drivers/staging/usbip/vhci_rx.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/slab.h>
  21 #include <linux/kthread.h>
  22
  23 #include "usbip_common.h"
  24 #include "vhci.h"
  25
  26
  27 /* get URB from transmitted urb queue. caller must hold vdev->priv_lock */
  28 struct urb *pickup_urb_and_free_priv(struct vhci_device *vdev,
  29                                             __u32 seqnum)
  30 {
  31         struct vhci_priv *priv, *tmp;
  32         struct urb *urb = NULL;
  33         int status;
  34
  35         list_for_each_entry_safe(priv, tmp, &vdev->priv_rx, list) {
  36                 if (priv->seqnum == seqnum) {
  37                         urb = priv->urb;
  38                         status = urb->status;
  39
  40                         usbip_dbg_vhci_rx("find urb %p vurb %p seqnum %u\n",
  41                                     urb, priv, seqnum);
  42
  43                         /* TODO: fix logic here to improve indent situtation */
  44                         if (status != -EINPROGRESS) {
  45                                 if (status == -ENOENT ||
  46                                      status == -ECONNRESET)
  47                                         dev_info(&urb->dev->dev,
  48                                                  "urb %p was unlinked "
  49                                                  "%ssynchronuously.\n", urb,
  50                                                  status == -ENOENT ? "" : "a");
  51                                 else
  52                                         dev_info(&urb->dev->dev,
  53                                                  "urb %p may be in a error, "
  54                                                  "status %d\n", urb, status);
  55                         }
  56
  57                         list_del(&priv->list);
  58                         kfree(priv);
  59                         urb->hcpriv = NULL;
  60
  61                         break;
  62                 }
  63         }
  64
  65         return urb;
  66 }
  67
  68 static void vhci_recv_ret_submit(struct vhci_device *vdev,
  69                                                 struct usbip_header *pdu)
  70 {
  71         struct usbip_device *ud = &vdev->ud;
  72         struct urb *urb;
  73
  74         spin_lock(&vdev->priv_lock);
  75
  76         urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
  77
  78         spin_unlock(&vdev->priv_lock);
  79
  80         if (!urb) {
  81                 usbip_uerr("cannot find a urb of seqnum %u\n",
  82                                                         pdu->base.seqnum);
  83                 usbip_uinfo("max seqnum %d\n",
  84                                         atomic_read(&the_controller->seqnum));
  85                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
  86                 return;
  87         }
  88
  89
  90         /* unpack the pdu to a urb */
  91         usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
  92
  93
  94         /* recv transfer buffer */
  95         if (usbip_recv_xbuff(ud, urb) < 0)
  96                 return;
  97
  98
  99         /* recv iso_packet_descriptor */
 100         if (usbip_recv_iso(ud, urb) < 0)
 101                 return;
 102
 103         /* restore the padding in iso packets */
 104         if (usbip_pad_iso(ud, urb) < 0)
 105                 return;
 106
 107         if (usbip_dbg_flag_vhci_rx)
 108                 usbip_dump_urb(urb);
 109
 110
 111         usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 112
 113         spin_lock(&the_controller->lock);
 114         usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 115         spin_unlock(&the_controller->lock);
 116
 117         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
 118
 119
 120         usbip_dbg_vhci_rx("Leave\n");
 121
 122         return;
 123 }
 124
 125
 126 static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
 127                 struct usbip_header *pdu)
 128 {
 129         struct vhci_unlink *unlink, *tmp;
 130
 131         spin_lock(&vdev->priv_lock);
 132
 133         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
 134                 usbip_uinfo("unlink->seqnum %lu\n", unlink->seqnum);
 135                 if (unlink->seqnum == pdu->base.seqnum) {
 136                         usbip_dbg_vhci_rx("found pending unlink, %lu\n",
 137                                                         unlink->seqnum);
 138                         list_del(&unlink->list);
 139
 140                         spin_unlock(&vdev->priv_lock);
 141                         return unlink;
 142                 }
 143         }
 144
 145         spin_unlock(&vdev->priv_lock);
 146
 147         return NULL;
 148 }
 149
 150
 151 static void vhci_recv_ret_unlink(struct vhci_device *vdev,
 152                                                 struct usbip_header *pdu)
 153 {
 154         struct vhci_unlink *unlink;
 155         struct urb *urb;
 156
 157         usbip_dump_header(pdu);
 158
 159         unlink = dequeue_pending_unlink(vdev, pdu);
 160         if (!unlink) {
 161                 usbip_uinfo("cannot find the pending unlink %u\n",
 162                                                         pdu->base.seqnum);
 163                 return;
 164         }
 165
 166         spin_lock(&vdev->priv_lock);
 167
 168         urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 169
 170         spin_unlock(&vdev->priv_lock);
 171
 172         if (!urb) {
 173                 /*
 174                  * I get the result of a unlink request. But, it seems that I
 175                  * already received the result of its submit result and gave
 176                  * back the URB.
