drivers/usb/gadget/f_rndis.c

   1 /*
   2  * f_rndis.c -- RNDIS link function driver
   3  *
   4  * Copyright (C) 2003-2005,2008 David Brownell
   5  * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
   6  * Copyright (C) 2008 Nokia Corporation
   7  * Copyright (C) 2009 Samsung Electronics
   8  *                    Author: Michal Nazarewicz (mina86@mina86.com)
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  */
  15
  16 /* #define VERBOSE_DEBUG */
  17
  18 #include <linux/slab.h>
  19 #include <linux/kernel.h>
  20 #include <linux/device.h>
  21 #include <linux/etherdevice.h>
  22
  23 #include <linux/atomic.h>
  24
  25 #include "u_ether.h"
  26 #include "rndis.h"
  27
  28
  29 /*
  30  * This function is an RNDIS Ethernet port -- a Microsoft protocol that's
  31  * been promoted instead of the standard CDC Ethernet.  The published RNDIS
  32  * spec is ambiguous, incomplete, and needlessly complex.  Variants such as
  33  * ActiveSync have even worse status in terms of specification.
  34  *
  35  * In short:  it's a protocol controlled by (and for) Microsoft, not for an
  36  * Open ecosystem or markets.  Linux supports it *only* because Microsoft
  37  * doesn't support the CDC Ethernet standard.
  38  *
  39  * The RNDIS data transfer model is complex, with multiple Ethernet packets
  40  * per USB message, and out of band data.  The control model is built around
  41  * what's essentially an "RNDIS RPC" protocol.  It's all wrapped in a CDC ACM
  42  * (modem, not Ethernet) veneer, with those ACM descriptors being entirely
  43  * useless (they're ignored).  RNDIS expects to be the only function in its
  44  * configuration, so it's no real help if you need composite devices; and
  45  * it expects to be the first configuration too.
  46  *
  47  * There is a single technical advantage of RNDIS over CDC Ethernet, if you
  48  * discount the fluff that its RPC can be made to deliver: it doesn't need
  49  * a NOP altsetting for the data interface.  That lets it work on some of the
  50  * "so smart it's stupid" hardware which takes over configuration changes
  51  * from the software, and adds restrictions like "no altsettings".
  52  *
  53  * Unfortunately MSFT's RNDIS drivers are buggy.  They hang or oops, and
  54  * have all sorts of contrary-to-specification oddities that can prevent
  55  * them from working sanely.  Since bugfixes (or accurate specs, letting
  56  * Linux work around those bugs) are unlikely to ever come from MSFT, you
  57  * may want to avoid using RNDIS on purely operational grounds.
  58  *
  59  * Omissions from the RNDIS 1.0 specification include:
  60  *
  61  *   - Power management ... references data that's scattered around lots
  62  *     of other documentation, which is incorrect/incomplete there too.
  63  *
  64  *   - There are various undocumented protocol requirements, like the need
  65  *     to send garbage in some control-OUT messages.
  66  *
  67  *   - MS-Windows drivers sometimes emit undocumented requests.
  68  */
  69
  70 struct f_rndis {
  71         struct gether                   port;
  72         u8                              ctrl_id, data_id;
  73         u8                              ethaddr[ETH_ALEN];
  74         u32                             vendorID;
  75         const char                      *manufacturer;
  76         int                             config;
  77
  78         struct usb_ep                   *notify;
  79         struct usb_request              *notify_req;
  80         atomic_t                        notify_count;
  81 };
  82
  83 static inline struct f_rndis *func_to_rndis(struct usb_function *f)
  84 {
  85         return container_of(f, struct f_rndis, port.func);
  86 }
  87
  88 /* peak (theoretical) bulk transfer rate in bits-per-second */
  89 static unsigned int bitrate(struct usb_gadget *g)
  90 {
  91         if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
  92                 return 13 * 1024 * 8 * 1000 * 8;
  93         else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  94                 return 13 * 512 * 8 * 1000 * 8;
