changing usbd driver open() return type, add max_len

only done with cdc and msc, push this interim for feedback first

1 files changed, 18 insertions, 12 deletions

diff --git a/src/device/usbd.c b/src/device/usbd.c
index f7918c07e..971417a35 100644
--- a/src/device/usbd.c
+++ b/src/device/usbd.c
@@ -85,13 +85,13 @@ typedef struct
   char const* name;
   #endif
 
-  void (* init             ) (void);
-  void (* reset            ) (uint8_t rhport);
-  bool (* open             ) (uint8_t rhport, tusb_desc_interface_t const * desc_intf, uint16_t* p_length);
-  bool (* control_request  ) (uint8_t rhport, tusb_control_request_t const * request);
-  bool (* control_complete ) (uint8_t rhport, tusb_control_request_t const * request);
-  bool (* xfer_cb          ) (uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes);
-  void (* sof              ) (uint8_t rhport); /* optional */
+  void     (* init             ) (void);
+  void     (* reset            ) (uint8_t rhport);
+  uint16_t (* open             ) (uint8_t rhport, tusb_desc_interface_t const * desc_intf, uint16_t max_len);
+  bool     (* control_request  ) (uint8_t rhport, tusb_control_request_t const * request);
+  bool     (* control_complete ) (uint8_t rhport, tusb_control_request_t const * request);
+  bool     (* xfer_cb          ) (uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes);
+  void     (* sof              ) (uint8_t rhport); /* optional */
 } usbd_class_driver_t;
 
 static usbd_class_driver_t const _usbd_driver[] =
@@ -713,6 +713,8 @@ static bool process_set_config(uint8_t rhport, uint8_t cfg_num)
     TU_ASSERT( TUSB_DESC_INTERFACE == tu_desc_type(p_desc) );
 
     tusb_desc_interface_t const * desc_itf = (tusb_desc_interface_t const*) p_desc;
+    uint16_t const remaining_len = desc_end-p_desc;
+
     uint8_t drv_id;
     uint16_t drv_len;
 
@@ -720,13 +722,17 @@ static bool process_set_config(uint8_t rhport, uint8_t cfg_num)
     {
       usbd_class_driver_t const *driver = &_usbd_driver[drv_id];
 
-      drv_len = 0;
-      if ( driver->open(rhport, desc_itf, &drv_len) )
+      drv_len = driver->open(rhport, desc_itf, remaining_len);
+
+      if ( drv_len > 0 )
       {
+        // Open successfully, check if length is correct
+        TU_ASSERT( sizeof(tusb_desc_interface_t) <= drv_len && drv_len <= remaining_len);
+
         // Interface number must not be used already
         TU_ASSERT( DRVID_INVALID == _usbd_dev.itf2drv[desc_itf->bInterfaceNumber] );
 
-        TU_LOG2("  %s opened\r\n", _usbd_driver[drv_id].name);
+        TU_LOG2("  %s opened\r\n", driver->name);
         _usbd_dev.itf2drv[desc_itf->bInterfaceNumber] = drv_id;
 
         // If IAD exist, assign all interfaces to the same driver
@@ -748,8 +754,8 @@ static bool process_set_config(uint8_t rhport, uint8_t cfg_num)
       }
     }
 
-    // Assert if cannot find supported driver
-    TU_ASSERT( drv_id < USBD_CLASS_DRIVER_COUNT && drv_len >= sizeof(tusb_desc_interface_t) );
+    // Failed if cannot find supported driver
+    TU_ASSERT(drv_id < USBD_CLASS_DRIVER_COUNT);
 
     mark_interface_endpoint(_usbd_dev.ep2drv, p_desc, drv_len, drv_id); // TODO refactor