1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 2003-2008 Takahiro Hirofuchi 4 */ 5 6 #include <linux/kthread.h> 7 #include <linux/socket.h> 8 9 #include "usbip_common.h" 10 #include "stub.h" 11 12 static void stub_free_priv_and_urb(struct stub_priv *priv) 13 { 14 struct urb *urb = priv->urb; 15 16 kfree(urb->setup_packet); 17 urb->setup_packet = NULL; 18 19 kfree(urb->transfer_buffer); 20 urb->transfer_buffer = NULL; 21 22 list_del(&priv->list); 23 kmem_cache_free(stub_priv_cache, priv); 24 usb_free_urb(urb); 25 } 26 27 /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */ 28 void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum, 29 __u32 status) 30 { 31 struct stub_unlink *unlink; 32 33 unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC); 34 if (!unlink) { 35 usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC); 36 return; 37 } 38 39 unlink->seqnum = seqnum; 40 unlink->status = status; 41 42 list_add_tail(&unlink->list, &sdev->unlink_tx); 43 } 44 45 /** 46 * stub_complete - completion handler of a usbip urb 47 * @urb: pointer to the urb completed 48 * 49 * When a urb has completed, the USB core driver calls this function mostly in 50 * the interrupt context. To return the result of a urb, the completed urb is 51 * linked to the pending list of returning. 52 * 53 */ 54 void stub_complete(struct urb *urb) 55 { 56 struct stub_priv *priv = (struct stub_priv *) urb->context; 57 struct stub_device *sdev = priv->sdev; 58 unsigned long flags; 59 60 usbip_dbg_stub_tx("complete! status %d\n", urb->status); 61 62 switch (urb->status) { 63 case 0: 64 /* OK */ 65 break; 66 case -ENOENT: 67 dev_info(&urb->dev->dev, 68 "stopped by a call to usb_kill_urb() because of cleaning up a virtual connection\n"); 69 return; 70 case -ECONNRESET: 71 dev_info(&urb->dev->dev, 72 "unlinked by a call to usb_unlink_urb()\n"); 73 break; 74 case -EPIPE: 75 dev_info(&urb->dev->dev, "endpoint %d is stalled\n", 76 usb_pipeendpoint(urb->pipe)); 77 break; 78 case -ESHUTDOWN: 79 dev_info(&urb->dev->dev, "device removed?\n"); 80 break; 81 default: 82 dev_info(&urb->dev->dev, 83 "urb completion with non-zero status %d\n", 84 urb->status); 85 break; 86 } 87 88 /* link a urb to the queue of tx. */ 89 spin_lock_irqsave(&sdev->priv_lock, flags); 90 if (sdev->ud.tcp_socket == NULL) { 91 usbip_dbg_stub_tx("ignore urb for closed connection %p", urb); 92 /* It will be freed in stub_device_cleanup_urbs(). */ 93 } else if (priv->unlinking) { 94 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status); 95 stub_free_priv_and_urb(priv); 96 } else { 97 list_move_tail(&priv->list, &sdev->priv_tx); 98 } 99 spin_unlock_irqrestore(&sdev->priv_lock, flags); 100 101 /* wake up tx_thread */ 102 wake_up(&sdev->tx_waitq); 103 } 104 105 static inline void setup_base_pdu(struct usbip_header_basic *base, 106 __u32 command, __u32 seqnum) 107 { 108 base->command = command; 109 base->seqnum = seqnum; 110 base->devid = 0; 111 base->ep = 0; 112 base->direction = 0; 113 } 114 115 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb) 116 { 117 struct stub_priv *priv = (struct stub_priv *) urb->context; 118 119 setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum); 120 usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1); 121 } 122 123 static void setup_ret_unlink_pdu(struct usbip_header *rpdu, 124 struct stub_unlink *unlink) 125 { 126 setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum); 127 rpdu->u.ret_unlink.status = unlink->status; 128 } 129 130 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev) 131 { 132 unsigned long flags; 133 struct stub_priv *priv, *tmp; 134 135 spin_lock_irqsave(&sdev->priv_lock, flags); 