feat: set permissions to the service

.github/workflows/build.yml

@@ -22,13 +22,19 @@ jobs:
     if: ${{ needs.check-changes.outputs.should_run != 'false' }}
     steps:
       - uses: actions/checkout@v4
-      - name: Build the dummy
+      - name: Setup 
         working-directory: dummy-service
-        run: gcc -o GalaxyCommunication.exe main.c -ladvapi32
+        run: meson setup build
+      - name: Build
+        working-directory: dummy-service
+        run: meson compile -C build
+      - name: Move files
+        working-directory: dummy-service
+        run: move build/*.exe .
       - uses: actions/upload-artifact@v4
         with:
           name: dummy-GalaxyCommunication.exe
-          path: dummy-service/GalaxyCommunication.exe
+          path: dummy-service/*.exe
   build:
     strategy:
       matrix:

dummy-service/README.md

@@ -30,7 +30,11 @@ In case of Wine/Proton make sure to run the command above in the context of your
 
 Use 
 ```shell
-gcc -o GalaxyCommunication.exe main.c -ladvapi32
+meson setup builddir
 ```
 
-For cross compilation on Linux use `x86_64-w64-mingw32-gcc`
+For cross compilation on Linux/Mac make sure `mingw` is installed and add a `--cross-file meson/x86_64-w64-mingw32.ini` to the setup command
+
+```shell
+meson compile -C builddir
+``

dummy-service/install-dummy-service.bat

@@ -6,3 +6,4 @@ SET targetdir=C:\ProgramData\GOG.com\Galaxy\redists
 sc create GalaxyCommunication binpath=%targetdir%\GalaxyCommunication.exe
 if not exist "%targetdir%" mkdir %targetdir% 
 xcopy /y /q %currdir%GalaxyCommunication.exe %targetdir%
+%currdir%update-permissions.exe

dummy-service/meson.build

@@ -0,0 +1,8 @@
+project('dummy-service', 'c',
+  version : '0.1',
+  default_options : ['warning_level=3'])
+
+executable('GalaxyCommunication',
+           'communication.c')
+
+executable('update-permissions', 'permissions.c')

dummy-service/meson/x86_64-w64-mingw32.ini

@@ -0,0 +1,18 @@
+[properties]
+needs_exe_wrapper = true
+
+[binaries]
+c = 'x86_64-w64-mingw32-gcc'
+cpp = 'x86_64-w64-mingw32-g++'
+ar = 'x86_64-w64-mingw32-ar'
+strip = 'x86_64-w64-mingw32-strip'
+pkg-config = 'x86_64-w64-mingw32-pkg-config'
+windres = 'x86_64-w64-mingw32-windres'
+
+exe_wrapper = 'wine64'
+
+[host_machine]
+system = 'windows'
+cpu_family = 'x86_64'
+cpu = 'x86_64'
+endian = 'little'

