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 Routing Functions (Endnode and Router) 7 * 8 * Authors: Steve Whitehouse <SteveW@ACM.org> 9 * Eduardo Marcelo Serrat <emserrat@geocities.com> 10 * 11 * Changes: 12 * Steve Whitehouse : Fixes to allow "intra-ethernet" and 13 * "return-to-sender" bits on outgoing 14 * packets. 15 * Steve Whitehouse : Timeouts for cached routes. 16 * Steve Whitehouse : Use dst cache for input routes too. 17 * Steve Whitehouse : Fixed error values in dn_send_skb. 18 * Steve Whitehouse : Rework routing functions to better fit 19 * DECnet routing design 20 * Alexey Kuznetsov : New SMP locking 21 * Steve Whitehouse : More SMP locking changes & dn_cache_dump() 22 * Steve Whitehouse : Prerouting NF hook, now really is prerouting. 23 * Fixed possible skb leak in rtnetlink funcs. 24 * Steve Whitehouse : Dave Miller's dynamic hash table sizing and 25 * Alexey Kuznetsov's finer grained locking 26 * from ipv4/route.c. 27 * Steve Whitehouse : Routing is now starting to look like a 28 * sensible set of code now, mainly due to 29 * my copying the IPv4 routing code. The 30 * hooks here are modified and will continue 31 * to evolve for a while. 32 * Steve Whitehouse : Real SMP at last :-) Also new netfilter 33 * stuff. Look out raw sockets your days 34 * are numbered! 35 * Steve Whitehouse : Added return-to-sender functions. Added 36 * backlog congestion level return codes. 37 * Steve Whitehouse : Fixed bug where routes were set up with 38 * no ref count on net devices. 39 * Steve Whitehouse : RCU for the route cache 40 * Steve Whitehouse : Preparations for the flow cache 41 * Steve Whitehouse : Prepare for nonlinear skbs 42 */ 43 44/****************************************************************************** 45 (c) 1995-1998 E.M. Serrat emserrat@geocities.com 46 47 This program is free software; you can redistribute it and/or modify 48 it under the terms of the GNU General Public License as published by 49 the Free Software Foundation; either version 2 of the License, or 50 any later version. 51 52 This program is distributed in the hope that it will be useful, 53 but WITHOUT ANY WARRANTY; without even the implied warranty of 54 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 55 GNU General Public License for more details. 56*******************************************************************************/ 57 58#include <linux/errno.h> 59#include <linux/types.h> 60#include <linux/socket.h> 61#include <linux/in.h> 62#include <linux/kernel.h> 63#include <linux/sockios.h> 64#include <linux/net.h> 65#include <linux/netdevice.h> 66#include <linux/inet.h> 67#include <linux/route.h> 68#include <linux/in_route.h> 69#include <linux/slab.h> 70#include <net/sock.h> 71#include <linux/mm.h> 72#include <linux/proc_fs.h> 73#include <linux/seq_file.h> 74#include <linux/init.h> 75#include <linux/rtnetlink.h> 76#include <linux/string.h> 77#include <linux/netfilter_decnet.h> 78#include <linux/rcupdate.h> 79#include <linux/times.h> 80#include <linux/export.h> 81#include <asm/errno.h> 82#include <net/net_namespace.h> 83#include <net/netlink.h> 84#include <net/neighbour.h> 85#include <net/dst.h> 86#include <net/flow.h> 87#include <net/fib_rules.h> 88#include <net/dn.h> 89#include <net/dn_dev.h> 90#include <net/dn_nsp.h> 91#include <net/dn_route.h> 92#include <net/dn_neigh.h> 93#include <net/dn_fib.h> 94 95struct dn_rt_hash_bucket 96{ 97 struct dn_route __rcu *chain; 98 spinlock_t lock; 99}; 100 101extern struct neigh_table dn_neigh_table; 102 103 104static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00}; 105 106static const int dn_rt_min_delay = 2 * HZ; 107static const int dn_rt_max_delay = 10 * HZ; 108static const int dn_rt_mtu_expires = 10 * 60 * HZ; 109 110static unsigned long dn_rt_deadline; 111 112static int dn_dst_gc(struct dst_ops *ops); 113static struct dst_entry *dn_dst_check(struct dst_entry *, __u32); 114static unsigned int dn_dst_default_advmss(const struct dst_entry *dst); 115static unsigned int dn_dst_mtu(const struct dst_entry *dst); 116static void dn_dst_destroy(struct dst_entry *); 117static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how); 118static struct dst_entry *dn_dst_negative_advice(struct dst_entry *); 119static void dn_dst_link_failure(struct sk_buff *); 120static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk, 121 struct sk_buff *skb , u32 mtu); 122static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk, 123 struct sk_buff *skb); 124static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst, 125 struct sk_buff *skb, 126 const void *daddr); 127static int dn_route_input(struct sk_buff *); 128static void dn_run_flush(unsigned long dummy); 129 130static struct dn_rt_hash_bucket *dn_rt_hash_table; 131static unsigned int dn_rt_hash_mask; 132 133static struct timer_list dn_route_timer; 134static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0); 135int decnet_dst_gc_interval = 2; 136 137static struct dst_ops dn_dst_ops = { 138 .family = PF_DECnet, 139 .gc_thresh = 128, 140 .gc = dn_dst_gc, 141 .check = dn_dst_check, 142 .default_advmss = dn_dst_default_advmss, 143 .mtu = dn_dst_mtu, 144 .cow_metrics = dst_cow_metrics_generic, 145 .destroy = dn_dst_destroy, 146 .ifdown = dn_dst_ifdown, 147 .negative_advice = dn_dst_negative_advice, 148 .link_failure = dn_dst_link_failure, 149 .update_pmtu = dn_dst_update_pmtu, 150 .redirect = dn_dst_redirect, 151 .neigh_lookup = dn_dst_neigh_lookup, 152}; 153 154static void dn_dst_destroy(struct dst_entry *dst) 155{ 156 struct dn_route *rt = (struct dn_route *) dst; 157 158 if (rt->n) 159 neigh_release(rt->n); 160 dst_destroy_metrics_generic(dst); 161} 162 163static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how) 164{ 165 if (how) { 166 struct dn_route *rt = (struct dn_route *) dst; 167 struct neighbour *n = rt->n; 168 169 if (n && n->dev == dev) { 170 n->dev = dev_net(dev)->loopback_dev; 171 dev_hold(n->dev); 172 dev_put(dev); 173 } 174 } 175} 176 177static __inline__ unsigned int dn_hash(__le16 src, __le16 dst) 178{ 179 __u16 tmp = (__u16 __force)(src ^ dst); 180 tmp ^= (tmp >> 3); 181 tmp ^= (tmp >> 5); 182 tmp ^= (tmp >> 10); 183 return dn_rt_hash_mask & (unsigned int)tmp; 184} 185 186static inline void dnrt_free(struct dn_route *rt) 187{ 188 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); 189} 190 191static inline void dnrt_drop(struct dn_route *rt) 192{ 193 dst_release(&rt->dst); 194 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); 195} 196 197static void dn_dst_check_expire(unsigned long dummy) 198{ 199 int i; 200 struct dn_route *rt; 201 struct dn_route __rcu **rtp; 202 unsigned long now = jiffies; 203 unsigned long expire = 120 * HZ; 204 205 for (i = 0; i <= dn_rt_hash_mask; i++) { 206 rtp = &dn_rt_hash_table[i].chain; 207 208 spin_lock(&dn_rt_hash_table[i].lock); 209 while ((rt = rcu_dereference_protected(*rtp, 210 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) { 211 if (atomic_read(&rt->dst.