xref: /linux/drivers/firewire/net.c (revision d27656d02d85078c63f060fca9c5d99794791a75) 
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 <asm/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  * Get fifo address embedded in hwaddr
206  */
207 static __u64 fwnet_hwaddr_fifo(union fwnet_hwaddr *ha)
208 {
209 	return (u64)get_unaligned_be16(&ha->uc.fifo_hi) << 32
210 	       | get_unaligned_be32(&ha->uc.fifo_lo);
211 }
212 
213 /*
214  * saddr == NULL means use device source address.
215  * daddr == NULL means leave destination address (eg unresolved arp).
216  */
217 static int fwnet_header_create(struct sk_buff *skb, struct net_device *net,
218 			unsigned short type, const void *daddr,
219 			const void *saddr, unsigned len)
220 {
221 	struct fwnet_header *h;
222 
223 	h = skb_push(skb, sizeof(*h));
224 	put_unaligned_be16(type, &h->h_proto);
225 
226 	if (net->flags & (IFF_LOOPBACK | IFF_NOARP)) {
227 		memset(h->h_dest, 0, net->addr_len);
228 
229 		return net->hard_header_len;
230 	}
231 
232 	if (daddr) {
233 		memcpy(h->h_dest, daddr, net->addr_len);
234 
235 		return net->hard_header_len;
236 	}
237 
238 	return -net->hard_header_len;
239 }
240 
241 static int fwnet_header_cache(const struct neighbour *neigh,
242 			      struct hh_cache *hh, __be16 type)
243 {
244 	struct net_device *net;
245 	struct fwnet_header *h;
246 
247 	if (type == cpu_to_be16(ETH_P_802_3))
248 		return -1;
249 	net = neigh->dev;
250 	h = (struct fwnet_header *)((u8 *)hh->hh_data + HH_DATA_OFF(sizeof(*h)));
251 	h->h_proto = type;
252 	memcpy(h->h_dest, neigh->ha, net->addr_len);
253 
254 	/* Pairs with the READ_ONCE() in neigh_resolve_output(),
255 	 * neigh_hh_output() and neigh_update_hhs().
256 	 */
257 	smp_store_release(&hh->hh_len, FWNET_HLEN);
258 
259 	return 0;
260 }
261 
262 /* Called by Address Resolution module to notify changes in address. */
263 static void fwnet_header_cache_update(struct hh_cache *hh,
264 		const struct net_device *net, const unsigned char *haddr)
265 {
266 	memcpy((u8 *)hh->hh_data + HH_DATA_OFF(FWNET_HLEN), haddr, net->addr_len);
267 }
268 
269 static int fwnet_header_parse(const struct sk_buff *skb, unsigned char *haddr)
270 {
271 	memcpy(haddr, skb->dev->dev_addr, FWNET_ALEN);
272 
273 	return FWNET_ALEN;
274 }
275 
276 static const struct header_ops fwnet_header_ops = {
277 	.create         = fwnet_header_create,
278 	.cache		= fwnet_header_cache,
279 	.cache_update	= fwnet_header_cache_update,
280 	.parse          = fwnet_header_parse,
281 };
282 
283 /* FIXME: is this correct for all cases? */
284 static bool fwnet_frag_overlap(struct fwnet_partial_datagram *pd,
285 			       unsigned offset, unsigned len)
286 {
287 	struct fwnet_fragment_info *fi;
288 	unsigned end = offset + len;
289 
290 	list_for_each_entry(fi, &pd->fi_list, fi_link)
291 		if (offset < fi->offset + fi->len && end > fi->offset)
292 			return true;
293 
294 	return false;
295 }
296 
297 /* Assumes that new fragment does not overlap any existing fragments */
298 static struct fwnet_fragment_info *fwnet_frag_new(
299 	struct fwnet_partial_datagram *pd, unsigned offset, unsigned len)
300 {
301 	struct fwnet_fragment_info *fi, *fi2, *new;
302 	struct list_head *list;
303 
304 	list = &pd->fi_list;
305 	list_for_each_entry(fi, &pd->fi_list, fi_link) {
306 		if (fi->offset + fi->len == offset) {
307 			/* The new fragment can be tacked on to the end */
308 			/* Did the new fragment plug a hole? */
309 			fi2 = list_entry(fi->fi_link.next,
310 					 struct fwnet_fragment_info, fi_link);
311 			if (fi->offset + fi->len == fi2->offset) {
312 				/* glue fragments together */
313 				fi->len += len + fi2->len;
314 				list_del(&fi2->fi_link);
315 				kfree(fi2);
316 			} else {
317 				fi->len += len;
318 			}
319 
320 			return fi;
321 		}
322 		if (offset + len == fi->offset) {
323 			/* The new fragment can be tacked on to the beginning */
324 			/* Did the new fragment plug a hole? */
325 			fi2 = list_entry(fi->fi_link.prev,
326 					 struct fwnet_fragment_info, fi_link);
327 			if (fi2->offset + fi2->len == fi->offset) {
328 				/* glue fragments together */
329 				fi2->len += fi->len + len;
330 				list_del(&fi->fi_link);
331 				kfree(fi);
332 
333 				return fi2;
334 			}
335 			fi->offset = offset;
336 			fi->len += len;
337 
338 			return fi;
339 		}
340 		if (offset > fi->offset + fi->len) {
341 			list = &fi->fi_link;
342 			break;
343 		}
344 		if (offset + len < fi->offset) {
345 			list = fi->fi_link.prev;
346 			break;
347 		}
348 	}
349 
350 	new = kmalloc(sizeof(*new), GFP_ATOMIC);
351 	if (!new)
352 		return NULL;
353 
354 	new->offset = offset;
355 	new->len = len;
356 	list_add(&new->fi_link, list);
357 
358 	return new;
359 }
360 
361 static struct fwnet_partial_datagram *fwnet_pd_new(struct net_device *net,
362 		struct fwnet_peer *peer, u16 datagram_label, unsigned dg_size,
363 		void *frag_buf, unsigned frag_off, unsigned frag_len)
364 {
365 	struct fwnet_partial_datagram *new;
366 	struct fwnet_fragment_info *fi;
367 
368 	new = kmalloc(sizeof(*new), GFP_ATOMIC);
369 	if (!new)
370 		goto fail;
371 
372 	INIT_LIST_HEAD(&new->fi_list);
373 	fi = fwnet_frag_new(new, frag_off, frag_len);
374 	if (fi == NULL)
375 		goto fail_w_new;
376 
377 	new->datagram_label = datagram_label;
378 	new->datagram_size = dg_size;
379 	new->skb = dev_alloc_skb(dg_size + LL_RESERVED_SPACE(net));
380 	if (new->skb == NULL)
381 		goto fail_w_fi;
382 
383 	skb_reserve(new->skb, LL_RESERVED_SPACE(net));
384 	new->pbuf = skb_put(new->skb, dg_size);
