root/drivers/usb/usbip/vhci_sysfs.c

DEFINITIONS

1. port_show_vhci
2. status_show_vhci
3. status_show_not_ready
4. status_name_to_id
5. status_show
6. nports_show
7. vhci_port_disconnect
8. valid_port
9. detach_store
10. valid_args
11. attach_store
12. set_status_attr
13. init_status_attrs
14. finish_status_attrs
15. vhci_init_attr_group
16. vhci_finish_attr_group

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2003-2008 Takahiro Hirofuchi
   4  * Copyright (C) 2015-2016 Nobuo Iwata
   5  */
   6 
   7 #include <linux/kthread.h>
   8 #include <linux/file.h>
   9 #include <linux/net.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/slab.h>
  12 
  13 /* Hardening for Spectre-v1 */
  14 #include <linux/nospec.h>
  15 
  16 #include "usbip_common.h"
  17 #include "vhci.h"
  18 
  19 /* TODO: refine locking ?*/
  20 
  21 /*
  22  * output example:
  23  * hub port sta spd dev       sockfd local_busid
  24  * hs  0000 004 000 00000000  000003 1-2.3
  25  * ................................................
  26  * ss  0008 004 000 00000000  000004 2-3.4
  27  * ................................................
  28  *
  29  * Output includes socket fd instead of socket pointer address to avoid
  30  * leaking kernel memory address in:
  31  *      /sys/devices/platform/vhci_hcd.0/status and in debug output.
  32  * The socket pointer address is not used at the moment and it was made
  33  * visible as a convenient way to find IP address from socket pointer
  34  * address by looking up /proc/net/{tcp,tcp6}. As this opens a security
  35  * hole, the change is made to use sockfd instead.
  36  *
  37  */
  38 static void port_show_vhci(char **out, int hub, int port, struct vhci_device *vdev)
  39 {
  40         if (hub == HUB_SPEED_HIGH)
  41                 *out += sprintf(*out, "hs  %04u %03u ",
  42                                       port, vdev->ud.status);
  43         else /* hub == HUB_SPEED_SUPER */
  44                 *out += sprintf(*out, "ss  %04u %03u ",
  45                                       port, vdev->ud.status);
  46 
  47         if (vdev->ud.status == VDEV_ST_USED) {
  48                 *out += sprintf(*out, "%03u %08x ",
  49                                       vdev->speed, vdev->devid);
  50                 *out += sprintf(*out, "%06u %s",
  51                                       vdev->ud.sockfd,
  52                                       dev_name(&vdev->udev->dev));
  53 
  54         } else {
  55                 *out += sprintf(*out, "000 00000000 ");
  56                 *out += sprintf(*out, "000000 0-0");
  57         }
  58 
  59         *out += sprintf(*out, "\n");
  60 }
  61 
  62 /* Sysfs entry to show port status */
  63 static ssize_t status_show_vhci(int pdev_nr, char *out)
  64 {
  65         struct platform_device *pdev = vhcis[pdev_nr].pdev;
  66         struct vhci *vhci;
  67         struct usb_hcd *hcd;
  68         struct vhci_hcd *vhci_hcd;
  69         char *s = out;
  70         int i;
  71         unsigned long flags;
  72 
  73         if (!pdev || !out) {
  74                 usbip_dbg_vhci_sysfs("show status error\n");
  75                 return 0;
  76         }
  77 
  78         hcd = platform_get_drvdata(pdev);
  79         vhci_hcd = hcd_to_vhci_hcd(hcd);
  80         vhci = vhci_hcd->vhci;
  81 
  82         spin_lock_irqsave(&vhci->lock, flags);
  83 
  84         for (i = 0; i < VHCI_HC_PORTS; i++) {
  85                 struct vhci_device *vdev = &vhci->vhci_hcd_hs->vdev[i];
  86 
  87                 spin_lock(&vdev->ud.lock);
  88                 port_show_vhci(&out, HUB_SPEED_HIGH,
  89                                pdev_nr * VHCI_PORTS + i, vdev);
  90                 spin_unlock(&vdev->ud.lock);
  91         }
  92 
  93         for (i = 0; i < VHCI_HC_PORTS; i++) {
  94                 struct vhci_device *vdev = &vhci->vhci_hcd_ss->vdev[i];
  95 
  96                 spin_lock(&vdev->ud.lock);
  97                 port_show_vhci(&out, HUB_SPEED_SUPER,
  98                                pdev_nr * VHCI_PORTS + VHCI_HC_PORTS + i, vdev);
  99                 spin_unlock(&vdev->ud.lock);
 100         }
 101 
 102         spin_unlock_irqrestore(&vhci->lock, flags);
 103 
 104         return out - s;
 105 }
 106 
 107 static ssize_t status_show_not_ready(int pdev_nr, char *out)
 108 {
 109         char *s = out;
 110         int i = 0;
 111 
 112         for (i = 0; i < VHCI_HC_PORTS; i++) {
 113                 out += sprintf(out, "hs  %04u %03u ",
