xref: /openbmc/linux/drivers/usb/usbip/vhci_sysfs.c (revision 9cfc5c90)
1 /*
2  * Copyright (C) 2003-2008 Takahiro Hirofuchi
3  *
4  * This is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
17  * USA.
18  */
19 
20 #include <linux/kthread.h>
21 #include <linux/file.h>
22 #include <linux/net.h>
23 
24 #include "usbip_common.h"
25 #include "vhci.h"
26 
27 /* TODO: refine locking ?*/
28 
29 /* Sysfs entry to show port status */
30 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
31 			   char *out)
32 {
33 	char *s = out;
34 	int i = 0;
35 
36 	BUG_ON(!the_controller || !out);
37 
38 	spin_lock(&the_controller->lock);
39 
40 	/*
41 	 * output example:
42 	 * prt sta spd dev socket           local_busid
43 	 * 000 004 000 000         c5a7bb80 1-2.3
44 	 * 001 004 000 000         d8cee980 2-3.4
45 	 *
46 	 * IP address can be retrieved from a socket pointer address by looking
47 	 * up /proc/net/{tcp,tcp6}. Also, a userland program may remember a
48 	 * port number and its peer IP address.
49 	 */
50 	out += sprintf(out,
51 		       "prt sta spd bus dev socket           local_busid\n");
52 
53 	for (i = 0; i < VHCI_NPORTS; i++) {
54 		struct vhci_device *vdev = port_to_vdev(i);
55 
56 		spin_lock(&vdev->ud.lock);
57 		out += sprintf(out, "%03u %03u ", i, vdev->ud.status);
58 
59 		if (vdev->ud.status == VDEV_ST_USED) {
60 			out += sprintf(out, "%03u %08x ",
61 				       vdev->speed, vdev->devid);
62 			out += sprintf(out, "%16p ", vdev->ud.tcp_socket);
63 			out += sprintf(out, "%s", dev_name(&vdev->udev->dev));
64 
65 		} else {
66 			out += sprintf(out, "000 000 000 0000000000000000 0-0");
67 		}
68 
69 		out += sprintf(out, "\n");
70 		spin_unlock(&vdev->ud.lock);
71 	}
72 
73 	spin_unlock(&the_controller->lock);
74 
75 	return out - s;
76 }
77 static DEVICE_ATTR_RO(status);
78 
79 /* Sysfs entry to shutdown a virtual connection */
80 static int vhci_port_disconnect(__u32 rhport)
81 {
82 	struct vhci_device *vdev;
83 
84 	usbip_dbg_vhci_sysfs("enter\n");
85 
86 	/* lock */
87 	spin_lock(&the_controller->lock);
88 
89 	vdev = port_to_vdev(rhport);
90 
91 	spin_lock(&vdev->ud.lock);
92 	if (vdev->ud.status == VDEV_ST_NULL) {
93 		pr_err("not connected %d\n", vdev->ud.status);
94 
95 		/* unlock */
96 		spin_unlock(&vdev->ud.lock);
97 		spin_unlock(&the_controller->lock);
98 
99 		return -EINVAL;
100 	}
101 
102 	/* unlock */
103 	spin_unlock(&vdev->ud.lock);
104 	spin_unlock(&the_controller->lock);
105 
106 	usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);
107 
108 	return 0;
109 }
110 
111 static ssize_t store_detach(struct device *dev, struct device_attribute *attr,
112 			    const char *buf, size_t count)
113 {
114 	int err;
115 	__u32 rhport = 0;
116 
117 	if (sscanf(buf, "%u", &rhport) != 1)
118 		return -EINVAL;
119 
120 	/* check rhport */
121 	if (rhport >= VHCI_NPORTS) {
122 		dev_err(dev, "invalid port %u\n", rhport);
123 		return -EINVAL;
124 	}
125 
126 	err = vhci_port_disconnect(rhport);
127 	if (err < 0)
128 		return -EINVAL;
129 
130 	usbip_dbg_vhci_sysfs("Leave\n");
131 
132 	return count;
133 }
134 static DEVICE_ATTR(detach, S_IWUSR, NULL, store_detach);
135 
136 /* Sysfs entry to establish a virtual connection */
137 static int valid_args(__u32 rhport, enum usb_device_speed speed)
138 {
139 	/* check rhport */
140 	if (rhport >= VHCI_NPORTS) {
141 		pr_err("port %u\n", rhport);
142 		return -EINVAL;
143 	}
144 
145 	/* check speed */
146 	switch (speed) {
147 	case USB_SPEED_LOW:
148 	case USB_SPEED_FULL:
149 	case USB_SPEED_HIGH:
150 	case USB_SPEED_WIRELESS:
151 		break;
152 	default:
153 		pr_err("Failed attach request for unsupported USB speed: %s\n",
154 			usb_speed_string(speed));
155 		return -EINVAL;
156 	}
157 
158 	return 0;
159 }
160 
161 /*
162  * To start a new USB/IP attachment, a userland program needs to setup a TCP
163  * connection and then write its socket descriptor with remote device
164  * information into this sysfs file.
