1 /*
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 <linux/module.h>
20 #include <linux/types.h>
21 #include <linux/kernel.h>
22 #include <linux/jiffies.h>
23 #include <linux/string.h>
24 #include <linux/mm.h>
25 #include <linux/socket.h>
26 #include <linux/in.h>
27 #include <linux/inet.h>
28 #include <linux/netdevice.h>
29 #include <linux/trdevice.h>
30 #include <linux/skbuff.h>
31 #include <linux/errno.h>
32 #include <linux/timer.h>
33 #include <linux/net.h>
34 #include <linux/proc_fs.h>
35 #include <linux/seq_file.h>
36 #include <linux/init.h>
37 #include <linux/sysctl.h>
38 #include <linux/slab.h>
39 #include <net/arp.h>
40 #include <net/net_namespace.h>
41
42 static void tr_add_rif_info(struct trh_hdr *trh, struct net_device *dev);
43 static void rif_check_expire(unsigned long dummy);
44
45 #define TR_SR_DEBUG 0
46
47 /*
48 * Each RIF entry we learn is kept this way
49 */
50
51 struct rif_cache {
52 unsigned char addr[TR_ALEN];
53 int iface;
54 __be16 rcf;
55 __be16 rseg[8];
56 struct rif_cache *next;
57 unsigned long last_used;
58 unsigned char local_ring;
59 };
60
61 #define RIF_TABLE_SIZE 32
62
63 /*
64 * We hash the RIF cache 32 ways. We do after all have to look it
65 * up a lot.
66 */
67
68 static struct rif_cache *rif_table[RIF_TABLE_SIZE];
69
70 static DEFINE_SPINLOCK(rif_lock);
71
72
73 /*
74 * Garbage disposal timer.
75 */
76
77 static struct timer_list rif_timer;
78
79 static int sysctl_tr_rif_timeout = 60*10*HZ;
80
rif_hash(const unsigned char * addr)81 static inline unsigned long rif_hash(const unsigned char *addr)
82 {
83 unsigned long x;
84
85 x = addr[0];
86 x = (x << 2) ^ addr[1];
87 x = (x << 2) ^ addr[2];
88 x = (x << 2) ^ addr[3];
89 x = (x << 2) ^ addr[4];
90 x = (x << 2) ^ addr[5];
91
92 x ^= x >> 8;
93
94 return x & (RIF_TABLE_SIZE - 1);
95 }
96
97 /*
98 * Put the headers on a token ring packet. Token ring source routing
99 * makes this a little more exciting than on ethernet.
100 */
101
tr_header(struct sk_buff * skb,struct net_device * dev,unsigned short type,const void * daddr,const void * saddr,unsigned len)102 static int tr_header(struct sk_buff *skb, struct net_device *dev,
103 unsigned short type,
104 const void *daddr, const void *saddr, unsigned len)
105 {
106 struct trh_hdr *trh;
107 int hdr_len;
108
109 /*
110 * Add the 802.2 SNAP header if IP as the IPv4/IPv6 code calls
111 * dev->hard_header directly.
112 */
113 if (type == ETH_P_IP || type == ETH_P_IPV6 || type == ETH_P_ARP)
114 {
115 struct trllc *trllc;
116
117 hdr_len = sizeof(struct trh_hdr) + sizeof(struct trllc);
118 trh = (struct trh_hdr *)skb_push(skb, hdr_len);
119 trllc = (struct trllc *)(trh+1);
120 trllc->dsap = trllc->ssap = EXTENDED_SAP;
121 trllc->llc = UI_CMD;
122 trllc->protid[0] = trllc->protid[1] = trllc->protid[2] = 0x00;
123 trllc->ethertype = htons(type);
124 }
125 else
126 {
127 hdr_len = sizeof(struct trh_hdr);
128 trh = (struct trh_hdr *)skb_push(skb, hdr_len);
129 }
130
131 trh->ac=AC;
132 trh->fc=LLC_FRAME;
133
134 if(saddr)
135 memcpy(trh->saddr,saddr,dev->addr_len);
136 else
137 memcpy(trh->saddr,dev->dev_addr,dev->addr_len);
138
139 /*
140 * Build the destination and then source route the frame
141 */
142
143 if(daddr)
144 {
145 memcpy(trh->daddr,daddr,dev->addr_len);
146 tr_source_route(skb, trh, dev);
147 return hdr_len;
148 }
149
150 return -hdr_len;
151 }
152
153 /*
154 * A neighbour discovery of some species (eg arp) has completed. We
155 * can now send the packet.
