lib/nexthop.c

   1 /* A generic nexthop structure
   2  * Copyright (C) 2013 Cumulus Networks, Inc.
   3  *
   4  * This file is part of Quagga.
   5  *
   6  * Quagga is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * Quagga is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20 #include <zebra.h>
  21
  22 #include "prefix.h"
  23 #include "table.h"
  24 #include "memory.h"
  25 #include "command.h"
  26 #include "if.h"
  27 #include "log.h"
  28 #include "sockunion.h"
  29 #include "linklist.h"
  30 #include "thread.h"
  31 #include "prefix.h"
  32 #include "nexthop.h"
  33 #include "mpls.h"
  34 #include "jhash.h"
  35 #include "printfrr.h"
  36 #include "vrf.h"
  37
  38 DEFINE_MTYPE_STATIC(LIB, NEXTHOP, "Nexthop")
  39 DEFINE_MTYPE_STATIC(LIB, NH_LABEL, "Nexthop label")
  40
  41 static int _nexthop_labels_cmp(const struct nexthop *nh1,
  42                                const struct nexthop *nh2)
  43 {
  44         const struct mpls_label_stack *nhl1 = NULL;
  45         const struct mpls_label_stack *nhl2 = NULL;
  46
  47         nhl1 = nh1->nh_label;
  48         nhl2 = nh2->nh_label;
  49
  50         /* No labels is a match */
  51         if (!nhl1 && !nhl2)
  52                 return 0;
  53
  54         if (nhl1 && !nhl2)
  55                 return 1;
  56
  57         if (nhl2 && !nhl1)
  58                 return -1;
  59
  60         if (nhl1->num_labels > nhl2->num_labels)
  61                 return 1;
  62
  63         if (nhl1->num_labels < nhl2->num_labels)
  64                 return -1;
  65
  66         return memcmp(nhl1->label, nhl2->label, nhl1->num_labels);
  67 }
  68
  69 int nexthop_g_addr_cmp(enum nexthop_types_t type, const union g_addr *addr1,
  70                        const union g_addr *addr2)
  71 {
  72         int ret = 0;
  73
  74         switch (type) {
  75         case NEXTHOP_TYPE_IPV4:
  76         case NEXTHOP_TYPE_IPV4_IFINDEX:
  77                 ret = IPV4_ADDR_CMP(&addr1->ipv4, &addr2->ipv4);
  78                 break;
  79         case NEXTHOP_TYPE_IPV6:
  80         case NEXTHOP_TYPE_IPV6_IFINDEX:
  81                 ret = IPV6_ADDR_CMP(&addr1->ipv6, &addr2->ipv6);
  82                 break;
  83         case NEXTHOP_TYPE_IFINDEX:
  84         case NEXTHOP_TYPE_BLACKHOLE:
  85                 /* No addr here */
  86                 break;
  87         }
  88
  89         return ret;
  90 }
  91
  92 static int _nexthop_gateway_cmp(const struct nexthop *nh1,
  93                                 const struct nexthop *nh2)
  94 {
  95         return nexthop_g_addr_cmp(nh1->type, &nh1->gate, &nh2->gate);
  96 }
  97
  98 static int _nexthop_source_cmp(const struct nexthop *nh1,
  99                                const struct nexthop *nh2)
 100 {
 101         return nexthop_g_addr_cmp(nh1->type, &nh1->src, &nh2->src);
 102 }
 103
 104 static int _nexthop_cmp_no_labels(const struct nexthop *next1,
 105                                   const struct nexthop *next2)
 106 {
 107         int ret = 0;
 108
 109         if (next1->vrf_id < next2->vrf_id)
 110                 return -1;
 111
 112         if (next1->vrf_id > next2->vrf_id)
 113                 return 1;
 114
 115         if (next1->type < next2->type)
 116                 return -1;
 117
 118         if (next1->type > next2->type)
 119                 return 1;
 120
 121         if (next1->weight < next2->weight)
