dn_route.c (47858B)
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * DECnet An implementation of the DECnet protocol suite for the LINUX 4 * operating system. DECnet is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * DECnet Routing Functions (Endnode and Router) 8 * 9 * Authors: Steve Whitehouse <SteveW@ACM.org> 10 * Eduardo Marcelo Serrat <emserrat@geocities.com> 11 * 12 * Changes: 13 * Steve Whitehouse : Fixes to allow "intra-ethernet" and 14 * "return-to-sender" bits on outgoing 15 * packets. 16 * Steve Whitehouse : Timeouts for cached routes. 17 * Steve Whitehouse : Use dst cache for input routes too. 18 * Steve Whitehouse : Fixed error values in dn_send_skb. 19 * Steve Whitehouse : Rework routing functions to better fit 20 * DECnet routing design 21 * Alexey Kuznetsov : New SMP locking 22 * Steve Whitehouse : More SMP locking changes & dn_cache_dump() 23 * Steve Whitehouse : Prerouting NF hook, now really is prerouting. 24 * Fixed possible skb leak in rtnetlink funcs. 25 * Steve Whitehouse : Dave Miller's dynamic hash table sizing and 26 * Alexey Kuznetsov's finer grained locking 27 * from ipv4/route.c. 28 * Steve Whitehouse : Routing is now starting to look like a 29 * sensible set of code now, mainly due to 30 * my copying the IPv4 routing code. The 31 * hooks here are modified and will continue 32 * to evolve for a while. 33 * Steve Whitehouse : Real SMP at last :-) Also new netfilter 34 * stuff. Look out raw sockets your days 35 * are numbered! 36 * Steve Whitehouse : Added return-to-sender functions. Added 37 * backlog congestion level return codes. 38 * Steve Whitehouse : Fixed bug where routes were set up with 39 * no ref count on net devices. 40 * Steve Whitehouse : RCU for the route cache 41 * Steve Whitehouse : Preparations for the flow cache 42 * Steve Whitehouse : Prepare for nonlinear skbs 43 */ 44 45/****************************************************************************** 46 (c) 1995-1998 E.M. Serrat emserrat@geocities.com 47 48*******************************************************************************/ 49 50#include <linux/errno.h> 51#include <linux/types.h> 52#include <linux/socket.h> 53#include <linux/in.h> 54#include <linux/kernel.h> 55#include <linux/sockios.h> 56#include <linux/net.h> 57#include <linux/netdevice.h> 58#include <linux/inet.h> 59#include <linux/route.h> 60#include <linux/in_route.h> 61#include <linux/slab.h> 62#include <net/sock.h> 63#include <linux/mm.h> 64#include <linux/proc_fs.h> 65#include <linux/seq_file.h> 66#include <linux/init.h> 67#include <linux/rtnetlink.h> 68#include <linux/string.h> 69#include <linux/netfilter_decnet.h> 70#include <linux/rcupdate.h> 71#include <linux/times.h> 72#include <linux/export.h> 73#include <asm/errno.h> 74#include <net/net_namespace.h> 75#include <net/netlink.h> 76#include <net/neighbour.h> 77#include <net/dst.h> 78#include <net/flow.h> 79#include <net/fib_rules.h> 80#include <net/dn.h> 81#include <net/dn_dev.h> 82#include <net/dn_nsp.h> 83#include <net/dn_route.h> 84#include <net/dn_neigh.h> 85#include <net/dn_fib.h> 86 87struct dn_rt_hash_bucket { 88 struct dn_route __rcu *chain; 89 spinlock_t lock; 90}; 91 92extern struct neigh_table dn_neigh_table; 93 94 95static unsigned char dn_hiord_addr[6] = {0xAA, 0x00, 0x04, 0x00, 0x00, 0x00}; 96 97static const int dn_rt_min_delay = 2 * HZ; 98static const int dn_rt_max_delay = 10 * HZ; 99static const int dn_rt_mtu_expires = 10 * 60 * HZ; 100 101static unsigned long dn_rt_deadline; 102 103static int dn_dst_gc(struct dst_ops *ops); 104static struct dst_entry *dn_dst_check(struct dst_entry *, __u32); 105static unsigned int dn_dst_default_advmss(const struct dst_entry *dst); 106static unsigned int dn_dst_mtu(const struct dst_entry *dst); 107static void dn_dst_destroy(struct dst_entry *); 108static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how); 109static struct dst_entry *dn_dst_negative_advice(struct dst_entry *); 110static void dn_dst_link_failure(struct sk_buff *); 111static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk, 112 struct sk_buff *skb , u32 mtu, 113 bool confirm_neigh); 114static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk, 115 struct sk_buff *skb); 116static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst, 117 struct sk_buff *skb, 118 const void *daddr); 119static int dn_route_input(struct sk_buff *); 120static void dn_run_flush(struct timer_list *unused); 121 122static struct dn_rt_hash_bucket *dn_rt_hash_table; 123static unsigned int dn_rt_hash_mask; 124 125static struct timer_list dn_route_timer; 126static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush); 127int decnet_dst_gc_interval = 2; 128 129static struct dst_ops dn_dst_ops = { 130 .family = PF_DECnet, 131 .gc_thresh = 128, 132 .gc = dn_dst_gc, 133 .check = dn_dst_check, 134 .default_advmss = dn_dst_default_advmss, 135 .mtu = dn_dst_mtu, 136 .cow_metrics = dst_cow_metrics_generic, 137 .destroy = dn_dst_destroy, 138 .ifdown = dn_dst_ifdown, 139 .negative_advice = dn_dst_negative_advice, 140 .link_failure = dn_dst_link_failure, 141 .update_pmtu = dn_dst_update_pmtu, 142 .redirect = dn_dst_redirect, 143 .neigh_lookup = dn_dst_neigh_lookup, 144}; 145 146static void dn_dst_destroy(struct dst_entry *dst) 147{ 148 struct dn_route *rt = (struct dn_route *) dst; 149 150 if (rt->n) 151 neigh_release(rt->n); 152 dst_destroy_metrics_generic(dst); 153} 154 155static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how) 156{ 157 if (how) { 158 struct dn_route *rt = (struct dn_route *) dst; 159 struct neighbour *n = rt->n; 160 161 if (n && n->dev == dev) { 162 n->dev = blackhole_netdev; 163 dev_hold(n->dev); 164 dev_put(dev); 165 } 166 } 167} 168 169static __inline__ unsigned int dn_hash(__le16 src, __le16 dst) 170{ 171 __u16 tmp = (__u16 __force)(src ^ dst); 172 tmp ^= (tmp >> 3); 173 tmp ^= (tmp >> 5); 174 tmp ^= (tmp >> 10); 175 return dn_rt_hash_mask & (unsigned int)tmp; 176} 177 178static void dn_dst_check_expire(struct timer_list *unused) 179{ 180 int i; 181 struct dn_route *rt; 182 struct dn_route __rcu **rtp; 183 unsigned long now = jiffies; 184 unsigned long expire = 120 * HZ; 185 186 for (i = 0; i <= dn_rt_hash_mask; i++) { 187 rtp = &dn_rt_hash_table[i].chain; 188 189 spin_lock(&dn_rt_hash_table[i].lock); 190 while ((rt = rcu_dereference_protected(*rtp, 191 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) { 192 if (atomic_read(&rt->dst.