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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#include <linux/string_helpers.h>
21#include <linux/usb/composite.h>
22
23#include "u_ether.h"
24
25
26/*
27 * This component encapsulates the Ethernet link glue needed to provide
28 * one (!) network link through the USB gadget stack, normally "usb0".
29 *
30 * The control and data models are handled by the function driver which
31 * connects to this code; such as CDC Ethernet (ECM or EEM),
32 * "CDC Subset", or RNDIS. That includes all descriptor and endpoint
33 * management.
34 *
35 * Link level addressing is handled by this component using module
36 * parameters; if no such parameters are provided, random link level
37 * addresses are used. Each end of the link uses one address. The
38 * host end address is exported in various ways, and is often recorded
39 * in configuration databases.
40 *
41 * The driver which assembles each configuration using such a link is
42 * responsible for ensuring that each configuration includes at most one
43 * instance of is network link. (The network layer provides ways for
44 * this single "physical" link to be used by multiple virtual links.)
45 */
46
47#define UETH__VERSION "29-May-2008"
48
49/* Experiments show that both Linux and Windows hosts allow up to 16k
50 * frame sizes. Set the max MTU size to 15k+52 to prevent allocating 32k
51 * blocks and still have efficient handling. */
52#define GETHER_MAX_MTU_SIZE 15412
53#define GETHER_MAX_ETH_FRAME_LEN (GETHER_MAX_MTU_SIZE + ETH_HLEN)
54
55struct eth_dev {
56 /* lock is held while accessing port_usb
57 */
58 spinlock_t lock;
59 struct gether *port_usb;
60
61 struct net_device *net;
62 struct usb_gadget *gadget;
63
64 spinlock_t req_lock; /* guard {rx,tx}_reqs */
65 struct list_head tx_reqs, rx_reqs;
66 atomic_t tx_qlen;
67
68 struct sk_buff_head rx_frames;
69
70 unsigned qmult;
71
72 unsigned header_len;
73 struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
74 int (*unwrap)(struct gether *,
75 struct sk_buff *skb,
76 struct sk_buff_head *list);
77
78 struct work_struct work;
79
80 unsigned long todo;
81#define WORK_RX_MEMORY 0
82
83 bool zlp;
84 bool no_skb_reserve;
85 bool ifname_set;
86 u8 host_mac[ETH_ALEN];
87 u8 dev_mac[ETH_ALEN];
88};
89
90/*-------------------------------------------------------------------------*/
91
92#define RX_EXTRA 20 /* bytes guarding against rx overflows */
93
94#define DEFAULT_QLEN 2 /* double buffering by default */
95
96/* use deeper queues at high/super speed */
97static inline int qlen(struct usb_gadget *gadget, unsigned qmult)
98{
99 if (gadget->speed == USB_SPEED_HIGH || gadget->speed >= USB_SPEED_SUPER)
100 return qmult * DEFAULT_QLEN;
101 else
102 return DEFAULT_QLEN;
103}
104
105/*-------------------------------------------------------------------------*/
106
107/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
108
109static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
110{
111 struct eth_dev *dev = netdev_priv(net);
112
113 strscpy(p->driver, "g_ether", sizeof(p->driver));
114 strscpy(p->version, UETH__VERSION, sizeof(p->version));
115 strscpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version));
116 strscpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof(p->bus_info));
117}
118
119/* REVISIT can also support:
120 * - WOL (by tracking suspends and issuing remote wakeup)
121 * - msglevel (implies updated messaging)
122 * - ... probably more ethtool ops
123 */
124
125static const struct ethtool_ops ops = {
126 .get_drvinfo = eth_get_drvinfo,
127 .get_link = ethtool_op_get_link,
128};
129
130static void defer_kevent(struct eth_dev *dev, int flag)
131{
132 if (test_and_set_bit(flag, &dev->todo))
133 return;
134 if (!schedule_work(&dev->work))
135 ERROR(dev, "kevent %d may have been dropped\n", flag);
136 else
137 DBG(dev, "kevent %d scheduled\n", flag);
138}
139
140static void rx_complete(struct usb_ep *ep, struct usb_request *req);
141
142static int
143rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
144{
145 struct usb_gadget *g = dev->gadget;
146 struct sk_buff *skb;
147 int retval = -ENOMEM;
148 size_t size = 0;
149 struct usb_ep *out;
150 unsigned long flags;
151
152 spin_lock_irqsave(&dev->lock, flags);
153 if (dev->port_usb)
154 out = dev->port_usb->out_ep;
155 else
156 out = NULL;
157
158 if (!out)
159 {
160 spin_unlock_irqrestore(&dev->lock, flags);
161 return -ENOTCONN;
162 }
163
164 /* Padding up to RX_EXTRA handles minor disagreements with host.
165 * Normally we use the USB "terminate on short read" convention;
166 * so allow up to (N*maxpacket), since that memory is normally
167 * already allocated. Some hardware doesn't deal well with short
168 * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
169 * byte off the end (to force hardware errors on overflow).
170 *
171 * RNDIS uses internal framing, and explicitly allows senders to
172 * pad to end-of-packet. That's potentially nice for speed, but
173 * means receivers can't recover lost synch on their own (because
174 * new packets don't only start after a short RX).
175 */
176 size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
177 size += dev->port_usb->header_len;
178
179 if (g->quirk_ep_out_aligned_size) {
180 size += out->maxpacket - 1;
181 size -= size % out->maxpacket;
182 }
183
184 if (dev->port_usb->is_fixed)
185 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
186 spin_unlock_irqrestore(&dev->lock, flags);
187
188 skb = __netdev_alloc_skb(dev->net, size + NET_IP_ALIGN, gfp_flags);
189 if (skb == NULL) {
190 DBG(dev, "no rx skb\n");
191 goto enomem;
192 }
193
194 /* Some platforms perform better when IP packets are aligned,
195 * but on at least one, checksumming fails otherwise. Note:
196 * RNDIS headers involve variable numbers of LE32 values.
197 */
198 if (likely(!dev->no_skb_reserve))
199 skb_reserve(skb, NET_IP_ALIGN);
200
201 req->buf = skb->data;
202 req->length = size;
203 req->complete = rx_complete;
204 req->context = skb;
205
206 retval = usb_ep_queue(out, req, gfp_flags);
207 if (retval == -ENOMEM)
208enomem:
209 defer_kevent(dev, WORK_RX_MEMORY);
210 if (retval) {
211 DBG(dev, "rx submit --> %d\n", retval);
212 if (skb)
213 dev_kfree_skb_any(skb);
214 spin_lock_irqsave(&dev->req_lock, flags);
215 list_add(&req->list, &dev->rx_reqs);
216 spin_unlock_irqrestore(&dev->req_lock, flags);
217 }
218 return retval;
219}
220
221static void rx_complete(struct usb_ep *ep, struct usb_request *req)
222{
223 struct sk_buff *skb = req->context, *skb2;
224 struct eth_dev *dev = ep->driver_data;
225 int status = req->status;
226
227 switch (status) {
228
229 /* normal completion */
230 case 0:
231 skb_put(skb, req->actual);
232
233 if (dev->unwrap) {
234 unsigned long flags;
235
236 spin_lock_irqsave(&dev->lock, flags);
237 if (dev->port_usb) {
238 status = dev->unwrap(dev->port_usb,
239 skb,
240 &dev->rx_frames);
241 } else {
242 dev_kfree_skb_any(skb);
243 status = -ENOTCONN;
244 }
245 spin_unlock_irqrestore(&dev->lock, flags);
246 } else {
247 skb_queue_tail(&dev->rx_frames, skb);
248 }
249 skb = NULL;
250
251 skb2 = skb_dequeue(&dev->rx_frames);
252 while (skb2) {
253 if (status < 0
254 || ETH_HLEN > skb2->len
255 || skb2->len > GETHER_MAX_ETH_FRAME_LEN) {
256 dev->net->stats.rx_errors++;
257 dev->net->stats.rx_length_errors++;
258 DBG(dev, "rx length %d\n", skb2->len);
259 dev_kfree_skb_any(skb2);
260 goto next_frame;
261 }
262 skb2->protocol = eth_type_trans(skb2, dev->net);
263 dev->net->stats.rx_packets++;
264 dev->net->stats.rx_bytes += skb2->len;
265
266 /* no buffer copies needed, unless hardware can't
267 * use skb buffers.
