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1/*
2 * u_ether.c -- Ethernet-over-USB link layer utilities for Gadget stack
3 *
4 * Copyright (C) 2003-2005,2008 David Brownell
5 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
6 * Copyright (C) 2008 Nokia Corporation
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 */
13
14/* #define VERBOSE_DEBUG */
15
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/gfp.h>
19#include <linux/device.h>
20#include <linux/ctype.h>
21#include <linux/etherdevice.h>
22#include <linux/ethtool.h>
23#include <linux/if_vlan.h>
24
25#include "u_ether.h"
26
27
28/*
29 * This component encapsulates the Ethernet link glue needed to provide
30 * one (!) network link through the USB gadget stack, normally "usb0".
31 *
32 * The control and data models are handled by the function driver which
33 * connects to this code; such as CDC Ethernet (ECM or EEM),
34 * "CDC Subset", or RNDIS. That includes all descriptor and endpoint
35 * management.
36 *
37 * Link level addressing is handled by this component using module
38 * parameters; if no such parameters are provided, random link level
39 * addresses are used. Each end of the link uses one address. The
40 * host end address is exported in various ways, and is often recorded
41 * in configuration databases.
42 *
43 * The driver which assembles each configuration using such a link is
44 * responsible for ensuring that each configuration includes at most one
45 * instance of is network link. (The network layer provides ways for
46 * this single "physical" link to be used by multiple virtual links.)
47 */
48
49#define UETH__VERSION "29-May-2008"
50
51struct eth_dev {
52 /* lock is held while accessing port_usb
53 */
54 spinlock_t lock;
55 struct gether *port_usb;
56
57 struct net_device *net;
58 struct usb_gadget *gadget;
59
60 spinlock_t req_lock; /* guard {rx,tx}_reqs */
61 struct list_head tx_reqs, rx_reqs;
62 atomic_t tx_qlen;
63
64 struct sk_buff_head rx_frames;
65
66 unsigned qmult;
67
68 unsigned header_len;
69 struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
70 int (*unwrap)(struct gether *,
71 struct sk_buff *skb,
72 struct sk_buff_head *list);
73
74 struct work_struct work;
75
76 unsigned long todo;
77#define WORK_RX_MEMORY 0
78
79 bool zlp;
80 u8 host_mac[ETH_ALEN];
81 u8 dev_mac[ETH_ALEN];
82};
83
84/*-------------------------------------------------------------------------*/
85
86#define RX_EXTRA 20 /* bytes guarding against rx overflows */
87
88#define DEFAULT_QLEN 2 /* double buffering by default */
89
90/* for dual-speed hardware, use deeper queues at high/super speed */
91static inline int qlen(struct usb_gadget *gadget, unsigned qmult)
92{
93 if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
94 gadget->speed == USB_SPEED_SUPER))
95 return qmult * DEFAULT_QLEN;
96 else
97 return DEFAULT_QLEN;
98}
99
100/*-------------------------------------------------------------------------*/
101
102/* REVISIT there must be a better way than having two sets
103 * of debug calls ...
104 */
105
106#undef DBG
107#undef VDBG
108#undef ERROR
109#undef INFO
110
111#define xprintk(d, level, fmt, args...) \
112 printk(level "%s: " fmt , (d)->net->name , ## args)
113
114#ifdef DEBUG
115#undef DEBUG
116#define DBG(dev, fmt, args...) \
117 xprintk(dev , KERN_DEBUG , fmt , ## args)
118#else
119#define DBG(dev, fmt, args...) \
120 do { } while (0)
121#endif /* DEBUG */
122
123#ifdef VERBOSE_DEBUG
124#define VDBG DBG
125#else
126#define VDBG(dev, fmt, args...) \
127 do { } while (0)
128#endif /* DEBUG */
129
130#define ERROR(dev, fmt, args...) \
131 xprintk(dev , KERN_ERR , fmt , ## args)
132#define INFO(dev, fmt, args...) \
133 xprintk(dev , KERN_INFO , fmt , ## args)
134
135/*-------------------------------------------------------------------------*/
136
137/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
138
139static int ueth_change_mtu(struct net_device *net, int new_mtu)
140{
141 struct eth_dev *dev = netdev_priv(net);
142 unsigned long flags;
143 int status = 0;
144
145 /* don't change MTU on "live" link (peer won't know) */
146 spin_lock_irqsave(&dev->lock, flags);
147 if (dev->port_usb)
148 status = -EBUSY;
149 else if (new_mtu <= ETH_HLEN || new_mtu > ETH_FRAME_LEN)
150 status = -ERANGE;
151 else
152 net->mtu = new_mtu;
153 spin_unlock_irqrestore(&dev->lock, flags);
154
155 return status;
156}
157
158static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
159{
