
{"path", medName, "110 path=" + medName + "\n", true},
{"foo", "ba", "9 foo=ba\n", true},
{"foo", "bar", "11 foo=bar\n", true},
{"foo", "b=\nar=\n==\x00", "18 foo=b=\nar=\n==\x00\n", true},
{"foo", "hello9 foo=ba\nworld", "27 foo=hello9 foo=ba\nworld\n", true},
{"☺☻☹", "日a本b語ç", "27 ☺☻☹=日a本b語ç\n", true},
{"xhello", "\x00world", "17 xhello=\x00world\n", true},
{"path", "null\x00", "", false},
{"null\x00", "value", "", false},
{paxSchilyXattr + "key", "null\x00", "26 SCHILY.xattr.key=null\x00\n", true},
}
for _, v := range vectors {
got, err := formatPAXRecord(v.inKey, v.inVal)
ok := (err == nil)
if ok != v.ok {
if v.ok {
t.Errorf("formatPAXRecord(%q, %q): got format failure, want success", v.inKey, v.inVal)
} else {
t.Errorf("formatPAXRecord(%q, %q): got format success, want failure", v.inKey, v.inVal)
}
}
if got != v.want {
t.Errorf("formatPAXRecord(%q, %q): got %q, want %q",
v.inKey, v.inVal, got, v.want)
}
}
}

819
archive/tar/tar_test.go
View File

@ -6,15 +6,208 @@ package tar
import (
"bytes"
"errors"
"fmt"
"io"
"io/ioutil"
"math"
"os"
"path"
"path/filepath"
"reflect"
"runtime"
"strings"
"testing"
"time"
)
type testError struct{ error }
type fileOps []interface{} // []T where T is (string | int64)
// testFile is an io.ReadWriteSeeker where the IO operations performed
// on it must match the list of operations in ops.
type testFile struct {
ops fileOps
pos int64
}
func (f *testFile) Read(b []byte) (int, error) {
if len(b) == 0 {
return 0, nil
}
if len(f.ops) == 0 {
return 0, io.EOF
}
s, ok := f.ops[0].(string)
if !ok {
return 0, errors.New("unexpected Read operation")
}
n := copy(b, s)
if len(s) > n {
f.ops[0] = s[n:]
} else {
f.ops = f.ops[1:]
}
f.pos += int64(len(b))
return n, nil
}
func (f *testFile) Write(b []byte) (int, error) {
if len(b) == 0 {
return 0, nil
}
if len(f.ops) == 0 {
return 0, errors.New("unexpected Write operation")
}
s, ok := f.ops[0].(string)
if !ok {
return 0, errors.New("unexpected Write operation")
}
if !strings.HasPrefix(s, string(b)) {
return 0, testError{fmt.Errorf("got Write(%q), want Write(%q)", b, s)}
}
if len(s) > len(b) {
f.ops[0] = s[len(b):]
} else {
f.ops = f.ops[1:]
}
f.pos += int64(len(b))
return len(b), nil
}
func (f *testFile) Seek(pos int64, whence int) (int64, error) {
if pos == 0 && whence == io.SeekCurrent {
return f.pos, nil
}
if len(f.ops) == 0 {
return 0, errors.New("unexpected Seek operation")
}
s, ok := f.ops[0].(int64)
if !ok {
return 0, errors.New("unexpected Seek operation")
}
if s != pos || whence != io.SeekCurrent {
return 0, testError{fmt.Errorf("got Seek(%d, %d), want Seek(%d, %d)", pos, whence, s, io.SeekCurrent)}
}
f.pos += s
f.ops = f.ops[1:]
return f.pos, nil
}
func equalSparseEntries(x, y []sparseEntry) bool {
return (len(x) == 0 && len(y) == 0) || reflect.DeepEqual(x, y)
}
func TestSparseEntries(t *testing.T) {
vectors := []struct {
in []sparseEntry
size int64
wantValid bool // Result of validateSparseEntries
wantAligned []sparseEntry // Result of alignSparseEntries
wantInverted []sparseEntry // Result of invertSparseEntries
}{{
in: []sparseEntry{}, size: 0,
wantValid: true,
wantInverted: []sparseEntry{{0, 0}},
}, {
in: []sparseEntry{}, size: 5000,
wantValid: true,
wantInverted: []sparseEntry{{0, 5000}},
}, {
in: []sparseEntry{{0, 5000}}, size: 5000,
wantValid: true,
wantAligned: []sparseEntry{{0, 5000}},
wantInverted: []sparseEntry{{5000, 0}},
}, {
in: []sparseEntry{{1000, 4000}}, size: 5000,
wantValid: true,
wantAligned: []sparseEntry{{1024, 3976}},
wantInverted: []sparseEntry{{0, 1000}, {5000, 0}},
}, {
in: []sparseEntry{{0, 3000}}, size: 5000,
wantValid: true,
wantAligned: []sparseEntry{{0, 2560}},
wantInverted: []sparseEntry{{3000, 2000}},
}, {
in: []sparseEntry{{3000, 2000}}, size: 5000,
wantValid: true,
wantAligned: []sparseEntry{{3072, 1928}},
wantInverted: []sparseEntry{{0, 3000}, {5000, 0}},
}, {
in: []sparseEntry{{2000, 2000}}, size: 5000,
wantValid: true,
wantAligned: []sparseEntry{{2048, 1536}},
wantInverted: []sparseEntry{{0, 2000}, {4000, 1000}},
}, {
in: []sparseEntry{{0, 2000}, {8000, 2000}}, size: 10000,
wantValid: true,
wantAligned: []sparseEntry{{0, 1536}, {8192, 1808}},
wantInverted: []sparseEntry{{2000, 6000}, {10000, 0}},
}, {
in: []sparseEntry{{0, 2000}, {2000, 2000}, {4000, 0}, {4000, 3000}, {7000, 1000}, {8000, 0}, {8000, 2000}}, size: 10000,
wantValid: true,
wantAligned: []sparseEntry{{0, 1536}, {2048, 1536}, {4096, 2560}, {7168, 512}, {8192, 1808}},
wantInverted: []sparseEntry{{10000, 0}},
}, {
in: []sparseEntry{{0, 0}, {1000, 0}, {2000, 0}, {3000, 0}, {4000, 0}, {5000, 0}}, size: 5000,
wantValid: true,
wantInverted: []sparseEntry{{0, 5000}},
}, {
in: []sparseEntry{{1, 0}}, size: 0,
wantValid: false,
}, {
in: []sparseEntry{{-1, 0}}, size: 100,
wantValid: false,
}, {
in: []sparseEntry{{0, -1}}, size: 100,
wantValid: false,
}, {
in: []sparseEntry{{0, 0}}, size: -100,
wantValid: false,
}, {
in: []sparseEntry{{math.MaxInt64, 3}, {6, -5}}, size: 35,
wantValid: false,
}, {
in: []sparseEntry{{1, 3}, {6, -5}}, size: 35,
wantValid: false,
}, {
in: []sparseEntry{{math.MaxInt64, math.MaxInt64}}, size: math.MaxInt64,
wantValid: false,
}, {
in: []sparseEntry{{3, 3}}, size: 5,
wantValid: false,
}, {
in: []sparseEntry{{2, 0}, {1, 0}, {0, 0}}, size: 3,
wantValid: false,
