Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes
[linux-2.6] / drivers / net / arcnet / rfc1201.c
1 /*
2  * Linux ARCnet driver - RFC1201 (standard) packet encapsulation
3  * 
4  * Written 1994-1999 by Avery Pennarun.
5  * Derived from skeleton.c by Donald Becker.
6  *
7  * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
8  *  for sponsoring the further development of this driver.
9  *
10  * **********************
11  *
12  * The original copyright of skeleton.c was as follows:
13  *
14  * skeleton.c Written 1993 by Donald Becker.
15  * Copyright 1993 United States Government as represented by the
16  * Director, National Security Agency.  This software may only be used
17  * and distributed according to the terms of the GNU General Public License as
18  * modified by SRC, incorporated herein by reference.
19  *
20  * **********************
21  *
22  * For more details, see drivers/net/arcnet.c
23  *
24  * **********************
25  */
26 #include <linux/module.h>
27 #include <linux/init.h>
28 #include <linux/if_arp.h>
29 #include <linux/netdevice.h>
30 #include <linux/skbuff.h>
31 #include <linux/arcdevice.h>
32
33 MODULE_LICENSE("GPL");
34 #define VERSION "arcnet: RFC1201 \"standard\" (`a') encapsulation support loaded.\n"
35
36
37 static __be16 type_trans(struct sk_buff *skb, struct net_device *dev);
38 static void rx(struct net_device *dev, int bufnum,
39                struct archdr *pkthdr, int length);
40 static int build_header(struct sk_buff *skb, struct net_device *dev,
41                         unsigned short type, uint8_t daddr);
42 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
43                       int bufnum);
44 static int continue_tx(struct net_device *dev, int bufnum);
45
46 static struct ArcProto rfc1201_proto =
47 {
48         .suffix         = 'a',
49         .mtu            = 1500, /* could be more, but some receivers can't handle it... */
50         .is_ip          = 1,    /* This is for sending IP and ARP packages */
51         .rx             = rx,
52         .build_header   = build_header,
53         .prepare_tx     = prepare_tx,
54         .continue_tx    = continue_tx,
55         .ack_tx         = NULL
56 };
57
58
59 static int __init arcnet_rfc1201_init(void)
60 {
61         printk(VERSION);
62
63         arc_proto_map[ARC_P_IP]
64             = arc_proto_map[ARC_P_IPV6]
65             = arc_proto_map[ARC_P_ARP]
66             = arc_proto_map[ARC_P_RARP]
67             = arc_proto_map[ARC_P_IPX]
68             = arc_proto_map[ARC_P_NOVELL_EC]
69             = &rfc1201_proto;
70
71         /* if someone else already owns the broadcast, we won't take it */
72         if (arc_bcast_proto == arc_proto_default)
73                 arc_bcast_proto = &rfc1201_proto;
74
75         return 0;
76 }
77
78 static void __exit arcnet_rfc1201_exit(void)
79 {
80         arcnet_unregister_proto(&rfc1201_proto);
81 }
82
83 module_init(arcnet_rfc1201_init);
84 module_exit(arcnet_rfc1201_exit);
85
86 /*
87  * Determine a packet's protocol ID.
88  * 
89  * With ARCnet we have to convert everything to Ethernet-style stuff.