  95         else
  96                 return 19 * 64 * 1 * 1000 * 8;
  97 }
  98
  99 /*-------------------------------------------------------------------------*/
 100
 101 /*
 102  */
 103
 104 #define LOG2_STATUS_INTERVAL_MSEC       5       /* 1 << 5 == 32 msec */
 105 #define STATUS_BYTECOUNT                8       /* 8 bytes data */
 106
 107
 108 /* interface descriptor: */
 109
 110 static struct usb_interface_descriptor rndis_control_intf = {
 111         .bLength =              sizeof rndis_control_intf,
 112         .bDescriptorType =      USB_DT_INTERFACE,
 113
 114         /* .bInterfaceNumber = DYNAMIC */
 115         /* status endpoint is optional; this could be patched later */
 116         .bNumEndpoints =        1,
 117         .bInterfaceClass =      USB_CLASS_COMM,
 118         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 119         .bInterfaceProtocol =   USB_CDC_ACM_PROTO_VENDOR,
 120         /* .iInterface = DYNAMIC */
 121 };
 122
 123 static struct usb_cdc_header_desc header_desc = {
 124         .bLength =              sizeof header_desc,
 125         .bDescriptorType =      USB_DT_CS_INTERFACE,
 126         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 127
 128         .bcdCDC =               cpu_to_le16(0x0110),
 129 };
 130
 131 static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor = {
 132         .bLength =              sizeof call_mgmt_descriptor,
 133         .bDescriptorType =      USB_DT_CS_INTERFACE,
 134         .bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
 135
 136         .bmCapabilities =       0x00,
 137         .bDataInterface =       0x01,
 138 };
 139
 140 static struct usb_cdc_acm_descriptor rndis_acm_descriptor = {
 141         .bLength =              sizeof rndis_acm_descriptor,
 142         .bDescriptorType =      USB_DT_CS_INTERFACE,
 143         .bDescriptorSubType =   USB_CDC_ACM_TYPE,
 144
 145         .bmCapabilities =       0x00,
 146 };
 147
 148 static struct usb_cdc_union_desc rndis_union_desc = {
 149         .bLength =              sizeof(rndis_union_desc),
 150         .bDescriptorType =      USB_DT_CS_INTERFACE,
 151         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 152         /* .bMasterInterface0 = DYNAMIC */
 153         /* .bSlaveInterface0 =  DYNAMIC */
 154 };
 155
 156 /* the data interface has two bulk endpoints */
 157
 158 static struct usb_interface_descriptor rndis_data_intf = {
 159         .bLength =              sizeof rndis_data_intf,
 160         .bDescriptorType =      USB_DT_INTERFACE,
 161
 162         /* .bInterfaceNumber = DYNAMIC */
 163         .bNumEndpoints =        2,
 164         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 165         .bInterfaceSubClass =   0,
 166         .bInterfaceProtocol =   0,
 167         /* .iInterface = DYNAMIC */
 168 };
 169
 170
 171 static struct usb_interface_assoc_descriptor
 172 rndis_iad_descriptor = {
 173         .bLength =              sizeof rndis_iad_descriptor,
 174         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 175
 176         .bFirstInterface =      0, /* XXX, hardcoded */
 177         .bInterfaceCount =      2,      // control + data
 178         .bFunctionClass =       USB_CLASS_COMM,
 179         .bFunctionSubClass =    USB_CDC_SUBCLASS_ETHERNET,
 180         .bFunctionProtocol =    USB_CDC_PROTO_NONE,
 181         /* .iFunction = DYNAMIC */
 182 };
 183
 184 /* full speed support: */
 185
 186 static struct usb_endpoint_descriptor fs_notify_desc = {
 187         .bLength =              USB_DT_ENDPOINT_SIZE,
 188         .bDescriptorType =      USB_DT_ENDPOINT,
 189
 190         .bEndpointAddress =     USB_DIR_IN,
 191         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 192         .wMaxPacketSize =       cpu_to_le16(STATUS_BYTECOUNT),
 193         .bInterval =            1 << LOG2_STATUS_INTERVAL_MSEC,
 194 };
 195
 196 static struct usb_endpoint_descriptor fs_in_desc = {
 197         .bLength =              USB_DT_ENDPOINT_SIZE,
 198         .bDescriptorType =      USB_DT_ENDPOINT,
