summaryrefslogtreecommitdiffstats
path: root/drivers/firewire/net.c
blob: d923d1dc458fbe5405f90d9a24fa4f19afa900d9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
/*
 * IPv4 over IEEE 1394, per RFC 2734
 *
 * Copyright (C) 2009 Jay Fenlason <fenlason@redhat.com>
 *
 * based on eth1394 by Ben Collins et al
 */

#include <linux/bug.h>
#include <linux/device.h>
#include <linux/ethtool.h>
#include <linux/firewire.h>
#include <linux/firewire-constants.h>
#include <linux/highmem.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/jiffies.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>

#include <asm/unaligned.h>
#include <net/arp.h>

#define FWNET_MAX_FRAGMENTS	25	/* arbitrary limit */
#define FWNET_ISO_PAGE_COUNT	(PAGE_SIZE < 16 * 1024 ? 4 : 2)

#define IEEE1394_BROADCAST_CHANNEL	31
#define IEEE1394_ALL_NODES		(0xffc0 | 0x003f)
#define IEEE1394_MAX_PAYLOAD_S100	512
#define FWNET_NO_FIFO_ADDR		(~0ULL)

#define IANA_SPECIFIER_ID		0x00005eU
#define RFC2734_SW_VERSION		0x000001U

#define IEEE1394_GASP_HDR_SIZE	8

#define RFC2374_UNFRAG_HDR_SIZE	4
#define RFC2374_FRAG_HDR_SIZE	8
#define RFC2374_FRAG_OVERHEAD	4

#define RFC2374_HDR_UNFRAG	0	/* unfragmented		*/
#define RFC2374_HDR_FIRSTFRAG	1	/* first fragment	*/
#define RFC2374_HDR_LASTFRAG	2	/* last fragment	*/
#define RFC2374_HDR_INTFRAG	3	/* interior fragment	*/

#define RFC2734_HW_ADDR_LEN	16

struct rfc2734_arp {
	__be16 hw_type;		/* 0x0018	*/
	__be16 proto_type;	/* 0x0806       */
	u8 hw_addr_len;		/* 16		*/
	u8 ip_addr_len;		/* 4		*/
	__be16 opcode;		/* ARP Opcode	*/
	/* Above is exactly the same format as struct arphdr */

	__be64 s_uniq_id;	/* Sender's 64bit EUI			*/
	u8 max_rec;		/* Sender's max packet size		*/
	u8 sspd;		/* Sender's max speed			*/
	__be16 fifo_hi;		/* hi 16bits of sender's FIFO addr	*/
	__be32 fifo_lo;		/* lo 32bits of sender's FIFO addr	*/
	__be32 sip;		/* Sender's IP Address			*/
	__be32 tip;		/* IP Address of requested hw addr	*/
} __attribute__((packed));

/* This header format is specific to this driver implementation. */
#define FWNET_ALEN	8
#define FWNET_HLEN	10
struct fwnet_header {
	u8 h_dest[FWNET_ALEN];	/* destination address */
	__be16 h_proto;		/* packet type ID field */
} __attribute__((packed));

/* IPv4 and IPv6 encapsulation header */
struct rfc2734_header {
	u32 w0;
	u32 w1;
};

#define fwnet_get_hdr_lf(h)		(((h)->w0 & 0xc0000000) >> 30)
#define fwnet_get_hdr_ether_type(h)	(((h)->w0 & 0x0000ffff))
#define fwnet_get_hdr_dg_size(h)	(((h)->w0 & 0x0fff0000) >> 16)
#define fwnet_get_hdr_fg_off(h)		(((h)->w0 & 0x00000fff))
#define fwnet_get_hdr_dgl(h)		(((h)->w1 & 0xffff0000) >> 16)

#define fwnet_set_hdr_lf(lf)		((lf)  << 30)
#define fwnet_set_hdr_ether_type(et)	(et)
#define fwnet_set_hdr_dg_size(dgs)	((dgs) << 16)
#define fwnet_set_hdr_fg_off(fgo)	(fgo)

#define fwnet_set_hdr_dgl(dgl)		((dgl) << 16)

static inline void fwnet_make_uf_hdr(struct rfc2734_header *hdr,
		unsigned ether_type)
{
	hdr->w0 = fwnet_set_hdr_lf(RFC2374_HDR_UNFRAG)
		  | fwnet_set_hdr_ether_type(ether_type);
}

static inline void fwnet_make_ff_hdr(struct rfc2734_header *hdr,
		unsigned ether_type, unsigned dg_size, unsigned dgl)
{
	hdr->w0 = fwnet_set_hdr_lf(RFC2374_HDR_FIRSTFRAG)
		  | fwnet_set_hdr_dg_size(dg_size)
		  | fwnet_set_hdr_ether_type(ether_type);
	hdr->w1 = fwnet_set_hdr_dgl(dgl);
}

static inline void fwnet_make_sf_hdr(struct rfc2734_header *hdr,
		unsigned lf, unsigned dg_size, unsigned fg_off, unsigned dgl)
{
	hdr->w0 = fwnet_set_hdr_lf(lf)
		  | fwnet_set_hdr_dg_size(dg_size)
		  | fwnet_set_hdr_fg_off(fg_off);
	hdr->w1 = fwnet_set_hdr_dgl(dgl);
}

/* This list keeps track of what parts of the datagram have been filled in */
struct fwnet_fragment_info {
	struct list_head fi_link;
	u16 offset;
	u16 len;
};

struct fwnet_partial_datagram {
	struct list_head pd_link;
	struct list_head fi_list;
	struct sk_buff *skb;
	/* FIXME Why not use skb->data? */
	char *pbuf;
	u16 datagram_label;
	u16 ether_type;
	u16 datagram_size;
};

static DEFINE_MUTEX(fwnet_device_mutex);
static LIST_HEAD(fwnet_device_list);

struct fwnet_device {
	struct list_head dev_link;
	spinlock_t lock;
	enum {
		FWNET_BROADCAST_ERROR,
		FWNET_BROADCAST_RUNNING,
		FWNET_BROADCAST_STOPPED,
	} broadcast_state;
	struct fw_iso_context *broadcast_rcv_context;
	struct fw_iso_buffer broadcast_rcv_buffer;
	void **broadcast_rcv_buffer_ptrs;
	unsigned broadcast_rcv_next_ptr;
	unsigned num_broadcast_rcv_ptrs;
	unsigned rcv_buffer_size;
	/*
	 * This value is the maximum unfragmented datagram size that can be
	 * sent by the hardware.  It already has the GASP overhead and the
	 * unfragmented datagram header overhead calculated into it.
	 */
	unsigned broadcast_xmt_max_payload;
	u16 broadcast_xmt_datagramlabel;

	/*
	 * The CSR address that remote nodes must send datagrams to for us to
	 * receive them.
	 */
	struct fw_address_handler handler;
	u64 local_fifo;

