1 /*
2 * f_rndis.c -- RNDIS link function driver
3 *
4 * Copyright (C) 2003-2005,2008 David Brownell
5 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
6 * Copyright (C) 2008 Nokia Corporation
7 * Copyright (C) 2009 Samsung Electronics
8 * Author: Michal Nazarewicz (mina86@mina86.com)
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 */
15
16 /* #define VERBOSE_DEBUG */
17
18 #include <linux/slab.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/device.h>
22 #include <linux/etherdevice.h>
23
24 #include <linux/atomic.h>
25
26 #include "u_ether.h"
27 #include "u_ether_configfs.h"
28 #include "u_rndis.h"
29 #include "rndis.h"
30 #include "configfs.h"
31
32 /*
33 * This function is an RNDIS Ethernet port -- a Microsoft protocol that's
34 * been promoted instead of the standard CDC Ethernet. The published RNDIS
35 * spec is ambiguous, incomplete, and needlessly complex. Variants such as
36 * ActiveSync have even worse status in terms of specification.
37 *
38 * In short: it's a protocol controlled by (and for) Microsoft, not for an
39 * Open ecosystem or markets. Linux supports it *only* because Microsoft
40 * doesn't support the CDC Ethernet standard.
41 *
42 * The RNDIS data transfer model is complex, with multiple Ethernet packets
43 * per USB message, and out of band data. The control model is built around
44 * what's essentially an "RNDIS RPC" protocol. It's all wrapped in a CDC ACM
45 * (modem, not Ethernet) veneer, with those ACM descriptors being entirely
46 * useless (they're ignored). RNDIS expects to be the only function in its
47 * configuration, so it's no real help if you need composite devices; and
48 * it expects to be the first configuration too.
49 *
50 * There is a single technical advantage of RNDIS over CDC Ethernet, if you
51 * discount the fluff that its RPC can be made to deliver: it doesn't need
52 * a NOP altsetting for the data interface. That lets it work on some of the
53 * "so smart it's stupid" hardware which takes over configuration changes
54 * from the software, and adds restrictions like "no altsettings".
55 *
56 * Unfortunately MSFT's RNDIS drivers are buggy. They hang or oops, and
57 * have all sorts of contrary-to-specification oddities that can prevent
58 * them from working sanely. Since bugfixes (or accurate specs, letting
59 * Linux work around those bugs) are unlikely to ever come from MSFT, you
60 * may want to avoid using RNDIS on purely operational grounds.
61 *
62 * Omissions from the RNDIS 1.0 specification include:
63 *
64 * - Power management ... references data that's scattered around lots
65 * of other documentation, which is incorrect/incomplete there too.
66 *
67 * - There are various undocumented protocol requirements, like the need
68 * to send garbage in some control-OUT messages.
69 *
70 * - MS-Windows drivers sometimes emit undocumented requests.
71 */
72
73 static unsigned int rndis_dl_max_pkt_per_xfer = 3;
74 module_param(rndis_dl_max_pkt_per_xfer, uint, S_IRUGO | S_IWUSR);
75 MODULE_PARM_DESC(rndis_dl_max_pkt_per_xfer,
76 "Maximum packets per transfer for DL aggregation");
77
78 static unsigned int rndis_ul_max_pkt_per_xfer = 3;
79 module_param(rndis_ul_max_pkt_per_xfer, uint, S_IRUGO | S_IWUSR);
80 MODULE_PARM_DESC(rndis_ul_max_pkt_per_xfer,
81 "Maximum packets per transfer for UL aggregation");
82
83 struct f_rndis {
84 struct gether port;
85 u8 ctrl_id, data_id;
86 u8 ethaddr[ETH_ALEN];
87 u32 vendorID;
88 const char *manufacturer;
89 struct rndis_params *params;
90
91 struct usb_ep *notify;
92 struct usb_request *notify_req;
93 atomic_t notify_count;
94 };
95
func_to_rndis(struct usb_function * f)96 static inline struct f_rndis *func_to_rndis(struct usb_function *f)
97 {
98 return container_of(f, struct f_rndis, port.func);
99 }
100
101 /* peak (theoretical) bulk transfer rate in bits-per-second */
bitrate(struct usb_gadget * g)102 static unsigned int bitrate(struct usb_gadget *g)
103 {
104 if (gadget_is_superspeed(g) && g->speed >= USB_SPEED_SUPER_PLUS)
105 return 4250000000U;
106 if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
107 return 3750000000U;
108 else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
109 return 13 * 512 * 8 * 1000 * 8;
110 else
111 return 19 * 64 * 1 * 1000 * 8;
112 }
113
