xref: /linux/drivers/firewire/net.c (revision b7405dcf7385445e10821777143f18c3ce20fa04) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * IPv4 over IEEE 1394, per RFC 2734
4  * IPv6 over IEEE 1394, per RFC 3146
5  *
6  * Copyright (C) 2009 Jay Fenlason <fenlason@redhat.com>
7  *
8  * based on eth1394 by Ben Collins et al
9  */
10 
11 #include <linux/bug.h>
12 #include <linux/compiler.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/ethtool.h>
16 #include <linux/firewire.h>
17 #include <linux/firewire-constants.h>
18 #include <linux/highmem.h>
19 #include <linux/in.h>
20 #include <linux/ip.h>
21 #include <linux/jiffies.h>
22 #include <linux/mod_devicetable.h>
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/mutex.h>
26 #include <linux/netdevice.h>
27 #include <linux/skbuff.h>
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 
31 #include <linux/unaligned.h>
32 #include <net/arp.h>
33 #include <net/firewire.h>
34 
35 /* rx limits */
36 #define FWNET_MAX_FRAGMENTS		30 /* arbitrary, > TX queue depth */
37 #define FWNET_ISO_PAGE_COUNT		(PAGE_SIZE < 16*1024 ? 4 : 2)
38 
39 /* tx limits */
40 #define FWNET_MAX_QUEUED_DATAGRAMS	20 /* < 64 = number of tlabels */
41 #define FWNET_MIN_QUEUED_DATAGRAMS	10 /* should keep AT DMA busy enough */
42 #define FWNET_TX_QUEUE_LEN		FWNET_MAX_QUEUED_DATAGRAMS /* ? */
43 
44 #define IEEE1394_BROADCAST_CHANNEL	31
45 #define IEEE1394_ALL_NODES		(0xffc0 | 0x003f)
46 #define IEEE1394_MAX_PAYLOAD_S100	512
47 #define FWNET_NO_FIFO_ADDR		(~0ULL)
48 
49 #define IANA_SPECIFIER_ID		0x00005eU
50 #define RFC2734_SW_VERSION		0x000001U
51 #define RFC3146_SW_VERSION		0x000002U
52 
53 #define IEEE1394_GASP_HDR_SIZE	8
54 
55 #define RFC2374_UNFRAG_HDR_SIZE	4
56 #define RFC2374_FRAG_HDR_SIZE	8
57 #define RFC2374_FRAG_OVERHEAD	4
58 
59 #define RFC2374_HDR_UNFRAG	0	/* unfragmented		*/
60 #define RFC2374_HDR_FIRSTFRAG	1	/* first fragment	*/
61 #define RFC2374_HDR_LASTFRAG	2	/* last fragment	*/
62 #define RFC2374_HDR_INTFRAG	3	/* interior fragment	*/
63 
64 static bool fwnet_hwaddr_is_multicast(u8 *ha)
65 {
66 	return !!(*ha & 1);
67 }
68 
69 /* IPv4 and IPv6 encapsulation header */
70 struct rfc2734_header {
71 	u32 w0;
72 	u32 w1;
73 };
74 
75 #define fwnet_get_hdr_lf(h)		(((h)->w0 & 0xc0000000) >> 30)
76 #define fwnet_get_hdr_ether_type(h)	(((h)->w0 & 0x0000ffff))
77 #define fwnet_get_hdr_dg_size(h)	((((h)->w0 & 0x0fff0000) >> 16) + 1)
78 #define fwnet_get_hdr_fg_off(h)		(((h)->w0 & 0x00000fff))
79 #define fwnet_get_hdr_dgl(h)		(((h)->w1 & 0xffff0000) >> 16)
80 
81 #define fwnet_set_hdr_lf(lf)		((lf) << 30)
82 #define fwnet_set_hdr_ether_type(et)	(et)
83 #define fwnet_set_hdr_dg_size(dgs)	(((dgs) - 1) << 16)
84 #define fwnet_set_hdr_fg_off(fgo)	(fgo)
85 
86 #define fwnet_set_hdr_dgl(dgl)		((dgl) << 16)
87 
88 static inline void fwnet_make_uf_hdr(struct rfc2734_header *hdr,
89 		unsigned ether_type)
90 {
91 	hdr->w0 = fwnet_set_hdr_lf(RFC2374_HDR_UNFRAG)
92 		  | fwnet_set_hdr_ether_type(ether_type);
93 }
94 
95 static inline void fwnet_make_ff_hdr(struct rfc2734_header *hdr,
96 		unsigned ether_type, unsigned dg_size, unsigned dgl)
97 {
98 	hdr->w0 = fwnet_set_hdr_lf(RFC2374_HDR_FIRSTFRAG)
99 		  | fwnet_set_hdr_dg_size(dg_size)
100 		  | fwnet_set_hdr_ether_type(ether_type);
101 	hdr->w1 = fwnet_set_hdr_dgl(dgl);
102 }
103 
104 static inline void fwnet_make_sf_hdr(struct rfc2734_header *hdr,
105 		unsigned lf, unsigned dg_size, unsigned fg_off, unsigned dgl)
106 {
107 	hdr->w0 = fwnet_set_hdr_lf(lf)
108 		  | fwnet_set_hdr_dg_size(dg_size)
109 		  | fwnet_set_hdr_fg_off(fg_off);
110 	hdr->w1 = fwnet_set_hdr_dgl(dgl);
111 }
112 
113 /* This list keeps track of what parts of the datagram have been filled in */
114 struct fwnet_fragment_info {
115 	struct list_head fi_link;
116 	u16 offset;
117 	u16 len;
118 };
119 
120 struct fwnet_partial_datagram {
121 	struct list_head pd_link;
122 	struct list_head fi_list;
123 	struct sk_buff *skb;
124 	/* FIXME Why not use skb->data? */
125 	char *pbuf;
126 	u16 datagram_label;
127 	u16 ether_type;
128 	u16 datagram_size;
129 };
130 
131 static DEFINE_MUTEX(fwnet_device_mutex);
132 static LIST_HEAD(fwnet_device_list);
133 
134 struct fwnet_device {
135 	struct list_head dev_link;
136 	spinlock_t lock;
137 	enum {
138 		FWNET_BROADCAST_ERROR,
139 		FWNET_BROADCAST_RUNNING,
140 		FWNET_BROADCAST_STOPPED,
141 	} broadcast_state;
142 	struct fw_iso_context *broadcast_rcv_context;
143 	struct fw_iso_buffer broadcast_rcv_buffer;
144 	void **broadcast_rcv_buffer_ptrs;
145 	unsigned broadcast_rcv_next_ptr;
146 	unsigned num_broadcast_rcv_ptrs;
147 	unsigned rcv_buffer_size;
148 	/*
149 	 * This value is the maximum unfragmented datagram size that can be
150 	 * sent by the hardware.  It already has the GASP overhead and the
151 	 * unfragmented datagram header overhead calculated into it.
152 	 */
153 	unsigned broadcast_xmt_max_payload;
154 	u16 broadcast_xmt_datagramlabel;
155 
156 	/*
157 	 * The CSR address that remote nodes must send datagrams to for us to
158 	 * receive them.
159 	 */
160 	struct fw_address_handler handler;
161 	u64 local_fifo;
162 
163 	/* Number of tx datagrams that have been queued but not yet acked */
164 	int queued_datagrams;
165 
166 	int peer_count;
167 	struct list_head peer_list;
168 	struct fw_card *card;
169 	struct net_device *netdev;
170 };
171 
172 struct fwnet_peer {
173 	struct list_head peer_link;
174 	struct fwnet_device *dev;
175 	u64 guid;
176 
177 	/* guarded by dev->lock */
178 	struct list_head pd_list; /* received partial datagrams */
179 	unsigned pdg_size;        /* pd_list size */
180 
181 	u16 datagram_label;       /* outgoing datagram label */
182 	u16 max_payload;          /* includes RFC2374_FRAG_HDR_SIZE overhead */
183 	int node_id;
184 	int generation;
185 	unsigned speed;
186 };
187 
188 /* This is our task struct. It's used for the packet complete callback.  */
189 struct fwnet_packet_task {
190 	struct fw_transaction transaction;
191 	struct rfc2734_header hdr;
192 	struct sk_buff *skb;
193 	struct fwnet_device *dev;
194 
195 	int outstanding_pkts;
196 	u64 fifo_addr;
197 	u16 dest_node;
198 	u16 max_payload;
199 	u8 generation;
200 	u8 speed;
201 	u8 enqueued;
202 };
203 
204 /*
205  * saddr == NULL means use device source address.
