1 files changed, 453 insertions, 0 deletions

diff --git a/drivers/usb/usbip/stub_tx.c b/drivers/usb/usbip/stub_tx.c
new file mode 100644
index 000000000..36010a82b
--- /dev/null
+++ b/drivers/usb/usbip/stub_tx.c
@@ -0,0 +1,453 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ */
+
+#include <linux/kthread.h>
+#include <linux/socket.h>
+#include <linux/scatterlist.h>
+
+#include "usbip_common.h"
+#include "stub.h"
+
+/* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
+void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
+			     __u32 status)
+{
+	struct stub_unlink *unlink;
+
+	unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
+	if (!unlink) {
+		usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
+		return;
+	}
+
+	unlink->seqnum = seqnum;
+	unlink->status = status;
+
+	list_add_tail(&unlink->list, &sdev->unlink_tx);
+}
+
+/**
+ * stub_complete - completion handler of a usbip urb
+ * @urb: pointer to the urb completed
+ *
+ * When a urb has completed, the USB core driver calls this function mostly in
+ * the interrupt context. To return the result of a urb, the completed urb is
+ * linked to the pending list of returning.
+ *
+ */
+void stub_complete(struct urb *urb)
+{
+	struct stub_priv *priv = (struct stub_priv *) urb->context;
+	struct stub_device *sdev = priv->sdev;
+	unsigned long flags;
+
+	usbip_dbg_stub_tx("complete! status %d\n", urb->status);
+
+	switch (urb->status) {
+	case 0:
+		/* OK */
+		break;
+	case -ENOENT:
+		dev_info(&urb->dev->dev,
+			 "stopped by a call to usb_kill_urb() because of cleaning up a virtual connection\n");
+		return;
+	case -ECONNRESET:
+		dev_info(&urb->dev->dev,
+			 "unlinked by a call to usb_unlink_urb()\n");
+		break;
+	case -EPIPE:
+		dev_info(&urb->dev->dev, "endpoint %d is stalled\n",
+			 usb_pipeendpoint(urb->pipe));
+		break;
+	case -ESHUTDOWN:
+		dev_info(&urb->dev->dev, "device removed?\n");
+		break;
+	default:
+		dev_info(&urb->dev->dev,
+			 "urb completion with non-zero status %d\n",
+			 urb->status);
+		break;
+	}
+
+	/*
+	 * If the server breaks single SG request into the several URBs, the
+	 * URBs must be reassembled before sending completed URB to the vhci.
+	 * Don't wake up the tx thread until all the URBs are completed.
+	 */
+	if (priv->sgl) {
+		priv->completed_urbs++;
+
+		/* Only save the first error status */
+		if (urb->status && !priv->urb_status)
+			priv->urb_status = urb->status;
+
+		if (priv->completed_urbs < priv->num_urbs)
+			return;
+	}
+
+	/* link a urb to the queue of tx. */
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+	if (sdev->ud.tcp_socket == NULL) {
+		usbip_dbg_stub_tx("ignore urb for closed connection\n");
+		/* It will be freed in stub_device_cleanup_urbs(). */
+	} else if (priv->unlinking) {
+		stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
+		stub_free_priv_and_urb(priv);
+	} else {
+		list_move_tail(&priv->list, &sdev->priv_tx);
+	}
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	/* wake up tx_thread */
+	wake_up(&sdev->tx_waitq);
+}
+
+static inline void setup_base_pdu(struct usbip_header_basic *base,
+				  __u32 command, __u32 seqnum)
+{
+	base->command	= command;
+	base->seqnum	= seqnum;
+	base->devid	= 0;
+	base->ep	= 0;
+	base->direction = 0;
+}
+
+static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
+{
+	struct stub_priv *priv = (struct stub_priv *) urb->context;
+
+	setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
+	usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
+}
+
+static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
+				 struct stub_unlink *unlink)
+{
+	setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
+	rpdu->u.ret_unlink.status = unlink->status;
+}
+
+static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
