net/decnet/dn_fib.c

   1 /*
   2  * DECnet       An implementation of the DECnet protocol suite for the LINUX
   3  *              operating system.  DECnet is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              DECnet Routing Forwarding Information Base (Glue/Info List)
   7  *
   8  * Author:      Steve Whitehouse <SteveW@ACM.org>
   9  *
  10  *
  11  * Changes:
  12  *              Alexey Kuznetsov : SMP locking changes
  13  *              Steve Whitehouse : Rewrote it... Well to be more correct, I
  14  *                                 copied most of it from the ipv4 fib code.
  15  *              Steve Whitehouse : Updated it in style and fixed a few bugs
  16  *                                 which were fixed in the ipv4 code since
  17  *                                 this code was copied from it.
  18  *
  19  */
  20 #include <linux/string.h>
  21 #include <linux/net.h>
  22 #include <linux/socket.h>
  23 #include <linux/slab.h>
  24 #include <linux/sockios.h>
  25 #include <linux/init.h>
  26 #include <linux/skbuff.h>
  27 #include <linux/netlink.h>
  28 #include <linux/rtnetlink.h>
  29 #include <linux/proc_fs.h>
  30 #include <linux/netdevice.h>
  31 #include <linux/timer.h>
  32 #include <linux/spinlock.h>
  33 #include <linux/atomic.h>
  34 #include <asm/uaccess.h>
  35 #include <net/neighbour.h>
  36 #include <net/dst.h>
  37 #include <net/flow.h>
  38 #include <net/fib_rules.h>
  39 #include <net/dn.h>
  40 #include <net/dn_route.h>
  41 #include <net/dn_fib.h>
  42 #include <net/dn_neigh.h>
  43 #include <net/dn_dev.h>
  44
  45 #define RT_MIN_TABLE 1
  46
  47 #define for_fib_info() { struct dn_fib_info *fi;\
  48         for(fi = dn_fib_info_list; fi; fi = fi->fib_next)
  49 #define endfor_fib_info() }
  50
  51 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
  52         for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
  53
  54 #define change_nexthops(fi) { int nhsel; struct dn_fib_nh *nh;\
  55         for(nhsel = 0, nh = (struct dn_fib_nh *)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nh++, nhsel++)
  56
  57 #define endfor_nexthops(fi) }
  58
  59 static DEFINE_SPINLOCK(dn_fib_multipath_lock);
  60 static struct dn_fib_info *dn_fib_info_list;
  61 static DEFINE_SPINLOCK(dn_fib_info_lock);
  62
  63 static struct
  64 {
  65         int error;
  66         u8 scope;
  67 } dn_fib_props[RTN_MAX+1] = {
  68         [RTN_UNSPEC] =      { .error = 0,       .scope = RT_SCOPE_NOWHERE },
  69         [RTN_UNICAST] =     { .error = 0,       .scope = RT_SCOPE_UNIVERSE },
  70         [RTN_LOCAL] =       { .error = 0,       .scope = RT_SCOPE_HOST },
  71         [RTN_BROADCAST] =   { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
  72         [RTN_ANYCAST] =     { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
  73         [RTN_MULTICAST] =   { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
  74         [RTN_BLACKHOLE] =   { .error = -EINVAL, .scope = RT_SCOPE_UNIVERSE },
  75         [RTN_UNREACHABLE] = { .error = -EHOSTUNREACH, .scope = RT_SCOPE_UNIVERSE },
  76         [RTN_PROHIBIT] =    { .error = -EACCES, .scope = RT_SCOPE_UNIVERSE },
  77         [RTN_THROW] =       { .error = -EAGAIN, .scope = RT_SCOPE_UNIVERSE },
  78         [RTN_NAT] =         { .error = 0,       .scope = RT_SCOPE_NOWHERE },
  79         [RTN_XRESOLVE] =    { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
  80 };
  81
  82 static int dn_fib_sync_down(__le16 local, struct net_device *dev, int force);
  83 static int dn_fib_sync_up(struct net_device *dev);
  84
  85 void dn_fib_free_info(struct dn_fib_info *fi)
  86 {
  87         if (fi->fib_dead == 0) {
  88                 printk(KERN_DEBUG "DECnet: BUG! Attempt to free alive dn_fib_info\n");
  89                 return;
