ioctl_linux.go

     1  // Copyright 2021 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  package unix
     6  
     7  import (
     8  	"unsafe"
     9  )
    10  
    11  // IoctlRetInt performs an ioctl operation specified by req on a device
    12  // associated with opened file descriptor fd, and returns a non-negative
    13  // integer that is returned by the ioctl syscall.
    14  func IoctlRetInt(fd int, req uint) (int, error) {
    15  	ret, _, err := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), 0)
    16  	if err != 0 {
    17  		return 0, err
    18  	}
    19  	return int(ret), nil
    20  }
    21  
    22  func IoctlGetUint32(fd int, req uint) (uint32, error) {
    23  	var value uint32
    24  	err := ioctlPtr(fd, req, unsafe.Pointer(&value))
    25  	return value, err
    26  }
    27  
    28  func IoctlGetRTCTime(fd int) (*RTCTime, error) {
    29  	var value RTCTime
    30  	err := ioctlPtr(fd, RTC_RD_TIME, unsafe.Pointer(&value))
    31  	return &value, err
    32  }
    33  
    34  func IoctlSetRTCTime(fd int, value *RTCTime) error {
    35  	return ioctlPtr(fd, RTC_SET_TIME, unsafe.Pointer(value))
    36  }
    37  
    38  func IoctlGetRTCWkAlrm(fd int) (*RTCWkAlrm, error) {
    39  	var value RTCWkAlrm
    40  	err := ioctlPtr(fd, RTC_WKALM_RD, unsafe.Pointer(&value))
    41  	return &value, err
    42  }
    43  
    44  func IoctlSetRTCWkAlrm(fd int, value *RTCWkAlrm) error {
    45  	return ioctlPtr(fd, RTC_WKALM_SET, unsafe.Pointer(value))
    46  }
    47  
    48  // IoctlGetEthtoolDrvinfo fetches ethtool driver information for the network
    49  // device specified by ifname.
    50  func IoctlGetEthtoolDrvinfo(fd int, ifname string) (*EthtoolDrvinfo, error) {
    51  	ifr, err := NewIfreq(ifname)
    52  	if err != nil {
    53  		return nil, err
    54  	}
    55  
    56  	value := EthtoolDrvinfo{Cmd: ETHTOOL_GDRVINFO}
    57  	ifrd := ifr.withData(unsafe.Pointer(&value))
    58  
    59  	err = ioctlIfreqData(fd, SIOCETHTOOL, &ifrd)
    60  	return &value, err
    61  }
    62  
    63  // IoctlGetWatchdogInfo fetches information about a watchdog device from the
    64  // Linux watchdog API. For more information, see:
    65  // https://www.kernel.org/doc/html/latest/watchdog/watchdog-api.html.
    66  func IoctlGetWatchdogInfo(fd int) (*WatchdogInfo, error) {
    67  	var value WatchdogInfo
    68  	err := ioctlPtr(fd, WDIOC_GETSUPPORT, unsafe.Pointer(&value))
    69  	return &value, err
    70  }
    71  
    72  // IoctlWatchdogKeepalive issues a keepalive ioctl to a watchdog device. For
    73  // more information, see:
    74  // https://www.kernel.org/doc/html/latest/watchdog/watchdog-api.html.
    75  func IoctlWatchdogKeepalive(fd int) error {
    76  	// arg is ignored and not a pointer, so ioctl is fine instead of ioctlPtr.
    77  	return ioctl(fd, WDIOC_KEEPALIVE, 0)
    78  }
    79  
    80  // IoctlFileCloneRange performs an FICLONERANGE ioctl operation to clone the
    81  // range of data conveyed in value to the file associated with the file
    82  // descriptor destFd. See the ioctl_ficlonerange(2) man page for details.
    83  func IoctlFileCloneRange(destFd int, value *FileCloneRange) error {
    84  	return ioctlPtr(destFd, FICLONERANGE, unsafe.Pointer(value))
    85  }
    86  
    87  // IoctlFileClone performs an FICLONE ioctl operation to clone the entire file
    88  // associated with the file description srcFd to the file associated with the
    89  // file descriptor destFd. See the ioctl_ficlone(2) man page for details.
    90  func IoctlFileClone(destFd, srcFd int) error {
    91  	return ioctl(destFd, FICLONE, uintptr(srcFd))
    92  }
    93  
    94  type FileDedupeRange struct {
    95  	Src_offset uint64
    96  	Src_length uint64
    97  	Reserved1  uint16
    98  	Reserved2  uint32
    99  	Info       []FileDedupeRangeInfo
   100  }
   101  
   102  type FileDedupeRangeInfo struct {
   103  	Dest_fd       int64
   104  	Dest_offset   uint64
   105  	Bytes_deduped uint64
   106  	Status        int32
   107  	Reserved      uint32
   108  }
   109  
   110  // IoctlFileDedupeRange performs an FIDEDUPERANGE ioctl operation to share the
   111  // range of data conveyed in value from the file associated with the file
   112  // descriptor srcFd to the value.Info destinations. See the
   113  // ioctl_fideduperange(2) man page for details.
