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1// SPDX-License-Identifier: GPL-2.0+
2/*
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
8 */
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
48 * frame sizes. Set the max size to 15k+52 to prevent allocating 32k
49 * blocks and still have efficient handling. */
50#define GETHER_MAX_ETH_FRAME_LEN 15412
51
52struct eth_dev {
53 /* lock is held while accessing port_usb
54 */
55 spinlock_t lock;
56 struct gether *port_usb;
57
58 struct net_device *net;
59 struct usb_gadget *gadget;
60
61 spinlock_t req_lock; /* guard {rx,tx}_reqs */
62 struct list_head tx_reqs, rx_reqs;
63 atomic_t tx_qlen;
64
65 struct sk_buff_head rx_frames;
66
67 unsigned qmult;
68
69 unsigned header_len;
70 struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
71 int (*unwrap)(struct gether *,
72 struct sk_buff *skb,
73 struct sk_buff_head *list);
74
75 struct work_struct work;
76
77 unsigned long todo;
78#define WORK_RX_MEMORY 0
79
80 bool zlp;
81 bool no_skb_reserve;
82 u8 host_mac[ETH_ALEN];
83 u8 dev_mac[ETH_ALEN];
84};
85
86/*-------------------------------------------------------------------------*/
87
88#define RX_EXTRA 20 /* bytes guarding against rx overflows */
89
90#define DEFAULT_QLEN 2 /* double buffering by default */
91
92/* for dual-speed hardware, use deeper queues at high/super speed */
93static inline int qlen(struct usb_gadget *gadget, unsigned qmult)
94{
95 if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
96 gadget->speed == USB_SPEED_SUPER))
97 return qmult * DEFAULT_QLEN;
98 else
99 return DEFAULT_QLEN;
100}
101
102/*-------------------------------------------------------------------------*/
103
104/* REVISIT there must be a better way than having two sets
105 * of debug calls ...
106 */
107
108#undef DBG
109#undef VDBG
110#undef ERROR
111#undef INFO
112
113#define xprintk(d, level, fmt, args...) \
114 printk(level "%s: " fmt , (d)->net->name , ## args)
115
116#ifdef DEBUG
117#undef DEBUG
118#define DBG(dev, fmt, args...) \
119 xprintk(dev , KERN_DEBUG , fmt , ## args)
120#else
121#define DBG(dev, fmt, args...) \
122 do { } while (0)
123#endif /* DEBUG */
124
125#ifdef VERBOSE_DEBUG
126#define VDBG DBG
127#else
128#define VDBG(dev, fmt, args...) \
129 do { } while (0)
130#endif /* DEBUG */
131
132#define ERROR(dev, fmt, args...) \
133 xprintk(dev , KERN_ERR , fmt , ## args)
134#define INFO(dev, fmt, args...) \
135 xprintk(dev , KERN_INFO , fmt , ## args)
136
137/*-------------------------------------------------------------------------*/
138
139/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
140
141static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
142{
143 struct eth_dev *dev = netdev_priv(net);
144
145 strlcpy(p->driver, "g_ether", sizeof(p->driver));
146 strlcpy(p->version, UETH__VERSION, sizeof(p->version));
147 strlcpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version));
148 strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof(p->bus_info));
149}
150
151/* REVISIT can also support:
152 * - WOL (by tracking suspends and issuing remote wakeup)
153 * - msglevel (implies updated messaging)
154 * - ... probably more ethtool ops
155 */
156
157static const struct ethtool_ops ops = {
158 .get_drvinfo = eth_get_drvinfo,
159 .get_link = ethtool_op_get_link,
160};
161
162static void defer_kevent(struct eth_dev *dev, int flag)
163{
164 if (test_and_set_bit(flag, &dev->todo))
165 return;
166 if (!schedule_work(&dev->work))
167 ERROR(dev, "kevent %d may have been dropped\n", flag);
168 else
169 DBG(dev, "kevent %d scheduled\n", flag);
170}
171
172static void rx_complete(struct usb_ep *ep, struct usb_request *req);
173
174static int
175rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
176{
177 struct usb_gadget *g = dev->gadget;
178 struct sk_buff *skb;
179 int retval = -ENOMEM;
180 size_t size = 0;
181 struct usb_ep *out;
182 unsigned long flags;
183
184 spin_lock_irqsave(&dev->lock, flags);
185 if (dev->port_usb)
186 out = dev->port_usb->out_ep;
187 else
188 out = NULL;
189 spin_unlock_irqrestore(&dev->lock, flags);
190
191 if (!out)
192 return -ENOTCONN;
193
194
195 /* Padding up to RX_EXTRA handles minor disagreements with host.
