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
func_to_rndis(struct usb_function * f)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 */
bitrate(struct usb_gadget * g)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_WIRELESS_CONTROLLER,
119 .bInterfaceSubClass = 1,
120 .bInterfaceProtocol = 3,
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_WIRELESS_CONTROLLER,
180 .bFunctionSubClass = 1,
181 .bFunctionProtocol = 3,
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
rndis_add_header(struct gether * port,struct sk_buff * skb)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
rndis_response_available(void * _rndis)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
rndis_response_complete(struct usb_ep * ep,struct usb_request * req)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
rndis_command_complete(struct usb_ep * ep,struct usb_request * req)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
rndis_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)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 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
516 | USB_CDC_SET_ETHERNET_PACKET_FILTER:
517 /*
518 * see 6.2.30: no data, wIndex = interface, wValue = packet
519 * filter bitmap. However, we don't really set cdc_filter to
520 * wValue for rndis, because cdc_filter is not RNDIS-specific.
521 * Return value 0 to avoid usb controllers stall ep0.
522 */
523 if (w_length != 0 || w_index != rndis->ctrl_id)
524 goto invalid;
525 DBG(cdev, "packet filter %02x\n", w_value);
526 value = 0;
527 break;
528
529 default:
530 invalid:
531 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
532 ctrl->bRequestType, ctrl->bRequest,
533 w_value, w_index, w_length);
534 }
535
536 /* respond with data transfer or status phase? */
537 if (value >= 0) {
538 DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
539 ctrl->bRequestType, ctrl->bRequest,
540 w_value, w_index, w_length);
541 req->zero = (value < w_length);
542 req->length = value;
543 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
544 if (value < 0)
545 ERROR(cdev, "rndis response on err %d\n", value);
546 }
547
548 /* device either stalls (value < 0) or reports success */
549 return value;
550 }
551
552
rndis_set_alt(struct usb_function * f,unsigned intf,unsigned alt)553 static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
554 {
555 struct f_rndis *rndis = func_to_rndis(f);
556 struct usb_composite_dev *cdev = f->config->cdev;
557
558 /* we know alt == 0 */
559
560 if (intf == rndis->ctrl_id) {
561 VDBG(cdev, "reset rndis control %d\n", intf);
562 usb_ep_disable(rndis->notify);
563
564 if (!rndis->notify->desc) {
565 VDBG(cdev, "init rndis ctrl %d\n", intf);
566 if (config_ep_by_speed(cdev->gadget, f, rndis->notify))
567 goto fail;
568 }
569 usb_ep_enable(rndis->notify);
570
571 } else if (intf == rndis->data_id) {
572 struct net_device *net;
573
574 if (rndis->port.in_ep->enabled) {
575 DBG(cdev, "reset rndis\n");
576 gether_disconnect(&rndis->port);
577 }
578
579 if (!rndis->port.in_ep->desc || !rndis->port.out_ep->desc) {
580 DBG(cdev, "init rndis\n");
581 if (config_ep_by_speed(cdev->gadget, f,
582 rndis->port.in_ep) ||
583 config_ep_by_speed(cdev->gadget, f,
584 rndis->port.out_ep)) {
585 rndis->port.in_ep->desc = NULL;
586 rndis->port.out_ep->desc = NULL;
587 goto fail;
588 }
589 }
590
591 /* Avoid ZLPs; they can be troublesome. */
592 rndis->port.is_zlp_ok = false;
593
594 /* RNDIS should be in the "RNDIS uninitialized" state,
595 * either never activated or after rndis_uninit().
596 *
597 * We don't want data to flow here until a nonzero packet
598 * filter is set, at which point it enters "RNDIS data
599 * initialized" state ... but we do want the endpoints
600 * to be activated. It's a strange little state.
601 *
602 * REVISIT the RNDIS gadget code has done this wrong for a
603 * very long time. We need another call to the link layer
604 * code -- gether_updown(...bool) maybe -- to do it right.