	/* List of packets to be sent */
	struct list_head packet_list;
	/*
	 * List of packets that were broadcasted.  When we get an ISO interrupt
	 * one of them has been sent
	 */
	struct list_head broadcasted_list;
	/* List of packets that have been sent but not yet acked */
	struct list_head sent_list;

	struct list_head peer_list;
	struct fw_card *card;
	struct net_device *netdev;
};

struct fwnet_peer {
	struct list_head peer_link;
	struct fwnet_device *dev;
	u64 guid;
	u64 fifo;

	/* guarded by dev->lock */
	struct list_head pd_list; /* received partial datagrams */
	unsigned pdg_size;        /* pd_list size */

	u16 datagram_label;       /* outgoing datagram label */
	unsigned max_payload;     /* includes RFC2374_FRAG_HDR_SIZE overhead */
	int node_id;
	int generation;
	unsigned speed;
};

/* This is our task struct. It's used for the packet complete callback.  */
struct fwnet_packet_task {
	/*
	 * ptask can actually be on dev->packet_list, dev->broadcasted_list,
	 * or dev->sent_list depending on its current state.
	 */
	struct list_head pt_link;
	struct fw_transaction transaction;
	struct rfc2734_header hdr;
	struct sk_buff *skb;
	struct fwnet_device *dev;

	int outstanding_pkts;
	unsigned max_payload;
	u64 fifo_addr;
	u16 dest_node;
	u8 generation;
	u8 speed;
};

/*
 * saddr == NULL means use device source address.
 * daddr == NULL means leave destination address (eg unresolved arp).
 */
static int fwnet_header_create(struct sk_buff *skb, struct net_device *net,
			unsigned short type, const void *daddr,
			const void *saddr, unsigned len)
{
	struct fwnet_header *h;

	h = (struct fwnet_header *)skb_push(skb, sizeof(*h));
	put_unaligned_be16(type, &h->h_proto);

	if (net->flags & (IFF_LOOPBACK | IFF_NOARP)) {
		memset(h->h_dest, 0, net->addr_len);

		return net->hard_header_len;
	}

	if (daddr) {
		memcpy(h->h_dest, daddr, net->addr_len);

		return net->hard_header_len;
	}

	return -net->hard_header_len;
}

static int fwnet_header_rebuild(struct sk_buff *skb)
{
	struct fwnet_header *h = (struct fwnet_header *)skb->data;

	if (get_unaligned_be16(&h->h_proto) == ETH_P_IP)
		return arp_find((unsigned char *)&h->h_dest, skb);

	fw_notify("%s: unable to resolve type %04x addresses\n",
		  skb->dev->name, be16_to_cpu(h->h_proto));
	return 0;
}

static int fwnet_header_cache(const struct neighbour *neigh,
			      struct hh_cache *hh)
{
	struct net_device *net;
	struct fwnet_header *h;

	if (hh->hh_type == cpu_to_be16(ETH_P_802_3))
		return -1;
	net = neigh->dev;
	h = (struct fwnet_header *)((u8 *)hh->hh_data + 16 - sizeof(*h));
	h->h_proto = hh->hh_type;
	memcpy(h->h_dest, neigh->ha, net->addr_len);
	hh->hh_len = FWNET_HLEN;

	return 0;
}

/* Called by Address Resolution module to notify changes in address. */
static void fwnet_header_cache_update(struct hh_cache *hh,
		const struct net_device *net, const unsigned char *haddr)
{
	memcpy((u8 *)hh->hh_data + 16 - FWNET_HLEN, haddr, net->addr_len);
}

static int fwnet_header_parse(const struct sk_buff *skb, unsigned char *haddr)
{
	memcpy(haddr, skb->dev->dev_addr, FWNET_ALEN);

	return FWNET_ALEN;
}

static const struct header_ops fwnet_header_ops = {
	.create         = fwnet_header_create,
	.rebuild        = fwnet_header_rebuild,
	.cache		= fwnet_header_cache,
	.cache_update	= fwnet_header_cache_update,
	.parse          = fwnet_header_parse,
};

/* FIXME: is this correct for all cases? */
static bool fwnet_frag_overlap(struct fwnet_partial_datagram *pd,
			       unsigned offset, unsigned len)
{
	struct fwnet_fragment_info *fi;
	unsigned end = offset + len;

	list_for_each_entry(fi, &pd->fi_list, fi_link)
		if (offset < fi->offset + fi->len && end > fi->offset)
			return true;

	return false;
}

/* Assumes that new fragment does not overlap any existing fragments */
static struct fwnet_fragment_info *fwnet_frag_new(
	struct fwnet_partial_datagram *pd, unsigned offset, unsigned len)
{
	struct fwnet_fragment_info *fi, *fi2, *new;
	struct list_head *list;

	list = &pd->fi_list;
	list_for_each_entry(fi, &pd->fi_list, fi_link) {
		if (fi->offset + fi->len == offset) {
			/* The new fragment can be tacked on to the end */
			/* Did the new fragment plug a hole? */
			fi2 = list_entry(fi->fi_link.next,
					 struct fwnet_fragment_info, fi_link);
			if (fi->offset + fi->len == fi2->offset) {
				/* glue fragments together */
				fi->len += len + fi2->len;
				list_del(&fi2->fi_link);
				kfree(fi2);
			} else {
				fi->len += len;
			}

			return fi;
		}
		if (offset + len == fi->offset) {
			/* The new fragment can be tacked on to the beginning */
			/* Did the new fragment plug a hole? */
			fi2 = list_entry(fi->fi_link.prev,
					 struct fwnet_fragment_info, fi_link);
			if (fi2->offset + fi2->len == fi->offset) {
				/* glue fragments together */
				fi2->len += fi->len + len;
				list_del(&fi->fi_link);
				kfree(fi);

				return fi2;
			}
			fi->offset = offset;
			fi->len += len;

			return fi;
		}
		if (offset > fi->offset + fi->len) {
			list = &fi->fi_link;
			break;
		}
		if (offset + len < fi->offset) {
			list = fi->fi_link.prev;
			break;
		}
	}

	new = kmalloc(sizeof(*new), GFP_ATOMIC);
	if (!new) {
		fw_error("out of memory\n");
		return NULL;
	}

	new->offset = offset;
	new->len = len;
	list_add(&new->fi_link, list);

	return new;
}

static struct fwnet_partial_datagram *fwnet_pd_new(struct net_device *net,
		struct fwnet_peer *peer, u16 datagram_label, unsigned dg_size,
		void *frag_buf, unsigned frag_off, unsigned frag_len)
{
	struct fwnet_partial_datagram *new;
	struct fwnet_fragment_info *fi;

	new = kmalloc(sizeof(*new), GFP_ATOMIC);
	if (!new)
		goto fail;