   114  func IoctlFileDedupeRange(srcFd int, value *FileDedupeRange) error {
   115  	buf := make([]byte, SizeofRawFileDedupeRange+
   116  		len(value.Info)*SizeofRawFileDedupeRangeInfo)
   117  	rawrange := (*RawFileDedupeRange)(unsafe.Pointer(&buf[0]))
   118  	rawrange.Src_offset = value.Src_offset
   119  	rawrange.Src_length = value.Src_length
   120  	rawrange.Dest_count = uint16(len(value.Info))
   121  	rawrange.Reserved1 = value.Reserved1
   122  	rawrange.Reserved2 = value.Reserved2
   123  
   124  	for i := range value.Info {
   125  		rawinfo := (*RawFileDedupeRangeInfo)(unsafe.Pointer(
   126  			uintptr(unsafe.Pointer(&buf[0])) + uintptr(SizeofRawFileDedupeRange) +
   127  				uintptr(i*SizeofRawFileDedupeRangeInfo)))
   128  		rawinfo.Dest_fd = value.Info[i].Dest_fd
   129  		rawinfo.Dest_offset = value.Info[i].Dest_offset
   130  		rawinfo.Bytes_deduped = value.Info[i].Bytes_deduped
   131  		rawinfo.Status = value.Info[i].Status
   132  		rawinfo.Reserved = value.Info[i].Reserved
   133  	}
   134  
   135  	err := ioctlPtr(srcFd, FIDEDUPERANGE, unsafe.Pointer(&buf[0]))
   136  
   137  	// Output
   138  	for i := range value.Info {
   139  		rawinfo := (*RawFileDedupeRangeInfo)(unsafe.Pointer(
   140  			uintptr(unsafe.Pointer(&buf[0])) + uintptr(SizeofRawFileDedupeRange) +
   141  				uintptr(i*SizeofRawFileDedupeRangeInfo)))
   142  		value.Info[i].Dest_fd = rawinfo.Dest_fd
   143  		value.Info[i].Dest_offset = rawinfo.Dest_offset
   144  		value.Info[i].Bytes_deduped = rawinfo.Bytes_deduped
   145  		value.Info[i].Status = rawinfo.Status
   146  		value.Info[i].Reserved = rawinfo.Reserved
   147  	}
   148  
   149  	return err
   150  }
   151  
   152  func IoctlHIDGetDesc(fd int, value *HIDRawReportDescriptor) error {
   153  	return ioctlPtr(fd, HIDIOCGRDESC, unsafe.Pointer(value))
   154  }
   155  
   156  func IoctlHIDGetRawInfo(fd int) (*HIDRawDevInfo, error) {
   157  	var value HIDRawDevInfo
   158  	err := ioctlPtr(fd, HIDIOCGRAWINFO, unsafe.Pointer(&value))
   159  	return &value, err
   160  }
   161  
   162  func IoctlHIDGetRawName(fd int) (string, error) {
   163  	var value [_HIDIOCGRAWNAME_LEN]byte
   164  	err := ioctlPtr(fd, _HIDIOCGRAWNAME, unsafe.Pointer(&value[0]))
   165  	return ByteSliceToString(value[:]), err
   166  }
   167  
   168  func IoctlHIDGetRawPhys(fd int) (string, error) {
   169  	var value [_HIDIOCGRAWPHYS_LEN]byte
   170  	err := ioctlPtr(fd, _HIDIOCGRAWPHYS, unsafe.Pointer(&value[0]))
   171  	return ByteSliceToString(value[:]), err
   172  }
   173  
   174  func IoctlHIDGetRawUniq(fd int) (string, error) {
   175  	var value [_HIDIOCGRAWUNIQ_LEN]byte
   176  	err := ioctlPtr(fd, _HIDIOCGRAWUNIQ, unsafe.Pointer(&value[0]))
   177  	return ByteSliceToString(value[:]), err
   178  }
   179  
   180  // IoctlIfreq performs an ioctl using an Ifreq structure for input and/or
   181  // output. See the netdevice(7) man page for details.
   182  func IoctlIfreq(fd int, req uint, value *Ifreq) error {
   183  	// It is possible we will add more fields to *Ifreq itself later to prevent
   184  	// misuse, so pass the raw *ifreq directly.
   185  	return ioctlPtr(fd, req, unsafe.Pointer(&value.raw))
   186  }
   187  
   188  // TODO(mdlayher): export if and when IfreqData is exported.
   189  
   190  // ioctlIfreqData performs an ioctl using an ifreqData structure for input
   191  // and/or output. See the netdevice(7) man page for details.
   192  func ioctlIfreqData(fd int, req uint, value *ifreqData) error {
   193  	// The memory layout of IfreqData (type-safe) and ifreq (not type-safe) are
   194  	// identical so pass *IfreqData directly.
   195  	return ioctlPtr(fd, req, unsafe.Pointer(value))
   196  }
   197
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