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 int config;
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)
105 return 13 * 1024 * 8 * 1000 * 8;
106 else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
107 return 13 * 512 * 8 * 1000 * 8;
108 else
109 return 19 * 64 * 1 * 1000 * 8;
110 }
111
112 /*-------------------------------------------------------------------------*/
113
114 /*
115 */
116
117 #define RNDIS_STATUS_INTERVAL_MS 32
118 #define STATUS_BYTECOUNT 8 /* 8 bytes data */
119
120
121 /* interface descriptor: */
122
123 static struct usb_interface_descriptor rndis_control_intf = {
124 .bLength = sizeof rndis_control_intf,
125 .bDescriptorType = USB_DT_INTERFACE,
126
127 /* .bInterfaceNumber = DYNAMIC */
128 /* status endpoint is optional; this could be patched later */
129 .bNumEndpoints = 1,
130 .bInterfaceClass = USB_CLASS_COMM,
131 .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
132 .bInterfaceProtocol = USB_CDC_ACM_PROTO_VENDOR,
133 /* .iInterface = DYNAMIC */
134 };
135
136 static struct usb_cdc_header_desc header_desc = {
137 .bLength = sizeof header_desc,
138 .bDescriptorType = USB_DT_CS_INTERFACE,
139 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
140
141 .bcdCDC = cpu_to_le16(0x0110),
142 };
143
144 static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor = {
145 .bLength = sizeof call_mgmt_descriptor,
146 .bDescriptorType = USB_DT_CS_INTERFACE,
147 .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE,
148
149 .bmCapabilities = 0x00,
150 .bDataInterface = 0x01,
151 };
152
153 static struct usb_cdc_acm_descriptor rndis_acm_descriptor = {
154 .bLength = sizeof rndis_acm_descriptor,
155 .bDescriptorType = USB_DT_CS_INTERFACE,
156 .bDescriptorSubType = USB_CDC_ACM_TYPE,
157
158 .bmCapabilities = 0x00,
159 };
160
161 static struct usb_cdc_union_desc rndis_union_desc = {
162 .bLength = sizeof(rndis_union_desc),
163 .bDescriptorType = USB_DT_CS_INTERFACE,
164 .bDescriptorSubType = USB_CDC_UNION_TYPE,
165 /* .bMasterInterface0 = DYNAMIC */
166 /* .bSlaveInterface0 = DYNAMIC */
167 };
168
169 /* the data interface has two bulk endpoints */
170
171 static struct usb_interface_descriptor rndis_data_intf = {
172 .bLength = sizeof rndis_data_intf,
173 .bDescriptorType = USB_DT_INTERFACE,
174
175 /* .bInterfaceNumber = DYNAMIC */
176 .bNumEndpoints = 2,
177 .bInterfaceClass = USB_CLASS_CDC_DATA,
178 .bInterfaceSubClass = 0,
179 .bInterfaceProtocol = 0,
180 /* .iInterface = DYNAMIC */
181 };
182
183
184 static struct usb_interface_assoc_descriptor
185 rndis_iad_descriptor = {
186 .bLength = sizeof rndis_iad_descriptor,
187 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
188
189 .bFirstInterface = 0, /* XXX, hardcoded */
190 .bInterfaceCount = 2, // control + data
191 .bFunctionClass = USB_CLASS_COMM,
192 .bFunctionSubClass = USB_CDC_SUBCLASS_ETHERNET,
193 .bFunctionProtocol = USB_CDC_PROTO_NONE,
194 /* .iFunction = DYNAMIC */
195 };
196
197 /* full speed support: */
198
199 static struct usb_endpoint_descriptor fs_notify_desc = {
200 .bLength = USB_DT_ENDPOINT_SIZE,
201 .bDescriptorType = USB_DT_ENDPOINT,
202
203 .bEndpointAddress = USB_DIR_IN,
204 .bmAttributes = USB_ENDPOINT_XFER_INT,
205 .wMaxPacketSize = cpu_to_le16(STATUS_BYTECOUNT),
206 .bInterval = RNDIS_STATUS_INTERVAL_MS,
207 };
208
209 static struct usb_endpoint_descriptor fs_in_desc = {
