[mirror_ubuntu-eoan-kernel.git] / drivers / staging / usbip / vhci_rx.c

/*
 * Copyright (C) 2003-2008 Takahiro Hirofuchi
 *
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 * USA.
 */

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

#include "usbip_common.h"
#include "vhci.h"

/* get URB from transmitted urb queue. caller must hold vdev->priv_lock */
struct urb *pickup_urb_and_free_priv(struct vhci_device *vdev, __u32 seqnum)
{
	struct vhci_priv *priv, *tmp;
	struct urb *urb = NULL;
	int status;

	list_for_each_entry_safe(priv, tmp, &vdev->priv_rx, list) {
		if (priv->seqnum == seqnum) {
			urb = priv->urb;
			status = urb->status;

			usbip_dbg_vhci_rx("find urb %p vurb %p seqnum %u\n",
					  urb, priv, seqnum);

			/* TODO: fix logic here to improve indent situtation */
			if (status != -EINPROGRESS) {
				if (status == -ENOENT ||
				    status == -ECONNRESET)
					dev_info(&urb->dev->dev,
						 "urb %p was unlinked "
						 "%ssynchronuously.\n", urb,
						 status == -ENOENT ? "" : "a");
				else
					dev_info(&urb->dev->dev,
						 "urb %p may be in a error, "
						 "status %d\n", urb, status);
			}

			list_del(&priv->list);
			kfree(priv);
			urb->hcpriv = NULL;

			break;
		}
	}

	return urb;
}

static void vhci_recv_ret_submit(struct vhci_device *vdev,
				 struct usbip_header *pdu)
{
	struct usbip_device *ud = &vdev->ud;
	struct urb *urb;

	spin_lock(&vdev->priv_lock);
	urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
	spin_unlock(&vdev->priv_lock);

	if (!urb) {
		pr_err("cannot find a urb of seqnum %u\n", pdu->base.seqnum);
		pr_info("max seqnum %d\n",
			atomic_read(&the_controller->seqnum));
		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
		return;
	}

	/* unpack the pdu to a urb */
	usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);

	/* recv transfer buffer */
	if (usbip_recv_xbuff(ud, urb) < 0)
		return;

	/* recv iso_packet_descriptor */
	if (usbip_recv_iso(ud, urb) < 0)
		return;

	/* restore the padding in iso packets */
	if (usbip_pad_iso(ud, urb) < 0)
		return;

	if (usbip_dbg_flag_vhci_rx)
		usbip_dump_urb(urb);

	usbip_dbg_vhci_rx("now giveback urb %p\n", urb);

	spin_lock(&the_controller->lock);
	usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
	spin_unlock(&the_controller->lock);

	usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);

	usbip_dbg_vhci_rx("Leave\n");

	return;
}

static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
						  struct usbip_header *pdu)
{
	struct vhci_unlink *unlink, *tmp;

	spin_lock(&vdev->priv_lock);

	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
		pr_info("unlink->seqnum %lu\n", unlink->seqnum);
		if (unlink->seqnum == pdu->base.seqnum) {
			usbip_dbg_vhci_rx("found pending unlink, %lu\n",
					  unlink->seqnum);
			list_del(&unlink->list);

			spin_unlock(&vdev->priv_lock);
			return unlink;
		}
	}

	spin_unlock(&vdev->priv_lock);

	return NULL;
}

static void vhci_recv_ret_unlink(struct vhci_device *vdev,
				 struct usbip_header *pdu)
{
	struct vhci_unlink *unlink;
	struct urb *urb;

	usbip_dump_header(pdu);

	unlink = dequeue_pending_unlink(vdev, pdu);
	if (!unlink) {
		pr_info("cannot find the pending unlink %u\n",
			pdu->base.seqnum);
		return;
	}

	spin_lock(&vdev->priv_lock);
	urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
	spin_unlock(&vdev->priv_lock);

	if (!urb) {
		/*
		 * I get the result of a unlink request. But, it seems that I
		 * already received the result of its submit result and gave
		 * back the URB.
		 */
		pr_info("the urb (seqnum %d) was already given backed\n",
			pdu->base.seqnum);
	} else {
		usbip_dbg_vhci_rx("now giveback urb %p\n", urb);