__refcnt) > 1 || 193 (now - rt->dst.lastuse) < expire) { 194 rtp = &rt->dn_next; 195 continue; 196 } 197 *rtp = rt->dn_next; 198 rt->dn_next = NULL; 199 dst_dev_put(&rt->dst); 200 dst_release(&rt->dst); 201 } 202 spin_unlock(&dn_rt_hash_table[i].lock); 203 204 if ((jiffies - now) > 0) 205 break; 206 } 207 208 mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ); 209} 210 211static int dn_dst_gc(struct dst_ops *ops) 212{ 213 struct dn_route *rt; 214 struct dn_route __rcu **rtp; 215 int i; 216 unsigned long now = jiffies; 217 unsigned long expire = 10 * HZ; 218 219 for (i = 0; i <= dn_rt_hash_mask; i++) { 220 221 spin_lock_bh(&dn_rt_hash_table[i].lock); 222 rtp = &dn_rt_hash_table[i].chain; 223 224 while ((rt = rcu_dereference_protected(*rtp, 225 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) { 226 if (atomic_read(&rt->dst.__refcnt) > 1 || 227 (now - rt->dst.lastuse) < expire) { 228 rtp = &rt->dn_next; 229 continue; 230 } 231 *rtp = rt->dn_next; 232 rt->dn_next = NULL; 233 dst_dev_put(&rt->dst); 234 dst_release(&rt->dst); 235 break; 236 } 237 spin_unlock_bh(&dn_rt_hash_table[i].lock); 238 } 239 240 return 0; 241} 242 243/* 244 * The decnet standards don't impose a particular minimum mtu, what they 245 * do insist on is that the routing layer accepts a datagram of at least 246 * 230 bytes long. Here we have to subtract the routing header length from 247 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we 248 * assume the worst and use a long header size. 249 * 250 * We update both the mtu and the advertised mss (i.e. the segment size we 251 * advertise to the other end). 252 */ 253static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk, 254 struct sk_buff *skb, u32 mtu, 255 bool confirm_neigh) 256{ 257 struct dn_route *rt = (struct dn_route *) dst; 258 struct neighbour *n = rt->n; 259 u32 min_mtu = 230; 260 struct dn_dev *dn; 261 262 dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL; 263 264 if (dn && dn->use_long == 0) 265 min_mtu -= 6; 266 else 267 min_mtu -= 21; 268 269 if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) { 270 if (!(dst_metric_locked(dst, RTAX_MTU))) { 271 dst_metric_set(dst, RTAX_MTU, mtu); 272 dst_set_expires(dst, dn_rt_mtu_expires); 273 } 274 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) { 275 u32 mss = mtu - DN_MAX_NSP_DATA_HEADER; 276 u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS); 277 if (!existing_mss || existing_mss > mss) 278 dst_metric_set(dst, RTAX_ADVMSS, mss); 279 } 280 } 281} 282 283static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk, 284 struct sk_buff *skb) 285{ 286} 287 288/* 289 * When a route has been marked obsolete. (e.g. routing cache flush) 290 */ 291static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie) 292{ 293 return NULL; 294} 295 296static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst) 297{ 298 dst_release(dst); 299 return NULL; 300} 301 302static void dn_dst_link_failure(struct sk_buff *skb) 303{ 304} 305 306static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2) 307{ 308 return ((fl1->daddr ^ fl2->daddr) | 309 (fl1->saddr ^ fl2->saddr) | 310 (fl1->flowidn_mark ^ fl2->flowidn_mark) | 311 (fl1->flowidn_scope ^ fl2->flowidn_scope) | 312 (fl1->flowidn_oif ^ fl2->flowidn_oif) | 313 (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0; 314} 315 316static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp) 317{ 318 struct dn_route *rth; 319 struct dn_route __rcu **rthp; 320 unsigned long now = jiffies; 321 322 rthp = &dn_rt_hash_table[hash].chain; 323 324 spin_lock_bh(&dn_rt_hash_table[hash].lock); 325 while ((rth = rcu_dereference_protected(*rthp, 326 lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) { 327 if (compare_keys(&rth->fld, &rt->fld)) { 328 /* Put it first */ 329 *rthp = rth->dn_next; 330 rcu_assign_pointer(rth->dn_next, 331 dn_rt_hash_table[hash].chain); 332 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth); 333 334 dst_hold_and_use(&rth->dst, now); 335 spin_unlock_bh(&dn_rt_hash_table[hash].lock); 336 337 dst_release_immediate(&rt->dst); 338 *rp = rth; 339 return 0; 340 } 341 rthp = &rth->dn_next; 342 } 343 344 rcu_assign_pointer(rt->dn_next, dn_rt_hash_table[hash].chain); 345 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt); 346 347 dst_hold_and_use(&rt->dst, now); 348 spin_unlock_bh(&dn_rt_hash_table[hash].lock); 349 *rp = rt; 350 return 0; 351} 352 353static void dn_run_flush(struct timer_list *unused) 354{ 355 int i; 356 struct dn_route *rt, *next; 357 358 for (i = 0; i < dn_rt_hash_mask; i++) { 359 spin_lock_bh(&dn_rt_hash_table[i].lock); 360 361 rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL); 362 if (!rt) 363 goto nothing_to_declare; 364 365 for (; rt; rt = next) { 366 next = rcu_dereference_raw(rt->dn_next); 367 RCU_INIT_POINTER(rt->dn_next, NULL); 368 dst_dev_put(&rt->dst); 369 dst_release(&rt->dst); 370 } 371 372nothing_to_declare: 373 spin_unlock_bh(&dn_rt_hash_table[i].lock); 