drivers/net/usb/rndis_host.c

   1 /*
   2  * Host Side support for RNDIS Networking Links
   3  * Copyright (C) 2005 by David Brownell
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19 #include <linux/module.h>
  20 #include <linux/init.h>
  21 #include <linux/netdevice.h>
  22 #include <linux/etherdevice.h>
  23 #include <linux/ethtool.h>
  24 #include <linux/workqueue.h>
  25 #include <linux/slab.h>
  26 #include <linux/mii.h>
  27 #include <linux/usb.h>
  28 #include <linux/usb/cdc.h>
  29 #include <linux/usb/usbnet.h>
  30 #include <linux/usb/rndis_host.h>
  31
  32
  33 /*
  34  * RNDIS is NDIS remoted over USB.  It's a MSFT variant of CDC ACM ... of
  35  * course ACM was intended for modems, not Ethernet links!  USB's standard
  36  * for Ethernet links is "CDC Ethernet", which is significantly simpler.
  37  *
  38  * NOTE that Microsoft's "RNDIS 1.0" specification is incomplete.  Issues
  39  * include:
  40  *    - Power management in particular relies on information that's scattered
  41  *      through other documentation, and which is incomplete or incorrect even
  42  *      there.
  43  *    - There are various undocumented protocol requirements, such as the
  44  *      need to send unused garbage in control-OUT messages.
  45  *    - In some cases, MS-Windows will emit undocumented requests; this
  46  *      matters more to peripheral implementations than host ones.
  47  *
  48  * Moreover there's a no-open-specs variant of RNDIS called "ActiveSync".
  49  *
  50  * For these reasons and others, ** USE OF RNDIS IS STRONGLY DISCOURAGED ** in
  51  * favor of such non-proprietary alternatives as CDC Ethernet or the newer (and
  52  * currently rare) "Ethernet Emulation Model" (EEM).
  53  */
  54
  55 /*
  56  * RNDIS notifications from device: command completion; "reverse"
  57  * keepalives; etc
  58  */
  59 void rndis_status(struct usbnet *dev, struct urb *urb)
  60 {
  61         netdev_dbg(dev->net, "rndis status urb, len %d stat %d\n",
  62                    urb->actual_length, urb->status);
  63         // FIXME for keepalives, respond immediately (asynchronously)
  64         // if not an RNDIS status, do like cdc_status(dev,urb) does
  65 }
  66 EXPORT_SYMBOL_GPL(rndis_status);
  67
  68 /*
  69  * RNDIS indicate messages.
  70  */
  71 static void rndis_msg_indicate(struct usbnet *dev, struct rndis_indicate *msg,
  72                                 int buflen)
  73 {
  74         struct cdc_state *info = (void *)&dev->data;
  75         struct device *udev = &info->control->dev;
  76
  77         if (dev->driver_info->indication) {
  78                 dev->driver_info->indication(dev, msg, buflen);
  79         } else {
  80                 switch (msg->status) {
  81                 case RNDIS_STATUS_MEDIA_CONNECT:
  82                         dev_info(udev, "rndis media connect\n");
  83                         break;
  84                 case RNDIS_STATUS_MEDIA_DISCONNECT:
  85                         dev_info(udev, "rndis media disconnect\n");
  86                         break;
  87                 default:
  88                         dev_info(udev, "rndis indication: 0x%08x\n",
  89                                         le32_to_cpu(msg->status));
  90                 }
  91         }
  92 }
  93
  94 /*
  95  * RPC done RNDIS-style.  Caller guarantees:
  96  * - message is properly byteswapped
  97  * - there's no other request pending
  98  * - buf can hold up to 1KB response (required by RNDIS spec)
  99  * On return, the first few entries are already byteswapped.
 100  *
 101  * Call context is likely probe(), before interface name is known,
 102  * which is why we won't try to use it in the diagnostics.
