tests: gadget0: Added testing for the BOS descriptor retrieval and invalid BOS request handling

tests/gadget-zero/test_gadget0.py

@@ -13,6 +13,7 @@ import array
 import datetime
 import random
 import usb.core
+import usb.control
 import usb.util as uu
 import random
 import sys
@@ -41,6 +42,13 @@ GZ_REQ_READ_LOOPBACK_BUFFER=11
 GZ_REQ_INTEL_WRITE=0x5b
 GZ_REQ_INTEL_READ=0x5c
 
+DESC_TYPE_BOS = 0x0F
+DESC_TYPE_DEVICE_CAPABILITY = 0x10
+
+DEVCAP_TYPE_PLATFORM = 5
+
+MICROSOFT_WINDOWS_VERSION_WINBLUE = 0x06030000
+
 class find_by_serial(object):
     def __init__(self, serial):
         self._serial = serial
@@ -260,7 +268,6 @@ class TestConfigLoopBack(unittest.TestCase):
         expected = array.array('B', [x for x in data])
         self.assertEqual(expected, read, "should have read back what we wrote")
 
-
     def test_simple_loop(self):
         """Plain simple loopback, does it work at all"""
         eout = self.eps_out[0]
@@ -506,6 +513,68 @@ class TestUnaligned(unittest.TestCase):
         self.do_readwrite()
 
 
+class TestBOSDescriptor(unittest.TestCase):
+    """
+    Make sure the stack correctly handles a request for the BOS descriptor, and discards invalid BOS requests
+    """
+
+    def setUp(self):
+        self.dev : usb.core.Device = usb.core.find(idVendor=VENDOR_ID, idProduct=PRODUCT_ID, custom_match=find_by_serial(DUT_SERIAL))
+        self.assertIsNotNone(self.dev, "Couldn't find locm3 gadget0 device")
+
+    def tearDown(self):
+        uu.dispose_resources(self.dev)
+
+    def test_partial_request(self):
+        bos : bytes = usb.control.get_descriptor(self.dev, 5, DESC_TYPE_BOS, 0).tobytes()
+        self.assertEqual(len(bos), 5)
+        # Check the BOS descriptor returned is valid
+        self.assertEqual(bos[0], 5)
+        self.assertEqual(bos[1], DESC_TYPE_BOS)
+        self.assertEqual(bos[4], 1)
+
+        bos_total_length = bos[2] + (bos[3] << 8)
+        self.assertNotEqual(bos_total_length, 0)
+        self.assertEqual(bos_total_length, 33)
+
+    def test_complete_request(self):
+        bos : bytes = usb.control.get_descriptor(self.dev, 33, DESC_TYPE_BOS, 0).tobytes()
+        self.assertEqual(len(bos), 33)
+        # Check the BOS descriptor returned is valid
+        self.assertEqual(bos[0], 5)
+        self.assertEqual(bos[1], DESC_TYPE_BOS)
+        self.assertEqual(bos[4], 1)
+
+        # This BOS descriptor is followed by a platform capability descriptor
+        platform_capability = bos[5:]
+        self.assertEqual(platform_capability[0], 28)
+        self.assertEqual(platform_capability[1], DESC_TYPE_DEVICE_CAPABILITY)
+        self.assertEqual(platform_capability[2], DEVCAP_TYPE_PLATFORM)
+        self.assertEqual(platform_capability[3], 0)
+
+        # Make sure it's a Microsoft OS 2.0 Descriptors platform capability
+        self.assertEqual(platform_capability[4:20].hex(), 'df60ddd88945c74c9cd2659d9e648a9f')
+
+        # The PCD is followed by a Microsoft OS Descriptor Set Info descriptor
+        descriptor_set_info = platform_capability[20:]
+        windows_version = (descriptor_set_info[0] | (descriptor_set_info[1] << 8) |
+            (descriptor_set_info[2] << 16) | (descriptor_set_info[3] << 24))
+        self.assertEqual(windows_version, MICROSOFT_WINDOWS_VERSION_WINBLUE)
+        total_length = descriptor_set_info[4] | (descriptor_set_info[5] << 8)
+        self.assertNotEqual(total_length, 0)
+        self.assertEqual(descriptor_set_info[6], 1)
+        self.assertEqual(descriptor_set_info[7], 0)
+
+    def test_invalid_request(self):
+        try:
+            usb.control.get_descriptor(self.dev, 5, DESC_TYPE_BOS, 1)
+            self.fail("get_descriptor() for an invalid BOS request suceeded")
+        except usb.core.USBError as e:
+            # Make sure we got a pipe error (EP0 STALL)
+            # Why libusb returns stalls as this and makes them fatal is.. a subject for a different place..
+            self.assertEqual(e.errno, 32)
+
+
 def run_ci_test(dut):
     # Avoids the import for non-CI users!
     import xmlrunner
@@ -542,4 +611,3 @@ if __name__ == "__main__":
                 print("Detected %s on bus:port-address: %s:%s-%s" % (DUT_SERIAL, dev.bus, '.'.join(map(str,dev.port_numbers)), dev.address))
             else:
                 runner(DUT_SERIAL)
-