	INIT_LIST_HEAD(&new->fi_list);
	fi = fwnet_frag_new(new, frag_off, frag_len);
	if (fi == NULL)
		goto fail_w_new;

	new->datagram_label = datagram_label;
	new->datagram_size = dg_size;
	new->skb = dev_alloc_skb(dg_size + net->hard_header_len + 15);
	if (new->skb == NULL)
		goto fail_w_fi;

	skb_reserve(new->skb, (net->hard_header_len + 15) & ~15);
	new->pbuf = skb_put(new->skb, dg_size);
	memcpy(new->pbuf + frag_off, frag_buf, frag_len);
	list_add_tail(&new->pd_link, &peer->pd_list);

	return new;

fail_w_fi:
	kfree(fi);
fail_w_new:
	kfree(new);
fail:
	fw_error("out of memory\n");

	return NULL;
}

static struct fwnet_partial_datagram *fwnet_pd_find(struct fwnet_peer *peer,
						    u16 datagram_label)
{
	struct fwnet_partial_datagram *pd;

	list_for_each_entry(pd, &peer->pd_list, pd_link)
		if (pd->datagram_label == datagram_label)
			return pd;

	return NULL;
}


static void fwnet_pd_delete(struct fwnet_partial_datagram *old)
{
	struct fwnet_fragment_info *fi, *n;

	list_for_each_entry_safe(fi, n, &old->fi_list, fi_link)
		kfree(fi);

	list_del(&old->pd_link);
	dev_kfree_skb_any(old->skb);
	kfree(old);
}

static bool fwnet_pd_update(struct fwnet_peer *peer,
		struct fwnet_partial_datagram *pd, void *frag_buf,
		unsigned frag_off, unsigned frag_len)
{
	if (fwnet_frag_new(pd, frag_off, frag_len) == NULL)
		return false;

	memcpy(pd->pbuf + frag_off, frag_buf, frag_len);

	/*
	 * Move list entry to beginnig of list so that oldest partial
	 * datagrams percolate to the end of the list
	 */
	list_move_tail(&pd->pd_link, &peer->pd_list);

	return true;
}

static bool fwnet_pd_is_complete(struct fwnet_partial_datagram *pd)
{
	struct fwnet_fragment_info *fi;

	fi = list_entry(pd->fi_list.next, struct fwnet_fragment_info, fi_link);

	return fi->len == pd->datagram_size;
}

/* caller must hold dev->lock */
static struct fwnet_peer *fwnet_peer_find_by_guid(struct fwnet_device *dev,
						  u64 guid)
{
	struct fwnet_peer *peer;

	list_for_each_entry(peer, &dev->peer_list, peer_link)
		if (peer->guid == guid)
			return peer;

	return NULL;
}

/* caller must hold dev->lock */
static struct fwnet_peer *fwnet_peer_find_by_node_id(struct fwnet_device *dev,
						int node_id, int generation)
{
	struct fwnet_peer *peer;

	list_for_each_entry(peer, &dev->peer_list, peer_link)
		if (peer->node_id    == node_id &&
		    peer->generation == generation)
			return peer;

	return NULL;
}

/* See IEEE 1394-2008 table 6-4, table 8-8, table 16-18. */
static unsigned fwnet_max_payload(unsigned max_rec, unsigned speed)
{
	max_rec = min(max_rec, speed + 8);
	max_rec = min(max_rec, 0xbU); /* <= 4096 */
	if (max_rec < 8) {
		fw_notify("max_rec %x out of range\n", max_rec);
		max_rec = 8;
	}

	return (1 << (max_rec + 1)) - RFC2374_FRAG_HDR_SIZE;
}


static int fwnet_finish_incoming_packet(struct net_device *net,
					struct sk_buff *skb, u16 source_node_id,
					bool is_broadcast, u16 ether_type)
{
	struct fwnet_device *dev;
	static const __be64 broadcast_hw = cpu_to_be64(~0ULL);
	int status;
	__be64 guid;

	dev = netdev_priv(net);
	/* Write metadata, and then pass to the receive level */
	skb->dev = net;
	skb->ip_summed = CHECKSUM_UNNECESSARY;  /* don't check it */

	/*
	 * Parse the encapsulation header. This actually does the job of
	 * converting to an ethernet frame header, as well as arp
	 * conversion if needed. ARP conversion is easier in this
	 * direction, since we are using ethernet as our backend.
	 */
	/*
	 * If this is an ARP packet, convert it. First, we want to make
	 * use of some of the fields, since they tell us a little bit
	 * about the sending machine.
	 */
	if (ether_type == ETH_P_ARP) {
		struct rfc2734_arp *arp1394;
		struct arphdr *arp;
		unsigned char *arp_ptr;
		u64 fifo_addr;
		u64 peer_guid;
		unsigned sspd;
		u16 max_payload;
		struct fwnet_peer *peer;
		unsigned long flags;

		arp1394   = (struct rfc2734_arp *)skb->data;
		arp       = (struct arphdr *)skb->data;
		arp_ptr   = (unsigned char *)(arp + 1);
		peer_guid = get_unaligned_be64(&arp1394->s_uniq_id);
		fifo_addr = (u64)get_unaligned_be16(&arp1394->fifo_hi) << 32
				| get_unaligned_be32(&arp1394->fifo_lo);

		sspd = arp1394->sspd;
		/* Sanity check.  OS X 10.3 PPC reportedly sends 131. */
		if (sspd > SCODE_3200) {
			fw_notify("sspd %x out of range\n", sspd);
			sspd = SCODE_3200;
		}
		max_payload = fwnet_max_payload(arp1394->max_rec, sspd);

		spin_lock_irqsave(&dev->lock, flags);
		peer = fwnet_peer_find_by_guid(dev, peer_guid);
		if (peer) {
			peer->fifo = fifo_addr;

			if (peer->speed > sspd)
				peer->speed = sspd;
			if (peer->max_payload > max_payload)
				peer->max_payload = max_payload;
		}
		spin_unlock_irqrestore(&dev->lock, flags);

		if (!peer) {
			fw_notify("No peer for ARP packet from %016llx\n",
				  (unsigned long long)peer_guid);
			goto failed_proto;
		}

		/*
		 * Now that we're done with the 1394 specific stuff, we'll
		 * need to alter some of the data.  Believe it or not, all
		 * that needs to be done is sender_IP_address needs to be
		 * moved, the destination hardware address get stuffed
		 * in and the hardware address length set to 8.
		 *
		 * IMPORTANT: The code below overwrites 1394 specific data
		 * needed above so keep the munging of the data for the
		 * higher level IP stack last.
		 */

		arp->ar_hln = 8;
		/* skip over sender unique id */
		arp_ptr += arp->ar_hln;
		/* move sender IP addr */
		put_unaligned(arp1394->sip, (u32 *)arp_ptr);
		/* skip over sender IP addr */
		arp_ptr += arp->ar_pln;

		if (arp->ar_op == htons(ARPOP_REQUEST))
			memset(arp_ptr, 0, sizeof(u64));
		else
			memcpy(arp_ptr, net->dev_addr, sizeof(u64));
	}

