drivers/usb/gadget/function/f_rndis.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * f_rndis.c -- RNDIS link function driver
   4  *
   5  * Copyright (C) 2003-2005,2008 David Brownell
   6  * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
   7  * Copyright (C) 2008 Nokia Corporation
   8  * Copyright (C) 2009 Samsung Electronics
   9  *                    Author: Michal Nazarewicz (mina86@mina86.com)
  10  */
  11
  12 /* #define VERBOSE_DEBUG */
  13
  14 #include <linux/slab.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/device.h>
  18 #include <linux/etherdevice.h>
  19
  20 #include <linux/atomic.h>
  21
  22 #include "u_ether.h"
  23 #include "u_ether_configfs.h"
  24 #include "u_rndis.h"
  25 #include "rndis.h"
  26 #include "configfs.h"
  27
  28 /*
  29  * This function is an RNDIS Ethernet port -- a Microsoft protocol that's
  30  * been promoted instead of the standard CDC Ethernet.  The published RNDIS
  31  * spec is ambiguous, incomplete, and needlessly complex.  Variants such as
  32  * ActiveSync have even worse status in terms of specification.
  33  *
  34  * In short:  it's a protocol controlled by (and for) Microsoft, not for an
  35  * Open ecosystem or markets.  Linux supports it *only* because Microsoft
  36  * doesn't support the CDC Ethernet standard.
  37  *
  38  * The RNDIS data transfer model is complex, with multiple Ethernet packets
  39  * per USB message, and out of band data.  The control model is built around
  40  * what's essentially an "RNDIS RPC" protocol.  It's all wrapped in a CDC ACM
  41  * (modem, not Ethernet) veneer, with those ACM descriptors being entirely
  42  * useless (they're ignored).  RNDIS expects to be the only function in its
  43  * configuration, so it's no real help if you need composite devices; and
  44  * it expects to be the first configuration too.
  45  *
  46  * There is a single technical advantage of RNDIS over CDC Ethernet, if you
  47  * discount the fluff that its RPC can be made to deliver: it doesn't need
  48  * a NOP altsetting for the data interface.  That lets it work on some of the
  49  * "so smart it's stupid" hardware which takes over configuration changes
  50  * from the software, and adds restrictions like "no altsettings".
  51  *
  52  * Unfortunately MSFT's RNDIS drivers are buggy.  They hang or oops, and
  53  * have all sorts of contrary-to-specification oddities that can prevent
  54  * them from working sanely.  Since bugfixes (or accurate specs, letting
  55  * Linux work around those bugs) are unlikely to ever come from MSFT, you
  56  * may want to avoid using RNDIS on purely operational grounds.
  57  *
  58  * Omissions from the RNDIS 1.0 specification include:
  59  *
  60  *   - Power management ... references data that's scattered around lots
  61  *     of other documentation, which is incorrect/incomplete there too.
  62  *
  63  *   - There are various undocumented protocol requirements, like the need
  64  *     to send garbage in some control-OUT messages.
  65  *
  66  *   - MS-Windows drivers sometimes emit undocumented requests.
  67  */
  68
  69 struct f_rndis {
  70         struct gether                   port;
  71         u8                              ctrl_id, data_id;
  72         u8                              ethaddr[ETH_ALEN];
  73         u32                             vendorID;
  74         const char                      *manufacturer;
  75         struct rndis_params             *params;
  76
  77         struct usb_ep                   *notify;
  78         struct usb_request              *notify_req;
  79         atomic_t                        notify_count;
  80 };
  81
  82 static inline struct f_rndis *func_to_rndis(struct usb_function *f)
  83 {
  84         return container_of(f, struct f_rndis, port.func);
  85 }
  86
  87 /* peak (theoretical) bulk transfer rate in bits-per-second */
  88 static unsigned int bitrate(struct usb_gadget *g)
  89 {
  90         if (gadget_is_superspeed(g) && g->speed >= USB_SPEED_SUPER_PLUS)
  91                 return 4250000000U;
  92         if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
  93                 return 3750000000U;
  94         else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  95                 return 13 * 512 * 8 * 1000 * 8;
  96         else
  97                 return 19 * 64 * 1 * 1000 * 8;
  98 }
  99
 100 /*-------------------------------------------------------------------------*/
 101
 102 /*
 103  */
 104
 105 #define RNDIS_STATUS_INTERVAL_MS        32
 106 #define STATUS_BYTECOUNT                8       /* 8 bytes data */
 107
 108
 109 /* interface descriptor: */
 110
 111 static struct usb_interface_descriptor rndis_control_intf = {
 112         .bLength =              sizeof rndis_control_intf,
 113         .bDescriptorType =      USB_DT_INTERFACE,
 114
 115         /* .bInterfaceNumber = DYNAMIC */
 116         /* status endpoint is optional; this could be patched later */
