nhrpd/nhrp_nhs.c

   1 /* NHRP NHC nexthop server functions (registration)
   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 "zbuf.h"
  12 #include "memory.h"
  13 #include "thread.h"
  14 #include "nhrpd.h"
  15 #include "nhrp_protocol.h"
  16
  17 DEFINE_MTYPE_STATIC(NHRPD, NHRP_NHS, "NHRP next hop server")
  18 DEFINE_MTYPE_STATIC(NHRPD, NHRP_REGISTRATION, "NHRP registration entries")
  19
  20 static int nhrp_nhs_resolve(struct thread *t);
  21 static int nhrp_reg_send_req(struct thread *t);
  22
  23 static void nhrp_reg_reply(struct nhrp_reqid *reqid, void *arg)
  24 {
  25         struct nhrp_packet_parser *p = arg;
  26         struct nhrp_registration *r = container_of(reqid, struct nhrp_registration, reqid);
  27         struct nhrp_nhs *nhs = r->nhs;
  28         struct interface *ifp = nhs->ifp;
  29         struct nhrp_interface *nifp = ifp->info;
  30         struct nhrp_extension_header *ext;
  31         struct nhrp_cie_header *cie;
  32         struct nhrp_cache *c;
  33         struct zbuf extpl;
  34         union sockunion cie_nbma, cie_proto, *proto;
  35         char buf[64];
  36         int ok = 0, holdtime;
  37
  38         nhrp_reqid_free(&nhrp_packet_reqid, &r->reqid);
  39
  40         if (p->hdr->type != NHRP_PACKET_REGISTRATION_REPLY) {
  41                 debugf(NHRP_DEBUG_COMMON, "NHS: Registration failed");
  42                 return;
  43         }
  44
  45         debugf(NHRP_DEBUG_COMMON, "NHS: Reg.reply received");
  46
  47         ok = 1;
  48         while ((cie = nhrp_cie_pull(&p->payload, p->hdr, &cie_nbma, &cie_proto)) != NULL) {
  49                 proto = sockunion_family(&cie_proto) != AF_UNSPEC ? &cie_proto : &p->src_proto;
  50                 debugf(NHRP_DEBUG_COMMON, "NHS: CIE registration: %s: %d",
  51                         sockunion2str(proto, buf, sizeof(buf)),
  52                         cie->code);
  53                 if (!((cie->code == NHRP_CODE_SUCCESS) ||
  54                       (cie->code == NHRP_CODE_ADMINISTRATIVELY_PROHIBITED && nhs->hub)))
  55                         ok = 0;
  56         }
  57
  58         if (!ok)
  59                 return;
  60
  61         /* Parse extensions */
  62         sockunion_family(&nifp->nat_nbma) = AF_UNSPEC;
  63         while ((ext = nhrp_ext_pull(&p->extensions, &extpl)) != NULL) {
  64                 switch (htons(ext->type) & ~NHRP_EXTENSION_FLAG_COMPULSORY) {
  65                 case NHRP_EXTENSION_NAT_ADDRESS:
  66                         /* NHS adds second CIE if NAT is detected */
  67                         if (nhrp_cie_pull(&extpl, p->hdr, &cie_nbma, &cie_proto) &&
  68                             nhrp_cie_pull(&extpl, p->hdr, &cie_nbma, &cie_proto)) {
  69                                 nifp->nat_nbma = cie_nbma;
  70                                 debugf(NHRP_DEBUG_IF, "%s: NAT detected, real NBMA address: %s",
  71                                         ifp->name, sockunion2str(&nifp->nbma, buf, sizeof(buf)));
  72                         }
  73                         break;
  74                 }
  75         }
  76
  77         /* Success - schedule next registration, and route NHS */
  78         r->timeout = 2;
  79         holdtime = nifp->afi[nhs->afi].holdtime;
  80         THREAD_OFF(r->t_register);
  81
  82         /* RFC 2332 5.2.3 - Registration is recommend to be renewed
  83          * every one third of holdtime */
  84         THREAD_TIMER_ON(master, r->t_register, nhrp_reg_send_req, r, holdtime / 3);
  85
  86         r->proto_addr = p->dst_proto;
  87         c = nhrp_cache_get(ifp, &p->dst_proto, 1);
  88         if (c) nhrp_cache_update_binding(c, NHRP_CACHE_NHS, holdtime, nhrp_peer_ref(r->peer), 0, NULL);
  89 }
  90
  91 static int nhrp_reg_timeout(struct thread *t)
  92 {
  93         struct nhrp_registration *r = THREAD_ARG(t);