196 * Normally we use the USB "terminate on short read" convention;
197 * so allow up to (N*maxpacket), since that memory is normally
198 * already allocated. Some hardware doesn't deal well with short
199 * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
200 * byte off the end (to force hardware errors on overflow).
201 *
202 * RNDIS uses internal framing, and explicitly allows senders to
203 * pad to end-of-packet. That's potentially nice for speed, but
204 * means receivers can't recover lost synch on their own (because
205 * new packets don't only start after a short RX).
206 */
207 size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
208 size += dev->port_usb->header_len;
209
210 if (g->quirk_ep_out_aligned_size) {
211 size += out->maxpacket - 1;
212 size -= size % out->maxpacket;
213 }
214
215 if (dev->port_usb->is_fixed)
216 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
217
218 skb = __netdev_alloc_skb(dev->net, size + NET_IP_ALIGN, gfp_flags);
219 if (skb == NULL) {
220 DBG(dev, "no rx skb\n");
221 goto enomem;
222 }
223
224 /* Some platforms perform better when IP packets are aligned,
225 * but on at least one, checksumming fails otherwise. Note:
226 * RNDIS headers involve variable numbers of LE32 values.
227 */
228 if (likely(!dev->no_skb_reserve))
229 skb_reserve(skb, NET_IP_ALIGN);
230
231 req->buf = skb->data;
232 req->length = size;
233 req->complete = rx_complete;
234 req->context = skb;
235
236 retval = usb_ep_queue(out, req, gfp_flags);
237 if (retval == -ENOMEM)
238enomem:
239 defer_kevent(dev, WORK_RX_MEMORY);
240 if (retval) {
241 DBG(dev, "rx submit --> %d\n", retval);
242 if (skb)
243 dev_kfree_skb_any(skb);
244 spin_lock_irqsave(&dev->req_lock, flags);
245 list_add(&req->list, &dev->rx_reqs);
246 spin_unlock_irqrestore(&dev->req_lock, flags);
247 }
248 return retval;
249}
250
251static void rx_complete(struct usb_ep *ep, struct usb_request *req)
252{
253 struct sk_buff *skb = req->context, *skb2;
254 struct eth_dev *dev = ep->driver_data;
255 int status = req->status;
256
257 switch (status) {
258
259 /* normal completion */
260 case 0:
261 skb_put(skb, req->actual);
262
263 if (dev->unwrap) {
264 unsigned long flags;
265
266 spin_lock_irqsave(&dev->lock, flags);
267 if (dev->port_usb) {
268 status = dev->unwrap(dev->port_usb,
269 skb,
270 &dev->rx_frames);
271 } else {
272 dev_kfree_skb_any(skb);
273 status = -ENOTCONN;
274 }
275 spin_unlock_irqrestore(&dev->lock, flags);
276 } else {
277 skb_queue_tail(&dev->rx_frames, skb);
278 }
279 skb = NULL;
280
281 skb2 = skb_dequeue(&dev->rx_frames);
282 while (skb2) {
283 if (status < 0
284 || ETH_HLEN > skb2->len
285 || skb2->len > GETHER_MAX_ETH_FRAME_LEN) {
286 dev->net->stats.rx_errors++;
287 dev->net->stats.rx_length_errors++;
288 DBG(dev, "rx length %d\n", skb2->len);
289 dev_kfree_skb_any(skb2);
290 goto next_frame;
291 }
292 skb2->protocol = eth_type_trans(skb2, dev->net);
293 dev->net->stats.rx_packets++;
294 dev->net->stats.rx_bytes += skb2->len;
295
296 /* no buffer copies needed, unless hardware can't
297 * use skb buffers.