 117         .bNumEndpoints =        1,
 118         .bInterfaceClass =      USB_CLASS_COMM,
 119         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 120         .bInterfaceProtocol =   USB_CDC_ACM_PROTO_VENDOR,
 121         /* .iInterface = DYNAMIC */
 122 };
 123
 124 static struct usb_cdc_header_desc header_desc = {
 125         .bLength =              sizeof header_desc,
 126         .bDescriptorType =      USB_DT_CS_INTERFACE,
 127         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 128
 129         .bcdCDC =               cpu_to_le16(0x0110),
 130 };
 131
 132 static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor = {
 133         .bLength =              sizeof call_mgmt_descriptor,
 134         .bDescriptorType =      USB_DT_CS_INTERFACE,
 135         .bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
 136
 137         .bmCapabilities =       0x00,
 138         .bDataInterface =       0x01,
 139 };
 140
 141 static struct usb_cdc_acm_descriptor rndis_acm_descriptor = {
 142         .bLength =              sizeof rndis_acm_descriptor,
 143         .bDescriptorType =      USB_DT_CS_INTERFACE,
 144         .bDescriptorSubType =   USB_CDC_ACM_TYPE,
 145
 146         .bmCapabilities =       0x00,
 147 };
 148
 149 static struct usb_cdc_union_desc rndis_union_desc = {
 150         .bLength =              sizeof(rndis_union_desc),
 151         .bDescriptorType =      USB_DT_CS_INTERFACE,
 152         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 153         /* .bMasterInterface0 = DYNAMIC */
 154         /* .bSlaveInterface0 =  DYNAMIC */
 155 };
 156
 157 /* the data interface has two bulk endpoints */
 158
 159 static struct usb_interface_descriptor rndis_data_intf = {
 160         .bLength =              sizeof rndis_data_intf,
 161         .bDescriptorType =      USB_DT_INTERFACE,
 162
 163         /* .bInterfaceNumber = DYNAMIC */
 164         .bNumEndpoints =        2,
 165         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 166         .bInterfaceSubClass =   0,
 167         .bInterfaceProtocol =   0,
 168         /* .iInterface = DYNAMIC */
 169 };
 170
 171
 172 static struct usb_interface_assoc_descriptor
 173 rndis_iad_descriptor = {
 174         .bLength =              sizeof rndis_iad_descriptor,
 175         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 176
 177         .bFirstInterface =      0, /* XXX, hardcoded */
 178         .bInterfaceCount =      2,      // control + data
 179         .bFunctionClass =       USB_CLASS_COMM,
 180         .bFunctionSubClass =    USB_CDC_SUBCLASS_ETHERNET,
 181         .bFunctionProtocol =    USB_CDC_PROTO_NONE,
 182         /* .iFunction = DYNAMIC */
 183 };
 184
 185 /* full speed support: */
 186
 187 static struct usb_endpoint_descriptor fs_notify_desc = {
 188         .bLength =              USB_DT_ENDPOINT_SIZE,
 189         .bDescriptorType =      USB_DT_ENDPOINT,
 190
 191         .bEndpointAddress =     USB_DIR_IN,
 192         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 193         .wMaxPacketSize =       cpu_to_le16(STATUS_BYTECOUNT),
 194         .bInterval =            RNDIS_STATUS_INTERVAL_MS,
 195 };
 196
 197 static struct usb_endpoint_descriptor fs_in_desc = {
 198         .bLength =              USB_DT_ENDPOINT_SIZE,
 199         .bDescriptorType =      USB_DT_ENDPOINT,
 200
 201         .bEndpointAddress =     USB_DIR_IN,
 202         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 203 };
 204
 205 static struct usb_endpoint_descriptor fs_out_desc = {
 206         .bLength =              USB_DT_ENDPOINT_SIZE,
 207         .bDescriptorType =      USB_DT_ENDPOINT,
 208
 209         .bEndpointAddress =     USB_DIR_OUT,
 210         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 211 };
 212
 213 static struct usb_descriptor_header *eth_fs_function[] = {
 214         (struct usb_descriptor_header *) &rndis_iad_descriptor,
 215
 216         /* control interface matches ACM, not Ethernet */
 217         (struct usb_descriptor_header *) &rndis_control_intf,
 218         (struct usb_descriptor_header *) &header_desc,
 219         (struct usb_descriptor_header *) &call_mgmt_descriptor,
 220         (struct usb_descriptor_header *) &rndis_acm_descriptor,
 221         (struct usb_descriptor_header *) &rndis_union_desc,
 222         (struct usb_descriptor_header *) &fs_notify_desc,
 223
 224         /* data interface has no altsetting */
 225         (struct usb_descriptor_header *) &rndis_data_intf,
 226         (struct usb_descriptor_header *) &fs_in_desc,
 227         (struct usb_descriptor_header *) &fs_out_desc,
 228         NULL,
 229 };
 230
 231 /* high speed support: */
 232
 233 static struct usb_endpoint_descriptor hs_notify_desc = {
 234         .bLength =              USB_DT_ENDPOINT_SIZE,
 235         .bDescriptorType =      USB_DT_ENDPOINT,
 236
 237         .bEndpointAddress =     USB_DIR_IN,