210 .bLength = USB_DT_ENDPOINT_SIZE,
211 .bDescriptorType = USB_DT_ENDPOINT,
212
213 .bEndpointAddress = USB_DIR_IN,
214 .bmAttributes = USB_ENDPOINT_XFER_BULK,
215 };
216
217 static struct usb_endpoint_descriptor fs_out_desc = {
218 .bLength = USB_DT_ENDPOINT_SIZE,
219 .bDescriptorType = USB_DT_ENDPOINT,
220
221 .bEndpointAddress = USB_DIR_OUT,
222 .bmAttributes = USB_ENDPOINT_XFER_BULK,
223 };
224
225 static struct usb_descriptor_header *eth_fs_function[] = {
226 (struct usb_descriptor_header *) &rndis_iad_descriptor,
227
228 /* control interface matches ACM, not Ethernet */
229 (struct usb_descriptor_header *) &rndis_control_intf,
230 (struct usb_descriptor_header *) &header_desc,
231 (struct usb_descriptor_header *) &call_mgmt_descriptor,
232 (struct usb_descriptor_header *) &rndis_acm_descriptor,
233 (struct usb_descriptor_header *) &rndis_union_desc,
234 (struct usb_descriptor_header *) &fs_notify_desc,
235
236 /* data interface has no altsetting */
237 (struct usb_descriptor_header *) &rndis_data_intf,
238 (struct usb_descriptor_header *) &fs_in_desc,
239 (struct usb_descriptor_header *) &fs_out_desc,
240 NULL,
241 };
242
243 /* high speed support: */
244
245 static struct usb_endpoint_descriptor hs_notify_desc = {
246 .bLength = USB_DT_ENDPOINT_SIZE,
247 .bDescriptorType = USB_DT_ENDPOINT,
248
249 .bEndpointAddress = USB_DIR_IN,
250 .bmAttributes = USB_ENDPOINT_XFER_INT,
251 .wMaxPacketSize = cpu_to_le16(STATUS_BYTECOUNT),
252 .bInterval = USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
253 };
254
255 static struct usb_endpoint_descriptor hs_in_desc = {
256 .bLength = USB_DT_ENDPOINT_SIZE,
257 .bDescriptorType = USB_DT_ENDPOINT,
258
259 .bEndpointAddress = USB_DIR_IN,
260 .bmAttributes = USB_ENDPOINT_XFER_BULK,
261 .wMaxPacketSize = cpu_to_le16(512),
262 };
263
264 static struct usb_endpoint_descriptor hs_out_desc = {
265 .bLength = USB_DT_ENDPOINT_SIZE,
266 .bDescriptorType = USB_DT_ENDPOINT,
267
268 .bEndpointAddress = USB_DIR_OUT,
269 .bmAttributes = USB_ENDPOINT_XFER_BULK,
270 .wMaxPacketSize = cpu_to_le16(512),
271 };
272
273 static struct usb_descriptor_header *eth_hs_function[] = {
274 (struct usb_descriptor_header *) &rndis_iad_descriptor,
275
276 /* control interface matches ACM, not Ethernet */
277 (struct usb_descriptor_header *) &rndis_control_intf,
278 (struct usb_descriptor_header *) &header_desc,
279 (struct usb_descriptor_header *) &call_mgmt_descriptor,
280 (struct usb_descriptor_header *) &rndis_acm_descriptor,
281 (struct usb_descriptor_header *) &rndis_union_desc,
282 (struct usb_descriptor_header *) &hs_notify_desc,
283
284 /* data interface has no altsetting */
285 (struct usb_descriptor_header *) &rndis_data_intf,
286 (struct usb_descriptor_header *) &hs_in_desc,
287 (struct usb_descriptor_header *) &hs_out_desc,
288 NULL,
289 };
290
291 /* super speed support: */
292
293 static struct usb_endpoint_descriptor ss_notify_desc = {
294 .bLength = USB_DT_ENDPOINT_SIZE,
295 .bDescriptorType = USB_DT_ENDPOINT,
296
297 .bEndpointAddress = USB_DIR_IN,
298 .bmAttributes = USB_ENDPOINT_XFER_INT,
299 .wMaxPacketSize = cpu_to_le16(STATUS_BYTECOUNT),
300 .bInterval = USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
301 };
302
303 static struct usb_ss_ep_comp_descriptor ss_intr_comp_desc = {
304 .bLength = sizeof ss_intr_comp_desc,
305 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
