net/decnet/dn_fib.c

   1 // SPDX-License-Identifier: GPL-2.0
   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 Forwarding Information Base (Glue/Info List)
   8  *
   9  * Author:      Steve Whitehouse <SteveW@ACM.org>
  10  *
  11  *
  12  * Changes:
  13  *              Alexey Kuznetsov : SMP locking changes
  14  *              Steve Whitehouse : Rewrote it... Well to be more correct, I
  15  *                                 copied most of it from the ipv4 fib code.
  16  *              Steve Whitehouse : Updated it in style and fixed a few bugs
  17  *                                 which were fixed in the ipv4 code since
  18  *                                 this code was copied from it.
  19  *
  20  */
  21 #include <linux/string.h>
  22 #include <linux/net.h>
  23 #include <linux/socket.h>
  24 #include <linux/slab.h>
  25 #include <linux/sockios.h>
  26 #include <linux/init.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/netlink.h>
  29 #include <linux/rtnetlink.h>
  30 #include <linux/proc_fs.h>
  31 #include <linux/netdevice.h>
  32 #include <linux/timer.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/atomic.h>
  35 #include <linux/uaccess.h>
  36 #include <net/neighbour.h>
  37 #include <net/dst.h>
  38 #include <net/flow.h>
  39 #include <net/fib_rules.h>
  40 #include <net/dn.h>
  41 #include <net/dn_route.h>
  42 #include <net/dn_fib.h>
  43 #include <net/dn_neigh.h>
  44 #include <net/dn_dev.h>
  45 #include <net/nexthop.h>
  46
  47 #define RT_MIN_TABLE 1
  48
  49 #define for_fib_info() { struct dn_fib_info *fi;\
  50         for(fi = dn_fib_info_list; fi; fi = fi->fib_next)
  51 #define endfor_fib_info() }
  52
  53 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
  54         for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
  55
  56 #define change_nexthops(fi) { int nhsel; struct dn_fib_nh *nh;\
  57         for(nhsel = 0, nh = (struct dn_fib_nh *)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nh++, nhsel++)
  58
  59 #define endfor_nexthops(fi) }
  60
  61 static DEFINE_SPINLOCK(dn_fib_multipath_lock);
  62 static struct dn_fib_info *dn_fib_info_list;
  63 static DEFINE_SPINLOCK(dn_fib_info_lock);
  64
  65 static struct
  66 {
  67         int error;
  68         u8 scope;
  69 } dn_fib_props[RTN_MAX+1] = {
  70         [RTN_UNSPEC] =      { .error = 0,       .scope = RT_SCOPE_NOWHERE },
  71         [RTN_UNICAST] =     { .error = 0,       .scope = RT_SCOPE_UNIVERSE },
  72         [RTN_LOCAL] =       { .error = 0,       .scope = RT_SCOPE_HOST },
  73         [RTN_BROADCAST] =   { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
  74         [RTN_ANYCAST] =     { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
  75         [RTN_MULTICAST] =   { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
  76         [RTN_BLACKHOLE] =   { .error = -EINVAL, .scope = RT_SCOPE_UNIVERSE },
  77         [RTN_UNREACHABLE] = { .error = -EHOSTUNREACH, .scope = RT_SCOPE_UNIVERSE },
  78         [RTN_PROHIBIT] =    { .error = -EACCES, .scope = RT_SCOPE_UNIVERSE },
  79         [RTN_THROW] =       { .error = -EAGAIN, .scope = RT_SCOPE_UNIVERSE },
  80         [RTN_NAT] =         { .error = 0,       .scope = RT_SCOPE_NOWHERE },
  81         [RTN_XRESOLVE] =    { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
  82 };
  83
  84 static int dn_fib_sync_down(__le16 local, struct net_device *dev, int force);
  85 static int dn_fib_sync_up(struct net_device *dev);
  86
  87 void dn_fib_free_info(struct dn_fib_info *fi)
  88 {
  89         if (fi->fib_dead == 0) {
  90                 printk(KERN_DEBUG "DECnet: BUG! Attempt to free alive dn_fib_info\n");
  91                 return;
  92         }
  93
  94         change_nexthops(fi) {
  95                 if (nh->nh_dev)
  96                         dev_put(nh->nh_dev);
