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/module.h>
  21 #include <linux/device.h>
  22 #include <linux/etherdevice.h>
  23
  24 #include <linux/atomic.h>
  25
  26 #include "u_ether.h"
  27 #include "u_ether_configfs.h"
  28 #include "u_rndis.h"
  29 #include "rndis.h"
  30
  31 /*
  32  * This function is an RNDIS Ethernet port -- a Microsoft protocol that's
  33  * been promoted instead of the standard CDC Ethernet.  The published RNDIS
  34  * spec is ambiguous, incomplete, and needlessly complex.  Variants such as
  35  * ActiveSync have even worse status in terms of specification.
  36  *
  37  * In short:  it's a protocol controlled by (and for) Microsoft, not for an
  38  * Open ecosystem or markets.  Linux supports it *only* because Microsoft
  39  * doesn't support the CDC Ethernet standard.
  40  *
  41  * The RNDIS data transfer model is complex, with multiple Ethernet packets
  42  * per USB message, and out of band data.  The control model is built around
  43  * what's essentially an "RNDIS RPC" protocol.  It's all wrapped in a CDC ACM
  44  * (modem, not Ethernet) veneer, with those ACM descriptors being entirely
  45  * useless (they're ignored).  RNDIS expects to be the only function in its
  46  * configuration, so it's no real help if you need composite devices; and
  47  * it expects to be the first configuration too.
  48  *
  49  * There is a single technical advantage of RNDIS over CDC Ethernet, if you
  50  * discount the fluff that its RPC can be made to deliver: it doesn't need
  51  * a NOP altsetting for the data interface.  That lets it work on some of the
  52  * "so smart it's stupid" hardware which takes over configuration changes
  53  * from the software, and adds restrictions like "no altsettings".
  54  *
  55  * Unfortunately MSFT's RNDIS drivers are buggy.  They hang or oops, and
  56  * have all sorts of contrary-to-specification oddities that can prevent
  57  * them from working sanely.  Since bugfixes (or accurate specs, letting
  58  * Linux work around those bugs) are unlikely to ever come from MSFT, you
  59  * may want to avoid using RNDIS on purely operational grounds.
  60  *
  61  * Omissions from the RNDIS 1.0 specification include:
  62  *
  63  *   - Power management ... references data that's scattered around lots
  64  *     of other documentation, which is incorrect/incomplete there too.
  65  *
  66  *   - There are various undocumented protocol requirements, like the need
  67  *     to send garbage in some control-OUT messages.
  68  *
  69  *   - MS-Windows drivers sometimes emit undocumented requests.
  70  */
  71
  72 struct f_rndis {
  73         struct gether                   port;
  74         u8                              ctrl_id, data_id;
  75         u8                              ethaddr[ETH_ALEN];
  76         u32                             vendorID;
  77         const char                      *manufacturer;
  78         int                             config;
  79
  80         struct usb_ep                   *notify;
  81         struct usb_request              *notify_req;
  82         atomic_t                        notify_count;
  83 };
  84
  85 static inline struct f_rndis *func_to_rndis(struct usb_function *f)
  86 {
  87         return container_of(f, struct f_rndis, port.func);
  88 }
  89
  90 /* peak (theoretical) bulk transfer rate in bits-per-second */
  91 static unsigned int bitrate(struct usb_gadget *g)
  92 {
  93         if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
  94                 return 13 * 1024 * 8 * 1000 * 8;
  95         else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  96                 return 13 * 512 * 8 * 1000 * 8;
  97         else
  98                 return 19 * 64 * 1 * 1000 * 8;
  99 }
 100
 101 /*-------------------------------------------------------------------------*/
 102
 103 /*
 104  */
 105
 106 #define RNDIS_STATUS_INTERVAL_MS        32
 107 #define STATUS_BYTECOUNT                8       /* 8 bytes data */
 108
 109
 110 /* interface descriptor: */
 111
 112 static struct usb_interface_descriptor rndis_control_intf = {
 113         .bLength =              sizeof rndis_control_intf,
 114         .bDescriptorType =      USB_DT_INTERFACE,
 115
 116         /* .bInterfaceNumber = DYNAMIC */
 117         /* status endpoint is optional; this could be patched later */
 118         .bNumEndpoints =        1,
 119         .bInterfaceClass =      USB_CLASS_COMM,
 120         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 121         .bInterfaceProtocol =   USB_CDC_ACM_PROTO_VENDOR,
 122         /* .iInterface = DYNAMIC */
 123 };
 124
 125 static struct usb_cdc_header_desc header_desc = {
 126         .bLength =              sizeof header_desc,
 127         .bDescriptorType =      USB_DT_CS_INTERFACE,
 128         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 129