298 */
299 status = netif_rx(skb2);
300next_frame:
301 skb2 = skb_dequeue(&dev->rx_frames);
302 }
303 break;
304
305 /* software-driven interface shutdown */
306 case -ECONNRESET: /* unlink */
307 case -ESHUTDOWN: /* disconnect etc */
308 VDBG(dev, "rx shutdown, code %d\n", status);
309 goto quiesce;
310
311 /* for hardware automagic (such as pxa) */
312 case -ECONNABORTED: /* endpoint reset */
313 DBG(dev, "rx %s reset\n", ep->name);
314 defer_kevent(dev, WORK_RX_MEMORY);
315quiesce:
316 dev_kfree_skb_any(skb);
317 goto clean;
318
319 /* data overrun */
320 case -EOVERFLOW:
321 dev->net->stats.rx_over_errors++;
322 /* FALLTHROUGH */
323
324 default:
325 dev->net->stats.rx_errors++;
326 DBG(dev, "rx status %d\n", status);
327 break;
328 }
329
330 if (skb)
331 dev_kfree_skb_any(skb);
332 if (!netif_running(dev->net)) {
333clean:
334 spin_lock(&dev->req_lock);
335 list_add(&req->list, &dev->rx_reqs);
336 spin_unlock(&dev->req_lock);
337 req = NULL;
338 }
339 if (req)
340 rx_submit(dev, req, GFP_ATOMIC);
341}
342
343static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
344{
345 unsigned i;
346 struct usb_request *req;
347
348 if (!n)
349 return -ENOMEM;
350
351 /* queue/recycle up to N requests */
352 i = n;
353 list_for_each_entry(req, list, list) {
354 if (i-- == 0)
355 goto extra;
356 }
357 while (i--) {
358 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
359 if (!req)
360 return list_empty(list) ? -ENOMEM : 0;
361 list_add(&req->list, list);
362 }
363 return 0;
364
365extra:
366 /* free extras */
367 for (;;) {
368 struct list_head *next;
369
370 next = req->list.next;
371 list_del(&req->list);
372 usb_ep_free_request(ep, req);
373
374 if (next == list)
375 break;
376
377 req = container_of(next, struct usb_request, list);
378 }
379 return 0;
380}
381
382static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
383{
384 int status;
385
386 spin_lock(&dev->req_lock);
387 status = prealloc(&dev->tx_reqs, link->in_ep, n);
388 if (status < 0)
389 goto fail;
390 status = prealloc(&dev->rx_reqs, link->out_ep, n);
391 if (status < 0)
392 goto fail;
393 goto done;
394fail:
395 DBG(dev, "can't alloc requests\n");
396done:
397 spin_unlock(&dev->req_lock);
398 return status;
399}
400
401static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
402{
403 struct usb_request *req;
404 struct usb_request *tmp;
405 unsigned long flags;
406
407 /* fill unused rxq slots with some skb */
408 spin_lock_irqsave(&dev->req_lock, flags);
409 list_for_each_entry_safe(req, tmp, &dev->rx_reqs, list) {
410 list_del_init(&req->list);
411 spin_unlock_irqrestore(&dev->req_lock, flags);
412
413 if (rx_submit(dev, req, gfp_flags) < 0) {
414 defer_kevent(dev, WORK_RX_MEMORY);
415 return;
416 }
417
418 spin_lock_irqsave(&dev->req_lock, flags);
419 }
420 spin_unlock_irqrestore(&dev->req_lock, flags);
421}
422
423static void eth_work(struct work_struct *work)
424{
425 struct eth_dev *dev = container_of(work, struct eth_dev, work);
426
427 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
428 if (netif_running(dev->net))
429 rx_fill(dev, GFP_KERNEL);
430 }
431
432 if (dev->todo)
433 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
434}
435
436static void tx_complete(struct usb_ep *ep, struct usb_request *req)
437{
438 struct sk_buff *skb = req->context;
439 struct eth_dev *dev = ep->driver_data;
440
441 switch (req->status) {
442 default:
443 dev->net->stats.tx_errors++;
444 VDBG(dev, "tx err %d\n", req->status);
445 /* FALLTHROUGH */
446 case -ECONNRESET: /* unlink */
447 case -ESHUTDOWN: /* disconnect etc */
448 dev_kfree_skb_any(skb);
449 break;
450 case 0:
451 dev->net->stats.tx_bytes += skb->len;
452 dev_consume_skb_any(skb);
453 }
454 dev->net->stats.tx_packets++;
455
456 spin_lock(&dev->req_lock);
457 list_add(&req->list, &dev->tx_reqs);
458 spin_unlock(&dev->req_lock);
459
460 atomic_dec(&dev->tx_qlen);
461 if (netif_carrier_ok(dev->net))
462 netif_wake_queue(dev->net);
463}
464
465static inline int is_promisc(u16 cdc_filter)
466{
467 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
468}
469
470static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
471 struct net_device *net)
472{
473 struct eth_dev *dev = netdev_priv(net);
474 int length = 0;
475 int retval;
476 struct usb_request *req = NULL;
477 unsigned long flags;
478 struct usb_ep *in;
479 u16 cdc_filter;
480
481 spin_lock_irqsave(&dev->lock, flags);
482 if (dev->port_usb) {
483 in = dev->port_usb->in_ep;
484 cdc_filter = dev->port_usb->cdc_filter;
485 } else {
486 in = NULL;
487 cdc_filter = 0;
488 }
489 spin_unlock_irqrestore(&dev->lock, flags);
490
491 if (skb && !in) {
492 dev_kfree_skb_any(skb);
493 return NETDEV_TX_OK;
494 }
495
496 /* apply outgoing CDC or RNDIS filters */
497 if (skb && !is_promisc(cdc_filter)) {
498 u8 *dest = skb->data;
499
500 if (is_multicast_ether_addr(dest)) {
501 u16 type;
502
503 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
504 * SET_ETHERNET_MULTICAST_FILTERS requests
505 */
506 if (is_broadcast_ether_addr(dest))
507 type = USB_CDC_PACKET_TYPE_BROADCAST;
508 else
509 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
510 if (!(cdc_filter & type)) {
511 dev_kfree_skb_any(skb);
512 return NETDEV_TX_OK;
513 }
514 }
515 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
516 }
517
518 spin_lock_irqsave(&dev->req_lock, flags);
519 /*
520 * this freelist can be empty if an interrupt triggered disconnect()
521 * and reconfigured the gadget (shutting down this queue) after the
522 * network stack decided to xmit but before we got the spinlock.
