vnet/vnet/fib/fib_path.c

   1 /*
   2  * Copyright (c) 2016 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <vlib/vlib.h>
  17 #include <vnet/vnet.h>
  18 #include <vnet/ip/format.h>
  19 #include <vnet/ip/ip.h>
  20 #include <vnet/dpo/drop_dpo.h>
  21 #include <vnet/dpo/receive_dpo.h>
  22 #include <vnet/dpo/load_balance_map.h>
  23 #include <vnet/dpo/lookup_dpo.h>
  24
  25 #include <vnet/adj/adj.h>
  26
  27 #include "fib_path.h"
  28 #include "fib_node.h"
  29 #include "fib_table.h"
  30 #include "fib_entry.h"
  31 #include "fib_path_list.h"
  32 #include "fib_internal.h"
  33
  34 /**
  35  * Enurmeration of path types
  36  */
  37 typedef enum fib_path_type_t_ {
  38     /**
  39      * Marker. Add new types after this one.
  40      */
  41     FIB_PATH_TYPE_FIRST = 0,
  42     /**
  43      * Attached-nexthop. An interface and a nexthop are known.
  44      */
  45     FIB_PATH_TYPE_ATTACHED_NEXT_HOP = FIB_PATH_TYPE_FIRST,
  46     /**
  47      * attached. Only the interface is known.
  48      */
  49     FIB_PATH_TYPE_ATTACHED,
  50     /**
  51      * recursive. Only the next-hop is known.
  52      */
  53     FIB_PATH_TYPE_RECURSIVE,
  54     /**
  55      * special. nothing is known. so we drop.
  56      */
  57     FIB_PATH_TYPE_SPECIAL,
  58     /**
  59      * exclusive. user provided adj.
  60      */
  61     FIB_PATH_TYPE_EXCLUSIVE,
  62     /**
  63      * deag. Link to a lookup adj in the next table
  64      */
  65     FIB_PATH_TYPE_DEAG,
  66     /**
  67      * receive. it's for-us.
  68      */
  69     FIB_PATH_TYPE_RECEIVE,
  70     /**
  71      * Marker. Add new types before this one, then update it.
  72      */
  73     FIB_PATH_TYPE_LAST = FIB_PATH_TYPE_RECEIVE,
  74 } __attribute__ ((packed)) fib_path_type_t;
  75
  76 /**
  77  * The maximum number of path_types
  78  */
  79 #define FIB_PATH_TYPE_MAX (FIB_PATH_TYPE_LAST + 1)
  80
  81 #define FIB_PATH_TYPES {                                        \
  82     [FIB_PATH_TYPE_ATTACHED_NEXT_HOP] = "attached-nexthop",     \
  83     [FIB_PATH_TYPE_ATTACHED]          = "attached",             \
  84     [FIB_PATH_TYPE_RECURSIVE]         = "recursive",            \
  85     [FIB_PATH_TYPE_SPECIAL]           = "special",              \
  86     [FIB_PATH_TYPE_EXCLUSIVE]         = "exclusive",            \
  87     [FIB_PATH_TYPE_DEAG]              = "deag",                 \
  88     [FIB_PATH_TYPE_RECEIVE]           = "receive",              \
  89 }
  90
  91 #define FOR_EACH_FIB_PATH_TYPE(_item) \
  92     for (_item = FIB_PATH_TYPE_FIRST; _item <= FIB_PATH_TYPE_LAST; _item++)
  93
  94 /**
  95  * Enurmeration of path operational (i.e. derived) attributes
  96  */
  97 typedef enum fib_path_oper_attribute_t_ {
  98     /**
  99      * Marker. Add new types after this one.
 100      */
 101     FIB_PATH_OPER_ATTRIBUTE_FIRST = 0,
 102     /**
 103      * The path forms part of a recursive loop.
 104      */
 105     FIB_PATH_OPER_ATTRIBUTE_RECURSIVE_LOOP = FIB_PATH_OPER_ATTRIBUTE_FIRST,
 106     /**
 107      * The path is resolved
 108      */
 109     FIB_PATH_OPER_ATTRIBUTE_RESOLVED,
 110     /**
 111      * The path has become a permanent drop.
 112      */
 113     FIB_PATH_OPER_ATTRIBUTE_DROP,
 114     /**
 115      * Marker. Add new types before this one, then update it.
 116      */
 117     FIB_PATH_OPER_ATTRIBUTE_LAST = FIB_PATH_OPER_ATTRIBUTE_DROP,
 118 } __attribute__ ((packed)) fib_path_oper_attribute_t;
 119
 120 /**
 121  * The maximum number of path operational attributes
 122  */
 123 #define FIB_PATH_OPER_ATTRIBUTE_MAX (FIB_PATH_OPER_ATTRIBUTE_LAST + 1)
 124
 125 #define FIB_PATH_OPER_ATTRIBUTES {                                      \
 126     [FIB_PATH_OPER_ATTRIBUTE_RECURSIVE_LOOP] = "recursive-loop",        \
 127     [FIB_PATH_OPER_ATTRIBUTE_RESOLVED]       = "resolved",              \
 128     [FIB_PATH_OPER_ATTRIBUTE_DROP]           = "drop",                  \
 129 }
 130
 131 #define FOR_EACH_FIB_PATH_OPER_ATTRIBUTE(_item) \
 132     for (_item = FIB_PATH_OPER_ATTRIBUTE_FIRST; \
 133          _item <= FIB_PATH_OPER_ATTRIBUTE_LAST; \
 134          _item++)
 135
 136 /**
 137  * Path flags from the attributes
 138  */
 139 typedef enum fib_path_oper_flags_t_ {
 140     FIB_PATH_OPER_FLAG_NONE = 0,
 141     FIB_PATH_OPER_FLAG_RECURSIVE_LOOP = (1 << FIB_PATH_OPER_ATTRIBUTE_RECURSIVE_LOOP),
 142     FIB_PATH_OPER_FLAG_DROP = (1 << FIB_PATH_OPER_ATTRIBUTE_DROP),
 143     FIB_PATH_OPER_FLAG_RESOLVED = (1 << FIB_PATH_OPER_ATTRIBUTE_RESOLVED),
 144 } __attribute__ ((packed)) fib_path_oper_flags_t;
 145
 146 /**
 147  * A FIB path
 148  */
 149 typedef struct fib_path_t_ {
 150     /**
 151      * A path is a node in the FIB graph.
 152      */
 153     fib_node_t fp_node;
 154
 155     /**
 156      * The index of the path-list to which this path belongs
 157      */
 158     u32 fp_pl_index;
 159
 160     /**
 161      * This marks the start of the memory area used to hash
 162      * the path
 163      */
 164     STRUCT_MARK(path_hash_start);
 165
 166     /**
 167      * Configuration Flags
 168      */
 169     fib_path_cfg_flags_t fp_cfg_flags;
 170
 171     /**
 172      * The type of the path. This is the selector for the union
 173      */
 174     fib_path_type_t fp_type;
 175
 176     /**
 177      * The protocol of the next-hop, i.e. the address family of the
 178      * next-hop's address. We can't derive this from the address itself
 179      * since the address can be all zeros
 180      */
 181     fib_protocol_t fp_nh_proto;
 182
 183     /**
 184      * UCMP [unnormalised] weigt
 185      */
 186     u32 fp_weight;
 187
 188     /**
 189      * per-type union of the data required to resolve the path
 190      */
 191     union {
 192         struct {
 193             /**
 194              * The next-hop
 195              */
 196             ip46_address_t fp_nh;
 197             /**
 198              * The interface
 199              */
 200             u32 fp_interface;
 201         } attached_next_hop;
 202         struct {
 203             /**
 204              * The interface
 205              */
 206             u32 fp_interface;
 207         } attached;
 208         struct {
 209             /**
 210              * The next-hop
 211              */
 212             ip46_address_t fp_nh;
 213             /**
 214              * The FIB table index in which to find the next-hop.