__refcnt) || 212 (now - rt->dst.lastuse) < expire) { 213 rtp = &rt->dst.dn_next; 214 continue; 215 } 216 *rtp = rt->dst.dn_next; 217 rt->dst.dn_next = NULL; 218 dnrt_free(rt); 219 } 220 spin_unlock(&dn_rt_hash_table[i].lock); 221 222 if ((jiffies - now) > 0) 223 break; 224 } 225 226 mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ); 227} 228 229static int dn_dst_gc(struct dst_ops *ops) 230{ 231 struct dn_route *rt; 232 struct dn_route __rcu **rtp; 233 int i; 234 unsigned long now = jiffies; 235 unsigned long expire = 10 * HZ; 236 237 for (i = 0; i <= dn_rt_hash_mask; i++) { 238 239 spin_lock_bh(&dn_rt_hash_table[i].lock); 240 rtp = &dn_rt_hash_table[i].chain; 241 242 while ((rt = rcu_dereference_protected(*rtp, 243 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) { 244 if (atomic_read(&rt->dst.__refcnt) || 245 (now - rt->dst.lastuse) < expire) { 246 rtp = &rt->dst.dn_next; 247 continue; 248 } 249 *rtp = rt->dst.dn_next; 250 rt->dst.dn_next = NULL; 251 dnrt_drop(rt); 252 break; 253 } 254 spin_unlock_bh(&dn_rt_hash_table[i].lock); 255 } 256 257 return 0; 258} 259 260/* 261 * The decnet standards don't impose a particular minimum mtu, what they 262 * do insist on is that the routing layer accepts a datagram of at least 263 * 230 bytes long. Here we have to subtract the routing header length from 264 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we 265 * assume the worst and use a long header size. 266 * 267 * We update both the mtu and the advertised mss (i.e. the segment size we 268 * advertise to the other end). 269 */ 270static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk, 271 struct sk_buff *skb, u32 mtu) 272{ 273 struct dn_route *rt = (struct dn_route *) dst; 274 struct neighbour *n = rt->n; 275 u32 min_mtu = 230; 276 struct dn_dev *dn; 277 278 dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL; 279 280 if (dn && dn->use_long == 0) 281 min_mtu -= 6; 282 else 283 min_mtu -= 21; 284 285 if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) { 286 if (!(dst_metric_locked(dst, RTAX_MTU))) { 287 dst_metric_set(dst, RTAX_MTU, mtu); 288 dst_set_expires(dst, dn_rt_mtu_expires); 289 } 290 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) { 291 u32 mss = mtu - DN_MAX_NSP_DATA_HEADER; 292 u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS); 293 if (!existing_mss || existing_mss > mss) 294 dst_metric_set(dst, RTAX_ADVMSS, mss); 295 } 296 } 297} 298 299static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk, 300 struct sk_buff *skb) 301{ 302} 303 304/* 305 * When a route has been marked obsolete. (e.g. routing cache flush) 306 */ 307static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie) 308{ 309 return NULL; 310} 311 312static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst) 313{ 314 dst_release(dst); 315 return NULL; 316} 317 318static void dn_dst_link_failure(struct sk_buff *skb) 319{ 320} 321 322static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2) 323{ 324 return ((fl1->daddr ^ fl2->daddr) | 325 (fl1->saddr ^ fl2->saddr) | 326 (fl1->flowidn_mark ^ fl2->flowidn_mark) | 327 (fl1->flowidn_scope ^ fl2->flowidn_scope) | 328 (fl1->flowidn_oif ^ fl2->flowidn_oif) | 329 (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0; 330} 331 332static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp) 333{ 334 struct dn_route *rth; 335 struct dn_route __rcu **rthp; 336 unsigned long now = jiffies; 337 338 rthp = &dn_rt_hash_table[hash].chain; 339 340 spin_lock_bh(&dn_rt_hash_table[hash].lock); 341 while ((rth = rcu_dereference_protected(*rthp, 342 lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) { 343 if (compare_keys(&rth->fld, &rt->fld)) { 344 /* Put it first */ 345 *rthp = rth->dst.dn_next; 346 rcu_assign_pointer(rth->dst.dn_next, 347 dn_rt_hash_table[hash].chain); 348 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth); 349 350 dst_use(&rth->dst, now); 351 spin_unlock_bh(&dn_rt_hash_table[hash].lock); 352 353 dnrt_drop(rt); 354 *rp = rth; 355 return 0; 356 } 357 rthp = &rth->dst.dn_next; 358 } 359 360 rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain); 361 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt); 362 363 dst_use(&rt->dst, now); 364 spin_unlock_bh(&dn_rt_hash_table[hash].lock); 365 *rp = rt; 366 return 0; 367} 368 369static void dn_run_flush(unsigned long dummy) 370{ 371 int i; 372 struct dn_route *rt, *next; 373 374 for (i = 0; i < dn_rt_hash_mask; i++) { 375 spin_lock_bh(&dn_rt_hash_table[i].lock); 376 377 if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL) 378 goto nothing_to_declare; 379 380 for(; rt; rt = next) { 381 next = rcu_dereference_raw(rt->dst.dn_next); 382 RCU_INIT_POINTER(rt->dst.dn_next, NULL); 383 dst_free((struct dst_entry *)rt); 384 } 385 386nothing_to_declare: 387 spin_unlock_bh(&dn_rt_hash_table[i].lock); 388 } 389} 390 391static DEFINE_SPINLOCK(dn_rt_flush_lock); 392 393void dn_rt_cache_flush(int delay) 394{ 395 unsigned long now = jiffies; 396 int user_mode = !in_interrupt(); 397 398 if (delay < 0) 399 delay = dn_rt_min_delay; 400 401 spin_lock_bh(&dn_rt_flush_lock); 402 403 if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) { 404 long tmo = (long)(dn_rt_deadline - now); 405 406 if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay) 407 tmo = 0; 408 409 if (delay > tmo) 410 delay = tmo; 411 } 412 413 if (delay <= 0) { 414 spin_unlock_bh(&dn_rt_flush_lock); 415 dn_run_flush(0); 416 return; 417 } 418 419 if (dn_rt_deadline == 0) 420 dn_rt_deadline = now + dn_rt_max_delay; 421 422 dn_rt_flush_timer.expires = now + delay; 423 add_timer(&dn_rt_flush_timer); 424 spin_unlock_bh(&dn_rt_flush_lock); 425} 426 427/** 428 * dn_return_short - Return a short packet to its sender 429 * @skb: The packet to return 430 * 431 */ 432static int dn_return_short(struct sk_buff *skb) 433{ 434 struct dn_skb_cb *cb; 435 unsigned char *ptr; 436 __le16 *src; 437 __le16 *dst; 438 439 /* Add back headers */ 440 skb_push(skb, skb->data - skb_network_header(skb)); 441 442 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL) 443 return NET_RX_DROP; 444 