blob: 99b840daf3d94d68083acfd8523ae0f8f4758350 [file] [log] [blame]
Googler9398cc32022-12-02 17:21:52 +08001// SPDX-License-Identifier: GPL-2.0+
Googleraf606d22022-10-26 21:40:12 -07002/*
3 * u_ether.c -- Ethernet-over-USB link layer utilities for Gadget stack
4 *
5 * Copyright (C) 2003-2005,2008 David Brownell
6 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
7 * Copyright (C) 2008 Nokia Corporation
Googleraf606d22022-10-26 21:40:12 -07008 */
9
10/* #define VERBOSE_DEBUG */
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/gfp.h>
15#include <linux/device.h>
16#include <linux/ctype.h>
17#include <linux/etherdevice.h>
18#include <linux/ethtool.h>
19#include <linux/if_vlan.h>
20
21#include "u_ether.h"
22
23
24/*
25 * This component encapsulates the Ethernet link glue needed to provide
26 * one (!) network link through the USB gadget stack, normally "usb0".
27 *
28 * The control and data models are handled by the function driver which
29 * connects to this code; such as CDC Ethernet (ECM or EEM),
30 * "CDC Subset", or RNDIS. That includes all descriptor and endpoint
31 * management.
32 *
33 * Link level addressing is handled by this component using module
34 * parameters; if no such parameters are provided, random link level
35 * addresses are used. Each end of the link uses one address. The
36 * host end address is exported in various ways, and is often recorded
37 * in configuration databases.
38 *
39 * The driver which assembles each configuration using such a link is
40 * responsible for ensuring that each configuration includes at most one
41 * instance of is network link. (The network layer provides ways for
42 * this single "physical" link to be used by multiple virtual links.)
43 */
44
45#define UETH__VERSION "29-May-2008"
46
47/* Experiments show that both Linux and Windows hosts allow up to 16k
Googler9398cc32022-12-02 17:21:52 +080048 * frame sizes. Set the max MTU size to 15k+52 to prevent allocating 32k
Googleraf606d22022-10-26 21:40:12 -070049 * blocks and still have efficient handling. */
Googler9398cc32022-12-02 17:21:52 +080050#define GETHER_MAX_MTU_SIZE 15412
51#define GETHER_MAX_ETH_FRAME_LEN (GETHER_MAX_MTU_SIZE + ETH_HLEN)
Googleraf606d22022-10-26 21:40:12 -070052
53struct eth_dev {
54 /* lock is held while accessing port_usb
55 */
56 spinlock_t lock;
57 struct gether *port_usb;
58
59 struct net_device *net;
60 struct usb_gadget *gadget;
61
62 spinlock_t req_lock; /* guard {rx,tx}_reqs */
63 struct list_head tx_reqs, rx_reqs;
64 atomic_t tx_qlen;
65
66 struct sk_buff_head rx_frames;
67
68 unsigned qmult;
69
70 unsigned header_len;
71 struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
72 int (*unwrap)(struct gether *,
73 struct sk_buff *skb,
74 struct sk_buff_head *list);
75
76 struct work_struct work;
77
78 unsigned long todo;
79#define WORK_RX_MEMORY 0
80
81 bool zlp;
82 bool no_skb_reserve;
83 u8 host_mac[ETH_ALEN];
84 u8 dev_mac[ETH_ALEN];
85};
86
87/*-------------------------------------------------------------------------*/
88
89#define RX_EXTRA 20 /* bytes guarding against rx overflows */
90
91#define DEFAULT_QLEN 2 /* double buffering by default */
92
93/* for dual-speed hardware, use deeper queues at high/super speed */
94static inline int qlen(struct usb_gadget *gadget, unsigned qmult)
95{
96 if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
97 gadget->speed >= USB_SPEED_SUPER))
98 return qmult * DEFAULT_QLEN;
99 else
100 return DEFAULT_QLEN;
101}
102
103/*-------------------------------------------------------------------------*/
104
105/* REVISIT there must be a better way than having two sets
106 * of debug calls ...