374 } 375} 376 377static DEFINE_SPINLOCK(dn_rt_flush_lock); 378 379void dn_rt_cache_flush(int delay) 380{ 381 unsigned long now = jiffies; 382 int user_mode = !in_interrupt(); 383 384 if (delay < 0) 385 delay = dn_rt_min_delay; 386 387 spin_lock_bh(&dn_rt_flush_lock); 388 389 if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) { 390 long tmo = (long)(dn_rt_deadline - now); 391 392 if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay) 393 tmo = 0; 394 395 if (delay > tmo) 396 delay = tmo; 397 } 398 399 if (delay <= 0) { 400 spin_unlock_bh(&dn_rt_flush_lock); 401 dn_run_flush(NULL); 402 return; 403 } 404 405 if (dn_rt_deadline == 0) 406 dn_rt_deadline = now + dn_rt_max_delay; 407 408 dn_rt_flush_timer.expires = now + delay; 409 add_timer(&dn_rt_flush_timer); 410 spin_unlock_bh(&dn_rt_flush_lock); 411} 412 413/** 414 * dn_return_short - Return a short packet to its sender 415 * @skb: The packet to return 416 * 417 */ 418static int dn_return_short(struct sk_buff *skb) 419{ 420 struct dn_skb_cb *cb; 421 unsigned char *ptr; 422 __le16 *src; 423 __le16 *dst; 424 425 /* Add back headers */ 426 skb_push(skb, skb->data - skb_network_header(skb)); 427 428 skb = skb_unshare(skb, GFP_ATOMIC); 429 if (!skb) 430 return NET_RX_DROP; 431 432 cb = DN_SKB_CB(skb); 433 /* Skip packet length and point to flags */ 434 ptr = skb->data + 2; 435 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS; 436 437 dst = (__le16 *)ptr; 438 ptr += 2; 439 src = (__le16 *)ptr; 440 ptr += 2; 441 *ptr = 0; /* Zero hop count */ 442 443 swap(*src, *dst); 444 445 skb->pkt_type = PACKET_OUTGOING; 446 dn_rt_finish_output(skb, NULL, NULL); 447 return NET_RX_SUCCESS; 448} 449 450/** 451 * dn_return_long - Return a long packet to its sender 452 * @skb: The long format packet to return 453 * 454 */ 455static int dn_return_long(struct sk_buff *skb) 456{ 457 struct dn_skb_cb *cb; 458 unsigned char *ptr; 459 unsigned char *src_addr, *dst_addr; 460 unsigned char tmp[ETH_ALEN]; 461 462 /* Add back all headers */ 463 skb_push(skb, skb->data - skb_network_header(skb)); 464 465 skb = skb_unshare(skb, GFP_ATOMIC); 466 if (!skb) 467 return NET_RX_DROP; 468 469 cb = DN_SKB_CB(skb); 470 /* Ignore packet length and point to flags */ 471 ptr = skb->data + 2; 472 473 /* Skip padding */ 474 if (*ptr & DN_RT_F_PF) { 475 char padlen = (*ptr & ~DN_RT_F_PF); 476 ptr += padlen; 477 } 478 479 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS; 480 ptr += 2; 481 dst_addr = ptr; 482 ptr += 8; 483 src_addr = ptr; 484 ptr += 6; 485 *ptr = 0; /* Zero hop count */ 486 487 /* Swap source and destination */ 488 memcpy(tmp, src_addr, ETH_ALEN); 489 memcpy(src_addr, dst_addr, ETH_ALEN); 490 memcpy(dst_addr, tmp, ETH_ALEN); 491 492 skb->pkt_type = PACKET_OUTGOING; 493 dn_rt_finish_output(skb, dst_addr, src_addr); 494 return NET_RX_SUCCESS; 495} 496 497/** 498 * dn_route_rx_packet - Try and find a route for an incoming packet 499 * @net: The applicable net namespace 500 * @sk: Socket packet transmitted on 501 * @skb: The packet to find a route for 502 * 503 * Returns: result of input function if route is found, error code otherwise 504 */ 505static int dn_route_rx_packet(struct net *net, struct sock *sk, struct sk_buff *skb) 506{ 507 struct dn_skb_cb *cb; 508 int err; 509 510 err = dn_route_input(skb); 511 if (err == 0) 512 return dst_input(skb); 513 514 cb = DN_SKB_CB(skb); 515 if (decnet_debug_level & 4) { 516 char *devname = skb->dev ? skb->dev->name : "???"; 517 518 printk(KERN_DEBUG 519 "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n", 520 (int)cb->rt_flags, devname, skb->len, 521 le16_to_cpu(cb->src), le16_to_cpu(cb->dst), 522 err, skb->pkt_type); 523 } 524 525 if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) { 526 switch (cb->rt_flags & DN_RT_PKT_MSK) { 527 case DN_RT_PKT_SHORT: 528 return dn_return_short(skb); 529 case DN_RT_PKT_LONG: 530 return dn_return_long(skb); 531 } 532 } 533 534 kfree_skb(skb); 535 return NET_RX_DROP; 536} 537 538static int dn_route_rx_long(struct sk_buff *skb) 539{ 540 struct dn_skb_cb *cb = DN_SKB_CB(skb); 541 unsigned char *ptr = skb->data; 542 543 if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */ 544 goto drop_it; 545 546 skb_pull(skb, 20); 547 skb_reset_transport_header(skb); 548 549 /* Destination info */ 550 ptr += 2; 551 cb->dst = dn_eth2dn(ptr); 552 if (memcmp(ptr, dn_hiord_addr, 4) != 0) 553 goto drop_it; 554 ptr += 6; 555 556 557 /* Source info */ 558 ptr += 2; 559 cb->src = dn_eth2dn(ptr); 560 if (memcmp(ptr, dn_hiord_addr, 4) != 0) 561 goto drop_it; 562 ptr += 6; 563 /* Other junk */ 564 ptr++; 565 cb->hops = *ptr++; /* Visit Count */ 566 567 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, 568 &init_net, NULL, skb, skb->dev, NULL, 569 dn_route_rx_packet); 570 571drop_it: 572 kfree_skb(skb); 573 return NET_RX_DROP; 574} 575 576 577 578static int dn_route_rx_short(struct sk_buff *skb) 579{ 580 struct dn_skb_cb *cb = DN_SKB_CB(skb); 581 unsigned char *ptr = skb->data; 582 583 if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */ 584 goto drop_it; 585 586 skb_pull(skb, 5); 587 skb_reset_transport_header(skb); 588 589 cb->dst = *(__le16 *)ptr; 590 ptr += 2; 591 cb->src = *(__le16 *)ptr; 592 ptr += 2; 593 cb->hops = *ptr & 0x3f; 594 595 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, 596 &init_net, NULL, skb, skb->dev, NULL, 597 dn_route_rx_packet); 598 599drop_it: 600 kfree_skb(skb); 601 return NET_RX_DROP; 602} 603 604static int dn_route_discard(struct net *net, struct sock *sk, struct sk_buff *skb) 605{ 606 /* 607 * I know we drop the packet here, but that's considered success in 608 * this case 609 */ 610 kfree_skb(skb); 611 return