206  * daddr == NULL means leave destination address (eg unresolved arp).
207  */
208 static int fwnet_header_create(struct sk_buff *skb, struct net_device *net,
209 			unsigned short type, const void *daddr,
210 			const void *saddr, unsigned len)
211 {
212 	struct fwnet_header *h;
213 
214 	h = skb_push(skb, sizeof(*h));
215 	put_unaligned_be16(type, &h->h_proto);
216 
217 	if (net->flags & (IFF_LOOPBACK | IFF_NOARP)) {
218 		memset(h->h_dest, 0, net->addr_len);
219 
220 		return net->hard_header_len;
221 	}
222 
223 	if (daddr) {
224 		memcpy(h->h_dest, daddr, net->addr_len);
225 
226 		return net->hard_header_len;
227 	}
228 
229 	return -net->hard_header_len;
230 }
231 
232 static int fwnet_header_cache(const struct neighbour *neigh,
233 			      struct hh_cache *hh, __be16 type)
234 {
235 	struct net_device *net;
236 	struct fwnet_header *h;
237 
238 	if (type == cpu_to_be16(ETH_P_802_3))
239 		return -1;
240 	net = neigh->dev;
241 	h = (struct fwnet_header *)((u8 *)hh->hh_data + HH_DATA_OFF(sizeof(*h)));
242 	h->h_proto = type;
243 	memcpy(h->h_dest, neigh->ha, net->addr_len);
244 
245 	/* Pairs with the READ_ONCE() in neigh_resolve_output(),
246 	 * neigh_hh_output() and neigh_update_hhs().
247 	 */
248 	smp_store_release(&hh->hh_len, FWNET_HLEN);
249 
250 	return 0;
251 }
252 
253 /* Called by Address Resolution module to notify changes in address. */
254 static void fwnet_header_cache_update(struct hh_cache *hh,
255 		const struct net_device *net, const unsigned char *haddr)
256 {
257 	memcpy((u8 *)hh->hh_data + HH_DATA_OFF(FWNET_HLEN), haddr, net->addr_len);
258 }
259 
260 static int fwnet_header_parse(const struct sk_buff *skb, const struct net_device *dev,
261 			      unsigned char *haddr)
262 {
263 	memcpy(haddr, dev->dev_addr, FWNET_ALEN);
264 
265 	return FWNET_ALEN;
266 }
267 
268 static const struct header_ops fwnet_header_ops = {
269 	.create         = fwnet_header_create,
270 	.cache		= fwnet_header_cache,
271 	.cache_update	= fwnet_header_cache_update,
272 	.parse          = fwnet_header_parse,
273 };
274 
275 /* FIXME: is this correct for all cases? */
276 static bool fwnet_frag_overlap(struct fwnet_partial_datagram *pd,
277 			       unsigned offset, unsigned len)
278 {
279 	struct fwnet_fragment_info *fi;
280 	unsigned end = offset + len;
281 
282 	list_for_each_entry(fi, &pd->fi_list, fi_link)
283 		if (offset < fi->offset + fi->len && end > fi->offset)
284 			return true;
285 
286 	return false;
287 }
288 
289 /* Assumes that new fragment does not overlap any existing fragments */
290 static struct fwnet_fragment_info *fwnet_frag_new(
291 	struct fwnet_partial_datagram *pd, unsigned offset, unsigned len)
292 {
293 	struct fwnet_fragment_info *fi, *fi2, *new;
294 	struct list_head *list;
295 
296 	list = &pd->fi_list;
297 	list_for_each_entry(fi, &pd->fi_list, fi_link) {
298 		if (fi->offset + fi->len == offset) {
299 			/* The new fragment can be tacked on to the end */
300 			/* Did the new fragment plug a hole? */
301 			fi2 = list_entry(fi->fi_link.next,
302 					 struct fwnet_fragment_info, fi_link);
303 			if (fi->offset + fi->len == fi2->offset) {
304 				/* glue fragments together */
305 				fi->len += len + fi2->len;
306 				list_del(&fi2->fi_link);
307 				kfree(fi2);
308 			} else {
309 				fi->len += len;
310 			}
311 
312 			return fi;
313 		}
314 		if (offset + len == fi->offset) {
315 			/* The new fragment can be tacked on to the beginning */
316 			/* Did the new fragment plug a hole? */
317 			fi2 = list_entry(fi->fi_link.prev,
318 					 struct fwnet_fragment_info, fi_link);
319 			if (fi2->offset + fi2->len == fi->offset) {
320 				/* glue fragments together */
321 				fi2->len += fi->len + len;
322 				list_del(&fi->fi_link);
323 				kfree(fi);
324 
325 				return fi2;
326 			}
327 			fi->offset = offset;
328 			fi->len += len;
329 
330 			return fi;
331 		}
332 		if (offset > fi->offset + fi->len) {
333 			list = &fi->fi_link;
334 			break;
335 		}
336 		if (offset + len < fi->offset) {
337 			list = fi->fi_link.prev;
338 			break;
339 		}
340 	}
341 
342 	new = kmalloc_obj(*new, GFP_ATOMIC);
343 	if (!new)
344 		return NULL;
345 
346 	new->offset = offset;
347 	new->len = len;
348 	list_add(&new->fi_link, list);
349 
350 	return new;
351 }
352 
353 static struct fwnet_partial_datagram *fwnet_pd_new(struct net_device *net,
354 		struct fwnet_peer *peer, u16 datagram_label, unsigned dg_size,
355 		void *frag_buf, unsigned frag_off, unsigned frag_len)
356 {
357 	struct fwnet_partial_datagram *new;
358 	struct fwnet_fragment_info *fi;
359 
360 	new = kmalloc_obj(*new, GFP_ATOMIC);
361 	if (!new)
362 		goto fail;
363 
364 	INIT_LIST_HEAD(&new->fi_list);
365 	fi = fwnet_frag_new(new, frag_off, frag_len);
366 	if (fi == NULL)
367 		goto fail_w_new;
368 
369 	new->datagram_label = datagram_label;
370 	new->datagram_size = dg_size;
371 	new->skb = dev_alloc_skb(dg_size + LL_RESERVED_SPACE(net));
372 	if (new->skb == NULL)
373 		goto fail_w_fi;
374 
375 	skb_reserve(new->skb, LL_RESERVED_SPACE(net));
376 	new->pbuf = skb_put(new->skb, dg_size);
377 	memcpy(new->pbuf + frag_off, frag_buf, frag_len);
378 	list_add_tail(&new->pd_link, &peer->pd_list);
379 
380 	return new;
381 
382 fail_w_fi:
383 	kfree(fi);
384 fail_w_new:
385 	kfree(new);
386 fail:
387 	return NULL;
388 }
389 
390 static struct fwnet_partial_datagram *fwnet_pd_find(struct fwnet_peer *peer,
391 						    u16 datagram_label)
392 {
393 	struct fwnet_partial_datagram *pd;
394 
395 	list_for_each_entry(pd, &peer->pd_list, pd_link)
396 		if (pd->datagram_label == datagram_label)
397 			return pd;
398 
399 	return NULL;
400 }
401 
402 
403 static void fwnet_pd_delete(struct fwnet_partial_datagram *old)
404 {
405 	struct fwnet_fragment_info *fi, *n;
406 
407 	list_for_each_entry_safe(fi, n, &old->fi_list, fi_link)
408 		kfree(fi);
409 
410 	list_del(&old->pd_link);
411 	dev_kfree_skb_any(old->skb);
412 	kfree(old);
413 }
414 
415 static bool fwnet_pd_update(struct fwnet_peer *peer,
416 		struct fwnet_partial_datagram *pd, void *frag_buf,
417 		unsigned frag_off, unsigned frag_len)
418 {
419 	if (fwnet_frag_new(pd, frag_off, frag_len) == NULL)
420 		return false;
421 
422 	memcpy(pd->pbuf + frag_off, frag_buf, frag_len);
423 
424 	/*
425 	 * Move list entry to beginning of list so that oldest partial
