xref: /linux/drivers/virt/vboxguest/vboxguest_linux.c (revision eb2f932100288dbb881eadfed02e1459c6b9504c)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * vboxguest linux pci driver, char-dev and input-device code,
4  *
5  * Copyright (C) 2006-2016 Oracle Corporation
6  */
7 
8 #include <linux/cred.h>
9 #include <linux/input.h>
10 #include <linux/kernel.h>
11 #include <linux/miscdevice.h>
12 #include <linux/module.h>
13 #include <linux/pci.h>
14 #include <linux/poll.h>
15 #include <linux/vbox_utils.h>
16 #include "vboxguest_core.h"
17 
18 /** The device name. */
19 #define DEVICE_NAME		"vboxguest"
20 /** The device name for the device node open to everyone. */
21 #define DEVICE_NAME_USER	"vboxuser"
22 /** VirtualBox PCI vendor ID. */
23 #define VBOX_VENDORID		0x80ee
24 /** VMMDev PCI card product ID. */
25 #define VMMDEV_DEVICEID		0xcafe
26 
27 /** Mutex protecting the global vbg_gdev pointer used by vbg_get/put_gdev. */
28 static DEFINE_MUTEX(vbg_gdev_mutex);
29 /** Global vbg_gdev pointer used by vbg_get/put_gdev. */
30 static struct vbg_dev *vbg_gdev;
31 
32 static u32 vbg_misc_device_requestor(struct inode *inode)
33 {
34 	u32 requestor = VMMDEV_REQUESTOR_USERMODE |
35 			VMMDEV_REQUESTOR_CON_DONT_KNOW |
36 			VMMDEV_REQUESTOR_TRUST_NOT_GIVEN;
37 
38 	if (from_kuid(current_user_ns(), current_uid()) == 0)
39 		requestor |= VMMDEV_REQUESTOR_USR_ROOT;
40 	else
41 		requestor |= VMMDEV_REQUESTOR_USR_USER;
42 
43 	if (in_egroup_p(inode->i_gid))
44 		requestor |= VMMDEV_REQUESTOR_GRP_VBOX;
45 
46 	return requestor;
47 }
48 
49 static int vbg_misc_device_open(struct inode *inode, struct file *filp)
50 {
51 	struct vbg_session *session;
52 	struct vbg_dev *gdev;
53 
54 	/* misc_open sets filp->private_data to our misc device */
55 	gdev = container_of(filp->private_data, struct vbg_dev, misc_device);
56 
57 	session = vbg_core_open_session(gdev, vbg_misc_device_requestor(inode));
58 	if (IS_ERR(session))
59 		return PTR_ERR(session);
60 
61 	filp->private_data = session;
62 	return 0;
63 }
64 
65 static int vbg_misc_device_user_open(struct inode *inode, struct file *filp)
66 {
67 	struct vbg_session *session;
68 	struct vbg_dev *gdev;
69 
70 	/* misc_open sets filp->private_data to our misc device */
71 	gdev = container_of(filp->private_data, struct vbg_dev,
72 			    misc_device_user);
73 
74 	session = vbg_core_open_session(gdev, vbg_misc_device_requestor(inode) |
75 					      VMMDEV_REQUESTOR_USER_DEVICE);
76 	if (IS_ERR(session))
77 		return PTR_ERR(session);
78 
79 	filp->private_data = session;
80 	return 0;
81 }
82 
83 /**
84  * vbg_misc_device_close - Close device.
85  * @inode:		Pointer to inode info structure.
86  * @filp:		Associated file pointer.
87  *
88  * Return: %0 on success, negated errno on failure.
89  */
90 static int vbg_misc_device_close(struct inode *inode, struct file *filp)
91 {
92 	vbg_core_close_session(filp->private_data);
93 	filp->private_data = NULL;
94 	return 0;
95 }
96 
97 /**
98  * vbg_misc_device_ioctl - Device I/O Control entry point.
99  * @filp:		Associated file pointer.
100  * @req:		The request specified to ioctl().
101  * @arg:		The argument specified to ioctl().
