Loading...
Note: File does not exist in v3.1.
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 MTU size to 15k+52 to prevent allocating 32k
49 * blocks and still have efficient handling. */
50#define GETHER_MAX_MTU_SIZE 15412
51#define GETHER_MAX_ETH_FRAME_LEN (GETHER_MAX_MTU_SIZE + ETH_HLEN)
52
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 bool ifname_set;
84 u8 host_mac[ETH_ALEN];
85 u8 dev_mac[ETH_ALEN];
86};
87
88/*-------------------------------------------------------------------------*/
89
90#define RX_EXTRA 20 /* bytes guarding against rx overflows */
91
92#define DEFAULT_QLEN 2 /* double buffering by default */
93
94/* for dual-speed hardware, use deeper queues at high/super speed */
95static inline int qlen(struct usb_gadget *gadget, unsigned qmult)
96{
97 if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
98 gadget->speed >= USB_SPEED_SUPER))
99 return qmult * DEFAULT_QLEN;
100 else
101 return DEFAULT_QLEN;
102}
103
104/*-------------------------------------------------------------------------*/
105
106/* REVISIT there must be a better way than having two sets
107 * of debug calls ...
108 */
109
110#undef DBG
111#undef VDBG
112#undef ERROR
113#undef INFO
114
115#define xprintk(d, level, fmt, args...) \
116 printk(level "%s: " fmt , (d)->net->name , ## args)
117
118#ifdef DEBUG
119#undef DEBUG
120#define DBG(dev, fmt, args...) \
121 xprintk(dev , KERN_DEBUG , fmt , ## args)
122#else
123#define DBG(dev, fmt, args...) \
124 do { } while (0)
125#endif /* DEBUG */
126
127#ifdef VERBOSE_DEBUG
128#define VDBG DBG
129#else
130#define VDBG(dev, fmt, args...) \
131 do { } while (0)
132#endif /* DEBUG */
133
134#define ERROR(dev, fmt, args...) \
135 xprintk(dev , KERN_ERR , fmt , ## args)
136#define INFO(dev, fmt, args...) \
137 xprintk(dev , KERN_INFO , fmt , ## args)
138
139/*-------------------------------------------------------------------------*/
140
141/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
142
143static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
144{
145 struct eth_dev *dev = netdev_priv(net);
146
147 strlcpy(p->driver, "g_ether", sizeof(p->driver));
148 strlcpy(p->version, UETH__VERSION, sizeof(p->version));
149 strlcpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version));
150 strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof(p->bus_info));
151}
152
153/* REVISIT can also support:
154 * - WOL (by tracking suspends and issuing remote wakeup)
155 * - msglevel (implies updated messaging)
156 * - ... probably more ethtool ops
157 */
158
159static const struct ethtool_ops ops = {
160 .get_drvinfo = eth_get_drvinfo,
161 .get_link = ethtool_op_get_link,
162};
163
164static void defer_kevent(struct eth_dev *dev, int flag)
165{
166 if (test_and_set_bit(flag, &dev->todo))
167 return;
168 if (!schedule_work(&dev->work))
169 ERROR(dev, "kevent %d may have been dropped\n", flag);
170 else
171 DBG(dev, "kevent %d scheduled\n", flag);
172}
173
174static void rx_complete(struct usb_ep *ep, struct usb_request *req);
175
176static int
177rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
178{
179 struct usb_gadget *g = dev->gadget;
180 struct sk_buff *skb;
181 int retval = -ENOMEM;
182 size_t size = 0;
183 struct usb_ep *out;
184 unsigned long flags;
185
186 spin_lock_irqsave(&dev->lock, flags);
187 if (dev->port_usb)
188 out = dev->port_usb->out_ep;
189 else
190 out = NULL;
191
192 if (!out)
193 {
194 spin_unlock_irqrestore(&dev->lock, flags);
195 return -ENOTCONN;
196 }
197
198 /* Padding up to RX_EXTRA handles minor disagreements with host.
199 * Normally we use the USB "terminate on short read" convention;
200 * so allow up to (N*maxpacket), since that memory is normally
201 * already allocated. Some hardware doesn't deal well with short
202 * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
203 * byte off the end (to force hardware errors on overflow).
204 *
205 * RNDIS uses internal framing, and explicitly allows senders to
206 * pad to end-of-packet. That's potentially nice for speed, but
207 * means receivers can't recover lost synch on their own (because
208 * new packets don't only start after a short RX).