 199
 200         .bEndpointAddress =     USB_DIR_IN,
 201         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 202 };
 203
 204 static struct usb_endpoint_descriptor fs_out_desc = {
 205         .bLength =              USB_DT_ENDPOINT_SIZE,
 206         .bDescriptorType =      USB_DT_ENDPOINT,
 207
 208         .bEndpointAddress =     USB_DIR_OUT,
 209         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 210 };
 211
 212 static struct usb_descriptor_header *eth_fs_function[] = {
 213         (struct usb_descriptor_header *) &rndis_iad_descriptor,
 214
 215         /* control interface matches ACM, not Ethernet */
 216         (struct usb_descriptor_header *) &rndis_control_intf,
 217         (struct usb_descriptor_header *) &header_desc,
 218         (struct usb_descriptor_header *) &call_mgmt_descriptor,
 219         (struct usb_descriptor_header *) &rndis_acm_descriptor,
 220         (struct usb_descriptor_header *) &rndis_union_desc,
 221         (struct usb_descriptor_header *) &fs_notify_desc,
 222
 223         /* data interface has no altsetting */
 224         (struct usb_descriptor_header *) &rndis_data_intf,
 225         (struct usb_descriptor_header *) &fs_in_desc,
 226         (struct usb_descriptor_header *) &fs_out_desc,
 227         NULL,
 228 };
 229
 230 /* high speed support: */
 231
 232 static struct usb_endpoint_descriptor hs_notify_desc = {
 233         .bLength =              USB_DT_ENDPOINT_SIZE,
 234         .bDescriptorType =      USB_DT_ENDPOINT,
 235
 236         .bEndpointAddress =     USB_DIR_IN,
 237         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 238         .wMaxPacketSize =       cpu_to_le16(STATUS_BYTECOUNT),
 239         .bInterval =            LOG2_STATUS_INTERVAL_MSEC + 4,
 240 };
 241
 242 static struct usb_endpoint_descriptor hs_in_desc = {
 243         .bLength =              USB_DT_ENDPOINT_SIZE,
 244         .bDescriptorType =      USB_DT_ENDPOINT,
 245
 246         .bEndpointAddress =     USB_DIR_IN,
 247         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 248         .wMaxPacketSize =       cpu_to_le16(512),
 249 };
 250
 251 static struct usb_endpoint_descriptor hs_out_desc = {
 252         .bLength =              USB_DT_ENDPOINT_SIZE,
 253         .bDescriptorType =      USB_DT_ENDPOINT,
 254
 255         .bEndpointAddress =     USB_DIR_OUT,
 256         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 257         .wMaxPacketSize =       cpu_to_le16(512),
 258 };
 259
 260 static struct usb_descriptor_header *eth_hs_function[] = {
 261         (struct usb_descriptor_header *) &rndis_iad_descriptor,
 262
 263         /* control interface matches ACM, not Ethernet */
 264         (struct usb_descriptor_header *) &rndis_control_intf,
 265         (struct usb_descriptor_header *) &header_desc,
 266         (struct usb_descriptor_header *) &call_mgmt_descriptor,
 267         (struct usb_descriptor_header *) &rndis_acm_descriptor,
 268         (struct usb_descriptor_header *) &rndis_union_desc,
 269         (struct usb_descriptor_header *) &hs_notify_desc,
 270
 271         /* data interface has no altsetting */
 272         (struct usb_descriptor_header *) &rndis_data_intf,
 273         (struct usb_descriptor_header *) &hs_in_desc,
 274         (struct usb_descriptor_header *) &hs_out_desc,
 275         NULL,
 276 };
 277
 278 /* super speed support: */
 279
 280 static struct usb_endpoint_descriptor ss_notify_desc = {
 281         .bLength =              USB_DT_ENDPOINT_SIZE,
 282         .bDescriptorType =      USB_DT_ENDPOINT,
 283
 284         .bEndpointAddress =     USB_DIR_IN,
 285         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 286         .wMaxPacketSize =       cpu_to_le16(STATUS_BYTECOUNT),
 287         .bInterval =            LOG2_STATUS_INTERVAL_MSEC + 4,
 288 };
 289
 290 static struct usb_ss_ep_comp_descriptor ss_intr_comp_desc = {
 291         .bLength =              sizeof ss_intr_comp_desc,
 292         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 293
 294         /* the following 3 values can be tweaked if necessary */
