xref: /linux/tools/usb/usbip/libsrc/usbip_host_driver.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
1 /*
2  * Copyright (C) 2011 matt mooney <mfm@muteddisk.com>
3  *               2005-2007 Takahiro Hirofuchi
4  *
5  * This program is free software: you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation, either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program. If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/stat.h>
21 #include <fcntl.h>
22 
23 #include <errno.h>
24 #include <unistd.h>
25 
26 #include <libudev.h>
27 
28 #include "usbip_common.h"
29 #include "usbip_host_driver.h"
30 #include "list.h"
31 #include "sysfs_utils.h"
32 
33 #undef  PROGNAME
34 #define PROGNAME "libusbip"
35 
36 struct usbip_host_driver *host_driver;
37 struct udev *udev_context;
38 
39 static int32_t read_attr_usbip_status(struct usbip_usb_device *udev)
40 {
41 	char status_attr_path[SYSFS_PATH_MAX];
42 	int fd;
43 	int length;
44 	char status;
45 	int value = 0;
46 
47 	snprintf(status_attr_path, SYSFS_PATH_MAX, "%s/usbip_status",
48 		 udev->path);
49 
50 	fd = open(status_attr_path, O_RDONLY);
51 	if (fd < 0) {
52 		err("error opening attribute %s", status_attr_path);
53 		return -1;
54 	}
55 
56 	length = read(fd, &status, 1);
57 	if (length < 0) {
58 		err("error reading attribute %s", status_attr_path);
59 		close(fd);
60 		return -1;
61 	}
62 
63 	value = atoi(&status);
64 
65 	return value;
66 }
67 
68 static
69 struct usbip_exported_device *usbip_exported_device_new(const char *sdevpath)
70 {
71 	struct usbip_exported_device *edev = NULL;
72 	struct usbip_exported_device *edev_old;
73 	size_t size;
74 	int i;
75 
76 	edev = calloc(1, sizeof(struct usbip_exported_device));
77 
78 	edev->sudev = udev_device_new_from_syspath(udev_context, sdevpath);
79 	if (!edev->sudev) {
80 		err("udev_device_new_from_syspath: %s", sdevpath);
81 		goto err;
82 	}
83 
84 	read_usb_device(edev->sudev, &edev->udev);
85 
86 	edev->status = read_attr_usbip_status(&edev->udev);
87 	if (edev->status < 0)
88 		goto err;
89 
90 	/* reallocate buffer to include usb interface data */
91 	size = sizeof(struct usbip_exported_device) +
92 		edev->udev.bNumInterfaces * sizeof(struct usbip_usb_interface);
93 
94 	edev_old = edev;
95 	edev = realloc(edev, size);
96 	if (!edev) {
97 		edev = edev_old;
98 		dbg("realloc failed");
99 		goto err;
100 	}
101 
102 	for (i = 0; i < edev->udev.bNumInterfaces; i++)
103 		read_usb_interface(&edev->udev, i, &edev->uinf[i]);
104 
105 	return edev;
106 err:
107 	if (edev->sudev)
108 		udev_device_unref(edev->sudev);
109 	if (edev)
110 		free(edev);
111 
112 	return NULL;
113 }
114 
115 static int refresh_exported_devices(void)
116 {
117 	struct usbip_exported_device *edev;
118 	struct udev_enumerate *enumerate;
119 	struct udev_list_entry *devices, *dev_list_entry;
120 	struct udev_device *dev;
121 	const char *path;
122 	const char *driver;
123 
124 	enumerate = udev_enumerate_new(udev_context);
125 	udev_enumerate_add_match_subsystem(enumerate, "usb");
126 	udev_enumerate_scan_devices(enumerate);
127 
128 	devices = udev_enumerate_get_list_entry(enumerate);
129 
130 	udev_list_entry_foreach(dev_list_entry, devices) {
131 		path = udev_list_entry_get_name(dev_list_entry);
132 		dev = udev_device_new_from_syspath(udev_context, path);
