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                         continue;
  36
  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                 switch (status) {
  44                 case -ENOENT:
  45                         /* fall through */
  46                 case -ECONNRESET:
  47                         dev_info(&urb->dev->dev,
  48                                  "urb %p was unlinked %ssynchronuously.\n", urb,
  49                                  status == -ENOENT ? "" : "a");
  50                         break;
  51                 case -EINPROGRESS:
  52                         /* no info output */
  53                         break;
  54                 default:
  55                         dev_info(&urb->dev->dev,
  56                                  "urb %p may be in a error, status %d\n", urb,
  57                                  status);
  58                 }
  59
  60                 list_del(&priv->list);
  61                 kfree(priv);
  62                 urb->hcpriv = NULL;
  63
  64                 break;
  65         }
  66
  67         return urb;
  68 }
  69
  70 static void vhci_recv_ret_submit(struct vhci_device *vdev,
  71                                  struct usbip_header *pdu)
  72 {
  73         struct usbip_device *ud = &vdev->ud;
  74         struct urb *urb;
  75
  76         spin_lock(&vdev->priv_lock);
  77         urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
  78         spin_unlock(&vdev->priv_lock);
  79
  80         if (!urb) {
  81                 pr_err("cannot find a urb of seqnum %u\n", pdu->base.seqnum);
  82                 pr_info("max seqnum %d\n",
  83                         atomic_read(&the_controller->seqnum));
  84                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
  85                 return;
  86         }
  87
  88         /* unpack the pdu to a urb */
  89         usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
  90
  91         /* recv transfer buffer */
  92         if (usbip_recv_xbuff(ud, urb) < 0)
  93                 return;
  94
  95         /* recv iso_packet_descriptor */
  96         if (usbip_recv_iso(ud, urb) < 0)
  97                 return;
  98
  99         /* restore the padding in iso packets */
 100         usbip_pad_iso(ud, urb);
 101
 102         if (usbip_dbg_flag_vhci_rx)
 103                 usbip_dump_urb(urb);
 104
 105         usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 106
 107         spin_lock(&the_controller->lock);
 108         usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 109         spin_unlock(&the_controller->lock);
 110
 111         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
 112
 113         usbip_dbg_vhci_rx("Leave\n");
 114
 115         return;
 116 }
 117
 118 static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
 119                                                   struct usbip_header *pdu)
 120 {
 121         struct vhci_unlink *unlink, *tmp;
 122
 123         spin_lock(&vdev->priv_lock);
 124
 125         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
 126                 pr_info("unlink->seqnum %lu\n", unlink->seqnum);
 127                 if (unlink->seqnum == pdu->base.seqnum) {
 128                         usbip_dbg_vhci_rx("found pending unlink, %lu\n",
 129                                           unlink->seqnum);
 130                         list_del(&unlink->list);
 131
 132                         spin_unlock(&vdev->priv_lock);
 133                         return unlink;
 134                 }
 135         }
 136
 137         spin_unlock(&vdev->priv_lock);
 138
 139         return NULL;
 140 }
 141
 142 static void vhci_recv_ret_unlink(struct vhci_device *vdev,
 143                                  struct usbip_header *pdu)
 144 {
 145         struct vhci_unlink *unlink;
 146         struct urb *urb;
 147
 148         usbip_dump_header(pdu);
 149
 150         unlink = dequeue_pending_unlink(vdev, pdu);
 151         if (!unlink) {
 152                 pr_info("cannot find the pending unlink %u\n",
 153                         pdu->base.seqnum);
 154                 return;
 155         }
 156
 157         spin_lock(&vdev->priv_lock);
 158         urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 159         spin_unlock(&vdev->priv_lock);
 160
 161         if (!urb) {
 162                 /*
 163                  * I get the result of a unlink request. But, it seems that I
 164                  * already received the result of its submit result and gave
 165                  * back the URB.
 166                  */
 167                 pr_info("the urb (seqnum %d) was already given back\n",
 168                         pdu->base.seqnum);
 169         } else {
 170                 usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 171
 172                 /* If unlink is successful, status is -ECONNRESET */
 173                 urb->status = pdu->u.ret_unlink.status;
 174                 pr_info("urb->status %d\n", urb->status);
 175
 176                 spin_lock(&the_controller->lock);
 177                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 178                 spin_unlock(&the_controller->lock);
 179
 180                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 181                                      urb->status);
 182         }
 183
 184         kfree(unlink);
 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         /* receive a pdu header */
 210         ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
 211         if (ret < 0) {
 212                 if (ret == -ECONNRESET)
 213                         pr_info("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                         pr_info("connection timed out with pending urbs\n");
 219                 } else if (ret != -ERESTARTSYS)
 220                         pr_info("xmit failed %d\n", ret);
 221
 222                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 223                 return;
 224         }
 225         if (ret == 0) {
 226                 pr_info("connection closed");
 227                 usbip_event_add(ud, VDEV_EVENT_DOWN);
 228                 return;
 229         }
 230         if (ret != sizeof(pdu)) {
 231                 pr_err("received pdu size is %d, should be %d\n", ret,
 232                        (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                 pr_err("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 }