 130         .bcdCDC =               cpu_to_le16(0x0110),
 131 };
 132
 133 static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor = {
 134         .bLength =              sizeof call_mgmt_descriptor,
 135         .bDescriptorType =      USB_DT_CS_INTERFACE,
 136         .bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
 137
 138         .bmCapabilities =       0x00,
 139         .bDataInterface =       0x01,
 140 };
 141
 142 static struct usb_cdc_acm_descriptor rndis_acm_descriptor = {
 143         .bLength =              sizeof rndis_acm_descriptor,
 144         .bDescriptorType =      USB_DT_CS_INTERFACE,
 145         .bDescriptorSubType =   USB_CDC_ACM_TYPE,
 146
 147         .bmCapabilities =       0x00,
 148 };
 149
 150 static struct usb_cdc_union_desc rndis_union_desc = {
 151         .bLength =              sizeof(rndis_union_desc),
 152         .bDescriptorType =      USB_DT_CS_INTERFACE,
 153         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 154         /* .bMasterInterface0 = DYNAMIC */
 155         /* .bSlaveInterface0 =  DYNAMIC */
 156 };
 157
 158 /* the data interface has two bulk endpoints */
 159
 160 static struct usb_interface_descriptor rndis_data_intf = {
 161         .bLength =              sizeof rndis_data_intf,
 162         .bDescriptorType =      USB_DT_INTERFACE,
 163
 164         /* .bInterfaceNumber = DYNAMIC */
 165         .bNumEndpoints =        2,
 166         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 167         .bInterfaceSubClass =   0,
 168         .bInterfaceProtocol =   0,
 169         /* .iInterface = DYNAMIC */
 170 };
 171
 172
 173 static struct usb_interface_assoc_descriptor
 174 rndis_iad_descriptor = {
 175         .bLength =              sizeof rndis_iad_descriptor,
 176         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 177
 178         .bFirstInterface =      0, /* XXX, hardcoded */
 179         .bInterfaceCount =      2,      // control + data
 180         .bFunctionClass =       USB_CLASS_COMM,
 181         .bFunctionSubClass =    USB_CDC_SUBCLASS_ETHERNET,
 182         .bFunctionProtocol =    USB_CDC_PROTO_NONE,
 183         /* .iFunction = DYNAMIC */
 184 };
 185
 186 /* full speed support: */
 187
 188 static struct usb_endpoint_descriptor fs_notify_desc = {
 189         .bLength =              USB_DT_ENDPOINT_SIZE,
 190         .bDescriptorType =      USB_DT_ENDPOINT,
 191
 192         .bEndpointAddress =     USB_DIR_IN,
 193         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 194         .wMaxPacketSize =       cpu_to_le16(STATUS_BYTECOUNT),
 195         .bInterval =            RNDIS_STATUS_INTERVAL_MS,
 196 };
 197
 198 static struct usb_endpoint_descriptor fs_in_desc = {
 199         .bLength =              USB_DT_ENDPOINT_SIZE,
 200         .bDescriptorType =      USB_DT_ENDPOINT,
 201
 202         .bEndpointAddress =     USB_DIR_IN,
 203         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 204 };
 205
 206 static struct usb_endpoint_descriptor fs_out_desc = {
 207         .bLength =              USB_DT_ENDPOINT_SIZE,
 208         .bDescriptorType =      USB_DT_ENDPOINT,
 209
 210         .bEndpointAddress =     USB_DIR_OUT,
 211         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 212 };
 213
 214 static struct usb_descriptor_header *eth_fs_function[] = {
 215         (struct usb_descriptor_header *) &rndis_iad_descriptor,
 216
 217         /* control interface matches ACM, not Ethernet */
 218         (struct usb_descriptor_header *) &rndis_control_intf,
 219         (struct usb_descriptor_header *) &header_desc,
 220         (struct usb_descriptor_header *) &call_mgmt_descriptor,
 221         (struct usb_descriptor_header *) &rndis_acm_descriptor,
 222         (struct usb_descriptor_header *) &rndis_union_desc,
 223         (struct usb_descriptor_header *) &fs_notify_desc,
 224
 225         /* data interface has no altsetting */
 226         (struct usb_descriptor_header *) &rndis_data_intf,
 227         (struct usb_descriptor_header *) &fs_in_desc,
 228         (struct usb_descriptor_header *) &fs_out_desc,
 229         NULL,
 230 };
 231
 232 /* high speed support: */
 233
 234 static struct usb_endpoint_descriptor hs_notify_desc = {
 235         .bLength =              USB_DT_ENDPOINT_SIZE,
 236         .bDescriptorType =      USB_DT_ENDPOINT,
 237
 238         .bEndpointAddress =     USB_DIR_IN,
 239         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 240         .wMaxPacketSize =       cpu_to_le16(STATUS_BYTECOUNT),
 241         .bInterval =            USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
 242 };
 243
 244 static struct usb_endpoint_descriptor hs_in_desc = {
 245         .bLength =              USB_DT_ENDPOINT_SIZE,
 246         .bDescriptorType =      USB_DT_ENDPOINT,
 247