268 */
269 status = netif_rx(skb2);
270next_frame:
271 skb2 = skb_dequeue(&dev->rx_frames);
272 }
273 break;
274
275 /* software-driven interface shutdown */
276 case -ECONNRESET: /* unlink */
277 case -ESHUTDOWN: /* disconnect etc */
278 VDBG(dev, "rx shutdown, code %d\n", status);
279 goto quiesce;
280
281 /* for hardware automagic (such as pxa) */
282 case -ECONNABORTED: /* endpoint reset */
283 DBG(dev, "rx %s reset\n", ep->name);
284 defer_kevent(dev, WORK_RX_MEMORY);
285quiesce:
286 dev_kfree_skb_any(skb);
287 goto clean;
288
289 /* data overrun */
290 case -EOVERFLOW:
291 dev->net->stats.rx_over_errors++;
292 fallthrough;
293
294 default:
295 dev->net->stats.rx_errors++;
296 DBG(dev, "rx status %d\n", status);
297 break;
298 }
299
300 if (skb)
301 dev_kfree_skb_any(skb);
302 if (!netif_running(dev->net)) {
303clean:
304 spin_lock(&dev->req_lock);
305 list_add(&req->list, &dev->rx_reqs);
306 spin_unlock(&dev->req_lock);
307 req = NULL;
308 }
309 if (req)
310 rx_submit(dev, req, GFP_ATOMIC);
311}
312
313static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
314{
315 unsigned i;
316 struct usb_request *req;
317
318 if (!n)
319 return -ENOMEM;
320
321 /* queue/recycle up to N requests */
322 i = n;
323 list_for_each_entry(req, list, list) {
324 if (i-- == 0)
325 goto extra;
326 }
327 while (i--) {
328 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
329 if (!req)
330 return list_empty(list) ? -ENOMEM : 0;
331 list_add(&req->list, list);
332 }
333 return 0;
334
335extra:
336 /* free extras */
337 for (;;) {
338 struct list_head *next;
339
340 next = req->list.next;
341 list_del(&req->list);
342 usb_ep_free_request(ep, req);
343
344 if (next == list)
345 break;
346
347 req = container_of(next, struct usb_request, list);
348 }
349 return 0;
350}
351
352static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
353{
354 int status;
355
356 spin_lock(&dev->req_lock);
357 status = prealloc(&dev->tx_reqs, link->in_ep, n);
358 if (status < 0)
359 goto fail;
360 status = prealloc(&dev->rx_reqs, link->out_ep, n);
361 if (status < 0)
362 goto fail;
363 goto done;
364fail:
365 DBG(dev, "can't alloc requests\n");
366done:
367 spin_unlock(&dev->req_lock);
368 return status;
369}
370
371static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
372{
373 struct usb_request *req;
374 unsigned long flags;
375
376 /* fill unused rxq slots with some skb */
377 spin_lock_irqsave(&dev->req_lock, flags);
378 while (!list_empty(&dev->rx_reqs)) {
379 req = list_first_entry(&dev->rx_reqs, struct usb_request, list);
380 list_del_init(&req->list);
381 spin_unlock_irqrestore(&dev->req_lock, flags);
382
383 if (rx_submit(dev, req, gfp_flags) < 0) {
384 defer_kevent(dev, WORK_RX_MEMORY);
385 return;
386 }
387
388 spin_lock_irqsave(&dev->req_lock, flags);
389 }
390 spin_unlock_irqrestore(&dev->req_lock, flags);
391}
392
393static void eth_work(struct work_struct *work)
394{
395 struct eth_dev *dev = container_of(work, struct eth_dev, work);
396
397 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
398 if (netif_running(dev->net))
399 rx_fill(dev, GFP_KERNEL);
400 }
401
402 if (dev->todo)
403 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
404}
405
406static void tx_complete(struct usb_ep *ep, struct usb_request *req)
407{
408 struct sk_buff *skb = req->context;
409 struct eth_dev *dev = ep->driver_data;
410
411 switch (req->status) {
412 default:
413 dev->net->stats.tx_errors++;
414 VDBG(dev, "tx err %d\n", req->status);
415 fallthrough;
416 case -ECONNRESET: /* unlink */
417 case -ESHUTDOWN: /* disconnect etc */
418 dev_kfree_skb_any(skb);
419 break;
420 case 0:
421 dev->net->stats.tx_bytes += skb->len;
422 dev_consume_skb_any(skb);
423 }
424 dev->net->stats.tx_packets++;
425
426 spin_lock(&dev->req_lock);
427 list_add(&req->list, &dev->tx_reqs);
428 spin_unlock(&dev->req_lock);
429
430 atomic_dec(&dev->tx_qlen);
431 if (netif_carrier_ok(dev->net))
432 netif_wake_queue(dev->net);
433}
434
435static inline int is_promisc(u16 cdc_filter)
436{
437 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
438}
439
440static int ether_wakeup_host(struct gether *port)
441{
442 int ret;
443 struct usb_function *func = &port->func;
444 struct usb_gadget *gadget = func->config->cdev->gadget;
445
446 if (func->func_suspended)
447 ret = usb_func_wakeup(func);
448 else
449 ret = usb_gadget_wakeup(gadget);
450
451 return ret;
452}
453
454static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
455 struct net_device *net)
456{
457 struct eth_dev *dev = netdev_priv(net);
458 int length = 0;
459 int retval;
460 struct usb_request *req = NULL;
461 unsigned long flags;
462 struct usb_ep *in;
463 u16 cdc_filter;
464
465 spin_lock_irqsave(&dev->lock, flags);
466 if (dev->port_usb) {
467 in = dev->port_usb->in_ep;
468 cdc_filter = dev->port_usb->cdc_filter;
469 } else {
470 in = NULL;
471 cdc_filter = 0;
472 }
473
474 if (dev->port_usb && dev->port_usb->is_suspend) {
475 DBG(dev, "Port suspended. Triggering wakeup\n");
476 netif_stop_queue(net);
477 spin_unlock_irqrestore(&dev->lock, flags);
478 ether_wakeup_host(dev->port_usb);
479 return NETDEV_TX_BUSY;
480 }
481
482 spin_unlock_irqrestore(&dev->lock, flags);
483
484 if (!in) {
485 if (skb)
486 dev_kfree_skb_any(skb);
487 return NETDEV_TX_OK;
488 }
489
490 /* apply outgoing CDC or RNDIS filters */
491 if (skb && !is_promisc(cdc_filter)) {
492 u8 *dest = skb->data;
493
494 if (is_multicast_ether_addr(dest)) {
495 u16 type;
496
497 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
498 * SET_ETHERNET_MULTICAST_FILTERS requests
499 */
500 if (is_broadcast_ether_addr(dest))
501 type = USB_CDC_PACKET_TYPE_BROADCAST;
502 else
503 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
504 if (!(cdc_filter & type)) {
505 dev_kfree_skb_any(skb);
506 return NETDEV_TX_OK;
507 }
508 }
509 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
510 }
511
512 spin_lock_irqsave(&dev->req_lock, flags);
513 /*
514 * this freelist can be empty if an interrupt triggered disconnect()
515 * and reconfigured the gadget (shutting down this queue) after the
516 * network stack decided to xmit but before we got the spinlock.
517 */
518 if (list_empty(&dev->tx_reqs)) {
519 spin_unlock_irqrestore(&dev->req_lock, flags);
520 return NETDEV_TX_BUSY;
521 }
522
523 req = list_first_entry(&dev->tx_reqs, struct usb_request, list);
524 list_del(&req->list);
525
526 /* temporarily stop TX queue when the freelist empties */
527 if (list_empty(&dev->tx_reqs))
528 netif_stop_queue(net);
529 spin_unlock_irqrestore(&dev->req_lock, flags);
530
531 /* no buffer copies needed, unless the network stack did it
532 * or the hardware can't use skb buffers.