605 */
606 rndis->port.cdc_filter = 0;
607
608 DBG(cdev, "RNDIS RX/TX early activation ... \n");
609 net = gether_connect(&rndis->port);
610 if (IS_ERR(net))
611 return PTR_ERR(net);
612
613 rndis_set_param_dev(rndis->params, net,
614 &rndis->port.cdc_filter);
615 } else
616 goto fail;
617
618 return 0;
619 fail:
620 return -EINVAL;
621 }
622
rndis_disable(struct usb_function * f)623 static void rndis_disable(struct usb_function *f)
624 {
625 struct f_rndis *rndis = func_to_rndis(f);
626 struct usb_composite_dev *cdev = f->config->cdev;
627
628 if (!rndis->notify->enabled)
629 return;
630
631 DBG(cdev, "rndis deactivated\n");
632
633 rndis_uninit(rndis->params);
634 gether_disconnect(&rndis->port);
635
636 usb_ep_disable(rndis->notify);
637 rndis->notify->desc = NULL;
638 }
639
640 /*-------------------------------------------------------------------------*/
641
642 /*
643 * This isn't quite the same mechanism as CDC Ethernet, since the
644 * notification scheme passes less data, but the same set of link
645 * states must be tested. A key difference is that altsettings are
646 * not used to tell whether the link should send packets or not.
647 */
648
rndis_open(struct gether * geth)649 static void rndis_open(struct gether *geth)
650 {
651 struct f_rndis *rndis = func_to_rndis(&geth->func);
652 struct usb_composite_dev *cdev = geth->func.config->cdev;
653
654 DBG(cdev, "%s\n", __func__);
655
656 rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3,
657 bitrate(cdev->gadget) / 100);
658 rndis_signal_connect(rndis->params);
659 }
660
rndis_close(struct gether * geth)661 static void rndis_close(struct gether *geth)
662 {
663 struct f_rndis *rndis = func_to_rndis(&geth->func);
664
665 DBG(geth->func.config->cdev, "%s\n", __func__);
666
667 rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
668 rndis_signal_disconnect(rndis->params);
669 }
670
671 /*-------------------------------------------------------------------------*/
672
673 /* Some controllers can't support RNDIS ... */
can_support_rndis(struct usb_configuration * c)674 static inline bool can_support_rndis(struct usb_configuration *c)
675 {
676 /* everything else is *presumably* fine */
677 return true;
678 }
679
680 /* ethernet function driver setup/binding */
681
682 static int
rndis_bind(struct usb_configuration * c,struct usb_function * f)683 rndis_bind(struct usb_configuration *c, struct usb_function *f)
684 {
685 struct usb_composite_dev *cdev = c->cdev;
686 struct f_rndis *rndis = func_to_rndis(f);
687 struct usb_string *us;
688 int status;
689 struct usb_ep *ep;
690
691 struct f_rndis_opts *rndis_opts;
692
693 if (!can_support_rndis(c))
694 return -EINVAL;
695
696 rndis_opts = container_of(f->fi, struct f_rndis_opts, func_inst);
697
698 if (cdev->use_os_string) {
699 f->os_desc_table = kzalloc(sizeof(*f->os_desc_table),
700 GFP_KERNEL);
701 if (!f->os_desc_table)
702 return -ENOMEM;
703 f->os_desc_n = 1;
704 f->os_desc_table[0].os_desc = &rndis_opts->rndis_os_desc;
705 }
706
707 rndis_iad_descriptor.bFunctionClass = rndis_opts->class;
708 rndis_iad_descriptor.bFunctionSubClass = rndis_opts->subclass;
709 rndis_iad_descriptor.bFunctionProtocol = rndis_opts->protocol;
710
711 /*
712 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
713 * configurations are bound in sequence with list_for_each_entry,
714 * in each configuration its functions are bound in sequence
715 * with list_for_each_entry, so we assume no race condition
