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/config.h> 21#include <linux/types.h> 22#include <linux/kernel.h> 23#include <linux/sched.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/init.h> 37#include <net/arp.h> 38 39void tr_source_route(struct sk_buff *skb, struct trh_hdr *trh, 40 struct net_device *dev); 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 46typedef struct rif_cache_s *rif_cache; 47 48/* 49 * Each RIF entry we learn is kept this way 50 */ 51 52struct rif_cache_s { 53 unsigned char addr[TR_ALEN]; 54 int iface; 55 __u16 rcf; 56 __u16 rseg[8]; 57 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 69rif_cache rif_table[RIF_TABLE_SIZE]; 70 71static spinlock_t rif_lock = SPIN_LOCK_UNLOCKED; 72 73#define RIF_TIMEOUT 60*10*HZ 74#define RIF_CHECK_INTERVAL 60*HZ 75 76/* 77 * Garbage disposal timer. 78 */ 79 80static struct timer_list rif_timer; 81 82int sysctl_tr_rif_timeout = RIF_TIMEOUT; 83 84/* 85 * Put the headers on a token ring packet. Token ring source routing 86 * makes this a little more exciting than on ethernet. 87 */ 88 89int tr_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, 90 void *daddr, void *saddr, unsigned len) 91{ 92 struct trh_hdr *trh; 93 int hdr_len; 94 95 /* 96 * Add the 802.2 SNAP header if IP as the IPv4 code calls 97 * dev->hard_header directly. 98 */ 99 if (type == ETH_P_IP || type == ETH_P_ARP) 100 { 101 struct trllc *trllc=(struct trllc *)(trh+1); 102 103 hdr_len = sizeof(struct trh_hdr) + sizeof(struct trllc); 104 trh = (struct trh_hdr *)skb_push(skb, hdr_len); 105 trllc = (struct trllc *)(trh+1); 106 trllc->dsap = trllc->ssap = EXTENDED_SAP; 107 trllc->llc = UI_CMD; 108 trllc->protid[0] = trllc->protid[1] = trllc->protid[2] = 0x00; 109 trllc->ethertype = htons(type); 110 } 111 else 112 { 113 hdr_len = sizeof(struct trh_hdr); 114 trh = (struct trh_hdr *)skb_push(skb, hdr_len); 115 } 116 117 trh->ac=AC; 118 trh->fc=LLC_FRAME; 119 120 if(saddr) 121 memcpy(trh->saddr,saddr,dev->addr_len); 122 else 123 memcpy(trh->saddr,dev->dev_addr,dev->addr_len); 124 125 /* 126 * Build the destination and then source route the frame 127 */ 128 129 if(daddr) 130 { 131 memcpy(trh->daddr,daddr,dev->addr_len); 132 tr_source_route(skb,trh,dev); 133 return(hdr_len); 134 } 135 136 return -hdr_len; 137} 138 139/* 140 * A neighbour discovery of some species (eg arp) has completed. We 141 * can now send the packet. 142 */ 143 144int tr_rebuild_header(struct sk_buff *skb) 145{ 146 struct trh_hdr *trh=(struct trh_hdr *)skb->data; 147 struct trllc *trllc=(struct trllc *)(skb->data+sizeof(struct trh_hdr)); 148 struct net_device *dev = skb->dev; 149 150 151 if(trllc->ethertype != htons(ETH_P_IP)) { 152 printk("tr_rebuild_header: Don't know how to resolve type %04X addresses ?