1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * Copyright (C) 2003-2008 Takahiro Hirofuchi |
4 | */ |
5 | |
6 | #include <linux/kthread.h> |
7 | #include <linux/slab.h> |
8 | |
9 | #include "usbip_common.h" |
10 | #include "vhci.h" |
11 | |
12 | /* get URB from transmitted urb queue. caller must hold vdev->priv_lock */ |
13 | struct urb *pickup_urb_and_free_priv(struct vhci_device *vdev, __u32 seqnum) |
14 | { |
15 | struct vhci_priv *priv, *tmp; |
16 | struct urb *urb = NULL; |
17 | int status; |
18 | |
19 | list_for_each_entry_safe(priv, tmp, &vdev->priv_rx, list) { |
20 | if (priv->seqnum != seqnum) |
21 | continue; |
22 | |
23 | urb = priv->urb; |
24 | status = urb->status; |
25 | |
26 | usbip_dbg_vhci_rx("find urb seqnum %u\n" , seqnum); |
27 | |
28 | switch (status) { |
29 | case -ENOENT: |
30 | fallthrough; |
31 | case -ECONNRESET: |
32 | dev_dbg(&urb->dev->dev, |
33 | "urb seq# %u was unlinked %ssynchronously\n" , |
34 | seqnum, status == -ENOENT ? "" : "a" ); |
35 | break; |
36 | case -EINPROGRESS: |
37 | /* no info output */ |
38 | break; |
39 | default: |
40 | dev_dbg(&urb->dev->dev, |
41 | "urb seq# %u may be in a error, status %d\n" , |
42 | seqnum, status); |
43 | } |
44 | |
45 | list_del(entry: &priv->list); |
46 | kfree(objp: priv); |
47 | urb->hcpriv = NULL; |
48 | |
49 | break; |
50 | } |
51 | |
52 | return urb; |
53 | } |
54 | |
55 | static void vhci_recv_ret_submit(struct vhci_device *vdev, |
56 | struct usbip_header *pdu) |
57 | { |
58 | struct vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev); |
59 | struct vhci *vhci = vhci_hcd->vhci; |
60 | struct usbip_device *ud = &vdev->ud; |
61 | struct urb *urb; |
62 | unsigned long flags; |
63 | |
64 | spin_lock_irqsave(&vdev->priv_lock, flags); |
65 | urb = pickup_urb_and_free_priv(vdev, seqnum: pdu->base.seqnum); |
66 | spin_unlock_irqrestore(lock: &vdev->priv_lock, flags); |
67 | |
68 | if (!urb) { |
69 | pr_err("cannot find a urb of seqnum %u max seqnum %d\n" , |
70 | pdu->base.seqnum, |
71 | atomic_read(&vhci_hcd->seqnum)); |
72 | usbip_event_add(ud, VDEV_EVENT_ERROR_TCP); |
73 | return; |
74 | } |
75 | |
76 | /* unpack the pdu to a urb */ |
77 | usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, pack: 0); |
78 | |
79 | /* recv transfer buffer */ |
80 | if (usbip_recv_xbuff(ud, urb) < 0) { |
81 | urb->status = -EPROTO; |
82 | goto error; |
83 | } |
84 | |
85 | /* recv iso_packet_descriptor */ |
86 | if (usbip_recv_iso(ud, urb) < 0) { |
87 | urb->status = -EPROTO; |
88 | goto error; |
89 | } |
90 | |
91 | /* restore the padding in iso packets */ |
92 | usbip_pad_iso(ud, urb); |
93 | |
94 | error: |
95 | if (usbip_dbg_flag_vhci_rx) |
96 | usbip_dump_urb(purb: urb); |
97 | |
98 | if (urb->num_sgs) |
99 | urb->transfer_flags &= ~URB_DMA_MAP_SG; |
100 | |
101 | usbip_dbg_vhci_rx("now giveback urb %u\n" , pdu->base.seqnum); |
102 | |
103 | spin_lock_irqsave(&vhci->lock, flags); |
104 | usb_hcd_unlink_urb_from_ep(hcd: vhci_hcd_to_hcd(vhci_hcd), urb); |
105 | spin_unlock_irqrestore(lock: &vhci->lock, flags); |
106 | |
107 | usb_hcd_giveback_urb(hcd: vhci_hcd_to_hcd(vhci_hcd), urb, status: urb->status); |
108 | |
109 | usbip_dbg_vhci_rx("Leave\n" ); |
110 | } |
111 | |
112 | static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev, |
113 | struct usbip_header *pdu) |
114 | { |
115 | struct vhci_unlink *unlink, *tmp; |
116 | unsigned long flags; |
117 | |
118 | spin_lock_irqsave(&vdev->priv_lock, flags); |
119 | |
120 | list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) { |
121 | pr_info("unlink->seqnum %lu\n" , unlink->seqnum); |
122 | if (unlink->seqnum == pdu->base.seqnum) { |
123 | usbip_dbg_vhci_rx("found pending unlink, %lu\n" , |
124 | unlink->seqnum); |
125 | list_del(entry: &unlink->list); |
126 | |
127 | spin_unlock_irqrestore(lock: &vdev->priv_lock, flags); |
128 | return unlink; |
129 | } |
130 | } |
131 | |
132 | spin_unlock_irqrestore(lock: &vdev->priv_lock, flags); |
133 | |
134 | return NULL; |
135 | } |
136 | |
137 | static void vhci_recv_ret_unlink(struct vhci_device *vdev, |
138 | struct usbip_header *pdu) |
