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 (m.nazarewicz@samsung.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         int                             config;
  75
  76         struct usb_ep                   *notify;
  77         struct usb_request              *notify_req;
  78         atomic_t                        notify_count;
  79 };
  80
  81 static inline struct f_rndis *func_to_rndis(struct usb_function *f)
  82 {
  83         return container_of(f, struct f_rndis, port.func);
  84 }
  85
  86 /* peak (theoretical) bulk transfer rate in bits-per-second */
  87 static unsigned int bitrate(struct usb_gadget *g)
  88 {
  89         if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
  90                 return 13 * 1024 * 8 * 1000 * 8;
  91         else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  92                 return 13 * 512 * 8 * 1000 * 8;
  93         else
  94                 return 19 * 64 * 1 * 1000 * 8;
  95 }
  96
  97 /*-------------------------------------------------------------------------*/
  98
  99 /*
 100  */
 101
 102 #define LOG2_STATUS_INTERVAL_MSEC       5       /* 1 << 5 == 32 msec */
 103 #define STATUS_BYTECOUNT                8       /* 8 bytes data */
 104
 105
 106 /* interface descriptor: */
 107
 108 static struct usb_interface_descriptor rndis_control_intf = {
 109         .bLength =              sizeof rndis_control_intf,
 110         .bDescriptorType =      USB_DT_INTERFACE,
 111
 112         /* .bInterfaceNumber = DYNAMIC */
 113         /* status endpoint is optional; this could be patched later */
 114         .bNumEndpoints =        1,
 115         .bInterfaceClass =      USB_CLASS_COMM,
 116         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 117         .bInterfaceProtocol =   USB_CDC_ACM_PROTO_VENDOR,
 118         /* .iInterface = DYNAMIC */
 119 };
 120
 121 static struct usb_cdc_header_desc header_desc = {
 122         .bLength =              sizeof header_desc,
 123         .bDescriptorType =      USB_DT_CS_INTERFACE,
 124         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 125
 126         .bcdCDC =               cpu_to_le16(0x0110),
 127 };
 128
 129 static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor = {
 130         .bLength =              sizeof call_mgmt_descriptor,
 131         .bDescriptorType =      USB_DT_CS_INTERFACE,
 132         .bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
 133
 134         .bmCapabilities =       0x00,
 135         .bDataInterface =       0x01,
 136 };
 137
 138 static struct usb_cdc_acm_descriptor rndis_acm_descriptor = {
 139         .bLength =              sizeof rndis_acm_descriptor,
 140         .bDescriptorType =      USB_DT_CS_INTERFACE,
 141         .bDescriptorSubType =   USB_CDC_ACM_TYPE,
 142
 143         .bmCapabilities =       0x00,
 144 };
 145
 146 static struct usb_cdc_union_desc rndis_union_desc = {
 147         .bLength =              sizeof(rndis_union_desc),
 148         .bDescriptorType =      USB_DT_CS_INTERFACE,
 149         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 150         /* .bMasterInterface0 = DYNAMIC */
 151         /* .bSlaveInterface0 =  DYNAMIC */
 152 };
 153
 154 /* the data interface has two bulk endpoints */
 155
 156 static struct usb_interface_descriptor rndis_data_intf = {
 157         .bLength =              sizeof rndis_data_intf,
 158         .bDescriptorType =      USB_DT_INTERFACE,
 159
 160         /* .bInterfaceNumber = DYNAMIC */
 161         .bNumEndpoints =        2,
 162         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 163         .bInterfaceSubClass =   0,
 164         .bInterfaceProtocol =   0,
 165         /* .iInterface = DYNAMIC */
 166 };
 167
 168
 169 static struct usb_interface_assoc_descriptor
 170 rndis_iad_descriptor = {
 171         .bLength =              sizeof rndis_iad_descriptor,
 172         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 173
 174         .bFirstInterface =      0, /* XXX, hardcoded */
 175         .bInterfaceCount =      2,      // control + data
 176         .bFunctionClass =       USB_CLASS_COMM,
 177         .bFunctionSubClass =    USB_CDC_SUBCLASS_ETHERNET,
 178         .bFunctionProtocol =    USB_CDC_PROTO_NONE,
 179         /* .iFunction = DYNAMIC */
 180 };
 181
 182 /* full speed support: */
 183
 184 static struct usb_endpoint_descriptor fs_notify_desc = {