533 * or there's not enough space for extra headers we need
534 */
535 if (dev->wrap) {
536 unsigned long flags;
537
538 spin_lock_irqsave(&dev->lock, flags);
539 if (dev->port_usb)
540 skb = dev->wrap(dev->port_usb, skb);
541 spin_unlock_irqrestore(&dev->lock, flags);
542 if (!skb) {
543 /* Multi frame CDC protocols may store the frame for
544 * later which is not a dropped frame.
545 */
546 if (dev->port_usb &&
547 dev->port_usb->supports_multi_frame)
548 goto multiframe;
549 goto drop;
550 }
551 }
552
553 length = skb->len;
554 req->buf = skb->data;
555 req->context = skb;
556 req->complete = tx_complete;
557
558 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
559 if (dev->port_usb &&
560 dev->port_usb->is_fixed &&
561 length == dev->port_usb->fixed_in_len &&
562 (length % in->maxpacket) == 0)
563 req->zero = 0;
564 else
565 req->zero = 1;
566
567 /* use zlp framing on tx for strict CDC-Ether conformance,
568 * though any robust network rx path ignores extra padding.
569 * and some hardware doesn't like to write zlps.
570 */
571 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
572 length++;
573
574 req->length = length;
575
576 retval = usb_ep_queue(in, req, GFP_ATOMIC);
577 switch (retval) {
578 default:
579 DBG(dev, "tx queue err %d\n", retval);
580 break;
581 case 0:
582 netif_trans_update(net);
583 atomic_inc(&dev->tx_qlen);
584 }
585
586 if (retval) {
587 dev_kfree_skb_any(skb);
588drop:
589 dev->net->stats.tx_dropped++;
590multiframe:
591 spin_lock_irqsave(&dev->req_lock, flags);
592 if (list_empty(&dev->tx_reqs))
593 netif_start_queue(net);
594 list_add(&req->list, &dev->tx_reqs);
595 spin_unlock_irqrestore(&dev->req_lock, flags);
596 }
597 return NETDEV_TX_OK;
598}
599
600/*-------------------------------------------------------------------------*/
601
602static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
603{
604 DBG(dev, "%s\n", __func__);
605
606 /* fill the rx queue */
607 rx_fill(dev, gfp_flags);
608
609 /* and open the tx floodgates */
610 atomic_set(&dev->tx_qlen, 0);
611 netif_wake_queue(dev->net);
612}
613
614static int eth_open(struct net_device *net)
615{
616 struct eth_dev *dev = netdev_priv(net);
617 struct gether *link;
618
619 DBG(dev, "%s\n", __func__);
620 if (netif_carrier_ok(dev->net))
621 eth_start(dev, GFP_KERNEL);
622
623 spin_lock_irq(&dev->lock);
624 link = dev->port_usb;
625 if (link && link->open)
626 link->open(link);
627 spin_unlock_irq(&dev->lock);
628
629 return 0;
630}
631
632static int eth_stop(struct net_device *net)
633{
634 struct eth_dev *dev = netdev_priv(net);
635 unsigned long flags;
636
637 VDBG(dev, "%s\n", __func__);
638 netif_stop_queue(net);
639
640 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
641 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
642 dev->net->stats.rx_errors, dev->net->stats.tx_errors
643 );
644
645 /* ensure there are no more active requests */
646 spin_lock_irqsave(&dev->lock, flags);
647 if (dev->port_usb) {
648 struct gether *link = dev->port_usb;
649 const struct usb_endpoint_descriptor *in;
650 const struct usb_endpoint_descriptor *out;
651
652 if (link->close)
653 link->close(link);
654
655 /* NOTE: we have no abort-queue primitive we could use
656 * to cancel all pending I/O. Instead, we disable then
657 * reenable the endpoints ... this idiom may leave toggle
658 * wrong, but that's a self-correcting error.
659 *
660 * REVISIT: we *COULD* just let the transfers complete at
661 * their own pace; the network stack can handle old packets.
662 * For the moment we leave this here, since it works.
663 */
664 in = link->in_ep->desc;
665 out = link->out_ep->desc;
666 usb_ep_disable(link->in_ep);
667 usb_ep_disable(link->out_ep);
668 if (netif_carrier_ok(net)) {
669 DBG(dev, "host still using in/out endpoints\n");
670 link->in_ep->desc = in;
671 link->out_ep->desc = out;
672 usb_ep_enable(link->in_ep);
673 usb_ep_enable(link->out_ep);
674 }
675 }
676 spin_unlock_irqrestore(&dev->lock, flags);
677
678 return 0;
679}
680
681/*-------------------------------------------------------------------------*/
682
683static int get_ether_addr(const char *str, u8 *dev_addr)
684{
685 if (str) {
686 unsigned i;
687
688 for (i = 0; i < 6; i++) {
689 unsigned char num;
690
691 if ((*str == '.') || (*str == ':'))
692 str++;
693 num = hex_to_bin(*str++) << 4;
694 num |= hex_to_bin(*str++);
695 dev_addr [i] = num;
696 }
697 if (is_valid_ether_addr(dev_addr))
698 return 0;
699 }
700 eth_random_addr(dev_addr);
701 return 1;
702}
703
704static int get_ether_addr_str(u8 dev_addr[ETH_ALEN], char *str, int len)
705{
706 if (len < 18)
707 return -EINVAL;
708
709 snprintf(str, len, "%pM", dev_addr);
710 return 18;
711}
712
713static const struct net_device_ops eth_netdev_ops = {
714 .ndo_open = eth_open,
715 .ndo_stop = eth_stop,
716 .ndo_start_xmit = eth_start_xmit,
717 .ndo_set_mac_address = eth_mac_addr,
718 .ndo_validate_addr = eth_validate_addr,
719};
720
721static struct device_type gadget_type = {
722 .name = "gadget",
723};
724
725/*
726 * gether_setup_name - initialize one ethernet-over-usb link
727 * @g: gadget to associated with these links
728 * @ethaddr: NULL, or a buffer in which the ethernet address of the
729 * host side of the link is recorded
730 * @netname: name for network device (for example, "usb")
731 * Context: may sleep
732 *
733 * This sets up the single network link that may be exported by a
734 * gadget driver using this framework. The link layer addresses are
735 * set up using module parameters.
736 *
737 * Returns an eth_dev pointer on success, or an ERR_PTR on failure.