160 struct eth_dev *dev = netdev_priv(net);
161
162 strlcpy(p->driver, "g_ether", sizeof(p->driver));
163 strlcpy(p->version, UETH__VERSION, sizeof(p->version));
164 strlcpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version));
165 strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof(p->bus_info));
166}
167
168/* REVISIT can also support:
169 * - WOL (by tracking suspends and issuing remote wakeup)
170 * - msglevel (implies updated messaging)
171 * - ... probably more ethtool ops
172 */
173
174static const struct ethtool_ops ops = {
175 .get_drvinfo = eth_get_drvinfo,
176 .get_link = ethtool_op_get_link,
177};
178
179static void defer_kevent(struct eth_dev *dev, int flag)
180{
181 if (test_and_set_bit(flag, &dev->todo))
182 return;
183 if (!schedule_work(&dev->work))
184 ERROR(dev, "kevent %d may have been dropped\n", flag);
185 else
186 DBG(dev, "kevent %d scheduled\n", flag);
187}
188
189static void rx_complete(struct usb_ep *ep, struct usb_request *req);
190
191static int
192rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
193{
194 struct sk_buff *skb;
195 int retval = -ENOMEM;
196 size_t size = 0;
197 struct usb_ep *out;
198 unsigned long flags;
199
200 spin_lock_irqsave(&dev->lock, flags);
201 if (dev->port_usb)
202 out = dev->port_usb->out_ep;
203 else
204 out = NULL;
205 spin_unlock_irqrestore(&dev->lock, flags);
206
207 if (!out)
208 return -ENOTCONN;
209
210
211 /* Padding up to RX_EXTRA handles minor disagreements with host.
212 * Normally we use the USB "terminate on short read" convention;
213 * so allow up to (N*maxpacket), since that memory is normally
214 * already allocated. Some hardware doesn't deal well with short
215 * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
216 * byte off the end (to force hardware errors on overflow).
217 *
218 * RNDIS uses internal framing, and explicitly allows senders to
219 * pad to end-of-packet. That's potentially nice for speed, but
220 * means receivers can't recover lost synch on their own (because
221 * new packets don't only start after a short RX).
222 */
223 size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
224 size += dev->port_usb->header_len;
225 size += out->maxpacket - 1;
226 size -= size % out->maxpacket;
227
228 if (dev->port_usb->is_fixed)
229 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
230
231 skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
232 if (skb == NULL) {
233 DBG(dev, "no rx skb\n");
234 goto enomem;
235 }
236
237 /* Some platforms perform better when IP packets are aligned,
238 * but on at least one, checksumming fails otherwise. Note:
239 * RNDIS headers involve variable numbers of LE32 values.
240 */
241 skb_reserve(skb, NET_IP_ALIGN);
242
243 req->buf = skb->data;
244 req->length = size;
245 req->complete = rx_complete;
246 req->context = skb;
247
248 retval = usb_ep_queue(out, req, gfp_flags);
249 if (retval == -ENOMEM)
250enomem:
251 defer_kevent(dev, WORK_RX_MEMORY);
252 if (retval) {
253 DBG(dev, "rx submit --> %d\n", retval);
254 if (skb)
255 dev_kfree_skb_any(skb);
256 spin_lock_irqsave(&dev->req_lock, flags);
257 list_add(&req->list, &dev->rx_reqs);
258 spin_unlock_irqrestore(&dev->req_lock, flags);
259 }
260 return retval;
261}
262
263static void rx_complete(struct usb_ep *ep, struct usb_request *req)
264{
265 struct sk_buff *skb = req->context, *skb2;
266 struct eth_dev *dev = ep->driver_data;
267 int status = req->status;
268
269 switch (status) {
270
271 /* normal completion */
272 case 0:
273 skb_put(skb, req->actual);
274
275 if (dev->unwrap) {
276 unsigned long flags;
277
278 spin_lock_irqsave(&dev->lock, flags);
279 if (dev->port_usb) {
280 status = dev->unwrap(dev->port_usb,
281 skb,
282 &dev->rx_frames);
283 } else {
284 dev_kfree_skb_any(skb);
285 status = -ENOTCONN;
286 }
287 spin_unlock_irqrestore(&dev->lock, flags);
288 } else {
289 skb_queue_tail(&dev->rx_frames, skb);
290 }
291 skb = NULL;
292
293 skb2 = skb_dequeue(&dev->rx_frames);
294 while (skb2) {
295 if (status < 0
296 || ETH_HLEN > skb2->len
297 || skb2->len > VLAN_ETH_FRAME_LEN) {
298 dev->net->stats.rx_errors++;
299 dev->net->stats.rx_length_errors++;
300 DBG(dev, "rx length %d\n", skb2->len);
301 dev_kfree_skb_any(skb2);
302 goto next_frame;
303 }
304 skb2->protocol = eth_type_trans(skb2, dev->net);
305 dev->net->stats.rx_packets++;
306 dev->net->stats.rx_bytes += skb2->len;
307
308 /* no buffer copies needed, unless hardware can't
309 * use skb buffers.