  97                 nh->nh_dev = NULL;
  98         } endfor_nexthops(fi);
  99         kfree(fi);
 100 }
 101
 102 void dn_fib_release_info(struct dn_fib_info *fi)
 103 {
 104         spin_lock(&dn_fib_info_lock);
 105         if (fi && --fi->fib_treeref == 0) {
 106                 if (fi->fib_next)
 107                         fi->fib_next->fib_prev = fi->fib_prev;
 108                 if (fi->fib_prev)
 109                         fi->fib_prev->fib_next = fi->fib_next;
 110                 if (fi == dn_fib_info_list)
 111                         dn_fib_info_list = fi->fib_next;
 112                 fi->fib_dead = 1;
 113                 dn_fib_info_put(fi);
 114         }
 115         spin_unlock(&dn_fib_info_lock);
 116 }
 117
 118 static inline int dn_fib_nh_comp(const struct dn_fib_info *fi, const struct dn_fib_info *ofi)
 119 {
 120         const struct dn_fib_nh *onh = ofi->fib_nh;
 121
 122         for_nexthops(fi) {
 123                 if (nh->nh_oif != onh->nh_oif ||
 124                         nh->nh_gw != onh->nh_gw ||
 125                         nh->nh_scope != onh->nh_scope ||
 126                         nh->nh_weight != onh->nh_weight ||
 127                         ((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD))
 128                                 return -1;
 129                 onh++;
 130         } endfor_nexthops(fi);
 131         return 0;
 132 }
 133
 134 static inline struct dn_fib_info *dn_fib_find_info(const struct dn_fib_info *nfi)
 135 {
 136         for_fib_info() {
 137                 if (fi->fib_nhs != nfi->fib_nhs)
 138                         continue;
 139                 if (nfi->fib_protocol == fi->fib_protocol &&
 140                         nfi->fib_prefsrc == fi->fib_prefsrc &&
 141                         nfi->fib_priority == fi->fib_priority &&
 142                         memcmp(nfi->fib_metrics, fi->fib_metrics, sizeof(fi->fib_metrics)) == 0 &&
 143                         ((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 &&
 144                         (nfi->fib_nhs == 0 || dn_fib_nh_comp(fi, nfi) == 0))
 145                                 return fi;
 146         } endfor_fib_info();
 147         return NULL;
 148 }
 149
 150 static int dn_fib_count_nhs(const struct nlattr *attr)
 151 {
 152         struct rtnexthop *nhp = nla_data(attr);
 153         int nhs = 0, nhlen = nla_len(attr);
 154
 155         while (rtnh_ok(nhp, nhlen)) {
 156                 nhs++;
 157                 nhp = rtnh_next(nhp, &nhlen);
 158         }
 159
 160         /* leftover implies invalid nexthop configuration, discard it */
 161         return nhlen > 0 ? 0 : nhs;
 162 }
 163
 164 static int dn_fib_get_nhs(struct dn_fib_info *fi, const struct nlattr *attr,
 165                           const struct rtmsg *r)
 166 {
 167         struct rtnexthop *nhp = nla_data(attr);
 168         int nhlen = nla_len(attr);
 169
 170         change_nexthops(fi) {
 171                 int attrlen;
 172
 173                 if (!rtnh_ok(nhp, nhlen))
 174                         return -EINVAL;
 175
 176                 nh->nh_flags  = (r->rtm_flags&~0xFF) | nhp->rtnh_flags;
 177                 nh->nh_oif    = nhp->rtnh_ifindex;
 178                 nh->nh_weight = nhp->rtnh_hops + 1;
 179
 180                 attrlen = rtnh_attrlen(nhp);
 181                 if (attrlen > 0) {
 182                         struct nlattr *gw_attr;
 183
 184                         gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
 185                         nh->nh_gw = gw_attr ? nla_get_le16(gw_attr) : 0;
 186                 }
 187
 188                 nhp = rtnh_next(nhp, &nhlen);
 189         } endfor_nexthops(fi);
 190
 191         return 0;
 192 }
 193
 194