165  *
166  * A remote device is virtually attached to the root-hub port of @rhport with
167  * @speed. @devid is embedded into a request to specify the remote device in a
168  * server host.
169  *
170  * write() returns 0 on success, else negative errno.
171  */
172 static ssize_t store_attach(struct device *dev, struct device_attribute *attr,
173 			    const char *buf, size_t count)
174 {
175 	struct vhci_device *vdev;
176 	struct socket *socket;
177 	int sockfd = 0;
178 	__u32 rhport = 0, devid = 0, speed = 0;
179 	int err;
180 
181 	/*
182 	 * @rhport: port number of vhci_hcd
183 	 * @sockfd: socket descriptor of an established TCP connection
184 	 * @devid: unique device identifier in a remote host
185 	 * @speed: usb device speed in a remote host
186 	 */
187 	if (sscanf(buf, "%u %u %u %u", &rhport, &sockfd, &devid, &speed) != 4)
188 		return -EINVAL;
189 
190 	usbip_dbg_vhci_sysfs("rhport(%u) sockfd(%u) devid(%u) speed(%u)\n",
191 			     rhport, sockfd, devid, speed);
192 
193 	/* check received parameters */
194 	if (valid_args(rhport, speed) < 0)
195 		return -EINVAL;
196 
197 	/* Extract socket from fd. */
198 	socket = sockfd_lookup(sockfd, &err);
199 	if (!socket)
200 		return -EINVAL;
201 
202 	/* now need lock until setting vdev status as used */
203 
204 	/* begin a lock */
205 	spin_lock(&the_controller->lock);
206 	vdev = port_to_vdev(rhport);
207 	spin_lock(&vdev->ud.lock);
208 
209 	if (vdev->ud.status != VDEV_ST_NULL) {
210 		/* end of the lock */
211 		spin_unlock(&vdev->ud.lock);
212 		spin_unlock(&the_controller->lock);
213 
214 		sockfd_put(socket);
215 
216 		dev_err(dev, "port %d already used\n", rhport);
217 		return -EINVAL;
218 	}
219 
220 	dev_info(dev,
221 		 "rhport(%u) sockfd(%d) devid(%u) speed(%u) speed_str(%s)\n",
222 		 rhport, sockfd, devid, speed, usb_speed_string(speed));
223 
224 	vdev->devid         = devid;
225 	vdev->speed         = speed;
226 	vdev->ud.tcp_socket = socket;
227 	vdev->ud.status     = VDEV_ST_NOTASSIGNED;
228 
229 	spin_unlock(&vdev->ud.lock);
230 	spin_unlock(&the_controller->lock);
231 	/* end the lock */
232 
233 	vdev->ud.tcp_rx = kthread_get_run(vhci_rx_loop, &vdev->ud, "vhci_rx");
234 	vdev->ud.tcp_tx = kthread_get_run(vhci_tx_loop, &vdev->ud, "vhci_tx");
235 
236 	rh_port_connect(rhport, speed);
237 
238 	return count;
239 }
240 static DEVICE_ATTR(attach, S_IWUSR, NULL, store_attach);
241 
242 static struct attribute *dev_attrs[] = {
243 	&dev_attr_status.attr,
244 	&dev_attr_detach.attr,
245 	&dev_attr_attach.attr,
246 	&dev_attr_usbip_debug.attr,
247 	NULL,
248 };
249 
250 const struct attribute_group dev_attr_group = {
251 	.attrs = dev_attrs,
252 };
253