		/* If unlink is succeed, status is -ECONNRESET */
		urb->status = pdu->u.ret_unlink.status;
		pr_info("urb->status %d\n", urb->status);

		spin_lock(&the_controller->lock);
		usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
		spin_unlock(&the_controller->lock);

		usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
				     urb->status);
	}

	kfree(unlink);
}

static int vhci_priv_tx_empty(struct vhci_device *vdev)
{
	int empty = 0;

	spin_lock(&vdev->priv_lock);
	empty = list_empty(&vdev->priv_rx);
	spin_unlock(&vdev->priv_lock);

	return empty;
}

/* recv a pdu */
static void vhci_rx_pdu(struct usbip_device *ud)
{
	int ret;
	struct usbip_header pdu;
	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);

	usbip_dbg_vhci_rx("Enter\n");

	memset(&pdu, 0, sizeof(pdu));

	/* 1. receive a pdu header */
	ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
	if (ret < 0) {
		if (ret == -ECONNRESET)
			pr_info("connection reset by peer\n");
		else if (ret == -EAGAIN) {
			/* ignore if connection was idle */
			if (vhci_priv_tx_empty(vdev))
				return;
			pr_info("connection timed out with pending urbs\n");
		} else if (ret != -ERESTARTSYS)
			pr_info("xmit failed %d\n", ret);

		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
		return;
	}
	if (ret == 0) {
		pr_info("connection closed");
		usbip_event_add(ud, VDEV_EVENT_DOWN);
		return;
	}
	if (ret != sizeof(pdu)) {
		pr_err("received pdu size is %d, should be %d\n", ret,
		       (unsigned int)sizeof(pdu));
		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
		return;
	}

	usbip_header_correct_endian(&pdu, 0);

	if (usbip_dbg_flag_vhci_rx)
		usbip_dump_header(&pdu);

	switch (pdu.base.command) {
	case USBIP_RET_SUBMIT:
		vhci_recv_ret_submit(vdev, &pdu);
		break;
	case USBIP_RET_UNLINK:
		vhci_recv_ret_unlink(vdev, &pdu);
		break;
	default:
		/* NOT REACHED */
		pr_err("unknown pdu %u\n", pdu.base.command);
		usbip_dump_header(&pdu);
		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
		break;
	}
}

int vhci_rx_loop(void *data)
{
	struct usbip_device *ud = data;

	while (!kthread_should_stop()) {
		if (usbip_event_happened(ud))
			break;