 195 static int dn_fib_check_nh(const struct rtmsg *r, struct dn_fib_info *fi, struct dn_fib_nh *nh)
 196 {
 197         int err;
 198
 199         if (nh->nh_gw) {
 200                 struct flowidn fld;
 201                 struct dn_fib_res res;
 202
 203                 if (nh->nh_flags&RTNH_F_ONLINK) {
 204                         struct net_device *dev;
 205
 206                         if (r->rtm_scope >= RT_SCOPE_LINK)
 207                                 return -EINVAL;
 208                         if (dnet_addr_type(nh->nh_gw) != RTN_UNICAST)
 209                                 return -EINVAL;
 210                         if ((dev = __dev_get_by_index(&init_net, nh->nh_oif)) == NULL)
 211                                 return -ENODEV;
 212                         if (!(dev->flags&IFF_UP))
 213                                 return -ENETDOWN;
 214                         nh->nh_dev = dev;
 215                         dev_hold(dev);
 216                         nh->nh_scope = RT_SCOPE_LINK;
 217                         return 0;
 218                 }
 219
 220                 memset(&fld, 0, sizeof(fld));
 221                 fld.daddr = nh->nh_gw;
 222                 fld.flowidn_oif = nh->nh_oif;
 223                 fld.flowidn_scope = r->rtm_scope + 1;
 224
 225                 if (fld.flowidn_scope < RT_SCOPE_LINK)
 226                         fld.flowidn_scope = RT_SCOPE_LINK;
 227
 228                 if ((err = dn_fib_lookup(&fld, &res)) != 0)
 229                         return err;
 230
 231                 err = -EINVAL;
 232                 if (res.type != RTN_UNICAST && res.type != RTN_LOCAL)
 233                         goto out;
 234                 nh->nh_scope = res.scope;
 235                 nh->nh_oif = DN_FIB_RES_OIF(res);
 236                 nh->nh_dev = DN_FIB_RES_DEV(res);
 237                 if (nh->nh_dev == NULL)
 238                         goto out;
 239                 dev_hold(nh->nh_dev);
 240                 err = -ENETDOWN;
 241                 if (!(nh->nh_dev->flags & IFF_UP))
 242                         goto out;
 243                 err = 0;
 244 out:
 245                 dn_fib_res_put(&res);
 246                 return err;
 247         } else {
 248                 struct net_device *dev;
 249
 250                 if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK))
 251                         return -EINVAL;
 252
 253                 dev = __dev_get_by_index(&init_net, nh->nh_oif);
 254                 if (dev == NULL || dev->dn_ptr == NULL)
 255                         return -ENODEV;
 256                 if (!(dev->flags&IFF_UP))
 257                         return -ENETDOWN;
 258                 nh->nh_dev = dev;
 259                 dev_hold(nh->nh_dev);
 260                 nh->nh_scope = RT_SCOPE_HOST;
 261         }
 262
 263         return 0;
 264 }
 265
 266
 267 struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r, struct nlattr *attrs[],
 268                                        const struct nlmsghdr *nlh, int *errp)
 269 {
 270         int err;
 271         struct dn_fib_info *fi = NULL;
 272         struct dn_fib_info *ofi;
 273         int nhs = 1;
 274
 275         if (r->rtm_type > RTN_MAX)
 276                 goto err_inval;
 277
 278         if (dn_fib_props[r->rtm_type].scope > r->rtm_scope)
 279                 goto err_inval;
 280
 281         if (attrs[RTA_MULTIPATH] &&
 282             (nhs = dn_fib_count_nhs(attrs[RTA_MULTIPATH])) == 0)
 283                 goto err_inval;
 284
 285         fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct dn_fib_nh), GFP_KERNEL);
 286         err = -ENOBUFS;
 287         if (fi == NULL)
 288                 goto failure;
 289
 290         fi->fib_protocol = r->rtm_protocol;
 291         fi->fib_nhs = nhs;
 292         fi->fib_flags = r->rtm_flags;
 293