}, {
in: []sparseEntry{{1, 3}, {2, 2}}, size: 10,
wantValid: false,
}}
for i, v := range vectors {
gotValid := validateSparseEntries(v.in, v.size)
if gotValid != v.wantValid {
t.Errorf("test %d, validateSparseEntries() = %v, want %v", i, gotValid, v.wantValid)
}
if !v.wantValid {
continue
}
gotAligned := alignSparseEntries(append([]sparseEntry{}, v.in...), v.size)
if !equalSparseEntries(gotAligned, v.wantAligned) {
t.Errorf("test %d, alignSparseEntries():\ngot %v\nwant %v", i, gotAligned, v.wantAligned)
}
gotInverted := invertSparseEntries(append([]sparseEntry{}, v.in...), v.size)
if !equalSparseEntries(gotInverted, v.wantInverted) {
t.Errorf("test %d, inverseSparseEntries():\ngot %v\nwant %v", i, gotInverted, v.wantInverted)
}
}
}
func TestFileInfoHeader(t *testing.T) {
fi, err := os.Stat("testdata/small.txt")
if err != nil {
@ -27,7 +220,7 @@ func TestFileInfoHeader(t *testing.T) {
if g, e := h.Name, "small.txt"; g != e {
t.Errorf("Name = %q; want %q", g, e)
}
if g, e := h.Mode, int64(fi.Mode().Perm())|c_ISREG; g != e {
if g, e := h.Mode, int64(fi.Mode().Perm()); g != e {
t.Errorf("Mode = %#o; want %#o", g, e)
}
if g, e := h.Size, int64(5); g != e {
@ -55,7 +248,7 @@ func TestFileInfoHeaderDir(t *testing.T) {
t.Errorf("Name = %q; want %q", g, e)
}
// Ignoring c_ISGID for golang.org/issue/4867
if g, e := h.Mode&^c_ISGID, int64(fi.Mode().Perm())|c_ISDIR; g != e {
if g, e := h.Mode&^c_ISGID, int64(fi.Mode().Perm()); g != e {
t.Errorf("Mode = %#o; want %#o", g, e)
}
if g, e := h.Size, int64(0); g != e {
@ -67,38 +260,55 @@ func TestFileInfoHeaderDir(t *testing.T) {
}
func TestFileInfoHeaderSymlink(t *testing.T) {
h, err := FileInfoHeader(symlink{}, "some-target")
switch runtime.GOOS {
case "android", "nacl", "plan9", "windows":
t.Skip("symlinks not supported")
}
tmpdir, err := ioutil.TempDir("", "TestFileInfoHeaderSymlink")
if err != nil {
t.Fatal(err)
}
if g, e := h.Name, "some-symlink"; g != e {
defer os.RemoveAll(tmpdir)
link := filepath.Join(tmpdir, "link")
target := tmpdir
err = os.Symlink(target, link)
if err != nil {
t.Fatal(err)
}
fi, err := os.Lstat(link)
if err != nil {
t.Fatal(err)
}
h, err := FileInfoHeader(fi, target)
if err != nil {
t.Fatal(err)
}
if g, e := h.Name, fi.Name(); g != e {
t.Errorf("Name = %q; want %q", g, e)
}
if g, e := h.Linkname, "some-target"; g != e {
if g, e := h.Linkname, target; g != e {
t.Errorf("Linkname = %q; want %q", g, e)
}
if g, e := h.Typeflag, byte(TypeSymlink); g != e {
t.Errorf("Typeflag = %v; want %v", g, e)
}
}
type symlink struct{}
func (symlink) Name() string { return "some-symlink" }
func (symlink) Size() int64 { return 0 }
func (symlink) Mode() os.FileMode { return os.ModeSymlink }
func (symlink) ModTime() time.Time { return time.Time{} }
func (symlink) IsDir() bool { return false }
func (symlink) Sys() interface{} { return nil }
func TestRoundTrip(t *testing.T) {
data := []byte("some file contents")
var b bytes.Buffer
tw := NewWriter(&b)
hdr := &Header{
Name: "file.txt",
Uid: 1 << 21, // too big for 8 octal digits
Size: int64(len(data)),
// https://github.com/golang/go/commit/0e3355903d2ebcf5ee9e76096f51ac9a116a9dbb#diff-d7bf2a98d7b57b6ff754ca406f1b7581R105
ModTime: time.Now().AddDate(0, 0, 0).Round(1 * time.Second),
Name: "file.txt",
Uid: 1 << 21, // Too big for 8 octal digits
Size: int64(len(data)),
ModTime: time.Now().Round(time.Second),
PAXRecords: map[string]string{"uid": "2097152"},
Format: FormatPAX,
Typeflag: TypeReg,
}
if err := tw.WriteHeader(hdr); err != nil {
t.Fatalf("tw.WriteHeader: %v", err)
@ -134,191 +344,514 @@ type headerRoundTripTest struct {
}
func TestHeaderRoundTrip(t *testing.T) {
golden := []headerRoundTripTest{
vectors := []headerRoundTripTest{{
// regular file.
{
h: &Header{
Name: "test.txt",
Mode: 0644 | c_ISREG,
Size: 12,
ModTime: time.Unix(1360600916, 0),
Typeflag: TypeReg,
},
fm: 0644,
h: &Header{
Name: "test.txt",
Mode: 0644,
Size: 12,
ModTime: time.Unix(1360600916, 0),
Typeflag: TypeReg,
},
fm: 0644,
}, {
// symbolic link.
{
h: &Header{
Name: "link.txt",
Mode: 0777 | c_ISLNK,
Size: 0,
ModTime: time.Unix(1360600852, 0),
Typeflag: TypeSymlink,
},
fm: 0777 | os.ModeSymlink,
h: &Header{
Name: "link.txt",
Mode: 0777,
Size: 0,
ModTime: time.Unix(1360600852, 0),
Typeflag: TypeSymlink,
},
fm: 0777 | os.ModeSymlink,
}, {
// character device node.
{
h: &Header{
Name: "dev/null",
Mode: 0666 | c_ISCHR,
Size: 0,
ModTime: time.Unix(1360578951, 0),
Typeflag: TypeChar,
},
fm: 0666 | os.ModeDevice | os.ModeCharDevice,
h: &Header{
Name: "dev/null",
Mode: 0666,
Size: 0,
ModTime: time.Unix(1360578951, 0),
Typeflag: TypeChar,
},
fm: 0666 | os.ModeDevice | os.ModeCharDevice,
}, {
// block device node.
{
h: &Header{
Name: "dev/sda",
Mode: 0660 | c_ISBLK,
Size: 0,
ModTime: time.Unix(1360578954, 0),
Typeflag: TypeBlock,
},
fm: 0660 | os.ModeDevice,
h: &Header{
Name: "dev/sda",
Mode: 0660,
Size: 0,
ModTime: time.Unix(1360578954, 0),
Typeflag: TypeBlock,
},
fm: 0660 | os.ModeDevice,
}, {
// directory.
{
h: &Header{
Name: "dir/",
Mode: 0755 | c_ISDIR,
Size: 0,
ModTime: time.Unix(1360601116, 0),
Typeflag: TypeDir,
},
fm: 0755 | os.ModeDir,
h: &Header{
Name: "dir/",
Mode: 0755,
Size: 0,
ModTime: time.Unix(1360601116, 0),
Typeflag: TypeDir,
},
fm: 0755 | os.ModeDir,
}, {
// fifo node.
