Fixed MTP to work with TWRP

drivers/usb/usbip/vhci_sysfs.c

@@ -0,0 +1,252 @@
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+#include <linux/kthread.h>
+#include <linux/file.h>
+#include <linux/net.h>
+
+#include "usbip_common.h"
+#include "vhci.h"
+
+/* TODO: refine locking ?*/
+
+/* Sysfs entry to show port status */
+static ssize_t status_show(struct device *dev, struct device_attribute *attr,
+			   char *out)
+{
+	char *s = out;
+	int i = 0;
+
+	BUG_ON(!the_controller || !out);
+
+	spin_lock(&the_controller->lock);
+
+	/*
+	 * output example:
+	 * prt sta spd dev socket           local_busid
+	 * 000 004 000 000         c5a7bb80 1-2.3
+	 * 001 004 000 000         d8cee980 2-3.4
+	 *
+	 * IP address can be retrieved from a socket pointer address by looking
+	 * up /proc/net/{tcp,tcp6}. Also, a userland program may remember a
+	 * port number and its peer IP address.
+	 */
+	out += sprintf(out,
+		       "prt sta spd bus dev socket           local_busid\n");
+
+	for (i = 0; i < VHCI_NPORTS; i++) {
+		struct vhci_device *vdev = port_to_vdev(i);
+
+		spin_lock(&vdev->ud.lock);
+		out += sprintf(out, "%03u %03u ", i, vdev->ud.status);
+
+		if (vdev->ud.status == VDEV_ST_USED) {
+			out += sprintf(out, "%03u %08x ",
+				       vdev->speed, vdev->devid);
+			out += sprintf(out, "%16p ", vdev->ud.tcp_socket);
+			out += sprintf(out, "%s", dev_name(&vdev->udev->dev));
+
+		} else {
+			out += sprintf(out, "000 000 000 0000000000000000 0-0");
+		}
+
+		out += sprintf(out, "\n");
+		spin_unlock(&vdev->ud.lock);
+	}
+
+	spin_unlock(&the_controller->lock);
+
+	return out - s;
+}
+static DEVICE_ATTR_RO(status);
+
+/* Sysfs entry to shutdown a virtual connection */
+static int vhci_port_disconnect(__u32 rhport)
+{
+	struct vhci_device *vdev;
+
+	usbip_dbg_vhci_sysfs("enter\n");
+
+	/* lock */
+	spin_lock(&the_controller->lock);
+
+	vdev = port_to_vdev(rhport);
+
+	spin_lock(&vdev->ud.lock);
+	if (vdev->ud.status == VDEV_ST_NULL) {
+		pr_err("not connected %d\n", vdev->ud.status);
+
+		/* unlock */
+		spin_unlock(&vdev->ud.lock);
+		spin_unlock(&the_controller->lock);
+
+		return -EINVAL;
+	}
+
+	/* unlock */
+	spin_unlock(&vdev->ud.lock);
+	spin_unlock(&the_controller->lock);
+
+	usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);
+
+	return 0;
+}
+
+static ssize_t store_detach(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	int err;
+	__u32 rhport = 0;
+
+	if (sscanf(buf, "%u", &rhport) != 1)
+		return -EINVAL;
+
+	/* check rhport */
+	if (rhport >= VHCI_NPORTS) {
+		dev_err(dev, "invalid port %u\n", rhport);
+		return -EINVAL;
+	}
+
+	err = vhci_port_disconnect(rhport);
+	if (err < 0)
+		return -EINVAL;
+
+	usbip_dbg_vhci_sysfs("Leave\n");
+
+	return count;
+}
+static DEVICE_ATTR(detach, S_IWUSR, NULL, store_detach);
+
+/* Sysfs entry to establish a virtual connection */
+static int valid_args(__u32 rhport, enum usb_device_speed speed)
+{
+	/* check rhport */
+	if (rhport >= VHCI_NPORTS) {
+		pr_err("port %u\n", rhport);
+		return -EINVAL;
+	}
+
+	/* check speed */
+	switch (speed) {
+	case USB_SPEED_LOW:
+	case USB_SPEED_FULL:
+	case USB_SPEED_HIGH:
+	case USB_SPEED_WIRELESS:
+		break;
+	default:
+		pr_err("Failed attach request for unsupported USB speed: %s\n",
+			usb_speed_string(speed));
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * To start a new USB/IP attachment, a userland program needs to setup a TCP
+ * connection and then write its socket descriptor with remote device
+ * information into this sysfs file.
+ *
+ * A remote device is virtually attached to the root-hub port of @rhport with
+ * @speed. @devid is embedded into a request to specify the remote device in a
+ * server host.
+ *
+ * write() returns 0 on success, else negative errno.
+ */
+static ssize_t store_attach(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct vhci_device *vdev;
+	struct socket *socket;
+	int sockfd = 0;
+	__u32 rhport = 0, devid = 0, speed = 0;
+	int err;
+
+	/*
+	 * @rhport: port number of vhci_hcd
+	 * @sockfd: socket descriptor of an established TCP connection
+	 * @devid: unique device identifier in a remote host
+	 * @speed: usb device speed in a remote host
+	 */
+	if (sscanf(buf, "%u %u %u %u", &rhport, &sockfd, &devid, &speed) != 4)
+		return -EINVAL;
+
+	usbip_dbg_vhci_sysfs("rhport(%u) sockfd(%u) devid(%u) speed(%u)\n",
+			     rhport, sockfd, devid, speed);
+
+	/* check received parameters */
+	if (valid_args(rhport, speed) < 0)
+		return -EINVAL;
+
+	/* Extract socket from fd. */
+	socket = sockfd_lookup(sockfd, &err);
+	if (!socket)
+		return -EINVAL;
+
+	/* now need lock until setting vdev status as used */
+
+	/* begin a lock */
+	spin_lock(&the_controller->lock);
+	vdev = port_to_vdev(rhport);
+	spin_lock(&vdev->ud.lock);
+
+	if (vdev->ud.status != VDEV_ST_NULL) {
+		/* end of the lock */
+		spin_unlock(&vdev->ud.lock);
+		spin_unlock(&the_controller->lock);
+
+		sockfd_put(socket);
+
+		dev_err(dev, "port %d already used\n", rhport);
+		return -EINVAL;
+	}
+
+	dev_info(dev,
+		 "rhport(%u) sockfd(%d) devid(%u) speed(%u) speed_str(%s)\n",
+		 rhport, sockfd, devid, speed, usb_speed_string(speed));
+
+	vdev->devid         = devid;
+	vdev->speed         = speed;
+	vdev->ud.tcp_socket = socket;
+	vdev->ud.status     = VDEV_ST_NOTASSIGNED;
+
+	spin_unlock(&vdev->ud.lock);
+	spin_unlock(&the_controller->lock);
+	/* end the lock */
+
+	vdev->ud.tcp_rx = kthread_get_run(vhci_rx_loop, &vdev->ud, "vhci_rx");
+	vdev->ud.tcp_tx = kthread_get_run(vhci_tx_loop, &vdev->ud, "vhci_tx");
+
+	rh_port_connect(rhport, speed);
+
+	return count;
+}
+static DEVICE_ATTR(attach, S_IWUSR, NULL, store_attach);
+
+static struct attribute *dev_attrs[] = {
+	&dev_attr_status.attr,
+	&dev_attr_detach.attr,
+	&dev_attr_attach.attr,
+	&dev_attr_usbip_debug.attr,
+	NULL,
+};
+
+const struct attribute_group dev_attr_group = {
+	.attrs = dev_attrs,
+};