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 .protocol = cpu_to_be16(ETH_P_DNA_RT), 140 .gc_thresh = 128, 141 .gc = dn_dst_gc, 142 .check = dn_dst_check, 143 .default_advmss = dn_dst_default_advmss, 144 .mtu = dn_dst_mtu, 145 .cow_metrics = dst_cow_metrics_generic, 146 .destroy = dn_dst_destroy, 147 .ifdown = dn_dst_ifdown, 148 .negative_advice = dn_dst_negative_advice, 149 .link_failure = dn_dst_link_failure, 150 .update_pmtu = dn_dst_update_pmtu, 151 .redirect = dn_dst_redirect, 152 .neigh_lookup = dn_dst_neigh_lookup, 153}; 154 155static void dn_dst_destroy(struct dst_entry *dst) 156{ 157 struct dn_route *rt = (struct dn_route *) dst; 158 159 if (rt->n) 160 neigh_release(rt->n); 161 dst_destroy_metrics_generic(dst); 162} 163 164static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how) 165{ 166 if (how) { 167 struct dn_route *rt = (struct dn_route *) dst; 168 struct neighbour *n = rt->n; 169 170 if (n && n->dev == dev) { 171 n->dev = dev_net(dev)->loopback_dev; 172 dev_hold(n->dev); 173 dev_put(dev); 174 } 175 } 176} 177 178static __inline__ unsigned int dn_hash(__le16 src, __le16 dst) 179{ 180 __u16 tmp = (__u16 __force)(src ^ dst); 181 tmp ^= (tmp >> 3); 182 tmp ^= (tmp >> 5); 183 tmp ^= (tmp >> 10); 184 return dn_rt_hash_mask & (unsigned int)tmp; 185} 186 187static inline void dnrt_free(struct dn_route *rt) 188{ 189 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); 190} 191 192static inline void dnrt_drop(struct dn_route *rt) 193{ 194 dst_release(&rt->dst); 195 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); 196} 197 198static void dn_dst_check_expire(unsigned long dummy) 199{ 200 int i; 201 struct dn_route *rt; 202 struct dn_route __rcu **rtp; 203 unsigned long now = jiffies; 204 unsigned long expire = 120 * HZ; 205 206 for (i = 0; i <= dn_rt_hash_mask; i++) { 207 rtp = &dn_rt_hash_table[i].chain; 208 209 spin_lock(&dn_rt_hash_table[i].lock); 210 while ((rt = rcu_dereference_protected(*rtp, 211 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) { 212 if (atomic_read(&rt->dst.__refcnt) || 213 (now - rt->dst.lastuse) < expire) { 214 rtp = &rt->dst.dn_next; 215 continue; 216 } 217 *rtp = rt->dst.dn_next; 218 rt->dst.dn_next = NULL; 219 dnrt_free(rt); 220 } 221 spin_unlock(&dn_rt_hash_table[i].lock); 222 223 if ((jiffies - now) > 0) 224 break; 225 } 226 227 mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ); 228} 229 230static int dn_dst_gc(struct dst_ops *ops) 231{ 232 struct dn_route *rt; 233 struct dn_route __rcu **rtp; 234 int i; 235 unsigned long now = jiffies; 236 unsigned long expire = 10 * HZ; 237 238 for (i = 0; i <= dn_rt_hash_mask; i++) { 239 240 spin_lock_bh(&dn_rt_hash_table[i].lock); 241 rtp = &dn_rt_hash_table[i].chain; 242 243 while ((rt = rcu_dereference_protected(*rtp, 244 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) { 245 if (atomic_read(&rt->dst.__refcnt) || 246 (now - rt->dst.lastuse) < expire) { 247 rtp = &rt->dst.dn_next; 248 continue; 249 } 250 *rtp = rt->dst.dn_next; 251 rt->dst.dn_next = NULL; 252 dnrt_drop(rt); 253 break; 254 } 255 spin_unlock_bh(&dn_rt_hash_table[i].lock); 256 } 257 258 return 0; 259} 260 261/* 262 * The decnet standards don't impose a particular minimum mtu, what they 263 * do insist on is that the routing layer accepts a datagram of at least 264 * 230 bytes long. Here we have to subtract the routing header length from 265 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we 266 * assume the worst and use a long header size. 267 * 268 * We update both the mtu and the advertised mss (i.e. the segment size we 269 * advertise to the other end). 270 */ 271static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk, 272 struct sk_buff *skb, u32 mtu) 273{ 274 struct dn_route *rt = (struct dn_route *) dst; 275 struct neighbour *n = rt->n; 276 u32 min_mtu = 230; 277 struct dn_dev *dn; 278 279 dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL; 280 281 if (dn && dn->use_long == 0) 282 min_mtu -= 6; 283 else 284 min_mtu -= 21; 285 286 if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) { 287 if (!(dst_metric_locked(dst, RTAX_MTU))) { 288 dst_metric_set(dst, RTAX_MTU, mtu); 289 dst_set_expires(dst, dn_rt_mtu_expires); 290 } 291 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) { 292 u32 mss = mtu - DN_MAX_NSP_DATA_HEADER; 293 u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS); 294 if (!existing_mss || existing_mss > mss) 295 dst_metric_set(dst, RTAX_ADVMSS, mss); 296 } 297 } 298} 299 300static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk, 301 struct sk_buff *skb) 302{ 303} 304 305/* 306 * When a route has been marked obsolete. (e.g. routing cache flush) 307 */ 308static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie) 309{ 310 return NULL; 311} 312 313static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst) 314{ 315 dst_release(dst); 316 return NULL; 317} 318 319static void dn_dst_link_failure(struct sk_buff *skb) 320{ 321} 322 323static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2) 324{ 325 return ((fl1->daddr ^ fl2->daddr) | 326 (fl1->saddr ^ fl2->saddr) | 327 (fl1->flowidn_mark ^ fl2->flowidn_mark) | 328 (fl1->flowidn_scope ^ fl2->flowidn_scope) | 329 (fl1->flowidn_oif ^ fl2->flowidn_oif) | 330 (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0; 331} 332 333static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp) 334{ 335 struct dn_route *rth; 336 struct dn_route __rcu **rthp; 337 unsigned long now = jiffies; 338 339 rthp = &dn_rt_hash_table[hash].chain; 340 341 spin_lock_bh(&dn_rt_hash_table[hash].lock); 342 while ((rth = rcu_dereference_protected(*rthp, 343 lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) { 344 if (compare_keys(&rth->fld, &rt->fld)) { 345 /* Put it first */ 346 *rthp = rth->dst.dn_next; 347 rcu_assign_pointer(rth->dst.dn_next, 348 dn_rt_hash_table[hash].chain); 