drivers/net/usb/rndis

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This source file includes following definitions.
rndis_status
rndis_msg_indicate
rndis_command
rndis_query
generic_rndis_bind
rndis_bind
rndis_unbind
rndis_rx_fixup
rndis_tx_fixup
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Host Side support for RNDIS Networking Links
   4  * Copyright (C) 2005 by David Brownell
   5  */
   6 #include <linux/module.h>
   7 #include <linux/netdevice.h>
   8 #include <linux/etherdevice.h>
   9 #include <linux/ethtool.h>
  10 #include <linux/workqueue.h>
  11 #include <linux/slab.h>
  12 #include <linux/mii.h>
  13 #include <linux/usb.h>
  14 #include <linux/usb/cdc.h>
  15 #include <linux/usb/usbnet.h>
  16 #include <linux/usb/rndis_host.h>
  17 
  18 
  19 /*
  20  * RNDIS is NDIS remoted over USB.  It's a MSFT variant of CDC ACM ... of
  21  * course ACM was intended for modems, not Ethernet links!  USB's standard
  22  * for Ethernet links is "CDC Ethernet", which is significantly simpler.
  23  *
  24  * NOTE that Microsoft's "RNDIS 1.0" specification is incomplete.  Issues
  25  * include:
  26  *    - Power management in particular relies on information that's scattered
  27  *      through other documentation, and which is incomplete or incorrect even
  28  *      there.
  29  *    - There are various undocumented protocol requirements, such as the
  30  *      need to send unused garbage in control-OUT messages.
  31  *    - In some cases, MS-Windows will emit undocumented requests; this
  32  *      matters more to peripheral implementations than host ones.
  33  *
  34  * Moreover there's a no-open-specs variant of RNDIS called "ActiveSync".
  35  *
  36  * For these reasons and others, ** USE OF RNDIS IS STRONGLY DISCOURAGED ** in
  37  * favor of such non-proprietary alternatives as CDC Ethernet or the newer (and
  38  * currently rare) "Ethernet Emulation Model" (EEM).
  39  */
  40 
  41 /*
  42  * RNDIS notifications from device: command completion; "reverse"
  43  * keepalives; etc
  44  */
  45 void rndis_status(struct usbnet *dev, struct urb *urb)
  46 {
  47         netdev_dbg(dev->net, "rndis status urb, len %d stat %d\n",
  48                    urb->actual_length, urb->status);
  49         // FIXME for keepalives, respond immediately (asynchronously)
  50         // if not an RNDIS status, do like cdc_status(dev,urb) does
  51 }
  52 EXPORT_SYMBOL_GPL(rndis_status);
  53 
  54 /*
  55  * RNDIS indicate messages.
  56  */
  57 static void rndis_msg_indicate(struct usbnet *dev, struct rndis_indicate *msg,
  58                                 int buflen)
  59 {
  60         struct cdc_state *info = (void *)&dev->data;
  61         struct device *udev = &info->control->dev;
  62 
  63         if (dev->driver_info->indication) {
  64                 dev->driver_info->indication(dev, msg, buflen);
  65         } else {
  66                 u32 status = le32_to_cpu(msg->status);
  67 
  68                 switch (status) {
  69                 case RNDIS_STATUS_MEDIA_CONNECT:
  70                         dev_info(udev, "rndis media connect\n");
  71                         break;
  72                 case RNDIS_STATUS_MEDIA_DISCONNECT:
  73                         dev_info(udev, "rndis media disconnect\n");
  74                         break;
  75                 default:
  76                         dev_info(udev, "rndis indication: 0x%08x\n", status);
  77                 }
  78         }
  79 }
  80 
  81 /*
  82  * RPC done RNDIS-style.  Caller guarantees:
  83  * - message is properly byteswapped
  84  * - there's no other request pending
  85  * - buf can hold up to 1KB response (required by RNDIS spec)
  86  * On return, the first few entries are already byteswapped.
  87  *
  88  * Call context is likely probe(), before interface name is known,
  89  * which is why we won't try to use it in the diagnostics.
