[mirror_ubuntu-bionic-kernel.git] / drivers / usb / usbip / stub_tx.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2003-2008 Takahiro Hirofuchi
 */

#include <linux/kthread.h>
#include <linux/socket.h>

#include "usbip_common.h"
#include "stub.h"

static void stub_free_priv_and_urb(struct stub_priv *priv)
{
	struct urb *urb = priv->urb;

	kfree(urb->setup_packet);
	urb->setup_packet = NULL;

	kfree(urb->transfer_buffer);
	urb->transfer_buffer = NULL;

	list_del(&priv->list);
	kmem_cache_free(stub_priv_cache, priv);
	usb_free_urb(urb);
}

/* 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;
	}

	/* 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) {
		int ret;
		struct urb *urb = priv->urb;
		struct usbip_header pdu_header;
		struct usbip_iso_packet_descriptor *iso_buffer = NULL;
		struct kvec *iov = NULL;
		int iovnum = 0;

		txsize = 0;
		memset(&pdu_header, 0, sizeof(pdu_header));
		memset(&msg, 0, sizeof(msg));

		if (urb->actual_length > 0 && !urb->transfer_buffer) {
			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
			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);
		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) &&
		    usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
		    urb->actual_length > 0) {
			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;
}
Commit	Line	Data
5fd54ace	1	// SPDX-License-Identifier: GPL-2.0+
4d7b5c7f TH	2	/*
4d7b5c7f TH	3	* Copyright (C) 2003-2008 Takahiro Hirofuchi
4d7b5c7f TH	4	*/
4d7b5c7f TH	5
9720b4bc	6	#include <linux/kthread.h>
7aaacb43	7	#include <linux/socket.h>
5a0e3ad6	8
4d7b5c7f TH	9	#include "usbip_common.h"
	10	#include "stub.h"
	11
4d7b5c7f TH	12	static void stub_free_priv_and_urb(struct stub_priv *priv)
	13	{
	14	struct urb *urb = priv->urb;
	15
	16	kfree(urb->setup_packet);
b3b51417 MG	17	urb->setup_packet = NULL;
b3b51417 MG	18
4d7b5c7f	19	kfree(urb->transfer_buffer);
b3b51417 MG	20	urb->transfer_buffer = NULL;
b3b51417 MG	21
4d7b5c7f TH	22	list_del(&priv->list);
	23	kmem_cache_free(stub_priv_cache, priv);
	24	usb_free_urb(urb);
	25	}
	26
	27	/* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
	28	void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
	29	__u32 status)
	30	{
	31	struct stub_unlink *unlink;
	32
	33	unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
	34	if (!unlink) {
4d7b5c7f TH	35	usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
	36	return;
	37	}
	38
	39	unlink->seqnum = seqnum;
	40	unlink->status = status;
	41
	42	list_add_tail(&unlink->list, &sdev->unlink_tx);
	43	}
	44
	45	/**
	46	* stub_complete - completion handler of a usbip urb
	47	* @urb: pointer to the urb completed
4d7b5c7f TH	48	*
	49	* When a urb has completed, the USB core driver calls this function mostly in
	50	* the interrupt context. To return the result of a urb, the completed urb is
	51	* linked to the pending list of returning.
	52	*
	53	*/
	54	void stub_complete(struct urb *urb)
	55	{
	56	struct stub_priv priv = (struct stub_priv ) urb->context;
	57	struct stub_device *sdev = priv->sdev;
	58	unsigned long flags;
	59
b8868e45	60	usbip_dbg_stub_tx("complete! status %d\n", urb->status);
4d7b5c7f	61
4d7b5c7f TH	62	switch (urb->status) {
	63	case 0:
	64	/* OK */
	65	break;
	66	case -ENOENT:
6bb3ee69 CC	67	dev_info(&urb->dev->dev,
6bb3ee69 CC	68	"stopped by a call to usb_kill_urb() because of cleaning up a virtual connection\n");
4d7b5c7f TH	69	return;
4d7b5c7f TH	70	case -ECONNRESET:
6bb3ee69 CC	71	dev_info(&urb->dev->dev,
6bb3ee69 CC	72	"unlinked by a call to usb_unlink_urb()\n");