445 cb = DN_SKB_CB(skb); 446 /* Skip packet length and point to flags */ 447 ptr = skb->data + 2; 448 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS; 449 450 dst = (__le16 *)ptr; 451 ptr += 2; 452 src = (__le16 *)ptr; 453 ptr += 2; 454 *ptr = 0; /* Zero hop count */ 455 456 swap(*src, *dst); 457 458 skb->pkt_type = PACKET_OUTGOING; 459 dn_rt_finish_output(skb, NULL, NULL); 460 return NET_RX_SUCCESS; 461} 462 463/** 464 * dn_return_long - Return a long packet to its sender 465 * @skb: The long format packet to return 466 * 467 */ 468static int dn_return_long(struct sk_buff *skb) 469{ 470 struct dn_skb_cb *cb; 471 unsigned char *ptr; 472 unsigned char *src_addr, *dst_addr; 473 unsigned char tmp[ETH_ALEN]; 474 475 /* Add back all headers */ 476 skb_push(skb, skb->data - skb_network_header(skb)); 477 478 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL) 479 return NET_RX_DROP; 480 481 cb = DN_SKB_CB(skb); 482 /* Ignore packet length and point to flags */ 483 ptr = skb->data + 2; 484 485 /* Skip padding */ 486 if (*ptr & DN_RT_F_PF) { 487 char padlen = (*ptr & ~DN_RT_F_PF); 488 ptr += padlen; 489 } 490 491 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS; 492 ptr += 2; 493 dst_addr = ptr; 494 ptr += 8; 495 src_addr = ptr; 496 ptr += 6; 497 *ptr = 0; /* Zero hop count */ 498 499 /* Swap source and destination */ 500 memcpy(tmp, src_addr, ETH_ALEN); 501 memcpy(src_addr, dst_addr, ETH_ALEN); 502 memcpy(dst_addr, tmp, ETH_ALEN); 503 504 skb->pkt_type = PACKET_OUTGOING; 505 dn_rt_finish_output(skb, dst_addr, src_addr); 506 return NET_RX_SUCCESS; 507} 508 509/** 510 * dn_route_rx_packet - Try and find a route for an incoming packet 511 * @skb: The packet to find a route for 512 * 513 * Returns: result of input function if route is found, error code otherwise 514 */ 515static int dn_route_rx_packet(struct sock *sk, struct sk_buff *skb) 516{ 517 struct dn_skb_cb *cb; 518 int err; 519 520 if ((err = dn_route_input(skb)) == 0) 521 return dst_input(skb); 522 523 cb = DN_SKB_CB(skb); 524 if (decnet_debug_level & 4) { 525 char *devname = skb->dev ? skb->dev->name : "???"; 526 527 printk(KERN_DEBUG 528 "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n", 529 (int)cb->rt_flags, devname, skb->len, 530 le16_to_cpu(cb->src), le16_to_cpu(cb->dst), 531 err, skb->pkt_type); 532 } 533 534 if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) { 535 switch (cb->rt_flags & DN_RT_PKT_MSK) { 536 case DN_RT_PKT_SHORT: 537 return dn_return_short(skb); 538 case DN_RT_PKT_LONG: 539 return dn_return_long(skb); 540 } 541 } 542 543 kfree_skb(skb); 544 return NET_RX_DROP; 545} 546 547static int dn_route_rx_long(struct sk_buff *skb) 548{ 549 struct dn_skb_cb *cb = DN_SKB_CB(skb); 550 unsigned char *ptr = skb->data; 551 552 if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */ 553 goto drop_it; 554 555 skb_pull(skb, 20); 556 skb_reset_transport_header(skb); 557 558 /* Destination info */ 559 ptr += 2; 560 cb->dst = dn_eth2dn(ptr); 561 if (memcmp(ptr, dn_hiord_addr, 4) != 0) 562 goto drop_it; 563 ptr += 6; 564 565 566 /* Source info */ 567 ptr += 2; 568 cb->src = dn_eth2dn(ptr); 569 if (memcmp(ptr, dn_hiord_addr, 4) != 0) 570 goto drop_it; 571 ptr += 6; 572 /* Other junk */ 573 ptr++; 574 cb->hops = *ptr++; /* Visit Count */ 575 576 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, NULL, skb, 577 skb->dev, NULL, 578 dn_route_rx_packet); 579 580drop_it: 581 kfree_skb(skb); 582 return NET_RX_DROP; 583} 584 585 586 587static int dn_route_rx_short(struct sk_buff *skb) 588{ 589 struct dn_skb_cb *cb = DN_SKB_CB(skb); 590 unsigned char *ptr = skb->data; 591 592 if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */ 593 goto drop_it; 594 595 skb_pull(skb, 5); 596 skb_reset_transport_header(skb); 597 598 cb->dst = *(__le16 *)ptr; 599 ptr += 2; 600 cb->src = *(__le16 *)ptr; 601 ptr += 2; 602 cb->hops = *ptr & 0x3f; 603 604 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, NULL, skb, 605 skb->dev, NULL, 606 dn_route_rx_packet); 607 608drop_it: 609 kfree_skb(skb); 610 return NET_RX_DROP; 611} 612 613static int dn_route_discard(struct sock *sk, struct sk_buff *skb) 614{ 615 /* 616 * I know we drop the packet here, but thats considered success in 617 * this case 618 */ 619 kfree_skb(skb); 620 return NET_RX_SUCCESS; 621} 622 623static int dn_route_ptp_hello(struct sock *sk, struct sk_buff *skb) 624{ 625 dn_dev_hello(skb); 626 dn_neigh_pointopoint_hello(skb); 627 return NET_RX_SUCCESS; 628} 629 630int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) 631{ 632 struct dn_skb_cb *cb; 633 unsigned char flags = 0; 634 __u16 len = le16_to_cpu(*(__le16 *)skb->data); 635 struct dn_dev *dn = rcu_dereference(dev->dn_ptr); 636 unsigned char padlen = 0; 637 638 if (!net_eq(dev_net(dev), &init_net)) 639 goto dump_it; 640 641 if (dn == NULL) 642 goto dump_it; 643 644 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 645 goto out; 646 647 if (!pskb_may_pull(skb, 3)) 648 goto dump_it; 649 650 skb_pull(skb, 2); 651 652 if (len > skb->len) 653 goto dump_it; 654 655 skb_trim(skb, len); 656 657 flags = *skb->data; 658 659 cb = DN_SKB_CB(skb); 660 cb->stamp = jiffies; 661 cb->iif = dev->ifindex; 662 663 /* 664 * If we have padding, remove it. 665 */ 666 if (flags & DN_RT_F_PF) { 667 padlen = flags & ~DN_RT_F_PF; 668 if (!pskb_may_pull(skb, padlen + 1)) 669 goto dump_it; 670 skb_pull(skb, padlen); 671 flags = *skb->data; 672 } 673 674 skb_reset_network_header(skb); 675 676 /* 677 * Weed out future version DECnet 678 */ 679 if (flags & DN_RT_F_VER) 680 goto dump_it; 681 682 cb->rt_flags = flags; 683 684 if (decnet_debug_level & 1) 685 printk(KERN_DEBUG 686 "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n", 687 (int)flags, (dev) ? dev->name : "???", len, skb->len, 688 padlen); 689 690 if (flags & DN_RT_PKT_CNTL) { 691 if (unlikely(skb_linearize(skb))) 692 goto dump_it; 693 694 switch (flags & DN_RT_CNTL_MSK) { 695 case DN_RT_PKT_INIT: 696 dn_dev_init_pkt(skb); 697 break; 698 case DN_RT_PKT_VERI: 699 dn_dev_veri_pkt(skb); 700 break; 701 } 702 703 if (dn->parms.state != DN_DEV_S_RU) 704 goto dump_it; 705 706 switch (flags & DN_RT_CNTL_MSK) { 707 case DN_RT_PKT_HELO: 708 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO, 709 NULL, skb, skb->dev, NULL, 710 dn_route_ptp_hello); 711 712 case DN_RT_PKT_L1RT: 713 case DN_RT_PKT_L2RT: 714 return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE, 715 NULL, skb, skb->dev, NULL, 716 dn_route_discard); 717 case DN_RT_PKT_ERTH: 718 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO, 