90  */
91 static __be16 type_trans(struct sk_buff *skb, struct net_device *dev)
92 {
93         struct archdr *pkt = (struct archdr *) skb->data;
94         struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
95         int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
96
97         /* Pull off the arcnet header. */
98         skb_reset_mac_header(skb);
99         skb_pull(skb, hdr_size);
100
101         if (pkt->hard.dest == 0)
102                 skb->pkt_type = PACKET_BROADCAST;
103         else if (dev->flags & IFF_PROMISC) {
104                 /* if we're not sending to ourselves :) */
105                 if (pkt->hard.dest != dev->dev_addr[0])
106                         skb->pkt_type = PACKET_OTHERHOST;
107         }
108         /* now return the protocol number */
109         switch (soft->proto) {
110         case ARC_P_IP:
111                 return htons(ETH_P_IP);
112         case ARC_P_IPV6:
113                 return htons(ETH_P_IPV6);
114         case ARC_P_ARP:
115                 return htons(ETH_P_ARP);
116         case ARC_P_RARP:
117                 return htons(ETH_P_RARP);
118
119         case ARC_P_IPX:
120         case ARC_P_NOVELL_EC:
121                 return htons(ETH_P_802_3);
122         default:
123                 dev->stats.rx_errors++;
124                 dev->stats.rx_crc_errors++;
125                 return 0;
126         }
127
128         return htons(ETH_P_IP);
129 }
130
131
132 /* packet receiver */
133 static void rx(struct net_device *dev, int bufnum,
134                struct archdr *pkthdr, int length)
135 {
136         struct arcnet_local *lp = netdev_priv(dev);
137         struct sk_buff *skb;
138         struct archdr *pkt = pkthdr;
139         struct arc_rfc1201 *soft = &pkthdr->soft.rfc1201;
140         int saddr = pkt->hard.source, ofs;
141         struct Incoming *in = &lp->rfc1201.incoming[saddr];
142
143         BUGMSG(D_DURING, "it's an RFC1201 packet (length=%d)\n", length);
144
145         if (length >= MinTU)
146                 ofs = 512 - length;
147         else
148                 ofs = 256 - length;
149
150         if (soft->split_flag == 0xFF) {         /* Exception Packet */
151                 if (length >= 4 + RFC1201_HDR_SIZE)
152                         BUGMSG(D_DURING, "compensating for exception packet\n");
153                 else {
154                         BUGMSG(D_EXTRA, "short RFC1201 exception packet from %02Xh",
155                                saddr);
156                         return;
157                 }
158
159                 /* skip over 4-byte junkola */
160                 length -= 4;
161                 ofs += 4;
162                 lp->hw.copy_from_card(dev, bufnum, 512 - length,
163                                       soft, sizeof(pkt->soft));
164         }
165         if (!soft->split_flag) {        /* not split */
166                 BUGMSG(D_RX, "incoming is not split (splitflag=%d)\n",
167                        soft->split_flag);
168
169                 if (in->skb) {  /* already assembling one! */
170                         BUGMSG(D_EXTRA, "aborting assembly (seq=%d) for unsplit packet (splitflag=%d, seq=%d)\n",
171                          in->sequence, soft->split_flag, soft->sequence);
172                         lp->rfc1201.aborted_seq = soft->sequence;
173                         dev_kfree_skb_irq(in->skb);
174                         dev->stats.rx_errors++;
175                         dev->stats.rx_missed_errors++;
176                         in->skb = NULL;
177                 }
178                 in->sequence = soft->sequence;
179
180                 skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
181                 if (skb == NULL) {
182                         BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
183                         dev->stats.rx_dropped++;
184                         return;
185                 }
186                 skb_put(skb, length + ARC_HDR_SIZE);
187                 skb->dev = dev;
188
189                 pkt = (struct archdr *) skb->data;
190                 soft = &pkt->soft.rfc1201;
191
192                 /* up to sizeof(pkt->soft) has already been copied from the card */
193                 memcpy(pkt, pkthdr, sizeof(struct archdr));
194                 if (length > sizeof(pkt->soft))
195                         lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
196                                        pkt->soft.raw + sizeof(pkt->soft),
197                                               length - sizeof(pkt->soft));
198
199                 /*
200                  * ARP packets have problems when sent from some DOS systems: the
201                  * source address is always 0!  So we take the hardware source addr
202                  * (which is impossible to fumble) and insert it ourselves.
203                  */
204                 if (soft->proto == ARC_P_ARP) {
205                         struct arphdr *arp = (struct arphdr *) soft->payload;
206
207                         /* make sure addresses are the right length */
208                         if (arp->ar_hln == 1 && arp->ar_pln == 4) {
209                                 uint8_t *cptr = (uint8_t *) arp + sizeof(struct arphdr);
210
211                                 if (!*cptr) {   /* is saddr = 00? */
212                                         BUGMSG(D_EXTRA,
213                                                "ARP source address was 00h, set to %02Xh.\n",
214                                                saddr);
215                                         dev->stats.rx_crc_errors++;
216                                         *cptr = saddr;
217                                 } else {
218                                         BUGMSG(D_DURING, "ARP source address (%Xh) is fine.\n",
219                                                *cptr);
220                                 }
221                         } else {
222                                 BUGMSG(D_NORMAL, "funny-shaped ARP packet. (%Xh, %Xh)\n",
223                                        arp->ar_hln, arp->ar_pln);
224                                 dev->stats.rx_errors++;
225                                 dev->stats.rx_crc_errors++;
226                         }
227                 }
228                 BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
229
230                 skb->protocol = type_trans(skb, dev);
231                 netif_rx(skb);
232         } else {                /* split packet */
233                 /*
234                  * NOTE: MSDOS ARP packet correction should only need to apply to
235                  * unsplit packets, since ARP packets are so short.