NET_RX_SUCCESS; 612} 613 614static int dn_route_ptp_hello(struct net *net, struct sock *sk, struct sk_buff *skb) 615{ 616 dn_dev_hello(skb); 617 dn_neigh_pointopoint_hello(skb); 618 return NET_RX_SUCCESS; 619} 620 621int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) 622{ 623 struct dn_skb_cb *cb; 624 unsigned char flags = 0; 625 __u16 len = le16_to_cpu(*(__le16 *)skb->data); 626 struct dn_dev *dn = rcu_dereference(dev->dn_ptr); 627 unsigned char padlen = 0; 628 629 if (!net_eq(dev_net(dev), &init_net)) 630 goto dump_it; 631 632 if (dn == NULL) 633 goto dump_it; 634 635 skb = skb_share_check(skb, GFP_ATOMIC); 636 if (!skb) 637 goto out; 638 639 if (!pskb_may_pull(skb, 3)) 640 goto dump_it; 641 642 skb_pull(skb, 2); 643 644 if (len > skb->len) 645 goto dump_it; 646 647 skb_trim(skb, len); 648 649 flags = *skb->data; 650 651 cb = DN_SKB_CB(skb); 652 cb->stamp = jiffies; 653 cb->iif = dev->ifindex; 654 655 /* 656 * If we have padding, remove it. 657 */ 658 if (flags & DN_RT_F_PF) { 659 padlen = flags & ~DN_RT_F_PF; 660 if (!pskb_may_pull(skb, padlen + 1)) 661 goto dump_it; 662 skb_pull(skb, padlen); 663 flags = *skb->data; 664 } 665 666 skb_reset_network_header(skb); 667 668 /* 669 * Weed out future version DECnet 670 */ 671 if (flags & DN_RT_F_VER) 672 goto dump_it; 673 674 cb->rt_flags = flags; 675 676 if (decnet_debug_level & 1) 677 printk(KERN_DEBUG 678 "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n", 679 (int)flags, dev->name, len, skb->len, 680 padlen); 681 682 if (flags & DN_RT_PKT_CNTL) { 683 if (unlikely(skb_linearize(skb))) 684 goto dump_it; 685 686 switch (flags & DN_RT_CNTL_MSK) { 687 case DN_RT_PKT_INIT: 688 dn_dev_init_pkt(skb); 689 break; 690 case DN_RT_PKT_VERI: 691 dn_dev_veri_pkt(skb); 692 break; 693 } 694 695 if (dn->parms.state != DN_DEV_S_RU) 696 goto dump_it; 697 698 switch (flags & DN_RT_CNTL_MSK) { 699 case DN_RT_PKT_HELO: 700 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO, 701 &init_net, NULL, skb, skb->dev, NULL, 702 dn_route_ptp_hello); 703 704 case DN_RT_PKT_L1RT: 705 case DN_RT_PKT_L2RT: 706 return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE, 707 &init_net, NULL, skb, skb->dev, NULL, 708 dn_route_discard); 709 case DN_RT_PKT_ERTH: 710 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO, 711 &init_net, NULL, skb, skb->dev, NULL, 712 dn_neigh_router_hello); 713 714 case DN_RT_PKT_EEDH: 715 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO, 716 &init_net, NULL, skb, skb->dev, NULL, 717 dn_neigh_endnode_hello); 718 } 719 } else { 720 if (dn->parms.state != DN_DEV_S_RU) 721 goto dump_it; 722 723 skb_pull(skb, 1); /* Pull flags */ 724 725 switch (flags & DN_RT_PKT_MSK) { 726 case DN_RT_PKT_LONG: 727 return dn_route_rx_long(skb); 728 case DN_RT_PKT_SHORT: 729 return dn_route_rx_short(skb); 730 } 731 } 732 733dump_it: 734 kfree_skb(skb); 735out: 736 return NET_RX_DROP; 737} 738 739static int dn_output(struct net *net, struct sock *sk, struct sk_buff *skb) 740{ 741 struct dst_entry *dst = skb_dst(skb); 742 struct dn_route *rt = (struct dn_route *)dst; 743 struct net_device *dev = dst->dev; 744 struct dn_skb_cb *cb = DN_SKB_CB(skb); 745 746 int err = -EINVAL; 747 748 if (rt->n == NULL) 749 goto error; 750 751 skb->dev = dev; 752 753 cb->src = rt->rt_saddr; 754 cb->dst = rt->rt_daddr; 755 756 /* 757 * Always set the Intra-Ethernet bit on all outgoing packets 758 * originated on this node. Only valid flag from upper layers 759 * is return-to-sender-requested. Set hop count to 0 too. 760 */ 761 cb->rt_flags &= ~DN_RT_F_RQR; 762 cb->rt_flags |= DN_RT_F_IE; 763 cb->hops = 0; 764 765 return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT, 766 &init_net, sk, skb, NULL, dev, 767 dn_to_neigh_output); 768 769error: 770 net_dbg_ratelimited("dn_output: This should not happen\n"); 771 772 kfree_skb(skb); 773 774 return err; 775} 776 777static int dn_forward(struct sk_buff *skb) 778{ 779 struct dn_skb_cb *cb = DN_SKB_CB(skb); 780 struct dst_entry *dst = skb_dst(skb); 781 struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr); 782 struct dn_route *rt; 783 int header_len; 784 struct net_device *dev = skb->dev; 785 786 if (skb->pkt_type != PACKET_HOST) 787 goto drop; 788 789 /* Ensure that we have enough space for headers */ 790 rt = (struct dn_route *)skb_dst(skb); 791 header_len = dn_db->use_long ? 21 : 6; 792 if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len)) 793 goto drop; 794 795 /* 796 * Hop count exceeded. 797 */ 798 if (++cb->hops > 30) 799 goto drop; 800 801 skb->dev = rt->dst.dev; 802 803 /* 804 * If packet goes out same interface it came in on, then set 805 * the Intra-Ethernet bit. This has no effect for short 806 * packets, so we don't need to test for them here. 807 */ 808 cb->rt_flags &= ~DN_RT_F_IE; 809 if (rt->rt_flags & RTCF_DOREDIRECT) 810 cb->rt_flags |= DN_RT_F_IE; 811 812 return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD, 813 &init_net, NULL, skb, dev, skb->dev, 814 dn_to_neigh_output); 815 816drop: 817 kfree_skb(skb); 818 return NET_RX_DROP; 819} 820 821/* 822 * Used to catch bugs. This should never normally get 823 * called. 