{
h: &Header{
Name: "dev/initctl",
Mode: 0600 | c_ISFIFO,
Size: 0,
ModTime: time.Unix(1360578949, 0),
Typeflag: TypeFifo,
},
fm: 0600 | os.ModeNamedPipe,
h: &Header{
Name: "dev/initctl",
Mode: 0600,
Size: 0,
ModTime: time.Unix(1360578949, 0),
Typeflag: TypeFifo,
},
fm: 0600 | os.ModeNamedPipe,
}, {
// setuid.
{
h: &Header{
Name: "bin/su",
Mode: 0755 | c_ISREG | c_ISUID,
Size: 23232,
ModTime: time.Unix(1355405093, 0),
Typeflag: TypeReg,
},
fm: 0755 | os.ModeSetuid,
h: &Header{
Name: "bin/su",
Mode: 0755 | c_ISUID,
Size: 23232,
ModTime: time.Unix(1355405093, 0),
Typeflag: TypeReg,
},
fm: 0755 | os.ModeSetuid,
}, {
// setguid.
{
h: &Header{
Name: "group.txt",
Mode: 0750 | c_ISREG | c_ISGID,
Size: 0,
ModTime: time.Unix(1360602346, 0),
Typeflag: TypeReg,
},
fm: 0750 | os.ModeSetgid,
h: &Header{
Name: "group.txt",
Mode: 0750 | c_ISGID,
Size: 0,
ModTime: time.Unix(1360602346, 0),
Typeflag: TypeReg,
},
fm: 0750 | os.ModeSetgid,
}, {
// sticky.
{
h: &Header{
Name: "sticky.txt",
Mode: 0600 | c_ISREG | c_ISVTX,
Size: 7,
ModTime: time.Unix(1360602540, 0),
Typeflag: TypeReg,
},
fm: 0600 | os.ModeSticky,
h: &Header{
Name: "sticky.txt",
Mode: 0600 | c_ISVTX,
Size: 7,
ModTime: time.Unix(1360602540, 0),
Typeflag: TypeReg,
},
fm: 0600 | os.ModeSticky,
}, {
// hard link.
{
h: &Header{
Name: "hard.txt",
Mode: 0644 | c_ISREG,
Size: 0,
Linkname: "file.txt",
ModTime: time.Unix(1360600916, 0),
Typeflag: TypeLink,
},
fm: 0644,
h: &Header{
Name: "hard.txt",
Mode: 0644,
Size: 0,
Linkname: "file.txt",
ModTime: time.Unix(1360600916, 0),
Typeflag: TypeLink,
},
fm: 0644,
}, {
// More information.
{
h: &Header{
Name: "info.txt",
Mode: 0600 | c_ISREG,
Size: 0,
Uid: 1000,
Gid: 1000,
ModTime: time.Unix(1360602540, 0),
Uname: "slartibartfast",
Gname: "users",
Typeflag: TypeReg,
},
fm: 0600,
h: &Header{
Name: "info.txt",
Mode: 0600,
Size: 0,
Uid: 1000,
Gid: 1000,
ModTime: time.Unix(1360602540, 0),
Uname: "slartibartfast",
Gname: "users",
Typeflag: TypeReg,
},
}
fm: 0600,
}}
for i, g := range golden {
fi := g.h.FileInfo()
for i, v := range vectors {
fi := v.h.FileInfo()
h2, err := FileInfoHeader(fi, "")
if err != nil {
t.Error(err)
continue
}
if strings.Contains(fi.Name(), "/") {
t.Errorf("FileInfo of %q contains slash: %q", g.h.Name, fi.Name())
t.Errorf("FileInfo of %q contains slash: %q", v.h.Name, fi.Name())
}
name := path.Base(g.h.Name)
name := path.Base(v.h.Name)
if fi.IsDir() {
name += "/"
}
if got, want := h2.Name, name; got != want {
t.Errorf("i=%d: Name: got %v, want %v", i, got, want)
}
if got, want := h2.Size, g.h.Size; got != want {
if got, want := h2.Size, v.h.Size; got != want {
t.Errorf("i=%d: Size: got %v, want %v", i, got, want)
}
if got, want := h2.Uid, g.h.Uid; got != want {
if got, want := h2.Uid, v.h.Uid; got != want {
t.Errorf("i=%d: Uid: got %d, want %d", i, got, want)
}
if got, want := h2.Gid, g.h.Gid; got != want {
if got, want := h2.Gid, v.h.Gid; got != want {
t.Errorf("i=%d: Gid: got %d, want %d", i, got, want)
}
if got, want := h2.Uname, g.h.Uname; got != want {
if got, want := h2.Uname, v.h.Uname; got != want {
t.Errorf("i=%d: Uname: got %q, want %q", i, got, want)
}
if got, want := h2.Gname, g.h.Gname; got != want {
if got, want := h2.Gname, v.h.Gname; got != want {
t.Errorf("i=%d: Gname: got %q, want %q", i, got, want)
}
if got, want := h2.Linkname, g.h.Linkname; got != want {
if got, want := h2.Linkname, v.h.Linkname; got != want {
t.Errorf("i=%d: Linkname: got %v, want %v", i, got, want)
}
if got, want := h2.Typeflag, g.h.Typeflag; got != want {
t.Logf("%#v %#v", g.h, fi.Sys())
if got, want := h2.Typeflag, v.h.Typeflag; got != want {
t.Logf("%#v %#v", v.h, fi.Sys())
t.Errorf("i=%d: Typeflag: got %q, want %q", i, got, want)
}
if got, want := h2.Mode, g.h.Mode; got != want {
if got, want := h2.Mode, v.h.Mode; got != want {
t.Errorf("i=%d: Mode: got %o, want %o", i, got, want)
}
if got, want := fi.Mode(), g.fm; got != want {
if got, want := fi.Mode(), v.fm; got != want {
t.Errorf("i=%d: fi.Mode: got %o, want %o", i, got, want)
}
if got, want := h2.AccessTime, g.h.AccessTime; got != want {
if got, want := h2.AccessTime, v.h.AccessTime; got != want {
t.Errorf("i=%d: AccessTime: got %v, want %v", i, got, want)
}
if got, want := h2.ChangeTime, g.h.ChangeTime; got != want {
if got, want := h2.ChangeTime, v.h.ChangeTime; got != want {
t.Errorf("i=%d: ChangeTime: got %v, want %v", i, got, want)
}
if got, want := h2.ModTime, g.h.ModTime; got != want {
if got, want := h2.ModTime, v.h.ModTime; got != want {
t.Errorf("i=%d: ModTime: got %v, want %v", i, got, want)
}
if sysh, ok := fi.Sys().(*Header); !ok || sysh != g.h {
if sysh, ok := fi.Sys().(*Header); !ok || sysh != v.h {
t.Errorf("i=%d: Sys didn't return original *Header", i)
}
}
}
func TestHeaderAllowedFormats(t *testing.T) {
vectors := []struct {
header *Header // Input header
paxHdrs map[string]string // Expected PAX headers that may be needed
formats Format // Expected formats that can encode the header
}{{
header: &Header{},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{Size: 077777777777},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{Size: 077777777777, Format: FormatUSTAR},
formats: FormatUSTAR,
}, {
header: &Header{Size: 077777777777, Format: FormatPAX},
formats: FormatUSTAR | FormatPAX,
}, {
header: &Header{Size: 077777777777, Format: FormatGNU},
formats: FormatGNU,
}, {
header: &Header{Size: 077777777777 + 1},
paxHdrs: map[string]string{paxSize: "8589934592"},
formats: FormatPAX | FormatGNU,
}, {
header: &Header{Size: 077777777777 + 1, Format: FormatPAX},
paxHdrs: map[string]string{paxSize: "8589934592"},
formats: FormatPAX,
}, {
header: &Header{Size: 077777777777 + 1, Format: FormatGNU},
paxHdrs: map[string]string{paxSize: "8589934592"},
formats: FormatGNU,
}, {
header: &Header{Mode: 07777777},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{Mode: 07777777 + 1},
formats: FormatGNU,
}, {
header: &Header{Devmajor: -123},
formats: FormatGNU,
}, {
header: &Header{Devmajor: 1<<56 - 1},
formats: FormatGNU,
}, {
header: &Header{Devmajor: 1 << 56},
formats: FormatUnknown,
}, {
header: &Header{Devmajor: -1 << 56},
formats: FormatGNU,
}, {
header: &Header{Devmajor: -1<<56 - 1},
formats: FormatUnknown,
}, {
header: &Header{Name: "用戶名", Devmajor: -1 << 56},
formats: FormatGNU,
}, {
header: &Header{Size: math.MaxInt64},
