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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// SPDX-License-Identifier: GPL-2.0+
2/*
3 * u_ether.c -- Ethernet-over-USB link layer utilities for Gadget stack
4 *
5 * Copyright (C) 2003-2005,2008 David Brownell
6 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
7 * Copyright (C) 2008 Nokia Corporation
8 */
9
10/* #define VERBOSE_DEBUG */
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/gfp.h>
15#include <linux/device.h>
16#include <linux/ctype.h>
17#include <linux/etherdevice.h>
18#include <linux/ethtool.h>
19#include <linux/if_vlan.h>
20
21#include "u_ether.h"
22
23
24/*
25 * This component encapsulates the Ethernet link glue needed to provide
26 * one (!) network link through the USB gadget stack, normally "usb0".
27 *
28 * The control and data models are handled by the function driver which
29 * connects to this code; such as CDC Ethernet (ECM or EEM),
30 * "CDC Subset", or RNDIS. That includes all descriptor and endpoint
31 * management.
32 *
33 * Link level addressing is handled by this component using module
34 * parameters; if no such parameters are provided, random link level
35 * addresses are used. Each end of the link uses one address. The
36 * host end address is exported in various ways, and is often recorded
37 * in configuration databases.
38 *
39 * The driver which assembles each configuration using such a link is
40 * responsible for ensuring that each configuration includes at most one
41 * instance of is network link. (The network layer provides ways for
42 * this single "physical" link to be used by multiple virtual links.)
43 */
44
45#define UETH__VERSION "29-May-2008"
46
47/* Experiments show that both Linux and Windows hosts allow up to 16k
48 * frame sizes. Set the max size to 15k+52 to prevent allocating 32k
49 * blocks and still have efficient handling. */
50#define GETHER_MAX_ETH_FRAME_LEN 15412
51
52struct eth_dev {
53 /* lock is held while accessing port_usb
54 */
55 spinlock_t lock;
56 struct gether *port_usb;
57
58 struct net_device *net;
59 struct usb_gadget *gadget;
60
61 spinlock_t req_lock; /* guard {rx,tx}_reqs */
62 struct list_head tx_reqs, rx_reqs;
63 atomic_t tx_qlen;
64
65 struct sk_buff_head rx_frames;
66
67 unsigned qmult;
68
69 unsigned header_len;
70 struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
71 int (*unwrap)(struct gether *,
72 struct sk_buff *skb,
73 struct sk_buff_head *list);
74
75 struct work_struct work;
76
77 unsigned long todo;
78#define WORK_RX_MEMORY 0
79
80 bool zlp;
81 bool no_skb_reserve;
82 u8 host_mac[ETH_ALEN];
83 u8 dev_mac[ETH_ALEN];
84};
85
86/*-------------------------------------------------------------------------*/
87
88#define RX_EXTRA 20 /* bytes guarding against rx overflows */
89
90#define DEFAULT_QLEN 2 /* double buffering by default */
91
92/* for dual-speed hardware, use deeper queues at high/super speed */
93static inline int qlen(struct usb_gadget *gadget, unsigned qmult)
94{
95 if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
96 gadget->speed == USB_SPEED_SUPER))
97 return qmult * DEFAULT_QLEN;
98 else
99 return DEFAULT_QLEN;
100}
101
102/*-------------------------------------------------------------------------*/
103
104/* REVISIT there must be a better way than having two sets
105 * of debug calls ...