 215              * This needs to be fixed. We should lookup the adjacencies in
 216              * a separate table of adjacencies, rather than from the FIB.
 217              * Two reasons I can think of:
 218              *   - consider:
 219              *       int ip addr Gig0 10.0.0.1/24
 220              *       ip route 10.0.0.2/32 via Gig1 192.168.1.2
 221              *       ip route 1.1.1.1/32 via Gig0 10.0.0.2
 222              *     this is perfectly valid.
 223              *     Packets addressed to 10.0.0.2 should be sent via Gig1.
 224              *     Packets address to 1.1.1.1 should be sent via Gig0.
 225              *    when we perform the adj resolution from the FIB for the path
 226              *    "via Gig0 10.0.0.2" the lookup will result in the route via Gig1
 227              *    and so we will pick up the adj via Gig1 - which was not what the
 228              *    operator wanted.
 229              *  - we can only return link-type IPv4 and so not the link-type MPLS.
 230              *    more on this in a later commit.
 231              *
 232              * The table ID should only belong to a recursive path and indicate
 233              * which FIB should be used to resolve the next-hop.
 234              */
 235             fib_node_index_t fp_tbl_id;
 236         } recursive;
 237         struct {
 238             /**
 239              * The FIN index in which to perfom the next lookup
 240              */
 241             fib_node_index_t fp_tbl_id;
 242         } deag;
 243         struct {
 244         } special;
 245         struct {
 246             /**
 247              * The user provided 'exclusive' DPO
 248              */
 249             dpo_id_t fp_ex_dpo;
 250         } exclusive;
 251         struct {
 252             /**
 253              * The interface on which the local address is configured
 254              */
 255             u32 fp_interface;
 256             /**
 257              * The next-hop
 258              */
 259             ip46_address_t fp_addr;
 260         } receive;
 261     };
 262     STRUCT_MARK(path_hash_end);
 263
 264     /**
 265      * Memebers in this last section represent information that is
 266      * dervied during resolution. It should not be copied to new paths
 267      * nor compared.
 268      */
 269
 270     /**
 271      * Operational Flags
 272      */
 273     fib_path_oper_flags_t fp_oper_flags;
 274
 275     /**
 276      * the resolving via fib. not part of the union, since it it not part
 277      * of the path's hash.
 278      */
 279     fib_node_index_t fp_via_fib;
 280
 281     /**
 282      * The Data-path objects through which this path resolves for IP.
 283      */
 284     dpo_id_t fp_dpo;
 285
 286     /**
 287      * the index of this path in the parent's child list.
 288      */
 289     u32 fp_sibling;
 290 } fib_path_t;
 291
 292 /*
 293  * Array of strings/names for the path types and attributes
 294  */
 295 static const char *fib_path_type_names[] = FIB_PATH_TYPES;
 296 static const char *fib_path_oper_attribute_names[] = FIB_PATH_OPER_ATTRIBUTES;
 297 static const char *fib_path_cfg_attribute_names[]  = FIB_PATH_CFG_ATTRIBUTES;
 298
 299 /*
 300  * The memory pool from which we allocate all the paths
 301  */
 302 static fib_path_t *fib_path_pool;
 303
 304 /*
 305  * Debug macro
 306  */
 307 #ifdef FIB_DEBUG
 308 #define FIB_PATH_DBG(_p, _fmt, _args...)                        \
 309 {                                                               \
 310     u8 *_tmp = NULL;                                            \
 311     _tmp = fib_path_format(fib_path_get_index(_p), _tmp);       \
 312     clib_warning("path:[%d:%s]:" _fmt,                          \
 313                  fib_path_get_index(_p), _tmp,                  \
 314                  ##_args);                                      \
 315     vec_free(_tmp);                                             \
 316 }
 317 #else
 318 #define FIB_PATH_DBG(_p, _fmt, _args...)
 319 #endif
 320
 321 static fib_path_t *
 322 fib_path_get (fib_node_index_t index)
 323 {
 324     return (pool_elt_at_index(fib_path_pool, index));
 325 }
 326
 327 static fib_node_index_t
 328 fib_path_get_index (fib_path_t *path)
 329 {
 330     return (path - fib_path_pool);
 331 }
 332
 333 static fib_node_t *
 334 fib_path_get_node (fib_node_index_t index)
 335 {
 336     return ((fib_node_t*)fib_path_get(index));
 337 }
 338
 339 static fib_path_t*
 340 fib_path_from_fib_node (fib_node_t *node)
 341 {
 342 #if CLIB_DEBUG > 0
 343     ASSERT(FIB_NODE_TYPE_PATH == node->fn_type);
 344 #endif
 345     return ((fib_path_t*)node);
 346 }
 347
 348 u8 *
 349 format_fib_path (u8 * s, va_list * args)
 350 {
 351     fib_path_t *path = va_arg (*args, fib_path_t *);
 352     vnet_main_t * vnm = vnet_get_main();
 353     fib_path_oper_attribute_t oattr;
 354     fib_path_cfg_attribute_t cattr;
 355
 356     s = format (s, "      index:%d ", fib_path_get_index(path));
 357     s = format (s, "pl-index:%d ", path->fp_pl_index);
 358     s = format (s, "%U ", format_fib_protocol, path->fp_nh_proto);
 359     s = format (s, "weight=%d ", path->fp_weight);
 360     s = format (s, "%s: ", fib_path_type_names[path->fp_type]);
 361     if (FIB_PATH_OPER_FLAG_NONE != path->fp_oper_flags) {
 362         s = format(s, " oper-flags:");
 363         FOR_EACH_FIB_PATH_OPER_ATTRIBUTE(oattr) {
 364             if ((1<<oattr) & path->fp_oper_flags) {
 365                 s = format (s, "%s,", fib_path_oper_attribute_names[oattr]);
 366             }
 367         }
 368     }
 369     if (FIB_PATH_CFG_FLAG_NONE != path->fp_cfg_flags) {
 370         s = format(s, " cfg-flags:");
 371         FOR_EACH_FIB_PATH_CFG_ATTRIBUTE(cattr) {
 372             if ((1<<cattr) & path->fp_cfg_flags) {
 373                 s = format (s, "%s,", fib_path_cfg_attribute_names[cattr]);
 374             }
 375         }
 376     }
 377     s = format(s, "\n       ");
 378
 379     switch (path->fp_type)
 380     {
 381     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
 382         s = format (s, "%U", format_ip46_address,
 383                     &path->attached_next_hop.fp_nh,
 384                     IP46_TYPE_ANY);
 385         if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_DROP)
 386         {
 387             s = format (s, " if_index:%d", path->attached_next_hop.fp_interface);
 388         }
 389         else
 390         {
 391             s = format (s, " %U",
 392                         format_vnet_sw_interface_name,
 393                         vnm,
 394                         vnet_get_sw_interface(
 395                             vnm,
 396                             path->attached_next_hop.fp_interface));
 397             if (vnet_sw_interface_is_p2p(vnet_get_main(),
 398                                          path->attached_next_hop.fp_interface))
 399             {
 400                 s = format (s, " (p2p)");
 401             }
 402         }
 403         if (!dpo_id_is_valid(&path->fp_dpo))
 404         {
 405             s = format(s, "\n          unresolved");
 406         }
 407         else
 408         {
 409             s = format(s, "\n          %U",
 410                        format_dpo_id,
 411                        &path->fp_dpo, 13);
 412         }
 413         break;
 414     case FIB_PATH_TYPE_ATTACHED:
 415         if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_DROP)
 416         {
 417             s = format (s, " if_index:%d", path->attached_next_hop.fp_interface);
 418         }
 419         else
 420         {
 421             s = format (s, " %U",
 422                         format_vnet_sw_interface_name,
 423                         vnm,
 424                         vnet_get_sw_interface(