paxHdrs: map[string]string{paxSize: "9223372036854775807"},
formats: FormatPAX | FormatGNU,
}, {
header: &Header{Size: math.MinInt64},
paxHdrs: map[string]string{paxSize: "-9223372036854775808"},
formats: FormatUnknown,
}, {
header: &Header{Uname: "0123456789abcdef0123456789abcdef"},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{Uname: "0123456789abcdef0123456789abcdefx"},
paxHdrs: map[string]string{paxUname: "0123456789abcdef0123456789abcdefx"},
formats: FormatPAX,
}, {
header: &Header{Name: "foobar"},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{Name: strings.Repeat("a", nameSize)},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{Name: strings.Repeat("a", nameSize+1)},
paxHdrs: map[string]string{paxPath: strings.Repeat("a", nameSize+1)},
formats: FormatPAX | FormatGNU,
}, {
header: &Header{Linkname: "用戶名"},
paxHdrs: map[string]string{paxLinkpath: "用戶名"},
formats: FormatPAX | FormatGNU,
}, {
header: &Header{Linkname: strings.Repeat("用戶名\x00", nameSize)},
paxHdrs: map[string]string{paxLinkpath: strings.Repeat("用戶名\x00", nameSize)},
formats: FormatUnknown,
}, {
header: &Header{Linkname: "\x00hello"},
paxHdrs: map[string]string{paxLinkpath: "\x00hello"},
formats: FormatUnknown,
}, {
header: &Header{Uid: 07777777},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{Uid: 07777777 + 1},
paxHdrs: map[string]string{paxUid: "2097152"},
formats: FormatPAX | FormatGNU,
}, {
header: &Header{Xattrs: nil},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{Xattrs: map[string]string{"foo": "bar"}},
paxHdrs: map[string]string{paxSchilyXattr + "foo": "bar"},
formats: FormatPAX,
}, {
header: &Header{Xattrs: map[string]string{"foo": "bar"}, Format: FormatGNU},
paxHdrs: map[string]string{paxSchilyXattr + "foo": "bar"},
formats: FormatUnknown,
}, {
header: &Header{Xattrs: map[string]string{"用戶名": "\x00hello"}},
paxHdrs: map[string]string{paxSchilyXattr + "用戶名": "\x00hello"},
formats: FormatPAX,
}, {
header: &Header{Xattrs: map[string]string{"foo=bar": "baz"}},
formats: FormatUnknown,
}, {
header: &Header{Xattrs: map[string]string{"foo": ""}},
paxHdrs: map[string]string{paxSchilyXattr + "foo": ""},
formats: FormatPAX,
}, {
header: &Header{ModTime: time.Unix(0, 0)},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{ModTime: time.Unix(077777777777, 0)},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{ModTime: time.Unix(077777777777+1, 0)},
paxHdrs: map[string]string{paxMtime: "8589934592"},
formats: FormatPAX | FormatGNU,
}, {
header: &Header{ModTime: time.Unix(math.MaxInt64, 0)},
paxHdrs: map[string]string{paxMtime: "9223372036854775807"},
formats: FormatPAX | FormatGNU,
}, {
header: &Header{ModTime: time.Unix(math.MaxInt64, 0), Format: FormatUSTAR},
paxHdrs: map[string]string{paxMtime: "9223372036854775807"},
formats: FormatUnknown,
}, {
header: &Header{ModTime: time.Unix(-1, 0)},
paxHdrs: map[string]string{paxMtime: "-1"},
formats: FormatPAX | FormatGNU,
}, {
header: &Header{ModTime: time.Unix(1, 500)},
paxHdrs: map[string]string{paxMtime: "1.0000005"},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{ModTime: time.Unix(1, 0)},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{ModTime: time.Unix(1, 0), Format: FormatPAX},
formats: FormatUSTAR | FormatPAX,
}, {
header: &Header{ModTime: time.Unix(1, 500), Format: FormatUSTAR},
paxHdrs: map[string]string{paxMtime: "1.0000005"},
formats: FormatUSTAR,
}, {
header: &Header{ModTime: time.Unix(1, 500), Format: FormatPAX},
paxHdrs: map[string]string{paxMtime: "1.0000005"},
formats: FormatPAX,
}, {
header: &Header{ModTime: time.Unix(1, 500), Format: FormatGNU},
paxHdrs: map[string]string{paxMtime: "1.0000005"},
formats: FormatGNU,
}, {
header: &Header{ModTime: time.Unix(-1, 500)},
paxHdrs: map[string]string{paxMtime: "-0.9999995"},
formats: FormatPAX | FormatGNU,
}, {
header: &Header{ModTime: time.Unix(-1, 500), Format: FormatGNU},
paxHdrs: map[string]string{paxMtime: "-0.9999995"},
formats: FormatGNU,
}, {
header: &Header{AccessTime: time.Unix(0, 0)},
paxHdrs: map[string]string{paxAtime: "0"},
formats: FormatPAX | FormatGNU,
}, {
header: &Header{AccessTime: time.Unix(0, 0), Format: FormatUSTAR},
paxHdrs: map[string]string{paxAtime: "0"},
formats: FormatUnknown,
}, {
header: &Header{AccessTime: time.Unix(0, 0), Format: FormatPAX},
paxHdrs: map[string]string{paxAtime: "0"},
formats: FormatPAX,
}, {
header: &Header{AccessTime: time.Unix(0, 0), Format: FormatGNU},
paxHdrs: map[string]string{paxAtime: "0"},
formats: FormatGNU,
}, {
header: &Header{AccessTime: time.Unix(-123, 0)},
paxHdrs: map[string]string{paxAtime: "-123"},
formats: FormatPAX | FormatGNU,
}, {
header: &Header{AccessTime: time.Unix(-123, 0), Format: FormatPAX},
paxHdrs: map[string]string{paxAtime: "-123"},
formats: FormatPAX,
}, {
header: &Header{ChangeTime: time.Unix(123, 456)},
paxHdrs: map[string]string{paxCtime: "123.000000456"},
formats: FormatPAX | FormatGNU,
}, {
header: &Header{ChangeTime: time.Unix(123, 456), Format: FormatUSTAR},
paxHdrs: map[string]string{paxCtime: "123.000000456"},
formats: FormatUnknown,
}, {
header: &Header{ChangeTime: time.Unix(123, 456), Format: FormatGNU},
paxHdrs: map[string]string{paxCtime: "123.000000456"},
formats: FormatGNU,
}, {
header: &Header{ChangeTime: time.Unix(123, 456), Format: FormatPAX},
paxHdrs: map[string]string{paxCtime: "123.000000456"},
formats: FormatPAX,
}, {
header: &Header{Name: "foo/", Typeflag: TypeDir},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}, {
header: &Header{Name: "foo/", Typeflag: TypeReg},
formats: FormatUnknown,
}, {
header: &Header{Name: "foo/", Typeflag: TypeSymlink},
formats: FormatUSTAR | FormatPAX | FormatGNU,
}}
for i, v := range vectors {
formats, paxHdrs, err := v.header.allowedFormats()
if formats != v.formats {
t.Errorf("test %d, allowedFormats(): got %v, want %v", i, formats, v.formats)
}
if formats&FormatPAX > 0 && !reflect.DeepEqual(paxHdrs, v.paxHdrs) && !(len(paxHdrs) == 0 && len(v.paxHdrs) == 0) {
t.Errorf("test %d, allowedFormats():\ngot %v\nwant %s", i, paxHdrs, v.paxHdrs)
}
if (formats != FormatUnknown) && (err != nil) {
t.Errorf("test %d, unexpected error: %v", i, err)
}
if (formats == FormatUnknown) && (err == nil) {
t.Errorf("test %d, got nil-error, want non-nil error", i)
}
}
}
func Benchmark(b *testing.B) {
type file struct {
hdr *Header
body []byte
}
vectors := []struct {