114 /*-------------------------------------------------------------------------*/
115
116 /*
117 */
118
119 #define RNDIS_STATUS_INTERVAL_MS 32
120 #define STATUS_BYTECOUNT 8 /* 8 bytes data */
121
122
123 /* interface descriptor: */
124
125 static struct usb_interface_descriptor rndis_control_intf = {
126 .bLength = sizeof rndis_control_intf,
127 .bDescriptorType = USB_DT_INTERFACE,
128
129 /* .bInterfaceNumber = DYNAMIC */
130 /* status endpoint is optional; this could be patched later */
131 .bNumEndpoints = 1,
132 .bInterfaceClass = USB_CLASS_COMM,
133 .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
134 .bInterfaceProtocol = USB_CDC_ACM_PROTO_VENDOR,
135 /* .iInterface = DYNAMIC */
136 };
137
138 static struct usb_cdc_header_desc header_desc = {
139 .bLength = sizeof header_desc,
140 .bDescriptorType = USB_DT_CS_INTERFACE,
141 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
142
143 .bcdCDC = cpu_to_le16(0x0110),
144 };
145
146 static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor = {
147 .bLength = sizeof call_mgmt_descriptor,
148 .bDescriptorType = USB_DT_CS_INTERFACE,
149 .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE,
150
151 .bmCapabilities = 0x00,
152 .bDataInterface = 0x01,
153 };
154
155 static struct usb_cdc_acm_descriptor rndis_acm_descriptor = {
156 .bLength = sizeof rndis_acm_descriptor,
157 .bDescriptorType = USB_DT_CS_INTERFACE,
158 .bDescriptorSubType = USB_CDC_ACM_TYPE,
159
160 .bmCapabilities = 0x00,
161 };
162
163 static struct usb_cdc_union_desc rndis_union_desc = {
164 .bLength = sizeof(rndis_union_desc),
165 .bDescriptorType = USB_DT_CS_INTERFACE,
166 .bDescriptorSubType = USB_CDC_UNION_TYPE,
167 /* .bMasterInterface0 = DYNAMIC */
168 /* .bSlaveInterface0 = DYNAMIC */
169 };
170
171 /* the data interface has two bulk endpoints */
172
173 static struct usb_interface_descriptor rndis_data_intf = {
174 .bLength = sizeof rndis_data_intf,
175 .bDescriptorType = USB_DT_INTERFACE,
176
177 /* .bInterfaceNumber = DYNAMIC */
178 .bNumEndpoints = 2,
179 .bInterfaceClass = USB_CLASS_CDC_DATA,
180 .bInterfaceSubClass = 0,
181 .bInterfaceProtocol = 0,
182 /* .iInterface = DYNAMIC */
183 };
184
185
186 static struct usb_interface_assoc_descriptor
187 rndis_iad_descriptor = {
188 .bLength = sizeof rndis_iad_descriptor,
189 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
190
191 .bFirstInterface = 0, /* XXX, hardcoded */
192 .bInterfaceCount = 2, // control + data
193 .bFunctionClass = USB_CLASS_COMM,
194 .bFunctionSubClass = USB_CDC_SUBCLASS_ETHERNET,
195 .bFunctionProtocol = USB_CDC_PROTO_NONE,
196 /* .iFunction = DYNAMIC */
197 };
198
199 /* full speed support: */
200
201 static struct usb_endpoint_descriptor fs_notify_desc = {
202 .bLength = USB_DT_ENDPOINT_SIZE,
203 .bDescriptorType = USB_DT_ENDPOINT,
204
205 .bEndpointAddress = USB_DIR_IN,
206 .bmAttributes = USB_ENDPOINT_XFER_INT,
207 .wMaxPacketSize = cpu_to_le16(STATUS_BYTECOUNT),
208 .bInterval = RNDIS_STATUS_INTERVAL_MS,
209 };
210
211 static struct usb_endpoint_descriptor fs_in_desc = {
212 .bLength = USB_DT_ENDPOINT_SIZE,
213 .bDescriptorType = USB_DT_ENDPOINT,
214
215 .bEndpointAddress = USB_DIR_IN,
216 .bmAttributes = USB_ENDPOINT_XFER_BULK,
217 };
218
219 static struct usb_endpoint_descriptor fs_out_desc = {
220 .bLength = USB_DT_ENDPOINT_SIZE,
221 .bDescriptorType = USB_DT_ENDPOINT,
222
223 .bEndpointAddress = USB_DIR_OUT,
224 .bmAttributes = USB_ENDPOINT_XFER_BULK,
225 };
226
227 static struct usb_descriptor_header *eth_fs_function[] = {
228 (struct usb_descriptor_header *) &rndis_iad_descriptor,
229
230 /* control interface matches ACM, not Ethernet */
231 (struct usb_descriptor_header *) &rndis_control_intf,
232 (struct usb_descriptor_header *) &header_desc,
233 (struct usb_descriptor_header *) &call_mgmt_descriptor,
234 (struct usb_descriptor_header *) &rndis_acm_descriptor,
235 (struct usb_descriptor_header *) &rndis_union_desc,
236 (struct usb_descriptor_header *) &fs_notify_desc,
237
238 /* data interface has no altsetting */
239 (struct usb_descriptor_header *) &rndis_data_intf,
240 (struct usb_descriptor_header *) &fs_in_desc,
241 (struct usb_descriptor_header *) &fs_out_desc,
242 NULL,
243 };
244
245 /* high speed support: */
246
247 static struct usb_endpoint_descriptor hs_notify_desc = {