738 */
739struct eth_dev *gether_setup_name(struct usb_gadget *g,
740 const char *dev_addr, const char *host_addr,
741 u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname)
742{
743 struct eth_dev *dev;
744 struct net_device *net;
745 int status;
746 u8 addr[ETH_ALEN];
747
748 net = alloc_etherdev(sizeof *dev);
749 if (!net)
750 return ERR_PTR(-ENOMEM);
751
752 dev = netdev_priv(net);
753 spin_lock_init(&dev->lock);
754 spin_lock_init(&dev->req_lock);
755 INIT_WORK(&dev->work, eth_work);
756 INIT_LIST_HEAD(&dev->tx_reqs);
757 INIT_LIST_HEAD(&dev->rx_reqs);
758
759 skb_queue_head_init(&dev->rx_frames);
760
761 /* network device setup */
762 dev->net = net;
763 dev->qmult = qmult;
764 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
765
766 if (get_ether_addr(dev_addr, addr)) {
767 net->addr_assign_type = NET_ADDR_RANDOM;
768 dev_warn(&g->dev,
769 "using random %s ethernet address\n", "self");
770 } else {
771 net->addr_assign_type = NET_ADDR_SET;
772 }
773 eth_hw_addr_set(net, addr);
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_MTU_SIZE;
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
839 /* by default we always have a random MAC address */
840 net->addr_assign_type = NET_ADDR_RANDOM;
841
842 eth_random_addr(dev->host_mac);
843
844 net->netdev_ops = ð_netdev_ops;
845
846 net->ethtool_ops = &ops;
847 SET_NETDEV_DEVTYPE(net, &gadget_type);
848
849 /* MTU range: 14 - 15412 */
850 net->min_mtu = ETH_HLEN;
851 net->max_mtu = GETHER_MAX_MTU_SIZE;
852
853 return net;
854}
855EXPORT_SYMBOL_GPL(gether_setup_name_default);
856
857int gether_register_netdev(struct net_device *net)
858{
859 struct eth_dev *dev;
860 struct usb_gadget *g;
861 int status;
862
863 if (!net->dev.parent)
864 return -EINVAL;
865 dev = netdev_priv(net);
866 g = dev->gadget;
867
868 eth_hw_addr_set(net, dev->dev_mac);
869
870 status = register_netdev(net);
871 if (status < 0) {
872 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
873 return status;
874 } else {
875 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
876 INFO(dev, "MAC %pM\n", dev->dev_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
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 net->addr_assign_type = NET_ADDR_SET;
909 return 0;
910}
911EXPORT_SYMBOL_GPL(gether_set_dev_addr);
912
913int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len)
914{
915 struct eth_dev *dev;
916 int ret;
917
918 dev = netdev_priv(net);
919 ret = get_ether_addr_str(dev->dev_mac, dev_addr, len);
920 if (ret + 1 < len) {
921 dev_addr[ret++] = '\n';
922 dev_addr[ret] = '\0';
923 }
924
925 return ret;
926}
927EXPORT_SYMBOL_GPL(gether_get_dev_addr);
928
929int gether_set_host_addr(struct net_device *net, const char *host_addr)
930{
931 struct eth_dev *dev;
932 u8 new_addr[ETH_ALEN];
933
934 dev = netdev_priv(net);
935 if (get_ether_addr(host_addr, new_addr))
936 return -EINVAL;
937 memcpy(dev->host_mac, new_addr, ETH_ALEN);
938 return 0;
939}
940EXPORT_SYMBOL_GPL(gether_set_host_addr);
941
942int gether_get_host_addr(struct net_device *net, char *host_addr, int len)
943{
944 struct eth_dev *dev;
945 int ret;
946
947 dev = netdev_priv(net);
948 ret = get_ether_addr_str(dev->host_mac, host_addr, len);
949 if (ret + 1 < len) {
950 host_addr[ret++] = '\n';
951 host_addr[ret] = '\0';
952 }
953
954 return ret;
955}
956EXPORT_SYMBOL_GPL(gether_get_host_addr);
957
958int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len)
959{
960 struct eth_dev *dev;
961
962 if (len < 13)
963 return -EINVAL;
964
965 dev = netdev_priv(net);
966 snprintf(host_addr, len, "%pm", dev->host_mac);
967
968 string_upper(host_addr, host_addr);
969
970 return strlen(host_addr);
971}
972EXPORT_SYMBOL_GPL(gether_get_host_addr_cdc);
973
974void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN])
975{
976 struct eth_dev *dev;
977
978 dev = netdev_priv(net);
979 memcpy(host_mac, dev->host_mac, ETH_ALEN);
980}
981EXPORT_SYMBOL_GPL(gether_get_host_addr_u8);
982
983void gether_set_qmult(struct net_device *net, unsigned qmult)
984{
985 struct eth_dev *dev;
986
987 dev = netdev_priv(net);
988 dev->qmult = qmult;
989}
990EXPORT_SYMBOL_GPL(gether_set_qmult);
991
992unsigned gether_get_qmult(struct net_device *net)
993{
994 struct eth_dev *dev;
995
996 dev = netdev_priv(net);
997 return dev->qmult;
998}
999EXPORT_SYMBOL_GPL(gether_get_qmult);
1000
1001int gether_get_ifname(struct net_device *net, char *name, int len)
1002{
1003 struct eth_dev *dev = netdev_priv(net);
1004 int ret;
1005
1006 rtnl_lock();
1007 ret = scnprintf(name, len, "%s\n",
1008 dev->ifname_set ? net->name : netdev_name(net));
1009 rtnl_unlock();
1010 return ret;
1011}
1012EXPORT_SYMBOL_GPL(gether_get_ifname);
1013
1014int gether_set_ifname(struct net_device *net, const char *name, int len)
1015{
1016 struct eth_dev *dev = netdev_priv(net);
1017 char tmp[IFNAMSIZ];
1018 const char *p;
1019
1020 if (name[len - 1] == '\n')
1021 len--;
1022
1023 if (len >= sizeof(tmp))
1024 return -E2BIG;
1025
1026 strscpy(tmp, name, len + 1);
1027 if (!dev_valid_name(tmp))
1028 return -EINVAL;
1029
1030 /* Require exactly one %d, so binding will not fail with EEXIST. */
1031 p = strchr(name, '%');
1032 if (!p || p[1] != 'd' || strchr(p + 2, '%'))
1033 return -EINVAL;
1034
1035 strncpy(net->name, tmp, sizeof(net->name));
1036 dev->ifname_set = true;
1037
1038 return 0;
1039}
1040EXPORT_SYMBOL_GPL(gether_set_ifname);
1041
1042void gether_suspend(struct gether *link)
1043{
1044 struct eth_dev *dev = link->ioport;
1045 unsigned long flags;
1046
1047 if (!dev)
1048 return;
1049
1050 if (atomic_read(&dev->tx_qlen)) {
1051 /*
1052 * There is a transfer in progress. So we trigger a remote
1053 * wakeup to inform the host.
1054 */
1055 ether_wakeup_host(dev->port_usb);
1056 return;
1057 }
1058 spin_lock_irqsave(&dev->lock, flags);
1059 link->is_suspend = true;
1060 spin_unlock_irqrestore(&dev->lock, flags);
1061}
1062EXPORT_SYMBOL_GPL(gether_suspend);
1063
1064void gether_resume(struct gether *link)
1065{
1066 struct eth_dev *dev = link->ioport;
1067 unsigned long flags;
1068
1069 if (!dev)
1070 return;
1071
1072 if (netif_queue_stopped(dev->net))
1073 netif_start_queue(dev->net);
1074
1075 spin_lock_irqsave(&dev->lock, flags);
1076 link->is_suspend = false;
1077 spin_unlock_irqrestore(&dev->lock, flags);
1078}
1079EXPORT_SYMBOL_GPL(gether_resume);
1080
1081/*
1082 * gether_cleanup - remove Ethernet-over-USB device
1083 * Context: may sleep
1084 *
1085 * This is called to free all resources allocated by @gether_setup().
1086 */
1087void gether_cleanup(struct eth_dev *dev)
1088{
1089 if (!dev)
1090 return;
1091
1092 unregister_netdev(dev->net);
1093 flush_work(&dev->work);
1094 free_netdev(dev->net);
1095}
1096EXPORT_SYMBOL_GPL(gether_cleanup);
1097
1098/**
1099 * gether_connect - notify network layer that USB link is active
1100 * @link: the USB link, set up with endpoints, descriptors matching
1101 * current device speed, and any framing wrapper(s) set up.
1102 * Context: irqs blocked
1103 *
1104 * This is called to activate endpoints and let the network layer know
1105 * the connection is active ("carrier detect"). It may cause the I/O
1106 * queues to open and start letting network packets flow, but will in
1107 * any case activate the endpoints so that they respond properly to the
1108 * USB host.
1109 *
1110 * Verify net_device pointer returned using IS_ERR(). If it doesn't
1111 * indicate some error code (negative errno), ep->driver_data values
1112 * have been overwritten.
1113 */
1114struct net_device *gether_connect(struct gether *link)
1115{
1116 struct eth_dev *dev = link->ioport;
1117 int result = 0;
1118
1119 if (!dev)
1120 return ERR_PTR(-EINVAL);
1121
1122 link->in_ep->driver_data = dev;
1123 result = usb_ep_enable(link->in_ep);
1124 if (result != 0) {
1125 DBG(dev, "enable %s --> %d\n",
1126 link->in_ep->name, result);
1127 goto fail0;
1128 }
1129
1130 link->out_ep->driver_data = dev;
1131 result = usb_ep_enable(link->out_ep);
1132 if (result != 0) {
1133 DBG(dev, "enable %s --> %d\n",
1134 link->out_ep->name, result);
1135 goto fail1;
1136 }
1137
1138 if (result == 0)
1139 result = alloc_requests(dev, link, qlen(dev->gadget,
1140 dev->qmult));
1141
1142 if (result == 0) {
1143 dev->zlp = link->is_zlp_ok;
1144 dev->no_skb_reserve = gadget_avoids_skb_reserve(dev->gadget);
1145 DBG(dev, "qlen %d\n", qlen(dev->gadget, dev->qmult));
1146
1147 dev->header_len = link->header_len;
1148 dev->unwrap = link->unwrap;
1149 dev->wrap = link->wrap;
1150
1151 spin_lock(&dev->lock);
1152 dev->port_usb = link;
1153 if (netif_running(dev->net)) {
1154 if (link->open)
1155 link->open(link);
1156 } else {
1157 if (link->close)
1158 link->close(link);
1159 }
1160 spin_unlock(&dev->lock);
1161
1162 netif_carrier_on(dev->net);
1163 if (netif_running(dev->net))
1164 eth_start(dev, GFP_ATOMIC);
1165
1166 netif_device_attach(dev->net);
1167
1168 /* on error, disable any endpoints */
1169 } else {
1170 (void) usb_ep_disable(link->out_ep);
1171fail1:
1172 (void) usb_ep_disable(link->in_ep);
1173 }
1174fail0:
1175 /* caller is responsible for cleanup on error */
1176 if (result < 0)
1177 return ERR_PTR(result);
1178 return dev->net;
1179}
1180EXPORT_SYMBOL_GPL(gether_connect);
1181
1182/**
1183 * gether_disconnect - notify network layer that USB link is inactive
1184 * @link: the USB link, on which gether_connect() was called
1185 * Context: irqs blocked
1186 *
1187 * This is called to deactivate endpoints and let the network layer know
1188 * the connection went inactive ("no carrier").
