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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
69struct 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
82static 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 */
88static unsigned int bitrate(struct usb_gadget *g)
89{
90 if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
91 return 13 * 1024 * 8 * 1000 * 8;
92 else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
93 return 13 * 512 * 8 * 1000 * 8;
94 else
95 return 19 * 64 * 1 * 1000 * 8;
96}
97
98/*-------------------------------------------------------------------------*/
99
100/*
101 */
102
103#define RNDIS_STATUS_INTERVAL_MS 32
104#define STATUS_BYTECOUNT 8 /* 8 bytes data */
105
106
107/* interface descriptor: */
108
109static struct usb_interface_descriptor rndis_control_intf = {
110 .bLength = sizeof rndis_control_intf,
111 .bDescriptorType = USB_DT_INTERFACE,
112
113 /* .bInterfaceNumber = DYNAMIC */
114 /* status endpoint is optional; this could be patched later */
115 .bNumEndpoints = 1,
116 .bInterfaceClass = USB_CLASS_COMM,
117 .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
118 .bInterfaceProtocol = USB_CDC_ACM_PROTO_VENDOR,
119 /* .iInterface = DYNAMIC */
120};
121
122static struct usb_cdc_header_desc header_desc = {
123 .bLength = sizeof header_desc,
124 .bDescriptorType = USB_DT_CS_INTERFACE,
125 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
126
127 .bcdCDC = cpu_to_le16(0x0110),
128};
129
130static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor = {
131 .bLength = sizeof call_mgmt_descriptor,
132 .bDescriptorType = USB_DT_CS_INTERFACE,
133 .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE,
134
135 .bmCapabilities = 0x00,
136 .bDataInterface = 0x01,
137};
138
139static struct usb_cdc_acm_descriptor rndis_acm_descriptor = {
140 .bLength = sizeof rndis_acm_descriptor,
141 .bDescriptorType = USB_DT_CS_INTERFACE,
142 .bDescriptorSubType = USB_CDC_ACM_TYPE,
143
144 .bmCapabilities = 0x00,
145};
146
147static struct usb_cdc_union_desc rndis_union_desc = {
148 .bLength = sizeof(rndis_union_desc),
149 .bDescriptorType = USB_DT_CS_INTERFACE,
150 .bDescriptorSubType = USB_CDC_UNION_TYPE,
151 /* .bMasterInterface0 = DYNAMIC */
152 /* .bSlaveInterface0 = DYNAMIC */
153};
154
155/* the data interface has two bulk endpoints */
156
157static struct usb_interface_descriptor rndis_data_intf = {
158 .bLength = sizeof rndis_data_intf,
159 .bDescriptorType = USB_DT_INTERFACE,
160
161 /* .bInterfaceNumber = DYNAMIC */
162 .bNumEndpoints = 2,
163 .bInterfaceClass = USB_CLASS_CDC_DATA,
164 .bInterfaceSubClass = 0,
165 .bInterfaceProtocol = 0,
166 /* .iInterface = DYNAMIC */
167};
168
169
170static struct usb_interface_assoc_descriptor
171rndis_iad_descriptor = {
172 .bLength = sizeof rndis_iad_descriptor,
173 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
174
175 .bFirstInterface = 0, /* XXX, hardcoded */
176 .bInterfaceCount = 2, // control + data
177 .bFunctionClass = USB_CLASS_COMM,
178 .bFunctionSubClass = USB_CDC_SUBCLASS_ETHERNET,
179 .bFunctionProtocol = USB_CDC_PROTO_NONE,
180 /* .iFunction = DYNAMIC */
181};
182
183/* full speed support: */
184
185static struct usb_endpoint_descriptor fs_notify_desc = {
186 .bLength = USB_DT_ENDPOINT_SIZE,
187 .bDescriptorType = USB_DT_ENDPOINT,
188
189 .bEndpointAddress = USB_DIR_IN,
190 .bmAttributes = USB_ENDPOINT_XFER_INT,