 177                  */
 178                 usbip_uinfo("the urb (seqnum %d) was already given backed\n",
 179                                                         pdu->base.seqnum);
 180         } else {
 181                 usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 182
 183                 /* If unlink is succeed, status is -ECONNRESET */
 184                 urb->status = pdu->u.ret_unlink.status;
 185                 usbip_uinfo("%d\n", urb->status);
 186
 187                 spin_lock(&the_controller->lock);
 188                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 189                 spin_unlock(&the_controller->lock);
 190
 191                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 192                                                                 urb->status);
 193         }
 194
 195         kfree(unlink);
 196
 197         return;
 198 }
 199
 200 static int vhci_priv_tx_empty(struct vhci_device *vdev)
 201 {
 202         int empty = 0;
 203
 204         spin_lock(&vdev->priv_lock);
 205
 206         empty = list_empty(&vdev->priv_rx);
 207
 208         spin_unlock(&vdev->priv_lock);
 209
 210         return empty;
 211 }
 212
 213 /* recv a pdu */
 214 static void vhci_rx_pdu(struct usbip_device *ud)
 215 {
 216         int ret;
 217         struct usbip_header pdu;
 218         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 219
 220
 221         usbip_dbg_vhci_rx("Enter\n");
 222
 223         memset(&pdu, 0, sizeof(pdu));
 224
 225         /* 1. receive a pdu header */
 226         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
 227         if (ret < 0) {
 228                 if (ret == -ECONNRESET)
 229                         usbip_uinfo("connection reset by peer\n");
 230                 else if (ret == -EAGAIN) {
 231                         /* ignore if connection was idle */
 232                         if (vhci_priv_tx_empty(vdev))
 233                                 return;
 234                         usbip_uinfo("connection timed out with pending urbs\n");
 235                 } else if (ret != -ERESTARTSYS)
 236                         usbip_uinfo("xmit failed %d\n", ret);
 237
 238                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 239                 return;
 240         }
 241         if (ret == 0) {
 242                 usbip_uinfo("connection closed");
 243                 usbip_event_add(ud, VDEV_EVENT_DOWN);
 244                 return;
 245         }
 246         if (ret != sizeof(pdu)) {
 247                 usbip_uerr("received pdu size is %d, should be %d\n",
 248                                         ret, (unsigned int)sizeof(pdu));
 249                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 250                 return;
 251         }
 252
 253         usbip_header_correct_endian(&pdu, 0);
 254
 255         if (usbip_dbg_flag_vhci_rx)
 256                 usbip_dump_header(&pdu);
 257
 258         switch (pdu.base.command) {
 259         case USBIP_RET_SUBMIT:
 260                 vhci_recv_ret_submit(vdev, &pdu);
 261                 break;
 262         case USBIP_RET_UNLINK:
 263                 vhci_recv_ret_unlink(vdev, &pdu);
 264                 break;
 265         default:
 266                 /* NOTREACHED */
 267                 usbip_uerr("unknown pdu %u\n", pdu.base.command);
 268                 usbip_dump_header(&pdu);
 269                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 270         }
 271 }
 272
 273
 274 /*-------------------------------------------------------------------------*/
 275
 276 int vhci_rx_loop(void *data)
 277 {
 278         struct usbip_device *ud = data;
 279
 280
 281         while (!kthread_should_stop()) {
 282                 if (usbip_event_happened(ud))
 283                         break;
 284
 285                 vhci_rx_pdu(ud);
 286         }
 287
 288         return 0;
 289 }