linux/drivers/usb/usbip/vhci_sysfs.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2003-2008 Takahiro Hirofuchi
 * Copyright (C) 2015-2016 Nobuo Iwata
 */

#include <linux/kthread.h>
#include <linux/file.h>
#include <linux/net.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

/* Hardening for Spectre-v1 */
#include <linux/nospec.h>

#include "usbip_common.h"
#include "vhci.h"

/* TODO: refine locking ?*/

/*
 * output example:
 * hub port sta spd dev       sockfd local_busid
 * hs  0000 004 000 00000000  000003 1-2.3
 * ................................................
 * ss  0008 004 000 00000000  000004 2-3.4
 * ................................................
 *
 * Output includes socket fd instead of socket pointer address to avoid
 * leaking kernel memory address in:
 *	/sys/devices/platform/vhci_hcd.0/status and in debug output.
 * The socket pointer address is not used at the moment and it was made
 * visible as a convenient way to find IP address from socket pointer
 * address by looking up /proc/net/{tcp,tcp6}. As this opens a security
 * hole, the change is made to use sockfd instead.
 *
 */
static void port_show_vhci(char **out, int hub, int port, struct vhci_device *vdev)
{ … }

/* Sysfs entry to show port status */
static ssize_t status_show_vhci(int pdev_nr, char *out)
{ … }

static ssize_t status_show_not_ready(int pdev_nr, char *out)
{ … }

static int status_name_to_id(const char *name)
{ … }

static ssize_t status_show(struct device *dev,
			   struct device_attribute *attr, char *out)
{ … }

static ssize_t nports_show(struct device *dev, struct device_attribute *attr,
			   char *out)
{ … }
static DEVICE_ATTR_RO(nports);

/* Sysfs entry to shutdown a virtual connection */
static int vhci_port_disconnect(struct vhci_hcd *vhci_hcd, __u32 rhport)
{ … }

static int valid_port(__u32 *pdev_nr, __u32 *rhport)
{ … }

static ssize_t detach_store(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{ … }
static DEVICE_ATTR_WO(detach);

static int valid_args(__u32 *pdev_nr, __u32 *rhport,
		      enum usb_device_speed speed)
{ … }

/* Sysfs entry to establish a virtual connection */
/*
 * 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 attach_store(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{ … }
static DEVICE_ATTR_WO(attach);

#define MAX_STATUS_NAME …

struct status_attr { … };

static struct status_attr *status_attrs;

static void set_status_attr(int id)
{ … }

static int init_status_attrs(void)
{ … }

static void finish_status_attrs(void)
{ … }

struct attribute_group vhci_attr_group = …;

int vhci_init_attr_group(void)
{ … }

void vhci_finish_attr_group(void)
{ … }