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 seqnum %u\n", seqnum);
  41
  42                 switch (status) {
  43                 case -ENOENT:
  44                         /* fall through */
  45                 case -ECONNRESET:
  46                         dev_dbg(&urb->dev->dev,
  47                                  "urb seq# %u was unlinked %ssynchronuously\n",
  48                                  seqnum, status == -ENOENT ? "" : "a");
  49                         break;
  50                 case -EINPROGRESS:
  51                         /* no info output */
  52                         break;
  53                 default:
  54                         dev_dbg(&urb->dev->dev,
  55                                  "urb seq# %u may be in a error, status %d\n",
  56                                  seqnum, status);
  57                 }
  58
  59                 list_del(&priv->list);
  60                 kfree(priv);
  61                 urb->hcpriv = NULL;
  62
  63                 break;
  64         }
  65
  66         return urb;
  67 }
  68
  69 static void vhci_recv_ret_submit(struct vhci_device *vdev,
  70                                  struct usbip_header *pdu)
  71 {
  72         struct vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev);
  73         struct vhci *vhci = vhci_hcd->vhci;
  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 max seqnum %d\n",
  84                         pdu->base.seqnum,
  85                         atomic_read(&vhci_hcd->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                 urb->status = -EPROTO;
  96                 goto error;
  97         }
  98
  99         /* recv iso_packet_descriptor */
 100         if (usbip_recv_iso(ud, urb) < 0) {
 101                 urb->status = -EPROTO;
 102                 goto error;
 103         }
 104
 105         /* restore the padding in iso packets */
 106         usbip_pad_iso(ud, urb);
 107
 108 error:
 109         if (usbip_dbg_flag_vhci_rx)
 110                 usbip_dump_urb(urb);
 111
 112         if (urb->num_sgs)
 113                 urb->transfer_flags &= ~URB_DMA_MAP_SG;
 114
 115         usbip_dbg_vhci_rx("now giveback urb %u\n", pdu->base.seqnum);
 116
 117         spin_lock_irqsave(&vhci->lock, flags);
 118         usb_hcd_unlink_urb_from_ep(vhci_hcd_to_hcd(vhci_hcd), urb);
 119         spin_unlock_irqrestore(&vhci->lock, flags);
 120
 121         usb_hcd_giveback_urb(vhci_hcd_to_hcd(vhci_hcd), urb, urb->status);
 122
 123         usbip_dbg_vhci_rx("Leave\n");
 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         unsigned long flags;
 131
 132         spin_lock_irqsave(&vdev->priv_lock, flags);
 133
 134         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
 135                 pr_info("unlink->seqnum %lu\n", unlink->seqnum);
 136                 if (unlink->seqnum == pdu->base.seqnum) {
 137                         usbip_dbg_vhci_rx("found pending unlink, %lu\n",
 138                                           unlink->seqnum);
 139                         list_del(&unlink->list);
 140
 141                         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 142                         return unlink;
 143                 }
 144         }
 145
 146         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 147
 148         return NULL;
 149 }
 150
 151 static void vhci_recv_ret_unlink(struct vhci_device *vdev,
 152                                  struct usbip_header *pdu)
 153 {
 154         struct vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev);
 155         struct vhci *vhci = vhci_hcd->vhci;
 156         struct vhci_unlink *unlink;
 157         struct urb *urb;
 158         unsigned long flags;
 159
 160         usbip_dump_header(pdu);
 161
 162         unlink = dequeue_pending_unlink(vdev, pdu);
 163         if (!unlink) {
 164                 pr_info("cannot find the pending unlink %u\n",
 165                         pdu->base.seqnum);
 166                 return;
 167         }
 168
 169         spin_lock_irqsave(&vdev->priv_lock, flags);
 170         urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 171         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 172
 173         if (!urb) {
 174                 /*
 175                  * I get the result of a unlink request. But, it seems that I
 176                  * already received the result of its submit result and gave
 177                  * back the URB.
 178                  */
 179                 pr_info("the urb (seqnum %d) was already given back\n",
 180                         pdu->base.seqnum);
 181         } else {
 182                 usbip_dbg_vhci_rx("now giveback urb %d\n", pdu->base.seqnum);
 183
 184                 /* If unlink is successful, status is -ECONNRESET */
 185                 urb->status = pdu->u.ret_unlink.status;
 186                 pr_info("urb->status %d\n", urb->status);
 187
 188                 spin_lock_irqsave(&vhci->lock, flags);
 189                 usb_hcd_unlink_urb_from_ep(vhci_hcd_to_hcd(vhci_hcd), urb);
 190                 spin_unlock_irqrestore(&vhci->lock, flags);
 191
 192                 usb_hcd_giveback_urb(vhci_hcd_to_hcd(vhci_hcd), urb, urb->status);
 193         }
 194
 195         kfree(unlink);
 196 }
 197
 198 static int vhci_priv_tx_empty(struct vhci_device *vdev)
 199 {
 200         int empty = 0;
 201         unsigned long flags;
 202
 203         spin_lock_irqsave(&vdev->priv_lock, flags);
 204         empty = list_empty(&vdev->priv_rx);
 205         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 206
 207         return empty;
 208 }
 209
 210 /* recv a pdu */
 211 static void vhci_rx_pdu(struct usbip_device *ud)
 212 {
 213         int ret;
 214         struct usbip_header pdu;
 215         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 216
 217         usbip_dbg_vhci_rx("Enter\n");
 218
 219         memset(&pdu, 0, sizeof(pdu));
 220
 221         /* receive a pdu header */
 222         ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
 223         if (ret < 0) {
 224                 if (ret == -ECONNRESET)
 225                         pr_info("connection reset by peer\n");
 226                 else if (ret == -EAGAIN) {
 227                         /* ignore if connection was idle */
 228                         if (vhci_priv_tx_empty(vdev))
 229                                 return;
 230                         pr_info("connection timed out with pending urbs\n");
 231                 } else if (ret != -ERESTARTSYS)
 232                         pr_info("xmit failed %d\n", ret);
 233
 234                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 235                 return;
 236         }
 237         if (ret == 0) {
 238                 pr_info("connection closed");
 239                 usbip_event_add(ud, VDEV_EVENT_DOWN);
 240                 return;
 241         }
 242         if (ret != sizeof(pdu)) {
 243                 pr_err("received pdu size is %d, should be %d\n", ret,
 244                        (unsigned int)sizeof(pdu));
 245                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 246                 return;
 247         }
 248
 249         usbip_header_correct_endian(&pdu, 0);
 250
 251         if (usbip_dbg_flag_vhci_rx)
 252                 usbip_dump_header(&pdu);
 253
 254         switch (pdu.base.command) {
 255         case USBIP_RET_SUBMIT:
 256                 vhci_recv_ret_submit(vdev, &pdu);
 257                 break;
 258         case USBIP_RET_UNLINK:
 259                 vhci_recv_ret_unlink(vdev, &pdu);
 260                 break;
 261         default:
 262                 /* NOT REACHED */
 263                 pr_err("unknown pdu %u\n", pdu.base.command);
 264                 usbip_dump_header(&pdu);
 265                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 266                 break;
 267         }
 268 }
 269
 270 int vhci_rx_loop(void *data)
 271 {
 272         struct usbip_device *ud = data;
 273
 274         while (!kthread_should_stop()) {
 275                 if (usbip_event_happened(ud))
 276                         break;
 277
 278                 vhci_rx_pdu(ud);
 279         }
 280
 281         return 0;
 282 }