1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2015-2016 Samsung Electronics
4  *               Igor Kotrasinski <i.kotrasinsk@samsung.com>
5  *               Krzysztof Opasiak <k.opasiak@samsung.com>
6  *
7  * Refactored from usbip_host_driver.c, which is:
8  * Copyright (C) 2011 matt mooney <mfm@muteddisk.com>
9  *               2005-2007 Takahiro Hirofuchi
10  */
11 
12 #include <sys/types.h>
13 #include <sys/stat.h>
14 #include <fcntl.h>
15 
16 #include <errno.h>
17 #include <unistd.h>
18 
19 #include <libudev.h>
20 
21 #include "usbip_common.h"
22 #include "usbip_host_common.h"
23 #include "list.h"
24 #include "sysfs_utils.h"
25 
26 struct udev *udev_context;
27 
28 static int32_t read_attr_usbip_status(struct usbip_usb_device *udev)
29 {
30 	char status_attr_path[SYSFS_PATH_MAX];
31 	int size;
32 	int fd;
33 	int length;
34 	char status[2] = { 0 };
35 	int value = 0;
36 
37 	size = snprintf(status_attr_path, sizeof(status_attr_path),
38 			"%s/usbip_status", udev->path);
39 	if (size < 0 || (unsigned int)size >= sizeof(status_attr_path)) {
40 		err("usbip_status path length %i >= %lu or < 0", size,
41 		    (long unsigned)sizeof(status_attr_path));
42 		return -1;
43 	}
44 
45 
46 	fd = open(status_attr_path, O_RDONLY);
47 	if (fd < 0) {
48 		err("error opening attribute %s", status_attr_path);
49 		return -1;
50 	}
51 
52 	length = read(fd, status, 1);
53 	if (length < 0) {
54 		err("error reading attribute %s", status_attr_path);
55 		close(fd);
56 		return -1;
57 	}
58 
59 	value = atoi(status);
60 	close(fd);
61 	return value;
62 }
63 
64 static
65 struct usbip_exported_device *usbip_exported_device_new(
66 		struct usbip_host_driver *hdriver, const char *sdevpath)
67 {
68 	struct usbip_exported_device *edev = NULL;
69 	struct usbip_exported_device *edev_old;
70 	size_t size;
71 	int i;
72 
73 	edev = calloc(1, sizeof(struct usbip_exported_device));
74 
75 	edev->sudev =
76 		udev_device_new_from_syspath(udev_context, sdevpath);
77 	if (!edev->sudev) {
78 		err("udev_device_new_from_syspath: %s", sdevpath);
79 		goto err;
80 	}
81 
82 	if (hdriver->ops.read_device(edev->sudev, &edev->udev) < 0)
83 		goto err;
84 
85 	edev->status = read_attr_usbip_status(&edev->udev);
86 	if (edev->status < 0)
87 		goto err;
88 
89 	/* reallocate buffer to include usb interface data */
90 	size = sizeof(struct usbip_exported_device) +
91 		edev->udev.bNumInterfaces * sizeof(struct usbip_usb_interface);
92 
93 	edev_old = edev;
94 	edev = realloc(edev, size);
95 	if (!edev) {
96 		edev = edev_old;
97 		dbg("realloc failed");
98 		goto err;
99 	}
100 
101 	for (i = 0; i < edev->udev.bNumInterfaces; i++) {
102 		/* vudc does not support reading interfaces */
103 		if (!hdriver->ops.read_interface)
104 			break;
105 		hdriver->ops.read_interface(&edev->udev, i, &edev->uinf[i]);
106 	}
107 
108 	return edev;
109 err:
110 	if (edev->sudev)
111 		udev_device_unref(edev->sudev);
112 	if (edev)
113 		free(edev);
114 
115 	return NULL;
116 }
117 
118 static int refresh_exported_devices(struct usbip_host_driver *hdriver)
119 {
120 	struct usbip_exported_device *edev;
121 	struct udev_enumerate *enumerate;
122 	struct udev_list_entry *devices, *dev_list_entry;
123 	struct udev_device *dev;
124 	const char *path;
125 
126 	enumerate = udev_enumerate_new(udev_context);
127 	udev_enumerate_add_match_subsystem(enumerate, hdriver->udev_subsystem);
128 	udev_enumerate_scan_devices(enumerate);
129 
130 	devices = udev_enumerate_get_list_entry(enumerate);
131 
132 	udev_list_entry_foreach(dev_list_entry, devices) {
133 		path = udev_list_entry_get_name(dev_list_entry);
134 		dev = udev_device_new_from_syspath(udev_context,
135 						   path);
136 		if (dev == NULL)
