blob: 85293ccf7efcd3c66724dd8bfed62d9a1afef19c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * NET3: Token ring device handling subroutines
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Fixes: 3 Feb 97 Paul Norton <pnorton@cts.com> Minor routing fixes.
10 * Added rif table to /proc/net/tr_rif and rif timeout to
11 * /proc/sys/net/token-ring/rif_timeout.
12 * 22 Jun 98 Paul Norton <p.norton@computer.org> Rearranged
13 * tr_header and tr_type_trans to handle passing IPX SNAP and
14 * 802.2 through the correct layers. Eliminated tr_reformat.
15 *
16 */
17
18#include <asm/uaccess.h>
19#include <asm/system.h>
20#include <linux/config.h>
21#include <linux/module.h>
22#include <linux/types.h>
23#include <linux/kernel.h>
24#include <linux/jiffies.h>
25#include <linux/string.h>
26#include <linux/mm.h>
27#include <linux/socket.h>
28#include <linux/in.h>
29#include <linux/inet.h>
30#include <linux/netdevice.h>
31#include <linux/trdevice.h>
32#include <linux/skbuff.h>
33#include <linux/errno.h>
34#include <linux/timer.h>
35#include <linux/net.h>
36#include <linux/proc_fs.h>
37#include <linux/seq_file.h>
38#include <linux/init.h>
39#include <net/arp.h>
40
41static void tr_add_rif_info(struct trh_hdr *trh, struct net_device *dev);
42static void rif_check_expire(unsigned long dummy);
43
44#define TR_SR_DEBUG 0
45
46/*
47 * Each RIF entry we learn is kept this way
48 */
49
50struct rif_cache_s {
51 unsigned char addr[TR_ALEN];
52 int iface;
53 __u16 rcf;
54 __u16 rseg[8];
55 struct rif_cache_s *next;
56 unsigned long last_used;
57 unsigned char local_ring;
58};
59
60#define RIF_TABLE_SIZE 32
61
62/*
63 * We hash the RIF cache 32 ways. We do after all have to look it
64 * up a lot.
65 */
66
67static struct rif_cache_s *rif_table[RIF_TABLE_SIZE];
68
69static DEFINE_SPINLOCK(rif_lock);
70
71
72/*
73 * Garbage disposal timer.
74 */
75
76static struct timer_list rif_timer;
77
78int sysctl_tr_rif_timeout = 60*10*HZ;
79
80static inline unsigned long rif_hash(const unsigned char *addr)
81{
82 unsigned long x;
83
84 x = addr[0];
85 x = (x << 2) ^ addr[1];
86 x = (x << 2) ^ addr[2];
87 x = (x << 2) ^ addr[3];
88 x = (x << 2) ^ addr[4];
89 x = (x << 2) ^ addr[5];
90
91 x ^= x >> 8;
92
93 return x & (RIF_TABLE_SIZE - 1);
94}
95
96/*
97 * Put the headers on a token ring packet. Token ring source routing
98 * makes this a little more exciting than on ethernet.
99 */
100
101static int tr_header(struct sk_buff *skb, struct net_device *dev,
102 unsigned short type,
103 void *daddr, void *saddr, unsigned len)
104{
105 struct trh_hdr *trh;
106 int hdr_len;
107
108 /*
109 * Add the 802.2 SNAP header if IP as the IPv4/IPv6 code calls
110 * dev->hard_header directly.
111 */
112 if (type == ETH_P_IP || type == ETH_P_IPV6 || type == ETH_P_ARP)
113 {
114 struct trllc *trllc;
115
116 hdr_len = sizeof(struct trh_hdr) + sizeof(struct trllc);
117 trh = (struct trh_hdr *)skb_push(skb, hdr_len);
118 trllc = (struct trllc *)(trh+1);
119 trllc->dsap = trllc->ssap = EXTENDED_SAP;
120 trllc->llc = UI_CMD;
121 trllc->protid[0] = trllc->protid[1] = trllc->protid[2] = 0x00;
122 trllc->ethertype = htons(type);
123 }
124 else
125 {
126 hdr_len = sizeof(struct trh_hdr);
127 trh = (struct trh_hdr *)skb_push(skb, hdr_len);
128 }
129
130 trh->ac=AC;
131 trh->fc=LLC_FRAME;
132
133 if(saddr)
134 memcpy(trh->saddr,saddr,dev->addr_len);
135 else
136 memcpy(trh->saddr,dev->dev_addr,dev->addr_len);
137
138 /*
139 * Build the destination and then source route the frame
140 */
141
142 if(daddr)
143 {
144 memcpy(trh->daddr,daddr,dev->addr_len);
145 tr_source_route(skb,trh,dev);
146 return(hdr_len);
147 }
148
149 return -hdr_len;
150}
151
152/*
153 * A neighbour discovery of some species (eg arp) has completed. We
154 * can now send the packet.