 425                             vnm,
 426                             path->attached.fp_interface));
 427         }
 428         break;
 429     case FIB_PATH_TYPE_RECURSIVE:
 430         s = format (s, "via %U",
 431                     format_ip46_address,
 432                     &path->recursive.fp_nh,
 433                     IP46_TYPE_ANY);
 434         s = format (s, " in fib:%d", path->recursive.fp_tbl_id, path->fp_via_fib);
 435         s = format (s, " via-fib:%d", path->fp_via_fib);
 436         s = format (s, " via-dpo:[%U:%d]",
 437                     format_dpo_type, path->fp_dpo.dpoi_type,
 438                     path->fp_dpo.dpoi_index);
 439
 440         break;
 441     case FIB_PATH_TYPE_RECEIVE:
 442     case FIB_PATH_TYPE_SPECIAL:
 443     case FIB_PATH_TYPE_DEAG:
 444     case FIB_PATH_TYPE_EXCLUSIVE:
 445         if (dpo_id_is_valid(&path->fp_dpo))
 446         {
 447             s = format(s, "%U", format_dpo_id,
 448                        &path->fp_dpo, 2);
 449         }
 450         break;
 451     }
 452     return (s);
 453 }
 454
 455 u8 *
 456 fib_path_format (fib_node_index_t pi, u8 *s)
 457 {
 458     fib_path_t *path;
 459
 460     path = fib_path_get(pi);
 461     ASSERT(NULL != path);
 462
 463     return (format (s, "%U", format_fib_path, path));
 464 }
 465
 466 u8 *
 467 fib_path_adj_format (fib_node_index_t pi,
 468                      u32 indent,
 469                      u8 *s)
 470 {
 471     fib_path_t *path;
 472
 473     path = fib_path_get(pi);
 474     ASSERT(NULL != path);
 475
 476     if (!dpo_id_is_valid(&path->fp_dpo))
 477     {
 478         s = format(s, " unresolved");
 479     }
 480     else
 481     {
 482         s = format(s, "%U", format_dpo_id,
 483                    &path->fp_dpo, 2);
 484     }
 485
 486     return (s);
 487 }
 488
 489 /*
 490  * fib_path_last_lock_gone
 491  *
 492  * We don't share paths, we share path lists, so the [un]lock functions
 493  * are no-ops
 494  */
 495 static void
 496 fib_path_last_lock_gone (fib_node_t *node)
 497 {
 498     ASSERT(0);
 499 }
 500
 501 static const adj_index_t
 502 fib_path_attached_next_hop_get_adj (fib_path_t *path,
 503                                     fib_link_t link)
 504 {
 505     if (vnet_sw_interface_is_p2p(vnet_get_main(),
 506                                  path->attached_next_hop.fp_interface))
 507     {
 508         /*
 509          * if the interface is p2p then the adj for the specific
 510          * neighbour on that link will never exist. on p2p links
 511          * the subnet address (the attached route) links to the
 512          * auto-adj (see below), we want that adj here too.
 513          */
 514         return (adj_nbr_add_or_lock(path->fp_nh_proto,
 515                                     link,
 516                                     &zero_addr,
 517                                     path->attached_next_hop.fp_interface));
 518     }
 519     else
 520     {
 521         return (adj_nbr_add_or_lock(path->fp_nh_proto,
 522                                     link,
 523                                     &path->attached_next_hop.fp_nh,
 524                                     path->attached_next_hop.fp_interface));
 525     }
 526 }
 527
 528 static void
 529 fib_path_attached_next_hop_set (fib_path_t *path)
 530 {
 531     /*
 532      * resolve directly via the adjacnecy discribed by the
 533      * interface and next-hop
 534      */
 535     if (!vnet_sw_interface_is_admin_up(vnet_get_main(),
 536                                       path->attached_next_hop.fp_interface))
 537     {
 538         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 539     }
 540
 541     dpo_set(&path->fp_dpo,
 542             DPO_ADJACENCY,
 543             fib_proto_to_dpo(path->fp_nh_proto),
 544             fib_path_attached_next_hop_get_adj(
 545                  path,
 546                  fib_proto_to_link(path->fp_nh_proto)));
 547
 548     /*
 549      * become a child of the adjacency so we receive updates
 550      * when its rewrite changes
 551      */
 552     path->fp_sibling = adj_child_add(path->fp_dpo.dpoi_index,
 553                                      FIB_NODE_TYPE_PATH,
 554                                      fib_path_get_index(path));
 555 }
 556
 557 /*
 558  * create of update the paths recursive adj
 559  */
 560 static void
 561 fib_path_recursive_adj_update (fib_path_t *path,
 562                                fib_forward_chain_type_t fct,
 563                                dpo_id_t *dpo)
 564 {
 565     dpo_id_t via_dpo = DPO_NULL;
 566
 567     /*
 568      * get the DPO to resolve through from the via-entry
 569      */
 570     fib_entry_contribute_forwarding(path->fp_via_fib,
 571                                     fct,
 572                                     &via_dpo);
 573
 574
 575     /*
 576      * hope for the best - clear if restrictions apply.
 577      */
 578     path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
 579
 580     /*
 581      * Validate any recursion constraints and over-ride the via
 582      * adj if not met
 583      */
 584     if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RECURSIVE_LOOP)
 585     {
 586         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 587         dpo_copy(&via_dpo, drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
 588     }
 589     else if (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_RESOLVE_HOST)
 590     {
 591         /*
 592          * the via FIB must be a host route.
 593          * note the via FIB just added will always be a host route
 594          * since it is an RR source added host route. So what we need to
 595          * check is whether the route has other sources. If it does then
 596          * some other source has added it as a host route. If it doesn't
 597          * then it was added only here and inherits forwarding from a cover.
 598          * the cover is not a host route.
 599          * The RR source is the lowest priority source, so we check if it
 600          * is the best. if it is there are no other sources.
 601          */
 602         if (fib_entry_get_best_source(path->fp_via_fib) >= FIB_SOURCE_RR)
 603         {
 604             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 605             dpo_copy(&via_dpo, drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
 606
 607             /*
 608              * PIC edge trigger. let the load-balance maps know
 609              */
 610             load_balance_map_path_state_change(fib_path_get_index(path));
 611         }
 612     }
 613     else if (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_RESOLVE_ATTACHED)
 614     {
 615         /*
 616          * RR source entries inherit the flags from the cover, so
 617          * we can check the via directly
 618          */
 619         if (!(FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags(path->fp_via_fib)))
 620         {
 621             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 622             dpo_copy(&via_dpo, drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
 623
 624             /*
 625              * PIC edge trigger. let the load-balance maps know
 626              */
 627             load_balance_map_path_state_change(fib_path_get_index(path));
 628         }
 629     }
 630
 631     /*
 632      * update the path's contributed DPO
 633      */
 634     dpo_copy(dpo, &via_dpo);
 635
 636     FIB_PATH_DBG(path, "recursive update: %U",
 637                  fib_get_lookup_main(path->fp_nh_proto),
 638                  &path->fp_dpo, 2);
 639
 640     dpo_reset(&via_dpo);
 641 }
 642
 643 /*
 644  * fib_path_is_permanent_drop
 645  *
 646  * Return !0 if the path is configured to permanently drop,
 647  * despite other attributes.