106 */
107
108#undef DBG
109#undef VDBG
110#undef ERROR
111#undef INFO
112
113#define xprintk(d, level, fmt, args...) \
114 printk(level "%s: " fmt , (d)->net->name , ## args)
115
116#ifdef DEBUG
117#undef DEBUG
118#define DBG(dev, fmt, args...) \
119 xprintk(dev , KERN_DEBUG , fmt , ## args)
120#else
121#define DBG(dev, fmt, args...) \
122 do { } while (0)
123#endif /* DEBUG */
124
125#ifdef VERBOSE_DEBUG
126#define VDBG DBG
127#else
128#define VDBG(dev, fmt, args...) \
129 do { } while (0)
130#endif /* DEBUG */
131
132#define ERROR(dev, fmt, args...) \
133 xprintk(dev , KERN_ERR , fmt , ## args)
134#define INFO(dev, fmt, args...) \
135 xprintk(dev , KERN_INFO , fmt , ## args)
136
137/*-------------------------------------------------------------------------*/
138
139/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
140
141static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
142{
143 struct eth_dev *dev = netdev_priv(net);
144
145 strlcpy(p->driver, "g_ether", sizeof(p->driver));
146 strlcpy(p->version, UETH__VERSION, sizeof(p->version));
147 strlcpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version));
148 strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof(p->bus_info));
149}
150
151/* REVISIT can also support:
152 * - WOL (by tracking suspends and issuing remote wakeup)
153 * - msglevel (implies updated messaging)
154 * - ... probably more ethtool ops
155 */
156
157static const struct ethtool_ops ops = {
158 .get_drvinfo = eth_get_drvinfo,
159 .get_link = ethtool_op_get_link,
160};
161
162static void defer_kevent(struct eth_dev *dev, int flag)
163{
164 if (test_and_set_bit(flag, &dev->todo))
165 return;
166 if (!schedule_work(&dev->work))
167 ERROR(dev, "kevent %d may have been dropped\n", flag);
168 else
169 DBG(dev, "kevent %d scheduled\n", flag);
170}
171
172static void rx_complete(struct usb_ep *ep, struct usb_request *req);
173
174static int
175rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
176{
177 struct usb_gadget *g = dev->gadget;
178 struct sk_buff *skb;
179 int retval = -ENOMEM;
180 size_t size = 0;
181 struct usb_ep *out;
182 unsigned long flags;
183
184 spin_lock_irqsave(&dev->lock, flags);
185 if (dev->port_usb)
186 out = dev->port_usb->out_ep;
187 else
188 out = NULL;
189 spin_unlock_irqrestore(&dev->lock, flags);
190
191 if (!out)
192 return -ENOTCONN;
193
194
195 /* Padding up to RX_EXTRA handles minor disagreements with host.
196 * Normally we use the USB "terminate on short read" convention;
197 * so allow up to (N*maxpacket), since that memory is normally
198 * already allocated. Some hardware doesn't deal well with short
199 * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
200 * byte off the end (to force hardware errors on overflow).
201 *
202 * RNDIS uses internal framing, and explicitly allows senders to
203 * pad to end-of-packet. That's potentially nice for speed, but
204 * means receivers can't recover lost synch on their own (because
205 * new packets don't only start after a short RX).
206 */
207 size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
208 size += dev->port_usb->header_len;
209
210 if (g->quirk_ep_out_aligned_size) {
211 size += out->maxpacket - 1;
212 size -= size % out->maxpacket;
213 }
214
215 if (dev->port_usb->is_fixed)
216 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
217
218 skb = __netdev_alloc_skb(dev->net, size + NET_IP_ALIGN, gfp_flags);
219 if (skb == NULL) {
220 DBG(dev, "no rx skb\n");
221 goto enomem;
222 }
223
224 /* Some platforms perform better when IP packets are aligned,
225 * but on at least one, checksumming fails otherwise. Note:
226 * RNDIS headers involve variable numbers of LE32 values.
227 */
228 if (likely(!dev->no_skb_reserve))
229 skb_reserve(skb, NET_IP_ALIGN);
230
231 req->buf = skb->data;
232 req->length = size;
233 req->complete = rx_complete;
234 req->context = skb;
235
236 retval = usb_ep_queue(out, req, gfp_flags);
237 if (retval == -ENOMEM)
238enomem:
239 defer_kevent(dev, WORK_RX_MEMORY);
240 if (retval) {
241 DBG(dev, "rx submit --> %d\n", retval);
242 if (skb)
243 dev_kfree_skb_any(skb);
244 spin_lock_irqsave(&dev->req_lock, flags);
245 list_add(&req->list, &dev->rx_reqs);
246 spin_unlock_irqrestore(&dev->req_lock, flags);
247 }
248 return retval;
249}
250
251static void rx_complete(struct usb_ep *ep, struct usb_request *req)
252{
253 struct sk_buff *skb = req->context, *skb2;
254 struct eth_dev *dev = ep->driver_data;
255 int status = req->status;
256
257 switch (status) {
258
259 /* normal completion */
260 case 0:
261 skb_put(skb, req->actual);
262
263 if (dev->unwrap) {
264 unsigned long flags;
265
266 spin_lock_irqsave(&dev->lock, flags);
267 if (dev->port_usb) {
268 status = dev->unwrap(dev->port_usb,
269 skb,
270 &dev->rx_frames);
271 } else {
272 dev_kfree_skb_any(skb);
273 status = -ENOTCONN;
274 }
275 spin_unlock_irqrestore(&dev->lock, flags);
276 } else {
277 skb_queue_tail(&dev->rx_frames, skb);
278 }
279 skb = NULL;
280
281 skb2 = skb_dequeue(&dev->rx_frames);
282 while (skb2) {
283 if (status < 0
284 || ETH_HLEN > skb2->len
285 || skb2->len > GETHER_MAX_ETH_FRAME_LEN) {
286 dev->net->stats.rx_errors++;
287 dev->net->stats.rx_length_errors++;
288 DBG(dev, "rx length %d\n", skb2->len);
289 dev_kfree_skb_any(skb2);
290 goto next_frame;
291 }
292 skb2->protocol = eth_type_trans(skb2, dev->net);
293 dev->net->stats.rx_packets++;
294 dev->net->stats.rx_bytes += skb2->len;
295
296 /* no buffer copies needed, unless hardware can't
297 * use skb buffers.