 185         .bLength =              USB_DT_ENDPOINT_SIZE,
 186         .bDescriptorType =      USB_DT_ENDPOINT,
 187
 188         .bEndpointAddress =     USB_DIR_IN,
 189         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 190         .wMaxPacketSize =       cpu_to_le16(STATUS_BYTECOUNT),
 191         .bInterval =            1 << LOG2_STATUS_INTERVAL_MSEC,
 192 };
 193
 194 static struct usb_endpoint_descriptor fs_in_desc = {
 195         .bLength =              USB_DT_ENDPOINT_SIZE,
 196         .bDescriptorType =      USB_DT_ENDPOINT,
 197
 198         .bEndpointAddress =     USB_DIR_IN,
 199         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 200 };
 201
 202 static struct usb_endpoint_descriptor fs_out_desc = {
 203         .bLength =              USB_DT_ENDPOINT_SIZE,
 204         .bDescriptorType =      USB_DT_ENDPOINT,
 205
 206         .bEndpointAddress =     USB_DIR_OUT,
 207         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 208 };
 209
 210 static struct usb_descriptor_header *eth_fs_function[] = {
 211         (struct usb_descriptor_header *) &rndis_iad_descriptor,
 212
 213         /* control interface matches ACM, not Ethernet */
 214         (struct usb_descriptor_header *) &rndis_control_intf,
 215         (struct usb_descriptor_header *) &header_desc,
 216         (struct usb_descriptor_header *) &call_mgmt_descriptor,
 217         (struct usb_descriptor_header *) &rndis_acm_descriptor,
 218         (struct usb_descriptor_header *) &rndis_union_desc,
 219         (struct usb_descriptor_header *) &fs_notify_desc,
 220
 221         /* data interface has no altsetting */
 222         (struct usb_descriptor_header *) &rndis_data_intf,
 223         (struct usb_descriptor_header *) &fs_in_desc,
 224         (struct usb_descriptor_header *) &fs_out_desc,
 225         NULL,
 226 };
 227
 228 /* high speed support: */
 229
 230 static struct usb_endpoint_descriptor hs_notify_desc = {
 231         .bLength =              USB_DT_ENDPOINT_SIZE,
 232         .bDescriptorType =      USB_DT_ENDPOINT,
 233
 234         .bEndpointAddress =     USB_DIR_IN,
 235         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 236         .wMaxPacketSize =       cpu_to_le16(STATUS_BYTECOUNT),
 237         .bInterval =            LOG2_STATUS_INTERVAL_MSEC + 4,
 238 };
 239
 240 static struct usb_endpoint_descriptor hs_in_desc = {
 241         .bLength =              USB_DT_ENDPOINT_SIZE,
 242         .bDescriptorType =      USB_DT_ENDPOINT,
 243
 244         .bEndpointAddress =     USB_DIR_IN,
 245         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 246         .wMaxPacketSize =       cpu_to_le16(512),
 247 };
 248
 249 static struct usb_endpoint_descriptor hs_out_desc = {
 250         .bLength =              USB_DT_ENDPOINT_SIZE,
 251         .bDescriptorType =      USB_DT_ENDPOINT,
 252
 253         .bEndpointAddress =     USB_DIR_OUT,
 254         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 255         .wMaxPacketSize =       cpu_to_le16(512),
 256 };
 257
 258 static struct usb_descriptor_header *eth_hs_function[] = {
 259         (struct usb_descriptor_header *) &rndis_iad_descriptor,
 260
 261         /* control interface matches ACM, not Ethernet */
 262         (struct usb_descriptor_header *) &rndis_control_intf,
 263         (struct usb_descriptor_header *) &header_desc,
 264         (struct usb_descriptor_header *) &call_mgmt_descriptor,
 265         (struct usb_descriptor_header *) &rndis_acm_descriptor,
 266         (struct usb_descriptor_header *) &rndis_union_desc,
 267         (struct usb_descriptor_header *) &hs_notify_desc,
 268
 269         /* data interface has no altsetting */
 270         (struct usb_descriptor_header *) &rndis_data_intf,
 271         (struct usb_descriptor_header *) &hs_in_desc,
 272         (struct usb_descriptor_header *) &hs_out_desc,
 273         NULL,
 274 };
 275
 276 /* super speed support: */
 277
 278 static struct usb_endpoint_descriptor ss_notify_desc = {
 279         .bLength =              USB_DT_ENDPOINT_SIZE,
 280         .bDescriptorType =      USB_DT_ENDPOINT,
 281
 282         .bEndpointAddress =     USB_DIR_IN,
 283         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 284         .wMaxPacketSize =       cpu_to_le16(STATUS_BYTECOUNT),
 285         .bInterval =            LOG2_STATUS_INTERVAL_MSEC + 4,