107 */
108
109#undef DBG
110#undef VDBG
111#undef ERROR
112#undef INFO
113
114#define xprintk(d, level, fmt, args...) \
115 printk(level "%s: " fmt , (d)->net->name , ## args)
116
117#ifdef DEBUG
118#undef DEBUG
119#define DBG(dev, fmt, args...) \
120 xprintk(dev , KERN_DEBUG , fmt , ## args)
121#else
122#define DBG(dev, fmt, args...) \
123 do { } while (0)
124#endif /* DEBUG */
125
126#ifdef VERBOSE_DEBUG
127#define VDBG DBG
128#else
129#define VDBG(dev, fmt, args...) \
130 do { } while (0)
131#endif /* DEBUG */
132
133#define ERROR(dev, fmt, args...) \
134 xprintk(dev , KERN_ERR , fmt , ## args)
135#define INFO(dev, fmt, args...) \
136 xprintk(dev , KERN_INFO , fmt , ## args)
137
138/*-------------------------------------------------------------------------*/
139
140/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
141
Googleraf606d22022-10-26 21:40:12 -0700142static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
143{
144 struct eth_dev *dev = netdev_priv(net);
145
146 strlcpy(p->driver, "g_ether", sizeof(p->driver));
147 strlcpy(p->version, UETH__VERSION, sizeof(p->version));
148 strlcpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version));
149 strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof(p->bus_info));
150}
151
152/* REVISIT can also support:
153 * - WOL (by tracking suspends and issuing remote wakeup)
154 * - msglevel (implies updated messaging)
155 * - ... probably more ethtool ops
156 */
157
158static const struct ethtool_ops ops = {
159 .get_drvinfo = eth_get_drvinfo,
160 .get_link = ethtool_op_get_link,
161};
162
163static void defer_kevent(struct eth_dev *dev, int flag)
164{
165 if (test_and_set_bit(flag, &dev->todo))
166 return;
167 if (!schedule_work(&dev->work))
168 ERROR(dev, "kevent %d may have been dropped\n", flag);
169 else
170 DBG(dev, "kevent %d scheduled\n", flag);
171}
172
173static void rx_complete(struct usb_ep *ep, struct usb_request *req);
174
175static int
176rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
177{
Googler9398cc32022-12-02 17:21:52 +0800178 struct usb_gadget *g = dev->gadget;
Googleraf606d22022-10-26 21:40:12 -0700179 struct sk_buff *skb;
180 int retval = -ENOMEM;
181 size_t size = 0;
182 struct usb_ep *out;
183 unsigned long flags;
184
185 spin_lock_irqsave(&dev->lock, flags);
186 if (dev->port_usb)
187 out = dev->port_usb->out_ep;
188 else
189 out = NULL;
190
191 if (!out)
192 {
193 spin_unlock_irqrestore(&dev->lock, flags);
194 return -ENOTCONN;
195 }
196
197 /* Padding up to RX_EXTRA handles minor disagreements with host.
198 * Normally we use the USB "terminate on short read" convention;
199 * so allow up to (N*maxpacket), since that memory is normally
200 * already allocated. Some hardware doesn't deal well with short
201 * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
202 * byte off the end (to force hardware errors on overflow).
203 *
204 * RNDIS uses internal framing, and explicitly allows senders to
205 * pad to end-of-packet. That's potentially nice for speed, but
206 * means receivers can't recover lost synch on their own (because
207 * new packets don't only start after a short RX).
208 */
209 size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
210 size += dev->port_usb->header_len;
Googler9398cc32022-12-02 17:21:52 +0800211
212 if (g->quirk_ep_out_aligned_size) {
213 size += out->maxpacket - 1;
214 size -= size % out->maxpacket;
215 }
Googleraf606d22022-10-26 21:40:12 -0700216
217 if (dev->port_usb->is_fixed)
218 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
219 spin_unlock_irqrestore(&dev->lock, flags);
220
Googler9398cc32022-12-02 17:21:52 +0800221 skb = __netdev_alloc_skb(dev->net, size + NET_IP_ALIGN, gfp_flags);
Googleraf606d22022-10-26 21:40:12 -0700222 if (skb == NULL) {
223 DBG(dev, "no rx skb\n");
224 goto enomem;
225 }
226
227 /* Some platforms perform better when IP packets are aligned,
228 * but on at least one, checksumming fails otherwise. Note:
229 * RNDIS headers involve variable numbers of LE32 values.
230 */
231 if (likely(!dev->no_skb_reserve))
232 skb_reserve(skb, NET_IP_ALIGN);
233
234 req->buf = skb->data;
235 req->length = size;
236 req->complete = rx_complete;
237 req->context = skb;
238
239 retval = usb_ep_queue(out, req, gfp_flags);
240 if (retval == -ENOMEM)
241enomem:
242 defer_kevent(dev, WORK_RX_MEMORY);
243 if (retval) {
244 DBG(dev, "rx submit --> %d\n", retval);
245 if (skb)
246 dev_kfree_skb_any(skb);
247 spin_lock_irqsave(&dev->req_lock, flags);
248 list_add(&req->list, &dev->rx_reqs);
249 spin_unlock_irqrestore(&dev->req_lock, flags);
250 }
251 return retval;
252}
253
254static void rx_complete(struct usb_ep *ep, struct usb_request *req)
255{
256 struct sk_buff *skb = req->context, *skb2;
257 struct eth_dev *dev = ep->driver_data;
258 int status = req->status;
259
260 switch (status) {
261
262 /* normal completion */
263 case 0:
264 skb_put(skb, req->actual);
265
266 if (dev->unwrap) {
267 unsigned long flags;
268
269 spin_lock_irqsave(&dev->lock, flags);
270 if (dev->port_usb) {
271 status = dev->unwrap(dev->port_usb,
272 skb,
273 &dev->rx_frames);
274 } else {
275 dev_kfree_skb_any(skb);
276 status = -ENOTCONN;
277 }
278 spin_unlock_irqrestore(&dev->lock, flags);
279 } else {
280 skb_queue_tail(&dev->rx_frames, skb);
281 }
282 skb = NULL;
283
284 skb2 = skb_dequeue(&dev->rx_frames);
285 while (skb2) {
286 if (status < 0
287 || ETH_HLEN > skb2->len
288 || skb2->len > GETHER_MAX_ETH_FRAME_LEN) {
289 dev->net->stats.rx_errors++;
290 dev->net->stats.rx_length_errors++;
291 DBG(dev, "rx length %d\n", skb2->len);
292 dev_kfree_skb_any(skb2);
293 goto next_frame;
294 }
295 skb2->protocol = eth_type_trans(skb2, dev->net);
296 dev->net->stats.rx_packets++;
297 dev->net->stats.rx_bytes += skb2->len;
298
299 /* no buffer copies needed, unless hardware can't
300 * use skb buffers.