139 | { |
140 | struct vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev); |
141 | struct vhci *vhci = vhci_hcd->vhci; |
142 | struct vhci_unlink *unlink; |
143 | struct urb *urb; |
144 | unsigned long flags; |
145 | |
146 | usbip_dump_header(pdu); |
147 | |
148 | unlink = dequeue_pending_unlink(vdev, pdu); |
149 | if (!unlink) { |
150 | pr_info("cannot find the pending unlink %u\n" , |
151 | pdu->base.seqnum); |
152 | return; |
153 | } |
154 | |
155 | spin_lock_irqsave(&vdev->priv_lock, flags); |
156 | urb = pickup_urb_and_free_priv(vdev, seqnum: unlink->unlink_seqnum); |
157 | spin_unlock_irqrestore(lock: &vdev->priv_lock, flags); |
158 | |
159 | if (!urb) { |
160 | /* |
161 | * I get the result of a unlink request. But, it seems that I |
162 | * already received the result of its submit result and gave |
163 | * back the URB. |
164 | */ |
165 | pr_info("the urb (seqnum %d) was already given back\n" , |
166 | pdu->base.seqnum); |
167 | } else { |
168 | usbip_dbg_vhci_rx("now giveback urb %d\n" , pdu->base.seqnum); |
169 | |
170 | /* If unlink is successful, status is -ECONNRESET */ |
171 | urb->status = pdu->u.ret_unlink.status; |
172 | pr_info("urb->status %d\n" , urb->status); |
173 | |
174 | spin_lock_irqsave(&vhci->lock, flags); |
175 | usb_hcd_unlink_urb_from_ep(hcd: vhci_hcd_to_hcd(vhci_hcd), urb); |
176 | spin_unlock_irqrestore(lock: &vhci->lock, flags); |
177 | |
178 | usb_hcd_giveback_urb(hcd: vhci_hcd_to_hcd(vhci_hcd), urb, status: urb->status); |
179 | } |
180 | |
181 | kfree(objp: unlink); |
182 | } |
183 | |
184 | static int vhci_priv_tx_empty(struct vhci_device *vdev) |
185 | { |
186 | int empty = 0; |
187 | unsigned long flags; |
188 | |
189 | spin_lock_irqsave(&vdev->priv_lock, flags); |
190 | empty = list_empty(head: &vdev->priv_rx); |
191 | spin_unlock_irqrestore(lock: &vdev->priv_lock, flags); |
192 | |
193 | return empty; |
194 | } |
195 | |
196 | /* recv a pdu */ |
197 | static void vhci_rx_pdu(struct usbip_device *ud) |
198 | { |
199 | int ret; |
200 | struct usbip_header pdu; |
201 | struct vhci_device *vdev = container_of(ud, struct vhci_device, ud); |
202 | |
203 | usbip_dbg_vhci_rx("Enter\n" ); |
204 | |
205 | memset(&pdu, 0, sizeof(pdu)); |
206 | |
207 | /* receive a pdu header */ |
208 | ret = usbip_recv(sock: ud->tcp_socket, buf: &pdu, size: sizeof(pdu)); |
209 | if (ret < 0) { |
210 | if (ret == -ECONNRESET) |
211 | pr_info("connection reset by peer\n" ); |
212 | else if (ret == -EAGAIN) { |
213 | /* ignore if connection was idle */ |
214 | if (vhci_priv_tx_empty(vdev)) |
215 | return; |
216 | pr_info("connection timed out with pending urbs\n" ); |
217 | } else if (ret != -ERESTARTSYS) |
218 | pr_info("xmit failed %d\n" , ret); |
219 | |
220 | usbip_event_add(ud, VDEV_EVENT_ERROR_TCP); |
221 | return; |
222 | } |
223 | if (ret == 0) { |
224 | pr_info("connection closed" ); |
225 | usbip_event_add(ud, VDEV_EVENT_DOWN); |
226 | return; |
227 | } |
228 | if (ret != sizeof(pdu)) { |
229 | pr_err("received pdu size is %d, should be %d\n" , ret, |
230 | (unsigned int)sizeof(pdu)); |
231 | usbip_event_add(ud, VDEV_EVENT_ERROR_TCP); |
232 | return; |
233 | } |
234 | |
235 | usbip_header_correct_endian(pdu: &pdu, send: 0); |
236 | |
237 | if (usbip_dbg_flag_vhci_rx) |
238 | usbip_dump_header(pdu: &pdu); |
239 | |
240 | switch (pdu.base.command) { |
241 | case USBIP_RET_SUBMIT: |
242 | vhci_recv_ret_submit(vdev, pdu: &pdu); |
243 | break; |
244 | case USBIP_RET_UNLINK: |
245 | vhci_recv_ret_unlink(vdev, pdu: &pdu); |
246 | break; |
247 | default: |
248 | /* NOT REACHED */ |
249 | pr_err("unknown pdu %u\n" , pdu.base.command); |
250 | usbip_dump_header(pdu: &pdu); |
251 | usbip_event_add(ud, VDEV_EVENT_ERROR_TCP); |
252 | break; |
253 | } |
254 | } |
255 | |
256 | int vhci_rx_loop(void *data) |
257 | { |
258 | struct usbip_device *ud = data; |
259 | |
260 | while (!kthread_should_stop()) { |
261 | if (usbip_event_happened(ud)) |
262 | break; |
263 | |
264 | usbip_kcov_remote_start(ud); |
265 | vhci_rx_pdu(ud); |
266 | usbip_kcov_remote_stop(); |
267 | } |
268 | |
269 | return 0; |
270 | } |
271 | |