 294         if (attrs[RTA_PRIORITY])
 295                 fi->fib_priority = nla_get_u32(attrs[RTA_PRIORITY]);
 296
 297         if (attrs[RTA_METRICS]) {
 298                 struct nlattr *attr;
 299                 int rem;
 300
 301                 nla_for_each_nested(attr, attrs[RTA_METRICS], rem) {
 302                         int type = nla_type(attr);
 303
 304                         if (type) {
 305                                 if (type > RTAX_MAX || type == RTAX_CC_ALGO ||
 306                                     nla_len(attr) < 4)
 307                                         goto err_inval;
 308
 309                                 fi->fib_metrics[type-1] = nla_get_u32(attr);
 310                         }
 311                 }
 312         }
 313
 314         if (attrs[RTA_PREFSRC])
 315                 fi->fib_prefsrc = nla_get_le16(attrs[RTA_PREFSRC]);
 316
 317         if (attrs[RTA_MULTIPATH]) {
 318                 if ((err = dn_fib_get_nhs(fi, attrs[RTA_MULTIPATH], r)) != 0)
 319                         goto failure;
 320
 321                 if (attrs[RTA_OIF] &&
 322                     fi->fib_nh->nh_oif != nla_get_u32(attrs[RTA_OIF]))
 323                         goto err_inval;
 324
 325                 if (attrs[RTA_GATEWAY] &&
 326                     fi->fib_nh->nh_gw != nla_get_le16(attrs[RTA_GATEWAY]))
 327                         goto err_inval;
 328         } else {
 329                 struct dn_fib_nh *nh = fi->fib_nh;
 330
 331                 if (attrs[RTA_OIF])
 332                         nh->nh_oif = nla_get_u32(attrs[RTA_OIF]);
 333
 334                 if (attrs[RTA_GATEWAY])
 335                         nh->nh_gw = nla_get_le16(attrs[RTA_GATEWAY]);
 336
 337                 nh->nh_flags = r->rtm_flags;
 338                 nh->nh_weight = 1;
 339         }
 340
 341         if (r->rtm_type == RTN_NAT) {
 342                 if (!attrs[RTA_GATEWAY] || nhs != 1 || attrs[RTA_OIF])
 343                         goto err_inval;
 344
 345                 fi->fib_nh->nh_gw = nla_get_le16(attrs[RTA_GATEWAY]);
 346                 goto link_it;
 347         }
 348
 349         if (dn_fib_props[r->rtm_type].error) {
 350                 if (attrs[RTA_GATEWAY] || attrs[RTA_OIF] || attrs[RTA_MULTIPATH])
 351                         goto err_inval;
 352
 353                 goto link_it;
 354         }
 355
 356         if (r->rtm_scope > RT_SCOPE_HOST)
 357                 goto err_inval;
 358
 359         if (r->rtm_scope == RT_SCOPE_HOST) {
 360                 struct dn_fib_nh *nh = fi->fib_nh;
 361
 362                 /* Local address is added */
 363                 if (nhs != 1 || nh->nh_gw)
 364                         goto err_inval;
 365                 nh->nh_scope = RT_SCOPE_NOWHERE;
 366                 nh->nh_dev = dev_get_by_index(&init_net, fi->fib_nh->nh_oif);
 367                 err = -ENODEV;
 368                 if (nh->nh_dev == NULL)
 369                         goto failure;
 370         } else {
 371                 change_nexthops(fi) {
 372                         if ((err = dn_fib_check_nh(r, fi, nh)) != 0)
 373                                 goto failure;
 374                 } endfor_nexthops(fi)
 375         }
 376
 377         if (fi->fib_prefsrc) {
 378                 if (r->rtm_type != RTN_LOCAL || !attrs[RTA_DST] ||
 379                     fi->fib_prefsrc != nla_get_le16(attrs[RTA_DST]))
 380                         if (dnet_addr_type(fi->fib_prefsrc) != RTN_LOCAL)
 381                                 goto err_inval;
 382         }
 383
 384 link_it:
 385         if ((ofi = dn_fib_find_info(fi)) != NULL) {
 386                 fi->fib_dead = 1;
 387                 dn_fib_free_info(fi);
 388                 ofi->fib_treeref++;
 389                 return ofi;
 390         }
 391
 392         fi->fib_treeref++;