 122                 return -1;
 123
 124         if (next1->weight > next2->weight)
 125                 return 1;
 126
 127         switch (next1->type) {
 128         case NEXTHOP_TYPE_IPV4:
 129         case NEXTHOP_TYPE_IPV6:
 130                 ret = _nexthop_gateway_cmp(next1, next2);
 131                 if (ret != 0)
 132                         return ret;
 133                 break;
 134         case NEXTHOP_TYPE_IPV4_IFINDEX:
 135         case NEXTHOP_TYPE_IPV6_IFINDEX:
 136                 ret = _nexthop_gateway_cmp(next1, next2);
 137                 if (ret != 0)
 138                         return ret;
 139                 /* Intentional Fall-Through */
 140         case NEXTHOP_TYPE_IFINDEX:
 141                 if (next1->ifindex < next2->ifindex)
 142                         return -1;
 143
 144                 if (next1->ifindex > next2->ifindex)
 145                         return 1;
 146                 break;
 147         case NEXTHOP_TYPE_BLACKHOLE:
 148                 if (next1->bh_type < next2->bh_type)
 149                         return -1;
 150
 151                 if (next1->bh_type > next2->bh_type)
 152                         return 1;
 153                 break;
 154         }
 155
 156         ret = _nexthop_source_cmp(next1, next2);
 157
 158         return ret;
 159 }
 160
 161 int nexthop_cmp(const struct nexthop *next1, const struct nexthop *next2)
 162 {
 163         int ret = 0;
 164
 165         ret = _nexthop_cmp_no_labels(next1, next2);
 166         if (ret != 0)
 167                 return ret;
 168
 169         ret = _nexthop_labels_cmp(next1, next2);
 170
 171         return ret;
 172 }
 173
 174 int nexthop_same_firsthop(struct nexthop *next1, struct nexthop *next2)
 175 {
 176         int type1 = NEXTHOP_FIRSTHOPTYPE(next1->type);
 177         int type2 = NEXTHOP_FIRSTHOPTYPE(next2->type);
 178
 179         if (type1 != type2)
 180                 return 0;
 181         switch (type1) {
 182         case NEXTHOP_TYPE_IPV4_IFINDEX:
 183                 if (!IPV4_ADDR_SAME(&next1->gate.ipv4, &next2->gate.ipv4))
 184                         return 0;
 185                 if (next1->ifindex != next2->ifindex)
 186                         return 0;
 187                 break;
 188         case NEXTHOP_TYPE_IFINDEX:
 189                 if (next1->ifindex != next2->ifindex)
 190                         return 0;
 191                 break;
 192         case NEXTHOP_TYPE_IPV6_IFINDEX:
 193                 if (!IPV6_ADDR_SAME(&next1->gate.ipv6, &next2->gate.ipv6))
 194                         return 0;
 195                 if (next1->ifindex != next2->ifindex)
 196                         return 0;
 197                 break;
 198         default:
 199                 /* do nothing */
 200                 break;
 201         }
 202         return 1;
 203 }
 204
 205 /*
 206  * nexthop_type_to_str
 207  */
 208 const char *nexthop_type_to_str(enum nexthop_types_t nh_type)
 209 {
 210         static const char *const desc[] = {
 211                 "none",          "Directly connected",
 212                 "IPv4 nexthop",  "IPv4 nexthop with ifindex",
 213                 "IPv6 nexthop",  "IPv6 nexthop with ifindex",
 214                 "Null0 nexthop",
 215         };
 216
 217         return desc[nh_type];
 218 }
 219
 220 /*
 221  * Check if the labels match for the 2 nexthops specified.