155 */
156
157static int tr_rebuild_header(struct sk_buff *skb)
158{
159 struct trh_hdr *trh=(struct trh_hdr *)skb->data;
160 struct trllc *trllc=(struct trllc *)(skb->data+sizeof(struct trh_hdr));
161 struct net_device *dev = skb->dev;
162
163 /*
164 * FIXME: We don't yet support IPv6 over token rings
165 */
166
167 if(trllc->ethertype != htons(ETH_P_IP)) {
168 printk("tr_rebuild_header: Don't know how to resolve type %04X addresses ?\n",(unsigned int)htons(trllc->ethertype));
169 return 0;
170 }
171
172#ifdef CONFIG_INET
173 if(arp_find(trh->daddr, skb)) {
174 return 1;
175 }
176 else
177#endif
178 {
179 tr_source_route(skb,trh,dev);
180 return 0;
181 }
182}
183
184/*
185 * Some of this is a bit hackish. We intercept RIF information
186 * used for source routing. We also grab IP directly and don't feed
187 * it via SNAP.
188 */
189
190unsigned short tr_type_trans(struct sk_buff *skb, struct net_device *dev)
191{
192
193 struct trh_hdr *trh=(struct trh_hdr *)skb->data;
194 struct trllc *trllc;
195 unsigned riflen=0;
196
197 skb->mac.raw = skb->data;
198
199 if(trh->saddr[0] & TR_RII)
200 riflen = (ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8;
201
202 trllc = (struct trllc *)(skb->data+sizeof(struct trh_hdr)-TR_MAXRIFLEN+riflen);
203
204 skb_pull(skb,sizeof(struct trh_hdr)-TR_MAXRIFLEN+riflen);
205
206 if(*trh->daddr & 0x80)
207 {
208 if(!memcmp(trh->daddr,dev->broadcast,TR_ALEN))
209 skb->pkt_type=PACKET_BROADCAST;
210 else
211 skb->pkt_type=PACKET_MULTICAST;
212 }
213 else if ( (trh->daddr[0] & 0x01) && (trh->daddr[1] & 0x00) && (trh->daddr[2] & 0x5E))
214 {
215 skb->pkt_type=PACKET_MULTICAST;
216 }
217 else if(dev->flags & IFF_PROMISC)
218 {
219 if(memcmp(trh->daddr, dev->dev_addr, TR_ALEN))
220 skb->pkt_type=PACKET_OTHERHOST;
221 }
222
223 if ((skb->pkt_type != PACKET_BROADCAST) &&
224 (skb->pkt_type != PACKET_MULTICAST))
225 tr_add_rif_info(trh,dev) ;
226
227 /*
228 * Strip the SNAP header from ARP packets since we don't
229 * pass them through to the 802.2/SNAP layers.
230 */
231
232 if (trllc->dsap == EXTENDED_SAP &&
233 (trllc->ethertype == ntohs(ETH_P_IP) ||
234 trllc->ethertype == ntohs(ETH_P_IPV6) ||
235 trllc->ethertype == ntohs(ETH_P_ARP)))
236 {
237 skb_pull(skb, sizeof(struct trllc));
238 return trllc->ethertype;
239 }
240
241 return ntohs(ETH_P_802_2);
242}
243
244/*
245 * We try to do source routing...