 295         /* .bMaxBurst =         0, */
 296         /* .bmAttributes =      0, */
 297         .wBytesPerInterval =    cpu_to_le16(STATUS_BYTECOUNT),
 298 };
 299
 300 static struct usb_endpoint_descriptor ss_in_desc = {
 301         .bLength =              USB_DT_ENDPOINT_SIZE,
 302         .bDescriptorType =      USB_DT_ENDPOINT,
 303
 304         .bEndpointAddress =     USB_DIR_IN,
 305         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 306         .wMaxPacketSize =       cpu_to_le16(1024),
 307 };
 308
 309 static struct usb_endpoint_descriptor ss_out_desc = {
 310         .bLength =              USB_DT_ENDPOINT_SIZE,
 311         .bDescriptorType =      USB_DT_ENDPOINT,
 312
 313         .bEndpointAddress =     USB_DIR_OUT,
 314         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 315         .wMaxPacketSize =       cpu_to_le16(1024),
 316 };
 317
 318 static struct usb_ss_ep_comp_descriptor ss_bulk_comp_desc = {
 319         .bLength =              sizeof ss_bulk_comp_desc,
 320         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 321
 322         /* the following 2 values can be tweaked if necessary */
 323         /* .bMaxBurst =         0, */
 324         /* .bmAttributes =      0, */
 325 };
 326
 327 static struct usb_descriptor_header *eth_ss_function[] = {
 328         (struct usb_descriptor_header *) &rndis_iad_descriptor,
 329
 330         /* control interface matches ACM, not Ethernet */
 331         (struct usb_descriptor_header *) &rndis_control_intf,
 332         (struct usb_descriptor_header *) &header_desc,
 333         (struct usb_descriptor_header *) &call_mgmt_descriptor,
 334         (struct usb_descriptor_header *) &rndis_acm_descriptor,
 335         (struct usb_descriptor_header *) &rndis_union_desc,
 336         (struct usb_descriptor_header *) &ss_notify_desc,
 337         (struct usb_descriptor_header *) &ss_intr_comp_desc,
 338
 339         /* data interface has no altsetting */
 340         (struct usb_descriptor_header *) &rndis_data_intf,
 341         (struct usb_descriptor_header *) &ss_in_desc,
 342         (struct usb_descriptor_header *) &ss_bulk_comp_desc,
 343         (struct usb_descriptor_header *) &ss_out_desc,
 344         (struct usb_descriptor_header *) &ss_bulk_comp_desc,
 345         NULL,
 346 };
 347
 348 /* string descriptors: */
 349
 350 static struct usb_string rndis_string_defs[] = {
 351         [0].s = "RNDIS Communications Control",
 352         [1].s = "RNDIS Ethernet Data",
 353         [2].s = "RNDIS",
 354         {  } /* end of list */
 355 };
 356
 357 static struct usb_gadget_strings rndis_string_table = {
 358         .language =             0x0409, /* en-us */
 359         .strings =              rndis_string_defs,
 360 };
 361
 362 static struct usb_gadget_strings *rndis_strings[] = {
 363         &rndis_string_table,
 364         NULL,
 365 };
 366
 367 /*-------------------------------------------------------------------------*/
 368
 369 static struct sk_buff *rndis_add_header(struct gether *port,
 370                                         struct sk_buff *skb)
 371 {
 372         struct sk_buff *skb2;
 373
 374         skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
 375         if (skb2)
 376                 rndis_add_hdr(skb2);
 377
 378         dev_kfree_skb_any(skb);
 379         return skb2;
 380 }
 381
 382 static void rndis_response_available(void *_rndis)
 383 {
 384         struct f_rndis                  *rndis = _rndis;
 385         struct usb_request              *req = rndis->notify_req;
 386         struct usb_composite_dev        *cdev = rndis->port.func.config->cdev;
 387         __le32                          *data = req->buf;
 388         int                             status;
 389
 390         if (atomic_inc_return(&rndis->notify_count) != 1)
 391                 return;
 392
 393         /* Send RNDIS RESPONSE_AVAILABLE notification; a
 394          * USB_CDC_NOTIFY_RESPONSE_AVAILABLE "should" work too
 395          *
 396          * This is the only notification defined by RNDIS.
