nhrpd/nhrp_cache.c

   1 /* NHRP cache
   2  * Copyright (c) 2014-2015 Timo Teräs
   3  *
   4  * This file is free software: you may copy, redistribute and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  */
   9
  10 #include "zebra.h"
  11 #include "memory.h"
  12 #include "thread.h"
  13 #include "hash.h"
  14 #include "nhrpd.h"
  15
  16 #include "netlink.h"
  17
  18 DEFINE_MTYPE_STATIC(NHRPD, NHRP_CACHE, "NHRP cache entry")
  19
  20 unsigned long nhrp_cache_counts[NHRP_CACHE_NUM_TYPES];
  21
  22 const char *const nhrp_cache_type_str[] = {
  23                 [NHRP_CACHE_INVALID] = "invalid",
  24                 [NHRP_CACHE_INCOMPLETE] = "incomplete",
  25                 [NHRP_CACHE_NEGATIVE] = "negative",
  26                 [NHRP_CACHE_CACHED] = "cached",
  27                 [NHRP_CACHE_DYNAMIC] = "dynamic",
  28                 [NHRP_CACHE_NHS] = "nhs",
  29                 [NHRP_CACHE_STATIC] = "static",
  30                 [NHRP_CACHE_LOCAL] = "local",
  31 };
  32
  33 static unsigned int nhrp_cache_protocol_key(void *peer_data)
  34 {
  35         struct nhrp_cache *p = peer_data;
  36         return sockunion_hash(&p->remote_addr);
  37 }
  38
  39 static bool nhrp_cache_protocol_cmp(const void *cache_data,
  40                                     const void *key_data)
  41 {
  42         const struct nhrp_cache *a = cache_data;
  43         const struct nhrp_cache *b = key_data;
  44
  45         return sockunion_same(&a->remote_addr, &b->remote_addr);
  46 }
  47
  48 static void *nhrp_cache_alloc(void *data)
  49 {
  50         struct nhrp_cache *p, *key = data;
  51
  52         p = XMALLOC(MTYPE_NHRP_CACHE, sizeof(struct nhrp_cache));
  53
  54         *p = (struct nhrp_cache){
  55                 .cur.type = NHRP_CACHE_INVALID,
  56                 .new.type = NHRP_CACHE_INVALID,
  57                 .remote_addr = key->remote_addr,
  58                 .ifp = key->ifp,
  59                 .notifier_list =
  60                 NOTIFIER_LIST_INITIALIZER(&p->notifier_list),
  61         };
  62         nhrp_cache_counts[p->cur.type]++;
  63
  64         return p;
  65 }
  66
  67 static void nhrp_cache_free(struct nhrp_cache *c)
  68 {
  69         struct nhrp_interface *nifp = c->ifp->info;
  70
  71         zassert(c->cur.type == NHRP_CACHE_INVALID && c->cur.peer == NULL);
  72         zassert(c->new.type == NHRP_CACHE_INVALID && c->new.peer == NULL);
  73         nhrp_cache_counts[c->cur.type]--;
  74         notifier_call(&c->notifier_list, NOTIFY_CACHE_DELETE);
  75         zassert(!notifier_active(&c->notifier_list));
  76         hash_release(nifp->cache_hash, c);
  77         XFREE(MTYPE_NHRP_CACHE, c);
  78 }
  79
  80 struct nhrp_cache *nhrp_cache_get(struct interface *ifp,
  81                                   union sockunion *remote_addr, int create)
  82 {
  83         struct nhrp_interface *nifp = ifp->info;
  84         struct nhrp_cache key;
  85
  86         if (!nifp->cache_hash) {
  87                 nifp->cache_hash =
  88                         hash_create(nhrp_cache_protocol_key,
  89                                     nhrp_cache_protocol_cmp, "NHRP Cache");
  90                 if (!nifp->cache_hash)
  91                         return NULL;
  92         }
  93
  94         key.remote_addr = *remote_addr;
  95         key.ifp = ifp;
  96
  97         return hash_get(nifp->cache_hash, &key,
  98                         create ? nhrp_cache_alloc : NULL);
  99 }
 100
 101 static int nhrp_cache_do_free(struct thread *t)
 102 {
 103         struct nhrp_cache *c = THREAD_ARG(t);
 104         c->t_timeout = NULL;
 105         nhrp_cache_free(c);
 106         return 0;
 107 }
 108
 109 static int nhrp_cache_do_timeout(struct thread *t)