1189 *
1190 * On return, the state is as if gether_connect() had never been called.
1191 * The endpoints are inactive, and accordingly without active USB I/O.
1192 * Pointers to endpoint descriptors and endpoint private data are nulled.
1193 */
1194void gether_disconnect(struct gether *link)
1195{
1196 struct eth_dev *dev = link->ioport;
1197 struct usb_request *req;
1198
1199 WARN_ON(!dev);
1200 if (!dev)
1201 return;
1202
1203 DBG(dev, "%s\n", __func__);
1204
1205 netif_device_detach(dev->net);
1206 netif_carrier_off(dev->net);
1207
1208 /* disable endpoints, forcing (synchronous) completion
1209 * of all pending i/o. then free the request objects
1210 * and forget about the endpoints.
1211 */
1212 usb_ep_disable(link->in_ep);
1213 spin_lock(&dev->req_lock);
1214 while (!list_empty(&dev->tx_reqs)) {
1215 req = list_first_entry(&dev->tx_reqs, struct usb_request, list);
1216 list_del(&req->list);
1217
1218 spin_unlock(&dev->req_lock);
1219 usb_ep_free_request(link->in_ep, req);
1220 spin_lock(&dev->req_lock);
1221 }
1222 spin_unlock(&dev->req_lock);
1223 link->in_ep->desc = NULL;
1224
1225 usb_ep_disable(link->out_ep);
1226 spin_lock(&dev->req_lock);
1227 while (!list_empty(&dev->rx_reqs)) {
1228 req = list_first_entry(&dev->rx_reqs, struct usb_request, list);
1229 list_del(&req->list);
1230
1231 spin_unlock(&dev->req_lock);
1232 usb_ep_free_request(link->out_ep, req);
1233 spin_lock(&dev->req_lock);
1234 }
1235 spin_unlock(&dev->req_lock);
1236 link->out_ep->desc = NULL;
1237
1238 /* finish forgetting about this USB link episode */
1239 dev->header_len = 0;
1240 dev->unwrap = NULL;
1241 dev->wrap = NULL;
1242
1243 spin_lock(&dev->lock);
1244 dev->port_usb = NULL;
1245 link->is_suspend = false;
1246 spin_unlock(&dev->lock);
1247}
1248EXPORT_SYMBOL_GPL(gether_disconnect);
1249
1250MODULE_LICENSE("GPL");
1251MODULE_AUTHOR("David Brownell");
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
51/* Experiments show that both Linux and Windows hosts allow up to 16k
52 * frame sizes. Set the max size to 15k+52 to prevent allocating 32k
53 * blocks and still have efficient handling. */
54#define GETHER_MAX_ETH_FRAME_LEN 15412
55
56struct eth_dev {
57 /* lock is held while accessing port_usb
58 */
59 spinlock_t lock;
60 struct gether *port_usb;
61
62 struct net_device *net;
63 struct usb_gadget *gadget;
64
65 spinlock_t req_lock; /* guard {rx,tx}_reqs */
66 struct list_head tx_reqs, rx_reqs;
67 atomic_t tx_qlen;
68
69 struct sk_buff_head rx_frames;
70
71 unsigned qmult;
72
73 unsigned header_len;
74 struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
75 int (*unwrap)(struct gether *,
76 struct sk_buff *skb,
77 struct sk_buff_head *list);
78
79 struct work_struct work;
80
81 unsigned long todo;
82#define WORK_RX_MEMORY 0
83
84 bool zlp;
85 bool no_skb_reserve;
86 u8 host_mac[ETH_ALEN];
87 u8 dev_mac[ETH_ALEN];
88};
89
90/*-------------------------------------------------------------------------*/
91
92#define RX_EXTRA 20 /* bytes guarding against rx overflows */
93
94#define DEFAULT_QLEN 2 /* double buffering by default */
95
96/* for dual-speed hardware, use deeper queues at high/super speed */
97static inline int qlen(struct usb_gadget *gadget, unsigned qmult)
98{
99 if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
100 gadget->speed == USB_SPEED_SUPER))
101 return qmult * DEFAULT_QLEN;
102 else
103 return DEFAULT_QLEN;
104}
105
106/*-------------------------------------------------------------------------*/
107
108/* REVISIT there must be a better way than having two sets
109 * of debug calls ...
110 */
111
112#undef DBG
113#undef VDBG
114#undef ERROR
115#undef INFO
116
117#define xprintk(d, level, fmt, args...) \
118 printk(level "%s: " fmt , (d)->net->name , ## args)
119
120#ifdef DEBUG
121#undef DEBUG
122#define DBG(dev, fmt, args...) \
123 xprintk(dev , KERN_DEBUG , fmt , ## args)
124#else
125#define DBG(dev, fmt, args...) \
126 do { } while (0)
127#endif /* DEBUG */
128
129#ifdef VERBOSE_DEBUG
130#define VDBG DBG
131#else
132#define VDBG(dev, fmt, args...) \
133 do { } while (0)
134#endif /* DEBUG */
135
136#define ERROR(dev, fmt, args...) \
137 xprintk(dev , KERN_ERR , fmt , ## args)
138#define INFO(dev, fmt, args...) \
139 xprintk(dev , KERN_INFO , fmt , ## args)
140
141/*-------------------------------------------------------------------------*/
142
143/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
144
145static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
146{
147 struct eth_dev *dev = netdev_priv(net);
148
149 strlcpy(p->driver, "g_ether", sizeof(p->driver));
150 strlcpy(p->version, UETH__VERSION, sizeof(p->version));
151 strlcpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version));
152 strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof(p->bus_info));
153}
154
155/* REVISIT can also support:
156 * - WOL (by tracking suspends and issuing remote wakeup)
157 * - msglevel (implies updated messaging)
158 * - ... probably more ethtool ops
159 */
160
161static const struct ethtool_ops ops = {
162 .get_drvinfo = eth_get_drvinfo,
163 .get_link = ethtool_op_get_link,
164};
165
166static void defer_kevent(struct eth_dev *dev, int flag)
167{
168 if (test_and_set_bit(flag, &dev->todo))
169 return;
170 if (!schedule_work(&dev->work))
171 ERROR(dev, "kevent %d may have been dropped\n", flag);
172 else
173 DBG(dev, "kevent %d scheduled\n", flag);
174}
175
176static void rx_complete(struct usb_ep *ep, struct usb_request *req);
177
178static int
179rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
180{
181 struct sk_buff *skb;
182 int retval = -ENOMEM;
183 size_t size = 0;
184 struct usb_ep *out;
185 unsigned long flags;
186
187 spin_lock_irqsave(&dev->lock, flags);
188 if (dev->port_usb)
189 out = dev->port_usb->out_ep;
190 else
191 out = NULL;
192 spin_unlock_irqrestore(&dev->lock, flags);
193
194 if (!out)
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 size += out->maxpacket - 1;
213 size -= size % out->maxpacket;
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 unsigned long flags;
405
406 /* fill unused rxq slots with some skb */
407 spin_lock_irqsave(&dev->req_lock, flags);
408 while (!list_empty(&dev->rx_reqs)) {
409 req = container_of(dev->rx_reqs.next,
410 struct usb_request, list);
411 list_del_init(&req->list);
412 spin_unlock_irqrestore(&dev->req_lock, flags);
413
414 if (rx_submit(dev, req, gfp_flags) < 0) {
415 defer_kevent(dev, WORK_RX_MEMORY);
416 return;
417 }
418
419 spin_lock_irqsave(&dev->req_lock, flags);
420 }
421 spin_unlock_irqrestore(&dev->req_lock, flags);
422}
423
424static void eth_work(struct work_struct *work)
425{
