From ea19201d03499f36c564ae854b18c7622499f971 Mon Sep 17 00:00:00 2001 From: Kir Kolyshkin Date: Tue, 10 Apr 2018 15:46:21 -0700 Subject: [PATCH] archive/tar: vendor again Signed-off-by: Kir Kolyshkin (cherry picked from commit 7b30fd0e1d8bc77f0556181c82f85d046b058f27) Signed-off-by: Sebastiaan van Stijn Upstream-commit: 66720189e04d50ef06c12d1ffbbfebf41caa2ae3 Component: engine --- components/engine/Dockerfile.simple | 1 + components/engine/vendor.conf | 6 + components/engine/vendor/archive/tar/LICENSE | 27 + .../engine/vendor/archive/tar/README.md | 27 + .../engine/vendor/archive/tar/common.go | 720 +++++++++++++++ .../engine/vendor/archive/tar/format.go | 303 +++++++ .../engine/vendor/archive/tar/reader.go | 855 ++++++++++++++++++ .../engine/vendor/archive/tar/stat_actime1.go | 20 + .../engine/vendor/archive/tar/stat_actime2.go | 20 + .../engine/vendor/archive/tar/stat_unix.go | 76 ++ .../engine/vendor/archive/tar/strconv.go | 326 +++++++ .../engine/vendor/archive/tar/writer.go | 644 +++++++++++++ 12 files changed, 3025 insertions(+) create mode 100644 components/engine/vendor/archive/tar/LICENSE create mode 100644 components/engine/vendor/archive/tar/README.md create mode 100644 components/engine/vendor/archive/tar/common.go create mode 100644 components/engine/vendor/archive/tar/format.go create mode 100644 components/engine/vendor/archive/tar/reader.go create mode 100644 components/engine/vendor/archive/tar/stat_actime1.go create mode 100644 components/engine/vendor/archive/tar/stat_actime2.go create mode 100644 components/engine/vendor/archive/tar/stat_unix.go create mode 100644 components/engine/vendor/archive/tar/strconv.go create mode 100644 components/engine/vendor/archive/tar/writer.go diff --git a/components/engine/Dockerfile.simple b/components/engine/Dockerfile.simple index 44f29f0744..5c07a4f929 100644 --- a/components/engine/Dockerfile.simple +++ b/components/engine/Dockerfile.simple @@ -41,6 +41,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \ # IMPORTANT: If the version of Go is updated, the Windows to Linux CI machines # will need updating, to avoid errors. Ping #docker-maintainers on IRC # with a heads-up. +# IMPORTANT: When updating this please note that stdlib archive/tar pkg is vendored ENV GO_VERSION 1.10.1 RUN curl -fsSL "https://golang.org/dl/go${GO_VERSION}.linux-amd64.tar.gz" \ | tar -xzC /usr/local diff --git a/components/engine/vendor.conf b/components/engine/vendor.conf index 74a94e01ab..6f490779e8 100644 --- a/components/engine/vendor.conf +++ b/components/engine/vendor.conf @@ -150,3 +150,9 @@ github.com/Nvveen/Gotty a8b993ba6abdb0e0c12b0125c603323a71c7790c https://github. github.com/docker/go-metrics d466d4f6fd960e01820085bd7e1a24426ee7ef18 github.com/opencontainers/selinux b29023b86e4a69d1b46b7e7b4e2b6fda03f0b9cd + + +# archive/tar (for Go 1.10, see https://github.com/golang/go/issues/24787) +# mkdir -p ./vendor/archive +# git clone -b go-1.10 --depth=1 git@github.com:kolyshkin/go-tar.git ./vendor/archive/tar +# vndr # to clean up test files diff --git a/components/engine/vendor/archive/tar/LICENSE b/components/engine/vendor/archive/tar/LICENSE new file mode 100644 index 0000000000..6a66aea5ea --- /dev/null +++ b/components/engine/vendor/archive/tar/LICENSE @@ -0,0 +1,27 @@ +Copyright (c) 2009 The Go Authors. All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + + * Redistributions of source code must retain the above copyright +notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above +copyright notice, this list of conditions and the following disclaimer +in the documentation and/or other materials provided with the +distribution. + * Neither the name of Google Inc. nor the names of its +contributors may be used to endorse or promote products derived from +this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/components/engine/vendor/archive/tar/README.md b/components/engine/vendor/archive/tar/README.md new file mode 100644 index 0000000000..ec093ca88c --- /dev/null +++ b/components/engine/vendor/archive/tar/README.md @@ -0,0 +1,27 @@ +This is a fork of Go 1.10 `archive/tar` package from the official +[repo](https://github.com/golang/go/tree/release-branch.go1.10/src/archive/tar), +with a partial [revert](https://github.com/kolyshkin/go-tar/commit/d651d6e45972363e9bb62b8e9d876df440b31628) +of upstream [commit 0564e304a6ea](https://github.com/golang/go/commit/0564e304a6ea394a42929060c588469dbd6f32af). +It is suggested as a replacement to the original package included with Go 1.10 +in case you want to build a static Linux/glibc binary that works, and +can't afford to use `CGO_ENABLED=0`. + +## Details + +Using Go 1.10 [archive/tar](https://golang.org/pkg/archive/tar/) from a static binary +compiled with glibc on Linux