523 */
524 if (list_empty(&dev->tx_reqs)) {
525 spin_unlock_irqrestore(&dev->req_lock, flags);
526 return NETDEV_TX_BUSY;
527 }
528
529 req = list_first_entry(&dev->tx_reqs, struct usb_request, list);
530 list_del(&req->list);
531
532 /* temporarily stop TX queue when the freelist empties */
533 if (list_empty(&dev->tx_reqs))
534 netif_stop_queue(net);
535 spin_unlock_irqrestore(&dev->req_lock, flags);
536
537 /* no buffer copies needed, unless the network stack did it
538 * or the hardware can't use skb buffers.
539 * or there's not enough space for extra headers we need
540 */
541 if (dev->wrap) {
542 unsigned long flags;
543
544 spin_lock_irqsave(&dev->lock, flags);
545 if (dev->port_usb)
546 skb = dev->wrap(dev->port_usb, skb);
547 spin_unlock_irqrestore(&dev->lock, flags);
548 if (!skb) {
549 /* Multi frame CDC protocols may store the frame for
550 * later which is not a dropped frame.
551 */
552 if (dev->port_usb &&
553 dev->port_usb->supports_multi_frame)
554 goto multiframe;
555 goto drop;
556 }
557 }
558
559 length = skb->len;
560 req->buf = skb->data;
561 req->context = skb;
562 req->complete = tx_complete;
563
564 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
565 if (dev->port_usb &&
566 dev->port_usb->is_fixed &&
567 length == dev->port_usb->fixed_in_len &&
568 (length % in->maxpacket) == 0)
569 req->zero = 0;
570 else
571 req->zero = 1;
572
573 /* use zlp framing on tx for strict CDC-Ether conformance,
574 * though any robust network rx path ignores extra padding.
575 * and some hardware doesn't like to write zlps.
576 */
577 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
578 length++;
579
580 req->length = length;
581
582 retval = usb_ep_queue(in, req, GFP_ATOMIC);
583 switch (retval) {
584 default:
585 DBG(dev, "tx queue err %d\n", retval);
586 break;
587 case 0:
588 netif_trans_update(net);
589 atomic_inc(&dev->tx_qlen);
590 }
591
592 if (retval) {
593 dev_kfree_skb_any(skb);
594drop:
595 dev->net->stats.tx_dropped++;
596multiframe:
597 spin_lock_irqsave(&dev->req_lock, flags);
598 if (list_empty(&dev->tx_reqs))
599 netif_start_queue(net);
600 list_add(&req->list, &dev->tx_reqs);
601 spin_unlock_irqrestore(&dev->req_lock, flags);
602 }
603 return NETDEV_TX_OK;
604}
605
606/*-------------------------------------------------------------------------*/
607
608static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
609{
610 DBG(dev, "%s\n", __func__);
611
612 /* fill the rx queue */
613 rx_fill(dev, gfp_flags);
614
615 /* and open the tx floodgates */
616 atomic_set(&dev->tx_qlen, 0);
617 netif_wake_queue(dev->net);
618}
619
620static int eth_open(struct net_device *net)
621{
622 struct eth_dev *dev = netdev_priv(net);
623 struct gether *link;
624
625 DBG(dev, "%s\n", __func__);
626 if (netif_carrier_ok(dev->net))
627 eth_start(dev, GFP_KERNEL);
628
629 spin_lock_irq(&dev->lock);
630 link = dev->port_usb;
631 if (link && link->open)
632 link->open(link);
633 spin_unlock_irq(&dev->lock);
634
635 return 0;
636}
637
638static int eth_stop(struct net_device *net)
639{
640 struct eth_dev *dev = netdev_priv(net);
641 unsigned long flags;
642
643 VDBG(dev, "%s\n", __func__);
644 netif_stop_queue(net);
645
646 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
647 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
648 dev->net->stats.rx_errors, dev->net->stats.tx_errors
649 );
650
651 /* ensure there are no more active requests */
652 spin_lock_irqsave(&dev->lock, flags);
653 if (dev->port_usb) {
654 struct gether *link = dev->port_usb;
655 const struct usb_endpoint_descriptor *in;
656 const struct usb_endpoint_descriptor *out;
657
658 if (link->close)
659 link->close(link);
660
661 /* NOTE: we have no abort-queue primitive we could use
662 * to cancel all pending I/O. Instead, we disable then
663 * reenable the endpoints ... this idiom may leave toggle
664 * wrong, but that's a self-correcting error.