301 */
302 status = netif_rx(skb2);
303next_frame:
304 skb2 = skb_dequeue(&dev->rx_frames);
305 }
306 break;
307
308 /* software-driven interface shutdown */
309 case -ECONNRESET: /* unlink */
310 case -ESHUTDOWN: /* disconnect etc */
311 VDBG(dev, "rx shutdown, code %d\n", status);
312 goto quiesce;
313
314 /* for hardware automagic (such as pxa) */
315 case -ECONNABORTED: /* endpoint reset */
316 DBG(dev, "rx %s reset\n", ep->name);
317 defer_kevent(dev, WORK_RX_MEMORY);
318quiesce:
319 dev_kfree_skb_any(skb);
320 goto clean;
321
322 /* data overrun */
323 case -EOVERFLOW:
324 dev->net->stats.rx_over_errors++;
325 /* FALLTHROUGH */
326
327 default:
328 dev->net->stats.rx_errors++;
329 DBG(dev, "rx status %d\n", status);
330 break;
331 }
332
333 if (skb)
334 dev_kfree_skb_any(skb);
335 if (!netif_running(dev->net)) {
336clean:
337 spin_lock(&dev->req_lock);
338 list_add(&req->list, &dev->rx_reqs);
339 spin_unlock(&dev->req_lock);
340 req = NULL;
341 }
342 if (req)
343 rx_submit(dev, req, GFP_ATOMIC);
344}
345
346static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
347{
348 unsigned i;
349 struct usb_request *req;
350
351 if (!n)
352 return -ENOMEM;
353
354 /* queue/recycle up to N requests */
355 i = n;
356 list_for_each_entry(req, list, list) {
357 if (i-- == 0)
358 goto extra;
359 }
360 while (i--) {
361 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
362 if (!req)
363 return list_empty(list) ? -ENOMEM : 0;
364 list_add(&req->list, list);
365 }
366 return 0;
367
368extra:
369 /* free extras */
370 for (;;) {
371 struct list_head *next;
372
373 next = req->list.next;
374 list_del(&req->list);
375 usb_ep_free_request(ep, req);
376
377 if (next == list)
378 break;
379
380 req = container_of(next, struct usb_request, list);
381 }
382 return 0;
383}
384
385static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
386{
387 int status;
388
389 spin_lock(&dev->req_lock);
390 status = prealloc(&dev->tx_reqs, link->in_ep, n);
391 if (status < 0)
392 goto fail;
393 status = prealloc(&dev->rx_reqs, link->out_ep, n);
394 if (status < 0)
395 goto fail;
396 goto done;
397fail:
398 DBG(dev, "can't alloc requests\n");
399done:
400 spin_unlock(&dev->req_lock);
401 return status;
402}
403
404static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
405{
406 struct usb_request *req;
407 unsigned long flags;
408
409 /* fill unused rxq slots with some skb */
410 spin_lock_irqsave(&dev->req_lock, flags);
411 while (!list_empty(&dev->rx_reqs)) {
Googler9398cc32022-12-02 17:21:52 +0800412 req = list_first_entry(&dev->rx_reqs, struct usb_request, list);
Googleraf606d22022-10-26 21:40:12 -0700413 list_del_init(&req->list);
414 spin_unlock_irqrestore(&dev->req_lock, flags);
415
416 if (rx_submit(dev, req, gfp_flags) < 0) {
417 defer_kevent(dev, WORK_RX_MEMORY);
418 return;
419 }
420
421 spin_lock_irqsave(&dev->req_lock, flags);
422 }
423 spin_unlock_irqrestore(&dev->req_lock, flags);
424}
425
426static void eth_work(struct work_struct *work)
427{
428 struct eth_dev *dev = container_of(work, struct eth_dev, work);
429
430 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
431 if (netif_running(dev->net))
432 rx_fill(dev, GFP_KERNEL);
433 }
434
435 if (dev->todo)
436 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
437}
438
439static void tx_complete(struct usb_ep *ep, struct usb_request *req)
440{
441 struct sk_buff *skb = req->context;
442 struct eth_dev *dev = ep->driver_data;
443
444 switch (req->status) {
445 default:
446 dev->net->stats.tx_errors++;
447 VDBG(dev, "tx err %d\n", req->status);
448 /* FALLTHROUGH */
449 case -ECONNRESET: /* unlink */
450 case -ESHUTDOWN: /* disconnect etc */
Googler9398cc32022-12-02 17:21:52 +0800451 dev_kfree_skb_any(skb);
Googleraf606d22022-10-26 21:40:12 -0700452 break;