can result in a panic upon calling +[`tar.FileInfoHeader()`](https://golang.org/pkg/archive/tar/#FileInfoHeader). +This is a major regression in Go 1.10, filed as +[Go issue #24787](https://github.com/golang/go/issues/24787). + +The above issue is caused by an unfortunate combination of: +1. glibc way of dynamic loading of nss libraries even for a static build; +2. Go `os/user` package hard-coded reliance on libc to resolve user/group IDs to names (unless CGO is disabled). + +While glibc can probably not be fixed and is not considered a bug per se, +the `os/user` issue is documented (see [Go issue #23265](https://github.com/golang/go/issues/23265)) +and already fixed by [Go commit 62f0127d81](https://github.com/golang/go/commit/62f0127d8104d8266d9a3fb5a87e2f09ec8b6f5b). +The fix is expected to make its way to Go 1.11, and requires `osusergo` build tag +to be used for a static build. + +This repository serves as a temporary workaround until the above fix is available. diff --git a/components/engine/vendor/archive/tar/common.go b/components/engine/vendor/archive/tar/common.go new file mode 100644 index 0000000000..4a2c173bf3 --- /dev/null +++ b/components/engine/vendor/archive/tar/common.go @@ -0,0 +1,720 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package tar implements access to tar archives. +// +// 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 ( + "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 ( + // Type '0' indicates a regular file. + TypeReg = '0' + TypeRegA = '\x00' // For legacy support; 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 { + Typeflag byte // Type of header entry (should be TypeReg for most files) + + 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 + // 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 +} + +// 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} +} + +// headerFileInfo implements os.FileInfo. +type headerFileInfo struct { + h *Header +} + +func (fi headerFileInfo) Size() int64 { return fi.h.Size } +func (fi headerFileInfo) IsDir() bool { return fi.Mode().IsDir() } +func (fi headerFileInfo) ModTime() time.Time { return fi.h.ModTime } +func (fi headerFileInfo) Sys() interface{} { return fi.h } + +// Name returns the base name of the file. +func (fi headerFileInfo) Name() string { + if fi.IsDir() { + return path.Base(path.Clean(fi.h.Name)) + } + return path.Base(fi.h.Name) +} + +// Mode returns the permission and mode bits for the headerFileInfo. +func (fi headerFileInfo) Mode() (mode os.FileMode) { + // Set file permission bits. + mode = os.FileMode(fi.h.Mode).Perm() + + // Set setuid, setgid and sticky bits. + if fi.h.Mode&c_ISUID != 0 { + mode |= os.ModeSetuid + } + if fi.h.Mode&c_ISGID != 0 { + mode |= os.ModeSetgid + } + if fi.h.Mode&c_ISVTX != 0 { + mode |= os.ModeSticky + } + + // 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 + case c_ISFIFO: + mode |= os.ModeNamedPipe + case c_ISLNK: + mode |= os.ModeSymlink + case c_ISBLK: + mode |= os.ModeDevice + case c_ISCHR: + mode |= os.ModeDevice + mode |= os.ModeCharDevice + case c_ISSOCK: + mode |= os.ModeSocket + } + + switch fi.h.Typeflag { + case TypeSymlink: + mode |= os.ModeSymlink + case TypeChar: + mode |= os.ModeDevice + mode |= os.ModeCharDevice + case TypeBlock: + mode |= os.ModeDevice + case TypeDir: + mode |= os.ModeDir + case TypeFifo: + mode |= os.ModeNamedPipe + } + + return mode +} + +// sysStat, if non-nil, populates h from system-dependent fields of fi. +var sysStat func(fi os.FileInfo, h *Header) error + +const ( + // 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 + c_ISLNK = 0120000 // Symbolic link + c_ISBLK = 060000 // Block special file + c_ISCHR = 020000 // Character special file + c_ISSOCK = 0140000 // Socket +) + +// 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. +// +// 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("archive/tar: FileInfo is nil") + } + fm := fi.Mode() + h := &Header{ + Name: fi.Name(), + ModTime: fi.ModTime(), + Mode: int64(fm.Perm()), // or'd with c_IS* constants later + } + switch { + case fm.IsRegular(): + h.Typeflag = TypeReg + h.Size = fi.Size() + case fi.IsDir(): + h.Typeflag = TypeDir + h.Name += "/" + case fm&os.ModeSymlink != 0: + h.Typeflag = TypeSymlink + h.Linkname = link + case fm&os.ModeDevice != 0: + if fm&os.ModeCharDevice != 0 { + h.Typeflag = TypeChar + } else { + h.Typeflag = TypeBlock + } + case fm&os.ModeNamedPipe != 0: + h.Typeflag = TypeFifo + case fm&os.ModeSocket != 0: + return nil, fmt.Errorf("archive/tar: sockets not supported") + default: + return nil, fmt.Errorf("archive/tar: unknown file mode %v", fm) + } + if fm&os.ModeSetuid != 0 { + h.Mode |= c_ISUID + } + if fm&os.ModeSetgid != 0 { + h.Mode |= c_ISGID + } + if fm&os.ModeSticky != 0 { + h.Mode |= c_ISVTX + } + // If possible, populate additional fields from OS-specific + // FileInfo fields. + if sys, ok := fi.Sys().