 238         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 239         .wMaxPacketSize =       cpu_to_le16(STATUS_BYTECOUNT),
 240         .bInterval =            USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
 241 };
 242
 243 static struct usb_endpoint_descriptor hs_in_desc = {
 244         .bLength =              USB_DT_ENDPOINT_SIZE,
 245         .bDescriptorType =      USB_DT_ENDPOINT,
 246
 247         .bEndpointAddress =     USB_DIR_IN,
 248         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 249         .wMaxPacketSize =       cpu_to_le16(512),
 250 };
 251
 252 static struct usb_endpoint_descriptor hs_out_desc = {
 253         .bLength =              USB_DT_ENDPOINT_SIZE,
 254         .bDescriptorType =      USB_DT_ENDPOINT,
 255
 256         .bEndpointAddress =     USB_DIR_OUT,
 257         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 258         .wMaxPacketSize =       cpu_to_le16(512),
 259 };
 260
 261 static struct usb_descriptor_header *eth_hs_function[] = {
 262         (struct usb_descriptor_header *) &rndis_iad_descriptor,
 263
 264         /* control interface matches ACM, not Ethernet */
 265         (struct usb_descriptor_header *) &rndis_control_intf,
 266         (struct usb_descriptor_header *) &header_desc,
 267         (struct usb_descriptor_header *) &call_mgmt_descriptor,
 268         (struct usb_descriptor_header *) &rndis_acm_descriptor,
 269         (struct usb_descriptor_header *) &rndis_union_desc,
 270         (struct usb_descriptor_header *) &hs_notify_desc,
 271
 272         /* data interface has no altsetting */
 273         (struct usb_descriptor_header *) &rndis_data_intf,
 274         (struct usb_descriptor_header *) &hs_in_desc,
 275         (struct usb_descriptor_header *) &hs_out_desc,
 276         NULL,
 277 };
 278
 279 /* super speed support: */
 280
 281 static struct usb_endpoint_descriptor ss_notify_desc = {
 282         .bLength =              USB_DT_ENDPOINT_SIZE,
 283         .bDescriptorType =      USB_DT_ENDPOINT,
 284
 285         .bEndpointAddress =     USB_DIR_IN,
 286         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 287         .wMaxPacketSize =       cpu_to_le16(STATUS_BYTECOUNT),
 288         .bInterval =            USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
 289 };
 290
 291 static struct usb_ss_ep_comp_descriptor ss_intr_comp_desc = {
 292         .bLength =              sizeof ss_intr_comp_desc,
 293         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 294
 295         /* the following 3 values can be tweaked if necessary */
 296         /* .bMaxBurst =         0, */
 297         /* .bmAttributes =      0, */
 298         .wBytesPerInterval =    cpu_to_le16(STATUS_BYTECOUNT),
 299 };
 300
 301 static struct usb_endpoint_descriptor ss_in_desc = {
 302         .bLength =              USB_DT_ENDPOINT_SIZE,
 303         .bDescriptorType =      USB_DT_ENDPOINT,
 304
 305         .bEndpointAddress =     USB_DIR_IN,
 306         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 307         .wMaxPacketSize =       cpu_to_le16(1024),
 308 };
 309
 310 static struct usb_endpoint_descriptor ss_out_desc = {
 311         .bLength =              USB_DT_ENDPOINT_SIZE,
 312         .bDescriptorType =      USB_DT_ENDPOINT,
 313
 314         .bEndpointAddress =     USB_DIR_OUT,
 315         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 316         .wMaxPacketSize =       cpu_to_le16(1024),
 317 };
 318
 319 static struct usb_ss_ep_comp_descriptor ss_bulk_comp_desc = {
 320         .bLength =              sizeof ss_bulk_comp_desc,
 321         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 322
 323         /* the following 2 values can be tweaked if necessary */
 324         /* .bMaxBurst =         0, */
 325         /* .bmAttributes =      0, */
 326 };
 327
 328 static struct usb_descriptor_header *eth_ss_function[] = {
 329         (struct usb_descriptor_header *) &rndis_iad_descriptor,
 330
 331         /* control interface matches ACM, not Ethernet */
 332         (struct usb_descriptor_header *) &rndis_control_intf,
 333         (struct usb_descriptor_header *) &header_desc,
 334         (struct usb_descriptor_header *) &call_mgmt_descriptor,
 335         (struct usb_descriptor_header *) &rndis_acm_descriptor,
 336         (struct usb_descriptor_header *) &rndis_union_desc,
 337         (struct usb_descriptor_header *) &ss_notify_desc,
 338         (struct usb_descriptor_header *) &ss_intr_comp_desc,
 339
 340         /* data interface has no altsetting */
 341         (struct usb_descriptor_header *) &rndis_data_intf,
 342         (struct usb_descriptor_header *) &ss_in_desc,
 343         (struct usb_descriptor_header *) &ss_bulk_comp_desc,
 344         (struct usb_descriptor_header *) &ss_out_desc,
 345         (struct usb_descriptor_header *) &ss_bulk_comp_desc,
 346         NULL,
 347 };
 348
 349 /* string descriptors: */
 350