453 case 0:
454 dev->net->stats.tx_bytes += skb->len;
Googler9398cc32022-12-02 17:21:52 +0800455 dev_consume_skb_any(skb);
Googleraf606d22022-10-26 21:40:12 -0700456 }
457 dev->net->stats.tx_packets++;
458
459 spin_lock(&dev->req_lock);
460 list_add(&req->list, &dev->tx_reqs);
461 spin_unlock(&dev->req_lock);
Googleraf606d22022-10-26 21:40:12 -0700462
463 atomic_dec(&dev->tx_qlen);
464 if (netif_carrier_ok(dev->net))
465 netif_wake_queue(dev->net);
466}
467
468static inline int is_promisc(u16 cdc_filter)
469{
470 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
471}
472
473static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
474 struct net_device *net)
475{
476 struct eth_dev *dev = netdev_priv(net);
477 int length = 0;
478 int retval;
479 struct usb_request *req = NULL;
480 unsigned long flags;
481 struct usb_ep *in;
482 u16 cdc_filter;
483
484 spin_lock_irqsave(&dev->lock, flags);
485 if (dev->port_usb) {
486 in = dev->port_usb->in_ep;
487 cdc_filter = dev->port_usb->cdc_filter;
488 } else {
489 in = NULL;
490 cdc_filter = 0;
491 }
492 spin_unlock_irqrestore(&dev->lock, flags);
493
Googlerb48fa912023-03-17 12:40:29 +0530494 if (skb && !in) {
495 dev_kfree_skb_any(skb);
Googleraf606d22022-10-26 21:40:12 -0700496 return NETDEV_TX_OK;
497 }
498
499 /* apply outgoing CDC or RNDIS filters */
500 if (skb && !is_promisc(cdc_filter)) {
501 u8 *dest = skb->data;
502
503 if (is_multicast_ether_addr(dest)) {
504 u16 type;
505
506 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
507 * SET_ETHERNET_MULTICAST_FILTERS requests
508 */
509 if (is_broadcast_ether_addr(dest))
510 type = USB_CDC_PACKET_TYPE_BROADCAST;
511 else
512 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
513 if (!(cdc_filter & type)) {
514 dev_kfree_skb_any(skb);
515 return NETDEV_TX_OK;
516 }
517 }
518 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
519 }
520
521 spin_lock_irqsave(&dev->req_lock, flags);
522 /*
523 * this freelist can be empty if an interrupt triggered disconnect()
524 * and reconfigured the gadget (shutting down this queue) after the
525 * network stack decided to xmit but before we got the spinlock.
526 */
527 if (list_empty(&dev->tx_reqs)) {
528 spin_unlock_irqrestore(&dev->req_lock, flags);
529 return NETDEV_TX_BUSY;
530 }
531
Googler9398cc32022-12-02 17:21:52 +0800532 req = list_first_entry(&dev->tx_reqs, struct usb_request, list);
Googleraf606d22022-10-26 21:40:12 -0700533 list_del(&req->list);
534
535 /* temporarily stop TX queue when the freelist empties */
536 if (list_empty(&dev->tx_reqs))
537 netif_stop_queue(net);
538 spin_unlock_irqrestore(&dev->req_lock, flags);
539
540 /* no buffer copies needed, unless the network stack did it
541 * or the hardware can't use skb buffers.
542 * or there's not enough space for extra headers we need
543 */
544 if (dev->wrap) {
545 unsigned long flags;
546
547 spin_lock_irqsave(&dev->lock, flags);
548 if (dev->port_usb)
549 skb = dev->wrap(dev->port_usb, skb);
550 spin_unlock_irqrestore(&dev->lock, flags);
551 if (!skb) {
552 /* Multi frame CDC protocols may store the frame for
553 * later which is not a dropped frame.
554 */
555 if (dev->port_usb &&
556 dev->port_usb->supports_multi_frame)
557 goto multiframe;
558 goto drop;
559 }
560 }
561
562 length = skb->len;
563 req->buf = skb->data;
564 req->context = skb;
565 req->complete = tx_complete;
566
567 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
568 if (dev->port_usb &&
569 dev->port_usb->is_fixed &&
570 length == dev->port_usb->fixed_in_len &&
571 (length % in->maxpacket) == 0)
572 req->zero = 0;
573 else
574 req->zero = 1;
575
576 /* use zlp framing on tx for strict CDC-Ether conformance,
577 * though any robust network rx path ignores extra padding.
578 * and some hardware doesn't like to write zlps.
