drivers/usb/usbip/stub_tx.c

   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/socket.h>
  22
  23 #include "usbip_common.h"
  24 #include "stub.h"
  25
  26 static void stub_free_priv_and_urb(struct stub_priv *priv)
  27 {
  28         struct urb *urb = priv->urb;
  29
  30         kfree(urb->setup_packet);
  31         kfree(urb->transfer_buffer);
  32         list_del(&priv->list);
  33         kmem_cache_free(stub_priv_cache, priv);
  34         usb_free_urb(urb);
  35 }
  36
  37 /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
  38 void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
  39                              __u32 status)
  40 {
  41         struct stub_unlink *unlink;
  42
  43         unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
  44         if (!unlink) {
  45                 usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
  46                 return;
  47         }
  48
  49         unlink->seqnum = seqnum;
  50         unlink->status = status;
  51
  52         list_add_tail(&unlink->list, &sdev->unlink_tx);
  53 }
  54
  55 /**
  56  * stub_complete - completion handler of a usbip urb
  57  * @urb: pointer to the urb completed
  58  *
  59  * When a urb has completed, the USB core driver calls this function mostly in
  60  * the interrupt context. To return the result of a urb, the completed urb is
  61  * linked to the pending list of returning.
  62  *
  63  */
  64 void stub_complete(struct urb *urb)
  65 {
  66         struct stub_priv *priv = (struct stub_priv *) urb->context;
  67         struct stub_device *sdev = priv->sdev;
  68         unsigned long flags;
  69
  70         usbip_dbg_stub_tx("complete! status %d\n", urb->status);
  71
  72         switch (urb->status) {
  73         case 0:
  74                 /* OK */
  75                 break;
  76         case -ENOENT:
  77                 dev_info(&urb->dev->dev,
  78                          "stopped by a call to usb_kill_urb() because of cleaning up a virtual connection\n");
  79                 return;
  80         case -ECONNRESET:
  81                 dev_info(&urb->dev->dev,
  82                          "unlinked by a call to usb_unlink_urb()\n");
  83                 break;
  84         case -EPIPE:
  85                 dev_info(&urb->dev->dev, "endpoint %d is stalled\n",
  86                          usb_pipeendpoint(urb->pipe));
  87                 break;
  88         case -ESHUTDOWN:
  89                 dev_info(&urb->dev->dev, "device removed?\n");
  90                 break;
  91         default:
  92                 dev_info(&urb->dev->dev,
  93                          "urb completion with non-zero status %d\n",
  94                          urb->status);
  95                 break;
  96         }
  97
  98         /* link a urb to the queue of tx. */
  99         spin_lock_irqsave(&sdev->priv_lock, flags);
 100         if (sdev->ud.tcp_socket == NULL) {
 101                 usbip_dbg_stub_tx("ignore urb for closed connection %p", urb);
 102                 /* It will be freed in stub_device_cleanup_urbs(). */
 103         } else if (priv->unlinking) {
 104                 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
 105                 stub_free_priv_and_urb(priv);
 106         } else {
 107                 list_move_tail(&priv->list, &sdev->priv_tx);
 108         }
 109         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 110
 111         /* wake up tx_thread */
 112         wake_up(&sdev->tx_waitq);
 113 }
 114
 115 static inline void setup_base_pdu(struct usbip_header_basic *base,
 116                                   __u32 command, __u32 seqnum)
 117 {
 118         base->command   = command;
 119         base->seqnum    = seqnum;
 120         base->devid     = 0;
 121         base->ep        = 0;
 122         base->direction = 0;
 123 }
 124
 125 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
 126 {
 127         struct stub_priv *priv = (struct stub_priv *) urb->context;
 128
 129         setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
 130         usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
 131 }
 132
 133 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
 134                                  struct stub_unlink *unlink)
 135 {
 136         setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
 137         rpdu->u.ret_unlink.status = unlink->status;
 138 }
 139
 140 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
 141 {
 142         unsigned long flags;
 143         struct stub_priv *priv, *tmp;
 144
 145         spin_lock_irqsave(&sdev->priv_lock, flags);
 146
 147         list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
 148                 list_move_tail(&priv->list, &sdev->priv_free);
 149                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 150                 return priv;
 151         }
 152
 153         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 154
 155         return NULL;
 156 }
 157
 158 static int stub_send_ret_submit(struct stub_device *sdev)
 159 {
 160         unsigned long flags;
 161         struct stub_priv *priv, *tmp;
 162
