returned existing files to origin during restruct

agent/syscall/structs.go

@@ -0,0 +1,20 @@
+package syscall
+
+type EVENTLOGRECORD struct {
+	Length              uint32
+	Reserved            uint32
+	RecordNumber        uint32
+	TimeGenerated       uint32
+	TimeWritten         uint32
+	EventID             uint32
+	EventType           uint16
+	NumStrings          uint16
+	EventCategory       uint16
+	ReservedFlags       uint16
+	ClosingRecordNumber uint32
+	StringOffset        uint32
+	UserSidLength       uint32
+	UserSidOffset       uint32
+	DataLength          uint32
+	DataOffset          uint32
+}

agent/syscall/syscall_windows.go

@@ -0,0 +1,146 @@
+package syscall
+
+import (
+	"fmt"
+	"strings"
+	"syscall"
+	"unsafe"
+
+	"github.com/amidaware/rmmagent/agent/utils"
+	"github.com/gonutz/w32/v2"
+	"golang.org/x/sys/windows"
+	"golang.org/x/sys/windows/registry"
+)
+
+type ReadFlag uint32
+
+const (
+	EVENTLOG_SEQUENTIAL_READ ReadFlag = 1 << iota
+	EVENTLOG_SEEK_READ
+	EVENTLOG_FORWARDS_READ
+	EVENTLOG_BACKWARDS_READ
+)
+
+const (
+	DONT_RESOLVE_DLL_REFERENCES uint32 = 0x0001
+	LOAD_LIBRARY_AS_DATAFILE    uint32 = 0x0002
+)
+
+var (
+	modadvapi32 = windows.NewLazySystemDLL("advapi32.dll")
+	modkernel32 = windows.NewLazySystemDLL("kernel32.dll")
+
+	procFormatMessageW          = modkernel32.NewProc("FormatMessageW")
+	procGetOldestEventLogRecord = modadvapi32.NewProc("GetOldestEventLogRecord")
+	procLoadLibraryExW          = modkernel32.NewProc("LoadLibraryExW")
+	procReadEventLogW           = modadvapi32.NewProc("ReadEventLogW")
+)
+
+func GetOldestEventLogRecord(eventLog w32.HANDLE, oldestRecord *uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procGetOldestEventLogRecord.Addr(), 2, uintptr(eventLog), uintptr(unsafe.Pointer(oldestRecord)), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func ReadEventLog(eventLog w32.HANDLE, readFlags ReadFlag, recordOffset uint32, buffer *byte, numberOfBytesToRead uint32, bytesRead *uint32, minNumberOfBytesNeeded *uint32) (err error) {
+	r1, _, e1 := syscall.Syscall9(procReadEventLogW.Addr(), 7, uintptr(eventLog), uintptr(readFlags), uintptr(recordOffset), uintptr(unsafe.Pointer(buffer)), uintptr(numberOfBytesToRead), uintptr(unsafe.Pointer(bytesRead)), uintptr(unsafe.Pointer(minNumberOfBytesNeeded)), 0, 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func LoadLibraryEx(filename *uint16, file syscall.Handle, flags uint32) (handle syscall.Handle, err error) {
+	r0, _, e1 := syscall.Syscall(procLoadLibraryExW.Addr(), 3, uintptr(unsafe.Pointer(filename)), uintptr(file), uintptr(flags))
+	handle = syscall.Handle(r0)
+	if handle == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func FormatMessage(flags uint32, source syscall.Handle, messageID uint32, languageID uint32, buffer *byte, bufferSize uint32, arguments uintptr) (numChars uint32, err error) {
+	r0, _, e1 := syscall.Syscall9(procFormatMessageW.Addr(), 7, uintptr(flags), uintptr(source), uintptr(messageID), uintptr(languageID), uintptr(unsafe.Pointer(buffer)), uintptr(bufferSize), uintptr(arguments), 0, 0)
+	numChars = uint32(r0)
+	if numChars == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+
+	return
+}
+
+// https://github.com/mackerelio/go-check-plugins/blob/ad7910fdc45ccb892b5e5fda65ba0956c2b2885d/check-windows-eventlog/lib/check-windows-eventlog.go#L232
+func GetResourceMessage(providerName, sourceName string, eventID uint32, argsptr uintptr) (string, error) {
+	regkey := fmt.Sprintf(
+		"SYSTEM\\CurrentControlSet\\Services\\EventLog\\%s\\%s",
+		providerName, sourceName)
+	key, err := registry.OpenKey(registry.LOCAL_MACHINE, regkey, registry.QUERY_VALUE)
+	if err != nil {
+		return "", err
+	}
+
+	defer key.Close()
+	val, _, err := key.GetStringValue("EventMessageFile")
+	if err != nil {
+		return "", err
+	}
+
+	val, err = registry.ExpandString(val)
+	if err != nil {
+		return "", err
+	}
+
+	handle, err := LoadLibraryEx(syscall.StringToUTF16Ptr(val), 0,
+		DONT_RESOLVE_DLL_REFERENCES|LOAD_LIBRARY_AS_DATAFILE)
+	if err != nil {
+		return "", err
+	}
+
+	defer syscall.CloseHandle(handle)
+
+	msgbuf := make([]byte, 1<<16)
+	numChars, err := FormatMessage(
+		syscall.FORMAT_MESSAGE_FROM_SYSTEM|
+			syscall.FORMAT_MESSAGE_FROM_HMODULE|
+			syscall.FORMAT_MESSAGE_ARGUMENT_ARRAY,
+		handle,
+		eventID,
+		0,
+		&msgbuf[0],
+		uint32(len(msgbuf)),
+		argsptr)
+	if err != nil {
+		return "", err
+	}
+
+	message, _ := utils.BytesToString(msgbuf[:numChars*2])
+	message = strings.Replace(message, "\r", "", -1)
+	message = strings.TrimSuffix(message, "\n")
+	return message, nil
+}
+
+func StringToUTF16Ptr(val string) *uint16 {
+	return syscall.StringToUTF16Ptr(val)
+}
+
+func CloseHandle(handle syscall.Handle) {
+	defer syscall.CloseHandle(handle)
+}