426 	 * datagrams percolate to the end of the list
427 	 */
428 	list_move_tail(&pd->pd_link, &peer->pd_list);
429 
430 	return true;
431 }
432 
433 static bool fwnet_pd_is_complete(struct fwnet_partial_datagram *pd)
434 {
435 	struct fwnet_fragment_info *fi;
436 
437 	fi = list_entry(pd->fi_list.next, struct fwnet_fragment_info, fi_link);
438 
439 	return fi->len == pd->datagram_size;
440 }
441 
442 /* caller must hold dev->lock */
443 static struct fwnet_peer *fwnet_peer_find_by_guid(struct fwnet_device *dev,
444 						  u64 guid)
445 {
446 	struct fwnet_peer *peer;
447 
448 	list_for_each_entry(peer, &dev->peer_list, peer_link)
449 		if (peer->guid == guid)
450 			return peer;
451 
452 	return NULL;
453 }
454 
455 /* caller must hold dev->lock */
456 static struct fwnet_peer *fwnet_peer_find_by_node_id(struct fwnet_device *dev,
457 						int node_id, int generation)
458 {
459 	struct fwnet_peer *peer;
460 
461 	list_for_each_entry(peer, &dev->peer_list, peer_link)
462 		if (peer->node_id    == node_id &&
463 		    peer->generation == generation)
464 			return peer;
465 
466 	return NULL;
467 }
468 
469 /* See IEEE 1394-2008 table 6-4, table 8-8, table 16-18. */
470 static unsigned fwnet_max_payload(unsigned max_rec, unsigned speed)
471 {
472 	max_rec = min(max_rec, speed + 8);
473 	max_rec = clamp(max_rec, 8U, 11U); /* 512...4096 */
474 
475 	return (1 << (max_rec + 1)) - RFC2374_FRAG_HDR_SIZE;
476 }
477 
478 
479 static int fwnet_finish_incoming_packet(struct net_device *net,
480 					struct sk_buff *skb, u16 source_node_id,
481 					bool is_broadcast, u16 ether_type)
482 {
483 	int status, len;
484 
485 	switch (ether_type) {
486 	case ETH_P_ARP:
487 	case ETH_P_IP:
488 #if IS_ENABLED(CONFIG_IPV6)
489 	case ETH_P_IPV6:
490 #endif
491 		break;
492 	default:
493 		goto err;
494 	}
495 
496 	/* Write metadata, and then pass to the receive level */
497 	skb->dev = net;
498 	skb->ip_summed = CHECKSUM_NONE;
499 
500 	/*
501 	 * Parse the encapsulation header. This actually does the job of
502 	 * converting to an ethernet-like pseudo frame header.
503 	 */
504 	if (dev_hard_header(skb, net, ether_type,
505 			   is_broadcast ? net->broadcast : net->dev_addr,
506 			   NULL, skb->len) >= 0) {
507 		struct fwnet_header *eth;
508 		u16 *rawp;
509 		__be16 protocol;
510 
511 		skb_reset_mac_header(skb);
512 		skb_pull(skb, sizeof(*eth));
513 		eth = (struct fwnet_header *)skb_mac_header(skb);
514 		if (fwnet_hwaddr_is_multicast(eth->h_dest)) {
515 			if (memcmp(eth->h_dest, net->broadcast,
516 				   net->addr_len) == 0)
517 				skb->pkt_type = PACKET_BROADCAST;
518 #if 0
519 			else
520 				skb->pkt_type = PACKET_MULTICAST;
521 #endif
522 		} else {
523 			if (memcmp(eth->h_dest, net->dev_addr, net->addr_len))
524 				skb->pkt_type = PACKET_OTHERHOST;
525 		}
526 		if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN) {
527 			protocol = eth->h_proto;
528 		} else {
529 			rawp = (u16 *)skb->data;
530 			if (*rawp == 0xffff)
531 				protocol = htons(ETH_P_802_3);
532 			else
533 				protocol = htons(ETH_P_802_2);
534 		}
535 		skb->protocol = protocol;
536 	}
537 
538 	len = skb->len;
539 	status = netif_rx(skb);
540 	if (status == NET_RX_DROP) {
541 		net->stats.rx_errors++;
542 		net->stats.rx_dropped++;
543 	} else {
544 		net->stats.rx_packets++;
545 		net->stats.rx_bytes += len;
546 	}
547 
548 	return 0;
549 
550  err:
551 	net->stats.rx_errors++;
552 	net->stats.rx_dropped++;
553 
554 	dev_kfree_skb_any(skb);
555 
556 	return -ENOENT;
557 }
558 
559 static int fwnet_incoming_packet(struct fwnet_device *dev, __be32 *buf, int len,
560 				 int source_node_id, int generation,
561 				 bool is_broadcast)
562 {
563 	struct sk_buff *skb;
564 	struct net_device *net = dev->netdev;
565 	struct rfc2734_header hdr;
566 	unsigned lf;
567 	unsigned long flags;
568 	struct fwnet_peer *peer;
569 	struct fwnet_partial_datagram *pd;
570 	int fg_off;
571 	int dg_size;
572 	u16 datagram_label;
573 	int retval;
574 	u16 ether_type;
575 
576 	if (len <= RFC2374_UNFRAG_HDR_SIZE)
577 		return 0;
578 
579 	hdr.w0 = be32_to_cpu(buf[0]);
580 	lf = fwnet_get_hdr_lf(&hdr);
581 	if (lf == RFC2374_HDR_UNFRAG) {
582 		/*
583 		 * An unfragmented datagram has been received by the ieee1394
584 		 * bus. Build an skbuff around it so we can pass it to the
585 		 * high level network layer.
586 		 */
587 		ether_type = fwnet_get_hdr_ether_type(&hdr);
588 		buf++;
589 		len -= RFC2374_UNFRAG_HDR_SIZE;
590 
591 		skb = dev_alloc_skb(len + LL_RESERVED_SPACE(net));
592 		if (unlikely(!skb)) {
593 			net->stats.rx_dropped++;
594 
595 			return -ENOMEM;
596 		}
597 		skb_reserve(skb, LL_RESERVED_SPACE(net));
598 		skb_put_data(skb, buf, len);
599 
600 		return fwnet_finish_incoming_packet(net, skb, source_node_id,
601 						    is_broadcast, ether_type);
602 	}
603 
604 	/* A datagram fragment has been received, now the fun begins. */
605 
606 	if (len <= RFC2374_FRAG_HDR_SIZE)
607 		return 0;
608 
609 	hdr.w1 = ntohl(buf[1]);
610 	buf += 2;
611 	len -= RFC2374_FRAG_HDR_SIZE;
612 	if (lf == RFC2374_HDR_FIRSTFRAG) {
613 		ether_type = fwnet_get_hdr_ether_type(&hdr);
614 		fg_off = 0;
615 	} else {
616 		ether_type = 0;
617 		fg_off = fwnet_get_hdr_fg_off(&hdr);
618 	}
619 	datagram_label = fwnet_get_hdr_dgl(&hdr);
620 	dg_size = fwnet_get_hdr_dg_size(&hdr);
621 
622 	if (fg_off + len > dg_size)
623 		return 0;
624 
625 	spin_lock_irqsave(&dev->lock, flags);
626 
627 	peer = fwnet_peer_find_by_node_id(dev, source_node_id, generation);
628 	if (!peer) {
629 		retval = -ENOENT;
630 		goto fail;
631 	}
632 
633 	pd = fwnet_pd_find(peer, datagram_label);
634 	if (pd == NULL) {
635 		while (peer->pdg_size >= FWNET_MAX_FRAGMENTS) {
636 			/* remove the oldest */
637 			fwnet_pd_delete(list_first_entry(&peer->pd_list,
638 				struct fwnet_partial_datagram, pd_link));
639 			peer->pdg_size--;
640 		}
641 		pd = fwnet_pd_new(net, peer, datagram_label,
642 				  dg_size, buf, fg_off, len);
643 		if (pd == NULL) {
644 			retval = -ENOMEM;
645 			goto fail;
646 		}
647 		peer->pdg_size++;
648 	} else {
649 		if (fwnet_frag_overlap(pd, fg_off, len) ||
650 		    pd->datagram_size != dg_size) {
651 			/*
652 			 * Differing datagram sizes or overlapping fragments,
653 			 * discard old datagram and start a new one.
