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 "unsafe"
     8  
     9  // IoctlRetInt performs an ioctl operation specified by req on a device
    10  // associated with opened file descriptor fd, and returns a non-negative
    11  // integer that is returned by the ioctl syscall.
    12  func IoctlRetInt(fd int, req uint) (int, error) {
    13  	ret, _, err := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), 0)
    14  	if err != 0 {
    15  		return 0, err
    16  	}
    17  	return int(ret), nil
    18  }
    19  
    20  func IoctlGetUint32(fd int, req uint) (uint32, error) {
    21  	var value uint32
    22  	err := ioctlPtr(fd, req, unsafe.Pointer(&value))
    23  	return value, err
    24  }
    25  
    26  func IoctlGetRTCTime(fd int) (*RTCTime, error) {
    27  	var value RTCTime
    28  	err := ioctlPtr(fd, RTC_RD_TIME, unsafe.Pointer(&value))
    29  	return &value, err
    30  }
    31  
    32  func IoctlSetRTCTime(fd int, value *RTCTime) error {
    33  	return ioctlPtr(fd, RTC_SET_TIME, unsafe.Pointer(value))
    34  }
    35  
    36  func IoctlGetRTCWkAlrm(fd int) (*RTCWkAlrm, error) {
    37  	var value RTCWkAlrm
    38  	err := ioctlPtr(fd, RTC_WKALM_RD, unsafe.Pointer(&value))
    39  	return &value, err
    40  }
    41  
    42  func IoctlSetRTCWkAlrm(fd int, value *RTCWkAlrm) error {
    43  	return ioctlPtr(fd, RTC_WKALM_SET, unsafe.Pointer(value))
    44  }
    45  
    46  // IoctlGetEthtoolDrvinfo fetches ethtool driver information for the network
    47  // device specified by ifname.
    48  func IoctlGetEthtoolDrvinfo(fd int, ifname string) (*EthtoolDrvinfo, error) {
    49  	ifr, err := NewIfreq(ifname)
    50  	if err != nil {
    51  		return nil, err
    52  	}
    53  
    54  	value := EthtoolDrvinfo{Cmd: ETHTOOL_GDRVINFO}
    55  	ifrd := ifr.withData(unsafe.Pointer(&value))
    56  
    57  	err = ioctlIfreqData(fd, SIOCETHTOOL, &ifrd)
    58  	return &value, err
    59  }
    60  
    61  // IoctlGetWatchdogInfo fetches information about a watchdog device from the
    62  // Linux watchdog API. For more information, see:
    63  // https://www.kernel.org/doc/html/latest/watchdog/watchdog-api.html.
    64  func IoctlGetWatchdogInfo(fd int) (*WatchdogInfo, error) {
    65  	var value WatchdogInfo
    66  	err := ioctlPtr(fd, WDIOC_GETSUPPORT, unsafe.Pointer(&value))
    67  	return &value, err
    68  }
    69  
    70  // IoctlWatchdogKeepalive issues a keepalive ioctl to a watchdog device. For
    71  // more information, see:
    72  // https://www.kernel.org/doc/html/latest/watchdog/watchdog-api.html.
    73  func IoctlWatchdogKeepalive(fd int) error {
    74  	// arg is ignored and not a pointer, so ioctl is fine instead of ioctlPtr.
    75  	return ioctl(fd, WDIOC_KEEPALIVE, 0)
    76  }
    77  
    78  // IoctlFileCloneRange performs an FICLONERANGE ioctl operation to clone the
    79  // range of data conveyed in value to the file associated with the file
    80  // descriptor destFd. See the ioctl_ficlonerange(2) man page for details.
    81  func IoctlFileCloneRange(destFd int, value *FileCloneRange) error {
    82  	return ioctlPtr(destFd, FICLONERANGE, unsafe.Pointer(value))
    83  }
    84  
    85  // IoctlFileClone performs an FICLONE ioctl operation to clone the entire file
    86  // associated with the file description srcFd to the file associated with the
    87  // file descriptor destFd. See the ioctl_ficlone(2) man page for details.