 248         .bEndpointAddress =     USB_DIR_IN,
 249         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 250         .wMaxPacketSize =       cpu_to_le16(512),
 251 };
 252
 253 static struct usb_endpoint_descriptor hs_out_desc = {
 254         .bLength =              USB_DT_ENDPOINT_SIZE,
 255         .bDescriptorType =      USB_DT_ENDPOINT,
 256
 257         .bEndpointAddress =     USB_DIR_OUT,
 258         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 259         .wMaxPacketSize =       cpu_to_le16(512),
 260 };
 261
 262 static struct usb_descriptor_header *eth_hs_function[] = {
 263         (struct usb_descriptor_header *) &rndis_iad_descriptor,
 264
 265         /* control interface matches ACM, not Ethernet */
 266         (struct usb_descriptor_header *) &rndis_control_intf,
 267         (struct usb_descriptor_header *) &header_desc,
 268         (struct usb_descriptor_header *) &call_mgmt_descriptor,
 269         (struct usb_descriptor_header *) &rndis_acm_descriptor,
 270         (struct usb_descriptor_header *) &rndis_union_desc,
 271         (struct usb_descriptor_header *) &hs_notify_desc,
 272
 273         /* data interface has no altsetting */
 274         (struct usb_descriptor_header *) &rndis_data_intf,
 275         (struct usb_descriptor_header *) &hs_in_desc,
 276         (struct usb_descriptor_header *) &hs_out_desc,
 277         NULL,
 278 };
 279
 280 /* super speed support: */
 281
 282 static struct usb_endpoint_descriptor ss_notify_desc = {
 283         .bLength =              USB_DT_ENDPOINT_SIZE,
 284         .bDescriptorType =      USB_DT_ENDPOINT,
 285
 286         .bEndpointAddress =     USB_DIR_IN,
 287         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 288         .wMaxPacketSize =       cpu_to_le16(STATUS_BYTECOUNT),
 289         .bInterval =            USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
 290 };
 291
 292 static struct usb_ss_ep_comp_descriptor ss_intr_comp_desc = {
 293         .bLength =              sizeof ss_intr_comp_desc,
 294         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 295
 296         /* the following 3 values can be tweaked if necessary */
 297         /* .bMaxBurst =         0, */
 298         /* .bmAttributes =      0, */
 299         .wBytesPerInterval =    cpu_to_le16(STATUS_BYTECOUNT),
 300 };
 301
 302 static struct usb_endpoint_descriptor ss_in_desc = {
 303         .bLength =              USB_DT_ENDPOINT_SIZE,
 304         .bDescriptorType =      USB_DT_ENDPOINT,
 305
 306         .bEndpointAddress =     USB_DIR_IN,
 307         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 308         .wMaxPacketSize =       cpu_to_le16(1024),
 309 };
 310
 311 static struct usb_endpoint_descriptor ss_out_desc = {
 312         .bLength =              USB_DT_ENDPOINT_SIZE,
 313         .bDescriptorType =      USB_DT_ENDPOINT,
 314
 315         .bEndpointAddress =     USB_DIR_OUT,
 316         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 317         .wMaxPacketSize =       cpu_to_le16(1024),
 318 };
 319
 320 static struct usb_ss_ep_comp_descriptor ss_bulk_comp_desc = {
 321         .bLength =              sizeof ss_bulk_comp_desc,
 322         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 323
 324         /* the following 2 values can be tweaked if necessary */
 325         /* .bMaxBurst =         0, */
 326         /* .bmAttributes =      0, */
 327 };
 328
 329 static struct usb_descriptor_header *eth_ss_function[] = {
 330         (struct usb_descriptor_header *) &rndis_iad_descriptor,
 331
 332         /* control interface matches ACM, not Ethernet */
 333         (struct usb_descriptor_header *) &rndis_control_intf,
 334         (struct usb_descriptor_header *) &header_desc,
 335         (struct usb_descriptor_header *) &call_mgmt_descriptor,
 336         (struct usb_descriptor_header *) &rndis_acm_descriptor,
 337         (struct usb_descriptor_header *) &rndis_union_desc,
 338         (struct usb_descriptor_header *) &ss_notify_desc,
 339         (struct usb_descriptor_header *) &ss_intr_comp_desc,
 340
 341         /* data interface has no altsetting */
 342         (struct usb_descriptor_header *) &rndis_data_intf,
 343         (struct usb_descriptor_header *) &ss_in_desc,
 344         (struct usb_descriptor_header *) &ss_bulk_comp_desc,
 345         (struct usb_descriptor_header *) &ss_out_desc,
 346         (struct usb_descriptor_header *) &ss_bulk_comp_desc,
 347         NULL,
 348 };
 349
 350 /* string descriptors: */
 351
 352 static struct usb_string rndis_string_defs[] = {
 353         [0].s = "RNDIS Communications Control",
 354         [1].s = "RNDIS Ethernet Data",
 355         [2].s = "RNDIS",
 356         {  } /* end of list */
 357 };
 358
 359 static struct usb_gadget_strings rndis_string_table = {
 360         .language =             0x0409, /* en-us */