654 			 */
655 			fwnet_pd_delete(pd);
656 			pd = fwnet_pd_new(net, peer, datagram_label,
657 					  dg_size, buf, fg_off, len);
658 			if (pd == NULL) {
659 				peer->pdg_size--;
660 				retval = -ENOMEM;
661 				goto fail;
662 			}
663 		} else {
664 			if (!fwnet_pd_update(peer, pd, buf, fg_off, len)) {
665 				/*
666 				 * Couldn't save off fragment anyway
667 				 * so might as well obliterate the
668 				 * datagram now.
669 				 */
670 				fwnet_pd_delete(pd);
671 				peer->pdg_size--;
672 				retval = -ENOMEM;
673 				goto fail;
674 			}
675 		}
676 	} /* new datagram or add to existing one */
677 
678 	if (lf == RFC2374_HDR_FIRSTFRAG)
679 		pd->ether_type = ether_type;
680 
681 	if (fwnet_pd_is_complete(pd)) {
682 		ether_type = pd->ether_type;
683 		peer->pdg_size--;
684 		skb = skb_get(pd->skb);
685 		fwnet_pd_delete(pd);
686 
687 		spin_unlock_irqrestore(&dev->lock, flags);
688 
689 		return fwnet_finish_incoming_packet(net, skb, source_node_id,
690 						    false, ether_type);
691 	}
692 	/*
693 	 * Datagram is not complete, we're done for the
694 	 * moment.
695 	 */
696 	retval = 0;
697  fail:
698 	spin_unlock_irqrestore(&dev->lock, flags);
699 
700 	return retval;
701 }
702 
703 static void fwnet_receive_packet(struct fw_card *card, struct fw_request *r,
704 		int tcode, int destination, int source, int generation,
705 		unsigned long long offset, void *payload, size_t length,
706 		void *callback_data)
707 {
708 	struct fwnet_device *dev = callback_data;
709 	int rcode;
710 
711 	if (destination == IEEE1394_ALL_NODES) {
712 		// Although the response to the broadcast packet is not necessarily required, the
713 		// fw_send_response() function should still be called to maintain the reference
714 		// counting of the object. In the case, the call of function just releases the
715 		// object as a result to decrease the reference counting.
716 		rcode = RCODE_COMPLETE;
717 	} else if (offset != dev->handler.offset) {
718 		rcode = RCODE_ADDRESS_ERROR;
719 	} else if (tcode != TCODE_WRITE_BLOCK_REQUEST) {
720 		rcode = RCODE_TYPE_ERROR;
721 	} else if (fwnet_incoming_packet(dev, payload, length,
722 					 source, generation, false) != 0) {
723 		dev_err(&dev->netdev->dev, "incoming packet failure\n");
724 		rcode = RCODE_CONFLICT_ERROR;
725 	} else {
726 		rcode = RCODE_COMPLETE;
727 	}
728 
729 	fw_send_response(card, r, rcode);
730 }
731 
732 static int gasp_source_id(__be32 *p)
733 {
734 	return be32_to_cpu(p[0]) >> 16;
735 }
736 
737 static u32 gasp_specifier_id(__be32 *p)
738 {
739 	return (be32_to_cpu(p[0]) & 0xffff) << 8 |
740 	       (be32_to_cpu(p[1]) & 0xff000000) >> 24;
741 }
742 
743 static u32 gasp_version(__be32 *p)
744 {
745 	return be32_to_cpu(p[1]) & 0xffffff;
746 }
747 
748 static void fwnet_receive_broadcast(struct fw_iso_context *context,
749 		u32 cycle, size_t header_length, void *header, void *data)
750 {
751 	struct fwnet_device *dev;
752 	struct fw_iso_packet packet;
753 	__be16 *hdr_ptr;
754 	__be32 *buf_ptr;
755 	int retval;
756 	u32 length;
757 	unsigned long offset;
758 	unsigned long flags;
759 
760 	dev = data;
761 	hdr_ptr = header;
762 	length = be16_to_cpup(hdr_ptr);
763 
764 	spin_lock_irqsave(&dev->lock, flags);
765 
766 	offset = dev->rcv_buffer_size * dev->broadcast_rcv_next_ptr;
767 	buf_ptr = dev->broadcast_rcv_buffer_ptrs[dev->broadcast_rcv_next_ptr++];
768 	if (dev->broadcast_rcv_next_ptr == dev->num_broadcast_rcv_ptrs)
769 		dev->broadcast_rcv_next_ptr = 0;
770 
771 	spin_unlock_irqrestore(&dev->lock, flags);
772 
773 	if (length > IEEE1394_GASP_HDR_SIZE &&
774 	    gasp_specifier_id(buf_ptr) == IANA_SPECIFIER_ID &&
775 	    (gasp_version(buf_ptr) == RFC2734_SW_VERSION
776 #if IS_ENABLED(CONFIG_IPV6)
777 	     || gasp_version(buf_ptr) == RFC3146_SW_VERSION
778 #endif
779 	    ))
780 		fwnet_incoming_packet(dev, buf_ptr + 2,
781 				      length - IEEE1394_GASP_HDR_SIZE,
782 				      gasp_source_id(buf_ptr),
783 				      context->card->generation, true);
784 
785 	packet.payload_length = dev->rcv_buffer_size;
786 	packet.interrupt = 1;
787 	packet.skip = 0;
788 	packet.tag = 3;
789 	packet.sy = 0;
790 	packet.header_length = IEEE1394_GASP_HDR_SIZE;
791 
792 	spin_lock_irqsave(&dev->lock, flags);
793 
794 	retval = fw_iso_context_queue(dev->broadcast_rcv_context, &packet,
795 				      &dev->broadcast_rcv_buffer, offset);
796 
797 	spin_unlock_irqrestore(&dev->lock, flags);
798 
799 	if (retval >= 0)
800 		fw_iso_context_queue_flush(dev->broadcast_rcv_context);
801 	else
802 		dev_err(&dev->netdev->dev, "requeue failed\n");
803 }
804 
805 static struct kmem_cache *fwnet_packet_task_cache;
806 
807 static void fwnet_free_ptask(struct fwnet_packet_task *ptask)
808 {
809 	dev_kfree_skb_any(ptask->skb);
810 	kmem_cache_free(fwnet_packet_task_cache, ptask);
811 }
812 
813 /* Caller must hold dev->lock. */
814 static void dec_queued_datagrams(struct fwnet_device *dev)
815 {
816 	if (--dev->queued_datagrams == FWNET_MIN_QUEUED_DATAGRAMS)
817 		netif_wake_queue(dev->netdev);
818 }
819 
820 static int fwnet_send_packet(struct fwnet_packet_task *ptask);
821 
822 static void fwnet_transmit_packet_done(struct fwnet_packet_task *ptask)
823 {
824 	struct fwnet_device *dev = ptask->dev;
825 	struct sk_buff *skb = ptask->skb;
826 	unsigned long flags;
827 	bool free;
828 
829 	spin_lock_irqsave(&dev->lock, flags);
830 
831 	ptask->outstanding_pkts--;
832 
833 	/* Check whether we or the networking TX soft-IRQ is last user. */
834 	free = (ptask->outstanding_pkts == 0 && ptask->enqueued);
835 	if (free)
836 		dec_queued_datagrams(dev);
837 
838 	if (ptask->outstanding_pkts == 0) {
839 		dev->netdev->stats.tx_packets++;
840 		dev->netdev->stats.tx_bytes += skb->len;
841 	}
842 
843 	spin_unlock_irqrestore(&dev->lock, flags);
844 
845 	if (ptask->outstanding_pkts > 0) {
846 		u16 dg_size;
847 		u16 fg_off;
848 		u16 datagram_label;
849 		u16 lf;
850 
851 		/* Update the ptask to point to the next fragment and send it */
852 		lf = fwnet_get_hdr_lf(&ptask->hdr);
853 		switch (lf) {
854 		case RFC2374_HDR_LASTFRAG:
855 		case RFC2374_HDR_UNFRAG:
856 		default:
857 			dev_err(&dev->netdev->dev,
858 				"outstanding packet %x lf %x, header %x,%x\n",