156 */
157
tr_rebuild_header(struct sk_buff * skb)158 static int tr_rebuild_header(struct sk_buff *skb)
159 {
160 struct trh_hdr *trh=(struct trh_hdr *)skb->data;
161 struct trllc *trllc=(struct trllc *)(skb->data+sizeof(struct trh_hdr));
162 struct net_device *dev = skb->dev;
163
164 /*
165 * FIXME: We don't yet support IPv6 over token rings
166 */
167
168 if(trllc->ethertype != htons(ETH_P_IP)) {
169 printk("tr_rebuild_header: Don't know how to resolve type %04X addresses ?\n", ntohs(trllc->ethertype));
170 return 0;
171 }
172
173 #ifdef CONFIG_INET
174 if(arp_find(trh->daddr, skb)) {
175 return 1;
176 }
177 else
178 #endif
179 {
180 tr_source_route(skb,trh,dev);
181 return 0;
182 }
183 }
184
185 /*
186 * Some of this is a bit hackish. We intercept RIF information
187 * used for source routing. We also grab IP directly and don't feed
188 * it via SNAP.
189 */
190
tr_type_trans(struct sk_buff * skb,struct net_device * dev)191 __be16 tr_type_trans(struct sk_buff *skb, struct net_device *dev)
192 {
193
194 struct trh_hdr *trh;
195 struct trllc *trllc;
196 unsigned riflen=0;
197
198 skb->dev = dev;
199 skb_reset_mac_header(skb);
200 trh = tr_hdr(skb);
201
202 if(trh->saddr[0] & TR_RII)
203 riflen = (ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8;
204
205 trllc = (struct trllc *)(skb->data+sizeof(struct trh_hdr)-TR_MAXRIFLEN+riflen);
206
207 skb_pull(skb,sizeof(struct trh_hdr)-TR_MAXRIFLEN+riflen);
208
209 if(*trh->daddr & 0x80)
210 {
211 if(!memcmp(trh->daddr,dev->broadcast,TR_ALEN))
212 skb->pkt_type=PACKET_BROADCAST;
213 else
214 skb->pkt_type=PACKET_MULTICAST;
215 }
216 else if ( (trh->daddr[0] & 0x01) && (trh->daddr[1] & 0x00) && (trh->daddr[2] & 0x5E))
217 {
218 skb->pkt_type=PACKET_MULTICAST;
219 }
220 else if(dev->flags & IFF_PROMISC)
221 {
222 if(memcmp(trh->daddr, dev->dev_addr, TR_ALEN))
223 skb->pkt_type=PACKET_OTHERHOST;
224 }
225
226 if ((skb->pkt_type != PACKET_BROADCAST) &&
227 (skb->pkt_type != PACKET_MULTICAST))
228 tr_add_rif_info(trh,dev) ;
229
230 /*
231 * Strip the SNAP header from ARP packets since we don't
232 * pass them through to the 802.2/SNAP layers.
233 */
234
235 if (trllc->dsap == EXTENDED_SAP &&
236 (trllc->ethertype == htons(ETH_P_IP) ||
237 trllc->ethertype == htons(ETH_P_IPV6) ||
238 trllc->ethertype == htons(ETH_P_ARP)))
239 {
240 skb_pull(skb, sizeof(struct trllc));
241 return trllc->ethertype;
242 }
243
244 return htons(ETH_P_TR_802_2);
245 }
246
247 /*
248 * We try to do source routing...
249 */
250
tr_source_route(struct sk_buff * skb,struct trh_hdr * trh,struct net_device * dev)251 void tr_source_route(struct sk_buff *skb,struct trh_hdr *trh,
252 struct net_device *dev)
253 {
254 int slack;
255 unsigned int hash;
256 struct rif_cache *entry;
257 unsigned char *olddata;
258 unsigned long flags;
259 static const unsigned char mcast_func_addr[]
260 = {0xC0,0x00,0x00,0x04,0x00,0x00};
261
262 spin_lock_irqsave(&rif_lock, flags);
263
264 /*
265 * Broadcasts are single route as stated in RFC 1042
266 */
267 if( (!memcmp(&(trh->daddr[0]),&(dev->broadcast[0]),TR_ALEN)) ||
268 (!memcmp(&(trh->daddr[0]),&(mcast_func_addr[0]), TR_ALEN)) )
269 {
270 trh->rcf=htons((((sizeof(trh->rcf)) << 8) & TR_RCF_LEN_MASK)
271 | TR_RCF_FRAME2K | TR_RCF_LIMITED_BROADCAST);
272 trh->saddr[0]|=TR_RII;
273 }
274 else
275 {
276 hash = rif_hash(trh->daddr);
277 /*
278 * Walk the hash table and look for an entry
279 */
280 for(entry=rif_table[hash];entry && memcmp(&(entry->addr[0]),&(trh->daddr[0]),TR_ALEN);entry=entry->next);
281
282 /*
283 * If we found an entry we can route the frame.