579 */
580 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
581 length++;
582
583 req->length = length;
584
585 retval = usb_ep_queue(in, req, GFP_ATOMIC);
586 switch (retval) {
587 default:
588 DBG(dev, "tx queue err %d\n", retval);
589 break;
590 case 0:
591 netif_trans_update(net);
592 atomic_inc(&dev->tx_qlen);
593 }
594
595 if (retval) {
596 dev_kfree_skb_any(skb);
597drop:
598 dev->net->stats.tx_dropped++;
599multiframe:
600 spin_lock_irqsave(&dev->req_lock, flags);
601 if (list_empty(&dev->tx_reqs))
602 netif_start_queue(net);
603 list_add(&req->list, &dev->tx_reqs);
604 spin_unlock_irqrestore(&dev->req_lock, flags);
605 }
606 return NETDEV_TX_OK;
607}
608
609/*-------------------------------------------------------------------------*/
610
611static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
612{
613 DBG(dev, "%s\n", __func__);
614
615 /* fill the rx queue */
616 rx_fill(dev, gfp_flags);
617
618 /* and open the tx floodgates */
619 atomic_set(&dev->tx_qlen, 0);
620 netif_wake_queue(dev->net);
621}
622
623static int eth_open(struct net_device *net)
624{
625 struct eth_dev *dev = netdev_priv(net);
626 struct gether *link;
627
628 DBG(dev, "%s\n", __func__);
629 if (netif_carrier_ok(dev->net))
630 eth_start(dev, GFP_KERNEL);
631
632 spin_lock_irq(&dev->lock);
633 link = dev->port_usb;
634 if (link && link->open)
635 link->open(link);
636 spin_unlock_irq(&dev->lock);
637
638 return 0;
639}
640
641static int eth_stop(struct net_device *net)
642{
643 struct eth_dev *dev = netdev_priv(net);
644 unsigned long flags;
645
646 VDBG(dev, "%s\n", __func__);
647 netif_stop_queue(net);
648
649 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
650 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
651 dev->net->stats.rx_errors, dev->net->stats.tx_errors
652 );
653
654 /* ensure there are no more active requests */
655 spin_lock_irqsave(&dev->lock, flags);
656 if (dev->port_usb) {
657 struct gether *link = dev->port_usb;
658 const struct usb_endpoint_descriptor *in;
659 const struct usb_endpoint_descriptor *out;
660
661 if (link->close)
662 link->close(link);
663
664 /* NOTE: we have no abort-queue primitive we could use
665 * to cancel all pending I/O. Instead, we disable then
666 * reenable the endpoints ... this idiom may leave toggle
667 * wrong, but that's a self-correcting error.
668 *
669 * REVISIT: we *COULD* just let the transfers complete at
670 * their own pace; the network stack can handle old packets.
671 * For the moment we leave this here, since it works.
672 */
673 in = link->in_ep->desc;
674 out = link->out_ep->desc;
675 usb_ep_disable(link->in_ep);
676 usb_ep_disable(link->out_ep);
677 if (netif_carrier_ok(net)) {
678 DBG(dev, "host still using in/out endpoints\n");
679 link->in_ep->desc = in;
680 link->out_ep->desc = out;
681 usb_ep_enable(link->in_ep);
682 usb_ep_enable(link->out_ep);
683 }
684 }
685 spin_unlock_irqrestore(&dev->lock, flags);
686
687 return 0;
688}
689
690/*-------------------------------------------------------------------------*/
691
692static int get_ether_addr(const char *str, u8 *dev_addr)
693{
694 if (str) {
695 unsigned i;
696
697 for (i = 0; i < 6; i++) {
698 unsigned char num;
699
700 if ((*str == '.') || (*str == ':'))
701 str++;
702 num = hex_to_bin(*str++) << 4;
703 num |= hex_to_bin(*str++);
704 dev_addr [i] = num;
705 }
706 if (is_valid_ether_addr(dev_addr))
707 return 0;
708 }
709 eth_random_addr(dev_addr);
710 return 1;
711}
712
713static int get_ether_addr_str(u8 dev_addr[ETH_ALEN], char *str, int len)
714{
715 if (len < 18)
716 return -EINVAL;
717
718 snprintf(str, len, "%pM", dev_addr);
719 return 18;
720}
721
722static const struct net_device_ops eth_netdev_ops = {
723 .ndo_open = eth_open,
724 .ndo_stop = eth_stop,
725 .ndo_start_xmit = eth_start_xmit,
Googleraf606d22022-10-26 21:40:12 -0700726 .ndo_set_mac_address = eth_mac_addr,
727 .ndo_validate_addr = eth_validate_addr,
728};
729
730static struct device_type gadget_type = {
731 .name = "gadget",
732};
733
734/**
735 * gether_setup_name - initialize one ethernet-over-usb link
736 * @g: gadget to associated with these links
737 * @ethaddr: NULL, or a buffer in which the ethernet address of the
738 * host side of the link is recorded
739 * @netname: name for network device (for example, "usb")
740 * Context: may sleep
741 *
742 * This sets up the single network link that may be exported by a
743 * gadget driver using this framework. The link layer addresses are
744 * set up using module parameters.
745 *
746 * Returns an eth_dev pointer on success, or an ERR_PTR on failure.
