drivers/usb/usbip/stub_tx.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2003-2008 Takahiro Hirofuchi
   4  */
   5
   6 #include <linux/kthread.h>
   7 #include <linux/socket.h>
   8
   9 #include "usbip_common.h"
  10 #include "stub.h"
  11
  12 static void stub_free_priv_and_urb(struct stub_priv *priv)
  13 {
  14         struct urb *urb = priv->urb;
  15
  16         kfree(urb->setup_packet);
  17         urb->setup_packet = NULL;
  18
  19         kfree(urb->transfer_buffer);
  20         urb->transfer_buffer = NULL;
  21
  22         list_del(&priv->list);
  23         kmem_cache_free(stub_priv_cache, priv);
  24         usb_free_urb(urb);
  25 }
  26
  27 /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
  28 void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
  29                              __u32 status)
  30 {
  31         struct stub_unlink *unlink;
  32
  33         unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
  34         if (!unlink) {
  35                 usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
  36                 return;
  37         }
  38
  39         unlink->seqnum = seqnum;
  40         unlink->status = status;
  41
  42         list_add_tail(&unlink->list, &sdev->unlink_tx);
  43 }
  44
  45 /**
  46  * stub_complete - completion handler of a usbip urb
  47  * @urb: pointer to the urb completed
  48  *
  49  * When a urb has completed, the USB core driver calls this function mostly in
  50  * the interrupt context. To return the result of a urb, the completed urb is
  51  * linked to the pending list of returning.
  52  *
  53  */
  54 void stub_complete(struct urb *urb)
  55 {
  56         struct stub_priv *priv = (struct stub_priv *) urb->context;
  57         struct stub_device *sdev = priv->sdev;
  58         unsigned long flags;
  59
  60         usbip_dbg_stub_tx("complete! status %d\n", urb->status);
  61
  62         switch (urb->status) {
  63         case 0:
  64                 /* OK */
  65                 break;
  66         case -ENOENT:
  67                 dev_info(&urb->dev->dev,
  68                          "stopped by a call to usb_kill_urb() because of cleaning up a virtual connection\n");
  69                 return;
  70         case -ECONNRESET:
  71                 dev_info(&urb->dev->dev,
  72                          "unlinked by a call to usb_unlink_urb()\n");
  73                 break;
  74         case -EPIPE:
  75                 dev_info(&urb->dev->dev, "endpoint %d is stalled\n",
  76                          usb_pipeendpoint(urb->pipe));
  77                 break;
  78         case -ESHUTDOWN:
  79                 dev_info(&urb->dev->dev, "device removed?\n");
  80                 break;
  81         default:
  82                 dev_info(&urb->dev->dev,
  83                          "urb completion with non-zero status %d\n",
  84                          urb->status);
  85                 break;
  86         }
  87
  88         /* link a urb to the queue of tx. */
  89         spin_lock_irqsave(&sdev->priv_lock, flags);
  90         if (sdev->ud.tcp_socket == NULL) {
  91                 usbip_dbg_stub_tx("ignore urb for closed connection\n");
  92                 /* It will be freed in stub_device_cleanup_urbs(). */
  93         } else if (priv->unlinking) {
  94                 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
  95                 stub_free_priv_and_urb(priv);
  96         } else {
  97                 list_move_tail(&priv->list, &sdev->priv_tx);
  98         }
  99         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 100
 101         /* wake up tx_thread */
 102         wake_up(&sdev->tx_waitq);
 103 }
 104
 105 static inline void setup_base_pdu(struct usbip_header_basic *base,
 106                                   __u32 command, __u32 seqnum)
 107 {
 108         base->command   = command;
 109         base->seqnum    = seqnum;
 110         base->devid     = 0;
 111         base->ep        = 0;
 112         base->direction = 0;
 113 }
 114
 115 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
 116 {
 117         struct stub_priv *priv = (struct stub_priv *) urb->context;
 118
 119         setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
 120         usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
 121 }
 122
 123 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
 124                                  struct stub_unlink *unlink)
 125 {
 126         setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
 127         rpdu->u.ret_unlink.status = unlink->status;
 128 }
 129
 130 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
 131 {
 132         unsigned long flags;
 133         struct stub_priv *priv, *tmp;
 134
 135         spin_lock_irqsave(&sdev->priv_lock, flags);
 136
 137         list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
 138                 list_move_tail(&priv->list, &sdev->priv_free);
 139                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 140                 return priv;
 141         }
 142
 143         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 144
 145         return NULL;
 146 }
 147
 148 static int stub_send_ret_submit(struct stub_device *sdev)
 149 {
 150         unsigned long flags;
 151         struct stub_priv *priv, *tmp;