248 .bLength = USB_DT_ENDPOINT_SIZE,
249 .bDescriptorType = USB_DT_ENDPOINT,
250
251 .bEndpointAddress = USB_DIR_IN,
252 .bmAttributes = USB_ENDPOINT_XFER_INT,
253 .wMaxPacketSize = cpu_to_le16(STATUS_BYTECOUNT),
254 .bInterval = USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
255 };
256
257 static struct usb_endpoint_descriptor hs_in_desc = {
258 .bLength = USB_DT_ENDPOINT_SIZE,
259 .bDescriptorType = USB_DT_ENDPOINT,
260
261 .bEndpointAddress = USB_DIR_IN,
262 .bmAttributes = USB_ENDPOINT_XFER_BULK,
263 .wMaxPacketSize = cpu_to_le16(512),
264 };
265
266 static struct usb_endpoint_descriptor hs_out_desc = {
267 .bLength = USB_DT_ENDPOINT_SIZE,
268 .bDescriptorType = USB_DT_ENDPOINT,
269
270 .bEndpointAddress = USB_DIR_OUT,
271 .bmAttributes = USB_ENDPOINT_XFER_BULK,
272 .wMaxPacketSize = cpu_to_le16(512),
273 };
274
275 static struct usb_descriptor_header *eth_hs_function[] = {
276 (struct usb_descriptor_header *) &rndis_iad_descriptor,
277
278 /* control interface matches ACM, not Ethernet */
279 (struct usb_descriptor_header *) &rndis_control_intf,
280 (struct usb_descriptor_header *) &header_desc,
281 (struct usb_descriptor_header *) &call_mgmt_descriptor,
282 (struct usb_descriptor_header *) &rndis_acm_descriptor,
283 (struct usb_descriptor_header *) &rndis_union_desc,
284 (struct usb_descriptor_header *) &hs_notify_desc,
285
286 /* data interface has no altsetting */
287 (struct usb_descriptor_header *) &rndis_data_intf,
288 (struct usb_descriptor_header *) &hs_in_desc,
289 (struct usb_descriptor_header *) &hs_out_desc,
290 NULL,
291 };
292
293 /* super speed support: */
294
295 static struct usb_endpoint_descriptor ss_notify_desc = {
296 .bLength = USB_DT_ENDPOINT_SIZE,
297 .bDescriptorType = USB_DT_ENDPOINT,
298
299 .bEndpointAddress = USB_DIR_IN,
300 .bmAttributes = USB_ENDPOINT_XFER_INT,
301 .wMaxPacketSize = cpu_to_le16(STATUS_BYTECOUNT),
302 .bInterval = USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
303 };
304
305 static struct usb_ss_ep_comp_descriptor ss_intr_comp_desc = {
306 .bLength = sizeof ss_intr_comp_desc,
307 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
308
309 /* the following 3 values can be tweaked if necessary */
310 /* .bMaxBurst = 0, */
311 /* .bmAttributes = 0, */
312 .wBytesPerInterval = cpu_to_le16(STATUS_BYTECOUNT),
313 };
314
315 static struct usb_endpoint_descriptor ss_in_desc = {
316 .bLength = USB_DT_ENDPOINT_SIZE,
317 .bDescriptorType = USB_DT_ENDPOINT,
318
319 .bEndpointAddress = USB_DIR_IN,
320 .bmAttributes = USB_ENDPOINT_XFER_BULK,
321 .wMaxPacketSize = cpu_to_le16(1024),
322 };
323
324 static struct usb_endpoint_descriptor ss_out_desc = {
325 .bLength = USB_DT_ENDPOINT_SIZE,
326 .bDescriptorType = USB_DT_ENDPOINT,
327
328 .bEndpointAddress = USB_DIR_OUT,
329 .bmAttributes = USB_ENDPOINT_XFER_BULK,
330 .wMaxPacketSize = cpu_to_le16(1024),
331 };
332
333 static struct usb_ss_ep_comp_descriptor ss_bulk_comp_desc = {
334 .bLength = sizeof ss_bulk_comp_desc,
335 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
336
337 /* the following 2 values can be tweaked if necessary */
338 /* .bMaxBurst = 0, */
339 /* .bmAttributes = 0, */
340 };
341
342 static struct usb_descriptor_header *eth_ss_function[] = {
343 (struct usb_descriptor_header *) &rndis_iad_descriptor,
344
345 /* control interface matches ACM, not Ethernet */
346 (struct usb_descriptor_header *) &rndis_control_intf,
347 (struct usb_descriptor_header *) &header_desc,
348 (struct usb_descriptor_header *) &call_mgmt_descriptor,
349 (struct usb_descriptor_header *) &rndis_acm_descriptor,
350 (struct usb_descriptor_header *) &rndis_union_desc,
351 (struct usb_descriptor_header *) &ss_notify_desc,
352 (struct usb_descriptor_header *) &ss_intr_comp_desc,
353
354 /* data interface has no altsetting */
355 (struct usb_descriptor_header *) &rndis_data_intf,
356 (struct usb_descriptor_header *) &ss_in_desc,
357 (struct usb_descriptor_header *) &ss_bulk_comp_desc,
358 (struct usb_descriptor_header *) &ss_out_desc,
359 (struct usb_descriptor_header *) &ss_bulk_comp_desc,
360 NULL,
361 };
362
363 /* string descriptors: */
364
365 static struct usb_string rndis_string_defs[] = {
366 [0].s = "RNDIS Communications Control",
367 [1].s = "RNDIS Ethernet Data",