  90         }
  91
  92         change_nexthops(fi) {
  93                 if (nh->nh_dev)
  94                         dev_put(nh->nh_dev);
  95                 nh->nh_dev = NULL;
  96         } endfor_nexthops(fi);
  97         kfree(fi);
  98 }
  99
 100 void dn_fib_release_info(struct dn_fib_info *fi)
 101 {
 102         spin_lock(&dn_fib_info_lock);
 103         if (fi && --fi->fib_treeref == 0) {
 104                 if (fi->fib_next)
 105                         fi->fib_next->fib_prev = fi->fib_prev;
 106                 if (fi->fib_prev)
 107                         fi->fib_prev->fib_next = fi->fib_next;
 108                 if (fi == dn_fib_info_list)
 109                         dn_fib_info_list = fi->fib_next;
 110                 fi->fib_dead = 1;
 111                 dn_fib_info_put(fi);
 112         }
 113         spin_unlock(&dn_fib_info_lock);
 114 }
 115
 116 static inline int dn_fib_nh_comp(const struct dn_fib_info *fi, const struct dn_fib_info *ofi)
 117 {
 118         const struct dn_fib_nh *onh = ofi->fib_nh;
 119
 120         for_nexthops(fi) {
 121                 if (nh->nh_oif != onh->nh_oif ||
 122                         nh->nh_gw != onh->nh_gw ||
 123                         nh->nh_scope != onh->nh_scope ||
 124                         nh->nh_weight != onh->nh_weight ||
 125                         ((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD))
 126                                 return -1;
 127                 onh++;
 128         } endfor_nexthops(fi);
 129         return 0;
 130 }
 131
 132 static inline struct dn_fib_info *dn_fib_find_info(const struct dn_fib_info *nfi)
 133 {
 134         for_fib_info() {
 135                 if (fi->fib_nhs != nfi->fib_nhs)
 136                         continue;
 137                 if (nfi->fib_protocol == fi->fib_protocol &&
 138                         nfi->fib_prefsrc == fi->fib_prefsrc &&
 139                         nfi->fib_priority == fi->fib_priority &&
 140                         memcmp(nfi->fib_metrics, fi->fib_metrics, sizeof(fi->fib_metrics)) == 0 &&
 141                         ((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 &&
 142                         (nfi->fib_nhs == 0 || dn_fib_nh_comp(fi, nfi) == 0))
 143                                 return fi;
 144         } endfor_fib_info();
 145         return NULL;
 146 }
 147
 148 static int dn_fib_count_nhs(const struct nlattr *attr)
 149 {
 150         struct rtnexthop *nhp = nla_data(attr);
 151         int nhs = 0, nhlen = nla_len(attr);
 152
 153         while(nhlen >= (int)sizeof(struct rtnexthop)) {
 154                 if ((nhlen -= nhp->rtnh_len) < 0)
 155                         return 0;
 156                 nhs++;
 157                 nhp = RTNH_NEXT(nhp);
 158         }
 159
 160         return nhs;
 161 }
 162
 163 static int dn_fib_get_nhs(struct dn_fib_info *fi, const struct nlattr *attr,
 164                           const struct rtmsg *r)
 165 {
 166         struct rtnexthop *nhp = nla_data(attr);
 167         int nhlen = nla_len(attr);
 168
 169         change_nexthops(fi) {
 170                 int attrlen = nhlen - sizeof(struct rtnexthop);
 171                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 172                         return -EINVAL;
 173
 174                 nh->nh_flags  = (r->rtm_flags&~0xFF) | nhp->rtnh_flags;
 175                 nh->nh_oif    = nhp->rtnh_ifindex;
 176                 nh->nh_weight = nhp->rtnh_hops + 1;
 177
 178                 if (attrlen) {
 179                         struct nlattr *gw_attr;
 180
 181                         gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
 182                         nh->nh_gw = gw_attr ? nla_get_le16(gw_attr) : 0;
 183                 }