236                  *
237                  * My interpretation of the RFC1201 document is that if a packet is
238                  * received out of order, the entire assembly process should be
239                  * aborted.
240                  *
241                  * The RFC also mentions "it is possible for successfully received
242                  * packets to be retransmitted." As of 0.40 all previously received
243                  * packets are allowed, not just the most recent one.
244                  *
245                  * We allow multiple assembly processes, one for each ARCnet card
246                  * possible on the network.  Seems rather like a waste of memory,
247                  * but there's no other way to be reliable.
248                  */
249
250                 BUGMSG(D_RX, "packet is split (splitflag=%d, seq=%d)\n",
251                        soft->split_flag, in->sequence);
252
253                 if (in->skb && in->sequence != soft->sequence) {
254                         BUGMSG(D_EXTRA, "wrong seq number (saddr=%d, expected=%d, seq=%d, splitflag=%d)\n",
255                                saddr, in->sequence, soft->sequence,
256                                soft->split_flag);
257                         dev_kfree_skb_irq(in->skb);
258                         in->skb = NULL;
259                         dev->stats.rx_errors++;
260                         dev->stats.rx_missed_errors++;
261                         in->lastpacket = in->numpackets = 0;
262                 }
263                 if (soft->split_flag & 1) {     /* first packet in split */
264                         BUGMSG(D_RX, "brand new splitpacket (splitflag=%d)\n",
265                                soft->split_flag);
266                         if (in->skb) {  /* already assembling one! */
267                                 BUGMSG(D_EXTRA, "aborting previous (seq=%d) assembly "
268                                        "(splitflag=%d, seq=%d)\n",
269                                        in->sequence, soft->split_flag,
270                                        soft->sequence);
271                                 dev->stats.rx_errors++;
272                                 dev->stats.rx_missed_errors++;
273                                 dev_kfree_skb_irq(in->skb);
274                         }
275                         in->sequence = soft->sequence;
276                         in->numpackets = ((unsigned) soft->split_flag >> 1) + 2;
277                         in->lastpacket = 1;
278
279                         if (in->numpackets > 16) {
280                                 BUGMSG(D_EXTRA, "incoming packet more than 16 segments; dropping. (splitflag=%d)\n",
281                                        soft->split_flag);
282                                 lp->rfc1201.aborted_seq = soft->sequence;
283                                 dev->stats.rx_errors++;
284                                 dev->stats.rx_length_errors++;
285                                 return;
286                         }
287                         in->skb = skb = alloc_skb(508 * in->numpackets + ARC_HDR_SIZE,
288                                                   GFP_ATOMIC);
289                         if (skb == NULL) {
290                                 BUGMSG(D_NORMAL, "(split) memory squeeze, dropping packet.\n");
291                                 lp->rfc1201.aborted_seq = soft->sequence;
292                                 dev->stats.rx_dropped++;
293                                 return;
294                         }
295                         skb->dev = dev;
296                         pkt = (struct archdr *) skb->data;
297                         soft = &pkt->soft.rfc1201;
298
299                         memcpy(pkt, pkthdr, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
300                         skb_put(skb, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
301
302                         soft->split_flag = 0;   /* end result won't be split */
303                 } else {        /* not first packet */
304                         int packetnum = ((unsigned) soft->split_flag >> 1) + 1;
305
306                         /*
307                          * if we're not assembling, there's no point trying to
308                          * continue.
