github.com/go-asm/go@v1.21.1-0.20240213172139-40c5ead50c48/syscall/unix/getentropy_netbsd.go (about)

     1  // Copyright 2023 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build netbsd
     6  
     7  package unix
     8  
     9  import (
    10  	"syscall"
    11  	"unsafe"
    12  )
    13  
    14  const (
    15  	_CTL_KERN = 1
    16  
    17  	_KERN_ARND = 81
    18  )
    19  
    20  func GetEntropy(p []byte) error {
    21  	mib := [2]uint32{_CTL_KERN, _KERN_ARND}
    22  	n := uintptr(len(p))
    23  	_, _, errno := syscall.Syscall6(
    24  		syscall.SYS___SYSCTL,
    25  		uintptr(unsafe.Pointer(&mib[0])),
    26  		uintptr(len(mib)),
    27  		uintptr(unsafe.Pointer(&p[0])), // olddata
    28  		uintptr(unsafe.Pointer(&n)),    // &oldlen
    29  		uintptr(unsafe.Pointer(nil)),   // newdata
    30  		0)                              // newlen
    31  	if errno != 0 {
    32  		return syscall.Errno(errno)
    33  	}
    34  	if n != uintptr(len(p)) {
    35  		return syscall.EINVAL
    36  	}
    37  	return nil
    38  }