(*Header); ok { + // This FileInfo came from a Header (not the OS). Use the + // original Header to populate all remaining fields. + h.Uid = sys.Uid + h.Gid = sys.Gid + h.Uname = sys.Uname + h.Gname = sys.Gname + h.AccessTime = sys.AccessTime + h.ChangeTime = sys.ChangeTime + if sys.Xattrs != nil { + h.Xattrs = make(map[string]string) + for k, v := range sys.Xattrs { + h.Xattrs[k] = v + } + } + if sys.Typeflag == TypeLink { + // hard link + h.Typeflag = TypeLink + h.Size = 0 + h.Linkname = sys.Linkname + } + if 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) + } + return h, nil +} + +// isHeaderOnlyType checks if the given type flag is of the type that has no +// data section even if a size is specified. +func isHeaderOnlyType(flag byte) bool { + switch flag { + case TypeLink, TypeSymlink, TypeChar, TypeBlock, TypeDir, TypeFifo: + return true + default: + return false + } +} + +func min(a, b int64) int64 { + if a < b { + return a + } + return b +} diff --git a/components/engine/vendor/archive/tar/format.go b/components/engine/vendor/archive/tar/format.go new file mode 100644 index 0000000000..6e29698a14 --- /dev/null +++ b/components/engine/vendor/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: + // http://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 "" + 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/components/engine/vendor/archive/tar/reader.go b/components/engine/vendor/archive/tar/reader.go new file mode 100644 index 0000000000..f4eeb557be --- /dev/null +++ b/components/engine/vendor/archive/tar/reader.go @@ -0,0 +1,855 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package tar + +import ( + "bytes" + "io" + "io/ioutil" + "strconv" + "strings" + "time" +) + +// 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 + 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 +} + +type fileReader interface { + io.Reader + fileState + + WriteTo(io.Writer) (int64, error) +} + +// NewReader creates a new Reader reading from 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 + + // 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". + format := FormatUSTAR | FormatPAX | FormatGNU +loop: + for { + // Discard the remainder of the file and any padding. + if err := discard(tr.r, tr.curr.PhysicalRemaining()); err != nil { + return nil, err + } + if _, err := tryReadFull(tr.r, tr.blk[:tr.pad]); err != nil { + return nil, err + } + tr.pad = 0 + + 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, TypeXGlobalHeader: + format.mayOnlyBe(FormatPAX) + paxHdrs, err = parsePAX(tr) + if err != nil { + return nil, err + } + 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 loop // This is a meta header affecting the next header + case TypeGNULongName, TypeGNULongLink: + format.mayOnlyBe(FormatGNU) + realname, err := ioutil.ReadAll(tr) + if err != nil { + return nil, err + } + + var p parser + switch hdr.Typeflag { + case TypeGNULongName: + gnuLongName = p.parseString(realname) + case TypeGNULongLink: + gnuLongLink = p.parseString(realname) + } + continue loop // This is a meta header affecting the next header + default: + // The old GNU sparse format is handled here since it is technically + // just a regular file with additional attributes. + + if err := mergePAX(hdr, paxHdrs); err != nil { + return nil, err + } + if gnuLongName != "" { + hdr.Name = gnuLongName + } + if gnuLongLink != "" { + hdr.Linkname = gnuLongLink + } + if hdr.Typeflag == TypeRegA && strings.HasSuffix(hdr.Name, "/") { + hdr.Typeflag = TypeDir // Legacy archives use trailing slash for directories + } + + // 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 + } + } +} + +// handleRegularFile sets up the current file reader and padding such that it +// can only read the following logical data section. It will properly handle +// special headers that contain no data section. +func (tr *Reader) handleRegularFile(hdr *Header) error { + nb := hdr.Size + if isHeaderOnlyType(hdr.Typeflag) { + nb = 0 + } + if nb < 0 { + return ErrHeader + } + + tr.pad = 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 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 + } + 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 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 = n + } + + // Read the sparse map according to the appropriate format. + if is1x0 { + return readGNUSparseMap1x0(tr.curr) + } + return readGNUSparseMap0x1(hdr.PAXRecords) +} + +// 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 paxUname: + hdr.Uname = v + case paxGname: + hdr.Gname = v + case paxUid: + id64, err = strconv.ParseInt(v, 10, 64) + hdr.Uid = int(id64) // Integer