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/slab.h> 32#include <linux/if_ether.h> 33#include <linux/init.h> 34#include <linux/proc_fs.h> 35#include <linux/string.h> 36#include <linux/netfilter_decnet.h> 37#include <linux/spinlock.h> 38#include <linux/seq_file.h> 39#include <linux/rcupdate.h> 40#include <linux/jhash.h> 41#include <linux/atomic.h> 42#include <net/net_namespace.h> 43#include <net/neighbour.h> 44#include <net/dst.h> 45#include <net/flow.h> 46#include <net/dn.h> 47#include <net/dn_dev.h> 48#include <net/dn_neigh.h> 49#include <net/dn_route.h> 50 51static int dn_neigh_construct(struct neighbour *); 52static void dn_long_error_report(struct neighbour *, struct sk_buff *); 53static void dn_short_error_report(struct neighbour *, struct sk_buff *); 54static int dn_long_output(struct neighbour *, struct sk_buff *); 55static int dn_short_output(struct neighbour *, struct sk_buff *); 56static int dn_phase3_output(struct neighbour *, struct sk_buff *); 57 58 59/* 60 * For talking to broadcast devices: Ethernet & PPP 61 */ 62static const struct neigh_ops dn_long_ops = { 63 .family = AF_DECnet, 64 .error_report = dn_long_error_report, 65 .output = dn_long_output, 66 .connected_output = dn_long_output, 67}; 68 69/* 70 * For talking to pointopoint and multidrop devices: DDCMP and X.25 71 */ 72static const struct neigh_ops dn_short_ops = { 73 .family = AF_DECnet, 74 .error_report = dn_short_error_report, 75 .output = dn_short_output, 76 .connected_output = dn_short_output, 77}; 78 79/* 80 * For talking to DECnet phase III nodes 81 */ 82static const struct neigh_ops dn_phase3_ops = { 83 .family = AF_DECnet, 84 .error_report = dn_short_error_report, /* Can use short version here */ 85 .output = dn_phase3_output, 86 .connected_output = dn_phase3_output, 87}; 88 89static u32 dn_neigh_hash(const void *pkey, 90 const struct net_device *dev, 91 __u32 *hash_rnd) 92{ 93 return jhash_2words(*(__u16 *)pkey, 0, hash_rnd[0]); 94} 95 96struct neigh_table dn_neigh_table = { 97 .family = PF_DECnet, 98 .entry_size = NEIGH_ENTRY_SIZE(sizeof(struct dn_neigh)), 99 .key_len = sizeof(__le16), 100 .hash = dn_neigh_hash, 101 .constructor = dn_neigh_construct, 102 .id = "dn_neigh_cache", 103 .parms ={ 104 .tbl = &dn_neigh_table, 105 .base_reachable_time = 30 * HZ, 106 .retrans_time = 1 * HZ, 107 .gc_staletime = 60 * HZ, 108 .reachable_time = 30 * HZ, 109 .delay_probe_time = 5 * HZ, 110 .queue_len_bytes = 64*1024, 111 .ucast_probes = 0, 112 .app_probes = 0, 113 .mcast_probes = 0, 114 .anycast_delay = 0, 115 .proxy_delay = 0, 116 .proxy_qlen = 0, 117 .locktime = 1 * HZ, 118 }, 119 .gc_interval = 30 * HZ, 120 .gc_thresh1 = 128, 121 .gc_thresh2 = 512, 122 .gc_thresh3 = 1024, 123}; 124 125static int dn_neigh_construct(struct neighbour *neigh) 126{ 127 struct net_device *dev = neigh->dev; 128 struct dn_neigh *dn = (struct dn_neigh *)neigh; 129 struct dn_dev *dn_db; 130 struct neigh_parms *parms; 131 132 rcu_read_lock(); 133 dn_db = rcu_dereference(dev->dn_ptr); 134 if (dn_db == NULL) { 135 rcu_read_unlock(); 136 return -EINVAL; 137 } 138 139 parms = dn_db->neigh_parms; 140 if (!parms) { 141 rcu_read_unlock(); 142 return -EINVAL; 143 } 144 145 __neigh_parms_put(neigh->parms); 146 neigh->parms = neigh_parms_clone(parms); 147 148 if (dn_db->use_long) 149 neigh->ops = &dn_long_ops; 150 else 151 neigh->ops = &dn_short_ops; 152 rcu_read_unlock(); 153 154 if (dn->flags & DN_NDFLAG_P3) 155 neigh->ops = &dn_phase3_ops; 156 157 neigh->nud_state = NUD_NOARP; 158 neigh->output = neigh->ops->connected_output; 159 160 if ((dev->type == ARPHRD_IPGRE) || (dev->flags & IFF_POINTOPOINT)) 161 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 162 else if ((dev->type == ARPHRD_ETHER) || (dev->type == ARPHRD_LOOPBACK)) 163 dn_dn2eth(neigh->ha, dn->addr); 164 else { 165 net_dbg_ratelimited("Trying to create neigh for hw %d\n", 166 dev->type); 167 return -EINVAL; 168 } 169 170 /* 171 * Make an estimate of the remote block size by assuming that its 172 * two less then the device mtu, which it true for ethernet (and 173 * other things which support long format headers) since there is 174 * an extra length field (of 16 bits) which isn't part of the 175 * ethernet headers and which the DECnet specs won't admit is part 176 * of the DECnet routing headers either. 