 351 static struct usb_string rndis_string_defs[] = {
 352         [0].s = "RNDIS Communications Control",
 353         [1].s = "RNDIS Ethernet Data",
 354         [2].s = "RNDIS",
 355         {  } /* end of list */
 356 };
 357
 358 static struct usb_gadget_strings rndis_string_table = {
 359         .language =             0x0409, /* en-us */
 360         .strings =              rndis_string_defs,
 361 };
 362
 363 static struct usb_gadget_strings *rndis_strings[] = {
 364         &rndis_string_table,
 365         NULL,
 366 };
 367
 368 /*-------------------------------------------------------------------------*/
 369
 370 static struct sk_buff *rndis_add_header(struct gether *port,
 371                                         struct sk_buff *skb)
 372 {
 373         struct sk_buff *skb2;
 374
 375         if (!skb)
 376                 return NULL;
 377
 378         skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
 379         rndis_add_hdr(skb2);
 380
 381         dev_kfree_skb(skb);
 382         return skb2;
 383 }
 384
 385 static void rndis_response_available(void *_rndis)
 386 {
 387         struct f_rndis                  *rndis = _rndis;
 388         struct usb_request              *req = rndis->notify_req;
 389         struct usb_composite_dev        *cdev = rndis->port.func.config->cdev;
 390         __le32                          *data = req->buf;
 391         int                             status;
 392
 393         if (atomic_inc_return(&rndis->notify_count) != 1)
 394                 return;
 395
 396         /* Send RNDIS RESPONSE_AVAILABLE notification; a
 397          * USB_CDC_NOTIFY_RESPONSE_AVAILABLE "should" work too
 398          *
 399          * This is the only notification defined by RNDIS.
 400          */
 401         data[0] = cpu_to_le32(1);
 402         data[1] = cpu_to_le32(0);
 403
 404         status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
 405         if (status) {
 406                 atomic_dec(&rndis->notify_count);
 407                 DBG(cdev, "notify/0 --> %d\n", status);
 408         }
 409 }
 410
 411 static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
 412 {
 413         struct f_rndis                  *rndis = req->context;
 414         struct usb_composite_dev        *cdev = rndis->port.func.config->cdev;
 415         int                             status = req->status;
 416
 417         /* after TX:
 418          *  - USB_CDC_GET_ENCAPSULATED_RESPONSE (ep0/control)
 419          *  - RNDIS_RESPONSE_AVAILABLE (status/irq)
 420          */
 421         switch (status) {
 422         case -ECONNRESET:
 423         case -ESHUTDOWN:
 424                 /* connection gone */
 425                 atomic_set(&rndis->notify_count, 0);
 426                 break;
 427         default:
 428                 DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
 429                         ep->name, status,
 430                         req->actual, req->length);
 431                 fallthrough;
 432         case 0:
 433                 if (ep != rndis->notify)
 434                         break;
 435
 436                 /* handle multiple pending RNDIS_RESPONSE_AVAILABLE
 437                  * notifications by resending until we're done
 438                  */
 439                 if (atomic_dec_and_test(&rndis->notify_count))
 440                         break;
 441                 status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
 442                 if (status) {
 443                         atomic_dec(&rndis->notify_count);
 444                         DBG(cdev, "notify/1 --> %d\n", status);
 445                 }
 446                 break;
 447         }
 448 }
 449
 450 static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
 451 {
 452         struct f_rndis                  *rndis = req->context;
 453         int                             status;
 454
 455         /* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
 456 //      spin_lock(&dev->lock);
 457         status = rndis_msg_parser(rndis->params, (u8 *) req->buf);
 458         if (status < 0)
 459                 pr_err("RNDIS command error %d, %d/%d\n",
 460                         status, req->actual, req->length);
 461 //      spin_unlock(&dev->lock);
 462 }
 463
 464 static int
 465 rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 466 {
 467         struct f_rndis          *rndis = func_to_rndis(f);
 468         struct usb_composite_dev *cdev = f->config->cdev;
 469         struct usb_request      *req = cdev->req;
 470         int                     value = -EOPNOTSUPP;
 471         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 472         u16                     w_value = le16_to_cpu(ctrl->wValue);
 473         u16                     w_length = le16_to_cpu(ctrl->wLength);
 474
 475         /* composite driver infrastructure handles everything except
 476          * CDC class messages; interface activation uses set_alt().