 361         .strings =              rndis_string_defs,
 362 };
 363
 364 static struct usb_gadget_strings *rndis_strings[] = {
 365         &rndis_string_table,
 366         NULL,
 367 };
 368
 369 /*-------------------------------------------------------------------------*/
 370
 371 static struct sk_buff *rndis_add_header(struct gether *port,
 372                                         struct sk_buff *skb)
 373 {
 374         struct sk_buff *skb2;
 375
 376         skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
 377         if (skb2)
 378                 rndis_add_hdr(skb2);
 379
 380         dev_kfree_skb_any(skb);
 381         return skb2;
 382 }
 383
 384 static void rndis_response_available(void *_rndis)
 385 {
 386         struct f_rndis                  *rndis = _rndis;
 387         struct usb_request              *req = rndis->notify_req;
 388         struct usb_composite_dev        *cdev = rndis->port.func.config->cdev;
 389         __le32                          *data = req->buf;
 390         int                             status;
 391
 392         if (atomic_inc_return(&rndis->notify_count) != 1)
 393                 return;
 394
 395         /* Send RNDIS RESPONSE_AVAILABLE notification; a
 396          * USB_CDC_NOTIFY_RESPONSE_AVAILABLE "should" work too
 397          *
 398          * This is the only notification defined by RNDIS.
 399          */
 400         data[0] = cpu_to_le32(1);
 401         data[1] = cpu_to_le32(0);
 402
 403         status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
 404         if (status) {
 405                 atomic_dec(&rndis->notify_count);
 406                 DBG(cdev, "notify/0 --> %d\n", status);
 407         }
 408 }
 409
 410 static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
 411 {
 412         struct f_rndis                  *rndis = req->context;
 413         struct usb_composite_dev        *cdev = rndis->port.func.config->cdev;
 414         int                             status = req->status;
 415
 416         /* after TX:
 417          *  - USB_CDC_GET_ENCAPSULATED_RESPONSE (ep0/control)
 418          *  - RNDIS_RESPONSE_AVAILABLE (status/irq)
 419          */
 420         switch (status) {
 421         case -ECONNRESET:
 422         case -ESHUTDOWN:
 423                 /* connection gone */
 424                 atomic_set(&rndis->notify_count, 0);
 425                 break;
 426         default:
 427                 DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
 428                         ep->name, status,
 429                         req->actual, req->length);
 430                 /* FALLTHROUGH */
 431         case 0:
 432                 if (ep != rndis->notify)
 433                         break;
 434
 435                 /* handle multiple pending RNDIS_RESPONSE_AVAILABLE
 436                  * notifications by resending until we're done
 437                  */
 438                 if (atomic_dec_and_test(&rndis->notify_count))
 439                         break;
 440                 status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
 441                 if (status) {
 442                         atomic_dec(&rndis->notify_count);
 443                         DBG(cdev, "notify/1 --> %d\n", status);
 444                 }
 445                 break;
 446         }
 447 }
 448
 449 static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
 450 {
 451         struct f_rndis                  *rndis = req->context;
 452         int                             status;
 453
 454         /* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
 455 //      spin_lock(&dev->lock);
 456         status = rndis_msg_parser(rndis->config, (u8 *) req->buf);
 457         if (status < 0)
 458                 pr_err("RNDIS command error %d, %d/%d\n",
 459                         status, req->actual, req->length);
 460 //      spin_unlock(&dev->lock);
 461 }
 462
 463 static int
 464 rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 465 {
 466         struct f_rndis          *rndis = func_to_rndis(f);
 467         struct usb_composite_dev *cdev = f->config->cdev;
 468         struct usb_request      *req = cdev->req;
 469         int                     value = -EOPNOTSUPP;
 470         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 471         u16                     w_value = le16_to_cpu(ctrl->wValue);
 472         u16                     w_length = le16_to_cpu(ctrl->wLength);
 473
 474         /* composite driver infrastructure handles everything except
 475          * CDC class messages; interface activation uses set_alt().
 476          */
 477         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 478
 479         /* RNDIS uses the CDC command encapsulation mechanism to implement
 480          * an RPC scheme, with much getting/setting of attributes by OID.