 286 };
 287
 288 static struct usb_ss_ep_comp_descriptor ss_intr_comp_desc = {
 289         .bLength =              sizeof ss_intr_comp_desc,
 290         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 291
 292         /* the following 3 values can be tweaked if necessary */
 293         /* .bMaxBurst =         0, */
 294         /* .bmAttributes =      0, */
 295         .wBytesPerInterval =    cpu_to_le16(STATUS_BYTECOUNT),
 296 };
 297
 298 static struct usb_endpoint_descriptor ss_in_desc = {
 299         .bLength =              USB_DT_ENDPOINT_SIZE,
 300         .bDescriptorType =      USB_DT_ENDPOINT,
 301
 302         .bEndpointAddress =     USB_DIR_IN,
 303         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 304         .wMaxPacketSize =       cpu_to_le16(1024),
 305 };
 306
 307 static struct usb_endpoint_descriptor ss_out_desc = {
 308         .bLength =              USB_DT_ENDPOINT_SIZE,
 309         .bDescriptorType =      USB_DT_ENDPOINT,
 310
 311         .bEndpointAddress =     USB_DIR_OUT,
 312         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 313         .wMaxPacketSize =       cpu_to_le16(1024),
 314 };
 315
 316 static struct usb_ss_ep_comp_descriptor ss_bulk_comp_desc = {
 317         .bLength =              sizeof ss_bulk_comp_desc,
 318         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 319
 320         /* the following 2 values can be tweaked if necessary */
 321         /* .bMaxBurst =         0, */
 322         /* .bmAttributes =      0, */
 323 };
 324
 325 static struct usb_descriptor_header *eth_ss_function[] = {
 326         (struct usb_descriptor_header *) &rndis_iad_descriptor,
 327
 328         /* control interface matches ACM, not Ethernet */
 329         (struct usb_descriptor_header *) &rndis_control_intf,
 330         (struct usb_descriptor_header *) &header_desc,
 331         (struct usb_descriptor_header *) &call_mgmt_descriptor,
 332         (struct usb_descriptor_header *) &rndis_acm_descriptor,
 333         (struct usb_descriptor_header *) &rndis_union_desc,
 334         (struct usb_descriptor_header *) &ss_notify_desc,
 335         (struct usb_descriptor_header *) &ss_intr_comp_desc,
 336
 337         /* data interface has no altsetting */
 338         (struct usb_descriptor_header *) &rndis_data_intf,
 339         (struct usb_descriptor_header *) &ss_in_desc,
 340         (struct usb_descriptor_header *) &ss_bulk_comp_desc,
 341         (struct usb_descriptor_header *) &ss_out_desc,
 342         (struct usb_descriptor_header *) &ss_bulk_comp_desc,
 343         NULL,
 344 };
 345
 346 /* string descriptors: */
 347
 348 static struct usb_string rndis_string_defs[] = {
 349         [0].s = "RNDIS Communications Control",
 350         [1].s = "RNDIS Ethernet Data",
 351         [2].s = "RNDIS",
 352         {  } /* end of list */
 353 };
 354
 355 static struct usb_gadget_strings rndis_string_table = {
 356         .language =             0x0409, /* en-us */
 357         .strings =              rndis_string_defs,
 358 };
 359
 360 static struct usb_gadget_strings *rndis_strings[] = {
 361         &rndis_string_table,
 362         NULL,
 363 };
 364
 365 /*-------------------------------------------------------------------------*/
 366
 367 static struct sk_buff *rndis_add_header(struct gether *port,
 368                                         struct sk_buff *skb)
 369 {
 370         struct sk_buff *skb2;
 371
 372         skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
 373         if (skb2)
 374                 rndis_add_hdr(skb2);
 375
 376         dev_kfree_skb_any(skb);
 377         return skb2;
 378 }
 379
 380 static void rndis_response_available(void *_rndis)
 381 {
 382         struct f_rndis                  *rndis = _rndis;
 383         struct usb_request              *req = rndis->notify_req;
 384         struct usb_composite_dev        *cdev = rndis->port.func.config->cdev;
 385         __le32                          *data = req->buf;
 386         int                             status;
 387
 388         if (atomic_inc_return(&rndis->notify_count) != 1)
 389                 return;
 390
 391         /* Send RNDIS RESPONSE_AVAILABLE notification; a
 392          * USB_CDC_NOTIFY_RESPONSE_AVAILABLE "should" work too
 393          *
 394          * This is the only notification defined by RNDIS.