	/* Now add the ethernet header. */
	guid = cpu_to_be64(dev->card->guid);
	if (dev_hard_header(skb, net, ether_type,
			   is_broadcast ? &broadcast_hw : &guid,
			   NULL, skb->len) >= 0) {
		struct fwnet_header *eth;
		u16 *rawp;
		__be16 protocol;

		skb_reset_mac_header(skb);
		skb_pull(skb, sizeof(*eth));
		eth = (struct fwnet_header *)skb_mac_header(skb);
		if (*eth->h_dest & 1) {
			if (memcmp(eth->h_dest, net->broadcast,
				   net->addr_len) == 0)
				skb->pkt_type = PACKET_BROADCAST;
#if 0
			else
				skb->pkt_type = PACKET_MULTICAST;
#endif
		} else {
			if (memcmp(eth->h_dest, net->dev_addr, net->addr_len))
				skb->pkt_type = PACKET_OTHERHOST;
		}
		if (ntohs(eth->h_proto) >= 1536) {
			protocol = eth->h_proto;
		} else {
			rawp = (u16 *)skb->data;
			if (*rawp == 0xffff)
				protocol = htons(ETH_P_802_3);
			else
				protocol = htons(ETH_P_802_2);
		}
		skb->protocol = protocol;
	}
	status = netif_rx(skb);
	if (status == NET_RX_DROP) {
		net->stats.rx_errors++;
		net->stats.rx_dropped++;
	} else {
		net->stats.rx_packets++;
		net->stats.rx_bytes += skb->len;
	}
	if (netif_queue_stopped(net))
		netif_wake_queue(net);

	return 0;

 failed_proto:
	net->stats.rx_errors++;
	net->stats.rx_dropped++;

	dev_kfree_skb_any(skb);
	if (netif_queue_stopped(net))
		netif_wake_queue(net);

	net->last_rx = jiffies;

	return 0;
}

static int fwnet_incoming_packet(struct fwnet_device *dev, __be32 *buf, int len,
				 int source_node_id, int generation,
				 bool is_broadcast)
{
	struct sk_buff *skb;
	struct net_device *net = dev->netdev;
	struct rfc2734_header hdr;
	unsigned lf;
	unsigned long flags;
	struct fwnet_peer *peer;
	struct fwnet_partial_datagram *pd;
	int fg_off;
	int dg_size;
	u16 datagram_label;
	int retval;
	u16 ether_type;

	hdr.w0 = be32_to_cpu(buf[0]);
	lf = fwnet_get_hdr_lf(&hdr);
	if (lf == RFC2374_HDR_UNFRAG) {
		/*
		 * An unfragmented datagram has been received by the ieee1394
		 * bus. Build an skbuff around it so we can pass it to the
		 * high level network layer.
		 */
		ether_type = fwnet_get_hdr_ether_type(&hdr);
		buf++;
		len -= RFC2374_UNFRAG_HDR_SIZE;

		skb = dev_alloc_skb(len + net->hard_header_len + 15);
		if (unlikely(!skb)) {
			fw_error("out of memory\n");
			net->stats.rx_dropped++;

			return -1;
		}
		skb_reserve(skb, (net->hard_header_len + 15) & ~15);
		memcpy(skb_put(skb, len), buf, len);

		return fwnet_finish_incoming_packet(net, skb, source_node_id,
						    is_broadcast, ether_type);
	}
	/* A datagram fragment has been received, now the fun begins. */
	hdr.w1 = ntohl(buf[1]);
	buf += 2;
	len -= RFC2374_FRAG_HDR_SIZE;
	if (lf == RFC2374_HDR_FIRSTFRAG) {
		ether_type = fwnet_get_hdr_ether_type(&hdr);
		fg_off = 0;
	} else {
		ether_type = 0;
		fg_off = fwnet_get_hdr_fg_off(&hdr);
	}
	datagram_label = fwnet_get_hdr_dgl(&hdr);
	dg_size = fwnet_get_hdr_dg_size(&hdr); /* ??? + 1 */

	spin_lock_irqsave(&dev->lock, flags);

	peer = fwnet_peer_find_by_node_id(dev, source_node_id, generation);
	if (!peer)
		goto bad_proto;

	pd = fwnet_pd_find(peer, datagram_label);
	if (pd == NULL) {
		while (peer->pdg_size >= FWNET_MAX_FRAGMENTS) {
			/* remove the oldest */
			fwnet_pd_delete(list_first_entry(&peer->pd_list,
				struct fwnet_partial_datagram, pd_link));
			peer->pdg_size--;
		}
		pd = fwnet_pd_new(net, peer, datagram_label,
				  dg_size, buf, fg_off, len);
		if (pd == NULL) {
			retval = -ENOMEM;
			goto bad_proto;
		}
		peer->pdg_size++;
	} else {
		if (fwnet_frag_overlap(pd, fg_off, len) ||
		    pd->datagram_size != dg_size) {
			/*
			 * Differing datagram sizes or overlapping fragments,
			 * discard old datagram and start a new one.
			 */
			fwnet_pd_delete(pd);
			pd = fwnet_pd_new(net, peer, datagram_label,
					  dg_size, buf, fg_off, len);
			if (pd == NULL) {
				retval = -ENOMEM;
				peer->pdg_size--;
				goto bad_proto;
			}
		} else {
			if (!fwnet_pd_update(peer, pd, buf, fg_off, len)) {
				/*
				 * Couldn't save off fragment anyway
				 * so might as well obliterate the
				 * datagram now.
				 */
				fwnet_pd_delete(pd);
				peer->pdg_size--;
				goto bad_proto;
			}
		}
	} /* new datagram or add to existing one */

	if (lf == RFC2374_HDR_FIRSTFRAG)
		pd->ether_type = ether_type;

	if (fwnet_pd_is_complete(pd)) {
		ether_type = pd->ether_type;
		peer->pdg_size--;
		skb = skb_get(pd->skb);
		fwnet_pd_delete(pd);

		spin_unlock_irqrestore(&dev->lock, flags);

		return fwnet_finish_incoming_packet(net, skb, source_node_id,
						    false, ether_type);
	}
	/*
	 * Datagram is not complete, we're done for the
	 * moment.
	 */
	spin_unlock_irqrestore(&dev->lock, flags);

	return 0;

 bad_proto:
	spin_unlock_irqrestore(&dev->lock, flags);

	if (netif_queue_stopped(net))
		netif_wake_queue(net);

	return 0;
}

static void fwnet_receive_packet(struct fw_card *card, struct fw_request *r,
		int tcode, int destination, int source, int generation,
		int speed, unsigned long long offset, void *payload,
		size_t length, void *callback_data)
{
	struct fwnet_device *dev = callback_data;
	int rcode;

	if (destination == IEEE1394_ALL_NODES) {
		kfree(r);

		return;
	}

	if (offset != dev->handler.offset)
		rcode = RCODE_ADDRESS_ERROR;
	else if (tcode != TCODE_WRITE_BLOCK_REQUEST)
		rcode = RCODE_TYPE_ERROR;
	else if (fwnet_incoming_packet(dev, payload, length,
				       source, generation, false) != 0) {
		fw_error("Incoming packet failure\n");
		rcode = RCODE_CONFLICT_ERROR;
	} else
		rcode = RCODE_COMPLETE;

	fw_send_response(card, r, rcode);
}

static void fwnet_receive_broadcast(struct fw_iso_context *context,
		u32 cycle, size_t header_length, void *header, void *data)
{
	struct fwnet_device *dev;
	struct fw_iso_packet packet;
	struct fw_card *card;
	__be16 *hdr_ptr;
	__be32 *buf_ptr;
	int retval;
	u32 length;
	u16 source_node_id;
	u32 specifier_id;
	u32 ver;
	unsigned long offset;
	unsigned long flags;