 648  */
 649 static int
 650 fib_path_is_permanent_drop (fib_path_t *path)
 651 {
 652     return ((path->fp_cfg_flags & FIB_PATH_CFG_FLAG_DROP) ||
 653             (path->fp_oper_flags & FIB_PATH_OPER_FLAG_DROP));
 654 }
 655
 656 /*
 657  * fib_path_unresolve
 658  *
 659  * Remove our dependency on the resolution target
 660  */
 661 static void
 662 fib_path_unresolve (fib_path_t *path)
 663 {
 664     /*
 665      * the forced drop path does not need unresolving
 666      */
 667     if (fib_path_is_permanent_drop(path))
 668     {
 669         return;
 670     }
 671
 672     switch (path->fp_type)
 673     {
 674     case FIB_PATH_TYPE_RECURSIVE:
 675         if (FIB_NODE_INDEX_INVALID != path->fp_via_fib)
 676         {
 677             fib_prefix_t pfx;
 678
 679             fib_prefix_from_ip46_addr(&path->recursive.fp_nh, &pfx);
 680             fib_entry_child_remove(path->fp_via_fib,
 681                                    path->fp_sibling);
 682             fib_table_entry_special_remove(path->recursive.fp_tbl_id,
 683                                            &pfx,
 684                                            FIB_SOURCE_RR);
 685             path->fp_via_fib = FIB_NODE_INDEX_INVALID;
 686         }
 687         break;
 688     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
 689     case FIB_PATH_TYPE_ATTACHED:
 690         adj_child_remove(path->fp_dpo.dpoi_index,
 691                          path->fp_sibling);
 692         adj_unlock(path->fp_dpo.dpoi_index);
 693         break;
 694     case FIB_PATH_TYPE_EXCLUSIVE:
 695         dpo_reset(&path->exclusive.fp_ex_dpo);
 696         break;
 697     case FIB_PATH_TYPE_SPECIAL:
 698     case FIB_PATH_TYPE_RECEIVE:
 699     case FIB_PATH_TYPE_DEAG:
 700         /*
 701          * these hold only the path's DPO, which is reset below.
 702          */
 703         break;
 704     }
 705
 706     /*
 707      * release the adj we were holding and pick up the
 708      * drop just in case.
 709      */
 710     dpo_reset(&path->fp_dpo);
 711     path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 712
 713     return;
 714 }
 715
 716 static fib_forward_chain_type_t
 717 fib_path_proto_to_chain_type (fib_protocol_t proto)
 718 {
 719     switch (proto)
 720     {
 721     case FIB_PROTOCOL_IP4:
 722         return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
 723     case FIB_PROTOCOL_IP6:
 724         return (FIB_FORW_CHAIN_TYPE_UNICAST_IP6);
 725     case FIB_PROTOCOL_MPLS:
 726         return (FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS);
 727     }
 728     return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
 729 }
 730
 731 /*
 732  * fib_path_back_walk_notify
 733  *
 734  * A back walk has reach this path.
 735  */
 736 static fib_node_back_walk_rc_t
 737 fib_path_back_walk_notify (fib_node_t *node,
 738                            fib_node_back_walk_ctx_t *ctx)
 739 {
 740     fib_path_t *path;
 741
 742     path = fib_path_from_fib_node(node);
 743
 744     switch (path->fp_type)
 745     {
 746     case FIB_PATH_TYPE_RECURSIVE:
 747         if (FIB_NODE_BW_REASON_FLAG_EVALUATE & ctx->fnbw_reason)
 748         {
 749             /*
 750              * modify the recursive adjacency to use the new forwarding
 751              * of the via-fib.
 752              * this update is visible to packets in flight in the DP.
 753              */
 754             fib_path_recursive_adj_update(
 755                 path,
 756                 fib_path_proto_to_chain_type(path->fp_nh_proto),
 757                 &path->fp_dpo);
 758         }
 759         break;
 760     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
 761         /*
 762 FIXME comment
 763          * ADJ_UPDATE backwalk pass silently through here and up to
 764          * the path-list when the multipath adj collapse occurs.
 765          * The reason we do this is that the assumtption is that VPP
 766          * runs in an environment where the Control-Plane is remote
 767          * and hence reacts slowly to link up down. In order to remove
 768          * this down link from the ECMP set quickly, we back-walk.
 769          * VPP also has dedicated CPUs, so we are not stealing resources
 770          * from the CP to do so.
 771          */
 772         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_UP & ctx->fnbw_reason)
 773         {
 774             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
 775         }
 776         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DOWN & ctx->fnbw_reason)
 777         {
 778             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 779         }
 780         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DELETE & ctx->fnbw_reason)
 781         {
 782             /*
 783              * The interface this path resolves through has been deleted.
 784              * This will leave the path in a permanent drop state. The route
 785              * needs to be removed and readded (and hence the path-list deleted)
 786              * before it can forward again.
 787              */
 788             fib_path_unresolve(path);
 789             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_DROP;
 790         }
 791         if (FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE & ctx->fnbw_reason)
 792         {
 793             /*
 794              * restack the DPO to pick up the correct DPO sub-type
 795              */
 796             adj_index_t ai;
 797
 798             ai = fib_path_attached_next_hop_get_adj(
 799                      path,
 800                      fib_proto_to_link(path->fp_nh_proto));
 801
 802             dpo_set(&path->fp_dpo, DPO_ADJACENCY,
 803                     fib_proto_to_dpo(path->fp_nh_proto),
 804                     ai);
 805             adj_unlock(ai);
 806         }
 807         break;
 808     case FIB_PATH_TYPE_ATTACHED:
 809         /*
 810          * FIXME; this could schedule a lower priority walk, since attached
 811          * routes are not usually in ECMP configurations so the backwalk to
 812          * the FIB entry does not need to be high priority
 813          */
 814         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_UP & ctx->fnbw_reason)
 815         {
 816             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
 817         }
 818         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DOWN & ctx->fnbw_reason)
 819         {
 820             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 821         }
 822         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DELETE & ctx->fnbw_reason)
 823         {
 824             fib_path_unresolve(path);
 825             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_DROP;
 826         }
 827         break;
 828     case FIB_PATH_TYPE_DEAG:
 829         /*
 830          * FIXME When VRF delete is allowed this will need a poke.
 831          */
 832     case FIB_PATH_TYPE_SPECIAL:
 833     case FIB_PATH_TYPE_RECEIVE:
 834     case FIB_PATH_TYPE_EXCLUSIVE:
 835         /*
 836          * these path types have no parents. so to be
 837          * walked from one is unexpected.
 838          */
 839         ASSERT(0);
 840         break;
 841     }
 842
 843     /*
 844      * propagate the backwalk further to the path-list
 845      */
 846     fib_path_list_back_walk(path->fp_pl_index, ctx);
 847
 848     return (FIB_NODE_BACK_WALK_CONTINUE);
 849 }
 850
 851 static void
 852 fib_path_memory_show (void)
 853 {
 854     fib_show_memory_usage("Path",
 855                           pool_elts(fib_path_pool),
 856                           pool_len(fib_path_pool),
 857                           sizeof(fib_path_t));
 858 }
 859
 860 /*
 861  * The FIB path's graph node virtual function table
 862  */
 863 static const fib_node_vft_t fib_path_vft = {
 864     .fnv_get = fib_path_get_node,
 865     .fnv_last_lock = fib_path_last_lock_gone,
 866     .fnv_back_walk = fib_path_back_walk_notify,
 867     .fnv_mem_show = fib_path_memory_show,
 868 };
 869
 870 static fib_path_cfg_flags_t
 871 fib_path_route_flags_to_cfg_flags (const fib_route_path_t *rpath)
 872 {
 873     fib_path_cfg_flags_t cfg_flags = FIB_PATH_CFG_ATTRIBUTE_FIRST;
 874
 875     if (rpath->frp_flags & FIB_ROUTE_PATH_RESOLVE_VIA_HOST)
 876         cfg_flags |= FIB_PATH_CFG_FLAG_RESOLVE_HOST;
 877     if (rpath->frp_flags & FIB_ROUTE_PATH_RESOLVE_VIA_ATTACHED)
 878         cfg_flags |= FIB_PATH_CFG_FLAG_RESOLVE_ATTACHED;
 879
 880     return (cfg_flags);
 881 }
 882
 883 /*
 884  * fib_path_create
 885  *
 886  * Create and initialise a new path object.
