[mqtt] Implements mqtt publish tooling

vendor/github.com/containerd/continuity/sysx/README.md

@@ -0,0 +1,3 @@
+This package is for internal use only. It is intended to only have
+temporary changes before they are upstreamed to golang.org/x/sys/
+(a.k.a. https://github.com/golang/sys).

vendor/github.com/containerd/continuity/sysx/file_posix.go

@@ -0,0 +1,128 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package sysx
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/containerd/continuity/syscallx"
+)
+
+// Readlink returns the destination of the named symbolic link.
+// If there is an error, it will be of type *PathError.
+func Readlink(name string) (string, error) {
+	for len := 128; ; len *= 2 {
+		b := make([]byte, len)
+		n, e := fixCount(syscallx.Readlink(fixLongPath(name), b))
+		if e != nil {
+			return "", &os.PathError{Op: "readlink", Path: name, Err: e}
+		}
+		if n < len {
+			return string(b[0:n]), nil
+		}
+	}
+}
+
+// Many functions in package syscall return a count of -1 instead of 0.
+// Using fixCount(call()) instead of call() corrects the count.
+func fixCount(n int, err error) (int, error) {
+	if n < 0 {
+		n = 0
+	}
+	return n, err
+}
+
+// fixLongPath returns the extended-length (\\?\-prefixed) form of
+// path when needed, in order to avoid the default 260 character file
+// path limit imposed by Windows. If path is not easily converted to
+// the extended-length form (for example, if path is a relative path
+// or contains .. elements), or is short enough, fixLongPath returns
+// path unmodified.
+//
+// See https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx#maxpath
+func fixLongPath(path string) string {
+	// Do nothing (and don't allocate) if the path is "short".
+	// Empirically (at least on the Windows Server 2013 builder),
+	// the kernel is arbitrarily okay with < 248 bytes. That
+	// matches what the docs above say:
+	// "When using an API to create a directory, the specified
+	// path cannot be so long that you cannot append an 8.3 file
+	// name (that is, the directory name cannot exceed MAX_PATH
+	// minus 12)." Since MAX_PATH is 260, 260 - 12 = 248.
+	//
+	// The MSDN docs appear to say that a normal path that is 248 bytes long
+	// will work; empirically the path must be less then 248 bytes long.
+	if len(path) < 248 {
+		// Don't fix. (This is how Go 1.7 and earlier worked,
+		// not automatically generating the \\?\ form)
+		return path
+	}
+
+	// The extended form begins with \\?\, as in
+	// \\?\c:\windows\foo.txt or \\?\UNC\server\share\foo.txt.
+	// The extended form disables evaluation of . and .. path
+	// elements and disables the interpretation of / as equivalent
+	// to \. The conversion here rewrites / to \ and elides
+	// . elements as well as trailing or duplicate separators. For
+	// simplicity it avoids the conversion entirely for relative
+	// paths or paths containing .. elements. For now,
+	// \\server\share paths are not converted to
+	// \\?\UNC\server\share paths because the rules for doing so
+	// are less well-specified.
+	if len(path) >= 2 && path[:2] == `\\` {
+		// Don't canonicalize UNC paths.
+		return path
+	}
+	if !filepath.IsAbs(path) {
+		// Relative path
+		return path
+	}
+
+	const prefix = `\\?`
+
+	pathbuf := make([]byte, len(prefix)+len(path)+len(`\`))
+	copy(pathbuf, prefix)
+	n := len(path)
+	r, w := 0, len(prefix)
+	for r < n {
+		switch {
+		case os.IsPathSeparator(path[r]):
+			// empty block
+			r++
+		case path[r] == '.' && (r+1 == n || os.IsPathSeparator(path[r+1])):
+			// /./
+			r++
+		case r+1 < n && path[r] == '.' && path[r+1] == '.' && (r+2 == n || os.IsPathSeparator(path[r+2])):
+			// /../ is currently unhandled
+			return path
+		default:
+			pathbuf[w] = '\\'
+			w++
+			for ; r < n && !os.IsPathSeparator(path[r]); r++ {
+				pathbuf[w] = path[r]
+				w++
+			}
+		}
+	}
+	// A drive's root directory needs a trailing \
+	if w == len(`\\?\c:`) {
+		pathbuf[w] = '\\'
+		w++
+	}
+	return string(pathbuf[:w])
+}