306
307 /* the following 3 values can be tweaked if necessary */
308 /* .bMaxBurst = 0, */
309 /* .bmAttributes = 0, */
310 .wBytesPerInterval = cpu_to_le16(STATUS_BYTECOUNT),
311 };
312
313 static struct usb_endpoint_descriptor ss_in_desc = {
314 .bLength = USB_DT_ENDPOINT_SIZE,
315 .bDescriptorType = USB_DT_ENDPOINT,
316
317 .bEndpointAddress = USB_DIR_IN,
318 .bmAttributes = USB_ENDPOINT_XFER_BULK,
319 .wMaxPacketSize = cpu_to_le16(1024),
320 };
321
322 static struct usb_endpoint_descriptor ss_out_desc = {
323 .bLength = USB_DT_ENDPOINT_SIZE,
324 .bDescriptorType = USB_DT_ENDPOINT,
325
326 .bEndpointAddress = USB_DIR_OUT,
327 .bmAttributes = USB_ENDPOINT_XFER_BULK,
328 .wMaxPacketSize = cpu_to_le16(1024),
329 };
330
331 static struct usb_ss_ep_comp_descriptor ss_bulk_comp_desc = {
332 .bLength = sizeof ss_bulk_comp_desc,
333 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
334
335 /* the following 2 values can be tweaked if necessary */
336 /* .bMaxBurst = 0, */
337 /* .bmAttributes = 0, */
338 };
339
340 static struct usb_descriptor_header *eth_ss_function[] = {
341 (struct usb_descriptor_header *) &rndis_iad_descriptor,
342
343 /* control interface matches ACM, not Ethernet */
344 (struct usb_descriptor_header *) &rndis_control_intf,
345 (struct usb_descriptor_header *) &header_desc,
346 (struct usb_descriptor_header *) &call_mgmt_descriptor,
347 (struct usb_descriptor_header *) &rndis_acm_descriptor,
348 (struct usb_descriptor_header *) &rndis_union_desc,
349 (struct usb_descriptor_header *) &ss_notify_desc,
350 (struct usb_descriptor_header *) &ss_intr_comp_desc,
351
352 /* data interface has no altsetting */
353 (struct usb_descriptor_header *) &rndis_data_intf,
354 (struct usb_descriptor_header *) &ss_in_desc,
355 (struct usb_descriptor_header *) &ss_bulk_comp_desc,
356 (struct usb_descriptor_header *) &ss_out_desc,
357 (struct usb_descriptor_header *) &ss_bulk_comp_desc,
358 NULL,
359 };
360
361 /* string descriptors: */
362
363 static struct usb_string rndis_string_defs[] = {
364 [0].s = "RNDIS Communications Control",
365 [1].s = "RNDIS Ethernet Data",
366 [2].s = "RNDIS",
367 { } /* end of list */
368 };
369
370 static struct usb_gadget_strings rndis_string_table = {
371 .language = 0x0409, /* en-us */
372 .strings = rndis_string_defs,
373 };
374
375 static struct usb_gadget_strings *rndis_strings[] = {
376 &rndis_string_table,
377 NULL,
378 };
379
380 /*-------------------------------------------------------------------------*/
381
rndis_add_header(struct gether * port,struct sk_buff * skb)382 static struct sk_buff *rndis_add_header(struct gether *port,
383 struct sk_buff *skb)
384 {
385 struct sk_buff *skb2;
386
387 skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
388 if (skb2)
389 rndis_add_hdr(skb2);
390
391 dev_kfree_skb(skb);
392 return skb2;
393 }
394
rndis_response_available(void * _rndis)395 static void rndis_response_available(void *_rndis)
396 {
397 struct f_rndis *rndis = _rndis;
398 struct usb_request *req = rndis->notify_req;
399 struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
400 __le32 *data = req->buf;
401 int status;
402
403 if (atomic_inc_return(&rndis->notify_count) != 1)
404 return;
405
406 /* Send RNDIS RESPONSE_AVAILABLE notification; a
407 * USB_CDC_NOTIFY_RESPONSE_AVAILABLE "should" work too
408 *
409 * This is the only notification defined by RNDIS.