  90  */
  91 int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf, int buflen)
  92 {
  93         struct cdc_state        *info = (void *) &dev->data;
  94         struct usb_cdc_notification notification;
  95         int                     master_ifnum;
  96         int                     retval;
  97         int                     partial;
  98         unsigned                count;
  99         u32                     xid = 0, msg_len, request_id, msg_type, rsp,
 100                                 status;
 101 
 102         /* REVISIT when this gets called from contexts other than probe() or
 103          * disconnect(): either serialize, or dispatch responses on xid
 104          */
 105 
 106         msg_type = le32_to_cpu(buf->msg_type);
 107 
 108         /* Issue the request; xid is unique, don't bother byteswapping it */
 109         if (likely(msg_type != RNDIS_MSG_HALT && msg_type != RNDIS_MSG_RESET)) {
 110                 xid = dev->xid++;
 111                 if (!xid)
 112                         xid = dev->xid++;
 113                 buf->request_id = (__force __le32) xid;
 114         }
 115         master_ifnum = info->control->cur_altsetting->desc.bInterfaceNumber;
 116         retval = usb_control_msg(dev->udev,
 117                 usb_sndctrlpipe(dev->udev, 0),
 118                 USB_CDC_SEND_ENCAPSULATED_COMMAND,
 119                 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 120                 0, master_ifnum,
 121                 buf, le32_to_cpu(buf->msg_len),
 122                 RNDIS_CONTROL_TIMEOUT_MS);
 123         if (unlikely(retval < 0 || xid == 0))
 124                 return retval;
 125 
 126         /* Some devices don't respond on the control channel until
 127          * polled on the status channel, so do that first. */
 128         if (dev->driver_info->data & RNDIS_DRIVER_DATA_POLL_STATUS) {
 129                 retval = usb_interrupt_msg(
 130                         dev->udev,
 131                         usb_rcvintpipe(dev->udev,
 132                                        dev->status->desc.bEndpointAddress),
 133                         &notification, sizeof(notification), &partial,
 134                         RNDIS_CONTROL_TIMEOUT_MS);
 135                 if (unlikely(retval < 0))
 136                         return retval;
 137         }
 138 
 139         /* Poll the control channel; the request probably completed immediately */
 140         rsp = le32_to_cpu(buf->msg_type) | RNDIS_MSG_COMPLETION;
 141         for (count = 0; count < 10; count++) {
 142                 memset(buf, 0, CONTROL_BUFFER_SIZE);
 143                 retval = usb_control_msg(dev->udev,
 144                         usb_rcvctrlpipe(dev->udev, 0),
 145                         USB_CDC_GET_ENCAPSULATED_RESPONSE,
 146                         USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 147                         0, master_ifnum,
 148                         buf, buflen,
 149                         RNDIS_CONTROL_TIMEOUT_MS);
 150                 if (likely(retval >= 8)) {
 151                         msg_type = le32_to_cpu(buf->msg_type);
 152                         msg_len = le32_to_cpu(buf->msg_len);
 153                         status = le32_to_cpu(buf->status);
 154                         request_id = (__force u32) buf->request_id;
 155                         if (likely(msg_type == rsp)) {
 156                                 if (likely(request_id == xid)) {
 157                                         if (unlikely(rsp == RNDIS_MSG_RESET_C))
 158                                                 return 0;
 159                                         if (likely(RNDIS_STATUS_SUCCESS ==
 160                                                         status))
 161                                                 return 0;
 162                                         dev_dbg(&info->control->dev,
 163                                                 "rndis reply status %08x\n",
 164                                                 status);
 165                                         return -EL3RST;
 166                                 }
 167                                 dev_dbg(&info->control->dev,
 168                                         "rndis reply id %d expected %d\n",
 169                                         request_id, xid);
 170                                 /* then likely retry */
 171                         } else switch (msg_type) {