209 */
210 size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
211 size += dev->port_usb->header_len;
212
213 if (g->quirk_ep_out_aligned_size) {
214 size += out->maxpacket - 1;
215 size -= size % out->maxpacket;
216 }
217
218 if (dev->port_usb->is_fixed)
219 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
220 spin_unlock_irqrestore(&dev->lock, flags);
221
222 skb = __netdev_alloc_skb(dev->net, size + NET_IP_ALIGN, gfp_flags);
223 if (skb == NULL) {
224 DBG(dev, "no rx skb\n");
225 goto enomem;
226 }
227
228 /* Some platforms perform better when IP packets are aligned,
229 * but on at least one, checksumming fails otherwise. Note:
230 * RNDIS headers involve variable numbers of LE32 values.
231 */
232 if (likely(!dev->no_skb_reserve))
233 skb_reserve(skb, NET_IP_ALIGN);
234
235 req->buf = skb->data;
236 req->length = size;
237 req->complete = rx_complete;
238 req->context = skb;
239
240 retval = usb_ep_queue(out, req, gfp_flags);
241 if (retval == -ENOMEM)
242enomem:
243 defer_kevent(dev, WORK_RX_MEMORY);
244 if (retval) {
245 DBG(dev, "rx submit --> %d\n", retval);
246 if (skb)
247 dev_kfree_skb_any(skb);
248 spin_lock_irqsave(&dev->req_lock, flags);
249 list_add(&req->list, &dev->rx_reqs);
250 spin_unlock_irqrestore(&dev->req_lock, flags);
251 }
252 return retval;
253}
254
255static void rx_complete(struct usb_ep *ep, struct usb_request *req)
256{
257 struct sk_buff *skb = req->context, *skb2;
258 struct eth_dev *dev = ep->driver_data;
259 int status = req->status;
260
261 switch (status) {
262
263 /* normal completion */
264 case 0:
265 skb_put(skb, req->actual);
266
267 if (dev->unwrap) {
268 unsigned long flags;
269
270 spin_lock_irqsave(&dev->lock, flags);
271 if (dev->port_usb) {
272 status = dev->unwrap(dev->port_usb,
273 skb,
274 &dev->rx_frames);
275 } else {
276 dev_kfree_skb_any(skb);
277 status = -ENOTCONN;
278 }
279 spin_unlock_irqrestore(&dev->lock, flags);
280 } else {
281 skb_queue_tail(&dev->rx_frames, skb);
282 }
283 skb = NULL;
284
285 skb2 = skb_dequeue(&dev->rx_frames);
286 while (skb2) {
287 if (status < 0
288 || ETH_HLEN > skb2->len
289 || skb2->len > GETHER_MAX_ETH_FRAME_LEN) {
290 dev->net->stats.rx_errors++;
291 dev->net->stats.rx_length_errors++;
292 DBG(dev, "rx length %d\n", skb2->len);
293 dev_kfree_skb_any(skb2);
294 goto next_frame;
295 }
296 skb2->protocol = eth_type_trans(skb2, dev->net);
297 dev->net->stats.rx_packets++;
298 dev->net->stats.rx_bytes += skb2->len;
299
300 /* no buffer copies needed, unless hardware can't
301 * use skb buffers.
302 */
303 status = netif_rx(skb2);
304next_frame:
305 skb2 = skb_dequeue(&dev->rx_frames);
306 }
307 break;
308
309 /* software-driven interface shutdown */
310 case -ECONNRESET: /* unlink */
311 case -ESHUTDOWN: /* disconnect etc */
312 VDBG(dev, "rx shutdown, code %d\n", status);
313 goto quiesce;
314
315 /* for hardware automagic (such as pxa) */
316 case -ECONNABORTED: /* endpoint reset */
317 DBG(dev, "rx %s reset\n", ep->name);
318 defer_kevent(dev, WORK_RX_MEMORY);
319quiesce:
320 dev_kfree_skb_any(skb);
321 goto clean;
322
323 /* data overrun */
324 case -EOVERFLOW:
325 dev->net->stats.rx_over_errors++;
326 fallthrough;
327
328 default:
329 dev->net->stats.rx_errors++;
330 DBG(dev, "rx status %d\n", status);
331 break;
332 }
333
334 if (skb)
335 dev_kfree_skb_any(skb);
336 if (!netif_running(dev->net)) {
337clean:
338 spin_lock(&dev->req_lock);
339 list_add(&req->list, &dev->rx_reqs);
340 spin_unlock(&dev->req_lock);
341 req = NULL;
342 }
343 if (req)
344 rx_submit(dev, req, GFP_ATOMIC);
345}
346
347static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
348{
349 unsigned i;
350 struct usb_request *req;
351
352 if (!n)
353 return -ENOMEM;
354
355 /* queue/recycle up to N requests */
356 i = n;
357 list_for_each_entry(req, list, list) {
358 if (i-- == 0)
359 goto extra;
360 }
361 while (i--) {
362 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
363 if (!req)
364 return list_empty(list) ? -ENOMEM : 0;
365 list_add(&req->list, list);
366 }
367 return 0;
368
369extra:
370 /* free extras */
371 for (;;) {
372 struct list_head *next;
373
374 next = req->list.next;
375 list_del(&req->list);
376 usb_ep_free_request(ep, req);
377
378 if (next == list)
379 break;
380
381 req = container_of(next, struct usb_request, list);
382 }
383 return 0;
384}
385
386static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
387{
388 int status;
389
390 spin_lock(&dev->req_lock);
391 status = prealloc(&dev->tx_reqs, link->in_ep, n);
392 if (status < 0)
393 goto fail;
394 status = prealloc(&dev->rx_reqs, link->out_ep, n);
395 if (status < 0)
396 goto fail;
397 goto done;
398fail:
399 DBG(dev, "can't alloc requests\n");
400done:
401 spin_unlock(&dev->req_lock);
402 return status;
403}
404
405static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
406{
407 struct usb_request *req;
408 unsigned long flags;
409
410 /* fill unused rxq slots with some skb */
411 spin_lock_irqsave(&dev->req_lock, flags);
412 while (!list_empty(&dev->rx_reqs)) {
413 req = list_first_entry(&dev->rx_reqs, struct usb_request, list);
414 list_del_init(&req->list);
415 spin_unlock_irqrestore(&dev->req_lock, flags);
416
417 if (rx_submit(dev, req, gfp_flags) < 0) {
418 defer_kevent(dev, WORK_RX_MEMORY);
419 return;
420 }
421
422 spin_lock_irqsave(&dev->req_lock, flags);
423 }
424 spin_unlock_irqrestore(&dev->req_lock, flags);
425}
426
427static void eth_work(struct work_struct *work)
428{
429 struct eth_dev *dev = container_of(work, struct eth_dev, work);
430
431 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
432 if (netif_running(dev->net))
433 rx_fill(dev, GFP_KERNEL);
434 }
435
436 if (dev->todo)
437 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
438}
439
440static void tx_complete(struct usb_ep *ep, struct usb_request *req)
441{
442 struct sk_buff *skb = req->context;
443 struct eth_dev *dev = ep->driver_data;
444
445 switch (req->status) {
446 default:
447 dev->net->stats.tx_errors++;
448 VDBG(dev, "tx err %d\n", req->status);
449 fallthrough;
450 case -ECONNRESET: /* unlink */
451 case -ESHUTDOWN: /* disconnect etc */
452 dev_kfree_skb_any(skb);
453 break;
454 case 0:
455 dev->net->stats.tx_bytes += skb->len;
456 dev_consume_skb_any(skb);
457 }
458 dev->net->stats.tx_packets++;
459
460 spin_lock(&dev->req_lock);
461 list_add(&req->list, &dev->tx_reqs);
462 spin_unlock(&dev->req_lock);
463
464 atomic_dec(&dev->tx_qlen);
465 if (netif_carrier_ok(dev->net))
466 netif_wake_queue(dev->net);
467}
468
469static inline int is_promisc(u16 cdc_filter)
470{
471 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
472}
473
474static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
475 struct net_device *net)
476{
477 struct eth_dev *dev = netdev_priv(net);
478 int length = 0;
479 int retval;
480 struct usb_request *req = NULL;
481 unsigned long flags;
482 struct usb_ep *in;
483 u16 cdc_filter;
484
485 spin_lock_irqsave(&dev->lock, flags);
486 if (dev->port_usb) {
487 in = dev->port_usb->in_ep;
488 cdc_filter = dev->port_usb->cdc_filter;
489 } else {
490 in = NULL;
491 cdc_filter = 0;
492 }
493 spin_unlock_irqrestore(&dev->lock, flags);
494
495 if (!in) {
496 if (skb)
497 dev_kfree_skb_any(skb);
498 return NETDEV_TX_OK;
499 }
500
501 /* apply outgoing CDC or RNDIS filters */
502 if (skb && !is_promisc(cdc_filter)) {
503 u8 *dest = skb->data;
504
505 if (is_multicast_ether_addr(dest)) {
506 u16 type;
507
508 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
509 * SET_ETHERNET_MULTICAST_FILTERS requests
510 */
511 if (is_broadcast_ether_addr(dest))
512 type = USB_CDC_PACKET_TYPE_BROADCAST;
513 else
514 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
515 if (!(cdc_filter & type)) {
516 dev_kfree_skb_any(skb);
517 return NETDEV_TX_OK;
518 }
519 }
520 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
521 }
522
523 spin_lock_irqsave(&dev->req_lock, flags);
524 /*
525 * this freelist can be empty if an interrupt triggered disconnect()
526 * and reconfigured the gadget (shutting down this queue) after the
527 * network stack decided to xmit but before we got the spinlock.