310 */
311 status = netif_rx(skb2);
312next_frame:
313 skb2 = skb_dequeue(&dev->rx_frames);
314 }
315 break;
316
317 /* software-driven interface shutdown */
318 case -ECONNRESET: /* unlink */
319 case -ESHUTDOWN: /* disconnect etc */
320 VDBG(dev, "rx shutdown, code %d\n", status);
321 goto quiesce;
322
323 /* for hardware automagic (such as pxa) */
324 case -ECONNABORTED: /* endpoint reset */
325 DBG(dev, "rx %s reset\n", ep->name);
326 defer_kevent(dev, WORK_RX_MEMORY);
327quiesce:
328 dev_kfree_skb_any(skb);
329 goto clean;
330
331 /* data overrun */
332 case -EOVERFLOW:
333 dev->net->stats.rx_over_errors++;
334 /* FALLTHROUGH */
335
336 default:
337 dev->net->stats.rx_errors++;
338 DBG(dev, "rx status %d\n", status);
339 break;
340 }
341
342 if (skb)
343 dev_kfree_skb_any(skb);
344 if (!netif_running(dev->net)) {
345clean:
346 spin_lock(&dev->req_lock);
347 list_add(&req->list, &dev->rx_reqs);
348 spin_unlock(&dev->req_lock);
349 req = NULL;
350 }
351 if (req)
352 rx_submit(dev, req, GFP_ATOMIC);
353}
354
355static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
356{
357 unsigned i;
358 struct usb_request *req;
359
360 if (!n)
361 return -ENOMEM;
362
363 /* queue/recycle up to N requests */
364 i = n;
365 list_for_each_entry(req, list, list) {
366 if (i-- == 0)
367 goto extra;
368 }
369 while (i--) {
370 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
371 if (!req)
372 return list_empty(list) ? -ENOMEM : 0;
373 list_add(&req->list, list);
374 }
375 return 0;
376
377extra:
378 /* free extras */
379 for (;;) {
380 struct list_head *next;
381
382 next = req->list.next;
383 list_del(&req->list);
384 usb_ep_free_request(ep, req);
385
386 if (next == list)
387 break;
388
389 req = container_of(next, struct usb_request, list);
390 }
391 return 0;
392}
393
394static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
395{
396 int status;
397
398 spin_lock(&dev->req_lock);
399 status = prealloc(&dev->tx_reqs, link->in_ep, n);
400 if (status < 0)
401 goto fail;
402 status = prealloc(&dev->rx_reqs, link->out_ep, n);
403 if (status < 0)
404 goto fail;
405 goto done;
406fail:
407 DBG(dev, "can't alloc requests\n");
408done:
409 spin_unlock(&dev->req_lock);
410 return status;
411}
412
413static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
414{
415 struct usb_request *req;
416 unsigned long flags;
417
418 /* fill unused rxq slots with some skb */
419 spin_lock_irqsave(&dev->req_lock, flags);
420 while (!list_empty(&dev->rx_reqs)) {
421 req = container_of(dev->rx_reqs.next,
422 struct usb_request, list);
423 list_del_init(&req->list);
424 spin_unlock_irqrestore(&dev->req_lock, flags);
425
426 if (rx_submit(dev, req, gfp_flags) < 0) {
427 defer_kevent(dev, WORK_RX_MEMORY);
428 return;
429 }
430
431 spin_lock_irqsave(&dev->req_lock, flags);
432 }
433 spin_unlock_irqrestore(&dev->req_lock, flags);
434}
435
436static void eth_work(struct work_struct *work)
437{
438 struct eth_dev *dev = container_of(work, struct eth_dev, work);
439
440 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
441 if (netif_running(dev->net))
442 rx_fill(dev, GFP_KERNEL);
443 }
444
445 if (dev->todo)
446 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
447}
448
449static void tx_complete(struct usb_ep *ep, struct usb_request *req)
450{
451 struct sk_buff *skb = req->context;
452 struct eth_dev *dev = ep->driver_data;