665 *
666 * REVISIT: we *COULD* just let the transfers complete at
667 * their own pace; the network stack can handle old packets.
668 * For the moment we leave this here, since it works.
669 */
670 in = link->in_ep->desc;
671 out = link->out_ep->desc;
672 usb_ep_disable(link->in_ep);
673 usb_ep_disable(link->out_ep);
674 if (netif_carrier_ok(net)) {
675 DBG(dev, "host still using in/out endpoints\n");
676 link->in_ep->desc = in;
677 link->out_ep->desc = out;
678 usb_ep_enable(link->in_ep);
679 usb_ep_enable(link->out_ep);
680 }
681 }
682 spin_unlock_irqrestore(&dev->lock, flags);
683
684 return 0;
685}
686
687/*-------------------------------------------------------------------------*/
688
689static int get_ether_addr(const char *str, u8 *dev_addr)
690{
691 if (str) {
692 unsigned i;
693
694 for (i = 0; i < 6; i++) {
695 unsigned char num;
696
697 if ((*str == '.') || (*str == ':'))
698 str++;
699 num = hex_to_bin(*str++) << 4;
700 num |= hex_to_bin(*str++);
701 dev_addr [i] = num;
702 }
703 if (is_valid_ether_addr(dev_addr))
704 return 0;
705 }
706 eth_random_addr(dev_addr);
707 return 1;
708}
709
710static int get_ether_addr_str(u8 dev_addr[ETH_ALEN], char *str, int len)
711{
712 if (len < 18)
713 return -EINVAL;
714
715 snprintf(str, len, "%pM", dev_addr);
716 return 18;
717}
718
719static const struct net_device_ops eth_netdev_ops = {
720 .ndo_open = eth_open,
721 .ndo_stop = eth_stop,
722 .ndo_start_xmit = eth_start_xmit,
723 .ndo_set_mac_address = eth_mac_addr,
724 .ndo_validate_addr = eth_validate_addr,
725};
726
727static struct device_type gadget_type = {
728 .name = "gadget",
729};
730
731/**
732 * gether_setup_name - initialize one ethernet-over-usb link
733 * @g: gadget to associated with these links
734 * @ethaddr: NULL, or a buffer in which the ethernet address of the
735 * host side of the link is recorded
736 * @netname: name for network device (for example, "usb")
737 * Context: may sleep
738 *
739 * This sets up the single network link that may be exported by a
740 * gadget driver using this framework. The link layer addresses are
741 * set up using module parameters.
742 *
743 * Returns an eth_dev pointer on success, or an ERR_PTR on failure.