 184                 nhp = RTNH_NEXT(nhp);
 185         } endfor_nexthops(fi);
 186
 187         return 0;
 188 }
 189
 190
 191 static int dn_fib_check_nh(const struct rtmsg *r, struct dn_fib_info *fi, struct dn_fib_nh *nh)
 192 {
 193         int err;
 194
 195         if (nh->nh_gw) {
 196                 struct flowidn fld;
 197                 struct dn_fib_res res;
 198
 199                 if (nh->nh_flags&RTNH_F_ONLINK) {
 200                         struct net_device *dev;
 201
 202                         if (r->rtm_scope >= RT_SCOPE_LINK)
 203                                 return -EINVAL;
 204                         if (dnet_addr_type(nh->nh_gw) != RTN_UNICAST)
 205                                 return -EINVAL;
 206                         if ((dev = __dev_get_by_index(&init_net, nh->nh_oif)) == NULL)
 207                                 return -ENODEV;
 208                         if (!(dev->flags&IFF_UP))
 209                                 return -ENETDOWN;
 210                         nh->nh_dev = dev;
 211                         dev_hold(dev);
 212                         nh->nh_scope = RT_SCOPE_LINK;
 213                         return 0;
 214                 }
 215
 216                 memset(&fld, 0, sizeof(fld));
 217                 fld.daddr = nh->nh_gw;
 218                 fld.flowidn_oif = nh->nh_oif;
 219                 fld.flowidn_scope = r->rtm_scope + 1;
 220
 221                 if (fld.flowidn_scope < RT_SCOPE_LINK)
 222                         fld.flowidn_scope = RT_SCOPE_LINK;
 223
 224                 if ((err = dn_fib_lookup(&fld, &res)) != 0)
 225                         return err;
 226
 227                 err = -EINVAL;
 228                 if (res.type != RTN_UNICAST && res.type != RTN_LOCAL)
 229                         goto out;
 230                 nh->nh_scope = res.scope;
 231                 nh->nh_oif = DN_FIB_RES_OIF(res);
 232                 nh->nh_dev = DN_FIB_RES_DEV(res);
 233                 if (nh->nh_dev == NULL)
 234                         goto out;
 235                 dev_hold(nh->nh_dev);
 236                 err = -ENETDOWN;
 237                 if (!(nh->nh_dev->flags & IFF_UP))
 238                         goto out;
 239                 err = 0;
 240 out:
 241                 dn_fib_res_put(&res);
 242                 return err;
 243         } else {
 244                 struct net_device *dev;
 245
 246                 if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK))
 247                         return -EINVAL;
 248
 249                 dev = __dev_get_by_index(&init_net, nh->nh_oif);
 250                 if (dev == NULL || dev->dn_ptr == NULL)
 251                         return -ENODEV;
 252                 if (!(dev->flags&IFF_UP))
 253                         return -ENETDOWN;
 254                 nh->nh_dev = dev;
 255                 dev_hold(nh->nh_dev);
 256                 nh->nh_scope = RT_SCOPE_HOST;
 257         }
 258
 259         return 0;
 260 }
 261
 262
 263 struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r, struct nlattr *attrs[],
 264                                        const struct nlmsghdr *nlh, int *errp)
 265 {
 266         int err;
 267         struct dn_fib_info *fi = NULL;
 268         struct dn_fib_info *ofi;
 269         int nhs = 1;
 270
 271         if (r->rtm_type > RTN_MAX)
 272                 goto err_inval;
 273
 274         if (dn_fib_props[r->rtm_type].scope > r->rtm_scope)
 275                 goto err_inval;
 276
 277         if (attrs[RTA_MULTIPATH] &&
 278             (nhs = dn_fib_count_nhs(attrs[RTA_MULTIPATH])) == 0)
 279                 goto err_inval;
 280
 281         fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct dn_fib_nh), GFP_KERNEL);
 282         err = -ENOBUFS;
 283         if (fi == NULL)