719 NULL, skb, skb->dev, NULL, 720 dn_neigh_router_hello); 721 722 case DN_RT_PKT_EEDH: 723 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO, 724 NULL, skb, skb->dev, NULL, 725 dn_neigh_endnode_hello); 726 } 727 } else { 728 if (dn->parms.state != DN_DEV_S_RU) 729 goto dump_it; 730 731 skb_pull(skb, 1); /* Pull flags */ 732 733 switch (flags & DN_RT_PKT_MSK) { 734 case DN_RT_PKT_LONG: 735 return dn_route_rx_long(skb); 736 case DN_RT_PKT_SHORT: 737 return dn_route_rx_short(skb); 738 } 739 } 740 741dump_it: 742 kfree_skb(skb); 743out: 744 return NET_RX_DROP; 745} 746 747static int dn_output(struct sock *sk, struct sk_buff *skb) 748{ 749 struct dst_entry *dst = skb_dst(skb); 750 struct dn_route *rt = (struct dn_route *)dst; 751 struct net_device *dev = dst->dev; 752 struct dn_skb_cb *cb = DN_SKB_CB(skb); 753 754 int err = -EINVAL; 755 756 if (rt->n == NULL) 757 goto error; 758 759 skb->dev = dev; 760 761 cb->src = rt->rt_saddr; 762 cb->dst = rt->rt_daddr; 763 764 /* 765 * Always set the Intra-Ethernet bit on all outgoing packets 766 * originated on this node. Only valid flag from upper layers 767 * is return-to-sender-requested. Set hop count to 0 too. 768 */ 769 cb->rt_flags &= ~DN_RT_F_RQR; 770 cb->rt_flags |= DN_RT_F_IE; 771 cb->hops = 0; 772 773 return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT, sk, skb, 774 NULL, dev, 775 dn_to_neigh_output); 776 777error: 778 net_dbg_ratelimited("dn_output: This should not happen\n"); 779 780 kfree_skb(skb); 781 782 return err; 783} 784 785static int dn_forward(struct sk_buff *skb) 786{ 787 struct dn_skb_cb *cb = DN_SKB_CB(skb); 788 struct dst_entry *dst = skb_dst(skb); 789 struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr); 790 struct dn_route *rt; 791 int header_len; 792#ifdef CONFIG_NETFILTER 793 struct net_device *dev = skb->dev; 794#endif 795 796 if (skb->pkt_type != PACKET_HOST) 797 goto drop; 798 799 /* Ensure that we have enough space for headers */ 800 rt = (struct dn_route *)skb_dst(skb); 801 header_len = dn_db->use_long ? 21 : 6; 802 if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len)) 803 goto drop; 804 805 /* 806 * Hop count exceeded. 807 */ 808 if (++cb->hops > 30) 809 goto drop; 810 811 skb->dev = rt->dst.dev; 812 813 /* 814 * If packet goes out same interface it came in on, then set 815 * the Intra-Ethernet bit. This has no effect for short 816 * packets, so we don't need to test for them here. 817 */ 818 cb->rt_flags &= ~DN_RT_F_IE; 819 if (rt->rt_flags & RTCF_DOREDIRECT) 820 cb->rt_flags |= DN_RT_F_IE; 821 822 return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD, NULL, skb, 823 dev, skb->dev, 824 dn_to_neigh_output); 825 826drop: 827 kfree_skb(skb); 828 return NET_RX_DROP; 829} 830 831/* 832 * Used to catch bugs. This should never normally get 833 * called. 834 */ 835static int dn_rt_bug_sk(struct sock *sk, struct sk_buff *skb) 836{ 837 struct dn_skb_cb *cb = DN_SKB_CB(skb); 838 839 net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n", 840 le16_to_cpu(cb->src), le16_to_cpu(cb->dst)); 841 842 kfree_skb(skb); 843 844 return NET_RX_DROP; 845} 846 847static int dn_rt_bug(struct sk_buff *skb) 848{ 849 struct dn_skb_cb *cb = DN_SKB_CB(skb); 850 851 net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n", 852 le16_to_cpu(cb->src), le16_to_cpu(cb->dst)); 853 854 kfree_skb(skb); 855 856 return NET_RX_DROP; 857} 858 859static unsigned int dn_dst_default_advmss(const struct dst_entry *dst) 860{ 861 return dn_mss_from_pmtu(dst->dev, dst_mtu(dst)); 862} 863 864static unsigned int dn_dst_mtu(const struct dst_entry *dst) 865{ 866 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 867 868 return mtu ? : dst->dev->mtu; 869} 870 871static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst, 872 struct sk_buff *skb, 873 const void *daddr) 874{ 875 return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev); 876} 877 878static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res) 879{ 880 struct dn_fib_info *fi = res->fi; 881 struct net_device *dev = rt->dst.dev; 882 unsigned int mss_metric; 883 struct neighbour *n; 884 885 if (fi) { 886 if (DN_FIB_RES_GW(*res) && 887 DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) 888 rt->rt_gateway = DN_FIB_RES_GW(*res); 889 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 890 } 891 rt->rt_type = res->type; 892 893 if (dev != NULL && rt->n == NULL) { 894 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev); 895 if (IS_ERR(n)) 896 return PTR_ERR(n); 897 rt->n = n; 898 } 899 900 if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu) 901 dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu); 902 mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS); 903 if (mss_metric) { 904 unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst)); 905 if (mss_metric > mss) 906 dst_metric_set(&rt->dst, RTAX_ADVMSS, mss); 907 } 908 return 0; 909} 910 911static inline int dn_match_addr(__le16 addr1, __le16 addr2) 912{ 913 __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2); 914 int match = 16; 915 while(tmp) { 916 tmp >>= 1; 917 match--; 918 } 919 return match; 920} 921 922static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope) 923{ 924 __le16 saddr = 0; 925 struct dn_dev *dn_db; 926 struct dn_ifaddr *ifa; 927 int best_match = 0; 928 int ret; 929 930 rcu_read_lock(); 931 dn_db = rcu_dereference(dev->dn_ptr); 932 for (ifa = rcu_dereference(dn_db->ifa_list); 933 ifa != NULL; 934 ifa = rcu_dereference(ifa->ifa_next)) { 935 if (ifa->ifa_scope > scope) 936 continue; 937 if (!daddr) { 938 saddr = ifa->ifa_local; 939 break; 940 } 941 ret = dn_match_addr(daddr, ifa->ifa_local); 942 if (ret > best_match) 943 saddr = ifa->ifa_local; 944 if (best_match == 0) 945 saddr = ifa->ifa_local; 946 } 947 rcu_read_unlock(); 948 949 return saddr; 950} 951 952static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res) 953{ 954 return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope); 955} 956 957static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res) 958{ 959 __le16 mask = dnet_make_mask(res->prefixlen); 960 return (daddr&~mask)|res->fi->fib_nh->nh_gw; 961} 962 963static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard) 964{ 965 struct flowidn fld = { 966 .daddr = oldflp->daddr, 967 .saddr = oldflp->saddr, 968 .flowidn_scope = RT_SCOPE_UNIVERSE, 969 .flowidn_mark = oldflp->flowidn_mark, 970 .flowidn_iif = LOOPBACK_IFINDEX, 971 .flowidn_oif = oldflp->flowidn_oif, 972 }; 973 struct dn_route *rt = NULL; 974 struct