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