453
454 switch (req->status) {
455 default:
456 dev->net->stats.tx_errors++;
457 VDBG(dev, "tx err %d\n", req->status);
458 /* FALLTHROUGH */
459 case -ECONNRESET: /* unlink */
460 case -ESHUTDOWN: /* disconnect etc */
461 break;
462 case 0:
463 dev->net->stats.tx_bytes += skb->len;
464 }
465 dev->net->stats.tx_packets++;
466
467 spin_lock(&dev->req_lock);
468 list_add(&req->list, &dev->tx_reqs);
469 spin_unlock(&dev->req_lock);
470 dev_kfree_skb_any(skb);
471
472 atomic_dec(&dev->tx_qlen);
473 if (netif_carrier_ok(dev->net))
474 netif_wake_queue(dev->net);
475}
476
477static inline int is_promisc(u16 cdc_filter)
478{
479 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
480}
481
482static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
483 struct net_device *net)
484{
485 struct eth_dev *dev = netdev_priv(net);
486 int length = skb->len;
487 int retval;
488 struct usb_request *req = NULL;
489 unsigned long flags;
490 struct usb_ep *in;
491 u16 cdc_filter;
492
493 spin_lock_irqsave(&dev->lock, flags);
494 if (dev->port_usb) {
495 in = dev->port_usb->in_ep;
496 cdc_filter = dev->port_usb->cdc_filter;
497 } else {
498 in = NULL;
499 cdc_filter = 0;
500 }
501 spin_unlock_irqrestore(&dev->lock, flags);
502
503 if (!in) {
504 dev_kfree_skb_any(skb);
505 return NETDEV_TX_OK;
506 }
507
508 /* apply outgoing CDC or RNDIS filters */
509 if (!is_promisc(cdc_filter)) {
510 u8 *dest = skb->data;
511
512 if (is_multicast_ether_addr(dest)) {
513 u16 type;
514
515 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
516 * SET_ETHERNET_MULTICAST_FILTERS requests
517 */
518 if (is_broadcast_ether_addr(dest))
519 type = USB_CDC_PACKET_TYPE_BROADCAST;
520 else
521 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
522 if (!(cdc_filter & type)) {
523 dev_kfree_skb_any(skb);
524 return NETDEV_TX_OK;
525 }
526 }
527 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
528 }
529
530 spin_lock_irqsave(&dev->req_lock, flags);
531 /*
532 * this freelist can be empty if an interrupt triggered disconnect()
533 * and reconfigured the gadget (shutting down this queue) after the
534 * network stack decided to xmit but before we got the spinlock.
535 */
536 if (list_empty(&dev->tx_reqs)) {
537 spin_unlock_irqrestore(&dev->req_lock, flags);
538 return NETDEV_TX_BUSY;
539 }
540
541 req = container_of(dev->tx_reqs.next, struct usb_request, list);
542 list_del(&req->list);
543
544 /* temporarily stop TX queue when the freelist empties */
545 if (list_empty(&dev->tx_reqs))
546 netif_stop_queue(net);
547 spin_unlock_irqrestore(&dev->req_lock, flags);
548
549 /* no buffer copies needed, unless the network stack did it
550 * or the hardware can't use skb buffers.
551 * or there's not enough space for extra headers we need
552 */
553 if (dev->wrap) {
554 unsigned long flags;
555
556 spin_lock_irqsave(&dev->lock, flags);
557 if (dev->port_usb)
558 skb = dev->wrap(dev->port_usb, skb);
559 spin_unlock_irqrestore(&dev->lock, flags);
560 if (!skb)
561 goto drop;
562
563 length = skb->len;
564 }
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->is_fixed &&
571 length == dev->port_usb->fixed_in_len &&
572 (length % in->maxpacket) == 0)
573 req->zero = 0;
574 else
575 req->zero = 1;
576
577 /* use zlp framing on tx for strict CDC-Ether conformance,
578 * though any robust network rx path ignores extra padding.