 395          */
 396         data[0] = cpu_to_le32(1);
 397         data[1] = cpu_to_le32(0);
 398
 399         status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
 400         if (status) {
 401                 atomic_dec(&rndis->notify_count);
 402                 DBG(cdev, "notify/0 --> %d\n", status);
 403         }
 404 }
 405
 406 static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
 407 {
 408         struct f_rndis                  *rndis = req->context;
 409         struct usb_composite_dev        *cdev = rndis->port.func.config->cdev;
 410         int                             status = req->status;
 411
 412         /* after TX:
 413          *  - USB_CDC_GET_ENCAPSULATED_RESPONSE (ep0/control)
 414          *  - RNDIS_RESPONSE_AVAILABLE (status/irq)
 415          */
 416         switch (status) {
 417         case -ECONNRESET:
 418         case -ESHUTDOWN:
 419                 /* connection gone */
 420                 atomic_set(&rndis->notify_count, 0);
 421                 break;
 422         default:
 423                 DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
 424                         ep->name, status,
 425                         req->actual, req->length);
 426                 /* FALLTHROUGH */
 427         case 0:
 428                 if (ep != rndis->notify)
 429                         break;
 430
 431                 /* handle multiple pending RNDIS_RESPONSE_AVAILABLE
 432                  * notifications by resending until we're done
 433                  */
 434                 if (atomic_dec_and_test(&rndis->notify_count))
 435                         break;
 436                 status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
 437                 if (status) {
 438                         atomic_dec(&rndis->notify_count);
 439                         DBG(cdev, "notify/1 --> %d\n", status);
 440                 }
 441                 break;
 442         }
 443 }
 444
 445 static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
 446 {
 447         struct f_rndis                  *rndis = req->context;
 448         struct usb_composite_dev        *cdev = rndis->port.func.config->cdev;
 449         int                             status;
 450
 451         /* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
 452 //      spin_lock(&dev->lock);
 453         status = rndis_msg_parser(rndis->config, (u8 *) req->buf);
 454         if (status < 0)
 455                 ERROR(cdev, "RNDIS command error %d, %d/%d\n",
 456                         status, req->actual, req->length);
 457 //      spin_unlock(&dev->lock);
 458 }
 459
 460 static int
 461 rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 462 {
 463         struct f_rndis          *rndis = func_to_rndis(f);
 464         struct usb_composite_dev *cdev = f->config->cdev;
 465         struct usb_request      *req = cdev->req;
 466         int                     value = -EOPNOTSUPP;
 467         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 468         u16                     w_value = le16_to_cpu(ctrl->wValue);
 469         u16                     w_length = le16_to_cpu(ctrl->wLength);
 470
 471         /* composite driver infrastructure handles everything except
 472          * CDC class messages; interface activation uses set_alt().
 473          */
 474         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 475
 476         /* RNDIS uses the CDC command encapsulation mechanism to implement
 477          * an RPC scheme, with much getting/setting of attributes by OID.