410 */
411 data[0] = cpu_to_le32(1);
412 data[1] = cpu_to_le32(0);
413
414 status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
415 if (status) {
416 atomic_dec(&rndis->notify_count);
417 DBG(cdev, "notify/0 --> %d\n", status);
418 }
419 }
420
rndis_response_complete(struct usb_ep * ep,struct usb_request * req)421 static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
422 {
423 struct f_rndis *rndis = req->context;
424 struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
425 int status = req->status;
426
427 /* after TX:
428 * - USB_CDC_GET_ENCAPSULATED_RESPONSE (ep0/control)
429 * - RNDIS_RESPONSE_AVAILABLE (status/irq)
430 */
431 switch (status) {
432 case -ECONNRESET:
433 case -ESHUTDOWN:
434 /* connection gone */
435 atomic_set(&rndis->notify_count, 0);
436 break;
437 default:
438 DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
439 ep->name, status,
440 req->actual, req->length);
441 /* FALLTHROUGH */
442 case 0:
443 if (ep != rndis->notify)
444 break;
445
446 /* handle multiple pending RNDIS_RESPONSE_AVAILABLE
447 * notifications by resending until we're done
448 */
449 if (atomic_dec_and_test(&rndis->notify_count))
450 break;
451 status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
452 if (status) {
453 atomic_dec(&rndis->notify_count);
454 DBG(cdev, "notify/1 --> %d\n", status);
455 }
456 break;
457 }
458 }
459
rndis_command_complete(struct usb_ep * ep,struct usb_request * req)460 static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
461 {
462 struct f_rndis *rndis = req->context;
463 int status;
464 rndis_init_msg_type *buf;
465
466 /* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
467 // spin_lock(&dev->lock);
468 status = rndis_msg_parser(rndis->config, (u8 *) req->buf);
469 if (status < 0)
470 pr_err("RNDIS command error %d, %d/%d\n",
471 status, req->actual, req->length);
472
473 buf = (rndis_init_msg_type *)req->buf;
474
475 if (buf->MessageType == RNDIS_MSG_INIT) {
476 if (buf->MaxTransferSize > 2048)
477 rndis->port.multi_pkt_xfer = 1;
478 else
479 rndis->port.multi_pkt_xfer = 0;
480 pr_info("%s: MaxTransferSize: %d : Multi_pkt_txr: %s\n",
481 __func__, buf->MaxTransferSize,
482 rndis->port.multi_pkt_xfer ? "enabled" :
483 "disabled");
484 if (rndis_dl_max_pkt_per_xfer <= 1)
485 rndis->port.multi_pkt_xfer = 0;
486 }
487 // spin_unlock(&dev->lock);
488 }
489
490 static int
rndis_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)491 rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
492 {
493 struct f_rndis *rndis = func_to_rndis(f);
494 struct usb_composite_dev *cdev = f->config->cdev;
495 struct usb_request *req = cdev->req;
496 int value = -EOPNOTSUPP;
497 u16 w_index = le16_to_cpu(ctrl->wIndex);
498 u16 w_value = le16_to_cpu(ctrl->wValue);
499 u16 w_length = le16_to_cpu(ctrl->wLength);
500
501 /* composite driver infrastructure handles everything except
502 * CDC class messages; interface activation uses set_alt().
503 */
504 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
505
506 /* RNDIS uses the CDC command encapsulation mechanism to implement
507 * an RPC scheme, with much getting/setting of attributes by OID.