246 */
247
248void tr_source_route(struct sk_buff *skb,struct trh_hdr *trh,struct net_device *dev)
249{
250 int slack;
251 unsigned int hash;
252 struct rif_cache_s *entry;
253 unsigned char *olddata;
254 static const unsigned char mcast_func_addr[]
255 = {0xC0,0x00,0x00,0x04,0x00,0x00};
256
257 spin_lock_bh(&rif_lock);
258
259 /*
260 * Broadcasts are single route as stated in RFC 1042
261 */
262 if( (!memcmp(&(trh->daddr[0]),&(dev->broadcast[0]),TR_ALEN)) ||
263 (!memcmp(&(trh->daddr[0]),&(mcast_func_addr[0]), TR_ALEN)) )
264 {
265 trh->rcf=htons((((sizeof(trh->rcf)) << 8) & TR_RCF_LEN_MASK)
266 | TR_RCF_FRAME2K | TR_RCF_LIMITED_BROADCAST);
267 trh->saddr[0]|=TR_RII;
268 }
269 else
270 {
271 hash = rif_hash(trh->daddr);
272 /*
273 * Walk the hash table and look for an entry
274 */
275 for(entry=rif_table[hash];entry && memcmp(&(entry->addr[0]),&(trh->daddr[0]),TR_ALEN);entry=entry->next);
276
277 /*
278 * If we found an entry we can route the frame.
279 */
280 if(entry)
281 {
282#if TR_SR_DEBUG
283printk("source routing for %02X:%02X:%02X:%02X:%02X:%02X\n",trh->daddr[0],
284 trh->daddr[1],trh->daddr[2],trh->daddr[3],trh->daddr[4],trh->daddr[5]);
285#endif
286 if(!entry->local_ring && (ntohs(entry->rcf) & TR_RCF_LEN_MASK) >> 8)
287 {
288 trh->rcf=entry->rcf;
289 memcpy(&trh->rseg[0],&entry->rseg[0],8*sizeof(unsigned short));
290 trh->rcf^=htons(TR_RCF_DIR_BIT);
291 trh->rcf&=htons(0x1fff); /* Issam Chehab <ichehab@madge1.demon.co.uk> */
292
293 trh->saddr[0]|=TR_RII;
294#if TR_SR_DEBUG
295 printk("entry found with rcf %04x\n", entry->rcf);
296 }
297 else
298 {
299 printk("entry found but without rcf length, local=%02x\n", entry->local_ring);
300#endif
301 }
302 entry->last_used=jiffies;
303 }
304 else
305 {
306 /*
307 * Without the information we simply have to shout
308 * on the wire. The replies should rapidly clean this
309 * situation up.
310 */
311 trh->rcf=htons((((sizeof(trh->rcf)) << 8) & TR_RCF_LEN_MASK)
312 | TR_RCF_FRAME2K | TR_RCF_LIMITED_BROADCAST);
313 trh->saddr[0]|=TR_RII;
314#if TR_SR_DEBUG
315 printk("no entry in rif table found - broadcasting frame\n");
316#endif
317 }
318 }
319
320 /* Compress the RIF here so we don't have to do it in the driver(s) */
321 if (!(trh->saddr[0] & 0x80))
322 slack = 18;
323 else
324 slack = 18 - ((ntohs(trh->rcf) & TR_RCF_LEN_MASK)>>8);
325 olddata = skb->data;
326 spin_unlock_bh(&rif_lock);
327
328 skb_pull(skb, slack);
329 memmove(skb->data, olddata, sizeof(struct trh_hdr) - slack);
330}
331
332/*
333 * We have learned some new RIF information for our source
334 * routing.
335 */
336
337static void tr_add_rif_info(struct trh_hdr *trh, struct net_device *dev)
338{
339 unsigned int hash, rii_p = 0;
340 struct rif_cache_s *entry;
341
342
343 spin_lock_bh(&rif_lock);
344
345 /*
346 * Firstly see if the entry exists
347 */
348
349 if(trh->saddr[0] & TR_RII)
350 {
351 trh->saddr[0]&=0x7f;
352 if (((ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8) > 2)
353 {
354 rii_p = 1;
355 }
356 }
357
358 hash = rif_hash(trh->saddr);
359 for(entry=rif_table[hash];entry && memcmp(&(entry->addr[0]),&(trh->saddr[0]),TR_ALEN);entry=entry->next);
360
361 if(entry==NULL)
362 {
363#if TR_SR_DEBUG
364printk("adding rif_entry: addr:%02X:%02X:%02X:%02X:%02X:%02X rcf:%04X\n",
365 trh->saddr[0],trh->saddr[1],trh->saddr[2],
366 trh->saddr[3],trh->saddr[4],trh->saddr[5],
367 ntohs(trh->rcf));
368#endif
369 /*
370 * Allocate our new entry. A failure to allocate loses
371 * use the information. This is harmless.
