diff options
Diffstat (limited to 'vendor/github.com/vbatts')
| -rw-r--r-- | vendor/github.com/vbatts/tar-split/README.md | 3 | ||||
| -rw-r--r-- | vendor/github.com/vbatts/tar-split/archive/tar/common.go | 689 | ||||
| -rw-r--r-- | vendor/github.com/vbatts/tar-split/archive/tar/format.go | 303 | ||||
| -rw-r--r-- | vendor/github.com/vbatts/tar-split/archive/tar/reader.go | 1377 | ||||
| -rw-r--r-- | vendor/github.com/vbatts/tar-split/archive/tar/stat_actime1.go (renamed from vendor/github.com/vbatts/tar-split/archive/tar/stat_atim.go) | 0 | ||||
| -rw-r--r-- | vendor/github.com/vbatts/tar-split/archive/tar/stat_actime2.go (renamed from vendor/github.com/vbatts/tar-split/archive/tar/stat_atimespec.go) | 0 | ||||
| -rw-r--r-- | vendor/github.com/vbatts/tar-split/archive/tar/stat_unix.go | 72 | ||||
| -rw-r--r-- | vendor/github.com/vbatts/tar-split/archive/tar/strconv.go | 326 | ||||
| -rw-r--r-- | vendor/github.com/vbatts/tar-split/archive/tar/writer.go | 871 |
9 files changed, 2406 insertions, 1235 deletions
diff --git a/vendor/github.com/vbatts/tar-split/README.md b/vendor/github.com/vbatts/tar-split/README.md index 03e3ec430..fe997f69b 100644 --- a/vendor/github.com/vbatts/tar-split/README.md +++ b/vendor/github.com/vbatts/tar-split/README.md @@ -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) - diff --git a/vendor/github.com/vbatts/tar-split/archive/tar/common.go b/vendor/github.com/vbatts/tar-split/archive/tar/common.go index 36f4e2398..dee9e47e4 100644 --- a/vendor/github.com/vbatts/tar-split/archive/tar/common.go +++ b/vendor/github.com/vbatts/tar-split/archive/tar/common.go @@ -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" ) +// 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. + +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 ( - blockSize = 512 - - // Types - TypeReg = '0' // regular file - TypeRegA = '\x00' // regular file - TypeLink = '1' // hard link - TypeSymlink = '2' // symbolic link - TypeChar = '3' // character device node - TypeBlock = '4' // block device node - TypeDir = '5' // directory - TypeFifo = '6' // fifo node - TypeCont = '7' // reserved - TypeXHeader = 'x' // extended header - TypeXGlobalHeader = 'g' // global extended header - TypeGNULongName = 'L' // Next file has a long name - TypeGNULongLink = 'K' // Next file symlinks to a file w/ a long name - TypeGNUSparse = 'S' // sparse file + // 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 +} diff --git a/vendor/github.com/vbatts/tar-split/archive/tar/format.go b/vendor/github.com/vbatts/tar-split/archive/tar/format.go new file mode 100644 index 000000000..1f89d0c59 --- /dev/null +++ b/vendor/github.com/vbatts/tar-split/archive/tar/format.go @@ -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] } diff --git a/vendor/github.com/vbatts/tar-split/archive/tar/reader.go b/vendor/github.com/vbatts/tar-split/archive/tar/reader.go index adf32122e..ea64a3820 100644 --- a/vendor/github.com/vbatts/tar-split/archive/tar/reader.go +++ b/vendor/github.com/vbatts/tar-split/archive/tar/reader.go @@ -4,44 +4,38 @@ package tar -// TODO(dsymonds): -// - pax extensions - import ( "bytes" - "errors" "io" "io/ioutil" - "math" - "os" "strconv" "strings" "time" ) -var ( - ErrHeader = errors.New("archive/tar: invalid tar header") -) - -const maxNanoSecondIntSize = 9 - -// A Reader provides sequential access to the contents of a tar archive. -// A tar archive consists of a sequence of files. -// The Next method advances to the next file in the archive (including the first), -// and then it can be treated as an io.Reader to access the file's data. +// Reader provides sequential access to the contents of a tar archive. +// Reader.Next advances to the next file in the archive (including the first), +// and then Reader can be treated as an io.Reader to access the file's data. type Reader struct { - r io.Reader - err error - pad int64 // amount of padding (ignored) after current file entry - curr numBytesReader // reader for current file entry - hdrBuff [blockSize]byte // buffer to use in readHeader + r io.Reader + pad int64 // Amount of padding (ignored) after current file entry + curr fileReader // Reader for current file entry + blk block // Buffer to use as temporary local storage + + // err is a persistent error. + // It is only the responsibility of every exported method of Reader to + // ensure that this error is sticky. + err error RawAccounting bool // Whether to enable the access needed to reassemble the tar from raw bytes. Some performance/memory hit for this. rawBytes *bytes.Buffer // last raw bits } -type parser struct { - err error // Last error seen +type fileReader interface { + io.Reader + fileState + + WriteTo(io.Writer) (int64, error) } // RawBytes accesses the raw bytes of the archive, apart from the file payload itself. @@ -57,87 +51,35 @@ func (tr *Reader) RawBytes() []byte { if tr.rawBytes == nil { tr.rawBytes = bytes.NewBuffer(nil) } - // if we've read them, then flush them. - defer tr.rawBytes.Reset() - return tr.rawBytes.Bytes() -} + defer tr.rawBytes.Reset() // if we've read them, then flush them. -// A numBytesReader is an io.Reader with a numBytes method, returning the number -// of bytes remaining in the underlying encoded data. -type numBytesReader interface { - io.Reader - numBytes() int64 -} - -// A regFileReader is a numBytesReader for reading file data from a tar archive. -type regFileReader struct { - r io.Reader // underlying reader - nb int64 // number of unread bytes for current file entry -} - -// A sparseFileReader is a numBytesReader for reading sparse file data from a -// tar archive. -type sparseFileReader struct { - rfr numBytesReader // Reads the sparse-encoded file data - sp []sparseEntry // The sparse map for the file - pos int64 // Keeps track of file position - total int64 // Total size of the file -} + return tr.rawBytes.Bytes() -// A sparseEntry holds a single entry in a sparse file's sparse map. -// -// Sparse files are represented using a series of sparseEntrys. -// Despite the name, a sparseEntry represents an actual data fragment that -// references data found in the underlying archive stream. All regions not -// covered by a sparseEntry are logically filled with zeros. -// -// For example, if the underlying raw file contains the 10-byte data: -// var compactData = "abcdefgh" -// -// And the sparse map has the following entries: -// var sp = []sparseEntry{ -// {offset: 2, numBytes: 5} // Data fragment for [2..7] -// {offset: 18, numBytes: 3} // Data fragment for [18..21] -// } -// -// Then the content of the resulting sparse file with a "real" size of 25 is: -// var sparseData = "\x00"*2 + "abcde" + "\x00"*11 + "fgh" + "\x00"*4 -type sparseEntry struct { - offset int64 // Starting position of the fragment - numBytes int64 // Length of the fragment } -// Keywords for GNU sparse files in a PAX extended header -const ( - paxGNUSparseNumBlocks = "GNU.sparse.numblocks" - paxGNUSparseOffset = "GNU.sparse.offset" - paxGNUSparseNumBytes = "GNU.sparse.numbytes" - paxGNUSparseMap = "GNU.sparse.map" - paxGNUSparseName = "GNU.sparse.name" - paxGNUSparseMajor = "GNU.sparse.major" - paxGNUSparseMinor = "GNU.sparse.minor" - paxGNUSparseSize = "GNU.sparse.size" - paxGNUSparseRealSize = "GNU.sparse.realsize" -) - -// Keywords for old GNU sparse headers -const ( - oldGNUSparseMainHeaderOffset = 386 - oldGNUSparseMainHeaderIsExtendedOffset = 482 - oldGNUSparseMainHeaderNumEntries = 4 - oldGNUSparseExtendedHeaderIsExtendedOffset = 504 - oldGNUSparseExtendedHeaderNumEntries = 21 - oldGNUSparseOffsetSize = 12 - oldGNUSparseNumBytesSize = 12 -) - // NewReader creates a new Reader reading from r. -func NewReader(r io.Reader) *Reader { return &Reader{r: r} } +func NewReader(r io.Reader) *Reader { + return &Reader{r: r, curr: ®FileReader{r, 0}} +} // Next advances to the