overflow possible + case paxGid: + id64, err = strconv.ParseInt(v, 10, 64) + hdr.Gid = int(id64) // Integer overflow possible + case paxAtime: + hdr.AccessTime, err = parsePAXTime(v) + case paxMtime: + hdr.ModTime, err = parsePAXTime(v) + case paxCtime: + hdr.ChangeTime, err = parsePAXTime(v) + case paxSize: + hdr.Size, err = strconv.ParseInt(v, 10, 64) + default: + if strings.HasPrefix(k, paxSchilyXattr) { + if hdr.Xattrs == nil { + hdr.Xattrs = make(map[string]string) + } + hdr.Xattrs[k[len(paxSchilyXattr):]] = v + } + } + if err != nil { + return ErrHeader + } + } + hdr.PAXRecords = paxHdrs + return nil +} + +// parsePAX parses PAX headers. +// If an extended header (type 'x') is invalid, ErrHeader is returned +func parsePAX(r io.Reader) (map[string]string, error) { + buf, err := ioutil.ReadAll(r) + if err != nil { + return nil, err + } + sbuf := string(buf) + + // For GNU PAX sparse format 0.0 support. + // This function transforms the sparse format 0.0 headers into format 0.1 + // headers since 0.0 headers were not PAX compliant. + var sparseMap []string + + paxHdrs := make(map[string]string) + for len(sbuf) > 0 { + key, value, residual, err := parsePAXRecord(sbuf) + if err != nil { + return nil, ErrHeader + } + sbuf = residual + + switch key { + case paxGNUSparseOffset, paxGNUSparseNumBytes: + // Validate sparse header order and value. + if (len(sparseMap)%2 == 0 && key != paxGNUSparseOffset) || + (len(sparseMap)%2 == 1 && key != paxGNUSparseNumBytes) || + strings.Contains(value, ",") { + return nil, ErrHeader + } + sparseMap = append(sparseMap, value) + default: + paxHdrs[key] = value + } + } + if len(sparseMap) > 0 { + paxHdrs[paxGNUSparseMap] = strings.Join(sparseMap, ",") + } + return paxHdrs, nil +} + +// readHeader reads the next block header and assumes that the underlying reader +// is already aligned to a block boundary. It returns the raw block of the +// header in case further processing is required. +// +// The err will be set to io.EOF only when one of the following occurs: +// * Exactly 0 bytes are read and EOF is hit. +// * Exactly 1 block of zeros is read and EOF is hit. +// * At least 2 blocks of zeros are read. +func (tr *Reader) readHeader() (*Header, *block, error) { + // Two blocks of zero bytes marks the end of the archive. + if _, err := io.ReadFull(tr.r, tr.blk[:]); err != nil { + return nil, nil, err // EOF is okay here; exactly 0 bytes read + } + if bytes.Equal(tr.blk[:], zeroBlock[:]) { + if _, err := io.ReadFull(tr.r, tr.blk[:]); err != nil { + return nil, nil, err // EOF is okay here; exactly 1 block of zeros read + } + if bytes.Equal(tr.blk[:], zeroBlock[:]) { + return nil, nil, io.EOF // normal EOF; exactly 2 block of zeros read + } + return nil, nil, ErrHeader // Zero block and then non-zero block + } + + // Verify the header matches a known format. + format := tr.blk.GetFormat() + if format == FormatUnknown { + return nil, nil, ErrHeader + } + + var p parser + hdr := new(Header) + + // Unpack the V7 header. + v7 := tr.blk.V7() + hdr.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 { + 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 +} + +// 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) + + var p parser + hdr.Size = p.parseNumeric(blk.GNU().RealSize()) + if p.err != nil { + return nil, p.err + } + 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}) + } + + 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 + } + s = blk.Sparse() + continue + } + return spd, nil // Done + } +} + +// readGNUSparseMap1x0 reads the sparse map as stored in GNU's PAX sparse format +// version 1.0. The format of the sparse map consists of a series of +// newline-terminated numeric fields. The first field is the number of entries +// and is always present. Following this are the entries, consisting of two +// fields (offset, 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) (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. + feedTokens := func(n int64) error { + for cntNewline < n { + if _, err := mustReadFull(r, blk[:]); err != nil { + return err + } + buf.Write(blk[:]) + for _, c := range blk { + if c == '\n' { + cntNewline++ + } + } + } + return nil + } + + // nextToken gets the next token delimited by a newline. This assumes that + // at least one newline exists in the buffer. + nextToken := func() string { + cntNewline-- + tok, _ := buf.ReadString('\n') + return strings.TrimRight(tok, "\n") + } + + // Parse for the number of entries. + // Use integer overflow resistant math to check this. + if err := feedTokens(1); err != nil { + return nil, err + } + numEntries, err := strconv.ParseInt(nextToken(), 10, 0) // Intentionally parse as native int + if err != nil || numEntries < 0 || int(2*numEntries) < int(numEntries) { + return