349 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth); 350 351 dst_use(&rth->dst, now); 352 spin_unlock_bh(&dn_rt_hash_table[hash].lock); 353 354 dnrt_drop(rt); 355 *rp = rth; 356 return 0; 357 } 358 rthp = &rth->dst.dn_next; 359 } 360 361 rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain); 362 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt); 363 364 dst_use(&rt->dst, now); 365 spin_unlock_bh(&dn_rt_hash_table[hash].lock); 366 *rp = rt; 367 return 0; 368} 369 370static void dn_run_flush(unsigned long dummy) 371{ 372 int i; 373 struct dn_route *rt, *next; 374 375 for (i = 0; i < dn_rt_hash_mask; i++) { 376 spin_lock_bh(&dn_rt_hash_table[i].lock); 377 378 if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL) 379 goto nothing_to_declare; 380 381 for(; rt; rt = next) { 382 next = rcu_dereference_raw(rt->dst.dn_next); 383 RCU_INIT_POINTER(rt->dst.dn_next, NULL); 384 dst_free((struct dst_entry *)rt); 385 } 386 387nothing_to_declare: 388 spin_unlock_bh(&dn_rt_hash_table[i].lock); 389 } 390} 391 392static DEFINE_SPINLOCK(dn_rt_flush_lock); 393 394void dn_rt_cache_flush(int delay) 395{ 396 unsigned long now = jiffies; 397 int user_mode = !in_interrupt(); 398 399 if (delay < 0) 400 delay = dn_rt_min_delay; 401 402 spin_lock_bh(&dn_rt_flush_lock); 403 404 if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) { 405 long tmo = (long)(dn_rt_deadline - now); 406 407 if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay) 408 tmo = 0; 409 410 if (delay > tmo) 411 delay = tmo; 412 } 413 414 if (delay <= 0) { 415 spin_unlock_bh(&dn_rt_flush_lock); 416 dn_run_flush(0); 417 return; 418 } 419 420 if (dn_rt_deadline == 0) 421 dn_rt_deadline = now + dn_rt_max_delay; 422 423 dn_rt_flush_timer.expires = now + delay; 424 add_timer(&dn_rt_flush_timer); 425 spin_unlock_bh(&dn_rt_flush_lock); 426} 427 428/** 429 * dn_return_short - Return a short packet to its sender 430 * @skb: The packet to return 431 * 432 */ 433static int dn_return_short(struct sk_buff *skb) 434{ 435 struct dn_skb_cb *cb; 436 unsigned char *ptr; 437 __le16 *src; 438 __le16 *dst; 439 440 /* Add back headers */ 441 skb_push(skb, skb->data - skb_network_header(skb)); 442 443 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL) 444 return NET_RX_DROP; 445 446 cb = DN_SKB_CB(skb); 447 /* Skip packet length and point to flags */ 448 ptr = skb->data + 2; 449 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS; 450 451 dst = (__le16 *)ptr; 452 ptr += 2; 453 src = (__le16 *)ptr; 454 ptr += 2; 455 *ptr = 0; /* Zero hop count */ 456 457 swap(*src, *dst); 458 459 skb->pkt_type = PACKET_OUTGOING; 460 dn_rt_finish_output(skb, NULL, NULL); 461 return NET_RX_SUCCESS; 462} 463 464/** 465 * dn_return_long - Return a long packet to its sender 466 * @skb: The long format packet to return 467 * 468 */ 469static int dn_return_long(struct sk_buff *skb) 470{ 471 struct dn_skb_cb *cb; 472 unsigned char *ptr; 473 unsigned char *src_addr, *dst_addr; 474 unsigned char tmp[ETH_ALEN]; 475 476 /* Add back all headers */ 477 skb_push(skb, skb->data - skb_network_header(skb)); 478 479 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL) 480 return NET_RX_DROP; 481 482 cb = DN_SKB_CB(skb); 483 /* Ignore packet length and point to flags */ 484 ptr = skb->data + 2; 485 486 /* Skip padding */ 487 if (*ptr & DN_RT_F_PF) { 488 char padlen = (*ptr & ~DN_RT_F_PF); 489 ptr += padlen; 490 } 491 492 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS; 493 ptr += 2; 494 dst_addr = ptr; 495 ptr += 8; 496 src_addr = ptr; 497 ptr += 6; 498 *ptr = 0; /* Zero hop count */ 499 500 /* Swap source and destination */ 501 memcpy(tmp, src_addr, ETH_ALEN); 502 memcpy(src_addr, dst_addr, ETH_ALEN); 503 memcpy(dst_addr, tmp, ETH_ALEN); 504 505 skb->pkt_type = PACKET_OUTGOING; 506 dn_rt_finish_output(skb, dst_addr, src_addr); 507 return NET_RX_SUCCESS; 508} 509 510/** 511 * dn_route_rx_packet - Try and find a route for an incoming packet 512 * @skb: The packet to find a route for 513 * 514 * Returns: result of input function if route is found, error code otherwise 515 */ 516static int dn_route_rx_packet(struct sk_buff *skb) 517{ 518 struct dn_skb_cb *cb; 519 int err; 520 521 if ((err = dn_route_input(skb)) == 0) 522 return dst_input(skb); 523 524 cb = DN_SKB_CB(skb); 525 if (decnet_debug_level & 4) { 526 char *devname = skb->dev ? skb->dev->name : "???"; 527 528 printk(KERN_DEBUG 529 "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n", 530 (int)cb->rt_flags, devname, skb->len, 531 le16_to_cpu(cb->src), le16_to_cpu(cb->dst), 532 err, skb->pkt_type); 533 } 534 535 if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) { 536 switch (cb->rt_flags & DN_RT_PKT_MSK) { 537 case DN_RT_PKT_SHORT: 538 return dn_return_short(skb); 539 case DN_RT_PKT_LONG: 540 return dn_return_long(skb); 541 } 542 } 543 544 kfree_skb(skb); 545 return NET_RX_DROP; 546} 547 548static int dn_route_rx_long(struct sk_buff *skb) 549{ 550 struct dn_skb_cb *cb = DN_SKB_CB(skb); 551 unsigned char *ptr = skb->data; 552 553 if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */ 554 goto drop_it; 555 556 skb_pull(skb, 20); 557 skb_reset_transport_header(skb); 558 559 /* Destination info */ 560 ptr += 2; 561 cb->dst = dn_eth2dn(ptr); 562 if (memcmp(ptr, dn_hiord_addr, 4) != 0) 563 goto drop_it; 564 ptr += 6; 565 566 567 /* Source info */ 568 ptr += 2; 569 cb->src = dn_eth2dn(ptr); 570 if (memcmp(ptr, dn_hiord_addr, 4) != 0) 571 goto drop_it; 572 ptr += 6; 573 /* Other junk */ 574 ptr++; 575 cb->hops = *ptr++; /* Visit Count */ 576 577 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, 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, skb, skb->dev, NULL, 605 dn_route_rx_packet); 606 607drop_it: 608 kfree_skb(skb); 609 return NET_RX_DROP; 610} 611 612static int dn_route_discard(struct sk_buff *skb) 613{ 614 /* 