Client: add some error reporting to WSL detection

client/hostinfo_wsl.cpp

@@ -48,6 +48,7 @@ int get_all_distros(WSL_DISTROS& distros) {
         lxss_path.c_str(), 0, KEY_QUERY_VALUE | KEY_ENUMERATE_SUB_KEYS, &hKey
     );
     if (lRet != ERROR_SUCCESS) {
+        msg_printf(0, MSG_INFO, "WSL: registry open failed");
         return -1;
     }
 
@@ -59,6 +60,7 @@ int get_all_distros(WSL_DISTROS& distros) {
         (LPBYTE)default_wsl_guid, &default_wsl_guid_len
     );
     if ((lRet != ERROR_SUCCESS) || (default_wsl_guid_len > buf_len)) {
+        msg_printf(0, MSG_INFO, "WSL: registry query failed");
         return -1;
     }
 
@@ -179,10 +181,12 @@ int get_wsl_information(WSL_DISTROS &distros) {
     WSL_DISTROS all_distros;
     int retval = get_all_distros(all_distros);
     if (retval) return retval;
+    string err_msg;
 
     WSL_CMD rs;
 
-    if (rs.setup()) {
+    if (rs.setup(err_msg)) {
+        msg_printf(0, MSG_INFO, "WSL setup error: %s", err_msg.c_str());
         return -1;
     }
 

lib/win_util.cpp

@@ -199,7 +199,7 @@ typedef HRESULT(WINAPI *PWslLaunch)(
 static PWslLaunch pWslLaunch = NULL;
 static HINSTANCE wsl_lib = NULL;
 
-int WSL_CMD::setup() {
+int WSL_CMD::setup(string &err_msg) {
     in_read = NULL;
     in_write = NULL;
     out_read = NULL;
@@ -207,9 +207,15 @@ int WSL_CMD::setup() {
 
     if (!pWslLaunch) {
         wsl_lib = LoadLibraryA("wslapi.dll");
-        if (!wsl_lib) return -1;
+        if (!wsl_lib) {
+            err_msg = "Can't load wslapi.dll");
+            return -1;
+        }
         pWslLaunch = (PWslLaunch)GetProcAddress(wsl_lib, "WslLaunch");
-        if (!pWslLaunch) return -1;
+        if (!pWslLaunch) {
+            err_msg = "WslLaunch not in wslapi.dll");
+            return -1;
+        }
     }
 
     SECURITY_ATTRIBUTES sa;
@@ -217,10 +223,22 @@ int WSL_CMD::setup() {
     sa.bInheritHandle = TRUE;
     sa.lpSecurityDescriptor = NULL;
 
-    if (!CreatePipe(&out_read, &out_write, &sa, 0)) return -1;
-    if (!SetHandleInformation(out_read, HANDLE_FLAG_INHERIT, 0)) return -1;
-    if (!CreatePipe(&in_read, &in_write, &sa, 0)) return -1;
-    if (!SetHandleInformation(in_write, HANDLE_FLAG_INHERIT, 0)) return -1;
+    if (!CreatePipe(&out_read, &out_write, &sa, 0)) {
+        err_msg = "Can't create out pipe");
+        return -1;
+    }
+    if (!SetHandleInformation(out_read, HANDLE_FLAG_INHERIT, 0)) {
+        err_msg = "Can't inherit out pipe");
+        return -1;
+    }
+    if (!CreatePipe(&in_read, &in_write, &sa, 0)) {
+        err_msg = "Can't create in pipe");
+        return -1;
+    }
+    if (!SetHandleInformation(in_write, HANDLE_FLAG_INHERIT, 0)) {
+        err_msg = "Can't inherit in pipe");
+        return -1;
+    }
     return 0;
 }
 

lib/win_util.h

@@ -53,7 +53,7 @@ struct WSL_CMD {
     // Use WslLaunch() to run a shell in the WSL container
     // The shell will run as the default user
     //
-    int setup();
+    int setup(std::string&);
 
     // Use wsl.exe to run a shell as root in the WSL container
     //