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