368 [2].s = "RNDIS",
369 { } /* end of list */
370 };
371
372 static struct usb_gadget_strings rndis_string_table = {
373 .language = 0x0409, /* en-us */
374 .strings = rndis_string_defs,
375 };
376
377 static struct usb_gadget_strings *rndis_strings[] = {
378 &rndis_string_table,
379 NULL,
380 };
381
382 /*-------------------------------------------------------------------------*/
383
rndis_add_header(struct gether * port,struct sk_buff * skb)384 static struct sk_buff *rndis_add_header(struct gether *port,
385 struct sk_buff *skb)
386 {
387 struct sk_buff *skb2;
388
389 skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
390 rndis_add_hdr(skb2);
391
392 dev_kfree_skb(skb);
393 return skb2;
394 }
395
rndis_response_available(void * _rndis)396 static void rndis_response_available(void *_rndis)
397 {
398 struct f_rndis *rndis = _rndis;
399 struct usb_request *req = rndis->notify_req;
400 struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
401 __le32 *data = req->buf;
402 int status;
403
404 if (atomic_inc_return(&rndis->notify_count) != 1)
405 return;
406
407 /* Send RNDIS RESPONSE_AVAILABLE notification; a
408 * USB_CDC_NOTIFY_RESPONSE_AVAILABLE "should" work too
409 *
410 * This is the only notification defined by RNDIS.
411 */
412 data[0] = cpu_to_le32(1);
413 data[1] = cpu_to_le32(0);
414
415 status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
416 if (status) {
417 atomic_dec(&rndis->notify_count);
418 DBG(cdev, "notify/0 --> %d\n", status);
419 }
420 }
421
rndis_response_complete(struct usb_ep * ep,struct usb_request * req)422 static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
423 {
424 struct f_rndis *rndis = req->context;
425 struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
426 int status = req->status;
427
428 /* after TX:
429 * - USB_CDC_GET_ENCAPSULATED_RESPONSE (ep0/control)
430 * - RNDIS_RESPONSE_AVAILABLE (status/irq)
431 */
432 switch (status) {
433 case -ECONNRESET:
434 case -ESHUTDOWN:
435 /* connection gone */
436 atomic_set(&rndis->notify_count, 0);
437 break;
438 default:
439 DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
440 ep->name, status,
441 req->actual, req->length);
442 /* FALLTHROUGH */
443 case 0:
444 if (ep != rndis->notify)
445 break;
446
447 /* handle multiple pending RNDIS_RESPONSE_AVAILABLE
448 * notifications by resending until we're done
449 */
450 if (atomic_dec_and_test(&rndis->notify_count))
451 break;
452 status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
453 if (status) {
454 atomic_dec(&rndis->notify_count);
455 DBG(cdev, "notify/1 --> %d\n", status);
456 }
457 break;
458 }
459 }
460
rndis_command_complete(struct usb_ep * ep,struct usb_request * req)461 static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
462 {
463 struct f_rndis *rndis = req->context;
464 struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
465 int status;
466 rndis_init_msg_type *buf;
467
468 /* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
469 // spin_lock(&dev->lock);
470 status = rndis_msg_parser(rndis->params, (u8 *) req->buf);
471 if (status < 0)
472 pr_err("RNDIS command error %d, %d/%d\n",
473 status, req->actual, req->length);
474
475 buf = (rndis_init_msg_type *)req->buf;
476
477 if (buf->MessageType == RNDIS_MSG_INIT) {
478 if (buf->MaxTransferSize > 2048)
479 rndis->port.multi_pkt_xfer = 1;
480 else
481 rndis->port.multi_pkt_xfer = 0;
482 DBG(cdev, "%s: MaxTransferSize: %d : Multi_pkt_txr: %s\n",
483 __func__, buf->MaxTransferSize,
484 rndis->port.multi_pkt_xfer ? "enabled" :
485 "disabled");
486 if (rndis_dl_max_pkt_per_xfer <= 1)
487 rndis->port.multi_pkt_xfer = 0;
488 }
489 // spin_unlock(&dev->lock);
490 }
491
492 static int
rndis_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)493 rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
494 {
495 struct f_rndis *rndis = func_to_rndis(f);
496 struct usb_composite_dev *cdev = f->config->cdev;
497 struct usb_request *req = cdev->req;
498 int value = -EOPNOTSUPP;
499 u16 w_index = le16_to_cpu(ctrl->wIndex);
500 u16 w_value = le16_to_cpu(ctrl->wValue);
501 u16 w_length = le16_to_cpu(ctrl->wLength);
502
503 /* composite driver infrastructure handles everything except
504 * CDC class messages; interface activation uses set_alt().