372 *
373 * FIXME: We ought to keep some kind of cache size
374 * limiting and adjust the timers to suit.
375 */
376 entry=kmalloc(sizeof(struct rif_cache_s),GFP_ATOMIC);
377
378 if(!entry)
379 {
380 printk(KERN_DEBUG "tr.c: Couldn't malloc rif cache entry !\n");
381 spin_unlock_bh(&rif_lock);
382 return;
383 }
384
385 memcpy(&(entry->addr[0]),&(trh->saddr[0]),TR_ALEN);
386 entry->iface = dev->ifindex;
387 entry->next=rif_table[hash];
388 entry->last_used=jiffies;
389 rif_table[hash]=entry;
390
391 if (rii_p)
392 {
393 entry->rcf = trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK);
394 memcpy(&(entry->rseg[0]),&(trh->rseg[0]),8*sizeof(unsigned short));
395 entry->local_ring = 0;
396 trh->saddr[0]|=TR_RII; /* put the routing indicator back for tcpdump */
397 }
398 else
399 {
400 entry->local_ring = 1;
401 }
402 }
403 else /* Y. Tahara added */
404 {
405 /*
406 * Update existing entries
407 */
408 if (!entry->local_ring)
409 if (entry->rcf != (trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK)) &&
410 !(trh->rcf & htons(TR_RCF_BROADCAST_MASK)))
411 {
412#if TR_SR_DEBUG
413printk("updating rif_entry: addr:%02X:%02X:%02X:%02X:%02X:%02X rcf:%04X\n",
414 trh->saddr[0],trh->saddr[1],trh->saddr[2],
415 trh->saddr[3],trh->saddr[4],trh->saddr[5],
416 ntohs(trh->rcf));
417#endif
418 entry->rcf = trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK);
419 memcpy(&(entry->rseg[0]),&(trh->rseg[0]),8*sizeof(unsigned short));
420 }
421 entry->last_used=jiffies;
422 }
423 spin_unlock_bh(&rif_lock);
424}
425
426/*
427 * Scan the cache with a timer and see what we need to throw out.
428 */
429
430static void rif_check_expire(unsigned long dummy)
431{
432 int i;
433 unsigned long next_interval = jiffies + sysctl_tr_rif_timeout/2;
434
435 spin_lock_bh(&rif_lock);
436
437 for(i =0; i < RIF_TABLE_SIZE; i++) {
438 struct rif_cache_s *entry, **pentry;
439
440 pentry = rif_table+i;
441 while((entry=*pentry) != NULL) {
442 unsigned long expires
443 = entry->last_used + sysctl_tr_rif_timeout;
444
445 if (time_before_eq(expires, jiffies)) {
446 *pentry = entry->next;
447 kfree(entry);
448 } else {
449 pentry = &entry->next;
450
451 if (time_before(expires, next_interval))
452 next_interval = expires;
453 }
454 }
455 }
456
457 spin_unlock_bh(&rif_lock);
458
459 mod_timer(&rif_timer, next_interval);
460
461}
462
463/*
464 * Generate the /proc/net information for the token ring RIF
465 * routing.