  94         struct nhrp_cache *c;
  95
  96         r->t_register = NULL;
  97
  98         if (r->timeout >= 16 && sockunion_family(&r->proto_addr) != AF_UNSPEC) {
  99                 nhrp_reqid_free(&nhrp_packet_reqid, &r->reqid);
 100                 c = nhrp_cache_get(r->nhs->ifp, &r->proto_addr, 0);
 101                 if (c) nhrp_cache_update_binding(c, NHRP_CACHE_NHS, -1, NULL, 0, NULL);
 102                 sockunion_family(&r->proto_addr) = AF_UNSPEC;
 103         }
 104
 105         r->timeout <<= 1;
 106         if (r->timeout > 64) r->timeout = 2;
 107         THREAD_TIMER_MSEC_ON(master, r->t_register, nhrp_reg_send_req, r, 10);
 108
 109         return 0;
 110 }
 111
 112 static void nhrp_reg_peer_notify(struct notifier_block *n, unsigned long cmd)
 113 {
 114         struct nhrp_registration *r = container_of(n, struct nhrp_registration, peer_notifier);
 115         char buf[SU_ADDRSTRLEN];
 116
 117         switch (cmd) {
 118         case NOTIFY_PEER_UP:
 119         case NOTIFY_PEER_DOWN:
 120         case NOTIFY_PEER_IFCONFIG_CHANGED:
 121         case NOTIFY_PEER_MTU_CHANGED:
 122                 debugf(NHRP_DEBUG_COMMON, "NHS: Flush timer for %s",
 123                         sockunion2str(&r->peer->vc->remote.nbma, buf, sizeof buf));
 124                 THREAD_TIMER_OFF(r->t_register);
 125                 THREAD_TIMER_MSEC_ON(master, r->t_register, nhrp_reg_send_req, r, 10);
 126                 break;
 127         }
 128 }
 129
 130 static int nhrp_reg_send_req(struct thread *t)
 131 {
 132         struct nhrp_registration *r = THREAD_ARG(t);
 133         struct nhrp_nhs *nhs = r->nhs;
 134         char buf1[SU_ADDRSTRLEN], buf2[SU_ADDRSTRLEN];
 135         struct interface *ifp = nhs->ifp;
 136         struct nhrp_interface *nifp = ifp->info;
 137         struct nhrp_afi_data *if_ad = &nifp->afi[nhs->afi];
 138         union sockunion *dst_proto;
 139         struct zbuf *zb;
 140         struct nhrp_packet_header *hdr;
 141         struct nhrp_extension_header *ext;
 142         struct nhrp_cie_header *cie;
 143
 144         r->t_register = NULL;
 145         if (!nhrp_peer_check(r->peer, 2)) {
 146                 debugf(NHRP_DEBUG_COMMON, "NHS: Waiting link for %s",
 147                         sockunion2str(&r->peer->vc->remote.nbma, buf1, sizeof buf1));
 148                 THREAD_TIMER_ON(master, r->t_register, nhrp_reg_send_req, r, 120);
 149                 return 0;
 150         }
 151
 152         THREAD_TIMER_ON(master, r->t_register, nhrp_reg_timeout, r, r->timeout);
 153
 154         /* RFC2332 5.2.3 NHC uses it's own address as dst if NHS is unknown */
 155         dst_proto = &nhs->proto_addr;
 156         if (sockunion_family(dst_proto) == AF_UNSPEC)
 157                 dst_proto = &if_ad->addr;
 158
 159         sockunion2str(&if_ad->addr, buf1, sizeof(buf1));
 160         sockunion2str(dst_proto, buf2, sizeof(buf2));
 161         debugf(NHRP_DEBUG_COMMON, "NHS: Register %s -> %s (timeout %d)", buf1, buf2, r->timeout);
 162
 163         /* No protocol address configured for tunnel interface */
 164         if (sockunion_family(&if_ad->addr) == AF_UNSPEC)
 165                 return 0;
 166
 167         zb = zbuf_alloc(1400);
 168         hdr = nhrp_packet_push(zb, NHRP_PACKET_REGISTRATION_REQUEST, &nifp->nbma, &if_ad->addr, dst_proto);
 169         hdr->hop_count = 0;
 170         if (!(if_ad->flags & NHRP_IFF_REG_NO_UNIQUE))
 171                 hdr->flags |= htons(NHRP_FLAG_REGISTRATION_UNIQUE);
 172
 173         hdr->u.request_id = htonl(nhrp_reqid_alloc(&nhrp_packet_reqid, &r->reqid, nhrp_reg_reply));
 174
 175         /* FIXME: push CIE for each local protocol address */
 176         cie = nhrp_cie_push(zb, NHRP_CODE_SUCCESS, NULL, NULL);
 177         cie->prefix_length = 0xff;
 178         cie->holding_time = htons(if_ad->holdtime);
