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