net/decnet/dn

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This source file includes following definitions.
dn_dst_destroy
dn_dst_ifdown
dn_hash
dn_dst_check_expire
dn_dst_gc
dn_dst_update_pmtu
dn_dst_redirect
dn_dst_check
dn_dst_negative_advice
dn_dst_link_failure
compare_keys
dn_insert_route
dn_run_flush
dn_rt_cache_flush
dn_return_short
dn_return_long
dn_route_rx_packet
dn_route_rx_long
dn_route_rx_short
dn_route_discard
dn_route_ptp_hello
dn_route_rcv
dn_output
dn_forward
dn_rt_bug_out
dn_rt_bug
dn_dst_default_advmss
dn_dst_mtu
dn_dst_neigh_lookup
dn_rt_set_next_hop
dn_match_addr
dnet_select_source
__dn_fib_res_prefsrc
dn_fib_rules_map_destination
dn_route_output_slow
__dn_route_output_key
dn_route_output_key
dn_route_output_sock
dn_route_input_slow
dn_route_input
dn_rt_fill_info
dn_cache_getroute
dn_cache_dump
dn_rt_cache_get_first
dn_rt_cache_get_next
dn_rt_cache_seq_start
dn_rt_cache_seq_next
dn_rt_cache_seq_stop
dn_rt_cache_seq_show
dn_route_init
dn_route_cleanup
   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 
  87 struct dn_rt_hash_bucket
  88 {
  89         struct dn_route __rcu *chain;
  90         spinlock_t lock;
  91 };
  92 
  93 extern struct neigh_table dn_neigh_table;
  94 
  95 
  96 static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
  97 
  98 static const int dn_rt_min_delay = 2 * HZ;
  99 static const int dn_rt_max_delay = 10 * HZ;
 100 static const int dn_rt_mtu_expires = 10 * 60 * HZ;
 101 
 102 static unsigned long dn_rt_deadline;
 103 
 104 static int dn_dst_gc(struct dst_ops *ops);
 105 static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
 106 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
 107 static unsigned int dn_dst_mtu(const struct dst_entry *dst);
 108 static void dn_dst_destroy(struct dst_entry *);
 109 static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how);
 110 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
 111 static void dn_dst_link_failure(struct sk_buff *);
 112 static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 113                                struct sk_buff *skb , u32 mtu,
 114                                bool confirm_neigh);
 115 static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 116                             struct sk_buff *skb);
 117 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 118                                              struct sk_buff *skb,
 119                                              const void *daddr);
 120 static int dn_route_input(struct sk_buff *);
 121 static void dn_run_flush(struct timer_list *unused);
 122 
 123 static struct dn_rt_hash_bucket *dn_rt_hash_table;
 124 static unsigned int dn_rt_hash_mask;
 125 
 126 static struct timer_list dn_route_timer;
 127 static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush);
 128 int decnet_dst_gc_interval = 2;
 129 
 130 static struct dst_ops dn_dst_ops = {
 131         .family =               PF_DECnet,
 132         .gc_thresh =            128,
 133         .gc =                   dn_dst_gc,
 134         .check =                dn_dst_check,
 135         .default_advmss =       dn_dst_default_advmss,
 136         .mtu =                  dn_dst_mtu,
 137         .cow_metrics =          dst_cow_metrics_generic,
 138         .destroy =              dn_dst_destroy,
 139         .ifdown =               dn_dst_ifdown,
 140         .negative_advice =      dn_dst_negative_advice,
 141         .link_failure =         dn_dst_link_failure,
 142         .update_pmtu =          dn_dst_update_pmtu,
 143         .redirect =             dn_dst_redirect,
 144         .neigh_lookup =         dn_dst_neigh_lookup,
 145 };
 146 
 147 static void dn_dst_destroy(struct dst_entry *dst)
 148 {
 149         struct dn_route *rt = (struct dn_route *) dst;
 150 
 151         if (rt->n)
 152                 neigh_release(rt->n);
 153         dst_destroy_metrics_generic(dst);
 154 }
 155 
 156 static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how)
 157 {
 158         if (how) {
 159                 struct dn_route *rt = (struct dn_route *) dst;
 160                 struct neighbour *n = rt->n;
 161 
 162                 if (n && n->dev == dev) {
 163                         n->dev = dev_net(dev)->loopback_dev;
 164                         dev_hold(n->dev);
 165                         dev_put(dev);
 166                 }
 167         }
 168 }
 169 
 170 static __inline__ unsigned int dn_hash(__le16 src, __le16 dst)
 171 {
 172         __u16 tmp = (__u16 __force)(src ^ dst);
 173         tmp ^= (tmp >> 3);
 174         tmp ^= (tmp >> 5);
 175         tmp ^= (tmp >> 10);
 176         return dn_rt_hash_mask & (unsigned int)tmp;
 177 }
 178 
 179 static void dn_dst_check_expire(struct timer_list *unused)
 180 {
 181         int i;
 182         struct dn_route *rt;
 183         struct dn_route __rcu **rtp;
 184         unsigned long now = jiffies;
 185         unsigned long expire = 120 * HZ;
 186 
 187         for (i = 0; i <= dn_rt_hash_mask; i++) {
 188                 rtp = &dn_rt_hash_table[i].chain;
 189 
 190                 spin_lock(&dn_rt_hash_table[i].lock);
 191                 while ((rt = rcu_dereference_protected(*rtp,
 192                                                 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 193                         if (atomic_read(&rt->dst.__refcnt) > 1 ||
 194                             (now - rt->dst.lastuse) < expire) {
 195                                 rtp = &rt->dn_next;
 196                                 continue;
 197                         }
 198                         *rtp = rt->dn_next;
 199                         rt->dn_next = NULL;
 200                         dst_dev_put(&rt->dst);
 201                         dst_release(&rt->dst);
 202                 }
 203                 spin_unlock(&dn_rt_hash_table[i].lock);
 204 
 205                 if ((jiffies - now) > 0)
 206                         break;
 207         }
 208 
 209         mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
 210 }
 211 
 212 static int dn_dst_gc(struct dst_ops *ops)
 213 {
 214         struct dn_route *rt;
 215         struct dn_route __rcu **rtp;
 216         int i;
 217         unsigned long now = jiffies;
 218         unsigned long expire = 10 * HZ;
 219 
 220         for (i = 0; i <= dn_rt_hash_mask; i++) {
 221 
 222                 spin_lock_bh(&dn_rt_hash_table[i].lock);
 223                 rtp = &dn_rt_hash_table[i].chain;
 224 
 225                 while ((rt = rcu_dereference_protected(*rtp,
 226                                                 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 227                         if (atomic_read(&rt->dst.__refcnt) > 1 ||
 228                             (now - rt->dst.lastuse) < expire) {
 229                                 rtp = &rt->dn_next;
 230                                 continue;
 231                         }
 232                         *rtp = rt->dn_next;
 233                         rt->dn_next = NULL;
 234                         dst_dev_put(&rt->dst);
 235                         dst_release(&rt->dst);
 236                         break;
 237                 }
 238                 spin_unlock_bh(&dn_rt_hash_table[i].lock);
 239         }
 240 
 241         return 0;
 242 }
 243 
 244 /*
 245  * The decnet standards don't impose a particular minimum mtu, what they
 246  * do insist on is that the routing layer accepts a datagram of at least
 247  * 230 bytes long. Here we have to subtract the routing header length from
 248  * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
 249  * assume the worst and use a long header size.