 179         cie->mtu = htons(if_ad->mtu);
 180
 181         nhrp_ext_request(zb, hdr, ifp);
 182
 183         /* Cisco NAT detection extension */
 184         hdr->flags |= htons(NHRP_FLAG_REGISTRATION_NAT);
 185         ext = nhrp_ext_push(zb, hdr, NHRP_EXTENSION_NAT_ADDRESS);
 186         cie = nhrp_cie_push(zb, NHRP_CODE_SUCCESS, &nifp->nbma, &if_ad->addr);
 187         cie->prefix_length = 8 * sockunion_get_addrlen(&nifp->nbma);
 188         nhrp_ext_complete(zb, ext);
 189
 190         nhrp_packet_complete(zb, hdr);
 191         nhrp_peer_send(r->peer, zb);
 192         zbuf_free(zb);
 193
 194         return 0;
 195 }
 196
 197 static void nhrp_reg_delete(struct nhrp_registration *r)
 198 {
 199         nhrp_peer_notify_del(r->peer, &r->peer_notifier);
 200         nhrp_peer_unref(r->peer);
 201         list_del(&r->reglist_entry);
 202         THREAD_OFF(r->t_register);
 203         XFREE(MTYPE_NHRP_REGISTRATION, r);
 204 }
 205
 206 static struct nhrp_registration *nhrp_reg_by_nbma(struct nhrp_nhs *nhs, const union sockunion *nbma_addr)
 207 {
 208         struct nhrp_registration *r;
 209
 210         list_for_each_entry(r, &nhs->reglist_head, reglist_entry)
 211                 if (sockunion_same(&r->peer->vc->remote.nbma, nbma_addr))
 212                         return r;
 213         return NULL;
 214 }
 215
 216 static void nhrp_nhs_resolve_cb(struct resolver_query *q, int n, union sockunion *addrs)
 217 {
 218         struct nhrp_nhs *nhs = container_of(q, struct nhrp_nhs, dns_resolve);
 219         struct nhrp_interface *nifp = nhs->ifp->info;
 220         struct nhrp_registration *reg, *regn;
 221         int i;
 222
 223         nhs->t_resolve = NULL;
 224         if (n < 0) {
 225                 /* Failed, retry in a moment */
 226                 THREAD_TIMER_ON(master, nhs->t_resolve, nhrp_nhs_resolve, nhs, 5);
 227                 return;
 228         }
 229
 230         THREAD_TIMER_ON(master, nhs->t_resolve, nhrp_nhs_resolve, nhs, 2*60*60);
 231
 232         list_for_each_entry(reg, &nhs->reglist_head, reglist_entry)
 233                 reg->mark = 1;
 234
 235         nhs->hub = 0;
 236         for (i = 0; i < n; i++) {
 237                 if (sockunion_same(&addrs[i], &nifp->nbma)) {
 238                         nhs->hub = 1;
 239                         continue;
 240                 }
 241
 242                 reg = nhrp_reg_by_nbma(nhs, &addrs[i]);
 243                 if (reg) {
 244                         reg->mark = 0;
 245                         continue;
 246                 }
 247
 248                 reg = XCALLOC(MTYPE_NHRP_REGISTRATION, sizeof(*reg));
 249                 reg->peer = nhrp_peer_get(nhs->ifp, &addrs[i]);
 250                 reg->nhs = nhs;
 251                 reg->timeout = 1;
 252                 list_init(&reg->reglist_entry);
 253                 list_add_tail(&reg->reglist_entry, &nhs->reglist_head);
 254                 nhrp_peer_notify_add(reg->peer, &reg->peer_notifier, nhrp_reg_peer_notify);
 255                 THREAD_TIMER_MSEC_ON(master, reg->t_register, nhrp_reg_send_req, reg, 50);
 256         }
 257
 258         list_for_each_entry_safe(reg, regn, &nhs->reglist_head, reglist_entry) {
 259                 if (reg->mark)
 260                         nhrp_reg_delete(reg);
 261         }
 262 }
 263
 264 static int nhrp_nhs_resolve(struct thread *t)
 265 {
 266         struct nhrp_nhs *nhs = THREAD_ARG(t);
 267
 268         resolver_resolve(&nhs->dns_resolve, AF_INET, nhs->nbma_fqdn, nhrp_nhs_resolve_cb);
 269
 270         return 0;
 271 }
 272
 273 int nhrp_nhs_add(struct interface *ifp, afi_t afi, union sockunion *proto_addr, const char *nbma_fqdn)
 274 {
 275         struct nhrp_interface *nifp = ifp->info;
 276         struct nhrp_nhs *nhs;
 277
 278         if (sockunion_family(proto_addr) != AF_UNSPEC &&
 279             sockunion_family(proto_addr) != afi2family(afi))
