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 } 274