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  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Copyright (C) 2003-2008 Takahiro Hirofuchi
  4 * Copyright (C) 2015-2016 Nobuo Iwata
  5 */
  6
  7#include <linux/kthread.h>
  8#include <linux/file.h>
  9#include <linux/net.h>
 10#include <linux/platform_device.h>
 11#include <linux/slab.h>
 12
 13/* Hardening for Spectre-v1 */
 14#include <linux/nospec.h>
 15
 16#include "usbip_common.h"
 17#include "vhci.h"
 18
 19/* TODO: refine locking ?*/
 20
 21/*
 22 * output example:
 23 * hub port sta spd dev       sockfd local_busid
 24 * hs  0000 004 000 00000000  000003 1-2.3
 25 * ................................................
 26 * ss  0008 004 000 00000000  000004 2-3.4
 27 * ................................................
 28 *
 29 * Output includes socket fd instead of socket pointer address to avoid
 30 * leaking kernel memory address in:
 31 *	/sys/devices/platform/vhci_hcd.0/status and in debug output.
 32 * The socket pointer address is not used at the moment and it was made
 33 * visible as a convenient way to find IP address from socket pointer
 34 * address by looking up /proc/net/{tcp,tcp6}. As this opens a security
 35 * hole, the change is made to use sockfd instead.
 36 *
 37 */
 38static void port_show_vhci(char **out, int hub, int port, struct vhci_device *vdev)
 39{
 40	if (hub == HUB_SPEED_HIGH)
 41		*out += sprintf(*out, "hs  %04u %03u ",
 42				      port, vdev->ud.status);
 43	else /* hub == HUB_SPEED_SUPER */
 44		*out += sprintf(*out, "ss  %04u %03u ",
 45				      port, vdev->ud.status);
 46
 47	if (vdev->ud.status == VDEV_ST_USED) {
 48		*out += sprintf(*out, "%03u %08x ",
 49				      vdev->speed, vdev->devid);
 50		*out += sprintf(*out, "%06u %s",
 51				      vdev->ud.sockfd,
 52				      dev_name(&vdev->udev->dev));
 53
 54	} else {
 55		*out += sprintf(*out, "000 00000000 ");
 56		*out += sprintf(*out, "000000 0-0");
 57	}
 58
 59	*out += sprintf(*out, "\n");
 60}
 61
 62/* Sysfs entry to show port status */
 63static ssize_t status_show_vhci(int pdev_nr, char *out)
 64{
 65	struct platform_device *pdev = vhcis[pdev_nr].pdev;
 66	struct vhci *vhci;
 67	struct usb_hcd *hcd;
 68	struct vhci_hcd *vhci_hcd;
 69	char *s = out;
 70	int i;
 71	unsigned long flags;
 72
 73	if (!pdev || !out) {
 74		usbip_dbg_vhci_sysfs("show status error\n");
 75		return 0;
 76	}
 77
 78	hcd = platform_get_drvdata(pdev);
 79	vhci_hcd = hcd_to_vhci_hcd(hcd);
 80	vhci = vhci_hcd->vhci;
 81
 82	spin_lock_irqsave(&vhci->lock, flags);
 83
 84	for (i = 0; i < VHCI_HC_PORTS; i++) {
 85		struct vhci_device *vdev = &vhci->vhci_hcd_hs->vdev[i];
 86
 87		spin_lock(&vdev->ud.lock);
 88		port_show_vhci(&out, HUB_SPEED_HIGH,
 89			       pdev_nr * VHCI_PORTS + i, vdev);
 90		spin_unlock(&vdev->ud.lock);
 91	}
 92
 93	for (i = 0; i < VHCI_HC_PORTS; i++) {
 94		struct vhci_device *vdev = &vhci->vhci_hcd_ss->vdev[i];
 95
 96		spin_lock(&vdev->ud.lock);
 97		port_show_vhci(&out, HUB_SPEED_SUPER,
 98			       pdev_nr * VHCI_PORTS + VHCI_HC_PORTS + i, vdev);
 99		spin_unlock(&vdev->ud.lock);
100	}
101
102	spin_unlock_irqrestore(&vhci->lock, flags);
103
104	return out - s;
105}
106
107static ssize_t status_show_not_ready(int pdev_nr, char *out)
108{
109	char *s = out;
110	int i = 0;
111
112	for (i = 0; i < VHCI_HC_PORTS; i++) {
113		out += sprintf(out, "hs  %04u %03u ",
114				    (pdev_nr * VHCI_PORTS) + i,