next entry in the tar archive. +// The Header.Size determines how many bytes can be read for the next file. +// Any remaining data in the current file is automatically discarded. // // io.EOF is returned at the end of the input. func (tr *Reader) Next() (*Header, error) { + if tr.err != nil { + return nil, tr.err + } + hdr, err := tr.next() + tr.err = err + return hdr, err +} + +func (tr *Reader) next() (*Header, error) { + var paxHdrs map[string]string + var gnuLongName, gnuLongLink string + if tr.RawAccounting { if tr.rawBytes == nil { tr.rawBytes = bytes.NewBuffer(nil) @@ -146,248 +88,245 @@ func (tr *Reader) Next() (*Header, error) { } } - if tr.err != nil { - return nil, tr.err - } - - var hdr *Header - var extHdrs map[string]string - // Externally, Next iterates through the tar archive as if it is a series of // files. Internally, the tar format often uses fake "files" to add meta // data that describes the next file. These meta data "files" should not // normally be visible to the outside. As such, this loop iterates through // one or more "header files" until it finds a "normal file". -loop: + format := FormatUSTAR | FormatPAX | FormatGNU for { - tr.err = tr.skipUnread() - if tr.err != nil { - return nil, tr.err + // Discard the remainder of the file and any padding. + if err := discard(tr, tr.curr.PhysicalRemaining()); err != nil { + return nil, err + } + n, err := tryReadFull(tr.r, tr.blk[:tr.pad]) + if err != nil { + return nil, err } + if tr.RawAccounting { + tr.rawBytes.Write(tr.blk[:n]) + } + tr.pad = 0 - hdr = tr.readHeader() - if tr.err != nil { - return nil, tr.err + hdr, rawHdr, err := tr.readHeader() + if err != nil { + return nil, err + } + if err := tr.handleRegularFile(hdr); err != nil { + return nil, err } + format.mayOnlyBe(hdr.Format) + // Check for PAX/GNU special headers and files. switch hdr.Typeflag { - case TypeXHeader: - extHdrs, tr.err = parsePAX(tr) - if tr.err != nil { - return nil, tr.err + case TypeXHeader, TypeXGlobalHeader: + format.mayOnlyBe(FormatPAX) + paxHdrs, err = parsePAX(tr) + if err != nil { + return nil, err } - continue loop // This is a meta header affecting the next header + if hdr.Typeflag == TypeXGlobalHeader { + mergePAX(hdr, paxHdrs) + return &Header{ + Name: hdr.Name, + Typeflag: hdr.Typeflag, + Xattrs: hdr.Xattrs, + PAXRecords: hdr.PAXRecords, + Format: format, + }, nil + } + continue // This is a meta header affecting the next header case TypeGNULongName, TypeGNULongLink: - var realname []byte - realname, tr.err = ioutil.ReadAll(tr) - if tr.err != nil { - return nil, tr.err + format.mayOnlyBe(FormatGNU) + realname, err := ioutil.ReadAll(tr) + if err != nil { + return nil, err } if tr.RawAccounting { - if _, tr.err = tr.rawBytes.Write(realname); tr.err != nil { - return nil, tr.err - } + tr.rawBytes.Write(realname) } - // Convert GNU extensions to use PAX headers. - if extHdrs == nil { - extHdrs = make(map[string]string) - } var p parser switch hdr.Typeflag { case TypeGNULongName: - extHdrs[paxPath] = p.parseString(realname) + gnuLongName = p.parseString(realname) case TypeGNULongLink: - extHdrs[paxLinkpath] = p.parseString(realname) - } - if p.err != nil { - tr.err = p.err - return nil, tr.err + gnuLongLink = p.parseString(realname) } - continue loop // This is a meta header affecting the next header + continue // This is a meta header affecting the next header default: - mergePAX(hdr, extHdrs) + // The old GNU sparse format is handled here since it is technically + // just a regular file with additional attributes. - // Check for a PAX format sparse file - sp, err := tr.checkForGNUSparsePAXHeaders(hdr, extHdrs) - if err != nil { - tr.err = err + if err := mergePAX(hdr, paxHdrs); err != nil { return nil, err } - if sp != nil { - // Current file is a PAX format GNU sparse file. - // Set the current file reader to a sparse file reader. - tr.curr, tr.err = newSparseFileReader(tr.curr, sp, hdr.Size) - if tr.err != nil { - return nil, tr.err + if gnuLongName != "" { + hdr.Name = gnuLongName + } + if gnuLongLink != "" { + hdr.Linkname = gnuLongLink + } + if hdr.Typeflag == TypeRegA { + if strings.HasSuffix(hdr.Name, "/") { + hdr.Typeflag = TypeDir // Legacy archives use trailing slash for directories + } else { + hdr.Typeflag = TypeReg } } - break loop // This is a file, so stop + + // The extended headers may have updated the size. + // Thus, setup the regFileReader again after merging PAX headers. + if err := tr.handleRegularFile(hdr); err != nil { + return nil, err + } + + // Sparse formats rely on being able to read from the logical data + // section; there must be a preceding call to handleRegularFile. + if err := tr.handleSparseFile(hdr, rawHdr); err != nil { + return nil, err + } + + // Set the final guess at the format. + if format.has(FormatUSTAR) && format.has(FormatPAX) { + format.mayOnlyBe(FormatUSTAR) + } + hdr.Format = format + return hdr, nil // This is a file, so stop } } - return hdr, nil } -// checkForGNUSparsePAXHeaders checks the PAX headers for GNU sparse headers. If they are found, then -// this function reads the sparse map and returns it. Unknown sparse formats are ignored, causing the file to -// be treated as a regular file. -func (tr *Reader) checkForGNUSparsePAXHeaders(hdr *Header, headers map[string]string) ([]sparseEntry, error) { - var sparseFormat string - - // Check for sparse format indicators - major, majorOk := headers[paxGNUSparseMajor] - minor, minorOk := headers[paxGNUSparseMinor] - sparseName, sparseNameOk := headers[paxGNUSparseName] - _, sparseMapOk := headers[paxGNUSparseMap] - sparseSize, sparseSizeOk := headers[paxGNUSparseSize] - sparseRealSize, sparseRealSizeOk := headers[paxGNUSparseRealSize] - - // Identify which, if any, sparse format applies from which PAX headers are set - if majorOk && minorOk { - sparseFormat = major + "." + minor - } else if sparseNameOk && sparseMapOk { - sparseFormat = "0.1" - } else if sparseSizeOk { - sparseFormat = "0.0" - } else { - // Not a PAX format GNU sparse file. - return nil, nil +// handleRegularFile sets up the current file reader and padding such that it +// can only read the following logical data section. It will properly handle +// special headers that contain no data section. +func (tr *Reader) handleRegularFile(hdr *Header) error { + nb := hdr.Size + if isHeaderOnlyType(hdr.Typeflag) { + nb = 0 } - - // Check for unknown sparse format - if sparseFormat != "0.0" && sparseFormat != "0.1" && sparseFormat != "1.0" { - return nil, nil + if nb < 0 { + return ErrHeader } - // Update hdr from GNU sparse PAX headers - if sparseNameOk { - hdr.Name = sparseName + tr.pad = blockPadding(nb) + tr.curr = ®FileReader{r: tr.r, nb: nb} + return nil +} + +// handleSparseFile checks if the current file is a sparse format of any type +// and sets the curr reader appropriately. +func (tr *Reader) handleSparseFile(hdr *Header, rawHdr *block) error { + var spd sparseDatas + var err error + if hdr.Typeflag == TypeGNUSparse { + spd, err = tr.readOldGNUSparseMap(hdr, rawHdr) + } else { + spd, err = tr.readGNUSparsePAXHeaders(hdr) } - if sparseSizeOk { - realSize, err := strconv.ParseInt(sparseSize, 10, 0) - if err != nil { - return nil, ErrHeader + + // If sp is non-nil, then this is a sparse file. + // Note that it is possible for len(sp) == 0. + if err == nil && spd != nil { + if isHeaderOnlyType(hdr.Typeflag) || !validateSparseEntries(spd, hdr.Size) { + return ErrHeader } - hdr.Size = realSize - } else if sparseRealSizeOk { - realSize, err := strconv.ParseInt(sparseRealSize, 10, 0) + sph := invertSparseEntries(spd, hdr.Size) + tr.curr = &sparseFileReader{tr.curr, sph, 0} + } + return err +} + +// readGNUSparsePAXHeaders checks the PAX headers for GNU sparse headers. +// If they are found, then this function reads the sparse map and returns it. +// This assumes that 0.0 