426 struct eth_dev *dev = container_of(work, struct eth_dev, work);
427
428 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
429 if (netif_running(dev->net))
430 rx_fill(dev, GFP_KERNEL);
431 }
432
433 if (dev->todo)
434 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
435}
436
437static void tx_complete(struct usb_ep *ep, struct usb_request *req)
438{
439 struct sk_buff *skb = req->context;
440 struct eth_dev *dev = ep->driver_data;
441
442 switch (req->status) {
443 default:
444 dev->net->stats.tx_errors++;
445 VDBG(dev, "tx err %d\n", req->status);
446 /* FALLTHROUGH */
447 case -ECONNRESET: /* unlink */
448 case -ESHUTDOWN: /* disconnect etc */
449 dev_kfree_skb_any(skb);
450 break;
451 case 0:
452 dev->net->stats.tx_bytes += skb->len;
453 dev_consume_skb_any(skb);
454 }
455 dev->net->stats.tx_packets++;
456
457 spin_lock(&dev->req_lock);
458 list_add(&req->list, &dev->tx_reqs);
459 spin_unlock(&dev->req_lock);
460
461 atomic_dec(&dev->tx_qlen);
462 if (netif_carrier_ok(dev->net))
463 netif_wake_queue(dev->net);
464}
465
466static inline int is_promisc(u16 cdc_filter)
467{
468 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
469}
470
471static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
472 struct net_device *net)
473{
474 struct eth_dev *dev = netdev_priv(net);
475 int length = 0;
476 int retval;
477 struct usb_request *req = NULL;
478 unsigned long flags;
479 struct usb_ep *in;
480 u16 cdc_filter;
481
482 spin_lock_irqsave(&dev->lock, flags);
483 if (dev->port_usb) {
484 in = dev->port_usb->in_ep;
485 cdc_filter = dev->port_usb->cdc_filter;
486 } else {
487 in = NULL;
488 cdc_filter = 0;
489 }
490 spin_unlock_irqrestore(&dev->lock, flags);
491
492 if (skb && !in) {
493 dev_kfree_skb_any(skb);
494 return NETDEV_TX_OK;
495 }
496
497 /* apply outgoing CDC or RNDIS filters */
498 if (skb && !is_promisc(cdc_filter)) {
499 u8 *dest = skb->data;
500
501 if (is_multicast_ether_addr(dest)) {
502 u16 type;
503
504 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
505 * SET_ETHERNET_MULTICAST_FILTERS requests
506 */
507 if (is_broadcast_ether_addr(dest))
508 type = USB_CDC_PACKET_TYPE_BROADCAST;
509 else
510 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
511 if (!(cdc_filter & type)) {
512 dev_kfree_skb_any(skb);
513 return NETDEV_TX_OK;
514 }
515 }
516 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
517 }
518
519 spin_lock_irqsave(&dev->req_lock, flags);
520 /*
521 * this freelist can be empty if an interrupt triggered disconnect()
522 * and reconfigured the gadget (shutting down this queue) after the
523 * network stack decided to xmit but before we got the spinlock.
524 */
525 if (list_empty(&dev->tx_reqs)) {
526 spin_unlock_irqrestore(&dev->req_lock, flags);
527 return NETDEV_TX_BUSY;
528 }
529
530 req = container_of(dev->tx_reqs.next, struct usb_request, list);
531 list_del(&req->list);
532
533 /* temporarily stop TX queue when the freelist empties */
534 if (list_empty(&dev->tx_reqs))
535 netif_stop_queue(net);
536 spin_unlock_irqrestore(&dev->req_lock, flags);
537
538 /* no buffer copies needed, unless the network stack did it
539 * or the hardware can't use skb buffers.
540 * or there's not enough space for extra headers we need
541 */
542 if (dev->wrap) {
543 unsigned long flags;
544
545 spin_lock_irqsave(&dev->lock, flags);
546 if (dev->port_usb)
547 skb = dev->wrap(dev->port_usb, skb);
548 spin_unlock_irqrestore(&dev->lock, flags);
549 if (!skb) {
550 /* Multi frame CDC protocols may store the frame for
551 * later which is not a dropped frame.
552 */
553 if (dev->port_usb &&
554 dev->port_usb->supports_multi_frame)
555 goto multiframe;
556 goto drop;
557 }
558 }
559
560 length = skb->len;
561 req->buf = skb->data;
562 req->context = skb;
563 req->complete = tx_complete;
564
565 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
566 if (dev->port_usb &&
567 dev->port_usb->is_fixed &&
568 length == dev->port_usb->fixed_in_len &&
569 (length % in->maxpacket) == 0)
570 req->zero = 0;
571 else
572 req->zero = 1;
573
574 /* use zlp framing on tx for strict CDC-Ether conformance,
575 * though any robust network rx path ignores extra padding.
576 * and some hardware doesn't like to write zlps.
577 */
578 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
579 length++;
580
581 req->length = length;
582
583 retval = usb_ep_queue(in, req, GFP_ATOMIC);
584 switch (retval) {
585 default:
586 DBG(dev, "tx queue err %d\n", retval);
587 break;
588 case 0:
589 netif_trans_update(net);
590 atomic_inc(&dev->tx_qlen);
591 }
592
593 if (retval) {
594 dev_kfree_skb_any(skb);
595drop:
596 dev->net->stats.tx_dropped++;
597multiframe:
598 spin_lock_irqsave(&dev->req_lock, flags);
599 if (list_empty(&dev->tx_reqs))
600 netif_start_queue(net);
601 list_add(&req->list, &dev->tx_reqs);
602 spin_unlock_irqrestore(&dev->req_lock, flags);
603 }
604 return NETDEV_TX_OK;
605}
606
607/*-------------------------------------------------------------------------*/
608
609static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
610{
611 DBG(dev, "%s\n", __func__);
612
613 /* fill the rx queue */
614 rx_fill(dev, gfp_flags);
615
616 /* and open the tx floodgates */
617 atomic_set(&dev->tx_qlen, 0);
618 netif_wake_queue(dev->net);
619}
620
621static int eth_open(struct net_device *net)
622{
623 struct eth_dev *dev = netdev_priv(net);
624 struct gether *link;
625
626 DBG(dev, "%s\n", __func__);
627 if (netif_carrier_ok(dev->net))
628 eth_start(dev, GFP_KERNEL);
629
630 spin_lock_irq(&dev->lock);
631 link = dev->port_usb;
632 if (link && link->open)
633 link->open(link);
634 spin_unlock_irq(&dev->lock);
635
636 return 0;
637}
638
639static int eth_stop(struct net_device *net)
640{
641 struct eth_dev *dev = netdev_priv(net);
642 unsigned long flags;
643
644 VDBG(dev, "%s\n", __func__);
645 netif_stop_queue(net);
646
647 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
648 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
649 dev->net->stats.rx_errors, dev->net->stats.tx_errors
650 );
651
652 /* ensure there are no more active requests */
653 spin_lock_irqsave(&dev->lock, flags);
654 if (dev->port_usb) {
655 struct gether *link = dev->port_usb;
656 const struct usb_endpoint_descriptor *in;
657 const struct usb_endpoint_descriptor *out;
658
659 if (link->close)
660 link->close(link);
661
662 /* NOTE: we have no abort-queue primitive we could use
663 * to cancel all pending I/O. Instead, we disable then
664 * reenable the endpoints ... this idiom may leave toggle
665 * wrong, but that's a self-correcting error.
666 *
667 * REVISIT: we *COULD* just let the transfers complete at
668 * their own pace; the network stack can handle old packets.