 172                         case RNDIS_MSG_INDICATE: /* fault/event */
 173                                 rndis_msg_indicate(dev, (void *)buf, buflen);
 174                                 break;
 175                         case RNDIS_MSG_KEEPALIVE: { /* ping */
 176                                 struct rndis_keepalive_c *msg = (void *)buf;
 177 
 178                                 msg->msg_type = cpu_to_le32(RNDIS_MSG_KEEPALIVE_C);
 179                                 msg->msg_len = cpu_to_le32(sizeof *msg);
 180                                 msg->status = cpu_to_le32(RNDIS_STATUS_SUCCESS);
 181                                 retval = usb_control_msg(dev->udev,
 182                                         usb_sndctrlpipe(dev->udev, 0),
 183                                         USB_CDC_SEND_ENCAPSULATED_COMMAND,
 184                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 185                                         0, master_ifnum,
 186                                         msg, sizeof *msg,
 187                                         RNDIS_CONTROL_TIMEOUT_MS);
 188                                 if (unlikely(retval < 0))
 189                                         dev_dbg(&info->control->dev,
 190                                                 "rndis keepalive err %d\n",
 191                                                 retval);
 192                                 }
 193                                 break;
 194                         default:
 195                                 dev_dbg(&info->control->dev,
 196                                         "unexpected rndis msg %08x len %d\n",
 197                                         le32_to_cpu(buf->msg_type), msg_len);
 198                         }
 199                 } else {
 200                         /* device probably issued a protocol stall; ignore */
 201                         dev_dbg(&info->control->dev,
 202                                 "rndis response error, code %d\n", retval);
 203                 }
 204                 msleep(20);
 205         }
 206         dev_dbg(&info->control->dev, "rndis response timeout\n");
 207         return -ETIMEDOUT;
 208 }
 209 EXPORT_SYMBOL_GPL(rndis_command);
 210 
 211 /*
 212  * rndis_query:
 213  *
 214  * Performs a query for @oid along with 0 or more bytes of payload as
 215  * specified by @in_len. If @reply_len is not set to -1 then the reply
 216  * length is checked against this value, resulting in an error if it
 217  * doesn't match.
 218  *
 219  * NOTE: Adding a payload exactly or greater than the size of the expected
 220  * response payload is an evident requirement MSFT added for ActiveSync.
 221  *
 222  * The only exception is for OIDs that return a variably sized response,
 223  * in which case no payload should be added.  This undocumented (and
 224  * nonsensical!) issue was found by sniffing protocol requests from the
 225  * ActiveSync 4.1 Windows driver.
 226  */
 227 static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
 228                 void *buf, u32 oid, u32 in_len,
 229                 void **reply, int *reply_len)
 230 {
 231         int retval;
 232         union {
 233                 void                    *buf;
 234                 struct rndis_msg_hdr    *header;
 235                 struct rndis_query      *get;
 236                 struct rndis_query_c    *get_c;
 237         } u;
 238         u32 off, len;
 239 
 240         u.buf = buf;
 241 
 242         memset(u.get, 0, sizeof *u.get + in_len);
 243         u.get->msg_type = cpu_to_le32(RNDIS_MSG_QUERY);
 244         u.get->msg_len = cpu_to_le32(sizeof *u.get + in_len);
 245         u.get->oid = cpu_to_le32(oid);
 246         u.get->len = cpu_to_le32(in_len);
 247         u.get->offset = cpu_to_le32(20);
 248 
 249         retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
 250         if (unlikely(retval < 0)) {
 251                 dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) failed, %d\n",
 252                                 oid, retval);
 253                 return retval;
 254         }
 255 
 256         off = le32_to_cpu(u.get_c->offset);
 257         len = le32_to_cpu(u.get_c->len);
 258         if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
 259                 goto response_error;
 260 
 261         if (*reply_len != -1 && len != *reply_len)
 262                 goto response_error;
 263 
 264         *reply = (unsigned char *) &u.get_c->request_id + off;