 280                 return NHRP_ERR_PROTOCOL_ADDRESS_MISMATCH;
 281
 282         list_for_each_entry(nhs, &nifp->afi[afi].nhslist_head, nhslist_entry) {
 283                 if (sockunion_family(&nhs->proto_addr) != AF_UNSPEC &&
 284                     sockunion_family(proto_addr) != AF_UNSPEC &&
 285                     sockunion_same(&nhs->proto_addr, proto_addr))
 286                         return NHRP_ERR_ENTRY_EXISTS;
 287
 288                 if (strcmp(nhs->nbma_fqdn, nbma_fqdn) == 0)
 289                         return NHRP_ERR_ENTRY_EXISTS;
 290         }
 291
 292         nhs = XMALLOC(MTYPE_NHRP_NHS, sizeof(struct nhrp_nhs));
 293         if (!nhs) return NHRP_ERR_NO_MEMORY;
 294
 295         *nhs = (struct nhrp_nhs) {
 296                 .afi = afi,
 297                 .ifp = ifp,
 298                 .proto_addr = *proto_addr,
 299                 .nbma_fqdn = strdup(nbma_fqdn),
 300                 .reglist_head = LIST_INITIALIZER(nhs->reglist_head),
 301         };
 302         list_add_tail(&nhs->nhslist_entry, &nifp->afi[afi].nhslist_head);
 303         THREAD_TIMER_MSEC_ON(master, nhs->t_resolve, nhrp_nhs_resolve, nhs, 1000);
 304
 305         return NHRP_OK;
 306 }
 307
 308 int nhrp_nhs_del(struct interface *ifp, afi_t afi, union sockunion *proto_addr, const char *nbma_fqdn)
 309 {
 310         struct nhrp_interface *nifp = ifp->info;
 311         struct nhrp_nhs *nhs, *nnhs;
 312         int ret = NHRP_ERR_ENTRY_NOT_FOUND;
 313
 314         if (sockunion_family(proto_addr) != AF_UNSPEC &&
 315             sockunion_family(proto_addr) != afi2family(afi))
 316                 return NHRP_ERR_PROTOCOL_ADDRESS_MISMATCH;
 317
 318         list_for_each_entry_safe(nhs, nnhs, &nifp->afi[afi].nhslist_head, nhslist_entry) {
 319                 if (!sockunion_same(&nhs->proto_addr, proto_addr))
 320                         continue;
 321                 if (strcmp(nhs->nbma_fqdn, nbma_fqdn) != 0)
 322                         continue;
 323
 324                 nhrp_nhs_free(nhs);
 325                 ret = NHRP_OK;
 326         }
 327
 328         return ret;
 329 }
 330
 331 int nhrp_nhs_free(struct nhrp_nhs *nhs)
 332 {
 333         struct nhrp_registration *r, *rn;
 334
 335         list_for_each_entry_safe(r, rn, &nhs->reglist_head, reglist_entry)
 336                 nhrp_reg_delete(r);
 337         THREAD_OFF(nhs->t_resolve);
 338         list_del(&nhs->nhslist_entry);
 339         free((void*) nhs->nbma_fqdn);
 340         XFREE(MTYPE_NHRP_NHS, nhs);
 341         return 0;
 342 }
 343
 344 void nhrp_nhs_terminate(void)
 345 {
 346         struct interface *ifp;
 347         struct nhrp_interface *nifp;
 348         struct nhrp_nhs *nhs, *tmp;
 349         struct listnode *node;
 350         afi_t afi;
 351
 352         for (ALL_LIST_ELEMENTS_RO(vrf_iflist (VRF_DEFAULT), node, ifp)) {
 353                 nifp = ifp->info;
 354                 for (afi = 0; afi < AFI_MAX; afi++) {
 355                         list_for_each_entry_safe(nhs, tmp, &nifp->afi[afi].nhslist_head, nhslist_entry)
 356                                 nhrp_nhs_free(nhs);
 357                 }
 358         }
 359 }
 360
 361 void nhrp_nhs_foreach(struct interface *ifp, afi_t afi, void (*cb)(struct nhrp_nhs *, struct nhrp_registration *, void *), void *ctx)
 362 {
 363         struct nhrp_interface *nifp = ifp->info;
 364         struct nhrp_nhs *nhs;
 365         struct nhrp_registration *reg;
 366
 367         list_for_each_entry(nhs, &nifp->afi[afi].nhslist_head, nhslist_entry) {
 368                 if (!list_empty(&nhs->reglist_head)) {
 369                         list_for_each_entry(reg, &nhs->reglist_head, reglist_entry)
 370                                 cb(nhs, reg, ctx);
 371                 } else
 372                         cb(nhs, 0, ctx);
 373         }
 374 }