191 .wMaxPacketSize = cpu_to_le16(STATUS_BYTECOUNT),
192 .bInterval = RNDIS_STATUS_INTERVAL_MS,
193};
194
195static struct usb_endpoint_descriptor fs_in_desc = {
196 .bLength = USB_DT_ENDPOINT_SIZE,
197 .bDescriptorType = USB_DT_ENDPOINT,
198
199 .bEndpointAddress = USB_DIR_IN,
200 .bmAttributes = USB_ENDPOINT_XFER_BULK,
201};
202
203static struct usb_endpoint_descriptor fs_out_desc = {
204 .bLength = USB_DT_ENDPOINT_SIZE,
205 .bDescriptorType = USB_DT_ENDPOINT,
206
207 .bEndpointAddress = USB_DIR_OUT,
208 .bmAttributes = USB_ENDPOINT_XFER_BULK,
209};
210
211static struct usb_descriptor_header *eth_fs_function[] = {
212 (struct usb_descriptor_header *) &rndis_iad_descriptor,
213
214 /* control interface matches ACM, not Ethernet */
215 (struct usb_descriptor_header *) &rndis_control_intf,
216 (struct usb_descriptor_header *) &header_desc,
217 (struct usb_descriptor_header *) &call_mgmt_descriptor,
218 (struct usb_descriptor_header *) &rndis_acm_descriptor,
219 (struct usb_descriptor_header *) &rndis_union_desc,
220 (struct usb_descriptor_header *) &fs_notify_desc,
221
222 /* data interface has no altsetting */
223 (struct usb_descriptor_header *) &rndis_data_intf,
224 (struct usb_descriptor_header *) &fs_in_desc,
225 (struct usb_descriptor_header *) &fs_out_desc,
226 NULL,
227};
228
229/* high speed support: */
230
231static struct usb_endpoint_descriptor hs_notify_desc = {
232 .bLength = USB_DT_ENDPOINT_SIZE,
233 .bDescriptorType = USB_DT_ENDPOINT,
234
235 .bEndpointAddress = USB_DIR_IN,
236 .bmAttributes = USB_ENDPOINT_XFER_INT,
237 .wMaxPacketSize = cpu_to_le16(STATUS_BYTECOUNT),
238 .bInterval = USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
239};
240
241static struct usb_endpoint_descriptor hs_in_desc = {
242 .bLength = USB_DT_ENDPOINT_SIZE,
243 .bDescriptorType = USB_DT_ENDPOINT,
244
245 .bEndpointAddress = USB_DIR_IN,
246 .bmAttributes = USB_ENDPOINT_XFER_BULK,
247 .wMaxPacketSize = cpu_to_le16(512),
248};
249
250static struct usb_endpoint_descriptor hs_out_desc = {
251 .bLength = USB_DT_ENDPOINT_SIZE,
252 .bDescriptorType = USB_DT_ENDPOINT,
253
254 .bEndpointAddress = USB_DIR_OUT,
255 .bmAttributes = USB_ENDPOINT_XFER_BULK,
256 .wMaxPacketSize = cpu_to_le16(512),
257};
258
259static struct usb_descriptor_header *eth_hs_function[] = {
260 (struct usb_descriptor_header *) &rndis_iad_descriptor,
261
262 /* control interface matches ACM, not Ethernet */
263 (struct usb_descriptor_header *) &rndis_control_intf,
264 (struct usb_descriptor_header *) &header_desc,
265 (struct usb_descriptor_header *) &call_mgmt_descriptor,
266 (struct usb_descriptor_header *) &rndis_acm_descriptor,
267 (struct usb_descriptor_header *) &rndis_union_desc,
268 (struct usb_descriptor_header *) &hs_notify_desc,
269
270 /* data interface has no altsetting */
271 (struct usb_descriptor_header *) &rndis_data_intf,
272 (struct usb_descriptor_header *) &hs_in_desc,
273 (struct usb_descriptor_header *) &hs_out_desc,
274 NULL,
275};
276
277/* super speed support: */
278
279static struct usb_endpoint_descriptor ss_notify_desc = {
280 .bLength = USB_DT_ENDPOINT_SIZE,
281 .bDescriptorType = USB_DT_ENDPOINT,
282
283 .bEndpointAddress = USB_DIR_IN,
284 .bmAttributes = USB_ENDPOINT_XFER_INT,
285 .wMaxPacketSize = cpu_to_le16(STATUS_BYTECOUNT),
286 .bInterval = USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
287};
288
289static struct usb_ss_ep_comp_descriptor ss_intr_comp_desc = {