177 * 178 * If we over estimate here its no big deal, the NSP negotiations 179 * will prevent us from sending packets which are too large for the 180 * remote node to handle. In any case this figure is normally updated 181 * by a hello message in most cases. 182 */ 183 dn->blksize = dev->mtu - 2; 184 185 return 0; 186} 187 188static void dn_long_error_report(struct neighbour *neigh, struct sk_buff *skb) 189{ 190 printk(KERN_DEBUG "dn_long_error_report: called\n"); 191 kfree_skb(skb); 192} 193 194 195static void dn_short_error_report(struct neighbour *neigh, struct sk_buff *skb) 196{ 197 printk(KERN_DEBUG "dn_short_error_report: called\n"); 198 kfree_skb(skb); 199} 200 201static int dn_neigh_output_packet(struct sk_buff *skb) 202{ 203 struct dst_entry *dst = skb_dst(skb); 204 struct dn_route *rt = (struct dn_route *)dst; 205 struct neighbour *neigh = rt->n; 206 struct net_device *dev = neigh->dev; 207 char mac_addr[ETH_ALEN]; 208 unsigned int seq; 209 int err; 210 211 dn_dn2eth(mac_addr, rt->rt_local_src); 212 do { 213 seq = read_seqbegin(&neigh->ha_lock); 214 err = dev_hard_header(skb, dev, ntohs(skb->protocol), 215 neigh->ha, mac_addr, skb->len); 216 } while (read_seqretry(&neigh->ha_lock, seq)); 217 218 if (err >= 0) 219 err = dev_queue_xmit(skb); 220 else { 221 kfree_skb(skb); 222 err = -EINVAL; 223 } 224 return err; 225} 226 227static int dn_long_output(struct neighbour *neigh, struct sk_buff *skb) 228{ 229 struct net_device *dev = neigh->dev; 230 int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3; 231 unsigned char *data; 232 struct dn_long_packet *lp; 233 struct dn_skb_cb *cb = DN_SKB_CB(skb); 234 235 236 if (skb_headroom(skb) < headroom) { 237 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom); 238 if (skb2 == NULL) { 239 net_crit_ratelimited("dn_long_output: no memory\n"); 240 kfree_skb(skb); 241 return -ENOBUFS; 242 } 243 consume_skb(skb); 244 skb = skb2; 245 net_info_ratelimited("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) = cpu_to_le16(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(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL, 267 neigh->dev, dn_neigh_output_packet); 268} 269 270static int dn_short_output(struct neighbour *neigh, struct sk_buff *skb) 271{ 272 struct net_device *dev = neigh->dev; 273 int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2; 274 struct dn_short_packet *sp; 275 unsigned char *data; 276 struct dn_skb_cb *cb = DN_SKB_CB(skb); 277 278 279 if (skb_headroom(skb) < headroom) { 280 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom); 281 if (skb2 == NULL) { 282 net_crit_ratelimited("dn_short_output: no memory\n"); 283 kfree_skb(skb); 284 return -ENOBUFS; 285 } 286 consume_skb(skb); 287 skb = skb2; 288 net_info_ratelimited("dn_short_output: Increasing headroom\n"); 289 } 290 291 data = skb_push(skb, sizeof(struct dn_short_packet) + 2); 292 *((__le16 *)data) = cpu_to_le16(skb->len - 2); 293 sp = (struct dn_short_packet *)(data+2); 294 295 sp->msgflg = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS)); 296 sp->dstnode = cb->dst; 297 sp->srcnode = cb->src; 298 sp->forward = cb->hops & 0x3f; 299 300 skb_reset_network_header(skb); 301 302 return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL, 303 neigh->dev, dn_neigh_output_packet); 304} 305 306/* 307 * Phase 3 output is the same is short output, execpt that 308 * it clears the area bits before transmission. 