xref: /openbmc/linux/drivers/usb/usbip/vhci_sysfs.c (revision 8ffdff6a)
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  */
38 static 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 */
63 static 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 
107 static 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 
130 static 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 
147 static 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 
165 static 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 }
177 static DEVICE_ATTR_RO(nports);
178 
179 /* Sysfs entry to shutdown a virtual connection */
180 static 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 
211 static 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 
228 static 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 }
266 static DEVICE_ATTR_WO(detach);
267 
268 static 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  */
303 static 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 	struct task_struct *tcp_rx = NULL;
316 	struct task_struct *tcp_tx = NULL;
317 
318 	/*
319 	 * @rhport: port number of vhci_hcd
320 	 * @sockfd: socket descriptor of an established TCP connection
321 	 * @devid: unique device identifier in a remote host
322 	 * @speed: usb device speed in a remote host
323 	 */
324 	if (sscanf(buf, "%u %u %u %u", &port, &sockfd, &devid, &speed) != 4)
325 		return -EINVAL;
326 	pdev_nr = port_to_pdev_nr(port);
327 	rhport = port_to_rhport(port);
328 
329 	usbip_dbg_vhci_sysfs("port(%u) pdev(%d) rhport(%u)\n",
330 			     port, pdev_nr, rhport);
331 	usbip_dbg_vhci_sysfs("sockfd(%u) devid(%u) speed(%u)\n",
332 			     sockfd, devid, speed);
333 
334 	/* check received parameters */
335 	if (!valid_args(&pdev_nr, &rhport, speed))
336 		return -EINVAL;
337 
338 	hcd = platform_get_drvdata(vhcis[pdev_nr].pdev);
339 	if (hcd == NULL) {
340 		dev_err(dev, "port %d is not ready\n", port);
341 		return -EAGAIN;
342 	}
343 
344 	vhci_hcd = hcd_to_vhci_hcd(hcd);
345 	vhci = vhci_hcd->vhci;
346 
347 	if (speed == USB_SPEED_SUPER)
348 		vdev = &vhci->vhci_hcd_ss->vdev[rhport];
349 	else
350 		vdev = &vhci->vhci_hcd_hs->vdev[rhport];
351 
352 	/* Extract socket from fd. */
353 	socket = sockfd_lookup(sockfd, &err);
354 	if (!socket) {
355 		dev_err(dev, "failed to lookup sock");
356 		return -EINVAL;
357 	}
358 	if (socket->type != SOCK_STREAM) {
359 		dev_err(dev, "Expecting SOCK_STREAM - found %d",
360 			socket->type);
361 		sockfd_put(socket);
362 		return -EINVAL;
363 	}
364 
365 	/* create threads before locking */
366 	tcp_rx = kthread_create(vhci_rx_loop, &vdev->ud, "vhci_rx");
367 	if (IS_ERR(tcp_rx)) {
368 		sockfd_put(socket);
369 		return -EINVAL;
370 	}
371 	tcp_tx = kthread_create(vhci_tx_loop, &vdev->ud, "vhci_tx");
372 	if (IS_ERR(tcp_tx)) {
373 		kthread_stop(tcp_rx);
374 		sockfd_put(socket);
375 		return -EINVAL;
376 	}
377 
378 	/* get task structs now */
379 	get_task_struct(tcp_rx);
380 	get_task_struct(tcp_tx);
381 
382 	/* now begin lock until setting vdev status set */
383 	spin_lock_irqsave(&vhci->lock, flags);
384 	spin_lock(&vdev->ud.lock);
385 
386 	if (vdev->ud.status != VDEV_ST_NULL) {
387 		/* end of the lock */
388 		spin_unlock(&vdev->ud.lock);
389 		spin_unlock_irqrestore(&vhci->lock, flags);
390 
391 		sockfd_put(socket);
392 		kthread_stop_put(tcp_rx);
393 		kthread_stop_put(tcp_tx);
394 
395 		dev_err(dev, "port %d already used\n", rhport);
396 		/*
397 		 * Will be retried from userspace
398 		 * if there's another free port.