 478          */
 479         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 480                         | USB_CDC_SEND_ENCAPSULATED_COMMAND:
 481                 if (w_value || w_index != rndis->ctrl_id)
 482                         goto invalid;
 483                 /* read the request; process it later */
 484                 value = w_length;
 485                 req->complete = rndis_command_complete;
 486                 req->context = rndis;
 487                 /* later, rndis_response_available() sends a notification */
 488                 break;
 489
 490         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 491                         | USB_CDC_GET_ENCAPSULATED_RESPONSE:
 492                 if (w_value || w_index != rndis->ctrl_id)
 493                         goto invalid;
 494                 else {
 495                         u8 *buf;
 496                         u32 n;
 497
 498                         /* return the result */
 499                         buf = rndis_get_next_response(rndis->config, &n);
 500                         if (buf) {
 501                                 memcpy(req->buf, buf, n);
 502                                 req->complete = rndis_response_complete;
 503                                 rndis_free_response(rndis->config, buf);
 504                                 value = n;
 505                         }
 506                         /* else stalls ... spec says to avoid that */
 507                 }
 508                 break;
 509
 510         default:
 511 invalid:
 512                 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 513                         ctrl->bRequestType, ctrl->bRequest,
 514                         w_value, w_index, w_length);
 515         }
 516
 517         /* respond with data transfer or status phase? */
 518         if (value >= 0) {
 519                 DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
 520                         ctrl->bRequestType, ctrl->bRequest,
 521                         w_value, w_index, w_length);
 522                 req->zero = (value < w_length);
 523                 req->length = value;
 524                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 525                 if (value < 0)
 526                         ERROR(cdev, "rndis response on err %d\n", value);
 527         }
 528
 529         /* device either stalls (value < 0) or reports success */
 530         return value;
 531 }
 532
 533
 534 static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 535 {
 536         struct f_rndis          *rndis = func_to_rndis(f);
 537         struct usb_composite_dev *cdev = f->config->cdev;
 538
 539         /* we know alt == 0 */
 540
 541         if (intf == rndis->ctrl_id) {
 542                 if (rndis->notify->driver_data) {
 543                         VDBG(cdev, "reset rndis control %d\n", intf);
 544                         usb_ep_disable(rndis->notify);
 545                 }
 546                 if (!rndis->notify->desc) {
 547                         VDBG(cdev, "init rndis ctrl %d\n", intf);
 548                         if (config_ep_by_speed(cdev->gadget, f, rndis->notify))
 549                                 goto fail;
 550                 }
 551                 usb_ep_enable(rndis->notify);
 552                 rndis->notify->driver_data = rndis;
 553
 554         } else if (intf == rndis->data_id) {
 555                 struct net_device       *net;
 556
 557                 if (rndis->port.in_ep->driver_data) {
 558                         DBG(cdev, "reset rndis\n");
 559                         gether_disconnect(&rndis->port);
 560                 }
 561
 562                 if (!rndis->port.in_ep->desc || !rndis->port.out_ep->desc) {
 563                         DBG(cdev, "init rndis\n");
 564                         if (config_ep_by_speed(cdev->gadget, f,
 565                                                rndis->port.in_ep) ||
 566                             config_ep_by_speed(cdev->gadget, f,
 567                                                rndis->port.out_ep)) {
 568                                 rndis->port.in_ep->desc = NULL;
 569                                 rndis->port.out_ep->desc = NULL;
 570                                 goto fail;
 571                         }
 572                 }
 573
 574                 /* Avoid ZLPs; they can be troublesome. */
 575                 rndis->port.is_zlp_ok = false;
 576
 577                 /* RNDIS should be in the "RNDIS uninitialized" state,
 578                  * either never activated or after rndis_uninit().
 579                  *
 580                  * We don't want data to flow here until a nonzero packet
 581                  * filter is set, at which point it enters "RNDIS data
 582                  * initialized" state ... but we do want the endpoints
 583                  * to be activated.  It's a strange little state.
 584                  *
 585                  * REVISIT the RNDIS gadget code has done this wrong for a
 586                  * very long time.  We need another call to the link layer
 587                  * code -- gether_updown(...bool) maybe -- to do it right.