 284                 goto failure;
 285
 286         fi->fib_protocol = r->rtm_protocol;
 287         fi->fib_nhs = nhs;
 288         fi->fib_flags = r->rtm_flags;
 289
 290         if (attrs[RTA_PRIORITY])
 291                 fi->fib_priority = nla_get_u32(attrs[RTA_PRIORITY]);
 292
 293         if (attrs[RTA_METRICS]) {
 294                 struct nlattr *attr;
 295                 int rem;
 296
 297                 nla_for_each_nested(attr, attrs[RTA_METRICS], rem) {
 298                         int type = nla_type(attr);
 299
 300                         if (type) {
 301                                 if (type > RTAX_MAX || nla_len(attr) < 4)
 302                                         goto err_inval;
 303
 304                                 fi->fib_metrics[type-1] = nla_get_u32(attr);
 305                         }
 306                 }
 307         }
 308
 309         if (attrs[RTA_PREFSRC])
 310                 fi->fib_prefsrc = nla_get_le16(attrs[RTA_PREFSRC]);
 311
 312         if (attrs[RTA_MULTIPATH]) {
 313                 if ((err = dn_fib_get_nhs(fi, attrs[RTA_MULTIPATH], r)) != 0)
 314                         goto failure;
 315
 316                 if (attrs[RTA_OIF] &&
 317                     fi->fib_nh->nh_oif != nla_get_u32(attrs[RTA_OIF]))
 318                         goto err_inval;
 319
 320                 if (attrs[RTA_GATEWAY] &&
 321                     fi->fib_nh->nh_gw != nla_get_le16(attrs[RTA_GATEWAY]))
 322                         goto err_inval;
 323         } else {
 324                 struct dn_fib_nh *nh = fi->fib_nh;
 325
 326                 if (attrs[RTA_OIF])
 327                         nh->nh_oif = nla_get_u32(attrs[RTA_OIF]);
 328
 329                 if (attrs[RTA_GATEWAY])
 330                         nh->nh_gw = nla_get_le16(attrs[RTA_GATEWAY]);
 331
 332                 nh->nh_flags = r->rtm_flags;
 333                 nh->nh_weight = 1;
 334         }
 335
 336         if (r->rtm_type == RTN_NAT) {
 337                 if (!attrs[RTA_GATEWAY] || nhs != 1 || attrs[RTA_OIF])
 338                         goto err_inval;
 339
 340                 fi->fib_nh->nh_gw = nla_get_le16(attrs[RTA_GATEWAY]);
 341                 goto link_it;
 342         }
 343
 344         if (dn_fib_props[r->rtm_type].error) {
 345                 if (attrs[RTA_GATEWAY] || attrs[RTA_OIF] || attrs[RTA_MULTIPATH])
 346                         goto err_inval;
 347
 348                 goto link_it;
 349         }
 350
 351         if (r->rtm_scope > RT_SCOPE_HOST)
 352                 goto err_inval;
 353
 354         if (r->rtm_scope == RT_SCOPE_HOST) {
 355                 struct dn_fib_nh *nh = fi->fib_nh;
 356
 357                 /* Local address is added */
 358                 if (nhs != 1 || nh->nh_gw)
 359                         goto err_inval;
 360                 nh->nh_scope = RT_SCOPE_NOWHERE;
 361                 nh->nh_dev = dev_get_by_index(&init_net, fi->fib_nh->nh_oif);
 362                 err = -ENODEV;
 363                 if (nh->nh_dev == NULL)
 364                         goto failure;
 365         } else {
 366                 change_nexthops(fi) {
 367                         if ((err = dn_fib_check_nh(r, fi, nh)) != 0)
 368                                 goto failure;
 369                 } endfor_nexthops(fi)
 370         }
 371
 372         if (fi->fib_prefsrc) {
 373                 if (r->rtm_type != RTN_LOCAL || !attrs[RTA_DST] ||
 374                     fi->fib_prefsrc != nla_get_le16(attrs[RTA_DST]))
 375                         if (dnet_addr_type(fi->fib_prefsrc) != RTN_LOCAL)
 376                                 goto err_inval;
 377         }
 378
 379 link_it:
 380         if ((ofi = dn_fib_find_info(fi)) != NULL) {
 381                 fi->fib_dead = 1;
