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         urb->setup_packet = NULL;
  32
  33         kfree(urb->transfer_buffer);
  34         urb->transfer_buffer = NULL;
  35
  36         list_del(&priv->list);
  37         kmem_cache_free(stub_priv_cache, priv);
  38         usb_free_urb(urb);
  39 }
  40
  41 /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
  42 void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
  43                              __u32 status)
  44 {
  45         struct stub_unlink *unlink;
  46
  47         unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
  48         if (!unlink) {
  49                 usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
  50                 return;
  51         }
  52
  53         unlink->seqnum = seqnum;
  54         unlink->status = status;
  55
  56         list_add_tail(&unlink->list, &sdev->unlink_tx);
  57 }
  58
  59 /**
  60  * stub_complete - completion handler of a usbip urb
  61  * @urb: pointer to the urb completed
  62  *
  63  * When a urb has completed, the USB core driver calls this function mostly in
  64  * the interrupt context. To return the result of a urb, the completed urb is
  65  * linked to the pending list of returning.
  66  *
  67  */
  68 void stub_complete(struct urb *urb)
  69 {
  70         struct stub_priv *priv = (struct stub_priv *) urb->context;
  71         struct stub_device *sdev = priv->sdev;
  72         unsigned long flags;
  73
  74         usbip_dbg_stub_tx("complete! status %d\n", urb->status);
  75
  76         switch (urb->status) {
  77         case 0:
  78                 /* OK */
  79                 break;
  80         case -ENOENT:
  81                 dev_info(&urb->dev->dev,
  82                          "stopped by a call to usb_kill_urb() because of cleaning up a virtual connection\n");
  83                 return;
  84         case -ECONNRESET:
  85                 dev_info(&urb->dev->dev,
  86                          "unlinked by a call to usb_unlink_urb()\n");
  87                 break;
  88         case -EPIPE:
  89                 dev_info(&urb->dev->dev, "endpoint %d is stalled\n",
  90                          usb_pipeendpoint(urb->pipe));
  91                 break;
  92         case -ESHUTDOWN:
  93                 dev_info(&urb->dev->dev, "device removed?\n");
  94                 break;
  95         default:
  96                 dev_info(&urb->dev->dev,
  97                          "urb completion with non-zero status %d\n",
  98                          urb->status);
  99                 break;
 100         }
 101
 102         /* link a urb to the queue of tx. */
 103         spin_lock_irqsave(&sdev->priv_lock, flags);
 104         if (sdev->ud.tcp_socket == NULL) {
 105                 usbip_dbg_stub_tx("ignore urb for closed connection\n");
 106                 /* It will be freed in stub_device_cleanup_urbs(). */
 107         } else if (priv->unlinking) {
 108                 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
 109                 stub_free_priv_and_urb(priv);
 110         } else {
 111                 list_move_tail(&priv->list, &sdev->priv_tx);
 112         }
 113         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 114
 115         /* wake up tx_thread */
 116         wake_up(&sdev->tx_waitq);
 117 }
 118
 119 static inline void setup_base_pdu(struct usbip_header_basic *base,
 120                                   __u32 command, __u32 seqnum)
 121 {
 122         base->command   = command;
 123         base->seqnum    = seqnum;
 124         base->devid     = 0;
 125         base->ep        = 0;
 126         base->direction = 0;
 127 }
 128
 129 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
 130 {
 131         struct stub_priv *priv = (struct stub_priv *) urb->context;
 132
 133         setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
 134         usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
 135 }
 136
 137 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
 138                                  struct stub_unlink *unlink)
 139 {
 140         setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
 141         rpdu->u.ret_unlink.status = unlink->status;
 142 }
 143
 144 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
 145 {
 146         unsigned long flags;
 147         struct stub_priv *priv, *tmp;
 148
 149         spin_lock_irqsave(&sdev->priv_lock, flags);
 150
 151         list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
 152                 list_move_tail(&priv->list, &sdev->priv_free);
 153                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 154                 return priv;
 155         }
 156
 157         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 158
 159         return NULL;
 160 }
 161
 162 static int stub_send_ret_submit(struct stub_device *sdev)
 163 {
 164         unsigned long flags;
 165         struct stub_priv *priv, *tmp;
 166
 167         struct msghdr msg;
 168         size_t txsize;
 169
 170         size_t total_size = 0;
 171
 172         while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
 173                 int ret;
 174                 struct urb *urb = priv->urb;