 887  * return the index of the path.
 888  */
 889 fib_node_index_t
 890 fib_path_create (fib_node_index_t pl_index,
 891                  fib_protocol_t nh_proto,
 892                  fib_path_cfg_flags_t flags,
 893                  const fib_route_path_t *rpath)
 894 {
 895     fib_path_t *path;
 896
 897     pool_get(fib_path_pool, path);
 898     memset(path, 0, sizeof(*path));
 899
 900     fib_node_init(&path->fp_node,
 901                   FIB_NODE_TYPE_PATH);
 902
 903     dpo_reset(&path->fp_dpo);
 904     path->fp_pl_index = pl_index;
 905     path->fp_nh_proto = nh_proto;
 906     path->fp_via_fib = FIB_NODE_INDEX_INVALID;
 907     path->fp_weight = rpath->frp_weight;
 908     path->fp_cfg_flags = flags;
 909     path->fp_cfg_flags |= fib_path_route_flags_to_cfg_flags(rpath);
 910
 911     /*
 912      * deduce the path's tpye from the parementers and save what is needed.
 913      */
 914     if (~0 != rpath->frp_sw_if_index)
 915     {
 916         if (flags & FIB_PATH_CFG_FLAG_LOCAL)
 917         {
 918             path->fp_type = FIB_PATH_TYPE_RECEIVE;
 919             path->receive.fp_interface = rpath->frp_sw_if_index;
 920             path->receive.fp_addr = rpath->frp_addr;
 921         }
 922         else
 923         {
 924             if (ip46_address_is_zero(&rpath->frp_addr))
 925             {
 926                 path->fp_type = FIB_PATH_TYPE_ATTACHED;
 927                 path->attached.fp_interface = rpath->frp_sw_if_index;
 928             }
 929             else
 930             {
 931                 path->fp_type = FIB_PATH_TYPE_ATTACHED_NEXT_HOP;
 932                 path->attached_next_hop.fp_interface = rpath->frp_sw_if_index;
 933                 path->attached_next_hop.fp_nh = rpath->frp_addr;
 934             }
 935         }
 936     }
 937     else
 938     {
 939         if (ip46_address_is_zero(&rpath->frp_addr))
 940         {
 941             if (~0 == rpath->frp_fib_index)
 942             {
 943                 path->fp_type = FIB_PATH_TYPE_SPECIAL;
 944             }
 945             else
 946             {
 947                 path->fp_type = FIB_PATH_TYPE_DEAG;
 948                 path->deag.fp_tbl_id = rpath->frp_fib_index;
 949             }
 950         }
 951         else
 952         {
 953             path->fp_type = FIB_PATH_TYPE_RECURSIVE;
 954             path->recursive.fp_nh = rpath->frp_addr;
 955             path->recursive.fp_tbl_id = rpath->frp_fib_index;
 956         }
 957     }
 958
 959     FIB_PATH_DBG(path, "create");
 960
 961     return (fib_path_get_index(path));
 962 }
 963
 964 /*
 965  * fib_path_create_special
 966  *
 967  * Create and initialise a new path object.
 968  * return the index of the path.
 969  */
 970 fib_node_index_t
 971 fib_path_create_special (fib_node_index_t pl_index,
 972                          fib_protocol_t nh_proto,
 973                          fib_path_cfg_flags_t flags,
 974                          const dpo_id_t *dpo)
 975 {
 976     fib_path_t *path;
 977
 978     pool_get(fib_path_pool, path);
 979     memset(path, 0, sizeof(*path));
 980
 981     fib_node_init(&path->fp_node,
 982                   FIB_NODE_TYPE_PATH);
 983     dpo_reset(&path->fp_dpo);
 984
 985     path->fp_pl_index = pl_index;
 986     path->fp_weight = 1;
 987     path->fp_nh_proto = nh_proto;
 988     path->fp_via_fib = FIB_NODE_INDEX_INVALID;
 989     path->fp_cfg_flags = flags;
 990
 991     if (FIB_PATH_CFG_FLAG_DROP & flags)
 992     {
 993         path->fp_type = FIB_PATH_TYPE_SPECIAL;
 994     }
 995     else if (FIB_PATH_CFG_FLAG_LOCAL & flags)
 996     {
 997         path->fp_type = FIB_PATH_TYPE_RECEIVE;
 998         path->attached.fp_interface = FIB_NODE_INDEX_INVALID;
 999     }
1000     else
1001     {
1002         path->fp_type = FIB_PATH_TYPE_EXCLUSIVE;
1003         ASSERT(NULL != dpo);
1004         dpo_copy(&path->exclusive.fp_ex_dpo, dpo);
1005     }
1006
1007     return (fib_path_get_index(path));
1008 }
1009
1010 /*
1011  * fib_path_copy
1012  *
1013  * Copy a path. return index of new path.
1014  */
1015 fib_node_index_t
1016 fib_path_copy (fib_node_index_t path_index,
1017                fib_node_index_t path_list_index)
1018 {
1019     fib_path_t *path, *orig_path;
1020
1021     pool_get(fib_path_pool, path);
1022
1023     orig_path = fib_path_get(path_index);
1024     ASSERT(NULL != orig_path);
1025
1026     memcpy(path, orig_path, sizeof(*path));
1027
1028     FIB_PATH_DBG(path, "create-copy:%d", path_index);
1029
1030     /*
1031      * reset the dynamic section
1032      */
1033     fib_node_init(&path->fp_node, FIB_NODE_TYPE_PATH);
1034     path->fp_oper_flags     = FIB_PATH_OPER_FLAG_NONE;
1035     path->fp_pl_index  = path_list_index;
1036     path->fp_via_fib   = FIB_NODE_INDEX_INVALID;
1037     memset(&path->fp_dpo, 0, sizeof(path->fp_dpo));
1038     dpo_reset(&path->fp_dpo);
1039
1040     return (fib_path_get_index(path));
1041 }
1042
1043 /*
1044  * fib_path_destroy
1045  *
1046  * destroy a path that is no longer required
1047  */
1048 void
1049 fib_path_destroy (fib_node_index_t path_index)
1050 {
1051     fib_path_t *path;
1052
1053     path = fib_path_get(path_index);
1054
1055     ASSERT(NULL != path);
1056     FIB_PATH_DBG(path, "destroy");
1057
1058     fib_path_unresolve(path);
1059
1060     fib_node_deinit(&path->fp_node);
1061     pool_put(fib_path_pool, path);
1062 }
1063
1064 /*
1065  * fib_path_destroy
1066  *
1067  * destroy a path that is no longer required
1068  */
1069 uword
1070 fib_path_hash (fib_node_index_t path_index)
1071 {
1072     fib_path_t *path;
1073
1074     path = fib_path_get(path_index);
1075
1076     return (hash_memory(STRUCT_MARK_PTR(path, path_hash_start),
1077                         (STRUCT_OFFSET_OF(fib_path_t, path_hash_end) -
1078                          STRUCT_OFFSET_OF(fib_path_t, path_hash_start)),
1079                         0));
1080 }
1081
1082 /*
1083  * fib_path_cmp_i
1084  *
1085  * Compare two paths for equivalence.
