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