 175                 struct usbip_header pdu_header;
 176                 struct usbip_iso_packet_descriptor *iso_buffer = NULL;
 177                 struct kvec *iov = NULL;
 178                 int iovnum = 0;
 179
 180                 txsize = 0;
 181                 memset(&pdu_header, 0, sizeof(pdu_header));
 182                 memset(&msg, 0, sizeof(msg));
 183
 184                 if (urb->actual_length > 0 && !urb->transfer_buffer) {
 185                         dev_err(&sdev->udev->dev,
 186                                 "urb: actual_length %d transfer_buffer null\n",
 187                                 urb->actual_length);
 188                         return -1;
 189                 }
 190
 191                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
 192                         iovnum = 2 + urb->number_of_packets;
 193                 else
 194                         iovnum = 2;
 195
 196                 iov = kcalloc(iovnum, sizeof(struct kvec), GFP_KERNEL);
 197
 198                 if (!iov) {
 199                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
 200                         return -1;
 201                 }
 202
 203                 iovnum = 0;
 204
 205                 /* 1. setup usbip_header */
 206                 setup_ret_submit_pdu(&pdu_header, urb);
 207                 usbip_dbg_stub_tx("setup txdata seqnum: %d\n",
 208                                   pdu_header.base.seqnum);
 209                 usbip_header_correct_endian(&pdu_header, 1);
 210
 211                 iov[iovnum].iov_base = &pdu_header;
 212                 iov[iovnum].iov_len  = sizeof(pdu_header);
 213                 iovnum++;
 214                 txsize += sizeof(pdu_header);
 215
 216                 /* 2. setup transfer buffer */
 217                 if (usb_pipein(urb->pipe) &&
 218                     usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
 219                     urb->actual_length > 0) {
 220                         iov[iovnum].iov_base = urb->transfer_buffer;
 221                         iov[iovnum].iov_len  = urb->actual_length;
 222                         iovnum++;
 223                         txsize += urb->actual_length;
 224                 } else if (usb_pipein(urb->pipe) &&
 225                            usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 226                         /*
 227                          * For isochronous packets: actual length is the sum of
 228                          * the actual length of the individual, packets, but as
 229                          * the packet offsets are not changed there will be
 230                          * padding between the packets. To optimally use the
 231                          * bandwidth the padding is not transmitted.
 232                          */
 233
 234                         int i;
 235
 236                         for (i = 0; i < urb->number_of_packets; i++) {
 237                                 iov[iovnum].iov_base = urb->transfer_buffer +
 238                                         urb->iso_frame_desc[i].offset;
 239                                 iov[iovnum].iov_len =
 240                                         urb->iso_frame_desc[i].actual_length;
 241                                 iovnum++;
 242                                 txsize += urb->iso_frame_desc[i].actual_length;
 243                         }
 244
 245                         if (txsize != sizeof(pdu_header) + urb->actual_length) {
 246                                 dev_err(&sdev->udev->dev,
 247                                         "actual length of urb %d does not match iso packet sizes %zu\n",
 248                                         urb->actual_length,
 249                                         txsize-sizeof(pdu_header));
 250                                 kfree(iov);
 251                                 usbip_event_add(&sdev->ud,
 252                                                 SDEV_EVENT_ERROR_TCP);
 253                            return -1;
 254                         }
 255                 }
 256
 257                 /* 3. setup iso_packet_descriptor */
 258                 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
 259                         ssize_t len = 0;
 260
 261                         iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
 262                         if (!iso_buffer) {
 263                                 usbip_event_add(&sdev->ud,
 264                                                 SDEV_EVENT_ERROR_MALLOC);
 265                                 kfree(iov);
 266                                 return -1;
 267                         }
 268
 269                         iov[iovnum].iov_base = iso_buffer;
 270                         iov[iovnum].iov_len  = len;
 271                         txsize += len;
 272                         iovnum++;
 273                 }
 274
 275                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
 276                                                 iov,  iovnum, txsize);
 277                 if (ret != txsize) {
 278                         dev_err(&sdev->udev->dev,
 279                                 "sendmsg failed!, retval %d for %zd\n",