 393         refcount_set(&fi->fib_clntref, 1);
 394         spin_lock(&dn_fib_info_lock);
 395         fi->fib_next = dn_fib_info_list;
 396         fi->fib_prev = NULL;
 397         if (dn_fib_info_list)
 398                 dn_fib_info_list->fib_prev = fi;
 399         dn_fib_info_list = fi;
 400         spin_unlock(&dn_fib_info_lock);
 401         return fi;
 402
 403 err_inval:
 404         err = -EINVAL;
 405
 406 failure:
 407         *errp = err;
 408         if (fi) {
 409                 fi->fib_dead = 1;
 410                 dn_fib_free_info(fi);
 411         }
 412
 413         return NULL;
 414 }
 415
 416 int dn_fib_semantic_match(int type, struct dn_fib_info *fi, const struct flowidn *fld, struct dn_fib_res *res)
 417 {
 418         int err = dn_fib_props[type].error;
 419
 420         if (err == 0) {
 421                 if (fi->fib_flags & RTNH_F_DEAD)
 422                         return 1;
 423
 424                 res->fi = fi;
 425
 426                 switch (type) {
 427                 case RTN_NAT:
 428                         DN_FIB_RES_RESET(*res);
 429                         refcount_inc(&fi->fib_clntref);
 430                         return 0;
 431                 case RTN_UNICAST:
 432                 case RTN_LOCAL:
 433                         for_nexthops(fi) {
 434                                 if (nh->nh_flags & RTNH_F_DEAD)
 435                                         continue;
 436                                 if (!fld->flowidn_oif ||
 437                                     fld->flowidn_oif == nh->nh_oif)
 438                                         break;
 439                         }
 440                         if (nhsel < fi->fib_nhs) {
 441                                 res->nh_sel = nhsel;
 442                                 refcount_inc(&fi->fib_clntref);
 443                                 return 0;
 444                         }
 445                         endfor_nexthops(fi);
 446                         res->fi = NULL;
 447                         return 1;
 448                 default:
 449                         net_err_ratelimited("DECnet: impossible routing event : dn_fib_semantic_match type=%d\n",
 450                                             type);
 451                         res->fi = NULL;
 452                         return -EINVAL;
 453                 }
 454         }
 455         return err;
 456 }
 457
 458 void dn_fib_select_multipath(const struct flowidn *fld, struct dn_fib_res *res)
 459 {
 460         struct dn_fib_info *fi = res->fi;
 461         int w;
 462
 463         spin_lock_bh(&dn_fib_multipath_lock);
 464         if (fi->fib_power <= 0) {
 465                 int power = 0;
 466                 change_nexthops(fi) {
 467                         if (!(nh->nh_flags&RTNH_F_DEAD)) {
 468                                 power += nh->nh_weight;
 469                                 nh->nh_power = nh->nh_weight;
 470                         }
 471                 } endfor_nexthops(fi);
 472                 fi->fib_power = power;
 473                 if (power < 0) {
 474                         spin_unlock_bh(&dn_fib_multipath_lock);
 475                         res->nh_sel = 0;
 476                         return;
 477                 }
 478         }
 479
 480         w = jiffies % fi->fib_power;
 481
 482         change_nexthops(fi) {
 483                 if (!(nh->nh_flags&RTNH_F_DEAD) && nh->nh_power) {
 484                         if ((w -= nh->nh_power) <= 0) {
 485                                 nh->nh_power--;
 486                                 fi->fib_power--;
 487                                 res->nh_sel = nhsel;
 488                                 spin_unlock_bh(&dn_fib_multipath_lock);
 489                                 return;