 152
 153         struct msghdr msg;
 154         size_t txsize;
 155
 156         size_t total_size = 0;
 157
 158         while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
 159                 int ret;
 160                 struct urb *urb = priv->urb;
 161                 struct usbip_header pdu_header;
 162                 struct usbip_iso_packet_descriptor *iso_buffer = NULL;
 163                 struct kvec *iov = NULL;
 164                 int iovnum = 0;
 165
 166                 txsize = 0;
 167                 memset(&pdu_header, 0, sizeof(pdu_header));
 168                 memset(&msg, 0, sizeof(msg));
 169
 170                 if (urb->actual_length > 0 && !urb->transfer_buffer) {
 171                         dev_err(&sdev->udev->dev,
 172                                 "urb: actual_length %d transfer_buffer null\n",
 173                                 urb->actual_length);
 174                         return -1;
 175                 }
 176
 177                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
 178                         iovnum = 2 + urb->number_of_packets;
 179                 else
 180                         iovnum = 2;
 181
 182                 iov = kcalloc(iovnum, sizeof(struct kvec), GFP_KERNEL);
 183
 184                 if (!iov) {
 185                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
 186                         return -1;
 187                 }
 188
 189                 iovnum = 0;
 190
 191                 /* 1. setup usbip_header */
 192                 setup_ret_submit_pdu(&pdu_header, urb);
 193                 usbip_dbg_stub_tx("setup txdata seqnum: %d\n",
 194                                   pdu_header.base.seqnum);
 195                 usbip_header_correct_endian(&pdu_header, 1);
 196
 197                 iov[iovnum].iov_base = &pdu_header;
 198                 iov[iovnum].iov_len  = sizeof(pdu_header);
 199                 iovnum++;
 200                 txsize += sizeof(pdu_header);
 201
 202                 /* 2. setup transfer buffer */
 203                 if (usb_pipein(urb->pipe) &&
 204                     usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
 205                     urb->actual_length > 0) {
 206                         iov[iovnum].iov_base = urb->transfer_buffer;
 207                         iov[iovnum].iov_len  = urb->actual_length;
 208                         iovnum++;
 209                         txsize += urb->actual_length;
 210                 } else if (usb_pipein(urb->pipe) &&
 211                            usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 212                         /*
 213                          * For isochronous packets: actual length is the sum of
 214                          * the actual length of the individual, packets, but as
 215                          * the packet offsets are not changed there will be
 216                          * padding between the packets. To optimally use the
 217                          * bandwidth the padding is not transmitted.
 218                          */
 219
 220                         int i;
 221
 222                         for (i = 0; i < urb->number_of_packets; i++) {
 223                                 iov[iovnum].iov_base = urb->transfer_buffer +
 224                                         urb->iso_frame_desc[i].offset;
 225                                 iov[iovnum].iov_len =
 226                                         urb->iso_frame_desc[i].actual_length;
 227                                 iovnum++;
 228                                 txsize += urb->iso_frame_desc[i].actual_length;
 229                         }
 230
 231                         if (txsize != sizeof(pdu_header) + urb->actual_length) {
 232                                 dev_err(&sdev->udev->dev,
 233                                         "actual length of urb %d does not match iso packet sizes %zu\n",
 234                                         urb->actual_length,
 235                                         txsize-sizeof(pdu_header));
 236                                 kfree(iov);
 237                                 usbip_event_add(&sdev->ud,
 238                                                 SDEV_EVENT_ERROR_TCP);
 239                            return -1;
 240                         }
 241                 }
 242
 243                 /* 3. setup iso_packet_descriptor */
 244                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 245                         ssize_t len = 0;
 246
 247                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 248                         if (!iso_buffer) {
 249                                 usbip_event_add(&sdev->ud,
 250                                                 SDEV_EVENT_ERROR_MALLOC);
 251                                 kfree(iov);
 252                                 return -1;
 253                         }
 254
 255                         iov[iovnum].iov_base = iso_buffer;
 256                         iov[iovnum].iov_len  = len;
 257                         txsize += len;
 258                         iovnum++;
 259                 }
 260
 261                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
 262                                                 iov,  iovnum, txsize);
