wpasvc: Add skip_on_error registry value to skip interfaces on error

This can be used to include binding information for multiple interfaces
in Windows registry and only use the ones that match with an available
network interface.

wpa_supplicant/main_winsvc.c

@@ -70,9 +70,10 @@ static int read_interface(struct wpa_global *global, HKEY _hk,
 	HKEY hk;
 #define TBUFLEN 255
 	TCHAR adapter[TBUFLEN], config[TBUFLEN], ctrl_interface[TBUFLEN];
-	DWORD buflen;
+	DWORD buflen, val;
 	LONG ret;
 	struct wpa_interface iface;
+	int skip_on_error = 0;
 
 	ret = RegOpenKeyEx(_hk, name, 0, KEY_QUERY_VALUE, &hk);
 	if (ret != ERROR_SUCCESS) {
@@ -116,10 +117,21 @@ static int read_interface(struct wpa_global *global, HKEY _hk,
 		iface.confname = (char *) config;
 	}
 
+	buflen = sizeof(val);
+	ret = RegQueryValueEx(hk, TEXT("skip_on_error"), NULL, NULL,
+			      (LPBYTE) &val, &buflen);
+	if (ret == ERROR_SUCCESS && buflen == sizeof(val))
+		skip_on_error = val;
+
 	RegCloseKey(hk);
 
-	if (wpa_supplicant_add_iface(global, &iface) == NULL)
-		return -1;
+	if (wpa_supplicant_add_iface(global, &iface) == NULL) {
+		if (skip_on_error)
+			wpa_printf(MSG_DEBUG, "Skipped interface '%s' due to "
+				   "initialization failure", iface.ifname);
+		else
+			return -1;
+	}
 
 	return 0;
 }

wpa_supplicant/win_example.reg

@@ -38,4 +38,5 @@ REGEDIT4
 "adapter"="{A7627643-C310-49E5-BD89-7E77709C04AB}"
 "config"="test"
 "ctrl_interface"=""
+"skip_on_error"=dword:00000000