 490                         }
 491                 }
 492         } endfor_nexthops(fi);
 493         res->nh_sel = 0;
 494         spin_unlock_bh(&dn_fib_multipath_lock);
 495 }
 496
 497 static inline u32 rtm_get_table(struct nlattr *attrs[], u8 table)
 498 {
 499         if (attrs[RTA_TABLE])
 500                 table = nla_get_u32(attrs[RTA_TABLE]);
 501
 502         return table;
 503 }
 504
 505 static int dn_fib_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
 506                                struct netlink_ext_ack *extack)
 507 {
 508         struct net *net = sock_net(skb->sk);
 509         struct dn_fib_table *tb;
 510         struct rtmsg *r = nlmsg_data(nlh);
 511         struct nlattr *attrs[RTA_MAX+1];
 512         int err;
 513
 514         if (!netlink_capable(skb, CAP_NET_ADMIN))
 515                 return -EPERM;
 516
 517         if (!net_eq(net, &init_net))
 518                 return -EINVAL;
 519
 520         err = nlmsg_parse(nlh, sizeof(*r), attrs, RTA_MAX, rtm_dn_policy,
 521                           extack);
 522         if (err < 0)
 523                 return err;
 524
 525         tb = dn_fib_get_table(rtm_get_table(attrs, r->rtm_table), 0);
 526         if (!tb)
 527                 return -ESRCH;
 528
 529         return tb->delete(tb, r, attrs, nlh, &NETLINK_CB(skb));
 530 }
 531
 532 static int dn_fib_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
 533                                struct netlink_ext_ack *extack)
 534 {
 535         struct net *net = sock_net(skb->sk);
 536         struct dn_fib_table *tb;
 537         struct rtmsg *r = nlmsg_data(nlh);
 538         struct nlattr *attrs[RTA_MAX+1];
 539         int err;
 540
 541         if (!netlink_capable(skb, CAP_NET_ADMIN))
 542                 return -EPERM;
 543
 544         if (!net_eq(net, &init_net))
 545                 return -EINVAL;
 546
 547         err = nlmsg_parse(nlh, sizeof(*r), attrs, RTA_MAX, rtm_dn_policy,
 548                           extack);
 549         if (err < 0)
 550                 return err;
 551
 552         tb = dn_fib_get_table(rtm_get_table(attrs, r->rtm_table), 1);
 553         if (!tb)
 554                 return -ENOBUFS;
 555
 556         return tb->insert(tb, r, attrs, nlh, &NETLINK_CB(skb));
 557 }
 558
 559 static void fib_magic(int cmd, int type, __le16 dst, int dst_len, struct dn_ifaddr *ifa)
 560 {
 561         struct dn_fib_table *tb;
 562         struct {
 563                 struct nlmsghdr nlh;
 564                 struct rtmsg rtm;
 565         } req;
 566         struct {
 567                 struct nlattr hdr;
 568                 __le16 dst;
 569         } dst_attr = {
 570                 .dst = dst,
 571         };
 572         struct {
 573                 struct nlattr hdr;
 574                 __le16 prefsrc;
 575         } prefsrc_attr = {
 576                 .prefsrc = ifa->ifa_local,
 577         };
 578         struct {
 579                 struct nlattr hdr;
 580                 u32 oif;
 581         } oif_attr = {
 582                 .oif = ifa->ifa_dev->dev->ifindex,
 583         };
 584         struct nlattr *attrs[RTA_MAX+1] = {
 585                 [RTA_DST] = (struct nlattr *) &dst_attr,
 586                 [RTA_PREFSRC] = (struct nlattr * ) &prefsrc_attr,
 587                 [RTA_OIF] = (struct nlattr *) &oif_attr,
 588         };
 589
 590         memset(&req.rtm, 0, sizeof(req.rtm));
 591
 592         if (type == RTN_UNICAST)
 593                 tb = dn_fib_get_table(RT_MIN_TABLE, 1);
 594         else
 595                 tb = dn_fib_get_table(RT_TABLE_LOCAL, 1);
 596
 597         if (tb == NULL)
 598                 return;
 599
 600         req.nlh.nlmsg_len = sizeof(req);
 601         req.nlh.nlmsg_type = cmd;
 602         req.nlh.nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE|NLM_F_APPEND;