528 */
529 if (list_empty(&dev->tx_reqs)) {
530 spin_unlock_irqrestore(&dev->req_lock, flags);
531 return NETDEV_TX_BUSY;
532 }
533
534 req = list_first_entry(&dev->tx_reqs, struct usb_request, list);
535 list_del(&req->list);
536
537 /* temporarily stop TX queue when the freelist empties */
538 if (list_empty(&dev->tx_reqs))
539 netif_stop_queue(net);
540 spin_unlock_irqrestore(&dev->req_lock, flags);
541
542 /* no buffer copies needed, unless the network stack did it
543 * or the hardware can't use skb buffers.
544 * or there's not enough space for extra headers we need
545 */
546 if (dev->wrap) {
547 unsigned long flags;
548
549 spin_lock_irqsave(&dev->lock, flags);
550 if (dev->port_usb)
551 skb = dev->wrap(dev->port_usb, skb);
552 spin_unlock_irqrestore(&dev->lock, flags);
553 if (!skb) {
554 /* Multi frame CDC protocols may store the frame for
555 * later which is not a dropped frame.
556 */
557 if (dev->port_usb &&
558 dev->port_usb->supports_multi_frame)
559 goto multiframe;
560 goto drop;
561 }
562 }
563
564 length = skb->len;
565 req->buf = skb->data;
566 req->context = skb;
567 req->complete = tx_complete;
568
569 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
570 if (dev->port_usb &&
571 dev->port_usb->is_fixed &&
572 length == dev->port_usb->fixed_in_len &&
573 (length % in->maxpacket) == 0)
574 req->zero = 0;
575 else
576 req->zero = 1;
577
578 /* use zlp framing on tx for strict CDC-Ether conformance,
579 * though any robust network rx path ignores extra padding.
580 * and some hardware doesn't like to write zlps.
581 */
582 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
583 length++;
584
585 req->length = length;
586
587 retval = usb_ep_queue(in, req, GFP_ATOMIC);
588 switch (retval) {
589 default:
590 DBG(dev, "tx queue err %d\n", retval);
591 break;
592 case 0:
593 netif_trans_update(net);
594 atomic_inc(&dev->tx_qlen);
595 }
596
597 if (retval) {
598 dev_kfree_skb_any(skb);
599drop:
600 dev->net->stats.tx_dropped++;
601multiframe:
602 spin_lock_irqsave(&dev->req_lock, flags);
603 if (list_empty(&dev->tx_reqs))
604 netif_start_queue(net);
605 list_add(&req->list, &dev->tx_reqs);
606 spin_unlock_irqrestore(&dev->req_lock, flags);
607 }
608 return NETDEV_TX_OK;
609}
610
611/*-------------------------------------------------------------------------*/
612
613static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
614{
615 DBG(dev, "%s\n", __func__);
616
617 /* fill the rx queue */
618 rx_fill(dev, gfp_flags);
619
620 /* and open the tx floodgates */
621 atomic_set(&dev->tx_qlen, 0);
622 netif_wake_queue(dev->net);
623}
624
625static int eth_open(struct net_device *net)
626{
627 struct eth_dev *dev = netdev_priv(net);
628 struct gether *link;
629
630 DBG(dev, "%s\n", __func__);
631 if (netif_carrier_ok(dev->net))
632 eth_start(dev, GFP_KERNEL);
633
634 spin_lock_irq(&dev->lock);
635 link = dev->port_usb;
636 if (link && link->open)
637 link->open(link);
638 spin_unlock_irq(&dev->lock);
639
640 return 0;
641}
642
643static int eth_stop(struct net_device *net)
644{
645 struct eth_dev *dev = netdev_priv(net);
646 unsigned long flags;
647
648 VDBG(dev, "%s\n", __func__);
649 netif_stop_queue(net);
650
651 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
652 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
653 dev->net->stats.rx_errors, dev->net->stats.tx_errors
654 );
655
656 /* ensure there are no more active requests */
657 spin_lock_irqsave(&dev->lock, flags);
658 if (dev->port_usb) {
659 struct gether *link = dev->port_usb;
660 const struct usb_endpoint_descriptor *in;
661 const struct usb_endpoint_descriptor *out;
662
663 if (link->close)
664 link->close(link);
665
666 /* NOTE: we have no abort-queue primitive we could use
667 * to cancel all pending I/O. Instead, we disable then
668 * reenable the endpoints ... this idiom may leave toggle
669 * wrong, but that's a self-correcting error.