284 */
285 if(entry)
286 {
287 #if TR_SR_DEBUG
288 printk("source routing for %pM\n", trh->daddr);
289 #endif
290 if(!entry->local_ring && (ntohs(entry->rcf) & TR_RCF_LEN_MASK) >> 8)
291 {
292 trh->rcf=entry->rcf;
293 memcpy(&trh->rseg[0],&entry->rseg[0],8*sizeof(unsigned short));
294 trh->rcf^=htons(TR_RCF_DIR_BIT);
295 trh->rcf&=htons(0x1fff); /* Issam Chehab <ichehab@madge1.demon.co.uk> */
296
297 trh->saddr[0]|=TR_RII;
298 #if TR_SR_DEBUG
299 printk("entry found with rcf %04x\n", entry->rcf);
300 }
301 else
302 {
303 printk("entry found but without rcf length, local=%02x\n", entry->local_ring);
304 #endif
305 }
306 entry->last_used=jiffies;
307 }
308 else
309 {
310 /*
311 * Without the information we simply have to shout
312 * on the wire. The replies should rapidly clean this
313 * situation up.
314 */
315 trh->rcf=htons((((sizeof(trh->rcf)) << 8) & TR_RCF_LEN_MASK)
316 | TR_RCF_FRAME2K | TR_RCF_LIMITED_BROADCAST);
317 trh->saddr[0]|=TR_RII;
318 #if TR_SR_DEBUG
319 printk("no entry in rif table found - broadcasting frame\n");
320 #endif
321 }
322 }
323
324 /* Compress the RIF here so we don't have to do it in the driver(s) */
325 if (!(trh->saddr[0] & 0x80))
326 slack = 18;
327 else
328 slack = 18 - ((ntohs(trh->rcf) & TR_RCF_LEN_MASK)>>8);
329 olddata = skb->data;
330 spin_unlock_irqrestore(&rif_lock, flags);
331
332 skb_pull(skb, slack);
333 memmove(skb->data, olddata, sizeof(struct trh_hdr) - slack);
334 }
335
336 /*
337 * We have learned some new RIF information for our source
338 * routing.
339 */
340
tr_add_rif_info(struct trh_hdr * trh,struct net_device * dev)341 static void tr_add_rif_info(struct trh_hdr *trh, struct net_device *dev)
342 {
343 unsigned int hash, rii_p = 0;
344 unsigned long flags;
345 struct rif_cache *entry;
346 unsigned char saddr0;
347
348 spin_lock_irqsave(&rif_lock, flags);
349 saddr0 = trh->saddr[0];
350
351 /*
352 * Firstly see if the entry exists
353 */
354
355 if(trh->saddr[0] & TR_RII)
356 {
357 trh->saddr[0]&=0x7f;
358 if (((ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8) > 2)
359 {
360 rii_p = 1;
361 }
362 }
363
364 hash = rif_hash(trh->saddr);
365 for(entry=rif_table[hash];entry && memcmp(&(entry->addr[0]),&(trh->saddr[0]),TR_ALEN);entry=entry->next);
366
367 if(entry==NULL)
368 {
369 #if TR_SR_DEBUG
370 printk("adding rif_entry: addr:%pM rcf:%04X\n",
371 trh->saddr, ntohs(trh->rcf));
372 #endif
373 /*
374 * Allocate our new entry. A failure to allocate loses
375 * use the information. This is harmless.
376 *
377 * FIXME: We ought to keep some kind of cache size
378 * limiting and adjust the timers to suit.