579 * and some hardware doesn't like to write zlps.
580 */
581 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
582 length++;
583
584 req->length = length;
585
586 /* throttle high/super speed IRQ rate back slightly */
587 if (gadget_is_dualspeed(dev->gadget))
588 req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH ||
589 dev->gadget->speed == USB_SPEED_SUPER)
590 ? ((atomic_read(&dev->tx_qlen) % dev->qmult) != 0)
591 : 0;
592
593 retval = usb_ep_queue(in, req, GFP_ATOMIC);
594 switch (retval) {
595 default:
596 DBG(dev, "tx queue err %d\n", retval);
597 break;
598 case 0:
599 net->trans_start = jiffies;
600 atomic_inc(&dev->tx_qlen);
601 }
602
603 if (retval) {
604 dev_kfree_skb_any(skb);
605drop:
606 dev->net->stats.tx_dropped++;
607 spin_lock_irqsave(&dev->req_lock, flags);
608 if (list_empty(&dev->tx_reqs))
609 netif_start_queue(net);
610 list_add(&req->list, &dev->tx_reqs);
611 spin_unlock_irqrestore(&dev->req_lock, flags);
612 }
613 return NETDEV_TX_OK;
614}
615
616/*-------------------------------------------------------------------------*/
617
618static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
619{
620 DBG(dev, "%s\n", __func__);
621
622 /* fill the rx queue */
623 rx_fill(dev, gfp_flags);
624
625 /* and open the tx floodgates */
626 atomic_set(&dev->tx_qlen, 0);
627 netif_wake_queue(dev->net);
628}
629
630static int eth_open(struct net_device *net)
631{
632 struct eth_dev *dev = netdev_priv(net);
633 struct gether *link;
634
635 DBG(dev, "%s\n", __func__);
636 if (netif_carrier_ok(dev->net))
637 eth_start(dev, GFP_KERNEL);
638
639 spin_lock_irq(&dev->lock);
640 link = dev->port_usb;
641 if (link && link->open)
642 link->open(link);
643 spin_unlock_irq(&dev->lock);
644
645 return 0;
646}
647
648static int eth_stop(struct net_device *net)
649{
650 struct eth_dev *dev = netdev_priv(net);
651 unsigned long flags;
652
653 VDBG(dev, "%s\n", __func__);
654 netif_stop_queue(net);
655
656 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
657 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
658 dev->net->stats.rx_errors, dev->net->stats.tx_errors
659 );
660
661 /* ensure there are no more active requests */
662 spin_lock_irqsave(&dev->lock, flags);
663 if (dev->port_usb) {
664 struct gether *link = dev->port_usb;
665 const struct usb_endpoint_descriptor *in;
666 const struct usb_endpoint_descriptor *out;
667
668 if (link->close)
669 link->close(link);
670
671 /* NOTE: we have no abort-queue primitive we could use
672 * to cancel all pending I/O. Instead, we disable then
673 * reenable the endpoints ... this idiom may leave toggle
674 * wrong, but that's a self-correcting error.
675 *
676 * REVISIT: we *COULD* just let the transfers complete at
677 * their own pace; the network stack can handle old packets.
678 * For the moment we leave this here, since it works.