 265         *reply_len = len;
 266 
 267         return retval;
 268 
 269 response_error:
 270         dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) "
 271                         "invalid response - off %d len %d\n",
 272                 oid, off, len);
 273         return -EDOM;
 274 }
 275 
 276 /* same as usbnet_netdev_ops but MTU change not allowed */
 277 static const struct net_device_ops rndis_netdev_ops = {
 278         .ndo_open               = usbnet_open,
 279         .ndo_stop               = usbnet_stop,
 280         .ndo_start_xmit         = usbnet_start_xmit,
 281         .ndo_tx_timeout         = usbnet_tx_timeout,
 282         .ndo_get_stats64        = usbnet_get_stats64,
 283         .ndo_set_mac_address    = eth_mac_addr,
 284         .ndo_validate_addr      = eth_validate_addr,
 285 };
 286 
 287 int
 288 generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf, int flags)
 289 {
 290         int                     retval;
 291         struct net_device       *net = dev->net;
 292         struct cdc_state        *info = (void *) &dev->data;
 293         union {
 294                 void                    *buf;
 295                 struct rndis_msg_hdr    *header;
 296                 struct rndis_init       *init;
 297                 struct rndis_init_c     *init_c;
 298                 struct rndis_query      *get;
 299                 struct rndis_query_c    *get_c;
 300                 struct rndis_set        *set;
 301                 struct rndis_set_c      *set_c;
 302                 struct rndis_halt       *halt;
 303         } u;
 304         u32                     tmp;
 305         __le32                  phym_unspec, *phym;
 306         int                     reply_len;
 307         unsigned char           *bp;
 308 
 309         /* we can't rely on i/o from stack working, or stack allocation */
 310         u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
 311         if (!u.buf)
 312                 return -ENOMEM;
 313         retval = usbnet_generic_cdc_bind(dev, intf);
 314         if (retval < 0)
 315                 goto fail;
 316 
 317         u.init->msg_type = cpu_to_le32(RNDIS_MSG_INIT);
 318         u.init->msg_len = cpu_to_le32(sizeof *u.init);
 319         u.init->major_version = cpu_to_le32(1);
 320         u.init->minor_version = cpu_to_le32(0);
 321 
 322         /* max transfer (in spec) is 0x4000 at full speed, but for
 323          * TX we'll stick to one Ethernet packet plus RNDIS framing.
 324          * For RX we handle drivers that zero-pad to end-of-packet.
 325          * Don't let userspace change these settings.
 326          *
 327          * NOTE: there still seems to be wierdness here, as if we need
 328          * to do some more things to make sure WinCE targets accept this.
 329          * They default to jumbograms of 8KB or 16KB, which is absurd
 330          * for such low data rates and which is also more than Linux
 331          * can usually expect to allocate for SKB data...
 332          */
 333         net->hard_header_len += sizeof (struct rndis_data_hdr);
 334         dev->hard_mtu = net->mtu + net->hard_header_len;
 335 
 336         dev->maxpacket = usb_maxpacket(dev->udev, dev->out, 1);
 337         if (dev->maxpacket == 0) {
 338                 netif_dbg(dev, probe, dev->net,
 339                           "dev->maxpacket can't be 0\n");
 340                 retval = -EINVAL;
 341                 goto fail_and_release;
 342         }
 343 
 344         dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
 345         dev->rx_urb_size &= ~(dev->maxpacket - 1);
 346         u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
 347 
 348         net->netdev_ops = &rndis_netdev_ops;
 349 
 350         retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
 351         if (unlikely(retval < 0)) {
 352                 /* it might not even be an RNDIS device!! */
 353                 dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
 354                 goto fail_and_release;
 355         }
 356         tmp = le32_to_cpu(u.init_c->max_transfer_size);
 357         if (tmp < dev->hard_mtu) {
 358                 if (tmp <= net->hard_header_len) {
 359                         dev_err(&intf->dev,
 360                                 "dev can't take %u byte packets (max %u)\n",
 361                                 dev->hard_mtu, tmp);
 362                         retval = -EINVAL;
