1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2011 matt mooney <mfm@muteddisk.com>
4 *               2005-2007 Takahiro Hirofuchi
5 */
6
7#include <libudev.h>
8
9#include <errno.h>
10#include <stdio.h>
11#include <string.h>
12
13#include <getopt.h>
14
15#include "usbip_common.h"
16#include "utils.h"
17#include "usbip.h"
18#include "sysfs_utils.h"
19
20static const char usbip_unbind_usage_string[] =
21	"usbip unbind <args>\n"
22	"    -b, --busid=<busid>    Unbind " USBIP_HOST_DRV_NAME ".ko from "
23	"device on <busid>\n";
24
25void usbip_unbind_usage(void)
26{
27	printf("usage: %s", usbip_unbind_usage_string);
28}
29
30static int unbind_device(char *busid)
31{
32	char bus_type[] = "usb";
33	int rc, ret = -1;
34
35	char unbind_attr_name[] = "unbind";
36	char unbind_attr_path[SYSFS_PATH_MAX];
37	char rebind_attr_name[] = "rebind";
38	char rebind_attr_path[SYSFS_PATH_MAX];
39
40	struct udev *udev;
41	struct udev_device *dev;
42	const char *driver;
43
44	/* Create libudev context. */
45	udev = udev_new();
46
47	/* Check whether the device with this bus ID exists. */
48	dev = udev_device_new_from_subsystem_sysname(udev, "usb", busid);
49	if (!dev) {
50		err("device with the specified bus ID does not exist");
51		goto err_close_udev;
52	}
53
54	/* Check whether the device is using usbip-host driver. */
55	driver = udev_device_get_driver(dev);
56	if (!driver || strcmp(driver, "usbip-host")) {
57		err("device is not bound to usbip-host driver");
58		goto err_close_udev;
59	}
60
61	/* Unbind device from driver. */
62	snprintf(unbind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",
63		 SYSFS_MNT_PATH, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,
64		 USBIP_HOST_DRV_NAME, unbind_attr_name);
65
66	rc = write_sysfs_attribute(unbind_attr_path, busid, strlen(busid));
67	if (rc < 0) {
68		err("error unbinding device %s from driver", busid);
69		goto err_close_udev;
70	}
71
72	/* Notify driver of unbind. */
73	rc = modify_match_busid(busid, 0);
74	if (rc < 0) {
75		err("unable to unbind device on %s", busid);
76		goto err_close_udev;
77	}
78
79	/* Trigger new probing. */
80	snprintf(rebind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",
81			SYSFS_MNT_PATH, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,
82			USBIP_HOST_DRV_NAME, rebind_attr_name);
83
84	rc = write_sysfs_attribute(rebind_attr_path, busid, strlen(busid));
85	if (rc < 0) {
86		err("error rebinding");
87		goto err_close_udev;
88	}
89
90	ret = 0;
91	info("unbind device on busid %s: complete", busid);
92
93err_close_udev:
94	udev_device_unref(dev);
95	udev_unref(udev);
96
97	return ret;
98}
99
100int usbip_unbind(int argc, char *argv[])
101{
102	static const struct option opts[] = {
103		{ "busid", required_argument, NULL, 'b' },
104		{ NULL,    0,                 NULL,  0  }
105	};
106
107	int opt;
108	int ret = -1;
109
110	for (;;) {
111		opt = getopt_long(argc, argv, "b:", opts, NULL);
112
113		if (opt == -1)
114			break;
115
116		switch (opt) {
117		case 'b':
118			ret = unbind_device(optarg);
119			goto out;
120		default:
121			goto err_out;
122		}
123	}
124
125err_out:
126	usbip_unbind_usage();
127out:
128	return ret;
129}
130