vendor/github.com/containerd/continuity/sysx/generate.sh

@@ -0,0 +1,52 @@
+#!/bin/bash
+
+#   Copyright The containerd Authors.
+
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+
+#       http://www.apache.org/licenses/LICENSE-2.0
+
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+
+
+set -e
+
+mksyscall="$(go env GOROOT)/src/syscall/mksyscall.pl"
+
+fix() {
+	sed 's,^package syscall$,package sysx,' \
+		| sed 's,^import "unsafe"$,import (\n\t"syscall"\n\t"unsafe"\n),' \
+		| gofmt -r='BytePtrFromString -> syscall.BytePtrFromString' \
+		| gofmt -r='Syscall6 -> syscall.Syscall6' \
+		| gofmt -r='Syscall -> syscall.Syscall' \
+		| gofmt -r='SYS_GETXATTR -> syscall.SYS_GETXATTR' \
+		| gofmt -r='SYS_LISTXATTR -> syscall.SYS_LISTXATTR' \
+		| gofmt -r='SYS_SETXATTR -> syscall.SYS_SETXATTR' \
+		| gofmt -r='SYS_REMOVEXATTR -> syscall.SYS_REMOVEXATTR' \
+		| gofmt -r='SYS_LGETXATTR -> syscall.SYS_LGETXATTR' \
+		| gofmt -r='SYS_LLISTXATTR -> syscall.SYS_LLISTXATTR' \
+		| gofmt -r='SYS_LSETXATTR -> syscall.SYS_LSETXATTR' \
+		| gofmt -r='SYS_LREMOVEXATTR -> syscall.SYS_LREMOVEXATTR'
+}
+
+if [ "$GOARCH" == "" ] || [ "$GOOS" == "" ]; then
+	echo "Must specify \$GOARCH and \$GOOS"
+	exit 1
+fi
+
+mkargs=""
+
+if [ "$GOARCH" == "386" ] || [ "$GOARCH" == "arm" ]; then
+	mkargs="-l32"
+fi
+
+for f in "$@"; do
+	$mksyscall $mkargs "${f}_${GOOS}.go" | fix > "${f}_${GOOS}_${GOARCH}.go"
+done
+

vendor/github.com/containerd/continuity/sysx/nodata_linux.go

@@ -0,0 +1,23 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package sysx
+
+import (
+	"syscall"
+)
+
+const ENODATA = syscall.ENODATA

vendor/github.com/containerd/continuity/sysx/nodata_solaris.go

@@ -0,0 +1,24 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package sysx
+
+import (
+	"syscall"
+)
+
+// This should actually be a set that contains ENOENT and EPERM
+const ENODATA = syscall.ENOENT

vendor/github.com/containerd/continuity/sysx/nodata_unix.go

@@ -0,0 +1,25 @@
+// +build darwin freebsd
+
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package sysx
+
+import (
+	"syscall"
+)
+
+const ENODATA = syscall.ENOATTR