716 * with regard to rndis_opts->bound access
717 */
718 if (!rndis_opts->bound) {
719 gether_set_gadget(rndis_opts->net, cdev->gadget);
720 status = gether_register_netdev(rndis_opts->net);
721 if (status)
722 goto fail;
723 rndis_opts->bound = true;
724 }
725
726 us = usb_gstrings_attach(cdev, rndis_strings,
727 ARRAY_SIZE(rndis_string_defs));
728 if (IS_ERR(us)) {
729 status = PTR_ERR(us);
730 goto fail;
731 }
732 rndis_control_intf.iInterface = us[0].id;
733 rndis_data_intf.iInterface = us[1].id;
734 rndis_iad_descriptor.iFunction = us[2].id;
735
736 /* allocate instance-specific interface IDs */
737 status = usb_interface_id(c, f);
738 if (status < 0)
739 goto fail;
740 rndis->ctrl_id = status;
741 rndis_iad_descriptor.bFirstInterface = status;
742
743 rndis_control_intf.bInterfaceNumber = status;
744 rndis_union_desc.bMasterInterface0 = status;
745
746 if (cdev->use_os_string)
747 f->os_desc_table[0].if_id =
748 rndis_iad_descriptor.bFirstInterface;
749
750 status = usb_interface_id(c, f);
751 if (status < 0)
752 goto fail;
753 rndis->data_id = status;
754
755 rndis_data_intf.bInterfaceNumber = status;
756 rndis_union_desc.bSlaveInterface0 = status;
757
758 status = -ENODEV;
759
760 /* allocate instance-specific endpoints */
761 ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
762 if (!ep)
763 goto fail;
764 rndis->port.in_ep = ep;
765
766 ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
767 if (!ep)
768 goto fail;
769 rndis->port.out_ep = ep;
770
771 /* NOTE: a status/notification endpoint is, strictly speaking,
772 * optional. We don't treat it that way though! It's simpler,
773 * and some newer profiles don't treat it as optional.
774 */
775 ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
776 if (!ep)
777 goto fail;
778 rndis->notify = ep;
779
780 status = -ENOMEM;
781
782 /* allocate notification request and buffer */
783 rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
784 if (!rndis->notify_req)
785 goto fail;
786 rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
787 if (!rndis->notify_req->buf)
788 goto fail;
789 rndis->notify_req->length = STATUS_BYTECOUNT;
790 rndis->notify_req->context = rndis;
791 rndis->notify_req->complete = rndis_response_complete;
792
793 /* support all relevant hardware speeds... we expect that when
794 * hardware is dual speed, all bulk-capable endpoints work at
795 * both speeds
796 */
797 hs_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
798 hs_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
799 hs_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
800
801 ss_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
802 ss_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
803 ss_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
804
805 status = usb_assign_descriptors(f, eth_fs_function, eth_hs_function,
806 eth_ss_function, eth_ss_function);
807 if (status)
808 goto fail;
809
810 rndis->port.open = rndis_open;
811 rndis->port.close = rndis_close;
812
813 rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
814 rndis_set_host_mac(rndis->params, rndis->ethaddr);
815
816 if (rndis->manufacturer && rndis->vendorID &&
817 rndis_set_param_vendor(rndis->params, rndis->vendorID,
818 rndis->manufacturer)) {
819 status = -EINVAL;
820 goto fail_free_descs;
821 }
822
823 /* NOTE: all that is done without knowing or caring about
824 * the network link ... which is unavailable to this code
825 * until we're activated via set_alt().
