89 lines
2.3 KiB
Go
89 lines
2.3 KiB
Go
// +build windows
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package memcall
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import (
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"errors"
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"fmt"
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"golang.org/x/sys/windows"
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)
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// Lock is a wrapper for windows.VirtualLock()
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func Lock(b []byte) error {
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if err := windows.VirtualLock(_getPtr(b), uintptr(len(b))); err != nil {
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return fmt.Errorf("<memcall> could not acquire lock on %p, limit reached? [Err: %s]", _getStartPtr(b), err)
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}
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return nil
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}
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// Unlock is a wrapper for windows.VirtualUnlock()
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func Unlock(b []byte) error {
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if err := windows.VirtualUnlock(_getPtr(b), uintptr(len(b))); err != nil {
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return fmt.Errorf("<memcall> could not free lock on %p [Err: %s]", _getStartPtr(b), err)
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}
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return nil
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}
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// Alloc allocates a byte slice of length n and returns it.
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func Alloc(n int) ([]byte, error) {
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// Allocate the memory.
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ptr, err := windows.VirtualAlloc(_zero, uintptr(n), 0x1000|0x2000, 0x4)
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if err != nil {
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return nil, fmt.Errorf("<memcall> could not allocate [Err: %s]", err)
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}
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// Convert this pointer to a slice.
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b := _getBytes(ptr, n, n)
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// Wipe it just in case there is some remnant data.
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wipe(b)
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// Return the allocated memory.
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return b, nil
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}
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// Free deallocates the byte slice specified.
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func Free(b []byte) error {
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// Make the memory region readable and writable.
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if err := Protect(b, ReadWrite()); err != nil {
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return err
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}
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// Wipe the memory region in case of remnant data.
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wipe(b)
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// Free the memory back to the kernel.
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if err := windows.VirtualFree(_getPtr(b), uintptr(0), 0x8000); err != nil {
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return fmt.Errorf("<memcall> could not deallocate %p [Err: %s]", _getStartPtr(b), err)
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}
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return nil
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}
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// Protect modifies the memory protection flags for a specified byte slice.
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func Protect(b []byte, mpf MemoryProtectionFlag) error {
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var prot int
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if mpf.flag == ReadWrite().flag {
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prot = 0x4 // PAGE_READWRITE
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} else if mpf.flag == ReadOnly().flag {
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prot = 0x2 // PAGE_READ
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} else if mpf.flag == NoAccess().flag {
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prot = 0x1 // PAGE_NOACCESS
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} else {
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return errors.New(ErrInvalidFlag)
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}
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var oldProtect uint32
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if err := windows.VirtualProtect(_getPtr(b), uintptr(len(b)), uint32(prot), &oldProtect); err != nil {
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return fmt.Errorf("<memcall> could not set %d on %p [Err: %s]", prot, _getStartPtr(b), err)
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}
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return nil
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}
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// DisableCoreDumps is included for compatibility reasons. On windows it is a no-op function.
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func DisableCoreDumps() error { return nil }
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