669 * For the moment we leave this here, since it works.
670 */
671 in = link->in_ep->desc;
672 out = link->out_ep->desc;
673 usb_ep_disable(link->in_ep);
674 usb_ep_disable(link->out_ep);
675 if (netif_carrier_ok(net)) {
676 DBG(dev, "host still using in/out endpoints\n");
677 link->in_ep->desc = in;
678 link->out_ep->desc = out;
679 usb_ep_enable(link->in_ep);
680 usb_ep_enable(link->out_ep);
681 }
682 }
683 spin_unlock_irqrestore(&dev->lock, flags);
684
685 return 0;
686}
687
688/*-------------------------------------------------------------------------*/
689
690static int get_ether_addr(const char *str, u8 *dev_addr)
691{
692 if (str) {
693 unsigned i;
694
695 for (i = 0; i < 6; i++) {
696 unsigned char num;
697
698 if ((*str == '.') || (*str == ':'))
699 str++;
700 num = hex_to_bin(*str++) << 4;
701 num |= hex_to_bin(*str++);
702 dev_addr [i] = num;
703 }
704 if (is_valid_ether_addr(dev_addr))
705 return 0;
706 }
707 eth_random_addr(dev_addr);
708 return 1;
709}
710
711static int get_ether_addr_str(u8 dev_addr[ETH_ALEN], char *str, int len)
712{
713 if (len < 18)
714 return -EINVAL;
715
716 snprintf(str, len, "%pM", dev_addr);
717 return 18;
718}
719
720static const struct net_device_ops eth_netdev_ops = {
721 .ndo_open = eth_open,
722 .ndo_stop = eth_stop,
723 .ndo_start_xmit = eth_start_xmit,
724 .ndo_set_mac_address = eth_mac_addr,
725 .ndo_validate_addr = eth_validate_addr,
726};
727
728static struct device_type gadget_type = {
729 .name = "gadget",
730};
731
732/**
733 * gether_setup_name - initialize one ethernet-over-usb link
734 * @g: gadget to associated with these links
735 * @ethaddr: NULL, or a buffer in which the ethernet address of the
736 * host side of the link is recorded
737 * @netname: name for network device (for example, "usb")
738 * Context: may sleep
739 *
740 * This sets up the single network link that may be exported by a
741 * gadget driver using this framework. The link layer addresses are
742 * set up using module parameters.
743 *
744 * Returns an eth_dev pointer on success, or an ERR_PTR on failure.
745 */
746struct eth_dev *gether_setup_name(struct usb_gadget *g,
747 const char *dev_addr, const char *host_addr,
748 u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname)
749{
750 struct eth_dev *dev;
751 struct net_device *net;
752 int status;
753
754 net = alloc_etherdev(sizeof *dev);
755 if (!net)
756 return ERR_PTR(-ENOMEM);
757
758 dev = netdev_priv(net);
759 spin_lock_init(&dev->lock);
760 spin_lock_init(&dev->req_lock);
761 INIT_WORK(&dev->work, eth_work);
762 INIT_LIST_HEAD(&dev->tx_reqs);
763 INIT_LIST_HEAD(&dev->rx_reqs);
764
765 skb_queue_head_init(&dev->rx_frames);
766
767 /* network device setup */
768 dev->net = net;
769 dev->qmult = qmult;
770 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
771
772 if (get_ether_addr(dev_addr, net->dev_addr))
773 dev_warn(&g->dev,
774 "using random %s ethernet address\n", "self");
775 if (get_ether_addr(host_addr, dev->host_mac))
776 dev_warn(&g->dev,
777 "using random %s ethernet address\n", "host");
778
779 if (ethaddr)
780 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
781
782 net->netdev_ops = ð_netdev_ops;
783
784 net->ethtool_ops = &ops;
785
786 /* MTU range: 14 - 15412 */
787 net->min_mtu = ETH_HLEN;
788 net->max_mtu = GETHER_MAX_ETH_FRAME_LEN;
789
790 dev->gadget = g;
791 SET_NETDEV_DEV(net, &g->dev);
792 SET_NETDEV_DEVTYPE(net, &gadget_type);
793
794 status = register_netdev(net);
795 if (status < 0) {
796 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
797 free_netdev(net);
798 dev = ERR_PTR(status);
799 } else {
800 INFO(dev, "MAC %pM\n", net->dev_addr);
801 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
802
803 /*
804 * two kinds of host-initiated state changes:
805 * - iff DATA transfer is active, carrier is "on"
806 * - tx queueing enabled if open *and* carrier is "on"
807 */
808 netif_carrier_off(net);
809 }
810
811 return dev;
812}
813EXPORT_SYMBOL_GPL(gether_setup_name);
814
815struct net_device *gether_setup_name_default(const char *netname)
816{
817 struct net_device *net;
818 struct eth_dev *dev;
819
820 net = alloc_etherdev(sizeof(*dev));
821 if (!net)
822 return ERR_PTR(-ENOMEM);
823
824 dev = netdev_priv(net);
825 spin_lock_init(&dev->lock);
826 spin_lock_init(&dev->req_lock);
827 INIT_WORK(&dev->work, eth_work);
828 INIT_LIST_HEAD(&dev->tx_reqs);
829 INIT_LIST_HEAD(&dev->rx_reqs);
830
831 skb_queue_head_init(&dev->rx_frames);
832
833 /* network device setup */
834 dev->net = net;
835 dev->qmult = QMULT_DEFAULT;
836 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
837
838 eth_random_addr(dev->dev_mac);
839 pr_warn("using random %s ethernet address\n", "self");
840 eth_random_addr(dev->host_mac);
841 pr_warn("using random %s ethernet address\n", "host");
842
843 net->netdev_ops = ð_netdev_ops;
844
845 net->ethtool_ops = &ops;
846 SET_NETDEV_DEVTYPE(net, &gadget_type);
847
848 return net;
849}
850EXPORT_SYMBOL_GPL(gether_setup_name_default);
851
852int gether_register_netdev(struct net_device *net)
853{
854 struct eth_dev *dev;
855 struct usb_gadget *g;
856 struct sockaddr sa;
857 int status;
858
859 if (!net->dev.parent)
860 return -EINVAL;
861 dev = netdev_priv(net);
862 g = dev->gadget;
863 status = register_netdev(net);
864 if (status < 0) {
865 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
866 return status;
867 } else {
868 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
869
870 /* two kinds of host-initiated state changes:
871 * - iff DATA transfer is active, carrier is "on"
872 * - tx queueing enabled if open *and* carrier is "on"
873 */
874 netif_carrier_off(net);
875 }
876 sa.sa_family = net->type;
877 memcpy(sa.sa_data, dev->dev_mac, ETH_ALEN);
878 rtnl_lock();
879 status = dev_set_mac_address(net, &sa);
880 rtnl_unlock();
881 if (status)
882 pr_warn("cannot set self ethernet address: %d\n", status);
883 else
884 INFO(dev, "MAC %pM\n", dev->dev_mac);
885
886 return status;
887}
888EXPORT_SYMBOL_GPL(gether_register_netdev);
889
890void gether_set_gadget(struct net_device *net, struct usb_gadget *g)
891{
892 struct eth_dev *dev;
893
894 dev = netdev_priv(net);
895 dev->gadget = g;
896 SET_NETDEV_DEV(net, &g->dev);
897}
898EXPORT_SYMBOL_GPL(gether_set_gadget);
899
900int gether_set_dev_addr(struct net_device *net, const char *dev_addr)
901{
902 struct eth_dev *dev;
903 u8 new_addr[ETH_ALEN];
904
905 dev = netdev_priv(net);
906 if (get_ether_addr(dev_addr, new_addr))
907 return -EINVAL;
908 memcpy(dev->dev_mac, new_addr, ETH_ALEN);
909 return 0;
910}
911EXPORT_SYMBOL_GPL(gether_set_dev_addr);
912
913int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len)
914{
915 struct eth_dev *dev;
916
917 dev = netdev_priv(net);
918 return get_ether_addr_str(dev->dev_mac, dev_addr, len);
919}
920EXPORT_SYMBOL_GPL(gether_get_dev_addr);
921
922int gether_set_host_addr(struct net_device *net, const char *host_addr)
923{
924 struct eth_dev *dev;
925 u8 new_addr[ETH_ALEN];
926
927 dev = netdev_priv(net);
928 if (get_ether_addr(host_addr, new_addr))
929 return -EINVAL;
930 memcpy(dev->host_mac, new_addr, ETH_ALEN);
931 return 0;
932}
933EXPORT_SYMBOL_GPL(gether_set_host_addr);
934
935int gether_get_host_addr(struct net_device *net, char *host_addr, int len)
936{
937 struct eth_dev *dev;
938
939 dev = netdev_priv(net);
940 return get_ether_addr_str(dev->host_mac, host_addr, len);
941}
942EXPORT_SYMBOL_GPL(gether_get_host_addr);
943
944int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len)
945{
946 struct eth_dev *dev;
947
948 if (len < 13)
949 return -EINVAL;
950
951 dev = netdev_priv(net);
952 snprintf(host_addr, len, "%pm", dev->host_mac);
953
954 return strlen(host_addr);
955}
956EXPORT_SYMBOL_GPL(gether_get_host_addr_cdc);
957
958void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN])
959{
960 struct eth_dev *dev;
961
962 dev = netdev_priv(net);
963 memcpy(host_mac, dev->host_mac, ETH_ALEN);
964}
965EXPORT_SYMBOL_GPL(gether_get_host_addr_u8);
966
967void gether_set_qmult(struct net_device *net, unsigned qmult)
968{
969 struct eth_dev *dev;
970
971 dev = netdev_priv(net);
972 dev->qmult = qmult;
973}
974EXPORT_SYMBOL_GPL(gether_set_qmult);
975
976unsigned gether_get_qmult(struct net_device *net)
977{
978 struct eth_dev *dev;
979
980 dev = netdev_priv(net);
981 return dev->qmult;
982}
983EXPORT_SYMBOL_GPL(gether_get_qmult);
984
985int gether_get_ifname(struct net_device *net, char *name, int len)
986{
987 rtnl_lock();
988 strlcpy(name, netdev_name(net), len);
989 rtnl_unlock();
990 return strlen(name);
991}
992EXPORT_SYMBOL_GPL(gether_get_ifname);
993
994/**
995 * gether_cleanup - remove Ethernet-over-USB device
996 * Context: may sleep
997 *
998 * This is called to free all resources allocated by @gether_setup().