 280                                 ret, txsize);
 281                         kfree(iov);
 282                         kfree(iso_buffer);
 283                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 284                         return -1;
 285                 }
 286
 287                 kfree(iov);
 288                 kfree(iso_buffer);
 289
 290                 total_size += txsize;
 291         }
 292
 293         spin_lock_irqsave(&sdev->priv_lock, flags);
 294         list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
 295                 stub_free_priv_and_urb(priv);
 296         }
 297         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 298
 299         return total_size;
 300 }
 301
 302 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
 303 {
 304         unsigned long flags;
 305         struct stub_unlink *unlink, *tmp;
 306
 307         spin_lock_irqsave(&sdev->priv_lock, flags);
 308
 309         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 310                 list_move_tail(&unlink->list, &sdev->unlink_free);
 311                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 312                 return unlink;
 313         }
 314
 315         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 316
 317         return NULL;
 318 }
 319
 320 static int stub_send_ret_unlink(struct stub_device *sdev)
 321 {
 322         unsigned long flags;
 323         struct stub_unlink *unlink, *tmp;
 324
 325         struct msghdr msg;
 326         struct kvec iov[1];
 327         size_t txsize;
 328
 329         size_t total_size = 0;
 330
 331         while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
 332                 int ret;
 333                 struct usbip_header pdu_header;
 334
 335                 txsize = 0;
 336                 memset(&pdu_header, 0, sizeof(pdu_header));
 337                 memset(&msg, 0, sizeof(msg));
 338                 memset(&iov, 0, sizeof(iov));
 339
 340                 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
 341
 342                 /* 1. setup usbip_header */
 343                 setup_ret_unlink_pdu(&pdu_header, unlink);
 344                 usbip_header_correct_endian(&pdu_header, 1);
 345
 346                 iov[0].iov_base = &pdu_header;
 347                 iov[0].iov_len  = sizeof(pdu_header);
 348                 txsize += sizeof(pdu_header);
 349
 350                 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
 351                                      1, txsize);
 352                 if (ret != txsize) {
 353                         dev_err(&sdev->udev->dev,
 354                                 "sendmsg failed!, retval %d for %zd\n",
 355                                 ret, txsize);
 356                         usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
 357                         return -1;
 358                 }
 359
 360                 usbip_dbg_stub_tx("send txdata\n");
 361                 total_size += txsize;
 362         }
 363
 364         spin_lock_irqsave(&sdev->priv_lock, flags);
 365
 366         list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
 367                 list_del(&unlink->list);
 368                 kfree(unlink);
 369         }
 370
 371         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 372
 373         return total_size;
 374 }
 375
 376 int stub_tx_loop(void *data)
 377 {
 378         struct usbip_device *ud = data;
 379         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 380
 381         while (!kthread_should_stop()) {
 382                 if (usbip_event_happened(ud))
 383                         break;
 384
 385                 /*
 386                  * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
 387                  * looks at only priv_init queue. If the completion of a URB is
 388                  * earlier than the receive of CMD_UNLINK, priv is moved to
 389                  * priv_tx queue and stub_rx does not find the target priv. In
 390                  * this case, vhci_rx receives the result of the submit request
 391                  * and then receives the result of the unlink request. The
 392                  * result of the submit is given back to the usbcore as the
 393                  * completion of the unlink request. The request of the
 394                  * unlink is ignored. This is ok because a driver who calls
 395                  * usb_unlink_urb() understands the unlink was too late by
 396                  * getting the status of the given-backed URB which has the
 397                  * status of usb_submit_urb().
 398                  */
 399                 if (stub_send_ret_submit(sdev) < 0)
 400                         break;
 401
 402                 if (stub_send_ret_unlink(sdev) < 0)
 403                         break;
 404
 405                 wait_event_interruptible(sdev->tx_waitq,
 406                                          (!list_empty(&sdev->priv_tx) ||
 407                                           !list_empty(&sdev->unlink_tx) ||
 408                                           kthread_should_stop()));
 409         }
 410
 411         return 0;
 412 }