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 <libudev.h>
20
21#include <errno.h>
22#include <stdio.h>
23#include <stdlib.h>
24#include <string.h>
25
26#include <getopt.h>
27
28#include "usbip_common.h"
29#include "utils.h"
30#include "usbip.h"
31#include "sysfs_utils.h"
32
33enum unbind_status {
34	UNBIND_ST_OK,
35	UNBIND_ST_USBIP_HOST,
36	UNBIND_ST_FAILED
37};
38
39static const char usbip_bind_usage_string[] =
40	"usbip bind <args>\n"
41	"    -b, --busid=<busid>    Bind " USBIP_HOST_DRV_NAME ".ko to device "
42	"on <busid>\n";
43
44void usbip_bind_usage(void)
45{
46	printf("usage: %s", usbip_bind_usage_string);
47}
48
49/* call at unbound state */
50static int bind_usbip(char *busid)
51{
52	char attr_name[] = "bind";
53	char bind_attr_path[SYSFS_PATH_MAX];
54	int rc = -1;
55
56	snprintf(bind_attr_path, sizeof(bind_attr_path), "%s/%s/%s/%s/%s/%s",
57		 SYSFS_MNT_PATH, SYSFS_BUS_NAME, SYSFS_BUS_TYPE,
58		 SYSFS_DRIVERS_NAME, USBIP_HOST_DRV_NAME, attr_name);
59
60	rc = write_sysfs_attribute(bind_attr_path, busid, strlen(busid));
61	if (rc < 0) {
62		err("error binding device %s to driver: %s", busid,
63		    strerror(errno));
64		return -1;
65	}
66
67	return 0;
68}
69
70/* buggy driver may cause dead lock */
71static int unbind_other(char *busid)
72{
73	enum unbind_status status = UNBIND_ST_OK;
74
75	char attr_name[] = "unbind";
76	char unbind_attr_path[SYSFS_PATH_MAX];
77	int rc = -1;
78
79	struct udev *udev;
80	struct udev_device *dev;
81	const char *driver;
82	const char *bDevClass;
83
84	/* Create libudev context. */
85	udev = udev_new();
86
87	/* Get the device. */
88	dev = udev_device_new_from_subsystem_sysname(udev, "usb", busid);
89	if (!dev) {
90		dbg("unable to find device with bus ID %s", busid);
91		goto err_close_busid_dev;
92	}
93
94	/* Check what kind of device it is. */
95	bDevClass  = udev_device_get_sysattr_value(dev, "bDeviceClass");
96	if (!bDevClass) {
97		dbg("unable to get bDevClass device attribute");
98		goto err_close_busid_dev;
99	}
100
101	if (!strncmp(bDevClass, "09", strlen(bDevClass))) {
102		dbg("skip unbinding of hub");
103		goto err_close_busid_dev;
104	}
105
106	/* Get the device driver. */
107	driver = udev_device_get_driver(dev);
108	if (!driver) {
109		/* No driver bound to this device. */
110		goto out;
111	}
112
113	if (!strncmp(USBIP_HOST_DRV_NAME, driver,
114				strlen(USBIP_HOST_DRV_NAME))) {
115		/* Already bound to usbip-host. */
116		status = UNBIND_ST_USBIP_HOST;
117		goto out;
118	}
119
120	/* Unbind device from driver. */
121	snprintf(unbind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",
122		 SYSFS_MNT_PATH, SYSFS_BUS_NAME, SYSFS_BUS_TYPE,
123		 SYSFS_DRIVERS_NAME, driver, attr_name);
124
125	rc = write_sysfs_attribute(unbind_attr_path, busid, strlen(busid));
126	if (rc < 0) {
127		err("error unbinding device %s from driver", busid);
128		goto err_close_busid_dev;
129	}
130
131	goto out;
132
133err_close_busid_dev:
134	status = UNBIND_ST_FAILED;
135out:
136	udev_device_unref(dev);
137	udev_unref(udev);
138
139	return status;
140}
141
142static int bind_device(char *busid)
143{
144	int rc;
145	struct udev *udev;
146	struct udev_device *dev;
147
148	/* Check whether the device with this bus ID exists. */
149	udev = udev_new();
150	dev = udev_device_new_from_subsystem_sysname(udev, "usb", busid);
151	if (!dev) {
152		err("device with the specified bus ID does not exist");
153		return -1;
154	}
155	udev_unref(udev);
156
157	rc = unbind_other(busid);
158	if (rc == UNBIND_ST_FAILED) {
159		err("could not unbind driver from device on busid %s", busid);
160		return -1;
161	} else if (rc == UNBIND_ST_USBIP_HOST) {
162		err("device on busid %s is already bound to %s", busid,
163		    USBIP_HOST_DRV_NAME);
164		return -1;
165	}
166
167	rc = modify_match_busid(busid, 1);
168	if (rc < 0) {
169		err("unable to bind device on %s", busid);
170		return -1;
171	}
172
173	rc = bind_usbip(busid);
174	if (rc < 0) {
175		err("could not bind device to %s", USBIP_HOST_DRV_NAME);
176		modify_match_busid(busid, 0);
177		return -1;
178	}
179
180	info("bind device on busid %s: complete", busid);
181
182	return 0;
183}
184
185int usbip_bind(int argc, char *argv[])
186{
187	static const struct option opts[] = {
188		{ "busid", required_argument, NULL, 'b' },
189		{ NULL,    0,                 NULL,  0  }
190	};
191
192	int opt;
193	int ret = -1;
194
195	for (;;) {
196		opt = getopt_long(argc, argv, "b:", opts, NULL);
197
198		if (opt == -1)
199			break;
200
201		switch (opt) {
202		case 'b':
203			ret = bind_device(optarg);
204			goto out;
205		default:
206			goto err_out;
207		}
208	}
209
210err_out:
211	usbip_bind_usage();
212out:
213	return ret;
214}
215