label string
files []file
}{{
"USTAR",
[]file{{
&Header{Name: "bar", Mode: 0640, Size: int64(3)},
[]byte("foo"),
}, {
&Header{Name: "world", Mode: 0640, Size: int64(5)},
[]byte("hello"),
}},
}, {
"GNU",
[]file{{
&Header{Name: "bar", Mode: 0640, Size: int64(3), Devmajor: -1},
[]byte("foo"),
}, {
&Header{Name: "world", Mode: 0640, Size: int64(5), Devmajor: -1},
[]byte("hello"),
}},
}, {
"PAX",
[]file{{
&Header{Name: "bar", Mode: 0640, Size: int64(3), Xattrs: map[string]string{"foo": "bar"}},
[]byte("foo"),
}, {
&Header{Name: "world", Mode: 0640, Size: int64(5), Xattrs: map[string]string{"foo": "bar"}},
[]byte("hello"),
}},
}}
b.Run("Writer", func(b *testing.B) {
for _, v := range vectors {
b.Run(v.label, func(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
// Writing to ioutil.Discard because we want to
// test purely the writer code and not bring in disk performance into this.
tw := NewWriter(ioutil.Discard)
for _, file := range v.files {
if err := tw.WriteHeader(file.hdr); err != nil {
b.Errorf("unexpected WriteHeader error: %v", err)
}
if _, err := tw.Write(file.body); err != nil {
b.Errorf("unexpected Write error: %v", err)
}
}
if err := tw.Close(); err != nil {
b.Errorf("unexpected Close error: %v", err)
}
}
})
}
})
b.Run("Reader", func(b *testing.B) {
for _, v := range vectors {
var buf bytes.Buffer
var r bytes.Reader
// Write the archive to a byte buffer.
tw := NewWriter(&buf)
for _, file := range v.files {
tw.WriteHeader(file.hdr)
tw.Write(file.body)
}
tw.Close()
b.Run(v.label, func(b *testing.B) {
b.ReportAllocs()
// Read from the byte buffer.
for i := 0; i < b.N; i++ {
r.Reset(buf.Bytes())
tr := NewReader(&r)
if _, err := tr.Next(); err != nil {
b.Errorf("unexpected Next error: %v", err)
}
if _, err := io.Copy(ioutil.Discard, tr); err != nil {
b.Errorf("unexpected Copy error : %v", err)
}
}
})
}
})
}

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@ -4,295 +4,410 @@
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.
// Writer provides sequential writing of a tar archive.
// Write.WriteHeader begins a new file with the provided Header,
// and then Writer can be treated as an io.Writer to supply that file's data.
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 [blockSize]byte // buffer to use in writeHeader when writing a regular header
paxHdrBuff [blockSize]byte // buffer to use in writeHeader when writing a pax header
}
w io.Writer
pad int64 // Amount of padding to write after current file entry
curr fileWriter // Writer for current file entry
hdr Header // Shallow copy of Header that is safe for mutations
blk block // Buffer to use as temporary local storage
type formatter struct {
err error // Last error seen
// err is a persistent error.
// It is only the responsibility of every exported method of Writer to
// ensure that this error is sticky.
err error
}
// 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
func NewWriter(w io.Writer) *Writer {
return &Writer{w: w, curr: &regFileWriter{w, 0}}
}
// 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
}
type fileWriter interface {
io.Writer
fileState
ReadFrom(io.Reader) (int64, error)
}
// Encode x as an octal ASCII string and write it into b with leading zeros.
func (f *formatter) formatOctal(b []byte, x int64) {
s := strconv.FormatInt(x, 8)
// leading zeros, but leave room for a NUL.
for len(s)+1 < len(b) {
s = "0" + s
}
f.formatString(b, s)
}
// 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.
// Flush finishes writing the current file's block padding.
// The current file must be fully written before Flush can be called.
//
// 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)
}
// 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
}
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()
}
// This is unnecessary as the next call to WriteHeader or Close
// will implicitly flush out the file's padding.
func (tw *Writer) Flush() error {
if tw.err != nil {
return tw.err
}
// a map to hold pax header records, if any are needed
paxHeaders := make(map[string]string)
// TODO(shanemhansen): 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
var f formatter
var header []byte
// 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[:]
if nb := tw.curr.LogicalRemaining(); nb > 0 {
return fmt.Errorf("archive/tar: missed writing %d bytes", nb)
}
copy(header, zeroBlock)
s := slicer(header)
// Wrappers around formatter that automatically sets paxHeaders if the
// argument extends beyond the capacity of the input byte slice.
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)
}
// keep a reference to the filename to allow to overwrite it later if we detect that we can use ustar longnames instead of pax
pathHeaderBytes := s.next(fileNameSize)
formatString(pathHeaderBytes, hdr.Name, paxPath)
// Handle out of range ModTime carefully.
var modTime int64
if !hdr.ModTime.Before(minTime) && !hdr.ModTime.After(maxTime) {
modTime = hdr.ModTime.Unix()
}
f.formatOctal(s.next(8), hdr.Mode) // 100:108
formatNumeric(s.next(8), int64(hdr.Uid), paxUid) // 108:116
formatNumeric(s.next(8), int64(hdr.Gid), paxGid) // 116:124
formatNumeric(s.next(12), hdr.Size, paxSize) // 124:136
formatNumeric(s.next(12), modTime, paxNone) // 136:148 --- consider using pax for finer granularity
s.next(8) // chksum (148:156)
s.next(1)[0] = hdr.Typeflag // 156:157
formatString(s.next(100), hdr.Linkname, paxLinkpath)
copy(s.next(8), []byte("ustar\x0000")) // 257:265
formatString(s.next(32), hdr.Uname, paxUname) // 265:297
formatString(s.next(32), hdr.Gname, paxGname) // 297:329
formatNumeric(s.next(8), hdr.Devmajor, paxNone) // 329:337
formatNumeric(s.next(8), hdr.Devminor, paxNone) // 337:345
// keep a reference to the prefix to allow to overwrite it later if we detect that we can use ustar longnames instead of pax
prefixHeaderBytes := s.next(155)
formatString(prefixHeaderBytes, "", paxNone) // 345:500 prefix
// Use the GNU magic instead of POSIX magic if we used any GNU extensions.
if tw.usedBinary {
copy(header[257:265], []byte("ustar \x00"))
}
_, paxPathUsed := paxHeaders[paxPath]
// try to use a ustar header when only the name is too long
if !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(pathHeaderBytes, suffix, paxNone)
formatString(prefixHeaderBytes, prefix, paxNone)
}
}
// The chksum field is terminated by a NUL and a space.
