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