Merge pull request #895 from desowin/usb

Probe CONFIGURATION descriptor of connected USB devices

diff --git a/pcap-usb-linux.c b/pcap-usb-linux.c
index d6e368ddb6454d6d4f15a9534112846238f1199f..4debdee1dc8280430d4f58d5d7a4c7ee0c66ca5b 100644 (file)
--- a/pcap-usb-linux.c
+++ b/pcap-usb-linux.c
@@ -489,8 +489,10 @@ int usb_mmap(pcap_t* handle)
 #define USB_REQ_GET_DESCRIPTOR 6
 
 #define USB_DT_DEVICE          1
+#define USB_DT_CONFIG          2
 
 #define USB_DEVICE_DESCRIPTOR_SIZE     18
+#define USB_CONFIG_DESCRIPTOR_SIZE     9
 
 /* probe the descriptors of the devices attached to the bus */
 /* the descriptors will end up in the captured packet stream */
@@ -504,7 +506,8 @@ probe_devices(int bus)
        int ret = 0;
        char busdevpath[sizeof("/dev/bus/usb/000/") + NAME_MAX];
        DIR* dir;
-       char descriptor[USB_DEVICE_DESCRIPTOR_SIZE];
+       uint8_t descriptor[USB_DEVICE_DESCRIPTOR_SIZE];
+       uint8_t configdesc[USB_CONFIG_DESCRIPTOR_SIZE];
 
        /* scan usb bus directories for device nodes */
        snprintf(busdevpath, sizeof(busdevpath), "/dev/bus/usb/%03d", bus);
@@ -547,6 +550,30 @@ probe_devices(int bus)
 
                ret = ioctl(fd, USBDEVFS_CONTROL, &ctrl);
 
+               /* Request CONFIGURATION descriptor alone to know wTotalLength */
+#ifdef HAVE_STRUCT_USBDEVFS_CTRLTRANSFER_BREQUESTTYPE
+               ctrl.wValue = USB_DT_CONFIG << 8;
+               ctrl.wLength = sizeof(configdesc);
+#else
+               ctrl.value = USB_DT_CONFIG << 8;
+               ctrl.length = sizeof(configdesc);
+#endif
+               ctrl.data = configdesc;
+               ret = ioctl(fd, USBDEVFS_CONTROL, &ctrl);
+               if (ret >= 0) {
+                       uint16_t wtotallength;
+                       wtotallength = (configdesc[2]) | (configdesc[3] << 8);
+#ifdef HAVE_STRUCT_USBDEVFS_CTRLTRANSFER_BREQUESTTYPE
+                       ctrl.wLength = wtotallength;
+#else
+                       ctrl.length = wtotallength;
+#endif
+                       ctrl.data = malloc(wtotallength);
+                       if (ctrl.data) {
+                               ret = ioctl(fd, USBDEVFS_CONTROL, &ctrl);
+                               free(ctrl.data);
+                       }
+               }
                close(fd);
        }
        closedir(dir);