// This is different from the other octal fields.
chksum, _ := checksum(header)
f.formatOctal(header[148:155], chksum) // Never fails
header[155] = ' '
// Check if there were any formatting errors.
if f.err != nil {
tw.err = f.err
if _, tw.err = tw.w.Write(zeroBlock[:tw.pad]); tw.err != nil {
return tw.err
}
tw.pad = 0
return nil
}
if allowPax {
for k, v := range hdr.Xattrs {
paxHeaders[paxXattr+k] = v
// WriteHeader writes hdr and prepares to accept the file's contents.
// The Header.Size determines how many bytes can be written for the next file.
// If the current file is not fully written, then this returns an error.
// This implicitly flushes any padding necessary before writing the header.
func (tw *Writer) WriteHeader(hdr *Header) error {
if err := tw.Flush(); err != nil {
return err
}
tw.hdr = *hdr // Shallow copy of Header
// Avoid usage of the legacy TypeRegA flag, and automatically promote
// it to use TypeReg or TypeDir.
if tw.hdr.Typeflag == TypeRegA {
if strings.HasSuffix(tw.hdr.Name, "/") {
tw.hdr.Typeflag = TypeDir
} else {
tw.hdr.Typeflag = TypeReg
}
}
if len(paxHeaders) > 0 {
if !allowPax {
return errInvalidHeader
// Round ModTime and ignore AccessTime and ChangeTime unless
// the format is explicitly chosen.
// This ensures nominal usage of WriteHeader (without specifying the format)
// does not always result in the PAX format being chosen, which
// causes a 1KiB increase to every header.
if tw.hdr.Format == FormatUnknown {
tw.hdr.ModTime = tw.hdr.ModTime.Round(time.Second)
tw.hdr.AccessTime = time.Time{}
tw.hdr.ChangeTime = time.Time{}
}
allowedFormats, paxHdrs, err := tw.hdr.allowedFormats()
switch {
case allowedFormats.has(FormatUSTAR):
tw.err = tw.writeUSTARHeader(&tw.hdr)
return tw.err
case allowedFormats.has(FormatPAX):
tw.err = tw.writePAXHeader(&tw.hdr, paxHdrs)
return tw.err
case allowedFormats.has(FormatGNU):
tw.err = tw.writeGNUHeader(&tw.hdr)
return tw.err
default:
return err // Non-fatal error
}
}
func (tw *Writer) writeUSTARHeader(hdr *Header) error {
// Check if we can use USTAR prefix/suffix splitting.
var namePrefix string
if prefix, suffix, ok := splitUSTARPath(hdr.Name); ok {
namePrefix, hdr.Name = prefix, suffix
}
// Pack the main header.
var f formatter
blk := tw.templateV7Plus(hdr, f.formatString, f.formatOctal)
f.formatString(blk.USTAR().Prefix(), namePrefix)
blk.SetFormat(FormatUSTAR)
if f.err != nil {
return f.err // Should never happen since header is validated
}
return tw.writeRawHeader(blk, hdr.Size, hdr.Typeflag)
}
func (tw *Writer) writePAXHeader(hdr *Header, paxHdrs map[string]string) error {
realName, realSize := hdr.Name, hdr.Size
// TODO(dsnet): Re-enable this when adding sparse support.
// See https://golang.org/issue/22735
/*
// Handle sparse files.
var spd sparseDatas
var spb []byte
if len(hdr.SparseHoles) > 0 {
sph := append([]sparseEntry{}, hdr.SparseHoles...) // Copy sparse map
sph = alignSparseEntries(sph, hdr.Size)
spd = invertSparseEntries(sph, hdr.Size)
// Format the sparse map.
hdr.Size = 0 // Replace with encoded size
spb = append(strconv.AppendInt(spb, int64(len(spd)), 10), '\n')
for _, s := range spd {
hdr.Size += s.Length
spb = append(strconv.AppendInt(spb, s.Offset, 10), '\n')
spb = append(strconv.AppendInt(spb, s.Length, 10), '\n')
}
pad := blockPadding(int64(len(spb)))
spb = append(spb, zeroBlock[:pad]...)
hdr.Size += int64(len(spb)) // Accounts for encoded sparse map
// Add and modify appropriate PAX records.
dir, file := path.Split(realName)
hdr.Name = path.Join(dir, "GNUSparseFile.0", file)
paxHdrs[paxGNUSparseMajor] = "1"
paxHdrs[paxGNUSparseMinor] = "0"
paxHdrs[paxGNUSparseName] = realName
paxHdrs[paxGNUSparseRealSize] = strconv.FormatInt(realSize, 10)
paxHdrs[paxSize] = strconv.FormatInt(hdr.Size, 10)
delete(paxHdrs, paxPath) // Recorded by paxGNUSparseName
}
if err := tw.writePAXHeader(hdr, paxHeaders); err != nil {
*/
_ = realSize
// Write PAX records to the output.
isGlobal := hdr.Typeflag == TypeXGlobalHeader
if len(paxHdrs) > 0 || isGlobal {
// Sort keys for deterministic ordering.
var keys []string
for k := range paxHdrs {
keys = append(keys, k)
}
sort.Strings(keys)
// Write each record to a buffer.
var buf strings.Builder
for _, k := range keys {
rec, err := formatPAXRecord(k, paxHdrs[k])
if err != nil {
return err
}
buf.WriteString(rec)
}
// Write the extended header file.
var name string
var flag byte
if isGlobal {
name = realName
if name == "" {
name = "GlobalHead.0.0"
}
flag = TypeXGlobalHeader
} else {
dir, file := path.Split(realName)
name = path.Join(dir, "PaxHeaders.0", file)
flag = TypeXHeader
}
data := buf.String()
if err := tw.writeRawFile(name, data, flag, FormatPAX); err != nil || isGlobal {
return err // Global headers return here
}
}
// Pack the main header.
var f formatter // Ignore errors since they are expected
fmtStr := func(b []byte, s string) { f.formatString(b, toASCII(s)) }
blk := tw.templateV7Plus(hdr, fmtStr, f.formatOctal)
blk.SetFormat(FormatPAX)
if err := tw.writeRawHeader(blk, hdr.Size, hdr.Typeflag); err != nil {
return err
}
// TODO(dsnet): Re-enable this when adding sparse support.