headers have already been converted to 0.1 headers +// by the PAX header parsing logic. +func (tr *Reader) readGNUSparsePAXHeaders(hdr *Header) (sparseDatas, error) { + // Identify the version of GNU headers. + var is1x0 bool + major, minor := hdr.PAXRecords[paxGNUSparseMajor], hdr.PAXRecords[paxGNUSparseMinor] + switch { + case major == "0" && (minor == "0" || minor == "1"): + is1x0 = false + case major == "1" && minor == "0": + is1x0 = true + case major != "" || minor != "": + return nil, nil // Unknown GNU sparse PAX version + case hdr.PAXRecords[paxGNUSparseMap] != "": + is1x0 = false // 0.0 and 0.1 did not have explicit version records, so guess + default: + return nil, nil // Not a PAX format GNU sparse file. + } + hdr.Format.mayOnlyBe(FormatPAX) + + // Update hdr from GNU sparse PAX headers. + if name := hdr.PAXRecords[paxGNUSparseName]; name != "" { + hdr.Name = name + } + size := hdr.PAXRecords[paxGNUSparseSize] + if size == "" { + size = hdr.PAXRecords[paxGNUSparseRealSize] + } + if size != "" { + n, err := strconv.ParseInt(size, 10, 64) if err != nil { return nil, ErrHeader } - hdr.Size = realSize + hdr.Size = n } - // Set up the sparse map, according to the particular sparse format in use - var sp []sparseEntry - var err error - switch sparseFormat { - case "0.0", "0.1": - sp, err = readGNUSparseMap0x1(headers) - case "1.0": - sp, err = readGNUSparseMap1x0(tr.curr) + // Read the sparse map according to the appropriate format. + if is1x0 { + return readGNUSparseMap1x0(tr.curr) } - return sp, err + return readGNUSparseMap0x1(hdr.PAXRecords) } -// mergePAX merges well known headers according to PAX standard. -// In general headers with the same name as those found -// in the header struct overwrite those found in the header -// struct with higher precision or longer values. Esp. useful -// for name and linkname fields. -func mergePAX(hdr *Header, headers map[string]string) error { - for k, v := range headers { +// mergePAX merges paxHdrs into hdr for all relevant fields of Header. +func mergePAX(hdr *Header, paxHdrs map[string]string) (err error) { + for k, v := range paxHdrs { + if v == "" { + continue // Keep the original USTAR value + } + var id64 int64 switch k { case paxPath: hdr.Name = v case paxLinkpath: hdr.Linkname = v - case paxGname: - hdr.Gname = v case paxUname: hdr.Uname = v + case paxGname: + hdr.Gname = v case paxUid: - uid, err := strconv.ParseInt(v, 10, 0) - if err != nil { - return err - } - hdr.Uid = int(uid) + id64, err = strconv.ParseInt(v, 10, 64) + hdr.Uid = int(id64) // Integer overflow possible case paxGid: - gid, err := strconv.ParseInt(v, 10, 0) - if err != nil { - return err - } - hdr.Gid = int(gid) + id64, err = strconv.ParseInt(v, 10, 64) + hdr.Gid = int(id64) // Integer overflow possible case paxAtime: - t, err := parsePAXTime(v) - if err != nil { - return err - } - hdr.AccessTime = t + hdr.AccessTime, err = parsePAXTime(v) case paxMtime: - t, err := parsePAXTime(v) - if err != nil { - return err - } - hdr.ModTime = t + hdr.ModTime, err = parsePAXTime(v) case paxCtime: - t, err := parsePAXTime(v) - if err != nil { - return err - } - hdr.ChangeTime = t + hdr.ChangeTime, err = parsePAXTime(v) case paxSize: - size, err := strconv.ParseInt(v, 10, 0) - if err != nil { - return err - } - hdr.Size = int64(size) + hdr.Size, err = strconv.ParseInt(v, 10, 64) default: - if strings.HasPrefix(k, paxXattr) { + if strings.HasPrefix(k, paxSchilyXattr) { if hdr.Xattrs == nil { hdr.Xattrs = make(map[string]string) } - hdr.Xattrs[k[len(paxXattr):]] = v + hdr.Xattrs[k[len(paxSchilyXattr):]] = v } } - } - return nil -} - -// parsePAXTime takes a string of the form %d.%d as described in -// the PAX specification. -func parsePAXTime(t string) (time.Time, error) { - buf := []byte(t) - pos := bytes.IndexByte(buf, '.') - var seconds, nanoseconds int64 - var err error - if pos == -1 { - seconds, err = strconv.ParseInt(t, 10, 0) - if err != nil { - return time.Time{}, err - } - } else { - seconds, err = strconv.ParseInt(string(buf[:pos]), 10, 0) if err != nil { - return time.Time{}, err - } - nano_buf := string(buf[pos+1:]) - // Pad as needed before converting to a decimal. - // For example .030 -> .030000000 -> 30000000 nanoseconds - if len(nano_buf) < maxNanoSecondIntSize { - // Right pad - nano_buf += strings.Repeat("0", maxNanoSecondIntSize-len(nano_buf)) - } else if len(nano_buf) > maxNanoSecondIntSize { - // Right truncate - nano_buf = nano_buf[:maxNanoSecondIntSize] - } - nanoseconds, err = strconv.ParseInt(string(nano_buf), 10, 0) - if err != nil { - return time.Time{}, err + return ErrHeader } } - ts := time.Unix(seconds, nanoseconds) - return ts, nil + hdr.PAXRecords = paxHdrs + return nil } // parsePAX parses PAX headers. @@ -406,12 +345,11 @@ func parsePAX(r io.Reader) (map[string]string, error) { sbuf := string(buf) // For GNU PAX sparse format 0.0 support. - // This function transforms the sparse format 0.0 headers into sparse format 0.1 headers. - var sparseMap bytes.Buffer + // This function transforms the sparse format 0.0 headers into format 0.1 + // headers since 0.0 headers were not PAX compliant. + var sparseMap []string - headers := make(map[string]string) - // Each record is constructed as - // "%d %s=%s\n", length, keyword, value + paxHdrs := make(map[string]string) for len(sbuf) > 0 { key, value, residual, err := parsePAXRecord(sbuf) if err != nil { @@ -419,422 +357,234 @@ func parsePAX(r io.Reader) (map[string]string, error) { } sbuf = residual - keyStr := string(key) - if keyStr == paxGNUSparseOffset || keyStr == paxGNUSparseNumBytes { - // GNU sparse format 0.0 special key. Write to sparseMap instead of using the headers map. - sparseMap.WriteString(value) - sparseMap.Write([]byte{','}) - } else { - // Normal key. Set the value in the headers map. - headers[keyStr] = string(value) - } - } - if sparseMap.Len() != 0 { - // Add sparse info to headers, chopping off the extra comma - sparseMap.Truncate(sparseMap.Len() - 1) - headers[paxGNUSparseMap] = sparseMap.String() - } - return headers, nil -} - -// parsePAXRecord parses the input PAX record string into a key-value pair. -// If parsing is successful, it will slice off the currently read record and -// return the remainder as r. -// -// A PAX record is of the following form: -// "%d %s=%s\n" % (size, key, value) -func parsePAXRecord(s string) (k, v, r string, err error) { - // The size field ends at the first space. - sp := strings.IndexByte(s, ' ') - if sp == -1 { - return "", "", s, ErrHeader - } - - // Parse the first token as a decimal integer. - n, perr := strconv.ParseInt(s[:sp], 10, 0) // Intentionally parse as native int - if perr != nil || n < 5 || int64(len(s)) < n { - return "", "", s, ErrHeader - } - - // Extract everything between the space and the final newline. - rec, nl, rem := s[sp+1:n-1], s[n-1:n], s[n:] - if nl != "\n" { - return "", "", s, ErrHeader - } - - // The first equals separates the key from the value. - eq := strings.IndexByte(rec, '=') - if eq == -1 { - return "", "", s, ErrHeader - } - return rec[:eq], rec[eq+1:], rem, nil -} - -// parseString parses bytes as a NUL-terminated C-style string. -// If a NUL byte is not found then the whole slice is returned as a string. -func (*parser) parseString(b []byte) string { - n := 0 - for n < len(b) && b[n] != 0 { - n++ - } - return string(b[0:n]) -} - -// 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 + switch key { + case paxGNUSparseOffset, paxGNUSparseNumBytes: + // Validate sparse header order and value. + if (len(sparseMap)%2 == 0 && key != paxGNUSparseOffset) || + (len(sparseMap)%2 == 1 && key != paxGNUSparseNumBytes) || + strings.Contains(value, ",") { + return nil, ErrHeader } - 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) -} - -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) -} - -// skipUnread skips any unread bytes in the existing file entry, as well as any -// alignment padding. It returns io.ErrUnexpectedEOF if any io.EOF is -// encountered in the data portion; it is okay to hit io.EOF in the padding. -// -// Note that this function still works properly even when sparse files are being -// used since numBytes returns the bytes remaining in the underlying io.Reader. -func (tr *Reader) skipUnread() error { - dataSkip := tr.numBytes() // Number of data bytes to skip - totalSkip := dataSkip + tr.pad // Total number of bytes to skip - tr.curr, tr.pad = nil, 0 - if tr.RawAccounting { - _, tr.err = io.CopyN(tr.rawBytes, tr.r, totalSkip) - return tr.err - } - // If possible, Seek to the last byte before the end of the data section. - // Do this because Seek is often lazy about reporting errors; this will mask - // the fact that the tar stream may be truncated. We can rely on the - // io.CopyN done shortly afterwards to trigger any IO errors. - var seekSkipped int64 // Number of bytes skipped via Seek - if sr, ok := tr.r.