290 .bLength = sizeof ss_intr_comp_desc,
291 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
292
293 /* the following 3 values can be tweaked if necessary */
294 /* .bMaxBurst = 0, */
295 /* .bmAttributes = 0, */
296 .wBytesPerInterval = cpu_to_le16(STATUS_BYTECOUNT),
297};
298
299static struct usb_endpoint_descriptor ss_in_desc = {
300 .bLength = USB_DT_ENDPOINT_SIZE,
301 .bDescriptorType = USB_DT_ENDPOINT,
302
303 .bEndpointAddress = USB_DIR_IN,
304 .bmAttributes = USB_ENDPOINT_XFER_BULK,
305 .wMaxPacketSize = cpu_to_le16(1024),
306};
307
308static struct usb_endpoint_descriptor ss_out_desc = {
309 .bLength = USB_DT_ENDPOINT_SIZE,
310 .bDescriptorType = USB_DT_ENDPOINT,
311
312 .bEndpointAddress = USB_DIR_OUT,
313 .bmAttributes = USB_ENDPOINT_XFER_BULK,
314 .wMaxPacketSize = cpu_to_le16(1024),
315};
316
317static struct usb_ss_ep_comp_descriptor ss_bulk_comp_desc = {
318 .bLength = sizeof ss_bulk_comp_desc,
319 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
320
321 /* the following 2 values can be tweaked if necessary */
322 /* .bMaxBurst = 0, */
323 /* .bmAttributes = 0, */
324};
325
326static struct usb_descriptor_header *eth_ss_function[] = {
327 (struct usb_descriptor_header *) &rndis_iad_descriptor,
328
329 /* control interface matches ACM, not Ethernet */
330 (struct usb_descriptor_header *) &rndis_control_intf,
331 (struct usb_descriptor_header *) &header_desc,
332 (struct usb_descriptor_header *) &call_mgmt_descriptor,
333 (struct usb_descriptor_header *) &rndis_acm_descriptor,
334 (struct usb_descriptor_header *) &rndis_union_desc,
335 (struct usb_descriptor_header *) &ss_notify_desc,
336 (struct usb_descriptor_header *) &ss_intr_comp_desc,
337
338 /* data interface has no altsetting */
339 (struct usb_descriptor_header *) &rndis_data_intf,
340 (struct usb_descriptor_header *) &ss_in_desc,
341 (struct usb_descriptor_header *) &ss_bulk_comp_desc,
342 (struct usb_descriptor_header *) &ss_out_desc,
343 (struct usb_descriptor_header *) &ss_bulk_comp_desc,
344 NULL,
345};
346
347/* string descriptors: */
348
349static struct usb_string rndis_string_defs[] = {
350 [0].s = "RNDIS Communications Control",
351 [1].s = "RNDIS Ethernet Data",
352 [2].s = "RNDIS",
353 { } /* end of list */
354};
355
356static struct usb_gadget_strings rndis_string_table = {
357 .language = 0x0409, /* en-us */
358 .strings = rndis_string_defs,
359};
360
361static struct usb_gadget_strings *rndis_strings[] = {
362 &rndis_string_table,
363 NULL,
364};
365
366/*-------------------------------------------------------------------------*/
367
368static struct sk_buff *rndis_add_header(struct gether *port,
369 struct sk_buff *skb)
370{
371 struct sk_buff *skb2;
372
373 if (!skb)
374 return NULL;
375
376 skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
377 rndis_add_hdr(skb2);
378
379 dev_kfree_skb(skb);
380 return skb2;
381}
382
383static void rndis_response_available(void *_rndis)
384{
385 struct f_rndis *rndis = _rndis;
386 struct usb_request *req = rndis->notify_req;
387 struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
388 __le32 *data = req->buf;
389 int status;
390
391 if (atomic_inc_return(&rndis->notify_count) != 1)
392 return;
393
394 /* Send RNDIS RESPONSE_AVAILABLE notification; a
395 * USB_CDC_NOTIFY_RESPONSE_AVAILABLE "should" work too
396 *
397 * This is the only notification defined by RNDIS.