 114                                     (pdev_nr * VHCI_PORTS) + i,
 115                                     VDEV_ST_NOTASSIGNED);
 116                 out += sprintf(out, "000 00000000 0000000000000000 0-0");
 117                 out += sprintf(out, "\n");
 118         }
 119 
 120         for (i = 0; i < VHCI_HC_PORTS; i++) {
 121                 out += sprintf(out, "ss  %04u %03u ",
 122                                     (pdev_nr * VHCI_PORTS) + VHCI_HC_PORTS + i,
 123                                     VDEV_ST_NOTASSIGNED);
 124                 out += sprintf(out, "000 00000000 0000000000000000 0-0");
 125                 out += sprintf(out, "\n");
 126         }
 127         return out - s;
 128 }
 129 
 130 static int status_name_to_id(const char *name)
 131 {
 132         char *c;
 133         long val;
 134         int ret;
 135 
 136         c = strchr(name, '.');
 137         if (c == NULL)
 138                 return 0;
 139 
 140         ret = kstrtol(c+1, 10, &val);
 141         if (ret < 0)
 142                 return ret;
 143 
 144         return val;
 145 }
 146 
 147 static ssize_t status_show(struct device *dev,
 148                            struct device_attribute *attr, char *out)
 149 {
 150         char *s = out;
 151         int pdev_nr;
 152 
 153         out += sprintf(out,
 154                        "hub port sta spd dev      sockfd local_busid\n");
 155 
 156         pdev_nr = status_name_to_id(attr->attr.name);
 157         if (pdev_nr < 0)
 158                 out += status_show_not_ready(pdev_nr, out);
 159         else
 160                 out += status_show_vhci(pdev_nr, out);
 161 
 162         return out - s;
 163 }
 164 
 165 static ssize_t nports_show(struct device *dev, struct device_attribute *attr,
 166                            char *out)
 167 {
 168         char *s = out;
 169 
 170         /*
 171          * Half the ports are for SPEED_HIGH and half for SPEED_SUPER,
 172          * thus the * 2.
 173          */
 174         out += sprintf(out, "%d\n", VHCI_PORTS * vhci_num_controllers);
 175         return out - s;
 176 }
 177 static DEVICE_ATTR_RO(nports);
 178 
 179 /* Sysfs entry to shutdown a virtual connection */
 180 static int vhci_port_disconnect(struct vhci_hcd *vhci_hcd, __u32 rhport)
 181 {
 182         struct vhci_device *vdev = &vhci_hcd->vdev[rhport];
 183         struct vhci *vhci = vhci_hcd->vhci;
 184         unsigned long flags;
 185 
 186         usbip_dbg_vhci_sysfs("enter\n");
 187 
 188         /* lock */
 189         spin_lock_irqsave(&vhci->lock, flags);
 190         spin_lock(&vdev->ud.lock);
 191 
 192         if (vdev->ud.status == VDEV_ST_NULL) {
 193                 pr_err("not connected %d\n", vdev->ud.status);
 194 
 195                 /* unlock */
 196                 spin_unlock(&vdev->ud.lock);
 197                 spin_unlock_irqrestore(&vhci->lock, flags);
 198 
 199                 return -EINVAL;
 200         }
 201 
 202         /* unlock */
 203         spin_unlock(&vdev->ud.lock);
 204         spin_unlock_irqrestore(&vhci->lock, flags);
 205 
 206         usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);
 207 
 208         return 0;
 209 }
 210 
 211 static int valid_port(__u32 *pdev_nr, __u32 *rhport)
 212 {
 213         if (*pdev_nr >= vhci_num_controllers) {
 214                 pr_err("pdev %u\n", *pdev_nr);
 215                 return 0;
 216         }
 217         *pdev_nr = array_index_nospec(*pdev_nr, vhci_num_controllers);
 218 
 219         if (*rhport >= VHCI_HC_PORTS) {
 220                 pr_err("rhport %u\n", *rhport);
 221                 return 0;
 222         }
 223         *rhport = array_index_nospec(*rhport, VHCI_HC_PORTS);
 224 
 225         return 1;
 226 }
 227 
 228 static ssize_t detach_store(struct device *dev, struct device_attribute *attr,
 229                             const char *buf, size_t count)
 230 {
 231         __u32 port = 0, pdev_nr = 0, rhport = 0;
 232         struct usb_hcd *hcd;
 233         struct vhci_hcd *vhci_hcd;
 234         int ret;
 235 
 236         if (kstrtoint(buf, 10, &port) < 0)
 237                 return -EINVAL;
 238 
 239         pdev_nr = port_to_pdev_nr(port);
 240         rhport = port_to_rhport(port);
 241 
 242         if (!valid_port(&pdev_nr, &rhport))
 243                 return -EINVAL;
 244 
 245         hcd = platform_get_drvdata(vhcis[pdev_nr].pdev);
 246         if (hcd == NULL) {
 247                 dev_err(dev, "port is not ready %u\n", port);
 248                 return -EAGAIN;