 110 {
 111         struct nhrp_cache *c = THREAD_ARG(t);
 112         c->t_timeout = NULL;
 113         if (c->cur.type != NHRP_CACHE_INVALID)
 114                 nhrp_cache_update_binding(c, c->cur.type, -1, NULL, 0, NULL);
 115         return 0;
 116 }
 117
 118 static void nhrp_cache_update_route(struct nhrp_cache *c)
 119 {
 120         struct prefix pfx;
 121         struct nhrp_peer *p = c->cur.peer;
 122
 123         sockunion2hostprefix(&c->remote_addr, &pfx);
 124
 125         if (p && nhrp_peer_check(p, 1)) {
 126                 netlink_update_binding(p->ifp, &c->remote_addr,
 127                                        &p->vc->remote.nbma);
 128                 nhrp_route_announce(1, c->cur.type, &pfx, c->ifp, NULL,
 129                                     c->cur.mtu);
 130                 if (c->cur.type >= NHRP_CACHE_DYNAMIC) {
 131                         nhrp_route_update_nhrp(&pfx, c->ifp);
 132                         c->nhrp_route_installed = 1;
 133                 } else if (c->nhrp_route_installed) {
 134                         nhrp_route_update_nhrp(&pfx, NULL);
 135                         c->nhrp_route_installed = 0;
 136                 }
 137                 if (!c->route_installed) {
 138                         notifier_call(&c->notifier_list, NOTIFY_CACHE_UP);
 139                         c->route_installed = 1;
 140                 }
 141         } else {
 142                 if (c->nhrp_route_installed) {
 143                         nhrp_route_update_nhrp(&pfx, NULL);
 144                         c->nhrp_route_installed = 0;
 145                 }
 146                 if (c->route_installed) {
 147                         sockunion2hostprefix(&c->remote_addr, &pfx);
 148                         notifier_call(&c->notifier_list, NOTIFY_CACHE_DOWN);
 149                         nhrp_route_announce(0, c->cur.type, &pfx, NULL, NULL,
 150                                             0);
 151                         c->route_installed = 0;
 152                 }
 153         }
 154 }
 155
 156 static void nhrp_cache_peer_notifier(struct notifier_block *n,
 157                                      unsigned long cmd)
 158 {
 159         struct nhrp_cache *c =
 160                 container_of(n, struct nhrp_cache, peer_notifier);
 161
 162         switch (cmd) {
 163         case NOTIFY_PEER_UP:
 164                 nhrp_cache_update_route(c);
 165                 break;
 166         case NOTIFY_PEER_DOWN:
 167         case NOTIFY_PEER_IFCONFIG_CHANGED:
 168                 notifier_call(&c->notifier_list, NOTIFY_CACHE_DOWN);
 169                 nhrp_cache_update_binding(c, c->cur.type, -1, NULL, 0, NULL);
 170                 break;
 171         case NOTIFY_PEER_NBMA_CHANGING:
 172                 if (c->cur.type == NHRP_CACHE_DYNAMIC)
 173                         c->cur.peer->vc->abort_migration = 1;
 174                 break;
 175         }
 176 }
 177
 178 static void nhrp_cache_reset_new(struct nhrp_cache *c)
 179 {
 180         THREAD_OFF(c->t_auth);
 181         if (list_hashed(&c->newpeer_notifier.notifier_entry))
 182                 nhrp_peer_notify_del(c->new.peer, &c->newpeer_notifier);
 183         nhrp_peer_unref(c->new.peer);
 184         memset(&c->new, 0, sizeof(c->new));
 185         c->new.type = NHRP_CACHE_INVALID;
 186 }
 187
 188 static void nhrp_cache_update_timers(struct nhrp_cache *c)
 189 {
 190         THREAD_OFF(c->t_timeout);
 191
 192         switch (c->cur.type) {
 193         case NHRP_CACHE_INVALID:
 194                 if (!c->t_auth)
 195                         thread_add_timer_msec(master, nhrp_cache_do_free, c, 10,
 196                                               &c->t_timeout);
 197                 break;
 198         default:
