[PATCH 1/2] mountmgr: Create devices and registry entries for serial ports.

[Alex Henrie]

2017-04-18 7:00 GMT-06:00 Hugh McMaster <hugh.mcmaster at outlook.com>:
> Hi Alex,
>
> Just a few things I noticed.
>
> On Monday, 17 April 2017 2:23 PM, Alex Henrie wrote:
>>+    /* create registry entry */
>>+    sprintfW( reg_value, reg_value_format, n );
>>+    RegSetValueExW( windows_ports_key, nt_name.Buffer, 0, REG_SZ,
>>+                    (BYTE *)reg_value, strlenW( reg_value ) * sizeof(WCHAR) );
>>+
>>+    return TRUE;
>>+}
>
> You need to pass RegSetValueExW() the string length plus the null-terminating character.

Good catch.

>>+/* find and create serial or parallel ports */
>>+static void create_port_devices( DRIVER_OBJECT *driver )
>>+{
>>+    static const char *serial_search_paths[] = {
>>+#ifdef linux
>>+        "/dev/ttyS%u",
>>+        "/dev/ttyUSB%u",
>>+#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
>>+        "/dev/cuau%u",
>>+#elif defined(__DragonFly__)
>>+        "/dev/cuaa%u",
>>+#else
>>+        "",
>>+#endif
>>+    };
>>+    static const WCHAR serialcomm_keyW[] = {'H','A','R','D','W','A','R','E','\\',
>>+                                            'D','E','V','I','C','E','M','A','P','\\',
>>+                                            'S','E','R','I','A','L','C','O','M','M',0};
>>+    const char **search_paths;
>>+    const WCHAR *windows_ports_key_name;
>>+    char *dosdevices_path, *p;
>>+    HKEY wine_ports_key = NULL, windows_ports_key = NULL;
>>+    char unix_path[256];
>>+    int i, j, n = 1;
>>+
>>+    if (!(dosdevices_path = get_dosdevices_path( &p )))
>>+        return;
>>+
>>+    if (driver == serial_driver)
>>+    {
>>+        p[0] = 'c';
>>+        p[1] = 'o';
>>+        p[2] = 'm';
>>+        search_paths = serial_search_paths;
>>+        windows_ports_key_name = serialcomm_keyW;
>>+    }
>>+    else
>>+    {
>>+        /* TODO: support parallel ports */
>>+    }
>>+    p += 3;
>>+
>>+    RegOpenKeyW( HKEY_LOCAL_MACHINE, ports_keyW, &wine_ports_key );
>>+    RegOpenKeyW( HKEY_LOCAL_MACHINE, windows_ports_key_name, &windows_ports_key );
>
> Please use RegOpenKeyExW() and check for any failures from these functions.

If these functions fail, wine_ports_key and windows_ports_key will
still be NULL, and symlinks will be created for the detected devices
even though registry entries will not. I think that is desired
behavior.

>>+    /* remove old symlinks */
>>+    for (n = 1; n <= MAX_PORTS; n++)
>>+    {
>>+        sprintf( p, "%u", n );
>>+        if (unlink( dosdevices_path ) != 0 && !errno)
>>+            break;
>>+    }
>>+
>>+    /* look for ports in the usual places */
>>+    n = 1;
>>+    for (i = 0; i < sizeof(search_paths)/sizeof(search_paths[0]); i++)
>
> This won't do what you expect. sizeof(search_paths)/sizeof(search_paths[0]) is 1.
> You need to pass in the number of elements in the array. Also, it's better to avoid making this calculation
> during each loop.

Good catch.

Thanks for the feedback, that was very helpful!

-Alex