 250  *
 251  * We update both the mtu and the advertised mss (i.e. the segment size we
 252  * advertise to the other end).
 253  */
 254 static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 255                                struct sk_buff *skb, u32 mtu,
 256                                bool confirm_neigh)
 257 {
 258         struct dn_route *rt = (struct dn_route *) dst;
 259         struct neighbour *n = rt->n;
 260         u32 min_mtu = 230;
 261         struct dn_dev *dn;
 262 
 263         dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
 264 
 265         if (dn && dn->use_long == 0)
 266                 min_mtu -= 6;
 267         else
 268                 min_mtu -= 21;
 269 
 270         if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
 271                 if (!(dst_metric_locked(dst, RTAX_MTU))) {
 272                         dst_metric_set(dst, RTAX_MTU, mtu);
 273                         dst_set_expires(dst, dn_rt_mtu_expires);
 274                 }
 275                 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
 276                         u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
 277                         u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
 278                         if (!existing_mss || existing_mss > mss)
 279                                 dst_metric_set(dst, RTAX_ADVMSS, mss);
 280                 }
 281         }
 282 }
 283 
 284 static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 285                             struct sk_buff *skb)
 286 {
 287 }
 288 
 289 /*
 290  * When a route has been marked obsolete. (e.g. routing cache flush)
 291  */
 292 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
 293 {
 294         return NULL;
 295 }
 296 
 297 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
 298 {
 299         dst_release(dst);
 300         return NULL;
 301 }
 302 
 303 static void dn_dst_link_failure(struct sk_buff *skb)
 304 {
 305 }
 306 
 307 static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
 308 {
 309         return ((fl1->daddr ^ fl2->daddr) |
 310                 (fl1->saddr ^ fl2->saddr) |
 311                 (fl1->flowidn_mark ^ fl2->flowidn_mark) |
 312                 (fl1->flowidn_scope ^ fl2->flowidn_scope) |
 313                 (fl1->flowidn_oif ^ fl2->flowidn_oif) |
 314                 (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
 315 }
 316 
 317 static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp)
 318 {
 319         struct dn_route *rth;
 320         struct dn_route __rcu **rthp;
 321         unsigned long now = jiffies;
 322 
 323         rthp = &dn_rt_hash_table[hash].chain;
 324 
 325         spin_lock_bh(&dn_rt_hash_table[hash].lock);
 326         while ((rth = rcu_dereference_protected(*rthp,
 327                                                 lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
 328                 if (compare_keys(&rth->fld, &rt->fld)) {
 329                         /* Put it first */
 330                         *rthp = rth->dn_next;
 331                         rcu_assign_pointer(rth->dn_next,
 332                                            dn_rt_hash_table[hash].chain);
 333                         rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
 334 
 335                         dst_hold_and_use(&rth->dst, now);
 336                         spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 337 
 338                         dst_release_immediate(&rt->dst);
 339                         *rp = rth;
 340                         return 0;
 341                 }
 342                 rthp = &rth->dn_next;
 343         }
 344 
 345         rcu_assign_pointer(rt->dn_next, dn_rt_hash_table[hash].chain);
 346         rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
 347 
 348         dst_hold_and_use(&rt->dst, now);
 349         spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 350         *rp = rt;
 351         return 0;
 352 }
 353 
 354 static void dn_run_flush(struct timer_list *unused)
 355 {
 356         int i;
 357         struct dn_route *rt, *next;
 358 
 359         for (i = 0; i < dn_rt_hash_mask; i++) {
 360                 spin_lock_bh(&dn_rt_hash_table[i].lock);
 361 
 362                 if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
 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 
 372 nothing_to_declare:
 373                 spin_unlock_bh(&dn_rt_hash_table[i].lock);
 374         }
 375 }
 376 
 377 static DEFINE_SPINLOCK(dn_rt_flush_lock);
 378 
 379 void 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  */
 418 static 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         if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 429                 return NET_RX_DROP;
 430 
 431         cb = DN_SKB_CB(skb);
 432         /* Skip packet length and point to flags */
 433         ptr = skb->data + 2;
 434         *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 435 
 436         dst = (__le16 *)ptr;
 437         ptr += 2;
 438         src = (__le16 *)ptr;
 439         ptr += 2;
 440         *ptr = 0; /* Zero hop count */
 441 
 442         swap(*src, *dst);
 443 
 444         skb->pkt_type = PACKET_OUTGOING;
 445         dn_rt_finish_output(skb, NULL, NULL);
 446         return NET_RX_SUCCESS;
 447 }
 448 
 449 /**
 450  * dn_return_long - Return a long packet to its sender
 451  * @skb: The long format packet to return
 452  *
 453  */
 454 static int dn_return_long(struct sk_buff *skb)
 455 {
 456         struct dn_skb_cb *cb;
 457         unsigned char *ptr;
 458         unsigned char *src_addr, *dst_addr;
 459         unsigned char tmp[ETH_ALEN];
 460 
 461         /* Add back all headers */
 462         skb_push(skb, skb->data - skb_network_header(skb));
 463 
 464         if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 465                 return NET_RX_DROP;
 466 
 467         cb = DN_SKB_CB(skb);
 468         /* Ignore packet length and point to flags */
 469         ptr = skb->data + 2;
 470 
 471         /* Skip padding */
 472         if (*ptr & DN_RT_F_PF) {
 473                 char padlen = (*ptr & ~DN_RT_F_PF);
 474                 ptr += padlen;
 475         }
 476 
 477         *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 478         ptr += 2;
 479         dst_addr = ptr;
 480         ptr += 8;
 481         src_addr = ptr;
 482         ptr += 6;
 483         *ptr = 0; /* Zero hop count */
 484 
 485         /* Swap source and destination */
 486         memcpy(tmp, src_addr, ETH_ALEN);
 487         memcpy(src_addr, dst_addr, ETH_ALEN);
 488         memcpy(dst_addr, tmp, ETH_ALEN);
 489 
 490         skb->pkt_type = PACKET_OUTGOING;
 491         dn_rt_finish_output(skb, dst_addr, src_addr);
 492         return NET_RX_SUCCESS;
 493 }
 494 
 495 /**
 496  * dn_route_rx_packet - Try and find a route for an incoming packet
 497  * @skb: The packet to find a route for
 498  *
 499  * Returns: result of input function if route is found, error code otherwise
 500  */
 501 static int dn_route_rx_packet(struct net *net, struct sock *sk, struct sk_buff *skb)
 502 {
 503         struct dn_skb_cb *cb;
 504         int err;
 505 
 506         if ((err = dn_route_input(skb)) == 0)
 507                 return dst_input(skb);
 508 
 509         cb = DN_SKB_CB(skb);
 510         if (decnet_debug_level & 4) {
 511                 char *devname = skb->dev ? skb->dev->name : "???";
 512 
 513                 printk(KERN_DEBUG
 514                         "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
 515                         (int)cb->rt_flags, devname, skb->len,
 516                         le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
 517                         err, skb->pkt_type);
 518         }
 519 
 520         if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
 521                 switch (cb->rt_flags & DN_RT_PKT_MSK) {
 522                 case DN_RT_PKT_SHORT:
 523                         return dn_return_short(skb);
 524                 case DN_RT_PKT_LONG:
 525                         return dn_return_long(skb);
 526                 }
 527         }
 528 
 529         kfree_skb(skb);
 530         return NET_RX_DROP;
 531 }
 532 
 533 static int dn_route_rx_long(struct sk_buff *skb)
 534 {
 535         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 536         unsigned char *ptr = skb->data;
 537 
 538         if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
 539                 goto drop_it;
 540 
 541         skb_pull(skb, 20);