 199                 if (c->cur.expires)
 200                         thread_add_timer(master, nhrp_cache_do_timeout, c,
 201                                          c->cur.expires - monotime(NULL),
 202                                          &c->t_timeout);
 203                 break;
 204         }
 205 }
 206
 207 static void nhrp_cache_authorize_binding(struct nhrp_reqid *r, void *arg)
 208 {
 209         struct nhrp_cache *c = container_of(r, struct nhrp_cache, eventid);
 210         char buf[SU_ADDRSTRLEN];
 211
 212         debugf(NHRP_DEBUG_COMMON, "cache: %s %s: %s", c->ifp->name,
 213                sockunion2str(&c->remote_addr, buf, sizeof buf),
 214                (const char *)arg);
 215
 216         nhrp_reqid_free(&nhrp_event_reqid, r);
 217
 218         if (arg && strcmp(arg, "accept") == 0) {
 219                 if (c->cur.peer) {
 220                         netlink_update_binding(c->cur.peer->ifp,
 221                                                &c->remote_addr, NULL);
 222                         nhrp_peer_notify_del(c->cur.peer, &c->peer_notifier);
 223                         nhrp_peer_unref(c->cur.peer);
 224                 }
 225                 nhrp_cache_counts[c->cur.type]--;
 226                 nhrp_cache_counts[c->new.type]++;
 227                 c->cur = c->new;
 228                 c->cur.peer = nhrp_peer_ref(c->cur.peer);
 229                 nhrp_cache_reset_new(c);
 230                 if (c->cur.peer)
 231                         nhrp_peer_notify_add(c->cur.peer, &c->peer_notifier,
 232                                              nhrp_cache_peer_notifier);
 233                 nhrp_cache_update_route(c);
 234                 notifier_call(&c->notifier_list, NOTIFY_CACHE_BINDING_CHANGE);
 235         } else {
 236                 nhrp_cache_reset_new(c);
 237         }
 238
 239         nhrp_cache_update_timers(c);
 240 }
 241
 242 static int nhrp_cache_do_auth_timeout(struct thread *t)
 243 {
 244         struct nhrp_cache *c = THREAD_ARG(t);
 245         c->t_auth = NULL;
 246         nhrp_cache_authorize_binding(&c->eventid, (void *)"timeout");
 247         return 0;
 248 }
 249
 250 static void nhrp_cache_newpeer_notifier(struct notifier_block *n,
 251                                         unsigned long cmd)
 252 {
 253         struct nhrp_cache *c =
 254                 container_of(n, struct nhrp_cache, newpeer_notifier);
 255
 256         switch (cmd) {
 257         case NOTIFY_PEER_UP:
 258                 if (nhrp_peer_check(c->new.peer, 1)) {
 259                         evmgr_notify("authorize-binding", c,
 260                                      nhrp_cache_authorize_binding);
 261                         thread_add_timer(master, nhrp_cache_do_auth_timeout, c,
 262                                          10, &c->t_auth);
 263                 }
 264                 break;
 265         case NOTIFY_PEER_DOWN:
 266         case NOTIFY_PEER_IFCONFIG_CHANGED:
 267                 nhrp_cache_reset_new(c);
 268                 break;
 269         }
 270 }
 271
 272 int nhrp_cache_update_binding(struct nhrp_cache *c, enum nhrp_cache_type type,
 273                               int holding_time, struct nhrp_peer *p,
 274                               uint32_t mtu, union sockunion *nbma_oa)
 275 {
 276         if (c->cur.type > type || c->new.type > type) {
 277                 nhrp_peer_unref(p);
 278                 return 0;
 279         }
 280
 281         /* Sanitize MTU */
 282         switch (sockunion_family(&c->remote_addr)) {
 283         case AF_INET:
 284                 if (mtu < 576 || mtu >= 1500)
 285                         mtu = 0;
 286                 /* Opennhrp announces nbma mtu, but we use protocol mtu.