309 */ 310static int dn_phase3_output(struct neighbour *neigh, struct sk_buff *skb) 311{ 312 struct net_device *dev = neigh->dev; 313 int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2; 314 struct dn_short_packet *sp; 315 unsigned char *data; 316 struct dn_skb_cb *cb = DN_SKB_CB(skb); 317 318 if (skb_headroom(skb) < headroom) { 319 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom); 320 if (skb2 == NULL) { 321 net_crit_ratelimited("dn_phase3_output: no memory\n"); 322 kfree_skb(skb); 323 return -ENOBUFS; 324 } 325 consume_skb(skb); 326 skb = skb2; 327 net_info_ratelimited("dn_phase3_output: Increasing headroom\n"); 328 } 329 330 data = skb_push(skb, sizeof(struct dn_short_packet) + 2); 331 *((__le16 *)data) = cpu_to_le16(skb->len - 2); 332 sp = (struct dn_short_packet *)(data + 2); 333 334 sp->msgflg = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS)); 335 sp->dstnode = cb->dst & cpu_to_le16(0x03ff); 336 sp->srcnode = cb->src & cpu_to_le16(0x03ff); 337 sp->forward = cb->hops & 0x3f; 338 339 skb_reset_network_header(skb); 340 341 return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL, 342 neigh->dev, dn_neigh_output_packet); 343} 344 345/* 346 * Unfortunately, the neighbour code uses the device in its hash 347 * function, so we don't get any advantage from it. This function 348 * basically does a neigh_lookup(), but without comparing the device 349 * field. This is required for the On-Ethernet cache 350 */ 351 352/* 353 * Pointopoint link receives a hello message 354 */ 355void dn_neigh_pointopoint_hello(struct sk_buff *skb) 356{ 357 kfree_skb(skb); 358} 359 360/* 361 * Ethernet router hello message received 362 */ 363int dn_neigh_router_hello(struct sk_buff *skb) 364{ 365 struct rtnode_hello_message *msg = (struct rtnode_hello_message *)skb->data; 366 367 struct neighbour *neigh; 368 struct dn_neigh *dn; 369 struct dn_dev *dn_db; 370 __le16 src; 371 372 src = dn_eth2dn(msg->id); 373 374 neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1); 375 376 dn = (struct dn_neigh *)neigh; 377 378 if (neigh) { 379 write_lock(&neigh->lock); 380 381 neigh->used = jiffies; 382 dn_db = rcu_dereference(neigh->dev->dn_ptr); 383 384 if (!(neigh->nud_state & NUD_PERMANENT)) { 385 neigh->updated = jiffies; 386 387 if (neigh->dev->type == ARPHRD_ETHER) 388 memcpy(neigh->ha, ð_hdr(skb)->h_source, ETH_ALEN); 389 390 dn->blksize = le16_to_cpu(msg->blksize); 391 dn->priority = msg->priority; 392 393 dn->flags &= ~DN_NDFLAG_P3; 394 395 switch (msg->iinfo & DN_RT_INFO_TYPE) { 396 case DN_RT_INFO_L1RT: 397 dn->flags &=~DN_NDFLAG_R2; 398 dn->flags |= DN_NDFLAG_R1; 399 break; 400 case DN_RT_INFO_L2RT: 401 dn->flags |= DN_NDFLAG_R2; 402 } 403 } 404 405 /* Only use routers in our area */ 406 if ((le16_to_cpu(src)>>10) == (le16_to_cpu((decnet_address))>>10)) { 407 if (!dn_db->router) { 408 dn_db->router = neigh_clone(neigh); 409 } else { 410 if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority) 411 neigh_release(xchg(&dn_db->router, neigh_clone(neigh))); 412 } 413 } 414 write_unlock(&neigh->lock); 415 neigh_release(neigh); 416 } 417 418 kfree_skb(skb); 419 return 0; 420} 421 422/* 423 * Endnode hello message received 424 */ 425int dn_neigh_endnode_hello(struct sk_buff *skb) 426{ 427 struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data; 428 struct neighbour *neigh; 429 struct dn_neigh *dn; 430 __le16 src; 431 432 src = dn_eth2dn(msg->id); 433 434 neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1); 435 436 dn = (struct dn_neigh *)neigh; 437 438 if (neigh) { 439 write_lock(&neigh->lock); 440 441 neigh->used = jiffies; 442 443 if (!