744 */
745struct eth_dev *gether_setup_name(struct usb_gadget *g,
746 const char *dev_addr, const char *host_addr,
747 u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname)
748{
749 struct eth_dev *dev;
750 struct net_device *net;
751 int status;
752
753 net = alloc_etherdev(sizeof *dev);
754 if (!net)
755 return ERR_PTR(-ENOMEM);
756
757 dev = netdev_priv(net);
758 spin_lock_init(&dev->lock);
759 spin_lock_init(&dev->req_lock);
760 INIT_WORK(&dev->work, eth_work);
761 INIT_LIST_HEAD(&dev->tx_reqs);
762 INIT_LIST_HEAD(&dev->rx_reqs);
763
764 skb_queue_head_init(&dev->rx_frames);
765
766 /* network device setup */
767 dev->net = net;
768 dev->qmult = qmult;
769 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
770
771 if (get_ether_addr(dev_addr, net->dev_addr))
772 dev_warn(&g->dev,
773 "using random %s ethernet address\n", "self");
774 if (get_ether_addr(host_addr, dev->host_mac))
775 dev_warn(&g->dev,
776 "using random %s ethernet address\n", "host");
777
778 if (ethaddr)
779 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
780
781 net->netdev_ops = ð_netdev_ops;
782
783 net->ethtool_ops = &ops;
784
785 /* MTU range: 14 - 15412 */
786 net->min_mtu = ETH_HLEN;
787 net->max_mtu = GETHER_MAX_ETH_FRAME_LEN;
788
789 dev->gadget = g;
790 SET_NETDEV_DEV(net, &g->dev);
791 SET_NETDEV_DEVTYPE(net, &gadget_type);
792
793 status = register_netdev(net);
794 if (status < 0) {
795 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
796 free_netdev(net);
797 dev = ERR_PTR(status);
798 } else {
799 INFO(dev, "MAC %pM\n", net->dev_addr);
800 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
801
802 /*
803 * two kinds of host-initiated state changes:
804 * - iff DATA transfer is active, carrier is "on"
805 * - tx queueing enabled if open *and* carrier is "on"
806 */
807 netif_carrier_off(net);
808 }
809
810 return dev;
811}
812EXPORT_SYMBOL_GPL(gether_setup_name);
813
814struct net_device *gether_setup_name_default(const char *netname)
815{
816 struct net_device *net;
817 struct eth_dev *dev;
818
819 net = alloc_etherdev(sizeof(*dev));
820 if (!net)
821 return ERR_PTR(-ENOMEM);
822
823 dev = netdev_priv(net);
824 spin_lock_init(&dev->lock);
825 spin_lock_init(&dev->req_lock);
826 INIT_WORK(&dev->work, eth_work);
827 INIT_LIST_HEAD(&dev->tx_reqs);
828 INIT_LIST_HEAD(&dev->rx_reqs);
829
830 skb_queue_head_init(&dev->rx_frames);
831
832 /* network device setup */
833 dev->net = net;
834 dev->qmult = QMULT_DEFAULT;
835 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
836
837 eth_random_addr(dev->dev_mac);
838 pr_warn("using random %s ethernet address\n", "self");
839 eth_random_addr(dev->host_mac);
840 pr_warn("using random %s ethernet address\n", "host");
841
842 net->netdev_ops = ð_netdev_ops;
843
844 net->ethtool_ops = &ops;
845 SET_NETDEV_DEVTYPE(net, &gadget_type);
846
847 return net;
848}
849EXPORT_SYMBOL_GPL(gether_setup_name_default);
850
851int gether_register_netdev(struct net_device *net)
852{
853 struct eth_dev *dev;
854 struct usb_gadget *g;
855 struct sockaddr sa;
856 int status;
857
858 if (!net->dev.parent)
859 return -EINVAL;
860 dev = netdev_priv(net);
861 g = dev->gadget;
862 status = register_netdev(net);
863 if (status < 0) {
864 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
865 return status;
866 } else {
867 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
868
869 /* two kinds of host-initiated state changes:
870 * - iff DATA transfer is active, carrier is "on"
871 * - tx queueing enabled if open *and* carrier is "on"
872 */
873 netif_carrier_off(net);
874 }
875 sa.sa_family = net->type;
876 memcpy(sa.sa_data, dev->dev_mac, ETH_ALEN);
877 rtnl_lock();
878 status = dev_set_mac_address(net, &sa);
879 rtnl_unlock();
880 if (status)
881 pr_warn("cannot set self ethernet address: %d\n", status);
882 else
883 INFO(dev, "MAC %pM\n", dev->dev_mac);
884
885 return status;
886}
887EXPORT_SYMBOL_GPL(gether_register_netdev);
888
889void gether_set_gadget(struct net_device *net, struct usb_gadget *g)