385 	memcpy(new->pbuf + frag_off, frag_buf, frag_len);
386 	list_add_tail(&new->pd_link, &peer->pd_list);
387 
388 	return new;
389 
390 fail_w_fi:
391 	kfree(fi);
392 fail_w_new:
393 	kfree(new);
394 fail:
395 	return NULL;
396 }
397 
398 static struct fwnet_partial_datagram *fwnet_pd_find(struct fwnet_peer *peer,
399 						    u16 datagram_label)
400 {
401 	struct fwnet_partial_datagram *pd;
402 
403 	list_for_each_entry(pd, &peer->pd_list, pd_link)
404 		if (pd->datagram_label == datagram_label)
405 			return pd;
406 
407 	return NULL;
408 }
409 
410 
411 static void fwnet_pd_delete(struct fwnet_partial_datagram *old)
412 {
413 	struct fwnet_fragment_info *fi, *n;
414 
415 	list_for_each_entry_safe(fi, n, &old->fi_list, fi_link)
416 		kfree(fi);
417 
418 	list_del(&old->pd_link);
419 	dev_kfree_skb_any(old->skb);
420 	kfree(old);
421 }
422 
423 static bool fwnet_pd_update(struct fwnet_peer *peer,
424 		struct fwnet_partial_datagram *pd, void *frag_buf,
425 		unsigned frag_off, unsigned frag_len)
426 {
427 	if (fwnet_frag_new(pd, frag_off, frag_len) == NULL)
428 		return false;
429 
430 	memcpy(pd->pbuf + frag_off, frag_buf, frag_len);
431 
432 	/*
433 	 * Move list entry to beginning of list so that oldest partial
434 	 * datagrams percolate to the end of the list
435 	 */
436 	list_move_tail(&pd->pd_link, &peer->pd_list);
437 
438 	return true;
439 }
440 
441 static bool fwnet_pd_is_complete(struct fwnet_partial_datagram *pd)
442 {
443 	struct fwnet_fragment_info *fi;
444 
445 	fi = list_entry(pd->fi_list.next, struct fwnet_fragment_info, fi_link);
446 
447 	return fi->len == pd->datagram_size;
448 }
449 
450 /* caller must hold dev->lock */
451 static struct fwnet_peer *fwnet_peer_find_by_guid(struct fwnet_device *dev,
452 						  u64 guid)
453 {
454 	struct fwnet_peer *peer;
455 
456 	list_for_each_entry(peer, &dev->peer_list, peer_link)
457 		if (peer->guid == guid)
458 			return peer;
459 
460 	return NULL;
461 }
462 
463 /* caller must hold dev->lock */
464 static struct fwnet_peer *fwnet_peer_find_by_node_id(struct fwnet_device *dev,
465 						int node_id, int generation)
466 {
467 	struct fwnet_peer *peer;
468 
469 	list_for_each_entry(peer, &dev->peer_list, peer_link)
470 		if (peer->node_id    == node_id &&
471 		    peer->generation == generation)
472 			return peer;
473 
474 	return NULL;
475 }
476 
477 /* See IEEE 1394-2008 table 6-4, table 8-8, table 16-18. */
478 static unsigned fwnet_max_payload(unsigned max_rec, unsigned speed)
479 {
480 	max_rec = min(max_rec, speed + 8);
481 	max_rec = clamp(max_rec, 8U, 11U); /* 512...4096 */
482 
483 	return (1 << (max_rec + 1)) - RFC2374_FRAG_HDR_SIZE;
484 }
485 
486 
487 static int fwnet_finish_incoming_packet(struct net_device *net,
488 					struct sk_buff *skb, u16 source_node_id,
489 					bool is_broadcast, u16 ether_type)
490 {
491 	int status;
492 
493 	switch (ether_type) {
494 	case ETH_P_ARP:
495 	case ETH_P_IP:
496 #if IS_ENABLED(CONFIG_IPV6)
497 	case ETH_P_IPV6:
498 #endif
499 		break;
500 	default:
501 		goto err;
502 	}
503 
504 	/* Write metadata, and then pass to the receive level */
505 	skb->dev = net;
506 	skb->ip_summed = CHECKSUM_NONE;
507 
508 	/*
509 	 * Parse the encapsulation header. This actually does the job of
510 	 * converting to an ethernet-like pseudo frame header.
511 	 */
512 	if (dev_hard_header(skb, net, ether_type,
513 			   is_broadcast ? net->broadcast : net->dev_addr,
514 			   NULL, skb->len) >= 0) {
515 		struct fwnet_header *eth;
516 		u16 *rawp;
517 		__be16 protocol;
518 
519 		skb_reset_mac_header(skb);
520 		skb_pull(skb, sizeof(*eth));
521 		eth = (struct fwnet_header *)skb_mac_header(skb);
522 		if (fwnet_hwaddr_is_multicast(eth->h_dest)) {
523 			if (memcmp(eth->h_dest, net->broadcast,
524 				   net->addr_len) == 0)
525 				skb->pkt_type = PACKET_BROADCAST;
526 #if 0
527 			else
528 				skb->pkt_type = PACKET_MULTICAST;
529 #endif
530 		} else {
531 			if (memcmp(eth->h_dest, net->dev_addr, net->addr_len))
532 				skb->pkt_type = PACKET_OTHERHOST;
533 		}
534 		if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN) {
535 			protocol = eth->h_proto;
536 		} else {
537 			rawp = (u16 *)skb->data;
538 			if (*rawp == 0xffff)
539 				protocol = htons(ETH_P_802_3);
540 			else
541 				protocol = htons(ETH_P_802_2);
542 		}
543 		skb->protocol = protocol;
544 	}
545 	status = netif_rx(skb);
546 	if (status == NET_RX_DROP) {
547 		net->stats.rx_errors++;
548 		net->stats.rx_dropped++;
549 	} else {
550 		net->stats.rx_packets++;
551 		net->stats.rx_bytes += skb->len;
552 	}
553 
554 	return 0;
555 
556  err:
557 	net->stats.rx_errors++;
558 	net->stats.rx_dropped++;
559 
560 	dev_kfree_skb_any(skb);
561 
562 	return -ENOENT;
563 }
564 
565 static int fwnet_incoming_packet(struct fwnet_device *dev, __be32 *buf, int len,
566 				 int source_node_id, int generation,
567 				 bool is_broadcast)
568 {
569 	struct sk_buff *skb;
570 	struct net_device *net = dev->netdev;
571 	struct rfc2734_header hdr;
572 	unsigned lf;
573 	unsigned long flags;
574 	struct fwnet_peer *peer;
575 	struct fwnet_partial_datagram *pd;
576 	int fg_off;
577 	int dg_size;
578 	u16 datagram_label;
579 	int retval;
580 	u16 ether_type;
581 
582 	if (len <= RFC2374_UNFRAG_HDR_SIZE)
583 		return 0;
584 
585 	hdr.w0 = be32_to_cpu(buf[0]);
586 	lf = fwnet_get_hdr_lf(&hdr);
587 	if (lf == RFC2374_HDR_UNFRAG) {
588 		/*
589 		 * An unfragmented datagram has been received by the ieee1394
590 		 * bus. Build an skbuff around it so we can pass it to the
591 		 * high level network layer.
