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 <sysfs/libsysfs.h>
20
21 #include <errno.h>
22 #include <stdio.h>
23 #include <string.h>
24
25 #include <getopt.h>
26
27 #include "usbip_common.h"
28 #include "utils.h"
29 #include "usbip.h"
30
31 static const char usbip_unbind_usage_string[] =
32 "usbip unbind <args>\n"
33 " -b, --busid=<busid> Unbind " USBIP_HOST_DRV_NAME ".ko from "
34 "device on <busid>\n";
35
usbip_unbind_usage(void)36 void usbip_unbind_usage(void)
37 {
38 printf("usage: %s", usbip_unbind_usage_string);
39 }
40
unbind_device(char * busid)41 static int unbind_device(char *busid)
42 {
43 char bus_type[] = "usb";
44 struct sysfs_driver *usbip_host_drv;
45 struct sysfs_device *dev;
46 struct dlist *devlist;
47 int verified = 0;
48 int rc, ret = -1;
49
50 char attr_name[] = "bConfigurationValue";
51 char sysfs_mntpath[SYSFS_PATH_MAX];
52 char busid_attr_path[SYSFS_PATH_MAX];
53 struct sysfs_attribute *busid_attr;
54 char *val = NULL;
55 int len;
56
57 /* verify the busid device is using usbip-host */
58 usbip_host_drv = sysfs_open_driver(bus_type, USBIP_HOST_DRV_NAME);
59 if (!usbip_host_drv) {
60 err("could not open %s driver: %s", USBIP_HOST_DRV_NAME,
61 strerror(errno));
62 return -1;
63 }
64
65 devlist = sysfs_get_driver_devices(usbip_host_drv);
66 if (!devlist) {
67 err("%s is not in use by any devices", USBIP_HOST_DRV_NAME);
68 goto err_close_usbip_host_drv;
69 }
70
71 dlist_for_each_data(devlist, dev, struct sysfs_device) {
72 if (!strncmp(busid, dev->name, strlen(busid)) &&
73 !strncmp(dev->driver_name, USBIP_HOST_DRV_NAME,
74 strlen(USBIP_HOST_DRV_NAME))) {
75 verified = 1;
76 break;
77 }
78 }
79
80 if (!verified) {
81 err("device on busid %s is not using %s", busid,
82 USBIP_HOST_DRV_NAME);
83 goto err_close_usbip_host_drv;
84 }
85
86 /*
87 * NOTE: A read and write of an attribute value of the device busid
88 * refers to must be done to start probing. That way a rebind of the
89 * default driver for the device occurs.
90 *
91 * This seems very hackish and adds a lot of pointless code. I think it
92 * should be done in the kernel by the driver after del_match_busid is
93 * finished!
94 */
95
96 rc = sysfs_get_mnt_path(sysfs_mntpath, SYSFS_PATH_MAX);
97 if (rc < 0) {
98 err("sysfs must be mounted: %s", strerror(errno));
99 return -1;
100 }
101
102 snprintf(busid_attr_path, sizeof(busid_attr_path), "%s/%s/%s/%s/%s/%s",
103 sysfs_mntpath, SYSFS_BUS_NAME, bus_type, SYSFS_DEVICES_NAME,
104 busid, attr_name);
105
106 /* read a device attribute */
107 busid_attr = sysfs_open_attribute(busid_attr_path);
108 if (!busid_attr) {
109 err("could not open %s/%s: %s", busid, attr_name,
110 strerror(errno));
111 return -1;
112 }
113
114 if (sysfs_read_attribute(busid_attr) < 0) {
115 err("problem reading attribute: %s", strerror(errno));
116 goto err_out;
117 }
118
119 len = busid_attr->len;
120 val = malloc(len);
121 *val = *busid_attr->value;
122 sysfs_close_attribute(busid_attr);
123
124 /* notify driver of unbind */
125 rc = modify_match_busid(busid, 0);
126 if (rc < 0) {
127 err("unable to unbind device on %s", busid);
128 goto err_out;
129 }
130
131 /* write the device attribute */
132 busid_attr = sysfs_open_attribute(busid_attr_path);
133 if (!busid_attr) {
134 err("could not open %s/%s: %s", busid, attr_name,
135 strerror(errno));
136 return -1;
137 }
138
139 rc = sysfs_write_attribute(busid_attr, val, len);
140 if (rc < 0) {
141 err("problem writing attribute: %s", strerror(errno));
142 goto err_out;
143 }
144 sysfs_close_attribute(busid_attr);
145
146 ret = 0;
147 printf("unbind device on busid %s: complete\n", busid);
148
149 err_out:
150 free(val);
151 err_close_usbip_host_drv:
152 sysfs_close_driver(usbip_host_drv);
153
154 return ret;
155 }
156
usbip_unbind(int argc,char * argv[])157 int usbip_unbind(int argc, char *argv[])
158 {
159 static const struct option opts[] = {
160 { "busid", required_argument, NULL, 'b' },
161 { NULL, 0, NULL, 0 }
162 };
163
164 int opt;
165 int ret = -1;
166
167 for (;;) {
168 opt = getopt_long(argc, argv, "b:", opts, NULL);
169
170 if (opt == -1)
171 break;
172
173 switch (opt) {
174 case 'b':
175 ret = unbind_device(optarg);
176 goto out;
177 default:
178 goto err_out;
179 }
180 }
181
182 err_out:
183 usbip_unbind_usage();
184 out:
185 return ret;
186 }
187