// See https://golang.org/issue/22735
/*
// Write the sparse map and setup the sparse writer if necessary.
if len(spd) > 0 {
// Use tw.curr since the sparse map is accounted for in hdr.Size.
if _, err := tw.curr.Write(spb); err != nil {
return err
}
tw.curr = &sparseFileWriter{tw.curr, spd, 0}
}
*/
return nil
}
func (tw *Writer) writeGNUHeader(hdr *Header) error {
// Use long-link files if Name or Linkname exceeds the field size.
const longName = "././@LongLink"
if len(hdr.Name) > nameSize {
data := hdr.Name + "\x00"
if err := tw.writeRawFile(longName, data, TypeGNULongName, FormatGNU); err != nil {
return err
}
}
if len(hdr.Linkname) > nameSize {
data := hdr.Linkname + "\x00"
if err := tw.writeRawFile(longName, data, TypeGNULongLink, FormatGNU); err != nil {
return err
}
}
tw.nb = int64(hdr.Size)
tw.pad = (blockSize - (tw.nb % blockSize)) % blockSize
_, tw.err = tw.w.Write(header)
return tw.err
// Pack the main header.
var f formatter // Ignore errors since they are expected
var spd sparseDatas
var spb []byte
blk := tw.templateV7Plus(hdr, f.formatString, f.formatNumeric)
if !hdr.AccessTime.IsZero() {
f.formatNumeric(blk.GNU().AccessTime(), hdr.AccessTime.Unix())
}
if !hdr.ChangeTime.IsZero() {
f.formatNumeric(blk.GNU().ChangeTime(), hdr.ChangeTime.Unix())
}
// TODO(dsnet): Re-enable this when adding sparse support.
// See https://golang.org/issue/22735
/*
if hdr.Typeflag == TypeGNUSparse {
sph := append([]sparseEntry{}, hdr.SparseHoles...) // Copy sparse map
sph = alignSparseEntries(sph, hdr.Size)
spd = invertSparseEntries(sph, hdr.Size)
// Format the sparse map.
formatSPD := func(sp sparseDatas, sa sparseArray) sparseDatas {
for i := 0; len(sp) > 0 && i < sa.MaxEntries(); i++ {
f.formatNumeric(sa.Entry(i).Offset(), sp[0].Offset)
f.formatNumeric(sa.Entry(i).Length(), sp[0].Length)
sp = sp[1:]
}
if len(sp) > 0 {
sa.IsExtended()[0] = 1
}
return sp
}
sp2 := formatSPD(spd, blk.GNU().Sparse())
for len(sp2) > 0 {
var spHdr block
sp2 = formatSPD(sp2, spHdr.Sparse())
spb = append(spb, spHdr[:]...)
}
// Update size fields in the header block.
realSize := hdr.Size
hdr.Size = 0 // Encoded size; does not account for encoded sparse map
for _, s := range spd {
hdr.Size += s.Length
}
copy(blk.V7().Size(), zeroBlock[:]) // Reset field
f.formatNumeric(blk.V7().Size(), hdr.Size)
f.formatNumeric(blk.GNU().RealSize(), realSize)
}
*/
blk.SetFormat(FormatGNU)
if err := tw.writeRawHeader(blk, hdr.Size, hdr.Typeflag); err != nil {
return err
}
// Write the extended sparse map and setup the sparse writer if necessary.
if len(spd) > 0 {
// Use tw.w since the sparse map is not accounted for in hdr.Size.
if _, err := tw.w.Write(spb); err != nil {
return err
}
tw.curr = &sparseFileWriter{tw.curr, spd, 0}
}
return nil
}
type (
stringFormatter func([]byte, string)
numberFormatter func([]byte, int64)
)
// templateV7Plus fills out the V7 fields of a block using values from hdr.
// It also fills out fields (uname, gname, devmajor, devminor) that are
// shared in the USTAR, PAX, and GNU formats using the provided formatters.
//
// The block returned is only valid until the next call to
// templateV7Plus or writeRawFile.
func (tw *Writer) templateV7Plus(hdr *Header, fmtStr stringFormatter, fmtNum numberFormatter) *block {
tw.blk.Reset()
modTime := hdr.ModTime
if modTime.IsZero() {
modTime = time.Unix(0, 0)
}
v7 := tw.blk.V7()
v7.TypeFlag()[0] = hdr.Typeflag
fmtStr(v7.Name(), hdr.Name)
fmtStr(v7.LinkName(), hdr.Linkname)
fmtNum(v7.Mode(), hdr.Mode)
fmtNum(v7.UID(), int64(hdr.Uid))
fmtNum(v7.GID(), int64(hdr.Gid))
fmtNum(v7.Size(), hdr.Size)
fmtNum(v7.ModTime(), modTime.Unix())
ustar := tw.blk.USTAR()
fmtStr(ustar.UserName(), hdr.Uname)
fmtStr(ustar.GroupName(), hdr.Gname)
fmtNum(ustar.DevMajor(), hdr.Devmajor)
fmtNum(ustar.DevMinor(), hdr.Devminor)
return &tw.blk
}
// writeRawFile writes a minimal file with the given name and flag type.
// It uses format to encode the header format and will write data as the body.
// It uses default values for all of the other fields (as BSD and GNU tar does).
func (tw *Writer) writeRawFile(name, data string, flag byte, format Format) error {
tw.blk.Reset()
// Best effort for the filename.
name = toASCII(name)
if len(name) > nameSize {
name = name[:nameSize]
}
name = strings.TrimRight(name, "/")
var f formatter
v7 := tw.blk.V7()
v7.TypeFlag()[0] = flag
f.formatString(v7.Name(), name)
f.formatOctal(v7.Mode(), 0)
f.formatOctal(v7.UID(), 0)
f.formatOctal(v7.GID(), 0)
f.formatOctal(v7.Size(), int64(len(data))) // Must be < 8GiB
f.formatOctal(v7.ModTime(), 0)
tw.blk.SetFormat(format)
if f.err != nil {
return f.err // Only occurs if size condition is violated
}
// Write the header and data.
if err := tw.writeRawHeader(&tw.blk, int64(len(data)), flag); err != nil {
return err
}
_, err := io.WriteString(tw, data)
return err
}
// writeRawHeader writes the value of blk, regardless of its value.
// It sets up the Writer such that it can accept a file of the given size.
// If the flag is a special header-only flag, then the size is treated as zero.
func (tw *Writer) writeRawHeader(blk *block, size int64, flag byte) error {
if err := tw.Flush(); err != nil {
return err
}
if _, err := tw.w.Write(blk[:]); err != nil {
return err
}
if isHeaderOnlyType(flag) {
size = 0
}
tw.curr = &regFileWriter{tw.w, size}
tw.pad = blockPadding(size)
return nil
}
// 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 <= fileNameSize || !isASCII(name) {
if length <= nameSize || !isASCII(name) {
return "", "", false
} else if length > fileNamePrefixSize+1 {
length = fileNamePrefixSize + 1
} else if length > prefixSize+1 {
length = prefixSize + 1
} else if name[length-1] == '/' {
length--
}
@ -300,117 +415,239 @@ func splitUSTARPath(name string) (prefix, suffix string, ok bool) {
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 > fileNameSize || nlen == 0 || plen > fileNamePrefixSize {
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) > 100 {
ascii = ascii[:100]
}
ext.Name = ascii
// Construct the body
var buf bytes.Buffer
// Keys are sorted before writing to body to allow deterministic output.
var keys []string
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
}
// 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
}
// Write writes to the current entry in the tar archive.