859 				ptask->outstanding_pkts, lf, ptask->hdr.w0,
860 				ptask->hdr.w1);
861 			BUG();
862 
863 		case RFC2374_HDR_FIRSTFRAG:
864 			/* Set frag type here for future interior fragments */
865 			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
866 			fg_off = ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
867 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
868 			break;
869 
870 		case RFC2374_HDR_INTFRAG:
871 			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
872 			fg_off = fwnet_get_hdr_fg_off(&ptask->hdr)
873 				  + ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
874 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
875 			break;
876 		}
877 
878 		if (ptask->dest_node == IEEE1394_ALL_NODES) {
879 			skb_pull(skb,
880 				 ptask->max_payload + IEEE1394_GASP_HDR_SIZE);
881 		} else {
882 			skb_pull(skb, ptask->max_payload);
883 		}
884 		if (ptask->outstanding_pkts > 1) {
885 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_INTFRAG,
886 					  dg_size, fg_off, datagram_label);
887 		} else {
888 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_LASTFRAG,
889 					  dg_size, fg_off, datagram_label);
890 			ptask->max_payload = skb->len + RFC2374_FRAG_HDR_SIZE;
891 		}
892 		fwnet_send_packet(ptask);
893 	}
894 
895 	if (free)
896 		fwnet_free_ptask(ptask);
897 }
898 
899 static void fwnet_transmit_packet_failed(struct fwnet_packet_task *ptask)
900 {
901 	struct fwnet_device *dev = ptask->dev;
902 	unsigned long flags;
903 	bool free;
904 
905 	spin_lock_irqsave(&dev->lock, flags);
906 
907 	/* One fragment failed; don't try to send remaining fragments. */
908 	ptask->outstanding_pkts = 0;
909 
910 	/* Check whether we or the networking TX soft-IRQ is last user. */
911 	free = ptask->enqueued;
912 	if (free)
913 		dec_queued_datagrams(dev);
914 
915 	dev->netdev->stats.tx_dropped++;
916 	dev->netdev->stats.tx_errors++;
917 
918 	spin_unlock_irqrestore(&dev->lock, flags);
919 
920 	if (free)
921 		fwnet_free_ptask(ptask);
922 }
923 
924 static void fwnet_write_complete(struct fw_card *card, int rcode,
925 				 void *payload, size_t length, void *data)
926 {
927 	struct fwnet_packet_task *ptask = data;
928 	static unsigned long j;
929 	static int last_rcode, errors_skipped;
930 
931 	if (rcode == RCODE_COMPLETE) {
932 		fwnet_transmit_packet_done(ptask);
933 	} else {
934 		if (printk_timed_ratelimit(&j,  1000) || rcode != last_rcode) {
935 			dev_err(&ptask->dev->netdev->dev,
936 				"fwnet_write_complete failed: %x (skipped %d)\n",
937 				rcode, errors_skipped);
938 
939 			errors_skipped = 0;
940 			last_rcode = rcode;
941 		} else {
942 			errors_skipped++;
943 		}
944 		fwnet_transmit_packet_failed(ptask);
945 	}
946 }
947 
948 static int fwnet_send_packet(struct fwnet_packet_task *ptask)
949 {
950 	struct fwnet_device *dev;
951 	unsigned tx_len;
952 	struct rfc2734_header *bufhdr;
953 	unsigned long flags;
954 	bool free;
955 
956 	dev = ptask->dev;
957 	tx_len = ptask->max_payload;
958 	switch (fwnet_get_hdr_lf(&ptask->hdr)) {
959 	case RFC2374_HDR_UNFRAG:
960 		bufhdr = skb_push(ptask->skb, RFC2374_UNFRAG_HDR_SIZE);
961 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
962 		break;
963 
964 	case RFC2374_HDR_FIRSTFRAG:
965 	case RFC2374_HDR_INTFRAG:
966 	case RFC2374_HDR_LASTFRAG:
967 		bufhdr = skb_push(ptask->skb, RFC2374_FRAG_HDR_SIZE);
968 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
969 		put_unaligned_be32(ptask->hdr.w1, &bufhdr->w1);
970 		break;
971 
972 	default:
973 		BUG();
974 	}
975 	if (ptask->dest_node == IEEE1394_ALL_NODES) {
976 		u8 *p;
977 		int generation;
978 		int node_id;
979 		unsigned int sw_version;
980 
981 		/* ptask->generation may not have been set yet */
982 		generation = dev->card->generation;
983 		smp_rmb();
984 		node_id = dev->card->node_id;
985 
986 		switch (ptask->skb->protocol) {
987 		default:
988 			sw_version = RFC2734_SW_VERSION;
989 			break;
990 #if IS_ENABLED(CONFIG_IPV6)
991 		case htons(ETH_P_IPV6):
992 			sw_version = RFC3146_SW_VERSION;
993 #endif
994 		}
995 
996 		p = skb_push(ptask->skb, IEEE1394_GASP_HDR_SIZE);
997 		put_unaligned_be32(node_id << 16 | IANA_SPECIFIER_ID >> 8, p);
998 		put_unaligned_be32((IANA_SPECIFIER_ID & 0xff) << 24
999 						| sw_version, &p[4]);
1000 
1001 		/* We should not transmit if broadcast_channel.valid == 0. */
1002 		fw_send_request(dev->card, &ptask->transaction,
1003 				TCODE_STREAM_DATA,
1004 				fw_stream_packet_destination_id(3,
1005 						IEEE1394_BROADCAST_CHANNEL, 0),
1006 				generation, SCODE_100, 0ULL, ptask->skb->data,
1007 				tx_len + 8, fwnet_write_complete, ptask);
1008 
1009 		spin_lock_irqsave(&dev->lock, flags);
1010 
1011 		/* If the AT work item already ran, we may be last user. */
1012 		free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
1013 		if (!free)
1014 			ptask->enqueued = true;
1015 		else
1016 			dec_queued_datagrams(dev);
1017 
1018 		spin_unlock_irqrestore(&dev->lock, flags);
1019 
1020 		goto out;
1021 	}
1022 
1023 	fw_send_request(dev->card, &ptask->transaction,
1024 			TCODE_WRITE_BLOCK_REQUEST, ptask->dest_node,
1025 			ptask->generation, ptask->speed, ptask->fifo_addr,
1026 			ptask->skb->data, tx_len, fwnet_write_complete, ptask);
1027 
1028 	spin_lock_irqsave(&dev->lock, flags);
1029 
1030 	/* If the AT work item already ran, we may be last user. */
1031 	free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
1032 	if (!free)
1033 		ptask->enqueued = true;
1034 	else
1035 		dec_queued_datagrams(dev);
1036 
1037 	spin_unlock_irqrestore(&dev->lock, flags);
1038 
1039 	netif_trans_update(dev->netdev);
1040  out:
1041 	if (free)
1042 		fwnet_free_ptask(ptask);
1043 
1044 	return 0;
1045 }
1046 
1047 static void fwnet_fifo_stop(struct fwnet_device *dev)
1048 {
1049 	if (dev->local_fifo == FWNET_NO_FIFO_ADDR)
1050 		return;
1051 
1052 	fw_core_remove_address_handler(&dev->handler);
1053 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
1054 }
1055 
1056 static int fwnet_fifo_start(struct fwnet_device *dev)
1057 {
1058 	int retval;
1059 
1060 	if (dev->local_fifo != FWNET_NO_FIFO_ADDR)
1061 		return 0;
1062 
1063 	dev->handler.length = 4096;
