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         switch (next1->type) {
 122         case NEXTHOP_TYPE_IPV4:
 123         case NEXTHOP_TYPE_IPV6:
 124                 ret = _nexthop_gateway_cmp(next1, next2);
 125                 if (ret != 0)
 126                         return ret;
 127                 break;
 128         case NEXTHOP_TYPE_IPV4_IFINDEX:
 129         case NEXTHOP_TYPE_IPV6_IFINDEX:
 130                 ret = _nexthop_gateway_cmp(next1, next2);
 131                 if (ret != 0)
 132                         return ret;
 133                 /* Intentional Fall-Through */
 134         case NEXTHOP_TYPE_IFINDEX:
 135                 if (next1->ifindex < next2->ifindex)
 136                         return -1;
 137
 138                 if (next1->ifindex > next2->ifindex)
 139                         return 1;
 140                 break;
 141         case NEXTHOP_TYPE_BLACKHOLE:
 142                 if (next1->bh_type < next2->bh_type)
 143                         return -1;
 144
 145                 if (next1->bh_type > next2->bh_type)
 146                         return 1;
 147                 break;
 148         }
 149
 150         ret = _nexthop_source_cmp(next1, next2);
 151
 152         return ret;
 153 }
 154
 155 int nexthop_cmp(const struct nexthop *next1, const struct nexthop *next2)
 156 {
 157         int ret = 0;
 158
 159         ret = _nexthop_cmp_no_labels(next1, next2);
 160         if (ret != 0)
 161                 return ret;
 162
 163         ret = _nexthop_labels_cmp(next1, next2);
 164
 165         return ret;
 166 }
 167
 168 int nexthop_same_firsthop(struct nexthop *next1, struct nexthop *next2)
 169 {
 170         int type1 = NEXTHOP_FIRSTHOPTYPE(next1->type);
 171         int type2 = NEXTHOP_FIRSTHOPTYPE(next2->type);
 172
 173         if (type1 != type2)
 174                 return 0;
 175         switch (type1) {
 176         case NEXTHOP_TYPE_IPV4_IFINDEX:
 177                 if (!IPV4_ADDR_SAME(&next1->gate.ipv4, &next2->gate.ipv4))
 178                         return 0;
 179                 if (next1->ifindex != next2->ifindex)
 180                         return 0;
 181                 break;
 182         case NEXTHOP_TYPE_IFINDEX:
 183                 if (next1->ifindex != next2->ifindex)
 184                         return 0;
 185                 break;
 186         case NEXTHOP_TYPE_IPV6_IFINDEX:
 187                 if (!IPV6_ADDR_SAME(&next1->gate.ipv6, &next2->gate.ipv6))
 188                         return 0;
 189                 if (next1->ifindex != next2->ifindex)
 190                         return 0;
 191                 break;
 192         default:
 193                 /* do nothing */
 194                 break;
 195         }
 196         return 1;
 197 }
 198
 199 /*
 200  * nexthop_type_to_str
 201  */
 202 const char *nexthop_type_to_str(enum nexthop_types_t nh_type)
 203 {
 204         static const char *const desc[] = {
 205                 "none",          "Directly connected",
 206                 "IPv4 nexthop",  "IPv4 nexthop with ifindex",
 207                 "IPv6 nexthop",  "IPv6 nexthop with ifindex",
 208                 "Null0 nexthop",
 209         };
 210
 211         return desc[nh_type];
 212 }
 213
 214 /*
 215  * Check if the labels match for the 2 nexthops specified.