 481          */
 482         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 483                         | USB_CDC_SEND_ENCAPSULATED_COMMAND:
 484                 if (w_value || w_index != rndis->ctrl_id)
 485                         goto invalid;
 486                 /* read the request; process it later */
 487                 value = w_length;
 488                 req->complete = rndis_command_complete;
 489                 req->context = rndis;
 490                 /* later, rndis_response_available() sends a notification */
 491                 break;
 492
 493         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 494                         | USB_CDC_GET_ENCAPSULATED_RESPONSE:
 495                 if (w_value || w_index != rndis->ctrl_id)
 496                         goto invalid;
 497                 else {
 498                         u8 *buf;
 499                         u32 n;
 500
 501                         /* return the result */
 502                         buf = rndis_get_next_response(rndis->config, &n);
 503                         if (buf) {
 504                                 memcpy(req->buf, buf, n);
 505                                 req->complete = rndis_response_complete;
 506                                 req->context = rndis;
 507                                 rndis_free_response(rndis->config, buf);
 508                                 value = n;
 509                         }
 510                         /* else stalls ... spec says to avoid that */
 511                 }
 512                 break;
 513
 514         default:
 515 invalid:
 516                 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 517                         ctrl->bRequestType, ctrl->bRequest,
 518                         w_value, w_index, w_length);
 519         }
 520
 521         /* respond with data transfer or status phase? */
 522         if (value >= 0) {
 523                 DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
 524                         ctrl->bRequestType, ctrl->bRequest,
 525                         w_value, w_index, w_length);
 526                 req->zero = (value < w_length);
 527                 req->length = value;
 528                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 529                 if (value < 0)
 530                         ERROR(cdev, "rndis response on err %d\n", value);
 531         }
 532
 533         /* device either stalls (value < 0) or reports success */
 534         return value;
 535 }
 536
 537
 538 static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 539 {
 540         struct f_rndis          *rndis = func_to_rndis(f);
 541         struct usb_composite_dev *cdev = f->config->cdev;
 542
 543         /* we know alt == 0 */
 544
 545         if (intf == rndis->ctrl_id) {
 546                 if (rndis->notify->driver_data) {
 547                         VDBG(cdev, "reset rndis control %d\n", intf);
 548                         usb_ep_disable(rndis->notify);
 549                 }
 550                 if (!rndis->notify->desc) {
 551                         VDBG(cdev, "init rndis ctrl %d\n", intf);
 552                         if (config_ep_by_speed(cdev->gadget, f, rndis->notify))
 553                                 goto fail;
 554                 }
 555                 usb_ep_enable(rndis->notify);
 556                 rndis->notify->driver_data = rndis;
 557
 558         } else if (intf == rndis->data_id) {
 559                 struct net_device       *net;
 560
 561                 if (rndis->port.in_ep->driver_data) {
 562                         DBG(cdev, "reset rndis\n");
 563                         gether_disconnect(&rndis->port);
 564                 }
 565
 566                 if (!rndis->port.in_ep->desc || !rndis->port.out_ep->desc) {
 567                         DBG(cdev, "init rndis\n");
 568                         if (config_ep_by_speed(cdev->gadget, f,
 569                                                rndis->port.in_ep) ||
 570                             config_ep_by_speed(cdev->gadget, f,
 571                                                rndis->port.out_ep)) {
 572                                 rndis->port.in_ep->desc = NULL;
 573                                 rndis->port.out_ep->desc = NULL;
 574                                 goto fail;
 575                         }
 576                 }
 577
 578                 /* Avoid ZLPs; they can be troublesome. */
 579                 rndis->port.is_zlp_ok = false;
 580
 581                 /* RNDIS should be in the "RNDIS uninitialized" state,
 582                  * either never activated or after rndis_uninit().
 583                  *
 584                  * We don't want data to flow here until a nonzero packet
 585                  * filter is set, at which point it enters "RNDIS data
 586                  * initialized" state ... but we do want the endpoints
 587                  * to be activated.  It's a strange little state.
 588                  *
 589                  * REVISIT the RNDIS gadget code has done this wrong for a
 590                  * very long time.  We need another call to the link layer
 591                  * code -- gether_updown(...bool) maybe -- to do it right.