	dev = data;
	card = dev->card;
	hdr_ptr = header;
	length = be16_to_cpup(hdr_ptr);

	spin_lock_irqsave(&dev->lock, flags);

	offset = dev->rcv_buffer_size * dev->broadcast_rcv_next_ptr;
	buf_ptr = dev->broadcast_rcv_buffer_ptrs[dev->broadcast_rcv_next_ptr++];
	if (dev->broadcast_rcv_next_ptr == dev->num_broadcast_rcv_ptrs)
		dev->broadcast_rcv_next_ptr = 0;

	spin_unlock_irqrestore(&dev->lock, flags);

	specifier_id =    (be32_to_cpu(buf_ptr[0]) & 0xffff) << 8
			| (be32_to_cpu(buf_ptr[1]) & 0xff000000) >> 24;
	ver = be32_to_cpu(buf_ptr[1]) & 0xffffff;
	source_node_id = be32_to_cpu(buf_ptr[0]) >> 16;

	if (specifier_id == IANA_SPECIFIER_ID && ver == RFC2734_SW_VERSION) {
		buf_ptr += 2;
		length -= IEEE1394_GASP_HDR_SIZE;
		fwnet_incoming_packet(dev, buf_ptr, length,
				      source_node_id, -1, true);
	}

	packet.payload_length = dev->rcv_buffer_size;
	packet.interrupt = 1;
	packet.skip = 0;
	packet.tag = 3;
	packet.sy = 0;
	packet.header_length = IEEE1394_GASP_HDR_SIZE;

	spin_lock_irqsave(&dev->lock, flags);

	retval = fw_iso_context_queue(dev->broadcast_rcv_context, &packet,
				      &dev->broadcast_rcv_buffer, offset);

	spin_unlock_irqrestore(&dev->lock, flags);

	if (retval < 0)
		fw_error("requeue failed\n");
}

static struct kmem_cache *fwnet_packet_task_cache;

static int fwnet_send_packet(struct fwnet_packet_task *ptask);

static void fwnet_transmit_packet_done(struct fwnet_packet_task *ptask)
{
	struct fwnet_device *dev;
	unsigned long flags;

	dev = ptask->dev;

	spin_lock_irqsave(&dev->lock, flags);
	list_del(&ptask->pt_link);
	spin_unlock_irqrestore(&dev->lock, flags);

	ptask->outstanding_pkts--; /* FIXME access inside lock */

	if (ptask->outstanding_pkts > 0) {
		u16 dg_size;
		u16 fg_off;
		u16 datagram_label;
		u16 lf;
		struct sk_buff *skb;

		/* Update the ptask to point to the next fragment and send it */
		lf = fwnet_get_hdr_lf(&ptask->hdr);
		switch (lf) {
		case RFC2374_HDR_LASTFRAG:
		case RFC2374_HDR_UNFRAG:
		default:
			fw_error("Outstanding packet %x lf %x, header %x,%x\n",
				 ptask->outstanding_pkts, lf, ptask->hdr.w0,
				 ptask->hdr.w1);
			BUG();

		case RFC2374_HDR_FIRSTFRAG:
			/* Set frag type here for future interior fragments */
			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
			fg_off = ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
			break;

		case RFC2374_HDR_INTFRAG:
			dg_size = fwnet_get_hdr_dg_size(&ptask->hdr);
			fg_off = fwnet_get_hdr_fg_off(&ptask->hdr)
				  + ptask->max_payload - RFC2374_FRAG_HDR_SIZE;
			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
			break;
		}
		skb = ptask->skb;
		skb_pull(skb, ptask->max_payload);
		if (ptask->outstanding_pkts > 1) {
			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_INTFRAG,
					  dg_size, fg_off, datagram_label);
		} else {
			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_LASTFRAG,
					  dg_size, fg_off, datagram_label);
			ptask->max_payload = skb->len + RFC2374_FRAG_HDR_SIZE;
		}
		fwnet_send_packet(ptask);
	} else {
		dev_kfree_skb_any(ptask->skb);
		kmem_cache_free(fwnet_packet_task_cache, ptask);
	}
}

static void fwnet_write_complete(struct fw_card *card, int rcode,
				 void *payload, size_t length, void *data)
{
	struct fwnet_packet_task *ptask;

	ptask = data;

	if (rcode == RCODE_COMPLETE)
		fwnet_transmit_packet_done(ptask);
	else
		fw_error("fwnet_write_complete: failed: %x\n", rcode);
		/* ??? error recovery */
}

static int fwnet_send_packet(struct fwnet_packet_task *ptask)
{
	struct fwnet_device *dev;
	unsigned tx_len;
	struct rfc2734_header *bufhdr;
	unsigned long flags;

	dev = ptask->dev;
	tx_len = ptask->max_payload;
	switch (fwnet_get_hdr_lf(&ptask->hdr)) {
	case RFC2374_HDR_UNFRAG:
		bufhdr = (struct rfc2734_header *)
				skb_push(ptask->skb, RFC2374_UNFRAG_HDR_SIZE);
		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
		break;

	case RFC2374_HDR_FIRSTFRAG:
	case RFC2374_HDR_INTFRAG:
	case RFC2374_HDR_LASTFRAG:
		bufhdr = (struct rfc2734_header *)
				skb_push(ptask->skb, RFC2374_FRAG_HDR_SIZE);
		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
		put_unaligned_be32(ptask->hdr.w1, &bufhdr->w1);
		break;

	default:
		BUG();
	}
	if (ptask->dest_node == IEEE1394_ALL_NODES) {
		u8 *p;
		int generation;
		int node_id;

		/* ptask->generation may not have been set yet */
		generation = dev->card->generation;
		smp_rmb();
		node_id = dev->card->node_id;

		p = skb_push(ptask->skb, 8);
		put_unaligned_be32(node_id << 16 | IANA_SPECIFIER_ID >> 8, p);
		put_unaligned_be32((IANA_SPECIFIER_ID & 0xff) << 24
						| RFC2734_SW_VERSION, &p[4]);

		/* We should not transmit if broadcast_channel.valid == 0. */
		fw_send_request(dev->card, &ptask->transaction,
				TCODE_STREAM_DATA,
				fw_stream_packet_destination_id(3,
						IEEE1394_BROADCAST_CHANNEL, 0),
				generation, SCODE_100, 0ULL, ptask->skb->data,
				tx_len + 8, fwnet_write_complete, ptask);

		/* FIXME race? */
		spin_lock_irqsave(&dev->lock, flags);
		list_add_tail(&ptask->pt_link, &dev->broadcasted_list);
		spin_unlock_irqrestore(&dev->lock, flags);

		return 0;
	}

	fw_send_request(dev->card, &ptask->transaction,
			TCODE_WRITE_BLOCK_REQUEST, ptask->dest_node,
			ptask->generation, ptask->speed, ptask->fifo_addr,
			ptask->skb->data, tx_len, fwnet_write_complete, ptask);