 588                  */
 589                 rndis->port.cdc_filter = 0;
 590
 591                 DBG(cdev, "RNDIS RX/TX early activation ... \n");
 592                 net = gether_connect(&rndis->port);
 593                 if (IS_ERR(net))
 594                         return PTR_ERR(net);
 595
 596                 rndis_set_param_dev(rndis->config, net,
 597                                 &rndis->port.cdc_filter);
 598         } else
 599                 goto fail;
 600
 601         return 0;
 602 fail:
 603         return -EINVAL;
 604 }
 605
 606 static void rndis_disable(struct usb_function *f)
 607 {
 608         struct f_rndis          *rndis = func_to_rndis(f);
 609         struct usb_composite_dev *cdev = f->config->cdev;
 610
 611         if (!rndis->notify->driver_data)
 612                 return;
 613
 614         DBG(cdev, "rndis deactivated\n");
 615
 616         rndis_uninit(rndis->config);
 617         gether_disconnect(&rndis->port);
 618
 619         usb_ep_disable(rndis->notify);
 620         rndis->notify->driver_data = NULL;
 621 }
 622
 623 /*-------------------------------------------------------------------------*/
 624
 625 /*
 626  * This isn't quite the same mechanism as CDC Ethernet, since the
 627  * notification scheme passes less data, but the same set of link
 628  * states must be tested.  A key difference is that altsettings are
 629  * not used to tell whether the link should send packets or not.
 630  */
 631
 632 static void rndis_open(struct gether *geth)
 633 {
 634         struct f_rndis          *rndis = func_to_rndis(&geth->func);
 635         struct usb_composite_dev *cdev = geth->func.config->cdev;
 636
 637         DBG(cdev, "%s\n", __func__);
 638
 639         rndis_set_param_medium(rndis->config, NDIS_MEDIUM_802_3,
 640                                 bitrate(cdev->gadget) / 100);
 641         rndis_signal_connect(rndis->config);
 642 }
 643
 644 static void rndis_close(struct gether *geth)
 645 {
 646         struct f_rndis          *rndis = func_to_rndis(&geth->func);
 647
 648         DBG(geth->func.config->cdev, "%s\n", __func__);
 649
 650         rndis_set_param_medium(rndis->config, NDIS_MEDIUM_802_3, 0);
 651         rndis_signal_disconnect(rndis->config);
 652 }
 653
 654 /*-------------------------------------------------------------------------*/
 655
 656 /* ethernet function driver setup/binding */
 657
 658 static int
 659 rndis_bind(struct usb_configuration *c, struct usb_function *f)
 660 {
 661         struct usb_composite_dev *cdev = c->cdev;
 662         struct f_rndis          *rndis = func_to_rndis(f);
 663         int                     status;
 664         struct usb_ep           *ep;
 665
 666         /* allocate instance-specific interface IDs */
 667         status = usb_interface_id(c, f);
 668         if (status < 0)
 669                 goto fail;
 670         rndis->ctrl_id = status;
 671         rndis_iad_descriptor.bFirstInterface = status;
 672
 673         rndis_control_intf.bInterfaceNumber = status;
 674         rndis_union_desc.bMasterInterface0 = status;
 675
 676         status = usb_interface_id(c, f);
 677         if (status < 0)
 678                 goto fail;
 679         rndis->data_id = status;
 680
 681         rndis_data_intf.bInterfaceNumber = status;
 682         rndis_union_desc.bSlaveInterface0 = status;
 683
 684         status = -ENODEV;
 685
 686         /* allocate instance-specific endpoints */
 687         ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
 688         if (!ep)
 689                 goto fail;
 690         rndis->port.in_ep = ep;
 691         ep->driver_data = cdev; /* claim */
 692
 693         ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
 694         if (!ep)
 695                 goto fail;
 696         rndis->port.out_ep = ep;
 697         ep->driver_data = cdev; /* claim */
 698
 699         /* NOTE:  a status/notification endpoint is, strictly speaking,
 700          * optional.  We don't treat it that way though!  It's simpler,
 701          * and some newer profiles don't treat it as optional.