nil, ErrHeader + } + + // Parse for all member entries. + // numEntries is trusted after this since a potential attacker must have + // committed resources proportional to what this library used. + if err := feedTokens(2 * numEntries); err != nil { + return nil, err + } + spd := make(sparseDatas, 0, numEntries) + for i := int64(0); i < numEntries; i++ { + offset, err1 := strconv.ParseInt(nextToken(), 10, 64) + length, err2 := strconv.ParseInt(nextToken(), 10, 64) + if err1 != nil || err2 != nil { + return nil, ErrHeader + } + spd = append(spd, sparseEntry{Offset: offset, Length: length}) + } + 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(paxHdrs map[string]string) (sparseDatas, error) { + // Get number of entries. + // Use integer overflow resistant math to check this. + 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(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. + 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 + } + spd = append(spd, sparseEntry{Offset: offset, Length: length}) + sparseMap = sparseMap[2:] + } + return spd, nil +} + +// 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 +// the Header.Size claims. +func (tr *Reader) Read(b []byte) (int, error) { + if tr.err != nil { + return 0, tr.err + } + n, err := tr.curr.Read(b) + if err != nil && err != io.EOF { + tr.err = err + } + return n, err +} + +// 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 + } + n, err := tr.curr.WriteTo(w) + if err != nil { + tr.err = err + } + return n, err +} + +// 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 + } +} + +func (fr *regFileReader) WriteTo(w io.Writer) (int64, error) { + return io.Copy(w, struct{ io.Reader }{fr}) +} + +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()] + } + + 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 + } + } + + 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 + } +} + +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 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++ + } + + 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 + } +} + +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 +} + +// 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 { + err = io.ErrUnexpectedEOF + } + return n, err +} + +// 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 +} + +// discard skips n bytes in r, reporting an error if unable to do so. +func discard(r io.Reader, n int64) error { + // 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. + var seekSkipped int64 // Number of bytes skipped via Seek + 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) + if err == io.EOF && seekSkipped+copySkipped < n { + err = io.ErrUnexpectedEOF + } + return err +} diff --git a/components/engine/vendor/archive/tar/stat_actime1.go b/components/engine/vendor/archive/tar/stat_actime1.go new file mode 100644 index 0000000000..cf9cc79c59 --- /dev/null +++ b/components/engine/vendor/archive/tar/stat_actime1.go @@ -0,0 +1,20 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build linux dragonfly openbsd solaris + +package tar + +import ( + "syscall" + "time" +) + +func statAtime(st *syscall.Stat_t) time.Time { + return time.Unix(st.Atim.Unix()) +} + +func statCtime(st *syscall.Stat_t) time.Time { + return time.Unix(st.Ctim.Unix()) +} diff --git a/components/engine/vendor/archive/tar/stat_actime2.go b/components/engine/vendor/archive/tar/stat_actime2.go new file mode 100644 index 0000000000..6f17dbe307 --- /dev/null +++ b/components/engine/vendor/archive/tar/stat_actime2.go @@ -0,0 +1,20 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build darwin freebsd netbsd + +package tar + +import ( + "syscall" + "time" +) + +func statAtime(st *syscall.Stat_t) time.Time { + return time.Unix(st.Atimespec.Unix()) +} + +func statCtime(st *syscall.Stat_t) time.Time { + return time.Unix(st.Ctimespec.Unix()) +} diff --git a/components/engine/vendor/archive/tar/stat_unix.go b/components/engine/vendor/archive/tar/stat_unix.go new file mode 100644 index 0000000000..9640ed4bab --- /dev/null +++ b/components/engine/vendor/archive/tar/stat_unix.go @@ -0,0 +1,76 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build linux darwin dragonfly freebsd openbsd netbsd solaris + +package tar + +import ( + "os" + "runtime" + "syscall" +) + +func init() { + sysStat = statUnix +} + +func statUnix(fi os.FileInfo, h *Header) error { + sys, ok := fi.Sys().