Make Nix builds work

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
+}