 542         skb_reset_transport_header(skb);
 543 
 544         /* Destination info */
 545         ptr += 2;
 546         cb->dst = dn_eth2dn(ptr);
 547         if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 548                 goto drop_it;
 549         ptr += 6;
 550 
 551 
 552         /* Source info */
 553         ptr += 2;
 554         cb->src = dn_eth2dn(ptr);
 555         if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 556                 goto drop_it;
 557         ptr += 6;
 558         /* Other junk */
 559         ptr++;
 560         cb->hops = *ptr++; /* Visit Count */
 561 
 562         return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
 563                        &init_net, NULL, skb, skb->dev, NULL,
 564                        dn_route_rx_packet);
 565 
 566 drop_it:
 567         kfree_skb(skb);
 568         return NET_RX_DROP;
 569 }
 570 
 571 
 572 
 573 static int dn_route_rx_short(struct sk_buff *skb)
 574 {
 575         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 576         unsigned char *ptr = skb->data;
 577 
 578         if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
 579                 goto drop_it;
 580 
 581         skb_pull(skb, 5);
 582         skb_reset_transport_header(skb);
 583 
 584         cb->dst = *(__le16 *)ptr;
 585         ptr += 2;
 586         cb->src = *(__le16 *)ptr;
 587         ptr += 2;
 588         cb->hops = *ptr & 0x3f;
 589 
 590         return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
 591                        &init_net, NULL, skb, skb->dev, NULL,
 592                        dn_route_rx_packet);
 593 
 594 drop_it:
 595         kfree_skb(skb);
 596         return NET_RX_DROP;
 597 }
 598 
 599 static int dn_route_discard(struct net *net, struct sock *sk, struct sk_buff *skb)
 600 {
 601         /*
 602          * I know we drop the packet here, but thats considered success in
 603          * this case
 604          */
 605         kfree_skb(skb);
 606         return NET_RX_SUCCESS;
 607 }
 608 
 609 static int dn_route_ptp_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
 610 {
 611         dn_dev_hello(skb);
 612         dn_neigh_pointopoint_hello(skb);
 613         return NET_RX_SUCCESS;
 614 }
 615 
 616 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 617 {
 618         struct dn_skb_cb *cb;
 619         unsigned char flags = 0;
 620         __u16 len = le16_to_cpu(*(__le16 *)skb->data);
 621         struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
 622         unsigned char padlen = 0;
 623 
 624         if (!net_eq(dev_net(dev), &init_net))
 625                 goto dump_it;
 626 
 627         if (dn == NULL)
 628                 goto dump_it;
 629 
 630         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 631                 goto out;
 632 
 633         if (!pskb_may_pull(skb, 3))
 634                 goto dump_it;
 635 
 636         skb_pull(skb, 2);
 637 
 638         if (len > skb->len)
 639                 goto dump_it;
 640 
 641         skb_trim(skb, len);
 642 
 643         flags = *skb->data;
 644 
 645         cb = DN_SKB_CB(skb);
 646         cb->stamp = jiffies;
 647         cb->iif = dev->ifindex;
 648 
 649         /*
 650          * If we have padding, remove it.
 651          */
 652         if (flags & DN_RT_F_PF) {
 653                 padlen = flags & ~DN_RT_F_PF;
 654                 if (!pskb_may_pull(skb, padlen + 1))
 655                         goto dump_it;
 656                 skb_pull(skb, padlen);
 657                 flags = *skb->data;
 658         }
 659 
 660         skb_reset_network_header(skb);
 661 
 662         /*
 663          * Weed out future version DECnet
 664          */
 665         if (flags & DN_RT_F_VER)
 666                 goto dump_it;
 667 
 668         cb->rt_flags = flags;
 669 
 670         if (decnet_debug_level & 1)
 671                 printk(KERN_DEBUG
 672                         "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
 673                         (int)flags, (dev) ? dev->name : "???", len, skb->len,
 674                         padlen);
 675 
 676         if (flags & DN_RT_PKT_CNTL) {
 677                 if (unlikely(skb_linearize(skb)))
 678                         goto dump_it;
 679 
 680                 switch (flags & DN_RT_CNTL_MSK) {
 681                 case DN_RT_PKT_INIT:
 682                         dn_dev_init_pkt(skb);
 683                         break;
 684                 case DN_RT_PKT_VERI:
 685                         dn_dev_veri_pkt(skb);
 686                         break;
 687                 }
 688 
 689                 if (dn->parms.state != DN_DEV_S_RU)
 690                         goto dump_it;
 691 
 692                 switch (flags & DN_RT_CNTL_MSK) {
 693                 case DN_RT_PKT_HELO:
 694                         return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 695                                        &init_net, NULL, skb, skb->dev, NULL,
 696                                        dn_route_ptp_hello);
 697 
 698                 case DN_RT_PKT_L1RT:
 699                 case DN_RT_PKT_L2RT:
 700                         return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
 701                                        &init_net, NULL, skb, skb->dev, NULL,
 702                                        dn_route_discard);
 703                 case DN_RT_PKT_ERTH:
 704                         return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 705                                        &init_net, NULL, skb, skb->dev, NULL,
 706                                        dn_neigh_router_hello);
 707 
 708                 case DN_RT_PKT_EEDH:
 709                         return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 710                                        &init_net, NULL, skb, skb->dev, NULL,
 711                                        dn_neigh_endnode_hello);
 712                 }
 713         } else {
 714                 if (dn->parms.state != DN_DEV_S_RU)
 715                         goto dump_it;
 716 
 717                 skb_pull(skb, 1); /* Pull flags */
 718 
 719                 switch (flags & DN_RT_PKT_MSK) {
 720                 case DN_RT_PKT_LONG:
 721                         return dn_route_rx_long(skb);
 722                 case DN_RT_PKT_SHORT:
 723                         return dn_route_rx_short(skb);
 724                 }
 725         }
 726 
 727 dump_it:
 728         kfree_skb(skb);
 729 out:
 730         return NET_RX_DROP;
 731 }
 732 
 733 static int dn_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 734 {
 735         struct dst_entry *dst = skb_dst(skb);
 736         struct dn_route *rt = (struct dn_route *)dst;
 737         struct net_device *dev = dst->dev;
 738         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 739 
 740         int err = -EINVAL;
 741 
 742         if (rt->n == NULL)
 743                 goto error;
 744 
 745         skb->dev = dev;
 746 
 747         cb->src = rt->rt_saddr;
 748         cb->dst = rt->rt_daddr;
 749 
 750         /*
 751          * Always set the Intra-Ethernet bit on all outgoing packets
 752          * originated on this node. Only valid flag from upper layers
 753          * is return-to-sender-requested. Set hop count to 0 too.
 754          */
 755         cb->rt_flags &= ~DN_RT_F_RQR;
 756         cb->rt_flags |= DN_RT_F_IE;
 757         cb->hops = 0;
 758 
 759         return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT,
 760                        &init_net, sk, skb, NULL, dev,
 761                        dn_to_neigh_output);
 762 
 763 error:
 764         net_dbg_ratelimited("dn_output: This should not happen\n");
 765 
 766         kfree_skb(skb);
 767 
 768         return err;
 769 }
 770 
 771 static int dn_forward(struct sk_buff *skb)
 772 {
 773         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 774         struct dst_entry *dst = skb_dst(skb);
 775         struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
 776         struct dn_route *rt;
 777         int header_len;
 778         struct net_device *dev = skb->dev;
 779 
 780         if (skb->pkt_type != PACKET_HOST)
 781                 goto drop;
 782 
 783         /* Ensure that we have enough space for headers */
 784         rt = (struct dn_route *)skb_dst(skb);
 785         header_len = dn_db->use_long ? 21 : 6;
 786         if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
 787                 goto drop;
 788 
 789         /*
 790          * Hop count exceeded.
