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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2011 matt mooney <[email protected]>
4 * 2005-2007 Takahiro Hirofuchi
5 */
6
7#include <libudev.h>
8
9#include <errno.h>
10#include <stdio.h>
11#include <stdlib.h>
12#include <string.h>
13
14#include <getopt.h>
15
16#include "usbip_common.h"
17#include "utils.h"
18#include "usbip.h"
19#include "sysfs_utils.h"
20
21enum unbind_status {
22 UNBIND_ST_OK,
23 UNBIND_ST_USBIP_HOST,
24 UNBIND_ST_FAILED
25};
26
27static const char usbip_bind_usage_string[] =
28 "usbip bind <args>\n"
29 " -b, --busid=<busid> Bind " USBIP_HOST_DRV_NAME ".ko to device "
30 "on <busid>\n";
31
32void usbip_bind_usage(void)
33{
34 printf("usage: %s", usbip_bind_usage_string);
35}
36
37/* call at unbound state */
38static int bind_usbip(char *busid)
39{
40 char attr_name[] = "bind";
41 char bind_attr_path[SYSFS_PATH_MAX];
42 int rc = -1;
43
44 snprintf(bind_attr_path, sizeof(bind_attr_path), "%s/%s/%s/%s/%s/%s",
45 SYSFS_MNT_PATH, SYSFS_BUS_NAME, SYSFS_BUS_TYPE,
46 SYSFS_DRIVERS_NAME, USBIP_HOST_DRV_NAME, attr_name);
47
48 rc = write_sysfs_attribute(bind_attr_path, busid, strlen(busid));
49 if (rc < 0) {
50 err("error binding device %s to driver: %s", busid,
51 strerror(errno));
52 return -1;
53 }
54
55 return 0;
56}
57
58/* buggy driver may cause dead lock */
59static int unbind_other(char *busid)
60{
61 enum unbind_status status = UNBIND_ST_OK;
62
63 char attr_name[] = "unbind";
64 char unbind_attr_path[SYSFS_PATH_MAX];
65 int rc = -1;
66
67 struct udev *udev;
68 struct udev_device *dev;
69 const char *driver;
70 const char *bDevClass;
71
72 /* Create libudev context. */
73 udev = udev_new();
74
75 /* Get the device. */
76 dev = udev_device_new_from_subsystem_sysname(udev, "usb", busid);
77 if (!dev) {
78 dbg("unable to find device with bus ID %s", busid);
79 goto err_close_busid_dev;
80 }
81
82 /* Check what kind of device it is. */
83 bDevClass = udev_device_get_sysattr_value(dev, "bDeviceClass");
84 if (!bDevClass) {
85 dbg("unable to get bDevClass device attribute");
86 goto err_close_busid_dev;
87 }
88
89 if (!strncmp(bDevClass, "09", strlen(bDevClass))) {
90 dbg("skip unbinding of hub");
91 goto err_close_busid_dev;
92 }
93
94 /* Get the device driver. */
95 driver = udev_device_get_driver(dev);
96 if (!driver) {
97 /* No driver bound to this device. */
98 goto out;
99 }
100
101 if (!strncmp(USBIP_HOST_DRV_NAME, driver,
102 strlen(USBIP_HOST_DRV_NAME))) {
103 /* Already bound to usbip-host. */
104 status = UNBIND_ST_USBIP_HOST;
105 goto out;
106 }
107
108 /* Unbind device from driver. */
109 snprintf(unbind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",
110 SYSFS_MNT_PATH, SYSFS_BUS_NAME, SYSFS_BUS_TYPE,
111 SYSFS_DRIVERS_NAME, driver, attr_name);
112
113 rc = write_sysfs_attribute(unbind_attr_path, busid, strlen(busid));
114 if (rc < 0) {
115 err("error unbinding device %s from driver", busid);
116 goto err_close_busid_dev;
117 }
118
119 goto out;
120
121err_close_busid_dev:
122 status = UNBIND_ST_FAILED;
123out:
124 udev_device_unref(dev);
125 udev_unref(udev);
126
127 return status;
128}
129
130static int bind_device(char *busid)
131{
132 int rc;
133 struct udev *udev;
134 struct udev_device *dev;
135 const char *devpath;
136
137 /* Check whether the device with this bus ID exists. */
138 udev = udev_new();
139 dev = udev_device_new_from_subsystem_sysname(udev, "usb", busid);
140 if (!dev) {
141 err("device with the specified bus ID does not exist");
142 return -1;
143 }
144 devpath = udev_device_get_devpath(dev);
145 udev_unref(udev);
146
147 /* If the device is already attached to vhci_hcd - bail out */
148 if (strstr(devpath, USBIP_VHCI_DRV_NAME)) {
149 err("bind loop detected: device: %s is attached to %s\n",
150 devpath, USBIP_VHCI_DRV_NAME);
151 return -1;
152 }
153
154 rc = unbind_other(busid);
155 if (rc == UNBIND_ST_FAILED) {
156 err("could not unbind driver from device on busid %s", busid);
157 return -1;
158 } else if (rc == UNBIND_ST_USBIP_HOST) {
159 err("device on busid %s is already bound to %s", busid,
160 USBIP_HOST_DRV_NAME);
161 return -1;
162 }
163
164 rc = modify_match_busid(busid, 1);
165 if (rc < 0) {
166 err("unable to bind device on %s", busid);
167 return -1;
168 }
169
170 rc = bind_usbip(busid);
171 if (rc < 0) {
172 err("could not bind device to %s", USBIP_HOST_DRV_NAME);
173 modify_match_busid(busid, 0);
174 return -1;
175 }
176
177 info("bind device on busid %s: complete", busid);
178
179 return 0;
180}
181
182int usbip_bind(int argc, char *argv[])
183{
184 static const struct option opts[] = {
185 { "busid", required_argument, NULL, 'b' },
186 { NULL, 0, NULL, 0 }
187 };
188
189 int opt;
190 int ret = -1;
191
192 for (;;) {
193 opt = getopt_long(argc, argv, "b:", opts, NULL);
194
195 if (opt == -1)
196 break;
197
198 switch (opt) {
199 case 'b':
200 ret = bind_device(optarg);
201 goto out;
202 default:
203 goto err_out;
204 }
205 }
206
207err_out:
208 usbip_bind_usage();
209out:
210 return ret;
211}