1064 	dev->handler.address_callback = fwnet_receive_packet;
1065 	dev->handler.callback_data = dev;
1066 
1067 	retval = fw_core_add_address_handler(&dev->handler,
1068 					     &fw_high_memory_region);
1069 	if (retval < 0)
1070 		return retval;
1071 
1072 	dev->local_fifo = dev->handler.offset;
1073 
1074 	return 0;
1075 }
1076 
1077 static void __fwnet_broadcast_stop(struct fwnet_device *dev)
1078 {
1079 	unsigned u;
1080 
1081 	if (dev->broadcast_state != FWNET_BROADCAST_ERROR) {
1082 		for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++)
1083 			kunmap(dev->broadcast_rcv_buffer.pages[u]);
1084 		fw_iso_buffer_destroy(&dev->broadcast_rcv_buffer, dev->card);
1085 	}
1086 	if (dev->broadcast_rcv_context) {
1087 		fw_iso_context_destroy(dev->broadcast_rcv_context);
1088 		dev->broadcast_rcv_context = NULL;
1089 	}
1090 	kfree(dev->broadcast_rcv_buffer_ptrs);
1091 	dev->broadcast_rcv_buffer_ptrs = NULL;
1092 	dev->broadcast_state = FWNET_BROADCAST_ERROR;
1093 }
1094 
1095 static void fwnet_broadcast_stop(struct fwnet_device *dev)
1096 {
1097 	if (dev->broadcast_state == FWNET_BROADCAST_ERROR)
1098 		return;
1099 	fw_iso_context_stop(dev->broadcast_rcv_context);
1100 	__fwnet_broadcast_stop(dev);
1101 }
1102 
1103 static int fwnet_broadcast_start(struct fwnet_device *dev)
1104 {
1105 	struct fw_iso_context *context;
1106 	int retval;
1107 	unsigned num_packets;
1108 	unsigned max_receive;
1109 	struct fw_iso_packet packet;
1110 	unsigned long offset;
1111 	void **ptrptr;
1112 	unsigned u;
1113 
1114 	if (dev->broadcast_state != FWNET_BROADCAST_ERROR)
1115 		return 0;
1116 
1117 	max_receive = 1U << (dev->card->max_receive + 1);
1118 	num_packets = (FWNET_ISO_PAGE_COUNT * PAGE_SIZE) / max_receive;
1119 
1120 	ptrptr = kmalloc_array(num_packets, sizeof(void *), GFP_KERNEL);
1121 	if (!ptrptr) {
1122 		retval = -ENOMEM;
1123 		goto failed;
1124 	}
1125 	dev->broadcast_rcv_buffer_ptrs = ptrptr;
1126 
1127 	context = fw_iso_context_create(dev->card, FW_ISO_CONTEXT_RECEIVE,
1128 					IEEE1394_BROADCAST_CHANNEL,
1129 					dev->card->link_speed, 8,
1130 					fwnet_receive_broadcast, dev);
1131 	if (IS_ERR(context)) {
1132 		retval = PTR_ERR(context);
1133 		goto failed;
1134 	}
1135 
1136 	retval = fw_iso_buffer_init(&dev->broadcast_rcv_buffer, dev->card,
1137 				    FWNET_ISO_PAGE_COUNT, DMA_FROM_DEVICE);
1138 	if (retval < 0)
1139 		goto failed;
1140 
1141 	dev->broadcast_state = FWNET_BROADCAST_STOPPED;
1142 
1143 	for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++) {
1144 		void *ptr;
1145 		unsigned v;
1146 
1147 		ptr = kmap(dev->broadcast_rcv_buffer.pages[u]);
1148 		for (v = 0; v < num_packets / FWNET_ISO_PAGE_COUNT; v++)
1149 			*ptrptr++ = (void *) ((char *)ptr + v * max_receive);
1150 	}
1151 	dev->broadcast_rcv_context = context;
1152 
1153 	packet.payload_length = max_receive;
1154 	packet.interrupt = 1;
1155 	packet.skip = 0;
1156 	packet.tag = 3;
1157 	packet.sy = 0;
1158 	packet.header_length = IEEE1394_GASP_HDR_SIZE;
1159 	offset = 0;
1160 
1161 	for (u = 0; u < num_packets; u++) {
1162 		retval = fw_iso_context_queue(context, &packet,
1163 				&dev->broadcast_rcv_buffer, offset);
1164 		if (retval < 0)
1165 			goto failed;
1166 
1167 		offset += max_receive;
1168 	}
1169 	dev->num_broadcast_rcv_ptrs = num_packets;
1170 	dev->rcv_buffer_size = max_receive;
1171 	dev->broadcast_rcv_next_ptr = 0U;
1172 	retval = fw_iso_context_start(context, -1, 0,
1173 			FW_ISO_CONTEXT_MATCH_ALL_TAGS); /* ??? sync */
1174 	if (retval < 0)
1175 		goto failed;
1176 
1177 	/* FIXME: adjust it according to the min. speed of all known peers? */
1178 	dev->broadcast_xmt_max_payload = IEEE1394_MAX_PAYLOAD_S100
1179 			- IEEE1394_GASP_HDR_SIZE - RFC2374_UNFRAG_HDR_SIZE;
1180 	dev->broadcast_state = FWNET_BROADCAST_RUNNING;
1181 
1182 	return 0;
1183 
1184  failed:
1185 	__fwnet_broadcast_stop(dev);
1186 	return retval;
1187 }
1188 
1189 static void set_carrier_state(struct fwnet_device *dev)
1190 {
1191 	if (dev->peer_count > 1)
1192 		netif_carrier_on(dev->netdev);
1193 	else
1194 		netif_carrier_off(dev->netdev);
1195 }
1196 
1197 /* ifup */
1198 static int fwnet_open(struct net_device *net)
1199 {
1200 	struct fwnet_device *dev = netdev_priv(net);
1201 	int ret;
1202 
1203 	ret = fwnet_broadcast_start(dev);
1204 	if (ret)
1205 		return ret;
1206 
1207 	netif_start_queue(net);
1208 
1209 	spin_lock_irq(&dev->lock);
1210 	set_carrier_state(dev);
1211 	spin_unlock_irq(&dev->lock);
1212 
1213 	return 0;
1214 }
1215 
1216 /* ifdown */
1217 static int fwnet_stop(struct net_device *net)
1218 {
1219 	struct fwnet_device *dev = netdev_priv(net);
1220 
1221 	netif_stop_queue(net);
1222 	fwnet_broadcast_stop(dev);
1223 
1224 	return 0;
1225 }
1226 
1227 static netdev_tx_t fwnet_tx(struct sk_buff *skb, struct net_device *net)
1228 {
1229 	struct fwnet_header hdr_buf;
1230 	struct fwnet_device *dev = netdev_priv(net);
1231 	__be16 proto;
1232 	u16 dest_node;
1233 	unsigned max_payload;
1234 	u16 dg_size;
1235 	u16 *datagram_label_ptr;
1236 	struct fwnet_packet_task *ptask;
1237 	struct fwnet_peer *peer;
1238 	unsigned long flags;
1239 
1240 	spin_lock_irqsave(&dev->lock, flags);
1241 
1242 	/* Can this happen? */
1243 	if (netif_queue_stopped(dev->netdev)) {
1244 		spin_unlock_irqrestore(&dev->lock, flags);
1245 
1246 		return NETDEV_TX_BUSY;
1247 	}
1248 
1249 	ptask = kmem_cache_alloc(fwnet_packet_task_cache, GFP_ATOMIC);
1250 	if (ptask == NULL)
1251 		goto fail;
1252 
1253 	skb = skb_share_check(skb, GFP_ATOMIC);
1254 	if (!skb)
1255 		goto fail;
1256 
1257 	/*
1258 	 * Make a copy of the driver-specific header.
1259 	 * We might need to rebuild the header on tx failure.
1260 	 */
1261 	memcpy(&hdr_buf, skb->data, sizeof(hdr_buf));
1262 	proto = hdr_buf.h_proto;
1263 
1264 	switch (proto) {
1265 	case htons(ETH_P_ARP):
1266 	case htons(ETH_P_IP):
1267 #if IS_ENABLED(CONFIG_IPV6)
1268 	case htons(ETH_P_IPV6):
1269 #endif
1270 		break;
1271 	default:
1272 		goto fail;
1273 	}
1274 
1275 	skb_pull(skb, sizeof(hdr_buf));
1276 	dg_size = skb->len;
1277 
1278 	/*
1279 	 * Set the transmission type for the packet.  ARP packets and IP
1280 	 * broadcast packets are sent via GASP.