 222  */
 223 bool nexthop_labels_match(const struct nexthop *nh1, const struct nexthop *nh2)
 224 {
 225         if (_nexthop_labels_cmp(nh1, nh2) != 0)
 226                 return false;
 227
 228         return true;
 229 }
 230
 231 struct nexthop *nexthop_new(void)
 232 {
 233         return XCALLOC(MTYPE_NEXTHOP, sizeof(struct nexthop));
 234 }
 235
 236 /* Free nexthop. */
 237 void nexthop_free(struct nexthop *nexthop)
 238 {
 239         nexthop_del_labels(nexthop);
 240         if (nexthop->resolved)
 241                 nexthops_free(nexthop->resolved);
 242         XFREE(MTYPE_NEXTHOP, nexthop);
 243 }
 244
 245 /* Frees a list of nexthops */
 246 void nexthops_free(struct nexthop *nexthop)
 247 {
 248         struct nexthop *nh, *next;
 249
 250         for (nh = nexthop; nh; nh = next) {
 251                 next = nh->next;
 252                 nexthop_free(nh);
 253         }
 254 }
 255
 256 bool nexthop_same(const struct nexthop *nh1, const struct nexthop *nh2)
 257 {
 258         if (nh1 && !nh2)
 259                 return false;
 260
 261         if (!nh1 && nh2)
 262                 return false;
 263
 264         if (nh1 == nh2)
 265                 return true;
 266
 267         if (nexthop_cmp(nh1, nh2) != 0)
 268                 return false;
 269
 270         return true;
 271 }
 272
 273 bool nexthop_same_no_labels(const struct nexthop *nh1,
 274                             const struct nexthop *nh2)
 275 {
 276         if (nh1 && !nh2)
 277                 return false;
 278
 279         if (!nh1 && nh2)
 280                 return false;
 281
 282         if (nh1 == nh2)
 283                 return true;
 284
 285         if (_nexthop_cmp_no_labels(nh1, nh2) != 0)
 286                 return false;
 287
 288         return true;
 289 }
 290
 291 /*
 292  * Allocate a new nexthop object and initialize it from various args.
 293  */
 294 struct nexthop *nexthop_from_ifindex(ifindex_t ifindex, vrf_id_t vrf_id)
 295 {
 296         struct nexthop *nexthop;
 297
 298         nexthop = nexthop_new();
 299         nexthop->type = NEXTHOP_TYPE_IFINDEX;
 300         nexthop->ifindex = ifindex;
 301         nexthop->vrf_id = vrf_id;
 302
 303         return nexthop;
 304 }
 305
 306 struct nexthop *nexthop_from_ipv4(const struct in_addr *ipv4,
 307                                   const struct in_addr *src,
 308                                   vrf_id_t vrf_id)
 309 {
 310         struct nexthop *nexthop;
 311
 312         nexthop = nexthop_new();
 313         nexthop->type = NEXTHOP_TYPE_IPV4;
 314         nexthop->vrf_id = vrf_id;
 315         nexthop->gate.ipv4 = *ipv4;
 316         if (src)
 317                 nexthop->src.ipv4 = *src;
 318
 319         return nexthop;
 320 }
 321
 322 struct nexthop *nexthop_from_ipv4_ifindex(const struct in_addr *ipv4,
 323                                           const struct in_addr *src,
 324                                           ifindex_t ifindex, vrf_id_t vrf_id)
 325 {
 326         struct nexthop *nexthop;
 327
 328         nexthop = nexthop_new();
 329         nexthop->type = NEXTHOP_TYPE_IPV4_IFINDEX;
 330         nexthop->vrf_id = vrf_id;
 331         nexthop->gate.ipv4 = *ipv4;
 332         if (src)
 333                 nexthop->src.ipv4 = *src;
 334         nexthop->ifindex = ifindex;
 335
 336         return nexthop;
 337 }
 338
 339 struct nexthop *nexthop_from_ipv6(const struct in6_addr *ipv6,
 340                                   vrf_id_t vrf_id)
 341 {
 342         struct nexthop *nexthop;
 343
 344         nexthop = nexthop_new();
 345         nexthop->vrf_id = vrf_id;
 346         nexthop->type = NEXTHOP_TYPE_IPV6;