 477          */
 478         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 479
 480         /* RNDIS uses the CDC command encapsulation mechanism to implement
 481          * an RPC scheme, with much getting/setting of attributes by OID.
 482          */
 483         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 484                         | USB_CDC_SEND_ENCAPSULATED_COMMAND:
 485                 if (w_value || w_index != rndis->ctrl_id)
 486                         goto invalid;
 487                 /* read the request; process it later */
 488                 value = w_length;
 489                 req->complete = rndis_command_complete;
 490                 req->context = rndis;
 491                 /* later, rndis_response_available() sends a notification */
 492                 break;
 493
 494         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 495                         | USB_CDC_GET_ENCAPSULATED_RESPONSE:
 496                 if (w_value || w_index != rndis->ctrl_id)
 497                         goto invalid;
 498                 else {
 499                         u8 *buf;
 500                         u32 n;
 501
 502                         /* return the result */
 503                         buf = rndis_get_next_response(rndis->params, &n);
 504                         if (buf) {
 505                                 memcpy(req->buf, buf, n);
 506                                 req->complete = rndis_response_complete;
 507                                 req->context = rndis;
 508                                 rndis_free_response(rndis->params, buf);
 509                                 value = n;
 510                         }
 511                         /* else stalls ... spec says to avoid that */
 512                 }
 513                 break;
 514
 515         default:
 516 invalid:
 517                 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 518                         ctrl->bRequestType, ctrl->bRequest,
 519                         w_value, w_index, w_length);
 520         }
 521
 522         /* respond with data transfer or status phase? */
 523         if (value >= 0) {
 524                 DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
 525                         ctrl->bRequestType, ctrl->bRequest,
 526                         w_value, w_index, w_length);
 527                 req->zero = (value < w_length);
 528                 req->length = value;
 529                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 530                 if (value < 0)
 531                         ERROR(cdev, "rndis response on err %d\n", value);
 532         }
 533
 534         /* device either stalls (value < 0) or reports success */
 535         return value;
 536 }
 537
 538
 539 static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 540 {
 541         struct f_rndis          *rndis = func_to_rndis(f);
 542         struct usb_composite_dev *cdev = f->config->cdev;
 543
 544         /* we know alt == 0 */
 545
 546         if (intf == rndis->ctrl_id) {
 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
 557         } else if (intf == rndis->data_id) {
 558                 struct net_device       *net;
 559
 560                 if (rndis->port.in_ep->enabled) {
 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->params, 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->enabled)
 615                 return;
 616
 617         DBG(cdev, "rndis deactivated\n");
 618
 619         rndis_uninit(rndis->params);
 620         gether_disconnect(&rndis->port);
 621
 622         usb_ep_disable(rndis->notify);
 623         rndis->notify->desc = 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->params, RNDIS_MEDIUM_802_3,
 643                                 bitrate(cdev->gadget) / 100);
 644         rndis_signal_connect(rndis->params);
 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->params, RNDIS_MEDIUM_802_3, 0);
 654         rndis_signal_disconnect(rndis->params);
 655 }
 656
 657 /*-------------------------------------------------------------------------*/