309                          */
310                         if (!in->skb) {
311                                 if (lp->rfc1201.aborted_seq != soft->sequence) {
312                                         BUGMSG(D_EXTRA, "can't continue split without starting "
313                                                "first! (splitflag=%d, seq=%d, aborted=%d)\n",
314                                         soft->split_flag, soft->sequence,
315                                                lp->rfc1201.aborted_seq);
316                                         dev->stats.rx_errors++;
317                                         dev->stats.rx_missed_errors++;
318                                 }
319                                 return;
320                         }
321                         in->lastpacket++;
322                         if (packetnum != in->lastpacket) {      /* not the right flag! */
323                                 /* harmless duplicate? ignore. */
324                                 if (packetnum <= in->lastpacket - 1) {
325                                         BUGMSG(D_EXTRA, "duplicate splitpacket ignored! (splitflag=%d)\n",
326                                                soft->split_flag);
327                                         dev->stats.rx_errors++;
328                                         dev->stats.rx_frame_errors++;
329                                         return;
330                                 }
331                                 /* "bad" duplicate, kill reassembly */
332                                 BUGMSG(D_EXTRA, "out-of-order splitpacket, reassembly "
333                                        "(seq=%d) aborted (splitflag=%d, seq=%d)\n",
334                                        in->sequence, soft->split_flag, soft->sequence);
335                                 lp->rfc1201.aborted_seq = soft->sequence;
336                                 dev_kfree_skb_irq(in->skb);
337                                 in->skb = NULL;
338                                 dev->stats.rx_errors++;
339                                 dev->stats.rx_missed_errors++;
340                                 in->lastpacket = in->numpackets = 0;
341                                 return;
342                         }
343                         pkt = (struct archdr *) in->skb->data;
344                         soft = &pkt->soft.rfc1201;
345                 }
346
347                 skb = in->skb;
348
349                 lp->hw.copy_from_card(dev, bufnum, ofs + RFC1201_HDR_SIZE,
350                                       skb->data + skb->len,
351                                       length - RFC1201_HDR_SIZE);
352                 skb_put(skb, length - RFC1201_HDR_SIZE);
353
354                 /* are we done? */
355                 if (in->lastpacket == in->numpackets) {
356                         in->skb = NULL;
357                         in->lastpacket = in->numpackets = 0;
358
359             BUGMSG(D_SKB_SIZE, "skb: received %d bytes from %02X (unsplit)\n",
360                 skb->len, pkt->hard.source);
361             BUGMSG(D_SKB_SIZE, "skb: received %d bytes from %02X (split)\n",
362                 skb->len, pkt->hard.source);
363                         BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
364
365                         skb->protocol = type_trans(skb, dev);
366                         netif_rx(skb);
367                 }
368         }
369 }
370
371
372 /* Create the ARCnet hard/soft headers for RFC1201. */
373 static int build_header(struct sk_buff *skb, struct net_device *dev,
374                         unsigned short type, uint8_t daddr)
375 {
376         struct arcnet_local *lp = netdev_priv(dev);
377         int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
378         struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size);
379         struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
380
381         /* set the protocol ID according to RFC1201 */
382         switch (type) {
383         case ETH_P_IP:
384                 soft->proto = ARC_P_IP;
385                 break;
386         case ETH_P_IPV6:
387                 soft->proto = ARC_P_IPV6;
388                 break;
389         case ETH_P_ARP:
390                 soft->proto = ARC_P_ARP;
391                 break;
392         case ETH_P_RARP:
393                 soft->proto = ARC_P_RARP;
394                 break;
395         case ETH_P_IPX:
396         case ETH_P_802_3:
397         case ETH_P_802_2:
398                 soft->proto = ARC_P_IPX;
399                 break;
400         case ETH_P_ATALK:
401                 soft->proto = ARC_P_ATALK;
402                 break;
403         default:
404                 BUGMSG(D_NORMAL, "RFC1201: I don't understand protocol %d (%Xh)\n",
405                        type, type);
406                 dev->stats.tx_errors++;
407                 dev->stats.tx_aborted_errors++;
408                 return 0;
409         }
410
411         /*
412          * Set the source hardware address.
