1/* 2 * DECnet An implementation of the DECnet protocol suite for the LINUX 3 * operating system. DECnet is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * DECnet Neighbour Functions (Adjacency Database and 7 * On-Ethernet Cache) 8 * 9 * Author: Steve Whitehouse <SteveW@ACM.org> 10 * 11 * 12 * Changes: 13 * Steve Whitehouse : Fixed router listing routine 14 * Steve Whitehouse : Added error_report functions 15 * Steve Whitehouse : Added default router detection 16 * Steve Whitehouse : Hop counts in outgoing messages 17 * Steve Whitehouse : Fixed src/dst in outgoing messages so 18 * forwarding now stands a good chance of 19 * working. 20 * Steve Whitehouse : Fixed neighbour states (for now anyway). 21 * Steve Whitehouse : Made error_report functions dummies. This 22 * is not the right place to return skbs. 23 * Steve Whitehouse : Convert to seq_file 24 * 25 */ 26 27#include <linux/net.h> 28#include <linux/module.h> 29#include <linux/socket.h> 30#include <linux/if_arp.h> 31#include <linux/if_ether.h> 32#include <linux/init.h> 33#include <linux/proc_fs.h> 34#include <linux/string.h> 35#include <linux/netfilter_decnet.h> 36#include <linux/spinlock.h> 37#include <linux/seq_file.h> 38#include <linux/rcupdate.h> 39#include <linux/jhash.h> 40#include <asm/atomic.h> 41#include <net/neighbour.h> 42#include <net/dst.h> 43#include <net/flow.h> 44#include <net/dn.h> 45#include <net/dn_dev.h> 46#include <net/dn_neigh.h> 47#include <net/dn_route.h> 48 49static u32 dn_neigh_hash(const void *pkey, const struct net_device *dev); 50static int dn_neigh_construct(struct neighbour *); 51static void dn_long_error_report(struct neighbour *, struct sk_buff *); 52static void dn_short_error_report(struct neighbour *, struct sk_buff *); 53static int dn_long_output(struct sk_buff *); 54static int dn_short_output(struct sk_buff *); 55static int dn_phase3_output(struct sk_buff *); 56 57 58/* 59 * For talking to broadcast devices: Ethernet & PPP 60 */ 61static struct neigh_ops dn_long_ops = { 62 .family = AF_DECnet, 63 .error_report = dn_long_error_report, 64 .output = dn_long_output, 65 .connected_output = dn_long_output, 66 .hh_output = dev_queue_xmit, 67 .queue_xmit = dev_queue_xmit, 68}; 69 70/* 71 * For talking to pointopoint and multidrop devices: DDCMP and X.25 72 */ 73static struct neigh_ops dn_short_ops = { 74 .family = AF_DECnet, 75 .error_report = dn_short_error_report, 76 .output = dn_short_output, 77 .connected_output = dn_short_output, 78 .hh_output = dev_queue_xmit, 79 .queue_xmit = dev_queue_xmit, 80}; 81 82/* 83 * For talking to DECnet phase III nodes 84 */ 85static struct neigh_ops dn_phase3_ops = { 86 .family = AF_DECnet, 87 .error_report = dn_short_error_report, /* Can use short version here */ 88 .output = dn_phase3_output, 89 .connected_output = dn_phase3_output, 90 .hh_output = dev_queue_xmit, 91 .queue_xmit = dev_queue_xmit 92}; 93 94struct neigh_table dn_neigh_table = { 95 .family = PF_DECnet, 96 .entry_size = sizeof(struct dn_neigh), 97 .key_len = sizeof(__le16), 98 .hash = dn_neigh_hash, 99 .constructor = dn_neigh_construct, 100 .id = "dn_neigh_cache", 101 .parms ={ 102 .tbl = &dn_neigh_table, 103 .base_reachable_time = 30 * HZ, 104 .retrans_time = 1 * HZ, 105 .gc_staletime = 60 * HZ, 106 .reachable_time = 30 * HZ, 107 .delay_probe_time = 5 * HZ, 108 .queue_len = 3, 109 .ucast_probes = 0, 110 .app_probes = 0, 111 .mcast_probes = 0, 