 658
 659 /* Some controllers can't support RNDIS ... */
 660 static inline bool can_support_rndis(struct usb_configuration *c)
 661 {
 662         /* everything else is *presumably* fine */
 663         return true;
 664 }
 665
 666 /* ethernet function driver setup/binding */
 667
 668 static int
 669 rndis_bind(struct usb_configuration *c, struct usb_function *f)
 670 {
 671         struct usb_composite_dev *cdev = c->cdev;
 672         struct f_rndis          *rndis = func_to_rndis(f);
 673         struct usb_string       *us;
 674         int                     status;
 675         struct usb_ep           *ep;
 676
 677         struct f_rndis_opts *rndis_opts;
 678
 679         if (!can_support_rndis(c))
 680                 return -EINVAL;
 681
 682         rndis_opts = container_of(f->fi, struct f_rndis_opts, func_inst);
 683
 684         if (cdev->use_os_string) {
 685                 f->os_desc_table = kzalloc(sizeof(*f->os_desc_table),
 686                                            GFP_KERNEL);
 687                 if (!f->os_desc_table)
 688                         return -ENOMEM;
 689                 f->os_desc_n = 1;
 690                 f->os_desc_table[0].os_desc = &rndis_opts->rndis_os_desc;
 691         }
 692
 693         rndis_iad_descriptor.bFunctionClass = rndis_opts->class;
 694         rndis_iad_descriptor.bFunctionSubClass = rndis_opts->subclass;
 695         rndis_iad_descriptor.bFunctionProtocol = rndis_opts->protocol;
 696
 697         /*
 698          * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
 699          * configurations are bound in sequence with list_for_each_entry,
 700          * in each configuration its functions are bound in sequence
 701          * with list_for_each_entry, so we assume no race condition
 702          * with regard to rndis_opts->bound access
 703          */
 704         if (!rndis_opts->bound) {
 705                 gether_set_gadget(rndis_opts->net, cdev->gadget);
 706                 status = gether_register_netdev(rndis_opts->net);
 707                 if (status)
 708                         goto fail;
 709                 rndis_opts->bound = true;
 710         }
 711
 712         us = usb_gstrings_attach(cdev, rndis_strings,
 713                                  ARRAY_SIZE(rndis_string_defs));
 714         if (IS_ERR(us)) {
 715                 status = PTR_ERR(us);
 716                 goto fail;
 717         }
 718         rndis_control_intf.iInterface = us[0].id;
 719         rndis_data_intf.iInterface = us[1].id;
 720         rndis_iad_descriptor.iFunction = us[2].id;
 721
 722         /* allocate instance-specific interface IDs */
 723         status = usb_interface_id(c, f);
 724         if (status < 0)
 725                 goto fail;
 726         rndis->ctrl_id = status;
 727         rndis_iad_descriptor.bFirstInterface = status;
 728
 729         rndis_control_intf.bInterfaceNumber = status;
 730         rndis_union_desc.bMasterInterface0 = status;
 731
 732         if (cdev->use_os_string)
 733                 f->os_desc_table[0].if_id =
 734                         rndis_iad_descriptor.bFirstInterface;
 735
 736         status = usb_interface_id(c, f);
 737         if (status < 0)
 738                 goto fail;
 739         rndis->data_id = status;
 740
 741         rndis_data_intf.bInterfaceNumber = status;
 742         rndis_union_desc.bSlaveInterface0 = status;
 743
 744         status = -ENODEV;
 745
 746         /* allocate instance-specific endpoints */
 747         ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
 748         if (!ep)
 749                 goto fail;
 750         rndis->port.in_ep = ep;
 751
 752         ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
 753         if (!ep)
 754                 goto fail;
 755         rndis->port.out_ep = ep;
 756
 757         /* NOTE:  a status/notification endpoint is, strictly speaking,
 758          * optional.  We don't treat it that way though!  It's simpler,
 759          * and some newer profiles don't treat it as optional.