379 */
380 entry=kmalloc(sizeof(struct rif_cache),GFP_ATOMIC);
381
382 if(!entry)
383 {
384 printk(KERN_DEBUG "tr.c: Couldn't malloc rif cache entry !\n");
385 spin_unlock_irqrestore(&rif_lock, flags);
386 return;
387 }
388
389 memcpy(&(entry->addr[0]),&(trh->saddr[0]),TR_ALEN);
390 entry->iface = dev->ifindex;
391 entry->next=rif_table[hash];
392 entry->last_used=jiffies;
393 rif_table[hash]=entry;
394
395 if (rii_p)
396 {
397 entry->rcf = trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK);
398 memcpy(&(entry->rseg[0]),&(trh->rseg[0]),8*sizeof(unsigned short));
399 entry->local_ring = 0;
400 }
401 else
402 {
403 entry->local_ring = 1;
404 }
405 }
406 else /* Y. Tahara added */
407 {
408 /*
409 * Update existing entries
410 */
411 if (!entry->local_ring)
412 if (entry->rcf != (trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK)) &&
413 !(trh->rcf & htons(TR_RCF_BROADCAST_MASK)))
414 {
415 #if TR_SR_DEBUG
416 printk("updating rif_entry: addr:%pM rcf:%04X\n",
417 trh->saddr, ntohs(trh->rcf));
418 #endif
419 entry->rcf = trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK);
420 memcpy(&(entry->rseg[0]),&(trh->rseg[0]),8*sizeof(unsigned short));
421 }
422 entry->last_used=jiffies;
423 }
424 trh->saddr[0]=saddr0; /* put the routing indicator back for tcpdump */
425 spin_unlock_irqrestore(&rif_lock, flags);
426 }
427
428 /*
429 * Scan the cache with a timer and see what we need to throw out.
430 */
431
rif_check_expire(unsigned long dummy)432 static void rif_check_expire(unsigned long dummy)
433 {
434 int i;
435 unsigned long flags, next_interval = jiffies + sysctl_tr_rif_timeout/2;
436
437 spin_lock_irqsave(&rif_lock, flags);
438
439 for(i =0; i < RIF_TABLE_SIZE; i++) {
440 struct rif_cache *entry, **pentry;
441
442 pentry = rif_table+i;
443 while((entry=*pentry) != NULL) {
444 unsigned long expires
445 = entry->last_used + sysctl_tr_rif_timeout;
446
447 if (time_before_eq(expires, jiffies)) {
448 *pentry = entry->next;
449 kfree(entry);
450 } else {
451 pentry = &entry->next;
452
453 if (time_before(expires, next_interval))
454 next_interval = expires;
455 }
456 }
457 }
458
459 spin_unlock_irqrestore(&rif_lock, flags);
460
461 mod_timer(&rif_timer, next_interval);
462
463 }
464
465 /*
466 * Generate the /proc/net information for the token ring RIF
467 * routing.
468 */
469
470 #ifdef CONFIG_PROC_FS
471
rif_get_idx(loff_t pos)472 static struct rif_cache *rif_get_idx(loff_t pos)
473 {
474 int i;
475 struct rif_cache *entry;
476 loff_t off = 0;
477
478 for(i = 0; i < RIF_TABLE_SIZE; i++)
479 for(entry = rif_table[i]; entry; entry = entry->next) {
480 if (off == pos)
481 return entry;
482 ++off;
483 }
484
485 return NULL;
486 }
487
rif_seq_start(struct seq_file * seq,loff_t * pos)488 static void *rif_seq_start(struct seq_file *seq, loff_t *pos)
489 __acquires(&rif_lock)
490 {
491 spin_lock_irq(&rif_lock);
492
493 return *pos ? rif_get_idx(*pos - 1) : SEQ_START_TOKEN;
494 }
495
rif_seq_next(struct seq_file * seq,void * v,loff_t * pos)496 static void *rif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
497 {
498 int i;
499 struct rif_cache *ent = v;
500
501 ++*pos;
502
503 if (v == SEQ_START_TOKEN) {
504 i = -1;
505 goto scan;
506 }
507
508 if (ent->next)
509 return ent->next;
510
511 i = rif_hash(ent->addr);
512 scan:
513 while (++i < RIF_TABLE_SIZE) {
514 if ((ent = rif_table[i]) != NULL)
515 return ent;
516 }
517 return NULL;
518 }
519
rif_seq_stop(struct seq_file * seq,void * v)520 static void rif_seq_stop(struct seq_file *seq, void *v)
521 __releases(&rif_lock)
522 {
523 spin_unlock_irq(&rif_lock);
524 }
525
rif_seq_show(struct seq_file * seq,void * v)526 static int rif_seq_show(struct seq_file *seq, void *v)
527 {
528 int j, rcf_len, segment, brdgnmb;