826 */
827
828 DBG(cdev, "RNDIS: %s speed IN/%s OUT/%s NOTIFY/%s\n",
829 gadget_is_superspeed(c->cdev->gadget) ? "super" :
830 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
831 rndis->port.in_ep->name, rndis->port.out_ep->name,
832 rndis->notify->name);
833 return 0;
834
835 fail_free_descs:
836 usb_free_all_descriptors(f);
837 fail:
838 kfree(f->os_desc_table);
839 f->os_desc_n = 0;
840
841 if (rndis->notify_req) {
842 kfree(rndis->notify_req->buf);
843 usb_ep_free_request(rndis->notify, rndis->notify_req);
844 }
845
846 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
847
848 return status;
849 }
850
rndis_borrow_net(struct usb_function_instance * f,struct net_device * net)851 void rndis_borrow_net(struct usb_function_instance *f, struct net_device *net)
852 {
853 struct f_rndis_opts *opts;
854
855 opts = container_of(f, struct f_rndis_opts, func_inst);
856 if (opts->bound)
857 gether_cleanup(netdev_priv(opts->net));
858 else
859 free_netdev(opts->net);
860 opts->borrowed_net = opts->bound = true;
861 opts->net = net;
862 }
863 EXPORT_SYMBOL_GPL(rndis_borrow_net);
864
to_f_rndis_opts(struct config_item * item)865 static inline struct f_rndis_opts *to_f_rndis_opts(struct config_item *item)
866 {
867 return container_of(to_config_group(item), struct f_rndis_opts,
868 func_inst.group);
869 }
870
871 /* f_rndis_item_ops */
872 USB_ETHERNET_CONFIGFS_ITEM(rndis);
873
874 /* f_rndis_opts_dev_addr */
875 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(rndis);
876
877 /* f_rndis_opts_host_addr */
878 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(rndis);
879
880 /* f_rndis_opts_qmult */
881 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(rndis);
882
883 /* f_rndis_opts_ifname */
884 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(rndis);
885
886 /* f_rndis_opts_class */
887 USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, class);
888
889 /* f_rndis_opts_subclass */
890 USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, subclass);
891
892 /* f_rndis_opts_protocol */
893 USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, protocol);
894
895 static struct configfs_attribute *rndis_attrs[] = {
896 &rndis_opts_attr_dev_addr,
897 &rndis_opts_attr_host_addr,
898 &rndis_opts_attr_qmult,
899 &rndis_opts_attr_ifname,
900 &rndis_opts_attr_class,
901 &rndis_opts_attr_subclass,
902 &rndis_opts_attr_protocol,
903 NULL,
904 };
905
906 static const struct config_item_type rndis_func_type = {
907 .ct_item_ops = &rndis_item_ops,
908 .ct_attrs = rndis_attrs,
909 .ct_owner = THIS_MODULE,
910 };
911
rndis_free_inst(struct usb_function_instance * f)912 static void rndis_free_inst(struct usb_function_instance *f)
913 {
914 struct f_rndis_opts *opts;
915
916 opts = container_of(f, struct f_rndis_opts, func_inst);
917 if (!opts->borrowed_net) {
918 if (opts->bound)
919 gether_cleanup(netdev_priv(opts->net));
920 else
921 free_netdev(opts->net);
922 }
923
924 kfree(opts->rndis_interf_group); /* single VLA chunk */
925 kfree(opts);
926 }
927
rndis_alloc_inst(void)928 static struct usb_function_instance *rndis_alloc_inst(void)
929 {
930 struct f_rndis_opts *opts;
931 struct usb_os_desc *descs[1];
932 char *names[1];
933 struct config_group *rndis_interf_group;
934
935 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
936 if (!opts)
937 return ERR_PTR(-ENOMEM);
938 opts->rndis_os_desc.ext_compat_id = opts->rndis_ext_compat_id;
939
940 mutex_init(&opts->lock);