\n",(unsigned int)htons(trllc->ethertype)); 153 return 0; 154 } 155 156#ifdef CONFIG_INET 157 if(arp_find(trh->daddr, skb)) { 158 return 1; 159 } 160 else 161#endif 162 { 163 tr_source_route(skb,trh,dev); 164 return 0; 165 } 166} 167 168/* 169 * Some of this is a bit hackish. We intercept RIF information 170 * used for source routing. We also grab IP directly and don't feed 171 * it via SNAP. 172 */ 173 174unsigned short tr_type_trans(struct sk_buff *skb, struct net_device *dev) 175{ 176 177 struct trh_hdr *trh=(struct trh_hdr *)skb->data; 178 struct trllc *trllc; 179 unsigned riflen=0; 180 181 skb->mac.raw = skb->data; 182 183 if(trh->saddr[0] & TR_RII) 184 riflen = (ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8; 185 186 trllc = (struct trllc *)(skb->data+sizeof(struct trh_hdr)-TR_MAXRIFLEN+riflen); 187 188 skb_pull(skb,sizeof(struct trh_hdr)-TR_MAXRIFLEN+riflen); 189 190 if(*trh->daddr & 0x80) 191 { 192 if(!memcmp(trh->daddr,dev->broadcast,TR_ALEN)) 193 skb->pkt_type=PACKET_BROADCAST; 194 else 195 skb->pkt_type=PACKET_MULTICAST; 196 } 197 else if ( (trh->daddr[0] & 0x01) && (trh->daddr[1] & 0x00) && (trh->daddr[2] & 0x5E)) 198 { 199 skb->pkt_type=PACKET_MULTICAST; 200 } 201 else if(dev->flags & IFF_PROMISC) 202 { 203 if(memcmp(trh->daddr, dev->dev_addr, TR_ALEN)) 204 skb->pkt_type=PACKET_OTHERHOST; 205 } 206 207 if ((skb->pkt_type != PACKET_BROADCAST) && 208 (skb->pkt_type != PACKET_MULTICAST)) 209 tr_add_rif_info(trh,dev) ; 210 211 /* 212 * Strip the SNAP header from ARP packets since we don't 213 * pass them through to the 802.2/SNAP layers. 214 */ 215 216 if (trllc->dsap == EXTENDED_SAP && 217 (trllc->ethertype == ntohs(ETH_P_IP) || 218 trllc->ethertype == ntohs(ETH_P_ARP))) 219 { 220 skb_pull(skb, sizeof(struct trllc)); 221 return trllc->ethertype; 222 } 223 224 return ntohs(ETH_P_802_2); 225} 226 227/* 228 * We try to do source routing... 229 */ 230 231void tr_source_route(struct sk_buff *skb, struct trh_hdr *trh, 232 struct net_device *dev) 233{ 234 int i, slack; 235 unsigned int hash; 236 rif_cache entry; 237 unsigned char *olddata; 238 unsigned char mcast_func_addr[] = {0xC0,0x00,0x00,0x04,0x00,0x00}; 239 unsigned long flags ; 240 241 spin_lock_irqsave(&rif_lock,flags); 242 243 /* 244 * Broadcasts are single route as stated in RFC 1042 245 */ 246 if( (!memcmp(&(trh->daddr[0]),&(dev->broadcast[0]),TR_ALEN)) || 247 (!memcmp(&(trh->daddr[0]),&(mcast_func_addr[0]), TR_ALEN)) ) 248 { 249 trh->rcf=htons((((sizeof(trh->rcf)) << 8) & TR_RCF_LEN_MASK) 250 | TR_RCF_FRAME2K | TR_RCF_LIMITED_BROADCAST); 251 trh->saddr[0]|=TR_RII; 252 } 253 else 254 { 255 for(i=0,hash=0;i<TR_ALEN;hash+=trh->daddr[i++]); 256 hash&=RIF_TABLE_SIZE-1; 257 /* 258 * Walk the hash table and look for an entry 259 */ 260 for(entry=rif_table[hash];entry && memcmp(&(entry->addr[0]),&(trh->daddr[0]),TR_ALEN);entry=entry->next); 261 262 /* 263 * If we found an entry we can route the frame. 264 */ 265 if(entry) 266 { 267#if TR_SR_DEBUG 268printk("source routing for %02X:%02X:%02X:%02X:%02X:%02X\n",trh->daddr[0], 269 trh->daddr[1],trh->daddr[2],trh->daddr[3],trh->daddr[4],trh->daddr[5]); 270#endif 271 if(!entry->local_ring && (ntohs(entry->rcf) & TR_RCF_LEN_MASK) >> 8) 272 { 273 trh->rcf=entry->rcf; 274 memcpy(&trh->rseg[0],&entry->rseg[0],8*sizeof(unsigned short)); 275 trh->rcf^=htons(TR_RCF_DIR_BIT); 276 trh->rcf&=htons(0x1fff); /* Issam Chehab <ichehab@madge1.demon.co.uk> */ 277 278 trh->saddr[0]|=TR_RII; 279#if TR_SR_DEBUG 280 printk("entry found with rcf %04x\n", entry->rcf); 281 } 282 else 283 { 284 printk("entry found but without rcf length, local=%02x\n", entry->local_ring); 285#endif 286 } 287 entry->last_used=jiffies; 