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
  22 #include "usbip_common.h"
  23 #include "vhci.h"
  24
  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,
  28                                             __u32 seqnum)
  29 {
  30         struct vhci_priv *priv, *tmp;
  31         struct urb *urb = NULL;
  32         int status;
  33
  34         list_for_each_entry_safe(priv, tmp, &vdev->priv_rx, list) {
  35                 if (priv->seqnum == seqnum) {
  36                         urb = priv->urb;
  37                         status = urb->status;
  38
  39                         usbip_dbg_vhci_rx("find urb %p vurb %p seqnum %u\n",
  40                                     urb, priv, seqnum);
  41
  42                         /* TODO: fix logic here to improve indent situtation */
  43                         if (status != -EINPROGRESS) {
  44                                 if (status == -ENOENT ||
  45                                      status == -ECONNRESET)
  46                                         dev_info(&urb->dev->dev,
  47                                                  "urb %p was unlinked "
  48                                                  "%ssynchronuously.\n", urb,
  49                                                  status == -ENOENT ? "" : "a");
  50                                 else
  51                                         dev_info(&urb->dev->dev,
  52                                                  "urb %p may be in a error, "
  53                                                  "status %d\n", urb, status);
  54                         }
  55
  56                         list_del(&priv->list);
  57                         kfree(priv);
  58                         urb->hcpriv = NULL;
  59
  60                         break;
  61                 }
  62         }
  63
  64         return urb;
  65 }
  66
  67 static void vhci_recv_ret_submit(struct vhci_device *vdev,
  68                                                 struct usbip_header *pdu)
  69 {
  70         struct usbip_device *ud = &vdev->ud;
  71         struct urb *urb;
  72
  73         spin_lock(&vdev->priv_lock);
  74
  75         urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
  76
  77         spin_unlock(&vdev->priv_lock);
  78
  79         if (!urb) {
  80                 usbip_uerr("cannot find a urb of seqnum %u\n",
  81                                                         pdu->base.seqnum);
  82                 usbip_uinfo("max seqnum %d\n",
  83                                         atomic_read(&the_controller->seqnum));
  84                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
  85                 return;
  86         }
  87
  88
  89         /* unpack the pdu to a urb */
  90         usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
  91
  92
  93         /* recv transfer buffer */
  94         if (usbip_recv_xbuff(ud, urb) < 0)
  95                 return;
  96
  97
  98         /* recv iso_packet_descriptor */
  99         if (usbip_recv_iso(ud, urb) < 0)
 100                 return;
 101
 102
 103         if (usbip_dbg_flag_vhci_rx)
 104                 usbip_dump_urb(urb);
 105
 106
 107         usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 108
 109         spin_lock(&the_controller->lock);
 110         usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 111         spin_unlock(&the_controller->lock);
 112
 113         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
 114
 115
 116         usbip_dbg_vhci_rx("Leave\n");
 117
 118         return;
 119 }
 120
 121
 122 static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
 123                 struct usbip_header *pdu)
 124 {
 125         struct vhci_unlink *unlink, *tmp;
 126
 127         spin_lock(&vdev->priv_lock);
 128
 129         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
 130                 usbip_uinfo("unlink->seqnum %lu\n", unlink->seqnum);
 131                 if (unlink->seqnum == pdu->base.seqnum) {
 132                         usbip_dbg_vhci_rx("found pending unlink, %lu\n",
 133                                                         unlink->seqnum);
 134                         list_del(&unlink->list);
 135
 136                         spin_unlock(&vdev->priv_lock);
 137                         return unlink;
 138                 }
 139         }
 140
 141         spin_unlock(&vdev->priv_lock);
 142
 143         return NULL;
 144 }
 145
 146
 147 static void vhci_recv_ret_unlink(struct vhci_device *vdev,
 148                                                 struct usbip_header *pdu)
 149 {
 150         struct vhci_unlink *unlink;
 151         struct urb *urb;
 152
 153         usbip_dump_header(pdu);
 154
 155         unlink = dequeue_pending_unlink(vdev, pdu);
 156         if (!unlink) {
 157                 usbip_uinfo("cannot find the pending unlink %u\n",
 158                                                         pdu->base.seqnum);
 159                 return;
 160         }
 161
 162         spin_lock(&vdev->priv_lock);
 163
 164         urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 165
 166         spin_unlock(&vdev->priv_lock);
 167
 168         if (!urb) {
 169                 /*
 170                  * I get the result of a unlink request. But, it seems that I
 171                  * already received the result of its submit result and gave
 172                  * back the URB.
 173                  */
 174                 usbip_uinfo("the urb (seqnum %d) was already given backed\n",
 175                                                         pdu->base.seqnum);
 176         } else {
 177                 usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 178
 179                 /* If unlink is succeed, status is -ECONNRESET */
 180                 urb->status = pdu->u.ret_unlink.status;
 181                 usbip_uinfo("%d\n", urb->status);
 182
 183                 spin_lock(&the_controller->lock);
 184                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 185                 spin_unlock(&the_controller->lock);
 186
 187                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 188                                                                 urb->status);
 189         }
 190
 191         kfree(unlink);
 192
 193         return;
 194 }
 195
 196 static int vhci_priv_tx_empty(struct vhci_device *vdev)
 197 {
 198         int empty = 0;
 199
 200         spin_lock(&vdev->priv_lock);
 201
 202         empty = list_empty(&vdev->priv_rx);
 203
 204         spin_unlock(&vdev->priv_lock);
 205
 206         return empty;
 207 }
 208
 209 /* recv a pdu */
 210 static void vhci_rx_pdu(struct usbip_device *ud)
 211 {
 212         int ret;
 213         struct usbip_header pdu;
 214         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 215
 216
 217         usbip_dbg_vhci_rx("Enter\n");
 218
 219         memset(&pdu, 0, sizeof(pdu));
 220
 221         /* 1. receive a pdu header */
 222         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
 223         if (ret < 0) {
 224                 if (ret == -ECONNRESET)
 225                         usbip_uinfo("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                         usbip_uinfo("connection timed out with pending urbs\n");
 231                 } else if (ret != -ERESTARTSYS)
 232                         usbip_uinfo("xmit failed %d\n", ret);
 233
 234                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 235                 return;
 236         }
 237         if (ret == 0) {
 238                 usbip_uinfo("connection closed");
 239                 usbip_event_add(ud, VDEV_EVENT_DOWN);
 240                 return;
 241         }
 242         if (ret != sizeof(pdu)) {
 243                 usbip_uerr("received pdu size is %d, should be %d\n",
 244                                         ret, (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                 /* NOTREACHED */
 263                 usbip_uerr("unknown pdu %u\n", pdu.base.command);
 264                 usbip_dump_header(&pdu);
 265                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 266         }
 267 }
 268
 269
 270 /*-------------------------------------------------------------------------*/
 271
 272 void vhci_rx_loop(struct usbip_task *ut)
 273 {
 274         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_rx);
 275
 276
 277         while (1) {
 278                 if (signal_pending(current)) {
 279                         usbip_dbg_vhci_rx("signal catched!\n");
 280                         break;
 281                 }
 282
 283
 284                 if (usbip_event_happened(ud))
 285                         break;
 286
 287                 vhci_rx_pdu(ud);
 288         }
 289 }
 290