 363                         goto halt_fail_and_release;
 364                 }
 365                 dev_warn(&intf->dev,
 366                          "dev can't take %u byte packets (max %u), "
 367                          "adjusting MTU to %u\n",
 368                          dev->hard_mtu, tmp, tmp - net->hard_header_len);
 369                 dev->hard_mtu = tmp;
 370                 net->mtu = dev->hard_mtu - net->hard_header_len;
 371         }
 372 
 373         /* REVISIT:  peripheral "alignment" request is ignored ... */
 374         dev_dbg(&intf->dev,
 375                 "hard mtu %u (%u from dev), rx buflen %zu, align %d\n",
 376                 dev->hard_mtu, tmp, dev->rx_urb_size,
 377                 1 << le32_to_cpu(u.init_c->packet_alignment));
 378 
 379         /* module has some device initialization code needs to be done right
 380          * after RNDIS_INIT */
 381         if (dev->driver_info->early_init &&
 382                         dev->driver_info->early_init(dev) != 0)
 383                 goto halt_fail_and_release;
 384 
 385         /* Check physical medium */
 386         phym = NULL;
 387         reply_len = sizeof *phym;
 388         retval = rndis_query(dev, intf, u.buf,
 389                              RNDIS_OID_GEN_PHYSICAL_MEDIUM,
 390                              0, (void **) &phym, &reply_len);
 391         if (retval != 0 || !phym) {
 392                 /* OID is optional so don't fail here. */
 393                 phym_unspec = cpu_to_le32(RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED);
 394                 phym = &phym_unspec;
 395         }
 396         if ((flags & FLAG_RNDIS_PHYM_WIRELESS) &&
 397             le32_to_cpup(phym) != RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
 398                 netif_dbg(dev, probe, dev->net,
 399                           "driver requires wireless physical medium, but device is not\n");
 400                 retval = -ENODEV;
 401                 goto halt_fail_and_release;
 402         }
 403         if ((flags & FLAG_RNDIS_PHYM_NOT_WIRELESS) &&
 404             le32_to_cpup(phym) == RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
 405                 netif_dbg(dev, probe, dev->net,
 406                           "driver requires non-wireless physical medium, but device is wireless.\n");
 407                 retval = -ENODEV;
 408                 goto halt_fail_and_release;
 409         }
 410 
 411         /* Get designated host ethernet address */
 412         reply_len = ETH_ALEN;
 413         retval = rndis_query(dev, intf, u.buf,
 414                              RNDIS_OID_802_3_PERMANENT_ADDRESS,
 415                              48, (void **) &bp, &reply_len);
 416         if (unlikely(retval< 0)) {
 417                 dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
 418                 goto halt_fail_and_release;
 419         }
 420 
 421         if (bp[0] & 0x02)
 422                 eth_hw_addr_random(net);
 423         else
 424                 ether_addr_copy(net->dev_addr, bp);
 425 
 426         /* set a nonzero filter to enable data transfers */
 427         memset(u.set, 0, sizeof *u.set);
 428         u.set->msg_type = cpu_to_le32(RNDIS_MSG_SET);
 429         u.set->msg_len = cpu_to_le32(4 + sizeof *u.set);
 430         u.set->oid = cpu_to_le32(RNDIS_OID_GEN_CURRENT_PACKET_FILTER);
 431         u.set->len = cpu_to_le32(4);
 432         u.set->offset = cpu_to_le32((sizeof *u.set) - 8);
 433         *(__le32 *)(u.buf + sizeof *u.set) = cpu_to_le32(RNDIS_DEFAULT_FILTER);
 434 
 435         retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
 436         if (unlikely(retval < 0)) {
 437                 dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
 438                 goto halt_fail_and_release;
 439         }
 440 
 441         retval = 0;
 442 
 443         kfree(u.buf);
 444         return retval;
 445 
 446 halt_fail_and_release:
 447         memset(u.halt, 0, sizeof *u.halt);
 448         u.halt->msg_type = cpu_to_le32(RNDIS_MSG_HALT);
 449         u.halt->msg_len = cpu_to_le32(sizeof *u.halt);
 450         (void) rndis_command(dev, (void *)u.halt, CONTROL_BUFFER_SIZE);
 451 fail_and_release:
 452         usb_set_intfdata(info->data, NULL);
 453         usb_driver_release_interface(driver_of(intf), info->data);
 454         info->data = NULL;
 455 fail:
 456         kfree(u.buf);
 457         return retval;
 458 }
 459 EXPORT_SYMBOL_GPL(generic_rndis_bind);
 460 