398 */
399 data[0] = cpu_to_le32(1);
400 data[1] = cpu_to_le32(0);
401
402 status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
403 if (status) {
404 atomic_dec(&rndis->notify_count);
405 DBG(cdev, "notify/0 --> %d\n", status);
406 }
407}
408
409static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
410{
411 struct f_rndis *rndis = req->context;
412 struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
413 int status = req->status;
414
415 /* after TX:
416 * - USB_CDC_GET_ENCAPSULATED_RESPONSE (ep0/control)
417 * - RNDIS_RESPONSE_AVAILABLE (status/irq)
418 */
419 switch (status) {
420 case -ECONNRESET:
421 case -ESHUTDOWN:
422 /* connection gone */
423 atomic_set(&rndis->notify_count, 0);
424 break;
425 default:
426 DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
427 ep->name, status,
428 req->actual, req->length);
429 /* FALLTHROUGH */
430 case 0:
431 if (ep != rndis->notify)
432 break;
433
434 /* handle multiple pending RNDIS_RESPONSE_AVAILABLE
435 * notifications by resending until we're done
436 */
437 if (atomic_dec_and_test(&rndis->notify_count))
438 break;
439 status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
440 if (status) {
441 atomic_dec(&rndis->notify_count);
442 DBG(cdev, "notify/1 --> %d\n", status);
443 }
444 break;
445 }
446}
447
448static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
449{
450 struct f_rndis *rndis = req->context;
451 int status;
452
453 /* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
454// spin_lock(&dev->lock);
455 status = rndis_msg_parser(rndis->params, (u8 *) req->buf);
456 if (status < 0)
457 pr_err("RNDIS command error %d, %d/%d\n",
458 status, req->actual, req->length);
459// spin_unlock(&dev->lock);
460}
461
462static int
463rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
464{
465 struct f_rndis *rndis = func_to_rndis(f);
466 struct usb_composite_dev *cdev = f->config->cdev;
467 struct usb_request *req = cdev->req;
468 int value = -EOPNOTSUPP;
469 u16 w_index = le16_to_cpu(ctrl->wIndex);
470 u16 w_value = le16_to_cpu(ctrl->wValue);
471 u16 w_length = le16_to_cpu(ctrl->wLength);
472
473 /* composite driver infrastructure handles everything except
474 * CDC class messages; interface activation uses set_alt().
475 */
476 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
477
478 /* RNDIS uses the CDC command encapsulation mechanism to implement
479 * an RPC scheme, with much getting/setting of attributes by OID.
480 */
481 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
482 | USB_CDC_SEND_ENCAPSULATED_COMMAND:
483 if (w_value || w_index != rndis->ctrl_id)
484 goto invalid;
485 /* read the request; process it later */
486 value = w_length;
487 req->complete = rndis_command_complete;
488 req->context = rndis;
489 /* later, rndis_response_available() sends a notification */
490 break;
491
492 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
493 | USB_CDC_GET_ENCAPSULATED_RESPONSE:
494 if (w_value || w_index != rndis->ctrl_id)
495 goto invalid;
496 else {
497 u8 *buf;
498 u32 n;
499
500 /* return the result */
501 buf = rndis_get_next_response(rndis->params, &n);
502 if (buf) {
503 memcpy(req->buf, buf, n);
504 req->complete = rndis_response_complete;
505 req->context = rndis;
506 rndis_free_response(rndis->params, buf);
507 value = n;
508 }
509 /* else stalls ... spec says to avoid that */
510 }
511 break;
512
513 default:
514invalid:
515 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
516 ctrl->bRequestType, ctrl->bRequest,
517 w_value, w_index, w_length);
518 }
519
520 /* respond with data transfer or status phase? */
521 if (value >= 0) {
522 DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
523 ctrl->bRequestType, ctrl->bRequest,
524 w_value, w_index, w_length);
525 req->zero = (value < w_length);
526 req->length = value;
527 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
528 if (value < 0)