999 */
1000void gether_cleanup(struct eth_dev *dev)
1001{
1002 if (!dev)
1003 return;
1004
1005 unregister_netdev(dev->net);
1006 flush_work(&dev->work);
1007 free_netdev(dev->net);
1008}
1009EXPORT_SYMBOL_GPL(gether_cleanup);
1010
1011/**
1012 * gether_connect - notify network layer that USB link is active
1013 * @link: the USB link, set up with endpoints, descriptors matching
1014 * current device speed, and any framing wrapper(s) set up.
1015 * Context: irqs blocked
1016 *
1017 * This is called to activate endpoints and let the network layer know
1018 * the connection is active ("carrier detect"). It may cause the I/O
1019 * queues to open and start letting network packets flow, but will in
1020 * any case activate the endpoints so that they respond properly to the
1021 * USB host.
1022 *
1023 * Verify net_device pointer returned using IS_ERR(). If it doesn't
1024 * indicate some error code (negative errno), ep->driver_data values
1025 * have been overwritten.
1026 */
1027struct net_device *gether_connect(struct gether *link)
1028{
1029 struct eth_dev *dev = link->ioport;
1030 int result = 0;
1031
1032 if (!dev)
1033 return ERR_PTR(-EINVAL);
1034
1035 link->in_ep->driver_data = dev;
1036 result = usb_ep_enable(link->in_ep);
1037 if (result != 0) {
1038 DBG(dev, "enable %s --> %d\n",
1039 link->in_ep->name, result);
1040 goto fail0;
1041 }
1042
1043 link->out_ep->driver_data = dev;
1044 result = usb_ep_enable(link->out_ep);
1045 if (result != 0) {
1046 DBG(dev, "enable %s --> %d\n",
1047 link->out_ep->name, result);
1048 goto fail1;
1049 }
1050
1051 if (result == 0)
1052 result = alloc_requests(dev, link, qlen(dev->gadget,
1053 dev->qmult));
1054
1055 if (result == 0) {
1056 dev->zlp = link->is_zlp_ok;
1057 dev->no_skb_reserve = link->no_skb_reserve;
1058 DBG(dev, "qlen %d\n", qlen(dev->gadget, dev->qmult));
1059
1060 dev->header_len = link->header_len;
1061 dev->unwrap = link->unwrap;
1062 dev->wrap = link->wrap;
1063
1064 spin_lock(&dev->lock);
1065 dev->port_usb = link;
1066 if (netif_running(dev->net)) {
1067 if (link->open)
1068 link->open(link);
1069 } else {
1070 if (link->close)
1071 link->close(link);
1072 }
1073 spin_unlock(&dev->lock);
1074
1075 netif_carrier_on(dev->net);
1076 if (netif_running(dev->net))
1077 eth_start(dev, GFP_ATOMIC);
1078
1079 /* on error, disable any endpoints */
1080 } else {
1081 (void) usb_ep_disable(link->out_ep);
1082fail1:
1083 (void) usb_ep_disable(link->in_ep);
1084 }
1085fail0:
1086 /* caller is responsible for cleanup on error */
1087 if (result < 0)
1088 return ERR_PTR(result);
1089 return dev->net;
1090}
1091EXPORT_SYMBOL_GPL(gether_connect);
1092
1093/**
1094 * gether_disconnect - notify network layer that USB link is inactive
1095 * @link: the USB link, on which gether_connect() was called
1096 * Context: irqs blocked
1097 *
1098 * This is called to deactivate endpoints and let the network layer know
1099 * the connection went inactive ("no carrier").
1100 *
1101 * On return, the state is as if gether_connect() had never been called.
1102 * The endpoints are inactive, and accordingly without active USB I/O.
1103 * Pointers to endpoint descriptors and endpoint private data are nulled.
1104 */
1105void gether_disconnect(struct gether *link)
1106{
1107 struct eth_dev *dev = link->ioport;
1108 struct usb_request *req;
1109
1110 WARN_ON(!dev);
1111 if (!dev)
1112 return;
1113
1114 DBG(dev, "%s\n", __func__);
1115
1116 netif_stop_queue(dev->net);
1117 netif_carrier_off(dev->net);
1118
1119 /* disable endpoints, forcing (synchronous) completion
1120 * of all pending i/o. then free the request objects
1121 * and forget about the endpoints.
1122 */
1123 usb_ep_disable(link->in_ep);
1124 spin_lock(&dev->req_lock);
1125 while (!list_empty(&dev->tx_reqs)) {
1126 req = container_of(dev->tx_reqs.next,
1127 struct usb_request, list);
1128 list_del(&req->list);
1129
1130 spin_unlock(&dev->req_lock);
1131 usb_ep_free_request(link->in_ep, req);
1132 spin_lock(&dev->req_lock);
1133 }
1134 spin_unlock(&dev->req_lock);
1135 link->in_ep->desc = NULL;
1136
1137 usb_ep_disable(link->out_ep);
1138 spin_lock(&dev->req_lock);
1139 while (!list_empty(&dev->rx_reqs)) {
1140 req = container_of(dev->rx_reqs.next,
1141 struct usb_request, list);
1142 list_del(&req->list);
1143
1144 spin_unlock(&dev->req_lock);
1145 usb_ep_free_request(link->out_ep, req);
1146 spin_lock(&dev->req_lock);
1147 }
1148 spin_unlock(&dev->req_lock);
1149 link->out_ep->desc = NULL;
1150
1151 /* finish forgetting about this USB link episode */
1152 dev->header_len = 0;
1153 dev->unwrap = NULL;
1154 dev->wrap = NULL;
1155
1156 spin_lock(&dev->lock);
1157 dev->port_usb = NULL;
1158 spin_unlock(&dev->lock);
1159}
1160EXPORT_SYMBOL_GPL(gether_disconnect);
1161
1162MODULE_LICENSE("GPL");
1163MODULE_AUTHOR("David Brownell");