staging: usbip: bugfix for isochronous packets and optimization
For isochronous packets the actual_length is the sum of the actual
length of each of the packets, however between the packets might be
padding, so it is not sufficient to just send the first actual_length
bytes of the buffer. To fix this and simultanesouly optimize the
bandwidth the content of the isochronous packets are send without the
padding, the padding is restored on the receiving end.
Signed-off-by: Arjan Mels <arjan.mels@gmx.net>
Cc: Takahiro Hirofuchi <hirofuchi@users.sourceforge.net>
Cc: Max Vozeler <max@vozeler.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/usbip/usbip_common.c b/drivers/staging/usbip/usbip_common.c
index 8562215..7b1fe45 100644
--- a/drivers/staging/usbip/usbip_common.c
+++ b/drivers/staging/usbip/usbip_common.c
@@ -730,6 +730,7 @@
int size = np * sizeof(*iso);
int i;
int ret;
+ int total_length = 0;
if (!usb_pipeisoc(urb->pipe))
return 0;
@@ -759,19 +760,75 @@
return -EPIPE;
}
+
for (i = 0; i < np; i++) {
iso = buff + (i * sizeof(*iso));
usbip_iso_pakcet_correct_endian(iso, 0);
usbip_pack_iso(iso, &urb->iso_frame_desc[i], 0);
+ total_length += urb->iso_frame_desc[i].actual_length;
}
kfree(buff);
+ if (total_length != urb->actual_length) {
+ dev_err(&urb->dev->dev,
+ "total length of iso packets (%d) not equal to actual length of buffer (%d)\n",
+ total_length, urb->actual_length);
+
+ if (ud->side == USBIP_STUB)
+ usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
+ else
+ usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
+
+ return -EPIPE;
+ }
+
return ret;
}
EXPORT_SYMBOL_GPL(usbip_recv_iso);
+/*
+ * This functions restores the padding which was removed for optimizing
+ * the bandwidth during transfer over tcp/ip
+ *
+ * buffer and iso packets need to be stored and be in propeper endian in urb
+ * before calling this function
+ */
+int usbip_pad_iso(struct usbip_device *ud, struct urb *urb)
+{
+ int np = urb->number_of_packets;
+ int i;
+ int ret;
+ int actualoffset = urb->actual_length;
+
+ if (!usb_pipeisoc(urb->pipe))
+ return 0;
+
+ /* if no packets or length of data is 0, then nothing to unpack */
+ if (np == 0 || urb->actual_length == 0)
+ return 0;
+
+ /*
+ * if actual_length is transfer_buffer_length then no padding is
+ * present.
+ */
+ if (urb->actual_length == urb->transfer_buffer_length)
+ return 0;
+
+ /*
+ * loop over all packets from last to first (to prevent overwritting
+ * memory when padding) and move them into the proper place
+ */
+ for (i = np-1; i > 0; i--) {
+ actualoffset -= urb->iso_frame_desc[i].actual_length;
+ memmove(urb->transfer_buffer + urb->iso_frame_desc[i].offset,
+ urb->transfer_buffer + actualoffset,
+ urb->iso_frame_desc[i].actual_length);
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(usbip_pad_iso);
/* some members of urb must be substituted before. */
int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)