net_device *dev_out = NULL, *dev; 975 struct neighbour *neigh = NULL; 976 unsigned int hash; 977 unsigned int flags = 0; 978 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST }; 979 int err; 980 int free_res = 0; 981 __le16 gateway = 0; 982 983 if (decnet_debug_level & 16) 984 printk(KERN_DEBUG 985 "dn_route_output_slow: dst=%04x src=%04x mark=%d" 986 " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr), 987 le16_to_cpu(oldflp->saddr), 988 oldflp->flowidn_mark, LOOPBACK_IFINDEX, 989 oldflp->flowidn_oif); 990 991 /* If we have an output interface, verify its a DECnet device */ 992 if (oldflp->flowidn_oif) { 993 dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif); 994 err = -ENODEV; 995 if (dev_out && dev_out->dn_ptr == NULL) { 996 dev_put(dev_out); 997 dev_out = NULL; 998 } 999 if (dev_out == NULL) 1000 goto out; 1001 } 1002 1003 /* If we have a source address, verify that its a local address */ 1004 if (oldflp->saddr) { 1005 err = -EADDRNOTAVAIL; 1006 1007 if (dev_out) { 1008 if (dn_dev_islocal(dev_out, oldflp->saddr)) 1009 goto source_ok; 1010 dev_put(dev_out); 1011 goto out; 1012 } 1013 rcu_read_lock(); 1014 for_each_netdev_rcu(&init_net, dev) { 1015 if (!dev->dn_ptr) 1016 continue; 1017 if (!dn_dev_islocal(dev, oldflp->saddr)) 1018 continue; 1019 if ((dev->flags & IFF_LOOPBACK) && 1020 oldflp->daddr && 1021 !dn_dev_islocal(dev, oldflp->daddr)) 1022 continue; 1023 1024 dev_out = dev; 1025 break; 1026 } 1027 rcu_read_unlock(); 1028 if (dev_out == NULL) 1029 goto out; 1030 dev_hold(dev_out); 1031source_ok: 1032 ; 1033 } 1034 1035 /* No destination? Assume its local */ 1036 if (!fld.daddr) { 1037 fld.daddr = fld.saddr; 1038 1039 err = -EADDRNOTAVAIL; 1040 if (dev_out) 1041 dev_put(dev_out); 1042 dev_out = init_net.loopback_dev; 1043 dev_hold(dev_out); 1044 if (!fld.daddr) { 1045 fld.daddr = 1046 fld.saddr = dnet_select_source(dev_out, 0, 1047 RT_SCOPE_HOST); 1048 if (!fld.daddr) 1049 goto out; 1050 } 1051 fld.flowidn_oif = LOOPBACK_IFINDEX; 1052 res.type = RTN_LOCAL; 1053 goto make_route; 1054 } 1055 1056 if (decnet_debug_level & 16) 1057 printk(KERN_DEBUG 1058 "dn_route_output_slow: initial checks complete." 1059 " dst=%04x src=%04x oif=%d try_hard=%d\n", 1060 le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr), 1061 fld.flowidn_oif, try_hard); 1062 1063 /* 1064 * N.B. If the kernel is compiled without router support then 1065 * dn_fib_lookup() will evaluate to non-zero so this if () block 1066 * will always be executed. 1067 */ 1068 err = -ESRCH; 1069 if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) { 1070 struct dn_dev *dn_db; 1071 if (err != -ESRCH) 1072 goto out; 1073 /* 1074 * Here the fallback is basically the standard algorithm for 1075 * routing in endnodes which is described in the DECnet routing 1076 * docs 1077 * 1078 * If we are not trying hard, look in neighbour cache. 1079 * The result is tested to ensure that if a specific output 1080 * device/source address was requested, then we honour that 1081 * here 1082 */ 1083 if (!try_hard) { 1084 neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr); 1085 if (neigh) { 1086 if ((oldflp->flowidn_oif && 1087 (neigh->dev->ifindex != oldflp->flowidn_oif)) || 1088 (oldflp->saddr && 1089 (!dn_dev_islocal(neigh->dev, 1090 oldflp->saddr)))) { 1091 neigh_release(neigh); 1092 neigh = NULL; 1093 } else { 1094 if (dev_out) 1095 dev_put(dev_out); 1096 if (dn_dev_islocal(neigh->dev, fld.daddr)) { 1097 dev_out = init_net.loopback_dev; 1098 res.type = RTN_LOCAL; 1099 } else { 1100 dev_out = neigh->dev; 1101 } 1102 dev_hold(dev_out); 1103 goto select_source; 1104 } 1105 } 1106 } 1107 1108 /* Not there? Perhaps its a local address */ 1109 if (dev_out == NULL) 1110 dev_out = dn_dev_get_default(); 1111 err = -ENODEV; 1112 if (dev_out == NULL) 1113 goto out; 1114 dn_db = rcu_dereference_raw(dev_out->dn_ptr); 1115 /* Possible improvement - check all devices for local addr */ 1116 if (dn_dev_islocal(dev_out, fld.daddr)) { 1117 dev_put(dev_out); 1118 dev_out = init_net.loopback_dev; 1119 dev_hold(dev_out); 1120 res.type = RTN_LOCAL; 1121 goto select_source; 1122 } 1123 /* Not local either.... try sending it to the default router */ 1124 neigh = neigh_clone(dn_db->router); 1125 BUG_ON(neigh && neigh->dev != dev_out); 1126 1127 /* Ok then, we assume its directly connected and move on */ 1128select_source: 1129 if (neigh) 1130 gateway = ((struct dn_neigh *)neigh)->addr; 1131 if (gateway == 0) 1132 gateway = fld.daddr; 1133 if (fld.saddr == 0) { 1134 fld.saddr = dnet_select_source(dev_out, gateway, 1135 res.type == RTN_LOCAL ? 1136 RT_SCOPE_HOST : 1137 RT_SCOPE_LINK); 1138 if (fld.saddr == 0 && res.type != RTN_LOCAL) 1139 goto e_addr; 1140 } 1141 fld.flowidn_oif = dev_out->ifindex; 1142 goto make_route; 1143 } 1144 free_res = 1; 1145 1146 if (res.type == RTN_NAT) 1147 goto e_inval; 1148 1149 if (res.type == RTN_LOCAL) { 1150 if (!fld.saddr) 1151 fld.saddr = fld.daddr; 1152 if (dev_out) 1153 dev_put(dev_out); 1154 dev_out = init_net.loopback_dev; 1155 dev_hold(dev_out); 1156 fld.flowidn_oif = dev_out->ifindex; 1157 if (res.fi) 1158 dn_fib_info_put(res.fi); 1159 res.fi = NULL; 1160 goto make_route; 1161 } 1162 1163 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0) 1164 dn_fib_select_multipath(&fld, &res); 1165 1166 /* 1167 * We could add some logic to deal with default routes here and 1168 * get rid of some of the special casing above. 1169 */ 1170 1171 if (!fld.saddr) 1172 fld.saddr = DN_FIB_RES_PREFSRC(res); 1173 1174 if (dev_out) 1175 dev_put(dev_out); 1176 dev_out = DN_FIB_RES_DEV(res); 1177 dev_hold(dev_out); 1178 fld.flowidn_oif = dev_out->ifindex; 1179 gateway = DN_FIB_RES_GW(res); 1180 1181make_route: 1182 if (dev_out->flags & IFF_LOOPBACK) 1183 flags |= RTCF_LOCAL; 1184 1185 rt = dst_alloc(&dn_dst_ops, dev_out, 1, DST_OBSOLETE_NONE, DST_HOST); 1186 if (rt == NULL) 1187 goto e_nobufs; 1188 1189 memset(&rt->fld, 0, sizeof(rt->fld)); 1190 rt->fld.saddr = oldflp->saddr; 1191 rt->fld.daddr = oldflp->daddr; 1192 rt->fld.flowidn_oif = oldflp->flowidn_oif; 1193 rt->fld.flowidn_iif = 0; 1194 rt->fld.flowidn_mark = oldflp->flowidn_mark; 1195 1196 rt->rt_saddr = fld.saddr; 1197 rt->rt_daddr = fld.daddr; 1198 rt->rt_gateway = gateway ? gateway : fld.daddr; 1199 rt->rt_local_src = fld.saddr; 1200 1201 rt->rt_dst_map = fld.daddr; 1202 rt->rt_src_map = fld.saddr; 1203 1204 rt->n = neigh; 1205 neigh = NULL; 1206 1207 rt->dst.lastuse = jiffies; 1208 rt->dst.output = dn_output; 1209 rt->dst.input = dn_rt_bug; 1210 rt->rt_flags = flags; 1211 if (flags & RTCF_LOCAL) 1212 rt->dst.input = dn_nsp_rx; 1213 1214 err = dn_rt_set_next_hop(rt, &res); 1215 if (err) 1216 goto e_neighbour; 1217 1218 hash = dn_hash(rt->fld.saddr, rt->fld.daddr); 1219 dn_insert_route(rt, hash, (struct dn_route **)pprt); 1220 1221done: 1222 if (neigh) 1223 neigh_release(neigh); 1224 if (free_res) 1225 dn_fib_res_put(&res); 1226 if (dev_out) 1227 dev_put(dev_out); 1228out: 1229 return err; 1230 1231e_addr: 1232 err = -EADDRNOTAVAIL; 1233 goto done; 1234e_inval: 1235 err = -EINVAL; 1236 goto done; 1237e_nobufs: 1238 err = -ENOBUFS; 1239 goto done; 1240e_neighbour: 1241 dst_free(&rt->dst); 1242 goto e_nobufs; 1243} 1244 1245 1246/* 1247 * N.B. The flags may be moved into the flowi at some future stage. 