505 */
506 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
507
508 /* RNDIS uses the CDC command encapsulation mechanism to implement
509 * an RPC scheme, with much getting/setting of attributes by OID.
510 */
511 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
512 | USB_CDC_SEND_ENCAPSULATED_COMMAND:
513 if (w_value || w_index != rndis->ctrl_id)
514 goto invalid;
515 /* read the request; process it later */
516 value = w_length;
517 req->complete = rndis_command_complete;
518 req->context = rndis;
519 /* later, rndis_response_available() sends a notification */
520 break;
521
522 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
523 | USB_CDC_GET_ENCAPSULATED_RESPONSE:
524 if (w_value || w_index != rndis->ctrl_id)
525 goto invalid;
526 else {
527 u8 *buf;
528 u32 n;
529
530 /* return the result */
531 buf = rndis_get_next_response(rndis->params, &n);
532 if (buf) {
533 memcpy(req->buf, buf, n);
534 req->complete = rndis_response_complete;
535 req->context = rndis;
536 rndis_free_response(rndis->params, buf);
537 value = n;
538 }
539 /* else stalls ... spec says to avoid that */
540 }
541 break;
542
543 default:
544 invalid:
545 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
546 ctrl->bRequestType, ctrl->bRequest,
547 w_value, w_index, w_length);
548 }
549
550 /* respond with data transfer or status phase? */
551 if (value >= 0) {
552 DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
553 ctrl->bRequestType, ctrl->bRequest,
554 w_value, w_index, w_length);
555 req->zero = (value < w_length);
556 req->length = value;
557 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
558 if (value < 0)
559 ERROR(cdev, "rndis response on err %d\n", value);
560 }
561
562 /* device either stalls (value < 0) or reports success */
563 return value;
564 }
565
566
rndis_set_alt(struct usb_function * f,unsigned intf,unsigned alt)567 static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
568 {
569 struct f_rndis *rndis = func_to_rndis(f);
570 struct usb_composite_dev *cdev = f->config->cdev;
571
572 /* we know alt == 0 */
573
574 if (intf == rndis->ctrl_id) {
575 VDBG(cdev, "reset rndis control %d\n", intf);
576 usb_ep_disable(rndis->notify);
577
578 if (!rndis->notify->desc) {
579 VDBG(cdev, "init rndis ctrl %d\n", intf);
580 if (config_ep_by_speed(cdev->gadget, f, rndis->notify))
581 goto fail;
582 }
583 usb_ep_enable(rndis->notify);
584
585 } else if (intf == rndis->data_id) {
586 struct net_device *net;
587
588 if (rndis->port.in_ep->enabled) {
589 DBG(cdev, "reset rndis\n");
590 gether_disconnect(&rndis->port);
591 }
592
593 if (!rndis->port.in_ep->desc || !rndis->port.out_ep->desc) {
594 DBG(cdev, "init rndis\n");
595 if (config_ep_by_speed(cdev->gadget, f,
596 rndis->port.in_ep) ||
597 config_ep_by_speed(cdev->gadget, f,
598 rndis->port.out_ep)) {
599 rndis->port.in_ep->desc = NULL;
600 rndis->port.out_ep->desc = NULL;
601 goto fail;
602 }
603 }
604
605 /* Avoid ZLPs; they can be troublesome. */
606 rndis->port.is_zlp_ok = false;
607
608 /* RNDIS should be in the "RNDIS uninitialized" state,
609 * either never activated or after rndis_uninit().
610 *
611 * We don't want data to flow here until a nonzero packet
612 * filter is set, at which point it enters "RNDIS data
613 * initialized" state ... but we do want the endpoints
614 * to be activated. It's a strange little state.
615 *
616 * REVISIT the RNDIS gadget code has done this wrong for a
617 * very long time. We need another call to the link layer
618 * code -- gether_updown(...bool) maybe -- to do it right.