(*syscall.Stat_t) + if !ok { + return nil + } + h.Uid = int(sys.Uid) + h.Gid = int(sys.Gid) + + // TODO(bradfitz): populate username & group. os/user + // doesn't cache LookupId lookups, and lacks group + // lookup functions. + h.AccessTime = statAtime(sys) + h.ChangeTime = statCtime(sys) + + // 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/components/engine/vendor/archive/tar/strconv.go b/components/engine/vendor/archive/tar/strconv.go new file mode 100644 index 0000000000..d144485a49 --- /dev/null +++ b/components/engine/vendor/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< 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<= 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/components/engine/vendor/archive/tar/writer.go b/components/engine/vendor/archive/tar/writer.go new file mode 100644 index 0000000000..97d23f8038 --- /dev/null +++ b/components/engine/vendor/archive/tar/writer.go @@ -0,0 +1,644 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package tar + +import ( + "bytes" + "fmt" + "io" + "path" + "sort" + "strings" + "time" +) + +// 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 + 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 +} + +// NewWriter creates a new Writer writing to w. +func NewWriter(w io.Writer) *Writer { + return &Writer{w: w, curr: ®FileWriter{w, 0}} +} + +type fileWriter interface { + io.Writer + fileState + + 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.err != nil { + return tw.err + } + 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.pad = 0 + return nil +} + +// WriteHeader writes hdr and prepares to accept the file's contents. +// The Header.Size determines how many bytes can be written for the next file. +// If the current file is not fully written, then this returns an error. +// This implicitly flushes any padding necessary before writing the header. +func (tw *Writer) WriteHeader(hdr *Header) error { + if err := tw.Flush(); err != nil { + return err + } + tw.hdr = *hdr // Shallow copy of Header + + // Round ModTime and ignore AccessTime and ChangeTime unless + // the format is explicitly chosen. + // This ensures nominal usage of WriteHeader (without specifying the format) + // does not always result in the PAX format being chosen, which + // causes a 1KiB increase to every header. + if tw.hdr.Format == FormatUnknown { + tw.hdr.ModTime = tw.hdr.ModTime.Round(time.Second) + tw.hdr.AccessTime = time.Time{} + tw.hdr.ChangeTime = time.Time{} + } + + allowedFormats, paxHdrs, err := tw.hdr.allowedFormats() + switch { + case allowedFormats.has(FormatUSTAR): + tw.err = tw.writeUSTARHeader(&tw.hdr) + return tw.err + case allowedFormats.has(FormatPAX): + tw.err = tw.writePAXHeader(&tw.hdr, paxHdrs) + return tw.err + case allowedFormats.has(FormatGNU): + tw.err = tw.writeGNUHeader(&tw.hdr) + return tw.err + default: + return err // Non-fatal error + } +} + +func (tw *Writer) writeUSTARHeader(hdr *Header) error { + // Check if we can use USTAR prefix/suffix splitting. + var namePrefix string + if prefix, suffix, ok := splitUSTARPath(hdr.Name); ok { + namePrefix, hdr.Name = prefix, suffix + } + + // Pack the main header. + var f formatter + blk := tw.templateV7Plus(hdr, f.formatString, f.formatOctal) + f.formatString(blk.USTAR().Prefix(), namePrefix) + blk.SetFormat(FormatUSTAR) + if f.err != nil { + return f.err // Should never happen since header is validated + } + return tw.writeRawHeader(blk, hdr.Size, hdr.Typeflag) +} + +func (tw *Writer) writePAXHeader(hdr *Header, paxHdrs map[string]string) error { + realName, realSize := hdr.Name, hdr.Size + + // TODO(dsnet): Re-enable this when adding sparse support. + // See https://golang.org/issue/22735 + /* + // Handle sparse files. + var spd sparseDatas + var spb []byte + if len(hdr.SparseHoles) > 0 { + sph := append([]sparseEntry{}, hdr.SparseHoles...) // Copy sparse map + sph = alignSparseEntries(sph, hdr.Size) + spd = invertSparseEntries(sph, hdr.Size) + + // Format the sparse map. + hdr.Size = 0 // Replace with encoded size + spb = append(strconv.AppendInt(spb, int64(len(spd)), 10), '\n') + for _, s := range spd { + hdr.Size += s.Length + spb = append(strconv.AppendInt(spb, s.Offset, 10), '\n') + spb = append(strconv.AppendInt(spb, s.Length, 10), '\n') + } + pad := blockPadding(int64(len(spb))) + spb = append(spb, zeroBlock[:pad]...) + hdr.Size += int64(len(spb)) // Accounts for encoded sparse map + + // Add and modify appropriate PAX records. + dir, file := path.Split(realName) + hdr.Name = path.Join(dir, "GNUSparseFile.0", file) + paxHdrs[paxGNUSparseMajor] = "1" + paxHdrs[paxGNUSparseMinor] = "0" + paxHdrs[paxGNUSparseName] = realName + paxHdrs[paxGNUSparseRealSize] = strconv.FormatInt(realSize, 10) + paxHdrs[paxSize] = strconv.FormatInt(hdr.Size, 10) + delete(paxHdrs, paxPath) // Recorded by paxGNUSparseName + } + */ + _ = 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 bytes.Buffer + for _, k := range keys { + rec, err := formatPAXRecord(k, paxHdrs[k]) + if err != nil { + return err + } + buf.WriteString(rec) + } + + // Write the extended header file. + var name string + var