615 * I know we drop the packet here, but thats considered success in 616 * this case 617 */ 618 kfree_skb(skb); 619 return NET_RX_SUCCESS; 620} 621 622static int dn_route_ptp_hello(struct sk_buff *skb) 623{ 624 dn_dev_hello(skb); 625 dn_neigh_pointopoint_hello(skb); 626 return NET_RX_SUCCESS; 627} 628 629int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) 630{ 631 struct dn_skb_cb *cb; 632 unsigned char flags = 0; 633 __u16 len = le16_to_cpu(*(__le16 *)skb->data); 634 struct dn_dev *dn = rcu_dereference(dev->dn_ptr); 635 unsigned char padlen = 0; 636 637 if (!net_eq(dev_net(dev), &init_net)) 638 goto dump_it; 639 640 if (dn == NULL) 641 goto dump_it; 642 643 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 644 goto out; 645 646 if (!pskb_may_pull(skb, 3)) 647 goto dump_it; 648 649 skb_pull(skb, 2); 650 651 if (len > skb->len) 652 goto dump_it; 653 654 skb_trim(skb, len); 655 656 flags = *skb->data; 657 658 cb = DN_SKB_CB(skb); 659 cb->stamp = jiffies; 660 cb->iif = dev->ifindex; 661 662 /* 663 * If we have padding, remove it. 664 */ 665 if (flags & DN_RT_F_PF) { 666 padlen = flags & ~DN_RT_F_PF; 667 if (!pskb_may_pull(skb, padlen + 1)) 668 goto dump_it; 669 skb_pull(skb, padlen); 670 flags = *skb->data; 671 } 672 673 skb_reset_network_header(skb); 674 675 /* 676 * Weed out future version DECnet 677 */ 678 if (flags & DN_RT_F_VER) 679 goto dump_it; 680 681 cb->rt_flags = flags; 682 683 if (decnet_debug_level & 1) 684 printk(KERN_DEBUG 685 "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n", 686 (int)flags, (dev) ? dev->name : "???", len, skb->len, 687 padlen); 688 689 if (flags & DN_RT_PKT_CNTL) { 690 if (unlikely(skb_linearize(skb))) 691 goto dump_it; 692 693 switch (flags & DN_RT_CNTL_MSK) { 694 case DN_RT_PKT_INIT: 695 dn_dev_init_pkt(skb); 696 break; 697 case DN_RT_PKT_VERI: 698 dn_dev_veri_pkt(skb); 699 break; 700 } 701 702 if (dn->parms.state != DN_DEV_S_RU) 703 goto dump_it; 704 705 switch (flags & DN_RT_CNTL_MSK) { 706 case DN_RT_PKT_HELO: 707 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO, 708 skb, skb->dev, NULL, 709 dn_route_ptp_hello); 710 711 case DN_RT_PKT_L1RT: 712 case DN_RT_PKT_L2RT: 713 return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE, 714 skb, skb->dev, NULL, 715 dn_route_discard); 716 case DN_RT_PKT_ERTH: 717 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO, 718 skb, skb->dev, NULL, 719 dn_neigh_router_hello); 720 721 case DN_RT_PKT_EEDH: 722 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO, 723 skb, skb->dev, NULL, 724 dn_neigh_endnode_hello); 725 } 726 } else { 727 if (dn->parms.state != DN_DEV_S_RU) 728 goto dump_it; 729 730 skb_pull(skb, 1); /* Pull flags */ 731 732 switch (flags & DN_RT_PKT_MSK) { 733 case DN_RT_PKT_LONG: 734 return dn_route_rx_long(skb); 735 case DN_RT_PKT_SHORT: 736 return dn_route_rx_short(skb); 737 } 738 } 739 740dump_it: 741 kfree_skb(skb); 742out: 743 return NET_RX_DROP; 744} 745 746static int dn_to_neigh_output(struct sk_buff *skb) 747{ 748 struct dst_entry *dst = skb_dst(skb); 749 struct dn_route *rt = (struct dn_route *) dst; 750 struct neighbour *n = rt->n; 751 752 return n->output(n, skb); 753} 754 755static int dn_output(struct sk_buff *skb) 756{ 757 struct dst_entry *dst = skb_dst(skb); 758 struct dn_route *rt = (struct dn_route *)dst; 759 struct net_device *dev = dst->dev; 760 struct dn_skb_cb *cb = DN_SKB_CB(skb); 761 762 int err = -EINVAL; 763 764 if (rt->n == NULL) 765 goto error; 766 767 skb->dev = dev; 768 769 cb->src = rt->rt_saddr; 770 cb->dst = rt->rt_daddr; 771 772 /* 773 * Always set the Intra-Ethernet bit on all outgoing packets 774 * originated on this node. Only valid flag from upper layers 775 * is return-to-sender-requested. Set hop count to 0 too. 776 */ 777 cb->rt_flags &= ~DN_RT_F_RQR; 778 cb->rt_flags |= DN_RT_F_IE; 779 cb->hops = 0; 780 781 return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT, skb, NULL, dev, 782 dn_to_neigh_output); 783 784error: 785 net_dbg_ratelimited("dn_output: This should not happen\n"); 786 787 kfree_skb(skb); 788 789 return err; 790} 791 792static int dn_forward(struct sk_buff *skb) 793{ 794 struct dn_skb_cb *cb = DN_SKB_CB(skb); 795 struct dst_entry *dst = skb_dst(skb); 796 struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr); 797 struct dn_route *rt; 798 int header_len; 799#ifdef CONFIG_NETFILTER 800 struct net_device *dev = skb->dev; 801#endif 802 803 if (skb->pkt_type != PACKET_HOST) 804 goto drop; 805 806 /* Ensure that we have enough space for headers */ 807 rt = (struct dn_route *)skb_dst(skb); 808 header_len = dn_db->use_long ? 21 : 6; 809 if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len)) 810 goto drop; 811 812 /* 813 * Hop count exceeded. 814 */ 815 if (++cb->hops > 30) 816 goto drop; 817 818 skb->dev = rt->dst.dev; 819 820 /* 821 * If packet goes out same interface it came in on, then set 822 * the Intra-Ethernet bit. This has no effect for short 823 * packets, so we don't need to test for them here. 824 */ 825 cb->rt_flags &= ~DN_RT_F_IE; 826 if (rt->rt_flags & RTCF_DOREDIRECT) 827 cb->rt_flags |= DN_RT_F_IE; 828 829 return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD, skb, dev, skb->dev, 830 dn_to_neigh_output); 831 832drop: 833 kfree_skb(skb); 834 return NET_RX_DROP; 835} 836 837/* 838 * Used to catch bugs. This should never normally get 839 * called. 