dummy-service/permissions.c

@@ -0,0 +1,142 @@
+#include <windows.h>
+#include <stdio.h>
+#include <aclapi.h>
+
+// based on https://learn.microsoft.com/en-en/windows/win32/services/svccontrol-cpp
+
+SC_HANDLE schSCManager;
+SC_HANDLE schService;
+
+EXPLICIT_ACCESS      ea;
+SECURITY_DESCRIPTOR  sd;
+PSECURITY_DESCRIPTOR psd            = NULL;
+PACL                 pacl           = NULL;
+PACL                 pNewAcl        = NULL;
+BOOL                 bDaclPresent   = FALSE;
+BOOL                 bDaclDefaulted = FALSE;
+DWORD                dwError        = 0;
+DWORD                dwSize         = 0;
+DWORD                dwBytesNeeded  = 0;
+
+int main(int argc, char** argv) {
+
+schSCManager = OpenSCManager( 
+        NULL,                    // local computer
+        NULL,                    // ServicesActive database 
+        SC_MANAGER_ALL_ACCESS);  // full access rights 
+
+    if (NULL == schSCManager) 
+    {
+        printf("OpenSCManager failed (%ld)\n", GetLastError());
+        return 1;
+    }
+
+    // Get a handle to the service
+
+    schService = OpenService( 
+        schSCManager,              // SCManager database 
+        "GalaxyCommunication",     // name of service 
+        READ_CONTROL | WRITE_DAC); // access
+
+    if (schService == NULL)
+    { 
+        printf("OpenService failed (%ld)\n", GetLastError()); 
+        CloseServiceHandle(schSCManager);
+        return 1;
+    }    
+
+    // Get the current security descriptor.
+
+    if (!QueryServiceObjectSecurity(schService,
+        DACL_SECURITY_INFORMATION, 
+        &psd,           // using NULL does not work on all versions
+        0, 
+        &dwBytesNeeded))
+    {
+        if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
+        {
+            dwSize = dwBytesNeeded;
+            psd = (PSECURITY_DESCRIPTOR)HeapAlloc(GetProcessHeap(),
+                    HEAP_ZERO_MEMORY, dwSize);
+            if (psd == NULL)
+            {
+                // Note: HeapAlloc does not support GetLastError.
+                printf("HeapAlloc failed\n");
+                goto dacl_cleanup;
+            }
+
+            if (!QueryServiceObjectSecurity(schService,
+                DACL_SECURITY_INFORMATION, psd, dwSize, &dwBytesNeeded))
+            {
+                printf("QueryServiceObjectSecurity failed (%ld)\n", GetLastError());
+                goto dacl_cleanup;
+            }
+        }
+        else 
+        {
+            printf("QueryServiceObjectSecurity failed (%ld)\n", GetLastError());
+            goto dacl_cleanup;
+        }
+    }
+
+    // Get the DACL.
+
+    if (!GetSecurityDescriptorDacl(psd, &bDaclPresent, &pacl,
+                                   &bDaclDefaulted))
+    {
+        printf("GetSecurityDescriptorDacl failed(%ld)\n", GetLastError());
+        goto dacl_cleanup;
+    }
+
+    // Build the ACE.
+
+    BuildExplicitAccessWithName(&ea, TEXT("EVERYONE"),
+        SERVICE_START | SERVICE_STOP | READ_CONTROL,
+        SET_ACCESS, NO_INHERITANCE);
+
+    dwError = SetEntriesInAcl(1, &ea, pacl, &pNewAcl);
+    if (dwError != ERROR_SUCCESS)
+    {
+        printf("SetEntriesInAcl failed(%ld)\n", dwError);
+        goto dacl_cleanup;
+    }
+
+    // Initialize a new security descriptor.
+
+    if (!InitializeSecurityDescriptor(&sd, 
+        SECURITY_DESCRIPTOR_REVISION))
+    {
+        printf("InitializeSecurityDescriptor failed(%ld)\n", GetLastError());
+        goto dacl_cleanup;
+    }
+
+    // Set the new DACL in the security descriptor.
+
+    if (!SetSecurityDescriptorDacl(&sd, TRUE, pNewAcl, FALSE))
+    {
+        printf("SetSecurityDescriptorDacl failed(%ld)\n", GetLastError());
+        goto dacl_cleanup;
+    }
+
+    // Set the new DACL for the service object.
+
+    if (!SetServiceObjectSecurity(schService, 
+        DACL_SECURITY_INFORMATION, &sd))
+    {
+        printf("SetServiceObjectSecurity failed(%ld)\n", GetLastError());
+        goto dacl_cleanup;
+    }
+    else printf("Service DACL updated successfully\n");
+
+dacl_cleanup:
+    CloseServiceHandle(schSCManager);
+    CloseServiceHandle(schService);
+
+    if(NULL != pNewAcl)
+        LocalFree((HLOCAL)pNewAcl);
+    if(NULL != psd)
+        HeapFree(GetProcessHeap(), 0, (LPVOID)psd);
+
+
+    return 0;
+}