vendor/github.com/containerd/continuity/sysx/xattr.go

@@ -0,0 +1,125 @@
+// +build linux darwin
+
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package sysx
+
+import (
+	"bytes"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+// Listxattr calls syscall listxattr and reads all content
+// and returns a string array
+func Listxattr(path string) ([]string, error) {
+	return listxattrAll(path, unix.Listxattr)
+}
+
+// Removexattr calls syscall removexattr
+func Removexattr(path string, attr string) (err error) {
+	return unix.Removexattr(path, attr)
+}
+
+// Setxattr calls syscall setxattr
+func Setxattr(path string, attr string, data []byte, flags int) (err error) {
+	return unix.Setxattr(path, attr, data, flags)
+}
+
+// Getxattr calls syscall getxattr
+func Getxattr(path, attr string) ([]byte, error) {
+	return getxattrAll(path, attr, unix.Getxattr)
+}
+
+// LListxattr lists xattrs, not following symlinks
+func LListxattr(path string) ([]string, error) {
+	return listxattrAll(path, unix.Llistxattr)
+}
+
+// LRemovexattr removes an xattr, not following symlinks
+func LRemovexattr(path string, attr string) (err error) {
+	return unix.Lremovexattr(path, attr)
+}
+
+// LSetxattr sets an xattr, not following symlinks
+func LSetxattr(path string, attr string, data []byte, flags int) (err error) {
+	return unix.Lsetxattr(path, attr, data, flags)
+}
+
+// LGetxattr gets an xattr, not following symlinks
+func LGetxattr(path, attr string) ([]byte, error) {
+	return getxattrAll(path, attr, unix.Lgetxattr)
+}
+
+const defaultXattrBufferSize = 5
+
+type listxattrFunc func(path string, dest []byte) (int, error)
+
+func listxattrAll(path string, listFunc listxattrFunc) ([]string, error) {
+	var p []byte // nil on first execution
+
+	for {
+		n, err := listFunc(path, p) // first call gets buffer size.
+		if err != nil {
+			return nil, err
+		}
+
+		if n > len(p) {
+			p = make([]byte, n)
+			continue
+		}
+
+		p = p[:n]
+
+		ps := bytes.Split(bytes.TrimSuffix(p, []byte{0}), []byte{0})
+		var entries []string
+		for _, p := range ps {
+			s := string(p)
+			if s != "" {
+				entries = append(entries, s)
+			}
+		}
+
+		return entries, nil
+	}
+}
+
+type getxattrFunc func(string, string, []byte) (int, error)
+
+func getxattrAll(path, attr string, getFunc getxattrFunc) ([]byte, error) {
+	p := make([]byte, defaultXattrBufferSize)
+	for {
+		n, err := getFunc(path, attr, p)
+		if err != nil {
+			if errno, ok := err.(syscall.Errno); ok && errno == syscall.ERANGE {
+				p = make([]byte, len(p)*2) // this can't be ideal.
+				continue                   // try again!
+			}
+
+			return nil, err
+		}
+
+		// realloc to correct size and repeat
+		if n > len(p) {
+			p = make([]byte, n)
+			continue
+		}
+
+		return p[:n], nil
+	}
+}

vendor/github.com/containerd/continuity/sysx/xattr_unsupported.go

@@ -0,0 +1,67 @@
+// +build !linux,!darwin
+
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package sysx
+
+import (
+	"errors"
+	"runtime"
+)
+
+var unsupported = errors.New("extended attributes unsupported on " + runtime.GOOS)
+
+// Listxattr calls syscall listxattr and reads all content
+// and returns a string array
+func Listxattr(path string) ([]string, error) {
+	return []string{}, nil
+}
+
+// Removexattr calls syscall removexattr
+func Removexattr(path string, attr string) (err error) {
+	return unsupported
+}
+
+// Setxattr calls syscall setxattr
+func Setxattr(path string, attr string, data []byte, flags int) (err error) {
+	return unsupported
+}
+
+// Getxattr calls syscall getxattr
+func Getxattr(path, attr string) ([]byte, error) {
+	return []byte{}, unsupported
+}
+
+// LListxattr lists xattrs, not following symlinks
+func LListxattr(path string) ([]string, error) {
+	return []string{}, nil
+}
+
+// LRemovexattr removes an xattr, not following symlinks
+func LRemovexattr(path string, attr string) (err error) {
+	return unsupported
+}
+
+// LSetxattr sets an xattr, not following symlinks
+func LSetxattr(path string, attr string, data []byte, flags int) (err error) {
+	return unsupported
+}
+
+// LGetxattr gets an xattr, not following symlinks
+func LGetxattr(path, attr string) ([]byte, error) {
+	return []byte{}, nil
+}