840 */ 841static int dn_rt_bug(struct sk_buff *skb) 842{ 843 struct dn_skb_cb *cb = DN_SKB_CB(skb); 844 845 net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n", 846 le16_to_cpu(cb->src), le16_to_cpu(cb->dst)); 847 848 kfree_skb(skb); 849 850 return NET_RX_DROP; 851} 852 853static unsigned int dn_dst_default_advmss(const struct dst_entry *dst) 854{ 855 return dn_mss_from_pmtu(dst->dev, dst_mtu(dst)); 856} 857 858static unsigned int dn_dst_mtu(const struct dst_entry *dst) 859{ 860 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 861 862 return mtu ? : dst->dev->mtu; 863} 864 865static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst, 866 struct sk_buff *skb, 867 const void *daddr) 868{ 869 return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev); 870} 871 872static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res) 873{ 874 struct dn_fib_info *fi = res->fi; 875 struct net_device *dev = rt->dst.dev; 876 unsigned int mss_metric; 877 struct neighbour *n; 878 879 if (fi) { 880 if (DN_FIB_RES_GW(*res) && 881 DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) 882 rt->rt_gateway = DN_FIB_RES_GW(*res); 883 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 884 } 885 rt->rt_type = res->type; 886 887 if (dev != NULL && rt->n == NULL) { 888 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev); 889 if (IS_ERR(n)) 890 return PTR_ERR(n); 891 rt->n = n; 892 } 893 894 if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu) 895 dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu); 896 mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS); 897 if (mss_metric) { 898 unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst)); 899 if (mss_metric > mss) 900 dst_metric_set(&rt->dst, RTAX_ADVMSS, mss); 901 } 902 return 0; 903} 904 905static inline int dn_match_addr(__le16 addr1, __le16 addr2) 906{ 907 __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2); 908 int match = 16; 909 while(tmp) { 910 tmp >>= 1; 911 match--; 912 } 913 return match; 914} 915 916static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope) 917{ 918 __le16 saddr = 0; 919 struct dn_dev *dn_db; 920 struct dn_ifaddr *ifa; 921 int best_match = 0; 922 int ret; 923 924 rcu_read_lock(); 925 dn_db = rcu_dereference(dev->dn_ptr); 926 for (ifa = rcu_dereference(dn_db->ifa_list); 927 ifa != NULL; 928 ifa = rcu_dereference(ifa->ifa_next)) { 929 if (ifa->ifa_scope > scope) 930 continue; 931 if (!daddr) { 932 saddr = ifa->ifa_local; 933 break; 934 } 935 ret = dn_match_addr(daddr, ifa->ifa_local); 936 if (ret > best_match) 937 saddr = ifa->ifa_local; 938 if (best_match == 0) 939 saddr = ifa->ifa_local; 940 } 941 rcu_read_unlock(); 942 943 return saddr; 944} 945 946static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res) 947{ 948 return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope); 949} 950 951static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res) 952{ 953 __le16 mask = dnet_make_mask(res->prefixlen); 954 return (daddr&~mask)|res->fi->fib_nh->nh_gw; 955} 956 957static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard) 958{ 959 struct flowidn fld = { 960 .daddr = oldflp->daddr, 961 .saddr = oldflp->saddr, 962 .flowidn_scope = RT_SCOPE_UNIVERSE, 963 .flowidn_mark = oldflp->flowidn_mark, 964 .flowidn_iif = LOOPBACK_IFINDEX, 965 .flowidn_oif = oldflp->flowidn_oif, 966 }; 967 struct dn_route *rt = NULL; 968 struct net_device *dev_out = NULL, *dev; 969 struct neighbour *neigh = NULL; 970 unsigned int hash; 971 unsigned int flags = 0; 972 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST }; 973 int err; 974 int free_res = 0; 975 __le16 gateway = 0; 976 977 if (decnet_debug_level & 16) 978 printk(KERN_DEBUG 979 "dn_route_output_slow: dst=%04x src=%04x mark=%d" 980 " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr), 981 le16_to_cpu(oldflp->saddr), 982 oldflp->flowidn_mark, LOOPBACK_IFINDEX, 983 oldflp->flowidn_oif); 984 985 /* If we have an output interface, verify its a DECnet device */ 986 if (oldflp->flowidn_oif) { 987 dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif); 988 err = -ENODEV; 989 if (dev_out && dev_out->dn_ptr == NULL) { 990 dev_put(dev_out); 991 dev_out = NULL; 992 } 993 if (dev_out == NULL) 994 goto out; 995 } 996 997 /* If we have a source address, verify that its a local address */ 998 if (oldflp->saddr) { 999 err = -EADDRNOTAVAIL; 1000 1001 if (dev_out) { 1002 if (dn_dev_islocal(dev_out, oldflp->saddr)) 1003 goto source_ok; 1004 dev_put(dev_out); 1005 goto out; 1006 } 1007 rcu_read_lock(); 1008 for_each_netdev_rcu(&init_net, dev) { 1009 if (!dev->dn_ptr) 1010 continue; 1011 if (!dn_dev_islocal(dev, oldflp->saddr)) 1012 continue; 1013 if ((dev->flags & IFF_LOOPBACK) && 1014 oldflp->daddr && 1015 !dn_dev_islocal(dev, oldflp->daddr)) 1016 continue; 1017 1018 dev_out = dev; 1019 break; 1020 } 1021 rcu_read_unlock(); 1022 if (dev_out == NULL) 1023 goto out; 1024 dev_hold(dev_out); 1025source_ok: 1026 ; 1027 } 1028 1029 /* No destination? Assume its local */ 1030 if (!fld.daddr) { 1031 fld.daddr = fld.saddr; 1032 1033 err = -EADDRNOTAVAIL; 1034 if (dev_out) 1035 dev_put(dev_out); 1036 dev_out = init_net.loopback_dev; 1037 dev_hold(dev_out); 1038 if (!fld.daddr) { 1039 fld.daddr = 1040 fld.saddr = dnet_select_source(dev_out, 0, 1041 RT_SCOPE_HOST); 1042 if (!fld.daddr) 1043 goto out; 1044 } 1045 fld.flowidn_oif = LOOPBACK_IFINDEX; 1046 res.type = RTN_LOCAL; 1047 goto make_route; 1048 } 1049 1050 if (decnet_debug_level & 16) 1051 printk(KERN_DEBUG 1052 "dn_route_output_slow: initial checks complete." 1053 " dst=%o4x src=%04x oif=%d try_hard=%d\n", 1054 le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr), 1055 fld.flowidn_oif, try_hard); 1056 1057 /* 1058 * N.B. If the kernel is compiled without router support then 1059 * dn_fib_lookup() will evaluate to non-zero so this if () block 1060 * will always be executed. 1061 */ 1062 err = -ESRCH; 1063 if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) { 1064 struct dn_dev *dn_db; 1065 if (err != -ESRCH) 1066 goto out; 1067 /* 1068 * Here the fallback is basically the standard algorithm for 1069 * routing in endnodes which is described in the DECnet routing 1070 * docs 1071 * 1072 * If we are not trying hard, look in neighbour cache. 