102  *
103  * Return: %0 on success, negated errno on failure.
104  */
105 static long vbg_misc_device_ioctl(struct file *filp, unsigned int req,
106 				  unsigned long arg)
107 {
108 	struct vbg_session *session = filp->private_data;
109 	size_t returned_size, size;
110 	struct vbg_ioctl_hdr hdr;
111 	bool is_vmmdev_req;
112 	int ret = 0;
113 	void *buf;
114 
115 	if (copy_from_user(&hdr, (void *)arg, sizeof(hdr)))
116 		return -EFAULT;
117 
118 	if (hdr.version != VBG_IOCTL_HDR_VERSION)
119 		return -EINVAL;
120 
121 	if (hdr.size_in < sizeof(hdr) ||
122 	    (hdr.size_out && hdr.size_out < sizeof(hdr)))
123 		return -EINVAL;
124 
125 	size = max(hdr.size_in, hdr.size_out);
126 	if (_IOC_SIZE(req) && _IOC_SIZE(req) != size)
127 		return -EINVAL;
128 	if (size > SZ_16M)
129 		return -E2BIG;
130 
131 	/*
132 	 * IOCTL_VMMDEV_REQUEST needs the buffer to be below 4G to avoid
133 	 * the need for a bounce-buffer and another copy later on.
134 	 */
135 	is_vmmdev_req = (req & ~IOCSIZE_MASK) == VBG_IOCTL_VMMDEV_REQUEST(0) ||
136 			 req == VBG_IOCTL_VMMDEV_REQUEST_BIG ||
137 			 req == VBG_IOCTL_VMMDEV_REQUEST_BIG_ALT;
138 
139 	if (is_vmmdev_req)
140 		buf = vbg_req_alloc(size, VBG_IOCTL_HDR_TYPE_DEFAULT,
141 				    session->requestor);
142 	else
143 		buf = kmalloc(size, GFP_KERNEL);
144 	if (!buf)
145 		return -ENOMEM;
146 
147 	*((struct vbg_ioctl_hdr *)buf) = hdr;
148 	if (copy_from_user(buf + sizeof(hdr), (void *)arg + sizeof(hdr),
149 			   hdr.size_in - sizeof(hdr))) {
150 		ret = -EFAULT;
151 		goto out;
152 	}
153 	if (hdr.size_in < size)
154 		memset(buf + hdr.size_in, 0, size -  hdr.size_in);
155 
156 	ret = vbg_core_ioctl(session, req, buf);
157 	if (ret)
158 		goto out;
159 
160 	returned_size = ((struct vbg_ioctl_hdr *)buf)->size_out;
161 	if (returned_size > size) {
162 		vbg_debug("%s: too much output data %zu > %zu\n",
163 			  __func__, returned_size, size);
164 		returned_size = size;
165 	}
166 	if (copy_to_user((void *)arg, buf, returned_size) != 0)
167 		ret = -EFAULT;
168 
169 out:
170 	if (is_vmmdev_req)
171 		vbg_req_free(buf, size);
172 	else
173 		kfree(buf);
174 
175 	return ret;
176 }
177 
178 /* The file_operations structures. */
179 static const struct file_operations vbg_misc_device_fops = {
180 	.owner			= THIS_MODULE,
181 	.open			= vbg_misc_device_open,
182 	.release		= vbg_misc_device_close,
183 	.unlocked_ioctl		= vbg_misc_device_ioctl,
184 #ifdef CONFIG_COMPAT
185 	.compat_ioctl		= vbg_misc_device_ioctl,
186 #endif
187 };
188 static const struct file_operations vbg_misc_device_user_fops = {
189 	.owner			= THIS_MODULE,
190 	.open			= vbg_misc_device_user_open,
191 	.release		= vbg_misc_device_close,
192 	.unlocked_ioctl		= vbg_misc_device_ioctl,
193 #ifdef CONFIG_COMPAT
194 	.compat_ioctl		= vbg_misc_device_ioctl,
195 #endif
196 };
197 
198 /*
199  * Called when the input device is first opened.
200  *
201  * Sets up absolute mouse reporting.