298 */
299 status = netif_rx(skb2);
300next_frame:
301 skb2 = skb_dequeue(&dev->rx_frames);
302 }
303 break;
304
305 /* software-driven interface shutdown */
306 case -ECONNRESET: /* unlink */
307 case -ESHUTDOWN: /* disconnect etc */
308 VDBG(dev, "rx shutdown, code %d\n", status);
309 goto quiesce;
310
311 /* for hardware automagic (such as pxa) */
312 case -ECONNABORTED: /* endpoint reset */
313 DBG(dev, "rx %s reset\n", ep->name);
314 defer_kevent(dev, WORK_RX_MEMORY);
315quiesce:
316 dev_kfree_skb_any(skb);
317 goto clean;
318
319 /* data overrun */
320 case -EOVERFLOW:
321 dev->net->stats.rx_over_errors++;
322 /* FALLTHROUGH */
323
324 default:
325 dev->net->stats.rx_errors++;
326 DBG(dev, "rx status %d\n", status);
327 break;
328 }
329
330 if (skb)
331 dev_kfree_skb_any(skb);
332 if (!netif_running(dev->net)) {
333clean:
334 spin_lock(&dev->req_lock);
335 list_add(&req->list, &dev->rx_reqs);
336 spin_unlock(&dev->req_lock);
337 req = NULL;
338 }
339 if (req)
340 rx_submit(dev, req, GFP_ATOMIC);
341}
342
343static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
344{
345 unsigned i;
346 struct usb_request *req;
347
348 if (!n)
349 return -ENOMEM;
350
351 /* queue/recycle up to N requests */
352 i = n;
353 list_for_each_entry(req, list, list) {
354 if (i-- == 0)
355 goto extra;
356 }
357 while (i--) {
358 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
359 if (!req)
360 return list_empty(list) ? -ENOMEM : 0;
361 list_add(&req->list, list);
362 }
363 return 0;
364
365extra:
366 /* free extras */
367 for (;;) {
368 struct list_head *next;
369
370 next = req->list.next;
371 list_del(&req->list);
372 usb_ep_free_request(ep, req);
373
374 if (next == list)
375 break;
376
377 req = container_of(next, struct usb_request, list);
378 }
379 return 0;
380}
381
382static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
383{
384 int status;
385
386 spin_lock(&dev->req_lock);
387 status = prealloc(&dev->tx_reqs, link->in_ep, n);
388 if (status < 0)
389 goto fail;
390 status = prealloc(&dev->rx_reqs, link->out_ep, n);
391 if (status < 0)
392 goto fail;
393 goto done;
394fail:
395 DBG(dev, "can't alloc requests\n");
396done:
397 spin_unlock(&dev->req_lock);
398 return status;
399}
400
401static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
402{
403 struct usb_request *req;
404 struct usb_request *tmp;
405 unsigned long flags;
406
407 /* fill unused rxq slots with some skb */
408 spin_lock_irqsave(&dev->req_lock, flags);
409 list_for_each_entry_safe(req, tmp, &dev->rx_reqs, list) {
410 list_del_init(&req->list);
411 spin_unlock_irqrestore(&dev->req_lock, flags);
412
413 if (rx_submit(dev, req, gfp_flags) < 0) {
414 defer_kevent(dev, WORK_RX_MEMORY);
415 return;
416 }
417
418 spin_lock_irqsave(&dev->req_lock, flags);
419 }
420 spin_unlock_irqrestore(&dev->req_lock, flags);
421}
422
423static void eth_work(struct work_struct *work)
424{
425 struct eth_dev *dev = container_of(work, struct eth_dev, work);
426
427 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
428 if (netif_running(dev->net))
429 rx_fill(dev, GFP_KERNEL);
430 }
431
432 if (dev->todo)
433 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
434}
435
436static void tx_complete(struct usb_ep *ep, struct usb_request *req)
437{
438 struct sk_buff *skb = req->context;
439 struct eth_dev *dev = ep->driver_data;
440
441 switch (req->status) {
442 default:
443 dev->net->stats.tx_errors++;
444 VDBG(dev, "tx err %d\n", req->status);
445 /* FALLTHROUGH */
446 case -ECONNRESET: /* unlink */
447 case -ESHUTDOWN: /* disconnect etc */