 702          */
 703         ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
 704         if (!ep)
 705                 goto fail;
 706         rndis->notify = ep;
 707         ep->driver_data = cdev; /* claim */
 708
 709         status = -ENOMEM;
 710
 711         /* allocate notification request and buffer */
 712         rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
 713         if (!rndis->notify_req)
 714                 goto fail;
 715         rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
 716         if (!rndis->notify_req->buf)
 717                 goto fail;
 718         rndis->notify_req->length = STATUS_BYTECOUNT;
 719         rndis->notify_req->context = rndis;
 720         rndis->notify_req->complete = rndis_response_complete;
 721
 722         /* copy descriptors, and track endpoint copies */
 723         f->descriptors = usb_copy_descriptors(eth_fs_function);
 724         if (!f->descriptors)
 725                 goto fail;
 726
 727         /* support all relevant hardware speeds... we expect that when
 728          * hardware is dual speed, all bulk-capable endpoints work at
 729          * both speeds
 730          */
 731         if (gadget_is_dualspeed(c->cdev->gadget)) {
 732                 hs_in_desc.bEndpointAddress =
 733                                 fs_in_desc.bEndpointAddress;
 734                 hs_out_desc.bEndpointAddress =
 735                                 fs_out_desc.bEndpointAddress;
 736                 hs_notify_desc.bEndpointAddress =
 737                                 fs_notify_desc.bEndpointAddress;
 738
 739                 /* copy descriptors, and track endpoint copies */
 740                 f->hs_descriptors = usb_copy_descriptors(eth_hs_function);
 741                 if (!f->hs_descriptors)
 742                         goto fail;
 743         }
 744
 745         if (gadget_is_superspeed(c->cdev->gadget)) {
 746                 ss_in_desc.bEndpointAddress =
 747                                 fs_in_desc.bEndpointAddress;
 748                 ss_out_desc.bEndpointAddress =
 749                                 fs_out_desc.bEndpointAddress;
 750                 ss_notify_desc.bEndpointAddress =
 751                                 fs_notify_desc.bEndpointAddress;
 752
 753                 /* copy descriptors, and track endpoint copies */
 754                 f->ss_descriptors = usb_copy_descriptors(eth_ss_function);
 755                 if (!f->ss_descriptors)
 756                         goto fail;
 757         }
 758
 759         rndis->port.open = rndis_open;
 760         rndis->port.close = rndis_close;
 761
 762         status = rndis_register(rndis_response_available, rndis);
 763         if (status < 0)
 764                 goto fail;
 765         rndis->config = status;
 766
 767         rndis_set_param_medium(rndis->config, NDIS_MEDIUM_802_3, 0);
 768         rndis_set_host_mac(rndis->config, rndis->ethaddr);
 769
 770 #if 0
 771 // FIXME
 772         if (rndis_set_param_vendor(rndis->config, vendorID,
 773                                 manufacturer))
 774                 goto fail0;
 775 #endif
 776
 777         /* NOTE:  all that is done without knowing or caring about
 778          * the network link ... which is unavailable to this code
 779          * until we're activated via set_alt().