202  */
203 static int vbg_input_open(struct input_dev *input)
204 {
205 	struct vbg_dev *gdev = input_get_drvdata(input);
206 	u32 feat = VMMDEV_MOUSE_GUEST_CAN_ABSOLUTE | VMMDEV_MOUSE_NEW_PROTOCOL;
207 
208 	return vbg_core_set_mouse_status(gdev, feat);
209 }
210 
211 /*
212  * Called if all open handles to the input device are closed.
213  *
214  * Disables absolute reporting.
215  */
216 static void vbg_input_close(struct input_dev *input)
217 {
218 	struct vbg_dev *gdev = input_get_drvdata(input);
219 
220 	vbg_core_set_mouse_status(gdev, 0);
221 }
222 
223 /*
224  * Creates the kernel input device.
225  *
226  * Return: 0 on success, negated errno on failure.
227  */
228 static int vbg_create_input_device(struct vbg_dev *gdev)
229 {
230 	struct input_dev *input;
231 
232 	input = devm_input_allocate_device(gdev->dev);
233 	if (!input)
234 		return -ENOMEM;
235 
236 	input->id.bustype = BUS_PCI;
237 	input->id.vendor = VBOX_VENDORID;
238 	input->id.product = VMMDEV_DEVICEID;
239 	input->open = vbg_input_open;
240 	input->close = vbg_input_close;
241 	input->dev.parent = gdev->dev;
242 	input->name = "VirtualBox mouse integration";
243 
244 	input_set_abs_params(input, ABS_X, VMMDEV_MOUSE_RANGE_MIN,
245 			     VMMDEV_MOUSE_RANGE_MAX, 0, 0);
246 	input_set_abs_params(input, ABS_Y, VMMDEV_MOUSE_RANGE_MIN,
247 			     VMMDEV_MOUSE_RANGE_MAX, 0, 0);
248 	input_set_capability(input, EV_KEY, BTN_MOUSE);
249 	input_set_drvdata(input, gdev);
250 
251 	gdev->input = input;
252 
253 	return input_register_device(gdev->input);
254 }
255 
256 static ssize_t host_version_show(struct device *dev,
257 				 struct device_attribute *attr, char *buf)
258 {
259 	struct vbg_dev *gdev = dev_get_drvdata(dev);
260 
261 	return sprintf(buf, "%s\n", gdev->host_version);
262 }
263 
264 static ssize_t host_features_show(struct device *dev,
265 				 struct device_attribute *attr, char *buf)
266 {
267 	struct vbg_dev *gdev = dev_get_drvdata(dev);
268 
269 	return sprintf(buf, "%#x\n", gdev->host_features);
270 }
271 
272 static DEVICE_ATTR_RO(host_version);
273 static DEVICE_ATTR_RO(host_features);
274 
275 static struct attribute *vbg_pci_attrs[] = {
276 	&dev_attr_host_version.attr,
277 	&dev_attr_host_features.attr,
278 	NULL,
279 };
280 ATTRIBUTE_GROUPS(vbg_pci);
281 
282 /*
283  * Does the PCI detection and init of the device.
284  *
285  * Return: 0 on success, negated errno on failure.