448 dev_kfree_skb_any(skb);
449 break;
450 case 0:
451 dev->net->stats.tx_bytes += skb->len;
452 dev_consume_skb_any(skb);
453 }
454 dev->net->stats.tx_packets++;
455
456 spin_lock(&dev->req_lock);
457 list_add(&req->list, &dev->tx_reqs);
458 spin_unlock(&dev->req_lock);
459
460 atomic_dec(&dev->tx_qlen);
461 if (netif_carrier_ok(dev->net))
462 netif_wake_queue(dev->net);
463}
464
465static inline int is_promisc(u16 cdc_filter)
466{
467 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
468}
469
470static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
471 struct net_device *net)
472{
473 struct eth_dev *dev = netdev_priv(net);
474 int length = 0;
475 int retval;
476 struct usb_request *req = NULL;
477 unsigned long flags;
478 struct usb_ep *in;
479 u16 cdc_filter;
480
481 spin_lock_irqsave(&dev->lock, flags);
482 if (dev->port_usb) {
483 in = dev->port_usb->in_ep;
484 cdc_filter = dev->port_usb->cdc_filter;
485 } else {
486 in = NULL;
487 cdc_filter = 0;
488 }
489 spin_unlock_irqrestore(&dev->lock, flags);
490
491 if (skb && !in) {
492 dev_kfree_skb_any(skb);
493 return NETDEV_TX_OK;
494 }
495
496 /* apply outgoing CDC or RNDIS filters */
497 if (skb && !is_promisc(cdc_filter)) {
498 u8 *dest = skb->data;
499
500 if (is_multicast_ether_addr(dest)) {
501 u16 type;
502
503 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
504 * SET_ETHERNET_MULTICAST_FILTERS requests
505 */
506 if (is_broadcast_ether_addr(dest))
507 type = USB_CDC_PACKET_TYPE_BROADCAST;
508 else
509 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
510 if (!(cdc_filter & type)) {
511 dev_kfree_skb_any(skb);
512 return NETDEV_TX_OK;
513 }
514 }
515 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
516 }
517
518 spin_lock_irqsave(&dev->req_lock, flags);
519 /*
520 * this freelist can be empty if an interrupt triggered disconnect()
521 * and reconfigured the gadget (shutting down this queue) after the
522 * network stack decided to xmit but before we got the spinlock.
523 */
524 if (list_empty(&dev->tx_reqs)) {
525 spin_unlock_irqrestore(&dev->req_lock, flags);
526 return NETDEV_TX_BUSY;
527 }
528
529 req = list_first_entry(&dev->tx_reqs, struct usb_request, list);
530 list_del(&req->list);
531
532 /* temporarily stop TX queue when the freelist empties */
533 if (list_empty(&dev->tx_reqs))
534 netif_stop_queue(net);
535 spin_unlock_irqrestore(&dev->req_lock, flags);
536
537 /* no buffer copies needed, unless the network stack did it
538 * or the hardware can't use skb buffers.
539 * or there's not enough space for extra headers we need
540 */
541 if (dev->wrap) {
542 unsigned long flags;
543
544 spin_lock_irqsave(&dev->lock, flags);
545 if (dev->port_usb)
546 skb = dev->wrap(dev->port_usb, skb);
547 spin_unlock_irqrestore(&dev->lock, flags);
548 if (!skb) {
549 /* Multi frame CDC protocols may store the frame for
550 * later which is not a dropped frame.
551 */
552 if (dev->port_usb &&
553 dev->port_usb->supports_multi_frame)
554 goto multiframe;
555 goto drop;
556 }
557 }
558
559 length = skb->len;
560 req->buf = skb->data;
561 req->context = skb;
562 req->complete = tx_complete;
563
564 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
565 if (dev->port_usb &&
566 dev->port_usb->is_fixed &&
567 length == dev->port_usb->fixed_in_len &&
568 (length % in->maxpacket) == 0)
569 req->zero = 0;
570 else
571 req->zero = 1;
572
573 /* use zlp framing on tx for strict CDC-Ether conformance,
574 * though any robust network rx path ignores extra padding.
575 * and some hardware doesn't like to write zlps.