508 */
509 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
510 | USB_CDC_SEND_ENCAPSULATED_COMMAND:
511 if (w_value || w_index != rndis->ctrl_id)
512 goto invalid;
513 /* read the request; process it later */
514 value = w_length;
515 req->complete = rndis_command_complete;
516 req->context = rndis;
517 /* later, rndis_response_available() sends a notification */
518 break;
519
520 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
521 | USB_CDC_GET_ENCAPSULATED_RESPONSE:
522 if (w_value || w_index != rndis->ctrl_id)
523 goto invalid;
524 else {
525 u8 *buf;
526 u32 n;
527
528 /* return the result */
529 buf = rndis_get_next_response(rndis->config, &n);
530 if (buf) {
531 memcpy(req->buf, buf, n);
532 req->complete = rndis_response_complete;
533 req->context = rndis;
534 rndis_free_response(rndis->config, buf);
535 value = n;
536 }
537 /* else stalls ... spec says to avoid that */
538 }
539 break;
540
541 default:
542 invalid:
543 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
544 ctrl->bRequestType, ctrl->bRequest,
545 w_value, w_index, w_length);
546 }
547
548 /* respond with data transfer or status phase? */
549 if (value >= 0) {
550 DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
551 ctrl->bRequestType, ctrl->bRequest,
552 w_value, w_index, w_length);
553 req->zero = (value < w_length);
554 req->length = value;
555 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
556 if (value < 0)
557 ERROR(cdev, "rndis response on err %d\n", value);
558 }
559
560 /* device either stalls (value < 0) or reports success */
561 return value;
562 }
563
564
rndis_set_alt(struct usb_function * f,unsigned intf,unsigned alt)565 static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
566 {
567 struct f_rndis *rndis = func_to_rndis(f);
568 struct usb_composite_dev *cdev = f->config->cdev;
569
570 /* we know alt == 0 */
571
572 if (intf == rndis->ctrl_id) {
573 if (rndis->notify->driver_data) {
574 VDBG(cdev, "reset rndis control %d\n", intf);
575 usb_ep_disable(rndis->notify);
576 }
577 if (!rndis->notify->desc) {
578 VDBG(cdev, "init rndis ctrl %d\n", intf);
579 if (config_ep_by_speed(cdev->gadget, f, rndis->notify))
580 goto fail;
581 }
582 usb_ep_enable(rndis->notify);
583 rndis->notify->driver_data = rndis;
584
585 } else if (intf == rndis->data_id) {
586 struct net_device *net;
587
588 if (rndis->port.in_ep->driver_data) {
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->config, 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->driver_data)
643 return;
644
645 DBG(cdev, "rndis deactivated\n");
646
647 rndis_uninit(rndis->config);
648 gether_disconnect(&rndis->port);
649
650 usb_ep_disable(rndis->notify);
651 rndis->notify->driver_data = 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->config, RNDIS_MEDIUM_802_3,
671 bitrate(cdev->gadget) / 100);
672 rndis_signal_connect(rndis->config);
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->config, RNDIS_MEDIUM_802_3, 0);
682 rndis_signal_disconnect(rndis->config);
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 ep->driver_data = cdev; /* claim */
776
777 ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
778 if (!ep)
779 goto fail;
780 rndis->port.out_ep = ep;
781 ep->driver_data = cdev; /* claim */
782
783 /* NOTE: a status/notification endpoint is, strictly speaking,
784 * optional. We don't treat it that way though! It's simpler,
785 * and some newer profiles don't treat it as optional.
786 */
787 ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
788 if (!ep)
789 goto fail;
790 rndis->notify = ep;
791 ep->driver_data = cdev; /* claim */
792
793 status = -ENOMEM;
794
795 /* allocate notification request and buffer */
796 rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
797 if (!rndis->notify_req)
798 goto fail;
799 rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
800 if (!rndis->notify_req->buf)
801 goto fail;
802 rndis->notify_req->length = STATUS_BYTECOUNT;
803 rndis->notify_req->context = rndis;
804 rndis->notify_req->complete = rndis_response_complete;
805
806 /* support all relevant hardware speeds... we expect that when
807 * hardware is dual speed, all bulk-capable endpoints work at
808 * both speeds
809 */
810 hs_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
811 hs_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
812 hs_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
813
814 ss_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
815 ss_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
816 ss_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
817
818 status = usb_assign_descriptors(f, eth_fs_function, eth_hs_function,
819 eth_ss_function);
820 if (status)
821 goto fail;
822
823 rndis->port.open = rndis_open;
824 rndis->port.close = rndis_close;
825
826 rndis_set_param_medium(rndis->config, RNDIS_MEDIUM_802_3, 0);
827 rndis_set_host_mac(rndis->config, rndis->ethaddr);
828 rndis_set_max_pkt_xfer(rndis->config, rndis_ul_max_pkt_per_xfer);
829
830 if (rndis->manufacturer && rndis->vendorID &&
831 rndis_set_param_vendor(rndis->config, rndis->vendorID,
832 rndis->manufacturer)) {
833 status = -EINVAL;
834 goto fail_free_descs;
835 }
836
837 /* NOTE: all that is done without knowing or caring about
838 * the network link ... which is unavailable to this code
839 * until we're activated via set_alt().