// Write writes to the current file 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
// Header.Size bytes are written after WriteHeader.
//
// Calling Write on special types like TypeLink, TypeSymlink, TypeChar,
// TypeBlock, TypeDir, and TypeFifo returns (0, ErrWriteTooLong) regardless
// of what the Header.Size claims.
func (tw *Writer) Write(b []byte) (int, error) {
if tw.err != nil {
return 0, tw.err
}
overwrite := false
if int64(len(b)) > tw.nb {
b = b[0:tw.nb]
overwrite = true
n, err := tw.curr.Write(b)
if err != nil && err != ErrWriteTooLong {
tw.err = err
}
n, err = tw.w.Write(b)
tw.nb -= int64(n)
if err == nil && overwrite {
err = ErrWriteTooLong
return
}
tw.err = err
return
return n, err
}
// 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
// readFrom populates the content of the current file by reading from r.
// The bytes read must match the number of remaining bytes in the current file.
//
// If the current file is sparse and r is an io.ReadSeeker,
// then readFrom uses Seek to skip past holes defined in Header.SparseHoles,
// assuming that skipped regions are all NULs.
// This always reads the last byte to ensure r is the right size.
//
// TODO(dsnet): Re-export this when adding sparse file support.
// See https://golang.org/issue/22735
func (tw *Writer) readFrom(r io.Reader) (int64, error) {
if tw.err != nil {
return 0, tw.err
}
n, err := tw.curr.ReadFrom(r)
if err != nil && err != ErrWriteTooLong {
tw.err = err
}
return n, err
}
// Close closes the tar archive by flushing the padding, and writing the footer.
// If the current file (from a prior call to WriteHeader) is not fully written,
// then this returns an error.
func (tw *Writer) Close() error {
if tw.err == ErrWriteAfterClose {
return nil
}
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
// Trailer: two zero blocks.
err := tw.Flush()
for i := 0; i < 2 && err == nil; i++ {
_, err = tw.w.Write(zeroBlock[:])
}
// Ensure all future actions are invalid.
tw.err = ErrWriteAfterClose
return err // Report IO errors
}
// regFileWriter is a fileWriter for writing data to a regular file entry.
type regFileWriter struct {
w io.Writer // Underlying Writer
nb int64 // Number of remaining bytes to write
}
func (fw *regFileWriter) Write(b []byte) (n int, err error) {
overwrite := int64(len(b)) > fw.nb
if overwrite {
b = b[:fw.nb]
}
if len(b) > 0 {
n, err = fw.w.Write(b)
fw.nb -= int64(n)
}
switch {
case err != nil:
return n, err
case overwrite:
return n, ErrWriteTooLong
default:
return n, nil
}
}
func (fw *regFileWriter) ReadFrom(r io.Reader) (int64, error) {
return io.Copy(struct{ io.Writer }{fw}, r)
}
func (fw regFileWriter) LogicalRemaining() int64 {
return fw.nb
}
func (fw regFileWriter) PhysicalRemaining() int64 {
return fw.nb
}
// sparseFileWriter is a fileWriter for writing data to a sparse file entry.
type sparseFileWriter struct {
fw fileWriter // Underlying fileWriter
sp sparseDatas // Normalized list of data fragments
pos int64 // Current position in sparse file
}
func (sw *sparseFileWriter) Write(b []byte) (n int, err error) {
overwrite := int64(len(b)) > sw.LogicalRemaining()
if overwrite {
b = b[:sw.LogicalRemaining()]
}
b0 := b
endPos := sw.pos + int64(len(b))
for endPos > sw.pos && err == nil {
var nf int // Bytes written in fragment
dataStart, dataEnd := sw.sp[0].Offset, sw.sp[0].endOffset()
if sw.pos < dataStart { // In a hole fragment
bf := b[:min(int64(len(b)), dataStart-sw.pos)]
nf, err = zeroWriter{}.Write(bf)
} else { // In a data fragment
bf := b[:min(int64(len(b)), dataEnd-sw.pos)]
nf, err = sw.fw.Write(bf)
}
b = b[nf:]
sw.pos += int64(nf)
if sw.pos >= dataEnd && len(sw.sp) > 1 {
sw.sp = sw.sp[1:] // Ensure last fragment always remains
}
}
return tw.err
n = len(b0) - len(b)
switch {
case err == ErrWriteTooLong:
return n, errMissData // Not possible; implies bug in validation logic
case err != nil:
return n, err
case sw.LogicalRemaining() == 0 && sw.PhysicalRemaining() > 0:
return n, errUnrefData // Not possible; implies bug in validation logic
case overwrite:
return n, ErrWriteTooLong
default:
return n, nil
}
}
func (sw *sparseFileWriter) ReadFrom(r io.Reader) (n int64, err error) {
rs, ok := r.(io.ReadSeeker)
if ok {
if _, err := rs.Seek(0, io.SeekCurrent); err != nil {
ok = false // Not all io.Seeker can really seek
}
}
if !ok {
return io.Copy(struct{ io.Writer }{sw}, r)
}
var readLastByte bool
pos0 := sw.pos
for sw.LogicalRemaining() > 0 && !readLastByte && err == nil {
var nf int64 // Size of fragment
dataStart, dataEnd := sw.sp[0].Offset, sw.sp[0].endOffset()
if sw.pos < dataStart { // In a hole fragment
nf = dataStart - sw.pos
if sw.PhysicalRemaining() == 0 {
readLastByte = true
nf--
}
_, err = rs.Seek(nf, io.SeekCurrent)
} else { // In a data fragment
nf = dataEnd - sw.pos
nf, err = io.CopyN(sw.fw, rs, nf)
}
sw.pos += nf
if sw.pos >= dataEnd && len(sw.sp) > 1 {
sw.sp = sw.sp[1:] // Ensure last fragment always remains
}
}
// If the last fragment is a hole, then seek to 1-byte before EOF, and
// read a single byte to ensure the file is the right size.
if readLastByte && err == nil {
_, err = mustReadFull(rs, []byte{0})
sw.pos++
}
n = sw.pos - pos0
switch {
case err == io.EOF:
return n, io.ErrUnexpectedEOF
case err == ErrWriteTooLong:
return n, errMissData // Not possible; implies bug in validation logic
case err != nil:
return n, err
case sw.LogicalRemaining() == 0 && sw.PhysicalRemaining() > 0:
return n, errUnrefData // Not possible; implies bug in validation logic
default:
return n, ensureEOF(rs)
}
}
func (sw sparseFileWriter) LogicalRemaining() int64 {
return sw.sp[len(sw.sp)-1].endOffset() - sw.pos
}
func (sw sparseFileWriter) PhysicalRemaining() int64 {
return sw.fw.PhysicalRemaining()
}
// zeroWriter may only be written with NULs, otherwise it returns errWriteHole.
type zeroWriter struct{}
func (zeroWriter) Write(b []byte) (int, error) {
for i, c := range b {
if c != 0 {
return i, errWriteHole
}
}
return len(b), nil
}
// ensureEOF checks whether r is at EOF, reporting ErrWriteTooLong if not so.
func ensureEOF(r io.Reader) error {
n, err := tryReadFull(r, []byte{0})
switch {
case n > 0:
return ErrWriteTooLong
case err == io.EOF:
return nil
default:
return err
}
}

1309
archive/tar/writer_test.go
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