 461 static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
 462 {
 463         return generic_rndis_bind(dev, intf, FLAG_RNDIS_PHYM_NOT_WIRELESS);
 464 }
 465 
 466 void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
 467 {
 468         struct rndis_halt       *halt;
 469 
 470         /* try to clear any rndis state/activity (no i/o from stack!) */
 471         halt = kzalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
 472         if (halt) {
 473                 halt->msg_type = cpu_to_le32(RNDIS_MSG_HALT);
 474                 halt->msg_len = cpu_to_le32(sizeof *halt);
 475                 (void) rndis_command(dev, (void *)halt, CONTROL_BUFFER_SIZE);
 476                 kfree(halt);
 477         }
 478 
 479         usbnet_cdc_unbind(dev, intf);
 480 }
 481 EXPORT_SYMBOL_GPL(rndis_unbind);
 482 
 483 /*
 484  * DATA -- host must not write zlps
 485  */
 486 int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 487 {
 488         /* This check is no longer done by usbnet */
 489         if (skb->len < dev->net->hard_header_len)
 490                 return 0;
 491 
 492         /* peripheral may have batched packets to us... */
 493         while (likely(skb->len)) {
 494                 struct rndis_data_hdr   *hdr = (void *)skb->data;
 495                 struct sk_buff          *skb2;
 496                 u32                     msg_type, msg_len, data_offset, data_len;
 497 
 498                 msg_type = le32_to_cpu(hdr->msg_type);
 499                 msg_len = le32_to_cpu(hdr->msg_len);
 500                 data_offset = le32_to_cpu(hdr->data_offset);
 501                 data_len = le32_to_cpu(hdr->data_len);
 502 
 503                 /* don't choke if we see oob, per-packet data, etc */
 504                 if (unlikely(msg_type != RNDIS_MSG_PACKET || skb->len < msg_len
 505                                 || (data_offset + data_len + 8) > msg_len)) {
 506                         dev->net->stats.rx_frame_errors++;
 507                         netdev_dbg(dev->net, "bad rndis message %d/%d/%d/%d, len %d\n",
 508                                    le32_to_cpu(hdr->msg_type),
 509                                    msg_len, data_offset, data_len, skb->len);
 510                         return 0;
 511                 }
 512                 skb_pull(skb, 8 + data_offset);
 513 
 514                 /* at most one packet left? */
 515                 if (likely((data_len - skb->len) <= sizeof *hdr)) {
 516                         skb_trim(skb, data_len);
 517                         break;
 518                 }
 519 
 520                 /* try to return all the packets in the batch */
 521                 skb2 = skb_clone(skb, GFP_ATOMIC);
 522                 if (unlikely(!skb2))
 523                         break;
 524                 skb_pull(skb, msg_len - sizeof *hdr);
 525                 skb_trim(skb2, data_len);
 526                 usbnet_skb_return(dev, skb2);
 527         }
 528 
 529         /* caller will usbnet_skb_return the remaining packet */
 530         return 1;
 531 }
 532 EXPORT_SYMBOL_GPL(rndis_rx_fixup);
 533 
 534 struct sk_buff *
 535 rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 536 {
 537         struct rndis_data_hdr   *hdr;
 538         struct sk_buff          *skb2;
 539         unsigned                len = skb->len;
 540 
 541         if (likely(!skb_cloned(skb))) {
 542                 int     room = skb_headroom(skb);
 543 
 544                 /* enough head room as-is? */
 545                 if (unlikely((sizeof *hdr) <= room))
 546                         goto fill;
 547 
 548                 /* enough room, but needs to be readjusted? */
 549                 room += skb_tailroom(skb);
 550                 if (likely((sizeof *hdr) <= room)) {
 551                         skb->data = memmove(skb->head + sizeof *hdr,
 552                                             skb->data, len);
 553                         skb_set_tail_pointer(skb, len);
 554                         goto fill;
 555                 }
 556         }
 557 
 558         /* create a new skb, with the correct size (and tailpad) */
 559         skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
 560         dev_kfree_skb_any(skb);
 561         if (unlikely(!skb2))
 562                 return skb2;
 563         skb = skb2;
 564 
 565         /* fill out the RNDIS header.  we won't bother trying to batch
 566          * packets; Linux minimizes wasted bandwidth through tx queues.