1281 	 */
1282 	if (fwnet_hwaddr_is_multicast(hdr_buf.h_dest)) {
1283 		max_payload        = dev->broadcast_xmt_max_payload;
1284 		datagram_label_ptr = &dev->broadcast_xmt_datagramlabel;
1285 
1286 		ptask->fifo_addr   = FWNET_NO_FIFO_ADDR;
1287 		ptask->generation  = 0;
1288 		ptask->dest_node   = IEEE1394_ALL_NODES;
1289 		ptask->speed       = SCODE_100;
1290 	} else {
1291 		union fwnet_hwaddr *ha = (union fwnet_hwaddr *)hdr_buf.h_dest;
1292 		__be64 guid = get_unaligned(&ha->uc.uniq_id);
1293 		u8 generation;
1294 
1295 		peer = fwnet_peer_find_by_guid(dev, be64_to_cpu(guid));
1296 		if (!peer)
1297 			goto fail;
1298 
1299 		generation         = peer->generation;
1300 		dest_node          = peer->node_id;
1301 		max_payload        = peer->max_payload;
1302 		datagram_label_ptr = &peer->datagram_label;
1303 
1304 		ptask->fifo_addr   = get_unaligned_be48(ha->uc.fifo);
1305 		ptask->generation  = generation;
1306 		ptask->dest_node   = dest_node;
1307 		ptask->speed       = peer->speed;
1308 	}
1309 
1310 	ptask->hdr.w0 = 0;
1311 	ptask->hdr.w1 = 0;
1312 	ptask->skb = skb;
1313 	ptask->dev = dev;
1314 
1315 	/* Does it all fit in one packet? */
1316 	if (dg_size <= max_payload) {
1317 		fwnet_make_uf_hdr(&ptask->hdr, ntohs(proto));
1318 		ptask->outstanding_pkts = 1;
1319 		max_payload = dg_size + RFC2374_UNFRAG_HDR_SIZE;
1320 	} else {
1321 		u16 datagram_label;
1322 
1323 		max_payload -= RFC2374_FRAG_OVERHEAD;
1324 		datagram_label = (*datagram_label_ptr)++;
1325 		fwnet_make_ff_hdr(&ptask->hdr, ntohs(proto), dg_size,
1326 				  datagram_label);
1327 		ptask->outstanding_pkts = DIV_ROUND_UP(dg_size, max_payload);
1328 		max_payload += RFC2374_FRAG_HDR_SIZE;
1329 	}
1330 
1331 	if (++dev->queued_datagrams == FWNET_MAX_QUEUED_DATAGRAMS)
1332 		netif_stop_queue(dev->netdev);
1333 
1334 	spin_unlock_irqrestore(&dev->lock, flags);
1335 
1336 	ptask->max_payload = max_payload;
1337 	ptask->enqueued    = 0;
1338 
1339 	fwnet_send_packet(ptask);
1340 
1341 	return NETDEV_TX_OK;
1342 
1343  fail:
1344 	spin_unlock_irqrestore(&dev->lock, flags);
1345 
1346 	if (ptask)
1347 		kmem_cache_free(fwnet_packet_task_cache, ptask);
1348 
1349 	if (skb != NULL)
1350 		dev_kfree_skb(skb);
1351 
1352 	net->stats.tx_dropped++;
1353 	net->stats.tx_errors++;
1354 
1355 	/*
1356 	 * FIXME: According to a patch from 2003-02-26, "returning non-zero
1357 	 * causes serious problems" here, allegedly.  Before that patch,
1358 	 * -ERRNO was returned which is not appropriate under Linux 2.6.
1359 	 * Perhaps more needs to be done?  Stop the queue in serious
1360 	 * conditions and restart it elsewhere?
1361 	 */
1362 	return NETDEV_TX_OK;
1363 }
1364 
1365 static const struct ethtool_ops fwnet_ethtool_ops = {
1366 	.get_link	= ethtool_op_get_link,
1367 };
1368 
1369 static const struct net_device_ops fwnet_netdev_ops = {
1370 	.ndo_open       = fwnet_open,
1371 	.ndo_stop	= fwnet_stop,
1372 	.ndo_start_xmit = fwnet_tx,
1373 };
1374 
1375 static void fwnet_init_dev(struct net_device *net)
1376 {
1377 	net->header_ops		= &fwnet_header_ops;
1378 	net->netdev_ops		= &fwnet_netdev_ops;
1379 	net->watchdog_timeo	= 2 * HZ;
1380 	net->flags		= IFF_BROADCAST | IFF_MULTICAST;
1381 	net->features		= NETIF_F_HIGHDMA;
1382 	net->addr_len		= FWNET_ALEN;
1383 	net->hard_header_len	= FWNET_HLEN;
1384 	net->type		= ARPHRD_IEEE1394;
1385 	net->tx_queue_len	= FWNET_TX_QUEUE_LEN;
1386 	net->ethtool_ops	= &fwnet_ethtool_ops;
1387 }
1388 
1389 /* caller must hold fwnet_device_mutex */
1390 static struct fwnet_device *fwnet_dev_find(struct fw_card *card)
1391 {
1392 	struct fwnet_device *dev;
1393 
1394 	list_for_each_entry(dev, &fwnet_device_list, dev_link)
1395 		if (dev->card == card)
1396 			return dev;
1397 
1398 	return NULL;
1399 }
1400 
1401 static int fwnet_add_peer(struct fwnet_device *dev,
1402 			  struct fw_unit *unit, struct fw_device *device)
1403 {
1404 	struct fwnet_peer *peer;
1405 
1406 	peer = kmalloc_obj(*peer);
1407 	if (!peer)
1408 		return -ENOMEM;
1409 
1410 	dev_set_drvdata(&unit->device, peer);
1411 
1412 	peer->dev = dev;
1413 	peer->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1414 	INIT_LIST_HEAD(&peer->pd_list);
1415 	peer->pdg_size = 0;
1416 	peer->datagram_label = 0;
1417 	peer->speed = device->max_speed;
1418 	peer->max_payload = fwnet_max_payload(device->max_rec, peer->speed);
1419 
1420 	peer->generation = device->generation;
1421 	smp_rmb();
1422 	peer->node_id = device->node_id;
1423 
1424 	spin_lock_irq(&dev->lock);
1425 	list_add_tail(&peer->peer_link, &dev->peer_list);
1426 	dev->peer_count++;
1427 	set_carrier_state(dev);
1428 	spin_unlock_irq(&dev->lock);
1429 
1430 	return 0;
1431 }
1432 
1433 static int fwnet_probe(struct fw_unit *unit,
1434 		       const struct ieee1394_device_id *id)
1435 {
1436 	struct fw_device *device = fw_parent_device(unit);
1437 	struct fw_card *card = device->card;
1438 	struct net_device *net;
1439 	bool allocated_netdev = false;
1440 	struct fwnet_device *dev;
1441 	union fwnet_hwaddr ha;
1442 	int ret;
1443 
1444 	mutex_lock(&fwnet_device_mutex);
1445 
1446 	dev = fwnet_dev_find(card);
1447 	if (dev) {
1448 		net = dev->netdev;
1449 		goto have_dev;
1450 	}
1451 
1452 	net = alloc_netdev(sizeof(*dev), "firewire%d", NET_NAME_UNKNOWN,
1453 			   fwnet_init_dev);
1454 	if (net == NULL) {
1455 		mutex_unlock(&fwnet_device_mutex);
1456 		return -ENOMEM;
1457 	}
1458 
1459 	allocated_netdev = true;
1460 	SET_NETDEV_DEV(net, card->device);
1461 	dev = netdev_priv(net);
1462 
1463 	spin_lock_init(&dev->lock);
1464 	dev->broadcast_state = FWNET_BROADCAST_ERROR;
1465 	dev->broadcast_rcv_context = NULL;
1466 	dev->broadcast_xmt_max_payload = 0;
1467 	dev->broadcast_xmt_datagramlabel = 0;
1468 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
1469 	dev->queued_datagrams = 0;
1470 	INIT_LIST_HEAD(&dev->peer_list);
1471 	dev->card = card;
1472 	dev->netdev = net;
1473 
1474 	ret = fwnet_fifo_start(dev);
1475 	if (ret < 0)
1476 		goto out;
1477 	dev->local_fifo = dev->handler.offset;
1478 
1479 	/*
1480 	 * default MTU: RFC 2734 cl. 4, RFC 3146 cl. 4
1481 	 * maximum MTU: RFC 2734 cl. 4.2, fragment encapsulation header's
1482 	 *              maximum possible datagram_size + 1 = 0xfff + 1
1483 	 */
1484 	net->mtu = 1500U;
1485 	net->min_mtu = ETH_MIN_MTU;
1486 	net->max_mtu = 4096U;
1487 
1488 	/* Set our hardware address while we're at it */
1489 	ha.uc.uniq_id = cpu_to_be64(card->guid);
1490 	ha.uc.max_rec = dev->card->max_receive;