    88  func IoctlFileClone(destFd, srcFd int) error {
    89  	return ioctl(destFd, FICLONE, uintptr(srcFd))
    90  }
    91  
    92  type FileDedupeRange struct {
    93  	Src_offset uint64
    94  	Src_length uint64
    95  	Reserved1  uint16
    96  	Reserved2  uint32
    97  	Info       []FileDedupeRangeInfo
    98  }
    99  
   100  type FileDedupeRangeInfo struct {
   101  	Dest_fd       int64
   102  	Dest_offset   uint64
   103  	Bytes_deduped uint64
   104  	Status        int32
   105  	Reserved      uint32
   106  }
   107  
   108  // IoctlFileDedupeRange performs an FIDEDUPERANGE ioctl operation to share the
   109  // range of data conveyed in value from the file associated with the file
   110  // descriptor srcFd to the value.Info destinations. See the
   111  // ioctl_fideduperange(2) man page for details.
   112  func IoctlFileDedupeRange(srcFd int, value *FileDedupeRange) error {
   113  	buf := make([]byte, SizeofRawFileDedupeRange+
   114  		len(value.Info)*SizeofRawFileDedupeRangeInfo)
   115  	rawrange := (*RawFileDedupeRange)(unsafe.Pointer(&buf[0]))
   116  	rawrange.Src_offset = value.Src_offset
   117  	rawrange.Src_length = value.Src_length
   118  	rawrange.Dest_count = uint16(len(value.Info))
   119  	rawrange.Reserved1 = value.Reserved1
   120  	rawrange.Reserved2 = value.Reserved2
   121  
   122  	for i := range value.Info {
   123  		rawinfo := (*RawFileDedupeRangeInfo)(unsafe.Pointer(
   124  			uintptr(unsafe.Pointer(&buf[0])) + uintptr(SizeofRawFileDedupeRange) +
   125  				uintptr(i*SizeofRawFileDedupeRangeInfo)))
   126  		rawinfo.Dest_fd = value.Info[i].Dest_fd
   127  		rawinfo.Dest_offset = value.Info[i].Dest_offset
   128  		rawinfo.Bytes_deduped = value.Info[i].Bytes_deduped
   129  		rawinfo.Status = value.Info[i].Status
   130  		rawinfo.Reserved = value.Info[i].Reserved
   131  	}
   132  
   133  	err := ioctlPtr(srcFd, FIDEDUPERANGE, unsafe.Pointer(&buf[0]))
   134  
   135  	// Output
   136  	for i := range value.Info {
   137  		rawinfo := (*RawFileDedupeRangeInfo)(unsafe.Pointer(
   138  			uintptr(unsafe.Pointer(&buf[0])) + uintptr(SizeofRawFileDedupeRange) +
   139  				uintptr(i*SizeofRawFileDedupeRangeInfo)))
   140  		value.Info[i].Dest_fd = rawinfo.Dest_fd
   141  		value.Info[i].Dest_offset = rawinfo.Dest_offset
   142  		value.Info[i].Bytes_deduped = rawinfo.Bytes_deduped
   143  		value.Info[i].Status = rawinfo.Status
   144  		value.Info[i].Reserved = rawinfo.Reserved
   145  	}
   146  
   147  	return err
   148  }
   149  
   150  func IoctlHIDGetDesc(fd int, value *HIDRawReportDescriptor) error {
   151  	return ioctlPtr(fd, HIDIOCGRDESC, unsafe.Pointer(value))
   152  }
   153  
   154  func IoctlHIDGetRawInfo(fd int) (*HIDRawDevInfo, error) {
   155  	var value HIDRawDevInfo
   156  	err := ioctlPtr(fd, HIDIOCGRAWINFO, unsafe.Pointer(&value))
   157  	return &value, err
   158  }
   159  
   160  func IoctlHIDGetRawName(fd int) (string, error) {
   161  	var value [_HIDIOCGRAWNAME_LEN]byte
   162  	err := ioctlPtr(fd, _HIDIOCGRAWNAME, unsafe.Pointer(&value[0]))
   163  	return ByteSliceToString(value[:]), err
   164  }
   165  
   166  func IoctlHIDGetRawPhys(fd int) (string, error) {
   167  	var value [_HIDIOCGRAWPHYS_LEN]byte
   168  	err := ioctlPtr(fd, _HIDIOCGRAWPHYS, unsafe.Pointer(&value[0]))
   169  	return ByteSliceToString(value[:]), err
   170  }
   171  
   172  func IoctlHIDGetRawUniq(fd int) (string, error) {
   173  	var value [_HIDIOCGRAWUNIQ_LEN]byte
   174  	err := ioctlPtr(fd, _HIDIOCGRAWUNIQ, unsafe.Pointer(&value[0]))
   175  	return ByteSliceToString(value[:]), err
   176  }
   177  
   178  // IoctlIfreq performs an ioctl using an Ifreq structure for input and/or
   179  // output. See the netdevice(7) man page for details.