 103  */
 104 int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf, int buflen)
 105 {
 106         struct cdc_state        *info = (void *) &dev->data;
 107         struct usb_cdc_notification notification;
 108         int                     master_ifnum;
 109         int                     retval;
 110         int                     partial;
 111         unsigned                count;
 112         __le32                  rsp;
 113         u32                     xid = 0, msg_len, request_id;
 114
 115         /* REVISIT when this gets called from contexts other than probe() or
 116          * disconnect(): either serialize, or dispatch responses on xid
 117          */
 118
 119         /* Issue the request; xid is unique, don't bother byteswapping it */
 120         if (likely(buf->msg_type != RNDIS_MSG_HALT &&
 121                    buf->msg_type != RNDIS_MSG_RESET)) {
 122                 xid = dev->xid++;
 123                 if (!xid)
 124                         xid = dev->xid++;
 125                 buf->request_id = (__force __le32) xid;
 126         }
 127         master_ifnum = info->control->cur_altsetting->desc.bInterfaceNumber;
 128         retval = usb_control_msg(dev->udev,
 129                 usb_sndctrlpipe(dev->udev, 0),
 130                 USB_CDC_SEND_ENCAPSULATED_COMMAND,
 131                 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 132                 0, master_ifnum,
 133                 buf, le32_to_cpu(buf->msg_len),
 134                 RNDIS_CONTROL_TIMEOUT_MS);
 135         if (unlikely(retval < 0 || xid == 0))
 136                 return retval;
 137
 138         /* Some devices don't respond on the control channel until
 139          * polled on the status channel, so do that first. */
 140         if (dev->driver_info->data & RNDIS_DRIVER_DATA_POLL_STATUS) {
 141                 retval = usb_interrupt_msg(
 142                         dev->udev,
 143                         usb_rcvintpipe(dev->udev,
 144                                        dev->status->desc.bEndpointAddress),
 145                         &notification, sizeof(notification), &partial,
 146                         RNDIS_CONTROL_TIMEOUT_MS);
 147                 if (unlikely(retval < 0))
 148                         return retval;
 149         }
 150
 151         /* Poll the control channel; the request probably completed immediately */
 152         rsp = buf->msg_type | RNDIS_MSG_COMPLETION;
 153         for (count = 0; count < 10; count++) {
 154                 memset(buf, 0, CONTROL_BUFFER_SIZE);
 155                 retval = usb_control_msg(dev->udev,
 156                         usb_rcvctrlpipe(dev->udev, 0),
 157                         USB_CDC_GET_ENCAPSULATED_RESPONSE,
 158                         USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 159                         0, master_ifnum,
 160                         buf, buflen,
 161                         RNDIS_CONTROL_TIMEOUT_MS);
 162                 if (likely(retval >= 8)) {
 163                         msg_len = le32_to_cpu(buf->msg_len);
 164                         request_id = (__force u32) buf->request_id;
 165                         if (likely(buf->msg_type == rsp)) {
 166                                 if (likely(request_id == xid)) {
 167                                         if (unlikely(rsp == RNDIS_MSG_RESET_C))
 168                                                 return 0;
 169                                         if (likely(RNDIS_STATUS_SUCCESS
 170                                                         == buf->status))
 171                                                 return 0;
 172                                         dev_dbg(&info->control->dev,
 173                                                 "rndis reply status %08x\n",
 174                                                 le32_to_cpu(buf->status));
 175                                         return -EL3RST;
 176                                 }
 177                                 dev_dbg(&info->control->dev,
 178                                         "rndis reply id %d expected %d\n",
 179                                         request_id, xid);
 180                                 /* then likely retry */
 181                         } else switch (buf->msg_type) {
 182                         case RNDIS_MSG_INDICATE:        /* fault/event */
 183                                 rndis_msg_indicate(dev, (void *)buf, buflen);
 184
 185                                 break;
 186                         case RNDIS_MSG_KEEPALIVE: {     /* ping */
 187                                 struct rndis_keepalive_c *msg = (void *)buf;
 188
 189                                 msg->msg_type = RNDIS_MSG_KEEPALIVE_C;
 190                                 msg->msg_len = cpu_to_le32(sizeof *msg);
 191                                 msg->status = RNDIS_STATUS_SUCCESS;
 192                                 retval = usb_control_msg(dev->udev,
 193                                         usb_sndctrlpipe(dev->udev, 0),
 194                                         USB_CDC_SEND_ENCAPSULATED_COMMAND,
 195                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 196                                         0, master_ifnum,
 197                                         msg, sizeof *msg,
 198                                         RNDIS_CONTROL_TIMEOUT_MS);
 199                                 if (unlikely(retval < 0))
 200                                         dev_dbg(&info->control->dev,
 201                                                 "rndis keepalive err %d\n",
 202                                                 retval);
 203                                 }
 204                                 break;
 205                         default:
 206                                 dev_dbg(&info->control->dev,
 207                                         "unexpected rndis msg %08x len %d\n",
 208                                         le32_to_cpu(buf->msg_type), msg_len);
 209                         }
 210                 } else {
 211                         /* device probably issued a protocol stall; ignore */
 212                         dev_dbg(&info->control->dev,
 213                                 "rndis response error, code %d\n", retval);
 214                 }
 215                 msleep(20);
 216         }
 217         dev_dbg(&info->control->dev, "rndis response timeout\n");
 218         return -ETIMEDOUT;
 219 }
 220 EXPORT_SYMBOL_GPL(rndis_command);
 221
 222 /*
 223  * rndis_query:
 224  *
 225  * Performs a query for @oid along with 0 or more bytes of payload as
 226  * specified by @in_len. If @reply_len is not set to -1 then the reply
 227  * length is checked against this value, resulting in an error if it
 228  * doesn't match.
