ceph-csi/vendor/github.com/pkg/xattr/xattr_bsd.go
Marcel Lauhoff f8faffac89 vendor: vendor fscrypt integration dependencies
Signed-off-by: Marcel Lauhoff <marcel.lauhoff@suse.com>
2022-10-17 17:33:52 +00:00

202 lines
5.4 KiB
Go

//go:build freebsd || netbsd
// +build freebsd netbsd
package xattr
import (
"os"
"syscall"
"unsafe"
)
const (
// XATTR_SUPPORTED will be true if the current platform is supported
XATTR_SUPPORTED = true
EXTATTR_NAMESPACE_USER = 1
// ENOATTR is not exported by the syscall package on Linux, because it is
// an alias for ENODATA. We export it here so it is available on all
// our supported platforms.
ENOATTR = syscall.ENOATTR
)
func getxattr(path string, name string, data []byte) (int, error) {
return sysGet(syscall.SYS_EXTATTR_GET_FILE, path, name, data)
}
func lgetxattr(path string, name string, data []byte) (int, error) {
return sysGet(syscall.SYS_EXTATTR_GET_LINK, path, name, data)
}
func fgetxattr(f *os.File, name string, data []byte) (int, error) {
return getxattr(f.Name(), name, data)
}
// sysGet is called by getxattr and lgetxattr with the appropriate syscall
// number. This works because syscalls have the same signature and return
// values.
func sysGet(syscallNum uintptr, path string, name string, data []byte) (int, error) {
ptr, nbytes := bytePtrFromSlice(data)
/*
ssize_t extattr_get_file(
const char *path,
int attrnamespace,
const char *attrname,
void *data,
size_t nbytes);
ssize_t extattr_get_link(
const char *path,
int attrnamespace,
const char *attrname,
void *data,
size_t nbytes);
*/
r0, _, err := syscall.Syscall6(syscallNum, uintptr(unsafe.Pointer(syscall.StringBytePtr(path))),
EXTATTR_NAMESPACE_USER, uintptr(unsafe.Pointer(syscall.StringBytePtr(name))),
uintptr(unsafe.Pointer(ptr)), uintptr(nbytes), 0)
if err != syscall.Errno(0) {
return int(r0), err
}
return int(r0), nil
}
func setxattr(path string, name string, data []byte, flags int) error {
return sysSet(syscall.SYS_EXTATTR_SET_FILE, path, name, data)
}
func lsetxattr(path string, name string, data []byte, flags int) error {
return sysSet(syscall.SYS_EXTATTR_SET_LINK, path, name, data)
}
func fsetxattr(f *os.File, name string, data []byte, flags int) error {
return setxattr(f.Name(), name, data, flags)
}
// sysSet is called by setxattr and lsetxattr with the appropriate syscall
// number. This works because syscalls have the same signature and return
// values.
func sysSet(syscallNum uintptr, path string, name string, data []byte) error {
ptr, nbytes := bytePtrFromSlice(data)
/*
ssize_t extattr_set_file(
const char *path,
int attrnamespace,
const char *attrname,
const void *data,
size_t nbytes
);
ssize_t extattr_set_link(
const char *path,
int attrnamespace,
const char *attrname,
const void *data,
size_t nbytes
);
*/
r0, _, err := syscall.Syscall6(syscallNum, uintptr(unsafe.Pointer(syscall.StringBytePtr(path))),
EXTATTR_NAMESPACE_USER, uintptr(unsafe.Pointer(syscall.StringBytePtr(name))),
uintptr(unsafe.Pointer(ptr)), uintptr(nbytes), 0)
if err != syscall.Errno(0) {
return err
}
if int(r0) != nbytes {
return syscall.E2BIG
}
return nil
}
func removexattr(path string, name string) error {
return sysRemove(syscall.SYS_EXTATTR_DELETE_FILE, path, name)
}
func lremovexattr(path string, name string) error {
return sysRemove(syscall.SYS_EXTATTR_DELETE_LINK, path, name)
}
func fremovexattr(f *os.File, name string) error {
return removexattr(f.Name(), name)
}
// sysSet is called by removexattr and lremovexattr with the appropriate syscall
// number. This works because syscalls have the same signature and return
// values.
func sysRemove(syscallNum uintptr, path string, name string) error {
/*
int extattr_delete_file(
const char *path,
int attrnamespace,
const char *attrname
);
int extattr_delete_link(
const char *path,
int attrnamespace,
const char *attrname
);
*/
_, _, err := syscall.Syscall(syscallNum, uintptr(unsafe.Pointer(syscall.StringBytePtr(path))),
EXTATTR_NAMESPACE_USER, uintptr(unsafe.Pointer(syscall.StringBytePtr(name))),
)
if err != syscall.Errno(0) {
return err
}
return nil
}
func listxattr(path string, data []byte) (int, error) {
return sysList(syscall.SYS_EXTATTR_LIST_FILE, path, data)
}
func llistxattr(path string, data []byte) (int, error) {
return sysList(syscall.SYS_EXTATTR_LIST_LINK, path, data)
}
func flistxattr(f *os.File, data []byte) (int, error) {
return listxattr(f.Name(), data)
}
// sysSet is called by listxattr and llistxattr with the appropriate syscall
// number. This works because syscalls have the same signature and return
// values.
func sysList(syscallNum uintptr, path string, data []byte) (int, error) {
ptr, nbytes := bytePtrFromSlice(data)
/*
ssize_t extattr_list_file(
const char *path,
int attrnamespace,
void *data,
size_t nbytes
);
ssize_t extattr_list_link(
const char *path,
int attrnamespace,
void *data,
size_t nbytes
);
*/
r0, _, err := syscall.Syscall6(syscallNum, uintptr(unsafe.Pointer(syscall.StringBytePtr(path))),
EXTATTR_NAMESPACE_USER, uintptr(unsafe.Pointer(ptr)), uintptr(nbytes), 0, 0)
if err != syscall.Errno(0) {
return int(r0), err
}
return int(r0), nil
}
// stringsFromByteSlice converts a sequence of attributes to a []string.
// On FreeBSD, each entry consists of a single byte containing the length
// of the attribute name, followed by the attribute name.
// The name is _not_ terminated by NULL.
func stringsFromByteSlice(buf []byte) (result []string) {
index := 0
for index < len(buf) {
next := index + 1 + int(buf[index])
result = append(result, string(buf[index+1:next]))
index = next
}
return
}