 382                 dn_fib_free_info(fi);
 383                 ofi->fib_treeref++;
 384                 return ofi;
 385         }
 386
 387         fi->fib_treeref++;
 388         atomic_inc(&fi->fib_clntref);
 389         spin_lock(&dn_fib_info_lock);
 390         fi->fib_next = dn_fib_info_list;
 391         fi->fib_prev = NULL;
 392         if (dn_fib_info_list)
 393                 dn_fib_info_list->fib_prev = fi;
 394         dn_fib_info_list = fi;
 395         spin_unlock(&dn_fib_info_lock);
 396         return fi;
 397
 398 err_inval:
 399         err = -EINVAL;
 400
 401 failure:
 402         *errp = err;
 403         if (fi) {
 404                 fi->fib_dead = 1;
 405                 dn_fib_free_info(fi);
 406         }
 407
 408         return NULL;
 409 }
 410
 411 int dn_fib_semantic_match(int type, struct dn_fib_info *fi, const struct flowidn *fld, struct dn_fib_res *res)
 412 {
 413         int err = dn_fib_props[type].error;
 414
 415         if (err == 0) {
 416                 if (fi->fib_flags & RTNH_F_DEAD)
 417                         return 1;
 418
 419                 res->fi = fi;
 420
 421                 switch (type) {
 422                 case RTN_NAT:
 423                         DN_FIB_RES_RESET(*res);
 424                         atomic_inc(&fi->fib_clntref);
 425                         return 0;
 426                 case RTN_UNICAST:
 427                 case RTN_LOCAL:
 428                         for_nexthops(fi) {
 429                                 if (nh->nh_flags & RTNH_F_DEAD)
 430                                         continue;
 431                                 if (!fld->flowidn_oif ||
 432                                     fld->flowidn_oif == nh->nh_oif)
 433                                         break;
 434                         }
 435                         if (nhsel < fi->fib_nhs) {
 436                                 res->nh_sel = nhsel;
 437                                 atomic_inc(&fi->fib_clntref);
 438                                 return 0;
 439                         }
 440                         endfor_nexthops(fi);
 441                         res->fi = NULL;
 442                         return 1;
 443                 default:
 444                         net_err_ratelimited("DECnet: impossible routing event : dn_fib_semantic_match type=%d\n",
 445                                             type);
 446                         res->fi = NULL;
 447                         return -EINVAL;
 448                 }
 449         }
 450         return err;
 451 }
 452
 453 void dn_fib_select_multipath(const struct flowidn *fld, struct dn_fib_res *res)
 454 {
 455         struct dn_fib_info *fi = res->fi;
 456         int w;
 457
 458         spin_lock_bh(&dn_fib_multipath_lock);
 459         if (fi->fib_power <= 0) {
 460                 int power = 0;
 461                 change_nexthops(fi) {
 462                         if (!(nh->nh_flags&RTNH_F_DEAD)) {
 463                                 power += nh->nh_weight;
 464                                 nh->nh_power = nh->nh_weight;
 465                         }
 466                 } endfor_nexthops(fi);
 467                 fi->fib_power = power;
 468                 if (power < 0) {
 469                         spin_unlock_bh(&dn_fib_multipath_lock);
 470                         res->nh_sel = 0;
 471                         return;
 472                 }
 473         }
 474
 475         w = jiffies % fi->fib_power;
 476
 477         change_nexthops(fi) {
 478                 if (!(nh->nh_flags&RTNH_F_DEAD) && nh->nh_power) {
 479                         if ((w -= nh->nh_power) <= 0) {
 480                                 nh->nh_power--;
 481                                 fi->fib_power--;