112 .anycast_delay = 0, 113 .proxy_delay = 0, 114 .proxy_qlen = 0, 115 .locktime = 1 * HZ, 116 }, 117 .gc_interval = 30 * HZ, 118 .gc_thresh1 = 128, 119 .gc_thresh2 = 512, 120 .gc_thresh3 = 1024, 121}; 122 123static u32 dn_neigh_hash(const void *pkey, const struct net_device *dev) 124{ 125 return jhash_2words(*(__u16 *)pkey, 0, dn_neigh_table.hash_rnd); 126} 127 128static int dn_neigh_construct(struct neighbour *neigh) 129{ 130 struct net_device *dev = neigh->dev; 131 struct dn_neigh *dn = (struct dn_neigh *)neigh; 132 struct dn_dev *dn_db; 133 struct neigh_parms *parms; 134 135 rcu_read_lock(); 136 dn_db = rcu_dereference(dev->dn_ptr); 137 if (dn_db == NULL) { 138 rcu_read_unlock(); 139 return -EINVAL; 140 } 141 142 parms = dn_db->neigh_parms; 143 if (!parms) { 144 rcu_read_unlock(); 145 return -EINVAL; 146 } 147 148 __neigh_parms_put(neigh->parms); 149 neigh->parms = neigh_parms_clone(parms); 150 151 if (dn_db->use_long) 152 neigh->ops = &dn_long_ops; 153 else 154 neigh->ops = &dn_short_ops; 155 rcu_read_unlock(); 156 157 if (dn->flags & DN_NDFLAG_P3) 158 neigh->ops = &dn_phase3_ops; 159 160 neigh->nud_state = NUD_NOARP; 161 neigh->output = neigh->ops->connected_output; 162 163 if ((dev->type == ARPHRD_IPGRE) || (dev->flags & IFF_POINTOPOINT)) 164 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 165 else if ((dev->type == ARPHRD_ETHER) || (dev->type == ARPHRD_LOOPBACK)) 166 dn_dn2eth(neigh->ha, dn->addr); 167 else { 168 if (net_ratelimit()) 169 printk(KERN_DEBUG "Trying to create neigh for hw %d\n", dev->type); 170 return -EINVAL; 171 } 172 173 /* 174 * Make an estimate of the remote block size by assuming that its 175 * two less then the device mtu, which it true for ethernet (and 176 * other things which support long format headers) since there is 177 * an extra length field (of 16 bits) which isn't part of the 178 * ethernet headers and which the DECnet specs won't admit is part 179 * of the DECnet routing headers either. 180 * 181 * If we over estimate here its no big deal, the NSP negotiations 182 * will prevent us from sending packets which are too large for the 183 * remote node to handle. In any case this figure is normally updated 184 * by a hello message in most cases. 185 */ 186 dn->blksize = dev->mtu - 2; 187 188 return 0; 189} 190 191static void dn_long_error_report(struct neighbour *neigh, struct sk_buff *skb) 192{ 193 printk(KERN_DEBUG "dn_long_error_report: called\n"); 194 kfree_skb(skb); 195} 196 197 198static void dn_short_error_report(struct neighbour *neigh, struct sk_buff *skb) 199{ 200 printk(KERN_DEBUG "dn_short_error_report: called\n"); 201 kfree_skb(skb); 202} 203 204static int dn_neigh_output_packet(struct sk_buff *skb) 205{ 206 struct dst_entry *dst = skb->dst; 207 struct dn_route *rt = (struct dn_route *)dst; 208 struct neighbour *neigh = dst->neighbour; 209 struct net_device *dev = neigh->dev; 210 char mac_addr[ETH_ALEN]; 211 212 dn_dn2eth(mac_addr, rt->rt_local_src); 213 if (!dev->hard_header || dev->hard_header(skb, dev, ntohs(skb->protocol), neigh->ha, mac_addr, skb->len) >= 0) 214 return neigh->ops->queue_xmit(skb); 215 216 if (net_ratelimit()) 217 printk(KERN_DEBUG "dn_neigh_output_packet: oops, can't send packet\n"); 218 219 kfree_skb(skb); 220 return -EINVAL; 221} 222 223static int dn_long_output(struct sk_buff *skb) 224{ 225 struct dst_entry *dst = skb->dst; 226 struct neighbour *neigh = dst->neighbour; 227 struct net_device *dev = neigh->dev; 228 int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3; 229 unsigned char *data; 230 struct dn_long_packet *lp; 231 struct dn_skb_cb *cb = DN_SKB_CB(skb); 232 233 234 if (skb_headroom(skb) < headroom) { 235 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom); 236 if (skb2 == NULL) { 237 if (net_ratelimit()) 238 printk(KERN_CRIT "dn_long_output: no memory\n"); 239 kfree_skb(skb); 240 return -ENOBUFS; 241 } 242 kfree_skb(skb); 243 skb = skb2; 244 if (net_ratelimit()) 245 printk(KERN_INFO "dn_long_output: Increasing headroom\n"); 246 } 247 248 data = skb_push(skb, sizeof(struct dn_long_packet) + 3); 249 lp = (struct dn_long_packet *)(data+3); 250 251 *((__le16 *)data) = dn_htons(skb->len - 2); 252 *(data + 2) = 1 | DN_RT_F_PF; /* Padding */ 253 254 lp->msgflg = DN_RT_PKT_LONG|(cb->rt_flags&(DN_RT_F_IE|DN_RT_F_RQR|DN_RT_F_RTS)); 255 lp->d_area = lp->d_subarea = 0; 256 dn_dn2eth(lp->d_id, cb->dst); 257 lp->s_area = lp->s_subarea = 0; 258 dn_dn2eth(lp->s_id, cb->src); 259 lp->nl2 = 0; 260 lp->visit_ct = cb->hops & 0x3f; 261 lp->s_class = 0; 262 lp->pt = 0; 263 264 skb_reset_network_header(skb); 265 266 return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet); 267} 268 269static int dn_short_output(struct sk_buff *skb) 270{ 271 struct dst_entry *dst = skb->dst; 272 struct neighbour *neigh = dst->neighbour; 273 struct net_device *dev = neigh->dev; 274 int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2; 275 struct dn_short_packet *sp; 276 unsigned char *data; 277 struct dn_skb_cb *cb = DN_SKB_CB(skb); 278 279 280 if (skb_headroom(skb) < headroom) { 281 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom); 282 if (skb2 == NULL) { 283 if (net_ratelimit()) 284 printk(KERN_CRIT "dn_short_output: no memory\n"); 285 kfree_skb(skb); 286 return -ENOBUFS; 287 } 288 kfree_skb(skb); 289 skb = skb2; 290 if (net_ratelimit()) 291 printk(KERN_INFO "dn_short_output: Increasing headroom\n"); 292 } 293 294 data = skb_push(skb, sizeof(struct dn_short_packet) + 2); 295 *((__le16 *)data) = dn_htons(skb->len - 2); 296 sp = (struct dn_short_packet *)(data+2); 297 298 sp->msgflg = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS)); 299 sp->dstnode = cb->dst; 300 sp->srcnode = cb->src; 301 sp->forward = cb->hops & 0x3f; 302 303 skb_reset_network_header(skb); 304 305 return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet); 306} 307 308/* 309 * Phase 3 output is the same is short output, execpt that 310 * it clears the area bits before transmission. 311 */ 312static int dn_phase3_output(struct sk_buff *skb) 313{ 314 struct dst_entry *dst = skb->dst; 315 struct neighbour *neigh = dst->neighbour; 316 struct net_device *dev = neigh->dev; 317 int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2; 318 struct dn_short_packet *sp; 319 unsigned char *data; 320 struct dn_skb_cb *cb = DN_SKB_CB(skb); 321 322 if (skb_headroom(skb) < headroom) { 323 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom); 324 if (skb2 == NULL) { 325 if (net_ratelimit()) 326 printk(KERN_CRIT "dn_phase3_output: no memory\n"); 327 kfree_skb(skb); 328 return -ENOBUFS; 329 } 330 kfree_skb(skb); 331 skb = skb2; 332 if (net_ratelimit()) 333 printk(KERN_INFO "dn_phase3_output: Increasing headroom\n"); 334 } 335 336 data = skb_push(skb, sizeof(struct dn_short_packet) + 2); 337 *((__le16 *)data) = dn_htons(skb->len - 2); 338 sp = (struct dn_short_packet *)(data + 2); 339 340 sp->msgflg = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS)); 341 sp->dstnode = cb->dst & dn_htons(0x03ff); 342 sp->srcnode = cb->src & dn_htons(0x03ff); 343 sp->forward = cb->hops & 0x3f; 344 345 skb_reset_network_header(skb); 346 347 return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet); 348} 349 350/* 351 * Unfortunately, the neighbour code uses the device in its hash 352 * function, so we don't get any advantage from it. This function 353 * basically does a neigh_lookup(), but without comparing the device 354 * field. This is required for the On-Ethernet cache 355 */ 356 357/* 358 * Pointopoint link receives a hello message 359 */ 360void dn_neigh_pointopoint_hello(struct sk_buff *skb) 361{ 362 kfree_skb(skb); 363} 364 365/* 366 * Ethernet router hello message received 367 */ 368int dn_neigh_router_hello(struct sk_buff *skb) 369{ 370 struct rtnode_hello_message *msg = (struct rtnode_hello_message *)skb->data; 371 372 struct neighbour *neigh; 373 struct dn_neigh *dn; 374 struct dn_dev *dn_db; 375 __le16 src; 376 377 src = dn_eth2dn(msg->id); 378 379 neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1); 380 381 dn = (struct dn_neigh *)neigh; 382 383 if (neigh) { 384 write_lock(&neigh->lock); 385 386 neigh->used = jiffies; 387 dn_db = (struct dn_dev *)neigh->dev->dn_ptr; 388 389 if (!(neigh->nud_state & NUD_PERMANENT)) { 390 neigh->updated = jiffies; 391 392 if (neigh->dev->type == ARPHRD_ETHER) 393 memcpy(neigh->ha, ð_hdr(skb)->h_source, ETH_ALEN); 394 395 dn->blksize = dn_ntohs(msg->blksize); 396 dn->priority = msg->priority; 397 398 dn->flags &= ~DN_NDFLAG_P3; 399 400 switch(msg->iinfo & DN_RT_INFO_TYPE) { 401 case DN_RT_INFO_L1RT: 402 dn->flags &=~DN_NDFLAG_R2; 403 dn->flags |= DN_NDFLAG_R1; 404 break; 405 case DN_RT_INFO_L2RT: 406 dn->flags |= DN_NDFLAG_R2; 407 } 408 } 409 410 /* Only use routers in our area */ 411 if ((dn_ntohs(src)>>10) == (dn_ntohs((decnet_address))>>10)) { 412 if (!dn_db->router) { 413 dn_db->router = neigh_clone(neigh); 414 } else { 415 if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority) 416 neigh_release(xchg(&dn_db->router, neigh_clone(neigh))); 417 } 418 } 419 write_unlock(&neigh->lock); 420 neigh_release(neigh); 421 } 422 423 kfree_skb(skb); 424 return 0; 425} 426 427/* 428 * Endnode hello message received 429 */ 430int dn_neigh_endnode_hello(struct sk_buff *skb) 431{ 432 struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data; 433 struct neighbour *neigh; 434 struct dn_neigh *dn; 435 __le16 src; 436 437 src = dn_eth2dn(msg->id); 438 439 neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1); 440 441 dn = (struct dn_neigh *)neigh; 442 443 if (neigh) { 444 write_lock(&neigh->lock); 445 446 neigh->used = jiffies; 447 448 if (!(neigh->nud_state & NUD_PERMANENT)) { 449 neigh->updated = jiffies; 450 451 if (neigh->dev->type == ARPHRD_ETHER) 452 memcpy(neigh->ha, ð_hdr(skb)->h_source, ETH_ALEN); 453 dn->flags &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2); 454 dn->blksize = dn_ntohs(msg->blksize); 455 dn->priority = 0; 456 } 457 458 write_unlock(&neigh->lock); 459 neigh_release(neigh); 460 } 461 462 kfree_skb(skb); 463 return 0; 464} 465 466static char *dn_find_slot(char *base, int max, int priority) 467{ 468 int i; 469 unsigned char *min = NULL; 470 471 base += 6; /* skip first id */ 472 473 for(i = 0; i < max; i++) { 474 if (!min || (*base < *min)) 475 min = base; 476 base += 7; /* find next priority */ 477 } 478 479 if (!min) 480 return NULL; 481 482 return (*min < priority) ? (min - 6) : NULL; 483} 484 485struct elist_cb_state { 486 struct net_device *dev; 487 unsigned char *ptr; 488 unsigned char *rs; 489 int t, n; 490}; 491 492static void neigh_elist_cb(struct neighbour *neigh, void *_info) 493{ 494 struct elist_cb_state *s = _info; 495 struct dn_neigh *dn; 496 497 if (neigh->dev != s->dev) 498 return; 499 500 dn = (struct dn_neigh *) neigh; 501 if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2))) 502 return; 503 504 if (s->t == s->n) 505 s->rs = dn_find_slot(s->ptr, s->n, dn->priority); 506 else 507 s->t++; 508 if (s->rs == NULL) 509 return; 510 511 dn_dn2eth(s->rs, dn->addr); 512 s->rs += 6; 513 *(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0; 514 *(s->rs) |= dn->priority; 515 s->rs++; 516} 517 518int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n) 519{ 520 struct elist_cb_state state; 521 522 state.dev = dev; 523 state.t = 0; 524 state.n = n; 525 state.ptr = ptr; 526 state.rs = ptr; 527 528 neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state); 529 530 return state.t; 531} 532 533 534#ifdef CONFIG_PROC_FS 535 536static inline void dn_neigh_format_entry(struct seq_file *seq, 537 struct neighbour *n) 538{ 539 struct dn_neigh *dn = (struct dn_neigh *) n; 540 char buf[DN_ASCBUF_LEN]; 541 542 read_lock(&n->lock); 543 seq_printf(seq, "%-7s %s%s%s %02x %02d %07ld %-8s\n", 544 dn_addr2asc(dn_ntohs(dn->addr), buf), 545 (dn->flags&DN_NDFLAG_R1) ? "1" : "-", 546 (dn->flags&DN_NDFLAG_R2) ? "2" : "-", 547 (dn->flags&DN_NDFLAG_P3) ? "3" : "-", 548 dn->n.nud_state, 549 atomic_read(&dn->n.refcnt), 550 dn->blksize, 551 (dn->n.dev) ? dn->n.dev->name : "?"); 552 read_unlock(&n->lock); 553} 554 555static int dn_neigh_seq_show(struct seq_file *seq, void *v) 556{ 557 if (v == SEQ_START_TOKEN) { 558 seq_puts(seq, "Addr Flags State Use Blksize Dev\n"); 559 } else { 560 dn_neigh_format_entry(seq, v); 561 } 562 563 return 0; 564} 565 566static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos) 567{ 568 return neigh_seq_start(seq, pos, &dn_neigh_table, 569 NEIGH_SEQ_NEIGH_ONLY); 570} 571 572static struct seq_operations dn_neigh_seq_ops = { 573 .start = dn_neigh_seq_start, 574 .next = neigh_seq_next, 575 .stop = neigh_seq_stop, 576 .show = dn_neigh_seq_show, 577}; 578 579static int dn_neigh_seq_open(struct inode *inode, struct file *file) 580{ 581 struct seq_file *seq; 582 int rc = -ENOMEM; 583 struct neigh_seq_state *s = kzalloc(sizeof(*s), GFP_KERNEL); 584 585 if (!s) 586 goto out; 587 588 rc = seq_open(file, &dn_neigh_seq_ops); 589 if (rc) 590 goto out_kfree; 591 592 seq = file->private_data; 593 seq->private = s; 594out: 595 return rc; 596out_kfree: 597 kfree(s); 598 goto out; 599} 600 601static const struct file_operations dn_neigh_seq_fops = { 602 .owner = THIS_MODULE, 603 .open = dn_neigh_seq_open, 604 .read = seq_read, 605 .llseek = seq_lseek, 606 .release = seq_release_private, 607}; 608 609#endif 610 611void __init dn_neigh_init(void) 612{ 613 neigh_table_init(&dn_neigh_table); 614 proc_net_fops_create("decnet_neigh", S_IRUGO, &dn_neigh_seq_fops); 615} 616 617void __exit dn_neigh_cleanup(void) 618{ 619 proc_net_remove("decnet_neigh"); 620 neigh_table_clear(&dn_neigh_table); 621} 622