1491 	ha.uc.sspd = dev->card->link_speed;
1492 	put_unaligned_be48(dev->local_fifo, ha.uc.fifo);
1493 	dev_addr_set(net, ha.u);
1494 
1495 	memset(net->broadcast, -1, net->addr_len);
1496 
1497 	ret = register_netdev(net);
1498 	if (ret)
1499 		goto out;
1500 
1501 	list_add_tail(&dev->dev_link, &fwnet_device_list);
1502 	dev_notice(&net->dev, "IP over IEEE 1394 on card %s\n",
1503 		   dev_name(card->device));
1504  have_dev:
1505 	ret = fwnet_add_peer(dev, unit, device);
1506 	if (ret && allocated_netdev) {
1507 		unregister_netdev(net);
1508 		list_del(&dev->dev_link);
1509  out:
1510 		fwnet_fifo_stop(dev);
1511 		free_netdev(net);
1512 	}
1513 
1514 	mutex_unlock(&fwnet_device_mutex);
1515 
1516 	return ret;
1517 }
1518 
1519 /*
1520  * FIXME abort partially sent fragmented datagrams,
1521  * discard partially received fragmented datagrams
1522  */
1523 static void fwnet_update(struct fw_unit *unit)
1524 {
1525 	struct fw_device *device = fw_parent_device(unit);
1526 	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
1527 	int generation;
1528 
1529 	generation = device->generation;
1530 
1531 	spin_lock_irq(&peer->dev->lock);
1532 	peer->node_id    = device->node_id;
1533 	peer->generation = generation;
1534 	spin_unlock_irq(&peer->dev->lock);
1535 }
1536 
1537 static void fwnet_remove_peer(struct fwnet_peer *peer, struct fwnet_device *dev)
1538 {
1539 	struct fwnet_partial_datagram *pd, *pd_next;
1540 
1541 	spin_lock_irq(&dev->lock);
1542 	list_del(&peer->peer_link);
1543 	dev->peer_count--;
1544 	set_carrier_state(dev);
1545 	spin_unlock_irq(&dev->lock);
1546 
1547 	list_for_each_entry_safe(pd, pd_next, &peer->pd_list, pd_link)
1548 		fwnet_pd_delete(pd);
1549 
1550 	kfree(peer);
1551 }
1552 
1553 static void fwnet_remove(struct fw_unit *unit)
1554 {
1555 	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
1556 	struct fwnet_device *dev = peer->dev;
1557 	struct net_device *net;
1558 	int i;
1559 
1560 	mutex_lock(&fwnet_device_mutex);
1561 
1562 	net = dev->netdev;
1563 
1564 	fwnet_remove_peer(peer, dev);
1565 
1566 	if (list_empty(&dev->peer_list)) {
1567 		unregister_netdev(net);
1568 
1569 		fwnet_fifo_stop(dev);
1570 
1571 		for (i = 0; dev->queued_datagrams && i < 5; i++)
1572 			ssleep(1);
1573 		WARN_ON(dev->queued_datagrams);
1574 		list_del(&dev->dev_link);
1575 
1576 		free_netdev(net);
1577 	}
1578 
1579 	mutex_unlock(&fwnet_device_mutex);
1580 }
1581 
1582 static const struct ieee1394_device_id fwnet_id_table[] = {
1583 	{
1584 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1585 				IEEE1394_MATCH_VERSION,
1586 		.specifier_id = IANA_SPECIFIER_ID,
1587 		.version      = RFC2734_SW_VERSION,
1588 	},
1589 #if IS_ENABLED(CONFIG_IPV6)
1590 	{
1591 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1592 				IEEE1394_MATCH_VERSION,
1593 		.specifier_id = IANA_SPECIFIER_ID,
1594 		.version      = RFC3146_SW_VERSION,
1595 	},
1596 #endif
1597 	{ }
1598 };
1599 
1600 static struct fw_driver fwnet_driver = {
1601 	.driver = {
1602 		.owner  = THIS_MODULE,
1603 		.name   = KBUILD_MODNAME,
1604 		.bus    = &fw_bus_type,
1605 	},
1606 	.probe    = fwnet_probe,
1607 	.update   = fwnet_update,
1608 	.remove   = fwnet_remove,
1609 	.id_table = fwnet_id_table,
1610 };
1611 
1612 static const u32 rfc2374_unit_directory_data[] = {
1613 	0x00040000,	/* directory_length		*/
1614 	0x1200005e,	/* unit_specifier_id: IANA	*/
1615 	0x81000003,	/* textual descriptor offset	*/
1616 	0x13000001,	/* unit_sw_version: RFC 2734	*/
1617 	0x81000005,	/* textual descriptor offset	*/
1618 	0x00030000,	/* descriptor_length		*/
1619 	0x00000000,	/* text				*/
1620 	0x00000000,	/* minimal ASCII, en		*/
1621 	0x49414e41,	/* I A N A			*/
1622 	0x00030000,	/* descriptor_length		*/
1623 	0x00000000,	/* text				*/
1624 	0x00000000,	/* minimal ASCII, en		*/
1625 	0x49507634,	/* I P v 4			*/
1626 };
1627 
1628 static struct fw_descriptor rfc2374_unit_directory = {
1629 	.length = ARRAY_SIZE(rfc2374_unit_directory_data),
1630 	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
1631 	.data   = rfc2374_unit_directory_data
1632 };
1633 
1634 #if IS_ENABLED(CONFIG_IPV6)
1635 static const u32 rfc3146_unit_directory_data[] = {
1636 	0x00040000,	/* directory_length		*/
1637 	0x1200005e,	/* unit_specifier_id: IANA	*/
1638 	0x81000003,	/* textual descriptor offset	*/
1639 	0x13000002,	/* unit_sw_version: RFC 3146	*/
1640 	0x81000005,	/* textual descriptor offset	*/
1641 	0x00030000,	/* descriptor_length		*/
1642 	0x00000000,	/* text				*/
1643 	0x00000000,	/* minimal ASCII, en		*/
1644 	0x49414e41,	/* I A N A			*/
1645 	0x00030000,	/* descriptor_length		*/
1646 	0x00000000,	/* text				*/
1647 	0x00000000,	/* minimal ASCII, en		*/
1648 	0x49507636,	/* I P v 6			*/
1649 };
1650 
1651 static struct fw_descriptor rfc3146_unit_directory = {
1652 	.length = ARRAY_SIZE(rfc3146_unit_directory_data),
1653 	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
1654 	.data   = rfc3146_unit_directory_data
1655 };
1656 #endif
1657 
1658 static int __init fwnet_init(void)
1659 {
1660 	int err;
1661 
1662 	err = fw_core_add_descriptor(&rfc2374_unit_directory);
1663 	if (err)
1664 		return err;
1665 
1666 #if IS_ENABLED(CONFIG_IPV6)
1667 	err = fw_core_add_descriptor(&rfc3146_unit_directory);
1668 	if (err)
1669 		goto out;
1670 #endif
1671 
1672 	fwnet_packet_task_cache = kmem_cache_create("packet_task",
1673 			sizeof(struct fwnet_packet_task), 0, 0, NULL);
1674 	if (!fwnet_packet_task_cache) {
1675 		err = -ENOMEM;
1676 		goto out2;
1677 	}
1678 
1679 	err = driver_register(&fwnet_driver.driver);
1680 	if (!err)
1681 		return 0;
1682 
1683 	kmem_cache_destroy(fwnet_packet_task_cache);
1684 out2:
1685 #if IS_ENABLED(CONFIG_IPV6)
1686 	fw_core_remove_descriptor(&rfc3146_unit_directory);
1687 out:
1688 #endif
1689 	fw_core_remove_descriptor(&rfc2374_unit_directory);
1690 
1691 	return err;
1692 }
1693 module_init(fwnet_init);
1694 
1695 static void __exit fwnet_cleanup(void)
1696 {
1697 	driver_unregister(&fwnet_driver.driver);
1698 	kmem_cache_destroy(fwnet_packet_task_cache);
1699 #if IS_ENABLED(CONFIG_IPV6)
1700 	fw_core_remove_descriptor(&rfc3146_unit_directory);
1701 #endif
1702 	fw_core_remove_descriptor(&rfc2374_unit_directory);
1703 }
1704 module_exit(fwnet_cleanup);
1705 
1706 MODULE_AUTHOR("Jay Fenlason <fenlason@redhat.com>");
1707 MODULE_DESCRIPTION("IP over IEEE1394 as per RFC 2734/3146");
1708 MODULE_LICENSE("GPL");
1709 MODULE_DEVICE_TABLE(ieee1394, fwnet_id_table);
1710