941 opts->func_inst.free_func_inst = rndis_free_inst;
942 opts->net = gether_setup_default();
943 if (IS_ERR(opts->net)) {
944 struct net_device *net = opts->net;
945 kfree(opts);
946 return ERR_CAST(net);
947 }
948 INIT_LIST_HEAD(&opts->rndis_os_desc.ext_prop);
949
950 opts->class = rndis_iad_descriptor.bFunctionClass;
951 opts->subclass = rndis_iad_descriptor.bFunctionSubClass;
952 opts->protocol = rndis_iad_descriptor.bFunctionProtocol;
953
954 descs[0] = &opts->rndis_os_desc;
955 names[0] = "rndis";
956 config_group_init_type_name(&opts->func_inst.group, "",
957 &rndis_func_type);
958 rndis_interf_group =
959 usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs,
960 names, THIS_MODULE);
961 if (IS_ERR(rndis_interf_group)) {
962 rndis_free_inst(&opts->func_inst);
963 return ERR_CAST(rndis_interf_group);
964 }
965 opts->rndis_interf_group = rndis_interf_group;
966
967 return &opts->func_inst;
968 }
969
rndis_free(struct usb_function * f)970 static void rndis_free(struct usb_function *f)
971 {
972 struct f_rndis *rndis;
973 struct f_rndis_opts *opts;
974
975 rndis = func_to_rndis(f);
976 rndis_deregister(rndis->params);
977 opts = container_of(f->fi, struct f_rndis_opts, func_inst);
978 kfree(rndis);
979 mutex_lock(&opts->lock);
980 opts->refcnt--;
981 mutex_unlock(&opts->lock);
982 }
983
rndis_unbind(struct usb_configuration * c,struct usb_function * f)984 static void rndis_unbind(struct usb_configuration *c, struct usb_function *f)
985 {
986 struct f_rndis *rndis = func_to_rndis(f);
987
988 kfree(f->os_desc_table);
989 f->os_desc_n = 0;
990 usb_free_all_descriptors(f);
991
992 kfree(rndis->notify_req->buf);
993 usb_ep_free_request(rndis->notify, rndis->notify_req);
994 }
995
rndis_alloc(struct usb_function_instance * fi)996 static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
997 {
998 struct f_rndis *rndis;
999 struct f_rndis_opts *opts;
1000 struct rndis_params *params;
1001
1002 /* allocate and initialize one new instance */
1003 rndis = kzalloc(sizeof(*rndis), GFP_KERNEL);
1004 if (!rndis)
1005 return ERR_PTR(-ENOMEM);
1006
1007 opts = container_of(fi, struct f_rndis_opts, func_inst);
1008 mutex_lock(&opts->lock);
1009 opts->refcnt++;
1010
1011 gether_get_host_addr_u8(opts->net, rndis->ethaddr);
1012 rndis->vendorID = opts->vendor_id;
1013 rndis->manufacturer = opts->manufacturer;
1014
1015 rndis->port.ioport = netdev_priv(opts->net);
1016 mutex_unlock(&opts->lock);
1017 /* RNDIS activates when the host changes this filter */
1018 rndis->port.cdc_filter = 0;
1019
1020 /* RNDIS has special (and complex) framing */
1021 rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
1022 rndis->port.wrap = rndis_add_header;
1023 rndis->port.unwrap = rndis_rm_hdr;
1024
1025 rndis->port.func.name = "rndis";
1026 /* descriptors are per-instance copies */
1027 rndis->port.func.bind = rndis_bind;
1028 rndis->port.func.unbind = rndis_unbind;
1029 rndis->port.func.set_alt = rndis_set_alt;
1030 rndis->port.func.setup = rndis_setup;
1031 rndis->port.func.disable = rndis_disable;
1032 rndis->port.func.free_func = rndis_free;
1033
1034 params = rndis_register(rndis_response_available, rndis);
1035 if (IS_ERR(params)) {
1036 kfree(rndis);
1037 return ERR_CAST(params);
1038 }
1039 rndis->params = params;
1040
1041 return &rndis->port.func;
1042 }
1043
1044 DECLARE_USB_FUNCTION_INIT(rndis, rndis_alloc_inst, rndis_alloc);
1045 MODULE_LICENSE("GPL");
1046 MODULE_AUTHOR("David Brownell");
1047