 482                                 res->nh_sel = nhsel;
 483                                 spin_unlock_bh(&dn_fib_multipath_lock);
 484                                 return;
 485                         }
 486                 }
 487         } endfor_nexthops(fi);
 488         res->nh_sel = 0;
 489         spin_unlock_bh(&dn_fib_multipath_lock);
 490 }
 491
 492 static inline u32 rtm_get_table(struct nlattr *attrs[], u8 table)
 493 {
 494         if (attrs[RTA_TABLE])
 495                 table = nla_get_u32(attrs[RTA_TABLE]);
 496
 497         return table;
 498 }
 499
 500 static int dn_fib_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
 501 {
 502         struct net *net = sock_net(skb->sk);
 503         struct dn_fib_table *tb;
 504         struct rtmsg *r = nlmsg_data(nlh);
 505         struct nlattr *attrs[RTA_MAX+1];
 506         int err;
 507
 508         if (!capable(CAP_NET_ADMIN))
 509                 return -EPERM;
 510
 511         if (!net_eq(net, &init_net))
 512                 return -EINVAL;
 513
 514         err = nlmsg_parse(nlh, sizeof(*r), attrs, RTA_MAX, rtm_dn_policy);
 515         if (err < 0)
 516                 return err;
 517
 518         tb = dn_fib_get_table(rtm_get_table(attrs, r->rtm_table), 0);
 519         if (!tb)
 520                 return -ESRCH;
 521
 522         return tb->delete(tb, r, attrs, nlh, &NETLINK_CB(skb));
 523 }
 524
 525 static int dn_fib_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
 526 {
 527         struct net *net = sock_net(skb->sk);
 528         struct dn_fib_table *tb;
 529         struct rtmsg *r = nlmsg_data(nlh);
 530         struct nlattr *attrs[RTA_MAX+1];
 531         int err;
 532
 533         if (!capable(CAP_NET_ADMIN))
 534                 return -EPERM;
 535
 536         if (!net_eq(net, &init_net))
 537                 return -EINVAL;
 538
 539         err = nlmsg_parse(nlh, sizeof(*r), attrs, RTA_MAX, rtm_dn_policy);
 540         if (err < 0)
 541                 return err;
 542
 543         tb = dn_fib_get_table(rtm_get_table(attrs, r->rtm_table), 1);
 544         if (!tb)
 545                 return -ENOBUFS;
 546
 547         return tb->insert(tb, r, attrs, nlh, &NETLINK_CB(skb));
 548 }
 549
 550 static void fib_magic(int cmd, int type, __le16 dst, int dst_len, struct dn_ifaddr *ifa)
 551 {
 552         struct dn_fib_table *tb;
 553         struct {
 554                 struct nlmsghdr nlh;
 555                 struct rtmsg rtm;
 556         } req;
 557         struct {
 558                 struct nlattr hdr;
 559                 __le16 dst;
 560         } dst_attr = {
 561                 .dst = dst,
 562         };
 563         struct {
 564                 struct nlattr hdr;
 565                 __le16 prefsrc;
 566         } prefsrc_attr = {
 567                 .prefsrc = ifa->ifa_local,
 568         };
 569         struct {
 570                 struct nlattr hdr;
 571                 u32 oif;
 572         } oif_attr = {
 573                 .oif = ifa->ifa_dev->dev->ifindex,
 574         };
 575         struct nlattr *attrs[RTA_MAX+1] = {
 576                 [RTA_DST] = (struct nlattr *) &dst_attr,
 577                 [RTA_PREFSRC] = (struct nlattr * ) &prefsrc_attr,
 578                 [RTA_OIF] = (struct nlattr *) &oif_attr,
 579         };
 580
 581         memset(&req.rtm, 0, sizeof(req.rtm));
 582
 583         if (type == RTN_UNICAST)
 584                 tb = dn_fib_get_table(RT_MIN_TABLE, 1);
 585         else
 586                 tb = dn_fib_get_table(RT_TABLE_LOCAL, 1);
 587
 588         if (tb == NULL)
 589                 return;
 590
 591         req.nlh.nlmsg_len = sizeof(req);
 592         req.nlh.nlmsg_type = cmd;
 593         req.nlh.nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE|NLM_F_APPEND;