 229  *
 230  * NOTE: Adding a payload exactly or greater than the size of the expected
 231  * response payload is an evident requirement MSFT added for ActiveSync.
 232  *
 233  * The only exception is for OIDs that return a variably sized response,
 234  * in which case no payload should be added.  This undocumented (and
 235  * nonsensical!) issue was found by sniffing protocol requests from the
 236  * ActiveSync 4.1 Windows driver.
 237  */
 238 static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
 239                 void *buf, __le32 oid, u32 in_len,
 240                 void **reply, int *reply_len)
 241 {
 242         int retval;
 243         union {
 244                 void                    *buf;
 245                 struct rndis_msg_hdr    *header;
 246                 struct rndis_query      *get;
 247                 struct rndis_query_c    *get_c;
 248         } u;
 249         u32 off, len;
 250
 251         u.buf = buf;
 252
 253         memset(u.get, 0, sizeof *u.get + in_len);
 254         u.get->msg_type = RNDIS_MSG_QUERY;
 255         u.get->msg_len = cpu_to_le32(sizeof *u.get + in_len);
 256         u.get->oid = oid;
 257         u.get->len = cpu_to_le32(in_len);
 258         u.get->offset = cpu_to_le32(20);
 259
 260         retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
 261         if (unlikely(retval < 0)) {
 262                 dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) failed, %d\n",
 263                                 oid, retval);
 264                 return retval;
 265         }
 266
 267         off = le32_to_cpu(u.get_c->offset);
 268         len = le32_to_cpu(u.get_c->len);
 269         if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
 270                 goto response_error;
 271
 272         if (*reply_len != -1 && len != *reply_len)
 273                 goto response_error;
 274
 275         *reply = (unsigned char *) &u.get_c->request_id + off;
 276         *reply_len = len;
 277
 278         return retval;
 279
 280 response_error:
 281         dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) "
 282                         "invalid response - off %d len %d\n",
 283                 oid, off, len);
 284         return -EDOM;
 285 }
 286
 287 /* same as usbnet_netdev_ops but MTU change not allowed */
 288 static const struct net_device_ops rndis_netdev_ops = {
 289         .ndo_open               = usbnet_open,
 290         .ndo_stop               = usbnet_stop,
 291         .ndo_start_xmit         = usbnet_start_xmit,
 292         .ndo_tx_timeout         = usbnet_tx_timeout,
 293         .ndo_set_mac_address    = eth_mac_addr,
 294         .ndo_validate_addr      = eth_validate_addr,
 295 };
 296
 297 int
 298 generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf, int flags)
 299 {
 300         int                     retval;
 301         struct net_device       *net = dev->net;
 302         struct cdc_state        *info = (void *) &dev->data;
 303         union {
 304                 void                    *buf;
 305                 struct rndis_msg_hdr    *header;
 306                 struct rndis_init       *init;
 307                 struct rndis_init_c     *init_c;
 308                 struct rndis_query      *get;
 309                 struct rndis_query_c    *get_c;
 310                 struct rndis_set        *set;
 311                 struct rndis_set_c      *set_c;
 312                 struct rndis_halt       *halt;
 313         } u;
 314         u32                     tmp;
 315         __le32                  phym_unspec, *phym;
 316         int                     reply_len;
 317         unsigned char           *bp;
 318
 319         /* we can't rely on i/o from stack working, or stack allocation */
 320         u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
 321         if (!u.buf)
 322                 return -ENOMEM;
 323         retval = usbnet_generic_cdc_bind(dev, intf);
 324         if (retval < 0)
 325                 goto fail;
 326
 327         u.init->msg_type = RNDIS_MSG_INIT;
 328         u.init->msg_len = cpu_to_le32(sizeof *u.init);
 329         u.init->major_version = cpu_to_le32(1);
 330         u.init->minor_version = cpu_to_le32(0);
 331
 332         /* max transfer (in spec) is 0x4000 at full speed, but for
 333          * TX we'll stick to one Ethernet packet plus RNDIS framing.
