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         unsigned long flags;
  72
  73         spin_lock(&vdev->priv_lock);
  74         urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
  75         spin_unlock(&vdev->priv_lock);
  76
  77         if (!urb) {
  78                 pr_err("cannot find a urb of seqnum %u\n", pdu->base.seqnum);
  79                 pr_info("max seqnum %d\n",
  80                         atomic_read(&the_controller->seqnum));
  81                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
  82                 return;
  83         }
  84
  85         /* unpack the pdu to a urb */
  86         usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
  87
  88         /* recv transfer buffer */
  89         if (usbip_recv_xbuff(ud, urb) < 0)
  90                 return;
  91
  92         /* recv iso_packet_descriptor */
  93         if (usbip_recv_iso(ud, urb) < 0)
  94                 return;
  95
  96         /* restore the padding in iso packets */
  97         if (usbip_pad_iso(ud, urb) < 0)
  98                 return;
  99
 100         if (usbip_dbg_flag_vhci_rx)
 101                 usbip_dump_urb(urb);
 102
 103         usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 104
 105         spin_lock_irqsave(&the_controller->lock, flags);
 106         usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 107         spin_unlock_irqrestore(&the_controller->lock, flags);
 108
 109         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
 110
 111         usbip_dbg_vhci_rx("Leave\n");
 112
 113         return;
 114 }
 115
 116 static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
 117                                                   struct usbip_header *pdu)
 118 {
 119         struct vhci_unlink *unlink, *tmp;
 120
 121         spin_lock(&vdev->priv_lock);
 122
 123         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
 124                 pr_info("unlink->seqnum %lu\n", unlink->seqnum);
 125                 if (unlink->seqnum == pdu->base.seqnum) {
 126                         usbip_dbg_vhci_rx("found pending unlink, %lu\n",
 127                                           unlink->seqnum);
 128                         list_del(&unlink->list);
 129
 130                         spin_unlock(&vdev->priv_lock);
 131                         return unlink;
 132                 }
 133         }
 134
 135         spin_unlock(&vdev->priv_lock);
 136
 137         return NULL;
 138 }
 139
 140 static void vhci_recv_ret_unlink(struct vhci_device *vdev,
 141                                  struct usbip_header *pdu)
 142 {
 143         struct vhci_unlink *unlink;
 144         struct urb *urb;
 145         unsigned long flags;
 146
 147         usbip_dump_header(pdu);
 148
 149         unlink = dequeue_pending_unlink(vdev, pdu);
 150         if (!unlink) {
 151                 pr_info("cannot find the pending unlink %u\n",
 152                         pdu->base.seqnum);
 153                 return;
 154         }
 155
 156         spin_lock(&vdev->priv_lock);
 157         urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 158         spin_unlock(&vdev->priv_lock);
 159
 160         if (!urb) {
 161                 /*
 162                  * I get the result of a unlink request. But, it seems that I
 163                  * already received the result of its submit result and gave
 164                  * back the URB.
 165                  */
 166                 pr_info("the urb (seqnum %d) was already given backed\n",
 167                         pdu->base.seqnum);
 168         } else {
 169                 usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
 170
 171                 /* If unlink is succeed, status is -ECONNRESET */
 172                 urb->status = pdu->u.ret_unlink.status;
 173                 pr_info("urb->status %d\n", urb->status);
 174
 175                 spin_lock_irqsave(&the_controller->lock, flags);
 176                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 177                 spin_unlock_irqrestore(&the_controller->lock, flags);
 178
 179                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 180                                      urb->status);
 181         }
 182
 183         kfree(unlink);
 184 }
 185
 186 static int vhci_priv_tx_empty(struct vhci_device *vdev)
 187 {
 188         int empty = 0;
 189
 190         spin_lock(&vdev->priv_lock);
 191         empty = list_empty(&vdev->priv_rx);
 192         spin_unlock(&vdev->priv_lock);
 193
 194         return empty;
 195 }
 196
 197 /* recv a pdu */
 198 static void vhci_rx_pdu(struct usbip_device *ud)
 199 {
 200         int ret;
 201         struct usbip_header pdu;
 202         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 203
 204         usbip_dbg_vhci_rx("Enter\n");
 205
 206         memset(&pdu, 0, sizeof(pdu));
 207
 208         /* 1. receive a pdu header */
 209         ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
 210         if (ret < 0) {
 211                 if (ret == -ECONNRESET)
 212                         pr_info("connection reset by peer\n");
 213                 else if (ret == -EAGAIN) {
 214                         /* ignore if connection was idle */
 215                         if (vhci_priv_tx_empty(vdev))
 216                                 return;
 217                         pr_info("connection timed out with pending urbs\n");
 218                 } else if (ret != -ERESTARTSYS)
 219                         pr_info("xmit failed %d\n", ret);
 220
 221                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 222                 return;
 223         }
 224         if (ret == 0) {
 225                 pr_info("connection closed");
 226                 usbip_event_add(ud, VDEV_EVENT_DOWN);
 227                 return;
 228         }
 229         if (ret != sizeof(pdu)) {
 230                 pr_err("received pdu size is %d, should be %d\n", ret,
 231                        (unsigned int)sizeof(pdu));
 232                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 233                 return;
 234         }
 235
 236         usbip_header_correct_endian(&pdu, 0);
 237
 238         if (usbip_dbg_flag_vhci_rx)
 239                 usbip_dump_header(&pdu);
 240
 241         switch (pdu.base.command) {
 242         case USBIP_RET_SUBMIT:
 243                 vhci_recv_ret_submit(vdev, &pdu);
 244                 break;
 245         case USBIP_RET_UNLINK:
 246                 vhci_recv_ret_unlink(vdev, &pdu);
 247                 break;
 248         default:
 249                 /* NOT REACHED */
 250                 pr_err("unknown pdu %u\n", pdu.base.command);
 251                 usbip_dump_header(&pdu);
 252                 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 253                 break;
 254         }
 255 }
 256
 257 int vhci_rx_loop(void *data)
 258 {
 259         struct usbip_device *ud = data;
 260
 261         while (!kthread_should_stop()) {
 262                 if (usbip_event_happened(ud))
 263                         break;
 264
 265                 vhci_rx_pdu(ud);
 266         }
 267
 268         return 0;
 269 }