115				    VDEV_ST_NOTASSIGNED);
116		out += sprintf(out, "000 00000000 0000000000000000 0-0");
117		out += sprintf(out, "\n");
118	}
119
120	for (i = 0; i < VHCI_HC_PORTS; i++) {
121		out += sprintf(out, "ss  %04u %03u ",
122				    (pdev_nr * VHCI_PORTS) + VHCI_HC_PORTS + i,
123				    VDEV_ST_NOTASSIGNED);
124		out += sprintf(out, "000 00000000 0000000000000000 0-0");
125		out += sprintf(out, "\n");
126	}
127	return out - s;
128}
129
130static int status_name_to_id(const char *name)
131{
132	char *c;
133	long val;
134	int ret;
135
136	c = strchr(name, '.');
137	if (c == NULL)
138		return 0;
139
140	ret = kstrtol(c+1, 10, &val);
141	if (ret < 0)
142		return ret;
143
144	return val;
145}
146
147static ssize_t status_show(struct device *dev,
148			   struct device_attribute *attr, char *out)
149{
150	char *s = out;
151	int pdev_nr;
152
153	out += sprintf(out,
154		       "hub port sta spd dev      sockfd local_busid\n");
155
156	pdev_nr = status_name_to_id(attr->attr.name);
157	if (pdev_nr < 0)
158		out += status_show_not_ready(pdev_nr, out);
159	else
160		out += status_show_vhci(pdev_nr, out);
161
162	return out - s;
163}
164
165static ssize_t nports_show(struct device *dev, struct device_attribute *attr,
166			   char *out)
167{
168	char *s = out;
169
170	/*
171	 * Half the ports are for SPEED_HIGH and half for SPEED_SUPER,
172	 * thus the * 2.
173	 */
174	out += sprintf(out, "%d\n", VHCI_PORTS * vhci_num_controllers);
175	return out - s;
176}
177static DEVICE_ATTR_RO(nports);
178
179/* Sysfs entry to shutdown a virtual connection */
180static int vhci_port_disconnect(struct vhci_hcd *vhci_hcd, __u32 rhport)
181{
182	struct vhci_device *vdev = &vhci_hcd->vdev[rhport];
183	struct vhci *vhci = vhci_hcd->vhci;
184	unsigned long flags;
185
186	usbip_dbg_vhci_sysfs("enter\n");
187
188	/* lock */
189	spin_lock_irqsave(&vhci->lock, flags);
190	spin_lock(&vdev->ud.lock);
191
192	if (vdev->ud.status == VDEV_ST_NULL) {
193		pr_err("not connected %d\n", vdev->ud.status);
194
195		/* unlock */
196		spin_unlock(&vdev->ud.lock);
197		spin_unlock_irqrestore(&vhci->lock, flags);
198
199		return -EINVAL;
200	}
201
202	/* unlock */
203	spin_unlock(&vdev->ud.lock);
204	spin_unlock_irqrestore(&vhci->lock, flags);
205
206	usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);
207
208	return 0;
209}
210
211static int valid_port(__u32 *pdev_nr, __u32 *rhport)
212{
213	if (*pdev_nr >= vhci_num_controllers) {
214		pr_err("pdev %u\n", *pdev_nr);
215		return 0;
216	}
217	*pdev_nr = array_index_nospec(*pdev_nr, vhci_num_controllers);
218
219	if (*rhport >= VHCI_HC_PORTS) {
220		pr_err("rhport %u\n", *rhport);
221		return 0;
222	}
223	*rhport = array_index_nospec(*rhport, VHCI_HC_PORTS);
224
225	return 1;
226}
227
228static ssize_t detach_store(struct device *dev, struct device_attribute *attr,
229			    const char *buf, size_t count)
230{
231	__u32 port = 0, pdev_nr = 0, rhport = 0;
232	struct usb_hcd *hcd;
233	struct vhci_hcd *vhci_hcd;
234	int ret;
235
236	if (kstrtoint(buf, 10, &port) < 0)
237		return -EINVAL;
238
239	pdev_nr = port_to_pdev_nr(port);
240	rhport = port_to_rhport(port);
241
242	if (!valid_port(&pdev_nr, &rhport))
243		return -EINVAL;
244
245	hcd = platform_get_drvdata(vhcis[pdev_nr].pdev);
246	if (hcd == NULL) {
247		dev_err(dev, "port is not ready %u\n", port);
248		return -EAGAIN;
249	}
250
251	usbip_dbg_vhci_sysfs("rhport %d\n", rhport);
252