286  */
287 static int vbg_pci_probe(struct pci_dev *pci, const struct pci_device_id *id)
288 {
289 	struct device *dev = &pci->dev;
290 	resource_size_t io, io_len, mmio, mmio_len;
291 	struct vmmdev_memory *vmmdev;
292 	struct vbg_dev *gdev;
293 	int ret;
294 
295 	gdev = devm_kzalloc(dev, sizeof(*gdev), GFP_KERNEL);
296 	if (!gdev)
297 		return -ENOMEM;
298 
299 	ret = pci_enable_device(pci);
300 	if (ret != 0) {
301 		vbg_err("vboxguest: Error enabling device: %d\n", ret);
302 		return ret;
303 	}
304 
305 	ret = -ENODEV;
306 
307 	io = pci_resource_start(pci, 0);
308 	io_len = pci_resource_len(pci, 0);
309 	if (!io || !io_len) {
310 		vbg_err("vboxguest: Error IO-port resource (0) is missing\n");
311 		goto err_disable_pcidev;
312 	}
313 	if (devm_request_region(dev, io, io_len, DEVICE_NAME) == NULL) {
314 		vbg_err("vboxguest: Error could not claim IO resource\n");
315 		ret = -EBUSY;
316 		goto err_disable_pcidev;
317 	}
318 
319 	mmio = pci_resource_start(pci, 1);
320 	mmio_len = pci_resource_len(pci, 1);
321 	if (!mmio || !mmio_len) {
322 		vbg_err("vboxguest: Error MMIO resource (1) is missing\n");
323 		goto err_disable_pcidev;
324 	}
325 
326 	if (devm_request_mem_region(dev, mmio, mmio_len, DEVICE_NAME) == NULL) {
327 		vbg_err("vboxguest: Error could not claim MMIO resource\n");
328 		ret = -EBUSY;
329 		goto err_disable_pcidev;
330 	}
331 
332 	vmmdev = devm_ioremap(dev, mmio, mmio_len);
333 	if (!vmmdev) {
334 		vbg_err("vboxguest: Error ioremap failed; MMIO addr=%pap size=%pap\n",
335 			&mmio, &mmio_len);
336 		goto err_disable_pcidev;
337 	}
338 
339 	/* Validate MMIO region version and size. */
340 	if (vmmdev->version != VMMDEV_MEMORY_VERSION ||
341 	    vmmdev->size < 32 || vmmdev->size > mmio_len) {
342 		vbg_err("vboxguest: Bogus VMMDev memory; version=%08x (expected %08x) size=%d (expected <= %d)\n",
343 			vmmdev->version, VMMDEV_MEMORY_VERSION,
344 			vmmdev->size, (int)mmio_len);
345 		goto err_disable_pcidev;
346 	}
347 
348 	gdev->io_port = io;
349 	gdev->mmio = vmmdev;
350 	gdev->dev = dev;
351 	gdev->misc_device.minor = MISC_DYNAMIC_MINOR;
352 	gdev->misc_device.name = DEVICE_NAME;
353 	gdev->misc_device.fops = &vbg_misc_device_fops;
354 	gdev->misc_device_user.minor = MISC_DYNAMIC_MINOR;
355 	gdev->misc_device_user.name = DEVICE_NAME_USER;
356 	gdev->misc_device_user.fops = &vbg_misc_device_user_fops;
357 
358 	ret = vbg_core_init(gdev, VMMDEV_EVENT_MOUSE_POSITION_CHANGED);
359 	if (ret)
360 		goto err_disable_pcidev;
361 
362 	ret = vbg_create_input_device(gdev);
363 	if (ret) {
364 		vbg_err("vboxguest: Error creating input device: %d\n", ret);
365 		goto err_vbg_core_exit;
366 	}
367 
368 	ret = request_irq(pci->irq, vbg_core_isr, IRQF_SHARED, DEVICE_NAME,
369 			  gdev);
370 	if (ret) {
371 		vbg_err("vboxguest: Error requesting irq: %d\n", ret);
372 		goto err_vbg_core_exit;
373 	}
374 
375 	ret = misc_register(&gdev->misc_device);
376 	if (ret) {
377 		vbg_err("vboxguest: Error misc_register %s failed: %d\n",
378 			DEVICE_NAME, ret);
379 		goto err_free_irq;
380 	}
381 
382 	ret = misc_register(&gdev->misc_device_user);
383 	if (ret) {
384 		vbg_err("vboxguest: Error misc_register %s failed: %d\n",
385 			DEVICE_NAME_USER, ret);