 791          */
 792         if (++cb->hops > 30)
 793                 goto drop;
 794 
 795         skb->dev = rt->dst.dev;
 796 
 797         /*
 798          * If packet goes out same interface it came in on, then set
 799          * the Intra-Ethernet bit. This has no effect for short
 800          * packets, so we don't need to test for them here.
 801          */
 802         cb->rt_flags &= ~DN_RT_F_IE;
 803         if (rt->rt_flags & RTCF_DOREDIRECT)
 804                 cb->rt_flags |= DN_RT_F_IE;
 805 
 806         return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD,
 807                        &init_net, NULL, skb, dev, skb->dev,
 808                        dn_to_neigh_output);
 809 
 810 drop:
 811         kfree_skb(skb);
 812         return NET_RX_DROP;
 813 }
 814 
 815 /*
 816  * Used to catch bugs. This should never normally get
 817  * called.
 818  */
 819 static int dn_rt_bug_out(struct net *net, struct sock *sk, struct sk_buff *skb)
 820 {
 821         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 822 
 823         net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 824                             le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 825 
 826         kfree_skb(skb);
 827 
 828         return NET_RX_DROP;
 829 }
 830 
 831 static int dn_rt_bug(struct sk_buff *skb)
 832 {
 833         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 834 
 835         net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 836                             le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 837 
 838         kfree_skb(skb);
 839 
 840         return NET_RX_DROP;
 841 }
 842 
 843 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
 844 {
 845         return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
 846 }
 847 
 848 static unsigned int dn_dst_mtu(const struct dst_entry *dst)
 849 {
 850         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
 851 
 852         return mtu ? : dst->dev->mtu;
 853 }
 854 
 855 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 856                                              struct sk_buff *skb,
 857                                              const void *daddr)
 858 {
 859         return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
 860 }
 861 
 862 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
 863 {
 864         struct dn_fib_info *fi = res->fi;
 865         struct net_device *dev = rt->dst.dev;
 866         unsigned int mss_metric;
 867         struct neighbour *n;
 868 
 869         if (fi) {
 870                 if (DN_FIB_RES_GW(*res) &&
 871                     DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 872                         rt->rt_gateway = DN_FIB_RES_GW(*res);
 873                 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
 874         }
 875         rt->rt_type = res->type;
 876 
 877         if (dev != NULL && rt->n == NULL) {
 878                 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
 879                 if (IS_ERR(n))
 880                         return PTR_ERR(n);
 881                 rt->n = n;
 882         }
 883 
 884         if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
 885                 dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
 886         mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
 887         if (mss_metric) {
 888                 unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
 889                 if (mss_metric > mss)
 890                         dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
 891         }
 892         return 0;
 893 }
 894 
 895 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
 896 {
 897         __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
 898         int match = 16;
 899         while(tmp) {
 900                 tmp >>= 1;
 901                 match--;
 902         }
 903         return match;
 904 }
 905 
 906 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
 907 {
 908         __le16 saddr = 0;
 909         struct dn_dev *dn_db;
 910         struct dn_ifaddr *ifa;
 911         int best_match = 0;
 912         int ret;
 913 
 914         rcu_read_lock();
 915         dn_db = rcu_dereference(dev->dn_ptr);
 916         for (ifa = rcu_dereference(dn_db->ifa_list);
 917              ifa != NULL;
 918              ifa = rcu_dereference(ifa->ifa_next)) {
 919                 if (ifa->ifa_scope > scope)
 920                         continue;
 921                 if (!daddr) {
 922                         saddr = ifa->ifa_local;
 923                         break;
 924                 }
 925                 ret = dn_match_addr(daddr, ifa->ifa_local);
 926                 if (ret > best_match)
 927                         saddr = ifa->ifa_local;
 928                 if (best_match == 0)
 929                         saddr = ifa->ifa_local;
 930         }
 931         rcu_read_unlock();
 932 
 933         return saddr;
 934 }
 935 
 936 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
 937 {
 938         return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
 939 }
 940 
 941 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
 942 {
 943         __le16 mask = dnet_make_mask(res->prefixlen);
 944         return (daddr&~mask)|res->fi->fib_nh->nh_gw;
 945 }
 946 
 947 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
 948 {
 949         struct flowidn fld = {
 950                 .daddr = oldflp->daddr,
 951                 .saddr = oldflp->saddr,
 952                 .flowidn_scope = RT_SCOPE_UNIVERSE,
 953                 .flowidn_mark = oldflp->flowidn_mark,
 954                 .flowidn_iif = LOOPBACK_IFINDEX,
 955                 .flowidn_oif = oldflp->flowidn_oif,
 956         };
 957         struct dn_route *rt = NULL;
 958         struct net_device *dev_out = NULL, *dev;
 959         struct neighbour *neigh = NULL;
 960         unsigned int hash;
 961         unsigned int flags = 0;
 962         struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
 963         int err;
 964         int free_res = 0;
 965         __le16 gateway = 0;
 966 
 967         if (decnet_debug_level & 16)
 968                 printk(KERN_DEBUG
 969                        "dn_route_output_slow: dst=%04x src=%04x mark=%d"
 970                        " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
 971                        le16_to_cpu(oldflp->saddr),
 972                        oldflp->flowidn_mark, LOOPBACK_IFINDEX,
 973                        oldflp->flowidn_oif);
 974 
 975         /* If we have an output interface, verify its a DECnet device */
 976         if (oldflp->flowidn_oif) {
 977                 dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
 978                 err = -ENODEV;
 979                 if (dev_out && dev_out->dn_ptr == NULL) {
 980                         dev_put(dev_out);
 981                         dev_out = NULL;
 982                 }
 983                 if (dev_out == NULL)
 984                         goto out;
 985         }
 986 
 987         /* If we have a source address, verify that its a local address */
 988         if (oldflp->saddr) {
 989                 err = -EADDRNOTAVAIL;
 990 
 991                 if (dev_out) {
 992                         if (dn_dev_islocal(dev_out, oldflp->saddr))
 993                                 goto source_ok;
 994                         dev_put(dev_out);
 995                         goto out;
 996                 }
 997                 rcu_read_lock();
 998                 for_each_netdev_rcu(&init_net, dev) {
 999                         if (!dev->dn_ptr)
1000                                 continue;
1001                         if (!dn_dev_islocal(dev, oldflp->saddr))
1002                                 continue;
1003                         if ((dev->flags & IFF_LOOPBACK) &&
1004                             oldflp->daddr &&
1005                             !dn_dev_islocal(dev, oldflp->daddr))
1006                                 continue;
1007 
1008                         dev_out = dev;
1009                         break;
1010                 }
1011                 rcu_read_unlock();
1012                 if (dev_out == NULL)
1013                         goto out;
1014                 dev_hold(dev_out);
1015 source_ok:
1016                 ;
1017         }
1018 
1019         /* No destination? Assume its local */
1020         if (!fld.daddr) {
1021                 fld.daddr = fld.saddr;
1022 
1023                 if (dev_out)
1024                         dev_put(dev_out);
1025                 err = -EINVAL;
1026                 dev_out = init_net.loopback_dev;
1027                 if (!dev_out->dn_ptr)
1028                         goto out;
1029                 err = -EADDRNOTAVAIL;
1030                 dev_hold(dev_out);
1031                 if (!fld.daddr) {
1032                         fld.daddr =
1033                         fld.saddr = dnet_select_source(dev_out, 0,
1034                                                        RT_SCOPE_HOST);
1035                         if (!fld.daddr)
1036                                 goto out;
1037                 }
1038                 fld.flowidn_oif = LOOPBACK_IFINDEX;
1039                 res.type = RTN_LOCAL;
1040                 goto make_route;
1041         }
1042 
1043         if (decnet_debug_level & 16)
1044                 printk(KERN_DEBUG
1045                        "dn_route_output_slow: initial checks complete."