 592                  */
 593                 rndis->port.cdc_filter = 0;
 594
 595                 DBG(cdev, "RNDIS RX/TX early activation ... \n");
 596                 net = gether_connect(&rndis->port);
 597                 if (IS_ERR(net))
 598                         return PTR_ERR(net);
 599
 600                 rndis_set_param_dev(rndis->config, net,
 601                                 &rndis->port.cdc_filter);
 602         } else
 603                 goto fail;
 604
 605         return 0;
 606 fail:
 607         return -EINVAL;
 608 }
 609
 610 static void rndis_disable(struct usb_function *f)
 611 {
 612         struct f_rndis          *rndis = func_to_rndis(f);
 613         struct usb_composite_dev *cdev = f->config->cdev;
 614
 615         if (!rndis->notify->driver_data)
 616                 return;
 617
 618         DBG(cdev, "rndis deactivated\n");
 619
 620         rndis_uninit(rndis->config);
 621         gether_disconnect(&rndis->port);
 622
 623         usb_ep_disable(rndis->notify);
 624         rndis->notify->driver_data = NULL;
 625 }
 626
 627 /*-------------------------------------------------------------------------*/
 628
 629 /*
 630  * This isn't quite the same mechanism as CDC Ethernet, since the
 631  * notification scheme passes less data, but the same set of link
 632  * states must be tested.  A key difference is that altsettings are
 633  * not used to tell whether the link should send packets or not.
 634  */
 635
 636 static void rndis_open(struct gether *geth)
 637 {
 638         struct f_rndis          *rndis = func_to_rndis(&geth->func);
 639         struct usb_composite_dev *cdev = geth->func.config->cdev;
 640
 641         DBG(cdev, "%s\n", __func__);
 642
 643         rndis_set_param_medium(rndis->config, RNDIS_MEDIUM_802_3,
 644                                 bitrate(cdev->gadget) / 100);
 645         rndis_signal_connect(rndis->config);
 646 }
 647
 648 static void rndis_close(struct gether *geth)
 649 {
 650         struct f_rndis          *rndis = func_to_rndis(&geth->func);
 651
 652         DBG(geth->func.config->cdev, "%s\n", __func__);
 653
 654         rndis_set_param_medium(rndis->config, RNDIS_MEDIUM_802_3, 0);
 655         rndis_signal_disconnect(rndis->config);
 656 }
 657
 658 /*-------------------------------------------------------------------------*/
 659
 660 /* Some controllers can't support RNDIS ... */
 661 static inline bool can_support_rndis(struct usb_configuration *c)
 662 {
 663         /* everything else is *presumably* fine */
 664         return true;
 665 }
 666
 667 /* ethernet function driver setup/binding */
 668
 669 static int
 670 rndis_bind(struct usb_configuration *c, struct usb_function *f)
 671 {
 672         struct usb_composite_dev *cdev = c->cdev;
 673         struct f_rndis          *rndis = func_to_rndis(f);
 674         struct usb_string       *us;
 675         int                     status;
 676         struct usb_ep           *ep;
 677
 678         struct f_rndis_opts *rndis_opts;
 679
 680         if (!can_support_rndis(c))
 681                 return -EINVAL;
 682
 683         rndis_opts = container_of(f->fi, struct f_rndis_opts, func_inst);
 684
 685         /*
 686          * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
 687          * configurations are bound in sequence with list_for_each_entry,
 688          * in each configuration its functions are bound in sequence
 689          * with list_for_each_entry, so we assume no race condition
 690          * with regard to rndis_opts->bound access
 691          */
 692         if (!rndis_opts->bound) {
 693                 gether_set_gadget(rndis_opts->net, cdev->gadget);
 694                 status = gether_register_netdev(rndis_opts->net);
 695                 if (status)
 696                         return status;
 697                 rndis_opts->bound = true;
 698         }
 699
 700         us = usb_gstrings_attach(cdev, rndis_strings,
 701                                  ARRAY_SIZE(rndis_string_defs));
 702         if (IS_ERR(us))
 703                 return PTR_ERR(us);
 704         rndis_control_intf.iInterface = us[0].id;
 705         rndis_data_intf.iInterface = us[1].id;
 706         rndis_iad_descriptor.iFunction = us[2].id;
 707
 708         /* allocate instance-specific interface IDs */
 709         status = usb_interface_id(c, f);
 710         if (status < 0)
 711                 goto fail;
 712         rndis->ctrl_id = status;
 713         rndis_iad_descriptor.bFirstInterface = status;
 714
 715         rndis_control_intf.bInterfaceNumber = status;
 716         rndis_union_desc.bMasterInterface0 = status;
 717
 718         status = usb_interface_id(c, f);
 719         if (status < 0)
 720                 goto fail;
 721         rndis->data_id = status;
 722
 723         rndis_data_intf.bInterfaceNumber = status;
 724         rndis_union_desc.bSlaveInterface0 = status;
 725
 726         status = -ENODEV;
 727
 728         /* allocate instance-specific endpoints */
 729         ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
 730         if (!ep)
 731                 goto fail;
 732         rndis->port.in_ep = ep;
 733         ep->driver_data = cdev; /* claim */
 734
 735         ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
 736         if (!ep)
 737                 goto fail;
 738         rndis->port.out_ep = ep;
 739         ep->driver_data = cdev; /* claim */
 740
 741         /* NOTE:  a status/notification endpoint is, strictly speaking,
 742          * optional.  We don't treat it that way though!  It's simpler,
 743          * and some newer profiles don't treat it as optional.