679 */
680 in = link->in_ep->desc;
681 out = link->out_ep->desc;
682 usb_ep_disable(link->in_ep);
683 usb_ep_disable(link->out_ep);
684 if (netif_carrier_ok(net)) {
685 DBG(dev, "host still using in/out endpoints\n");
686 link->in_ep->desc = in;
687 link->out_ep->desc = out;
688 usb_ep_enable(link->in_ep);
689 usb_ep_enable(link->out_ep);
690 }
691 }
692 spin_unlock_irqrestore(&dev->lock, flags);
693
694 return 0;
695}
696
697/*-------------------------------------------------------------------------*/
698
699static int get_ether_addr(const char *str, u8 *dev_addr)
700{
701 if (str) {
702 unsigned i;
703
704 for (i = 0; i < 6; i++) {
705 unsigned char num;
706
707 if ((*str == '.') || (*str == ':'))
708 str++;
709 num = hex_to_bin(*str++) << 4;
710 num |= hex_to_bin(*str++);
711 dev_addr [i] = num;
712 }
713 if (is_valid_ether_addr(dev_addr))
714 return 0;
715 }
716 eth_random_addr(dev_addr);
717 return 1;
718}
719
720static int get_ether_addr_str(u8 dev_addr[ETH_ALEN], char *str, int len)
721{
722 if (len < 18)
723 return -EINVAL;
724
725 snprintf(str, len, "%02x:%02x:%02x:%02x:%02x:%02x",
726 dev_addr[0], dev_addr[1], dev_addr[2],
727 dev_addr[3], dev_addr[4], dev_addr[5]);
728 return 18;
729}
730
731static const struct net_device_ops eth_netdev_ops = {
732 .ndo_open = eth_open,
733 .ndo_stop = eth_stop,
734 .ndo_start_xmit = eth_start_xmit,
735 .ndo_change_mtu = ueth_change_mtu,
736 .ndo_set_mac_address = eth_mac_addr,
737 .ndo_validate_addr = eth_validate_addr,
738};
739
740static struct device_type gadget_type = {
741 .name = "gadget",
742};
743
744/**
745 * gether_setup_name - initialize one ethernet-over-usb link
746 * @g: gadget to associated with these links
747 * @ethaddr: NULL, or a buffer in which the ethernet address of the
748 * host side of the link is recorded
749 * @netname: name for network device (for example, "usb")
750 * Context: may sleep
751 *
752 * This sets up the single network link that may be exported by a
753 * gadget driver using this framework. The link layer addresses are
754 * set up using module parameters.
755 *
756 * Returns an eth_dev pointer on success, or an ERR_PTR on failure.
757 */
758struct eth_dev *gether_setup_name(struct usb_gadget *g,
759 const char *dev_addr, const char *host_addr,
760 u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname)
761{
762 struct eth_dev *dev;
763 struct net_device *net;
764 int status;
765
766 net = alloc_etherdev(sizeof *dev);
767 if (!net)
768 return ERR_PTR(-ENOMEM);
769
770 dev = netdev_priv(net);
771 spin_lock_init(&dev->lock);
772 spin_lock_init(&dev->req_lock);
773 INIT_WORK(&dev->work, eth_work);
774 INIT_LIST_HEAD(&dev->tx_reqs);
775 INIT_LIST_HEAD(&dev->rx_reqs);
776
777 skb_queue_head_init(&dev->rx_frames);
778
779 /* network device setup */
780 dev->net = net;
781 dev->qmult = qmult;
782 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
783
784 if (get_ether_addr(dev_addr, net->dev_addr))
785 dev_warn(&g->dev,
786 "using random %s ethernet address\n", "self");
787 if (get_ether_addr(host_addr, dev->host_mac))
788 dev_warn(&g->dev,
789 "using random %s ethernet address\n", "host");
790
791 if (ethaddr)
792 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
793
794 net->netdev_ops = ð_netdev_ops;
795
796 SET_ETHTOOL_OPS(net, &ops);
797
798 dev->gadget = g;
799 SET_NETDEV_DEV(net, &g->dev);
800 SET_NETDEV_DEVTYPE(net, &gadget_type);
801
802 status = register_netdev(net);
803 if (status < 0) {
804 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
805 free_netdev(net);
806 dev = ERR_PTR(status);
807 } else {
808 INFO(dev, "MAC %pM\n", net->dev_addr);
809 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
810
811 /*
812 * two kinds of host-initiated state changes:
813 * - iff DATA transfer is active, carrier is "on"
814 * - tx queueing enabled if open *and* carrier is "on"
815 */
816 netif_carrier_off(net);
817 }
818
819 return dev;
820}
821EXPORT_SYMBOL(gether_setup_name);
822
823struct net_device *gether_setup_name_default(const char *netname)
824{
825 struct net_device *net;
826 struct eth_dev *dev;
827