670 *
671 * REVISIT: we *COULD* just let the transfers complete at
672 * their own pace; the network stack can handle old packets.
673 * For the moment we leave this here, since it works.
674 */
675 in = link->in_ep->desc;
676 out = link->out_ep->desc;
677 usb_ep_disable(link->in_ep);
678 usb_ep_disable(link->out_ep);
679 if (netif_carrier_ok(net)) {
680 DBG(dev, "host still using in/out endpoints\n");
681 link->in_ep->desc = in;
682 link->out_ep->desc = out;
683 usb_ep_enable(link->in_ep);
684 usb_ep_enable(link->out_ep);
685 }
686 }
687 spin_unlock_irqrestore(&dev->lock, flags);
688
689 return 0;
690}
691
692/*-------------------------------------------------------------------------*/
693
694static int get_ether_addr(const char *str, u8 *dev_addr)
695{
696 if (str) {
697 unsigned i;
698
699 for (i = 0; i < 6; i++) {
700 unsigned char num;
701
702 if ((*str == '.') || (*str == ':'))
703 str++;
704 num = hex_to_bin(*str++) << 4;
705 num |= hex_to_bin(*str++);
706 dev_addr [i] = num;
707 }
708 if (is_valid_ether_addr(dev_addr))
709 return 0;
710 }
711 eth_random_addr(dev_addr);
712 return 1;
713}
714
715static int get_ether_addr_str(u8 dev_addr[ETH_ALEN], char *str, int len)
716{
717 if (len < 18)
718 return -EINVAL;
719
720 snprintf(str, len, "%pM", dev_addr);
721 return 18;
722}
723
724static const struct net_device_ops eth_netdev_ops = {
725 .ndo_open = eth_open,
726 .ndo_stop = eth_stop,
727 .ndo_start_xmit = eth_start_xmit,
728 .ndo_set_mac_address = eth_mac_addr,
729 .ndo_validate_addr = eth_validate_addr,
730};
731
732static struct device_type gadget_type = {
733 .name = "gadget",
734};
735
736/*
737 * gether_setup_name - initialize one ethernet-over-usb link
738 * @g: gadget to associated with these links
739 * @ethaddr: NULL, or a buffer in which the ethernet address of the
740 * host side of the link is recorded
741 * @netname: name for network device (for example, "usb")
742 * Context: may sleep
743 *
744 * This sets up the single network link that may be exported by a
745 * gadget driver using this framework. The link layer addresses are
746 * set up using module parameters.
747 *
748 * Returns an eth_dev pointer on success, or an ERR_PTR on failure.
749 */
750struct eth_dev *gether_setup_name(struct usb_gadget *g,
751 const char *dev_addr, const char *host_addr,
752 u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname)
753{
754 struct eth_dev *dev;
755 struct net_device *net;
756 int status;
757
758 net = alloc_etherdev(sizeof *dev);
759 if (!net)
760 return ERR_PTR(-ENOMEM);
761
762 dev = netdev_priv(net);
763 spin_lock_init(&dev->lock);
764 spin_lock_init(&dev->req_lock);
765 INIT_WORK(&dev->work, eth_work);
766 INIT_LIST_HEAD(&dev->tx_reqs);
767 INIT_LIST_HEAD(&dev->rx_reqs);
768
769 skb_queue_head_init(&dev->rx_frames);
770
771 /* network device setup */
772 dev->net = net;
773 dev->qmult = qmult;
774 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
775
776 if (get_ether_addr(dev_addr, net->dev_addr))
777 dev_warn(&g->dev,
778 "using random %s ethernet address\n", "self");
779 if (get_ether_addr(host_addr, dev->host_mac))
780 dev_warn(&g->dev,
781 "using random %s ethernet address\n", "host");
782
783 if (ethaddr)
784 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
785
786 net->netdev_ops = ð_netdev_ops;
787
788 net->ethtool_ops = &ops;
789
790 /* MTU range: 14 - 15412 */
791 net->min_mtu = ETH_HLEN;
792 net->max_mtu = GETHER_MAX_MTU_SIZE;
793
794 dev->gadget = g;
795 SET_NETDEV_DEV(net, &g->dev);
796 SET_NETDEV_DEVTYPE(net, &gadget_type);
797
798 status = register_netdev(net);
799 if (status < 0) {
800 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
801 free_netdev(net);