1046                        " dst=%04x src=%04x oif=%d try_hard=%d\n",
1047                        le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1048                        fld.flowidn_oif, try_hard);
1049 
1050         /*
1051          * N.B. If the kernel is compiled without router support then
1052          * dn_fib_lookup() will evaluate to non-zero so this if () block
1053          * will always be executed.
1054          */
1055         err = -ESRCH;
1056         if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1057                 struct dn_dev *dn_db;
1058                 if (err != -ESRCH)
1059                         goto out;
1060                 /*
1061                  * Here the fallback is basically the standard algorithm for
1062                  * routing in endnodes which is described in the DECnet routing
1063                  * docs
1064                  *
1065                  * If we are not trying hard, look in neighbour cache.
1066                  * The result is tested to ensure that if a specific output
1067                  * device/source address was requested, then we honour that
1068                  * here
1069                  */
1070                 if (!try_hard) {
1071                         neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1072                         if (neigh) {
1073                                 if ((oldflp->flowidn_oif &&
1074                                     (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1075                                     (oldflp->saddr &&
1076                                     (!dn_dev_islocal(neigh->dev,
1077                                                      oldflp->saddr)))) {
1078                                         neigh_release(neigh);
1079                                         neigh = NULL;
1080                                 } else {
1081                                         if (dev_out)
1082                                                 dev_put(dev_out);
1083                                         if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1084                                                 dev_out = init_net.loopback_dev;
1085                                                 res.type = RTN_LOCAL;
1086                                         } else {
1087                                                 dev_out = neigh->dev;
1088                                         }
1089                                         dev_hold(dev_out);
1090                                         goto select_source;
1091                                 }
1092                         }
1093                 }
1094 
1095                 /* Not there? Perhaps its a local address */
1096                 if (dev_out == NULL)
1097                         dev_out = dn_dev_get_default();
1098                 err = -ENODEV;
1099                 if (dev_out == NULL)
1100                         goto out;
1101                 dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1102                 if (!dn_db)
1103                         goto e_inval;
1104                 /* Possible improvement - check all devices for local addr */
1105                 if (dn_dev_islocal(dev_out, fld.daddr)) {
1106                         dev_put(dev_out);
1107                         dev_out = init_net.loopback_dev;
1108                         dev_hold(dev_out);
1109                         res.type = RTN_LOCAL;
1110                         goto select_source;
1111                 }
1112                 /* Not local either.... try sending it to the default router */
1113                 neigh = neigh_clone(dn_db->router);
1114                 BUG_ON(neigh && neigh->dev != dev_out);
1115 
1116                 /* Ok then, we assume its directly connected and move on */
1117 select_source:
1118                 if (neigh)
1119                         gateway = ((struct dn_neigh *)neigh)->addr;
1120                 if (gateway == 0)
1121                         gateway = fld.daddr;
1122                 if (fld.saddr == 0) {
1123                         fld.saddr = dnet_select_source(dev_out, gateway,
1124                                                        res.type == RTN_LOCAL ?
1125                                                        RT_SCOPE_HOST :
1126                                                        RT_SCOPE_LINK);
1127                         if (fld.saddr == 0 && res.type != RTN_LOCAL)
1128                                 goto e_addr;
1129                 }
1130                 fld.flowidn_oif = dev_out->ifindex;
1131                 goto make_route;
1132         }
1133         free_res = 1;
1134 
1135         if (res.type == RTN_NAT)
1136                 goto e_inval;
1137 
1138         if (res.type == RTN_LOCAL) {
1139                 if (!fld.saddr)
1140                         fld.saddr = fld.daddr;
1141                 if (dev_out)
1142                         dev_put(dev_out);
1143                 dev_out = init_net.loopback_dev;
1144                 dev_hold(dev_out);
1145                 if (!dev_out->dn_ptr)
1146                         goto e_inval;
1147                 fld.flowidn_oif = dev_out->ifindex;
1148                 if (res.fi)
1149                         dn_fib_info_put(res.fi);
1150                 res.fi = NULL;
1151                 goto make_route;
1152         }
1153 
1154         if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1155                 dn_fib_select_multipath(&fld, &res);
1156 
1157         /*
1158          * We could add some logic to deal with default routes here and
1159          * get rid of some of the special casing above.
1160          */
1161 
1162         if (!fld.saddr)
1163                 fld.saddr = DN_FIB_RES_PREFSRC(res);
1164 
1165         if (dev_out)
1166                 dev_put(dev_out);
1167         dev_out = DN_FIB_RES_DEV(res);
1168         dev_hold(dev_out);
1169         fld.flowidn_oif = dev_out->ifindex;
1170         gateway = DN_FIB_RES_GW(res);
1171 
1172 make_route:
1173         if (dev_out->flags & IFF_LOOPBACK)
1174                 flags |= RTCF_LOCAL;
1175 
1176         rt = dst_alloc(&dn_dst_ops, dev_out, 0, DST_OBSOLETE_NONE, DST_HOST);
1177         if (rt == NULL)
1178                 goto e_nobufs;
1179 
1180         rt->dn_next = NULL;
1181         memset(&rt->fld, 0, sizeof(rt->fld));
1182         rt->fld.saddr        = oldflp->saddr;
1183         rt->fld.daddr        = oldflp->daddr;
1184         rt->fld.flowidn_oif  = oldflp->flowidn_oif;
1185         rt->fld.flowidn_iif  = 0;
1186         rt->fld.flowidn_mark = oldflp->flowidn_mark;
1187 
1188         rt->rt_saddr      = fld.saddr;
1189         rt->rt_daddr      = fld.daddr;
1190         rt->rt_gateway    = gateway ? gateway : fld.daddr;
1191         rt->rt_local_src  = fld.saddr;
1192 
1193         rt->rt_dst_map    = fld.daddr;
1194         rt->rt_src_map    = fld.saddr;
1195 
1196         rt->n = neigh;
1197         neigh = NULL;
1198 
1199         rt->dst.lastuse = jiffies;
1200         rt->dst.output  = dn_output;
1201         rt->dst.input   = dn_rt_bug;
1202         rt->rt_flags      = flags;
1203         if (flags & RTCF_LOCAL)
1204                 rt->dst.input = dn_nsp_rx;
1205 
1206         err = dn_rt_set_next_hop(rt, &res);
1207         if (err)
1208                 goto e_neighbour;
1209 
1210         hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1211         /* dn_insert_route() increments dst->__refcnt */
1212         dn_insert_route(rt, hash, (struct dn_route **)pprt);
1213 
1214 done:
1215         if (neigh)
1216                 neigh_release(neigh);
1217         if (free_res)
1218                 dn_fib_res_put(&res);
1219         if (dev_out)
1220                 dev_put(dev_out);
1221 out:
1222         return err;
1223 
1224 e_addr:
1225         err = -EADDRNOTAVAIL;
1226         goto done;
1227 e_inval:
1228         err = -EINVAL;
1229         goto done;
1230 e_nobufs:
1231         err = -ENOBUFS;
1232         goto done;
1233 e_neighbour:
1234         dst_release_immediate(&rt->dst);
1235         goto e_nobufs;
1236 }
1237 
1238 
1239 /*
1240  * N.B. The flags may be moved into the flowi at some future stage.