 567          */
 568 fill:
 569         hdr = __skb_push(skb, sizeof *hdr);
 570         memset(hdr, 0, sizeof *hdr);
 571         hdr->msg_type = cpu_to_le32(RNDIS_MSG_PACKET);
 572         hdr->msg_len = cpu_to_le32(skb->len);
 573         hdr->data_offset = cpu_to_le32(sizeof(*hdr) - 8);
 574         hdr->data_len = cpu_to_le32(len);
 575 
 576         /* FIXME make the last packet always be short ... */
 577         return skb;
 578 }
 579 EXPORT_SYMBOL_GPL(rndis_tx_fixup);
 580 
 581 
 582 static const struct driver_info rndis_info = {
 583         .description =  "RNDIS device",
 584         .flags =        FLAG_ETHER | FLAG_POINTTOPOINT | FLAG_FRAMING_RN | FLAG_NO_SETINT,
 585         .bind =         rndis_bind,
 586         .unbind =       rndis_unbind,
 587         .status =       rndis_status,
 588         .rx_fixup =     rndis_rx_fixup,
 589         .tx_fixup =     rndis_tx_fixup,
 590 };
 591 
 592 static const struct driver_info rndis_poll_status_info = {
 593         .description =  "RNDIS device (poll status before control)",
 594         .flags =        FLAG_ETHER | FLAG_POINTTOPOINT | FLAG_FRAMING_RN | FLAG_NO_SETINT,
 595         .data =         RNDIS_DRIVER_DATA_POLL_STATUS,
 596         .bind =         rndis_bind,
 597         .unbind =       rndis_unbind,
 598         .status =       rndis_status,
 599         .rx_fixup =     rndis_rx_fixup,
 600         .tx_fixup =     rndis_tx_fixup,
 601 };
 602 
 603 /*-------------------------------------------------------------------------*/
 604 
 605 static const struct usb_device_id       products [] = {
 606 {
 607         /* 2Wire HomePortal 1000SW */
 608         USB_DEVICE_AND_INTERFACE_INFO(0x1630, 0x0042,
 609                                       USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
 610         .driver_info = (unsigned long) &rndis_poll_status_info,
 611 }, {
 612         /* RNDIS is MSFT's un-official variant of CDC ACM */
 613         USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
 614         .driver_info = (unsigned long) &rndis_info,
 615 }, {
 616         /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
 617         USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
 618         .driver_info = (unsigned long) &rndis_poll_status_info,
 619 }, {
 620         /* RNDIS for tethering */
 621         USB_INTERFACE_INFO(USB_CLASS_WIRELESS_CONTROLLER, 1, 3),
 622         .driver_info = (unsigned long) &rndis_info,
 623 }, {
 624         /* Novatel Verizon USB730L */
 625         USB_INTERFACE_INFO(USB_CLASS_MISC, 4, 1),
 626         .driver_info = (unsigned long) &rndis_info,
 627 },
 628         { },            // END
 629 };
 630 MODULE_DEVICE_TABLE(usb, products);
 631 
 632 static struct usb_driver rndis_driver = {
 633         .name =         "rndis_host",
 634         .id_table =     products,
 635         .probe =        usbnet_probe,
 636         .disconnect =   usbnet_disconnect,
 637         .suspend =      usbnet_suspend,
 638         .resume =       usbnet_resume,
 639         .disable_hub_initiated_lpm = 1,
 640 };
 641 
 642 module_usb_driver(rndis_driver);
 643 
 644 MODULE_AUTHOR("David Brownell");
 645 MODULE_DESCRIPTION("USB Host side RNDIS driver");
 646 MODULE_LICENSE("GPL");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/net/usb/rndis_host.c

DEFINITIONS