529 ERROR(cdev, "rndis response on err %d\n", value);
530 }
531
532 /* device either stalls (value < 0) or reports success */
533 return value;
534}
535
536
537static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
538{
539 struct f_rndis *rndis = func_to_rndis(f);
540 struct usb_composite_dev *cdev = f->config->cdev;
541
542 /* we know alt == 0 */
543
544 if (intf == rndis->ctrl_id) {
545 VDBG(cdev, "reset rndis control %d\n", intf);
546 usb_ep_disable(rndis->notify);
547
548 if (!rndis->notify->desc) {
549 VDBG(cdev, "init rndis ctrl %d\n", intf);
550 if (config_ep_by_speed(cdev->gadget, f, rndis->notify))
551 goto fail;
552 }
553 usb_ep_enable(rndis->notify);
554
555 } else if (intf == rndis->data_id) {
556 struct net_device *net;
557
558 if (rndis->port.in_ep->enabled) {
559 DBG(cdev, "reset rndis\n");
560 gether_disconnect(&rndis->port);
561 }
562
563 if (!rndis->port.in_ep->desc || !rndis->port.out_ep->desc) {
564 DBG(cdev, "init rndis\n");
565 if (config_ep_by_speed(cdev->gadget, f,
566 rndis->port.in_ep) ||
567 config_ep_by_speed(cdev->gadget, f,
568 rndis->port.out_ep)) {
569 rndis->port.in_ep->desc = NULL;
570 rndis->port.out_ep->desc = NULL;
571 goto fail;
572 }
573 }
574
575 /* Avoid ZLPs; they can be troublesome. */
576 rndis->port.is_zlp_ok = false;
577
578 /* RNDIS should be in the "RNDIS uninitialized" state,
579 * either never activated or after rndis_uninit().
580 *
581 * We don't want data to flow here until a nonzero packet
582 * filter is set, at which point it enters "RNDIS data
583 * initialized" state ... but we do want the endpoints
584 * to be activated. It's a strange little state.
585 *
586 * REVISIT the RNDIS gadget code has done this wrong for a
587 * very long time. We need another call to the link layer
588 * code -- gether_updown(...bool) maybe -- to do it right.
589 */
590 rndis->port.cdc_filter = 0;
591
592 DBG(cdev, "RNDIS RX/TX early activation ... \n");
593 net = gether_connect(&rndis->port);
594 if (IS_ERR(net))
595 return PTR_ERR(net);
596
597 rndis_set_param_dev(rndis->params, net,
598 &rndis->port.cdc_filter);
599 } else
600 goto fail;
601
602 return 0;
603fail:
604 return -EINVAL;
605}
606
607static void rndis_disable(struct usb_function *f)
608{
609 struct f_rndis *rndis = func_to_rndis(f);
610 struct usb_composite_dev *cdev = f->config->cdev;
611
612 if (!rndis->notify->enabled)
613 return;
614
615 DBG(cdev, "rndis deactivated\n");
616
617 rndis_uninit(rndis->params);
618 gether_disconnect(&rndis->port);
619
620 usb_ep_disable(rndis->notify);
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
632static 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->params, RNDIS_MEDIUM_802_3,
640 bitrate(cdev->gadget) / 100);
641 rndis_signal_connect(rndis->params);
642}
643
644static 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->params, RNDIS_MEDIUM_802_3, 0);
651 rndis_signal_disconnect(rndis->params);
652}
653
654/*-------------------------------------------------------------------------*/
655
656/* Some controllers can't support RNDIS ... */
657static inline bool can_support_rndis(struct usb_configuration *c)
658{
659 /* everything else is *presumably* fine */
660 return true;
661}
662
663/* ethernet function driver setup/binding */
664
665static int
666rndis_bind(struct usb_configuration *c, struct usb_function *f)
667{
668 struct usb_composite_dev *cdev = c->cdev;
669 struct f_rndis *rndis = func_to_rndis(f);
670 struct usb_string *us;
671 int status;
672 struct usb_ep *ep;
673
674 struct f_rndis_opts *rndis_opts;
675
676 if (!can_support_rndis(c))
677 return -EINVAL;
678
679 rndis_opts = container_of(f->fi, struct f_rndis_opts, func_inst);
680
681 if (cdev->use_os_string) {
682 f->os_desc_table = kzalloc(sizeof(*f->os_desc_table),
683 GFP_KERNEL);
684 if (!f->os_desc_table)
685 return -ENOMEM;
686 f->os_desc_n = 1;
687 f->os_desc_table[0].os_desc = &rndis_opts->rndis_os_desc;
688 }
689