576 */
577 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
578 length++;
579
580 req->length = length;
581
582 retval = usb_ep_queue(in, req, GFP_ATOMIC);
583 switch (retval) {
584 default:
585 DBG(dev, "tx queue err %d\n", retval);
586 break;
587 case 0:
588 netif_trans_update(net);
589 atomic_inc(&dev->tx_qlen);
590 }
591
592 if (retval) {
593 dev_kfree_skb_any(skb);
594drop:
595 dev->net->stats.tx_dropped++;
596multiframe:
597 spin_lock_irqsave(&dev->req_lock, flags);
598 if (list_empty(&dev->tx_reqs))
599 netif_start_queue(net);
600 list_add(&req->list, &dev->tx_reqs);
601 spin_unlock_irqrestore(&dev->req_lock, flags);
602 }
603 return NETDEV_TX_OK;
604}
605
606/*-------------------------------------------------------------------------*/
607
608static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
609{
610 DBG(dev, "%s\n", __func__);
611
612 /* fill the rx queue */
613 rx_fill(dev, gfp_flags);
614
615 /* and open the tx floodgates */
616 atomic_set(&dev->tx_qlen, 0);
617 netif_wake_queue(dev->net);
618}
619
620static int eth_open(struct net_device *net)
621{
622 struct eth_dev *dev = netdev_priv(net);
623 struct gether *link;
624
625 DBG(dev, "%s\n", __func__);
626 if (netif_carrier_ok(dev->net))
627 eth_start(dev, GFP_KERNEL);
628
629 spin_lock_irq(&dev->lock);
630 link = dev->port_usb;
631 if (link && link->open)
632 link->open(link);
633 spin_unlock_irq(&dev->lock);
634
635 return 0;
636}
637
638static int eth_stop(struct net_device *net)
639{
640 struct eth_dev *dev = netdev_priv(net);
641 unsigned long flags;
642
643 VDBG(dev, "%s\n", __func__);
644 netif_stop_queue(net);
645
646 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
647 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
648 dev->net->stats.rx_errors, dev->net->stats.tx_errors
649 );
650
651 /* ensure there are no more active requests */
652 spin_lock_irqsave(&dev->lock, flags);
653 if (dev->port_usb) {
654 struct gether *link = dev->port_usb;
655 const struct usb_endpoint_descriptor *in;
656 const struct usb_endpoint_descriptor *out;
657
658 if (link->close)
659 link->close(link);
660
661 /* NOTE: we have no abort-queue primitive we could use
662 * to cancel all pending I/O. Instead, we disable then
663 * reenable the endpoints ... this idiom may leave toggle
664 * wrong, but that's a self-correcting error.
665 *
666 * REVISIT: we *COULD* just let the transfers complete at
667 * their own pace; the network stack can handle old packets.
668 * For the moment we leave this here, since it works.
669 */
670 in = link->in_ep->desc;
671 out = link->out_ep->desc;
672 usb_ep_disable(link->in_ep);
673 usb_ep_disable(link->out_ep);
674 if (netif_carrier_ok(net)) {
675 DBG(dev, "host still using in/out endpoints\n");
676 link->in_ep->desc = in;
677 link->out_ep->desc = out;
678 usb_ep_enable(link->in_ep);
679 usb_ep_enable(link->out_ep);
680 }
681 }
682 spin_unlock_irqrestore(&dev->lock, flags);
683
684 return 0;
685}
686
687/*-------------------------------------------------------------------------*/
688
689static int get_ether_addr(const char *str, u8 *dev_addr)
690{
691 if (str) {
692 unsigned i;
693
694 for (i = 0; i < 6; i++) {
695 unsigned char num;
696
697 if ((*str == '.') || (*str == ':'))
698 str++;
699 num = hex_to_bin(*str++) << 4;
700 num |= hex_to_bin(*str++);
701 dev_addr [i] = num;
702 }
703 if (is_valid_ether_addr(dev_addr))
704 return 0;
705 }
706 eth_random_addr(dev_addr);
707 return 1;
708}
709
710static int get_ether_addr_str(u8 dev_addr[ETH_ALEN], char *str, int len)
711{
712 if (len < 18)
713 return -EINVAL;
714
715 snprintf(str, len, "%pM", dev_addr);
716 return 18;
717}
718
719static const struct net_device_ops eth_netdev_ops = {
720 .ndo_open = eth_open,
721 .ndo_stop = eth_stop,
722 .ndo_start_xmit = eth_start_xmit,
723 .ndo_set_mac_address = eth_mac_addr,
724 .ndo_validate_addr = eth_validate_addr,
725};
726
727static struct device_type gadget_type = {
728 .name = "gadget",
729};
730
731/**
732 * gether_setup_name - initialize one ethernet-over-usb link
733 * @g: gadget to associated with these links
734 * @ethaddr: NULL, or a buffer in which the ethernet address of the
735 * host side of the link is recorded
736 * @netname: name for network device (for example, "usb")
737 * Context: may sleep
738 *
739 * This sets up the single network link that may be exported by a
740 * gadget driver using this framework. The link layer addresses are
741 * set up using module parameters.
742 *
743 * Returns an eth_dev pointer on success, or an ERR_PTR on failure.
