Merge pull request #1877 from hathach/fix-host-cdc-without-iad

Fix host cdc without iad

Author: hathach

README.rst

@@ -1,7 +1,7 @@
 .. figure:: docs/assets/logo.svg
    :alt: TinyUSB
 
-|Build Status| |Documentation Status| |License|
+|Build Status| |Documentation Status| |Fuzzing Status| |License|
 
 TinyUSB is an open-source cross-platform USB Host/Device stack for
 embedded system, designed to be memory-safe with no dynamic allocation
@@ -130,6 +130,8 @@ in your project.
    :target: https://github.com/hathach/tinyusb/actions
 .. |Documentation Status| image:: https://readthedocs.org/projects/tinyusb/badge/?version=latest
    :target: https://docs.tinyusb.org/en/latest/?badge=latest
+.. |Fuzzing Status| image:: https://oss-fuzz-build-logs.storage.googleapis.com/badges/tinyusb.svg
+   :target: https://oss-fuzz-build-logs.storage.googleapis.com/index.html#tinyusb
 .. |License| image:: https://img.shields.io/badge/license-MIT-brightgreen.svg
    :target: https://opensource.org/licenses/MIT
 

examples/device/hid_generic_inout/src/usb_descriptors.c

@@ -103,7 +103,7 @@ uint8_t const desc_configuration[] =
   // Config number, interface count, string index, total length, attribute, power in mA
   TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
 
-  // Interface number, string index, protocol, report descriptor len, EP In & Out address, size & polling interval
+  // Interface number, string index, protocol, report descriptor len, EP Out & In address, size & polling interval
   TUD_HID_INOUT_DESCRIPTOR(ITF_NUM_HID, 0, HID_ITF_PROTOCOL_NONE, sizeof(desc_hid_report), EPNUM_HID, 0x80 | EPNUM_HID, CFG_TUD_HID_EP_BUFSIZE, 10)
 };
 

src/host/usbh.c

@@ -1522,7 +1522,7 @@ static bool _parse_configuration_descriptor(uint8_t dev_addr, tusb_desc_configur
 
 #if CFG_TUH_MIDI
     // MIDI has 2 interfaces (Audio Control v1 + MIDIStreaming) but does not have IAD
-    // manually increase the associated count
+    // manually force associated count = 2
     if (1                              == assoc_itf_count              &&
         TUSB_CLASS_AUDIO               == desc_itf->bInterfaceClass    &&
         AUDIO_SUBCLASS_CONTROL         == desc_itf->bInterfaceSubClass &&
@@ -1532,6 +1532,17 @@ static bool _parse_configuration_descriptor(uint8_t dev_addr, tusb_desc_configur
     }
 #endif
 
+#if CFG_TUH_CDC
+    // Some legacy CDC device does not use IAD but rather use device class as hint to combine 2 interfaces
+    // manually force associated count = 2
+    if (1                                        == assoc_itf_count              &&
+        TUSB_CLASS_CDC                           == desc_itf->bInterfaceClass    &&
+        CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL == desc_itf->bInterfaceSubClass)
+    {
+      assoc_itf_count = 2;
+    }
+#endif
+
     uint16_t const drv_len = tu_desc_get_interface_total_len(desc_itf, assoc_itf_count, (uint16_t) (desc_end-p_desc));
     TU_ASSERT(drv_len >= sizeof(tusb_desc_interface_t));