253	if ((port / VHCI_HC_PORTS) % 2)
254		vhci_hcd = hcd_to_vhci_hcd(hcd)->vhci->vhci_hcd_ss;
255	else
256		vhci_hcd = hcd_to_vhci_hcd(hcd)->vhci->vhci_hcd_hs;
257
258	ret = vhci_port_disconnect(vhci_hcd, rhport);
259	if (ret < 0)
260		return -EINVAL;
261
262	usbip_dbg_vhci_sysfs("Leave\n");
263
264	return count;
265}
266static DEVICE_ATTR_WO(detach);
267
268static int valid_args(__u32 *pdev_nr, __u32 *rhport,
269		      enum usb_device_speed speed)
270{
271	if (!valid_port(pdev_nr, rhport)) {
272		return 0;
273	}
274
275	switch (speed) {
276	case USB_SPEED_LOW:
277	case USB_SPEED_FULL:
278	case USB_SPEED_HIGH:
279	case USB_SPEED_WIRELESS:
280	case USB_SPEED_SUPER:
281		break;
282	default:
283		pr_err("Failed attach request for unsupported USB speed: %s\n",
284			usb_speed_string(speed));
285		return 0;
286	}
287
288	return 1;
289}
290
291/* Sysfs entry to establish a virtual connection */
292/*
293 * To start a new USB/IP attachment, a userland program needs to setup a TCP
294 * connection and then write its socket descriptor with remote device
295 * information into this sysfs file.
296 *
297 * A remote device is virtually attached to the root-hub port of @rhport with
298 * @speed. @devid is embedded into a request to specify the remote device in a
299 * server host.
300 *
301 * write() returns 0 on success, else negative errno.
302 */
303static ssize_t attach_store(struct device *dev, struct device_attribute *attr,
304			    const char *buf, size_t count)
305{
306	struct socket *socket;
307	int sockfd = 0;
308	__u32 port = 0, pdev_nr = 0, rhport = 0, devid = 0, speed = 0;
309	struct usb_hcd *hcd;
310	struct vhci_hcd *vhci_hcd;
311	struct vhci_device *vdev;
312	struct vhci *vhci;
313	int err;
314	unsigned long flags;
315
316	/*
317	 * @rhport: port number of vhci_hcd
318	 * @sockfd: socket descriptor of an established TCP connection
319	 * @devid: unique device identifier in a remote host
320	 * @speed: usb device speed in a remote host
321	 */
322	if (sscanf(buf, "%u %u %u %u", &port, &sockfd, &devid, &speed) != 4)
323		return -EINVAL;
324	pdev_nr = port_to_pdev_nr(port);
325	rhport = port_to_rhport(port);
326
327	usbip_dbg_vhci_sysfs("port(%u) pdev(%d) rhport(%u)\n",
328			     port, pdev_nr, rhport);
329	usbip_dbg_vhci_sysfs("sockfd(%u) devid(%u) speed(%u)\n",
330			     sockfd, devid, speed);
331
332	/* check received parameters */
333	if (!valid_args(&pdev_nr, &rhport, speed))
334		return -EINVAL;
335
336	hcd = platform_get_drvdata(vhcis[pdev_nr].pdev);
337	if (hcd == NULL) {
338		dev_err(dev, "port %d is not ready\n", port);
339		return -EAGAIN;
340	}
341
342	vhci_hcd = hcd_to_vhci_hcd(hcd);
343	vhci = vhci_hcd->vhci;
344
345	if (speed == USB_SPEED_SUPER)
346		vdev = &vhci->vhci_hcd_ss->vdev[rhport];
347	else
348		vdev = &vhci->vhci_hcd_hs->vdev[rhport];
349
350	/* Extract socket from fd. */
351	socket = sockfd_lookup(sockfd, &err);
352	if (!socket)
353		return -EINVAL;
354
355	/* now need lock until setting vdev status as used */
356
357	/* begin a lock */
358	spin_lock_irqsave(&vhci->lock, flags);
359	spin_lock(&vdev->ud.lock);
360
361	if (vdev->ud.status != VDEV_ST_NULL) {
362		/* end of the lock */
363		spin_unlock(&vdev->ud.lock);
364		spin_unlock_irqrestore(&vhci->lock, flags);
365
366		sockfd_put(socket);
367
368		dev_err(dev, "port %d already used\n", rhport);
369		/*
370		 * Will be retried from userspace
371		 * if there's another free port.
