drivers/usb/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 vhci_hcd *vhci = vdev_to_vhci(vdev);
  74         struct usbip_device *ud = &vdev->ud;
  75         struct urb *urb;
  76         unsigned long flags;
  77
  78         spin_lock_irqsave(&vdev->priv_lock, flags);
  79         urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
  80         spin_unlock_irqrestore(&vdev->priv_lock, flags);
  81
  82         if (!urb) {
  83                 pr_err("cannot find a urb of seqnum %u\n", pdu->base.seqnum);
  84                 pr_info("max seqnum %d\n",
  85                         atomic_read(&vhci->seqnum));
  86                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
  87                 return;
  88         }
  89
  90         /* unpack the pdu to a urb */
  91         usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
  92
  93         /* recv transfer buffer */
  94         if (usbip_recv_xbuff(ud, urb) < 0)
  95                 return;
  96
  97         /* recv iso_packet_descriptor */
  98         if (usbip_recv_iso(ud, urb) < 0)
  99                 return;
 100
 101         /* restore the padding in iso packets */
 102         usbip_pad_iso(ud, urb);
 103
 104         if (usbip_dbg_flag_vhci_rx)
 105                 usbip_dump_urb(urb);
 106
 107         usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 108
 109         spin_lock_irqsave(&vhci->lock, flags);
 110         usb_hcd_unlink_urb_from_ep(vhci_to_hcd(vhci), urb);
 111         spin_unlock_irqrestore(&vhci->lock, flags);
 112
 113         usb_hcd_giveback_urb(vhci_to_hcd(vhci), urb, urb->status);
 114
 115         usbip_dbg_vhci_rx("Leave\n");
 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         unsigned long flags;
 123
 124         spin_lock_irqsave(&vdev->priv_lock, flags);
 125
 126         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
 127                 pr_info("unlink->seqnum %lu\n", unlink->seqnum);
 128                 if (unlink->seqnum == pdu->base.seqnum) {
 129                         usbip_dbg_vhci_rx("found pending unlink, %lu\n",
 130                                           unlink->seqnum);
 131                         list_del(&unlink->list);
 132
 133                         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 134                         return unlink;
 135                 }
 136         }
 137
 138         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 139
 140         return NULL;
 141 }
 142
 143 static void vhci_recv_ret_unlink(struct vhci_device *vdev,
 144                                  struct usbip_header *pdu)
 145 {
 146         struct vhci_hcd *vhci = vdev_to_vhci(vdev);
 147         struct vhci_unlink *unlink;
 148         struct urb *urb;
 149         unsigned long flags;
 150
 151         usbip_dump_header(pdu);
 152
 153         unlink = dequeue_pending_unlink(vdev, pdu);
 154         if (!unlink) {
 155                 pr_info("cannot find the pending unlink %u\n",
 156                         pdu->base.seqnum);
 157                 return;
 158         }
 159
 160         spin_lock_irqsave(&vdev->priv_lock, flags);
 161         urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 162         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 163
 164         if (!urb) {
 165                 /*
 166                  * I get the result of a unlink request. But, it seems that I
 167                  * already received the result of its submit result and gave
 168                  * back the URB.
 169                  */
 170                 pr_info("the urb (seqnum %d) was already given back\n",
 171                         pdu->base.seqnum);
 172         } else {
 173                 usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 174
 175                 /* If unlink is successful, status is -ECONNRESET */
 176                 urb->status = pdu->u.ret_unlink.status;
 177                 pr_info("urb->status %d\n", urb->status);
 178
 179                 spin_lock_irqsave(&vhci->lock, flags);
 180                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(vhci), urb);
 181                 spin_unlock_irqrestore(&vhci->lock, flags);
 182
 183                 usb_hcd_giveback_urb(vhci_to_hcd(vhci), urb, urb->status);
 184         }
 185
 186         kfree(unlink);
 187 }
 188
 189 static int vhci_priv_tx_empty(struct vhci_device *vdev)
 190 {
 191         int empty = 0;
 192         unsigned long flags;
 193
 194         spin_lock_irqsave(&vdev->priv_lock, flags);
 195         empty = list_empty(&vdev->priv_rx);
 196         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 197
 198         return empty;
 199 }
 200
 201 /* recv a pdu */
 202 static void vhci_rx_pdu(struct usbip_device *ud)
 203 {
 204         int ret;
 205         struct usbip_header pdu;
 206         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 207
 208         usbip_dbg_vhci_rx("Enter\n");
 209
 210         memset(&pdu, 0, sizeof(pdu));
 211
 212         /* receive a pdu header */
 213         ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
 214         if (ret < 0) {
 215                 if (ret == -ECONNRESET)
 216                         pr_info("connection reset by peer\n");
 217                 else if (ret == -EAGAIN) {
 218                         /* ignore if connection was idle */
 219                         if (vhci_priv_tx_empty(vdev))
 220                                 return;
 221                         pr_info("connection timed out with pending urbs\n");
 222                 } else if (ret != -ERESTARTSYS)
 223                         pr_info("xmit failed %d\n", ret);
 224
 225                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 226                 return;
 227         }
 228         if (ret == 0) {
 229                 pr_info("connection closed");
 230                 usbip_event_add(ud, VDEV_EVENT_DOWN);
 231                 return;
 232         }
 233         if (ret != sizeof(pdu)) {
 234                 pr_err("received pdu size is %d, should be %d\n", ret,
 235                        (unsigned int)sizeof(pdu));
 236                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 237                 return;
 238         }
 239
 240         usbip_header_correct_endian(&pdu, 0);
 241
 242         if (usbip_dbg_flag_vhci_rx)
 243                 usbip_dump_header(&pdu);
 244
 245         switch (pdu.base.command) {
 246         case USBIP_RET_SUBMIT:
 247                 vhci_recv_ret_submit(vdev, &pdu);
 248                 break;
 249         case USBIP_RET_UNLINK:
 250                 vhci_recv_ret_unlink(vdev, &pdu);
 251                 break;
 252         default:
 253                 /* NOT REACHED */
 254                 pr_err("unknown pdu %u\n", pdu.base.command);
 255                 usbip_dump_header(&pdu);
 256                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 257                 break;
 258         }
 259 }
 260
 261 int vhci_rx_loop(void *data)
 262 {
 263         struct usbip_device *ud = data;
 264
 265         while (!kthread_should_stop()) {
 266                 if (usbip_event_happened(ud))
 267                         break;
 268
 269                 vhci_rx_pdu(ud);
 270         }
 271
 272         return 0;
 273 }