 603         req.nlh.nlmsg_pid = 0;
 604         req.nlh.nlmsg_seq = 0;
 605
 606         req.rtm.rtm_dst_len = dst_len;
 607         req.rtm.rtm_table = tb->n;
 608         req.rtm.rtm_protocol = RTPROT_KERNEL;
 609         req.rtm.rtm_scope = (type != RTN_LOCAL ? RT_SCOPE_LINK : RT_SCOPE_HOST);
 610         req.rtm.rtm_type = type;
 611
 612         if (cmd == RTM_NEWROUTE)
 613                 tb->insert(tb, &req.rtm, attrs, &req.nlh, NULL);
 614         else
 615                 tb->delete(tb, &req.rtm, attrs, &req.nlh, NULL);
 616 }
 617
 618 static void dn_fib_add_ifaddr(struct dn_ifaddr *ifa)
 619 {
 620
 621         fib_magic(RTM_NEWROUTE, RTN_LOCAL, ifa->ifa_local, 16, ifa);
 622
 623 #if 0
 624         if (!(dev->flags&IFF_UP))
 625                 return;
 626         /* In the future, we will want to add default routes here */
 627
 628 #endif
 629 }
 630
 631 static void dn_fib_del_ifaddr(struct dn_ifaddr *ifa)
 632 {
 633         int found_it = 0;
 634         struct net_device *dev;
 635         struct dn_dev *dn_db;
 636         struct dn_ifaddr *ifa2;
 637
 638         ASSERT_RTNL();
 639
 640         /* Scan device list */
 641         rcu_read_lock();
 642         for_each_netdev_rcu(&init_net, dev) {
 643                 dn_db = rcu_dereference(dev->dn_ptr);
 644                 if (dn_db == NULL)
 645                         continue;
 646                 for (ifa2 = rcu_dereference(dn_db->ifa_list);
 647                      ifa2 != NULL;
 648                      ifa2 = rcu_dereference(ifa2->ifa_next)) {
 649                         if (ifa2->ifa_local == ifa->ifa_local) {
 650                                 found_it = 1;
 651                                 break;
 652                         }
 653                 }
 654         }
 655         rcu_read_unlock();
 656
 657         if (found_it == 0) {
 658                 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 16, ifa);
 659
 660                 if (dnet_addr_type(ifa->ifa_local) != RTN_LOCAL) {
 661                         if (dn_fib_sync_down(ifa->ifa_local, NULL, 0))
 662                                 dn_fib_flush();
 663                 }
 664         }
 665 }
 666
 667 static void dn_fib_disable_addr(struct net_device *dev, int force)
 668 {
 669         if (dn_fib_sync_down(0, dev, force))
 670                 dn_fib_flush();
 671         dn_rt_cache_flush(0);
 672         neigh_ifdown(&dn_neigh_table, dev);
 673 }
 674
 675 static int dn_fib_dnaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
 676 {
 677         struct dn_ifaddr *ifa = (struct dn_ifaddr *)ptr;
 678
 679         switch (event) {
 680         case NETDEV_UP:
 681                 dn_fib_add_ifaddr(ifa);
 682                 dn_fib_sync_up(ifa->ifa_dev->dev);
 683                 dn_rt_cache_flush(-1);
 684                 break;
 685         case NETDEV_DOWN:
 686                 dn_fib_del_ifaddr(ifa);
 687                 if (ifa->ifa_dev && ifa->ifa_dev->ifa_list == NULL) {
 688                         dn_fib_disable_addr(ifa->ifa_dev->dev, 1);
 689                 } else {
 690                         dn_rt_cache_flush(-1);
 691                 }
 692                 break;
 693         }
 694         return NOTIFY_DONE;
 695 }
 696
 697 static int dn_fib_sync_down(__le16 local, struct net_device *dev, int force)
 698 {
 699         int ret = 0;
 700         int scope = RT_SCOPE_NOWHERE;
 701
 702         if (force)
 703                 scope = -1;
 704
 705         for_fib_info() {
 706                 /*
 707                  * This makes no sense for DECnet.... we will almost
 708                  * certainly have more than one local address the same
 709                  * over all our interfaces. It needs thinking about
 710                  * some more.