1241  */
1242 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1243 {
1244         unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1245         struct dn_route *rt = NULL;
1246 
1247         if (!(flags & MSG_TRYHARD)) {
1248                 rcu_read_lock_bh();
1249                 for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1250                         rt = rcu_dereference_bh(rt->dn_next)) {
1251                         if ((flp->daddr == rt->fld.daddr) &&
1252                             (flp->saddr == rt->fld.saddr) &&
1253                             (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1254                             dn_is_output_route(rt) &&
1255                             (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1256                                 dst_hold_and_use(&rt->dst, jiffies);
1257                                 rcu_read_unlock_bh();
1258                                 *pprt = &rt->dst;
1259                                 return 0;
1260                         }
1261                 }
1262                 rcu_read_unlock_bh();
1263         }
1264 
1265         return dn_route_output_slow(pprt, flp, flags);
1266 }
1267 
1268 static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1269 {
1270         int err;
1271 
1272         err = __dn_route_output_key(pprt, flp, flags);
1273         if (err == 0 && flp->flowidn_proto) {
1274                 *pprt = xfrm_lookup(&init_net, *pprt,
1275                                     flowidn_to_flowi(flp), NULL, 0);
1276                 if (IS_ERR(*pprt)) {
1277                         err = PTR_ERR(*pprt);
1278                         *pprt = NULL;
1279                 }
1280         }
1281         return err;
1282 }
1283 
1284 int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags)
1285 {
1286         int err;
1287 
1288         err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1289         if (err == 0 && fl->flowidn_proto) {
1290                 *pprt = xfrm_lookup(&init_net, *pprt,
1291                                     flowidn_to_flowi(fl), sk, 0);
1292                 if (IS_ERR(*pprt)) {
1293                         err = PTR_ERR(*pprt);
1294                         *pprt = NULL;
1295                 }
1296         }
1297         return err;
1298 }
1299 
1300 static int dn_route_input_slow(struct sk_buff *skb)
1301 {
1302         struct dn_route *rt = NULL;
1303         struct dn_skb_cb *cb = DN_SKB_CB(skb);
1304         struct net_device *in_dev = skb->dev;
1305         struct net_device *out_dev = NULL;
1306         struct dn_dev *dn_db;
1307         struct neighbour *neigh = NULL;
1308         unsigned int hash;
1309         int flags = 0;
1310         __le16 gateway = 0;
1311         __le16 local_src = 0;
1312         struct flowidn fld = {
1313                 .daddr = cb->dst,
1314                 .saddr = cb->src,
1315                 .flowidn_scope = RT_SCOPE_UNIVERSE,
1316                 .flowidn_mark = skb->mark,
1317                 .flowidn_iif = skb->dev->ifindex,
1318         };
1319         struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1320         int err = -EINVAL;
1321         int free_res = 0;
1322 
1323         dev_hold(in_dev);
1324 
1325         if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1326                 goto out;
1327 
1328         /* Zero source addresses are not allowed */
1329         if (fld.saddr == 0)
1330                 goto out;
1331 
1332         /*
1333          * In this case we've just received a packet from a source
1334          * outside ourselves pretending to come from us. We don't
1335          * allow it any further to prevent routing loops, spoofing and
1336          * other nasties. Loopback packets already have the dst attached
1337          * so this only affects packets which have originated elsewhere.
1338          */
1339         err  = -ENOTUNIQ;
1340         if (dn_dev_islocal(in_dev, cb->src))
1341                 goto out;
1342 
1343         err = dn_fib_lookup(&fld, &res);
1344         if (err) {
1345                 if (err != -ESRCH)
1346                         goto out;
1347                 /*
1348                  * Is the destination us ?
1349                  */
1350                 if (!dn_dev_islocal(in_dev, cb->dst))
1351                         goto e_inval;
1352 
1353                 res.type = RTN_LOCAL;
1354         } else {
1355                 __le16 src_map = fld.saddr;
1356                 free_res = 1;
1357 
1358                 out_dev = DN_FIB_RES_DEV(res);
1359                 if (out_dev == NULL) {
1360                         net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1361                         goto e_inval;
1362                 }
1363                 dev_hold(out_dev);
1364 
1365                 if (res.r)
1366                         src_map = fld.saddr; /* no NAT support for now */
1367 
1368                 gateway = DN_FIB_RES_GW(res);
1369                 if (res.type == RTN_NAT) {
1370                         fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1371                         dn_fib_res_put(&res);
1372                         free_res = 0;
1373                         if (dn_fib_lookup(&fld, &res))
1374                                 goto e_inval;
1375                         free_res = 1;
1376                         if (res.type != RTN_UNICAST)
1377                                 goto e_inval;
1378                         flags |= RTCF_DNAT;
1379                         gateway = fld.daddr;
1380                 }
1381                 fld.saddr = src_map;
1382         }
1383 
1384         switch(res.type) {
1385         case RTN_UNICAST:
1386                 /*
1387                  * Forwarding check here, we only check for forwarding
1388                  * being turned off, if you want to only forward intra
1389                  * area, its up to you to set the routing tables up
1390                  * correctly.
1391                  */
1392                 if (dn_db->parms.forwarding == 0)
1393                         goto e_inval;
1394 
1395                 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1396                         dn_fib_select_multipath(&fld, &res);
1397 
1398                 /*
1399                  * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1400                  * flag as a hint to set the intra-ethernet bit when
1401                  * forwarding. If we've got NAT in operation, we don't do
1402                  * this optimisation.