747 */
748struct eth_dev *gether_setup_name(struct usb_gadget *g,
749 const char *dev_addr, const char *host_addr,
750 u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname)
751{
752 struct eth_dev *dev;
753 struct net_device *net;
754 int status;
755
756 net = alloc_etherdev(sizeof *dev);
757 if (!net)
758 return ERR_PTR(-ENOMEM);
759
760 dev = netdev_priv(net);
761 spin_lock_init(&dev->lock);
762 spin_lock_init(&dev->req_lock);
763 INIT_WORK(&dev->work, eth_work);
764 INIT_LIST_HEAD(&dev->tx_reqs);
765 INIT_LIST_HEAD(&dev->rx_reqs);
766
767 skb_queue_head_init(&dev->rx_frames);
768
769 /* network device setup */
770 dev->net = net;
771 dev->qmult = qmult;
772 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
773
Googlerb48fa912023-03-17 12:40:29 +0530774 if (get_ether_addr(dev_addr, net->dev_addr))
Googleraf606d22022-10-26 21:40:12 -0700775 dev_warn(&g->dev,
776 "using random %s ethernet address\n", "self");
777 if (get_ether_addr(host_addr, dev->host_mac))
778 dev_warn(&g->dev,
779 "using random %s ethernet address\n", "host");
780
781 if (ethaddr)
782 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
783
784 net->netdev_ops = &eth_netdev_ops;
785
786 net->ethtool_ops = &ops;
787
Googler9398cc32022-12-02 17:21:52 +0800788 /* MTU range: 14 - 15412 */
789 net->min_mtu = ETH_HLEN;
790 net->max_mtu = GETHER_MAX_MTU_SIZE;
791
Googleraf606d22022-10-26 21:40:12 -0700792 dev->gadget = g;
793 SET_NETDEV_DEV(net, &g->dev);
794 SET_NETDEV_DEVTYPE(net, &gadget_type);
795
796 status = register_netdev(net);
797 if (status < 0) {
798 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
799 free_netdev(net);
800 dev = ERR_PTR(status);
801 } else {
802 INFO(dev, "MAC %pM\n", net->dev_addr);
803 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
804
805 /*
806 * two kinds of host-initiated state changes:
807 * - iff DATA transfer is active, carrier is "on"
808 * - tx queueing enabled if open *and* carrier is "on"
809 */
810 netif_carrier_off(net);
811 }
812
813 return dev;
814}
815EXPORT_SYMBOL_GPL(gether_setup_name);
816
817struct net_device *gether_setup_name_default(const char *netname)
818{
819 struct net_device *net;
820 struct eth_dev *dev;
821
822 net = alloc_etherdev(sizeof(*dev));
823 if (!net)
824 return ERR_PTR(-ENOMEM);
825
826 dev = netdev_priv(net);
827 spin_lock_init(&dev->lock);
828 spin_lock_init(&dev->req_lock);
829 INIT_WORK(&dev->work, eth_work);
830 INIT_LIST_HEAD(&dev->tx_reqs);
831 INIT_LIST_HEAD(&dev->rx_reqs);
832
833 skb_queue_head_init(&dev->rx_frames);
834
835 /* network device setup */
836 dev->net = net;
837 dev->qmult = QMULT_DEFAULT;
838 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
839
840 eth_random_addr(dev->dev_mac);
841 pr_warn("using random %s ethernet address\n", "self");
842 eth_random_addr(dev->host_mac);
843 pr_warn("using random %s ethernet address\n", "host");
844
845 net->netdev_ops = &eth_netdev_ops;
846
847 net->ethtool_ops = &ops;
848 SET_NETDEV_DEVTYPE(net, &gadget_type);
849
Googler9398cc32022-12-02 17:21:52 +0800850 /* MTU range: 14 - 15412 */
851 net->min_mtu = ETH_HLEN;
852 net->max_mtu = GETHER_MAX_MTU_SIZE;
853
Googleraf606d22022-10-26 21:40:12 -0700854 return net;
855}
856EXPORT_SYMBOL_GPL(gether_setup_name_default);
857
858int gether_register_netdev(struct net_device *net)
859{
860 struct eth_dev *dev;
861 struct usb_gadget *g;
Googlerb48fa912023-03-17 12:40:29 +0530862 struct sockaddr sa;
Googleraf606d22022-10-26 21:40:12 -0700863 int status;
864
865 if (!net->dev.parent)
866 return -EINVAL;
867 dev = netdev_priv(net);
868 g = dev->gadget;
869 status = register_netdev(net);
870 if (status < 0) {
871 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
872 return status;
873 } else {
874 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
875
876 /* two kinds of host-initiated state changes:
877 * - iff DATA transfer is active, carrier is "on"
878 * - tx queueing enabled if open *and* carrier is "on"
879 */
880 netif_carrier_off(net);
881 }
Googlerb48fa912023-03-17 12:40:29 +0530882 sa.sa_family = net->type;
883 memcpy(sa.sa_data, dev->dev_mac, ETH_ALEN);
884 rtnl_lock();
885 status = dev_set_mac_address(net, &sa, NULL);
886 rtnl_unlock();
887 if (status)
888 pr_warn("cannot set self ethernet address: %d\n", status);
889 else
890 INFO(dev, "MAC %pM\n", dev->dev_mac);
Googleraf606d22022-10-26 21:40:12 -0700891
892 return status;
893}
894EXPORT_SYMBOL_GPL(gether_register_netdev);
895
896void gether_set_gadget(struct net_device *net, struct usb_gadget *g)