413          *
414          * This is pretty pointless for most purposes, but it can help in
415          * debugging.  ARCnet does not allow us to change the source address in
416          * the actual packet sent)
417          */
418         pkt->hard.source = *dev->dev_addr;
419
420         soft->sequence = htons(lp->rfc1201.sequence++);
421         soft->split_flag = 0;   /* split packets are done elsewhere */
422
423         /* see linux/net/ethernet/eth.c to see where I got the following */
424
425         if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
426                 /* 
427                  * FIXME: fill in the last byte of the dest ipaddr here to better
428                  * comply with RFC1051 in "noarp" mode.  For now, always broadcasting
429                  * will probably at least get packets sent out :)
430                  */
431                 pkt->hard.dest = 0;
432                 return hdr_size;
433         }
434         /* otherwise, drop in the dest address */
435         pkt->hard.dest = daddr;
436         return hdr_size;
437 }
438
439
440 static void load_pkt(struct net_device *dev, struct arc_hardware *hard,
441                      struct arc_rfc1201 *soft, int softlen, int bufnum)
442 {
443         struct arcnet_local *lp = netdev_priv(dev);
444         int ofs;
445
446         /* assume length <= XMTU: someone should have handled that by now. */
447
448         if (softlen > MinTU) {
449                 hard->offset[0] = 0;
450                 hard->offset[1] = ofs = 512 - softlen;
451         } else if (softlen > MTU) {     /* exception packet - add an extra header */
452                 struct arc_rfc1201 excsoft;
453
454                 excsoft.proto = soft->proto;
455                 excsoft.split_flag = 0xff;
456                 excsoft.sequence = htons(0xffff);
457
458                 hard->offset[0] = 0;
459                 ofs = 512 - softlen;
460                 hard->offset[1] = ofs - RFC1201_HDR_SIZE;
461                 lp->hw.copy_to_card(dev, bufnum, ofs - RFC1201_HDR_SIZE,
462                                     &excsoft, RFC1201_HDR_SIZE);
463         } else
464                 hard->offset[0] = ofs = 256 - softlen;
465
466         lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
467         lp->hw.copy_to_card(dev, bufnum, ofs, soft, softlen);
468
469         lp->lastload_dest = hard->dest;
470 }
471
472
473 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
474                       int bufnum)
475 {
476         struct arcnet_local *lp = netdev_priv(dev);
477         const int maxsegsize = XMTU - RFC1201_HDR_SIZE;
478         struct Outgoing *out;
479
480
481         BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
482                lp->next_tx, lp->cur_tx, bufnum);
483
484         length -= ARC_HDR_SIZE; /* hard header is not included in packet length */
485         pkt->soft.rfc1201.split_flag = 0;
486
487         /* need to do a split packet? */
488         if (length > XMTU) {
489                 out = &lp->outgoing;
490
491                 out->length = length - RFC1201_HDR_SIZE;
492                 out->dataleft = lp->outgoing.length;
493                 out->numsegs = (out->dataleft + maxsegsize - 1) / maxsegsize;
494                 out->segnum = 0;
495
496                 BUGMSG(D_DURING, "rfc1201 prep_tx: ready for %d-segment split "
497                        "(%d bytes, seq=%d)\n", out->numsegs, out->length,
498                        pkt->soft.rfc1201.sequence);
499
500                 return 0;       /* not done */
501         }
502         /* just load the packet into the buffers and send it off */
503         load_pkt(dev, &pkt->hard, &pkt->soft.rfc1201, length, bufnum);
504
505         return 1;               /* done */
506 }
507
508
509 static int continue_tx(struct net_device *dev, int bufnum)
510 {
511         struct arcnet_local *lp = netdev_priv(dev);
512         struct Outgoing *out = &lp->outgoing;
513         struct arc_hardware *hard = &out->pkt->hard;
514         struct arc_rfc1201 *soft = &out->pkt->soft.rfc1201, *newsoft;
515         int maxsegsize = XMTU - RFC1201_HDR_SIZE;
516         int seglen;
517
518         BUGMSG(D_DURING,
519           "rfc1201 continue_tx: loading segment %d(+1) of %d (seq=%d)\n",
520                out->segnum, out->numsegs, soft->sequence);
521
522         /* the "new" soft header comes right before the data chunk */
523         newsoft = (struct arc_rfc1201 *)
524             (out->pkt->soft.raw + out->length - out->dataleft);
525
526         if (!out->segnum)       /* first packet; newsoft == soft */
527                 newsoft->split_flag = ((out->numsegs - 2) << 1) | 1;
528         else {
529                 newsoft->split_flag = out->segnum << 1;
530                 newsoft->proto = soft->proto;
531                 newsoft->sequence = soft->sequence;
532         }
533
534         seglen = maxsegsize;
535         if (seglen > out->dataleft)
536                 seglen = out->dataleft;
537         out->dataleft -= seglen;
538
539         load_pkt(dev, hard, newsoft, seglen + RFC1201_HDR_SIZE, bufnum);
540
541         out->segnum++;
542         if (out->segnum >= out->numsegs)
543                 return 1;
544         else
545                 return 0;
546 }