 347         nexthop->gate.ipv6 = *ipv6;
 348
 349         return nexthop;
 350 }
 351
 352 struct nexthop *nexthop_from_ipv6_ifindex(const struct in6_addr *ipv6,
 353                                           ifindex_t ifindex, vrf_id_t vrf_id)
 354 {
 355         struct nexthop *nexthop;
 356
 357         nexthop = nexthop_new();
 358         nexthop->vrf_id = vrf_id;
 359         nexthop->type = NEXTHOP_TYPE_IPV6_IFINDEX;
 360         nexthop->gate.ipv6 = *ipv6;
 361         nexthop->ifindex = ifindex;
 362
 363         return nexthop;
 364 }
 365
 366 struct nexthop *nexthop_from_blackhole(enum blackhole_type bh_type)
 367 {
 368         struct nexthop *nexthop;
 369
 370         nexthop = nexthop_new();
 371         nexthop->vrf_id = VRF_DEFAULT;
 372         nexthop->type = NEXTHOP_TYPE_BLACKHOLE;
 373         nexthop->bh_type = bh_type;
 374
 375         return nexthop;
 376 }
 377
 378 /* Update nexthop with label information. */
 379 void nexthop_add_labels(struct nexthop *nexthop, enum lsp_types_t type,
 380                         uint8_t num_labels, mpls_label_t *label)
 381 {
 382         struct mpls_label_stack *nh_label;
 383         int i;
 384
 385         if (num_labels == 0)
 386                 return;
 387
 388         nexthop->nh_label_type = type;
 389         nh_label = XCALLOC(MTYPE_NH_LABEL,
 390                            sizeof(struct mpls_label_stack)
 391                                    + num_labels * sizeof(mpls_label_t));
 392         nh_label->num_labels = num_labels;
 393         for (i = 0; i < num_labels; i++)
 394                 nh_label->label[i] = *(label + i);
 395         nexthop->nh_label = nh_label;
 396 }
 397
 398 /* Free label information of nexthop, if present. */
 399 void nexthop_del_labels(struct nexthop *nexthop)
 400 {
 401         if (nexthop->nh_label) {
 402                 XFREE(MTYPE_NH_LABEL, nexthop->nh_label);
 403                 nexthop->nh_label_type = ZEBRA_LSP_NONE;
 404         }
 405 }
 406
 407 const char *nexthop2str(const struct nexthop *nexthop, char *str, int size)
 408 {
 409         switch (nexthop->type) {
 410         case NEXTHOP_TYPE_IFINDEX:
 411                 snprintf(str, size, "if %u", nexthop->ifindex);
 412                 break;
 413         case NEXTHOP_TYPE_IPV4:
 414         case NEXTHOP_TYPE_IPV4_IFINDEX:
 415                 snprintf(str, size, "%s if %u", inet_ntoa(nexthop->gate.ipv4),
 416                          nexthop->ifindex);
 417                 break;
 418         case NEXTHOP_TYPE_IPV6:
 419         case NEXTHOP_TYPE_IPV6_IFINDEX:
 420                 snprintf(str, size, "%s if %u", inet6_ntoa(nexthop->gate.ipv6),
 421                          nexthop->ifindex);
 422                 break;
 423         case NEXTHOP_TYPE_BLACKHOLE:
 424                 snprintf(str, size, "blackhole");
 425                 break;
 426         default:
 427                 snprintf(str, size, "unknown");
 428                 break;
 429         }
 430
 431         return str;
 432 }
 433
 434 /*
 435  * Iteration step for ALL_NEXTHOPS macro:
 436  * This is the tricky part. Check if `nexthop' has
 437  * NEXTHOP_FLAG_RECURSIVE set. If yes, this implies that `nexthop' has
 438  * at least one nexthop attached to `nexthop->resolved', which will be
 439  * the next one.
 440  *
 441  * If NEXTHOP_FLAG_RECURSIVE is not set, `nexthop' will progress in its
 442  * current chain. In case its current chain end is reached, it will move
 443  * upwards in the recursion levels and progress there. Whenever a step
 444  * forward in a chain is done, recursion will be checked again.