466 */
467
468#ifdef CONFIG_PROC_FS
469
470static struct rif_cache_s *rif_get_idx(loff_t pos)
471{
472 int i;
473 struct rif_cache_s *entry;
474 loff_t off = 0;
475
476 for(i = 0; i < RIF_TABLE_SIZE; i++)
477 for(entry = rif_table[i]; entry; entry = entry->next) {
478 if (off == pos)
479 return entry;
480 ++off;
481 }
482
483 return NULL;
484}
485
486static void *rif_seq_start(struct seq_file *seq, loff_t *pos)
487{
488 spin_lock_bh(&rif_lock);
489
490 return *pos ? rif_get_idx(*pos - 1) : SEQ_START_TOKEN;
491}
492
493static void *rif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
494{
495 int i;
496 struct rif_cache_s *ent = v;
497
498 ++*pos;
499
500 if (v == SEQ_START_TOKEN) {
501 i = -1;
502 goto scan;
503 }
504
505 if (ent->next)
506 return ent->next;
507
508 i = rif_hash(ent->addr);
509 scan:
510 while (++i < RIF_TABLE_SIZE) {
511 if ((ent = rif_table[i]) != NULL)
512 return ent;
513 }
514 return NULL;
515}
516
517static void rif_seq_stop(struct seq_file *seq, void *v)
518{
519 spin_unlock_bh(&rif_lock);
520}
521
522static int rif_seq_show(struct seq_file *seq, void *v)
523{
524 int j, rcf_len, segment, brdgnmb;
525 struct rif_cache_s *entry = v;
526
527 if (v == SEQ_START_TOKEN)
528 seq_puts(seq,
529 "if TR address TTL rcf routing segments\n");
530 else {
531 struct net_device *dev = dev_get_by_index(entry->iface);
532 long ttl = (long) (entry->last_used + sysctl_tr_rif_timeout)
533 - (long) jiffies;
534
535 seq_printf(seq, "%s %02X:%02X:%02X:%02X:%02X:%02X %7li ",
536 dev?dev->name:"?",
537 entry->addr[0],entry->addr[1],entry->addr[2],
538 entry->addr[3],entry->addr[4],entry->addr[5],
539 ttl/HZ);
540
541 if (entry->local_ring)
542 seq_puts(seq, "local\n");
543 else {
544
545 seq_printf(seq, "%04X", ntohs(entry->rcf));
546 rcf_len = ((ntohs(entry->rcf) & TR_RCF_LEN_MASK)>>8)-2;
547 if (rcf_len)
548 rcf_len >>= 1;
549 for(j = 1; j < rcf_len; j++) {
550 if(j==1) {
551 segment=ntohs(entry->rseg[j-1])>>4;
552 seq_printf(seq," %03X",segment);
553 };
554 segment=ntohs(entry->rseg[j])>>4;
555 brdgnmb=ntohs(entry->rseg[j-1])&0x00f;
556 seq_printf(seq,"-%01X-%03X",brdgnmb,segment);
557 }
558 seq_putc(seq, '\n');
559 }
560 }
561 return 0;
562}
563
564
565static struct seq_operations rif_seq_ops = {
566 .start = rif_seq_start,
567 .next = rif_seq_next,
568 .stop = rif_seq_stop,
569 .show = rif_seq_show,
570};
571
572static int rif_seq_open(struct inode *inode, struct file *file)
573{
574 return seq_open(file, &rif_seq_ops);
575}
576
577static struct file_operations rif_seq_fops = {
578 .owner = THIS_MODULE,
579 .open = rif_seq_open,
580 .read = seq_read,
581 .llseek = seq_lseek,
582 .release = seq_release,
583};
584
585#endif
586
587static void tr_setup(struct net_device *dev)
588{
589 /*
590 * Configure and register
591 */
592
593 dev->hard_header = tr_header;
594 dev->rebuild_header = tr_rebuild_header;
595
596 dev->type = ARPHRD_IEEE802_TR;
597 dev->hard_header_len = TR_HLEN;
598 dev->mtu = 2000;
599 dev->addr_len = TR_ALEN;
600 dev->tx_queue_len = 100; /* Long queues on tr */
601
602 memset(dev->broadcast,0xFF, TR_ALEN);
603
604 /* New-style flags. */
605 dev->flags = IFF_BROADCAST | IFF_MULTICAST ;
606}
607
608/**
609 * alloc_trdev - Register token ring device
610 * @sizeof_priv: Size of additional driver-private structure to be allocated
611 * for this token ring device
612 *
613 * Fill in the fields of the device structure with token ring-generic values.
614 *
615 * Constructs a new net device, complete with a private data area of
616 * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for
617 * this private data area.
618 */
619struct net_device *alloc_trdev(int sizeof_priv)
620{
621 return alloc_netdev(sizeof_priv, "tr%d", tr_setup);
622}
623
624/*
625 * Called during bootup. We don't actually have to initialise
626 * too much for this.
627 */
628
629static int __init rif_init(void)
630{
631 init_timer(&rif_timer);
632 rif_timer.expires = sysctl_tr_rif_timeout;
633 rif_timer.data = 0L;
634 rif_timer.function = rif_check_expire;
635 add_timer(&rif_timer);
636
637 proc_net_fops_create("tr_rif", S_IRUGO, &rif_seq_fops);
638 return 0;
639}
640
641module_init(rif_init);
642
643EXPORT_SYMBOL(tr_source_route);
644EXPORT_SYMBOL(tr_type_trans);
645EXPORT_SYMBOL(alloc_trdev);