136 137 list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) { 138 list_move_tail(&priv->list, &sdev->priv_free); 139 spin_unlock_irqrestore(&sdev->priv_lock, flags); 140 return priv; 141 } 142 143 spin_unlock_irqrestore(&sdev->priv_lock, flags); 144 145 return NULL; 146 } 147 148 static int stub_send_ret_submit(struct stub_device *sdev) 149 { 150 unsigned long flags; 151 struct stub_priv *priv, *tmp; 152 153 struct msghdr msg; 154 size_t txsize; 155 156 size_t total_size = 0; 157 158 while ((priv = dequeue_from_priv_tx(sdev)) != NULL) { 159 int ret; 160 struct urb *urb = priv->urb; 161 struct usbip_header pdu_header; 162 struct usbip_iso_packet_descriptor *iso_buffer = NULL; 163 struct kvec *iov = NULL; 164 int iovnum = 0; 165 166 txsize = 0; 167 memset(&pdu_header, 0, sizeof(pdu_header)); 168 memset(&msg, 0, sizeof(msg)); 169 170 if (urb->actual_length > 0 && !urb->transfer_buffer) { 171 dev_err(&sdev->udev->dev, 172 "urb: actual_length %d transfer_buffer null\n", 173 urb->actual_length); 174 return -1; 175 } 176 177 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) 178 iovnum = 2 + urb->number_of_packets; 179 else 180 iovnum = 2; 181 182 iov = kcalloc(iovnum, sizeof(struct kvec), GFP_KERNEL); 183 184 if (!iov) { 185 usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC); 186 return -1; 187 } 188 189 iovnum = 0; 190 191 /* 1. setup usbip_header */ 192 setup_ret_submit_pdu(&pdu_header, urb); 193 usbip_dbg_stub_tx("setup txdata seqnum: %d urb: %p\n", 194 pdu_header.base.seqnum, urb); 195 usbip_header_correct_endian(&pdu_header, 1); 196 197 iov[iovnum].iov_base = &pdu_header; 198 iov[iovnum].iov_len = sizeof(pdu_header); 199 iovnum++; 200 txsize += sizeof(pdu_header); 201 202 /* 2. setup transfer buffer */ 203 if (usb_pipein(urb->pipe) && 204 usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS && 205 urb->actual_length > 0) { 206 iov[iovnum].iov_base = urb->transfer_buffer; 207 iov[iovnum].iov_len = urb->actual_length; 208 iovnum++; 209 txsize += urb->actual_length; 210 } else if (usb_pipein(urb->pipe) && 211 usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) { 212 /* 213 * For isochronous packets: actual length is the sum of 214 * the actual length of the individual, packets, but as 215 * the packet offsets are not changed there will be 216 * padding between the packets. To optimally use the 217 * bandwidth the padding is not transmitted. 218 */ 219 220 int i; 221 222 for (i = 0; i < urb->number_of_packets; i++) { 223 iov[iovnum].iov_base = urb->transfer_buffer + 224 urb->iso_frame_desc[i].offset; 225 iov[iovnum].iov_len = 226 urb->iso_frame_desc[i].actual_length; 227 iovnum++; 228 txsize += urb->iso_frame_desc[i].actual_length; 229 } 230 231 if (txsize != sizeof(pdu_header) + urb->actual_length) { 232 dev_err(&sdev->udev->dev, 233 "actual length of urb %d does not match iso packet sizes %zu\n", 234 urb->actual_length, 235 txsize-sizeof(pdu_header)); 236 kfree(iov); 237 usbip_event_add(&sdev->ud, 238 SDEV_EVENT_ERROR_TCP); 239 return -1; 240 } 241 } 242 243 /* 3. setup iso_packet_descriptor */ 244 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) { 245 ssize_t len = 0; 246 247 iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len); 248 if (!iso_buffer) { 249 usbip_event_add(&sdev->ud, 250 SDEV_EVENT_ERROR_MALLOC); 251 kfree(iov); 252 return -1; 253 } 254 255 iov[iovnum].iov_base = iso_buffer; 256 iov[iovnum].iov_len = len; 257 txsize += len; 258 iovnum++; 259 } 260 261 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, 262 iov, iovnum, txsize); 263 if (ret != txsize) { 264 dev_err(&sdev->udev->dev, 265 "sendmsg failed!, retval %d for %zd\n", 266 ret, txsize); 267 kfree(iov); 268 kfree(iso_buffer); 269 usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP); 270 return -1; 271 } 272 273 kfree(iov); 274 kfree(iso_buffer); 275 276 total_size += txsize; 277 } 278 279 spin_lock_irqsave(&sdev->priv_lock, flags); 280 list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) { 281 stub_free_priv_and_urb(priv); 282 } 283 spin_unlock_irqrestore(&sdev->priv_lock, flags); 284 285 return total_size; 286 } 287 288 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev) 289 { 290 unsigned long flags; 291 struct stub_unlink *unlink, *tmp; 292 293 spin_lock_irqsave(&sdev->priv_lock, flags); 294 295 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) { 296 list_move_tail(&unlink->list, &sdev->unlink_free); 297 spin_unlock_irqrestore(&sdev->priv_lock, flags); 298 return unlink; 299 } 300 301 spin_unlock_irqrestore(&sdev->priv_lock, flags); 302 303 return NULL; 304 } 305 306 static int stub_send_ret_unlink(struct stub_device *sdev) 307 { 308 unsigned long flags; 309 struct stub_unlink *unlink, *tmp; 310 311 struct msghdr msg; 312 struct kvec iov[1]; 313 size_t txsize; 314 315 size_t total_size = 0; 316 317 while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) { 318 int ret; 319 struct usbip_header pdu_header; 320 321 txsize = 0; 322 memset(&pdu_header, 0, sizeof(pdu_header)); 323 memset(&msg, 0, sizeof(msg)); 324 memset(&iov, 0, sizeof(iov)); 325 326 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum); 327 328 /* 1. setup usbip_header */ 329 setup_ret_unlink_pdu(&pdu_header, unlink); 330 usbip_header_correct_endian(&pdu_header, 1); 331 332 iov[0].iov_base = &pdu_header; 333 iov[0].iov_len = sizeof(pdu_header); 334 txsize += sizeof(pdu_header); 335 336 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov, 337 1, txsize); 338 if (ret != txsize) { 339 dev_err(&sdev->udev->dev, 340 "sendmsg failed!, retval %d for %zd\n", 341 ret, txsize); 342 usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP); 343 return -1; 344 } 345 346 usbip_dbg_stub_tx("send txdata\n"); 347 total_size += txsize; 348 } 349 350 spin_lock_irqsave(&sdev->priv_lock, flags); 351 352 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) { 353 list_del(&unlink->list); 354 kfree(unlink); 355 } 356 357 spin_unlock_irqrestore(&sdev->priv_lock, flags); 358 359 return total_size; 360 } 361 362 int stub_tx_loop(void *data) 363 { 364 struct usbip_device *ud = data; 365 struct stub_device *sdev = container_of(ud, struct stub_device, ud); 366 367 while (!kthread_should_stop()) { 368 if (usbip_event_happened(ud)) 369 break; 370 371 /* 372 * send_ret_submit comes earlier than send_ret_unlink. stub_rx 373 * looks at only priv_init queue. If the completion of a URB is 374 * earlier than the receive of CMD_UNLINK, priv is moved to 375 * priv_tx queue and stub_rx does not find the target priv. In 376 * this case, vhci_rx receives the result of the submit request 377 * and then receives the result of the unlink request. The 378 * result of the submit is given back to the usbcore as the 379 * completion of the unlink request. The request of the 380 * unlink is ignored. This is ok because a driver who calls 381 * usb_unlink_urb() understands the unlink was too late by 382 * getting the status of the given-backed URB which has the 383 * status of usb_submit_urb(). 384 */ 385 if (stub_send_ret_submit(sdev) < 0) 386 break; 387 388 if (stub_send_ret_unlink(sdev) < 0) 389 break; 390 391 wait_event_interruptible(sdev->tx_waitq, 392 (!list_empty(&sdev->priv_tx) || 393 !list_empty(&sdev->unlink_tx) || 394 kthread_should_stop())); 395 } 396 397 return 0; 398 } 399