592 		 */
593 		ether_type = fwnet_get_hdr_ether_type(&hdr);
594 		buf++;
595 		len -= RFC2374_UNFRAG_HDR_SIZE;
596 
597 		skb = dev_alloc_skb(len + LL_RESERVED_SPACE(net));
598 		if (unlikely(!skb)) {
599 			net->stats.rx_dropped++;
600 
601 			return -ENOMEM;
602 		}
603 		skb_reserve(skb, LL_RESERVED_SPACE(net));
604 		skb_put_data(skb, buf, len);
605 
606 		return fwnet_finish_incoming_packet(net, skb, source_node_id,
607 						    is_broadcast, ether_type);
608 	}
609 
610 	/* A datagram fragment has been received, now the fun begins. */
611 
612 	if (len <= RFC2374_FRAG_HDR_SIZE)
613 		return 0;
614 
615 	hdr.w1 = ntohl(buf[1]);
616 	buf += 2;
617 	len -= RFC2374_FRAG_HDR_SIZE;
618 	if (lf == RFC2374_HDR_FIRSTFRAG) {
619 		ether_type = fwnet_get_hdr_ether_type(&hdr);
620 		fg_off = 0;
621 	} else {
622 		ether_type = 0;
623 		fg_off = fwnet_get_hdr_fg_off(&hdr);
624 	}
625 	datagram_label = fwnet_get_hdr_dgl(&hdr);
626 	dg_size = fwnet_get_hdr_dg_size(&hdr);
627 
628 	if (fg_off + len > dg_size)
629 		return 0;
630 
631 	spin_lock_irqsave(&dev->lock, flags);
632 
633 	peer = fwnet_peer_find_by_node_id(dev, source_node_id, generation);
634 	if (!peer) {
635 		retval = -ENOENT;
636 		goto fail;
637 	}
638 
639 	pd = fwnet_pd_find(peer, datagram_label);
640 	if (pd == NULL) {
641 		while (peer->pdg_size >= FWNET_MAX_FRAGMENTS) {
642 			/* remove the oldest */
643 			fwnet_pd_delete(list_first_entry(&peer->pd_list,
644 				struct fwnet_partial_datagram, pd_link));
645 			peer->pdg_size--;
646 		}
647 		pd = fwnet_pd_new(net, peer, datagram_label,
648 				  dg_size, buf, fg_off, len);
649 		if (pd == NULL) {
650 			retval = -ENOMEM;
651 			goto fail;
652 		}
653 		peer->pdg_size++;
654 	} else {
655 		if (fwnet_frag_overlap(pd, fg_off, len) ||
656 		    pd->datagram_size != dg_size) {
657 			/*
658 			 * Differing datagram sizes or overlapping fragments,
659 			 * discard old datagram and start a new one.
660 			 */
661 			fwnet_pd_delete(pd);
662 			pd = fwnet_pd_new(net, peer, datagram_label,
663 					  dg_size, buf, fg_off, len);
664 			if (pd == NULL) {
665 				peer->pdg_size--;
666 				retval = -ENOMEM;
667 				goto fail;
668 			}
669 		} else {
670 			if (!fwnet_pd_update(peer, pd, buf, fg_off, len)) {
671 				/*
672 				 * Couldn't save off fragment anyway
673 				 * so might as well obliterate the
674 				 * datagram now.
675 				 */
676 				fwnet_pd_delete(pd);
677 				peer->pdg_size--;
678 				retval = -ENOMEM;
679 				goto fail;
680 			}
681 		}
682 	} /* new datagram or add to existing one */
683 
684 	if (lf == RFC2374_HDR_FIRSTFRAG)
685 		pd->ether_type = ether_type;
686 
687 	if (fwnet_pd_is_complete(pd)) {
688 		ether_type = pd->ether_type;
689 		peer->pdg_size--;
690 		skb = skb_get(pd->skb);
691 		fwnet_pd_delete(pd);
692 
693 		spin_unlock_irqrestore(&dev->lock, flags);
694 
695 		return fwnet_finish_incoming_packet(net, skb, source_node_id,
696 						    false, ether_type);
697 	}
698 	/*
699 	 * Datagram is not complete, we're done for the
700 	 * moment.
701 	 */
702 	retval = 0;
703  fail:
704 	spin_unlock_irqrestore(&dev->lock, flags);
705 
706 	return retval;
707 }
708 
709 static void fwnet_receive_packet(struct fw_card *card, struct fw_request *r,
710 		int tcode, int destination, int source, int generation,
711 		unsigned long long offset, void *payload, size_t length,
712 		void *callback_data)
713 {
714 	struct fwnet_device *dev = callback_data;
715 	int rcode;
716 
717 	if (destination == IEEE1394_ALL_NODES) {
718 		kfree(r);
719 
720 		return;
721 	}
722 
723 	if (offset != dev->handler.offset)
724 		rcode = RCODE_ADDRESS_ERROR;
725 	else if (tcode != TCODE_WRITE_BLOCK_REQUEST)
726 		rcode = RCODE_TYPE_ERROR;
727 	else if (fwnet_incoming_packet(dev, payload, length,
728 				       source, generation, false) != 0) {
729 		dev_err(&dev->netdev->dev, "incoming packet failure\n");
730 		rcode = RCODE_CONFLICT_ERROR;
731 	} else
732 		rcode = RCODE_COMPLETE;
733 
734 	fw_send_response(card, r, rcode);
735 }
736 
737 static int gasp_source_id(__be32 *p)
738 {
739 	return be32_to_cpu(p[0]) >> 16;
740 }
741 
742 static u32 gasp_specifier_id(__be32 *p)
743 {
744 	return (be32_to_cpu(p[0]) & 0xffff) << 8 |
745 	       (be32_to_cpu(p[1]) & 0xff000000) >> 24;
746 }
747 
748 static u32 gasp_version(__be32 *p)
749 {
750 	return be32_to_cpu(p[1]) & 0xffffff;
751 }
752 
753 static void fwnet_receive_broadcast(struct fw_iso_context *context,
754 		u32 cycle, size_t header_length, void *header, void *data)
755 {
756 	struct fwnet_device *dev;
757 	struct fw_iso_packet packet;
758 	__be16 *hdr_ptr;
759 	__be32 *buf_ptr;
760 	int retval;
761 	u32 length;
762 	unsigned long offset;
763 	unsigned long flags;
764 
765 	dev = data;
766 	hdr_ptr = header;
767 	length = be16_to_cpup(hdr_ptr);
768 
769 	spin_lock_irqsave(&dev->lock, flags);
770 
771 	offset = dev->rcv_buffer_size * dev->broadcast_rcv_next_ptr;
772 	buf_ptr = dev->broadcast_rcv_buffer_ptrs[dev->broadcast_rcv_next_ptr++];
773 	if (dev->broadcast_rcv_next_ptr == dev->num_broadcast_rcv_ptrs)
774 		dev->broadcast_rcv_next_ptr = 0;
775 
776 	spin_unlock_irqrestore(&dev->lock, flags);
777 
778 	if (length > IEEE1394_GASP_HDR_SIZE &&
779 	    gasp_specifier_id(buf_ptr) == IANA_SPECIFIER_ID &&
780 	    (gasp_version(buf_ptr) == RFC2734_SW_VERSION
781 #if IS_ENABLED(CONFIG_IPV6)
782 	     || gasp_version(buf_ptr) == RFC3146_SW_VERSION
783 #endif
784 	    ))
785 		fwnet_incoming_packet(dev, buf_ptr + 2,
786 				      length - IEEE1394_GASP_HDR_SIZE,
787 				      gasp_source_id(buf_ptr),
788 				      context->card->generation, true);
789 
790 	packet.payload_length = dev->rcv_buffer_size;
