git.oblomov.eu Git - linux-2.6/blob - net/802/tr.c

   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 <net/arp.h>
  39 #include <net/net_namespace.h>
  40
  41 static void tr_add_rif_info(struct trh_hdr *trh, struct net_device *dev);
  42 static 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
  50 struct rif_cache {
  51         unsigned char addr[TR_ALEN];
  52         int iface;
  53         __be16 rcf;
  54         __be16 rseg[8];
  55         struct rif_cache *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
  67 static struct rif_cache *rif_table[RIF_TABLE_SIZE];
  68
  69 static DEFINE_SPINLOCK(rif_lock);
  70
  71
  72 /*
  73  *      Garbage disposal timer.
  74  */
  75
  76 static struct timer_list rif_timer;
  77
  78 int sysctl_tr_rif_timeout = 60*10*HZ;
  79
  80 static 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
 101 static int tr_header(struct sk_buff *skb, struct net_device *dev,
 102                      unsigned short type,
 103                      const void *daddr, const 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
 157 static 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", ntohs(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
 190 __be16 tr_type_trans(struct sk_buff *skb, struct net_device *dev)
 191 {
 192
 193         struct trh_hdr *trh;
 194         struct trllc *trllc;
 195         unsigned riflen=0;
 196
 197         skb->dev = dev;
 198         skb_reset_mac_header(skb);
 199         trh = tr_hdr(skb);
 200
 201         if(trh->saddr[0] & TR_RII)
 202                 riflen = (ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8;
 203
 204         trllc = (struct trllc *)(skb->data+sizeof(struct trh_hdr)-TR_MAXRIFLEN+riflen);
 205
 206         skb_pull(skb,sizeof(struct trh_hdr)-TR_MAXRIFLEN+riflen);
 207
 208         if(*trh->daddr & 0x80)
 209         {
 210                 if(!memcmp(trh->daddr,dev->broadcast,TR_ALEN))
 211                         skb->pkt_type=PACKET_BROADCAST;
 212                 else
 213                         skb->pkt_type=PACKET_MULTICAST;
 214         }
 215         else if ( (trh->daddr[0] & 0x01) && (trh->daddr[1] & 0x00) && (trh->daddr[2] & 0x5E))
 216         {
 217                 skb->pkt_type=PACKET_MULTICAST;
 218         }
 219         else if(dev->flags & IFF_PROMISC)
 220         {
 221                 if(memcmp(trh->daddr, dev->dev_addr, TR_ALEN))
 222                         skb->pkt_type=PACKET_OTHERHOST;
 223         }
 224
 225         if ((skb->pkt_type != PACKET_BROADCAST) &&
 226             (skb->pkt_type != PACKET_MULTICAST))
 227                 tr_add_rif_info(trh,dev) ;
 228
 229         /*
 230          * Strip the SNAP header from ARP packets since we don't
 231          * pass them through to the 802.2/SNAP layers.
 232          */
 233
 234         if (trllc->dsap == EXTENDED_SAP &&
 235             (trllc->ethertype == htons(ETH_P_IP) ||
 236              trllc->ethertype == htons(ETH_P_IPV6) ||
 237              trllc->ethertype == htons(ETH_P_ARP)))
 238         {
 239                 skb_pull(skb, sizeof(struct trllc));
 240                 return trllc->ethertype;
 241         }
 242
 243         return htons(ETH_P_TR_802_2);
 244 }
 245
 246 /*
 247  *      We try to do source routing...
 248  */
 249
 250 void tr_source_route(struct sk_buff *skb,struct trh_hdr *trh,
 251                      struct net_device *dev)
 252 {
 253         int slack;
 254         unsigned int hash;
 255         struct rif_cache *entry;
 256         unsigned char *olddata;
 257         unsigned long flags;
 258         static const unsigned char mcast_func_addr[]
 259                 = {0xC0,0x00,0x00,0x04,0x00,0x00};
 260
 261         spin_lock_irqsave(&rif_lock, flags);
 262
 263         /*
 264          *      Broadcasts are single route as stated in RFC 1042
 265          */
 266         if( (!memcmp(&(trh->daddr[0]),&(dev->broadcast[0]),TR_ALEN)) ||
 267             (!memcmp(&(trh->daddr[0]),&(mcast_func_addr[0]), TR_ALEN))  )
 268         {
 269                 trh->rcf=htons((((sizeof(trh->rcf)) << 8) & TR_RCF_LEN_MASK)
 270                                | TR_RCF_FRAME2K | TR_RCF_LIMITED_BROADCAST);
 271                 trh->saddr[0]|=TR_RII;
 272         }
 273         else
 274         {
 275                 hash = rif_hash(trh->daddr);
 276                 /*
 277                  *      Walk the hash table and look for an entry
 278                  */
 279                 for(entry=rif_table[hash];entry && memcmp(&(entry->addr[0]),&(trh->daddr[0]),TR_ALEN);entry=entry->next);
 280
 281                 /*
 282                  *      If we found an entry we can route the frame.