   180  func IoctlIfreq(fd int, req uint, value *Ifreq) error {
   181  	// It is possible we will add more fields to *Ifreq itself later to prevent
   182  	// misuse, so pass the raw *ifreq directly.
   183  	return ioctlPtr(fd, req, unsafe.Pointer(&value.raw))
   184  }
   185  
   186  // TODO(mdlayher): export if and when IfreqData is exported.
   187  
   188  // ioctlIfreqData performs an ioctl using an ifreqData structure for input
   189  // and/or output. See the netdevice(7) man page for details.
   190  func ioctlIfreqData(fd int, req uint, value *ifreqData) error {
   191  	// The memory layout of IfreqData (type-safe) and ifreq (not type-safe) are
   192  	// identical so pass *IfreqData directly.
   193  	return ioctlPtr(fd, req, unsafe.Pointer(value))
   194  }
   195  
   196  // IoctlKCMClone attaches a new file descriptor to a multiplexor by cloning an
   197  // existing KCM socket, returning a structure containing the file descriptor of
   198  // the new socket.
   199  func IoctlKCMClone(fd int) (*KCMClone, error) {
   200  	var info KCMClone
   201  	if err := ioctlPtr(fd, SIOCKCMCLONE, unsafe.Pointer(&info)); err != nil {
   202  		return nil, err
   203  	}
   204  
   205  	return &info, nil
   206  }
   207  
   208  // IoctlKCMAttach attaches a TCP socket and associated BPF program file
   209  // descriptor to a multiplexor.
   210  func IoctlKCMAttach(fd int, info KCMAttach) error {
   211  	return ioctlPtr(fd, SIOCKCMATTACH, unsafe.Pointer(&info))
   212  }
   213  
   214  // IoctlKCMUnattach unattaches a TCP socket file descriptor from a multiplexor.
   215  func IoctlKCMUnattach(fd int, info KCMUnattach) error {
   216  	return ioctlPtr(fd, SIOCKCMUNATTACH, unsafe.Pointer(&info))
   217  }
   218  
   219  // IoctlLoopGetStatus64 gets the status of the loop device associated with the
   220  // file descriptor fd using the LOOP_GET_STATUS64 operation.
   221  func IoctlLoopGetStatus64(fd int) (*LoopInfo64, error) {
   222  	var value LoopInfo64
   223  	if err := ioctlPtr(fd, LOOP_GET_STATUS64, unsafe.Pointer(&value)); err != nil {
   224  		return nil, err
   225  	}
   226  	return &value, nil
   227  }
   228  
   229  // IoctlLoopSetStatus64 sets the status of the loop device associated with the
   230  // file descriptor fd using the LOOP_SET_STATUS64 operation.
   231  func IoctlLoopSetStatus64(fd int, value *LoopInfo64) error {
   232  	return ioctlPtr(fd, LOOP_SET_STATUS64, unsafe.Pointer(value))
   233  }
   234  
   235  // IoctlLoopConfigure configures all loop device parameters in a single step
   236  func IoctlLoopConfigure(fd int, value *LoopConfig) error {
   237  	return ioctlPtr(fd, LOOP_CONFIGURE, unsafe.Pointer(value))
   238  }
   239
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