 334          * For RX we handle drivers that zero-pad to end-of-packet.
 335          * Don't let userspace change these settings.
 336          *
 337          * NOTE: there still seems to be wierdness here, as if we need
 338          * to do some more things to make sure WinCE targets accept this.
 339          * They default to jumbograms of 8KB or 16KB, which is absurd
 340          * for such low data rates and which is also more than Linux
 341          * can usually expect to allocate for SKB data...
 342          */
 343         net->hard_header_len += sizeof (struct rndis_data_hdr);
 344         dev->hard_mtu = net->mtu + net->hard_header_len;
 345
 346         dev->maxpacket = usb_maxpacket(dev->udev, dev->out, 1);
 347         if (dev->maxpacket == 0) {
 348                 netif_dbg(dev, probe, dev->net,
 349                           "dev->maxpacket can't be 0\n");
 350                 retval = -EINVAL;
 351                 goto fail_and_release;
 352         }
 353
 354         dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
 355         dev->rx_urb_size &= ~(dev->maxpacket - 1);
 356         u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
 357
 358         net->netdev_ops = &rndis_netdev_ops;
 359
 360         retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
 361         if (unlikely(retval < 0)) {
 362                 /* it might not even be an RNDIS device!! */
 363                 dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
 364                 goto fail_and_release;
 365         }
 366         tmp = le32_to_cpu(u.init_c->max_transfer_size);
 367         if (tmp < dev->hard_mtu) {
 368                 if (tmp <= net->hard_header_len) {
 369                         dev_err(&intf->dev,
 370                                 "dev can't take %u byte packets (max %u)\n",
 371                                 dev->hard_mtu, tmp);
 372                         retval = -EINVAL;
 373                         goto halt_fail_and_release;
 374                 }
 375                 dev_warn(&intf->dev,
 376                          "dev can't take %u byte packets (max %u), "
 377                          "adjusting MTU to %u\n",
 378                          dev->hard_mtu, tmp, tmp - net->hard_header_len);
 379                 dev->hard_mtu = tmp;
 380                 net->mtu = dev->hard_mtu - net->hard_header_len;
 381         }
 382
 383         /* REVISIT:  peripheral "alignment" request is ignored ... */
 384         dev_dbg(&intf->dev,
 385                 "hard mtu %u (%u from dev), rx buflen %Zu, align %d\n",
 386                 dev->hard_mtu, tmp, dev->rx_urb_size,
 387                 1 << le32_to_cpu(u.init_c->packet_alignment));
 388
 389         /* module has some device initialization code needs to be done right
 390          * after RNDIS_INIT */
 391         if (dev->driver_info->early_init &&
 392                         dev->driver_info->early_init(dev) != 0)
 393                 goto halt_fail_and_release;
 394
 395         /* Check physical medium */
 396         phym = NULL;
 397         reply_len = sizeof *phym;
 398         retval = rndis_query(dev, intf, u.buf, OID_GEN_PHYSICAL_MEDIUM,
 399                         0, (void **) &phym, &reply_len);
 400         if (retval != 0 || !phym) {
 401                 /* OID is optional so don't fail here. */
 402                 phym_unspec = RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED;
 403                 phym = &phym_unspec;
 404         }
 405         if ((flags & FLAG_RNDIS_PHYM_WIRELESS) &&
 406                         *phym != RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
 407                 netif_dbg(dev, probe, dev->net,
 408                           "driver requires wireless physical medium, but device is not\n");
 409                 retval = -ENODEV;
 410                 goto halt_fail_and_release;
 411         }
 412         if ((flags & FLAG_RNDIS_PHYM_NOT_WIRELESS) &&
 413                         *phym == RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
 414                 netif_dbg(dev, probe, dev->net,
 415                           "driver requires non-wireless physical medium, but device is wireless.\n");
 416                 retval = -ENODEV;
 417                 goto halt_fail_and_release;
 418         }
 419
 420         /* Get designated host ethernet address */
 421         reply_len = ETH_ALEN;
 422         retval = rndis_query(dev, intf, u.buf, OID_802_3_PERMANENT_ADDRESS,
 423                         48, (void **) &bp, &reply_len);
 424         if (unlikely(retval< 0)) {
 425                 dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
 426                 goto halt_fail_and_release;
 427         }
 428         memcpy(net->dev_addr, bp, ETH_ALEN);
 429         memcpy(net->perm_addr, bp, ETH_ALEN);
 430
 431         /* set a nonzero filter to enable data transfers */
 432         memset(u.set, 0, sizeof *u.set);
 433         u.set->msg_type = RNDIS_MSG_SET;
 434         u.set->msg_len = cpu_to_le32(4 + sizeof *u.set);
 435         u.set->oid = OID_GEN_CURRENT_PACKET_FILTER;