 711                  */
 712                 if (local && fi->fib_prefsrc == local) {
 713                         fi->fib_flags |= RTNH_F_DEAD;
 714                         ret++;
 715                 } else if (dev && fi->fib_nhs) {
 716                         int dead = 0;
 717
 718                         change_nexthops(fi) {
 719                                 if (nh->nh_flags&RTNH_F_DEAD)
 720                                         dead++;
 721                                 else if (nh->nh_dev == dev &&
 722                                                 nh->nh_scope != scope) {
 723                                         spin_lock_bh(&dn_fib_multipath_lock);
 724                                         nh->nh_flags |= RTNH_F_DEAD;
 725                                         fi->fib_power -= nh->nh_power;
 726                                         nh->nh_power = 0;
 727                                         spin_unlock_bh(&dn_fib_multipath_lock);
 728                                         dead++;
 729                                 }
 730                         } endfor_nexthops(fi)
 731                         if (dead == fi->fib_nhs) {
 732                                 fi->fib_flags |= RTNH_F_DEAD;
 733                                 ret++;
 734                         }
 735                 }
 736         } endfor_fib_info();
 737         return ret;
 738 }
 739
 740
 741 static int dn_fib_sync_up(struct net_device *dev)
 742 {
 743         int ret = 0;
 744
 745         if (!(dev->flags&IFF_UP))
 746                 return 0;
 747
 748         for_fib_info() {
 749                 int alive = 0;
 750
 751                 change_nexthops(fi) {
 752                         if (!(nh->nh_flags&RTNH_F_DEAD)) {
 753                                 alive++;
 754                                 continue;
 755                         }
 756                         if (nh->nh_dev == NULL || !(nh->nh_dev->flags&IFF_UP))
 757                                 continue;
 758                         if (nh->nh_dev != dev || dev->dn_ptr == NULL)
 759                                 continue;
 760                         alive++;
 761                         spin_lock_bh(&dn_fib_multipath_lock);
 762                         nh->nh_power = 0;
 763                         nh->nh_flags &= ~RTNH_F_DEAD;
 764                         spin_unlock_bh(&dn_fib_multipath_lock);
 765                 } endfor_nexthops(fi);
 766
 767                 if (alive > 0) {
 768                         fi->fib_flags &= ~RTNH_F_DEAD;
 769                         ret++;
 770                 }
 771         } endfor_fib_info();
 772         return ret;
 773 }
 774
 775 static struct notifier_block dn_fib_dnaddr_notifier = {
 776         .notifier_call = dn_fib_dnaddr_event,
 777 };
 778
 779 void __exit dn_fib_cleanup(void)
 780 {
 781         dn_fib_table_cleanup();
 782         dn_fib_rules_cleanup();
 783
 784         unregister_dnaddr_notifier(&dn_fib_dnaddr_notifier);
 785 }
 786
 787
 788 void __init dn_fib_init(void)
 789 {
 790         dn_fib_table_init();
 791         dn_fib_rules_init();
 792
 793         register_dnaddr_notifier(&dn_fib_dnaddr_notifier);
 794
 795         rtnl_register(PF_DECnet, RTM_NEWROUTE, dn_fib_rtm_newroute, NULL, 0);
 796         rtnl_register(PF_DECnet, RTM_DELROUTE, dn_fib_rtm_delroute, NULL, 0);
 797 }
 798
 799