 760          */
 761         ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
 762         if (!ep)
 763                 goto fail;
 764         rndis->notify = ep;
 765
 766         status = -ENOMEM;
 767
 768         /* allocate notification request and buffer */
 769         rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
 770         if (!rndis->notify_req)
 771                 goto fail;
 772         rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
 773         if (!rndis->notify_req->buf)
 774                 goto fail;
 775         rndis->notify_req->length = STATUS_BYTECOUNT;
 776         rndis->notify_req->context = rndis;
 777         rndis->notify_req->complete = rndis_response_complete;
 778
 779         /* support all relevant hardware speeds... we expect that when
 780          * hardware is dual speed, all bulk-capable endpoints work at
 781          * both speeds
 782          */
 783         hs_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
 784         hs_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
 785         hs_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
 786
 787         ss_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
 788         ss_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
 789         ss_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
 790
 791         status = usb_assign_descriptors(f, eth_fs_function, eth_hs_function,
 792                         eth_ss_function, NULL);
 793         if (status)
 794                 goto fail;
 795
 796         rndis->port.open = rndis_open;
 797         rndis->port.close = rndis_close;
 798
 799         rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
 800         rndis_set_host_mac(rndis->params, rndis->ethaddr);
 801
 802         if (rndis->manufacturer && rndis->vendorID &&
 803                         rndis_set_param_vendor(rndis->params, rndis->vendorID,
 804                                                rndis->manufacturer)) {
 805                 status = -EINVAL;
 806                 goto fail_free_descs;
 807         }
 808
 809         /* NOTE:  all that is done without knowing or caring about
 810          * the network link ... which is unavailable to this code
 811          * until we're activated via set_alt().
 812          */
 813
 814         DBG(cdev, "RNDIS: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 815                         gadget_is_superspeed(c->cdev->gadget) ? "super" :
 816                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 817                         rndis->port.in_ep->name, rndis->port.out_ep->name,
 818                         rndis->notify->name);
 819         return 0;
 820
 821 fail_free_descs:
 822         usb_free_all_descriptors(f);
 823 fail:
 824         kfree(f->os_desc_table);
 825         f->os_desc_n = 0;
 826
 827         if (rndis->notify_req) {
 828                 kfree(rndis->notify_req->buf);
 829                 usb_ep_free_request(rndis->notify, rndis->notify_req);
 830         }
 831
 832         ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 833
 834         return status;
 835 }
 836
 837 void rndis_borrow_net(struct usb_function_instance *f, struct net_device *net)
 838 {
 839         struct f_rndis_opts *opts;
 840
 841         opts = container_of(f, struct f_rndis_opts, func_inst);
 842         if (opts->bound)
 843                 gether_cleanup(netdev_priv(opts->net));
 844         else
 845                 free_netdev(opts->net);
 846         opts->borrowed_net = opts->bound = true;
 847         opts->net = net;
 848 }
 849 EXPORT_SYMBOL_GPL(rndis_borrow_net);
 850
 851 static inline struct f_rndis_opts *to_f_rndis_opts(struct config_item *item)
 852 {
 853         return container_of(to_config_group(item), struct f_rndis_opts,
 854                             func_inst.group);
 855 }
 856
 857 /* f_rndis_item_ops */
 858 USB_ETHERNET_CONFIGFS_ITEM(rndis);
 859
 860 /* f_rndis_opts_dev_addr */
 861 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(rndis);
 862
 863 /* f_rndis_opts_host_addr */
 864 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(rndis);
 865
 866 /* f_rndis_opts_qmult */
 867 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(rndis);
 868
 869 /* f_rndis_opts_ifname */
 870 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(rndis);
 871
 872 /* f_rndis_opts_class */
 873 USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, class);
 874
 875 /* f_rndis_opts_subclass */
 876 USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, subclass);
 877
 878 /* f_rndis_opts_protocol */
 879 USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, protocol);
 880
 881 static struct configfs_attribute *rndis_attrs[] = {
 882         &rndis_opts_attr_dev_addr,
 883         &rndis_opts_attr_host_addr,
 884         &rndis_opts_attr_qmult,
 885         &rndis_opts_attr_ifname,
 886         &rndis_opts_attr_class,
 887         &rndis_opts_attr_subclass,
 888         &rndis_opts_attr_protocol,
 889         NULL,
 890 };
 891
 892 static const struct config_item_type rndis_func_type = {
 893         .ct_item_ops    = &rndis_item_ops,
 894         .ct_attrs       = rndis_attrs,