	/* FIXME race? */
	spin_lock_irqsave(&dev->lock, flags);
	list_add_tail(&ptask->pt_link, &dev->sent_list);
	spin_unlock_irqrestore(&dev->lock, flags);

	dev->netdev->trans_start = jiffies;

	return 0;
}

static int fwnet_broadcast_start(struct fwnet_device *dev)
{
	struct fw_iso_context *context;
	int retval;
	unsigned num_packets;
	unsigned max_receive;
	struct fw_iso_packet packet;
	unsigned long offset;
	unsigned u;

	if (dev->local_fifo == FWNET_NO_FIFO_ADDR) {
		/* outside OHCI posted write area? */
		static const struct fw_address_region region = {
			.start = 0xffff00000000ULL,
			.end   = CSR_REGISTER_BASE,
		};

		dev->handler.length = 4096;
		dev->handler.address_callback = fwnet_receive_packet;
		dev->handler.callback_data = dev;

		retval = fw_core_add_address_handler(&dev->handler, &region);
		if (retval < 0)
			goto failed_initial;

		dev->local_fifo = dev->handler.offset;
	}

	max_receive = 1U << (dev->card->max_receive + 1);
	num_packets = (FWNET_ISO_PAGE_COUNT * PAGE_SIZE) / max_receive;

	if (!dev->broadcast_rcv_context) {
		void **ptrptr;

		context = fw_iso_context_create(dev->card,
		    FW_ISO_CONTEXT_RECEIVE, IEEE1394_BROADCAST_CHANNEL,
		    dev->card->link_speed, 8, fwnet_receive_broadcast, dev);
		if (IS_ERR(context)) {
			retval = PTR_ERR(context);
			goto failed_context_create;
		}

		retval = fw_iso_buffer_init(&dev->broadcast_rcv_buffer,
		    dev->card, FWNET_ISO_PAGE_COUNT, DMA_FROM_DEVICE);
		if (retval < 0)
			goto failed_buffer_init;

		ptrptr = kmalloc(sizeof(void *) * num_packets, GFP_KERNEL);
		if (!ptrptr) {
			retval = -ENOMEM;
			goto failed_ptrs_alloc;
		}

		dev->broadcast_rcv_buffer_ptrs = ptrptr;
		for (u = 0; u < FWNET_ISO_PAGE_COUNT; u++) {
			void *ptr;
			unsigned v;

			ptr = kmap(dev->broadcast_rcv_buffer.pages[u]);
			for (v = 0; v < num_packets / FWNET_ISO_PAGE_COUNT; v++)
				*ptrptr++ = (void *)
						((char *)ptr + v * max_receive);
		}
		dev->broadcast_rcv_context = context;
	} else {
		context = dev->broadcast_rcv_context;
	}

	packet.payload_length = max_receive;
	packet.interrupt = 1;
	packet.skip = 0;
	packet.tag = 3;
	packet.sy = 0;
	packet.header_length = IEEE1394_GASP_HDR_SIZE;
	offset = 0;

	for (u = 0; u < num_packets; u++) {
		retval = fw_iso_context_queue(context, &packet,
				&dev->broadcast_rcv_buffer, offset);
		if (retval < 0)
			goto failed_rcv_queue;

		offset += max_receive;
	}
	dev->num_broadcast_rcv_ptrs = num_packets;
	dev->rcv_buffer_size = max_receive;
	dev->broadcast_rcv_next_ptr = 0U;
	retval = fw_iso_context_start(context, -1, 0,
			FW_ISO_CONTEXT_MATCH_ALL_TAGS); /* ??? sync */
	if (retval < 0)
		goto failed_rcv_queue;

	/* FIXME: adjust it according to the min. speed of all known peers? */
	dev->broadcast_xmt_max_payload = IEEE1394_MAX_PAYLOAD_S100
			- IEEE1394_GASP_HDR_SIZE - RFC2374_UNFRAG_HDR_SIZE;
	dev->broadcast_state = FWNET_BROADCAST_RUNNING;

	return 0;

 failed_rcv_queue:
	kfree(dev->broadcast_rcv_buffer_ptrs);
	dev->broadcast_rcv_buffer_ptrs = NULL;
 failed_ptrs_alloc:
	fw_iso_buffer_destroy(&dev->broadcast_rcv_buffer, dev->card);
 failed_buffer_init:
	fw_iso_context_destroy(context);
	dev->broadcast_rcv_context = NULL;
 failed_context_create:
	fw_core_remove_address_handler(&dev->handler);
 failed_initial:
	dev->local_fifo = FWNET_NO_FIFO_ADDR;

	return retval;
}

/* ifup */
static int fwnet_open(struct net_device *net)
{
	struct fwnet_device *dev = netdev_priv(net);
	int ret;

	if (dev->broadcast_state == FWNET_BROADCAST_ERROR) {
		ret = fwnet_broadcast_start(dev);
		if (ret)
			return ret;
	}
	netif_start_queue(net);

	return 0;
}

/* ifdown */
static int fwnet_stop(struct net_device *net)
{
	netif_stop_queue(net);

	/* Deallocate iso context for use by other applications? */

	return 0;
}

static netdev_tx_t fwnet_tx(struct sk_buff *skb, struct net_device *net)
{
	struct fwnet_header hdr_buf;
	struct fwnet_device *dev = netdev_priv(net);
	__be16 proto;
	u16 dest_node;
	unsigned max_payload;
	u16 dg_size;
	u16 *datagram_label_ptr;
	struct fwnet_packet_task *ptask;
	struct fwnet_peer *peer;
	unsigned long flags;

	ptask = kmem_cache_alloc(fwnet_packet_task_cache, GFP_ATOMIC);
	if (ptask == NULL)
		goto fail;

	skb = skb_share_check(skb, GFP_ATOMIC);
	if (!skb)
		goto fail;

	/*
	 * Make a copy of the driver-specific header.
	 * We might need to rebuild the header on tx failure.
	 */
	memcpy(&hdr_buf, skb->data, sizeof(hdr_buf));
	skb_pull(skb, sizeof(hdr_buf));

	proto = hdr_buf.h_proto;
	dg_size = skb->len;

	/* serialize access to peer, including peer->datagram_label */
	spin_lock_irqsave(&dev->lock, flags);

	/*
	 * Set the transmission type for the packet.  ARP packets and IP
	 * broadcast packets are sent via GASP.
	 */
	if (memcmp(hdr_buf.h_dest, net->broadcast, FWNET_ALEN) == 0
	    || proto == htons(ETH_P_ARP)
	    || (proto == htons(ETH_P_IP)
		&& IN_MULTICAST(ntohl(ip_hdr(skb)->daddr)))) {
		max_payload        = dev->broadcast_xmt_max_payload;
		datagram_label_ptr = &dev->broadcast_xmt_datagramlabel;

		ptask->fifo_addr   = FWNET_NO_FIFO_ADDR;
		ptask->generation  = 0;
		ptask->dest_node   = IEEE1394_ALL_NODES;
		ptask->speed       = SCODE_100;
	} else {
		__be64 guid = get_unaligned((__be64 *)hdr_buf.h_dest);
		u8 generation;

		peer = fwnet_peer_find_by_guid(dev, be64_to_cpu(guid));
		if (!peer || peer->fifo == FWNET_NO_FIFO_ADDR)
			goto fail_unlock;

		generation         = peer->generation;
		dest_node          = peer->node_id;
		max_payload        = peer->max_payload;
		datagram_label_ptr = &peer->datagram_label;

		ptask->fifo_addr   = peer->fifo;
		ptask->generation  = generation;
		ptask->dest_node   = dest_node;
		ptask->speed       = peer->speed;
	}