 436         u.set->len = cpu_to_le32(4);
 437         u.set->offset = cpu_to_le32((sizeof *u.set) - 8);
 438         *(__le32 *)(u.buf + sizeof *u.set) = RNDIS_DEFAULT_FILTER;
 439
 440         retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
 441         if (unlikely(retval < 0)) {
 442                 dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
 443                 goto halt_fail_and_release;
 444         }
 445
 446         retval = 0;
 447
 448         kfree(u.buf);
 449         return retval;
 450
 451 halt_fail_and_release:
 452         memset(u.halt, 0, sizeof *u.halt);
 453         u.halt->msg_type = RNDIS_MSG_HALT;
 454         u.halt->msg_len = cpu_to_le32(sizeof *u.halt);
 455         (void) rndis_command(dev, (void *)u.halt, CONTROL_BUFFER_SIZE);
 456 fail_and_release:
 457         usb_set_intfdata(info->data, NULL);
 458         usb_driver_release_interface(driver_of(intf), info->data);
 459         info->data = NULL;
 460 fail:
 461         kfree(u.buf);
 462         return retval;
 463 }
 464 EXPORT_SYMBOL_GPL(generic_rndis_bind);
 465
 466 static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
 467 {
 468         return generic_rndis_bind(dev, intf, FLAG_RNDIS_PHYM_NOT_WIRELESS);
 469 }
 470
 471 void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
 472 {
 473         struct rndis_halt       *halt;
 474
 475         /* try to clear any rndis state/activity (no i/o from stack!) */
 476         halt = kzalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
 477         if (halt) {
 478                 halt->msg_type = RNDIS_MSG_HALT;
 479                 halt->msg_len = cpu_to_le32(sizeof *halt);
 480                 (void) rndis_command(dev, (void *)halt, CONTROL_BUFFER_SIZE);
 481                 kfree(halt);
 482         }
 483
 484         usbnet_cdc_unbind(dev, intf);
 485 }
 486 EXPORT_SYMBOL_GPL(rndis_unbind);
 487
 488 /*
 489  * DATA -- host must not write zlps
 490  */
 491 int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 492 {
 493         /* peripheral may have batched packets to us... */
 494         while (likely(skb->len)) {
 495                 struct rndis_data_hdr   *hdr = (void *)skb->data;
 496                 struct sk_buff          *skb2;
 497                 u32                     msg_len, data_offset, data_len;
 498
 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(hdr->msg_type != RNDIS_MSG_PACKET ||
 505                              skb->len < msg_len ||
 506                              (data_offset + data_len + 8) > msg_len)) {
 507                         dev->net->stats.rx_frame_errors++;
 508                         netdev_dbg(dev->net, "bad rndis message %d/%d/%d/%d, len %d\n",
 509                                    le32_to_cpu(hdr->msg_type),
 510                                    msg_len, data_offset, data_len, skb->len);
 511                         return 0;
 512                 }
 513                 skb_pull(skb, 8 + data_offset);
 514
 515                 /* at most one packet left? */
 516                 if (likely((data_len - skb->len) <= sizeof *hdr)) {
 517                         skb_trim(skb, data_len);
 518                         break;
 519                 }
 520
 521                 /* try to return all the packets in the batch */
 522                 skb2 = skb_clone(skb, GFP_ATOMIC);
 523                 if (unlikely(!skb2))
 524                         break;
 525                 skb_pull(skb, msg_len - sizeof *hdr);
 526                 skb_trim(skb2, data_len);
 527                 usbnet_skb_return(dev, skb2);
 528         }
 529
 530         /* caller will usbnet_skb_return the remaining packet */
 531         return 1;
 532 }
 533 EXPORT_SYMBOL_GPL(rndis_rx_fixup);
 534
 535 struct sk_buff *
 536 rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 537 {
 538         struct rndis_data_hdr   *hdr;
 539         struct sk_buff          *skb2;
 540         unsigned                len = skb->len;
 541
 542         if (likely(!skb_cloned(skb))) {
 543                 int     room = skb_headroom(skb);
 544
 545                 /* enough head room as-is? */
 546                 if (unlikely((sizeof *hdr) <= room))
 547                         goto fill;
 548
 549                 /* enough room, but needs to be readjusted? */
 550                 room += skb_tailroom(skb);
 551                 if (likely((sizeof *hdr) <= room)) {
 552                         skb->data = memmove(skb->head + sizeof *hdr,
 553                                             skb->data, len);
 554                         skb_set_tail_pointer(skb, len);
 555                         goto fill;
 556                 }
 557         }
 558
 559         /* create a new skb, with the correct size (and tailpad) */
 560         skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
 561         dev_kfree_skb_any(skb);
 562         if (unlikely(!skb2))
 563                 return skb2;
 564         skb = skb2;
 565
 566         /* fill out the RNDIS header.  we won't bother trying to batch
 567          * packets; Linux minimizes wasted bandwidth through tx queues.