(io.Seeker); ok && dataSkip > 1 { - // Not all io.Seeker can actually Seek. For example, os.Stdin implements - // io.Seeker, but calling Seek always returns an error and performs - // no action. Thus, we try an innocent seek to the current position - // to see if Seek is really supported. - pos1, err := sr.Seek(0, os.SEEK_CUR) - if err == nil { - // Seek seems supported, so perform the real Seek. - pos2, err := sr.Seek(dataSkip-1, os.SEEK_CUR) - if err != nil { - tr.err = err - return tr.err - } - seekSkipped = pos2 - pos1 + sparseMap = append(sparseMap, value) + default: + paxHdrs[key] = value } } - - var copySkipped int64 // Number of bytes skipped via CopyN - copySkipped, tr.err = io.CopyN(ioutil.Discard, tr.r, totalSkip-seekSkipped) - if tr.err == io.EOF && seekSkipped+copySkipped < dataSkip { - tr.err = io.ErrUnexpectedEOF + if len(sparseMap) > 0 { + paxHdrs[paxGNUSparseMap] = strings.Join(sparseMap, ",") } - return tr.err -} - -func (tr *Reader) verifyChecksum(header []byte) bool { - if tr.err != nil { - return false - } - - var p parser - given := p.parseOctal(header[148:156]) - unsigned, signed := checksum(header) - return p.err == nil && (given == unsigned || given == signed) + return paxHdrs, nil } // readHeader reads the next block header and assumes that the underlying reader -// is already aligned to a block boundary. +// is already aligned to a block boundary. It returns the raw block of the +// header in case further processing is required. // // The err will be set to io.EOF only when one of the following occurs: // * Exactly 0 bytes are read and EOF is hit. // * Exactly 1 block of zeros is read and EOF is hit. // * At least 2 blocks of zeros are read. -func (tr *Reader) readHeader() *Header { - header := tr.hdrBuff[:] - copy(header, zeroBlock) - - if n, err := io.ReadFull(tr.r, header); err != nil { - tr.err = err - // because it could read some of the block, but reach EOF first - if tr.err == io.EOF && tr.RawAccounting { - if _, err := tr.rawBytes.Write(header[:n]); err != nil { - tr.err = err - } - } - return nil // io.EOF is okay here +func (tr *Reader) readHeader() (*Header, *block, error) { + // Two blocks of zero bytes marks the end of the archive. + n, err := io.ReadFull(tr.r, tr.blk[:]) + if tr.RawAccounting && (err == nil || err == io.EOF) { + tr.rawBytes.Write(tr.blk[:n]) } - if tr.RawAccounting { - if _, tr.err = tr.rawBytes.Write(header); tr.err != nil { - return nil - } + if err != nil { + return nil, nil, err // EOF is okay here; exactly 0 bytes read } - // Two blocks of zero bytes marks the end of the archive. - if bytes.Equal(header, zeroBlock[0:blockSize]) { - if n, err := io.ReadFull(tr.r, header); err != nil { - tr.err = err - // because it could read some of the block, but reach EOF first - if tr.err == io.EOF && tr.RawAccounting { - if _, err := tr.rawBytes.Write(header[:n]); err != nil { - tr.err = err - } - } - return nil // io.EOF is okay here + if bytes.Equal(tr.blk[:], zeroBlock[:]) { + n, err = io.ReadFull(tr.r, tr.blk[:]) + if tr.RawAccounting && (err == nil || err == io.EOF) { + tr.rawBytes.Write(tr.blk[:n]) } - if tr.RawAccounting { - if _, tr.err = tr.rawBytes.Write(header); tr.err != nil { - return nil - } + if err != nil { + return nil, nil, err // EOF is okay here; exactly 1 block of zeros read } - if bytes.Equal(header, zeroBlock[0:blockSize]) { - tr.err = io.EOF - } else { - tr.err = ErrHeader // zero block and then non-zero block + if bytes.Equal(tr.blk[:], zeroBlock[:]) { + return nil, nil, io.EOF // normal EOF; exactly 2 block of zeros read } - return nil + return nil, nil, ErrHeader // Zero block and then non-zero block } - if !tr.verifyChecksum(header) { - tr.err = ErrHeader - return nil + // Verify the header matches a known format. + format := tr.blk.GetFormat() + if format == FormatUnknown { + return nil, nil, ErrHeader } - // Unpack var p parser hdr := new(Header) - s := slicer(header) - - hdr.Name = p.parseString(s.next(100)) - hdr.Mode = p.parseNumeric(s.next(8)) - hdr.Uid = int(p.parseNumeric(s.next(8))) - hdr.Gid = int(p.parseNumeric(s.next(8))) - hdr.Size = p.parseNumeric(s.next(12)) - hdr.ModTime = time.Unix(p.parseNumeric(s.next(12)), 0) - s.next(8) // chksum - hdr.Typeflag = s.next(1)[0] - hdr.Linkname = p.parseString(s.next(100)) - - // The remainder of the header depends on the value of magic. - // The original (v7) version of tar had no explicit magic field, - // so its magic bytes, like the rest of the block, are NULs. - magic := string(s.next(8)) // contains version field as well. - var format string - switch { - case magic[:6] == "ustar\x00": // POSIX tar (1003.1-1988) - if string(header[508:512]) == "tar\x00" { - format = "star" - } else { - format = "posix" - } - case magic == "ustar \x00": // old GNU tar - format = "gnu" - } - switch format { - case "posix", "gnu", "star": - hdr.Uname = p.parseString(s.next(32)) - hdr.Gname = p.parseString(s.next(32)) - devmajor := s.next(8) - devminor := s.next(8) - if hdr.Typeflag == TypeChar || hdr.Typeflag == TypeBlock { - hdr.Devmajor = p.parseNumeric(devmajor) - hdr.Devminor = p.parseNumeric(devminor) - } + // Unpack the V7 header. + v7 := tr.blk.V7() + hdr.Typeflag = v7.TypeFlag()[0] + hdr.Name = p.parseString(v7.Name()) + hdr.Linkname = p.parseString(v7.LinkName()) + hdr.Size = p.parseNumeric(v7.Size()) + hdr.Mode = p.parseNumeric(v7.Mode()) + hdr.Uid = int(p.parseNumeric(v7.UID())) + hdr.Gid = int(p.parseNumeric(v7.GID())) + hdr.ModTime = time.Unix(p.parseNumeric(v7.ModTime()), 0) + + // Unpack format specific fields. + if format > formatV7 { + ustar := tr.blk.USTAR() + hdr.Uname = p.parseString(ustar.UserName()) + hdr.Gname = p.parseString(ustar.GroupName()) + hdr.Devmajor = p.parseNumeric(ustar.DevMajor()) + hdr.Devminor = p.parseNumeric(ustar.DevMinor()) + var prefix string - switch format { - case "posix", "gnu": - prefix = p.parseString(s.next(155)) - case "star": - prefix = p.parseString(s.next(131)) - hdr.AccessTime = time.Unix(p.parseNumeric(s.next(12)), 0) - hdr.ChangeTime = time.Unix(p.parseNumeric(s.next(12)), 0) + switch { + case format.has(FormatUSTAR | FormatPAX): + hdr.Format = format + ustar := tr.blk.USTAR() + prefix = p.parseString(ustar.Prefix()) + + // For Format detection, check if block is properly formatted since + // the parser is more liberal than what USTAR actually permits. + notASCII := func(r rune) bool { return r >= 0x80 } + if bytes.IndexFunc(tr.blk[:], notASCII) >= 0 { + hdr.Format = FormatUnknown // Non-ASCII characters in block. + } + nul := func(b []byte) bool { return int(b[len(b)-1]) == 0 } + if !