+{
+	unsigned long flags;
+	struct stub_priv *priv, *tmp;
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
+		list_move_tail(&priv->list, &sdev->priv_free);
+		spin_unlock_irqrestore(&sdev->priv_lock, flags);
+		return priv;
+	}
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return NULL;
+}
+
+static int stub_send_ret_submit(struct stub_device *sdev)
+{
+	unsigned long flags;
+	struct stub_priv *priv, *tmp;
+
+	struct msghdr msg;
+	size_t txsize;
+
+	size_t total_size = 0;
+
+	while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
+		struct urb *urb = priv->urbs[0];
+		struct usbip_header pdu_header;
+		struct usbip_iso_packet_descriptor *iso_buffer = NULL;
+		struct kvec *iov = NULL;
+		struct scatterlist *sg;
+		u32 actual_length = 0;
+		int iovnum = 0;
+		int ret;
+		int i;
+
+		txsize = 0;
+		memset(&pdu_header, 0, sizeof(pdu_header));
+		memset(&msg, 0, sizeof(msg));
+
+		if (urb->actual_length > 0 && !urb->transfer_buffer &&
+		   !urb->num_sgs) {
+			dev_err(&sdev->udev->dev,
+				"urb: actual_length %d transfer_buffer null\n",
+				urb->actual_length);
+			return -1;
+		}
+
+		if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
+			iovnum = 2 + urb->number_of_packets;
+		else if (usb_pipein(urb->pipe) && urb->actual_length > 0 &&
+			urb->num_sgs)
+			iovnum = 1 + urb->num_sgs;
+		else if (usb_pipein(urb->pipe) && priv->sgl)
+			iovnum = 1 + priv->num_urbs;
+		else
+			iovnum = 2;
+
+		iov = kcalloc(iovnum, sizeof(struct kvec), GFP_KERNEL);
+
+		if (!iov) {
+			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
+			return -1;
+		}
+
+		iovnum = 0;
+
+		/* 1. setup usbip_header */
+		setup_ret_submit_pdu(&pdu_header, urb);
+		usbip_dbg_stub_tx("setup txdata seqnum: %d\n",
+				  pdu_header.base.seqnum);
+
+		if (priv->sgl) {
+			for (i = 0; i < priv->num_urbs; i++)
+				actual_length += priv->urbs[i]->actual_length;
+
+			pdu_header.u.ret_submit.status = priv->urb_status;
+			pdu_header.u.ret_submit.actual_length = actual_length;
+		}
+
+		usbip_header_correct_endian(&pdu_header, 1);
+
+		iov[iovnum].iov_base = &pdu_header;
+		iov[iovnum].iov_len  = sizeof(pdu_header);
+		iovnum++;
+		txsize += sizeof(pdu_header);
+
+		/* 2. setup transfer buffer */
+		if (usb_pipein(urb->pipe) && priv->sgl) {
+			/* If the server split a single SG request into several
+			 * URBs because the server's HCD doesn't support SG,
+			 * reassemble the split URB buffers into a single
+			 * return command.
+			 */
+			for (i = 0; i < priv->num_urbs; i++) {
+				iov[iovnum].iov_base =
+					priv->urbs[i]->transfer_buffer;
+				iov[iovnum].iov_len =
+					priv->urbs[i]->actual_length;
+				iovnum++;
+			}
+			txsize += actual_length;
+		} else if (usb_pipein(urb->pipe) &&
+		    usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
+		    urb->actual_length > 0) {
+			if (urb->num_sgs) {
+				unsigned int copy = urb->actual_length;
+				int size;
+
+				for_each_sg(urb->sg, sg, urb->num_sgs, i) {
+					if (copy == 0)
+						break;
+
+					if (copy < sg->length)
+						size = copy;
+					else
+						size = sg->length;
+
+					iov[iovnum].iov_base = sg_virt(sg);
+					iov[iovnum].iov_len = size;
+
+					iovnum++;
+					copy -= size;
+				}
+			} else {
+				iov[iovnum].iov_base = urb->transfer_buffer;
+				iov[iovnum].iov_len  = urb->actual_length;
+				iovnum++;
+			}
+			txsize += urb->actual_length;
+		} else if (usb_pipein(urb->pipe) &&
+			   usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
+			/*
+			 * For isochronous packets: actual length is the sum of
+			 * the actual length of the individual, packets, but as
+			 * the packet offsets are not changed there will be
+			 * padding between the packets. To optimally use the
+			 * bandwidth the padding is not transmitted.
