xref: /openbmc/linux/tools/usb/usbip/src/usbip_unbind.c (revision aaf9128a)
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 <string.h>
24 
25 #include <getopt.h>
26 
27 #include "usbip_common.h"
28 #include "utils.h"
29 #include "usbip.h"
30 #include "sysfs_utils.h"
31 
32 static const char usbip_unbind_usage_string[] =
33 	"usbip unbind <args>\n"
34 	"    -b, --busid=<busid>    Unbind " USBIP_HOST_DRV_NAME ".ko from "
35 	"device on <busid>\n";
36 
37 void usbip_unbind_usage(void)
38 {
39 	printf("usage: %s", usbip_unbind_usage_string);
40 }
41 
42 static int unbind_device(char *busid)
43 {
44 	char bus_type[] = "usb";
45 	int rc, ret = -1;
46 
47 	char unbind_attr_name[] = "unbind";
48 	char unbind_attr_path[SYSFS_PATH_MAX];
49 	char rebind_attr_name[] = "rebind";
50 	char rebind_attr_path[SYSFS_PATH_MAX];
51 
52 	struct udev *udev;
53 	struct udev_device *dev;
54 	const char *driver;
55 
56 	/* Create libudev context. */
57 	udev = udev_new();
58 
59 	/* Check whether the device with this bus ID exists. */
60 	dev = udev_device_new_from_subsystem_sysname(udev, "usb", busid);
61 	if (!dev) {
62 		err("device with the specified bus ID does not exist");
63 		goto err_close_udev;
64 	}
65 
66 	/* Check whether the device is using usbip-host driver. */
67 	driver = udev_device_get_driver(dev);
68 	if (!driver || strcmp(driver, "usbip-host")) {
69 		err("device is not bound to usbip-host driver");
70 		goto err_close_udev;
71 	}
72 
73 	/* Unbind device from driver. */
74 	snprintf(unbind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",
75 		 SYSFS_MNT_PATH, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,
76 		 USBIP_HOST_DRV_NAME, unbind_attr_name);
77 
78 	rc = write_sysfs_attribute(unbind_attr_path, busid, strlen(busid));
79 	if (rc < 0) {
80 		err("error unbinding device %s from driver", busid);
81 		goto err_close_udev;
82 	}
83 
84 	/* Notify driver of unbind. */
85 	rc = modify_match_busid(busid, 0);
86 	if (rc < 0) {
87 		err("unable to unbind device on %s", busid);
88 		goto err_close_udev;
89 	}
90 
91 	/* Trigger new probing. */
92 	snprintf(rebind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",
93 			SYSFS_MNT_PATH, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,
94 			USBIP_HOST_DRV_NAME, rebind_attr_name);
95 
96 	rc = write_sysfs_attribute(rebind_attr_path, busid, strlen(busid));
97 	if (rc < 0) {
98 		err("error rebinding");
99 		goto err_close_udev;
100 	}
101 
102 	ret = 0;
103 	info("unbind device on busid %s: complete", busid);
104 
105 err_close_udev:
106 	udev_device_unref(dev);
107 	udev_unref(udev);
108 
109 	return ret;
110 }
111 
112 int usbip_unbind(int argc, char *argv[])
113 {
114 	static const struct option opts[] = {
115 		{ "busid", required_argument, NULL, 'b' },
116 		{ NULL,    0,                 NULL,  0  }
117 	};
118 
119 	int opt;
120 	int ret = -1;
121 
122 	for (;;) {
123 		opt = getopt_long(argc, argv, "b:", opts, NULL);
124 
125 		if (opt == -1)
126 			break;
127 
128 		switch (opt) {
129 		case 'b':
130 			ret = unbind_device(optarg);
131 			goto out;
132 		default:
133 			goto err_out;
134 		}
135 	}
136 
137 err_out:
138 	usbip_unbind_usage();
139 out:
140 	return ret;
141 }
142