386 		goto err_unregister_misc_device;
387 	}
388 
389 	mutex_lock(&vbg_gdev_mutex);
390 	if (!vbg_gdev)
391 		vbg_gdev = gdev;
392 	else
393 		ret = -EBUSY;
394 	mutex_unlock(&vbg_gdev_mutex);
395 
396 	if (ret) {
397 		vbg_err("vboxguest: Error more then 1 vbox guest pci device\n");
398 		goto err_unregister_misc_device_user;
399 	}
400 
401 	pci_set_drvdata(pci, gdev);
402 
403 	return 0;
404 
405 err_unregister_misc_device_user:
406 	misc_deregister(&gdev->misc_device_user);
407 err_unregister_misc_device:
408 	misc_deregister(&gdev->misc_device);
409 err_free_irq:
410 	free_irq(pci->irq, gdev);
411 err_vbg_core_exit:
412 	vbg_core_exit(gdev);
413 err_disable_pcidev:
414 	pci_disable_device(pci);
415 
416 	return ret;
417 }
418 
419 static void vbg_pci_remove(struct pci_dev *pci)
420 {
421 	struct vbg_dev *gdev = pci_get_drvdata(pci);
422 
423 	mutex_lock(&vbg_gdev_mutex);
424 	vbg_gdev = NULL;
425 	mutex_unlock(&vbg_gdev_mutex);
426 
427 	free_irq(pci->irq, gdev);
428 	misc_deregister(&gdev->misc_device_user);
429 	misc_deregister(&gdev->misc_device);
430 	vbg_core_exit(gdev);
431 	pci_disable_device(pci);
432 }
433 
434 struct vbg_dev *vbg_get_gdev(void)
435 {
436 	mutex_lock(&vbg_gdev_mutex);
437 
438 	/*
439 	 * Note on success we keep the mutex locked until vbg_put_gdev(),
440 	 * this stops vbg_pci_remove from removing the device from underneath
441 	 * vboxsf. vboxsf will only hold a reference for a short while.
442 	 */
443 	if (vbg_gdev)
444 		return vbg_gdev;
445 
446 	mutex_unlock(&vbg_gdev_mutex);
447 	return ERR_PTR(-ENODEV);
448 }
449 EXPORT_SYMBOL(vbg_get_gdev);
450 
451 void vbg_put_gdev(struct vbg_dev *gdev)
452 {
453 	WARN_ON(gdev != vbg_gdev);
454 	mutex_unlock(&vbg_gdev_mutex);
455 }
456 EXPORT_SYMBOL(vbg_put_gdev);
457 
458 /*
459  * Callback for mouse events.
460  *
461  * This is called at the end of the ISR, after leaving the event spinlock, if
462  * VMMDEV_EVENT_MOUSE_POSITION_CHANGED was raised by the host.
463  *
464  * @gdev:		The device extension.
465  */
466 void vbg_linux_mouse_event(struct vbg_dev *gdev)
467 {
468 	int rc;
469 
470 	/* Report events to the kernel input device */
471 	gdev->mouse_status_req->mouse_features = 0;
472 	gdev->mouse_status_req->pointer_pos_x = 0;
473 	gdev->mouse_status_req->pointer_pos_y = 0;
474 	rc = vbg_req_perform(gdev, gdev->mouse_status_req);
475 	if (rc >= 0) {
476 		input_report_abs(gdev->input, ABS_X,
477 				 gdev->mouse_status_req->pointer_pos_x);
478 		input_report_abs(gdev->input, ABS_Y,
479 				 gdev->mouse_status_req->pointer_pos_y);
480 		input_sync(gdev->input);
481 	}
482 }
483 
484 static const struct pci_device_id vbg_pci_ids[] = {
485 	{ .vendor = VBOX_VENDORID, .device = VMMDEV_DEVICEID },
486 	{}
487 };
488 MODULE_DEVICE_TABLE(pci,  vbg_pci_ids);
489 
490 static struct pci_driver vbg_pci_driver = {
491 	.name		= DEVICE_NAME,
492 	.dev_groups	= vbg_pci_groups,
493 	.id_table	= vbg_pci_ids,
494 	.probe		= vbg_pci_probe,
495 	.remove		= vbg_pci_remove,
496 };
497 
498 module_pci_driver(vbg_pci_driver);
499 
500 MODULE_AUTHOR("Oracle Corporation");
501 MODULE_DESCRIPTION("Oracle VM VirtualBox Guest Additions for Linux Module");
502 MODULE_LICENSE("GPL");
503