 744          */
 745         ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
 746         if (!ep)
 747                 goto fail;
 748         rndis->notify = ep;
 749         ep->driver_data = cdev; /* claim */
 750
 751         status = -ENOMEM;
 752
 753         /* allocate notification request and buffer */
 754         rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
 755         if (!rndis->notify_req)
 756                 goto fail;
 757         rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
 758         if (!rndis->notify_req->buf)
 759                 goto fail;
 760         rndis->notify_req->length = STATUS_BYTECOUNT;
 761         rndis->notify_req->context = rndis;
 762         rndis->notify_req->complete = rndis_response_complete;
 763
 764         /* support all relevant hardware speeds... we expect that when
 765          * hardware is dual speed, all bulk-capable endpoints work at
 766          * both speeds
 767          */
 768         hs_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
 769         hs_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
 770         hs_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
 771
 772         ss_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
 773         ss_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
 774         ss_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
 775
 776         status = usb_assign_descriptors(f, eth_fs_function, eth_hs_function,
 777                         eth_ss_function);
 778         if (status)
 779                 goto fail;
 780
 781         rndis->port.open = rndis_open;
 782         rndis->port.close = rndis_close;
 783
 784         rndis_set_param_medium(rndis->config, RNDIS_MEDIUM_802_3, 0);
 785         rndis_set_host_mac(rndis->config, rndis->ethaddr);
 786
 787         if (rndis->manufacturer && rndis->vendorID &&
 788                         rndis_set_param_vendor(rndis->config, rndis->vendorID,
 789                                                rndis->manufacturer))
 790                 goto fail;
 791
 792         /* NOTE:  all that is done without knowing or caring about
 793          * the network link ... which is unavailable to this code
 794          * until we're activated via set_alt().
 795          */
 796
 797         DBG(cdev, "RNDIS: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 798                         gadget_is_superspeed(c->cdev->gadget) ? "super" :
 799                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 800                         rndis->port.in_ep->name, rndis->port.out_ep->name,
 801                         rndis->notify->name);
 802         return 0;
 803
 804 fail:
 805         usb_free_all_descriptors(f);
 806
 807         if (rndis->notify_req) {
 808                 kfree(rndis->notify_req->buf);
 809                 usb_ep_free_request(rndis->notify, rndis->notify_req);
 810         }
 811
 812         /* we might as well release our claims on endpoints */
 813         if (rndis->notify)
 814                 rndis->notify->driver_data = NULL;
 815         if (rndis->port.out_ep)
 816                 rndis->port.out_ep->driver_data = NULL;
 817         if (rndis->port.in_ep)
 818                 rndis->port.in_ep->driver_data = NULL;
 819
 820         ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 821
 822         return status;
 823 }
 824
 825 void rndis_borrow_net(struct usb_function_instance *f, struct net_device *net)
 826 {
 827         struct f_rndis_opts *opts;
 828
 829         opts = container_of(f, struct f_rndis_opts, func_inst);
 830         if (opts->bound)
 831                 gether_cleanup(netdev_priv(opts->net));
 832         else
 833                 free_netdev(opts->net);
 834         opts->borrowed_net = opts->bound = true;
 835         opts->net = net;
 836 }
 837 EXPORT_SYMBOL(rndis_borrow_net);
 838
 839 static inline struct f_rndis_opts *to_f_rndis_opts(struct config_item *item)
 840 {
 841         return container_of(to_config_group(item), struct f_rndis_opts,
 842                             func_inst.group);
 843 }
 844
 845 /* f_rndis_item_ops */
 846 USB_ETHERNET_CONFIGFS_ITEM(rndis);
 847
 848 /* f_rndis_opts_dev_addr */
 849 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(rndis);
 850
 851 /* f_rndis_opts_host_addr */
 852 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(rndis);
 853
 854 /* f_rndis_opts_qmult */
 855 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(rndis);
 856
 857 /* f_rndis_opts_ifname */
 858 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(rndis);
 859
 860 static struct configfs_attribute *rndis_attrs[] = {
 861         &f_rndis_opts_dev_addr.attr,
 862         &f_rndis_opts_host_addr.attr,
