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