824 */ 825static int dn_rt_bug_out(struct net *net, struct sock *sk, struct sk_buff *skb) 826{ 827 struct dn_skb_cb *cb = DN_SKB_CB(skb); 828 829 net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n", 830 le16_to_cpu(cb->src), le16_to_cpu(cb->dst)); 831 832 kfree_skb(skb); 833 834 return NET_RX_DROP; 835} 836 837static int dn_rt_bug(struct sk_buff *skb) 838{ 839 struct dn_skb_cb *cb = DN_SKB_CB(skb); 840 841 net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n", 842 le16_to_cpu(cb->src), le16_to_cpu(cb->dst)); 843 844 kfree_skb(skb); 845 846 return NET_RX_DROP; 847} 848 849static unsigned int dn_dst_default_advmss(const struct dst_entry *dst) 850{ 851 return dn_mss_from_pmtu(dst->dev, dst_mtu(dst)); 852} 853 854static unsigned int dn_dst_mtu(const struct dst_entry *dst) 855{ 856 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 857 858 return mtu ? : dst->dev->mtu; 859} 860 861static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst, 862 struct sk_buff *skb, 863 const void *daddr) 864{ 865 return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev); 866} 867 868static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res) 869{ 870 struct dn_fib_info *fi = res->fi; 871 struct net_device *dev = rt->dst.dev; 872 unsigned int mss_metric; 873 struct neighbour *n; 874 875 if (fi) { 876 if (DN_FIB_RES_GW(*res) && 877 DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) 878 rt->rt_gateway = DN_FIB_RES_GW(*res); 879 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 880 } 881 rt->rt_type = res->type; 882 883 if (dev != NULL && rt->n == NULL) { 884 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev); 885 if (IS_ERR(n)) 886 return PTR_ERR(n); 887 rt->n = n; 888 } 889 890 if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu) 891 dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu); 892 mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS); 893 if (mss_metric) { 894 unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst)); 895 if (mss_metric > mss) 896 dst_metric_set(&rt->dst, RTAX_ADVMSS, mss); 897 } 898 return 0; 899} 900 901static inline int dn_match_addr(__le16 addr1, __le16 addr2) 902{ 903 __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2); 904 int match = 16; 905 while (tmp) { 906 tmp >>= 1; 907 match--; 908 } 909 return match; 910} 911 912static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope) 913{ 914 __le16 saddr = 0; 915 struct dn_dev *dn_db; 916 struct dn_ifaddr *ifa; 917 int best_match = 0; 918 int ret; 919 920 rcu_read_lock(); 921 dn_db = rcu_dereference(dev->dn_ptr); 922 for (ifa = rcu_dereference(dn_db->ifa_list); 923 ifa != NULL; 924 ifa = rcu_dereference(ifa->ifa_next)) { 925 if (ifa->ifa_scope > scope) 926 continue; 927 if (!daddr) { 928 saddr = ifa->ifa_local; 929 break; 930 } 931 ret = dn_match_addr(daddr, ifa->ifa_local); 932 if (ret > best_match) 933 saddr = ifa->ifa_local; 934 if (best_match == 0) 935 saddr = ifa->ifa_local; 936 } 937 rcu_read_unlock(); 938 939 return saddr; 940} 941 942static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res) 943{ 944 return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope); 945} 946 947static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res) 948{ 949 __le16 mask = dnet_make_mask(res->prefixlen); 950 return (daddr&~mask)|res->fi->fib_nh->nh_gw; 951} 952 953static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard) 954{ 955 struct flowidn fld = { 956 .daddr = oldflp->daddr, 957 .saddr = oldflp->saddr, 958 .flowidn_scope = RT_SCOPE_UNIVERSE, 959 .flowidn_mark = oldflp->flowidn_mark, 960 .flowidn_iif = LOOPBACK_IFINDEX, 961 .flowidn_oif = oldflp->flowidn_oif, 962 }; 963 struct dn_route *rt = NULL; 964 struct net_device *dev_out = NULL, *dev; 965 struct neighbour *neigh = NULL; 966 unsigned int hash; 967 unsigned int flags = 0; 968 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST }; 969 int err; 970 int free_res = 0; 971 __le16 gateway = 0; 972 973 if (decnet_debug_level & 16) 974 printk(KERN_DEBUG 975 "dn_route_output_slow: dst=%04x src=%04x mark=%d" 976 " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr), 977 le16_to_cpu(oldflp->saddr), 978 oldflp->flowidn_mark, LOOPBACK_IFINDEX, 979 oldflp->flowidn_oif); 980 981 /* If we have an output interface, verify its a DECnet device */ 982 if (oldflp->flowidn_oif) { 983 dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif); 984 err = -ENODEV; 985 if (dev_out && dev_out->dn_ptr == NULL) { 986 dev_put(dev_out); 987 dev_out = NULL; 988 } 989 if (dev_out == NULL) 990 goto out; 991 } 992 993 /* If we have a source address, verify that its a local address */ 994 if (oldflp->saddr) { 995 err = -EADDRNOTAVAIL; 996 997 if (dev_out) { 998 if (dn_dev_islocal(dev_out, oldflp->saddr)) 999 goto source_ok; 1000 dev_put(dev_out); 1001 goto out; 1002 } 1003 rcu_read_lock(); 1004 for_each_netdev_rcu(&init_net, dev) { 1005 if (!dev->dn_ptr) 1006 continue; 1007 if (!dn_dev_islocal(dev, oldflp->saddr)) 1008 continue; 1009 if ((dev->flags & IFF_LOOPBACK) && 1010 oldflp->daddr && 1011 !dn_dev_islocal(dev, oldflp->daddr)) 1012 continue; 1013 1014 dev_out = dev; 1015 break; 1016 } 1017 rcu_read_unlock(); 1018 if (dev_out == NULL) 1019 goto out; 1020 dev_hold(dev_out); 1021source_ok: 1022 ; 1023 } 1024 1025 /* No destination? Assume its local */ 1026 if (!fld.daddr) { 1027 fld.daddr = fld.saddr; 1028 1029 dev_put(dev_out); 1030 err = -EINVAL; 1031 dev_out = init_net.loopback_dev; 1032 if (!dev_out->dn_ptr) 1033 goto out; 1034 err = -EADDRNOTAVAIL; 1035 dev_hold(dev_out); 1036 if (!fld.daddr) { 1037 fld.daddr = 1038 fld.saddr = dnet_select_source(dev_out, 0, 1039 RT_SCOPE_HOST); 1040 if (!fld.daddr) 1041 goto done; 1042 } 1043 fld.flowidn_oif = LOOPBACK_IFINDEX; 1044 res.type = RTN_LOCAL; 1045 goto make_route; 1046 } 1047 1048 if (decnet_debug_level & 16) 1049 printk(KERN_DEBUG 1050 "dn_route_output_slow: initial checks complete." 1051 " dst=%04x src=%04x oif=%d try_hard=%d\n", 1052 le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr), 1053 fld.flowidn_oif, try_hard); 1054 1055 /* 1056 * N.B. If the kernel is compiled without router support then 1057 * dn_fib_lookup() will evaluate to non-zero so this if () block 1058 * will always be executed. 