commit aac89db8a541f609d8268966f7b3ded44da03bd1
author Patrick Tjin <pattjin@google.com> Fri Jul 11 08:59:01 2014 -0700
committer Patrick Tjin <pattjin@google.com> Fri Jul 11 14:15:30 2014 -0700
tree 61194822299c396e38ea8f70a235f6d46a8b8ae9
parent 56cbd19b1b8a42a0011be78aa1051304bc57127d

Scan all descriptors when checking for fastboot

For Linux, the USB code was only looking at the first
descriptor when searching for the fastboot interface
which caused some devices to not be found.

Also clarify some code by using the actual USB structures
instead of void or char pointers.

Change-Id: I9e4871c4d477ac10ba75bb17a955f176809af289
Signed-off-by: Patrick Tjin <pattjin@google.com>

fastboot/usb_linux.c

diff --git a/fastboot/usb_linux.c b/fastboot/usb_linux.c
index a45f9f8..fabbd51 100644
--- a/fastboot/usb_linux.c
+++ b/fastboot/usb_linux.c
@@ -100,12 +100,12 @@
 
 static int check(void *_desc, int len, unsigned type, int size)
 {
-    unsigned char *desc = _desc;
+    struct usb_descriptor_header *hdr = (struct usb_descriptor_header *)_desc;
 
     if(len < size) return -1;
-    if(desc[0] < size) return -1;
-    if(desc[0] > len) return -1;
-    if(desc[1] != type) return -1;
+    if(hdr->bLength < size) return -1;
+    if(hdr->bLength > len) return -1;
+    if(hdr->bDescriptorType != type) return -1;
 
     return 0;
 }
@@ -125,15 +125,15 @@
     unsigned i;
     unsigned e;
     
-    if(check(ptr, len, USB_DT_DEVICE, USB_DT_DEVICE_SIZE))
+    if (check(ptr, len, USB_DT_DEVICE, USB_DT_DEVICE_SIZE))
         return -1;
-    dev = (void*) ptr;
+    dev = (struct usb_device_descriptor *)ptr;
     len -= dev->bLength;
     ptr += dev->bLength;
 
-    if(check(ptr, len, USB_DT_CONFIG, USB_DT_CONFIG_SIZE))
+    if (check(ptr, len, USB_DT_CONFIG, USB_DT_CONFIG_SIZE))
         return -1;
-    cfg = (void*) ptr;
+    cfg = (struct usb_config_descriptor *)ptr;
     len -= cfg->bLength;
     ptr += cfg->bLength;
 
@@ -177,9 +177,19 @@
     }
 
     for(i = 0; i < cfg->bNumInterfaces; i++) {
-        if(check(ptr, len, USB_DT_INTERFACE, USB_DT_INTERFACE_SIZE))
+
+        while (len > 0) {
+	        struct usb_descriptor_header *hdr = (struct usb_descriptor_header *)ptr;
+            if (check(hdr, len, USB_DT_INTERFACE, USB_DT_INTERFACE_SIZE) == 0)
+                break;
+            len -= hdr->bLength;
+            ptr += hdr->bLength;
+        }
+
+        if (len <= 0)
             return -1;
-        ifc = (void*) ptr;
+
+        ifc = (struct usb_interface_descriptor *)ptr;
         len -= ifc->bLength;
         ptr += ifc->bLength;
 
@@ -190,16 +200,25 @@
         info.ifc_protocol = ifc->bInterfaceProtocol;
 
         for(e = 0; e < ifc->bNumEndpoints; e++) {
-            if(check(ptr, len, USB_DT_ENDPOINT, USB_DT_ENDPOINT_SIZE))
-                return -1;
-            ept = (void*) ptr;
+            while (len > 0) {
+	            struct usb_descriptor_header *hdr = (struct usb_descriptor_header *)ptr;
+                if (check(hdr, len, USB_DT_ENDPOINT, USB_DT_ENDPOINT_SIZE) == 0)
+                    break;
+                len -= hdr->bLength;
+                ptr += hdr->bLength;
+            }
+            if (len < 0) {
+                break;
+            }
+
+            ept = (struct usb_endpoint_descriptor *)ptr;
             len -= ept->bLength;
             ptr += ept->bLength;
 
-            if((ept->bmAttributes & 0x03) != 0x02)
+            if((ept->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_BULK)
                 continue;
 
-            if(ept->bEndpointAddress & 0x80) {
+            if(ept->bEndpointAddress & USB_ENDPOINT_DIR_MASK) {
                 in = ept->bEndpointAddress;
             } else {
                 out = ept->bEndpointAddress;