flag byte + if isGlobal { + name = realName + if name == "" { + name = "GlobalHead.0.0" + } + flag = TypeXGlobalHeader + } else { + dir, file := path.Split(realName) + name = path.Join(dir, "PaxHeaders.0", file) + flag = TypeXHeader + } + data := buf.String() + if err := tw.writeRawFile(name, data, flag, FormatPAX); err != nil || isGlobal { + return err // Global headers return here + } + } + + // Pack the main header. + var f formatter // Ignore errors since they are expected + fmtStr := func(b []byte, s string) { f.formatString(b, toASCII(s)) } + blk := tw.templateV7Plus(hdr, fmtStr, f.formatOctal) + blk.SetFormat(FormatPAX) + if err := tw.writeRawHeader(blk, hdr.Size, hdr.Typeflag); err != nil { + return err + } + + // TODO(dsnet): Re-enable this when adding sparse support. + // See https://golang.org/issue/22735 + /* + // Write the sparse map and setup the sparse writer if necessary. + if len(spd) > 0 { + // Use tw.curr since the sparse map is accounted for in hdr.Size. + if _, err := tw.curr.Write(spb); err != nil { + return err + } + tw.curr = &sparseFileWriter{tw.curr, spd, 0} + } + */ + return nil +} + +func (tw *Writer) writeGNUHeader(hdr *Header) error { + // Use long-link files if Name or Linkname exceeds the field size. + const longName = "././@LongLink" + if len(hdr.Name) > nameSize { + data := hdr.Name + "\x00" + if err := tw.writeRawFile(longName, data, TypeGNULongName, FormatGNU); err != nil { + return err + } + } + if len(hdr.Linkname) > nameSize { + data := hdr.Linkname + "\x00" + if err := tw.writeRawFile(longName, data, TypeGNULongLink, FormatGNU); err != nil { + return err + } + } + + // Pack the main header. + var f formatter // Ignore errors since they are expected + var spd sparseDatas + var spb []byte + blk := tw.templateV7Plus(hdr, f.formatString, f.formatNumeric) + if !hdr.AccessTime.IsZero() { + f.formatNumeric(blk.GNU().AccessTime(), hdr.AccessTime.Unix()) + } + if !hdr.ChangeTime.IsZero() { + f.formatNumeric(blk.GNU().ChangeTime(), hdr.ChangeTime.Unix()) + } + // TODO(dsnet): Re-enable this when adding sparse support. + // See https://golang.org/issue/22735 + /* + if hdr.Typeflag == TypeGNUSparse { + sph := append([]sparseEntry{}, hdr.SparseHoles...) // Copy sparse map + sph = alignSparseEntries(sph, hdr.Size) + spd = invertSparseEntries(sph, hdr.Size) + + // Format the sparse map. + formatSPD := func(sp sparseDatas, sa sparseArray) sparseDatas { + for i := 0; len(sp) > 0 && i < sa.MaxEntries(); i++ { + f.formatNumeric(sa.Entry(i).Offset(), sp[0].Offset) + f.formatNumeric(sa.Entry(i).Length(), sp[0].Length) + sp = sp[1:] + } + if len(sp) > 0 { + sa.IsExtended()[0] = 1 + } + return sp + } + sp2 := formatSPD(spd, blk.GNU().Sparse()) + for len(sp2) > 0 { + var spHdr block + sp2 = formatSPD(sp2, spHdr.Sparse()) + spb = append(spb, spHdr[:]...) + } + + // Update size fields in the header block. + realSize := hdr.Size + hdr.Size = 0 // Encoded size; does not account for encoded sparse map + for _, s := range spd { + hdr.Size += s.Length + } + copy(blk.V7().Size(), zeroBlock[:]) // Reset field + f.formatNumeric(blk.V7().Size(), hdr.Size) + f.formatNumeric(blk.GNU().RealSize(), realSize) + } + */ + blk.SetFormat(FormatGNU) + if err := tw.writeRawHeader(blk, hdr.Size, hdr.Typeflag); err != nil { + return err + } + + // Write the extended sparse map and setup the sparse writer if necessary. + if len(spd) > 0 { + // Use tw.w since the sparse map is not accounted for in hdr.Size. + if _, err := tw.w.Write(spb); err != nil { + return err + } + tw.curr = &sparseFileWriter{tw.curr, spd, 0} + } + return nil +} + +type ( + stringFormatter func([]byte, string) + numberFormatter func([]byte, int64) +) + +// templateV7Plus fills out the V7 fields of a block using values from hdr. +// It also fills out fields (uname, gname, devmajor, devminor) that are +// shared in the USTAR, PAX, and GNU formats using the provided formatters. +// +// The block returned is only valid until the next call to +// templateV7Plus or writeRawFile. +func (tw *Writer) templateV7Plus(hdr *Header, fmtStr stringFormatter, fmtNum numberFormatter) *block { + tw.blk.Reset() + + modTime := hdr.ModTime + if modTime.IsZero() { + modTime = time.Unix(0, 0) + } + + v7 := tw.blk.V7() + v7.TypeFlag()[0] = hdr.Typeflag + fmtStr(v7.Name(), hdr.Name) + fmtStr(v7.LinkName(), hdr.Linkname) + fmtNum(v7.Mode(), hdr.Mode) + fmtNum(v7.UID(), int64(hdr.Uid)) + fmtNum(v7.GID(), int64(hdr.Gid)) + fmtNum(v7.Size(), hdr.Size) + fmtNum(v7.ModTime(), modTime.Unix()) + + ustar := tw.blk.USTAR() + fmtStr(ustar.UserName(), hdr.Uname) + fmtStr(ustar.GroupName(), hdr.Gname) + fmtNum(ustar.DevMajor(), hdr.Devmajor) + fmtNum(ustar.DevMinor(), hdr.Devminor) + + return &tw.blk +} + +// writeRawFile writes a minimal file