690 rndis_iad_descriptor.bFunctionClass = rndis_opts->class;
691 rndis_iad_descriptor.bFunctionSubClass = rndis_opts->subclass;
692 rndis_iad_descriptor.bFunctionProtocol = rndis_opts->protocol;
693
694 /*
695 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
696 * configurations are bound in sequence with list_for_each_entry,
697 * in each configuration its functions are bound in sequence
698 * with list_for_each_entry, so we assume no race condition
699 * with regard to rndis_opts->bound access
700 */
701 if (!rndis_opts->bound) {
702 gether_set_gadget(rndis_opts->net, cdev->gadget);
703 status = gether_register_netdev(rndis_opts->net);
704 if (status)
705 goto fail;
706 rndis_opts->bound = true;
707 }
708
709 us = usb_gstrings_attach(cdev, rndis_strings,
710 ARRAY_SIZE(rndis_string_defs));
711 if (IS_ERR(us)) {
712 status = PTR_ERR(us);
713 goto fail;
714 }
715 rndis_control_intf.iInterface = us[0].id;
716 rndis_data_intf.iInterface = us[1].id;
717 rndis_iad_descriptor.iFunction = us[2].id;
718
719 /* allocate instance-specific interface IDs */
720 status = usb_interface_id(c, f);
721 if (status < 0)
722 goto fail;
723 rndis->ctrl_id = status;
724 rndis_iad_descriptor.bFirstInterface = status;
725
726 rndis_control_intf.bInterfaceNumber = status;
727 rndis_union_desc.bMasterInterface0 = status;
728
729 if (cdev->use_os_string)
730 f->os_desc_table[0].if_id =
731 rndis_iad_descriptor.bFirstInterface;
732
733 status = usb_interface_id(c, f);
734 if (status < 0)
735 goto fail;
736 rndis->data_id = status;
737
738 rndis_data_intf.bInterfaceNumber = status;
739 rndis_union_desc.bSlaveInterface0 = status;
740
741 status = -ENODEV;
742
743 /* allocate instance-specific endpoints */
744 ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
745 if (!ep)
746 goto fail;
747 rndis->port.in_ep = ep;
748
749 ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
750 if (!ep)
751 goto fail;
752 rndis->port.out_ep = ep;
753
754 /* NOTE: a status/notification endpoint is, strictly speaking,
755 * optional. We don't treat it that way though! It's simpler,
756 * and some newer profiles don't treat it as optional.
757 */
758 ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
759 if (!ep)
760 goto fail;
761 rndis->notify = ep;
762
763 status = -ENOMEM;
764
765 /* allocate notification request and buffer */
766 rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
767 if (!rndis->notify_req)
768 goto fail;
769 rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
770 if (!rndis->notify_req->buf)
771 goto fail;
772 rndis->notify_req->length = STATUS_BYTECOUNT;
773 rndis->notify_req->context = rndis;
774 rndis->notify_req->complete = rndis_response_complete;
775
776 /* support all relevant hardware speeds... we expect that when
777 * hardware is dual speed, all bulk-capable endpoints work at
778 * both speeds
779 */
780 hs_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
781 hs_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
782 hs_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
783
784 ss_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
785 ss_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
786 ss_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
787
788 status = usb_assign_descriptors(f, eth_fs_function, eth_hs_function,
789 eth_ss_function, NULL);
790 if (status)
791 goto fail;
792
793 rndis->port.open = rndis_open;
794 rndis->port.close = rndis_close;
795
796 rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
797 rndis_set_host_mac(rndis->params, rndis->ethaddr);
798
799 if (rndis->manufacturer && rndis->vendorID &&
800 rndis_set_param_vendor(rndis->params, rndis->vendorID,
801 rndis->manufacturer)) {
802 status = -EINVAL;
803 goto fail_free_descs;
804 }
805
806 /* NOTE: all that is done without knowing or caring about
807 * the network link ... which is unavailable to this code
808 * until we're activated via set_alt().
