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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_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
111static 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
124static 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
132static 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
141static 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
149static 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
159static 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
172static struct usb_interface_assoc_descriptor
173rndis_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
187static 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
197static 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
205static 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
213static 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
233static 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
243static 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
252static 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
261static 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
281static 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
291static 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
301static 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
310static 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
319static 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
328static 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
351static 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
358static struct usb_gadget_strings rndis_string_table = {
359 .language = 0x0409, /* en-us */
360 .strings = rndis_string_defs,
361};
362
363static struct usb_gadget_strings *rndis_strings[] = {
364 &rndis_string_table,
365 NULL,
366};
367
368/*-------------------------------------------------------------------------*/
369
370static 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
385static 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
411static 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
450static 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
464static int
465rndis_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:
516invalid:
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
539static 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;
605fail:
606 return -EINVAL;
607}
608
609static 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
635static 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
647static 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 ... */
660static 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
668static int
669rndis_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, eth_ss_function);
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
821fail_free_descs:
822 usb_free_all_descriptors(f);
823fail:
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
837void 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}
849EXPORT_SYMBOL_GPL(rndis_borrow_net);
850
851static 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 */
858USB_ETHERNET_CONFIGFS_ITEM(rndis);
859
860/* f_rndis_opts_dev_addr */
861USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(rndis);
862
863/* f_rndis_opts_host_addr */
864USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(rndis);
865
866/* f_rndis_opts_qmult */
867USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(rndis);
868
869/* f_rndis_opts_ifname */
870USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(rndis);
871
872/* f_rndis_opts_class */
873USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, class);
874
875/* f_rndis_opts_subclass */
876USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, subclass);
877
878/* f_rndis_opts_protocol */
879USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, protocol);
880
881static 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
892static 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
898static 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
914static 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
956static 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
970static 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
982static 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
1030DECLARE_USB_FUNCTION_INIT(rndis, rndis_alloc_inst, rndis_alloc);
1031MODULE_LICENSE("GPL");
1032MODULE_AUTHOR("David Brownell");