 568          */
 569 fill:
 570         hdr = (void *) __skb_push(skb, sizeof *hdr);
 571         memset(hdr, 0, sizeof *hdr);
 572         hdr->msg_type = RNDIS_MSG_PACKET;
 573         hdr->msg_len = cpu_to_le32(skb->len);
 574         hdr->data_offset = cpu_to_le32(sizeof(*hdr) - 8);
 575         hdr->data_len = cpu_to_le32(len);
 576
 577         /* FIXME make the last packet always be short ... */
 578         return skb;
 579 }
 580 EXPORT_SYMBOL_GPL(rndis_tx_fixup);
 581
 582
 583 static const struct driver_info rndis_info = {
 584         .description =  "RNDIS device",
 585         .flags =        FLAG_ETHER | FLAG_POINTTOPOINT | FLAG_FRAMING_RN | FLAG_NO_SETINT,
 586         .bind =         rndis_bind,
 587         .unbind =       rndis_unbind,
 588         .status =       rndis_status,
 589         .rx_fixup =     rndis_rx_fixup,
 590         .tx_fixup =     rndis_tx_fixup,
 591 };
 592
 593 static const struct driver_info rndis_poll_status_info = {
 594         .description =  "RNDIS device (poll status before control)",
 595         .flags =        FLAG_ETHER | FLAG_POINTTOPOINT | FLAG_FRAMING_RN | FLAG_NO_SETINT,
 596         .data =         RNDIS_DRIVER_DATA_POLL_STATUS,
 597         .bind =         rndis_bind,
 598         .unbind =       rndis_unbind,
 599         .status =       rndis_status,
 600         .rx_fixup =     rndis_rx_fixup,
 601         .tx_fixup =     rndis_tx_fixup,
 602 };
 603
 604 /*-------------------------------------------------------------------------*/
 605
 606 static const struct usb_device_id       products [] = {
 607 {
 608         /* 2Wire HomePortal 1000SW */
 609         USB_DEVICE_AND_INTERFACE_INFO(0x1630, 0x0042,
 610                                       USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
 611         .driver_info = (unsigned long) &rndis_poll_status_info,
 612 }, {
 613         /* RNDIS is MSFT's un-official variant of CDC ACM */
 614         USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
 615         .driver_info = (unsigned long) &rndis_info,
 616 }, {
 617         /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
 618         USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
 619         .driver_info = (unsigned long) &rndis_poll_status_info,
 620 }, {
 621         /* RNDIS for tethering */
 622         USB_INTERFACE_INFO(USB_CLASS_WIRELESS_CONTROLLER, 1, 3),
 623         .driver_info = (unsigned long) &rndis_info,
 624 },
 625         { },            // END
 626 };
 627 MODULE_DEVICE_TABLE(usb, products);
 628
 629 static struct usb_driver rndis_driver = {
 630         .name =         "rndis_host",
 631         .id_table =     products,
 632         .probe =        usbnet_probe,
 633         .disconnect =   usbnet_disconnect,
 634         .suspend =      usbnet_suspend,
 635         .resume =       usbnet_resume,
 636 };
 637
 638 module_usb_driver(rndis_driver);
 639
 640 MODULE_AUTHOR("David Brownell");
 641 MODULE_DESCRIPTION("USB Host side RNDIS driver");
 642 MODULE_LICENSE("GPL");