802 dev = ERR_PTR(status);
803 } else {
804 INFO(dev, "MAC %pM\n", net->dev_addr);
805 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
806
807 /*
808 * two kinds of host-initiated state changes:
809 * - iff DATA transfer is active, carrier is "on"
810 * - tx queueing enabled if open *and* carrier is "on"
811 */
812 netif_carrier_off(net);
813 }
814
815 return dev;
816}
817EXPORT_SYMBOL_GPL(gether_setup_name);
818
819struct net_device *gether_setup_name_default(const char *netname)
820{
821 struct net_device *net;
822 struct eth_dev *dev;
823
824 net = alloc_etherdev(sizeof(*dev));
825 if (!net)
826 return ERR_PTR(-ENOMEM);
827
828 dev = netdev_priv(net);
829 spin_lock_init(&dev->lock);
830 spin_lock_init(&dev->req_lock);
831 INIT_WORK(&dev->work, eth_work);
832 INIT_LIST_HEAD(&dev->tx_reqs);
833 INIT_LIST_HEAD(&dev->rx_reqs);
834
835 skb_queue_head_init(&dev->rx_frames);
836
837 /* network device setup */
838 dev->net = net;
839 dev->qmult = QMULT_DEFAULT;
840 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
841
842 eth_random_addr(dev->dev_mac);
843 pr_warn("using random %s ethernet address\n", "self");
844 eth_random_addr(dev->host_mac);
845 pr_warn("using random %s ethernet address\n", "host");
846
847 net->netdev_ops = ð_netdev_ops;
848
849 net->ethtool_ops = &ops;
850 SET_NETDEV_DEVTYPE(net, &gadget_type);
851
852 /* MTU range: 14 - 15412 */
853 net->min_mtu = ETH_HLEN;
854 net->max_mtu = GETHER_MAX_MTU_SIZE;
855
856 return net;
857}
858EXPORT_SYMBOL_GPL(gether_setup_name_default);
859
860int gether_register_netdev(struct net_device *net)
861{
862 struct eth_dev *dev;
863 struct usb_gadget *g;
864 struct sockaddr sa;
865 int status;
866
867 if (!net->dev.parent)
868 return -EINVAL;
869 dev = netdev_priv(net);
870 g = dev->gadget;
871 status = register_netdev(net);
872 if (status < 0) {
873 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
874 return status;
875 } else {
876 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
877
878 /* two kinds of host-initiated state changes:
879 * - iff DATA transfer is active, carrier is "on"
880 * - tx queueing enabled if open *and* carrier is "on"
881 */
882 netif_carrier_off(net);
883 }
884 sa.sa_family = net->type;
885 memcpy(sa.sa_data, dev->dev_mac, ETH_ALEN);
886 rtnl_lock();
887 status = dev_set_mac_address(net, &sa, NULL);
888 rtnl_unlock();
889 if (status)
890 pr_warn("cannot set self ethernet address: %d\n", status);
891 else
892 INFO(dev, "MAC %pM\n", dev->dev_mac);
893
894 return status;
895}
896EXPORT_SYMBOL_GPL(gether_register_netdev);
897
898void gether_set_gadget(struct net_device *net, struct usb_gadget *g)
899{
900 struct eth_dev *dev;
901
902 dev = netdev_priv(net);
903 dev->gadget = g;
904 SET_NETDEV_DEV(net, &g->dev);
905}
906EXPORT_SYMBOL_GPL(gether_set_gadget);
907
908int gether_set_dev_addr(struct net_device *net, const char *dev_addr)
909{
910 struct eth_dev *dev;
911 u8 new_addr[ETH_ALEN];
912
913 dev = netdev_priv(net);
914 if (get_ether_addr(dev_addr, new_addr))
915 return -EINVAL;
916 memcpy(dev->dev_mac, new_addr, ETH_ALEN);
917 return 0;
918}
919EXPORT_SYMBOL_GPL(gether_set_dev_addr);
920
921int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len)
922{
923 struct eth_dev *dev;
924 int ret;
925
926 dev = netdev_priv(net);
927 ret = get_ether_addr_str(dev->dev_mac, dev_addr, len);
928 if (ret + 1 < len) {
929 dev_addr[ret++] = '\n';
930 dev_addr[ret] = '\0';
931 }
932
933 return ret;
934}
935EXPORT_SYMBOL_GPL(gether_get_dev_addr);
936
937int gether_set_host_addr(struct net_device *net, const char *host_addr)
938{
939 struct eth_dev *dev;
940 u8 new_addr[ETH_ALEN];
941
942 dev = netdev_priv(net);
