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 fd;
44 	int length;
45 	char status;
46 	int value = 0;
47 
48 	snprintf(status_attr_path, SYSFS_PATH_MAX, "%s/usbip_status",
49 		 udev->path);
50 
51 	fd = open(status_attr_path, O_RDONLY);
52 	if (fd < 0) {
53 		err("error opening attribute %s", status_attr_path);
54 		return -1;
55 	}
56 
57 	length = read(fd, &status, 1);
58 	if (length < 0) {
59 		err("error reading attribute %s", status_attr_path);
60 		close(fd);
61 		return -1;
62 	}
63 
64 	value = atoi(&status);
65 
66 	return value;
67 }
68 
69 static
70 struct usbip_exported_device *usbip_exported_device_new(
71 		struct usbip_host_driver *hdriver, const char *sdevpath)
72 {
73 	struct usbip_exported_device *edev = NULL;
74 	struct usbip_exported_device *edev_old;
75 	size_t size;
76 	int i;
77 
78 	edev = calloc(1, sizeof(struct usbip_exported_device));
79 
80 	edev->sudev =
81 		udev_device_new_from_syspath(udev_context, sdevpath);
82 	if (!edev->sudev) {
83 		err("udev_device_new_from_syspath: %s", sdevpath);
84 		goto err;
85 	}
86 
87 	if (hdriver->ops.read_device(edev->sudev, &edev->udev) < 0)
88 		goto err;
89 
90 	edev->status = read_attr_usbip_status(&edev->udev);
91 	if (edev->status < 0)
92 		goto err;
93 
94 	/* reallocate buffer to include usb interface data */
95 	size = sizeof(struct usbip_exported_device) +
96 		edev->udev.bNumInterfaces * sizeof(struct usbip_usb_interface);
97 
98 	edev_old = edev;
99 	edev = realloc(edev, size);
100 	if (!edev) {
101 		edev = edev_old;
102 		dbg("realloc failed");
103 		goto err;
104 	}
105 
106 	for (i = 0; i < edev->udev.bNumInterfaces; i++) {
107 		/* vudc does not support reading interfaces */
108 		if (!hdriver->ops.read_interface)
109 			break;
110 		hdriver->ops.read_interface(&edev->udev, i, &edev->uinf[i]);
111 	}
112 
113 	return edev;
114 err:
115 	if (edev->sudev)
116 		udev_device_unref(edev->sudev);
117 	if (edev)
118 		free(edev);
119 
120 	return NULL;
121 }
122 
123 static int refresh_exported_devices(struct usbip_host_driver *hdriver)
124 {
125 	struct usbip_exported_device *edev;
126 	struct udev_enumerate *enumerate;
127 	struct udev_list_entry *devices, *dev_list_entry;
128 	struct udev_device *dev;
129 	const char *path;
130 
131 	enumerate = udev_enumerate_new(udev_context);
132 	udev_enumerate_add_match_subsystem(enumerate, hdriver->udev_subsystem);
133 	udev_enumerate_scan_devices(enumerate);
134 
135 	devices = udev_enumerate_get_list_entry(enumerate);
136 
137 	udev_list_entry_foreach(dev_list_entry, devices) {
138 		path = udev_list_entry_get_name(dev_list_entry);
139 		dev = udev_device_new_from_syspath(udev_context,
140 						   path);
141 		if (dev == NULL)
142 			continue;
143 
144 		/* Check whether device uses usbip driver. */
145 		if (hdriver->ops.is_my_device(dev)) {
146 			edev = usbip_exported_device_new(hdriver, path);
147 			if (!edev) {
148 				dbg("usbip_exported_device_new failed");
149 				continue;
150 			}
151 
152 			list_add(&edev->node, &hdriver->edev_list);
153 			hdriver->ndevs++;
154 		}
155 	}
156 
157 	return 0;
158 }
159 
160 static void usbip_exported_device_destroy(struct list_head *devs)
161 {
162 	struct list_head *i, *tmp;
163 	struct usbip_exported_device *edev;
164 
165 	list_for_each_safe(i, tmp, devs) {
166 		edev = list_entry(i, struct usbip_exported_device, node);
167 		list_del(i);
168 		free(edev);
169 	}
170 }
171 
172 int usbip_generic_driver_open(struct usbip_host_driver *hdriver)
173 {
174 	int rc;
175 
176 	udev_context = udev_new();
177 	if (!udev_context) {
178 		err("udev_new failed");
179 		return -1;
180 	}
181 
182 	rc = refresh_exported_devices(hdriver);
183 	if (rc < 0)
184 		goto err;
185 	return 0;
186 err:
187 	udev_unref(udev_context);
188 	return -1;
189 }
190 
191 void usbip_generic_driver_close(struct usbip_host_driver *hdriver)
192 {
193 	if (!hdriver)
194 		return;
195 
196 	usbip_exported_device_destroy(&hdriver->edev_list);
197 
198 	udev_unref(udev_context);
199 }
200 
201 int usbip_generic_refresh_device_list(struct usbip_host_driver *hdriver)
202 {
203 	int rc;
204 
205 	usbip_exported_device_destroy(&hdriver->edev_list);
206 
207 	hdriver->ndevs = 0;
208 	INIT_LIST_HEAD(&hdriver->edev_list);
209 
210 	rc = refresh_exported_devices(hdriver);
211 	if (rc < 0)
212 		return -1;
213 
214 	return 0;
215 }
216 
217 int usbip_export_device(struct usbip_exported_device *edev, int sockfd)
218 {
219 	char attr_name[] = "usbip_sockfd";
220 	char sockfd_attr_path[SYSFS_PATH_MAX];
221 	char sockfd_buff[30];
222 	int ret;
223 
224 	if (edev->status != SDEV_ST_AVAILABLE) {
225 		dbg("device not available: %s", edev->udev.busid);
226 		switch (edev->status) {
227 		case SDEV_ST_ERROR:
228 			dbg("status SDEV_ST_ERROR");
229 			break;
230 		case SDEV_ST_USED:
231 			dbg("status SDEV_ST_USED");
232 			break;
233 		default:
234 			dbg("status unknown: 0x%x", edev->status);
235 		}
236 		return -1;
237 	}
238 
239 	/* only the first interface is true */
240 	snprintf(sockfd_attr_path, sizeof(sockfd_attr_path), "%s/%s",
241 		 edev->udev.path, attr_name);
242 
243 	snprintf(sockfd_buff, sizeof(sockfd_buff), "%d\n", sockfd);
244 
245 	ret = write_sysfs_attribute(sockfd_attr_path, sockfd_buff,
246 				    strlen(sockfd_buff));
247 	if (ret < 0) {
248 		err("write_sysfs_attribute failed: sockfd %s to %s",
249 		    sockfd_buff, sockfd_attr_path);
250 		return ret;
251 	}
252 
253 	info("connect: %s", edev->udev.busid);
254 
255 	return ret;
256 }
257 
258 struct usbip_exported_device *usbip_generic_get_device(
259 		struct usbip_host_driver *hdriver, int num)
260 {
261 	struct list_head *i;
262 	struct usbip_exported_device *edev;
263 	int cnt = 0;
264 
265 	list_for_each(i, &hdriver->edev_list) {
266 		edev = list_entry(i, struct usbip_exported_device, node);
267 		if (num == cnt)
268 			return edev;
269 		cnt++;
270 	}
271 
272 	return NULL;
273 }
274