791 	packet.interrupt = 1;
792 	packet.skip = 0;
793 	packet.tag = 3;
794 	packet.sy = 0;
795 	packet.header_length = IEEE1394_GASP_HDR_SIZE;
796 
797 	spin_lock_irqsave(&dev->lock, flags);
798 
799 	retval = fw_iso_context_queue(dev->broadcast_rcv_context, &packet,
800 				      &dev->broadcast_rcv_buffer, offset);
801 
802 	spin_unlock_irqrestore(&dev->lock, flags);
803 
804 	if (retval >= 0)
805 		fw_iso_context_queue_flush(dev->broadcast_rcv_context);
806 	else
807 		dev_err(&dev->netdev->dev, "requeue failed\n");
808 }
809 
810 static struct kmem_cache *fwnet_packet_task_cache;
811 
812 static void fwnet_free_ptask(struct fwnet_packet_task *ptask)
813 {
814 	dev_kfree_skb_any(ptask->skb);
815 	kmem_cache_free(fwnet_packet_task_cache, ptask);
816 }
817 
818 /* Caller must hold dev->lock. */
819 static void dec_queued_datagrams(struct fwnet_device *dev)
820 {
821 	if (--dev->queued_datagrams == FWNET_MIN_QUEUED_DATAGRAMS)
822 		netif_wake_queue(dev->netdev);
823 }
824 
825 static int fwnet_send_packet(struct fwnet_packet_task *ptask);
826 
827 static void fwnet_transmit_packet_done(struct fwnet_packet_task *ptask)
828 {
829 	struct fwnet_device *dev = ptask->dev;
830 	struct sk_buff *skb = ptask->skb;
831 	unsigned long flags;
832 	bool free;
833 
834 	spin_lock_irqsave(&dev->lock, flags);
835 
836 	ptask->outstanding_pkts--;
837 
838 	/* Check whether we or the networking TX soft-IRQ is last user. */
839 	free = (ptask->outstanding_pkts == 0 && ptask->enqueued);
840 	if (free)
841 		dec_queued_datagrams(dev);
842 
843 	if (ptask->outstanding_pkts == 0) {
844 		dev->netdev->stats.tx_packets++;
845 		dev->netdev->stats.tx_bytes += skb->len;
846 	}
847 
848 	spin_unlock_irqrestore(&dev->lock, flags);
849 
850 	if (ptask->outstanding_pkts > 0) {
851 		u16 dg_size;
852 		u16 fg_off;
853 		u16 datagram_label;
854 		u16 lf;
855 
856 		/* Update the ptask to point to the next fragment and send it */
857 		lf = fwnet_get_hdr_lf(&ptask->hdr);
858 		switch (lf) {
859 		case RFC2374_HDR_LASTFRAG:
860 		case RFC2374_HDR_UNFRAG:
861 		default:
862 			dev_err(&dev->netdev->dev,
863 				"outstanding packet %x lf %x, header %x,%x\n",
864 				ptask->outstanding_pkts, lf, ptask->hdr.w0,
865 				ptask->hdr.w1);
866 			BUG();
867 
868 		case RFC2374_HDR_FIRSTFRAG:
869 			/* Set frag type here for future interior fragments */
870 			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
871 			fg_off = ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
872 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
873 			break;
874 
875 		case RFC2374_HDR_INTFRAG:
876 			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
877 			fg_off = fwnet_get_hdr_fg_off(&ptask->hdr)
878 				  + ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
879 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
880 			break;
881 		}
882 
883 		if (ptask->dest_node == IEEE1394_ALL_NODES) {
884 			skb_pull(skb,
885 				 ptask->max_payload + IEEE1394_GASP_HDR_SIZE);
886 		} else {
887 			skb_pull(skb, ptask->max_payload);
888 		}
889 		if (ptask->outstanding_pkts > 1) {
890 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_INTFRAG,
891 					  dg_size, fg_off, datagram_label);
892 		} else {
893 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_LASTFRAG,
894 					  dg_size, fg_off, datagram_label);
895 			ptask->max_payload = skb->len + RFC2374_FRAG_HDR_SIZE;
896 		}
897 		fwnet_send_packet(ptask);
898 	}
899 
900 	if (free)
901 		fwnet_free_ptask(ptask);
902 }
903 
904 static void fwnet_transmit_packet_failed(struct fwnet_packet_task *ptask)
905 {
906 	struct fwnet_device *dev = ptask->dev;
907 	unsigned long flags;
908 	bool free;
909 
910 	spin_lock_irqsave(&dev->lock, flags);
911 
912 	/* One fragment failed; don't try to send remaining fragments. */
913 	ptask->outstanding_pkts = 0;
914 
915 	/* Check whether we or the networking TX soft-IRQ is last user. */
916 	free = ptask->enqueued;
917 	if (free)
918 		dec_queued_datagrams(dev);
919 
920 	dev->netdev->stats.tx_dropped++;
921 	dev->netdev->stats.tx_errors++;
922 
923 	spin_unlock_irqrestore(&dev->lock, flags);
924 
925 	if (free)
926 		fwnet_free_ptask(ptask);
927 }
928 
929 static void fwnet_write_complete(struct fw_card *card, int rcode,
930 				 void *payload, size_t length, void *data)
931 {
932 	struct fwnet_packet_task *ptask = data;
933 	static unsigned long j;
934 	static int last_rcode, errors_skipped;
935 
936 	if (rcode == RCODE_COMPLETE) {
937 		fwnet_transmit_packet_done(ptask);
938 	} else {
939 		if (printk_timed_ratelimit(&j,  1000) || rcode != last_rcode) {
940 			dev_err(&ptask->dev->netdev->dev,
941 				"fwnet_write_complete failed: %x (skipped %d)\n",
942 				rcode, errors_skipped);
943 
944 			errors_skipped = 0;
945 			last_rcode = rcode;
946 		} else {
947 			errors_skipped++;
948 		}
949 		fwnet_transmit_packet_failed(ptask);
950 	}
951 }
952 
953 static int fwnet_send_packet(struct fwnet_packet_task *ptask)
954 {
955 	struct fwnet_device *dev;
956 	unsigned tx_len;
957 	struct rfc2734_header *bufhdr;
958 	unsigned long flags;
959 	bool free;
960 
961 	dev = ptask->dev;
962 	tx_len = ptask->max_payload;
963 	switch (fwnet_get_hdr_lf(&ptask->hdr)) {
964 	case RFC2374_HDR_UNFRAG:
965 		bufhdr = skb_push(ptask->skb, RFC2374_UNFRAG_HDR_SIZE);
966 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
967 		break;
968 
969 	case RFC2374_HDR_FIRSTFRAG:
970 	case RFC2374_HDR_INTFRAG:
971 	case RFC2374_HDR_LASTFRAG:
972 		bufhdr = skb_push(ptask->skb, RFC2374_FRAG_HDR_SIZE);
973 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
974 		put_unaligned_be32(ptask->hdr.w1, &bufhdr->w1);
975 		break;
976 
977 	default:
978 		BUG();