1073 * The result is tested to ensure that if a specific output 1074 * device/source address was requested, then we honour that 1075 * here 1076 */ 1077 if (!try_hard) { 1078 neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr); 1079 if (neigh) { 1080 if ((oldflp->flowidn_oif && 1081 (neigh->dev->ifindex != oldflp->flowidn_oif)) || 1082 (oldflp->saddr && 1083 (!dn_dev_islocal(neigh->dev, 1084 oldflp->saddr)))) { 1085 neigh_release(neigh); 1086 neigh = NULL; 1087 } else { 1088 if (dev_out) 1089 dev_put(dev_out); 1090 if (dn_dev_islocal(neigh->dev, fld.daddr)) { 1091 dev_out = init_net.loopback_dev; 1092 res.type = RTN_LOCAL; 1093 } else { 1094 dev_out = neigh->dev; 1095 } 1096 dev_hold(dev_out); 1097 goto select_source; 1098 } 1099 } 1100 } 1101 1102 /* Not there? Perhaps its a local address */ 1103 if (dev_out == NULL) 1104 dev_out = dn_dev_get_default(); 1105 err = -ENODEV; 1106 if (dev_out == NULL) 1107 goto out; 1108 dn_db = rcu_dereference_raw(dev_out->dn_ptr); 1109 /* Possible improvement - check all devices for local addr */ 1110 if (dn_dev_islocal(dev_out, fld.daddr)) { 1111 dev_put(dev_out); 1112 dev_out = init_net.loopback_dev; 1113 dev_hold(dev_out); 1114 res.type = RTN_LOCAL; 1115 goto select_source; 1116 } 1117 /* Not local either.... try sending it to the default router */ 1118 neigh = neigh_clone(dn_db->router); 1119 BUG_ON(neigh && neigh->dev != dev_out); 1120 1121 /* Ok then, we assume its directly connected and move on */ 1122select_source: 1123 if (neigh) 1124 gateway = ((struct dn_neigh *)neigh)->addr; 1125 if (gateway == 0) 1126 gateway = fld.daddr; 1127 if (fld.saddr == 0) { 1128 fld.saddr = dnet_select_source(dev_out, gateway, 1129 res.type == RTN_LOCAL ? 1130 RT_SCOPE_HOST : 1131 RT_SCOPE_LINK); 1132 if (fld.saddr == 0 && res.type != RTN_LOCAL) 1133 goto e_addr; 1134 } 1135 fld.flowidn_oif = dev_out->ifindex; 1136 goto make_route; 1137 } 1138 free_res = 1; 1139 1140 if (res.type == RTN_NAT) 1141 goto e_inval; 1142 1143 if (res.type == RTN_LOCAL) { 1144 if (!fld.saddr) 1145 fld.saddr = fld.daddr; 1146 if (dev_out) 1147 dev_put(dev_out); 1148 dev_out = init_net.loopback_dev; 1149 dev_hold(dev_out); 1150 fld.flowidn_oif = dev_out->ifindex; 1151 if (res.fi) 1152 dn_fib_info_put(res.fi); 1153 res.fi = NULL; 1154 goto make_route; 1155 } 1156 1157 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0) 1158 dn_fib_select_multipath(&fld, &res); 1159 1160 /* 1161 * We could add some logic to deal with default routes here and 1162 * get rid of some of the special casing above. 1163 */ 1164 1165 if (!fld.saddr) 1166 fld.saddr = DN_FIB_RES_PREFSRC(res); 1167 1168 if (dev_out) 1169 dev_put(dev_out); 1170 dev_out = DN_FIB_RES_DEV(res); 1171 dev_hold(dev_out); 1172 fld.flowidn_oif = dev_out->ifindex; 1173 gateway = DN_FIB_RES_GW(res); 1174 1175make_route: 1176 if (dev_out->flags & IFF_LOOPBACK) 1177 flags |= RTCF_LOCAL; 1178 1179 rt = dst_alloc(&dn_dst_ops, dev_out, 1, DST_OBSOLETE_NONE, DST_HOST); 1180 if (rt == NULL) 1181 goto e_nobufs; 1182 1183 memset(&rt->fld, 0, sizeof(rt->fld)); 1184 rt->fld.saddr = oldflp->saddr; 1185 rt->fld.daddr = oldflp->daddr; 1186 rt->fld.flowidn_oif = oldflp->flowidn_oif; 1187 rt->fld.flowidn_iif = 0; 1188 rt->fld.flowidn_mark = oldflp->flowidn_mark; 1189 1190 rt->rt_saddr = fld.saddr; 1191 rt->rt_daddr = fld.daddr; 1192 rt->rt_gateway = gateway ? gateway : fld.daddr; 1193 rt->rt_local_src = fld.saddr; 1194 1195 rt->rt_dst_map = fld.daddr; 1196 rt->rt_src_map = fld.saddr; 1197 1198 rt->n = neigh; 1199 neigh = NULL; 1200 1201 rt->dst.lastuse = jiffies; 1202 rt->dst.output = dn_output; 1203 rt->dst.input = dn_rt_bug; 1204 rt->rt_flags = flags; 1205 if (flags & RTCF_LOCAL) 1206 rt->dst.input = dn_nsp_rx; 1207 1208 err = dn_rt_set_next_hop(rt, &res); 1209 if (err) 1210 goto e_neighbour; 1211 1212 hash = dn_hash(rt->fld.saddr, rt->fld.daddr); 1213 dn_insert_route(rt, hash, (struct dn_route **)pprt); 1214 1215done: 1216 if (neigh) 1217 neigh_release(neigh); 1218 if (free_res) 1219 dn_fib_res_put(&res); 1220 if (dev_out) 1221 dev_put(dev_out); 1222out: 1223 return err; 1224 1225e_addr: 1226 err = -EADDRNOTAVAIL; 1227 goto done; 1228e_inval: 1229 err = -EINVAL; 1230 goto done; 1231e_nobufs: 1232 err = -ENOBUFS; 1233 goto done; 1234e_neighbour: 1235 dst_free(&rt->dst); 1236 goto e_nobufs; 1237} 1238 1239 1240/* 1241 * N.B. The flags may be moved into the flowi at some future stage. 1242 */ 1243static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags) 1244{ 1245 unsigned int hash = dn_hash(flp->saddr, flp->daddr); 1246 struct dn_route *rt = NULL; 1247 1248 if (!(flags & MSG_TRYHARD)) { 1249 rcu_read_lock_bh(); 1250 for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt; 1251 rt = rcu_dereference_bh(rt->dst.dn_next)) { 1252 if ((flp->daddr == rt->fld.daddr) && 1253 (flp->saddr == rt->fld.saddr) && 1254 (flp->flowidn_mark == rt->fld.flowidn_mark) && 1255 dn_is_output_route(rt) && 1256 (rt->fld.flowidn_oif == flp->flowidn_oif)) { 1257 dst_use(&rt->dst, jiffies); 1258 rcu_read_unlock_bh(); 1259 *pprt = &rt->dst; 1260 return 0; 1261 } 1262 } 1263 rcu_read_unlock_bh(); 1264 } 1265 1266 return dn_route_output_slow(pprt, flp, flags); 1267} 1268 1269static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags) 1270{ 1271 int err; 1272 1273 err = __dn_route_output_key(pprt, flp, flags); 1274 if (err == 0 && flp->flowidn_proto) { 1275 *pprt = xfrm_lookup(&init_net, *pprt, 1276 flowidn_to_flowi(flp), NULL, 0); 1277 if (IS_ERR(*pprt)) { 1278 err = PTR_ERR(*pprt); 1279 *pprt = NULL; 1280 } 1281 } 1282 return err; 1283} 1284 1285int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags) 1286{ 1287 int err; 1288 1289 err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD); 1290 if (err == 0 && fl->flowidn_proto) { 1291 if (!