133 		if (dev == NULL)
134 			continue;
135 
136 		/* Check whether device uses usbip-host driver. */
137 		driver = udev_device_get_driver(dev);
138 		if (driver != NULL && !strcmp(driver, USBIP_HOST_DRV_NAME)) {
139 			edev = usbip_exported_device_new(path);
140 			if (!edev) {
141 				dbg("usbip_exported_device_new failed");
142 				continue;
143 			}
144 
145 			list_add(&edev->node, &host_driver->edev_list);
146 			host_driver->ndevs++;
147 		}
148 	}
149 
150 	return 0;
151 }
152 
153 static void usbip_exported_device_destroy(void)
154 {
155 	struct list_head *i, *tmp;
156 	struct usbip_exported_device *edev;
157 
158 	list_for_each_safe(i, tmp, &host_driver->edev_list) {
159 		edev = list_entry(i, struct usbip_exported_device, node);
160 		list_del(i);
161 		free(edev);
162 	}
163 }
164 
165 int usbip_host_driver_open(void)
166 {
167 	int rc;
168 
169 	udev_context = udev_new();
170 	if (!udev_context) {
171 		err("udev_new failed");
172 		return -1;
173 	}
174 
175 	host_driver = calloc(1, sizeof(*host_driver));
176 
177 	host_driver->ndevs = 0;
178 	INIT_LIST_HEAD(&host_driver->edev_list);
179 
180 	rc = refresh_exported_devices();
181 	if (rc < 0)
182 		goto err_free_host_driver;
183 
184 	return 0;
185 
186 err_free_host_driver:
187 	free(host_driver);
188 	host_driver = NULL;
189 
190 	udev_unref(udev_context);
191 
192 	return -1;
193 }
194 
195 void usbip_host_driver_close(void)
196 {
197 	if (!host_driver)
198 		return;
199 
200 	usbip_exported_device_destroy();
201 
202 	free(host_driver);
203 	host_driver = NULL;
204 
205 	udev_unref(udev_context);
206 }
207 
208 int usbip_host_refresh_device_list(void)
209 {
210 	int rc;
211 
212 	usbip_exported_device_destroy();
213 
214 	host_driver->ndevs = 0;
215 	INIT_LIST_HEAD(&host_driver->edev_list);
216 
217 	rc = refresh_exported_devices();
218 	if (rc < 0)
219 		return -1;
220 
221 	return 0;
222 }
223 
224 int usbip_host_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 	char sockfd_buff[30];
229 	int ret;
230 
231 	if (edev->status != SDEV_ST_AVAILABLE) {
232 		dbg("device not available: %s", edev->udev.busid);
233 		switch (edev->status) {
234 		case SDEV_ST_ERROR:
235 			dbg("status SDEV_ST_ERROR");
236 			break;
237 		case SDEV_ST_USED:
238 			dbg("status SDEV_ST_USED");
239 			break;
240 		default:
241 			dbg("status unknown: 0x%x", edev->status);
242 		}
243 		return -1;
244 	}
245 
246 	/* only the first interface is true */
247 	snprintf(sockfd_attr_path, sizeof(sockfd_attr_path), "%s/%s",
248 		 edev->udev.path, attr_name);
249 
250 	snprintf(sockfd_buff, sizeof(sockfd_buff), "%d\n", sockfd);
251 
252 	ret = write_sysfs_attribute(sockfd_attr_path, sockfd_buff,
253 				    strlen(sockfd_buff));
254 	if (ret < 0) {
255 		err("write_sysfs_attribute failed: sockfd %s to %s",
256 		    sockfd_buff, sockfd_attr_path);
257 		return ret;
258 	}
259 
260 	info("connect: %s", edev->udev.busid);
261 
262 	return ret;
263 }
264 
265 struct usbip_exported_device *usbip_host_get_device(int num)
266 {
267 	struct list_head *i;
268 	struct usbip_exported_device *edev;
269 	int cnt = 0;
270 
271 	list_for_each(i, &host_driver->edev_list) {
272 		edev = list_entry(i, struct usbip_exported_device, node);
273 		if (num == cnt)
274 			return edev;
275 		else
276 			cnt++;
277 	}
278 
279 	return NULL;
280 }
281