744 */
745struct eth_dev *gether_setup_name(struct usb_gadget *g,
746 const char *dev_addr, const char *host_addr,
747 u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname)
748{
749 struct eth_dev *dev;
750 struct net_device *net;
751 int status;
752
753 net = alloc_etherdev(sizeof *dev);
754 if (!net)
755 return ERR_PTR(-ENOMEM);
756
757 dev = netdev_priv(net);
758 spin_lock_init(&dev->lock);
759 spin_lock_init(&dev->req_lock);
760 INIT_WORK(&dev->work, eth_work);
761 INIT_LIST_HEAD(&dev->tx_reqs);
762 INIT_LIST_HEAD(&dev->rx_reqs);
763
764 skb_queue_head_init(&dev->rx_frames);
765
766 /* network device setup */
767 dev->net = net;
768 dev->qmult = qmult;
769 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
770
771 if (get_ether_addr(dev_addr, net->dev_addr))
772 dev_warn(&g->dev,
773 "using random %s ethernet address\n", "self");
774 if (get_ether_addr(host_addr, dev->host_mac))
775 dev_warn(&g->dev,
776 "using random %s ethernet address\n", "host");
777
778 if (ethaddr)
779 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
780
781 net->netdev_ops = ð_netdev_ops;
782
783 net->ethtool_ops = &ops;
784
785 /* MTU range: 14 - 15412 */
786 net->min_mtu = ETH_HLEN;
787 net->max_mtu = GETHER_MAX_ETH_FRAME_LEN;
788
789 dev->gadget = g;
790 SET_NETDEV_DEV(net, &g->dev);
791 SET_NETDEV_DEVTYPE(net, &gadget_type);
792
793 status = register_netdev(net);
794 if (status < 0) {
795 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
796 free_netdev(net);
797 dev = ERR_PTR(status);
798 } else {
799 INFO(dev, "MAC %pM\n", net->dev_addr);
800 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
801
802 /*
803 * two kinds of host-initiated state changes:
804 * - iff DATA transfer is active, carrier is "on"
805 * - tx queueing enabled if open *and* carrier is "on"
806 */
807 netif_carrier_off(net);
808 }
809
810 return dev;
811}
812EXPORT_SYMBOL_GPL(gether_setup_name);
813
814struct net_device *gether_setup_name_default(const char *netname)
815{
816 struct net_device *net;
817 struct eth_dev *dev;
818
819 net = alloc_etherdev(sizeof(*dev));
820 if (!net)
821 return ERR_PTR(-ENOMEM);
822
823 dev = netdev_priv(net);
824 spin_lock_init(&dev->lock);
825 spin_lock_init(&dev->req_lock);
826 INIT_WORK(&dev->work, eth_work);
827 INIT_LIST_HEAD(&dev->tx_reqs);
828 INIT_LIST_HEAD(&dev->rx_reqs);
829
830 skb_queue_head_init(&dev->rx_frames);
831
832 /* network device setup */
833 dev->net = net;
834 dev->qmult = QMULT_DEFAULT;
835 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
836
837 eth_random_addr(dev->dev_mac);
838 pr_warn("using random %s ethernet address\n", "self");
839 eth_random_addr(dev->host_mac);
840 pr_warn("using random %s ethernet address\n", "host");
841
842 net->netdev_ops = ð_netdev_ops;
843
844 net->ethtool_ops = &ops;
845 SET_NETDEV_DEVTYPE(net, &gadget_type);
846
847 return net;
848}
849EXPORT_SYMBOL_GPL(gether_setup_name_default);
850
851int gether_register_netdev(struct net_device *net)
852{
853 struct eth_dev *dev;
854 struct usb_gadget *g;
855 struct sockaddr sa;
856 int status;
857
858 if (!net->dev.parent)
859 return -EINVAL;
860 dev = netdev_priv(net);
861 g = dev->gadget;
862 status = register_netdev(net);
863 if (status < 0) {
864 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
865 return status;
866 } else {
867 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
868
869 /* two kinds of host-initiated state changes:
870 * - iff DATA transfer is active, carrier is "on"
871 * - tx queueing enabled if open *and* carrier is "on"
872 */
873 netif_carrier_off(net);
874 }
875 sa.sa_family = net->type;
876 memcpy(sa.sa_data, dev->dev_mac, ETH_ALEN);
877 rtnl_lock();
878 status = dev_set_mac_address(net, &sa);
879 rtnl_unlock();
880 if (status)
881 pr_warn("cannot set self ethernet address: %d\n", status);
882 else
883 INFO(dev, "MAC %pM\n", dev->dev_mac);
884
885 return status;
886}
887EXPORT_SYMBOL_GPL(gether_register_netdev);
888
889void gether_set_gadget(struct net_device *net, struct usb_gadget *g)