1059 */ 1060 err = -ESRCH; 1061 if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) { 1062 struct dn_dev *dn_db; 1063 if (err != -ESRCH) 1064 goto out; 1065 /* 1066 * Here the fallback is basically the standard algorithm for 1067 * routing in endnodes which is described in the DECnet routing 1068 * docs 1069 * 1070 * If we are not trying hard, look in neighbour cache. 1071 * The result is tested to ensure that if a specific output 1072 * device/source address was requested, then we honour that 1073 * here 1074 */ 1075 if (!try_hard) { 1076 neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr); 1077 if (neigh) { 1078 if ((oldflp->flowidn_oif && 1079 (neigh->dev->ifindex != oldflp->flowidn_oif)) || 1080 (oldflp->saddr && 1081 (!dn_dev_islocal(neigh->dev, 1082 oldflp->saddr)))) { 1083 neigh_release(neigh); 1084 neigh = NULL; 1085 } else { 1086 dev_put(dev_out); 1087 if (dn_dev_islocal(neigh->dev, fld.daddr)) { 1088 dev_out = init_net.loopback_dev; 1089 res.type = RTN_LOCAL; 1090 } else { 1091 dev_out = neigh->dev; 1092 } 1093 dev_hold(dev_out); 1094 goto select_source; 1095 } 1096 } 1097 } 1098 1099 /* Not there? Perhaps its a local address */ 1100 if (dev_out == NULL) 1101 dev_out = dn_dev_get_default(); 1102 err = -ENODEV; 1103 if (dev_out == NULL) 1104 goto out; 1105 dn_db = rcu_dereference_raw(dev_out->dn_ptr); 1106 if (!dn_db) 1107 goto e_inval; 1108 /* Possible improvement - check all devices for local addr */ 1109 if (dn_dev_islocal(dev_out, fld.daddr)) { 1110 dev_put(dev_out); 1111 dev_out = init_net.loopback_dev; 1112 dev_hold(dev_out); 1113 res.type = RTN_LOCAL; 1114 goto select_source; 1115 } 1116 /* Not local either.... try sending it to the default router */ 1117 neigh = neigh_clone(dn_db->router); 1118 BUG_ON(neigh && neigh->dev != dev_out); 1119 1120 /* Ok then, we assume its directly connected and move on */ 1121select_source: 1122 if (neigh) 1123 gateway = container_of(neigh, struct dn_neigh, n)->addr; 1124 if (gateway == 0) 1125 gateway = fld.daddr; 1126 if (fld.saddr == 0) { 1127 fld.saddr = dnet_select_source(dev_out, gateway, 1128 res.type == RTN_LOCAL ? 1129 RT_SCOPE_HOST : 1130 RT_SCOPE_LINK); 1131 if (fld.saddr == 0 && res.type != RTN_LOCAL) 1132 goto e_addr; 1133 } 1134 fld.flowidn_oif = dev_out->ifindex; 1135 goto make_route; 1136 } 1137 free_res = 1; 1138 1139 if (res.type == RTN_NAT) 1140 goto e_inval; 1141 1142 if (res.type == RTN_LOCAL) { 1143 if (!fld.saddr) 1144 fld.saddr = fld.daddr; 1145 dev_put(dev_out); 1146 dev_out = init_net.loopback_dev; 1147 dev_hold(dev_out); 1148 if (!dev_out->dn_ptr) 1149 goto e_inval; 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 dev_put(dev_out); 1169 dev_out = DN_FIB_RES_DEV(res); 1170 dev_hold(dev_out); 1171 fld.flowidn_oif = dev_out->ifindex; 1172 gateway = DN_FIB_RES_GW(res); 1173 1174make_route: 1175 if (dev_out->flags & IFF_LOOPBACK) 1176 flags |= RTCF_LOCAL; 1177 1178 rt = dst_alloc(&dn_dst_ops, dev_out, 0, DST_OBSOLETE_NONE, 0); 1179 if (rt == NULL) 1180 goto e_nobufs; 1181 1182 rt->dn_next = NULL; 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() increments dst->__refcnt */ 1214 dn_insert_route(rt, hash, (struct dn_route **)pprt); 1215 1216done: 1217 if (neigh) 1218 neigh_release(neigh); 1219 if (free_res) 1220 dn_fib_res_put(&res); 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_release_immediate(&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->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_hold_and_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 *pprt = xfrm_lookup(&init_net, *pprt, 1292 flowidn_to_flowi(fl), sk, 0); 1293 if (IS_ERR(*pprt)) { 1294 err = PTR_ERR(*pprt); 1295 *pprt = NULL; 1296 } 1297 } 1298 return err; 1299} 1300 1301static int dn_route_input_slow(struct sk_buff *skb) 1302{ 1303 struct dn_route *rt = NULL; 1304 struct dn_skb_cb *cb = DN_SKB_CB(skb); 1305 struct net_device *in_dev = skb->dev; 1306 struct net_device *out_dev = NULL; 1307 struct dn_dev *dn_db; 1308 struct neighbour *neigh = NULL; 1309 unsigned int hash; 1310 int flags = 0; 1311 __le16 gateway = 0; 1312 __le16 local_src = 0; 1313 struct flowidn fld = { 1314 .daddr = cb->dst, 1315 .saddr = cb->src, 1316 .flowidn_scope = RT_SCOPE_UNIVERSE, 1317 .flowidn_mark = skb->mark, 1318 .flowidn_iif = skb->dev->ifindex, 1319 }; 1320 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE }; 1321 int err = -EINVAL; 1322 int free_res = 0; 1323 1324 dev_hold(in_dev); 1325 1326 dn_db = rcu_dereference(in_dev->dn_ptr); 1327 if (!dn_db) 1328 goto out; 1329 1330 /* Zero source addresses are not allowed */ 1331 if (fld.saddr == 0) 1332 goto out; 1333 1334 /* 1335 * In this case we've just received a packet from a source 1336 * outside ourselves pretending to come from us. We don't 1337 * allow it any further to prevent routing loops, spoofing and 1338 * other nasties. Loopback packets already have the dst attached 1339 * so this only affects packets which have originated elsewhere. 1340 */ 1341 err = -ENOTUNIQ; 1342 if (dn_dev_islocal(in_dev, cb->src)) 1343 goto out; 1344 1345 err = dn_fib_lookup(&fld, &res); 1346 if (err) { 1347 if (err != -ESRCH) 1348 goto out; 1349 /* 1350 * Is the destination us ? 