137 			continue;
138 
139 		/* Check whether device uses usbip driver. */
140 		if (hdriver->ops.is_my_device(dev)) {
141 			edev = usbip_exported_device_new(hdriver, path);
142 			if (!edev) {
143 				dbg("usbip_exported_device_new failed");
144 				continue;
145 			}
146 
147 			list_add(&edev->node, &hdriver->edev_list);
148 			hdriver->ndevs++;
149 		}
150 	}
151 
152 	return 0;
153 }
154 
155 static void usbip_exported_device_destroy(struct list_head *devs)
156 {
157 	struct list_head *i, *tmp;
158 	struct usbip_exported_device *edev;
159 
160 	list_for_each_safe(i, tmp, devs) {
161 		edev = list_entry(i, struct usbip_exported_device, node);
162 		list_del(i);
163 		free(edev);
164 	}
165 }
166 
167 int usbip_generic_driver_open(struct usbip_host_driver *hdriver)
168 {
169 	int rc;
170 
171 	udev_context = udev_new();
172 	if (!udev_context) {
173 		err("udev_new failed");
174 		return -1;
175 	}
176 
177 	rc = refresh_exported_devices(hdriver);
178 	if (rc < 0)
179 		goto err;
180 	return 0;
181 err:
182 	udev_unref(udev_context);
183 	return -1;
184 }
185 
186 void usbip_generic_driver_close(struct usbip_host_driver *hdriver)
187 {
188 	if (!hdriver)
189 		return;
190 
191 	usbip_exported_device_destroy(&hdriver->edev_list);
192 
193 	udev_unref(udev_context);
194 }
195 
196 int usbip_generic_refresh_device_list(struct usbip_host_driver *hdriver)
197 {
198 	int rc;
199 
200 	usbip_exported_device_destroy(&hdriver->edev_list);
201 
202 	hdriver->ndevs = 0;
203 	INIT_LIST_HEAD(&hdriver->edev_list);
204 
205 	rc = refresh_exported_devices(hdriver);
206 	if (rc < 0)
207 		return -1;
208 
209 	return 0;
210 }
211 
212 int usbip_export_device(struct usbip_exported_device *edev, int sockfd)
213 {
214 	char attr_name[] = "usbip_sockfd";
215 	char sockfd_attr_path[SYSFS_PATH_MAX];
216 	int size;
217 	char sockfd_buff[30];
218 	int ret;
219 
220 	if (edev->status != SDEV_ST_AVAILABLE) {
221 		dbg("device not available: %s", edev->udev.busid);
222 		switch (edev->status) {
223 		case SDEV_ST_ERROR:
224 			dbg("status SDEV_ST_ERROR");
225 			ret = ST_DEV_ERR;
226 			break;
227 		case SDEV_ST_USED:
228 			dbg("status SDEV_ST_USED");
229 			ret = ST_DEV_BUSY;
230 			break;
231 		default:
232 			dbg("status unknown: 0x%x", edev->status);
233 			ret = -1;
234 		}
235 		return ret;
236 	}
237 
238 	/* only the first interface is true */
239 	size = snprintf(sockfd_attr_path, sizeof(sockfd_attr_path), "%s/%s",
240 			edev->udev.path, attr_name);
241 	if (size < 0 || (unsigned int)size >= sizeof(sockfd_attr_path)) {
242 		err("exported device path length %i >= %lu or < 0", size,
243 		    (long unsigned)sizeof(sockfd_attr_path));
244 		return -1;
245 	}
246 
247 	size = snprintf(sockfd_buff, sizeof(sockfd_buff), "%d\n", sockfd);
248 	if (size < 0 || (unsigned int)size >= sizeof(sockfd_buff)) {
249 		err("socket length %i >= %lu or < 0", size,
250 		    (long unsigned)sizeof(sockfd_buff));
251 		return -1;
252 	}
253 
254 	ret = write_sysfs_attribute(sockfd_attr_path, sockfd_buff,
255 				    strlen(sockfd_buff));
256 	if (ret < 0) {
257 		err("write_sysfs_attribute failed: sockfd %s to %s",
258 		    sockfd_buff, sockfd_attr_path);
259 		return ret;
260 	}
261 
262 	info("connect: %s", edev->udev.busid);
263 
264 	return ret;
265 }
266 
267 struct usbip_exported_device *usbip_generic_get_device(
268 		struct usbip_host_driver *hdriver, int num)
269 {
270 	struct list_head *i;
271 	struct usbip_exported_device *edev;
272 	int cnt = 0;
273 
274 	list_for_each(i, &hdriver->edev_list) {
275 		edev = list_entry(i, struct usbip_exported_device, node);
276 		if (num == cnt)
277 			return edev;
278 		cnt++;
279 	}
280 
281 	return NULL;
282 }
283