	/* If this is an ARP packet, convert it */
	if (proto == htons(ETH_P_ARP)) {
		struct arphdr *arp = (struct arphdr *)skb->data;
		unsigned char *arp_ptr = (unsigned char *)(arp + 1);
		struct rfc2734_arp *arp1394 = (struct rfc2734_arp *)skb->data;
		__be32 ipaddr;

		ipaddr = get_unaligned((__be32 *)(arp_ptr + FWNET_ALEN));

		arp1394->hw_addr_len    = RFC2734_HW_ADDR_LEN;
		arp1394->max_rec        = dev->card->max_receive;
		arp1394->sspd		= dev->card->link_speed;

		put_unaligned_be16(dev->local_fifo >> 32,
				   &arp1394->fifo_hi);
		put_unaligned_be32(dev->local_fifo & 0xffffffff,
				   &arp1394->fifo_lo);
		put_unaligned(ipaddr, &arp1394->sip);
	}

	ptask->hdr.w0 = 0;
	ptask->hdr.w1 = 0;
	ptask->skb = skb;
	ptask->dev = dev;

	/* Does it all fit in one packet? */
	if (dg_size <= max_payload) {
		fwnet_make_uf_hdr(&ptask->hdr, ntohs(proto));
		ptask->outstanding_pkts = 1;
		max_payload = dg_size + RFC2374_UNFRAG_HDR_SIZE;
	} else {
		u16 datagram_label;

		max_payload -= RFC2374_FRAG_OVERHEAD;
		datagram_label = (*datagram_label_ptr)++;
		fwnet_make_ff_hdr(&ptask->hdr, ntohs(proto), dg_size,
				  datagram_label);
		ptask->outstanding_pkts = DIV_ROUND_UP(dg_size, max_payload);
		max_payload += RFC2374_FRAG_HDR_SIZE;
	}

	spin_unlock_irqrestore(&dev->lock, flags);

	ptask->max_payload = max_payload;
	fwnet_send_packet(ptask);

	return NETDEV_TX_OK;

 fail_unlock:
	spin_unlock_irqrestore(&dev->lock, flags);
 fail:
	if (ptask)
		kmem_cache_free(fwnet_packet_task_cache, ptask);

	if (skb != NULL)
		dev_kfree_skb(skb);

	net->stats.tx_dropped++;
	net->stats.tx_errors++;

	/*
	 * FIXME: According to a patch from 2003-02-26, "returning non-zero
	 * causes serious problems" here, allegedly.  Before that patch,
	 * -ERRNO was returned which is not appropriate under Linux 2.6.
	 * Perhaps more needs to be done?  Stop the queue in serious
	 * conditions and restart it elsewhere?
	 */
	return NETDEV_TX_OK;
}

static int fwnet_change_mtu(struct net_device *net, int new_mtu)
{
	if (new_mtu < 68)
		return -EINVAL;

	net->mtu = new_mtu;
	return 0;
}

static void fwnet_get_drvinfo(struct net_device *net,
			      struct ethtool_drvinfo *info)
{
	strcpy(info->driver, KBUILD_MODNAME);
	strcpy(info->bus_info, "ieee1394");
}

static struct ethtool_ops fwnet_ethtool_ops = {
	.get_drvinfo = fwnet_get_drvinfo,
};

static const struct net_device_ops fwnet_netdev_ops = {
	.ndo_open       = fwnet_open,
	.ndo_stop	= fwnet_stop,
	.ndo_start_xmit = fwnet_tx,
	.ndo_change_mtu = fwnet_change_mtu,
};

static void fwnet_init_dev(struct net_device *net)
{
	net->header_ops		= &fwnet_header_ops;
	net->netdev_ops		= &fwnet_netdev_ops;
	net->watchdog_timeo	= 2 * HZ;
	net->flags		= IFF_BROADCAST | IFF_MULTICAST;
	net->features		= NETIF_F_HIGHDMA;
	net->addr_len		= FWNET_ALEN;
	net->hard_header_len	= FWNET_HLEN;
	net->type		= ARPHRD_IEEE1394;
	net->tx_queue_len	= 10;
	SET_ETHTOOL_OPS(net, &fwnet_ethtool_ops);
}

/* caller must hold fwnet_device_mutex */
static struct fwnet_device *fwnet_dev_find(struct fw_card *card)
{
	struct fwnet_device *dev;

	list_for_each_entry(dev, &fwnet_device_list, dev_link)
		if (dev->card == card)
			return dev;

	return NULL;
}

static int fwnet_add_peer(struct fwnet_device *dev,
			  struct fw_unit *unit, struct fw_device *device)
{
	struct fwnet_peer *peer;

	peer = kmalloc(sizeof(*peer), GFP_KERNEL);
	if (!peer)
		return -ENOMEM;

	dev_set_drvdata(&unit->device, peer);

	peer->dev = dev;
	peer->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
	peer->fifo = FWNET_NO_FIFO_ADDR;
	INIT_LIST_HEAD(&peer->pd_list);
	peer->pdg_size = 0;
	peer->datagram_label = 0;
	peer->speed = device->max_speed;
	peer->max_payload = fwnet_max_payload(device->max_rec, peer->speed);

	peer->generation = device->generation;
	smp_rmb();
	peer->node_id = device->node_id;

	spin_lock_irq(&dev->lock);
	list_add_tail(&peer->peer_link, &dev->peer_list);
	spin_unlock_irq(&dev->lock);

	return 0;
}

static int fwnet_probe(struct device *_dev)
{
	struct fw_unit *unit = fw_unit(_dev);
	struct fw_device *device = fw_parent_device(unit);
	struct fw_card *card = device->card;
	struct net_device *net;
	bool allocated_netdev = false;
	struct fwnet_device *dev;
	unsigned max_mtu;
	int ret;

	mutex_lock(&fwnet_device_mutex);

	dev = fwnet_dev_find(card);
	if (dev) {
		net = dev->netdev;
		goto have_dev;
	}

	net = alloc_netdev(sizeof(*dev), "firewire%d", fwnet_init_dev);
	if (net == NULL) {
		ret = -ENOMEM;
		goto out;
	}

	allocated_netdev = true;
	SET_NETDEV_DEV(net, card->device);
	dev = netdev_priv(net);

	spin_lock_init(&dev->lock);
	dev->broadcast_state = FWNET_BROADCAST_ERROR;
	dev->broadcast_rcv_context = NULL;
	dev->broadcast_xmt_max_payload = 0;
	dev->broadcast_xmt_datagramlabel = 0;

	dev->local_fifo = FWNET_NO_FIFO_ADDR;