979 	}
980 	if (ptask->dest_node == IEEE1394_ALL_NODES) {
981 		u8 *p;
982 		int generation;
983 		int node_id;
984 		unsigned int sw_version;
985 
986 		/* ptask->generation may not have been set yet */
987 		generation = dev->card->generation;
988 		smp_rmb();
989 		node_id = dev->card->node_id;
990 
991 		switch (ptask->skb->protocol) {
992 		default:
993 			sw_version = RFC2734_SW_VERSION;
994 			break;
995 #if IS_ENABLED(CONFIG_IPV6)
996 		case htons(ETH_P_IPV6):
997 			sw_version = RFC3146_SW_VERSION;
998 #endif
999 		}
1000 
1001 		p = skb_push(ptask->skb, IEEE1394_GASP_HDR_SIZE);
1002 		put_unaligned_be32(node_id << 16 | IANA_SPECIFIER_ID >> 8, p);
1003 		put_unaligned_be32((IANA_SPECIFIER_ID & 0xff) << 24
1004 						| sw_version, &p[4]);
1005 
1006 		/* We should not transmit if broadcast_channel.valid == 0. */
1007 		fw_send_request(dev->card, &ptask->transaction,
1008 				TCODE_STREAM_DATA,
1009 				fw_stream_packet_destination_id(3,
1010 						IEEE1394_BROADCAST_CHANNEL, 0),
1011 				generation, SCODE_100, 0ULL, ptask->skb->data,
1012 				tx_len + 8, fwnet_write_complete, ptask);
1013 
1014 		spin_lock_irqsave(&dev->lock, flags);
1015 
1016 		/* If the AT tasklet already ran, we may be last user. */
1017 		free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
1018 		if (!free)
1019 			ptask->enqueued = true;
1020 		else
1021 			dec_queued_datagrams(dev);
1022 
1023 		spin_unlock_irqrestore(&dev->lock, flags);
1024 
1025 		goto out;
1026 	}
1027 
1028 	fw_send_request(dev->card, &ptask->transaction,
1029 			TCODE_WRITE_BLOCK_REQUEST, ptask->dest_node,
1030 			ptask->generation, ptask->speed, ptask->fifo_addr,
1031 			ptask->skb->data, tx_len, fwnet_write_complete, ptask);
1032 
1033 	spin_lock_irqsave(&dev->lock, flags);
1034 
1035 	/* If the AT tasklet already ran, we may be last user. */
1036 	free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
1037 	if (!free)
1038 		ptask->enqueued = true;
1039 	else
1040 		dec_queued_datagrams(dev);
1041 
1042 	spin_unlock_irqrestore(&dev->lock, flags);
1043 
1044 	netif_trans_update(dev->netdev);
1045  out:
1046 	if (free)
1047 		fwnet_free_ptask(ptask);
1048 
1049 	return 0;
1050 }
1051 
1052 static void fwnet_fifo_stop(struct fwnet_device *dev)
1053 {
1054 	if (dev->local_fifo == FWNET_NO_FIFO_ADDR)
1055 		return;
1056 
1057 	fw_core_remove_address_handler(&dev->handler);
1058 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
1059 }
1060 
1061 static int fwnet_fifo_start(struct fwnet_device *dev)
1062 {
1063 	int retval;
1064 
1065 	if (dev->local_fifo != FWNET_NO_FIFO_ADDR)
1066 		return 0;
1067 
1068 	dev->handler.length = 4096;
1069 	dev->handler.address_callback = fwnet_receive_packet;
1070 	dev->handler.callback_data = dev;
1071 
1072 	retval = fw_core_add_address_handler(&dev->handler,
1073 					     &fw_high_memory_region);
1074 	if (retval < 0)
1075 		return retval;
1076 
1077 	dev->local_fifo = dev->handler.offset;
1078 
1079 	return 0;
1080 }
1081 
1082 static void __fwnet_broadcast_stop(struct fwnet_device *dev)
1083 {
1084 	unsigned u;
1085 
1086 	if (dev->broadcast_state != FWNET_BROADCAST_ERROR) {
1087 		for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++)
1088 			kunmap(dev->broadcast_rcv_buffer.pages[u]);
1089 		fw_iso_buffer_destroy(&dev->broadcast_rcv_buffer, dev->card);
1090 	}
1091 	if (dev->broadcast_rcv_context) {
1092 		fw_iso_context_destroy(dev->broadcast_rcv_context);
1093 		dev->broadcast_rcv_context = NULL;
1094 	}
1095 	kfree(dev->broadcast_rcv_buffer_ptrs);
1096 	dev->broadcast_rcv_buffer_ptrs = NULL;
1097 	dev->broadcast_state = FWNET_BROADCAST_ERROR;
1098 }
1099 
1100 static void fwnet_broadcast_stop(struct fwnet_device *dev)
1101 {
1102 	if (dev->broadcast_state == FWNET_BROADCAST_ERROR)
1103 		return;
1104 	fw_iso_context_stop(dev->broadcast_rcv_context);
1105 	__fwnet_broadcast_stop(dev);
1106 }
1107 
1108 static int fwnet_broadcast_start(struct fwnet_device *dev)
1109 {
1110 	struct fw_iso_context *context;
1111 	int retval;
1112 	unsigned num_packets;
1113 	unsigned max_receive;
1114 	struct fw_iso_packet packet;
1115 	unsigned long offset;
1116 	void **ptrptr;
1117 	unsigned u;
1118 
1119 	if (dev->broadcast_state != FWNET_BROADCAST_ERROR)
1120 		return 0;
1121 
1122 	max_receive = 1U << (dev->card->max_receive + 1);
1123 	num_packets = (FWNET_ISO_PAGE_COUNT * PAGE_SIZE) / max_receive;
1124 
1125 	ptrptr = kmalloc_array(num_packets, sizeof(void *), GFP_KERNEL);
1126 	if (!ptrptr) {
1127 		retval = -ENOMEM;
1128 		goto failed;
1129 	}
1130 	dev->broadcast_rcv_buffer_ptrs = ptrptr;
1131 
1132 	context = fw_iso_context_create(dev->card, FW_ISO_CONTEXT_RECEIVE,
1133 					IEEE1394_BROADCAST_CHANNEL,
1134 					dev->card->link_speed, 8,
1135 					fwnet_receive_broadcast, dev);
1136 	if (IS_ERR(context)) {
1137 		retval = PTR_ERR(context);
1138 		goto failed;
1139 	}
1140 
1141 	retval = fw_iso_buffer_init(&dev->broadcast_rcv_buffer, dev->card,
1142 				    FWNET_ISO_PAGE_COUNT, DMA_FROM_DEVICE);
1143 	if (retval < 0)
1144 		goto failed;
1145 
1146 	dev->broadcast_state = FWNET_BROADCAST_STOPPED;
1147 
1148 	for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++) {
1149 		void *ptr;
1150 		unsigned v;
1151 
1152 		ptr = kmap(dev->broadcast_rcv_buffer.pages[u]);
1153 		for (v = 0; v < num_packets / FWNET_ISO_PAGE_COUNT; v++)
1154 			*ptrptr++ = (void *) ((char *)ptr + v * max_receive);
1155 	}
1156 	dev->broadcast_rcv_context = context;
1157 
1158 	packet.payload_length = max_receive;
1159 	packet.interrupt = 1;
1160 	packet.skip = 0;
1161 	packet.tag = 3;
1162 	packet.sy = 0;
1163 	packet.header_length = IEEE1394_GASP_HDR_SIZE;
1164 	offset = 0;
1165 