 895         .ct_owner       = THIS_MODULE,
 896 };
 897
 898 static void rndis_free_inst(struct usb_function_instance *f)
 899 {
 900         struct f_rndis_opts *opts;
 901
 902         opts = container_of(f, struct f_rndis_opts, func_inst);
 903         if (!opts->borrowed_net) {
 904                 if (opts->bound)
 905                         gether_cleanup(netdev_priv(opts->net));
 906                 else
 907                         free_netdev(opts->net);
 908         }
 909
 910         kfree(opts->rndis_interf_group);        /* single VLA chunk */
 911         kfree(opts);
 912 }
 913
 914 static struct usb_function_instance *rndis_alloc_inst(void)
 915 {
 916         struct f_rndis_opts *opts;
 917         struct usb_os_desc *descs[1];
 918         char *names[1];
 919         struct config_group *rndis_interf_group;
 920
 921         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 922         if (!opts)
 923                 return ERR_PTR(-ENOMEM);
 924         opts->rndis_os_desc.ext_compat_id = opts->rndis_ext_compat_id;
 925
 926         mutex_init(&opts->lock);
 927         opts->func_inst.free_func_inst = rndis_free_inst;
 928         opts->net = gether_setup_default();
 929         if (IS_ERR(opts->net)) {
 930                 struct net_device *net = opts->net;
 931                 kfree(opts);
 932                 return ERR_CAST(net);
 933         }
 934         INIT_LIST_HEAD(&opts->rndis_os_desc.ext_prop);
 935
 936         opts->class = rndis_iad_descriptor.bFunctionClass;
 937         opts->subclass = rndis_iad_descriptor.bFunctionSubClass;
 938         opts->protocol = rndis_iad_descriptor.bFunctionProtocol;
 939
 940         descs[0] = &opts->rndis_os_desc;
 941         names[0] = "rndis";
 942         config_group_init_type_name(&opts->func_inst.group, "",
 943                                     &rndis_func_type);
 944         rndis_interf_group =
 945                 usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs,
 946                                                names, THIS_MODULE);
 947         if (IS_ERR(rndis_interf_group)) {
 948                 rndis_free_inst(&opts->func_inst);
 949                 return ERR_CAST(rndis_interf_group);
 950         }
 951         opts->rndis_interf_group = rndis_interf_group;
 952
 953         return &opts->func_inst;
 954 }
 955
 956 static void rndis_free(struct usb_function *f)
 957 {
 958         struct f_rndis *rndis;
 959         struct f_rndis_opts *opts;
 960
 961         rndis = func_to_rndis(f);
 962         rndis_deregister(rndis->params);
 963         opts = container_of(f->fi, struct f_rndis_opts, func_inst);
 964         kfree(rndis);
 965         mutex_lock(&opts->lock);
 966         opts->refcnt--;
 967         mutex_unlock(&opts->lock);
 968 }
 969
 970 static void rndis_unbind(struct usb_configuration *c, struct usb_function *f)
 971 {
 972         struct f_rndis          *rndis = func_to_rndis(f);
 973
 974         kfree(f->os_desc_table);
 975         f->os_desc_n = 0;
 976         usb_free_all_descriptors(f);
 977
 978         kfree(rndis->notify_req->buf);
 979         usb_ep_free_request(rndis->notify, rndis->notify_req);
 980 }
 981
 982 static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
 983 {
 984         struct f_rndis  *rndis;
 985         struct f_rndis_opts *opts;
 986         struct rndis_params *params;
 987
 988         /* allocate and initialize one new instance */
 989         rndis = kzalloc(sizeof(*rndis), GFP_KERNEL);
 990         if (!rndis)
 991                 return ERR_PTR(-ENOMEM);
 992
 993         opts = container_of(fi, struct f_rndis_opts, func_inst);
 994         mutex_lock(&opts->lock);
 995         opts->refcnt++;
 996
 997         gether_get_host_addr_u8(opts->net, rndis->ethaddr);
 998         rndis->vendorID = opts->vendor_id;
 999         rndis->manufacturer = opts->manufacturer;
1000
1001         rndis->port.ioport = netdev_priv(opts->net);
1002         mutex_unlock(&opts->lock);
1003         /* RNDIS activates when the host changes this filter */
1004         rndis->port.cdc_filter = 0;
1005
1006         /* RNDIS has special (and complex) framing */
1007         rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
1008         rndis->port.wrap = rndis_add_header;
1009         rndis->port.unwrap = rndis_rm_hdr;
1010
1011         rndis->port.func.name = "rndis";
1012         /* descriptors are per-instance copies */
1013         rndis->port.func.bind = rndis_bind;
1014         rndis->port.func.unbind = rndis_unbind;
1015         rndis->port.func.set_alt = rndis_set_alt;
1016         rndis->port.func.setup = rndis_setup;
1017         rndis->port.func.disable = rndis_disable;
1018         rndis->port.func.free_func = rndis_free;
1019
1020         params = rndis_register(rndis_response_available, rndis);
1021         if (IS_ERR(params)) {
1022                 kfree(rndis);
1023                 return ERR_CAST(params);
1024         }
1025         rndis->params = params;
1026
1027         return &rndis->port.func;
1028 }
1029
1030 DECLARE_USB_FUNCTION_INIT(rndis, rndis_alloc_inst, rndis_alloc);
1031 MODULE_LICENSE("GPL");
1032 MODULE_AUTHOR("David Brownell");