897{
898 struct eth_dev *dev;
899
900 dev = netdev_priv(net);
901 dev->gadget = g;
902 SET_NETDEV_DEV(net, &g->dev);
903}
904EXPORT_SYMBOL_GPL(gether_set_gadget);
905
906int gether_set_dev_addr(struct net_device *net, const char *dev_addr)
907{
908 struct eth_dev *dev;
909 u8 new_addr[ETH_ALEN];
910
911 dev = netdev_priv(net);
912 if (get_ether_addr(dev_addr, new_addr))
913 return -EINVAL;
914 memcpy(dev->dev_mac, new_addr, ETH_ALEN);
915 return 0;
916}
917EXPORT_SYMBOL_GPL(gether_set_dev_addr);
918
919int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len)
920{
921 struct eth_dev *dev;
Googler9398cc32022-12-02 17:21:52 +0800922 int ret;
Googleraf606d22022-10-26 21:40:12 -0700923
924 dev = netdev_priv(net);
Googler9398cc32022-12-02 17:21:52 +0800925 ret = get_ether_addr_str(dev->dev_mac, dev_addr, len);
926 if (ret + 1 < len) {
927 dev_addr[ret++] = '\n';
928 dev_addr[ret] = '\0';
929 }
930
931 return ret;
Googleraf606d22022-10-26 21:40:12 -0700932}
933EXPORT_SYMBOL_GPL(gether_get_dev_addr);
934
935int gether_set_host_addr(struct net_device *net, const char *host_addr)
936{
937 struct eth_dev *dev;
938 u8 new_addr[ETH_ALEN];
939
940 dev = netdev_priv(net);
941 if (get_ether_addr(host_addr, new_addr))
942 return -EINVAL;
943 memcpy(dev->host_mac, new_addr, ETH_ALEN);
944 return 0;
945}
946EXPORT_SYMBOL_GPL(gether_set_host_addr);
947
948int gether_get_host_addr(struct net_device *net, char *host_addr, int len)
949{
950 struct eth_dev *dev;
Googler9398cc32022-12-02 17:21:52 +0800951 int ret;
Googleraf606d22022-10-26 21:40:12 -0700952
953 dev = netdev_priv(net);
Googler9398cc32022-12-02 17:21:52 +0800954 ret = get_ether_addr_str(dev->host_mac, host_addr, len);
955 if (ret + 1 < len) {
956 host_addr[ret++] = '\n';
957 host_addr[ret] = '\0';
958 }
959
960 return ret;
Googleraf606d22022-10-26 21:40:12 -0700961}
962EXPORT_SYMBOL_GPL(gether_get_host_addr);
963
964int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len)
965{
966 struct eth_dev *dev;
967
968 if (len < 13)
969 return -EINVAL;
970
971 dev = netdev_priv(net);
972 snprintf(host_addr, len, "%pm", dev->host_mac);
973
974 return strlen(host_addr);
975}
976EXPORT_SYMBOL_GPL(gether_get_host_addr_cdc);
977
978void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN])
979{
980 struct eth_dev *dev;
981
982 dev = netdev_priv(net);
983 memcpy(host_mac, dev->host_mac, ETH_ALEN);
984}
985EXPORT_SYMBOL_GPL(gether_get_host_addr_u8);
986
987void gether_set_qmult(struct net_device *net, unsigned qmult)
988{
989 struct eth_dev *dev;
990
991 dev = netdev_priv(net);
992 dev->qmult = qmult;
993}
994EXPORT_SYMBOL_GPL(gether_set_qmult);
995
996unsigned gether_get_qmult(struct net_device *net)
997{
998 struct eth_dev *dev;
999
1000 dev = netdev_priv(net);
1001 return dev->qmult;
1002}
1003EXPORT_SYMBOL_GPL(gether_get_qmult);
1004
1005int gether_get_ifname(struct net_device *net, char *name, int len)
1006{
Googler9398cc32022-12-02 17:21:52 +08001007 int ret;
1008
Googleraf606d22022-10-26 21:40:12 -07001009 rtnl_lock();
Googler9398cc32022-12-02 17:21:52 +08001010 ret = scnprintf(name, len, "%s\n", netdev_name(net));
Googleraf606d22022-10-26 21:40:12 -07001011 rtnl_unlock();
Googler9398cc32022-12-02 17:21:52 +08001012 return ret;
Googleraf606d22022-10-26 21:40:12 -07001013}
1014EXPORT_SYMBOL_GPL(gether_get_ifname);
1015
1016/**
1017 * gether_cleanup - remove Ethernet-over-USB device
1018 * Context: may sleep
1019 *
1020 * This is called to free all resources allocated by @gether_setup().
1021 */
1022void gether_cleanup(struct eth_dev *dev)
1023{
1024 if (!dev)
1025 return;
1026
1027 unregister_netdev(dev->net);
1028 flush_work(&dev->work);
1029 free_netdev(dev->net);
1030}
1031EXPORT_SYMBOL_GPL(gether_cleanup);
1032
1033/**
1034 * gether_connect - notify network layer that USB link is active
1035 * @link: the USB link, set up with endpoints, descriptors matching
1036 * current device speed, and any framing wrapper(s) set up.
1037 * Context: irqs blocked
1038 *
1039 * This is called to activate endpoints and let the network layer know
1040 * the connection is active ("carrier detect"). It may cause the I/O
1041 * queues to open and start letting network packets flow, but will in
1042 * any case activate the endpoints so that they respond properly to the
1043 * USB host.
1044 *
1045 * Verify net_device pointer returned using IS_ERR(). If it doesn't
1046 * indicate some error code (negative errno), ep->driver_data values
1047 * have been overwritten.