372		 */
373		return -EBUSY;
374	}
375
376	dev_info(dev, "pdev(%u) rhport(%u) sockfd(%d)\n",
377		 pdev_nr, rhport, sockfd);
378	dev_info(dev, "devid(%u) speed(%u) speed_str(%s)\n",
379		 devid, speed, usb_speed_string(speed));
380
381	vdev->devid         = devid;
382	vdev->speed         = speed;
383	vdev->ud.sockfd     = sockfd;
384	vdev->ud.tcp_socket = socket;
385	vdev->ud.status     = VDEV_ST_NOTASSIGNED;
386
387	spin_unlock(&vdev->ud.lock);
388	spin_unlock_irqrestore(&vhci->lock, flags);
389	/* end the lock */
390
391	vdev->ud.tcp_rx = kthread_get_run(vhci_rx_loop, &vdev->ud, "vhci_rx");
392	vdev->ud.tcp_tx = kthread_get_run(vhci_tx_loop, &vdev->ud, "vhci_tx");
393
394	rh_port_connect(vdev, speed);
395
396	return count;
397}
398static DEVICE_ATTR_WO(attach);
399
400#define MAX_STATUS_NAME 16
401
402struct status_attr {
403	struct device_attribute attr;
404	char name[MAX_STATUS_NAME+1];
405};
406
407static struct status_attr *status_attrs;
408
409static void set_status_attr(int id)
410{
411	struct status_attr *status;
412
413	status = status_attrs + id;
414	if (id == 0)
415		strcpy(status->name, "status");
416	else
417		snprintf(status->name, MAX_STATUS_NAME+1, "status.%d", id);
418	status->attr.attr.name = status->name;
419	status->attr.attr.mode = S_IRUGO;
420	status->attr.show = status_show;
421	sysfs_attr_init(&status->attr.attr);
422}
423
424static int init_status_attrs(void)
425{
426	int id;
427
428	status_attrs = kcalloc(vhci_num_controllers, sizeof(struct status_attr),
429			       GFP_KERNEL);
430	if (status_attrs == NULL)
431		return -ENOMEM;
432
433	for (id = 0; id < vhci_num_controllers; id++)
434		set_status_attr(id);
435
436	return 0;
437}
438
439static void finish_status_attrs(void)
440{
441	kfree(status_attrs);
442}
443
444struct attribute_group vhci_attr_group = {
445	.attrs = NULL,
446};
447
448int vhci_init_attr_group(void)
449{
450	struct attribute **attrs;
451	int ret, i;
452
453	attrs = kcalloc((vhci_num_controllers + 5), sizeof(struct attribute *),
454			GFP_KERNEL);
455	if (attrs == NULL)
456		return -ENOMEM;
457
458	ret = init_status_attrs();
459	if (ret) {
460		kfree(attrs);
461		return ret;
462	}
463	*attrs = &dev_attr_nports.attr;
464	*(attrs + 1) = &dev_attr_detach.attr;
465	*(attrs + 2) = &dev_attr_attach.attr;
466	*(attrs + 3) = &dev_attr_usbip_debug.attr;
467	for (i = 0; i < vhci_num_controllers; i++)
468		*(attrs + i + 4) = &((status_attrs + i)->attr.attr);
469	vhci_attr_group.attrs = attrs;
470	return 0;
471}
472
473void vhci_finish_attr_group(void)
474{
475	finish_status_attrs();
476	kfree(vhci_attr_group.attrs);
477}