828 net = alloc_etherdev(sizeof(*dev));
829 if (!net)
830 return ERR_PTR(-ENOMEM);
831
832 dev = netdev_priv(net);
833 spin_lock_init(&dev->lock);
834 spin_lock_init(&dev->req_lock);
835 INIT_WORK(&dev->work, eth_work);
836 INIT_LIST_HEAD(&dev->tx_reqs);
837 INIT_LIST_HEAD(&dev->rx_reqs);
838
839 skb_queue_head_init(&dev->rx_frames);
840
841 /* network device setup */
842 dev->net = net;
843 dev->qmult = QMULT_DEFAULT;
844 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
845
846 eth_random_addr(dev->dev_mac);
847 pr_warn("using random %s ethernet address\n", "self");
848 eth_random_addr(dev->host_mac);
849 pr_warn("using random %s ethernet address\n", "host");
850
851 net->netdev_ops = ð_netdev_ops;
852
853 SET_ETHTOOL_OPS(net, &ops);
854 SET_NETDEV_DEVTYPE(net, &gadget_type);
855
856 return net;
857}
858EXPORT_SYMBOL(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);
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(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(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(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
925 dev = netdev_priv(net);
926 return get_ether_addr_str(dev->dev_mac, dev_addr, len);
927}
928EXPORT_SYMBOL(gether_get_dev_addr);
929
930int gether_set_host_addr(struct net_device *net, const char *host_addr)
931{
932 struct eth_dev *dev;
933 u8 new_addr[ETH_ALEN];
934
935 dev = netdev_priv(net);
936 if (get_ether_addr(host_addr, new_addr))
937 return -EINVAL;
938 memcpy(dev->host_mac, new_addr, ETH_ALEN);
939 return 0;
940}
941EXPORT_SYMBOL(gether_set_host_addr);
942
943int gether_get_host_addr(struct net_device *net, char *host_addr, int len)
944{
945 struct eth_dev *dev;
946
947 dev = netdev_priv(net);
948 return get_ether_addr_str(dev->host_mac, host_addr, len);
949}
950EXPORT_SYMBOL(gether_get_host_addr);
951
952int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len)
953{
954 struct eth_dev *dev;
955
956 if (len < 13)
957 return -EINVAL;
958
959 dev = netdev_priv(net);
960 snprintf(host_addr, len, "%pm", dev->host_mac);
961
962 return strlen(host_addr);
963}
964EXPORT_SYMBOL(gether_get_host_addr_cdc);
965
966void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN])
967{
968 struct eth_dev *dev;
969
970 dev = netdev_priv(net);
971 memcpy(host_mac, dev->host_mac, ETH_ALEN);
972}
973EXPORT_SYMBOL(gether_get_host_addr_u8);
974
975void gether_set_qmult(struct net_device *net, unsigned qmult)
976{
977 struct eth_dev *dev;
978
979 dev = netdev_priv(net);
980 dev->qmult = qmult;
981}
982EXPORT_SYMBOL(gether_set_qmult);
983
984unsigned gether_get_qmult(struct net_device *net)
985{
986 struct eth_dev *dev;
987
988 dev = netdev_priv(net);
989 return dev->qmult;
990}
991EXPORT_SYMBOL(gether_get_qmult);
992
993int gether_get_ifname(struct net_device *net, char *name, int len)
994{
995 rtnl_lock();
996 strlcpy(name, netdev_name(net), len);
997 rtnl_unlock();
998 return strlen(name);
999}
1000EXPORT_SYMBOL(gether_get_ifname);
1001
1002/**
1003 * gether_cleanup - remove Ethernet-over-USB device
1004 * Context: may sleep
1005 *
1006 * This is called to free all resources allocated by @gether_setup().
1007 */
1008void gether_cleanup(struct eth_dev *dev)
1009{
1010 if (!dev)
1011 return;
1012
1013 unregister_netdev(dev->net);
1014 flush_work(&dev->work);
1015 free_netdev(dev->net);
1016}
1017EXPORT_SYMBOL(gether_cleanup);
1018
1019/**
1020 * gether_connect - notify network layer that USB link is active
1021 * @link: the USB link, set up with endpoints, descriptors matching
1022 * current device speed, and any framing wrapper(s) set up.
1023 * Context: irqs blocked
1024 *
1025 * This is called to activate endpoints and let the network layer know
1026 * the connection is active ("carrier detect"). It may cause the I/O
1027 * queues to open and start letting network packets flow, but will in
1028 * any case activate the endpoints so that they respond properly to the
1029 * USB host.
1030 *
1031 * Verify net_device pointer returned using IS_ERR(). If it doesn't
1032 * indicate some error code (negative errno), ep->driver_data values
1033 * have been overwritten.