619 */
620 rndis->port.cdc_filter = 0;
621
622 DBG(cdev, "RNDIS RX/TX early activation ... \n");
623 net = gether_connect(&rndis->port);
624 if (IS_ERR(net))
625 return PTR_ERR(net);
626
627 rndis_set_param_dev(rndis->params, net,
628 &rndis->port.cdc_filter);
629 } else
630 goto fail;
631
632 return 0;
633 fail:
634 return -EINVAL;
635 }
636
rndis_disable(struct usb_function * f)637 static void rndis_disable(struct usb_function *f)
638 {
639 struct f_rndis *rndis = func_to_rndis(f);
640 struct usb_composite_dev *cdev = f->config->cdev;
641
642 if (!rndis->notify->enabled)
643 return;
644
645 DBG(cdev, "rndis deactivated\n");
646
647 rndis_uninit(rndis->params);
648 gether_disconnect(&rndis->port);
649
650 usb_ep_disable(rndis->notify);
651 rndis->notify->desc = NULL;
652 }
653
654 /*-------------------------------------------------------------------------*/
655
656 /*
657 * This isn't quite the same mechanism as CDC Ethernet, since the
658 * notification scheme passes less data, but the same set of link
659 * states must be tested. A key difference is that altsettings are
660 * not used to tell whether the link should send packets or not.
661 */
662
rndis_open(struct gether * geth)663 static void rndis_open(struct gether *geth)
664 {
665 struct f_rndis *rndis = func_to_rndis(&geth->func);
666 struct usb_composite_dev *cdev = geth->func.config->cdev;
667
668 DBG(cdev, "%s\n", __func__);
669
670 rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3,
671 bitrate(cdev->gadget) / 100);
672 rndis_signal_connect(rndis->params);
673 }
674
rndis_close(struct gether * geth)675 static void rndis_close(struct gether *geth)
676 {
677 struct f_rndis *rndis = func_to_rndis(&geth->func);
678
679 DBG(geth->func.config->cdev, "%s\n", __func__);
680
681 rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
682 rndis_signal_disconnect(rndis->params);
683 }
684
685 /*-------------------------------------------------------------------------*/
686
687 /* Some controllers can't support RNDIS ... */
can_support_rndis(struct usb_configuration * c)688 static inline bool can_support_rndis(struct usb_configuration *c)
689 {
690 /* everything else is *presumably* fine */
691 return true;
692 }
693
694 /* ethernet function driver setup/binding */
695
696 static int
rndis_bind(struct usb_configuration * c,struct usb_function * f)697 rndis_bind(struct usb_configuration *c, struct usb_function *f)
698 {
699 struct usb_composite_dev *cdev = c->cdev;
700 struct f_rndis *rndis = func_to_rndis(f);
701 struct usb_string *us;
702 int status;
703 struct usb_ep *ep;
704
705 struct f_rndis_opts *rndis_opts;
706
707 if (!can_support_rndis(c))
708 return -EINVAL;
709
710 rndis_opts = container_of(f->fi, struct f_rndis_opts, func_inst);
711
712 if (cdev->use_os_string) {
713 f->os_desc_table = kzalloc(sizeof(*f->os_desc_table),
714 GFP_KERNEL);
715 if (!f->os_desc_table)
716 return -ENOMEM;
717 f->os_desc_n = 1;
718 f->os_desc_table[0].os_desc = &rndis_opts->rndis_os_desc;
719 }
720
721 /*
722 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
723 * configurations are bound in sequence with list_for_each_entry,
724 * in each configuration its functions are bound in sequence
725 * with list_for_each_entry, so we assume no race condition
726 * with regard to rndis_opts->bound access
727 */
728 if (!rndis_opts->bound) {
729 gether_set_gadget(rndis_opts->net, cdev->gadget);
730 status = gether_register_netdev(rndis_opts->net);
731 if (status)
732 goto fail;
733 rndis_opts->bound = true;
734 }
735
736 us = usb_gstrings_attach(cdev, rndis_strings,
737 ARRAY_SIZE(rndis_string_defs));
738 if (IS_ERR(us)) {
739 status = PTR_ERR(us);
740 goto fail;
741 }
742 rndis_control_intf.iInterface = us[0].id;
743 rndis_data_intf.iInterface = us[1].id;
744 rndis_iad_descriptor.iFunction = us[2].id;
745
746 /* allocate instance-specific interface IDs */
747 status = usb_interface_id(c, f);
748 if (status < 0)
749 goto fail;
750 rndis->ctrl_id = status;
751 rndis_iad_descriptor.bFirstInterface = status;
752
753 rndis_control_intf.bInterfaceNumber = status;
754 rndis_union_desc.bMasterInterface0 = status;
755
756 if (cdev->use_os_string)
757 f->os_desc_table[0].if_id =
758 rndis_iad_descriptor.bFirstInterface;
759
760 status = usb_interface_id(c, f);
761 if (status < 0)
762 goto fail;
763 rndis->data_id = status;
764
765 rndis_data_intf.bInterfaceNumber = status;
766 rndis_union_desc.bSlaveInterface0 = status;
767
768 status = -ENODEV;
769
770 /* allocate instance-specific endpoints */
771 ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
772 if (!ep)
773 goto fail;
774 rndis->port.in_ep = ep;
775
776 ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
777 if (!ep)
778 goto fail;
779 rndis->port.out_ep = ep;
780
781 /* NOTE: a status/notification endpoint is, strictly speaking,
782 * optional. We don't treat it that way though! It's simpler,
783 * and some newer profiles don't treat it as optional.
