service: split into tunnel and manager

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 105 insertions, 0 deletions

diff --git a/tunnel/firewall/helpers.go b/tunnel/firewall/helpers.go
new file mode 100644
index 00000000..e340b802
--- /dev/null
+++ b/tunnel/firewall/helpers.go
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package firewall
+
+import (
+	"fmt"
+	"os"
+	"runtime"
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+func runTransaction(session uintptr, operation wfpObjectInstaller) error {
+	err := fwpmTransactionBegin0(session, 0)
+	if err != nil {
+		return wrapErr(err)
+	}
+
+	err = operation(session)
+	if err != nil {
+		fwpmTransactionAbort0(session)
+		return wrapErr(err)
+	}
+
+	err = fwpmTransactionCommit0(session)
+	if err != nil {
+		fwpmTransactionAbort0(session)
+		return wrapErr(err)
+	}
+
+	return nil
+}
+
+func createWtFwpmDisplayData0(name, description string) (*wtFwpmDisplayData0, error) {
+	namePtr, err := windows.UTF16PtrFromString(name)
+	if err != nil {
+		return nil, wrapErr(err)
+	}
+
+	descriptionPtr, err := windows.UTF16PtrFromString(description)
+	if err != nil {
+		return nil, wrapErr(err)
+	}
+
+	return &wtFwpmDisplayData0{
+		name:        namePtr,
+		description: descriptionPtr,
+	}, nil
+}
+
+func filterWeight(weight uint8) wtFwpValue0 {
+	return wtFwpValue0{
+		_type: cFWP_UINT8,
+		value: uintptr(weight),
+	}
+}
+
+func wrapErr(err error) error {
+	if _, ok := err.(syscall.Errno); !ok {
+		return err
+	}
+	_, file, line, ok := runtime.Caller(1)
+	if !ok {
+		return fmt.Errorf("Firewall error at unknown location: %v", err)
+	}
+	return fmt.Errorf("Firewall error at %s:%d: %v", file, line, err)
+}
+
+func getCurrentProcessSecurityDescriptor() (*wtFwpByteBlob, error) {
+	procHandle, err := windows.GetCurrentProcess()
+	if err != nil {
+		panic(err)
+	}
+	blob := &wtFwpByteBlob{}
+	err = getSecurityInfo(procHandle, cSE_KERNEL_OBJECT, cDACL_SECURITY_INFORMATION, nil, nil, nil, nil, (*uintptr)(unsafe.Pointer(&blob.data)))
+	if err != nil {
+		return nil, wrapErr(err)
+	}
+	blob.size = getSecurityDescriptorLength(uintptr(unsafe.Pointer(blob.data)))
+	return blob, nil
+}
+
+func getCurrentProcessAppID() (*wtFwpByteBlob, error) {
+	currentFile, err := os.Executable()
+	if err != nil {
+		return nil, wrapErr(err)
+	}
+
+	curFilePtr, err := windows.UTF16PtrFromString(currentFile)
+	if err != nil {
+		return nil, wrapErr(err)
+	}
+
+	var appID *wtFwpByteBlob
+	err = fwpmGetAppIdFromFileName0(curFilePtr, unsafe.Pointer(&appID))
+	if err != nil {
+		return nil, wrapErr(err)
+	}
+	return appID, nil
+}