 163         struct msghdr msg;
 164         size_t txsize;
 165
 166         size_t total_size = 0;
 167
 168         while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
 169                 int ret;
 170                 struct urb *urb = priv->urb;
 171                 struct usbip_header pdu_header;
 172                 struct usbip_iso_packet_descriptor *iso_buffer = NULL;
 173                 struct kvec *iov = NULL;
 174                 int iovnum = 0;
 175
 176                 txsize = 0;
 177                 memset(&pdu_header, 0, sizeof(pdu_header));
 178                 memset(&msg, 0, sizeof(msg));
 179
 180                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
 181                         iovnum = 2 + urb->number_of_packets;
 182                 else
 183                         iovnum = 2;
 184
 185                 iov = kcalloc(iovnum, sizeof(struct kvec), GFP_KERNEL);
 186
 187                 if (!iov) {
 188                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
 189                         return -1;
 190                 }
 191
 192                 iovnum = 0;
 193
 194                 /* 1. setup usbip_header */
 195                 setup_ret_submit_pdu(&pdu_header, urb);
 196                 usbip_dbg_stub_tx("setup txdata seqnum: %d urb: %p\n",
 197                                   pdu_header.base.seqnum, urb);
 198                 usbip_header_correct_endian(&pdu_header, 1);
 199
 200                 iov[iovnum].iov_base = &pdu_header;
 201                 iov[iovnum].iov_len  = sizeof(pdu_header);
 202                 iovnum++;
 203                 txsize += sizeof(pdu_header);
 204
 205                 /* 2. setup transfer buffer */
 206                 if (usb_pipein(urb->pipe) &&
 207                     usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
 208                     urb->actual_length > 0) {
 209                         iov[iovnum].iov_base = urb->transfer_buffer;
 210                         iov[iovnum].iov_len  = urb->actual_length;
 211                         iovnum++;
 212                         txsize += urb->actual_length;
 213                 } else if (usb_pipein(urb->pipe) &&
 214                            usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 215                         /*
 216                          * For isochronous packets: actual length is the sum of
 217                          * the actual length of the individual, packets, but as
 218                          * the packet offsets are not changed there will be
 219                          * padding between the packets. To optimally use the
 220                          * bandwidth the padding is not transmitted.
 221                          */
 222
 223                         int i;
 224
 225                         for (i = 0; i < urb->number_of_packets; i++) {
 226                                 iov[iovnum].iov_base = urb->transfer_buffer +
 227                                         urb->iso_frame_desc[i].offset;
 228                                 iov[iovnum].iov_len =
 229                                         urb->iso_frame_desc[i].actual_length;
 230                                 iovnum++;
 231                                 txsize += urb->iso_frame_desc[i].actual_length;
 232                         }
 233
 234                         if (txsize != sizeof(pdu_header) + urb->actual_length) {
 235                                 dev_err(&sdev->udev->dev,
 236                                         "actual length of urb %d does not match iso packet sizes %zu\n",
 237                                         urb->actual_length,
 238                                         txsize-sizeof(pdu_header));
 239                                 kfree(iov);
 240                                 usbip_event_add(&sdev->ud,
 241                                                 SDEV_EVENT_ERROR_TCP);
 242                            return -1;
 243                         }
 244                 }
 245
 246                 /* 3. setup iso_packet_descriptor */
 247                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 248                         ssize_t len = 0;
 249
 250                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 251                         if (!iso_buffer) {
 252                                 usbip_event_add(&sdev->ud,
 253                                                 SDEV_EVENT_ERROR_MALLOC);
 254                                 kfree(iov);
 255                                 return -1;
 256                         }
 257
 258                         iov[iovnum].iov_base = iso_buffer;
 259                         iov[iovnum].iov_len  = len;
 260                         txsize += len;
 261                         iovnum++;
 262                 }
 263
 264                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
 265                                                 iov,  iovnum, txsize);
 266                 if (ret != txsize) {
 267                         dev_err(&sdev->udev->dev,
 268                                 "sendmsg failed!, retval %d for %zd\n",