1166 	for (u = 0; u < num_packets; u++) {
1167 		retval = fw_iso_context_queue(context, &packet,
1168 				&dev->broadcast_rcv_buffer, offset);
1169 		if (retval < 0)
1170 			goto failed;
1171 
1172 		offset += max_receive;
1173 	}
1174 	dev->num_broadcast_rcv_ptrs = num_packets;
1175 	dev->rcv_buffer_size = max_receive;
1176 	dev->broadcast_rcv_next_ptr = 0U;
1177 	retval = fw_iso_context_start(context, -1, 0,
1178 			FW_ISO_CONTEXT_MATCH_ALL_TAGS); /* ??? sync */
1179 	if (retval < 0)
1180 		goto failed;
1181 
1182 	/* FIXME: adjust it according to the min. speed of all known peers? */
1183 	dev->broadcast_xmt_max_payload = IEEE1394_MAX_PAYLOAD_S100
1184 			- IEEE1394_GASP_HDR_SIZE - RFC2374_UNFRAG_HDR_SIZE;
1185 	dev->broadcast_state = FWNET_BROADCAST_RUNNING;
1186 
1187 	return 0;
1188 
1189  failed:
1190 	__fwnet_broadcast_stop(dev);
1191 	return retval;
1192 }
1193 
1194 static void set_carrier_state(struct fwnet_device *dev)
1195 {
1196 	if (dev->peer_count > 1)
1197 		netif_carrier_on(dev->netdev);
1198 	else
1199 		netif_carrier_off(dev->netdev);
1200 }
1201 
1202 /* ifup */
1203 static int fwnet_open(struct net_device *net)
1204 {
1205 	struct fwnet_device *dev = netdev_priv(net);
1206 	int ret;
1207 
1208 	ret = fwnet_broadcast_start(dev);
1209 	if (ret)
1210 		return ret;
1211 
1212 	netif_start_queue(net);
1213 
1214 	spin_lock_irq(&dev->lock);
1215 	set_carrier_state(dev);
1216 	spin_unlock_irq(&dev->lock);
1217 
1218 	return 0;
1219 }
1220 
1221 /* ifdown */
1222 static int fwnet_stop(struct net_device *net)
1223 {
1224 	struct fwnet_device *dev = netdev_priv(net);
1225 
1226 	netif_stop_queue(net);
1227 	fwnet_broadcast_stop(dev);
1228 
1229 	return 0;
1230 }
1231 
1232 static netdev_tx_t fwnet_tx(struct sk_buff *skb, struct net_device *net)
1233 {
1234 	struct fwnet_header hdr_buf;
1235 	struct fwnet_device *dev = netdev_priv(net);
1236 	__be16 proto;
1237 	u16 dest_node;
1238 	unsigned max_payload;
1239 	u16 dg_size;
1240 	u16 *datagram_label_ptr;
1241 	struct fwnet_packet_task *ptask;
1242 	struct fwnet_peer *peer;
1243 	unsigned long flags;
1244 
1245 	spin_lock_irqsave(&dev->lock, flags);
1246 
1247 	/* Can this happen? */
1248 	if (netif_queue_stopped(dev->netdev)) {
1249 		spin_unlock_irqrestore(&dev->lock, flags);
1250 
1251 		return NETDEV_TX_BUSY;
1252 	}
1253 
1254 	ptask = kmem_cache_alloc(fwnet_packet_task_cache, GFP_ATOMIC);
1255 	if (ptask == NULL)
1256 		goto fail;
1257 
1258 	skb = skb_share_check(skb, GFP_ATOMIC);
1259 	if (!skb)
1260 		goto fail;
1261 
1262 	/*
1263 	 * Make a copy of the driver-specific header.
1264 	 * We might need to rebuild the header on tx failure.
1265 	 */
1266 	memcpy(&hdr_buf, skb->data, sizeof(hdr_buf));
1267 	proto = hdr_buf.h_proto;
1268 
1269 	switch (proto) {
1270 	case htons(ETH_P_ARP):
1271 	case htons(ETH_P_IP):
1272 #if IS_ENABLED(CONFIG_IPV6)
1273 	case htons(ETH_P_IPV6):
1274 #endif
1275 		break;
1276 	default:
1277 		goto fail;
1278 	}
1279 
1280 	skb_pull(skb, sizeof(hdr_buf));
1281 	dg_size = skb->len;
1282 
1283 	/*
1284 	 * Set the transmission type for the packet.  ARP packets and IP
1285 	 * broadcast packets are sent via GASP.
1286 	 */
1287 	if (fwnet_hwaddr_is_multicast(hdr_buf.h_dest)) {
1288 		max_payload        = dev->broadcast_xmt_max_payload;
1289 		datagram_label_ptr = &dev->broadcast_xmt_datagramlabel;
1290 
1291 		ptask->fifo_addr   = FWNET_NO_FIFO_ADDR;
1292 		ptask->generation  = 0;
1293 		ptask->dest_node   = IEEE1394_ALL_NODES;
1294 		ptask->speed       = SCODE_100;
1295 	} else {
1296 		union fwnet_hwaddr *ha = (union fwnet_hwaddr *)hdr_buf.h_dest;
1297 		__be64 guid = get_unaligned(&ha->uc.uniq_id);
1298 		u8 generation;
1299 
1300 		peer = fwnet_peer_find_by_guid(dev, be64_to_cpu(guid));
1301 		if (!peer)
1302 			goto fail;
1303 
1304 		generation         = peer->generation;
1305 		dest_node          = peer->node_id;
1306 		max_payload        = peer->max_payload;
1307 		datagram_label_ptr = &peer->datagram_label;
1308 
1309 		ptask->fifo_addr   = fwnet_hwaddr_fifo(ha);
1310 		ptask->generation  = generation;
1311 		ptask->dest_node   = dest_node;
1312 		ptask->speed       = peer->speed;
1313 	}
1314 
1315 	ptask->hdr.w0 = 0;
1316 	ptask->hdr.w1 = 0;
1317 	ptask->skb = skb;
1318 	ptask->dev = dev;
1319 
1320 	/* Does it all fit in one packet? */
1321 	if (dg_size <= max_payload) {
1322 		fwnet_make_uf_hdr(&ptask->hdr, ntohs(proto));
1323 		ptask->outstanding_pkts = 1;
1324 		max_payload = dg_size + RFC2374_UNFRAG_HDR_SIZE;
1325 	} else {
1326 		u16 datagram_label;
1327 
1328 		max_payload -= RFC2374_FRAG_OVERHEAD;
1329 		datagram_label = (*datagram_label_ptr)++;
1330 		fwnet_make_ff_hdr(&ptask->hdr, ntohs(proto), dg_size,
1331 				  datagram_label);
1332 		ptask->outstanding_pkts = DIV_ROUND_UP(dg_size, max_payload);
1333 		max_payload += RFC2374_FRAG_HDR_SIZE;
1334 	}
1335 
1336 	if (++dev->queued_datagrams == FWNET_MAX_QUEUED_DATAGRAMS)
1337 		netif_stop_queue(dev->netdev);
1338 
1339 	spin_unlock_irqrestore(&dev->lock, flags);
1340 
1341 	ptask->max_payload = max_payload;
1342 	ptask->enqueued    = 0;
1343 
1344 	fwnet_send_packet(ptask);
1345 
1346 	return NETDEV_TX_OK;
1347 
1348  fail:
1349 	spin_unlock_irqrestore(&dev->lock, flags);
1350 
1351 	if (ptask)
1352 		kmem_cache_free(fwnet_packet_task_cache, ptask);
1353 
1354 	if (skb != NULL)
1355 		dev_kfree_skb(skb);
1356 
1357 	net->stats.tx_dropped++;
1358 	net->stats.tx_errors++;
1359 
1360 	/*
1361 	 * FIXME: According to a patch from 2003-02-26, "returning non-zero
1362 	 * causes serious problems" here, allegedly.  Before that patch,
1363 	 * -ERRNO was returned which is not appropriate under Linux 2.6.