with the given name and flag type. +// It uses format to encode the header format and will write data as the body. +// It uses default values for all of the other fields (as BSD and GNU tar does). +func (tw *Writer) writeRawFile(name, data string, flag byte, format Format) error { + tw.blk.Reset() + + // Best effort for the filename. + name = toASCII(name) + if len(name) > nameSize { + name = name[:nameSize] + } + name = strings.TrimRight(name, "/") + + var f formatter + v7 := tw.blk.V7() + v7.TypeFlag()[0] = flag + f.formatString(v7.Name(), name) + f.formatOctal(v7.Mode(), 0) + f.formatOctal(v7.UID(), 0) + f.formatOctal(v7.GID(), 0) + f.formatOctal(v7.Size(), int64(len(data))) // Must be < 8GiB + f.formatOctal(v7.ModTime(), 0) + tw.blk.SetFormat(format) + if f.err != nil { + return f.err // Only occurs if size condition is violated + } + + // Write the header and data. + if err := tw.writeRawHeader(&tw.blk, int64(len(data)), flag); err != nil { + return err + } + _, err := io.WriteString(tw, data) + return err +} + +// writeRawHeader writes the value of blk, regardless of its value. +// It sets up the Writer such that it can accept a file of the given size. +// If the flag is a special header-only flag, then the size is treated as zero. +func (tw *Writer) writeRawHeader(blk *block, size int64, flag byte) error { + if err := tw.Flush(); err != nil { + return err + } + if _, err := tw.w.Write(blk[:]); err != nil { + return err + } + if isHeaderOnlyType(flag) { + size = 0 + } + tw.curr = ®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 <= nameSize || !isASCII(name) { + return "", "", false + } else if length > prefixSize+1 { + length = prefixSize + 1 + } else if name[length-1] == '/' { + length-- + } + + i := strings.LastIndex(name[:length], "/") + nlen := len(name) - i - 1 // nlen is length of suffix + plen := i // plen is length of prefix + if i <= 0 || nlen > nameSize || nlen == 0 || plen > prefixSize { + return "", "", false + } + return name[:i], name[i+1:], true +} + +// 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 + } + n, err := tw.curr.Write(b) + if err != nil && err != ErrWriteTooLong { + tw.err = 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 + } + n, err := tw.curr.ReadFrom(r) + if err != nil && err != ErrWriteTooLong { + tw.err = err + } + return n, err +} + +// Close closes the tar archive by flushing the padding, and writing the footer. +// If the current file (from a prior call to WriteHeader) is not fully written, +// then this returns an error. +func (tw *Writer) Close() error { + if tw.err == ErrWriteAfterClose { + return nil + } + if tw.err != nil { + return tw.err + } + + // Trailer: two zero blocks. + err := tw.Flush() + for i := 0; i < 2 && err == nil; i++ { + _, err = tw.w.Write(zeroBlock[:]) + } + + // Ensure all future actions are invalid. + tw.err = ErrWriteAfterClose + return err // Report IO errors +} + +// regFileWriter is a fileWriter for writing data to a regular file entry. +type regFileWriter struct { + w io.Writer // Underlying Writer + nb int64 // Number of remaining bytes to write +} + +func (fw *regFileWriter) Write(b []byte) (n int, err error) { + overwrite := int64(len(b)) > fw.nb + if overwrite { + b = b[:fw.nb] + } + if len(b) > 0 { + n, err = fw.w.Write(b) + fw.nb -= int64(n) + } + switch { + case err != nil: + return n, err + case overwrite: + return n, ErrWriteTooLong + default: + return n, nil + } +} + +func (fw *regFileWriter) ReadFrom(r io.Reader) (int64, error) { + return io.Copy(struct{ io.Writer }{fw}, r) +} + +func (fw regFileWriter) LogicalRemaining() int64 { + return fw.nb +} +func (fw regFileWriter) PhysicalRemaining() int64 { + return fw.nb +} + +// sparseFileWriter is a fileWriter for writing data to a sparse file entry. +type sparseFileWriter struct { + fw fileWriter // Underlying fileWriter + sp sparseDatas // Normalized list of data fragments + pos int64 // Current position in sparse file +} + +func (sw *sparseFileWriter) Write(b []byte) (n int, err error) { + overwrite := int64(len(b)) > sw.LogicalRemaining() + if overwrite { + b = b[:sw.LogicalRemaining()] + } + + b0 := b + endPos := sw.pos + int64(len(b)) + for endPos > sw.pos && err == nil { + var nf int // Bytes written in fragment + dataStart, dataEnd := sw.sp[0].Offset, sw.sp[0].endOffset() + if sw.pos < dataStart { // In a hole fragment + bf := b[:min(int64(len(b)), dataStart-sw.pos)] + nf, err = zeroWriter{}.Write(bf) + } else { // In a data fragment + bf := b[:min(int64(len(b)), dataEnd-sw.pos)] + nf, err = sw.fw.Write(bf) + } + b = b[nf:] + sw.pos += int64(nf) + if sw.pos >= dataEnd && len(sw.sp) > 1 { + sw.sp = sw.sp[1:] // Ensure last fragment always remains + } + } + + 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 + } +}