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(dev: 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(nr: flag, addr: &dev->todo))
133 return;
134 if (!schedule_work(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(lock: &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(lock: &dev->lock, flags);
187
188 skb = __netdev_alloc_skb(dev: dev->net, length: size + NET_IP_ALIGN, gfp_mask: 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(ep: 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(new: &req->list, head: &dev->rx_reqs);
216 spin_unlock_irqrestore(lock: &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, len: 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(lock: &dev->lock, flags);
246 } else {
247 skb_queue_tail(list: &dev->rx_frames, newsk: skb);
248 }
249 skb = NULL;
250
251 skb2 = skb_dequeue(list: &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(skb: skb2);
260 goto next_frame;
261 }
262 skb2->protocol = eth_type_trans(skb: skb2, dev: 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(skb: skb2);
270next_frame:
271 skb2 = skb_dequeue(list: &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: dev->net)) {
303clean:
304 spin_lock(lock: &dev->req_lock);
305 list_add(new: &req->list, head: &dev->rx_reqs);
306 spin_unlock(lock: &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(head: list) ? -ENOMEM : 0;
331 list_add(new: &req->list, head: 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(entry: &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(lock: &dev->req_lock);
357 status = prealloc(list: &dev->tx_reqs, ep: link->in_ep, n);
358 if (status < 0)
359 goto fail;
360 status = prealloc(list: &dev->rx_reqs, ep: 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(lock: &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(head: &dev->rx_reqs)) {
379 req = list_first_entry(&dev->rx_reqs, struct usb_request, list);
380 list_del_init(entry: &req->list);
381 spin_unlock_irqrestore(lock: &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(lock: &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, addr: &dev->todo)) {
398 if (netif_running(dev: 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(lock: &dev->req_lock);
427 list_add(new: &req->list, head: &dev->tx_reqs);
428 spin_unlock(lock: &dev->req_lock);
429
430 atomic_dec(v: &dev->tx_qlen);
431 if (netif_carrier_ok(dev: dev->net))
432 netif_wake_queue(dev: 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(dev: 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(dev: net);
477 spin_unlock_irqrestore(lock: &dev->lock, flags);
478 ether_wakeup_host(port: dev->port_usb);
479 return NETDEV_TX_BUSY;
480 }
481
482 spin_unlock_irqrestore(lock: &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(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(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(head: &dev->tx_reqs)) {
519 spin_unlock_irqrestore(lock: &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(entry: &req->list);
525
526 /* temporarily stop TX queue when the freelist empties */
527 if (list_empty(head: &dev->tx_reqs))
528 netif_stop_queue(dev: net);
529 spin_unlock_irqrestore(lock: &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(lock: &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(ep: 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(dev: net);
583 atomic_inc(v: &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(head: &dev->tx_reqs))
593 netif_start_queue(dev: net);
594 list_add(new: &req->list, head: &dev->tx_reqs);
595 spin_unlock_irqrestore(lock: &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(v: &dev->tx_qlen, i: 0);
611 netif_wake_queue(dev: dev->net);
612}
613
614static int eth_open(struct net_device *net)
615{
616 struct eth_dev *dev = netdev_priv(dev: net);
617 struct gether *link;
618
619 DBG(dev, "%s\n", __func__);
620 if (netif_carrier_ok(dev: dev->net))
621 eth_start(dev, GFP_KERNEL);
622
623 spin_lock_irq(lock: &dev->lock);
624 link = dev->port_usb;
625 if (link && link->open)
626 link->open(link);