 397          */
 398         data[0] = cpu_to_le32(1);
 399         data[1] = cpu_to_le32(0);
 400
 401         status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
 402         if (status) {
 403                 atomic_dec(&rndis->notify_count);
 404                 DBG(cdev, "notify/0 --> %d\n", status);
 405         }
 406 }
 407
 408 static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
 409 {
 410         struct f_rndis                  *rndis = req->context;
 411         struct usb_composite_dev        *cdev = rndis->port.func.config->cdev;
 412         int                             status = req->status;
 413
 414         /* after TX:
 415          *  - USB_CDC_GET_ENCAPSULATED_RESPONSE (ep0/control)
 416          *  - RNDIS_RESPONSE_AVAILABLE (status/irq)
 417          */
 418         switch (status) {
 419         case -ECONNRESET:
 420         case -ESHUTDOWN:
 421                 /* connection gone */
 422                 atomic_set(&rndis->notify_count, 0);
 423                 break;
 424         default:
 425                 DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
 426                         ep->name, status,
 427                         req->actual, req->length);
 428                 /* FALLTHROUGH */
 429         case 0:
 430                 if (ep != rndis->notify)
 431                         break;
 432
 433                 /* handle multiple pending RNDIS_RESPONSE_AVAILABLE
 434                  * notifications by resending until we're done
 435                  */
 436                 if (atomic_dec_and_test(&rndis->notify_count))
 437                         break;
 438                 status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
 439                 if (status) {
 440                         atomic_dec(&rndis->notify_count);
 441                         DBG(cdev, "notify/1 --> %d\n", status);
 442                 }
 443                 break;
 444         }
 445 }
 446
 447 static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
 448 {
 449         struct f_rndis                  *rndis = req->context;
 450         struct usb_composite_dev        *cdev = rndis->port.func.config->cdev;
 451         int                             status;
 452
 453         /* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
 454 //      spin_lock(&dev->lock);
 455         status = rndis_msg_parser(rndis->config, (u8 *) req->buf);
 456         if (status < 0)
 457                 ERROR(cdev, "RNDIS command error %d, %d/%d\n",
 458                         status, req->actual, req->length);
 459 //      spin_unlock(&dev->lock);
 460 }
 461
 462 static int
 463 rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 464 {
 465         struct f_rndis          *rndis = func_to_rndis(f);
 466         struct usb_composite_dev *cdev = f->config->cdev;
 467         struct usb_request      *req = cdev->req;
 468         int                     value = -EOPNOTSUPP;
 469         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 470         u16                     w_value = le16_to_cpu(ctrl->wValue);
 471         u16                     w_length = le16_to_cpu(ctrl->wLength);
 472
 473         /* composite driver infrastructure handles everything except
 474          * CDC class messages; interface activation uses set_alt().
 475          */
 476         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 477
 478         /* RNDIS uses the CDC command encapsulation mechanism to implement
 479          * an RPC scheme, with much getting/setting of attributes by OID.
 480          */
 481         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 482                         | USB_CDC_SEND_ENCAPSULATED_COMMAND:
 483                 if (w_value || w_index != rndis->ctrl_id)
 484                         goto invalid;
 485                 /* read the request; process it later */
 486                 value = w_length;
 487                 req->complete = rndis_command_complete;
 488                 req->context = rndis;
 489                 /* later, rndis_response_available() sends a notification */
 490                 break;
 491
 492         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 493                         | USB_CDC_GET_ENCAPSULATED_RESPONSE:
 494                 if (w_value || w_index != rndis->ctrl_id)
 495                         goto invalid;
 496                 else {
 497                         u8 *buf;
 498                         u32 n;
 499
 500                         /* return the result */
 501                         buf = rndis_get_next_response(rndis->config, &n);
 502                         if (buf) {
 503                                 memcpy(req->buf, buf, n);
 504                                 req->complete = rndis_response_complete;
 505                                 req->context = rndis;
 506                                 rndis_free_response(rndis->config, buf);
 507                                 value = n;
 508                         }
 509                         /* else stalls ... spec says to avoid that */
 510                 }
 511                 break;
 512
 513         default:
 514 invalid:
 515                 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 516                         ctrl->bRequestType, ctrl->bRequest,
 517                         w_value, w_index, w_length);
 518         }
 519
 520         /* respond with data transfer or status phase? */
 521         if (value >= 0) {
 522                 DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
 523                         ctrl->bRequestType, ctrl->bRequest,
 524                         w_value, w_index, w_length);
 525                 req->zero = (value < w_length);
 526                 req->length = value;
 527                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 528                 if (value < 0)
 529                         ERROR(cdev, "rndis response on err %d\n", value);
 530         }
 531
 532         /* device either stalls (value < 0) or reports success */
 533         return value;
 534 }
 535
 536
 537 static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 538 {
 539         struct f_rndis          *rndis = func_to_rndis(f);
 540         struct usb_composite_dev *cdev = f->config->cdev;
 541
 542         /* we know alt == 0 */
 543
 544         if (intf == rndis->ctrl_id) {
 545                 if (rndis->notify->driver_data) {
 546                         VDBG(cdev, "reset rndis control %d\n", intf);
 547                         usb_ep_disable(rndis->notify);
 548                 }
 549                 if (!rndis->notify->desc) {
 550                         VDBG(cdev, "init rndis ctrl %d\n", intf);
 551                         if (config_ep_by_speed(cdev->gadget, f, rndis->notify))
 552                                 goto fail;
 553                 }
 554                 usb_ep_enable(rndis->notify);
 555                 rndis->notify->driver_data = rndis;
 556
 557         } else if (intf == rndis->data_id) {
 558                 struct net_device       *net;
 559
 560                 if (rndis->port.in_ep->driver_data) {
 561                         DBG(cdev, "reset rndis\n");
 562                         gether_disconnect(&rndis->port);
 563                 }
 564
 565                 if (!rndis->port.in_ep->desc || !rndis->port.out_ep->desc) {
 566                         DBG(cdev, "init rndis\n");
 567                         if (config_ep_by_speed(cdev->gadget, f,
 568                                                rndis->port.in_ep) ||
 569                             config_ep_by_speed(cdev->gadget, f,
 570                                                rndis->port.out_ep)) {
 571                                 rndis->port.in_ep->desc = NULL;
 572                                 rndis->port.out_ep->desc = NULL;
 573                                 goto fail;
 574                         }
 575                 }
 576
 577                 /* Avoid ZLPs; they can be troublesome. */
 578                 rndis->port.is_zlp_ok = false;
 579
 580                 /* RNDIS should be in the "RNDIS uninitialized" state,
 581                  * either never activated or after rndis_uninit().