 216  */
 217 bool nexthop_labels_match(const struct nexthop *nh1, const struct nexthop *nh2)
 218 {
 219         if (_nexthop_labels_cmp(nh1, nh2) != 0)
 220                 return false;
 221
 222         return true;
 223 }
 224
 225 struct nexthop *nexthop_new(void)
 226 {
 227         return XCALLOC(MTYPE_NEXTHOP, sizeof(struct nexthop));
 228 }
 229
 230 /* Free nexthop. */
 231 void nexthop_free(struct nexthop *nexthop)
 232 {
 233         nexthop_del_labels(nexthop);
 234         if (nexthop->resolved)
 235                 nexthops_free(nexthop->resolved);
 236         XFREE(MTYPE_NEXTHOP, nexthop);
 237 }
 238
 239 /* Frees a list of nexthops */
 240 void nexthops_free(struct nexthop *nexthop)
 241 {
 242         struct nexthop *nh, *next;
 243
 244         for (nh = nexthop; nh; nh = next) {
 245                 next = nh->next;
 246                 nexthop_free(nh);
 247         }
 248 }
 249
 250 bool nexthop_same(const struct nexthop *nh1, const struct nexthop *nh2)
 251 {
 252         if (nh1 && !nh2)
 253                 return false;
 254
 255         if (!nh1 && nh2)
 256                 return false;
 257
 258         if (nh1 == nh2)
 259                 return true;
 260
 261         if (nexthop_cmp(nh1, nh2) != 0)
 262                 return false;
 263
 264         return true;
 265 }
 266
 267 bool nexthop_same_no_labels(const struct nexthop *nh1,
 268                             const struct nexthop *nh2)
 269 {
 270         if (nh1 && !nh2)
 271                 return false;
 272
 273         if (!nh1 && nh2)
 274                 return false;
 275
 276         if (nh1 == nh2)
 277                 return true;
 278
 279         if (_nexthop_cmp_no_labels(nh1, nh2) != 0)
 280                 return false;
 281
 282         return true;
 283 }
 284
 285 /*
 286  * Allocate a new nexthop object and initialize it from various args.
 287  */
 288 struct nexthop *nexthop_from_ifindex(ifindex_t ifindex, vrf_id_t vrf_id)
 289 {
 290         struct nexthop *nexthop;
 291
 292         nexthop = nexthop_new();
 293         nexthop->type = NEXTHOP_TYPE_IFINDEX;
 294         nexthop->ifindex = ifindex;
 295         nexthop->vrf_id = vrf_id;
 296
 297         return nexthop;
 298 }
 299
 300 struct nexthop *nexthop_from_ipv4(const struct in_addr *ipv4,
 301                                   const struct in_addr *src,
 302                                   vrf_id_t vrf_id)
 303 {
 304         struct nexthop *nexthop;
 305
 306         nexthop = nexthop_new();
 307         nexthop->type = NEXTHOP_TYPE_IPV4;
 308         nexthop->vrf_id = vrf_id;
 309         nexthop->gate.ipv4 = *ipv4;
 310         if (src)
 311                 nexthop->src.ipv4 = *src;
 312
 313         return nexthop;
 314 }
 315
 316 struct nexthop *nexthop_from_ipv4_ifindex(const struct in_addr *ipv4,
 317                                           const struct in_addr *src,
 318                                           ifindex_t ifindex, vrf_id_t vrf_id)
 319 {
 320         struct nexthop *nexthop;
 321
 322         nexthop = nexthop_new();
 323         nexthop->type = NEXTHOP_TYPE_IPV4_IFINDEX;
 324         nexthop->vrf_id = vrf_id;
 325         nexthop->gate.ipv4 = *ipv4;
 326         if (src)
 327                 nexthop->src.ipv4 = *src;
 328         nexthop->ifindex = ifindex;
 329
 330         return nexthop;
 331 }
 332
 333 struct nexthop *nexthop_from_ipv6(const struct in6_addr *ipv6,
 334                                   vrf_id_t vrf_id)
 335 {
 336         struct nexthop *nexthop;
 337
 338         nexthop = nexthop_new();
 339         nexthop->vrf_id = vrf_id;
