summaryrefslogtreecommitdiff
path: root/drivers/usb/usbip/vhci_rx.c
blob: 44cd645189250565ab0ea651a6a1a47b4649febd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2003-2008 Takahiro Hirofuchi
 */

#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)
			continue;

		urb = priv->urb;
		status = urb->status;

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

		switch (status) {
		case -ENOENT:
			/* fall through */
		case -ECONNRESET:
			dev_dbg(&urb->dev->dev,
				 "urb seq# %u was unlinked %ssynchronously\n",
				 seqnum, status == -ENOENT ? "" : "a");
			break;
		case -EINPROGRESS:
			/* no info output */
			break;
		default:
			dev_dbg(&urb->dev->dev,
				 "urb seq# %u may be in a error, status %d\n",
				 seqnum, 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 vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev);
	struct vhci *vhci = vhci_hcd->vhci;
	struct usbip_device *ud = &vdev->ud;
	struct urb *urb;
	unsigned long flags;

	spin_lock_irqsave(&vdev->priv_lock, flags);
	urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
	spin_unlock_irqrestore(&vdev->priv_lock, flags);

	if (!urb) {
		pr_err("cannot find a urb of seqnum %u max seqnum %d\n",
			pdu->base.seqnum,
			atomic_read(&vhci_hcd->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 */
	usbip_pad_iso(ud, urb);

	if (usbip_dbg_flag_vhci_rx)
		usbip_dump_urb(urb);

	usbip_dbg_vhci_rx("now giveback urb %u\n", pdu->base.seqnum);

	spin_lock_irqsave(&vhci->lock, flags);
	usb_hcd_unlink_urb_from_ep(vhci_hcd_to_hcd(vhci_hcd), urb);
	spin_unlock_irqrestore(&vhci->lock, flags);

	usb_hcd_giveback_urb(vhci_hcd_to_hcd(vhci_hcd), urb, urb->status);

	usbip_dbg_vhci_rx("Leave\n");
}

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

	spin_lock_irqsave(&vdev->priv_lock, flags);

	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_irqrestore(&vdev->priv_lock, flags);
			return unlink;
		}
	}

	spin_unlock_irqrestore(&vdev->priv_lock, flags);

	return NULL;
}

static void vhci_recv_ret_unlink(struct vhci_device *vdev,
				 struct usbip_header *pdu)
{
	struct vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev);
	struct vhci *vhci = vhci_hcd->vhci;
	struct vhci_unlink *unlink;
	struct urb *urb;
	unsigned long flags;

	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_irqsave(&vdev->priv_lock, flags);
	urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
	spin_unlock_irqrestore(&vdev->priv_lock, flags);

	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 back\n",
			pdu->base.seqnum);
	} else {
		usbip_dbg_vhci_rx("now giveback urb %d\n", pdu->base.seqnum);

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

		spin_lock_irqsave(&vhci->lock, flags);
		usb_hcd_unlink_urb_from_ep(vhci_hcd_to_hcd(vhci_hcd), urb);
		spin_unlock_irqrestore(&vhci->lock, flags);

		usb_hcd_giveback_urb(vhci_hcd_to_hcd(vhci_hcd), urb, urb->status);
	}

	kfree(unlink);
}

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

	spin_lock_irqsave(&vdev->priv_lock, flags);
	empty = list_empty(&vdev->priv_rx);
	spin_unlock_irqrestore(&vdev->priv_lock, flags);

	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));

	/* receive a pdu header */
	ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
	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;
}