943 if (get_ether_addr(host_addr, new_addr))
944 return -EINVAL;
945 memcpy(dev->host_mac, new_addr, ETH_ALEN);
946 return 0;
947}
948EXPORT_SYMBOL_GPL(gether_set_host_addr);
949
950int gether_get_host_addr(struct net_device *net, char *host_addr, int len)
951{
952 struct eth_dev *dev;
953 int ret;
954
955 dev = netdev_priv(net);
956 ret = get_ether_addr_str(dev->host_mac, host_addr, len);
957 if (ret + 1 < len) {
958 host_addr[ret++] = '\n';
959 host_addr[ret] = '\0';
960 }
961
962 return ret;
963}
964EXPORT_SYMBOL_GPL(gether_get_host_addr);
965
966int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len)
967{
968 struct eth_dev *dev;
969
970 if (len < 13)
971 return -EINVAL;
972
973 dev = netdev_priv(net);
974 snprintf(host_addr, len, "%pm", dev->host_mac);
975
976 return strlen(host_addr);
977}
978EXPORT_SYMBOL_GPL(gether_get_host_addr_cdc);
979
980void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN])
981{
982 struct eth_dev *dev;
983
984 dev = netdev_priv(net);
985 memcpy(host_mac, dev->host_mac, ETH_ALEN);
986}
987EXPORT_SYMBOL_GPL(gether_get_host_addr_u8);
988
989void gether_set_qmult(struct net_device *net, unsigned qmult)
990{
991 struct eth_dev *dev;
992
993 dev = netdev_priv(net);
994 dev->qmult = qmult;
995}
996EXPORT_SYMBOL_GPL(gether_set_qmult);
997
998unsigned gether_get_qmult(struct net_device *net)
999{
1000 struct eth_dev *dev;
1001
1002 dev = netdev_priv(net);
1003 return dev->qmult;
1004}
1005EXPORT_SYMBOL_GPL(gether_get_qmult);
1006
1007int gether_get_ifname(struct net_device *net, char *name, int len)
1008{
1009 struct eth_dev *dev = netdev_priv(net);
1010 int ret;
1011
1012 rtnl_lock();
1013 ret = scnprintf(name, len, "%s\n",
1014 dev->ifname_set ? net->name : netdev_name(net));
1015 rtnl_unlock();
1016 return ret;
1017}
1018EXPORT_SYMBOL_GPL(gether_get_ifname);
1019
1020int gether_set_ifname(struct net_device *net, const char *name, int len)
1021{
1022 struct eth_dev *dev = netdev_priv(net);
1023 char tmp[IFNAMSIZ];
1024 const char *p;
1025
1026 if (name[len - 1] == '\n')
1027 len--;
1028
1029 if (len >= sizeof(tmp))
1030 return -E2BIG;
1031
1032 strscpy(tmp, name, len + 1);
1033 if (!dev_valid_name(tmp))
1034 return -EINVAL;
1035
1036 /* Require exactly one %d, so binding will not fail with EEXIST. */
1037 p = strchr(name, '%');
1038 if (!p || p[1] != 'd' || strchr(p + 2, '%'))
1039 return -EINVAL;
1040
1041 strncpy(net->name, tmp, sizeof(net->name));
1042 dev->ifname_set = true;
1043
1044 return 0;
1045}
1046EXPORT_SYMBOL_GPL(gether_set_ifname);
1047
1048/*
1049 * gether_cleanup - remove Ethernet-over-USB device
1050 * Context: may sleep
1051 *
1052 * This is called to free all resources allocated by @gether_setup().
1053 */
1054void gether_cleanup(struct eth_dev *dev)
1055{
1056 if (!dev)
1057 return;
1058
1059 unregister_netdev(dev->net);
1060 flush_work(&dev->work);
1061 free_netdev(dev->net);
1062}
1063EXPORT_SYMBOL_GPL(gether_cleanup);
1064
1065/**
1066 * gether_connect - notify network layer that USB link is active
1067 * @link: the USB link, set up with endpoints, descriptors matching
1068 * current device speed, and any framing wrapper(s) set up.
1069 * Context: irqs blocked
1070 *
1071 * This is called to activate endpoints and let the network layer know
1072 * the connection is active ("carrier detect"). It may cause the I/O
1073 * queues to open and start letting network packets flow, but will in
1074 * any case activate the endpoints so that they respond properly to the
1075 * USB host.
1076 *
1077 * Verify net_device pointer returned using IS_ERR(). If it doesn't
1078 * indicate some error code (negative errno), ep->driver_data values
1079 * have been overwritten.