 340         nexthop->type = NEXTHOP_TYPE_IPV6;
 341         nexthop->gate.ipv6 = *ipv6;
 342
 343         return nexthop;
 344 }
 345
 346 struct nexthop *nexthop_from_ipv6_ifindex(const struct in6_addr *ipv6,
 347                                           ifindex_t ifindex, vrf_id_t vrf_id)
 348 {
 349         struct nexthop *nexthop;
 350
 351         nexthop = nexthop_new();
 352         nexthop->vrf_id = vrf_id;
 353         nexthop->type = NEXTHOP_TYPE_IPV6_IFINDEX;
 354         nexthop->gate.ipv6 = *ipv6;
 355         nexthop->ifindex = ifindex;
 356
 357         return nexthop;
 358 }
 359
 360 struct nexthop *nexthop_from_blackhole(enum blackhole_type bh_type)
 361 {
 362         struct nexthop *nexthop;
 363
 364         nexthop = nexthop_new();
 365         nexthop->vrf_id = VRF_DEFAULT;
 366         nexthop->type = NEXTHOP_TYPE_BLACKHOLE;
 367         nexthop->bh_type = bh_type;
 368
 369         return nexthop;
 370 }
 371
 372 /* Update nexthop with label information. */
 373 void nexthop_add_labels(struct nexthop *nexthop, enum lsp_types_t type,
 374                         uint8_t num_labels, mpls_label_t *label)
 375 {
 376         struct mpls_label_stack *nh_label;
 377         int i;
 378
 379         nexthop->nh_label_type = type;
 380         nh_label = XCALLOC(MTYPE_NH_LABEL,
 381                            sizeof(struct mpls_label_stack)
 382                                    + num_labels * sizeof(mpls_label_t));
 383         nh_label->num_labels = num_labels;
 384         for (i = 0; i < num_labels; i++)
 385                 nh_label->label[i] = *(label + i);
 386         nexthop->nh_label = nh_label;
 387 }
 388
 389 /* Free label information of nexthop, if present. */
 390 void nexthop_del_labels(struct nexthop *nexthop)
 391 {
 392         if (nexthop->nh_label) {
 393                 XFREE(MTYPE_NH_LABEL, nexthop->nh_label);
 394                 nexthop->nh_label_type = ZEBRA_LSP_NONE;
 395         }
 396 }
 397
 398 const char *nexthop2str(const struct nexthop *nexthop, char *str, int size)
 399 {
 400         switch (nexthop->type) {
 401         case NEXTHOP_TYPE_IFINDEX:
 402                 snprintf(str, size, "if %u", nexthop->ifindex);
 403                 break;
 404         case NEXTHOP_TYPE_IPV4:
 405         case NEXTHOP_TYPE_IPV4_IFINDEX:
 406                 snprintf(str, size, "%s if %u", inet_ntoa(nexthop->gate.ipv4),
 407                          nexthop->ifindex);
 408                 break;
 409         case NEXTHOP_TYPE_IPV6:
 410         case NEXTHOP_TYPE_IPV6_IFINDEX:
 411                 snprintf(str, size, "%s if %u", inet6_ntoa(nexthop->gate.ipv6),
 412                          nexthop->ifindex);
 413                 break;
 414         case NEXTHOP_TYPE_BLACKHOLE:
 415                 snprintf(str, size, "blackhole");
 416                 break;
 417         default:
 418                 snprintf(str, size, "unknown");
 419                 break;
 420         }
 421
 422         return str;
 423 }
 424
 425 /*
 426  * Iteration step for ALL_NEXTHOPS macro:
 427  * This is the tricky part. Check if `nexthop' has
 428  * NEXTHOP_FLAG_RECURSIVE set. If yes, this implies that `nexthop' has
 429  * at least one nexthop attached to `nexthop->resolved', which will be
 430  * the next one.
 431  *
 432  * If NEXTHOP_FLAG_RECURSIVE is not set, `nexthop' will progress in its
 433  * current chain. In case its current chain end is reached, it will move
 434  * upwards in the recursion levels and progress there. Whenever a step
 435  * forward in a chain is done, recursion will be checked again.