4d7b5c7f TH	73	break;
4d7b5c7f TH	74	case -EPIPE:
1a4b6f66	75	dev_info(&urb->dev->dev, "endpoint %d is stalled\n",
1a4b6f66	76	usb_pipeendpoint(urb->pipe));
4d7b5c7f TH	77	break;
4d7b5c7f TH	78	case -ESHUTDOWN:
1a4b6f66	79	dev_info(&urb->dev->dev, "device removed?\n");
4d7b5c7f TH	80	break;
4d7b5c7f TH	81	default:
6bb3ee69 CC	82	dev_info(&urb->dev->dev,
	83	"urb completion with non-zero status %d\n",
	84	urb->status);
49aecefc	85	break;
4d7b5c7f TH	86	}
	87
	88	/* link a urb to the queue of tx. */
	89	spin_lock_irqsave(&sdev->priv_lock, flags);
6dc38da4	90	if (sdev->ud.tcp_socket == NULL) {
248a2204	91	usbip_dbg_stub_tx("ignore urb for closed connection\n");
6dc38da4 NI	92	/* It will be freed in stub_device_cleanup_urbs(). */
6dc38da4 NI	93	} else if (priv->unlinking) {
4d7b5c7f TH	94	stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
4d7b5c7f TH	95	stub_free_priv_and_urb(priv);
87352760	96	} else {
4d7b5c7f	97	list_move_tail(&priv->list, &sdev->priv_tx);
87352760	98	}
4d7b5c7f TH	99	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	100
	101	/* wake up tx_thread */
	102	wake_up(&sdev->tx_waitq);
	103	}
	104
4d7b5c7f	105	static inline void setup_base_pdu(struct usbip_header_basic *base,
c6956c97	106	__u32 command, __u32 seqnum)
4d7b5c7f	107	{
87352760	108	base->command = command;
	109	base->seqnum = seqnum;
	110	base->devid = 0;
	111	base->ep = 0;
c6956c97	112	base->direction = 0;
4d7b5c7f TH	113	}
	114
	115	static void setup_ret_submit_pdu(struct usbip_header rpdu, struct urb urb)
	116	{
	117	struct stub_priv priv = (struct stub_priv ) urb->context;
	118
	119	setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
4d7b5c7f TH	120	usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
	121	}
	122
	123	static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
c6956c97	124	struct stub_unlink *unlink)
4d7b5c7f TH	125	{
4d7b5c7f TH	126	setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
4d7b5c7f TH	127	rpdu->u.ret_unlink.status = unlink->status;
	128	}
	129
4d7b5c7f TH	130	static struct stub_priv dequeue_from_priv_tx(struct stub_device sdev)
	131	{
	132	unsigned long flags;
	133	struct stub_priv priv, tmp;
	134
	135	spin_lock_irqsave(&sdev->priv_lock, flags);
	136
	137	list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
	138	list_move_tail(&priv->list, &sdev->priv_free);
	139	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	140	return priv;
	141	}
	142
	143	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	144
	145	return NULL;
	146	}
	147
	148	static int stub_send_ret_submit(struct stub_device *sdev)
	149	{
	150	unsigned long flags;
	151	struct stub_priv priv, tmp;
	152
	153	struct msghdr msg;
4d7b5c7f TH	154	size_t txsize;
	155
	156	size_t total_size = 0;
	157
	158	while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
	159	int ret;
	160	struct urb *urb = priv->urb;
	161	struct usbip_header pdu_header;
36ac9b05	162	struct usbip_iso_packet_descriptor *iso_buffer = NULL;
28276a28 AM	163	struct kvec *iov = NULL;
28276a28 AM	164	int iovnum = 0;
4d7b5c7f TH	165
	166	txsize = 0;
	167	memset(&pdu_header, 0, sizeof(pdu_header));
	168	memset(&msg, 0, sizeof(msg));
4d7b5c7f	169
be6123df SK	170	if (urb->actual_length > 0 && !urb->transfer_buffer) {
	171	dev_err(&sdev->udev->dev,
	172	"urb: actual_length %d transfer_buffer null\n",
	173	urb->actual_length);
	174	return -1;
	175	}
	176
28276a28 AM	177	if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
	178	iovnum = 2 + urb->number_of_packets;
	179	else