1351 */ 1352 if (!dn_dev_islocal(in_dev, cb->dst)) 1353 goto e_inval; 1354 1355 res.type = RTN_LOCAL; 1356 } else { 1357 __le16 src_map = fld.saddr; 1358 free_res = 1; 1359 1360 out_dev = DN_FIB_RES_DEV(res); 1361 if (out_dev == NULL) { 1362 net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n"); 1363 goto e_inval; 1364 } 1365 dev_hold(out_dev); 1366 1367 if (res.r) 1368 src_map = fld.saddr; /* no NAT support for now */ 1369 1370 gateway = DN_FIB_RES_GW(res); 1371 if (res.type == RTN_NAT) { 1372 fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res); 1373 dn_fib_res_put(&res); 1374 free_res = 0; 1375 if (dn_fib_lookup(&fld, &res)) 1376 goto e_inval; 1377 free_res = 1; 1378 if (res.type != RTN_UNICAST) 1379 goto e_inval; 1380 flags |= RTCF_DNAT; 1381 gateway = fld.daddr; 1382 } 1383 fld.saddr = src_map; 1384 } 1385 1386 switch (res.type) { 1387 case RTN_UNICAST: 1388 /* 1389 * Forwarding check here, we only check for forwarding 1390 * being turned off, if you want to only forward intra 1391 * area, its up to you to set the routing tables up 1392 * correctly. 1393 */ 1394 if (dn_db->parms.forwarding == 0) 1395 goto e_inval; 1396 1397 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0) 1398 dn_fib_select_multipath(&fld, &res); 1399 1400 /* 1401 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT 1402 * flag as a hint to set the intra-ethernet bit when 1403 * forwarding. If we've got NAT in operation, we don't do 1404 * this optimisation. 1405 */ 1406 if (out_dev == in_dev && !(flags & RTCF_NAT)) 1407 flags |= RTCF_DOREDIRECT; 1408 1409 local_src = DN_FIB_RES_PREFSRC(res); 1410 break; 1411 case RTN_BLACKHOLE: 1412 case RTN_UNREACHABLE: 1413 break; 1414 case RTN_LOCAL: 1415 flags |= RTCF_LOCAL; 1416 fld.saddr = cb->dst; 1417 fld.daddr = cb->src; 1418 1419 /* Routing tables gave us a gateway */ 1420 if (gateway) 1421 goto make_route; 1422 1423 /* Packet was intra-ethernet, so we know its on-link */ 1424 if (cb->rt_flags & DN_RT_F_IE) { 1425 gateway = cb->src; 1426 goto make_route; 1427 } 1428 1429 /* Use the default router if there is one */ 1430 neigh = neigh_clone(dn_db->router); 1431 if (neigh) { 1432 gateway = container_of(neigh, struct dn_neigh, n)->addr; 1433 goto make_route; 1434 } 1435 1436 /* Close eyes and pray */ 1437 gateway = cb->src; 1438 goto make_route; 1439 default: 1440 goto e_inval; 1441 } 1442 1443make_route: 1444 rt = dst_alloc(&dn_dst_ops, out_dev, 1, DST_OBSOLETE_NONE, 0); 1445 if (rt == NULL) 1446 goto e_nobufs; 1447 1448 rt->dn_next = NULL; 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_out; 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() increments dst->__refcnt */ 1492 dn_insert_route(rt, hash, &rt); 1493 skb_dst_set(skb, &rt->dst); 1494 1495done: 1496 if (neigh) 1497 neigh_release(neigh); 1498 if (free_res) 1499 dn_fib_res_put(&res); 1500 dev_put(in_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_release_immediate(&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->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_hold_and_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 nlmsg_end(skb, nlh); 1610 return 0; 1611 1612errout: 1613 nlmsg_cancel(skb, nlh); 1614 return -EMSGSIZE; 1615} 1616 1617const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = { 1618 [RTA_DST] = { .type = NLA_U16 }, 1619 [RTA_SRC] = { .type = NLA_U16 }, 1620 [RTA_IIF] = { .type = NLA_U32 }, 1621 [RTA_OIF] = { .type = NLA_U32 }, 1622 [RTA_GATEWAY] = { .type = NLA_U16 }, 1623 [RTA_PRIORITY] = { .type = NLA_U32 }, 1624 [RTA_PREFSRC] = { .type = NLA_U16 }, 1625 [RTA_METRICS] = { .type = NLA_NESTED }, 1626 [RTA_MULTIPATH] = { .type = NLA_NESTED }, 1627 [RTA_TABLE] = { .type = NLA_U32 }, 1628 [RTA_MARK] = { .type = NLA_U32 }, 1629}; 1630 1631/* 1632 * This is called by both endnodes and routers now. 1633 */ 1634static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 1635 struct netlink_ext_ack *extack) 1636{ 1637 struct net *net = sock_net(in_skb->sk); 1638 struct rtmsg *rtm = nlmsg_data(nlh); 1639 struct dn_route *rt = NULL; 1640 struct dn_skb_cb *cb; 1641 int err; 1642 struct sk_buff *skb; 1643 struct flowidn fld; 1644 struct nlattr *tb[RTA_MAX+1]; 1645 1646 if (!net_eq(net, &init_net)) 1647 return -EINVAL; 1648 1649 err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 1650 rtm_dn_policy, extack); 1651 if (err < 0) 1652 return err; 1653 1654 memset(&fld, 0, sizeof(fld)); 1655 fld.flowidn_proto = DNPROTO_NSP; 1656 1657 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 1658 if (skb == NULL) 1659 return -ENOBUFS; 1660 skb_reset_mac_header(skb); 1661 cb = DN_SKB_CB(skb); 1662 1663 if (tb[RTA_SRC]) 1664 fld.saddr = nla_get_le16(tb[RTA_SRC]); 1665 1666 if (tb[RTA_DST]) 1667 fld.daddr = nla_get_le16(tb[RTA_DST]); 1668 1669 if (tb[RTA_IIF]) 1670 fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]); 1671 1672 if (fld.flowidn_iif) { 1673 struct net_device *dev; 1674 dev = __dev_get_by_index(&init_net, fld.flowidn_iif); 1675 if (!dev || !dev->dn_ptr) { 1676 kfree_skb(skb); 1677 return -ENODEV; 1678 } 1679 skb->protocol = htons(ETH_P_DNA_RT); 1680 skb->dev = dev; 1681 cb->src = fld.saddr; 1682 cb->dst = fld.daddr; 1683 local_bh_disable(); 1684 err = dn_route_input(skb); 1685 local_bh_enable(); 1686 memset(cb, 0, sizeof(struct dn_skb_cb)); 1687 rt = (struct dn_route *)skb_dst(skb); 1688 if (!err && -rt->dst.error) 1689 err = rt->dst.error; 1690 } else { 1691 if (tb[RTA_OIF]) 1692 fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]); 1693 1694 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0); 1695 } 1696 1697 skb->dev = NULL; 1698 if (err) 1699 goto out_free; 1700 skb_dst_set(skb, &rt->dst); 1701 if (rtm->rtm_flags & RTM_F_NOTIFY) 1702 rt->rt_flags |= RTCF_NOTIFY; 1703 1704 err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0); 1705 if (err < 0) { 1706 err = -EMSGSIZE; 1707 goto out_free; 1708 } 1709 1710 return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid); 1711 1712out_free: 1713 kfree_skb(skb); 1714 return err; 1715} 1716 1717/* 1718 * For routers, this is called from dn_fib_dump, but for endnodes its 1719 * called directly from the rtnetlink dispatch table. 