890{
891 struct eth_dev *dev;
892
893 dev = netdev_priv(net);
894 dev->gadget = g;
895 SET_NETDEV_DEV(net, &g->dev);
896}
897EXPORT_SYMBOL_GPL(gether_set_gadget);
898
899int gether_set_dev_addr(struct net_device *net, const char *dev_addr)
900{
901 struct eth_dev *dev;
902 u8 new_addr[ETH_ALEN];
903
904 dev = netdev_priv(net);
905 if (get_ether_addr(dev_addr, new_addr))
906 return -EINVAL;
907 memcpy(dev->dev_mac, new_addr, ETH_ALEN);
908 return 0;
909}
910EXPORT_SYMBOL_GPL(gether_set_dev_addr);
911
912int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len)
913{
914 struct eth_dev *dev;
915 int ret;
916
917 dev = netdev_priv(net);
918 ret = get_ether_addr_str(dev->dev_mac, dev_addr, len);
919 if (ret + 1 < len) {
920 dev_addr[ret++] = '\n';
921 dev_addr[ret] = '\0';
922 }
923
924 return ret;
925}
926EXPORT_SYMBOL_GPL(gether_get_dev_addr);
927
928int gether_set_host_addr(struct net_device *net, const char *host_addr)
929{
930 struct eth_dev *dev;
931 u8 new_addr[ETH_ALEN];
932
933 dev = netdev_priv(net);
934 if (get_ether_addr(host_addr, new_addr))
935 return -EINVAL;
936 memcpy(dev->host_mac, new_addr, ETH_ALEN);
937 return 0;
938}
939EXPORT_SYMBOL_GPL(gether_set_host_addr);
940
941int gether_get_host_addr(struct net_device *net, char *host_addr, int len)
942{
943 struct eth_dev *dev;
944 int ret;
945
946 dev = netdev_priv(net);
947 ret = get_ether_addr_str(dev->host_mac, host_addr, len);
948 if (ret + 1 < len) {
949 host_addr[ret++] = '\n';
950 host_addr[ret] = '\0';
951 }
952
953 return ret;
954}
955EXPORT_SYMBOL_GPL(gether_get_host_addr);
956
957int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len)
958{
959 struct eth_dev *dev;
960
961 if (len < 13)
962 return -EINVAL;
963
964 dev = netdev_priv(net);
965 snprintf(host_addr, len, "%pm", dev->host_mac);
966
967 return strlen(host_addr);
968}
969EXPORT_SYMBOL_GPL(gether_get_host_addr_cdc);
970
971void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN])
972{
973 struct eth_dev *dev;
974
975 dev = netdev_priv(net);
976 memcpy(host_mac, dev->host_mac, ETH_ALEN);
977}
978EXPORT_SYMBOL_GPL(gether_get_host_addr_u8);
979
980void gether_set_qmult(struct net_device *net, unsigned qmult)
981{
982 struct eth_dev *dev;
983
984 dev = netdev_priv(net);
985 dev->qmult = qmult;
986}
987EXPORT_SYMBOL_GPL(gether_set_qmult);
988
989unsigned gether_get_qmult(struct net_device *net)
990{
991 struct eth_dev *dev;
992
993 dev = netdev_priv(net);
994 return dev->qmult;
995}
996EXPORT_SYMBOL_GPL(gether_get_qmult);
997
998int gether_get_ifname(struct net_device *net, char *name, int len)
999{
1000 int ret;
1001
1002 rtnl_lock();
1003 ret = snprintf(name, len, "%s\n", netdev_name(net));
1004 rtnl_unlock();
1005 return ret < len ? ret : len;
1006}
1007EXPORT_SYMBOL_GPL(gether_get_ifname);
1008
1009/**
1010 * gether_cleanup - remove Ethernet-over-USB device
1011 * Context: may sleep
1012 *
1013 * This is called to free all resources allocated by @gether_setup().
1014 */
1015void gether_cleanup(struct eth_dev *dev)
1016{
1017 if (!dev)
1018 return;
1019
1020 unregister_netdev(dev->net);
1021 flush_work(&dev->work);
1022 free_netdev(dev->net);
1023}
1024EXPORT_SYMBOL_GPL(gether_cleanup);
1025
1026/**
1027 * gether_connect - notify network layer that USB link is active
1028 * @link: the USB link, set up with endpoints, descriptors matching
1029 * current device speed, and any framing wrapper(s) set up.
1030 * Context: irqs blocked
1031 *
1032 * This is called to activate endpoints and let the network layer know
1033 * the connection is active ("carrier detect"). It may cause the I/O
1034 * queues to open and start letting network packets flow, but will in
1035 * any case activate the endpoints so that they respond properly to the
1036 * USB host.
1037 *
1038 * Verify net_device pointer returned using IS_ERR(). If it doesn't
1039 * indicate some error code (negative errno), ep->driver_data values
1040 * have been overwritten.