 582                  *
 583                  * We don't want data to flow here until a nonzero packet
 584                  * filter is set, at which point it enters "RNDIS data
 585                  * initialized" state ... but we do want the endpoints
 586                  * to be activated.  It's a strange little state.
 587                  *
 588                  * REVISIT the RNDIS gadget code has done this wrong for a
 589                  * very long time.  We need another call to the link layer
 590                  * code -- gether_updown(...bool) maybe -- to do it right.
 591                  */
 592                 rndis->port.cdc_filter = 0;
 593
 594                 DBG(cdev, "RNDIS RX/TX early activation ... \n");
 595                 net = gether_connect(&rndis->port);
 596                 if (IS_ERR(net))
 597                         return PTR_ERR(net);
 598
 599                 rndis_set_param_dev(rndis->config, net,
 600                                 &rndis->port.cdc_filter);
 601         } else
 602                 goto fail;
 603
 604         return 0;
 605 fail:
 606         return -EINVAL;
 607 }
 608
 609 static void rndis_disable(struct usb_function *f)
 610 {
 611         struct f_rndis          *rndis = func_to_rndis(f);
 612         struct usb_composite_dev *cdev = f->config->cdev;
 613
 614         if (!rndis->notify->driver_data)
 615                 return;
 616
 617         DBG(cdev, "rndis deactivated\n");
 618
 619         rndis_uninit(rndis->config);
 620         gether_disconnect(&rndis->port);
 621
 622         usb_ep_disable(rndis->notify);
 623         rndis->notify->driver_data = NULL;
 624 }
 625
 626 /*-------------------------------------------------------------------------*/
 627
 628 /*
 629  * This isn't quite the same mechanism as CDC Ethernet, since the
 630  * notification scheme passes less data, but the same set of link
 631  * states must be tested.  A key difference is that altsettings are
 632  * not used to tell whether the link should send packets or not.
 633  */
 634
 635 static void rndis_open(struct gether *geth)
 636 {
 637         struct f_rndis          *rndis = func_to_rndis(&geth->func);
 638         struct usb_composite_dev *cdev = geth->func.config->cdev;
 639
 640         DBG(cdev, "%s\n", __func__);
 641
 642         rndis_set_param_medium(rndis->config, RNDIS_MEDIUM_802_3,
 643                                 bitrate(cdev->gadget) / 100);
 644         rndis_signal_connect(rndis->config);
 645 }
 646
 647 static void rndis_close(struct gether *geth)
 648 {
 649         struct f_rndis          *rndis = func_to_rndis(&geth->func);
 650
 651         DBG(geth->func.config->cdev, "%s\n", __func__);
 652
 653         rndis_set_param_medium(rndis->config, RNDIS_MEDIUM_802_3, 0);
 654         rndis_signal_disconnect(rndis->config);
 655 }
 656
 657 /*-------------------------------------------------------------------------*/
 658
 659 /* ethernet function driver setup/binding */
 660
 661 static int
 662 rndis_bind(struct usb_configuration *c, struct usb_function *f)
 663 {
 664         struct usb_composite_dev *cdev = c->cdev;
 665         struct f_rndis          *rndis = func_to_rndis(f);
 666         int                     status;
 667         struct usb_ep           *ep;
 668
 669         /* allocate instance-specific interface IDs */
 670         status = usb_interface_id(c, f);
 671         if (status < 0)
 672                 goto fail;
 673         rndis->ctrl_id = status;
 674         rndis_iad_descriptor.bFirstInterface = status;
 675
 676         rndis_control_intf.bInterfaceNumber = status;
 677         rndis_union_desc.bMasterInterface0 = status;
 678
 679         status = usb_interface_id(c, f);
 680         if (status < 0)
 681                 goto fail;
 682         rndis->data_id = status;
 683
 684         rndis_data_intf.bInterfaceNumber = status;
 685         rndis_union_desc.bSlaveInterface0 = status;
 686
 687         status = -ENODEV;
 688
 689         /* allocate instance-specific endpoints */
 690         ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
 691         if (!ep)
 692                 goto fail;
 693         rndis->port.in_ep = ep;
 694         ep->driver_data = cdev; /* claim */
 695
 696         ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
 697         if (!ep)
 698                 goto fail;
 699         rndis->port.out_ep = ep;
 700         ep->driver_data = cdev; /* claim */
 701
 702         /* NOTE:  a status/notification endpoint is, strictly speaking,
 703          * optional.  We don't treat it that way though!  It's simpler,
 704          * and some newer profiles don't treat it as optional.