+			 */
+
+			int i;
+
+			for (i = 0; i < urb->number_of_packets; i++) {
+				iov[iovnum].iov_base = urb->transfer_buffer +
+					urb->iso_frame_desc[i].offset;
+				iov[iovnum].iov_len =
+					urb->iso_frame_desc[i].actual_length;
+				iovnum++;
+				txsize += urb->iso_frame_desc[i].actual_length;
+			}
+
+			if (txsize != sizeof(pdu_header) + urb->actual_length) {
+				dev_err(&sdev->udev->dev,
+					"actual length of urb %d does not match iso packet sizes %zu\n",
+					urb->actual_length,
+					txsize-sizeof(pdu_header));
+				kfree(iov);
+				usbip_event_add(&sdev->ud,
+						SDEV_EVENT_ERROR_TCP);
+			   return -1;
+			}
+		}
+
+		/* 3. setup iso_packet_descriptor */
+		if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
+			ssize_t len = 0;
+
+			iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
+			if (!iso_buffer) {
+				usbip_event_add(&sdev->ud,
+						SDEV_EVENT_ERROR_MALLOC);
+				kfree(iov);
+				return -1;
+			}
+
+			iov[iovnum].iov_base = iso_buffer;
+			iov[iovnum].iov_len  = len;
+			txsize += len;
+			iovnum++;
+		}
+
+		ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
+						iov,  iovnum, txsize);
+		if (ret != txsize) {
+			dev_err(&sdev->udev->dev,
+				"sendmsg failed!, retval %d for %zd\n",
+				ret, txsize);
+			kfree(iov);
+			kfree(iso_buffer);
+			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
+			return -1;
+		}
+
+		kfree(iov);
+		kfree(iso_buffer);
+
+		total_size += txsize;
+	}
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+	list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
+		stub_free_priv_and_urb(priv);
+	}
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return total_size;
+}
+
+static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
+{
+	unsigned long flags;
+	struct stub_unlink *unlink, *tmp;
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
+		list_move_tail(&unlink->list, &sdev->unlink_free);
+		spin_unlock_irqrestore(&sdev->priv_lock, flags);
+		return unlink;
+	}
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return NULL;
+}
+
+static int stub_send_ret_unlink(struct stub_device *sdev)
+{
+	unsigned long flags;
+	struct stub_unlink *unlink, *tmp;
+
+	struct msghdr msg;
+	struct kvec iov[1];
+	size_t txsize;
+
+	size_t total_size = 0;
+
+	while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
+		int ret;
+		struct usbip_header pdu_header;
+
+		txsize = 0;
+		memset(&pdu_header, 0, sizeof(pdu_header));
+		memset(&msg, 0, sizeof(msg));
+		memset(&iov, 0, sizeof(iov));
+
+		usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
+
+		/* 1. setup usbip_header */
+		setup_ret_unlink_pdu(&pdu_header, unlink);
+		usbip_header_correct_endian(&pdu_header, 1);
+
+		iov[0].iov_base = &pdu_header;
+		iov[0].iov_len  = sizeof(pdu_header);
+		txsize += sizeof(pdu_header);
+
+		ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
+				     1, txsize);
+		if (ret != txsize) {
+			dev_err(&sdev->udev->dev,
+				"sendmsg failed!, retval %d for %zd\n",
+				ret, txsize);
+			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
+			return -1;
+		}
+
+		usbip_dbg_stub_tx("send txdata\n");
+		total_size += txsize;
+	}
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
+		list_del(&unlink->list);
+		kfree(unlink);
+	}
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return total_size;
+}
+
+int stub_tx_loop(void *data)
+{
+	struct usbip_device *ud = data;
+	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
+
+	while (!kthread_should_stop()) {
+		if (usbip_event_happened(ud))
+			break;
+
+		/*
+		 * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
+		 * looks at only priv_init queue. If the completion of a URB is
+		 * earlier than the receive of CMD_UNLINK, priv is moved to
+		 * priv_tx queue and stub_rx does not find the target priv. In
+		 * this case, vhci_rx receives the result of the submit request
+		 * and then receives the result of the unlink request. The
+		 * result of the submit is given back to the usbcore as the
+		 * completion of the unlink request. The request of the
+		 * unlink is ignored. This is ok because a driver who calls
+		 * usb_unlink_urb() understands the unlink was too late by
+		 * getting the status of the given-backed URB which has the
+		 * status of usb_submit_urb().
+		 */
+		if (stub_send_ret_submit(sdev) < 0)
+			break;
+
+		if (stub_send_ret_unlink(sdev) < 0)
+			break;
+
+		wait_event_interruptible(sdev->tx_waitq,
+					 (!list_empty(&sdev->priv_tx) ||
+					  !list_empty(&sdev->unlink_tx) ||
+					  kthread_should_stop()));
+	}
+
+	return 0;
+}