890{
891 struct eth_dev *dev;
892
893 dev = netdev_priv(net);
894 dev->gadget = g;
895 SET_NETDEV_DEV(net, &g->dev);
896}
897EXPORT_SYMBOL_GPL(gether_set_gadget);
898
899int gether_set_dev_addr(struct net_device *net, const char *dev_addr)
900{
901 struct eth_dev *dev;
902 u8 new_addr[ETH_ALEN];
903
904 dev = netdev_priv(net);
905 if (get_ether_addr(dev_addr, new_addr))
906 return -EINVAL;
907 memcpy(dev->dev_mac, new_addr, ETH_ALEN);
908 return 0;
909}
910EXPORT_SYMBOL_GPL(gether_set_dev_addr);
911
912int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len)
913{
914 struct eth_dev *dev;
915 int ret;
916
917 dev = netdev_priv(net);
918 ret = get_ether_addr_str(dev->dev_mac, dev_addr, len);
919 if (ret + 1 < len) {
920 dev_addr[ret++] = '\n';
921 dev_addr[ret] = '\0';
922 }
923
924 return ret;
925}
926EXPORT_SYMBOL_GPL(gether_get_dev_addr);
927
928int gether_set_host_addr(struct net_device *net, const char *host_addr)
929{
930 struct eth_dev *dev;
931 u8 new_addr[ETH_ALEN];
932
933 dev = netdev_priv(net);
934 if (get_ether_addr(host_addr, new_addr))
935 return -EINVAL;
936 memcpy(dev->host_mac, new_addr, ETH_ALEN);
937 return 0;
938}
939EXPORT_SYMBOL_GPL(gether_set_host_addr);
940
941int gether_get_host_addr(struct net_device *net, char *host_addr, int len)
942{
943 struct eth_dev *dev;
944 int ret;
945
946 dev = netdev_priv(net);
947 ret = get_ether_addr_str(dev->host_mac, host_addr, len);
948 if (ret + 1 < len) {
949 host_addr[ret++] = '\n';
950 host_addr[ret] = '\0';
951 }
952
953 return ret;
954}
955EXPORT_SYMBOL_GPL(gether_get_host_addr);
956
957int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len)
958{
959 struct eth_dev *dev;
960
961 if (len < 13)
962 return -EINVAL;
963
964 dev = netdev_priv(net);
965 snprintf(host_addr, len, "%pm", dev->host_mac);
966
967 return strlen(host_addr);
968}
969EXPORT_SYMBOL_GPL(gether_get_host_addr_cdc);
970
971void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN])
972{
973 struct eth_dev *dev;
974
975 dev = netdev_priv(net);
976 memcpy(host_mac, dev->host_mac, ETH_ALEN);
977}
978EXPORT_SYMBOL_GPL(gether_get_host_addr_u8);
979
980void gether_set_qmult(struct net_device *net, unsigned qmult)
981{
982 struct eth_dev *dev;
983
984 dev = netdev_priv(net);
985 dev->qmult = qmult;
986}
987EXPORT_SYMBOL_GPL(gether_set_qmult);
988
989unsigned gether_get_qmult(struct net_device *net)
990{
991 struct eth_dev *dev;
992
993 dev = netdev_priv(net);
994 return dev->qmult;
995}
996EXPORT_SYMBOL_GPL(gether_get_qmult);
997
998int gether_get_ifname(struct net_device *net, char *name, int len)
999{
1000 int ret;
1001
1002 rtnl_lock();
1003 ret = snprintf(name, len, "%s\n", netdev_name(net));
1004 rtnl_unlock();
1005 return ret < len ? ret : len;
1006}
1007EXPORT_SYMBOL_GPL(gether_get_ifname);
1008
1009/**
1010 * gether_cleanup - remove Ethernet-over-USB device
1011 * Context: may sleep
1012 *
1013 * This is called to free all resources allocated by @gether_setup().
1014 */
1015void gether_cleanup(struct eth_dev *dev)
1016{
1017 if (!dev)
1018 return;
1019
1020 unregister_netdev(dev->net);
1021 flush_work(&dev->work);
1022 free_netdev(dev->net);
1023}
1024EXPORT_SYMBOL_GPL(gether_cleanup);
1025
1026/**
1027 * gether_connect - notify network layer that USB link is active
1028 * @link: the USB link, set up with endpoints, descriptors matching
1029 * current device speed, and any framing wrapper(s) set up.
1030 * Context: irqs blocked
1031 *
1032 * This is called to activate endpoints and let the network layer know
1033 * the connection is active ("carrier detect"). It may cause the I/O
1034 * queues to open and start letting network packets flow, but will in
1035 * any case activate the endpoints so that they respond properly to the
1036 * USB host.
1037 *
1038 * Verify net_device pointer returned using IS_ERR(). If it doesn't
1039 * indicate some error code (negative errno), ep->driver_data values
1040 * have been overwritten.