 705          */
 706         ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
 707         if (!ep)
 708                 goto fail;
 709         rndis->notify = ep;
 710         ep->driver_data = cdev; /* claim */
 711
 712         status = -ENOMEM;
 713
 714         /* allocate notification request and buffer */
 715         rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
 716         if (!rndis->notify_req)
 717                 goto fail;
 718         rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
 719         if (!rndis->notify_req->buf)
 720                 goto fail;
 721         rndis->notify_req->length = STATUS_BYTECOUNT;
 722         rndis->notify_req->context = rndis;
 723         rndis->notify_req->complete = rndis_response_complete;
 724
 725         /* copy descriptors, and track endpoint copies */
 726         f->descriptors = usb_copy_descriptors(eth_fs_function);
 727         if (!f->descriptors)
 728                 goto fail;
 729
 730         /* support all relevant hardware speeds... we expect that when
 731          * hardware is dual speed, all bulk-capable endpoints work at
 732          * both speeds
 733          */
 734         if (gadget_is_dualspeed(c->cdev->gadget)) {
 735                 hs_in_desc.bEndpointAddress =
 736                                 fs_in_desc.bEndpointAddress;
 737                 hs_out_desc.bEndpointAddress =
 738                                 fs_out_desc.bEndpointAddress;
 739                 hs_notify_desc.bEndpointAddress =
 740                                 fs_notify_desc.bEndpointAddress;
 741
 742                 /* copy descriptors, and track endpoint copies */
 743                 f->hs_descriptors = usb_copy_descriptors(eth_hs_function);
 744                 if (!f->hs_descriptors)
 745                         goto fail;
 746         }
 747
 748         if (gadget_is_superspeed(c->cdev->gadget)) {
 749                 ss_in_desc.bEndpointAddress =
 750                                 fs_in_desc.bEndpointAddress;
 751                 ss_out_desc.bEndpointAddress =
 752                                 fs_out_desc.bEndpointAddress;
 753                 ss_notify_desc.bEndpointAddress =
 754                                 fs_notify_desc.bEndpointAddress;
 755
 756                 /* copy descriptors, and track endpoint copies */
 757                 f->ss_descriptors = usb_copy_descriptors(eth_ss_function);
 758                 if (!f->ss_descriptors)
 759                         goto fail;
 760         }
 761
 762         rndis->port.open = rndis_open;
 763         rndis->port.close = rndis_close;
 764
 765         status = rndis_register(rndis_response_available, rndis);
 766         if (status < 0)
 767                 goto fail;
 768         rndis->config = status;
 769
 770         rndis_set_param_medium(rndis->config, RNDIS_MEDIUM_802_3, 0);
 771         rndis_set_host_mac(rndis->config, rndis->ethaddr);
 772
 773         if (rndis->manufacturer && rndis->vendorID &&
 774                         rndis_set_param_vendor(rndis->config, rndis->vendorID,
 775                                                rndis->manufacturer))
 776                 goto fail;
 777
 778         /* NOTE:  all that is done without knowing or caring about
 779          * the network link ... which is unavailable to this code
 780          * until we're activated via set_alt().