1403                  */
1404                 if (out_dev == in_dev && !(flags & RTCF_NAT))
1405                         flags |= RTCF_DOREDIRECT;
1406 
1407                 local_src = DN_FIB_RES_PREFSRC(res);
1408 
1409         case RTN_BLACKHOLE:
1410         case RTN_UNREACHABLE:
1411                 break;
1412         case RTN_LOCAL:
1413                 flags |= RTCF_LOCAL;
1414                 fld.saddr = cb->dst;
1415                 fld.daddr = cb->src;
1416 
1417                 /* Routing tables gave us a gateway */
1418                 if (gateway)
1419                         goto make_route;
1420 
1421                 /* Packet was intra-ethernet, so we know its on-link */
1422                 if (cb->rt_flags & DN_RT_F_IE) {
1423                         gateway = cb->src;
1424                         goto make_route;
1425                 }
1426 
1427                 /* Use the default router if there is one */
1428                 neigh = neigh_clone(dn_db->router);
1429                 if (neigh) {
1430                         gateway = ((struct dn_neigh *)neigh)->addr;
1431                         goto make_route;
1432                 }
1433 
1434                 /* Close eyes and pray */
1435                 gateway = cb->src;
1436                 goto make_route;
1437         default:
1438                 goto e_inval;
1439         }
1440 
1441 make_route:
1442         rt = dst_alloc(&dn_dst_ops, out_dev, 1, DST_OBSOLETE_NONE, DST_HOST);
1443         if (rt == NULL)
1444                 goto e_nobufs;
1445 
1446         rt->dn_next = NULL;
1447         memset(&rt->fld, 0, sizeof(rt->fld));
1448         rt->rt_saddr      = fld.saddr;
1449         rt->rt_daddr      = fld.daddr;
1450         rt->rt_gateway    = fld.daddr;
1451         if (gateway)
1452                 rt->rt_gateway = gateway;
1453         rt->rt_local_src  = local_src ? local_src : rt->rt_saddr;
1454 
1455         rt->rt_dst_map    = fld.daddr;
1456         rt->rt_src_map    = fld.saddr;
1457 
1458         rt->fld.saddr        = cb->src;
1459         rt->fld.daddr        = cb->dst;
1460         rt->fld.flowidn_oif  = 0;
1461         rt->fld.flowidn_iif  = in_dev->ifindex;
1462         rt->fld.flowidn_mark = fld.flowidn_mark;
1463 
1464         rt->n = neigh;
1465         rt->dst.lastuse = jiffies;
1466         rt->dst.output = dn_rt_bug_out;
1467         switch (res.type) {
1468         case RTN_UNICAST:
1469                 rt->dst.input = dn_forward;
1470                 break;
1471         case RTN_LOCAL:
1472                 rt->dst.output = dn_output;
1473                 rt->dst.input = dn_nsp_rx;
1474                 rt->dst.dev = in_dev;
1475                 flags |= RTCF_LOCAL;
1476                 break;
1477         default:
1478         case RTN_UNREACHABLE:
1479         case RTN_BLACKHOLE:
1480                 rt->dst.input = dst_discard;
1481         }
1482         rt->rt_flags = flags;
1483 
1484         err = dn_rt_set_next_hop(rt, &res);
1485         if (err)
1486                 goto e_neighbour;
1487 
1488         hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1489         /* dn_insert_route() increments dst->__refcnt */
1490         dn_insert_route(rt, hash, &rt);
1491         skb_dst_set(skb, &rt->dst);
1492 
1493 done:
1494         if (neigh)
1495                 neigh_release(neigh);
1496         if (free_res)
1497                 dn_fib_res_put(&res);
1498         dev_put(in_dev);
1499         if (out_dev)
1500                 dev_put(out_dev);
1501 out:
1502         return err;
1503 
1504 e_inval:
1505         err = -EINVAL;
1506         goto done;
1507 
1508 e_nobufs:
1509         err = -ENOBUFS;
1510         goto done;
1511 
1512 e_neighbour:
1513         dst_release_immediate(&rt->dst);
1514         goto done;
1515 }
1516 
1517 static int dn_route_input(struct sk_buff *skb)
1518 {
1519         struct dn_route *rt;
1520         struct dn_skb_cb *cb = DN_SKB_CB(skb);
1521         unsigned int hash = dn_hash(cb->src, cb->dst);
1522 
1523         if (skb_dst(skb))
1524                 return 0;
1525 
1526         rcu_read_lock();
1527         for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1528             rt = rcu_dereference(rt->dn_next)) {
1529                 if ((rt->fld.saddr == cb->src) &&
1530                     (rt->fld.daddr == cb->dst) &&
1531                     (rt->fld.flowidn_oif == 0) &&
1532                     (rt->fld.flowidn_mark == skb->mark) &&
1533                     (rt->fld.flowidn_iif == cb->iif)) {
1534                         dst_hold_and_use(&rt->dst, jiffies);
1535                         rcu_read_unlock();
1536                         skb_dst_set(skb, (struct dst_entry *)rt);
1537                         return 0;
1538                 }
1539         }
1540         rcu_read_unlock();
1541 
1542         return dn_route_input_slow(skb);
1543 }
1544 
1545 static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
1546                            int event, int nowait, unsigned int flags)
1547 {
1548         struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1549         struct rtmsg *r;
1550         struct nlmsghdr *nlh;
1551         long expires;
1552 
1553         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
1554         if (!nlh)
1555                 return -EMSGSIZE;
1556 
1557         r = nlmsg_data(nlh);
1558         r->rtm_family = AF_DECnet;
1559         r->rtm_dst_len = 16;
1560         r->rtm_src_len = 0;
1561         r->rtm_tos = 0;
1562         r->rtm_table = RT_TABLE_MAIN;
1563         r->rtm_type = rt->rt_type;
1564         r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1565         r->rtm_scope = RT_SCOPE_UNIVERSE;
1566         r->rtm_protocol = RTPROT_UNSPEC;
1567 
1568         if (rt->rt_flags & RTCF_NOTIFY)
1569                 r->rtm_flags |= RTM_F_NOTIFY;
1570 
1571         if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1572             nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1573                 goto errout;
1574 
1575         if (rt->fld.saddr) {
1576                 r->rtm_src_len = 16;
1577                 if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1578                         goto errout;
1579         }
1580         if (rt->dst.dev &&
1581             nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1582                 goto errout;
1583 
1584         /*
1585          * Note to self - change this if input routes reverse direction when
1586          * they deal only with inputs and not with replies like they do
1587          * currently.
1588          */
1589         if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1590                 goto errout;
1591 
1592         if (rt->rt_daddr != rt->rt_gateway &&
1593             nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1594                 goto errout;
1595 
1596         if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1597                 goto errout;
1598 
1599         expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1600         if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1601                                rt->dst.error) < 0)
1602                 goto errout;
1603 
1604         if (dn_is_input_route(rt) &&
1605             nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1606                 goto errout;
1607 
1608         nlmsg_end(skb, nlh);
1609         return 0;
1610 
1611 errout:
1612         nlmsg_cancel(skb, nlh);
1613         return -EMSGSIZE;
1614 }
1615 
1616 const 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  */
1633 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
1634                              struct netlink_ext_ack *extack)
1635 {
1636         struct net *net = sock_net(in_skb->sk);
1637         struct rtmsg *rtm = nlmsg_data(nlh);
1638         struct dn_route *rt = NULL;
1639         struct dn_skb_cb *cb;
1640         int err;
1641         struct sk_buff *skb;
1642         struct flowidn fld;
1643         struct nlattr *tb[RTA_MAX+1];
1644 
1645         if (!net_eq(net, &init_net))
1646                 return -EINVAL;
1647 
1648         err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
1649                                      rtm_dn_policy, extack);
1650         if (err < 0)
1651                 return err;
1652 
1653         memset(&fld, 0, sizeof(fld));
1654         fld.flowidn_proto = DNPROTO_NSP;
1655 
1656         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1657         if (skb == NULL)
1658                 return -ENOBUFS;
1659         skb_reset_mac_header(skb);
1660         cb = DN_SKB_CB(skb);
1661 
1662         if (tb[RTA_SRC])
1663                 fld.saddr = nla_get_le16(tb[RTA_SRC]);
1664 
1665         if (tb[RTA_DST])
1666                 fld.daddr = nla_get_le16(tb[RTA_DST]);
1667 
1668         if (tb[RTA_IIF])
1669                 fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
1670 
1671         if (fld.flowidn_iif) {
1672                 struct net_device *dev;
1673                 dev = __dev_get_by_index(&init_net, fld.flowidn_iif);
1674                 if (!dev || !dev->dn_ptr) {
1675                         kfree_skb(skb);
1676                         return -ENODEV;
1677                 }
1678                 skb->protocol = htons(ETH_P_DNA_RT);
1679                 skb->dev = dev;
1680                 cb->src = fld.saddr;
1681                 cb->dst = fld.daddr;
1682                 local_bh_disable();
1683                 err = dn_route_input(skb);
1684                 local_bh_enable();
1685                 memset(cb, 0, sizeof(struct dn_skb_cb));
1686                 rt = (struct dn_route *)skb_dst(skb);
1687                 if (!err && -rt->dst.error)
1688                         err = rt->dst.error;
1689         } else {
1690                 if (tb[RTA_OIF])
1691                         fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]);
1692 
1693                 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1694         }
1695 
1696         skb->dev = NULL;
1697         if (err)
1698                 goto out_free;
1699         skb_dst_set(skb, &rt->dst);
1700         if (rtm->rtm_flags & RTM_F_NOTIFY)
1701                 rt->rt_flags |= RTCF_NOTIFY;
1702 
1703         err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1704         if (err < 0) {
1705                 err = -EMSGSIZE;
1706                 goto out_free;
1707         }
1708 
1709         return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid);
1710 
1711 out_free:
1712         kfree_skb(skb);
1713         return err;
1714 }
1715 
1716 /*
1717  * For routers, this is called from dn_fib_dump, but for endnodes its
1718  * called directly from the rtnetlink dispatch table.