 283                  */
 284                 if(entry)
 285                 {
 286 #if TR_SR_DEBUG
 287 {
 288 DECLARE_MAC_BUF(mac);
 289 printk("source routing for %s\n",print_mac(mac, trh->daddr));
 290 }
 291 #endif
 292                         if(!entry->local_ring && (ntohs(entry->rcf) & TR_RCF_LEN_MASK) >> 8)
 293                         {
 294                                 trh->rcf=entry->rcf;
 295                                 memcpy(&trh->rseg[0],&entry->rseg[0],8*sizeof(unsigned short));
 296                                 trh->rcf^=htons(TR_RCF_DIR_BIT);
 297                                 trh->rcf&=htons(0x1fff);        /* Issam Chehab <ichehab@madge1.demon.co.uk> */
 298
 299                                 trh->saddr[0]|=TR_RII;
 300 #if TR_SR_DEBUG
 301                                 printk("entry found with rcf %04x\n", entry->rcf);
 302                         }
 303                         else
 304                         {
 305                                 printk("entry found but without rcf length, local=%02x\n", entry->local_ring);
 306 #endif
 307                         }
 308                         entry->last_used=jiffies;
 309                 }
 310                 else
 311                 {
 312                         /*
 313                          *      Without the information we simply have to shout
 314                          *      on the wire. The replies should rapidly clean this
 315                          *      situation up.
 316                          */
 317                         trh->rcf=htons((((sizeof(trh->rcf)) << 8) & TR_RCF_LEN_MASK)
 318                                        | TR_RCF_FRAME2K | TR_RCF_LIMITED_BROADCAST);
 319                         trh->saddr[0]|=TR_RII;
 320 #if TR_SR_DEBUG
 321                         printk("no entry in rif table found - broadcasting frame\n");
 322 #endif
 323                 }
 324         }
 325
 326         /* Compress the RIF here so we don't have to do it in the driver(s) */
 327         if (!(trh->saddr[0] & 0x80))
 328                 slack = 18;
 329         else
 330                 slack = 18 - ((ntohs(trh->rcf) & TR_RCF_LEN_MASK)>>8);
 331         olddata = skb->data;
 332         spin_unlock_irqrestore(&rif_lock, flags);
 333
 334         skb_pull(skb, slack);
 335         memmove(skb->data, olddata, sizeof(struct trh_hdr) - slack);
 336 }
 337
 338 /*
 339  *      We have learned some new RIF information for our source
 340  *      routing.
 341  */
 342
 343 static void tr_add_rif_info(struct trh_hdr *trh, struct net_device *dev)
 344 {
 345         unsigned int hash, rii_p = 0;
 346         unsigned long flags;
 347         struct rif_cache *entry;
 348         unsigned char saddr0;
 349
 350         spin_lock_irqsave(&rif_lock, flags);
 351         saddr0 = trh->saddr[0];
 352
 353         /*
 354          *      Firstly see if the entry exists
 355          */
 356
 357         if(trh->saddr[0] & TR_RII)
 358         {
 359                 trh->saddr[0]&=0x7f;
 360                 if (((ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8) > 2)
 361                 {
 362                         rii_p = 1;
 363                 }
 364         }
 365
 366         hash = rif_hash(trh->saddr);
 367         for(entry=rif_table[hash];entry && memcmp(&(entry->addr[0]),&(trh->saddr[0]),TR_ALEN);entry=entry->next);
 368
 369         if(entry==NULL)
 370         {
 371 #if TR_SR_DEBUG
 372                 DECLARE_MAC_BUF(mac);
 373                 printk("adding rif_entry: addr:%s rcf:%04X\n",
 374                        print_mac(mac, trh->saddr), ntohs(trh->rcf));
 375 #endif
 376                 /*
 377                  *      Allocate our new entry. A failure to allocate loses
 378                  *      use the information. This is harmless.
 379                  *
 380                  *      FIXME: We ought to keep some kind of cache size
 381                  *      limiting and adjust the timers to suit.