840 */
841
842 DBG(cdev, "RNDIS: %s speed IN/%s OUT/%s NOTIFY/%s\n",
843 gadget_is_superspeed(c->cdev->gadget) ? "super" :
844 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
845 rndis->port.in_ep->name, rndis->port.out_ep->name,
846 rndis->notify->name);
847 return 0;
848
849 fail_free_descs:
850 usb_free_all_descriptors(f);
851 fail:
852 kfree(f->os_desc_table);
853 f->os_desc_n = 0;
854
855 if (rndis->notify_req) {
856 kfree(rndis->notify_req->buf);
857 usb_ep_free_request(rndis->notify, rndis->notify_req);
858 }
859
860 /* we might as well release our claims on endpoints */
861 if (rndis->notify)
862 rndis->notify->driver_data = NULL;
863 if (rndis->port.out_ep)
864 rndis->port.out_ep->driver_data = NULL;
865 if (rndis->port.in_ep)
866 rndis->port.in_ep->driver_data = NULL;
867
868 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
869
870 return status;
871 }
872
rndis_borrow_net(struct usb_function_instance * f,struct net_device * net)873 void rndis_borrow_net(struct usb_function_instance *f, struct net_device *net)
874 {
875 struct f_rndis_opts *opts;
876
877 opts = container_of(f, struct f_rndis_opts, func_inst);
878 if (opts->bound)
879 gether_cleanup(netdev_priv(opts->net));
880 else
881 free_netdev(opts->net);
882 opts->borrowed_net = opts->bound = true;
883 opts->net = net;
884 }
885 EXPORT_SYMBOL_GPL(rndis_borrow_net);
886
to_f_rndis_opts(struct config_item * item)887 static inline struct f_rndis_opts *to_f_rndis_opts(struct config_item *item)
888 {
889 return container_of(to_config_group(item), struct f_rndis_opts,
890 func_inst.group);
891 }
892
893 /* f_rndis_item_ops */
894 USB_ETHERNET_CONFIGFS_ITEM(rndis);
895
896 /* f_rndis_opts_dev_addr */
897 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(rndis);
898
899 /* f_rndis_opts_host_addr */
900 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(rndis);
901
902 /* f_rndis_opts_qmult */
903 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(rndis);
904
905 /* f_rndis_opts_ifname */
906 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(rndis);
907
908 static struct configfs_attribute *rndis_attrs[] = {
909 &f_rndis_opts_dev_addr.attr,
910 &f_rndis_opts_host_addr.attr,
911 &f_rndis_opts_qmult.attr,
912 &f_rndis_opts_ifname.attr,
913 NULL,
914 };
915
916 static struct config_item_type rndis_func_type = {
917 .ct_item_ops = &rndis_item_ops,
918 .ct_attrs = rndis_attrs,
919 .ct_owner = THIS_MODULE,
920 };
921
rndis_free_inst(struct usb_function_instance * f)922 static void rndis_free_inst(struct usb_function_instance *f)
923 {
924 struct f_rndis_opts *opts;
925
926 opts = container_of(f, struct f_rndis_opts, func_inst);
927 if (!opts->borrowed_net) {
928 if (opts->bound)
929 gether_cleanup(netdev_priv(opts->net));
930 else
931 free_netdev(opts->net);
932 }
933
934 kfree(opts->rndis_os_desc.group.default_groups); /* single VLA chunk */
935 kfree(opts);
936 }
937
rndis_alloc_inst(void)938 static struct usb_function_instance *rndis_alloc_inst(void)
939 {
940 struct f_rndis_opts *opts;
941 struct usb_os_desc *descs[1];
942 char *names[1];
943
944 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
945 if (!opts)
946 return ERR_PTR(-ENOMEM);
947 opts->rndis_os_desc.ext_compat_id = opts->rndis_ext_compat_id;
948
949 mutex_init(&opts->lock);
950 opts->func_inst.free_func_inst = rndis_free_inst;
951 opts->net = gether_setup_default();
952 if (IS_ERR(opts->net)) {
953 struct net_device *net = opts->net;