 249         }
 250 
 251         usbip_dbg_vhci_sysfs("rhport %d\n", rhport);
 252 
 253         if ((port / VHCI_HC_PORTS) % 2)
 254                 vhci_hcd = hcd_to_vhci_hcd(hcd)->vhci->vhci_hcd_ss;
 255         else
 256                 vhci_hcd = hcd_to_vhci_hcd(hcd)->vhci->vhci_hcd_hs;
 257 
 258         ret = vhci_port_disconnect(vhci_hcd, rhport);
 259         if (ret < 0)
 260                 return -EINVAL;
 261 
 262         usbip_dbg_vhci_sysfs("Leave\n");
 263 
 264         return count;
 265 }
 266 static DEVICE_ATTR_WO(detach);
 267 
 268 static int valid_args(__u32 *pdev_nr, __u32 *rhport,
 269                       enum usb_device_speed speed)
 270 {
 271         if (!valid_port(pdev_nr, rhport)) {
 272                 return 0;
 273         }
 274 
 275         switch (speed) {
 276         case USB_SPEED_LOW:
 277         case USB_SPEED_FULL:
 278         case USB_SPEED_HIGH:
 279         case USB_SPEED_WIRELESS:
 280         case USB_SPEED_SUPER:
 281                 break;
 282         default:
 283                 pr_err("Failed attach request for unsupported USB speed: %s\n",
 284                         usb_speed_string(speed));
 285                 return 0;
 286         }
 287 
 288         return 1;
 289 }
 290 
 291 /* Sysfs entry to establish a virtual connection */
 292 /*
 293  * To start a new USB/IP attachment, a userland program needs to setup a TCP
 294  * connection and then write its socket descriptor with remote device
 295  * information into this sysfs file.
 296  *
 297  * A remote device is virtually attached to the root-hub port of @rhport with
 298  * @speed. @devid is embedded into a request to specify the remote device in a
 299  * server host.
 300  *
 301  * write() returns 0 on success, else negative errno.
 302  */
 303 static ssize_t attach_store(struct device *dev, struct device_attribute *attr,
 304                             const char *buf, size_t count)
 305 {
 306         struct socket *socket;
 307         int sockfd = 0;
 308         __u32 port = 0, pdev_nr = 0, rhport = 0, devid = 0, speed = 0;
 309         struct usb_hcd *hcd;
 310         struct vhci_hcd *vhci_hcd;
 311         struct vhci_device *vdev;
 312         struct vhci *vhci;
 313         int err;
 314         unsigned long flags;
 315 
 316         /*
 317          * @rhport: port number of vhci_hcd
 318          * @sockfd: socket descriptor of an established TCP connection
 319          * @devid: unique device identifier in a remote host
 320          * @speed: usb device speed in a remote host
 321          */
 322         if (sscanf(buf, "%u %u %u %u", &port, &sockfd, &devid, &speed) != 4)
 323                 return -EINVAL;
 324         pdev_nr = port_to_pdev_nr(port);
 325         rhport = port_to_rhport(port);
 326 
 327         usbip_dbg_vhci_sysfs("port(%u) pdev(%d) rhport(%u)\n",
 328                              port, pdev_nr, rhport);
 329         usbip_dbg_vhci_sysfs("sockfd(%u) devid(%u) speed(%u)\n",
 330                              sockfd, devid, speed);
 331 
 332         /* check received parameters */
 333         if (!valid_args(&pdev_nr, &rhport, speed))
 334                 return -EINVAL;
 335 
 336         hcd = platform_get_drvdata(vhcis[pdev_nr].pdev);
 337         if (hcd == NULL) {
 338                 dev_err(dev, "port %d is not ready\n", port);
 339                 return -EAGAIN;
 340         }
 341 
 342         vhci_hcd = hcd_to_vhci_hcd(hcd);
 343         vhci = vhci_hcd->vhci;
 344 
 345         if (speed == USB_SPEED_SUPER)
 346                 vdev = &vhci->vhci_hcd_ss->vdev[rhport];
 347         else
 348                 vdev = &vhci->vhci_hcd_hs->vdev[rhport];
 349 
 350         /* Extract socket from fd. */
 351         socket = sockfd_lookup(sockfd, &err);
 352         if (!socket)
 353                 return -EINVAL;
 354 
 355         /* now need lock until setting vdev status as used */
 356 
 357         /* begin a lock */
 358         spin_lock_irqsave(&vhci->lock, flags);
 359         spin_lock(&vdev->ud.lock);
 360 
 361         if (vdev->ud.status != VDEV_ST_NULL) {
 362                 /* end of the lock */
 363                 spin_unlock(&vdev->ud.lock);
 364                 spin_unlock_irqrestore(&vhci->lock, flags);
 365 
 366                 sockfd_put(socket);
 367 
 368                 dev_err(dev, "port %d already used\n", rhport);
 369                 /*
 370                  * Will be retried from userspace
 371                  * if there's another free port.