784 */
785 ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
786 if (!ep)
787 goto fail;
788 rndis->notify = ep;
789
790 status = -ENOMEM;
791
792 /* allocate notification request and buffer */
793 rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
794 if (!rndis->notify_req)
795 goto fail;
796 rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
797 if (!rndis->notify_req->buf)
798 goto fail;
799 rndis->notify_req->length = STATUS_BYTECOUNT;
800 rndis->notify_req->context = rndis;
801 rndis->notify_req->complete = rndis_response_complete;
802
803 /* support all relevant hardware speeds... we expect that when
804 * hardware is dual speed, all bulk-capable endpoints work at
805 * both speeds
806 */
807 hs_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
808 hs_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
809 hs_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
810
811 ss_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
812 ss_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
813 ss_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
814
815 status = usb_assign_descriptors(f, eth_fs_function, eth_hs_function,
816 eth_ss_function);
817 if (status)
818 goto fail;
819
820 rndis->port.open = rndis_open;
821 rndis->port.close = rndis_close;
822
823 rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
824 rndis_set_host_mac(rndis->params, rndis->ethaddr);
825 rndis_set_max_pkt_xfer(rndis->params, rndis_ul_max_pkt_per_xfer);
826
827 if (rndis->manufacturer && rndis->vendorID &&
828 rndis_set_param_vendor(rndis->params, rndis->vendorID,
829 rndis->manufacturer)) {
830 status = -EINVAL;
831 goto fail_free_descs;
832 }
833
834 /* NOTE: all that is done without knowing or caring about
835 * the network link ... which is unavailable to this code
836 * until we're activated via set_alt().
837 */
838
839 DBG(cdev, "RNDIS: %s speed IN/%s OUT/%s NOTIFY/%s\n",
840 gadget_is_superspeed(c->cdev->gadget) ? "super" :
841 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
842 rndis->port.in_ep->name, rndis->port.out_ep->name,
843 rndis->notify->name);
844 return 0;
845
846 fail_free_descs:
847 usb_free_all_descriptors(f);
848 fail:
849 kfree(f->os_desc_table);
850 f->os_desc_n = 0;
851
852 if (rndis->notify_req) {
853 kfree(rndis->notify_req->buf);
854 usb_ep_free_request(rndis->notify, rndis->notify_req);
855 }
856
857 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
858
859 return status;
860 }
861
rndis_borrow_net(struct usb_function_instance * f,struct net_device * net)862 void rndis_borrow_net(struct usb_function_instance *f, struct net_device *net)
863 {
864 struct f_rndis_opts *opts;
865
866 opts = container_of(f, struct f_rndis_opts, func_inst);
867 if (opts->bound)
868 gether_cleanup(netdev_priv(opts->net));
869 else
870 free_netdev(opts->net);
871 opts->borrowed_net = opts->bound = true;
872 opts->net = net;
873 }
874 EXPORT_SYMBOL_GPL(rndis_borrow_net);
875
to_f_rndis_opts(struct config_item * item)876 static inline struct f_rndis_opts *to_f_rndis_opts(struct config_item *item)
877 {
878 return container_of(to_config_group(item), struct f_rndis_opts,
879 func_inst.group);
880 }
881
882 /* f_rndis_item_ops */
883 USB_ETHERNET_CONFIGFS_ITEM(rndis);
884
885 /* f_rndis_opts_dev_addr */
886 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(rndis);
887
888 /* f_rndis_opts_host_addr */
889 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(rndis);
890
891 /* f_rndis_opts_qmult */
892 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(rndis);
893
894 /* f_rndis_opts_ifname */
895 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(rndis);
896
897 static struct configfs_attribute *rndis_attrs[] = {
898 &rndis_opts_attr_dev_addr,
899 &rndis_opts_attr_host_addr,
900 &rndis_opts_attr_qmult,
901 &rndis_opts_attr_ifname,
902 NULL,
903 };
904
905 static struct config_item_type rndis_func_type = {
906 .ct_item_ops = &rndis_item_ops,
907 .ct_attrs = rndis_attrs,
908 .ct_owner = THIS_MODULE,
909 };
910