288 } 289 else 290 { 291 /* 292 * Without the information we simply have to shout 293 * on the wire. The replies should rapidly clean this 294 * situation up. 295 */ 296 trh->rcf=htons((((sizeof(trh->rcf)) << 8) & TR_RCF_LEN_MASK) 297 | TR_RCF_FRAME2K | TR_RCF_LIMITED_BROADCAST); 298 trh->saddr[0]|=TR_RII; 299#if TR_SR_DEBUG 300 printk("no entry in rif table found - broadcasting frame\n"); 301#endif 302 } 303 } 304 305 /* Compress the RIF here so we don't have to do it in the driver(s) */ 306 if (!(trh->saddr[0] & 0x80)) 307 slack = 18; 308 else 309 slack = 18 - ((ntohs(trh->rcf) & TR_RCF_LEN_MASK)>>8); 310 olddata = skb->data; 311 spin_unlock_irqrestore(&rif_lock,flags); 312 313 skb_pull(skb, slack); 314 memmove(skb->data, olddata, sizeof(struct trh_hdr) - slack); 315} 316 317/* 318 * We have learned some new RIF information for our source 319 * routing. 320 */ 321 322static void tr_add_rif_info(struct trh_hdr *trh, struct net_device *dev) 323{ 324 int i; 325 unsigned int hash, rii_p = 0; 326 rif_cache entry; 327 328 329 spin_lock_bh(&rif_lock); 330 331 /* 332 * Firstly see if the entry exists 333 */ 334 335 if(trh->saddr[0] & TR_RII) 336 { 337 trh->saddr[0]&=0x7f; 338 if (((ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8) > 2) 339 { 340 rii_p = 1; 341 } 342 } 343 344 for(i=0,hash=0;i<TR_ALEN;hash+=trh->saddr[i++]); 345 hash&=RIF_TABLE_SIZE-1; 346 for(entry=rif_table[hash];entry && memcmp(&(entry->addr[0]),&(trh->saddr[0]),TR_ALEN);entry=entry->next); 347 348 if(entry==NULL) 349 { 350#if TR_SR_DEBUG 351printk("adding rif_entry: addr:%02X:%02X:%02X:%02X:%02X:%02X rcf:%04X\n", 352 trh->saddr[0],trh->saddr[1],trh->saddr[2], 353 trh->saddr[3],trh->saddr[4],trh->saddr[5], 354 ntohs(trh->rcf)); 355#endif 356 entry=kmalloc(sizeof(struct rif_cache_s),GFP_ATOMIC); 357 358 if(!entry) 359 { 360 printk(KERN_DEBUG "tr.c: Couldn't malloc rif cache entry !\n"); 361 spin_unlock_bh(&rif_lock); 362 return; 363 } 364 365 memcpy(&(entry->addr[0]),&(trh->saddr[0]),TR_ALEN); 366 entry->iface = dev->ifindex; 367 entry->next=rif_table[hash]; 368 entry->last_used=jiffies; 369 rif_table[hash]=entry; 370 371 if (rii_p) 372 { 373 entry->rcf = trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK); 374 memcpy(&(entry->rseg[0]),&(trh->rseg[0]),8*sizeof(unsigned short)); 375 entry->local_ring = 0; 376 trh->saddr[0]|=TR_RII; /* put the routing indicator back for tcpdump */ 377 } 378 else 379 { 380 entry->local_ring = 1; 381 } 382 } 383 else /* Y. Tahara added */ 384 { 385 /* 386 * Update existing entries 387 */ 388 if (!entry->local_ring) 389 if (entry->rcf != (trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK)) && 390 !(trh->rcf & htons(TR_RCF_BROADCAST_MASK))) 391 { 392#if TR_SR_DEBUG 393printk("updating rif_entry: addr:%02X:%02X:%02X:%02X:%02X:%02X rcf:%04X\n", 394 trh->saddr[0],trh->saddr[1],trh->saddr[2], 395 trh->saddr[3],trh->saddr[4],trh->saddr[5], 396 ntohs(trh->rcf)); 397#endif 398 entry->rcf = trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK); 399 memcpy(&(entry->rseg[0]),&(trh->rseg[0]),8*sizeof(unsigned short)); 400 } 401 entry->last_used=jiffies; 402 } 403 spin_unlock_bh(&rif_lock); 404} 405 406/* 407 * Scan the cache with a timer and see what