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/kthread.h>
  21 #include <linux/slab.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                 pr_err("cannot find a urb of seqnum %u\n", pdu->base.seqnum);
  78                 pr_info("max seqnum %d\n",
  79                         atomic_read(&the_controller->seqnum));
  80                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
  81                 return;
  82         }
  83
  84         /* unpack the pdu to a urb */
  85         usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
  86
  87         /* recv transfer buffer */
  88         if (usbip_recv_xbuff(ud, urb) < 0)
  89                 return;
  90
  91         /* recv iso_packet_descriptor */
  92         if (usbip_recv_iso(ud, urb) < 0)
  93                 return;
  94
  95         /* restore the padding in iso packets */
  96         if (usbip_pad_iso(ud, urb) < 0)
  97                 return;
  98
  99         if (usbip_dbg_flag_vhci_rx)
 100                 usbip_dump_urb(urb);
 101
 102         usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 103
 104         spin_lock(&the_controller->lock);
 105         usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 106         spin_unlock(&the_controller->lock);
 107
 108         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
 109
 110         usbip_dbg_vhci_rx("Leave\n");
 111
 112         return;
 113 }
 114
 115 static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
 116                                                   struct usbip_header *pdu)
 117 {
 118         struct vhci_unlink *unlink, *tmp;
 119
 120         spin_lock(&vdev->priv_lock);
 121
 122         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
 123                 pr_info("unlink->seqnum %lu\n", unlink->seqnum);
 124                 if (unlink->seqnum == pdu->base.seqnum) {
 125                         usbip_dbg_vhci_rx("found pending unlink, %lu\n",
 126                                           unlink->seqnum);
 127                         list_del(&unlink->list);
 128
 129                         spin_unlock(&vdev->priv_lock);
 130                         return unlink;
 131                 }
 132         }
 133
 134         spin_unlock(&vdev->priv_lock);
 135
 136         return NULL;
 137 }
 138
 139 static void vhci_recv_ret_unlink(struct vhci_device *vdev,
 140                                  struct usbip_header *pdu)
 141 {
 142         struct vhci_unlink *unlink;
 143         struct urb *urb;
 144
 145         usbip_dump_header(pdu);
 146
 147         unlink = dequeue_pending_unlink(vdev, pdu);
 148         if (!unlink) {
 149                 pr_info("cannot find the pending unlink %u\n",
 150                         pdu->base.seqnum);
 151                 return;
 152         }
 153
 154         spin_lock(&vdev->priv_lock);
 155         urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 156         spin_unlock(&vdev->priv_lock);
 157
 158         if (!urb) {
 159                 /*
 160                  * I get the result of a unlink request. But, it seems that I
 161                  * already received the result of its submit result and gave
 162                  * back the URB.
 163                  */
 164                 pr_info("the urb (seqnum %d) was already given backed\n",
 165                         pdu->base.seqnum);
 166         } else {
 167                 usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 168
 169                 /* If unlink is succeed, status is -ECONNRESET */
 170                 urb->status = pdu->u.ret_unlink.status;
 171                 pr_info("urb->status %d\n", urb->status);
 172
 173                 spin_lock(&the_controller->lock);
 174                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 175                 spin_unlock(&the_controller->lock);
 176
 177                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 178                                      urb->status);
 179         }
 180
 181         kfree(unlink);
 182 }
 183
 184 static int vhci_priv_tx_empty(struct vhci_device *vdev)
 185 {
 186         int empty = 0;
 187
 188         spin_lock(&vdev->priv_lock);
 189         empty = list_empty(&vdev->priv_rx);
 190         spin_unlock(&vdev->priv_lock);
 191
 192         return empty;
 193 }
 194
 195 /* recv a pdu */
 196 static void vhci_rx_pdu(struct usbip_device *ud)
 197 {
 198         int ret;
 199         struct usbip_header pdu;
 200         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 201
 202         usbip_dbg_vhci_rx("Enter\n");
 203
 204         memset(&pdu, 0, sizeof(pdu));
 205
 206         /* 1. receive a pdu header */
 207         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
 208         if (ret < 0) {
 209                 if (ret == -ECONNRESET)
 210                         pr_info("connection reset by peer\n");
 211                 else if (ret == -EAGAIN) {
 212                         /* ignore if connection was idle */
 213                         if (vhci_priv_tx_empty(vdev))
 214                                 return;
 215                         pr_info("connection timed out with pending urbs\n");
 216                 } else if (ret != -ERESTARTSYS)
 217                         pr_info("xmit failed %d\n", ret);
 218
 219                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 220                 return;
 221         }
 222         if (ret == 0) {
 223                 pr_info("connection closed");
 224                 usbip_event_add(ud, VDEV_EVENT_DOWN);
 225                 return;
 226         }
 227         if (ret != sizeof(pdu)) {
 228                 pr_err("received pdu size is %d, should be %d\n", ret,
 229                        (unsigned int)sizeof(pdu));
 230                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 231                 return;
 232         }
 233
 234         usbip_header_correct_endian(&pdu, 0);
 235
 236         if (usbip_dbg_flag_vhci_rx)
 237                 usbip_dump_header(&pdu);
 238
 239         switch (pdu.base.command) {
 240         case USBIP_RET_SUBMIT:
 241                 vhci_recv_ret_submit(vdev, &pdu);
 242                 break;
 243         case USBIP_RET_UNLINK:
 244                 vhci_recv_ret_unlink(vdev, &pdu);
 245                 break;
 246         default:
 247                 /* NOT REACHED */
 248                 pr_err("unknown pdu %u\n", pdu.base.command);
 249                 usbip_dump_header(&pdu);
 250                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 251                 break;
 252         }
 253 }
 254
 255 int vhci_rx_loop(void *data)
 256 {
 257         struct usbip_device *ud = data;
 258
 259         while (!kthread_should_stop()) {
 260                 if (usbip_event_happened(ud))
 261                         break;
 262
 263                 vhci_rx_pdu(ud);
 264         }
 265
 266         return 0;
 267 }