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