xref: /linux/tools/usb/usbip/libsrc/usbip_host_common.c (revision cfcd7b29e5191f5ff097f7c278188face0c79ab7)
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 extern 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 	if (hdriver->ndevs == 0)
153 		info("Please load appropriate modules or export devices.");
154 
155 	return 0;
156 }
157 
158 static void usbip_exported_device_destroy(struct list_head *devs)
159 {
160 	struct list_head *i, *tmp;
161 	struct usbip_exported_device *edev;
162 
163 	list_for_each_safe(i, tmp, devs) {
164 		edev = list_entry(i, struct usbip_exported_device, node);
165 		list_del(i);
166 		free(edev);
167 	}
168 }
169 
170 int usbip_generic_driver_open(struct usbip_host_driver *hdriver)
171 {
172 	int rc;
173 
174 	udev_context = udev_new();
175 	if (!udev_context) {
176 		err("udev_new failed");
177 		return -1;
178 	}
179 
180 	rc = refresh_exported_devices(hdriver);
181 	if (rc < 0)
182 		goto err;
183 	return 0;
184 err:
185 	udev_unref(udev_context);
186 	return -1;
187 }
188 
189 void usbip_generic_driver_close(struct usbip_host_driver *hdriver)
190 {
191 	if (!hdriver)
192 		return;
193 
194 	usbip_exported_device_destroy(&hdriver->edev_list);
195 
196 	udev_unref(udev_context);
197 }
198 
199 int usbip_generic_refresh_device_list(struct usbip_host_driver *hdriver)
200 {
201 	int rc;
202 
203 	usbip_exported_device_destroy(&hdriver->edev_list);
204 
205 	hdriver->ndevs = 0;
206 	INIT_LIST_HEAD(&hdriver->edev_list);
207 
208 	rc = refresh_exported_devices(hdriver);
209 	if (rc < 0)
210 		return -1;
211 
212 	return 0;
213 }
214 
215 int usbip_export_device(struct usbip_exported_device *edev, int sockfd)
216 {
217 	char attr_name[] = "usbip_sockfd";
218 	char sockfd_attr_path[SYSFS_PATH_MAX];
219 	int size;
220 	char sockfd_buff[30];
221 	int ret;
222 
223 	if (edev->status != SDEV_ST_AVAILABLE) {
224 		dbg("device not available: %s", edev->udev.busid);
225 		switch (edev->status) {
226 		case SDEV_ST_ERROR:
227 			dbg("status SDEV_ST_ERROR");
228 			ret = ST_DEV_ERR;
229 			break;
230 		case SDEV_ST_USED:
231 			dbg("status SDEV_ST_USED");
232 			ret = ST_DEV_BUSY;
233 			break;
234 		default:
235 			dbg("status unknown: 0x%x", edev->status);
236 			ret = -1;
237 		}
238 		return ret;
239 	}
240 
241 	/* only the first interface is true */
242 	size = snprintf(sockfd_attr_path, sizeof(sockfd_attr_path), "%s/%s",
243 			edev->udev.path, attr_name);
244 	if (size < 0 || (unsigned int)size >= sizeof(sockfd_attr_path)) {
245 		err("exported device path length %i >= %lu or < 0", size,
246 		    (long unsigned)sizeof(sockfd_attr_path));
247 		return -1;
248 	}
249 
250 	size = snprintf(sockfd_buff, sizeof(sockfd_buff), "%d\n", sockfd);
251 	if (size < 0 || (unsigned int)size >= sizeof(sockfd_buff)) {
252 		err("socket length %i >= %lu or < 0", size,
253 		    (long unsigned)sizeof(sockfd_buff));
254 		return -1;
255 	}
256 
257 	ret = write_sysfs_attribute(sockfd_attr_path, sockfd_buff,
258 				    strlen(sockfd_buff));
259 	if (ret < 0) {
260 		err("write_sysfs_attribute failed: sockfd %s to %s",
261 		    sockfd_buff, sockfd_attr_path);
262 		return ret;
263 	}
264 
265 	info("connect: %s", edev->udev.busid);
266 
267 	return ret;
268 }
269 
270 struct usbip_exported_device *usbip_generic_get_device(
271 		struct usbip_host_driver *hdriver, int num)
272 {
273 	struct list_head *i;
274 	struct usbip_exported_device *edev;
275 	int cnt = 0;
276 
277 	list_for_each(i, &hdriver->edev_list) {
278 		edev = list_entry(i, struct usbip_exported_device, node);
279 		if (num == cnt)
280 			return edev;
281 		cnt++;
282 	}
283 
284 	return NULL;
285 }
286