 436  * In a nustshell, it's equivalent to a pre-traversal order assuming that
 437  * left branch is 'resolved' and right branch is 'next':
 438  * https://en.wikipedia.org/wiki/Tree_traversal#/media/File:Sorted_binary_tree_preorder.svg
 439  */
 440 struct nexthop *nexthop_next(const struct nexthop *nexthop)
 441 {
 442         if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_RECURSIVE))
 443                 return nexthop->resolved;
 444
 445         if (nexthop->next)
 446                 return nexthop->next;
 447
 448         for (struct nexthop *par = nexthop->rparent; par; par = par->rparent)
 449                 if (par->next)
 450                         return par->next;
 451
 452         return NULL;
 453 }
 454
 455 /* Return the next nexthop in the tree that is resolved and active */
 456 struct nexthop *nexthop_next_active_resolved(const struct nexthop *nexthop)
 457 {
 458         struct nexthop *next = nexthop_next(nexthop);
 459
 460         while (next
 461                && (CHECK_FLAG(next->flags, NEXTHOP_FLAG_RECURSIVE)
 462                    || !CHECK_FLAG(next->flags, NEXTHOP_FLAG_ACTIVE)))
 463                 next = nexthop_next(next);
 464
 465         return next;
 466 }
 467
 468 unsigned int nexthop_level(struct nexthop *nexthop)
 469 {
 470         unsigned int rv = 0;
 471
 472         for (struct nexthop *par = nexthop->rparent; par; par = par->rparent)
 473                 rv++;
 474
 475         return rv;
 476 }
 477
 478 /* Only hash word-sized things, let cmp do the rest. */
 479 uint32_t nexthop_hash_quick(const struct nexthop *nexthop)
 480 {
 481         uint32_t key = 0x45afe398;
 482
 483         key = jhash_3words(nexthop->type, nexthop->vrf_id,
 484                            nexthop->nh_label_type, key);
 485
 486         if (nexthop->nh_label) {
 487                 int labels = nexthop->nh_label->num_labels;
 488                 int i = 0;
 489
 490                 while (labels >= 3) {
 491                         key = jhash_3words(nexthop->nh_label->label[i],
 492                                            nexthop->nh_label->label[i + 1],
 493                                            nexthop->nh_label->label[i + 2],
 494                                            key);
 495                         labels -= 3;
 496                         i += 3;
 497                 }
 498
 499                 if (labels >= 2) {
 500                         key = jhash_2words(nexthop->nh_label->label[i],
 501                                            nexthop->nh_label->label[i + 1],
 502                                            key);
 503                         labels -= 2;
 504                         i += 2;
 505                 }
 506
 507                 if (labels >= 1)
 508                         key = jhash_1word(nexthop->nh_label->label[i], key);
 509         }
 510
 511         key = jhash_2words(nexthop->ifindex,
 512                            CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_ONLINK),
 513                            key);
 514
 515         return key;
 516 }
 517
 518
 519 #define GATE_SIZE 4 /* Number of uint32_t words in struct g_addr */
 520
 521 /* For a more granular hash */
 522 uint32_t nexthop_hash(const struct nexthop *nexthop)
 523 {
 524         uint32_t gate_src_rmap_raw[GATE_SIZE * 3] = {};
 525         /* Get all the quick stuff */
 526         uint32_t key = nexthop_hash_quick(nexthop);
 527
 528         assert(((sizeof(nexthop->gate) + sizeof(nexthop->src)
 529                  + sizeof(nexthop->rmap_src))
 530                 / 3)
 531                == (GATE_SIZE * sizeof(uint32_t)));
 532
 533         memcpy(gate_src_rmap_raw, &nexthop->gate, GATE_SIZE);
 534         memcpy(gate_src_rmap_raw + GATE_SIZE, &nexthop->src, GATE_SIZE);
 535         memcpy(gate_src_rmap_raw + (2 * GATE_SIZE), &nexthop->rmap_src,
 536                GATE_SIZE);
 537
 538         key = jhash2(gate_src_rmap_raw, (GATE_SIZE * 3), key);
 539
 540         return key;
 541 }
 542
 543 void nexthop_copy(struct nexthop *copy, const struct nexthop *nexthop,
 544                   struct nexthop *rparent)
 545 {
 546         copy->vrf_id = nexthop->vrf_id;
 547         copy->ifindex = nexthop->ifindex;
 548         copy->type = nexthop->type;
 549         copy->flags = nexthop->flags;