399 		 */
400 		return -EBUSY;
401 	}
402 
403 	dev_info(dev, "pdev(%u) rhport(%u) sockfd(%d)\n",
404 		 pdev_nr, rhport, sockfd);
405 	dev_info(dev, "devid(%u) speed(%u) speed_str(%s)\n",
406 		 devid, speed, usb_speed_string(speed));
407 
408 	vdev->devid         = devid;
409 	vdev->speed         = speed;
410 	vdev->ud.sockfd     = sockfd;
411 	vdev->ud.tcp_socket = socket;
412 	vdev->ud.tcp_rx     = tcp_rx;
413 	vdev->ud.tcp_tx     = tcp_tx;
414 	vdev->ud.status     = VDEV_ST_NOTASSIGNED;
415 	usbip_kcov_handle_init(&vdev->ud);
416 
417 	spin_unlock(&vdev->ud.lock);
418 	spin_unlock_irqrestore(&vhci->lock, flags);
419 	/* end the lock */
420 
421 	wake_up_process(vdev->ud.tcp_rx);
422 	wake_up_process(vdev->ud.tcp_tx);
423 
424 	rh_port_connect(vdev, speed);
425 
426 	return count;
427 }
428 static DEVICE_ATTR_WO(attach);
429 
430 #define MAX_STATUS_NAME 16
431 
432 struct status_attr {
433 	struct device_attribute attr;
434 	char name[MAX_STATUS_NAME+1];
435 };
436 
437 static struct status_attr *status_attrs;
438 
439 static void set_status_attr(int id)
440 {
441 	struct status_attr *status;
442 
443 	status = status_attrs + id;
444 	if (id == 0)
445 		strcpy(status->name, "status");
446 	else
447 		snprintf(status->name, MAX_STATUS_NAME+1, "status.%d", id);
448 	status->attr.attr.name = status->name;
449 	status->attr.attr.mode = S_IRUGO;
450 	status->attr.show = status_show;
451 	sysfs_attr_init(&status->attr.attr);
452 }
453 
454 static int init_status_attrs(void)
455 {
456 	int id;
457 
458 	status_attrs = kcalloc(vhci_num_controllers, sizeof(struct status_attr),
459 			       GFP_KERNEL);
460 	if (status_attrs == NULL)
461 		return -ENOMEM;
462 
463 	for (id = 0; id < vhci_num_controllers; id++)
464 		set_status_attr(id);
465 
466 	return 0;
467 }
468 
469 static void finish_status_attrs(void)
470 {
471 	kfree(status_attrs);
472 }
473 
474 struct attribute_group vhci_attr_group = {
475 	.attrs = NULL,
476 };
477 
478 int vhci_init_attr_group(void)
479 {
480 	struct attribute **attrs;
481 	int ret, i;
482 
483 	attrs = kcalloc((vhci_num_controllers + 5), sizeof(struct attribute *),
484 			GFP_KERNEL);
485 	if (attrs == NULL)
486 		return -ENOMEM;
487 
488 	ret = init_status_attrs();
489 	if (ret) {
490 		kfree(attrs);
491 		return ret;
492 	}
493 	*attrs = &dev_attr_nports.attr;
494 	*(attrs + 1) = &dev_attr_detach.attr;
495 	*(attrs + 2) = &dev_attr_attach.attr;
496 	*(attrs + 3) = &dev_attr_usbip_debug.attr;
497 	for (i = 0; i < vhci_num_controllers; i++)
498 		*(attrs + i + 4) = &((status_attrs + i)->attr.attr);
499 	vhci_attr_group.attrs = attrs;
500 	return 0;
501 }
502 
503 void vhci_finish_attr_group(void)
504 {
505 	finish_status_attrs();
506 	kfree(vhci_attr_group.attrs);
507 }
508