1080 */
1081struct net_device *gether_connect(struct gether *link)
1082{
1083 struct eth_dev *dev = link->ioport;
1084 int result = 0;
1085
1086 if (!dev)
1087 return ERR_PTR(-EINVAL);
1088
1089 link->in_ep->driver_data = dev;
1090 result = usb_ep_enable(link->in_ep);
1091 if (result != 0) {
1092 DBG(dev, "enable %s --> %d\n",
1093 link->in_ep->name, result);
1094 goto fail0;
1095 }
1096
1097 link->out_ep->driver_data = dev;
1098 result = usb_ep_enable(link->out_ep);
1099 if (result != 0) {
1100 DBG(dev, "enable %s --> %d\n",
1101 link->out_ep->name, result);
1102 goto fail1;
1103 }
1104
1105 if (result == 0)
1106 result = alloc_requests(dev, link, qlen(dev->gadget,
1107 dev->qmult));
1108
1109 if (result == 0) {
1110 dev->zlp = link->is_zlp_ok;
1111 dev->no_skb_reserve = gadget_avoids_skb_reserve(dev->gadget);
1112 DBG(dev, "qlen %d\n", qlen(dev->gadget, dev->qmult));
1113
1114 dev->header_len = link->header_len;
1115 dev->unwrap = link->unwrap;
1116 dev->wrap = link->wrap;
1117
1118 spin_lock(&dev->lock);
1119 dev->port_usb = link;
1120 if (netif_running(dev->net)) {
1121 if (link->open)
1122 link->open(link);
1123 } else {
1124 if (link->close)
1125 link->close(link);
1126 }
1127 spin_unlock(&dev->lock);
1128
1129 netif_carrier_on(dev->net);
1130 if (netif_running(dev->net))
1131 eth_start(dev, GFP_ATOMIC);
1132
1133 /* on error, disable any endpoints */
1134 } else {
1135 (void) usb_ep_disable(link->out_ep);
1136fail1:
1137 (void) usb_ep_disable(link->in_ep);
1138 }
1139fail0:
1140 /* caller is responsible for cleanup on error */
1141 if (result < 0)
1142 return ERR_PTR(result);
1143 return dev->net;
1144}
1145EXPORT_SYMBOL_GPL(gether_connect);
1146
1147/**
1148 * gether_disconnect - notify network layer that USB link is inactive
1149 * @link: the USB link, on which gether_connect() was called
1150 * Context: irqs blocked
1151 *
1152 * This is called to deactivate endpoints and let the network layer know
1153 * the connection went inactive ("no carrier").
1154 *
1155 * On return, the state is as if gether_connect() had never been called.
1156 * The endpoints are inactive, and accordingly without active USB I/O.
1157 * Pointers to endpoint descriptors and endpoint private data are nulled.
1158 */
1159void gether_disconnect(struct gether *link)
1160{
1161 struct eth_dev *dev = link->ioport;
1162 struct usb_request *req;
1163
1164 WARN_ON(!dev);
1165 if (!dev)
1166 return;
1167
1168 DBG(dev, "%s\n", __func__);
1169
1170 netif_stop_queue(dev->net);
1171 netif_carrier_off(dev->net);
1172
1173 /* disable endpoints, forcing (synchronous) completion
1174 * of all pending i/o. then free the request objects
1175 * and forget about the endpoints.
1176 */
1177 usb_ep_disable(link->in_ep);
1178 spin_lock(&dev->req_lock);
1179 while (!list_empty(&dev->tx_reqs)) {
1180 req = list_first_entry(&dev->tx_reqs, struct usb_request, list);
1181 list_del(&req->list);
1182
1183 spin_unlock(&dev->req_lock);
1184 usb_ep_free_request(link->in_ep, req);
1185 spin_lock(&dev->req_lock);
1186 }
1187 spin_unlock(&dev->req_lock);
1188 link->in_ep->desc = NULL;
1189
1190 usb_ep_disable(link->out_ep);
1191 spin_lock(&dev->req_lock);
1192 while (!list_empty(&dev->rx_reqs)) {
1193 req = list_first_entry(&dev->rx_reqs, struct usb_request, list);
1194 list_del(&req->list);
1195
1196 spin_unlock(&dev->req_lock);
1197 usb_ep_free_request(link->out_ep, req);
1198 spin_lock(&dev->req_lock);
1199 }
1200 spin_unlock(&dev->req_lock);
1201 link->out_ep->desc = NULL;
1202
1203 /* finish forgetting about this USB link episode */
1204 dev->header_len = 0;
1205 dev->unwrap = NULL;
1206 dev->wrap = NULL;
1207
1208 spin_lock(&dev->lock);
1209 dev->port_usb = NULL;
1210 spin_unlock(&dev->lock);
1211}
1212EXPORT_SYMBOL_GPL(gether_disconnect);
1213
1214MODULE_LICENSE("GPL");
1215MODULE_AUTHOR("David Brownell");