mirror of
https://github.com/opencontainers/runc.git
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85de7ec363
It turns out that the standard "syscall" library is not recommended for new programs. runC will need to eventually move to this, but for now include it in vendor so we can use it for new features. Signed-off-by: Aleksa Sarai <asarai@suse.de>
103 lines
3.0 KiB
Go
103 lines
3.0 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris
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package unix
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import "unsafe"
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// readInt returns the size-bytes unsigned integer in native byte order at offset off.
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func readInt(b []byte, off, size uintptr) (u uint64, ok bool) {
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if len(b) < int(off+size) {
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return 0, false
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}
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if isBigEndian {
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return readIntBE(b[off:], size), true
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}
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return readIntLE(b[off:], size), true
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}
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func readIntBE(b []byte, size uintptr) uint64 {
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switch size {
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case 1:
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return uint64(b[0])
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case 2:
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_ = b[1] // bounds check hint to compiler; see golang.org/issue/14808
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return uint64(b[1]) | uint64(b[0])<<8
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case 4:
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_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
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return uint64(b[3]) | uint64(b[2])<<8 | uint64(b[1])<<16 | uint64(b[0])<<24
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case 8:
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_ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
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return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 |
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uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56
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default:
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panic("syscall: readInt with unsupported size")
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}
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}
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func readIntLE(b []byte, size uintptr) uint64 {
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switch size {
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case 1:
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return uint64(b[0])
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case 2:
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_ = b[1] // bounds check hint to compiler; see golang.org/issue/14808
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return uint64(b[0]) | uint64(b[1])<<8
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case 4:
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_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
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return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24
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case 8:
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_ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
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return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
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uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
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default:
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panic("syscall: readInt with unsupported size")
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}
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}
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// ParseDirent parses up to max directory entries in buf,
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// appending the names to names. It returns the number of
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// bytes consumed from buf, the number of entries added
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// to names, and the new names slice.
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func ParseDirent(buf []byte, max int, names []string) (consumed int, count int, newnames []string) {
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origlen := len(buf)
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count = 0
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for max != 0 && len(buf) > 0 {
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reclen, ok := direntReclen(buf)
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if !ok || reclen > uint64(len(buf)) {
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return origlen, count, names
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}
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rec := buf[:reclen]
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buf = buf[reclen:]
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ino, ok := direntIno(rec)
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if !ok {
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break
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}
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if ino == 0 { // File absent in directory.
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continue
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}
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const namoff = uint64(unsafe.Offsetof(Dirent{}.Name))
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namlen, ok := direntNamlen(rec)
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if !ok || namoff+namlen > uint64(len(rec)) {
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break
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}
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name := rec[namoff : namoff+namlen]
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for i, c := range name {
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if c == 0 {
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name = name[:i]
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break
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}
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}
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// Check for useless names before allocating a string.
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if string(name) == "." || string(name) == ".." {
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continue
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}
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max--
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count++
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names = append(names, string(name))
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}
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return origlen - len(buf), count, names
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}
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