 263                 if (ret != txsize) {
 264                         dev_err(&sdev->udev->dev,
 265                                 "sendmsg failed!, retval %d for %zd\n",
 266                                 ret, txsize);
 267                         kfree(iov);
 268                         kfree(iso_buffer);
 269                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 270                         return -1;
 271                 }
 272
 273                 kfree(iov);
 274                 kfree(iso_buffer);
 275
 276                 total_size += txsize;
 277         }
 278
 279         spin_lock_irqsave(&sdev->priv_lock, flags);
 280         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 281                 stub_free_priv_and_urb(priv);
 282         }
 283         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 284
 285         return total_size;
 286 }
 287
 288 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 289 {
 290         unsigned long flags;
 291         struct stub_unlink *unlink, *tmp;
 292
 293         spin_lock_irqsave(&sdev->priv_lock, flags);
 294
 295         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 296                 list_move_tail(&unlink->list, &sdev->unlink_free);
 297                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 298                 return unlink;
 299         }
 300
 301         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 302
 303         return NULL;
 304 }
 305
 306 static int stub_send_ret_unlink(struct stub_device *sdev)
 307 {
 308         unsigned long flags;
 309         struct stub_unlink *unlink, *tmp;
 310
 311         struct msghdr msg;
 312         struct kvec iov[1];
 313         size_t txsize;
 314
 315         size_t total_size = 0;
 316
 317         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 318                 int ret;
 319                 struct usbip_header pdu_header;
 320
 321                 txsize = 0;
 322                 memset(&pdu_header, 0, sizeof(pdu_header));
 323                 memset(&msg, 0, sizeof(msg));
 324                 memset(&iov, 0, sizeof(iov));
 325
 326                 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 327
 328                 /* 1. setup usbip_header */
 329                 setup_ret_unlink_pdu(&pdu_header, unlink);
 330                 usbip_header_correct_endian(&pdu_header, 1);
 331
 332                 iov[0].iov_base = &pdu_header;
 333                 iov[0].iov_len  = sizeof(pdu_header);
 334                 txsize += sizeof(pdu_header);
 335
 336                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 337                                      1, txsize);
 338                 if (ret != txsize) {
 339                         dev_err(&sdev->udev->dev,
 340                                 "sendmsg failed!, retval %d for %zd\n",
 341                                 ret, txsize);
 342                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 343                         return -1;
 344                 }
 345
 346                 usbip_dbg_stub_tx("send txdata\n");
 347                 total_size += txsize;
 348         }
 349
 350         spin_lock_irqsave(&sdev->priv_lock, flags);
 351
 352         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 353                 list_del(&unlink->list);
 354                 kfree(unlink);
 355         }
 356
 357         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 358
 359         return total_size;
 360 }
 361
 362 int stub_tx_loop(void *data)
 363 {
 364         struct usbip_device *ud = data;
 365         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 366
 367         while (!kthread_should_stop()) {
 368                 if (usbip_event_happened(ud))
 369                         break;
 370
 371                 /*
 372                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 373                  * looks at only priv_init queue. If the completion of a URB is
 374                  * earlier than the receive of CMD_UNLINK, priv is moved to
 375                  * priv_tx queue and stub_rx does not find the target priv. In
 376                  * this case, vhci_rx receives the result of the submit request
 377                  * and then receives the result of the unlink request. The
 378                  * result of the submit is given back to the usbcore as the
 379                  * completion of the unlink request. The request of the
 380                  * unlink is ignored. This is ok because a driver who calls
 381                  * usb_unlink_urb() understands the unlink was too late by
 382                  * getting the status of the given-backed URB which has the
 383                  * status of usb_submit_urb().
 384                  */
 385                 if (stub_send_ret_submit(sdev) < 0)
 386                         break;
 387
 388                 if (stub_send_ret_unlink(sdev) < 0)
 389                         break;
 390
 391                 wait_event_interruptible(sdev->tx_waitq,
 392                                          (!list_empty(&sdev->priv_tx) ||
 393                                           !list_empty(&sdev->unlink_tx) ||
 394                                           kthread_should_stop()));
 395         }
 396
 397         return 0;
 398 }