1 /*
2  * Copyright (C) 2015-2016 Samsung Electronics
3  *               Igor Kotrasinski <i.kotrasinsk@samsung.com>
4  *               Krzysztof Opasiak <k.opasiak@samsung.com>
5  *
6  * Refactored from usbip_host_driver.c, which is:
7  * Copyright (C) 2011 matt mooney <mfm@muteddisk.com>
8  *               2005-2007 Takahiro Hirofuchi
9  *
10  * This program is free software: you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation, either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program. If not, see <http://www.gnu.org/licenses/>.
22  */
23 
24 #include <sys/types.h>
25 #include <sys/stat.h>
26 #include <fcntl.h>
27 
28 #include <errno.h>
29 #include <unistd.h>
30 
31 #include <libudev.h>
32 
33 #include "usbip_common.h"
34 #include "usbip_host_common.h"
35 #include "list.h"
36 #include "sysfs_utils.h"
37 
38 struct udev *udev_context;
39 
40 static int32_t read_attr_usbip_status(struct usbip_usb_device *udev)
41 {
42 	char status_attr_path[SYSFS_PATH_MAX];
43 	int size;
44 	int fd;
45 	int length;
46 	char status;
47 	int value = 0;
48 
49 	size = snprintf(status_attr_path, sizeof(status_attr_path),
50 			"%s/usbip_status", udev->path);
51 	if (size < 0 || (unsigned int)size >= sizeof(status_attr_path)) {
52 		err("usbip_status path length %i >= %lu or < 0", size,
53 		    (long unsigned)sizeof(status_attr_path));
54 		return -1;
55 	}
56 
57 
58 	fd = open(status_attr_path, O_RDONLY);
59 	if (fd < 0) {
60 		err("error opening attribute %s", status_attr_path);
61 		return -1;
62 	}
63 
64 	length = read(fd, &status, 1);
65 	if (length < 0) {
66 		err("error reading attribute %s", status_attr_path);
67 		close(fd);
68 		return -1;
69 	}
70 
71 	value = atoi(&status);
72 
73 	return value;
74 }
75 
76 static
77 struct usbip_exported_device *usbip_exported_device_new(
78 		struct usbip_host_driver *hdriver, const char *sdevpath)
79 {
80 	struct usbip_exported_device *edev = NULL;
81 	struct usbip_exported_device *edev_old;
82 	size_t size;
83 	int i;
84 
85 	edev = calloc(1, sizeof(struct usbip_exported_device));
86 
87 	edev->sudev =
88 		udev_device_new_from_syspath(udev_context, sdevpath);
89 	if (!edev->sudev) {
90 		err("udev_device_new_from_syspath: %s", sdevpath);
91 		goto err;
92 	}
93 
94 	if (hdriver->ops.read_device(edev->sudev, &edev->udev) < 0)
95 		goto err;
96 
97 	edev->status = read_attr_usbip_status(&edev->udev);
98 	if (edev->status < 0)
99 		goto err;
100 
101 	/* reallocate buffer to include usb interface data */
102 	size = sizeof(struct usbip_exported_device) +
103 		edev->udev.bNumInterfaces * sizeof(struct usbip_usb_interface);
104 
105 	edev_old = edev;
106 	edev = realloc(edev, size);
107 	if (!edev) {
108 		edev = edev_old;
109 		dbg("realloc failed");
110 		goto err;
111 	}
112 
113 	for (i = 0; i < edev->udev.bNumInterfaces; i++) {
114 		/* vudc does not support reading interfaces */
115 		if (!hdriver->ops.read_interface)
116 			break;
117 		hdriver->ops.read_interface(&edev->udev, i, &edev->uinf[i]);
118 	}
119 
120 	return edev;
121 err:
122 	if (edev->sudev)
123 		udev_device_unref(edev->sudev);
124 	if (edev)
125 		free(edev);
126 
127 	return NULL;
128 }
129 
130 static int refresh_exported_devices(struct usbip_host_driver *hdriver)
131 {
132 	struct usbip_exported_device *edev;
133 	struct udev_enumerate *enumerate;
134 	struct udev_list_entry *devices, *dev_list_entry;
135 	struct udev_device *dev;
136 	const char *path;
137 
138 	enumerate = udev_enumerate_new(udev_context);
139 	udev_enumerate_add_match_subsystem(enumerate, hdriver->udev_subsystem);
140 	udev_enumerate_scan_devices(enumerate);
141 
142 	devices = udev_enumerate_get_list_entry(enumerate);
143 
144 	udev_list_entry_foreach(dev_list_entry, devices) {
145 		path = udev_list_entry_get_name(dev_list_entry);