954 kfree(opts);
955 return ERR_CAST(net);
956 }
957 INIT_LIST_HEAD(&opts->rndis_os_desc.ext_prop);
958
959 descs[0] = &opts->rndis_os_desc;
960 names[0] = "rndis";
961 usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs,
962 names, THIS_MODULE);
963 config_group_init_type_name(&opts->func_inst.group, "",
964 &rndis_func_type);
965
966 return &opts->func_inst;
967 }
968
rndis_free(struct usb_function * f)969 static void rndis_free(struct usb_function *f)
970 {
971 struct f_rndis *rndis;
972 struct f_rndis_opts *opts;
973
974 rndis = func_to_rndis(f);
975 rndis_deregister(rndis->config);
976 opts = container_of(f->fi, struct f_rndis_opts, func_inst);
977 kfree(rndis);
978 mutex_lock(&opts->lock);
979 opts->refcnt--;
980 mutex_unlock(&opts->lock);
981 }
982
rndis_unbind(struct usb_configuration * c,struct usb_function * f)983 static void rndis_unbind(struct usb_configuration *c, struct usb_function *f)
984 {
985 struct f_rndis *rndis = func_to_rndis(f);
986
987 kfree(f->os_desc_table);
988 f->os_desc_n = 0;
989 usb_free_all_descriptors(f);
990
991 kfree(rndis->notify_req->buf);
992 usb_ep_free_request(rndis->notify, rndis->notify_req);
993 }
994
rndis_alloc(struct usb_function_instance * fi)995 static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
996 {
997 struct f_rndis *rndis;
998 struct f_rndis_opts *opts;
999 int status;
1000
1001 /* allocate and initialize one new instance */
1002 rndis = kzalloc(sizeof(*rndis), GFP_KERNEL);
1003 if (!rndis)
1004 return ERR_PTR(-ENOMEM);
1005
1006 opts = container_of(fi, struct f_rndis_opts, func_inst);
1007 mutex_lock(&opts->lock);
1008 opts->refcnt++;
1009
1010 gether_get_host_addr_u8(opts->net, rndis->ethaddr);
1011 rndis->vendorID = opts->vendor_id;
1012 rndis->manufacturer = opts->manufacturer;
1013
1014 rndis->port.ioport = netdev_priv(opts->net);
1015 mutex_unlock(&opts->lock);
1016 /* RNDIS activates when the host changes this filter */
1017 rndis->port.cdc_filter = 0;
1018
1019 /* RNDIS has special (and complex) framing */
1020 rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
1021 rndis->port.wrap = rndis_add_header;
1022 rndis->port.unwrap = rndis_rm_hdr;
1023 rndis->port.ul_max_pkts_per_xfer = rndis_ul_max_pkt_per_xfer;
1024 rndis->port.dl_max_pkts_per_xfer = rndis_dl_max_pkt_per_xfer;
1025
1026 rndis->port.func.name = "rndis";
1027 /* descriptors are per-instance copies */
1028 rndis->port.func.bind = rndis_bind;
1029 rndis->port.func.unbind = rndis_unbind;
1030 rndis->port.func.set_alt = rndis_set_alt;
1031 rndis->port.func.setup = rndis_setup;
1032 rndis->port.func.disable = rndis_disable;
1033 rndis->port.func.free_func = rndis_free;
1034
1035 status = rndis_register(rndis_response_available, rndis);
1036 if (status < 0) {
1037 kfree(rndis);
1038 return ERR_PTR(status);
1039 }
1040 rndis->config = status;
1041
1042 return &rndis->port.func;
1043 }
1044
1045 DECLARE_USB_FUNCTION(rndis, rndis_alloc_inst, rndis_alloc);
1046
rndis_mod_init(void)1047 static int __init rndis_mod_init(void)
1048 {
1049 int ret;
1050
1051 ret = rndis_init();
1052 if (ret)
1053 return ret;
1054
1055 return usb_function_register(&rndisusb_func);
1056 }
1057 module_init(rndis_mod_init);
1058
rndis_mod_exit(void)1059 static void __exit rndis_mod_exit(void)
1060 {
1061 usb_function_unregister(&rndisusb_func);
1062 rndis_exit();
1063 }
1064 module_exit(rndis_mod_exit);
1065
1066 MODULE_LICENSE("GPL");
1067 MODULE_AUTHOR("David Brownell");
1068