	INIT_LIST_HEAD(&dev->packet_list);
	INIT_LIST_HEAD(&dev->broadcasted_list);
	INIT_LIST_HEAD(&dev->sent_list);
	INIT_LIST_HEAD(&dev->peer_list);

	dev->card = card;
	dev->netdev = net;

	/*
	 * Use the RFC 2734 default 1500 octets or the maximum payload
	 * as initial MTU
	 */
	max_mtu = (1 << (card->max_receive + 1))
		  - sizeof(struct rfc2734_header) - IEEE1394_GASP_HDR_SIZE;
	net->mtu = min(1500U, max_mtu);

	/* Set our hardware address while we're at it */
	put_unaligned_be64(card->guid, net->dev_addr);
	put_unaligned_be64(~0ULL, net->broadcast);
	ret = register_netdev(net);
	if (ret) {
		fw_error("Cannot register the driver\n");
		goto out;
	}

	list_add_tail(&dev->dev_link, &fwnet_device_list);
	fw_notify("%s: IPv4 over FireWire on device %016llx\n",
		  net->name, (unsigned long long)card->guid);
 have_dev:
	ret = fwnet_add_peer(dev, unit, device);
	if (ret && allocated_netdev) {
		unregister_netdev(net);
		list_del(&dev->dev_link);
	}
 out:
	if (ret && allocated_netdev)
		free_netdev(net);

	mutex_unlock(&fwnet_device_mutex);

	return ret;
}

static void fwnet_remove_peer(struct fwnet_peer *peer)
{
	struct fwnet_partial_datagram *pd, *pd_next;

	spin_lock_irq(&peer->dev->lock);
	list_del(&peer->peer_link);
	spin_unlock_irq(&peer->dev->lock);

	list_for_each_entry_safe(pd, pd_next, &peer->pd_list, pd_link)
		fwnet_pd_delete(pd);

	kfree(peer);
}

static int fwnet_remove(struct device *_dev)
{
	struct fwnet_peer *peer = dev_get_drvdata(_dev);
	struct fwnet_device *dev = peer->dev;
	struct net_device *net;
	struct fwnet_packet_task *ptask, *pt_next;

	mutex_lock(&fwnet_device_mutex);

	fwnet_remove_peer(peer);

	if (list_empty(&dev->peer_list)) {
		net = dev->netdev;
		unregister_netdev(net);

		if (dev->local_fifo != FWNET_NO_FIFO_ADDR)
			fw_core_remove_address_handler(&dev->handler);
		if (dev->broadcast_rcv_context) {
			fw_iso_context_stop(dev->broadcast_rcv_context);
			fw_iso_buffer_destroy(&dev->broadcast_rcv_buffer,
					      dev->card);
			fw_iso_context_destroy(dev->broadcast_rcv_context);
		}
		list_for_each_entry_safe(ptask, pt_next,
					 &dev->packet_list, pt_link) {
			dev_kfree_skb_any(ptask->skb);
			kmem_cache_free(fwnet_packet_task_cache, ptask);
		}
		list_for_each_entry_safe(ptask, pt_next,
					 &dev->broadcasted_list, pt_link) {
			dev_kfree_skb_any(ptask->skb);
			kmem_cache_free(fwnet_packet_task_cache, ptask);
		}
		list_for_each_entry_safe(ptask, pt_next,
					 &dev->sent_list, pt_link) {
			dev_kfree_skb_any(ptask->skb);
			kmem_cache_free(fwnet_packet_task_cache, ptask);
		}
		list_del(&dev->dev_link);

		free_netdev(net);
	}

	mutex_unlock(&fwnet_device_mutex);

	return 0;
}

/*
 * FIXME abort partially sent fragmented datagrams,
 * discard partially received fragmented datagrams
 */
static void fwnet_update(struct fw_unit *unit)
{
	struct fw_device *device = fw_parent_device(unit);
	struct fwnet_peer *peer = dev_get_drvdata(&unit->device);
	int generation;

	generation = device->generation;

	spin_lock_irq(&peer->dev->lock);
	peer->node_id    = device->node_id;
	peer->generation = generation;
	spin_unlock_irq(&peer->dev->lock);
}

static const struct ieee1394_device_id fwnet_id_table[] = {
	{
		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
				IEEE1394_MATCH_VERSION,
		.specifier_id = IANA_SPECIFIER_ID,
		.version      = RFC2734_SW_VERSION,
	},
	{ }
};

static struct fw_driver fwnet_driver = {
	.driver = {
		.owner  = THIS_MODULE,
		.name   = "net",
		.bus    = &fw_bus_type,
		.probe  = fwnet_probe,
		.remove = fwnet_remove,
	},
	.update   = fwnet_update,
	.id_table = fwnet_id_table,
};

static const u32 rfc2374_unit_directory_data[] = {
	0x00040000,	/* directory_length		*/
	0x1200005e,	/* unit_specifier_id: IANA	*/
	0x81000003,	/* textual descriptor offset	*/
	0x13000001,	/* unit_sw_version: RFC 2734	*/
	0x81000005,	/* textual descriptor offset	*/
	0x00030000,	/* descriptor_length		*/
	0x00000000,	/* text				*/
	0x00000000,	/* minimal ASCII, en		*/
	0x49414e41,	/* I A N A			*/
	0x00030000,	/* descriptor_length		*/
	0x00000000,	/* text				*/
	0x00000000,	/* minimal ASCII, en		*/
	0x49507634,	/* I P v 4			*/
};

static struct fw_descriptor rfc2374_unit_directory = {
	.length = ARRAY_SIZE(rfc2374_unit_directory_data),
	.key    = (CSR_DIRECTORY | CSR_UNIT) << 24,
	.data   = rfc2374_unit_directory_data
};

static int __init fwnet_init(void)
{
	int err;

	err = fw_core_add_descriptor(&rfc2374_unit_directory);
	if (err)
		return err;

	fwnet_packet_task_cache = kmem_cache_create("packet_task",
			sizeof(struct fwnet_packet_task), 0, 0, NULL);
	if (!fwnet_packet_task_cache) {
		err = -ENOMEM;
		goto out;
	}

	err = driver_register(&fwnet_driver.driver);
	if (!err)
		return 0;

	kmem_cache_destroy(fwnet_packet_task_cache);
out:
	fw_core_remove_descriptor(&rfc2374_unit_directory);

	return err;
}
module_init(fwnet_init);

static void __exit fwnet_cleanup(void)
{
	driver_unregister(&fwnet_driver.driver);
	kmem_cache_destroy(fwnet_packet_task_cache);
	fw_core_remove_descriptor(&rfc2374_unit_directory);
}
module_exit(fwnet_cleanup);

MODULE_AUTHOR("Jay Fenlason <fenlason@redhat.com>");
MODULE_DESCRIPTION("IPv4 over IEEE1394 as per RFC 2734");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(ieee1394, fwnet_id_table);