1041 */
1042struct net_device *gether_connect(struct gether *link)
1043{
1044 struct eth_dev *dev = link->ioport;
1045 int result = 0;
1046
1047 if (!dev)
1048 return ERR_PTR(-EINVAL);
1049
1050 link->in_ep->driver_data = dev;
1051 result = usb_ep_enable(link->in_ep);
1052 if (result != 0) {
1053 DBG(dev, "enable %s --> %d\n",
1054 link->in_ep->name, result);
1055 goto fail0;
1056 }
1057
1058 link->out_ep->driver_data = dev;
1059 result = usb_ep_enable(link->out_ep);
1060 if (result != 0) {
1061 DBG(dev, "enable %s --> %d\n",
1062 link->out_ep->name, result);
1063 goto fail1;
1064 }
1065
1066 if (result == 0)
1067 result = alloc_requests(dev, link, qlen(dev->gadget,
1068 dev->qmult));
1069
1070 if (result == 0) {
1071 dev->zlp = link->is_zlp_ok;
1072 dev->no_skb_reserve = gadget_avoids_skb_reserve(dev->gadget);
1073 DBG(dev, "qlen %d\n", qlen(dev->gadget, dev->qmult));
1074
1075 dev->header_len = link->header_len;
1076 dev->unwrap = link->unwrap;
1077 dev->wrap = link->wrap;
1078
1079 spin_lock(&dev->lock);
1080 dev->port_usb = link;
1081 if (netif_running(dev->net)) {
1082 if (link->open)
1083 link->open(link);
1084 } else {
1085 if (link->close)
1086 link->close(link);
1087 }
1088 spin_unlock(&dev->lock);
1089
1090 netif_carrier_on(dev->net);
1091 if (netif_running(dev->net))
1092 eth_start(dev, GFP_ATOMIC);
1093
1094 /* on error, disable any endpoints */
1095 } else {
1096 (void) usb_ep_disable(link->out_ep);
1097fail1:
1098 (void) usb_ep_disable(link->in_ep);
1099 }
1100fail0:
1101 /* caller is responsible for cleanup on error */
1102 if (result < 0)
1103 return ERR_PTR(result);
1104 return dev->net;
1105}
1106EXPORT_SYMBOL_GPL(gether_connect);
1107
1108/**
1109 * gether_disconnect - notify network layer that USB link is inactive
1110 * @link: the USB link, on which gether_connect() was called
1111 * Context: irqs blocked
1112 *
1113 * This is called to deactivate endpoints and let the network layer know
1114 * the connection went inactive ("no carrier").
1115 *
1116 * On return, the state is as if gether_connect() had never been called.
1117 * The endpoints are inactive, and accordingly without active USB I/O.
1118 * Pointers to endpoint descriptors and endpoint private data are nulled.
1119 */
1120void gether_disconnect(struct gether *link)
1121{
1122 struct eth_dev *dev = link->ioport;
1123 struct usb_request *req;
1124 struct usb_request *tmp;
1125
1126 WARN_ON(!dev);
1127 if (!dev)
1128 return;
1129
1130 DBG(dev, "%s\n", __func__);
1131
1132 netif_stop_queue(dev->net);
1133 netif_carrier_off(dev->net);
1134
1135 /* disable endpoints, forcing (synchronous) completion
1136 * of all pending i/o. then free the request objects
1137 * and forget about the endpoints.
1138 */
1139 usb_ep_disable(link->in_ep);
1140 spin_lock(&dev->req_lock);
1141 list_for_each_entry_safe(req, tmp, &dev->tx_reqs, list) {
1142 list_del(&req->list);
1143
1144 spin_unlock(&dev->req_lock);
1145 usb_ep_free_request(link->in_ep, req);
1146 spin_lock(&dev->req_lock);
1147 }
1148 spin_unlock(&dev->req_lock);
1149 link->in_ep->desc = NULL;
1150
1151 usb_ep_disable(link->out_ep);
1152 spin_lock(&dev->req_lock);
1153 list_for_each_entry_safe(req, tmp, &dev->rx_reqs, list) {
1154 list_del(&req->list);
1155
1156 spin_unlock(&dev->req_lock);
1157 usb_ep_free_request(link->out_ep, req);
1158 spin_lock(&dev->req_lock);
1159 }
1160 spin_unlock(&dev->req_lock);
1161 link->out_ep->desc = NULL;
1162
1163 /* finish forgetting about this USB link episode */
1164 dev->header_len = 0;
1165 dev->unwrap = NULL;
1166 dev->wrap = NULL;
1167
1168 spin_lock(&dev->lock);
1169 dev->port_usb = NULL;
1170 spin_unlock(&dev->lock);
1171}
1172EXPORT_SYMBOL_GPL(gether_disconnect);
1173
1174MODULE_LICENSE("GPL");
1175MODULE_AUTHOR("David Brownell");