 269                                 ret, txsize);
 270                         kfree(iov);
 271                         kfree(iso_buffer);
 272                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 273                         return -1;
 274                 }
 275
 276                 kfree(iov);
 277                 kfree(iso_buffer);
 278
 279                 total_size += txsize;
 280         }
 281
 282         spin_lock_irqsave(&sdev->priv_lock, flags);
 283         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 284                 stub_free_priv_and_urb(priv);
 285         }
 286         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 287
 288         return total_size;
 289 }
 290
 291 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 292 {
 293         unsigned long flags;
 294         struct stub_unlink *unlink, *tmp;
 295
 296         spin_lock_irqsave(&sdev->priv_lock, flags);
 297
 298         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 299                 list_move_tail(&unlink->list, &sdev->unlink_free);
 300                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 301                 return unlink;
 302         }
 303
 304         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 305
 306         return NULL;
 307 }
 308
 309 static int stub_send_ret_unlink(struct stub_device *sdev)
 310 {
 311         unsigned long flags;
 312         struct stub_unlink *unlink, *tmp;
 313
 314         struct msghdr msg;
 315         struct kvec iov[1];
 316         size_t txsize;
 317
 318         size_t total_size = 0;
 319
 320         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 321                 int ret;
 322                 struct usbip_header pdu_header;
 323
 324                 txsize = 0;
 325                 memset(&pdu_header, 0, sizeof(pdu_header));
 326                 memset(&msg, 0, sizeof(msg));
 327                 memset(&iov, 0, sizeof(iov));
 328
 329                 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 330
 331                 /* 1. setup usbip_header */
 332                 setup_ret_unlink_pdu(&pdu_header, unlink);
 333                 usbip_header_correct_endian(&pdu_header, 1);
 334
 335                 iov[0].iov_base = &pdu_header;
 336                 iov[0].iov_len  = sizeof(pdu_header);
 337                 txsize += sizeof(pdu_header);
 338
 339                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 340                                      1, txsize);
 341                 if (ret != txsize) {
 342                         dev_err(&sdev->udev->dev,
 343                                 "sendmsg failed!, retval %d for %zd\n",
 344                                 ret, txsize);
 345                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 346                         return -1;
 347                 }
 348
 349                 usbip_dbg_stub_tx("send txdata\n");
 350                 total_size += txsize;
 351         }
 352
 353         spin_lock_irqsave(&sdev->priv_lock, flags);
 354
 355         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 356                 list_del(&unlink->list);
 357                 kfree(unlink);
 358         }
 359
 360         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 361
 362         return total_size;
 363 }
 364
 365 int stub_tx_loop(void *data)
 366 {
 367         struct usbip_device *ud = data;
 368         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 369
 370         while (!kthread_should_stop()) {
 371                 if (usbip_event_happened(ud))
 372                         break;
 373
 374                 /*
 375                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 376                  * looks at only priv_init queue. If the completion of a URB is
 377                  * earlier than the receive of CMD_UNLINK, priv is moved to
 378                  * priv_tx queue and stub_rx does not find the target priv. In
 379                  * this case, vhci_rx receives the result of the submit request
 380                  * and then receives the result of the unlink request. The
 381                  * result of the submit is given back to the usbcore as the
 382                  * completion of the unlink request. The request of the
 383                  * unlink is ignored. This is ok because a driver who calls
 384                  * usb_unlink_urb() understands the unlink was too late by
 385                  * getting the status of the given-backed URB which has the
 386                  * status of usb_submit_urb().
 387                  */
 388                 if (stub_send_ret_submit(sdev) < 0)
 389                         break;
 390
 391                 if (stub_send_ret_unlink(sdev) < 0)
 392                         break;
 393
 394                 wait_event_interruptible(sdev->tx_waitq,
 395                                          (!list_empty(&sdev->priv_tx) ||
 396                                           !list_empty(&sdev->unlink_tx) ||
 397                                           kthread_should_stop()));
 398         }
 399
 400         return 0;
 401 }