1364 	 * Perhaps more needs to be done?  Stop the queue in serious
1365 	 * conditions and restart it elsewhere?
1366 	 */
1367 	return NETDEV_TX_OK;
1368 }
1369 
1370 static const struct ethtool_ops fwnet_ethtool_ops = {
1371 	.get_link	= ethtool_op_get_link,
1372 };
1373 
1374 static const struct net_device_ops fwnet_netdev_ops = {
1375 	.ndo_open       = fwnet_open,
1376 	.ndo_stop	= fwnet_stop,
1377 	.ndo_start_xmit = fwnet_tx,
1378 };
1379 
1380 static void fwnet_init_dev(struct net_device *net)
1381 {
1382 	net->header_ops		= &fwnet_header_ops;
1383 	net->netdev_ops		= &fwnet_netdev_ops;
1384 	net->watchdog_timeo	= 2 * HZ;
1385 	net->flags		= IFF_BROADCAST | IFF_MULTICAST;
1386 	net->features		= NETIF_F_HIGHDMA;
1387 	net->addr_len		= FWNET_ALEN;
1388 	net->hard_header_len	= FWNET_HLEN;
1389 	net->type		= ARPHRD_IEEE1394;
1390 	net->tx_queue_len	= FWNET_TX_QUEUE_LEN;
1391 	net->ethtool_ops	= &fwnet_ethtool_ops;
1392 }
1393 
1394 /* caller must hold fwnet_device_mutex */
1395 static struct fwnet_device *fwnet_dev_find(struct fw_card *card)
1396 {
1397 	struct fwnet_device *dev;
1398 
1399 	list_for_each_entry(dev, &fwnet_device_list, dev_link)
1400 		if (dev->card == card)
1401 			return dev;
1402 
1403 	return NULL;
1404 }
1405 
1406 static int fwnet_add_peer(struct fwnet_device *dev,
1407 			  struct fw_unit *unit, struct fw_device *device)
1408 {
1409 	struct fwnet_peer *peer;
1410 
1411 	peer = kmalloc(sizeof(*peer), GFP_KERNEL);
1412 	if (!peer)
1413 		return -ENOMEM;
1414 
1415 	dev_set_drvdata(&unit->device, peer);
1416 
1417 	peer->dev = dev;
1418 	peer->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1419 	INIT_LIST_HEAD(&peer->pd_list);
1420 	peer->pdg_size = 0;
1421 	peer->datagram_label = 0;
1422 	peer->speed = device->max_speed;
1423 	peer->max_payload = fwnet_max_payload(device->max_rec, peer->speed);
1424 
1425 	peer->generation = device->generation;
1426 	smp_rmb();
1427 	peer->node_id = device->node_id;
1428 
1429 	spin_lock_irq(&dev->lock);
1430 	list_add_tail(&peer->peer_link, &dev->peer_list);
1431 	dev->peer_count++;
1432 	set_carrier_state(dev);
1433 	spin_unlock_irq(&dev->lock);
1434 
1435 	return 0;
1436 }
1437 
1438 static int fwnet_probe(struct fw_unit *unit,
1439 		       const struct ieee1394_device_id *id)
1440 {
1441 	struct fw_device *device = fw_parent_device(unit);
1442 	struct fw_card *card = device->card;
1443 	struct net_device *net;
1444 	bool allocated_netdev = false;
1445 	struct fwnet_device *dev;
1446 	union fwnet_hwaddr ha;
1447 	int ret;
1448 
1449 	mutex_lock(&fwnet_device_mutex);
1450 
1451 	dev = fwnet_dev_find(card);
1452 	if (dev) {
1453 		net = dev->netdev;
1454 		goto have_dev;
1455 	}
1456 
1457 	net = alloc_netdev(sizeof(*dev), "firewire%d", NET_NAME_UNKNOWN,
1458 			   fwnet_init_dev);
1459 	if (net == NULL) {
1460 		mutex_unlock(&fwnet_device_mutex);
1461 		return -ENOMEM;
1462 	}
1463 
1464 	allocated_netdev = true;
1465 	SET_NETDEV_DEV(net, card->device);
1466 	dev = netdev_priv(net);
1467 
1468 	spin_lock_init(&dev->lock);
1469 	dev->broadcast_state = FWNET_BROADCAST_ERROR;
1470 	dev->broadcast_rcv_context = NULL;
1471 	dev->broadcast_xmt_max_payload = 0;
1472 	dev->broadcast_xmt_datagramlabel = 0;
1473 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
1474 	dev->queued_datagrams = 0;
1475 	INIT_LIST_HEAD(&dev->peer_list);
1476 	dev->card = card;
1477 	dev->netdev = net;
1478 
1479 	ret = fwnet_fifo_start(dev);
1480 	if (ret < 0)
1481 		goto out;
1482 	dev->local_fifo = dev->handler.offset;
1483 
1484 	/*
1485 	 * default MTU: RFC 2734 cl. 4, RFC 3146 cl. 4
1486 	 * maximum MTU: RFC 2734 cl. 4.2, fragment encapsulation header's
1487 	 *              maximum possible datagram_size + 1 = 0xfff + 1
1488 	 */
1489 	net->mtu = 1500U;
1490 	net->min_mtu = ETH_MIN_MTU;
1491 	net->max_mtu = 4096U;
1492 
1493 	/* Set our hardware address while we're at it */
1494 	ha.uc.uniq_id = cpu_to_be64(card->guid);
1495 	ha.uc.max_rec = dev->card->max_receive;
1496 	ha.uc.sspd = dev->card->link_speed;
1497 	ha.uc.fifo_hi = cpu_to_be16(dev->local_fifo >> 32);
1498 	ha.uc.fifo_lo = cpu_to_be32(dev->local_fifo & 0xffffffff);
1499 	dev_addr_set(net, ha.u);
1500 
1501 	memset(net->broadcast, -1, net->addr_len);
1502 
1503 	ret = register_netdev(net);
1504 	if (ret)
1505 		goto out;
1506 
1507 	list_add_tail(&dev->dev_link, &fwnet_device_list);
1508 	dev_notice(&net->dev, "IP over IEEE 1394 on card %s\n",
1509 		   dev_name(card->device));
1510  have_dev:
1511 	ret = fwnet_add_peer(dev, unit, device);
1512 	if (ret && allocated_netdev) {
1513 		unregister_netdev(net);
1514 		list_del(&dev->dev_link);
1515  out:
1516 		fwnet_fifo_stop(dev);
1517 		free_netdev(net);
1518 	}
1519 
1520 	mutex_unlock(&fwnet_device_mutex);
1521 
1522 	return ret;
1523 }
1524 
1525 /*
1526  * FIXME abort partially sent fragmented datagrams,
1527  * discard partially received fragmented datagrams
1528  */
1529 static void fwnet_update(struct fw_unit *unit)
1530 {
1531 	struct fw_device *device = fw_parent_device(unit);
1532 	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
1533 	int generation;
1534 
1535 	generation = device->generation;
1536 
1537 	spin_lock_irq(&peer->dev->lock);
1538 	peer->node_id    = device->node_id;