 780          */
 781
 782         DBG(cdev, "RNDIS: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 783                         gadget_is_superspeed(c->cdev->gadget) ? "super" :
 784                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 785                         rndis->port.in_ep->name, rndis->port.out_ep->name,
 786                         rndis->notify->name);
 787         return 0;
 788
 789 fail:
 790         if (gadget_is_superspeed(c->cdev->gadget) && f->ss_descriptors)
 791                 usb_free_descriptors(f->ss_descriptors);
 792         if (gadget_is_dualspeed(c->cdev->gadget) && f->hs_descriptors)
 793                 usb_free_descriptors(f->hs_descriptors);
 794         if (f->descriptors)
 795                 usb_free_descriptors(f->descriptors);
 796
 797         if (rndis->notify_req) {
 798                 kfree(rndis->notify_req->buf);
 799                 usb_ep_free_request(rndis->notify, rndis->notify_req);
 800         }
 801
 802         /* we might as well release our claims on endpoints */
 803         if (rndis->notify)
 804                 rndis->notify->driver_data = NULL;
 805         if (rndis->port.out_ep->desc)
 806                 rndis->port.out_ep->driver_data = NULL;
 807         if (rndis->port.in_ep->desc)
 808                 rndis->port.in_ep->driver_data = NULL;
 809
 810         ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 811
 812         return status;
 813 }
 814
 815 static void
 816 rndis_unbind(struct usb_configuration *c, struct usb_function *f)
 817 {
 818         struct f_rndis          *rndis = func_to_rndis(f);
 819
 820         rndis_deregister(rndis->config);
 821         rndis_exit();
 822
 823         if (gadget_is_superspeed(c->cdev->gadget))
 824                 usb_free_descriptors(f->ss_descriptors);
 825         if (gadget_is_dualspeed(c->cdev->gadget))
 826                 usb_free_descriptors(f->hs_descriptors);
 827         usb_free_descriptors(f->descriptors);
 828
 829         kfree(rndis->notify_req->buf);
 830         usb_ep_free_request(rndis->notify, rndis->notify_req);
 831
 832         kfree(rndis);
 833 }
 834
 835 /* Some controllers can't support RNDIS ... */
 836 static inline bool can_support_rndis(struct usb_configuration *c)
 837 {
 838         /* everything else is *presumably* fine */
 839         return true;
 840 }
 841
 842 /**
 843  * rndis_bind_config - add RNDIS network link to a configuration
 844  * @c: the configuration to support the network link
 845  * @ethaddr: a buffer in which the ethernet address of the host side
 846  *      side of the link was recorded
 847  * Context: single threaded during gadget setup
 848  *
 849  * Returns zero on success, else negative errno.
 850  *
 851  * Caller must have called @gether_setup().  Caller is also responsible
 852  * for calling @gether_cleanup() before module unload.
 853  */
 854 int
 855 rndis_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
 856 {
 857         struct f_rndis  *rndis;
 858         int             status;
 859
 860         if (!can_support_rndis(c) || !ethaddr)
 861                 return -EINVAL;
 862
 863         /* maybe allocate device-global string IDs */
 864         if (rndis_string_defs[0].id == 0) {
 865
 866                 /* ... and setup RNDIS itself */
 867                 status = rndis_init();
 868                 if (status < 0)
 869                         return status;
 870
 871                 /* control interface label */
 872                 status = usb_string_id(c->cdev);
 873                 if (status < 0)
 874                         return status;
 875                 rndis_string_defs[0].id = status;
 876                 rndis_control_intf.iInterface = status;
 877
 878                 /* data interface label */
 879                 status = usb_string_id(c->cdev);
 880                 if (status < 0)
 881                         return status;
 882                 rndis_string_defs[1].id = status;
 883                 rndis_data_intf.iInterface = status;
 884
 885                 /* IAD iFunction label */
 886                 status = usb_string_id(c->cdev);
 887                 if (status < 0)
 888                         return status;
 889                 rndis_string_defs[2].id = status;
 890                 rndis_iad_descriptor.iFunction = status;
 891         }
 892
 893         /* allocate and initialize one new instance */
 894         status = -ENOMEM;
 895         rndis = kzalloc(sizeof *rndis, GFP_KERNEL);
 896         if (!rndis)
 897                 goto fail;
 898
 899         memcpy(rndis->ethaddr, ethaddr, ETH_ALEN);
 900
 901         /* RNDIS activates when the host changes this filter */
 902         rndis->port.cdc_filter = 0;
 903
 904         /* RNDIS has special (and complex) framing */
 905         rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
 906         rndis->port.wrap = rndis_add_header;
 907         rndis->port.unwrap = rndis_rm_hdr;
 908
 909         rndis->port.func.name = "rndis";
 910         rndis->port.func.strings = rndis_strings;
 911         /* descriptors are per-instance copies */
 912         rndis->port.func.bind = rndis_bind;
 913         rndis->port.func.unbind = rndis_unbind;
 914         rndis->port.func.set_alt = rndis_set_alt;
 915         rndis->port.func.setup = rndis_setup;
 916         rndis->port.func.disable = rndis_disable;
 917
 918         status = usb_add_function(c, &rndis->port.func);
 919         if (status) {
 920                 kfree(rndis);
 921 fail:
 922                 rndis_exit();
 923         }
 924         return status;
 925 }