(flags & MSG_DONTWAIT)) 1292 fl->flowidn_flags |= FLOWI_FLAG_CAN_SLEEP; 1293 *pprt = xfrm_lookup(&init_net, *pprt, 1294 flowidn_to_flowi(fl), sk, 0); 1295 if (IS_ERR(*pprt)) { 1296 err = PTR_ERR(*pprt); 1297 *pprt = NULL; 1298 } 1299 } 1300 return err; 1301} 1302 1303static int dn_route_input_slow(struct sk_buff *skb) 1304{ 1305 struct dn_route *rt = NULL; 1306 struct dn_skb_cb *cb = DN_SKB_CB(skb); 1307 struct net_device *in_dev = skb->dev; 1308 struct net_device *out_dev = NULL; 1309 struct dn_dev *dn_db; 1310 struct neighbour *neigh = NULL; 1311 unsigned int hash; 1312 int flags = 0; 1313 __le16 gateway = 0; 1314 __le16 local_src = 0; 1315 struct flowidn fld = { 1316 .daddr = cb->dst, 1317 .saddr = cb->src, 1318 .flowidn_scope = RT_SCOPE_UNIVERSE, 1319 .flowidn_mark = skb->mark, 1320 .flowidn_iif = skb->dev->ifindex, 1321 }; 1322 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE }; 1323 int err = -EINVAL; 1324 int free_res = 0; 1325 1326 dev_hold(in_dev); 1327 1328 if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL) 1329 goto out; 1330 1331 /* Zero source addresses are not allowed */ 1332 if (fld.saddr == 0) 1333 goto out; 1334 1335 /* 1336 * In this case we've just received a packet from a source 1337 * outside ourselves pretending to come from us. We don't 1338 * allow it any further to prevent routing loops, spoofing and 1339 * other nasties. Loopback packets already have the dst attached 1340 * so this only affects packets which have originated elsewhere. 1341 */ 1342 err = -ENOTUNIQ; 1343 if (dn_dev_islocal(in_dev, cb->src)) 1344 goto out; 1345 1346 err = dn_fib_lookup(&fld, &res); 1347 if (err) { 1348 if (err != -ESRCH) 1349 goto out; 1350 /* 1351 * Is the destination us ? 1352 */ 1353 if (!dn_dev_islocal(in_dev, cb->dst)) 1354 goto e_inval; 1355 1356 res.type = RTN_LOCAL; 1357 } else { 1358 __le16 src_map = fld.saddr; 1359 free_res = 1; 1360 1361 out_dev = DN_FIB_RES_DEV(res); 1362 if (out_dev == NULL) { 1363 net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n"); 1364 goto e_inval; 1365 } 1366 dev_hold(out_dev); 1367 1368 if (res.r) 1369 src_map = fld.saddr; /* no NAT support for now */ 1370 1371 gateway = DN_FIB_RES_GW(res); 1372 if (res.type == RTN_NAT) { 1373 fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res); 1374 dn_fib_res_put(&res); 1375 free_res = 0; 1376 if (dn_fib_lookup(&fld, &res)) 1377 goto e_inval; 1378 free_res = 1; 1379 if (res.type != RTN_UNICAST) 1380 goto e_inval; 1381 flags |= RTCF_DNAT; 1382 gateway = fld.daddr; 1383 } 1384 fld.saddr = src_map; 1385 } 1386 1387 switch(res.type) { 1388 case RTN_UNICAST: 1389 /* 1390 * Forwarding check here, we only check for forwarding 1391 * being turned off, if you want to only forward intra 1392 * area, its up to you to set the routing tables up 1393 * correctly. 1394 */ 1395 if (dn_db->parms.forwarding == 0) 1396 goto e_inval; 1397 1398 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0) 1399 dn_fib_select_multipath(&fld, &res); 1400 1401 /* 1402 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT 1403 * flag as a hint to set the intra-ethernet bit when 1404 * forwarding. If we've got NAT in operation, we don't do 1405 * this optimisation. 1406 */ 1407 if (out_dev == in_dev && !(flags & RTCF_NAT)) 1408 flags |= RTCF_DOREDIRECT; 1409 1410 local_src = DN_FIB_RES_PREFSRC(res); 1411 1412 case RTN_BLACKHOLE: 1413 case RTN_UNREACHABLE: 1414 break; 1415 case RTN_LOCAL: 1416 flags |= RTCF_LOCAL; 1417 fld.saddr = cb->dst; 1418 fld.daddr = cb->src; 1419 1420 /* Routing tables gave us a gateway */ 1421 if (gateway) 1422 goto make_route; 1423 1424 /* Packet was intra-ethernet, so we know its on-link */ 1425 if (cb->rt_flags & DN_RT_F_IE) { 1426 gateway = cb->src; 1427 goto make_route; 1428 } 1429 1430 /* Use the default router if there is one */ 1431 neigh = neigh_clone(dn_db->router); 1432 if (neigh) { 1433 gateway = ((struct dn_neigh *)neigh)->addr; 1434 goto make_route; 1435 } 1436 1437 /* Close eyes and pray */ 1438 gateway = cb->src; 1439 goto make_route; 1440 default: 1441 goto e_inval; 1442 } 1443 1444make_route: 1445 rt = dst_alloc(&dn_dst_ops, out_dev, 0, DST_OBSOLETE_NONE, DST_HOST); 1446 if (rt == NULL) 1447 goto e_nobufs; 1448 1449 memset(&rt->fld, 0, sizeof(rt->fld)); 1450 rt->rt_saddr = fld.saddr; 1451 rt->rt_daddr = fld.daddr; 1452 rt->rt_gateway = fld.daddr; 1453 if (gateway) 1454 rt->rt_gateway = gateway; 1455 rt->rt_local_src = local_src ? local_src : rt->rt_saddr; 1456 1457 rt->rt_dst_map = fld.daddr; 1458 rt->rt_src_map = fld.saddr; 1459 1460 rt->fld.saddr = cb->src; 1461 rt->fld.daddr = cb->dst; 1462 rt->fld.flowidn_oif = 0; 1463 rt->fld.flowidn_iif = in_dev->ifindex; 1464 rt->fld.flowidn_mark = fld.flowidn_mark; 1465 1466 rt->n = neigh; 1467 rt->dst.lastuse = jiffies; 1468 rt->dst.output = dn_rt_bug; 1469 switch (res.type) { 1470 case RTN_UNICAST: 1471 rt->dst.input = dn_forward; 1472 break; 1473 case RTN_LOCAL: 1474 rt->dst.output = dn_output; 1475 rt->dst.input = dn_nsp_rx; 1476 rt->dst.dev = in_dev; 1477 flags |= RTCF_LOCAL; 1478 break; 1479 default: 1480 case RTN_UNREACHABLE: 1481 case RTN_BLACKHOLE: 1482 rt->dst.input = dst_discard; 1483 } 1484 rt->rt_flags = flags; 1485 1486 err = dn_rt_set_next_hop(rt, &res); 1487 if (err) 1488 goto e_neighbour; 1489 1490 hash = dn_hash(rt->fld.saddr, rt->fld.daddr); 1491 dn_insert_route(rt, hash, &rt); 1492 skb_dst_set(skb, &rt->dst); 1493 1494done: 1495 if (neigh) 1496 neigh_release(neigh); 1497 if (free_res) 1498 dn_fib_res_put(&res); 1499 dev_put(in_dev); 1500 if (out_dev) 1501 dev_put(out_dev); 1502out: 1503 return err; 1504 1505e_inval: 1506 err = -EINVAL; 1507 goto done; 1508 1509e_nobufs: 1510 err = -ENOBUFS; 1511 goto done; 1512 1513e_neighbour: 1514 dst_free(&rt->dst); 1515 goto done; 1516} 1517 1518static int dn_route_input(struct sk_buff *skb) 1519{ 1520 struct dn_route *rt; 1521 struct dn_skb_cb *cb = DN_SKB_CB(skb); 1522 unsigned int hash = dn_hash(cb->src, cb->dst); 1523 1524 if (skb_dst(skb)) 1525 return 