1719  */
1720 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1721 {
1722         struct net *net = sock_net(skb->sk);
1723         struct dn_route *rt;
1724         int h, s_h;
1725         int idx, s_idx;
1726         struct rtmsg *rtm;
1727 
1728         if (!net_eq(net, &init_net))
1729                 return 0;
1730 
1731         if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1732                 return -EINVAL;
1733 
1734         rtm = nlmsg_data(cb->nlh);
1735         if (!(rtm->rtm_flags & RTM_F_CLONED))
1736                 return 0;
1737 
1738         s_h = cb->args[0];
1739         s_idx = idx = cb->args[1];
1740         for(h = 0; h <= dn_rt_hash_mask; h++) {
1741                 if (h < s_h)
1742                         continue;
1743                 if (h > s_h)
1744                         s_idx = 0;
1745                 rcu_read_lock_bh();
1746                 for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1747                         rt;
1748                         rt = rcu_dereference_bh(rt->dn_next), idx++) {
1749                         if (idx < s_idx)
1750                                 continue;
1751                         skb_dst_set(skb, dst_clone(&rt->dst));
1752                         if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid,
1753                                         cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1754                                         1, NLM_F_MULTI) < 0) {
1755                                 skb_dst_drop(skb);
1756                                 rcu_read_unlock_bh();
1757                                 goto done;
1758                         }
1759                         skb_dst_drop(skb);
1760                 }
1761                 rcu_read_unlock_bh();
1762         }
1763 
1764 done:
1765         cb->args[0] = h;
1766         cb->args[1] = idx;
1767         return skb->len;
1768 }
1769 
1770 #ifdef CONFIG_PROC_FS
1771 struct dn_rt_cache_iter_state {
1772         int bucket;
1773 };
1774 
1775 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1776 {
1777         struct dn_route *rt = NULL;
1778         struct dn_rt_cache_iter_state *s = seq->private;
1779 
1780         for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1781                 rcu_read_lock_bh();
1782                 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1783                 if (rt)
1784                         break;
1785                 rcu_read_unlock_bh();
1786         }
1787         return rt;
1788 }
1789 
1790 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1791 {
1792         struct dn_rt_cache_iter_state *s = seq->private;
1793 
1794         rt = rcu_dereference_bh(rt->dn_next);
1795         while (!rt) {
1796                 rcu_read_unlock_bh();
1797                 if (--s->bucket < 0)
1798                         break;
1799                 rcu_read_lock_bh();
1800                 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1801         }
1802         return rt;
1803 }
1804 
1805 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1806 {
1807         struct dn_route *rt = dn_rt_cache_get_first(seq);
1808 
1809         if (rt) {
1810                 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1811                         --*pos;
1812         }
1813         return *pos ? NULL : rt;
1814 }
1815 
1816 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1817 {
1818         struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1819         ++*pos;
1820         return rt;
1821 }
1822 
1823 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1824 {
1825         if (v)
1826                 rcu_read_unlock_bh();
1827 }
1828 
1829 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1830 {
1831         struct dn_route *rt = v;
1832         char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1833 
1834         seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1835                    rt->dst.dev ? rt->dst.dev->name : "*",
1836                    dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1837                    dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1838                    atomic_read(&rt->dst.__refcnt),
1839                    rt->dst.__use, 0);
1840         return 0;
1841 }
1842 
1843 static const struct seq_operations dn_rt_cache_seq_ops = {
1844         .start  = dn_rt_cache_seq_start,
1845         .next   = dn_rt_cache_seq_next,
1846         .stop   = dn_rt_cache_seq_stop,
1847         .show   = dn_rt_cache_seq_show,
1848 };
1849 #endif /* CONFIG_PROC_FS */
1850 
1851 void __init dn_route_init(void)
1852 {
1853         int i, goal, order;
1854 
1855         dn_dst_ops.kmem_cachep =
1856                 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1857                                   SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1858         dst_entries_init(&dn_dst_ops);
1859         timer_setup(&dn_route_timer, dn_dst_check_expire, 0);
1860         dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1861         add_timer(&dn_route_timer);
1862 
1863         goal = totalram_pages() >> (26 - PAGE_SHIFT);
1864 
1865         for(order = 0; (1UL << order) < goal; order++)
1866                 /* NOTHING */;
1867 
1868         /*
1869          * Only want 1024 entries max, since the table is very, very unlikely
1870          * to be larger than that.
1871          */
1872         while(order && ((((1UL << order) * PAGE_SIZE) /
1873                                 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1874                 order--;
1875 
1876         do {
1877                 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1878                         sizeof(struct dn_rt_hash_bucket);
1879                 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1880                         dn_rt_hash_mask--;
1881                 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1882                         __get_free_pages(GFP_ATOMIC, order);
1883         } while (dn_rt_hash_table == NULL && --order > 0);
1884 
1885         if (!dn_rt_hash_table)
1886                 panic("Failed to allocate DECnet route cache hash table\n");
1887 
1888         printk(KERN_INFO
1889                 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1890                 dn_rt_hash_mask,
1891                 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1892 
1893         dn_rt_hash_mask--;
1894         for(i = 0; i <= dn_rt_hash_mask; i++) {
1895                 spin_lock_init(&dn_rt_hash_table[i].lock);
1896                 dn_rt_hash_table[i].chain = NULL;
1897         }
1898 
1899         dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1900 
1901         proc_create_seq_private("decnet_cache", 0444, init_net.proc_net,
1902                         &dn_rt_cache_seq_ops,
1903                         sizeof(struct dn_rt_cache_iter_state), NULL);
1904 
1905 #ifdef CONFIG_DECNET_ROUTER
1906         rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE,
1907                              dn_cache_getroute, dn_fib_dump, 0);
1908 #else
1909         rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE,
1910                              dn_cache_getroute, dn_cache_dump, 0);
1911 #endif
1912 }
1913 
1914 void __exit dn_route_cleanup(void)
1915 {
1916         del_timer(&dn_route_timer);
1917         dn_run_flush(NULL);
1918 
1919         remove_proc_entry("decnet_cache", init_net.proc_net);
1920         dst_entries_destroy(&dn_dst_ops);
1921 }
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root/net/decnet/dn_route.c

DEFINITIONS