1086  */
1087 static int
1088 fib_path_cmp_i (const fib_path_t *path1,
1089                 const fib_path_t *path2)
1090 {
1091     int res;
1092
1093     res = 1;
1094
1095     /*
1096      * paths of different types and protocol are not equal.
1097      * different weights only are the same path.
1098      */
1099     if (path1->fp_type != path2->fp_type)
1100     {
1101         res = (path1->fp_type - path2->fp_type);
1102     }
1103     if (path1->fp_nh_proto != path2->fp_nh_proto)
1104     {
1105         res = (path1->fp_nh_proto - path2->fp_nh_proto);
1106     }
1107     else
1108     {
1109         /*
1110          * both paths are of the same type.
1111          * consider each type and its attributes in turn.
1112          */
1113         switch (path1->fp_type)
1114         {
1115         case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1116             res = ip46_address_cmp(&path1->attached_next_hop.fp_nh,
1117                                    &path2->attached_next_hop.fp_nh);
1118             if (0 == res) {
1119                 res = vnet_sw_interface_compare(
1120                           vnet_get_main(),
1121                           path1->attached_next_hop.fp_interface,
1122                           path2->attached_next_hop.fp_interface);
1123             }
1124             break;
1125         case FIB_PATH_TYPE_ATTACHED:
1126             res = vnet_sw_interface_compare(
1127                       vnet_get_main(),
1128                       path1->attached.fp_interface,
1129                       path2->attached.fp_interface);
1130             break;
1131         case FIB_PATH_TYPE_RECURSIVE:
1132             res = ip46_address_cmp(&path1->recursive.fp_nh,
1133                                    &path2->recursive.fp_nh);
1134
1135             if (0 == res)
1136             {
1137                 res = (path1->recursive.fp_tbl_id - path2->recursive.fp_tbl_id);
1138             }
1139             break;
1140         case FIB_PATH_TYPE_DEAG:
1141             res = (path1->deag.fp_tbl_id - path2->deag.fp_tbl_id);
1142             break;
1143         case FIB_PATH_TYPE_SPECIAL:
1144         case FIB_PATH_TYPE_RECEIVE:
1145         case FIB_PATH_TYPE_EXCLUSIVE:
1146             res = 0;
1147             break;
1148         }
1149     }
1150     return (res);
1151 }
1152
1153 /*
1154  * fib_path_cmp_for_sort
1155  *
1156  * Compare two paths for equivalence. Used during path sorting.
1157  * As usual 0 means equal.
1158  */
1159 int
1160 fib_path_cmp_for_sort (void * v1,
1161                        void * v2)
1162 {
1163     fib_node_index_t *pi1 = v1, *pi2 = v2;
1164     fib_path_t *path1, *path2;
1165
1166     path1 = fib_path_get(*pi1);
1167     path2 = fib_path_get(*pi2);
1168
1169     return (fib_path_cmp_i(path1, path2));
1170 }
1171
1172 /*
1173  * fib_path_cmp
1174  *
1175  * Compare two paths for equivalence.
1176  */
1177 int
1178 fib_path_cmp (fib_node_index_t pi1,
1179               fib_node_index_t pi2)
1180 {
1181     fib_path_t *path1, *path2;
1182
1183     path1 = fib_path_get(pi1);
1184     path2 = fib_path_get(pi2);
1185
1186     return (fib_path_cmp_i(path1, path2));
1187 }
1188
1189 int
1190 fib_path_cmp_w_route_path (fib_node_index_t path_index,
1191                            const fib_route_path_t *rpath)
1192 {
1193     fib_path_t *path;
1194     int res;
1195
1196     path = fib_path_get(path_index);
1197
1198     res = 1;
1199
1200     if (path->fp_weight != rpath->frp_weight)
1201     {
1202         res = (path->fp_weight - rpath->frp_weight);
1203     }
1204     else
1205     {
1206         /*
1207          * both paths are of the same type.
1208          * consider each type and its attributes in turn.
1209          */
1210         switch (path->fp_type)
1211         {
1212         case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1213             res = ip46_address_cmp(&path->attached_next_hop.fp_nh,
1214                                    &rpath->frp_addr);
1215             if (0 == res)
1216             {
1217                 res = vnet_sw_interface_compare(
1218                           vnet_get_main(),
1219                           path->attached_next_hop.fp_interface,
1220                           rpath->frp_sw_if_index);
1221             }
1222             break;
1223         case FIB_PATH_TYPE_ATTACHED:
1224             res = vnet_sw_interface_compare(
1225                       vnet_get_main(),
1226                       path->attached.fp_interface,
1227                       rpath->frp_sw_if_index);
1228             break;
1229         case FIB_PATH_TYPE_RECURSIVE:
1230             res = ip46_address_cmp(&path->recursive.fp_nh,
1231                                    &rpath->frp_addr);
1232
1233             if (0 == res)
1234             {
1235                 res = (path->recursive.fp_tbl_id - rpath->frp_fib_index);
1236             }
1237             break;
1238         case FIB_PATH_TYPE_DEAG:
1239             res = (path->deag.fp_tbl_id - rpath->frp_fib_index);
1240             break;
1241         case FIB_PATH_TYPE_SPECIAL:
1242         case FIB_PATH_TYPE_RECEIVE:
1243         case FIB_PATH_TYPE_EXCLUSIVE:
1244             res = 0;
1245             break;
1246         }
1247     }
1248     return (res);
1249 }
1250
1251 /*
1252  * fib_path_recursive_loop_detect
1253  *
1254  * A forward walk of the FIB object graph to detect for a cycle/loop. This
1255  * walk is initiated when an entry is linking to a new path list or from an old.
1256  * The entry vector passed contains all the FIB entrys that are children of this
1257  * path (it is all the entries encountered on the walk so far). If this vector
1258  * contains the entry this path resolve via, then a loop is about to form.
1259  * The loop must be allowed to form, since we need the dependencies in place
1260  * so that we can track when the loop breaks.
1261  * However, we MUST not produce a loop in the forwarding graph (else packets
1262  * would loop around the switch path until the loop breaks), so we mark recursive
1263  * paths as looped so that they do not contribute forwarding information.
1264  * By marking the path as looped, an etry such as;
1265  *    X/Y
1266  *     via a.a.a.a (looped)
1267  *     via b.b.b.b (not looped)
1268  * can still forward using the info provided by b.b.b.b only
1269  */
1270 int
1271 fib_path_recursive_loop_detect (fib_node_index_t path_index,
1272                                 fib_node_index_t **entry_indicies)
1273 {
1274     fib_path_t *path;
1275
1276     path = fib_path_get(path_index);
1277
1278     /*
1279      * the forced drop path is never looped, cos it is never resolved.
1280      */
1281     if (fib_path_is_permanent_drop(path))
1282     {
1283         return (0);
1284     }
1285
1286     switch (path->fp_type)
1287     {
1288     case FIB_PATH_TYPE_RECURSIVE:
1289     {
1290         fib_node_index_t *entry_index, *entries;
1291         int looped = 0;
1292         entries = *entry_indicies;
1293
1294         vec_foreach(entry_index, entries) {
1295             if (*entry_index == path->fp_via_fib)
1296             {
1297                 /*
1298                  * the entry that is about to link to this path-list (or
1299                  * one of this path-list's children) is the same entry that
1300                  * this recursive path resolves through. this is a cycle.