 594         req.nlh.nlmsg_pid = 0;
 595         req.nlh.nlmsg_seq = 0;
 596
 597         req.rtm.rtm_dst_len = dst_len;
 598         req.rtm.rtm_table = tb->n;
 599         req.rtm.rtm_protocol = RTPROT_KERNEL;
 600         req.rtm.rtm_scope = (type != RTN_LOCAL ? RT_SCOPE_LINK : RT_SCOPE_HOST);
 601         req.rtm.rtm_type = type;
 602
 603         if (cmd == RTM_NEWROUTE)
 604                 tb->insert(tb, &req.rtm, attrs, &req.nlh, NULL);
 605         else
 606                 tb->delete(tb, &req.rtm, attrs, &req.nlh, NULL);
 607 }
 608
 609 static void dn_fib_add_ifaddr(struct dn_ifaddr *ifa)
 610 {
 611
 612         fib_magic(RTM_NEWROUTE, RTN_LOCAL, ifa->ifa_local, 16, ifa);
 613
 614 #if 0
 615         if (!(dev->flags&IFF_UP))
 616                 return;
 617         /* In the future, we will want to add default routes here */
 618
 619 #endif
 620 }
 621
 622 static void dn_fib_del_ifaddr(struct dn_ifaddr *ifa)
 623 {
 624         int found_it = 0;
 625         struct net_device *dev;
 626         struct dn_dev *dn_db;
 627         struct dn_ifaddr *ifa2;
 628
 629         ASSERT_RTNL();
 630
 631         /* Scan device list */
 632         rcu_read_lock();
 633         for_each_netdev_rcu(&init_net, dev) {
 634                 dn_db = rcu_dereference(dev->dn_ptr);
 635                 if (dn_db == NULL)
 636                         continue;
 637                 for (ifa2 = rcu_dereference(dn_db->ifa_list);
 638                      ifa2 != NULL;
 639                      ifa2 = rcu_dereference(ifa2->ifa_next)) {
 640                         if (ifa2->ifa_local == ifa->ifa_local) {
 641                                 found_it = 1;
 642                                 break;
 643                         }
 644                 }
 645         }
 646         rcu_read_unlock();
 647
 648         if (found_it == 0) {
 649                 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 16, ifa);
 650
 651                 if (dnet_addr_type(ifa->ifa_local) != RTN_LOCAL) {
 652                         if (dn_fib_sync_down(ifa->ifa_local, NULL, 0))
 653                                 dn_fib_flush();
 654                 }
 655         }
 656 }
 657
 658 static void dn_fib_disable_addr(struct net_device *dev, int force)
 659 {
 660         if (dn_fib_sync_down(0, dev, force))
 661                 dn_fib_flush();
 662         dn_rt_cache_flush(0);
 663         neigh_ifdown(&dn_neigh_table, dev);
 664 }
 665
 666 static int dn_fib_dnaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
 667 {
 668         struct dn_ifaddr *ifa = (struct dn_ifaddr *)ptr;
 669
 670         switch (event) {
 671         case NETDEV_UP:
 672                 dn_fib_add_ifaddr(ifa);
 673                 dn_fib_sync_up(ifa->ifa_dev->dev);
 674                 dn_rt_cache_flush(-1);
 675                 break;
 676         case NETDEV_DOWN:
 677                 dn_fib_del_ifaddr(ifa);
 678                 if (ifa->ifa_dev && ifa->ifa_dev->ifa_list == NULL) {
 679                         dn_fib_disable_addr(ifa->ifa_dev->dev, 1);
 680                 } else {
 681                         dn_rt_cache_flush(-1);
 682                 }
 683                 break;
 684         }
 685         return NOTIFY_DONE;
 686 }
 687
 688 static int dn_fib_sync_down(__le16 local, struct net_device *dev, int force)
 689 {
 690         int ret = 0;
 691         int scope = RT_SCOPE_NOWHERE;
 692
 693         if (force)
 694                 scope = -1;
 695
 696         for_fib_info() {
 697                 /*
 698                  * This makes no sense for DECnet.... we will almost
 699                  * certainly have more than one local address the same
 700                  * over all our interfaces. It needs thinking about
 701                  * some more.