(nul(v7.Size()) && nul(v7.Mode()) && nul(v7.UID()) && nul(v7.GID()) && + nul(v7.ModTime()) && nul(ustar.DevMajor()) && nul(ustar.DevMinor())) { + hdr.Format = FormatUnknown // Numeric fields must end in NUL + } + case format.has(formatSTAR): + star := tr.blk.STAR() + prefix = p.parseString(star.Prefix()) + hdr.AccessTime = time.Unix(p.parseNumeric(star.AccessTime()), 0) + hdr.ChangeTime = time.Unix(p.parseNumeric(star.ChangeTime()), 0) + case format.has(FormatGNU): + hdr.Format = format + var p2 parser + gnu := tr.blk.GNU() + if b := gnu.AccessTime(); b[0] != 0 { + hdr.AccessTime = time.Unix(p2.parseNumeric(b), 0) + } + if b := gnu.ChangeTime(); b[0] != 0 { + hdr.ChangeTime = time.Unix(p2.parseNumeric(b), 0) + } + + // Prior to Go1.8, the Writer had a bug where it would output + // an invalid tar file in certain rare situations because the logic + // incorrectly believed that the old GNU format had a prefix field. + // This is wrong and leads to an output file that mangles the + // atime and ctime fields, which are often left unused. + // + // In order to continue reading tar files created by former, buggy + // versions of Go, we skeptically parse the atime and ctime fields. + // If we are unable to parse them and the prefix field looks like + // an ASCII string, then we fallback on the pre-Go1.8 behavior + // of treating these fields as the USTAR prefix field. + // + // Note that this will not use the fallback logic for all possible + // files generated by a pre-Go1.8 toolchain. If the generated file + // happened to have a prefix field that parses as valid + // atime and ctime fields (e.g., when they are valid octal strings), + // then it is impossible to distinguish between an valid GNU file + // and an invalid pre-Go1.8 file. + // + // See https://golang.org/issues/12594 + // See https://golang.org/issues/21005 + if p2.err != nil { + hdr.AccessTime, hdr.ChangeTime = time.Time{}, time.Time{} + ustar := tr.blk.USTAR() + if s := p.parseString(ustar.Prefix()); isASCII(s) { + prefix = s + } + hdr.Format = FormatUnknown // Buggy file is not GNU + } } if len(prefix) > 0 { hdr.Name = prefix + "/" + hdr.Name } } + return hdr, &tr.blk, p.err +} - if p.err != nil { - tr.err = p.err - return nil - } - - nb := hdr.Size - if isHeaderOnlyType(hdr.Typeflag) { - nb = 0 - } - if nb < 0 { - tr.err = ErrHeader - return nil - } - - // Set the current file reader. - tr.pad = -nb & (blockSize - 1) // blockSize is a power of two - tr.curr = ®FileReader{r: tr.r, nb: nb} - - // Check for old GNU sparse format entry. - if hdr.Typeflag == TypeGNUSparse { - // Get the real size of the file. - hdr.Size = p.parseNumeric(header[483:495]) - if p.err != nil { - tr.err = p.err - return nil - } - - // Read the sparse map. - sp := tr.readOldGNUSparseMap(header) - if tr.err != nil { - return nil - } - - // Current file is a GNU sparse file. Update the current file reader. - tr.curr, tr.err = newSparseFileReader(tr.curr, sp, hdr.Size) - if tr.err != nil { - return nil - } +// readOldGNUSparseMap reads the sparse map from the old GNU sparse format. +// The sparse map is stored in the tar header if it's small enough. +// If it's larger than four entries, then one or more extension headers are used +// to store the rest of the sparse map. +// +// The Header.Size does not reflect the size of any extended headers used. +// Thus, this function will read from the raw io.Reader to fetch extra headers. +// This method mutates blk in the process. +func (tr *Reader) readOldGNUSparseMap(hdr *Header, blk *block) (sparseDatas, error) { + // Make sure that the input format is GNU. + // Unfortunately, the STAR format also has a sparse header format that uses + // the same type flag but has a completely different layout. + if blk.GetFormat() != FormatGNU { + return nil, ErrHeader } + hdr.Format.mayOnlyBe(FormatGNU) - return hdr -} - -// readOldGNUSparseMap reads the sparse map as stored in the old GNU sparse format. -// The sparse map is stored in the tar header if it's small enough. If it's larger than four entries, -// then one or more extension headers are used to store the rest of the sparse map. -func (tr *Reader) readOldGNUSparseMap(header []byte) []sparseEntry { var p parser - isExtended := header[oldGNUSparseMainHeaderIsExtendedOffset] != 0 - spCap := oldGNUSparseMainHeaderNumEntries - if isExtended { - spCap += oldGNUSparseExtendedHeaderNumEntries - } - sp := make([]sparseEntry, 0, spCap) - s := slicer(header[oldGNUSparseMainHeaderOffset:]) - - // Read the four entries from the main tar header - for i := 0; i < oldGNUSparseMainHeaderNumEntries; i++ { - offset := p.parseNumeric(s.next(oldGNUSparseOffsetSize)) - numBytes := p.parseNumeric(s.next(oldGNUSparseNumBytesSize)) - if p.err != nil { - tr.err = p.err - return nil - } - if offset == 0 && numBytes == 0 { - break - } - sp = append(sp, sparseEntry{offset: offset, numBytes: numBytes}) + hdr.Size = p.parseNumeric(blk.GNU().RealSize()) + if p.err != nil { + return nil, p.err } - - for isExtended { - // There are more entries. Read an extension header and parse its entries. - sparseHeader := make([]byte, blockSize) - if _, tr.err = io.ReadFull(tr.r, sparseHeader); tr.err != nil { - return nil - } - if tr.RawAccounting { - if _, tr.err = tr.rawBytes.Write(sparseHeader); tr.err != nil { - return nil + s := blk.GNU().Sparse() + spd := make(sparseDatas, 0, s.MaxEntries()) + for { + for i := 0; i < s.MaxEntries(); i++ { + // This termination condition is identical to GNU and BSD tar. + if s.Entry(i).Offset()[0] == 0x00 { + break // Don't return, need to process extended headers (even if empty) + } + offset := p.parseNumeric(s.Entry(i).Offset()) + length := p.parseNumeric(s.Entry(i).Length()) + if p.err != nil { + return nil, p.err } + spd = append(spd, sparseEntry{Offset: offset, Length: length}) } - isExtended = sparseHeader[oldGNUSparseExtendedHeaderIsExtendedOffset] != 0 - s = slicer(sparseHeader) - for i := 0; i < oldGNUSparseExtendedHeaderNumEntries; i++ { - offset := p.parseNumeric(s.next(oldGNUSparseOffsetSize)) - numBytes := p.parseNumeric(s.next(oldGNUSparseNumBytesSize)) - if p.err != nil { - tr.err = p.err - return nil + if s.IsExtended()[0] > 0 { + // There are more entries. Read an extension header and parse its entries. + if _, err := mustReadFull(tr.r, blk[:]); err != nil { + return nil, err } - if offset == 0 && numBytes == 0 { - break + if tr.RawAccounting { + tr.rawBytes.Write(blk[:]) } - sp = append(sp, sparseEntry{offset: offset, numBytes: numBytes}) + s = blk.Sparse() + continue } + return spd, nil // Done } - return sp } // readGNUSparseMap1x0 reads the sparse map as stored in GNU's PAX sparse format // version 1.0. The format of the sparse map consists of a series of // newline-terminated numeric fields. The first field is the number of entries // and is always present. Following this are the entries, consisting of two -// fields (offset, numBytes). This function must stop reading at the end +// fields (offset, length). This function must stop reading at the end // boundary of the block containing the last newline. // // Note that the GNU manual says that numeric values should be encoded in octal // format. However, the GNU tar utility itself outputs these values in decimal. // As such, this library treats values as being encoded in decimal. -func readGNUSparseMap1x0(r io.Reader) ([]sparseEntry, error) { - var cntNewline int64 - var buf bytes.Buffer - var blk = make([]byte, blockSize) - - // feedTokens copies data in numBlock chunks from r into buf until there are +func readGNUSparseMap1x0(r io.Reader) (sparseDatas, error) { + var ( + cntNewline int64 + buf bytes.Buffer + blk block + ) + + // feedTokens copies data in blocks from r into buf until there are // at least cnt newlines in buf. It will not read more blocks than needed. - var feedTokens = func(cnt int64) error { - for cntNewline < cnt { - if _, err := io.ReadFull(r, blk); err != nil { - if err == io.EOF { - err = io.ErrUnexpectedEOF - } + feedTokens := func(n int64) error { + for cntNewline < n { + if _, err := mustReadFull(r, blk[:]); err != nil { return err } - buf.Write(blk) + buf.Write(blk[:]) for _, c := range blk { if c == '\n' { cntNewline++ @@ -846,10 +596,10 @@ func readGNUSparseMap1x0(r io.Reader) ([]sparseEntry, error) { // nextToken gets the next token delimited by a newline. This assumes that // at least one newline exists in the buffer. - var nextToken = func() string { + nextToken := func() string { cntNewline-- tok, _ := buf.ReadString('\n') - return tok[:len(tok)-1] // Cut off newline + return strings.TrimRight(tok, "\n") } // Parse for the number of entries. @@ -868,197 +618,306 @@ func readGNUSparseMap1x0(r io.Reader) ([]sparseEntry, error) { if err := feedTokens(2 * numEntries); err != nil { return nil, err } - sp := make([]sparseEntry, 0, numEntries) + spd := make(sparseDatas, 0, numEntries) for i := int64(0); i < numEntries; i++ { - offset, err := strconv.ParseInt(nextToken(), 10, 64) - if err != nil { - return nil, ErrHeader - } - numBytes, err := strconv.ParseInt(nextToken(), 10, 64) - if err != nil { + offset, err1 := strconv.ParseInt(nextToken(), 10, 64) + length, err2 := strconv.ParseInt(nextToken(), 10, 64) + if err1 != nil || err2 != nil { return nil, ErrHeader } - sp = append(sp, sparseEntry{offset: offset, numBytes: numBytes}) + spd = append(spd, sparseEntry{Offset: offset, Length: length}) } - return sp, nil + return spd, nil } // readGNUSparseMap0x1 reads the sparse map as stored in GNU's PAX sparse format // version 0.1. The sparse map is stored in the PAX headers. -func readGNUSparseMap0x1(extHdrs map[string]string) ([]sparseEntry, error) { +func readGNUSparseMap0x1(paxHdrs map[string]string) (sparseDatas, error) { // Get number of entries. // Use integer overflow resistant math to check this. - numEntriesStr := extHdrs[paxGNUSparseNumBlocks] + numEntriesStr := paxHdrs[paxGNUSparseNumBlocks] numEntries, err := strconv.ParseInt(numEntriesStr, 10, 0) // Intentionally parse as native int if err != nil || numEntries < 0 || int(2*numEntries) < int(numEntries) { return nil, ErrHeader } // There should be two numbers in sparseMap for each entry. - sparseMap := strings.Split(extHdrs[paxGNUSparseMap], ",") + sparseMap := strings.Split(paxHdrs[paxGNUSparseMap], ",") + if len(sparseMap) == 1 && sparseMap[0] == "" { + sparseMap = sparseMap[:0] + } if int64(len(sparseMap)) != 2*numEntries { return nil, ErrHeader } // Loop through the entries in the sparse map. // numEntries is trusted now. - sp := make([]sparseEntry, 0, numEntries) - for i := int64(0); i < numEntries; i++ { - offset, err := strconv.ParseInt(sparseMap[2*i], 10, 64) - if err != nil { + spd := make(sparseDatas, 0, numEntries) + for len(sparseMap) >= 2 { + offset, err1 := strconv.ParseInt(sparseMap[0], 10, 64) + length, err2 := strconv.ParseInt(sparseMap[1], 10, 64) + if err1 != nil || err2 != nil { return nil, ErrHeader } - numBytes, err := strconv.ParseInt(sparseMap[2*i+1], 10, 64) - if err != nil { - return nil, ErrHeader - } - sp = append(sp, sparseEntry{offset: offset, numBytes: numBytes}) + spd = append(spd, sparseEntry{Offset: offset, Length: length}) + sparseMap = sparseMap[2:] } - return sp, nil + return spd, nil } -// numBytes returns the number of bytes left to read in the current file's entry -// in the tar archive, or 0 if there is no current file. -func (tr *Reader) numBytes() int64 { - if tr.curr == nil { - // No current file, so no bytes - return 0 - } - return tr.curr.numBytes() -} - -// Read reads from the current entry in the tar archive. -// It returns 0, io.EOF when it reaches the end of that entry, -// until Next is called to advance to the next entry. +// Read reads from the current file in the tar archive. +// It returns (0, io.EOF) when it reaches the end of that file, +// until Next is called to advance to the next file. +// +// If the current file is sparse, then the regions marked as a hole +// are read back as NUL-bytes. // -// Calling Read on special types like TypeLink, TypeSymLink, TypeChar, -// TypeBlock, TypeDir, and TypeFifo returns 0, io.EOF regardless of what +// Calling Read on special types like TypeLink, TypeSymlink, TypeChar, +// TypeBlock, TypeDir, and TypeFifo returns (0, io.EOF) regardless of what // the Header.Size claims. -func (tr *Reader) Read(b []byte) (n int, err error) { +func (tr *Reader) Read(b []byte) (int, error) { if tr.err != nil { return 0, tr.err } - if tr.curr == nil { - return 0, io.EOF - } - - n, err = tr.curr.Read(b) + n, err := tr.curr.Read(b) if err != nil && err != io.EOF { tr.err = err } - return + return n, err } -func (rfr *regFileReader) Read(b []byte) (n int, err error) { - if rfr.nb == 0 { - // file consumed - return 0, io.EOF +// writeTo writes the content of the current file to w. +// The bytes written matches the number of remaining bytes in the current file. +// +// If the current file is sparse and w is an io.WriteSeeker, +// then writeTo uses Seek to skip past holes defined in Header.SparseHoles, +// assuming that skipped regions are filled with NULs. +// This always writes the last byte to ensure w is the right size. +// +// TODO(dsnet): Re-export this when adding sparse file support. +// See https://golang.org/issue/22735 +func (tr *Reader) writeTo(w io.Writer) (int64, error) { + if tr.err != nil { + return 0, tr.err } - if int64(len(b)) > rfr.nb { - b = b[0:rfr.nb] + n, err := tr.curr.WriteTo(w) + if err != nil { + tr.err = err } - n, err = rfr.r.Read(b) - rfr.nb -= int64(n) + return n, err +} - if err == io.EOF && rfr.nb > 0 { - err = io.ErrUnexpectedEOF +// regFileReader is a fileReader for reading data from a regular file entry. +type regFileReader struct { + r io.Reader // Underlying Reader + nb int64 // Number of remaining bytes to read +} + +func (fr *regFileReader) Read(b []byte) (n int, err error) { + if int64(len(b)) > fr.nb { + b = b[:fr.nb] + } + if len(b) > 0 { + n, err = fr.r.Read(b) + fr.nb -= int64(n) + } + switch { + case err == io.EOF && fr.nb > 0: + return n, io.ErrUnexpectedEOF + case err == nil && fr.nb == 0: + return n, io.EOF + default: + return n, err } - return } -// numBytes returns the number of bytes left to read in the file's data in the tar archive. -func (rfr *regFileReader) numBytes() int64 { - return rfr.nb +func (fr *regFileReader) WriteTo(w io.Writer) (int64, error) { + return io.Copy(w, struct{ io.Reader }{fr}) } -// newSparseFileReader creates a new sparseFileReader, but validates all of the -// sparse entries before doing so. -func newSparseFileReader(rfr numBytesReader, sp []sparseEntry, total int64) (*sparseFileReader, error) { - if total < 0 { - return nil, ErrHeader // Total size cannot be negative +func (fr regFileReader) LogicalRemaining() int64 { + return fr.nb +} + +func (fr regFileReader) PhysicalRemaining() int64 { + return fr.nb +} + +// sparseFileReader is a fileReader for reading data from a sparse file entry. +type sparseFileReader struct { + fr fileReader // Underlying fileReader + sp sparseHoles // Normalized list of sparse holes + pos int64 // Current position in sparse file +} + +func (sr *sparseFileReader) Read(b []byte) (n int, err error) { + finished := int64(len(b)) >= sr.LogicalRemaining() + if finished { + b = b[:sr.LogicalRemaining()] } - // Validate all sparse entries. These are the same checks as performed by - // the BSD tar utility. - for i, s := range sp { - switch { - case s.offset < 0 || s.numBytes < 0: - return nil, ErrHeader // Negative values are never okay - case s.offset > math.MaxInt64-s.numBytes: - return nil, ErrHeader // Integer overflow with large length - case s.offset+s.numBytes > total: - return nil, ErrHeader // Region extends beyond the "real" size - case i > 0 && sp[i-1].offset+sp[i-1].numBytes > s.offset: - return nil, ErrHeader // Regions can't overlap and must be in order + b0 := b + endPos := sr.pos + int64(len(b)) + for endPos > sr.pos && err == nil { + var nf int // Bytes read in fragment + holeStart, holeEnd := sr.sp[0].Offset, sr.sp[0].endOffset() + if sr.pos < holeStart { // In a data fragment + bf := b[:min(int64(len(b)), holeStart-sr.pos)] + nf, err = tryReadFull(sr.fr, bf) + } else { // In a hole fragment + bf := b[:min(int64(len(b)), holeEnd-sr.pos)] + nf, err = tryReadFull(zeroReader{}, bf) + } + b = b[nf:] + sr.pos += int64(nf) + if sr.pos >= holeEnd && len(sr.sp) > 1 { + sr.sp = sr.sp[1:] // Ensure last fragment always remains } } - return &sparseFileReader{rfr: rfr, sp: sp, total: total}, nil -} -// readHole reads a sparse hole ending at endOffset. -func (sfr *sparseFileReader) readHole(b []byte, endOffset int64) int { - n64 := endOffset - sfr.pos - if n64 > int64(len(b)) { - n64 = int64(len(b)) - } - n := int(n64) - for i := 0; i < n; i++ { - b[i] = 0 + n = len(b0) - len(b) + switch { + case err == io.EOF: + return n, errMissData // Less data in dense file than sparse file + case err != nil: + return n, err + case sr.LogicalRemaining() == 0 && sr.PhysicalRemaining() > 0: + return n, errUnrefData // More data in dense file than sparse file + case finished: + return n, io.EOF + default: + return n, nil } - sfr.pos += n64 - return n } -// Read reads the sparse file data in expanded form. -func (sfr *sparseFileReader) Read(b []byte) (n int, err error) { - // Skip past all empty fragments. - for len(sfr.sp) > 0 && sfr.sp[0].numBytes == 0 { - sfr.sp = sfr.sp[1:] +func (sr *sparseFileReader) WriteTo(w io.Writer) (n int64, err error) { + ws, ok := w.(io.WriteSeeker) + if ok { + if _, err := ws.Seek(0, io.SeekCurrent); err != nil { + ok = false // Not all io.Seeker can really seek + } + } + if !ok { + return io.Copy(w, struct{ io.Reader }{sr}) + } + + var writeLastByte bool + pos0 := sr.pos + for sr.LogicalRemaining() > 0 && !writeLastByte && err == nil { + var nf int64 // Size of fragment + holeStart, holeEnd := sr.sp[0].Offset, sr.sp[0].endOffset() + if sr.pos < holeStart { // In a data fragment + nf = holeStart - sr.pos + nf, err = io.CopyN(ws, sr.fr, nf) + } else { // In a hole fragment + nf = holeEnd - sr.pos + if sr.PhysicalRemaining() == 0 { + writeLastByte = true + nf-- + } + _, err = ws.Seek(nf, io.SeekCurrent) + } + sr.pos += nf + if sr.pos >= holeEnd && len(sr.sp) > 1 { + sr.sp = sr.sp[1:] // Ensure last fragment always remains + } } - // If there are no more fragments, then it is possible that there - // is one last sparse hole. - if len(sfr.sp) == 0 { - // This behavior matches the BSD tar utility. - // However, GNU tar stops returning data even if sfr.total is unmet. - if sfr.pos < sfr.total { - return sfr.readHole(b, sfr.total), nil - } - return 0, io.EOF + // If the last fragment is a hole, then seek to 1-byte before EOF, and + // write a single byte to ensure the file is the right size. + if writeLastByte && err == nil { + _, err = ws.Write([]byte{0}) + sr.pos++ } - // In front of a data fragment, so read a hole. - if sfr.pos < sfr.sp[0].offset { - return sfr.readHole(b, sfr.sp[0].offset), nil + n = sr.pos - pos0 + switch { + case err == io.EOF: + return n, errMissData // Less data in dense file than sparse file + case err != nil: + return n, err + case sr.LogicalRemaining() == 0 && sr.PhysicalRemaining() > 0: + return n, errUnrefData // More data in dense file than sparse file + default: + return n, nil } +} - // In a data fragment, so read from it. - // This math is overflow free since we verify that offset and numBytes can - // be safely added when creating the sparseFileReader. - endPos := sfr.sp[0].offset + sfr.sp[0].numBytes // End offset of fragment - bytesLeft := endPos - sfr.pos // Bytes left in fragment - if int64(len(b)) > bytesLeft { - b = b[:bytesLeft] +func (sr sparseFileReader) LogicalRemaining() int64 { + return sr.sp[len(sr.sp)-1].endOffset() - sr.pos +} +func (sr sparseFileReader) PhysicalRemaining() int64 { + return sr.fr.PhysicalRemaining() +} + +type zeroReader struct{} + +func (zeroReader) Read(b []byte) (int, error) { + for i := range b { + b[i] = 0 } + return len(b), nil +} - n, err = sfr.rfr.Read(b) - sfr.pos += int64(n) +// mustReadFull is like io.ReadFull except it returns +// io.ErrUnexpectedEOF when io.EOF is hit before len(b) bytes are read. +func mustReadFull(r io.Reader, b []byte) (int, error) { + n, err := tryReadFull(r, b) if err == io.EOF { - if sfr.pos < endPos { - err = io.ErrUnexpectedEOF // There was supposed to be more data - } else if sfr.pos < sfr.total { - err = nil // There is still an implicit sparse hole at the end - } + err = io.ErrUnexpectedEOF } + return n, err +} - if sfr.pos == endPos { - sfr.sp = sfr.sp[1:] // We are done with this fragment, so pop it +// tryReadFull is like io.ReadFull except it returns +// io.EOF when it is hit before len(b) bytes are read. +func tryReadFull(r io.Reader, b []byte) (n int, err error) { + for len(b) > n && err == nil { + var nn int + nn, err = r.Read(b[n:]) + n += nn + } + if len(b) == n && err == io.EOF { + err = nil } return n, err } -// numBytes returns the number of bytes left to read in the sparse file's -// sparse-encoded data in the tar archive. -func (sfr *sparseFileReader) numBytes() int64 { - return sfr.rfr.numBytes() +// discard skips n bytes in r, reporting an error if unable to do so. +func discard(tr *Reader, n int64) error { + var seekSkipped, copySkipped int64 + var err error + r := tr.r + if tr.RawAccounting { + + copySkipped, err = io.CopyN(tr.rawBytes, tr.r, n) + goto out + } + + // If possible, Seek to the last byte before the end of the data section. + // Do this because Seek is often lazy about reporting errors; this will mask + // the fact that the stream may be truncated. We can rely on the + // io.CopyN done shortly afterwards to trigger any IO errors. + if sr, ok := r.(io.Seeker); ok && n > 1 { + // Not all io.Seeker can actually Seek. For example, os.Stdin implements + // io.Seeker, but calling Seek always returns an error and performs + // no action. Thus, we try an innocent seek to the current position + // to see if Seek is really supported. + pos1, err := sr.Seek(0, io.SeekCurrent) + if pos1 >= 0 && err == nil { + // Seek seems supported, so perform the real Seek. + pos2, err := sr.Seek(n-1, io.SeekCurrent) + if pos2 < 0 || err != nil { + return err + } + seekSkipped = pos2 - pos1 + } + } + + copySkipped, err = io.CopyN(ioutil.Discard, r, n-seekSkipped) +out: + if err == io.EOF && seekSkipped+copySkipped < n { + err = io.ErrUnexpectedEOF + } + return err } diff --git a/vendor/github.com/vbatts/tar-split/archive/tar/stat_atim.go b/vendor/github.com/vbatts/tar-split/archive/tar/stat_actime1.go index cf9cc79c5..cf9cc79c5 100644 --- a/vendor/github.com/vbatts/tar-split/archive/tar/stat_atim.go +++ b/vendor/github.com/vbatts/tar-split/archive/tar/stat_actime1.go diff --git a/vendor/github.com/vbatts/tar-split/archive/tar/stat_atimespec.go b/vendor/github.com/vbatts/tar-split/archive/tar/stat_actime2.go index 6f17dbe30..6f17dbe30 100644 --- a/vendor/github.com/vbatts/tar-split/archive/tar/stat_atimespec.go +++ b/vendor/github.com/vbatts/tar-split/archive/tar/stat_actime2.go diff --git a/vendor/github.com/vbatts/tar-split/archive/tar/stat_unix.go b/vendor/github.com/vbatts/tar-split/archive/tar/stat_unix.go index cb843db4c..868105f33 100644 --- a/vendor/github.com/vbatts/tar-split/archive/tar/stat_unix.go +++ b/vendor/github.com/vbatts/tar-split/archive/tar/stat_unix.go @@ -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 } diff --git a/vendor/github.com/vbatts/tar-split/archive/tar/strconv.go b/vendor/github.com/vbatts/tar-split/archive/tar/strconv.go new file mode 100644 index 000000000..d144485a4 --- /dev/null +++ b/vendor/github.com/vbatts/tar-split/archive/tar/strconv.go @@ -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) + } +} diff --git a/vendor/github.com/vbatts/tar-split/archive/tar/writer.go