		vhci_rx_pdu(ud);
	}

	return 0;
}
Commit	Line	Data
04679b34 TH	1	/*
	2	* Copyright (C) 2003-2008 Takahiro Hirofuchi
	3	*
	4	* This is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
	17	* USA.
	18	*/
	19
9720b4bc	20	#include <linux/kthread.h>
7aaacb43	21	#include <linux/slab.h>
5a0e3ad6	22
04679b34 TH	23	#include "usbip_common.h"
	24	#include "vhci.h"
	25
b92a5e23	26	/* get URB from transmitted urb queue. caller must hold vdev->priv_lock */
5ef6aceb	27	struct urb pickup_urb_and_free_priv(struct vhci_device vdev, __u32 seqnum)
04679b34 TH	28	{
	29	struct vhci_priv priv, tmp;
	30	struct urb *urb = NULL;
	31	int status;
	32
04679b34 TH	33	list_for_each_entry_safe(priv, tmp, &vdev->priv_rx, list) {
	34	if (priv->seqnum == seqnum) {
	35	urb = priv->urb;
	36	status = urb->status;
	37
b8868e45	38	usbip_dbg_vhci_rx("find urb %p vurb %p seqnum %u\n",
5ef6aceb	39	urb, priv, seqnum);
04679b34 TH	40
	41	/* TODO: fix logic here to improve indent situtation */
	42	if (status != -EINPROGRESS) {
	43	if (status == -ENOENT \|\|
5ef6aceb	44	status == -ECONNRESET)
04679b34 TH	45	dev_info(&urb->dev->dev,
	46	"urb %p was unlinked "
	47	"%ssynchronuously.\n", urb,
	48	status == -ENOENT ? "" : "a");
	49	else
	50	dev_info(&urb->dev->dev,
	51	"urb %p may be in a error, "
	52	"status %d\n", urb, status);
	53	}
	54
	55	list_del(&priv->list);
	56	kfree(priv);
	57	urb->hcpriv = NULL;
	58
	59	break;
	60	}
	61	}
	62
04679b34 TH	63	return urb;
	64	}
	65
	66	static void vhci_recv_ret_submit(struct vhci_device *vdev,
5ef6aceb	67	struct usbip_header *pdu)
04679b34 TH	68	{
	69	struct usbip_device *ud = &vdev->ud;
	70	struct urb *urb;
	71
b92a5e23	72	spin_lock(&vdev->priv_lock);
04679b34	73	urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
b92a5e23	74	spin_unlock(&vdev->priv_lock);
04679b34 TH	75
04679b34 TH	76	if (!urb) {
1a4b6f66	77	pr_err("cannot find a urb of seqnum %u\n", pdu->base.seqnum);
	78	pr_info("max seqnum %d\n",
	79	atomic_read(&the_controller->seqnum));
04679b34 TH	80	usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
	81	return;
	82	}
	83
04679b34 TH	84	/* unpack the pdu to a urb */
	85	usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
	86
04679b34 TH	87	/* recv transfer buffer */
	88	if (usbip_recv_xbuff(ud, urb) < 0)
	89	return;
	90
04679b34 TH	91	/* recv iso_packet_descriptor */
	92	if (usbip_recv_iso(ud, urb) < 0)
	93	return;
	94
28276a28 AM	95	/* restore the padding in iso packets */
	96	if (usbip_pad_iso(ud, urb) < 0)
	97	return;
04679b34	98
b8868e45	99	if (usbip_dbg_flag_vhci_rx)
04679b34 TH	100	usbip_dump_urb(urb);
04679b34 TH	101
b8868e45	102	usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
04679b34 TH	103
	104	spin_lock(&the_controller->lock);
	105	usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
	106	spin_unlock(&the_controller->lock);
	107
	108	usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
	109
b8868e45	110	usbip_dbg_vhci_rx("Leave\n");
04679b34 TH	111
	112	return;
	113	}
	114
04679b34	115	static struct vhci_unlink dequeue_pending_unlink(struct vhci_device vdev,
5ef6aceb	116	struct usbip_header *pdu)
04679b34 TH	117	{
	118	struct vhci_unlink unlink, tmp;
	119
	120	spin_lock(&vdev->priv_lock);
	121
	122	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
1a4b6f66	123	pr_info("unlink->seqnum %lu\n", unlink->seqnum);
04679b34	124	if (unlink->seqnum == pdu->base.seqnum) {
b8868e45	125	usbip_dbg_vhci_rx("found pending unlink, %lu\n",
5ef6aceb	126	unlink->seqnum);
04679b34 TH	127	list_del(&unlink->list);
	128
	129	spin_unlock(&vdev->priv_lock);
	130	return unlink;
	131	}
	132	}
	133
	134	spin_unlock(&vdev->priv_lock);
	135
	136	return NULL;
	137	}
	138
04679b34	139	static void vhci_recv_ret_unlink(struct vhci_device *vdev,
5ef6aceb	140	struct usbip_header *pdu)
04679b34 TH	141	{
	142	struct vhci_unlink *unlink;