 382                  */
 383                 entry=kmalloc(sizeof(struct rif_cache),GFP_ATOMIC);
 384
 385                 if(!entry)
 386                 {
 387                         printk(KERN_DEBUG "tr.c: Couldn't malloc rif cache entry !\n");
 388                         spin_unlock_irqrestore(&rif_lock, flags);
 389                         return;
 390                 }
 391
 392                 memcpy(&(entry->addr[0]),&(trh->saddr[0]),TR_ALEN);
 393                 entry->iface = dev->ifindex;
 394                 entry->next=rif_table[hash];
 395                 entry->last_used=jiffies;
 396                 rif_table[hash]=entry;
 397
 398                 if (rii_p)
 399                 {
 400                         entry->rcf = trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK);
 401                         memcpy(&(entry->rseg[0]),&(trh->rseg[0]),8*sizeof(unsigned short));
 402                         entry->local_ring = 0;
 403                 }
 404                 else
 405                 {
 406                         entry->local_ring = 1;
 407                 }
 408         }
 409         else    /* Y. Tahara added */
 410         {
 411                 /*
 412                  *      Update existing entries
 413                  */
 414                 if (!entry->local_ring)
 415                     if (entry->rcf != (trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK)) &&
 416                          !(trh->rcf & htons(TR_RCF_BROADCAST_MASK)))
 417                     {
 418 #if TR_SR_DEBUG
 419 {
 420 DECLARE_MAC_BUF(mac);
 421 printk("updating rif_entry: addr:%s rcf:%04X\n",
 422                 print_mac(mac, trh->saddr), ntohs(trh->rcf));
 423 }
 424 #endif
 425                             entry->rcf = trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK);
 426                             memcpy(&(entry->rseg[0]),&(trh->rseg[0]),8*sizeof(unsigned short));
 427                     }
 428                 entry->last_used=jiffies;
 429         }
 430         trh->saddr[0]=saddr0; /* put the routing indicator back for tcpdump */
 431         spin_unlock_irqrestore(&rif_lock, flags);
 432 }
 433
 434 /*
 435  *      Scan the cache with a timer and see what we need to throw out.
 436  */
 437
 438 static void rif_check_expire(unsigned long dummy)
 439 {
 440         int i;
 441         unsigned long flags, next_interval = jiffies + sysctl_tr_rif_timeout/2;
 442
 443         spin_lock_irqsave(&rif_lock, flags);
 444
 445         for(i =0; i < RIF_TABLE_SIZE; i++) {
 446                 struct rif_cache *entry, **pentry;
 447
 448                 pentry = rif_table+i;
 449                 while((entry=*pentry) != NULL) {
 450                         unsigned long expires
 451                                 = entry->last_used + sysctl_tr_rif_timeout;
 452
 453                         if (time_before_eq(expires, jiffies)) {
 454                                 *pentry = entry->next;
 455                                 kfree(entry);
 456                         } else {
 457                                 pentry = &entry->next;
 458
 459                                 if (time_before(expires, next_interval))
 460                                         next_interval = expires;
 461                         }
 462                 }
 463         }
 464
 465         spin_unlock_irqrestore(&rif_lock, flags);
 466
 467         mod_timer(&rif_timer, next_interval);
 468
 469 }
 470
 471 /*
 472  *      Generate the /proc/net information for the token ring RIF
 473  *      routing.
 474  */
 475
 476 #ifdef CONFIG_PROC_FS
 477
 478 static struct rif_cache *rif_get_idx(loff_t pos)
 479 {
 480         int i;
 481         struct rif_cache *entry;
 482         loff_t off = 0;
 483
 484         for(i = 0; i < RIF_TABLE_SIZE; i++)
 485                 for(entry = rif_table[i]; entry; entry = entry->next) {
 486                         if (off == pos)
 487                                 return entry;
 488                         ++off;
 489                 }
 490
 491         return NULL;
 492 }
 493
 494 static void *rif_seq_start(struct seq_file *seq, loff_t *pos)
 495 {
 496         spin_lock_irq(&rif_lock);
 497
 498         return *pos ? rif_get_idx(*pos - 1) : SEQ_START_TOKEN;
 499 }
 500
 501 static void *rif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 502 {
 503         int i;
 504         struct rif_cache *ent = v;
 505
 506         ++*pos;
 507
 508         if (v == SEQ_START_TOKEN) {
 509                 i = -1;
 510                 goto scan;
 511         }
 512
 513         if (ent->next)
 514                 return ent->next;
 515
 516         i = rif_hash(ent->addr);
 517  scan:
 518         while (++i < RIF_TABLE_SIZE) {
 519                 if ((ent = rif_table[i]) != NULL)