	180	iovnum = 2;
4d7b5c7f	181
6baf139e	182	iov = kcalloc(iovnum, sizeof(struct kvec), GFP_KERNEL);
28276a28 AM	183
	184	if (!iov) {
	185	usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
	186	return -1;
	187	}
	188
	189	iovnum = 0;
4d7b5c7f TH	190
	191	/* 1. setup usbip_header */
	192	setup_ret_submit_pdu(&pdu_header, urb);
248a2204 SK	193	usbip_dbg_stub_tx("setup txdata seqnum: %d\n",
248a2204 SK	194	pdu_header.base.seqnum);
4d7b5c7f TH	195	usbip_header_correct_endian(&pdu_header, 1);
4d7b5c7f TH	196
28276a28 AM	197	iov[iovnum].iov_base = &pdu_header;
	198	iov[iovnum].iov_len = sizeof(pdu_header);
	199	iovnum++;
4d7b5c7f TH	200	txsize += sizeof(pdu_header);
	201
	202	/* 2. setup transfer buffer */
28276a28	203	if (usb_pipein(urb->pipe) &&
c6956c97	204	usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
c6956c97	205	urb->actual_length > 0) {
28276a28 AM	206	iov[iovnum].iov_base = urb->transfer_buffer;
	207	iov[iovnum].iov_len = urb->actual_length;
	208	iovnum++;
4d7b5c7f	209	txsize += urb->actual_length;
28276a28	210	} else if (usb_pipein(urb->pipe) &&
c6956c97	211	usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
28276a28 AM	212	/*
	213	* For isochronous packets: actual length is the sum of
	214	* the actual length of the individual, packets, but as
	215	* the packet offsets are not changed there will be
	216	* padding between the packets. To optimally use the
	217	* bandwidth the padding is not transmitted.
	218	*/
	219
	220	int i;
3eed8c03	221
28276a28	222	for (i = 0; i < urb->number_of_packets; i++) {
c6956c97	223	iov[iovnum].iov_base = urb->transfer_buffer +
	224	urb->iso_frame_desc[i].offset;
	225	iov[iovnum].iov_len =
	226	urb->iso_frame_desc[i].actual_length;
28276a28 AM	227	iovnum++;
	228	txsize += urb->iso_frame_desc[i].actual_length;
	229	}
	230
	231	if (txsize != sizeof(pdu_header) + urb->actual_length) {
8c7003a3	232	dev_err(&sdev->udev->dev,
6bb3ee69	233	"actual length of urb %d does not match iso packet sizes %zu\n",
c6956c97	234	urb->actual_length,
c6956c97	235	txsize-sizeof(pdu_header));
28276a28	236	kfree(iov);
c6956c97	237	usbip_event_add(&sdev->ud,
c6956c97	238	SDEV_EVENT_ERROR_TCP);
28276a28 AM	239	return -1;
28276a28 AM	240	}
4d7b5c7f TH	241	}
	242
	243	/* 3. setup iso_packet_descriptor */
	244	if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
	245	ssize_t len = 0;
	246
	247	iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
	248	if (!iso_buffer) {
	249	usbip_event_add(&sdev->ud,
	250	SDEV_EVENT_ERROR_MALLOC);
28276a28	251	kfree(iov);
4d7b5c7f TH	252	return -1;
	253	}
	254
28276a28 AM	255	iov[iovnum].iov_base = iso_buffer;
28276a28 AM	256	iov[iovnum].iov_len = len;
4d7b5c7f	257	txsize += len;
28276a28	258	iovnum++;
4d7b5c7f TH	259	}
4d7b5c7f TH	260
28276a28 AM	261	ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
28276a28 AM	262	iov, iovnum, txsize);
4d7b5c7f	263	if (ret != txsize) {
8c7003a3	264	dev_err(&sdev->udev->dev,
4d7b5c7f TH	265	"sendmsg failed!, retval %d for %zd\n",
4d7b5c7f TH	266	ret, txsize);
28276a28	267	kfree(iov);
4d7b5c7f TH	268	kfree(iso_buffer);
	269	usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
	270	return -1;
	271	}
	272
28276a28	273	kfree(iov);
4d7b5c7f	274	kfree(iso_buffer);
4d7b5c7f TH	275
	276	total_size += txsize;
	277	}
	278
4d7b5c7f	279	spin_lock_irqsave(&sdev->priv_lock, flags);
4d7b5c7f TH	280	list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
	281	stub_free_priv_and_urb(priv);
	282	}
4d7b5c7f TH	283	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	284