 287                  * This heuristic tries to fix up it. */
 288                 if (mtu > 1420)
 289                         mtu = (mtu & -16) - 80;
 290                 break;
 291         default:
 292                 mtu = 0;
 293                 break;
 294         }
 295
 296         nhrp_cache_reset_new(c);
 297         if (c->cur.type == type && c->cur.peer == p && c->cur.mtu == mtu) {
 298                 if (holding_time > 0)
 299                         c->cur.expires = monotime(NULL) + holding_time;
 300                 if (nbma_oa)
 301                         c->cur.remote_nbma_natoa = *nbma_oa;
 302                 else
 303                         memset(&c->cur.remote_nbma_natoa, 0,
 304                                sizeof c->cur.remote_nbma_natoa);
 305                 nhrp_peer_unref(p);
 306         } else {
 307                 c->new.type = type;
 308                 c->new.peer = p;
 309                 c->new.mtu = mtu;
 310                 if (nbma_oa)
 311                         c->new.remote_nbma_natoa = *nbma_oa;
 312
 313                 if (holding_time > 0)
 314                         c->new.expires = monotime(NULL) + holding_time;
 315                 else if (holding_time < 0)
 316                         nhrp_cache_reset_new(c);
 317
 318                 if (c->new.type == NHRP_CACHE_INVALID
 319                     || c->new.type >= NHRP_CACHE_STATIC || c->map) {
 320                         nhrp_cache_authorize_binding(&c->eventid,
 321                                                      (void *)"accept");
 322                 } else {
 323                         nhrp_peer_notify_add(c->new.peer, &c->newpeer_notifier,
 324                                              nhrp_cache_newpeer_notifier);
 325                         nhrp_cache_newpeer_notifier(&c->newpeer_notifier,
 326                                                     NOTIFY_PEER_UP);
 327                         thread_add_timer(master, nhrp_cache_do_auth_timeout, c,
 328                                          60, &c->t_auth);
 329                 }
 330         }
 331         nhrp_cache_update_timers(c);
 332
 333         return 1;
 334 }
 335
 336 void nhrp_cache_set_used(struct nhrp_cache *c, int used)
 337 {
 338         c->used = used;
 339         if (c->used)
 340                 notifier_call(&c->notifier_list, NOTIFY_CACHE_USED);
 341 }
 342
 343 struct nhrp_cache_iterator_ctx {
 344         void (*cb)(struct nhrp_cache *, void *);
 345         void *ctx;
 346 };
 347
 348 static void nhrp_cache_iterator(struct hash_backet *b, void *ctx)
 349 {
 350         struct nhrp_cache_iterator_ctx *ic = ctx;
 351         ic->cb(b->data, ic->ctx);
 352 }
 353
 354 void nhrp_cache_foreach(struct interface *ifp,
 355                         void (*cb)(struct nhrp_cache *, void *), void *ctx)
 356 {
 357         struct nhrp_interface *nifp = ifp->info;
 358         struct nhrp_cache_iterator_ctx ic = {
 359                 .cb = cb, .ctx = ctx,
 360         };
 361
 362         if (nifp->cache_hash)
 363                 hash_iterate(nifp->cache_hash, nhrp_cache_iterator, &ic);
 364 }
 365
 366 void nhrp_cache_notify_add(struct nhrp_cache *c, struct notifier_block *n,
 367                            notifier_fn_t fn)
 368 {
 369         notifier_add(n, &c->notifier_list, fn);
 370 }
 371
 372 void nhrp_cache_notify_del(struct nhrp_cache *c, struct notifier_block *n)
 373 {
 374         notifier_del(n);
 375 }