b/vendor/github.com/vbatts/tar-split/archive/tar/writer.go index 042638175..e80498d03 100644 --- a/vendor/github.com/vbatts/tar-split/archive/tar/writer.go +++ b/vendor/github.com/vbatts/tar-split/archive/tar/writer.go @@ -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 + + // 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 } -type formatter struct { - err error // Last error seen +// NewWriter creates a new Writer writing to w. +func NewWriter(w io.Writer) *Writer { + return &Writer{w: w, curr: ®FileWriter{w, 0}} } -// NewWriter creates a new Writer writing to w. -func NewWriter(w io.Writer) *Writer { return &Writer{w: w} } +type fileWriter interface { + io.Writer + fileState -// Flush finishes writing the current file (optional). + ReadFrom(io.Reader) (int64, error) +} + +// Flush finishes writing the current file's block padding. +// The current file must be fully written before Flush can be called. +// +// 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.nb > 0 { - tw.err = fmt.Errorf("archive/tar: missed writing %d bytes", tw.nb) + if tw.err != nil { 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) + if nb := tw.curr.LogicalRemaining(); nb > 0 { + return fmt.Errorf("archive/tar: missed writing %d bytes", nb) + } + if _, tw.err = tw.w.Write(zeroBlock[:tw.pad]); tw.err != nil { + return tw.err } - tw.nb = 0 tw.pad = 0 - return tw.err + return nil } -// 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 +// 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 } - ascii := toASCII(s) - copy(b, ascii) - if len(ascii) < len(b) { - b[len(ascii)] = 0 + 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 + } } -} -// 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 + // 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{} } - 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. -// -// 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) + 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 + } } -// 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 +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 } - f.formatOctal(b, 0) // Last resort, just write zero - f.err = ErrFieldTooLong + // 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) } -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) -} +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 + } + */ + _ = 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) + } -// WriteHeader writes hdr and prepares to accept the file's contents. -// WriteHeader calls Flush if it is not the first header. -// Calling after a Close will return ErrWriteAfterClose. -// As this method is called internally by writePax header to allow it to -// suppress writing the pax header. -func (tw *Writer) writeHeader(hdr *Header, allowPax bool) error { - if tw.closed { - return ErrWriteAfterClose - } - if tw.err == nil { - tw.Flush() - } - if tw.err != nil { - return tw.err + // 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 + } } - // a map to hold pax header records, if any are needed - paxHeaders := make(map[string]string) + // 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(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 + // 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 +} - 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[:] - } - 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 +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 } - 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 len(hdr.Linkname) > nameSize { + data := hdr.Linkname + "\x00" + if err := tw.writeRawFile(longName, data, TypeGNULongLink, FormatGNU); err != nil { + return err } + } - // 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 + // 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) } - - tw.usedBinary = true - f.formatNumeric(b, x) + */ + blk.SetFormat(FormatGNU) + if err := tw.writeRawHeader(blk, hdr.Size, hdr.Typeflag); err != nil { + return err } - // 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() + // 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 +} - 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 +type ( + stringFormatter func([]byte, string) + numberFormatter func([]byte, int64) +) - // Use the GNU magic instead of POSIX magic if we used any GNU extensions. - if tw.usedBinary { - copy(header[257:265], []byte("ustar \x00")) - } +// 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 +} - _, 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) +// 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() - // Update the path fields - formatString(pathHeaderBytes, suffix, paxNone) - formatString(prefixHeaderBytes, prefix, paxNone) - } + // Best effort for the filename. + name = toASCII(name) + if len(name) > nameSize { + name = name[:nameSize] } + name = strings.TrimRight(name, "/") - // 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. + 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 { - tw.err = f.err - return tw.err + return f.err // Only occurs if size condition is violated } - if allowPax { - for k, v := range hdr.Xattrs { - paxHeaders[paxXattr+k] = v - } + // 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 +} - if len(paxHeaders) > 0 { - if !allowPax { - return errInvalidHeader - } - if err := tw.writePAXHeader(hdr, paxHeaders); err != nil { - 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 } - tw.nb = int64(hdr.Size) - tw.pad = (blockSize - (tw.nb % blockSize)) % blockSize - - _, tw.err = tw.w.Write(header) - return tw.err + if _, err := tw.w.Write(blk[:]); err != nil { + return err + } + if isHeaderOnlyType(flag) { + size = 0 + } + tw.curr = ®FileWriter{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 +// Write writes to the current file in the tar archive. +// Write returns the error ErrWriteTooLong if more than +// 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 } - if _, err := tw.Write(buf.Bytes()); err != nil { - return err + n, err := tw.curr.Write(b) + if err != nil && err != ErrWriteTooLong { + tw.err = err } - if err := tw.Flush(); err != nil { - return err + return n, 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 } - return nil + n, err := tw.curr.ReadFrom(r) + if err != nil && err != ErrWriteTooLong { + tw.err = err + } + return n, err } -// 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) +// 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 + } + if tw.err != nil { + return tw.err + } - // 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) + // Trailer: two zero blocks. + err := tw.Flush() + for i := 0; i < 2 && err == nil; i++ { + _, err = tw.w.Write(zeroBlock[:]) } - return record + + // Ensure all future actions are invalid. + tw.err = ErrWriteAfterClose + return err // Report IO errors } -// Write writes to the current entry in the tar archive. -// Write returns the error ErrWriteTooLong if more than -// hdr.Size bytes are written after WriteHeader. -func (tw *Writer) Write(b []byte) (n int, err error) { - if tw.closed { - err = ErrWriteAfterClose - return - } - overwrite := false - if int64(len(b)) > tw.nb { - b = b[0:tw.nb] - overwrite = true - } - n, err = tw.w.Write(b) - tw.nb -= int64(n) - if err == nil && overwrite { - err = ErrWriteTooLong - return - } - tw.err = err - return +// 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 } -// 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 +func (fw *regFileWriter) Write(b []byte) (n int, err error) { + overwrite := int64(len(b)) > fw.nb + if overwrite { + b = b[:fw.nb] } - tw.Flush() - tw.closed = true - if tw.err != nil { - return tw.err + 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) +} - // trailer: two zero blocks - for i := 0; i < 2; i++ { - _, tw.err = tw.w.Write(zeroBlock) - if tw.err != nil { - break +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 + } } |