1048 */
1049struct net_device *gether_connect(struct gether *link)
1050{
1051 struct eth_dev *dev = link->ioport;
1052 int result = 0;
1053
1054 if (!dev)
1055 return ERR_PTR(-EINVAL);
1056
1057 link->in_ep->driver_data = dev;
1058 result = usb_ep_enable(link->in_ep);
1059 if (result != 0) {
1060 DBG(dev, "enable %s --> %d\n",
1061 link->in_ep->name, result);
1062 goto fail0;
1063 }
1064
1065 link->out_ep->driver_data = dev;
1066 result = usb_ep_enable(link->out_ep);
1067 if (result != 0) {
1068 DBG(dev, "enable %s --> %d\n",
1069 link->out_ep->name, result);
1070 goto fail1;
1071 }
1072
1073 if (result == 0)
1074 result = alloc_requests(dev, link, qlen(dev->gadget,
1075 dev->qmult));
1076
1077 if (result == 0) {
1078 dev->zlp = link->is_zlp_ok;
Googler9398cc32022-12-02 17:21:52 +08001079 dev->no_skb_reserve = gadget_avoids_skb_reserve(dev->gadget);
Googleraf606d22022-10-26 21:40:12 -07001080 DBG(dev, "qlen %d\n", qlen(dev->gadget, dev->qmult));
1081
1082 dev->header_len = link->header_len;
1083 dev->unwrap = link->unwrap;
1084 dev->wrap = link->wrap;
1085
1086 spin_lock(&dev->lock);
1087 dev->port_usb = link;
1088 if (netif_running(dev->net)) {
1089 if (link->open)
1090 link->open(link);
1091 } else {
1092 if (link->close)
1093 link->close(link);
1094 }
1095 spin_unlock(&dev->lock);
1096
1097 netif_carrier_on(dev->net);
1098 if (netif_running(dev->net))
1099 eth_start(dev, GFP_ATOMIC);
1100
1101 /* on error, disable any endpoints */
1102 } else {
1103 (void) usb_ep_disable(link->out_ep);
1104fail1:
1105 (void) usb_ep_disable(link->in_ep);
1106 }
1107fail0:
1108 /* caller is responsible for cleanup on error */
1109 if (result < 0)
1110 return ERR_PTR(result);
1111 return dev->net;
1112}
1113EXPORT_SYMBOL_GPL(gether_connect);
1114
1115/**
1116 * gether_disconnect - notify network layer that USB link is inactive
1117 * @link: the USB link, on which gether_connect() was called
1118 * Context: irqs blocked
1119 *
1120 * This is called to deactivate endpoints and let the network layer know
1121 * the connection went inactive ("no carrier").
1122 *
1123 * On return, the state is as if gether_connect() had never been called.
1124 * The endpoints are inactive, and accordingly without active USB I/O.
1125 * Pointers to endpoint descriptors and endpoint private data are nulled.
1126 */
1127void gether_disconnect(struct gether *link)
1128{
1129 struct eth_dev *dev = link->ioport;
1130 struct usb_request *req;
1131
1132 WARN_ON(!dev);
1133 if (!dev)
1134 return;
1135
1136 DBG(dev, "%s\n", __func__);
1137
1138 netif_stop_queue(dev->net);
1139 netif_carrier_off(dev->net);
1140
1141 /* disable endpoints, forcing (synchronous) completion
1142 * of all pending i/o. then free the request objects
1143 * and forget about the endpoints.
1144 */
1145 usb_ep_disable(link->in_ep);
1146 spin_lock(&dev->req_lock);
1147 while (!list_empty(&dev->tx_reqs)) {
Googler9398cc32022-12-02 17:21:52 +08001148 req = list_first_entry(&dev->tx_reqs, struct usb_request, list);
Googleraf606d22022-10-26 21:40:12 -07001149 list_del(&req->list);
1150
1151 spin_unlock(&dev->req_lock);
1152 usb_ep_free_request(link->in_ep, req);
1153 spin_lock(&dev->req_lock);
1154 }
1155 spin_unlock(&dev->req_lock);
1156 link->in_ep->desc = NULL;
1157
1158 usb_ep_disable(link->out_ep);
1159 spin_lock(&dev->req_lock);
1160 while (!list_empty(&dev->rx_reqs)) {
Googler9398cc32022-12-02 17:21:52 +08001161 req = list_first_entry(&dev->rx_reqs, struct usb_request, list);
Googleraf606d22022-10-26 21:40:12 -07001162 list_del(&req->list);
1163
1164 spin_unlock(&dev->req_lock);
1165 usb_ep_free_request(link->out_ep, req);
1166 spin_lock(&dev->req_lock);
1167 }
1168 spin_unlock(&dev->req_lock);
1169 link->out_ep->desc = NULL;
1170
1171 /* finish forgetting about this USB link episode */
1172 dev->header_len = 0;
1173 dev->unwrap = NULL;
1174 dev->wrap = NULL;
1175
1176 spin_lock(&dev->lock);
1177 dev->port_usb = NULL;
1178 spin_unlock(&dev->lock);
1179}
1180EXPORT_SYMBOL_GPL(gether_disconnect);
1181
1182MODULE_LICENSE("GPL");
1183MODULE_AUTHOR("David Brownell");