0; 1526 1527 rcu_read_lock(); 1528 for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL; 1529 rt = rcu_dereference(rt->dst.dn_next)) { 1530 if ((rt->fld.saddr == cb->src) && 1531 (rt->fld.daddr == cb->dst) && 1532 (rt->fld.flowidn_oif == 0) && 1533 (rt->fld.flowidn_mark == skb->mark) && 1534 (rt->fld.flowidn_iif == cb->iif)) { 1535 dst_use(&rt->dst, jiffies); 1536 rcu_read_unlock(); 1537 skb_dst_set(skb, (struct dst_entry *)rt); 1538 return 0; 1539 } 1540 } 1541 rcu_read_unlock(); 1542 1543 return dn_route_input_slow(skb); 1544} 1545 1546static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq, 1547 int event, int nowait, unsigned int flags) 1548{ 1549 struct dn_route *rt = (struct dn_route *)skb_dst(skb); 1550 struct rtmsg *r; 1551 struct nlmsghdr *nlh; 1552 long expires; 1553 1554 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags); 1555 if (!nlh) 1556 return -EMSGSIZE; 1557 1558 r = nlmsg_data(nlh); 1559 r->rtm_family = AF_DECnet; 1560 r->rtm_dst_len = 16; 1561 r->rtm_src_len = 0; 1562 r->rtm_tos = 0; 1563 r->rtm_table = RT_TABLE_MAIN; 1564 r->rtm_type = rt->rt_type; 1565 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 1566 r->rtm_scope = RT_SCOPE_UNIVERSE; 1567 r->rtm_protocol = RTPROT_UNSPEC; 1568 1569 if (rt->rt_flags & RTCF_NOTIFY) 1570 r->rtm_flags |= RTM_F_NOTIFY; 1571 1572 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 || 1573 nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0) 1574 goto errout; 1575 1576 if (rt->fld.saddr) { 1577 r->rtm_src_len = 16; 1578 if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0) 1579 goto errout; 1580 } 1581 if (rt->dst.dev && 1582 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0) 1583 goto errout; 1584 1585 /* 1586 * Note to self - change this if input routes reverse direction when 1587 * they deal only with inputs and not with replies like they do 1588 * currently. 1589 */ 1590 if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0) 1591 goto errout; 1592 1593 if (rt->rt_daddr != rt->rt_gateway && 1594 nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0) 1595 goto errout; 1596 1597 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0) 1598 goto errout; 1599 1600 expires = rt->dst.expires ? rt->dst.expires - jiffies : 0; 1601 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, 1602 rt->dst.error) < 0) 1603 goto errout; 1604 1605 if (dn_is_input_route(rt) && 1606 nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0) 1607 goto errout; 1608 1609 return nlmsg_end(skb, nlh); 1610 1611errout: 1612 nlmsg_cancel(skb, nlh); 1613 return -EMSGSIZE; 1614} 1615 1616const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = { 1617 [RTA_DST] = { .type = NLA_U16 }, 1618 [RTA_SRC] = { .type = NLA_U16 }, 1619 [RTA_IIF] = { .type = NLA_U32 }, 1620 [RTA_OIF] = { .type = NLA_U32 }, 1621 [RTA_GATEWAY] = { .type = NLA_U16 }, 1622 [RTA_PRIORITY] = { .type = NLA_U32 }, 1623 [RTA_PREFSRC] = { .type = NLA_U16 }, 1624 [RTA_METRICS] = { .type = NLA_NESTED }, 1625 [RTA_MULTIPATH] = { .type = NLA_NESTED }, 1626 [RTA_TABLE] = { .type = NLA_U32 }, 1627 [RTA_MARK] = { .type = NLA_U32 }, 1628}; 1629 1630/* 1631 * This is called by both endnodes and routers now. 1632 */ 1633static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh) 1634{ 1635 struct net *net = sock_net(in_skb->sk); 1636 struct rtmsg *rtm = nlmsg_data(nlh); 1637 struct dn_route *rt = NULL; 1638 struct dn_skb_cb *cb; 1639 int err; 1640 struct sk_buff *skb; 1641 struct flowidn fld; 1642 struct nlattr *tb[RTA_MAX+1]; 1643 1644 if (!net_eq(net, &init_net)) 1645 return -EINVAL; 1646 1647 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_dn_policy); 1648 if (err < 0) 1649 return err; 1650 1651 memset(&fld, 0, sizeof(fld)); 1652 fld.flowidn_proto = DNPROTO_NSP; 1653 1654 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 1655 if (skb == NULL) 1656 return -ENOBUFS; 1657 skb_reset_mac_header(skb); 1658 cb = DN_SKB_CB(skb); 1659 1660 if (tb[RTA_SRC]) 1661 fld.saddr = nla_get_le16(tb[RTA_SRC]); 1662 1663 if (tb[RTA_DST]) 1664 fld.daddr = nla_get_le16(tb[RTA_DST]); 1665 1666 if (tb[RTA_IIF]) 1667 fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]); 1668 1669 if (fld.flowidn_iif) { 1670 struct net_device *dev; 1671 if ((dev = dev_get_by_index(&init_net, fld.flowidn_iif)) == NULL) { 1672 kfree_skb(skb); 1673 return -ENODEV; 1674 } 1675 if (!dev->dn_ptr) { 1676 dev_put(dev); 1677 kfree_skb(skb); 1678 return -ENODEV; 1679 } 1680 skb->protocol = htons(ETH_P_DNA_RT); 1681 skb->dev = dev; 1682 cb->src = fld.saddr; 1683 cb->dst = fld.daddr; 1684 local_bh_disable(); 1685 err = dn_route_input(skb); 1686 local_bh_enable(); 1687 memset(cb, 0, sizeof(struct dn_skb_cb)); 1688 rt = (struct dn_route *)skb_dst(skb); 1689 if (!err && -rt->dst.error) 1690 err = rt->dst.error; 1691 } else { 1692 if (tb[RTA_OIF]) 1693 fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]); 1694 1695 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0); 1696 } 1697 1698 if (skb->dev) 1699 dev_put(skb->dev); 1700 skb->dev = NULL; 1701 if (err) 1702 goto out_free; 1703 skb_dst_set(skb, &rt->dst); 1704 if (rtm->rtm_flags & RTM_F_NOTIFY) 1705 rt->rt_flags |= RTCF_NOTIFY; 1706 1707 err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0); 1708 1709 if (err == 0) 1710 goto out_free; 1711 if (err < 0) { 1712 err = -EMSGSIZE; 1713 goto out_free; 1714 } 1715 1716 return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid); 1717 1718out_free: 1719 kfree_skb(skb); 1720 return err; 1721} 1722 1723/* 1724 * For routers, this is called from dn_fib_dump, but for endnodes its 1725 * called directly from the rtnetlink dispatch table. 1726 */ 1727int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb) 1728{ 1729 struct net *net = sock_net(skb->sk); 1730 struct dn_route *rt; 1731 int h, s_h; 1732 int idx, s_idx; 1733 struct rtmsg *rtm; 1734 1735 if (!net_eq(net, &init_net)) 1736 return 0; 1737 1738 if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg)) 1739 return -EINVAL; 1740 1741 rtm = nlmsg_data(cb->nlh); 1742 if (!