rndis_free_inst(struct usb_function_instance * f)911 static void rndis_free_inst(struct usb_function_instance *f)
912 {
913 struct f_rndis_opts *opts;
914
915 opts = container_of(f, struct f_rndis_opts, func_inst);
916 if (!opts->borrowed_net) {
917 if (opts->bound)
918 gether_cleanup(netdev_priv(opts->net));
919 else
920 free_netdev(opts->net);
921 }
922
923 kfree(opts->rndis_os_desc.group.default_groups); /* single VLA chunk */
924 kfree(opts);
925 }
926
rndis_alloc_inst(void)927 static struct usb_function_instance *rndis_alloc_inst(void)
928 {
929 struct f_rndis_opts *opts;
930 struct usb_os_desc *descs[1];
931 char *names[1];
932
933 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
934 if (!opts)
935 return ERR_PTR(-ENOMEM);
936 opts->rndis_os_desc.ext_compat_id = opts->rndis_ext_compat_id;
937
938 mutex_init(&opts->lock);
939 opts->func_inst.free_func_inst = rndis_free_inst;
940 opts->net = gether_setup_default();
941 if (IS_ERR(opts->net)) {
942 struct net_device *net = opts->net;
943 kfree(opts);
944 return ERR_CAST(net);
945 }
946 INIT_LIST_HEAD(&opts->rndis_os_desc.ext_prop);
947
948 descs[0] = &opts->rndis_os_desc;
949 names[0] = "rndis";
950 usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs,
951 names, THIS_MODULE);
952 config_group_init_type_name(&opts->func_inst.group, "",
953 &rndis_func_type);
954
955 return &opts->func_inst;
956 }
957
rndis_free(struct usb_function * f)958 static void rndis_free(struct usb_function *f)
959 {
960 struct f_rndis *rndis;
961 struct f_rndis_opts *opts;
962
963 rndis = func_to_rndis(f);
964 rndis_deregister(rndis->params);
965 opts = container_of(f->fi, struct f_rndis_opts, func_inst);
966 kfree(rndis);
967 mutex_lock(&opts->lock);
968 opts->refcnt--;
969 mutex_unlock(&opts->lock);
970 }
971
rndis_unbind(struct usb_configuration * c,struct usb_function * f)972 static void rndis_unbind(struct usb_configuration *c, struct usb_function *f)
973 {
974 struct f_rndis *rndis = func_to_rndis(f);
975
976 kfree(f->os_desc_table);
977 f->os_desc_n = 0;
978 usb_free_all_descriptors(f);
979
980 kfree(rndis->notify_req->buf);
981 usb_ep_free_request(rndis->notify, rndis->notify_req);
982 }
983
rndis_alloc(struct usb_function_instance * fi)984 static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
985 {
986 struct f_rndis *rndis;
987 struct f_rndis_opts *opts;
988 struct rndis_params *params;
989
990 /* allocate and initialize one new instance */
991 rndis = kzalloc(sizeof(*rndis), GFP_KERNEL);
992 if (!rndis)
993 return ERR_PTR(-ENOMEM);
994
995 opts = container_of(fi, struct f_rndis_opts, func_inst);
996 mutex_lock(&opts->lock);
997 opts->refcnt++;
998
999 gether_get_host_addr_u8(opts->net, rndis->ethaddr);
1000 rndis->vendorID = opts->vendor_id;
1001 rndis->manufacturer = opts->manufacturer;
1002
1003 rndis->port.ioport = netdev_priv(opts->net);
1004 mutex_unlock(&opts->lock);
1005 /* RNDIS activates when the host changes this filter */
1006 rndis->port.cdc_filter = 0;
1007
1008 /* RNDIS has special (and complex) framing */
1009 rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
1010 rndis->port.wrap = rndis_add_header;
1011 rndis->port.unwrap = rndis_rm_hdr;
1012 rndis->port.ul_max_pkts_per_xfer = rndis_ul_max_pkt_per_xfer;
1013 rndis->port.dl_max_pkts_per_xfer = rndis_dl_max_pkt_per_xfer;
1014
1015 rndis->port.func.name = "rndis";
1016 /* descriptors are per-instance copies */
1017 rndis->port.func.bind = rndis_bind;
1018 rndis->port.func.unbind = rndis_unbind;
1019 rndis->port.func.set_alt = rndis_set_alt;
1020 rndis->port.func.setup = rndis_setup;
1021 rndis->port.func.disable = rndis_disable;
1022 rndis->port.func.free_func = rndis_free;
1023
1024 params = rndis_register(rndis_response_available, rndis);
1025 if (IS_ERR(params)) {
1026 kfree(rndis);
1027 return ERR_CAST(params);
1028 }
1029 rndis->params = params;
1030
1031 return &rndis->port.func;
1032 }
1033
1034 DECLARE_USB_FUNCTION_INIT(rndis, rndis_alloc_inst, rndis_alloc);
1035 MODULE_LICENSE("GPL");
1036 MODULE_AUTHOR("David Brownell");
1037