809 */
810
811 DBG(cdev, "RNDIS: %s speed IN/%s OUT/%s NOTIFY/%s\n",
812 gadget_is_superspeed(c->cdev->gadget) ? "super" :
813 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
814 rndis->port.in_ep->name, rndis->port.out_ep->name,
815 rndis->notify->name);
816 return 0;
817
818fail_free_descs:
819 usb_free_all_descriptors(f);
820fail:
821 kfree(f->os_desc_table);
822 f->os_desc_n = 0;
823
824 if (rndis->notify_req) {
825 kfree(rndis->notify_req->buf);
826 usb_ep_free_request(rndis->notify, rndis->notify_req);
827 }
828
829 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
830
831 return status;
832}
833
834void rndis_borrow_net(struct usb_function_instance *f, struct net_device *net)
835{
836 struct f_rndis_opts *opts;
837
838 opts = container_of(f, struct f_rndis_opts, func_inst);
839 if (opts->bound)
840 gether_cleanup(netdev_priv(opts->net));
841 else
842 free_netdev(opts->net);
843 opts->borrowed_net = opts->bound = true;
844 opts->net = net;
845}
846EXPORT_SYMBOL_GPL(rndis_borrow_net);
847
848static inline struct f_rndis_opts *to_f_rndis_opts(struct config_item *item)
849{
850 return container_of(to_config_group(item), struct f_rndis_opts,
851 func_inst.group);
852}
853
854/* f_rndis_item_ops */
855USB_ETHERNET_CONFIGFS_ITEM(rndis);
856
857/* f_rndis_opts_dev_addr */
858USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(rndis);
859
860/* f_rndis_opts_host_addr */
861USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(rndis);
862
863/* f_rndis_opts_qmult */
864USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(rndis);
865
866/* f_rndis_opts_ifname */
867USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(rndis);
868
869/* f_rndis_opts_class */
870USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, class);
871
872/* f_rndis_opts_subclass */
873USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, subclass);
874
875/* f_rndis_opts_protocol */
876USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, protocol);
877
878static struct configfs_attribute *rndis_attrs[] = {
879 &rndis_opts_attr_dev_addr,
880 &rndis_opts_attr_host_addr,
881 &rndis_opts_attr_qmult,
882 &rndis_opts_attr_ifname,
883 &rndis_opts_attr_class,
884 &rndis_opts_attr_subclass,
885 &rndis_opts_attr_protocol,
886 NULL,
887};
888
889static const struct config_item_type rndis_func_type = {
890 .ct_item_ops = &rndis_item_ops,
891 .ct_attrs = rndis_attrs,
892 .ct_owner = THIS_MODULE,
893};
894
895static void rndis_free_inst(struct usb_function_instance *f)
896{
897 struct f_rndis_opts *opts;
898
899 opts = container_of(f, struct f_rndis_opts, func_inst);
900 if (!opts->borrowed_net) {
901 if (opts->bound)
902 gether_cleanup(netdev_priv(opts->net));
903 else
904 free_netdev(opts->net);
905 }
906
907 kfree(opts->rndis_interf_group); /* single VLA chunk */
908 kfree(opts);
909}
910
911static struct usb_function_instance *rndis_alloc_inst(void)
912{
913 struct f_rndis_opts *opts;
914 struct usb_os_desc *descs[1];
915 char *names[1];
916 struct config_group *rndis_interf_group;
917
918 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
919 if (!opts)
920 return ERR_PTR(-ENOMEM);
921 opts->rndis_os_desc.ext_compat_id = opts->rndis_ext_compat_id;
922
923 mutex_init(&opts->lock);