(neigh->nud_state & NUD_PERMANENT)) { 444 neigh->updated = jiffies; 445 446 if (neigh->dev->type == ARPHRD_ETHER) 447 memcpy(neigh->ha, ð_hdr(skb)->h_source, ETH_ALEN); 448 dn->flags &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2); 449 dn->blksize = le16_to_cpu(msg->blksize); 450 dn->priority = 0; 451 } 452 453 write_unlock(&neigh->lock); 454 neigh_release(neigh); 455 } 456 457 kfree_skb(skb); 458 return 0; 459} 460 461static char *dn_find_slot(char *base, int max, int priority) 462{ 463 int i; 464 unsigned char *min = NULL; 465 466 base += 6; /* skip first id */ 467 468 for(i = 0; i < max; i++) { 469 if (!min || (*base < *min)) 470 min = base; 471 base += 7; /* find next priority */ 472 } 473 474 if (!min) 475 return NULL; 476 477 return (*min < priority) ? (min - 6) : NULL; 478} 479 480struct elist_cb_state { 481 struct net_device *dev; 482 unsigned char *ptr; 483 unsigned char *rs; 484 int t, n; 485}; 486 487static void neigh_elist_cb(struct neighbour *neigh, void *_info) 488{ 489 struct elist_cb_state *s = _info; 490 struct dn_neigh *dn; 491 492 if (neigh->dev != s->dev) 493 return; 494 495 dn = (struct dn_neigh *) neigh; 496 if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2))) 497 return; 498 499 if (s->t == s->n) 500 s->rs = dn_find_slot(s->ptr, s->n, dn->priority); 501 else 502 s->t++; 503 if (s->rs == NULL) 504 return; 505 506 dn_dn2eth(s->rs, dn->addr); 507 s->rs += 6; 508 *(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0; 509 *(s->rs) |= dn->priority; 510 s->rs++; 511} 512 513int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n) 514{ 515 struct elist_cb_state state; 516 517 state.dev = dev; 518 state.t = 0; 519 state.n = n; 520 state.ptr = ptr; 521 state.rs = ptr; 522 523 neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state); 524 525 return state.t; 526} 527 528 529#ifdef CONFIG_PROC_FS 530 531static inline void dn_neigh_format_entry(struct seq_file *seq, 532 struct neighbour *n) 533{ 534 struct dn_neigh *dn = (struct dn_neigh *) n; 535 char buf[DN_ASCBUF_LEN]; 536 537 read_lock(&n->lock); 538 seq_printf(seq, "%-7s %s%s%s %02x %02d %07ld %-8s\n", 539 dn_addr2asc(le16_to_cpu(dn->addr), buf), 540 (dn->flags&DN_NDFLAG_R1) ? "1" : "-", 541 (dn->flags&DN_NDFLAG_R2) ? "2" : "-", 542 (dn->flags&DN_NDFLAG_P3) ? "3" : "-", 543 dn->n.nud_state, 544 atomic_read(&dn->n.refcnt), 545 dn->blksize, 546 (dn->n.dev) ? dn->n.dev->name : "?"); 547 read_unlock(&n->lock); 548} 549 550static int dn_neigh_seq_show(struct seq_file *seq, void *v) 551{ 552 if (v == SEQ_START_TOKEN) { 553 seq_puts(seq, "Addr Flags State Use Blksize Dev\n"); 554 } else { 555 dn_neigh_format_entry(seq, v); 556 } 557 558 return 0; 559} 560 561static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos) 562{ 563 return neigh_seq_start(seq, pos, &dn_neigh_table, 564 NEIGH_SEQ_NEIGH_ONLY); 565} 566 567static const struct seq_operations dn_neigh_seq_ops = { 568 .start = dn_neigh_seq_start, 569 .next = neigh_seq_next, 570 .stop = neigh_seq_stop, 571 .show = dn_neigh_seq_show, 572}; 573 574static int dn_neigh_seq_open(struct inode *inode, struct file *file) 575{ 576 return seq_open_net(inode, file, &dn_neigh_seq_ops, 577 sizeof(struct neigh_seq_state)); 578} 579 580static const struct file_operations dn_neigh_seq_fops = { 581 .owner = THIS_MODULE, 582 .open = dn_neigh_seq_open, 583 .read = seq_read, 584 .llseek = seq_lseek, 585 .release = seq_release_net, 586}; 587 588#endif 589 590void __init dn_neigh_init(void) 591{ 592 neigh_table_init(&dn_neigh_table); 593 proc_create("decnet_neigh", S_IRUGO, init_net.proc_net, 594 &dn_neigh_seq_fops); 595} 596 597void __exit dn_neigh_cleanup(void) 598{ 599 remove_proc_entry("decnet_neigh", init_net.proc_net); 600 neigh_table_clear(&dn_neigh_table); 601} 602