we need to throw out. 408 */ 409 410static void rif_check_expire(unsigned long dummy) 411{ 412 int i; 413 unsigned long now=jiffies; 414 unsigned long flags ; 415 416 spin_lock_irqsave(&rif_lock,flags); 417 418 for(i=0; i < RIF_TABLE_SIZE;i++) 419 { 420 rif_cache entry, *pentry=rif_table+i; 421 while((entry=*pentry)) 422 { 423 /* 424 * Out it goes 425 */ 426 if((now-entry->last_used) > sysctl_tr_rif_timeout) 427 { 428 *pentry=entry->next; 429 kfree(entry); 430 } 431 else 432 pentry=&entry->next; 433 } 434 } 435 436 spin_unlock_irqrestore(&rif_lock,flags); 437 438 /* 439 * Reset the timer 440 */ 441 442 mod_timer(&rif_timer, jiffies+sysctl_tr_rif_timeout); 443 444} 445 446/* 447 * Generate the /proc/net information for the token ring RIF 448 * routing. 449 */ 450 451#ifndef CONFIG_PROC_FS 452static int rif_get_info(char *buffer,char **start, off_t offset, int length) { return 0;} 453#else 454static int rif_get_info(char *buffer,char **start, off_t offset, int length) 455{ 456 int len=0; 457 off_t begin=0; 458 off_t pos=0; 459 int size,i,j,rcf_len,segment,brdgnmb; 460 unsigned long now=jiffies; 461 462 rif_cache entry; 463 464 size=sprintf(buffer, 465 "if TR address TTL rcf routing segments\n"); 466 pos+=size; 467 len+=size; 468 469 spin_lock_bh(&rif_lock); 470 for(i=0;i < RIF_TABLE_SIZE;i++) 471 { 472 for(entry=rif_table[i];entry;entry=entry->next) { 473 struct net_device *dev = __dev_get_by_index(entry->iface); 474 475 size=sprintf(buffer+len,"%s %02X:%02X:%02X:%02X:%02X:%02X %7li ", 476 dev?dev->name:"?",entry->addr[0],entry->addr[1],entry->addr[2],entry->addr[3],entry->addr[4],entry->addr[5], 477 sysctl_tr_rif_timeout-(now-entry->last_used)); 478 len+=size; 479 pos=begin+len; 480 if (entry->local_ring) 481 size=sprintf(buffer+len,"local\n"); 482 else { 483 size=sprintf(buffer+len,"%04X", ntohs(entry->rcf)); 484 rcf_len = ((ntohs(entry->rcf) & TR_RCF_LEN_MASK)>>8)-2; 485 if (rcf_len) 486 rcf_len >>= 1; 487 for(j = 1; j < rcf_len; j++) { 488 if(j==1) { 489 segment=ntohs(entry->rseg[j-1])>>4; 490 len+=size; 491 pos=begin+len; 492 size=sprintf(buffer+len," %03X",segment); 493 }; 494 segment=ntohs(entry->rseg[j])>>4; 495 brdgnmb=ntohs(entry->rseg[j-1])&0x00f; 496 len+=size; 497 pos=begin+len; 498 size=sprintf(buffer+len,"-%01X-%03X",brdgnmb,segment); 499 } 500 len+=size; 501 pos=begin+len; 502 size=sprintf(buffer+len,"\n"); 503 } 504 len+=size; 505 pos=begin+len; 506 507 if(pos<offset) 508 { 509 len=0; 510 begin=pos; 511 } 512 if(pos>offset+length) 513 break; 514 } 515 if(pos>offset+length) 516 break; 517 } 518 spin_unlock_bh(&rif_lock); 519 520 *start=buffer+(offset-begin); /* Start of wanted data */ 521 len-=(offset-begin); /* Start slop */ 522 if(len>length) 523 len=length; /* Ending slop */ 524 if (len<0) 525 len=0; 526 return len; 527} 528#endif 529 530/* 531 * Called during bootup. We don't actually have to initialise 532 * too much for this. 533 */ 534 535static int __init rif_init(void) 536{ 537 rif_timer.expires = RIF_TIMEOUT; 538 rif_timer.data = 0L; 539 rif_timer.function = rif_check_expire; 540 init_timer(&rif_timer); 541 add_timer(&rif_timer); 542 543 proc_net_create("tr_rif",0,rif_get_info); 544 return 0; 545} 546 547module_init(rif_init); 548