529 struct rif_cache *entry = v;
530
531 if (v == SEQ_START_TOKEN)
532 seq_puts(seq,
533 "if TR address TTL rcf routing segments\n");
534 else {
535 struct net_device *dev = dev_get_by_index(&init_net, entry->iface);
536 long ttl = (long) (entry->last_used + sysctl_tr_rif_timeout)
537 - (long) jiffies;
538
539 seq_printf(seq, "%s %pM %7li ",
540 dev?dev->name:"?",
541 entry->addr,
542 ttl/HZ);
543
544 if (entry->local_ring)
545 seq_puts(seq, "local\n");
546 else {
547
548 seq_printf(seq, "%04X", ntohs(entry->rcf));
549 rcf_len = ((ntohs(entry->rcf) & TR_RCF_LEN_MASK)>>8)-2;
550 if (rcf_len)
551 rcf_len >>= 1;
552 for(j = 1; j < rcf_len; j++) {
553 if(j==1) {
554 segment=ntohs(entry->rseg[j-1])>>4;
555 seq_printf(seq," %03X",segment);
556 }
557
558 segment=ntohs(entry->rseg[j])>>4;
559 brdgnmb=ntohs(entry->rseg[j-1])&0x00f;
560 seq_printf(seq,"-%01X-%03X",brdgnmb,segment);
561 }
562 seq_putc(seq, '\n');
563 }
564
565 if (dev)
566 dev_put(dev);
567 }
568 return 0;
569 }
570
571
572 static const struct seq_operations rif_seq_ops = {
573 .start = rif_seq_start,
574 .next = rif_seq_next,
575 .stop = rif_seq_stop,
576 .show = rif_seq_show,
577 };
578
rif_seq_open(struct inode * inode,struct file * file)579 static int rif_seq_open(struct inode *inode, struct file *file)
580 {
581 return seq_open(file, &rif_seq_ops);
582 }
583
584 static const struct file_operations rif_seq_fops = {
585 .owner = THIS_MODULE,
586 .open = rif_seq_open,
587 .read = seq_read,
588 .llseek = seq_lseek,
589 .release = seq_release,
590 };
591
592 #endif
593
594 static const struct header_ops tr_header_ops = {
595 .create = tr_header,
596 .rebuild= tr_rebuild_header,
597 };
598
tr_setup(struct net_device * dev)599 static void tr_setup(struct net_device *dev)
600 {
601 /*
602 * Configure and register
603 */
604
605 dev->header_ops = &tr_header_ops;
606
607 dev->type = ARPHRD_IEEE802_TR;
608 dev->hard_header_len = TR_HLEN;
609 dev->mtu = 2000;
610 dev->addr_len = TR_ALEN;
611 dev->tx_queue_len = 100; /* Long queues on tr */
612
613 memset(dev->broadcast,0xFF, TR_ALEN);
614
615 /* New-style flags. */
616 dev->flags = IFF_BROADCAST | IFF_MULTICAST ;
617 }
618
619 /**
620 * alloc_trdev - Register token ring device
621 * @sizeof_priv: Size of additional driver-private structure to be allocated
622 * for this token ring device
623 *
624 * Fill in the fields of the device structure with token ring-generic values.
625 *
626 * Constructs a new net device, complete with a private data area of
627 * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for
628 * this private data area.
629 */
alloc_trdev(int sizeof_priv)630 struct net_device *alloc_trdev(int sizeof_priv)
631 {
632 return alloc_netdev(sizeof_priv, "tr%d", tr_setup);
633 }
634
635 #ifdef CONFIG_SYSCTL
636 static struct ctl_table tr_table[] = {
637 {
638 .procname = "rif_timeout",
639 .data = &sysctl_tr_rif_timeout,
640 .maxlen = sizeof(int),
641 .mode = 0644,
642 .proc_handler = proc_dointvec
643 },
644 { },
645 };
646
647 static __initdata struct ctl_path tr_path[] = {
648 { .procname = "net", },
649 { .procname = "token-ring", },
650 { }
651 };
652 #endif
653
654 /*
655 * Called during bootup. We don't actually have to initialise
656 * too much for this.
657 */
658
rif_init(void)659 static int __init rif_init(void)
660 {
661 rif_timer.expires = jiffies + sysctl_tr_rif_timeout;
662 setup_timer(&rif_timer, rif_check_expire, 0);
663 add_timer(&rif_timer);
664 #ifdef CONFIG_SYSCTL
665 register_sysctl_paths(tr_path, tr_table);
666 #endif
667 proc_net_fops_create(&init_net, "tr_rif", S_IRUGO, &rif_seq_fops);
668 return 0;
669 }
670
671 module_init(rif_init);
672
673 EXPORT_SYMBOL(tr_type_trans);
674 EXPORT_SYMBOL(alloc_trdev);
675
676 MODULE_LICENSE("GPL");
677