1301                  * abort the walk.
1302                  */
1303                 looped = 1;
1304                 break;
1305             }
1306         }
1307
1308         if (looped)
1309         {
1310             FIB_PATH_DBG(path, "recursive loop formed");
1311             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RECURSIVE_LOOP;
1312
1313             dpo_copy(&path->fp_dpo,
1314                     drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
1315         }
1316         else
1317         {
1318             /*
1319              * no loop here yet. keep forward walking the graph.
1320              */
1321             if (fib_entry_recursive_loop_detect(path->fp_via_fib, entry_indicies))
1322             {
1323                 FIB_PATH_DBG(path, "recursive loop formed");
1324                 path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RECURSIVE_LOOP;
1325             }
1326             else
1327             {
1328                 FIB_PATH_DBG(path, "recursive loop cleared");
1329                 path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RECURSIVE_LOOP;
1330             }
1331         }
1332         break;
1333     }
1334     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1335     case FIB_PATH_TYPE_ATTACHED:
1336     case FIB_PATH_TYPE_SPECIAL:
1337     case FIB_PATH_TYPE_DEAG:
1338     case FIB_PATH_TYPE_RECEIVE:
1339     case FIB_PATH_TYPE_EXCLUSIVE:
1340         /*
1341          * these path types cannot be part of a loop, since they are the leaves
1342          * of the graph.
1343          */
1344         break;
1345     }
1346
1347     return (fib_path_is_looped(path_index));
1348 }
1349
1350 int
1351 fib_path_resolve (fib_node_index_t path_index)
1352 {
1353     fib_path_t *path;
1354
1355     path = fib_path_get(path_index);
1356
1357     /*
1358      * hope for the best.
1359      */
1360     path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
1361
1362     /*
1363      * the forced drop path resolves via the drop adj
1364      */
1365     if (fib_path_is_permanent_drop(path))
1366     {
1367         dpo_copy(&path->fp_dpo,
1368                  drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
1369         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
1370         return (fib_path_is_resolved(path_index));
1371     }
1372
1373     switch (path->fp_type)
1374     {
1375     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1376         fib_path_attached_next_hop_set(path);
1377         break;
1378     case FIB_PATH_TYPE_ATTACHED:
1379         /*
1380          * path->attached.fp_interface
1381          */
1382         if (!vnet_sw_interface_is_admin_up(vnet_get_main(),
1383                                            path->attached.fp_interface))
1384         {
1385             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
1386         }
1387         if (vnet_sw_interface_is_p2p(vnet_get_main(),
1388                                      path->attached.fp_interface))
1389         {
1390             /*
1391              * point-2-point interfaces do not require a glean, since
1392              * there is nothing to ARP. Install a rewrite/nbr adj instead
1393              */
1394             dpo_set(&path->fp_dpo,
1395                     DPO_ADJACENCY,
1396                     fib_proto_to_dpo(path->fp_nh_proto),
1397                     adj_nbr_add_or_lock(
1398                         path->fp_nh_proto,
1399                         fib_proto_to_link(path->fp_nh_proto),
1400                         &zero_addr,
1401                         path->attached.fp_interface));
1402         }
1403         else
1404         {
1405             dpo_set(&path->fp_dpo,
1406                     DPO_ADJACENCY_GLEAN,
1407                     fib_proto_to_dpo(path->fp_nh_proto),
1408                     adj_glean_add_or_lock(path->fp_nh_proto,
1409                                           path->attached.fp_interface,
1410                                           NULL));
1411         }
1412         /*
1413          * become a child of the adjacency so we receive updates
1414          * when the interface state changes
1415          */
1416         path->fp_sibling = adj_child_add(path->fp_dpo.dpoi_index,
1417                                          FIB_NODE_TYPE_PATH,
1418                                          fib_path_get_index(path));
1419
1420         break;
1421     case FIB_PATH_TYPE_RECURSIVE:
1422     {
1423         /*
1424          * Create a RR source entry in the table for the address
1425          * that this path recurses through.
1426          * This resolve action is recursive, hence we may create
1427          * more paths in the process. more creates mean maybe realloc
1428          * of this path.
1429          */
1430         fib_node_index_t fei;
1431         fib_prefix_t pfx;
1432
1433         ASSERT(FIB_NODE_INDEX_INVALID == path->fp_via_fib);
1434
1435         fib_prefix_from_ip46_addr(&path->recursive.fp_nh, &pfx);
1436
1437         fei = fib_table_entry_special_add(path->recursive.fp_tbl_id,
1438                                           &pfx,
1439                                           FIB_SOURCE_RR,
1440                                           FIB_ENTRY_FLAG_NONE,
1441                                           ADJ_INDEX_INVALID);
1442
1443         path = fib_path_get(path_index);
1444         path->fp_via_fib = fei;
1445
1446         /*
1447          * become a dependent child of the entry so the path is
1448          * informed when the forwarding for the entry changes.
1449          */
1450         path->fp_sibling = fib_entry_child_add(path->fp_via_fib,
1451                                                FIB_NODE_TYPE_PATH,
1452                                                fib_path_get_index(path));
1453
1454         /*
1455          * create and configure the IP DPO
1456          */
1457         fib_path_recursive_adj_update(
1458             path,
1459             fib_path_proto_to_chain_type(path->fp_nh_proto),
1460             &path->fp_dpo);
1461
1462         break;
1463     }
1464     case FIB_PATH_TYPE_SPECIAL:
1465         /*
1466          * Resolve via the drop
1467          */
1468         dpo_copy(&path->fp_dpo,
1469                  drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
1470         break;
1471     case FIB_PATH_TYPE_DEAG:
1472         /*
1473          * Resolve via a lookup DPO.
1474          * FIXME. control plane should add routes with a table ID
1475          */
1476         lookup_dpo_add_or_lock_w_fib_index(path->deag.fp_tbl_id,
1477                                           fib_proto_to_dpo(path->fp_nh_proto),
1478                                           LOOKUP_INPUT_DST_ADDR,
1479                                           LOOKUP_TABLE_FROM_CONFIG,
1480                                           &path->fp_dpo);
1481         break;
1482     case FIB_PATH_TYPE_RECEIVE:
1483         /*
1484          * Resolve via a receive DPO.