1539 	peer->generation = generation;
1540 	spin_unlock_irq(&peer->dev->lock);
1541 }
1542 
1543 static void fwnet_remove_peer(struct fwnet_peer *peer, struct fwnet_device *dev)
1544 {
1545 	struct fwnet_partial_datagram *pd, *pd_next;
1546 
1547 	spin_lock_irq(&dev->lock);
1548 	list_del(&peer->peer_link);
1549 	dev->peer_count--;
1550 	set_carrier_state(dev);
1551 	spin_unlock_irq(&dev->lock);
1552 
1553 	list_for_each_entry_safe(pd, pd_next, &peer->pd_list, pd_link)
1554 		fwnet_pd_delete(pd);
1555 
1556 	kfree(peer);
1557 }
1558 
1559 static void fwnet_remove(struct fw_unit *unit)
1560 {
1561 	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
1562 	struct fwnet_device *dev = peer->dev;
1563 	struct net_device *net;
1564 	int i;
1565 
1566 	mutex_lock(&fwnet_device_mutex);
1567 
1568 	net = dev->netdev;
1569 
1570 	fwnet_remove_peer(peer, dev);
1571 
1572 	if (list_empty(&dev->peer_list)) {
1573 		unregister_netdev(net);
1574 
1575 		fwnet_fifo_stop(dev);
1576 
1577 		for (i = 0; dev->queued_datagrams && i < 5; i++)
1578 			ssleep(1);
1579 		WARN_ON(dev->queued_datagrams);
1580 		list_del(&dev->dev_link);
1581 
1582 		free_netdev(net);
1583 	}
1584 
1585 	mutex_unlock(&fwnet_device_mutex);
1586 }
1587 
1588 static const struct ieee1394_device_id fwnet_id_table[] = {
1589 	{
1590 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1591 				IEEE1394_MATCH_VERSION,
1592 		.specifier_id = IANA_SPECIFIER_ID,
1593 		.version      = RFC2734_SW_VERSION,
1594 	},
1595 #if IS_ENABLED(CONFIG_IPV6)
1596 	{
1597 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1598 				IEEE1394_MATCH_VERSION,
1599 		.specifier_id = IANA_SPECIFIER_ID,
1600 		.version      = RFC3146_SW_VERSION,
1601 	},
1602 #endif
1603 	{ }
1604 };
1605 
1606 static struct fw_driver fwnet_driver = {
1607 	.driver = {
1608 		.owner  = THIS_MODULE,
1609 		.name   = KBUILD_MODNAME,
1610 		.bus    = &fw_bus_type,
1611 	},
1612 	.probe    = fwnet_probe,
1613 	.update   = fwnet_update,
1614 	.remove   = fwnet_remove,
1615 	.id_table = fwnet_id_table,
1616 };
1617 
1618 static const u32 rfc2374_unit_directory_data[] = {
1619 	0x00040000,	/* directory_length		*/
1620 	0x1200005e,	/* unit_specifier_id: IANA	*/
1621 	0x81000003,	/* textual descriptor offset	*/
1622 	0x13000001,	/* unit_sw_version: RFC 2734	*/
1623 	0x81000005,	/* textual descriptor offset	*/
1624 	0x00030000,	/* descriptor_length		*/
1625 	0x00000000,	/* text				*/
1626 	0x00000000,	/* minimal ASCII, en		*/
1627 	0x49414e41,	/* I A N A			*/
1628 	0x00030000,	/* descriptor_length		*/
1629 	0x00000000,	/* text				*/
1630 	0x00000000,	/* minimal ASCII, en		*/
1631 	0x49507634,	/* I P v 4			*/
1632 };
1633 
1634 static struct fw_descriptor rfc2374_unit_directory = {
1635 	.length = ARRAY_SIZE(rfc2374_unit_directory_data),
1636 	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
1637 	.data   = rfc2374_unit_directory_data
1638 };
1639 
1640 #if IS_ENABLED(CONFIG_IPV6)
1641 static const u32 rfc3146_unit_directory_data[] = {
1642 	0x00040000,	/* directory_length		*/
1643 	0x1200005e,	/* unit_specifier_id: IANA	*/
1644 	0x81000003,	/* textual descriptor offset	*/
1645 	0x13000002,	/* unit_sw_version: RFC 3146	*/
1646 	0x81000005,	/* textual descriptor offset	*/
1647 	0x00030000,	/* descriptor_length		*/
1648 	0x00000000,	/* text				*/
1649 	0x00000000,	/* minimal ASCII, en		*/
1650 	0x49414e41,	/* I A N A			*/
1651 	0x00030000,	/* descriptor_length		*/
1652 	0x00000000,	/* text				*/
1653 	0x00000000,	/* minimal ASCII, en		*/
1654 	0x49507636,	/* I P v 6			*/
1655 };
1656 
1657 static struct fw_descriptor rfc3146_unit_directory = {
1658 	.length = ARRAY_SIZE(rfc3146_unit_directory_data),
1659 	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
1660 	.data   = rfc3146_unit_directory_data
1661 };
1662 #endif
1663 
1664 static int __init fwnet_init(void)
1665 {
1666 	int err;
1667 
1668 	err = fw_core_add_descriptor(&rfc2374_unit_directory);
1669 	if (err)
1670 		return err;
1671 
1672 #if IS_ENABLED(CONFIG_IPV6)
1673 	err = fw_core_add_descriptor(&rfc3146_unit_directory);
1674 	if (err)
1675 		goto out;
1676 #endif
1677 
1678 	fwnet_packet_task_cache = kmem_cache_create("packet_task",
1679 			sizeof(struct fwnet_packet_task), 0, 0, NULL);
1680 	if (!fwnet_packet_task_cache) {
1681 		err = -ENOMEM;
1682 		goto out2;
1683 	}
1684 
1685 	err = driver_register(&fwnet_driver.driver);
1686 	if (!err)
1687 		return 0;
1688 
1689 	kmem_cache_destroy(fwnet_packet_task_cache);
1690 out2:
1691 #if IS_ENABLED(CONFIG_IPV6)
1692 	fw_core_remove_descriptor(&rfc3146_unit_directory);
1693 out:
1694 #endif
1695 	fw_core_remove_descriptor(&rfc2374_unit_directory);
1696 
1697 	return err;
1698 }
1699 module_init(fwnet_init);
1700 
1701 static void __exit fwnet_cleanup(void)
1702 {
1703 	driver_unregister(&fwnet_driver.driver);
1704 	kmem_cache_destroy(fwnet_packet_task_cache);
1705 #if IS_ENABLED(CONFIG_IPV6)
1706 	fw_core_remove_descriptor(&rfc3146_unit_directory);
1707 #endif
1708 	fw_core_remove_descriptor(&rfc2374_unit_directory);
1709 }
1710 module_exit(fwnet_cleanup);
1711 
1712 MODULE_AUTHOR("Jay Fenlason <fenlason@redhat.com>");
1713 MODULE_DESCRIPTION("IP over IEEE1394 as per RFC 2734/3146");
1714 MODULE_LICENSE("GPL");
1715 MODULE_DEVICE_TABLE(ieee1394, fwnet_id_table);
1716