 520                         return ent;
 521         }
 522         return NULL;
 523 }
 524
 525 static void rif_seq_stop(struct seq_file *seq, void *v)
 526 {
 527         spin_unlock_irq(&rif_lock);
 528 }
 529
 530 static int rif_seq_show(struct seq_file *seq, void *v)
 531 {
 532         int j, rcf_len, segment, brdgnmb;
 533         struct rif_cache *entry = v;
 534         DECLARE_MAC_BUF(mac);
 535
 536         if (v == SEQ_START_TOKEN)
 537                 seq_puts(seq,
 538                      "if     TR address       TTL   rcf   routing segments\n");
 539         else {
 540                 struct net_device *dev = dev_get_by_index(&init_net, entry->iface);
 541                 long ttl = (long) (entry->last_used + sysctl_tr_rif_timeout)
 542                                 - (long) jiffies;
 543
 544                 seq_printf(seq, "%s %s %7li ",
 545                            dev?dev->name:"?",
 546                            print_mac(mac, entry->addr),
 547                            ttl/HZ);
 548
 549                         if (entry->local_ring)
 550                                 seq_puts(seq, "local\n");
 551                         else {
 552
 553                                 seq_printf(seq, "%04X", ntohs(entry->rcf));
 554                                 rcf_len = ((ntohs(entry->rcf) & TR_RCF_LEN_MASK)>>8)-2;
 555                                 if (rcf_len)
 556                                         rcf_len >>= 1;
 557                                 for(j = 1; j < rcf_len; j++) {
 558                                         if(j==1) {
 559                                                 segment=ntohs(entry->rseg[j-1])>>4;
 560                                                 seq_printf(seq,"  %03X",segment);
 561                                         }
 562
 563                                         segment=ntohs(entry->rseg[j])>>4;
 564                                         brdgnmb=ntohs(entry->rseg[j-1])&0x00f;
 565                                         seq_printf(seq,"-%01X-%03X",brdgnmb,segment);
 566                                 }
 567                                 seq_putc(seq, '\n');
 568                         }
 569                 }
 570         return 0;
 571 }
 572
 573
 574 static const struct seq_operations rif_seq_ops = {
 575         .start = rif_seq_start,
 576         .next  = rif_seq_next,
 577         .stop  = rif_seq_stop,
 578         .show  = rif_seq_show,
 579 };
 580
 581 static int rif_seq_open(struct inode *inode, struct file *file)
 582 {
 583         return seq_open(file, &rif_seq_ops);
 584 }
 585
 586 static const struct file_operations rif_seq_fops = {
 587         .owner   = THIS_MODULE,
 588         .open    = rif_seq_open,
 589         .read    = seq_read,
 590         .llseek  = seq_lseek,
 591         .release = seq_release,
 592 };
 593
 594 #endif
 595
 596 static const struct header_ops tr_header_ops = {
 597         .create = tr_header,
 598         .rebuild= tr_rebuild_header,
 599 };
 600
 601 static void tr_setup(struct net_device *dev)
 602 {
 603         /*
 604          *      Configure and register
 605          */
 606
 607         dev->header_ops = &tr_header_ops;
 608
 609         dev->type               = ARPHRD_IEEE802_TR;
 610         dev->hard_header_len    = TR_HLEN;
 611         dev->mtu                = 2000;
 612         dev->addr_len           = TR_ALEN;
 613         dev->tx_queue_len       = 100;  /* Long queues on tr */
 614
 615         memset(dev->broadcast,0xFF, TR_ALEN);
 616
 617         /* New-style flags. */
 618         dev->flags              = IFF_BROADCAST | IFF_MULTICAST ;
 619 }
 620
 621 /**
 622  * alloc_trdev - Register token ring device
 623  * @sizeof_priv: Size of additional driver-private structure to be allocated
 624  *      for this token ring device
 625  *
 626  * Fill in the fields of the device structure with token ring-generic values.
 627  *
 628  * Constructs a new net device, complete with a private data area of
 629  * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
 630  * this private data area.
 631  */
 632 struct net_device *alloc_trdev(int sizeof_priv)
 633 {
 634         return alloc_netdev(sizeof_priv, "tr%d", tr_setup);
 635 }
 636
 637 /*
 638  *      Called during bootup.  We don't actually have to initialise
 639  *      too much for this.
 640  */
 641
 642 static int __init rif_init(void)
 643 {
 644         rif_timer.expires  = jiffies + sysctl_tr_rif_timeout;
 645         setup_timer(&rif_timer, rif_check_expire, 0);
 646         add_timer(&rif_timer);
 647
 648         proc_net_fops_create(&init_net, "tr_rif", S_IRUGO, &rif_seq_fops);
 649         return 0;
 650 }
 651
 652 module_init(rif_init);
 653
 654 EXPORT_SYMBOL(tr_type_trans);
 655 EXPORT_SYMBOL(alloc_trdev);