 781          */
 782
 783         DBG(cdev, "RNDIS: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 784                         gadget_is_superspeed(c->cdev->gadget) ? "super" :
 785                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 786                         rndis->port.in_ep->name, rndis->port.out_ep->name,
 787                         rndis->notify->name);
 788         return 0;
 789
 790 fail:
 791         if (gadget_is_superspeed(c->cdev->gadget) && f->ss_descriptors)
 792                 usb_free_descriptors(f->ss_descriptors);
 793         if (gadget_is_dualspeed(c->cdev->gadget) && f->hs_descriptors)
 794                 usb_free_descriptors(f->hs_descriptors);
 795         if (f->descriptors)
 796                 usb_free_descriptors(f->descriptors);
 797
 798         if (rndis->notify_req) {
 799                 kfree(rndis->notify_req->buf);
 800                 usb_ep_free_request(rndis->notify, rndis->notify_req);
 801         }
 802
 803         /* we might as well release our claims on endpoints */
 804         if (rndis->notify)
 805                 rndis->notify->driver_data = NULL;
 806         if (rndis->port.out_ep->desc)
 807                 rndis->port.out_ep->driver_data = NULL;
 808         if (rndis->port.in_ep->desc)
 809                 rndis->port.in_ep->driver_data = NULL;
 810
 811         ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 812
 813         return status;
 814 }
 815
 816 static void
 817 rndis_unbind(struct usb_configuration *c, struct usb_function *f)
 818 {
 819         struct f_rndis          *rndis = func_to_rndis(f);
 820
 821         rndis_deregister(rndis->config);
 822         rndis_exit();
 823         rndis_string_defs[0].id = 0;
 824
 825         if (gadget_is_superspeed(c->cdev->gadget))
 826                 usb_free_descriptors(f->ss_descriptors);
 827         if (gadget_is_dualspeed(c->cdev->gadget))
 828                 usb_free_descriptors(f->hs_descriptors);
 829         usb_free_descriptors(f->descriptors);
 830
 831         kfree(rndis->notify_req->buf);
 832         usb_ep_free_request(rndis->notify, rndis->notify_req);
 833
 834         kfree(rndis);
 835 }
 836
 837 /* Some controllers can't support RNDIS ... */
 838 static inline bool can_support_rndis(struct usb_configuration *c)
 839 {
 840         /* everything else is *presumably* fine */
 841         return true;
 842 }
 843
 844 int
 845 rndis_bind_config_vendor(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
 846                                 u32 vendorID, const char *manufacturer)
 847 {
 848         struct f_rndis  *rndis;
 849         int             status;
 850
 851         if (!can_support_rndis(c) || !ethaddr)
 852                 return -EINVAL;
 853
 854         /* maybe allocate device-global string IDs */
 855         if (rndis_string_defs[0].id == 0) {
 856
 857                 /* ... and setup RNDIS itself */
 858                 status = rndis_init();
 859                 if (status < 0)
 860                         return status;
 861
 862                 /* control interface label */
 863                 status = usb_string_id(c->cdev);
 864                 if (status < 0)
 865                         return status;
 866                 rndis_string_defs[0].id = status;
 867                 rndis_control_intf.iInterface = status;
 868
 869                 /* data interface label */
 870                 status = usb_string_id(c->cdev);
 871                 if (status < 0)
 872                         return status;
 873                 rndis_string_defs[1].id = status;
 874                 rndis_data_intf.iInterface = status;
 875
 876                 /* IAD iFunction label */
 877                 status = usb_string_id(c->cdev);
 878                 if (status < 0)
 879                         return status;
 880                 rndis_string_defs[2].id = status;
 881                 rndis_iad_descriptor.iFunction = status;
 882         }
 883
 884         /* allocate and initialize one new instance */
 885         status = -ENOMEM;
 886         rndis = kzalloc(sizeof *rndis, GFP_KERNEL);
 887         if (!rndis)
 888                 goto fail;
 889
 890         memcpy(rndis->ethaddr, ethaddr, ETH_ALEN);
 891         rndis->vendorID = vendorID;
 892         rndis->manufacturer = manufacturer;
 893
 894         /* RNDIS activates when the host changes this filter */
 895         rndis->port.cdc_filter = 0;
 896
 897         /* RNDIS has special (and complex) framing */
 898         rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
 899         rndis->port.wrap = rndis_add_header;
 900         rndis->port.unwrap = rndis_rm_hdr;
 901
 902         rndis->port.func.name = "rndis";
 903         rndis->port.func.strings = rndis_strings;
 904         /* descriptors are per-instance copies */
 905         rndis->port.func.bind = rndis_bind;
 906         rndis->port.func.unbind = rndis_unbind;
 907         rndis->port.func.set_alt = rndis_set_alt;
 908         rndis->port.func.setup = rndis_setup;
 909         rndis->port.func.disable = rndis_disable;
 910
 911         status = usb_add_function(c, &rndis->port.func);
 912         if (status) {
 913                 kfree(rndis);
 914 fail:
 915                 rndis_exit();
 916         }
 917         return status;
 918 }