627 spin_unlock_irq(lock: &dev->lock);
628
629 return 0;
630}
631
632static int eth_stop(struct net_device *net)
633{
634 struct eth_dev *dev = netdev_priv(dev: net);
635 unsigned long flags;
636
637 VDBG(dev, "%s\n", __func__);
638 netif_stop_queue(dev: 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(ep: link->in_ep);
667 usb_ep_disable(ep: link->out_ep);
668 if (netif_carrier_ok(dev: 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(ep: link->in_ep);
673 usb_ep_enable(ep: link->out_ep);
674 }
675 }
676 spin_unlock_irqrestore(lock: &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(ch: *str++) << 4;
694 num |= hex_to_bin(ch: *str++);
695 dev_addr [i] = num;
696 }
697 if (is_valid_ether_addr(addr: dev_addr))
698 return 0;
699 }
700 eth_random_addr(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(buf: str, size: len, fmt: "%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 const 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(error: -ENOMEM);
751
752 dev = netdev_priv(dev: 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(list: &dev->tx_reqs);
757 INIT_LIST_HEAD(list: &dev->rx_reqs);
758
759 skb_queue_head_init(list: &dev->rx_frames);
760
761 /* network device setup */
762 dev->net = net;
763 dev->qmult = qmult;
764 snprintf(buf: net->name, size: sizeof(net->name), fmt: "%s%%d", netname);
765
766 if (get_ether_addr(str: dev_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(dev: net, addr);
774 if (get_ether_addr(str: host_addr, dev_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 = &eth_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(dev: net);
794 if (status < 0) {
795 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
796 free_netdev(dev: net);
797 dev = ERR_PTR(error: 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(dev: 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(error: -ENOMEM);
822
823 dev = netdev_priv(dev: 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(list: &dev->tx_reqs);
828 INIT_LIST_HEAD(list: &dev->rx_reqs);
829
830 skb_queue_head_init(list: &dev->rx_frames);
831
832 /* network device setup */
833 dev->net = net;
834 dev->qmult = QMULT_DEFAULT;
835 snprintf(buf: net->name, size: sizeof(net->name), fmt: "%s%%d", netname);
836
837 eth_random_addr(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(addr: dev->host_mac);
843
844 net->netdev_ops = &eth_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(dev: net);
866 g = dev->gadget;
867
868 eth_hw_addr_set(dev: net, addr: dev->dev_mac);
869
870 status = register_netdev(dev: 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(dev: 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(dev: 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(dev: net);
905 if (get_ether_addr(str: dev_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(dev: net);
919 ret = get_ether_addr_str(dev_addr: dev->dev_mac, str: 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(dev: net);
935 if (get_ether_addr(str: host_addr, dev_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(dev: net);
948 ret = get_ether_addr_str(dev_addr: dev->host_mac, str: 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(dev: net);
966 snprintf(buf: host_addr, size: len, fmt: "%pm", dev->host_mac);
967
968 string_upper(dst: host_addr, src: 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(dev: 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(dev: 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(dev: 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(dev: net);
1004 int ret;
1005
1006 rtnl_lock();
1007 ret = scnprintf(buf: name, size: len, fmt: "%s\n",
1008 dev->ifname_set ? net->name : netdev_name(dev: 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(dev: 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(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 strscpy(net->name, tmp);
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(v: &dev->tx_qlen)) {
1051 /*
1052 * There is a transfer in progress. So we trigger a remote
1053 * wakeup to inform the host.