 863         &f_rndis_opts_qmult.attr,
 864         &f_rndis_opts_ifname.attr,
 865         NULL,
 866 };
 867
 868 static struct config_item_type rndis_func_type = {
 869         .ct_item_ops    = &rndis_item_ops,
 870         .ct_attrs       = rndis_attrs,
 871         .ct_owner       = THIS_MODULE,
 872 };
 873
 874 static void rndis_free_inst(struct usb_function_instance *f)
 875 {
 876         struct f_rndis_opts *opts;
 877
 878         opts = container_of(f, struct f_rndis_opts, func_inst);
 879         if (!opts->borrowed_net) {
 880                 if (opts->bound)
 881                         gether_cleanup(netdev_priv(opts->net));
 882                 else
 883                         free_netdev(opts->net);
 884         }
 885         kfree(opts);
 886 }
 887
 888 static struct usb_function_instance *rndis_alloc_inst(void)
 889 {
 890         struct f_rndis_opts *opts;
 891
 892         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 893         if (!opts)
 894                 return ERR_PTR(-ENOMEM);
 895         mutex_init(&opts->lock);
 896         opts->func_inst.free_func_inst = rndis_free_inst;
 897         opts->net = gether_setup_default();
 898         if (IS_ERR(opts->net)) {
 899                 struct net_device *net = opts->net;
 900                 kfree(opts);
 901                 return ERR_CAST(net);
 902         }
 903
 904         config_group_init_type_name(&opts->func_inst.group, "",
 905                                     &rndis_func_type);
 906
 907         return &opts->func_inst;
 908 }
 909
 910 static void rndis_free(struct usb_function *f)
 911 {
 912         struct f_rndis *rndis;
 913         struct f_rndis_opts *opts;
 914
 915         rndis = func_to_rndis(f);
 916         rndis_deregister(rndis->config);
 917         opts = container_of(f->fi, struct f_rndis_opts, func_inst);
 918         kfree(rndis);
 919         mutex_lock(&opts->lock);
 920         opts->refcnt--;
 921         mutex_unlock(&opts->lock);
 922 }
 923
 924 static void rndis_unbind(struct usb_configuration *c, struct usb_function *f)
 925 {
 926         struct f_rndis          *rndis = func_to_rndis(f);
 927
 928         usb_free_all_descriptors(f);
 929
 930         kfree(rndis->notify_req->buf);
 931         usb_ep_free_request(rndis->notify, rndis->notify_req);
 932 }
 933
 934 static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
 935 {
 936         struct f_rndis  *rndis;
 937         struct f_rndis_opts *opts;
 938         int status;
 939
 940         /* allocate and initialize one new instance */
 941         rndis = kzalloc(sizeof(*rndis), GFP_KERNEL);
 942         if (!rndis)
 943                 return ERR_PTR(-ENOMEM);
 944
 945         opts = container_of(fi, struct f_rndis_opts, func_inst);
 946         mutex_lock(&opts->lock);
 947         opts->refcnt++;
 948
 949         gether_get_host_addr_u8(opts->net, rndis->ethaddr);
 950         rndis->vendorID = opts->vendor_id;
 951         rndis->manufacturer = opts->manufacturer;
 952
 953         rndis->port.ioport = netdev_priv(opts->net);
 954         mutex_unlock(&opts->lock);
 955         /* RNDIS activates when the host changes this filter */
 956         rndis->port.cdc_filter = 0;
 957
 958         /* RNDIS has special (and complex) framing */
 959         rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
 960         rndis->port.wrap = rndis_add_header;
 961         rndis->port.unwrap = rndis_rm_hdr;
 962
 963         rndis->port.func.name = "rndis";
 964         /* descriptors are per-instance copies */
 965         rndis->port.func.bind = rndis_bind;
 966         rndis->port.func.unbind = rndis_unbind;
 967         rndis->port.func.set_alt = rndis_set_alt;
 968         rndis->port.func.setup = rndis_setup;
 969         rndis->port.func.disable = rndis_disable;
 970         rndis->port.func.free_func = rndis_free;
 971
 972         status = rndis_register(rndis_response_available, rndis);
 973         if (status < 0) {
 974                 kfree(rndis);
 975                 return ERR_PTR(status);
 976         }
 977         rndis->config = status;
 978
 979         return &rndis->port.func;
 980 }
 981
 982 DECLARE_USB_FUNCTION(rndis, rndis_alloc_inst, rndis_alloc);
 983
 984 static int __init rndis_mod_init(void)
 985 {
 986         int ret;
 987
 988         ret = rndis_init();
 989         if (ret)
 990                 return ret;
 991
 992         return usb_function_register(&rndisusb_func);
 993 }
 994 module_init(rndis_mod_init);
 995
 996 static void __exit rndis_mod_exit(void)
 997 {
 998         usb_function_unregister(&rndisusb_func);
 999         rndis_exit();
1000 }
1001 module_exit(rndis_mod_exit);
1002
1003 MODULE_LICENSE("GPL");
1004 MODULE_AUTHOR("David Brownell");