 445  * In a nustshell, it's equivalent to a pre-traversal order assuming that
 446  * left branch is 'resolved' and right branch is 'next':
 447  * https://en.wikipedia.org/wiki/Tree_traversal#/media/File:Sorted_binary_tree_preorder.svg
 448  */
 449 struct nexthop *nexthop_next(const struct nexthop *nexthop)
 450 {
 451         if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_RECURSIVE))
 452                 return nexthop->resolved;
 453
 454         if (nexthop->next)
 455                 return nexthop->next;
 456
 457         for (struct nexthop *par = nexthop->rparent; par; par = par->rparent)
 458                 if (par->next)
 459                         return par->next;
 460
 461         return NULL;
 462 }
 463
 464 /* Return the next nexthop in the tree that is resolved and active */
 465 struct nexthop *nexthop_next_active_resolved(const struct nexthop *nexthop)
 466 {
 467         struct nexthop *next = nexthop_next(nexthop);
 468
 469         while (next
 470                && (CHECK_FLAG(next->flags, NEXTHOP_FLAG_RECURSIVE)
 471                    || !CHECK_FLAG(next->flags, NEXTHOP_FLAG_ACTIVE)))
 472                 next = nexthop_next(next);
 473
 474         return next;
 475 }
 476
 477 unsigned int nexthop_level(struct nexthop *nexthop)
 478 {
 479         unsigned int rv = 0;
 480
 481         for (struct nexthop *par = nexthop->rparent; par; par = par->rparent)
 482                 rv++;
 483
 484         return rv;
 485 }
 486
 487 /* Only hash word-sized things, let cmp do the rest. */
 488 uint32_t nexthop_hash_quick(const struct nexthop *nexthop)
 489 {
 490         uint32_t key = 0x45afe398;
 491
 492         key = jhash_3words(nexthop->type, nexthop->vrf_id,
 493                            nexthop->nh_label_type, key);
 494
 495         if (nexthop->nh_label) {
 496                 int labels = nexthop->nh_label->num_labels;
 497                 int i = 0;
 498
 499                 while (labels >= 3) {
 500                         key = jhash_3words(nexthop->nh_label->label[i],
 501                                            nexthop->nh_label->label[i + 1],
 502                                            nexthop->nh_label->label[i + 2],
 503                                            key);
 504                         labels -= 3;
 505                         i += 3;
 506                 }
 507
 508                 if (labels >= 2) {
 509                         key = jhash_2words(nexthop->nh_label->label[i],
 510                                            nexthop->nh_label->label[i + 1],
 511                                            key);
 512                         labels -= 2;
 513                         i += 2;
 514                 }
 515
 516                 if (labels >= 1)
 517                         key = jhash_1word(nexthop->nh_label->label[i], key);
 518         }
 519
 520         key = jhash_2words(nexthop->ifindex,
 521                            CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_ONLINK),
 522                            key);
 523
 524         return key;
 525 }
 526
 527
 528 #define GATE_SIZE 4 /* Number of uint32_t words in struct g_addr */
 529
 530 /* For a more granular hash */
 531 uint32_t nexthop_hash(const struct nexthop *nexthop)
 532 {
 533         uint32_t gate_src_rmap_raw[GATE_SIZE * 3] = {};
 534         /* Get all the quick stuff */
 535         uint32_t key = nexthop_hash_quick(nexthop);
 536
 537         assert(((sizeof(nexthop->gate) + sizeof(nexthop->src)
 538                  + sizeof(nexthop->rmap_src))
 539                 / 3)
 540                == (GATE_SIZE * sizeof(uint32_t)));
 541
 542         memcpy(gate_src_rmap_raw, &nexthop->gate, GATE_SIZE);
 543         memcpy(gate_src_rmap_raw + GATE_SIZE, &nexthop->src, GATE_SIZE);
 544         memcpy(gate_src_rmap_raw + (2 * GATE_SIZE), &nexthop->rmap_src,
 545                GATE_SIZE);
 546
 547         key = jhash2(gate_src_rmap_raw, (GATE_SIZE * 3), key);
 548
 549         return key;
 550 }
 551
 552 void nexthop_copy(struct nexthop *copy, const struct nexthop *nexthop,
 553                   struct nexthop *rparent)
 554 {
 555         copy->vrf_id = nexthop->vrf_id;
 556         copy->ifindex = nexthop->ifindex;
 557         copy->type = nexthop->type;
 558         copy->flags = nexthop->flags;