	285	return total_size;
	286	}
	287
4d7b5c7f TH	288	static struct stub_unlink dequeue_from_unlink_tx(struct stub_device sdev)
	289	{
	290	unsigned long flags;
	291	struct stub_unlink unlink, tmp;
	292
	293	spin_lock_irqsave(&sdev->priv_lock, flags);
	294
	295	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
	296	list_move_tail(&unlink->list, &sdev->unlink_free);
	297	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	298	return unlink;
	299	}
	300
	301	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	302
	303	return NULL;
	304	}
	305
4d7b5c7f TH	306	static int stub_send_ret_unlink(struct stub_device *sdev)
	307	{
	308	unsigned long flags;
	309	struct stub_unlink unlink, tmp;
	310
	311	struct msghdr msg;
	312	struct kvec iov[1];
	313	size_t txsize;
	314
	315	size_t total_size = 0;
	316
	317	while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
	318	int ret;
	319	struct usbip_header pdu_header;
	320
	321	txsize = 0;
	322	memset(&pdu_header, 0, sizeof(pdu_header));
	323	memset(&msg, 0, sizeof(msg));
	324	memset(&iov, 0, sizeof(iov));
	325
b8868e45	326	usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
4d7b5c7f TH	327
	328	/* 1. setup usbip_header */
	329	setup_ret_unlink_pdu(&pdu_header, unlink);
	330	usbip_header_correct_endian(&pdu_header, 1);
	331
	332	iov[0].iov_base = &pdu_header;
	333	iov[0].iov_len = sizeof(pdu_header);
	334	txsize += sizeof(pdu_header);
	335
	336	ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
	337	1, txsize);
	338	if (ret != txsize) {
8c7003a3	339	dev_err(&sdev->udev->dev,
4d7b5c7f TH	340	"sendmsg failed!, retval %d for %zd\n",
	341	ret, txsize);
	342	usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
	343	return -1;
	344	}
	345
b8868e45	346	usbip_dbg_stub_tx("send txdata\n");
4d7b5c7f TH	347	total_size += txsize;
	348	}
	349
4d7b5c7f TH	350	spin_lock_irqsave(&sdev->priv_lock, flags);
	351
	352	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
	353	list_del(&unlink->list);
	354	kfree(unlink);
	355	}
	356
	357	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	358
	359	return total_size;
	360	}
	361
9720b4bc	362	int stub_tx_loop(void *data)
4d7b5c7f	363	{
9720b4bc	364	struct usbip_device *ud = data;
4d7b5c7f TH	365	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
4d7b5c7f TH	366
9720b4bc	367	while (!kthread_should_stop()) {
b8868e45	368	if (usbip_event_happened(ud))
4d7b5c7f TH	369	break;
	370
	371	/*
	372	* send_ret_submit comes earlier than send_ret_unlink. stub_rx
	373	* looks at only priv_init queue. If the completion of a URB is
	374	* earlier than the receive of CMD_UNLINK, priv is moved to
	375	* priv_tx queue and stub_rx does not find the target priv. In
	376	* this case, vhci_rx receives the result of the submit request
	377	* and then receives the result of the unlink request. The
	378	* result of the submit is given back to the usbcore as the
	379	* completion of the unlink request. The request of the
	380	* unlink is ignored. This is ok because a driver who calls
	381	* usb_unlink_urb() understands the unlink was too late by
	382	* getting the status of the given-backed URB which has the
	383	* status of usb_submit_urb().
	384	*/
	385	if (stub_send_ret_submit(sdev) < 0)
	386	break;
	387
	388	if (stub_send_ret_unlink(sdev) < 0)
	389	break;
	390
	391	wait_event_interruptible(sdev->tx_waitq,
c6956c97	392	(!list_empty(&sdev->priv_tx) \|\|
	393	!list_empty(&sdev->unlink_tx) \|\|
	394	kthread_should_stop()));
4d7b5c7f	395	}
9720b4bc AB	396
9720b4bc AB	397	return 0;
4d7b5c7f	398	}