146 		dev = udev_device_new_from_syspath(udev_context,
147 						   path);
148 		if (dev == NULL)
149 			continue;
150 
151 		/* Check whether device uses usbip driver. */
152 		if (hdriver->ops.is_my_device(dev)) {
153 			edev = usbip_exported_device_new(hdriver, path);
154 			if (!edev) {
155 				dbg("usbip_exported_device_new failed");
156 				continue;
157 			}
158 
159 			list_add(&edev->node, &hdriver->edev_list);
160 			hdriver->ndevs++;
161 		}
162 	}
163 
164 	return 0;
165 }
166 
167 static void usbip_exported_device_destroy(struct list_head *devs)
168 {
169 	struct list_head *i, *tmp;
170 	struct usbip_exported_device *edev;
171 
172 	list_for_each_safe(i, tmp, devs) {
173 		edev = list_entry(i, struct usbip_exported_device, node);
174 		list_del(i);
175 		free(edev);
176 	}
177 }
178 
179 int usbip_generic_driver_open(struct usbip_host_driver *hdriver)
180 {
181 	int rc;
182 
183 	udev_context = udev_new();
184 	if (!udev_context) {
185 		err("udev_new failed");
186 		return -1;
187 	}
188 
189 	rc = refresh_exported_devices(hdriver);
190 	if (rc < 0)
191 		goto err;
192 	return 0;
193 err:
194 	udev_unref(udev_context);
195 	return -1;
196 }
197 
198 void usbip_generic_driver_close(struct usbip_host_driver *hdriver)
199 {
200 	if (!hdriver)
201 		return;
202 
203 	usbip_exported_device_destroy(&hdriver->edev_list);
204 
205 	udev_unref(udev_context);
206 }
207 
208 int usbip_generic_refresh_device_list(struct usbip_host_driver *hdriver)
209 {
210 	int rc;
211 
212 	usbip_exported_device_destroy(&hdriver->edev_list);
213 
214 	hdriver->ndevs = 0;
215 	INIT_LIST_HEAD(&hdriver->edev_list);
216 
217 	rc = refresh_exported_devices(hdriver);
218 	if (rc < 0)
219 		return -1;
220 
221 	return 0;
222 }
223 
224 int usbip_export_device(struct usbip_exported_device *edev, int sockfd)
225 {
226 	char attr_name[] = "usbip_sockfd";
227 	char sockfd_attr_path[SYSFS_PATH_MAX];
228 	int size;
229 	char sockfd_buff[30];
230 	int ret;
231 
232 	if (edev->status != SDEV_ST_AVAILABLE) {
233 		dbg("device not available: %s", edev->udev.busid);
234 		switch (edev->status) {
235 		case SDEV_ST_ERROR:
236 			dbg("status SDEV_ST_ERROR");
237 			ret = ST_DEV_ERR;
238 			break;
239 		case SDEV_ST_USED:
240 			dbg("status SDEV_ST_USED");
241 			ret = ST_DEV_BUSY;
242 			break;
243 		default:
244 			dbg("status unknown: 0x%x", edev->status);
245 			ret = -1;
246 		}
247 		return ret;
248 	}
249 
250 	/* only the first interface is true */
251 	size = snprintf(sockfd_attr_path, sizeof(sockfd_attr_path), "%s/%s",
252 			edev->udev.path, attr_name);
253 	if (size < 0 || (unsigned int)size >= sizeof(sockfd_attr_path)) {
254 		err("exported device path length %i >= %lu or < 0", size,
255 		    (long unsigned)sizeof(sockfd_attr_path));
256 		return -1;
257 	}
258 
259 	size = snprintf(sockfd_buff, sizeof(sockfd_buff), "%d\n", sockfd);
260 	if (size < 0 || (unsigned int)size >= sizeof(sockfd_buff)) {
261 		err("socket length %i >= %lu or < 0", size,
262 		    (long unsigned)sizeof(sockfd_buff));
263 		return -1;
264 	}
265 
266 	ret = write_sysfs_attribute(sockfd_attr_path, sockfd_buff,
267 				    strlen(sockfd_buff));
268 	if (ret < 0) {
269 		err("write_sysfs_attribute failed: sockfd %s to %s",
270 		    sockfd_buff, sockfd_attr_path);
271 		return ret;
272 	}
273 
274 	info("connect: %s", edev->udev.busid);
275 
276 	return ret;
277 }
278 
279 struct usbip_exported_device *usbip_generic_get_device(
280 		struct usbip_host_driver *hdriver, int num)
281 {
282 	struct list_head *i;
283 	struct usbip_exported_device *edev;
284 	int cnt = 0;
285 
286 	list_for_each(i, &hdriver->edev_list) {
287 		edev = list_entry(i, struct usbip_exported_device, node);
288 		if (num == cnt)
289 			return edev;
290 		cnt++;
291 	}
292 
293 	return NULL;
294 }
295