github.com/iDigitalFlame/xmt@v0.5.4/device/winapi/v_handler_v17.go (about)

     1  //go:build windows && go1.17
     2  // +build windows,go1.17
     3  
     4  // Copyright (C) 2020 - 2023 iDigitalFlame
     5  //
     6  // This program is free software: you can redistribute it and/or modify
     7  // it under the terms of the GNU General Public License as published by
     8  // the Free Software Foundation, either version 3 of the License, or
     9  // any later version.
    10  //
    11  // This program is distributed in the hope that it will be useful,
    12  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    13  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    14  // GNU General Public License for more details.
    15  //
    16  // You should have received a copy of the GNU General Public License
    17  // along with this program.  If not, see <https://www.gnu.org/licenses/>.
    18  //
    19  
    20  package winapi
    21  
    22  import (
    23  	"syscall"
    24  
    25  	// Importing unsafe to use "linkname"
    26  	_ "unsafe"
    27  )
    28  
    29  func removeCtrlHandler() {
    30  	var (
    31  		h = syscall.NewCallback(ctrlHandler)
    32  		z = callbackasmAddr(0) // Base of runtime.callbackasm
    33  		e = callbackasmAddr(1) - z
    34  	)
    35  	if e <= 0 {
    36  		// Weird shit, shouldn't happen.
    37  		return
    38  	}
    39  	// Instead of trying to use it directly (which never works), we grab a callback
    40  	// index and determine the entrySize between 1 and 0.
    41  	//
    42  	// We then loop until we hit the handle or hit the callbackasm address instead.
    43  	for ; h >= z; h -= e {
    44  		if h == 0 {
    45  			// DO NOT SET HANDLERS TO IGNORE.
    46  			break
    47  		}
    48  		if r, _, _ := syscallN(setConsoleCtrlHandler, h, 0); r > 0 {
    49  			break
    50  		}
    51  	}
    52  }
    53  
    54  //go:linkname ctrlHandler runtime.ctrlHandler
    55  func ctrlHandler(uint32) uintptr
    56  
    57  //go:linkname callbackasmAddr runtime.callbackasmAddr
    58  func callbackasmAddr(int) uintptr