1485          */
1486         receive_dpo_add_or_lock(fib_proto_to_dpo(path->fp_nh_proto),
1487                                 path->receive.fp_interface,
1488                                 &path->receive.fp_addr,
1489                                 &path->fp_dpo);
1490         break;
1491     case FIB_PATH_TYPE_EXCLUSIVE:
1492         /*
1493          * Resolve via the user provided DPO
1494          */
1495         dpo_copy(&path->fp_dpo, &path->exclusive.fp_ex_dpo);
1496         break;
1497     }
1498
1499     return (fib_path_is_resolved(path_index));
1500 }
1501
1502 u32
1503 fib_path_get_resolving_interface (fib_node_index_t path_index)
1504 {
1505     fib_path_t *path;
1506
1507     path = fib_path_get(path_index);
1508
1509     switch (path->fp_type)
1510     {
1511     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1512         return (path->attached_next_hop.fp_interface);
1513     case FIB_PATH_TYPE_ATTACHED:
1514         return (path->attached.fp_interface);
1515     case FIB_PATH_TYPE_RECEIVE:
1516         return (path->receive.fp_interface);
1517     case FIB_PATH_TYPE_RECURSIVE:
1518         return (fib_entry_get_resolving_interface(path->fp_via_fib));
1519     case FIB_PATH_TYPE_SPECIAL:
1520     case FIB_PATH_TYPE_DEAG:
1521     case FIB_PATH_TYPE_EXCLUSIVE:
1522         break;
1523     }
1524     return (~0);
1525 }
1526
1527 adj_index_t
1528 fib_path_get_adj (fib_node_index_t path_index)
1529 {
1530     fib_path_t *path;
1531
1532     path = fib_path_get(path_index);
1533
1534     ASSERT(dpo_is_adj(&path->fp_dpo));
1535     if (dpo_is_adj(&path->fp_dpo))
1536     {
1537         return (path->fp_dpo.dpoi_index);
1538     }
1539     return (ADJ_INDEX_INVALID);
1540 }
1541
1542 int
1543 fib_path_get_weight (fib_node_index_t path_index)
1544 {
1545     fib_path_t *path;
1546
1547     path = fib_path_get(path_index);
1548
1549     ASSERT(path);
1550
1551     return (path->fp_weight);
1552 }
1553
1554 void
1555 fib_path_contribute_forwarding (fib_node_index_t path_index,
1556                                 fib_forward_chain_type_t fct,
1557                                 dpo_id_t *dpo)
1558 {
1559     fib_path_t *path;
1560
1561     path = fib_path_get(path_index);
1562
1563     ASSERT(path);
1564     ASSERT(FIB_FORW_CHAIN_TYPE_MPLS_EOS != fct);
1565
1566     FIB_PATH_DBG(path, "contribute");
1567
1568     /*
1569      * The DPO stored in the path was created when the path was resolved.
1570      * This then represents the path's 'native' protocol; IP.
1571      * For all others will need to go find something else.
1572      */
1573     if (fib_path_proto_to_chain_type(path->fp_nh_proto) == fct)
1574     {
1575         dpo_copy(dpo, &path->fp_dpo);
1576     }
1577     else
1578     {
1579         switch (path->fp_type)
1580         {
1581         case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1582             switch (fct)
1583             {
1584             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
1585             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
1586             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
1587             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
1588             case FIB_FORW_CHAIN_TYPE_ETHERNET:
1589             {
1590                 adj_index_t ai;
1591
1592                 /*
1593                  * get a MPLS link type adj.
1594                  */
1595                 ai = fib_path_attached_next_hop_get_adj(
1596                          path,
1597                          fib_forw_chain_type_to_link_type(fct));
1598                 dpo_set(dpo, DPO_ADJACENCY,
1599                         fib_forw_chain_type_to_dpo_proto(fct), ai);
1600                 adj_unlock(ai);
1601
1602                 break;
1603             }
1604             }
1605             break;
1606         case FIB_PATH_TYPE_RECURSIVE:
1607             switch (fct)
1608             {
1609             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
1610             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
1611             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
1612                 /*
1613                  * Assume that EOS and IP forwarding is the same.
1614                  * revisit for ieBGP
1615                  */
1616                 dpo_copy(dpo, &path->fp_dpo);
1617                 break;
1618             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
1619                 fib_path_recursive_adj_update(path, fct, dpo);
1620                 break;
1621             case FIB_FORW_CHAIN_TYPE_ETHERNET:
1622                 ASSERT(0);
1623                 break;
1624             }
1625             break;
1626         case FIB_PATH_TYPE_DEAG:
1627             switch (fct)
1628             {
1629             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
1630                 lookup_dpo_add_or_lock_w_table_id(MPLS_FIB_DEFAULT_TABLE_ID,
1631                                                   DPO_PROTO_MPLS,
1632                                                   LOOKUP_INPUT_DST_ADDR,
1633                                                   LOOKUP_TABLE_FROM_CONFIG,
1634                                                   dpo);
1635                 break;
1636             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
1637             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
1638             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
1639                 dpo_copy(dpo, &path->fp_dpo);
1640                 break;
1641             case FIB_FORW_CHAIN_TYPE_ETHERNET:
1642                 ASSERT(0);
1643                 break;
1644             }
1645             break;
1646         case FIB_PATH_TYPE_EXCLUSIVE:
1647             dpo_copy(dpo, &path->exclusive.fp_ex_dpo);
1648             break;
1649         case FIB_PATH_TYPE_ATTACHED:
1650         case FIB_PATH_TYPE_RECEIVE:
1651         case FIB_PATH_TYPE_SPECIAL:
1652             ASSERT(0);
1653             break;
1654         }
1655
1656     }
1657 }
1658
1659 load_balance_path_t *
1660 fib_path_append_nh_for_multipath_hash (fib_node_index_t path_index,
1661                                        fib_forward_chain_type_t fct,
1662                                        load_balance_path_t *hash_key)
1663 {
1664     load_balance_path_t *mnh;
1665     fib_path_t *path;
1666
1667     path = fib_path_get(path_index);
1668
1669     ASSERT(path);
1670
1671     if (fib_path_is_resolved(path_index))
1672     {
1673         vec_add2(hash_key, mnh, 1);
1674
1675         mnh->path_weight = path->fp_weight;
1676         mnh->path_index = path_index;
1677         fib_path_contribute_forwarding(path_index, fct, &mnh->path_dpo);
1678     }
1679
1680     return (hash_key);
1681 }
1682
1683 int
1684 fib_path_is_recursive (fib_node_index_t path_index)
1685 {
1686     fib_path_t *path;
1687
1688     path = fib_path_get(path_index);
1689
1690     return (FIB_PATH_TYPE_RECURSIVE == path->fp_type);
1691 }
1692
1693 int
1694 fib_path_is_exclusive (fib_node_index_t path_index)
1695 {
1696     fib_path_t *path;
1697
1698     path = fib_path_get(path_index);
1699
1700     return (FIB_PATH_TYPE_EXCLUSIVE == path->fp_type);
1701 }
1702
1703 int
1704 fib_path_is_deag (fib_node_index_t path_index)
1705 {
1706     fib_path_t *path;
1707
1708     path = fib_path_get(path_index);
1709
1710     return (FIB_PATH_TYPE_DEAG == path->fp_type);
1711 }
1712
1713 int
1714 fib_path_is_resolved (fib_node_index_t path_index)
1715 {
1716     fib_path_t *path;
1717
1718     path = fib_path_get(path_index);
1719
1720     return (dpo_id_is_valid(&path->fp_dpo) &&
1721             (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED) &&
1722             !fib_path_is_looped(path_index) &&
1723             !fib_path_is_permanent_drop(path));
1724 }
1725
1726 int
1727 fib_path_is_looped (fib_node_index_t path_index)
1728 {
1729     fib_path_t *path;
1730
1731     path = fib_path_get(path_index);
1732
1733     return (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RECURSIVE_LOOP);
1734 }
1735
1736 void
1737 fib_path_module_init (void)
1738 {
1739     fib_node_register_type (FIB_NODE_TYPE_PATH, &fib_path_vft);
1740 }
1741
1742 static clib_error_t *
1743 show_fib_path_command (vlib_main_t * vm,
1744                         unformat_input_t * input,
1745                         vlib_cli_command_t * cmd)
1746 {
1747     fib_path_t *path;
1748
1749     vlib_cli_output (vm, "FIB Path Lists");
1750     pool_foreach(path, fib_path_pool,
1751     ({
1752         vlib_cli_output (vm, "%U", format_fib_path, path);
1753     }));
1754
1755     return (NULL);
1756 }
1757
1758 VLIB_CLI_COMMAND (show_fib_path, static) = {
1759   .path = "show fib paths",
1760   .function = show_fib_path_command,
1761   .short_help = "show fib paths",
1762 };