(rtm->rtm_flags & RTM_F_CLONED)) 1743 return 0; 1744 1745 s_h = cb->args[0]; 1746 s_idx = idx = cb->args[1]; 1747 for(h = 0; h <= dn_rt_hash_mask; h++) { 1748 if (h < s_h) 1749 continue; 1750 if (h > s_h) 1751 s_idx = 0; 1752 rcu_read_lock_bh(); 1753 for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0; 1754 rt; 1755 rt = rcu_dereference_bh(rt->dst.dn_next), idx++) { 1756 if (idx < s_idx) 1757 continue; 1758 skb_dst_set(skb, dst_clone(&rt->dst)); 1759 if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid, 1760 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 1761 1, NLM_F_MULTI) <= 0) { 1762 skb_dst_drop(skb); 1763 rcu_read_unlock_bh(); 1764 goto done; 1765 } 1766 skb_dst_drop(skb); 1767 } 1768 rcu_read_unlock_bh(); 1769 } 1770 1771done: 1772 cb->args[0] = h; 1773 cb->args[1] = idx; 1774 return skb->len; 1775} 1776 1777#ifdef CONFIG_PROC_FS 1778struct dn_rt_cache_iter_state { 1779 int bucket; 1780}; 1781 1782static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq) 1783{ 1784 struct dn_route *rt = NULL; 1785 struct dn_rt_cache_iter_state *s = seq->private; 1786 1787 for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) { 1788 rcu_read_lock_bh(); 1789 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain); 1790 if (rt) 1791 break; 1792 rcu_read_unlock_bh(); 1793 } 1794 return rt; 1795} 1796 1797static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt) 1798{ 1799 struct dn_rt_cache_iter_state *s = seq->private; 1800 1801 rt = rcu_dereference_bh(rt->dst.dn_next); 1802 while (!rt) { 1803 rcu_read_unlock_bh(); 1804 if (--s->bucket < 0) 1805 break; 1806 rcu_read_lock_bh(); 1807 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain); 1808 } 1809 return rt; 1810} 1811 1812static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 1813{ 1814 struct dn_route *rt = dn_rt_cache_get_first(seq); 1815 1816 if (rt) { 1817 while(*pos && (rt = dn_rt_cache_get_next(seq, rt))) 1818 --*pos; 1819 } 1820 return *pos ? NULL : rt; 1821} 1822 1823static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1824{ 1825 struct dn_route *rt = dn_rt_cache_get_next(seq, v); 1826 ++*pos; 1827 return rt; 1828} 1829 1830static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v) 1831{ 1832 if (v) 1833 rcu_read_unlock_bh(); 1834} 1835 1836static int dn_rt_cache_seq_show(struct seq_file *seq, void *v) 1837{ 1838 struct dn_route *rt = v; 1839 char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN]; 1840 1841 seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n", 1842 rt->dst.dev ? rt->dst.dev->name : "*", 1843 dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1), 1844 dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2), 1845 atomic_read(&rt->dst.__refcnt), 1846 rt->dst.__use, 0); 1847 return 0; 1848} 1849 1850static const struct seq_operations dn_rt_cache_seq_ops = { 1851 .start = dn_rt_cache_seq_start, 1852 .next = dn_rt_cache_seq_next, 1853 .stop = dn_rt_cache_seq_stop, 1854 .show = dn_rt_cache_seq_show, 1855}; 1856 1857static int dn_rt_cache_seq_open(struct inode *inode, struct file *file) 1858{ 1859 return seq_open_private(file, &dn_rt_cache_seq_ops, 1860 sizeof(struct dn_rt_cache_iter_state)); 1861} 1862 1863static const struct file_operations dn_rt_cache_seq_fops = { 1864 .owner = THIS_MODULE, 1865 .open = dn_rt_cache_seq_open, 1866 .read = seq_read, 1867 .llseek = seq_lseek, 1868 .release = seq_release_private, 1869}; 1870 1871#endif /* CONFIG_PROC_FS */ 1872 1873void __init dn_route_init(void) 1874{ 1875 int i, goal, order; 1876 1877 dn_dst_ops.kmem_cachep = 1878 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0, 1879 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 1880 dst_entries_init(&dn_dst_ops); 1881 setup_timer(&dn_route_timer, dn_dst_check_expire, 0); 1882 dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ; 1883 add_timer(&dn_route_timer); 1884 1885 goal = totalram_pages >> (26 - PAGE_SHIFT); 1886 1887 for(order = 0; (1UL << order) < goal; order++) 1888 /* NOTHING */; 1889 1890 /* 1891 * Only want 1024 entries max, since the table is very, very unlikely 1892 * to be larger than that. 1893 */ 1894 while(order && ((((1UL << order) * PAGE_SIZE) / 1895 sizeof(struct dn_rt_hash_bucket)) >= 2048)) 1896 order--; 1897 1898 do { 1899 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE / 1900 sizeof(struct dn_rt_hash_bucket); 1901 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1)) 1902 dn_rt_hash_mask--; 1903 dn_rt_hash_table = (struct dn_rt_hash_bucket *) 1904 __get_free_pages(GFP_ATOMIC, order); 1905 } while (dn_rt_hash_table == NULL && --order > 0); 1906 1907 if (!dn_rt_hash_table) 1908 panic("Failed to allocate DECnet route cache hash table\n"); 1909 1910 printk(KERN_INFO 1911 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n", 1912 dn_rt_hash_mask, 1913 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024); 1914 1915 dn_rt_hash_mask--; 1916 for(i = 0; i <= dn_rt_hash_mask; i++) { 1917 spin_lock_init(&dn_rt_hash_table[i].lock); 1918 dn_rt_hash_table[i].chain = NULL; 1919 } 1920 1921 dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1); 1922 1923 proc_create("decnet_cache", S_IRUGO, init_net.proc_net, 1924 &dn_rt_cache_seq_fops); 1925 1926#ifdef CONFIG_DECNET_ROUTER 1927 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute, 1928 dn_fib_dump, NULL); 1929#else 1930 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute, 1931 dn_cache_dump, NULL); 1932#endif 1933} 1934 1935void __exit dn_route_cleanup(void) 1936{ 1937 del_timer(&dn_route_timer); 1938 dn_run_flush(0); 1939 1940 remove_proc_entry("decnet_cache", init_net.proc_net); 1941 dst_entries_destroy(&dn_dst_ops); 1942} 1943 1944