924 opts->func_inst.free_func_inst = rndis_free_inst;
925 opts->net = gether_setup_default();
926 if (IS_ERR(opts->net)) {
927 struct net_device *net = opts->net;
928 kfree(opts);
929 return ERR_CAST(net);
930 }
931 INIT_LIST_HEAD(&opts->rndis_os_desc.ext_prop);
932
933 opts->class = rndis_iad_descriptor.bFunctionClass;
934 opts->subclass = rndis_iad_descriptor.bFunctionSubClass;
935 opts->protocol = rndis_iad_descriptor.bFunctionProtocol;
936
937 descs[0] = &opts->rndis_os_desc;
938 names[0] = "rndis";
939 config_group_init_type_name(&opts->func_inst.group, "",
940 &rndis_func_type);
941 rndis_interf_group =
942 usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs,
943 names, THIS_MODULE);
944 if (IS_ERR(rndis_interf_group)) {
945 rndis_free_inst(&opts->func_inst);
946 return ERR_CAST(rndis_interf_group);
947 }
948 opts->rndis_interf_group = rndis_interf_group;
949
950 return &opts->func_inst;
951}
952
953static void rndis_free(struct usb_function *f)
954{
955 struct f_rndis *rndis;
956 struct f_rndis_opts *opts;
957
958 rndis = func_to_rndis(f);
959 rndis_deregister(rndis->params);
960 opts = container_of(f->fi, struct f_rndis_opts, func_inst);
961 kfree(rndis);
962 mutex_lock(&opts->lock);
963 opts->refcnt--;
964 mutex_unlock(&opts->lock);
965}
966
967static void rndis_unbind(struct usb_configuration *c, struct usb_function *f)
968{
969 struct f_rndis *rndis = func_to_rndis(f);
970
971 kfree(f->os_desc_table);
972 f->os_desc_n = 0;
973 usb_free_all_descriptors(f);
974
975 kfree(rndis->notify_req->buf);
976 usb_ep_free_request(rndis->notify, rndis->notify_req);
977}
978
979static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
980{
981 struct f_rndis *rndis;
982 struct f_rndis_opts *opts;
983 struct rndis_params *params;
984
985 /* allocate and initialize one new instance */
986 rndis = kzalloc(sizeof(*rndis), GFP_KERNEL);
987 if (!rndis)
988 return ERR_PTR(-ENOMEM);
989
990 opts = container_of(fi, struct f_rndis_opts, func_inst);
991 mutex_lock(&opts->lock);
992 opts->refcnt++;
993
994 gether_get_host_addr_u8(opts->net, rndis->ethaddr);
995 rndis->vendorID = opts->vendor_id;
996 rndis->manufacturer = opts->manufacturer;
997
998 rndis->port.ioport = netdev_priv(opts->net);
999 mutex_unlock(&opts->lock);
1000 /* RNDIS activates when the host changes this filter */
1001 rndis->port.cdc_filter = 0;
1002
1003 /* RNDIS has special (and complex) framing */
1004 rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
1005 rndis->port.wrap = rndis_add_header;
1006 rndis->port.unwrap = rndis_rm_hdr;
1007
1008 rndis->port.func.name = "rndis";
1009 /* descriptors are per-instance copies */
1010 rndis->port.func.bind = rndis_bind;
1011 rndis->port.func.unbind = rndis_unbind;
1012 rndis->port.func.set_alt = rndis_set_alt;
1013 rndis->port.func.setup = rndis_setup;
1014 rndis->port.func.disable = rndis_disable;
1015 rndis->port.func.free_func = rndis_free;
1016
1017 params = rndis_register(rndis_response_available, rndis);
1018 if (IS_ERR(params)) {
1019 kfree(rndis);
1020 return ERR_CAST(params);
1021 }
1022 rndis->params = params;
1023
1024 return &rndis->port.func;
1025}
1026
1027DECLARE_USB_FUNCTION_INIT(rndis, rndis_alloc_inst, rndis_alloc);
1028MODULE_LICENSE("GPL");
1029MODULE_AUTHOR("David Brownell");