1054 */
1055 if (!ether_wakeup_host(port: dev->port_usb))
1056 return;
1057 }
1058 spin_lock_irqsave(&dev->lock, flags);
1059 link->is_suspend = true;
1060 spin_unlock_irqrestore(lock: &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: dev->net))
1073 netif_start_queue(dev: dev->net);
1074
1075 spin_lock_irqsave(&dev->lock, flags);
1076 link->is_suspend = false;
1077 spin_unlock_irqrestore(lock: &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: dev->net);
1093 flush_work(work: &dev->work);
1094 free_netdev(dev: 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(error: -EINVAL);
1121
1122 link->in_ep->driver_data = dev;
1123 result = usb_ep_enable(ep: 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(ep: 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, n: qlen(gadget: dev->gadget,
1140 qmult: dev->qmult));
1141
1142 if (result == 0) {
1143 dev->zlp = link->is_zlp_ok;
1144 dev->no_skb_reserve = gadget_avoids_skb_reserve(g: 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(lock: &dev->lock);
1152 dev->port_usb = link;
1153 if (netif_running(dev: dev->net)) {
1154 if (link->open)
1155 link->open(link);
1156 } else {
1157 if (link->close)
1158 link->close(link);
1159 }
1160 spin_unlock(lock: &dev->lock);
1161
1162 netif_carrier_on(dev: dev->net);
1163 if (netif_running(dev: dev->net))
1164 eth_start(dev, GFP_ATOMIC);
1165
1166 /* on error, disable any endpoints */
1167 } else {
1168 (void) usb_ep_disable(ep: link->out_ep);
1169fail1:
1170 (void) usb_ep_disable(ep: link->in_ep);
1171 }
1172fail0:
1173 /* caller is responsible for cleanup on error */
1174 if (result < 0)
1175 return ERR_PTR(error: result);
1176 return dev->net;
1177}
1178EXPORT_SYMBOL_GPL(gether_connect);
1179
1180/**
1181 * gether_disconnect - notify network layer that USB link is inactive
1182 * @link: the USB link, on which gether_connect() was called
1183 * Context: irqs blocked
1184 *
1185 * This is called to deactivate endpoints and let the network layer know
1186 * the connection went inactive ("no carrier").
1187 *
1188 * On return, the state is as if gether_connect() had never been called.
1189 * The endpoints are inactive, and accordingly without active USB I/O.
1190 * Pointers to endpoint descriptors and endpoint private data are nulled.
1191 */
1192void gether_disconnect(struct gether *link)
1193{
1194 struct eth_dev *dev = link->ioport;
1195 struct usb_request *req;
1196
1197 WARN_ON(!dev);
1198 if (!dev)
1199 return;
1200
1201 DBG(dev, "%s\n", __func__);
1202
1203 netif_stop_queue(dev: dev->net);
1204 netif_carrier_off(dev: dev->net);
1205
1206 /* disable endpoints, forcing (synchronous) completion
1207 * of all pending i/o. then free the request objects
1208 * and forget about the endpoints.
1209 */
1210 usb_ep_disable(ep: link->in_ep);
1211 spin_lock(lock: &dev->req_lock);
1212 while (!list_empty(head: &dev->tx_reqs)) {
1213 req = list_first_entry(&dev->tx_reqs, struct usb_request, list);
1214 list_del(entry: &req->list);
1215
1216 spin_unlock(lock: &dev->req_lock);
1217 usb_ep_free_request(ep: link->in_ep, req);
1218 spin_lock(lock: &dev->req_lock);
1219 }
1220 spin_unlock(lock: &dev->req_lock);
1221 link->in_ep->desc = NULL;
1222
1223 usb_ep_disable(ep: link->out_ep);
1224 spin_lock(lock: &dev->req_lock);
1225 while (!list_empty(head: &dev->rx_reqs)) {
1226 req = list_first_entry(&dev->rx_reqs, struct usb_request, list);
1227 list_del(entry: &req->list);
1228
1229 spin_unlock(lock: &dev->req_lock);
1230 usb_ep_free_request(ep: link->out_ep, req);
1231 spin_lock(lock: &dev->req_lock);
1232 }
1233 spin_unlock(lock: &dev->req_lock);
1234 link->out_ep->desc = NULL;
1235
1236 /* finish forgetting about this USB link episode */
1237 dev->header_len = 0;
1238 dev->unwrap = NULL;
1239 dev->wrap = NULL;
1240
1241 spin_lock(lock: &dev->lock);
1242 dev->port_usb = NULL;
1243 link->is_suspend = false;
1244 spin_unlock(lock: &dev->lock);
1245}
1246EXPORT_SYMBOL_GPL(gether_disconnect);
1247
1248MODULE_DESCRIPTION("Ethernet-over-USB link layer utilities for Gadget stack");
1249MODULE_LICENSE("GPL");
1250MODULE_AUTHOR("David Brownell");
1251

source code of linux/drivers/usb/gadget/function/u_ether.c