	143	struct urb *urb;
	144
	145	usbip_dump_header(pdu);
	146
	147	unlink = dequeue_pending_unlink(vdev, pdu);
	148	if (!unlink) {
1a4b6f66	149	pr_info("cannot find the pending unlink %u\n",
1a4b6f66	150	pdu->base.seqnum);
04679b34 TH	151	return;
	152	}
	153
b92a5e23	154	spin_lock(&vdev->priv_lock);
04679b34	155	urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
b92a5e23 MV	156	spin_unlock(&vdev->priv_lock);
b92a5e23 MV	157
04679b34 TH	158	if (!urb) {
	159	/*
	160	* I get the result of a unlink request. But, it seems that I
	161	* already received the result of its submit result and gave
	162	* back the URB.
	163	*/
1a4b6f66	164	pr_info("the urb (seqnum %d) was already given backed\n",
1a4b6f66	165	pdu->base.seqnum);
04679b34	166	} else {
b8868e45	167	usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
04679b34 TH	168
	169	/* If unlink is succeed, status is -ECONNRESET */
	170	urb->status = pdu->u.ret_unlink.status;
1a4b6f66	171	pr_info("urb->status %d\n", urb->status);
04679b34 TH	172
	173	spin_lock(&the_controller->lock);
	174	usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
	175	spin_unlock(&the_controller->lock);
	176
	177	usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
5ef6aceb	178	urb->status);
04679b34 TH	179	}
	180
	181	kfree(unlink);
04679b34 TH	182	}
04679b34 TH	183
bd65f623 MV	184	static int vhci_priv_tx_empty(struct vhci_device *vdev)
	185	{
	186	int empty = 0;
	187
	188	spin_lock(&vdev->priv_lock);
bd65f623	189	empty = list_empty(&vdev->priv_rx);
bd65f623 MV	190	spin_unlock(&vdev->priv_lock);
	191
	192	return empty;
	193	}
	194
04679b34 TH	195	/* recv a pdu */
	196	static void vhci_rx_pdu(struct usbip_device *ud)
	197	{
	198	int ret;
	199	struct usbip_header pdu;
	200	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
	201
b8868e45	202	usbip_dbg_vhci_rx("Enter\n");
04679b34 TH	203
	204	memset(&pdu, 0, sizeof(pdu));
	205
04679b34 TH	206	/* 1. receive a pdu header */
04679b34 TH	207	ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
7e249c8b MV	208	if (ret < 0) {
7e249c8b MV	209	if (ret == -ECONNRESET)
1a4b6f66	210	pr_info("connection reset by peer\n");
bd65f623 MV	211	else if (ret == -EAGAIN) {
	212	/* ignore if connection was idle */
	213	if (vhci_priv_tx_empty(vdev))
	214	return;
1a4b6f66	215	pr_info("connection timed out with pending urbs\n");
bd65f623	216	} else if (ret != -ERESTARTSYS)
1a4b6f66	217	pr_info("xmit failed %d\n", ret);
bd65f623	218
7e249c8b MV	219	usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
	220	return;
	221	}
	222	if (ret == 0) {
1a4b6f66	223	pr_info("connection closed");
7e249c8b MV	224	usbip_event_add(ud, VDEV_EVENT_DOWN);
	225	return;
	226	}
04679b34	227	if (ret != sizeof(pdu)) {
1a4b6f66	228	pr_err("received pdu size is %d, should be %d\n", ret,
1a4b6f66	229	(unsigned int)sizeof(pdu));
04679b34 TH	230	usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
	231	return;
	232	}
	233
	234	usbip_header_correct_endian(&pdu, 0);
	235
b8868e45	236	if (usbip_dbg_flag_vhci_rx)
04679b34 TH	237	usbip_dump_header(&pdu);
	238
	239	switch (pdu.base.command) {
	240	case USBIP_RET_SUBMIT:
	241	vhci_recv_ret_submit(vdev, &pdu);
	242	break;
	243	case USBIP_RET_UNLINK:
	244	vhci_recv_ret_unlink(vdev, &pdu);
	245	break;
	246	default:
49aecefc	247	/* NOT REACHED */
1a4b6f66	248	pr_err("unknown pdu %u\n", pdu.base.command);
04679b34 TH	249	usbip_dump_header(&pdu);
04679b34 TH	250	usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
49aecefc	251	break;
04679b34 TH	252	}
	253	}
	254
9720b4bc	255	int vhci_rx_loop(void *data)
04679b34	256	{
9720b4bc	257	struct usbip_device *ud = data;
04679b34	258
9720b4bc	259	while (!kthread_should_stop()) {
b8868e45	260	if (usbip_event_happened(ud))
04679b34 TH	261	break;
	262
	263	vhci_rx_pdu(ud);
	264	}
04679b34	265
9720b4bc AB	266	return 0;
9720b4bc AB	267	}