 550         memcpy(&copy->gate, &nexthop->gate, sizeof(nexthop->gate));
 551         memcpy(&copy->src, &nexthop->src, sizeof(nexthop->src));
 552         memcpy(&copy->rmap_src, &nexthop->rmap_src, sizeof(nexthop->rmap_src));
 553         copy->rparent = rparent;
 554         if (nexthop->nh_label)
 555                 nexthop_add_labels(copy, nexthop->nh_label_type,
 556                                    nexthop->nh_label->num_labels,
 557                                    &nexthop->nh_label->label[0]);
 558 }
 559
 560 struct nexthop *nexthop_dup(const struct nexthop *nexthop,
 561                             struct nexthop *rparent)
 562 {
 563         struct nexthop *new = nexthop_new();
 564
 565         nexthop_copy(new, nexthop, rparent);
 566         return new;
 567 }
 568
 569 /*
 570  * nexthop printing variants:
 571  *      %pNHvv
 572  *              via 1.2.3.4
 573  *              via 1.2.3.4, eth0
 574  *              is directly connected, eth0
 575  *              unreachable (blackhole)
 576  *      %pNHv
 577  *              1.2.3.4
 578  *              1.2.3.4, via eth0
 579  *              directly connected, eth0
 580  *              unreachable (blackhole)
 581  *      %pNHs
 582  *              nexthop2str()
 583  */
 584 printfrr_ext_autoreg_p("NH", printfrr_nh)
 585 static ssize_t printfrr_nh(char *buf, size_t bsz, const char *fmt,
 586                            int prec, const void *ptr)
 587 {
 588         const struct nexthop *nexthop = ptr;
 589         struct fbuf fb = { .buf = buf, .pos = buf, .len = bsz - 1 };
 590         bool do_ifi = false;
 591         const char *s, *v_is = "", *v_via = "", *v_viaif = "via ";
 592         ssize_t ret = 3;
 593
 594         switch (fmt[2]) {
 595         case 'v':
 596                 if (fmt[3] == 'v') {
 597                         v_is = "is ";
 598                         v_via = "via ";
 599                         v_viaif = "";
 600                         ret++;
 601                 }
 602
 603                 switch (nexthop->type) {
 604                 case NEXTHOP_TYPE_IPV4:
 605                 case NEXTHOP_TYPE_IPV4_IFINDEX:
 606                         bprintfrr(&fb, "%s%pI4", v_via, &nexthop->gate.ipv4);
 607                         do_ifi = true;
 608                         break;
 609                 case NEXTHOP_TYPE_IPV6:
 610                 case NEXTHOP_TYPE_IPV6_IFINDEX:
 611                         bprintfrr(&fb, "%s%pI6", v_via, &nexthop->gate.ipv6);
 612                         do_ifi = true;
 613                         break;
 614                 case NEXTHOP_TYPE_IFINDEX:
 615                         bprintfrr(&fb, "%sdirectly connected, %s", v_is,
 616                                 ifindex2ifname(nexthop->ifindex,
 617                                                nexthop->vrf_id));
 618                         break;
 619                 case NEXTHOP_TYPE_BLACKHOLE:
 620                         switch (nexthop->bh_type) {
 621                         case BLACKHOLE_REJECT:
 622                                 s = " (ICMP unreachable)";
 623                                 break;
 624                         case BLACKHOLE_ADMINPROHIB:
 625                                 s = " (ICMP admin-prohibited)";
 626                                 break;
 627                         case BLACKHOLE_NULL:
 628                                 s = " (blackhole)";
 629                                 break;
 630                         default:
 631                                 s = "";
 632                                 break;
 633                         }
 634                         bprintfrr(&fb, "unreachable%s", s);
 635                         break;
 636                 default:
 637                         break;
 638                 }
 639                 if (do_ifi && nexthop->ifindex)
 640                         bprintfrr(&fb, ", %s%s", v_viaif, ifindex2ifname(
 641                                         nexthop->ifindex,
 642                                         nexthop->vrf_id));
 643
 644                 *fb.pos = '\0';
 645                 return ret;
 646         case 's':
 647                 nexthop2str(nexthop, buf, bsz);
 648                 return 3;
 649         }
 650         return 0;
 651 }