1034 */
1035struct net_device *gether_connect(struct gether *link)
1036{
1037 struct eth_dev *dev = link->ioport;
1038 int result = 0;
1039
1040 if (!dev)
1041 return ERR_PTR(-EINVAL);
1042
1043 link->in_ep->driver_data = dev;
1044 result = usb_ep_enable(link->in_ep);
1045 if (result != 0) {
1046 DBG(dev, "enable %s --> %d\n",
1047 link->in_ep->name, result);
1048 goto fail0;
1049 }
1050
1051 link->out_ep->driver_data = dev;
1052 result = usb_ep_enable(link->out_ep);
1053 if (result != 0) {
1054 DBG(dev, "enable %s --> %d\n",
1055 link->out_ep->name, result);
1056 goto fail1;
1057 }
1058
1059 if (result == 0)
1060 result = alloc_requests(dev, link, qlen(dev->gadget,
1061 dev->qmult));
1062
1063 if (result == 0) {
1064 dev->zlp = link->is_zlp_ok;
1065 DBG(dev, "qlen %d\n", qlen(dev->gadget, dev->qmult));
1066
1067 dev->header_len = link->header_len;
1068 dev->unwrap = link->unwrap;
1069 dev->wrap = link->wrap;
1070
1071 spin_lock(&dev->lock);
1072 dev->port_usb = link;
1073 if (netif_running(dev->net)) {
1074 if (link->open)
1075 link->open(link);
1076 } else {
1077 if (link->close)
1078 link->close(link);
1079 }
1080 spin_unlock(&dev->lock);
1081
1082 netif_carrier_on(dev->net);
1083 if (netif_running(dev->net))
1084 eth_start(dev, GFP_ATOMIC);
1085
1086 /* on error, disable any endpoints */
1087 } else {
1088 (void) usb_ep_disable(link->out_ep);
1089fail1:
1090 (void) usb_ep_disable(link->in_ep);
1091 }
1092fail0:
1093 /* caller is responsible for cleanup on error */
1094 if (result < 0)
1095 return ERR_PTR(result);
1096 return dev->net;
1097}
1098EXPORT_SYMBOL(gether_connect);
1099
1100/**
1101 * gether_disconnect - notify network layer that USB link is inactive
1102 * @link: the USB link, on which gether_connect() was called
1103 * Context: irqs blocked
1104 *
1105 * This is called to deactivate endpoints and let the network layer know
1106 * the connection went inactive ("no carrier").
1107 *
1108 * On return, the state is as if gether_connect() had never been called.
1109 * The endpoints are inactive, and accordingly without active USB I/O.
1110 * Pointers to endpoint descriptors and endpoint private data are nulled.
1111 */
1112void gether_disconnect(struct gether *link)
1113{
1114 struct eth_dev *dev = link->ioport;
1115 struct usb_request *req;
1116
1117 WARN_ON(!dev);
1118 if (!dev)
1119 return;
1120
1121 DBG(dev, "%s\n", __func__);
1122
1123 netif_stop_queue(dev->net);
1124 netif_carrier_off(dev->net);
1125
1126 /* disable endpoints, forcing (synchronous) completion
1127 * of all pending i/o. then free the request objects
1128 * and forget about the endpoints.
1129 */
1130 usb_ep_disable(link->in_ep);
1131 spin_lock(&dev->req_lock);
1132 while (!list_empty(&dev->tx_reqs)) {
1133 req = container_of(dev->tx_reqs.next,
1134 struct usb_request, list);
1135 list_del(&req->list);
1136
1137 spin_unlock(&dev->req_lock);
1138 usb_ep_free_request(link->in_ep, req);
1139 spin_lock(&dev->req_lock);
1140 }
1141 spin_unlock(&dev->req_lock);
1142 link->in_ep->driver_data = NULL;
1143 link->in_ep->desc = NULL;
1144
1145 usb_ep_disable(link->out_ep);
1146 spin_lock(&dev->req_lock);
1147 while (!list_empty(&dev->rx_reqs)) {
1148 req = container_of(dev->rx_reqs.next,
1149 struct usb_request, list);
1150 list_del(&req->list);
1151
1152 spin_unlock(&dev->req_lock);
1153 usb_ep_free_request(link->out_ep, req);
1154 spin_lock(&dev->req_lock);
1155 }
1156 spin_unlock(&dev->req_lock);
1157 link->out_ep->driver_data = NULL;
1158 link->out_ep->desc = NULL;
1159
1160 /* finish forgetting about this USB link episode */
1161 dev->header_len = 0;
1162 dev->unwrap = NULL;
1163 dev->wrap = NULL;
1164
1165 spin_lock(&dev->lock);
1166 dev->port_usb = NULL;
1167 spin_unlock(&dev->lock);
1168}
1169EXPORT_SYMBOL(gether_disconnect);
1170
1171MODULE_LICENSE("GPL");
1172MODULE_AUTHOR("David Brownell");