1041 */
1042struct net_device *gether_connect(struct gether *link)
1043{
1044 struct eth_dev *dev = link->ioport;
1045 int result = 0;
1046
1047 if (!dev)
1048 return ERR_PTR(-EINVAL);
1049
1050 link->in_ep->driver_data = dev;
1051 result = usb_ep_enable(link->in_ep);
1052 if (result != 0) {
1053 DBG(dev, "enable %s --> %d\n",
1054 link->in_ep->name, result);
1055 goto fail0;
1056 }
1057
1058 link->out_ep->driver_data = dev;
1059 result = usb_ep_enable(link->out_ep);
1060 if (result != 0) {
1061 DBG(dev, "enable %s --> %d\n",
1062 link->out_ep->name, result);
1063 goto fail1;
1064 }
1065
1066 if (result == 0)
1067 result = alloc_requests(dev, link, qlen(dev->gadget,
1068 dev->qmult));
1069
1070 if (result == 0) {
1071 dev->zlp = link->is_zlp_ok;
1072 dev->no_skb_reserve = gadget_avoids_skb_reserve(dev->gadget);
1073 DBG(dev, "qlen %d\n", qlen(dev->gadget, dev->qmult));
1074
1075 dev->header_len = link->header_len;
1076 dev->unwrap = link->unwrap;
1077 dev->wrap = link->wrap;
1078
1079 spin_lock(&dev->lock);
1080 dev->port_usb = link;
1081 if (netif_running(dev->net)) {
1082 if (link->open)
1083 link->open(link);
1084 } else {
1085 if (link->close)
1086 link->close(link);
1087 }
1088 spin_unlock(&dev->lock);
1089
1090 netif_carrier_on(dev->net);
1091 if (netif_running(dev->net))
1092 eth_start(dev, GFP_ATOMIC);
1093
1094 /* on error, disable any endpoints */
1095 } else {
1096 (void) usb_ep_disable(link->out_ep);
1097fail1:
1098 (void) usb_ep_disable(link->in_ep);
1099 }
1100fail0:
1101 /* caller is responsible for cleanup on error */
1102 if (result < 0)
1103 return ERR_PTR(result);
1104 return dev->net;
1105}
1106EXPORT_SYMBOL_GPL(gether_connect);
1107
1108/**
1109 * gether_disconnect - notify network layer that USB link is inactive
1110 * @link: the USB link, on which gether_connect() was called
1111 * Context: irqs blocked
1112 *
1113 * This is called to deactivate endpoints and let the network layer know
1114 * the connection went inactive ("no carrier").
1115 *
1116 * On return, the state is as if gether_connect() had never been called.
1117 * The endpoints are inactive, and accordingly without active USB I/O.
1118 * Pointers to endpoint descriptors and endpoint private data are nulled.
1119 */
1120void gether_disconnect(struct gether *link)
1121{
1122 struct eth_dev *dev = link->ioport;
1123 struct usb_request *req;
1124 struct usb_request *tmp;
1125
1126 WARN_ON(!dev);
1127 if (!dev)
1128 return;
1129
1130 DBG(dev, "%s\n", __func__);
1131
1132 netif_stop_queue(dev->net);
1133 netif_carrier_off(dev->net);
1134
1135 /* disable endpoints, forcing (synchronous) completion
1136 * of all pending i/o. then free the request objects
1137 * and forget about the endpoints.
1138 */
1139 usb_ep_disable(link->in_ep);
1140 spin_lock(&dev->req_lock);
1141 list_for_each_entry_safe(req, tmp, &dev->tx_reqs, list) {
1142 list_del(&req->list);
1143
1144 spin_unlock(&dev->req_lock);
1145 usb_ep_free_request(link->in_ep, req);
1146 spin_lock(&dev->req_lock);
1147 }
1148 spin_unlock(&dev->req_lock);
1149 link->in_ep->desc = NULL;
1150
1151 usb_ep_disable(link->out_ep);
1152 spin_lock(&dev->req_lock);
1153 list_for_each_entry_safe(req, tmp, &dev->rx_reqs, list) {
1154 list_del(&req->list);
1155
1156 spin_unlock(&dev->req_lock);
1157 usb_ep_free_request(link->out_ep, req);
1158 spin_lock(&dev->req_lock);
1159 }
1160 spin_unlock(&dev->req_lock);
1161 link->out_ep->desc = NULL;
1162
1163 /* finish forgetting about this USB link episode */
1164 dev->header_len = 0;
1165 dev->unwrap = NULL;
1166 dev->wrap = NULL;
1167
1168 spin_lock(&dev->lock);
1169 dev->port_usb = NULL;
1170 spin_unlock(&dev->lock);
1171}
1172EXPORT_SYMBOL_GPL(gether_disconnect);
1173
1174MODULE_LICENSE("GPL");
1175MODULE_AUTHOR("David Brownell");