 702                  */
 703                 if (local && fi->fib_prefsrc == local) {
 704                         fi->fib_flags |= RTNH_F_DEAD;
 705                         ret++;
 706                 } else if (dev && fi->fib_nhs) {
 707                         int dead = 0;
 708
 709                         change_nexthops(fi) {
 710                                 if (nh->nh_flags&RTNH_F_DEAD)
 711                                         dead++;
 712                                 else if (nh->nh_dev == dev &&
 713                                                 nh->nh_scope != scope) {
 714                                         spin_lock_bh(&dn_fib_multipath_lock);
 715                                         nh->nh_flags |= RTNH_F_DEAD;
 716                                         fi->fib_power -= nh->nh_power;
 717                                         nh->nh_power = 0;
 718                                         spin_unlock_bh(&dn_fib_multipath_lock);
 719                                         dead++;
 720                                 }
 721                         } endfor_nexthops(fi)
 722                         if (dead == fi->fib_nhs) {
 723                                 fi->fib_flags |= RTNH_F_DEAD;
 724                                 ret++;
 725                         }
 726                 }
 727         } endfor_fib_info();
 728         return ret;
 729 }
 730
 731
 732 static int dn_fib_sync_up(struct net_device *dev)
 733 {
 734         int ret = 0;
 735
 736         if (!(dev->flags&IFF_UP))
 737                 return 0;
 738
 739         for_fib_info() {
 740                 int alive = 0;
 741
 742                 change_nexthops(fi) {
 743                         if (!(nh->nh_flags&RTNH_F_DEAD)) {
 744                                 alive++;
 745                                 continue;
 746                         }
 747                         if (nh->nh_dev == NULL || !(nh->nh_dev->flags&IFF_UP))
 748                                 continue;
 749                         if (nh->nh_dev != dev || dev->dn_ptr == NULL)
 750                                 continue;
 751                         alive++;
 752                         spin_lock_bh(&dn_fib_multipath_lock);
 753                         nh->nh_power = 0;
 754                         nh->nh_flags &= ~RTNH_F_DEAD;
 755                         spin_unlock_bh(&dn_fib_multipath_lock);
 756                 } endfor_nexthops(fi);
 757
 758                 if (alive > 0) {
 759                         fi->fib_flags &= ~RTNH_F_DEAD;
 760                         ret++;
 761                 }
 762         } endfor_fib_info();
 763         return ret;
 764 }
 765
 766 static struct notifier_block dn_fib_dnaddr_notifier = {
 767         .notifier_call = dn_fib_dnaddr_event,
 768 };
 769
 770 void __exit dn_fib_cleanup(void)
 771 {
 772         dn_fib_table_cleanup();
 773         dn_fib_rules_cleanup();
 774
 775         unregister_dnaddr_notifier(&dn_fib_dnaddr_notifier);
 776 }
 777
 778
 779 void __init dn_fib_init(void)
 780 {
 781         dn_fib_table_init();
 782         dn_fib_rules_init();
 783
 784         register_dnaddr_notifier(&dn_fib_dnaddr_notifier);
 785
 786         rtnl_register(PF_DECnet, RTM_NEWROUTE, dn_fib_rtm_newroute, NULL, NULL);
 787         rtnl_register(PF_DECnet, RTM_DELROUTE, dn_fib_rtm_delroute, NULL, NULL);
 788 }
 789
 790