 372                  */
 373                 return -EBUSY;
 374         }
 375 
 376         dev_info(dev, "pdev(%u) rhport(%u) sockfd(%d)\n",
 377                  pdev_nr, rhport, sockfd);
 378         dev_info(dev, "devid(%u) speed(%u) speed_str(%s)\n",
 379                  devid, speed, usb_speed_string(speed));
 380 
 381         vdev->devid         = devid;
 382         vdev->speed         = speed;
 383         vdev->ud.sockfd     = sockfd;
 384         vdev->ud.tcp_socket = socket;
 385         vdev->ud.status     = VDEV_ST_NOTASSIGNED;
 386 
 387         spin_unlock(&vdev->ud.lock);
 388         spin_unlock_irqrestore(&vhci->lock, flags);
 389         /* end the lock */
 390 
 391         vdev->ud.tcp_rx = kthread_get_run(vhci_rx_loop, &vdev->ud, "vhci_rx");
 392         vdev->ud.tcp_tx = kthread_get_run(vhci_tx_loop, &vdev->ud, "vhci_tx");
 393 
 394         rh_port_connect(vdev, speed);
 395 
 396         return count;
 397 }
 398 static DEVICE_ATTR_WO(attach);
 399 
 400 #define MAX_STATUS_NAME 16
 401 
 402 struct status_attr {
 403         struct device_attribute attr;
 404         char name[MAX_STATUS_NAME+1];
 405 };
 406 
 407 static struct status_attr *status_attrs;
 408 
 409 static void set_status_attr(int id)
 410 {
 411         struct status_attr *status;
 412 
 413         status = status_attrs + id;
 414         if (id == 0)
 415                 strcpy(status->name, "status");
 416         else
 417                 snprintf(status->name, MAX_STATUS_NAME+1, "status.%d", id);
 418         status->attr.attr.name = status->name;
 419         status->attr.attr.mode = S_IRUGO;
 420         status->attr.show = status_show;
 421         sysfs_attr_init(&status->attr.attr);
 422 }
 423 
 424 static int init_status_attrs(void)
 425 {
 426         int id;
 427 
 428         status_attrs = kcalloc(vhci_num_controllers, sizeof(struct status_attr),
 429                                GFP_KERNEL);
 430         if (status_attrs == NULL)
 431                 return -ENOMEM;
 432 
 433         for (id = 0; id < vhci_num_controllers; id++)
 434                 set_status_attr(id);
 435 
 436         return 0;
 437 }
 438 
 439 static void finish_status_attrs(void)
 440 {
 441         kfree(status_attrs);
 442 }
 443 
 444 struct attribute_group vhci_attr_group = {
 445         .attrs = NULL,
 446 };
 447 
 448 int vhci_init_attr_group(void)
 449 {
 450         struct attribute **attrs;
 451         int ret, i;
 452 
 453         attrs = kcalloc((vhci_num_controllers + 5), sizeof(struct attribute *),
 454                         GFP_KERNEL);
 455         if (attrs == NULL)
 456                 return -ENOMEM;
 457 
 458         ret = init_status_attrs();
 459         if (ret) {
 460                 kfree(attrs);
 461                 return ret;
 462         }
 463         *attrs = &dev_attr_nports.attr;
 464         *(attrs + 1) = &dev_attr_detach.attr;
 465         *(attrs + 2) = &dev_attr_attach.attr;
 466         *(attrs + 3) = &dev_attr_usbip_debug.attr;
 467         for (i = 0; i < vhci_num_controllers; i++)
 468                 *(attrs + i + 4) = &((status_attrs + i)->attr.attr);
 469         vhci_attr_group.attrs = attrs;
 470         return 0;
 471 }
 472 
 473 void vhci_finish_attr_group(void)
 474 {
 475         finish_status_attrs();
 476         kfree(vhci_attr_group.attrs);
 477 }