1720 */ 1721int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb) 1722{ 1723 struct net *net = sock_net(skb->sk); 1724 struct dn_route *rt; 1725 int h, s_h; 1726 int idx, s_idx; 1727 struct rtmsg *rtm; 1728 1729 if (!net_eq(net, &init_net)) 1730 return 0; 1731 1732 if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg)) 1733 return -EINVAL; 1734 1735 rtm = nlmsg_data(cb->nlh); 1736 if (!(rtm->rtm_flags & RTM_F_CLONED)) 1737 return 0; 1738 1739 s_h = cb->args[0]; 1740 s_idx = idx = cb->args[1]; 1741 for (h = 0; h <= dn_rt_hash_mask; h++) { 1742 if (h < s_h) 1743 continue; 1744 if (h > s_h) 1745 s_idx = 0; 1746 rcu_read_lock_bh(); 1747 for (rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0; 1748 rt; 1749 rt = rcu_dereference_bh(rt->dn_next), idx++) { 1750 if (idx < s_idx) 1751 continue; 1752 skb_dst_set(skb, dst_clone(&rt->dst)); 1753 if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid, 1754 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 1755 1, NLM_F_MULTI) < 0) { 1756 skb_dst_drop(skb); 1757 rcu_read_unlock_bh(); 1758 goto done; 1759 } 1760 skb_dst_drop(skb); 1761 } 1762 rcu_read_unlock_bh(); 1763 } 1764 1765done: 1766 cb->args[0] = h; 1767 cb->args[1] = idx; 1768 return skb->len; 1769} 1770 1771#ifdef CONFIG_PROC_FS 1772struct dn_rt_cache_iter_state { 1773 int bucket; 1774}; 1775 1776static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq) 1777{ 1778 struct dn_route *rt = NULL; 1779 struct dn_rt_cache_iter_state *s = seq->private; 1780 1781 for (s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) { 1782 rcu_read_lock_bh(); 1783 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain); 1784 if (rt) 1785 break; 1786 rcu_read_unlock_bh(); 1787 } 1788 return rt; 1789} 1790 1791static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt) 1792{ 1793 struct dn_rt_cache_iter_state *s = seq->private; 1794 1795 rt = rcu_dereference_bh(rt->dn_next); 1796 while (!rt) { 1797 rcu_read_unlock_bh(); 1798 if (--s->bucket < 0) 1799 break; 1800 rcu_read_lock_bh(); 1801 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain); 1802 } 1803 return rt; 1804} 1805 1806static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 1807{ 1808 struct dn_route *rt = dn_rt_cache_get_first(seq); 1809 1810 if (rt) { 1811 while (*pos && (rt = dn_rt_cache_get_next(seq, rt))) 1812 --*pos; 1813 } 1814 return *pos ? NULL : rt; 1815} 1816 1817static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1818{ 1819 struct dn_route *rt = dn_rt_cache_get_next(seq, v); 1820 ++*pos; 1821 return rt; 1822} 1823 1824static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v) 1825{ 1826 if (v) 1827 rcu_read_unlock_bh(); 1828} 1829 1830static int dn_rt_cache_seq_show(struct seq_file *seq, void *v) 1831{ 1832 struct dn_route *rt = v; 1833 char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN]; 1834 1835 seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n", 1836 rt->dst.dev ? rt->dst.dev->name : "*", 1837 dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1), 1838 dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2), 1839 atomic_read(&rt->dst.__refcnt), 1840 rt->dst.__use, 0); 1841 return 0; 1842} 1843 1844static const struct seq_operations dn_rt_cache_seq_ops = { 1845 .start = dn_rt_cache_seq_start, 1846 .next = dn_rt_cache_seq_next, 1847 .stop = dn_rt_cache_seq_stop, 1848 .show = dn_rt_cache_seq_show, 1849}; 1850#endif /* CONFIG_PROC_FS */ 1851 1852void __init dn_route_init(void) 1853{ 1854 int i, goal, order; 1855 1856 dn_dst_ops.kmem_cachep = 1857 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0, 1858 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 1859 dst_entries_init(&dn_dst_ops); 1860 timer_setup(&dn_route_timer, dn_dst_check_expire, 0); 1861 dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ; 1862 add_timer(&dn_route_timer); 1863 1864 goal = totalram_pages() >> (26 - PAGE_SHIFT); 1865 1866 for (order = 0; (1UL << order) < goal; order++) 1867 /* NOTHING */; 1868 1869 /* 1870 * Only want 1024 entries max, since the table is very, very unlikely 1871 * to be larger than that. 1872 */ 1873 while (order && ((((1UL << order) * PAGE_SIZE) / 1874 sizeof(struct dn_rt_hash_bucket)) >= 2048)) 1875 order--; 1876 1877 do { 1878 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE / 1879 sizeof(struct dn_rt_hash_bucket); 1880 while (dn_rt_hash_mask & (dn_rt_hash_mask - 1)) 1881 dn_rt_hash_mask--; 1882 dn_rt_hash_table = (struct dn_rt_hash_bucket *) 1883 __get_free_pages(GFP_ATOMIC, order); 1884 } while (dn_rt_hash_table == NULL && --order > 0); 1885 1886 if (!dn_rt_hash_table) 1887 panic("Failed to allocate DECnet route cache hash table\n"); 1888 1889 printk(KERN_INFO 1890 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n", 1891 dn_rt_hash_mask, 1892 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024); 1893 1894 dn_rt_hash_mask--; 1895 for (i = 0; i <= dn_rt_hash_mask; i++) { 1896 spin_lock_init(&dn_rt_hash_table[i].lock); 1897 dn_rt_hash_table[i].chain = NULL; 1898 } 1899 1900 dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1); 1901 1902 proc_create_seq_private("decnet_cache", 0444, init_net.proc_net, 1903 &dn_rt_cache_seq_ops, 1904 sizeof(struct dn_rt_cache_iter_state), NULL); 1905 1906#ifdef CONFIG_DECNET_ROUTER 1907 rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE, 1908 dn_cache_getroute, dn_fib_dump, 0); 1909#else 1910 rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE, 1911 dn_cache_getroute, dn_cache_dump, 0); 1912#endif 1913} 1914 1915void __exit dn_route_cleanup(void) 1916{ 1917 del_timer(&dn_route_timer); 1918 dn_run_flush(NULL); 1919 1920 remove_proc_entry("decnet_cache", init_net.proc_net); 1921 dst_entries_destroy(&dn_dst_ops); 1922}