1248 */ 1249static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags) 1250{ 1251 unsigned int hash = dn_hash(flp->saddr, flp->daddr); 1252 struct dn_route *rt = NULL; 1253 1254 if (!(flags & MSG_TRYHARD)) { 1255 rcu_read_lock_bh(); 1256 for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt; 1257 rt = rcu_dereference_bh(rt->dst.dn_next)) { 1258 if ((flp->daddr == rt->fld.daddr) && 1259 (flp->saddr == rt->fld.saddr) && 1260 (flp->flowidn_mark == rt->fld.flowidn_mark) && 1261 dn_is_output_route(rt) && 1262 (rt->fld.flowidn_oif == flp->flowidn_oif)) { 1263 dst_use(&rt->dst, jiffies); 1264 rcu_read_unlock_bh(); 1265 *pprt = &rt->dst; 1266 return 0; 1267 } 1268 } 1269 rcu_read_unlock_bh(); 1270 } 1271 1272 return dn_route_output_slow(pprt, flp, flags); 1273} 1274 1275static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags) 1276{ 1277 int err; 1278 1279 err = __dn_route_output_key(pprt, flp, flags); 1280 if (err == 0 && flp->flowidn_proto) { 1281 *pprt = xfrm_lookup(&init_net, *pprt, 1282 flowidn_to_flowi(flp), NULL, 0); 1283 if (IS_ERR(*pprt)) { 1284 err = PTR_ERR(*pprt); 1285 *pprt = NULL; 1286 } 1287 } 1288 return err; 1289} 1290 1291int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags) 1292{ 1293 int err; 1294 1295 err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD); 1296 if (err == 0 && fl->flowidn_proto) { 1297 *pprt = xfrm_lookup(&init_net, *pprt, 1298 flowidn_to_flowi(fl), sk, 0); 1299 if (IS_ERR(*pprt)) { 1300 err = PTR_ERR(*pprt); 1301 *pprt = NULL; 1302 } 1303 } 1304 return err; 1305} 1306 1307static int dn_route_input_slow(struct sk_buff *skb) 1308{ 1309 struct dn_route *rt = NULL; 1310 struct dn_skb_cb *cb = DN_SKB_CB(skb); 1311 struct net_device *in_dev = skb->dev; 1312 struct net_device *out_dev = NULL; 1313 struct dn_dev *dn_db; 1314 struct neighbour *neigh = NULL; 1315 unsigned int hash; 1316 int flags = 0; 1317 __le16 gateway = 0; 1318 __le16 local_src = 0; 1319 struct flowidn fld = { 1320 .daddr = cb->dst, 1321 .saddr = cb->src, 1322 .flowidn_scope = RT_SCOPE_UNIVERSE, 1323 .flowidn_mark = skb->mark, 1324 .flowidn_iif = skb->dev->ifindex, 1325 }; 1326 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE }; 1327 int err = -EINVAL; 1328 int free_res = 0; 1329 1330 dev_hold(in_dev); 1331 1332 if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL) 1333 goto out; 1334 1335 /* Zero source addresses are not allowed */ 1336 if (fld.saddr == 0) 1337 goto out; 1338 1339 /* 1340 * In this case we've just received a packet from a source 1341 * outside ourselves pretending to come from us. We don't 1342 * allow it any further to prevent routing loops, spoofing and 1343 * other nasties. Loopback packets already have the dst attached 1344 * so this only affects packets which have originated elsewhere. 1345 */ 1346 err = -ENOTUNIQ; 1347 if (dn_dev_islocal(in_dev, cb->src)) 1348 goto out; 1349 1350 err = dn_fib_lookup(&fld, &res); 1351 if (err) { 1352 if (err != -ESRCH) 1353 goto out; 1354 /* 1355 * Is the destination us ? 1356 */ 1357 if (!dn_dev_islocal(in_dev, cb->dst)) 1358 goto e_inval; 1359 1360 res.type = RTN_LOCAL; 1361 } else { 1362 __le16 src_map = fld.saddr; 1363 free_res = 1; 1364 1365 out_dev = DN_FIB_RES_DEV(res); 1366 if (out_dev == NULL) { 1367 net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n"); 1368 goto e_inval; 1369 } 1370 dev_hold(out_dev); 1371 1372 if (res.r) 1373 src_map = fld.saddr; /* no NAT support for now */ 1374 1375 gateway = DN_FIB_RES_GW(res); 1376 if (res.type == RTN_NAT) { 1377 fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res); 1378 dn_fib_res_put(&res); 1379 free_res = 0; 1380 if (dn_fib_lookup(&fld, &res)) 1381 goto e_inval; 1382 free_res = 1; 1383 if (res.type != RTN_UNICAST) 1384 goto e_inval; 1385 flags |= RTCF_DNAT; 1386 gateway = fld.daddr; 1387 } 1388 fld.saddr = src_map; 1389 } 1390 1391 switch(res.type) { 1392 case RTN_UNICAST: 1393 /* 1394 * Forwarding check here, we only check for forwarding 1395 * being turned off, if you want to only forward intra 1396 * area, its up to you to set the routing tables up 1397 * correctly. 1398 */ 1399 if (dn_db->parms.forwarding == 0) 1400 goto e_inval; 1401 1402 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0) 1403 dn_fib_select_multipath(&fld, &res); 1404 1405 /* 1406 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT 1407 * flag as a hint to set the intra-ethernet bit when 1408 * forwarding. If we've got NAT in operation, we don't do 1409 * this optimisation. 1410 */ 1411 if (out_dev == in_dev && !(flags & RTCF_NAT)) 1412 flags |= RTCF_DOREDIRECT; 1413 1414 local_src = DN_FIB_RES_PREFSRC(res); 1415 1416 case RTN_BLACKHOLE: 1417 case RTN_UNREACHABLE: 1418 break; 1419 case RTN_LOCAL: 1420 flags |= RTCF_LOCAL; 1421 fld.saddr = cb->dst; 1422 fld.daddr = cb->src; 1423 1424 /* Routing tables gave us a gateway */ 1425 if (gateway) 1426 goto make_route; 1427 1428 /* Packet was intra-ethernet, so we know its on-link */ 1429 if (cb->rt_flags & DN_RT_F_IE) { 1430 gateway = cb->src; 1431 goto make_route; 1432 } 1433 1434 /* Use the default router if there is one */ 1435 neigh = neigh_clone(dn_db->router); 1436 if (neigh) { 1437 gateway = ((struct dn_neigh *)neigh)->addr; 1438 goto make_route; 1439 } 1440 1441 /* Close eyes and pray */ 1442 gateway = cb->src; 1443 goto make_route; 1444 default: 1445 goto e_inval; 1446 } 1447 1448make_route: 1449 rt = dst_alloc(&dn_dst_ops, out_dev, 0, DST_OBSOLETE_NONE, DST_HOST); 1450 if (rt == NULL) 1451 goto e_nobufs; 1452 1453 memset(&rt->fld, 0, sizeof(rt->fld)); 1454 rt->rt_saddr = fld.saddr; 1455 rt->rt_daddr = fld.daddr; 1456 rt->rt_gateway = fld.daddr; 1457 if (gateway) 1458 rt->rt_gateway = gateway; 1459 rt->rt_local_src = local_src ? local_src : rt->rt_saddr; 1460 1461 rt->rt_dst_map = fld.daddr; 1462 rt->rt_src_map = fld.saddr; 1463 1464 rt->fld.saddr = cb->src; 1465 rt->fld.daddr = cb->dst; 1466 rt->fld.flowidn_oif = 0; 1467 rt->fld.flowidn_iif = in_dev->ifindex; 1468 rt->fld.flowidn_mark = fld.flowidn_mark; 1469 1470 rt->n = neigh; 1471 rt->dst.lastuse = jiffies; 1472 rt->dst.output = dn_rt_bug_sk; 1473 switch (res.type) { 1474 case RTN_UNICAST: 1475 rt->dst.input = dn_forward; 1476 break; 1477 case RTN_LOCAL: 1478 rt->dst.output = dn_output; 1479 rt->dst.input = dn_nsp_rx; 1480 rt->dst.dev = in_dev; 1481 flags |= RTCF_LOCAL; 1482 break; 1483 default: 1484 case RTN_UNREACHABLE: 1485 case RTN_BLACKHOLE: 1486 rt->dst.input = dst_discard; 1487 } 1488 rt->rt_flags = flags; 1489 1490 err = dn_rt_set_next_hop(rt, &res); 1491 if (err) 1492 goto e_neighbour; 1493 1494 hash = dn_hash(rt->fld.saddr, rt->fld.daddr); 1495 dn_insert_route(rt, hash, &rt); 1496 skb_dst_set(skb, &rt->dst); 1497 1498done: 1499 if (neigh) 1500 neigh_release(neigh); 1501 if (free_res) 1502 dn_fib_res_put(&res); 1503 dev_put(in_dev); 1504 if (out_dev) 1505 dev_put(out_dev); 1506out: 1507 return err; 1508 1509e_inval: 1510 err = -EINVAL; 1511 goto done; 1512 1513e_nobufs: 1514 err = -ENOBUFS; 1515 goto done; 1516 1517e_neighbour: 1518 dst_free(&rt->dst); 1519 goto done; 1520} 1521 1522static int dn_route_input(struct sk_buff *skb) 1523{ 1524 struct dn_route *rt; 1525 struct dn_skb_cb *cb = DN_SKB_CB(skb); 1526 unsigned int hash = dn_hash(cb->src, cb->dst); 1527 1528 if (skb_dst(skb)) 1529 return 0; 1530 1531 rcu_read_lock(); 1532 for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL; 1533 rt = rcu_dereference(rt->dst.dn_next)) { 1534 if ((rt->fld.saddr == cb->src) && 1535 (rt->fld.daddr == cb->dst) && 1536 (rt->fld.flowidn_oif == 0) && 1537 (rt->fld.flowidn_mark == skb->mark) && 1538 (rt->fld.flowidn_iif == cb->iif)) { 1539 dst_use(&rt->dst, jiffies); 1540 rcu_read_unlock(); 1541 skb_dst_set(skb, (struct dst_entry *)rt); 1542 return 0; 1543 } 1544 } 1545 rcu_read_unlock(); 1546 1547 return dn_route_input_slow(skb); 1548} 1549 1550static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq, 1551 int event, int nowait, unsigned int flags) 1552{ 1553 struct dn_route *rt = (struct dn_route *)skb_dst(skb); 1554 struct rtmsg *r; 1555 struct nlmsghdr *nlh; 1556 long expires; 1557 1558 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags); 1559 if (!nlh) 1560 return -EMSGSIZE; 1561 1562 r = nlmsg_data(nlh); 1563 r->rtm_family = AF_DECnet; 1564 r->rtm_dst_len = 16; 1565 r->rtm_src_len = 0; 1566 r->rtm_tos = 0; 1567 r->rtm_table = RT_TABLE_MAIN; 1568 r->rtm_type = rt->rt_type; 1569 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 1570 r->rtm_scope = RT_SCOPE_UNIVERSE; 1571 r->rtm_protocol = RTPROT_UNSPEC; 1572 1573 if (rt->rt_flags & RTCF_NOTIFY) 1574 r->rtm_flags |= RTM_F_NOTIFY; 1575 1576 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 || 1577 nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0) 1578 goto errout; 1579 1580 if (rt->fld.saddr) { 1581 r->rtm_src_len = 16; 1582 if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0) 1583 goto errout; 1584 } 1585 if (rt->dst.dev && 1586 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0) 1587 goto errout; 1588 1589 /* 1590 * Note to self - change this if input routes reverse direction when 1591 * they deal only with inputs and not with replies like they do 1592 * currently. 1593 */ 1594 if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0) 1595 goto errout; 1596 1597 if (rt->rt_daddr != rt->rt_gateway && 1598 nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0) 1599 goto errout; 1600 1601 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0) 1602 goto errout; 1603 1604 expires = rt->dst.expires ? rt->dst.expires - jiffies : 0; 1605 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, 1606 rt->dst.error) < 0) 1607 goto errout; 1608 1609 if (dn_is_input_route(rt) && 1610 nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0) 1611 goto errout; 1612 1613 nlmsg_end(skb, nlh); 1614 return 0; 1615 1616errout: 1617 nlmsg_cancel(skb, nlh); 1618 return -EMSGSIZE; 1619} 1620 1621const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = { 1622 [RTA_DST] = { .type = NLA_U16 }, 1623 [RTA_SRC] = { .type = NLA_U16 }, 1624 [RTA_IIF] = { .type = NLA_U32 }, 1625 [RTA_OIF] = { .type = NLA_U32 }, 1626 [RTA_GATEWAY] = { .type = NLA_U16 }, 1627 [RTA_PRIORITY] = { .type = NLA_U32 }, 1628 [RTA_PREFSRC] = { .type = NLA_U16 }, 1629 [RTA_METRICS] = { .type = NLA_NESTED }, 1630 [RTA_MULTIPATH] = { .type = NLA_NESTED }, 1631 [RTA_TABLE] = { .type = NLA_U32 }, 1632 [RTA_MARK] = { .type = NLA_U32 }, 1633}; 1634 1635/* 1636 * This is called by both endnodes and routers now. 1637 */ 1638static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh) 1639{ 1640 struct net *net = sock_net(in_skb->sk); 1641 struct rtmsg *rtm = nlmsg_data(nlh); 1642 struct dn_route *rt = NULL; 1643 struct dn_skb_cb *cb; 1644 int err; 1645 struct sk_buff *skb; 1646 struct flowidn fld; 1647 struct nlattr *tb[RTA_MAX+1]; 1648 1649 if (!net_eq(net, &init_net)) 1650 return -EINVAL; 1651 1652 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_dn_policy); 1653 if (err < 0) 1654 return err; 1655 1656 memset(&fld, 0, sizeof(fld)); 1657 fld.flowidn_proto = DNPROTO_NSP; 1658 1659 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 1660 if (skb == NULL) 1661 return -ENOBUFS; 1662 skb_reset_mac_header(skb); 1663 cb = DN_SKB_CB(skb); 1664 1665 if (tb[RTA_SRC]) 1666 fld.saddr = nla_get_le16(tb[RTA_SRC]); 1667 1668 if (tb[RTA_DST]) 1669 fld.daddr = nla_get_le16(tb[RTA_DST]); 1670 1671 if (tb[RTA_IIF]) 1672 fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]); 1673 1674 if (fld.flowidn_iif) { 1675 struct net_device *dev; 1676 dev = __dev_get_by_index(&init_net, fld.flowidn_iif); 1677 if (!dev || !dev->dn_ptr) { 1678 kfree_skb(skb); 1679 return -ENODEV; 1680 } 1681 skb->protocol = htons(ETH_P_DNA_RT); 1682 skb->dev = dev; 1683 cb->src = fld.saddr; 1684 cb->dst = fld.daddr; 1685 local_bh_disable(); 1686 err = dn_route_input(skb); 1687 local_bh_enable(); 1688 memset(cb, 0, sizeof(struct dn_skb_cb)); 1689 rt = (struct dn_route *)skb_dst(skb); 1690 if (!err && -rt->dst.error) 1691 err = rt->dst.error; 1692 } else { 1693 if (tb[RTA_OIF]) 1694 fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]); 1695 1696 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0); 1697 } 1698 1699 skb->dev = NULL; 1700 if (err) 1701 goto out_free; 1702 skb_dst_set(skb, &rt->dst); 1703 if (rtm->rtm_flags & RTM_F_NOTIFY) 1704 rt->rt_flags |= RTCF_NOTIFY; 1705 1706 err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0); 1707 if (err < 0) { 1708 err = -EMSGSIZE; 1709 goto out_free; 1710 } 1711 1712 return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid); 1713 1714out_free: 1715 kfree_skb(skb); 1716 return err; 1717} 1718 1719/* 1720 * For routers, this is called from dn_fib_dump, but for endnodes its 1721 * called directly from the rtnetlink dispatch table. 