 559         copy->weight = nexthop->weight;
 560         memcpy(&copy->gate, &nexthop->gate, sizeof(nexthop->gate));
 561         memcpy(&copy->src, &nexthop->src, sizeof(nexthop->src));
 562         memcpy(&copy->rmap_src, &nexthop->rmap_src, sizeof(nexthop->rmap_src));
 563         copy->rparent = rparent;
 564         if (nexthop->nh_label)
 565                 nexthop_add_labels(copy, nexthop->nh_label_type,
 566                                    nexthop->nh_label->num_labels,
 567                                    &nexthop->nh_label->label[0]);
 568 }
 569
 570 struct nexthop *nexthop_dup(const struct nexthop *nexthop,
 571                             struct nexthop *rparent)
 572 {
 573         struct nexthop *new = nexthop_new();
 574
 575         nexthop_copy(new, nexthop, rparent);
 576         return new;
 577 }
 578
 579 /*
 580  * nexthop printing variants:
 581  *      %pNHvv
 582  *              via 1.2.3.4
 583  *              via 1.2.3.4, eth0
 584  *              is directly connected, eth0
 585  *              unreachable (blackhole)
 586  *      %pNHv
 587  *              1.2.3.4
 588  *              1.2.3.4, via eth0
 589  *              directly connected, eth0
 590  *              unreachable (blackhole)
 591  *      %pNHs
 592  *              nexthop2str()
 593  */
 594 printfrr_ext_autoreg_p("NH", printfrr_nh)
 595 static ssize_t printfrr_nh(char *buf, size_t bsz, const char *fmt,
 596                            int prec, const void *ptr)
 597 {
 598         const struct nexthop *nexthop = ptr;
 599         struct fbuf fb = { .buf = buf, .pos = buf, .len = bsz - 1 };
 600         bool do_ifi = false;
 601         const char *s, *v_is = "", *v_via = "", *v_viaif = "via ";
 602         ssize_t ret = 3;
 603
 604         switch (fmt[2]) {
 605         case 'v':
 606                 if (fmt[3] == 'v') {
 607                         v_is = "is ";
 608                         v_via = "via ";
 609                         v_viaif = "";
 610                         ret++;
 611                 }
 612
 613                 switch (nexthop->type) {
 614                 case NEXTHOP_TYPE_IPV4:
 615                 case NEXTHOP_TYPE_IPV4_IFINDEX:
 616                         bprintfrr(&fb, "%s%pI4", v_via, &nexthop->gate.ipv4);
 617                         do_ifi = true;
 618                         break;
 619                 case NEXTHOP_TYPE_IPV6:
 620                 case NEXTHOP_TYPE_IPV6_IFINDEX:
 621                         bprintfrr(&fb, "%s%pI6", v_via, &nexthop->gate.ipv6);
 622                         do_ifi = true;
 623                         break;
 624                 case NEXTHOP_TYPE_IFINDEX:
 625                         bprintfrr(&fb, "%sdirectly connected, %s", v_is,
 626                                 ifindex2ifname(nexthop->ifindex,
 627                                                nexthop->vrf_id));
 628                         break;
 629                 case NEXTHOP_TYPE_BLACKHOLE:
 630                         switch (nexthop->bh_type) {
 631                         case BLACKHOLE_REJECT:
 632                                 s = " (ICMP unreachable)";
 633                                 break;
 634                         case BLACKHOLE_ADMINPROHIB:
 635                                 s = " (ICMP admin-prohibited)";
 636                                 break;
 637                         case BLACKHOLE_NULL:
 638                                 s = " (blackhole)";
 639                                 break;
 640                         default:
 641                                 s = "";
 642                                 break;
 643                         }
 644                         bprintfrr(&fb, "unreachable%s", s);
 645                         break;
 646                 default:
 647                         break;
 648                 }
 649                 if (do_ifi && nexthop->ifindex)
 650                         bprintfrr(&fb, ", %s%s", v_viaif, ifindex2ifname(
 651                                         nexthop->ifindex,
 652                                         nexthop->vrf_id));
 653
 654                 *fb.pos = '\0';
 655                 return ret;
 656         case 's':
 657                 nexthop2str(nexthop, buf, bsz);
 658                 return 3;
 659         }
 660         return 0;
 661 }