diff options
Diffstat (limited to 'vendor/golang.org/x/sys/unix/xattr_bsd.go')
| -rw-r--r-- | vendor/golang.org/x/sys/unix/xattr_bsd.go | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/vendor/golang.org/x/sys/unix/xattr_bsd.go b/vendor/golang.org/x/sys/unix/xattr_bsd.go new file mode 100644 index 0000000..e168793 --- /dev/null +++ b/vendor/golang.org/x/sys/unix/xattr_bsd.go @@ -0,0 +1,280 @@ +// Copyright 2018 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. + +//go:build freebsd || netbsd + +package unix + +import ( + "strings" + "unsafe" +) + +// Derive extattr namespace and attribute name + +func xattrnamespace(fullattr string) (ns int, attr string, err error) { + s := strings.IndexByte(fullattr, '.') + if s == -1 { + return -1, "", ENOATTR + } + + namespace := fullattr[0:s] + attr = fullattr[s+1:] + + switch namespace { + case "user": + return EXTATTR_NAMESPACE_USER, attr, nil + case "system": + return EXTATTR_NAMESPACE_SYSTEM, attr, nil + default: + return -1, "", ENOATTR + } +} + +func initxattrdest(dest []byte, idx int) (d unsafe.Pointer) { + if len(dest) > idx { + return unsafe.Pointer(&dest[idx]) + } + if dest != nil { + // extattr_get_file and extattr_list_file treat NULL differently from + // a non-NULL pointer of length zero. Preserve the property of nilness, + // even if we can't use dest directly. + return unsafe.Pointer(&_zero) + } + return nil +} + +// FreeBSD and NetBSD implement their own syscalls to handle extended attributes + +func Getxattr(file string, attr string, dest []byte) (sz int, err error) { + d := initxattrdest(dest, 0) + destsize := len(dest) + + nsid, a, err := xattrnamespace(attr) + if err != nil { + return -1, err + } + + return ExtattrGetFile(file, nsid, a, uintptr(d), destsize) +} + +func Fgetxattr(fd int, attr string, dest []byte) (sz int, err error) { + d := initxattrdest(dest, 0) + destsize := len(dest) + + nsid, a, err := xattrnamespace(attr) + if err != nil { + return -1, err + } + + return ExtattrGetFd(fd, nsid, a, uintptr(d), destsize) +} + +func Lgetxattr(link string, attr string, dest []byte) (sz int, err error) { + d := initxattrdest(dest, 0) + destsize := len(dest) + + nsid, a, err := xattrnamespace(attr) + if err != nil { + return -1, err + } + + return ExtattrGetLink(link, nsid, a, uintptr(d), destsize) +} + +// flags are unused on FreeBSD + +func Fsetxattr(fd int, attr string, data []byte, flags int) (err error) { + var d unsafe.Pointer + if len(data) > 0 { + d = unsafe.Pointer(&data[0]) + } + datasiz := len(data) + + nsid, a, err := xattrnamespace(attr) + if err != nil { + return + } + + _, err = ExtattrSetFd(fd, nsid, a, uintptr(d), datasiz) + return +} + +func Setxattr(file string, attr string, data []byte, flags int) (err error) { + var d unsafe.Pointer + if len(data) > 0 { + d = unsafe.Pointer(&data[0]) + } + datasiz := len(data) + + nsid, a, err := xattrnamespace(attr) + if err != nil { + return + } + + _, err = ExtattrSetFile(file, nsid, a, uintptr(d), datasiz) + return +} + +func Lsetxattr(link string, attr string, data []byte, flags int) (err error) { + var d unsafe.Pointer + if len(data) > 0 { + d = unsafe.Pointer(&data[0]) + } + datasiz := len(data) + + nsid, a, err := xattrnamespace(attr) + if err != nil { + return + } + + _, err = ExtattrSetLink(link, nsid, a, uintptr(d), datasiz) + return +} + +func Removexattr(file string, attr string) (err error) { + nsid, a, err := xattrnamespace(attr) + if err != nil { + return + } + + err = ExtattrDeleteFile(file, nsid, a) + return +} + +func Fremovexattr(fd int, attr string) (err error) { + nsid, a, err := xattrnamespace(attr) + if err != nil { + return + } + + err = ExtattrDeleteFd(fd, nsid, a) + return +} + +func Lremovexattr(link string, attr string) (err error) { + nsid, a, err := xattrnamespace(attr) + if err != nil { + return + } + + err = ExtattrDeleteLink(link, nsid, a) + return +} + +func Listxattr(file string, dest []byte) (sz int, err error) { + destsiz := len(dest) + + // FreeBSD won't allow you to list xattrs from multiple namespaces + s, pos := 0, 0 + for _, nsid := range [...]int{EXTATTR_NAMESPACE_USER, EXTATTR_NAMESPACE_SYSTEM} { + stmp, e := ListxattrNS(file, nsid, dest[pos:]) + + /* Errors accessing system attrs are ignored so that + * we can implement the Linux-like behavior of omitting errors that + * we don't have read permissions on + * + * Linux will still error if we ask for user attributes on a file that + * we don't have read permissions on, so don't ignore those errors + */ + if e != nil { + if e == EPERM && nsid != EXTATTR_NAMESPACE_USER { + continue + } + return s, e + } + + s += stmp + pos = s + if pos > destsiz { + pos = destsiz + } + } + + return s, nil +} + +func ListxattrNS(file string, nsid int, dest []byte) (sz int, err error) { + d := initxattrdest(dest, 0) + destsiz := len(dest) + + s, e := ExtattrListFile(file, nsid, uintptr(d), destsiz) + if e != nil { + return 0, err + } + + return s, nil +} + +func Flistxattr(fd int, dest []byte) (sz int, err error) { + destsiz := len(dest) + + s, pos := 0, 0 + for _, nsid := range [...]int{EXTATTR_NAMESPACE_USER, EXTATTR_NAMESPACE_SYSTEM} { + stmp, e := FlistxattrNS(fd, nsid, dest[pos:]) + + if e != nil { + if e == EPERM && nsid != EXTATTR_NAMESPACE_USER { + continue + } + return s, e + } + + s += stmp + pos = s + if pos > destsiz { + pos = destsiz + } + } + + return s, nil +} + +func FlistxattrNS(fd int, nsid int, dest []byte) (sz int, err error) { + d := initxattrdest(dest, 0) + destsiz := len(dest) + + s, e := ExtattrListFd(fd, nsid, uintptr(d), destsiz) + if e != nil { + return 0, err + } + + return s, nil +} + +func Llistxattr(link string, dest []byte) (sz int, err error) { + destsiz := len(dest) + + s, pos := 0, 0 + for _, nsid := range [...]int{EXTATTR_NAMESPACE_USER, EXTATTR_NAMESPACE_SYSTEM} { + stmp, e := LlistxattrNS(link, nsid, dest[pos:]) + + if e != nil { + if e == EPERM && nsid != EXTATTR_NAMESPACE_USER { + continue + } + return s, e + } + + s += stmp + pos = s + if pos > destsiz { + pos = destsiz + } + } + + return s, nil +} + +func LlistxattrNS(link string, nsid int, dest []byte) (sz int, err error) { + d := initxattrdest(dest, 0) + destsiz := len(dest) + + s, e := ExtattrListLink(link, nsid, uintptr(d), destsiz) + if e != nil { + return 0, err + } + + return s, nil +} |