1722 */ 1723int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb) 1724{ 1725 struct net *net = sock_net(skb->sk); 1726 struct dn_route *rt; 1727 int h, s_h; 1728 int idx, s_idx; 1729 struct rtmsg *rtm; 1730 1731 if (!net_eq(net, &init_net)) 1732 return 0; 1733 1734 if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg)) 1735 return -EINVAL; 1736 1737 rtm = nlmsg_data(cb->nlh); 1738 if (!(rtm->rtm_flags & RTM_F_CLONED)) 1739 return 0; 1740 1741 s_h = cb->args[0]; 1742 s_idx = idx = cb->args[1]; 1743 for(h = 0; h <= dn_rt_hash_mask; h++) { 1744 if (h < s_h) 1745 continue; 1746 if (h > s_h) 1747 s_idx = 0; 1748 rcu_read_lock_bh(); 1749 for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0; 1750 rt; 1751 rt = rcu_dereference_bh(rt->dst.dn_next), idx++) { 1752 if (idx < s_idx) 1753 continue; 1754 skb_dst_set(skb, dst_clone(&rt->dst)); 1755 if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid, 1756 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 1757 1, NLM_F_MULTI) < 0) { 1758 skb_dst_drop(skb); 1759 rcu_read_unlock_bh(); 1760 goto done; 1761 } 1762 skb_dst_drop(skb); 1763 } 1764 rcu_read_unlock_bh(); 1765 } 1766 1767done: 1768 cb->args[0] = h; 1769 cb->args[1] = idx; 1770 return skb->len; 1771} 1772 1773#ifdef CONFIG_PROC_FS 1774struct dn_rt_cache_iter_state { 1775 int bucket; 1776}; 1777 1778static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq) 1779{ 1780 struct dn_route *rt = NULL; 1781 struct dn_rt_cache_iter_state *s = seq->private; 1782 1783 for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) { 1784 rcu_read_lock_bh(); 1785 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain); 1786 if (rt) 1787 break; 1788 rcu_read_unlock_bh(); 1789 } 1790 return rt; 1791} 1792 1793static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt) 1794{ 1795 struct dn_rt_cache_iter_state *s = seq->private; 1796 1797 rt = rcu_dereference_bh(rt->dst.dn_next); 1798 while (!rt) { 1799 rcu_read_unlock_bh(); 1800 if (--s->bucket < 0) 1801 break; 1802 rcu_read_lock_bh(); 1803 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain); 1804 } 1805 return rt; 1806} 1807 1808static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 1809{ 1810 struct dn_route *rt = dn_rt_cache_get_first(seq); 1811 1812 if (rt) { 1813 while(*pos && (rt = dn_rt_cache_get_next(seq, rt))) 1814 --*pos; 1815 } 1816 return *pos ? NULL : rt; 1817} 1818 1819static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1820{ 1821 struct dn_route *rt = dn_rt_cache_get_next(seq, v); 1822 ++*pos; 1823 return rt; 1824} 1825 1826static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v) 1827{ 1828 if (v) 1829 rcu_read_unlock_bh(); 1830} 1831 1832static int dn_rt_cache_seq_show(struct seq_file *seq, void *v) 1833{ 1834 struct dn_route *rt = v; 1835 char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN]; 1836 1837 seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n", 1838 rt->dst.dev ? rt->dst.dev->name : "*", 1839 dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1), 1840 dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2), 1841 atomic_read(&rt->dst.__refcnt), 1842 rt->dst.__use, 0); 1843 return 0; 1844} 1845 1846static const struct seq_operations dn_rt_cache_seq_ops = { 1847 .start = dn_rt_cache_seq_start, 1848 .next = dn_rt_cache_seq_next, 1849 .stop = dn_rt_cache_seq_stop, 1850 .show = dn_rt_cache_seq_show, 1851}; 1852 1853static int dn_rt_cache_seq_open(struct inode *inode, struct file *file) 1854{ 1855 return seq_open_private(file, &dn_rt_cache_seq_ops, 1856 sizeof(struct dn_rt_cache_iter_state)); 1857} 1858 1859static const struct file_operations dn_rt_cache_seq_fops = { 1860 .owner = THIS_MODULE, 1861 .open = dn_rt_cache_seq_open, 1862 .read = seq_read, 1863 .llseek = seq_lseek, 1864 .release = seq_release_private, 1865}; 1866 1867#endif /* CONFIG_PROC_FS */ 1868 1869void __init dn_route_init(void) 1870{ 1871 int i, goal, order; 1872 1873 dn_dst_ops.kmem_cachep = 1874 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0, 1875 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 1876 dst_entries_init(&dn_dst_ops); 1877 setup_timer(&dn_route_timer, dn_dst_check_expire, 0); 1878 dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ; 1879 add_timer(&dn_route_timer); 1880 1881 goal = totalram_pages >> (26 - PAGE_SHIFT); 1882 1883 for(order = 0; (1UL << order) < goal; order++) 1884 /* NOTHING */; 1885 1886 /* 1887 * Only want 1024 entries max, since the table is very, very unlikely 1888 * to be larger than that. 1889 */ 1890 while(order && ((((1UL << order) * PAGE_SIZE) / 1891 sizeof(struct dn_rt_hash_bucket)) >= 2048)) 1892 order--; 1893 1894 do { 1895 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE / 1896 sizeof(struct dn_rt_hash_bucket); 1897 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1)) 1898 dn_rt_hash_mask--; 1899 dn_rt_hash_table = (struct dn_rt_hash_bucket *) 1900 __get_free_pages(GFP_ATOMIC, order); 1901 } while (dn_rt_hash_table == NULL && --order > 0); 1902 1903 if (!dn_rt_hash_table) 1904 panic("Failed to allocate DECnet route cache hash table\n"); 1905 1906 printk(KERN_INFO 1907 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n", 1908 dn_rt_hash_mask, 1909 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024); 1910 1911 dn_rt_hash_mask--; 1912 for(i = 0; i <= dn_rt_hash_mask; i++) { 1913 spin_lock_init(&dn_rt_hash_table[i].lock); 1914 dn_rt_hash_table[i].chain = NULL; 1915 } 1916 1917 dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1); 1918 1919 proc_create("decnet_cache", S_IRUGO, init_net.proc_net, 1920 &dn_rt_cache_seq_fops); 1921 1922#ifdef CONFIG_DECNET_ROUTER 1923 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute, 1924 dn_fib_dump, NULL); 1925#else 1926 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute, 1927 dn_cache_dump, NULL); 1928#endif 1929} 1930 1931void __exit dn_route_cleanup(void) 1932{ 1933 del_timer(&dn_route_timer); 1934 dn_run_flush(0); 1935 1936 remove_proc_entry("decnet_cache", init_net.proc_net); 1937 dst_entries_destroy(&dn_dst_ops); 1938} 1939 1940