src/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 #include <vnet/adj/adj_mcast.h>
  27
  28 #include <vnet/fib/fib_path.h>
  29 #include <vnet/fib/fib_node.h>
  30 #include <vnet/fib/fib_table.h>
  31 #include <vnet/fib/fib_entry.h>
  32 #include <vnet/fib/fib_path_list.h>
  33 #include <vnet/fib/fib_internal.h>
  34 #include <vnet/fib/fib_urpf_list.h>
  35 #include <vnet/fib/mpls_fib.h>
  36
  37 /**
  38  * Enurmeration of path types
  39  */
  40 typedef enum fib_path_type_t_ {
  41     /**
  42      * Marker. Add new types after this one.
  43      */
  44     FIB_PATH_TYPE_FIRST = 0,
  45     /**
  46      * Attached-nexthop. An interface and a nexthop are known.
  47      */
  48     FIB_PATH_TYPE_ATTACHED_NEXT_HOP = FIB_PATH_TYPE_FIRST,
  49     /**
  50      * attached. Only the interface is known.
  51      */
  52     FIB_PATH_TYPE_ATTACHED,
  53     /**
  54      * recursive. Only the next-hop is known.
  55      */
  56     FIB_PATH_TYPE_RECURSIVE,
  57     /**
  58      * special. nothing is known. so we drop.
  59      */
  60     FIB_PATH_TYPE_SPECIAL,
  61     /**
  62      * exclusive. user provided adj.
  63      */
  64     FIB_PATH_TYPE_EXCLUSIVE,
  65     /**
  66      * deag. Link to a lookup adj in the next table
  67      */
  68     FIB_PATH_TYPE_DEAG,
  69     /**
  70      * receive. it's for-us.
  71      */
  72     FIB_PATH_TYPE_RECEIVE,
  73     /**
  74      * Marker. Add new types before this one, then update it.
  75      */
  76     FIB_PATH_TYPE_LAST = FIB_PATH_TYPE_RECEIVE,
  77 } __attribute__ ((packed)) fib_path_type_t;
  78
  79 /**
  80  * The maximum number of path_types
  81  */
  82 #define FIB_PATH_TYPE_MAX (FIB_PATH_TYPE_LAST + 1)
  83
  84 #define FIB_PATH_TYPES {                                        \
  85     [FIB_PATH_TYPE_ATTACHED_NEXT_HOP] = "attached-nexthop",     \
  86     [FIB_PATH_TYPE_ATTACHED]          = "attached",             \
  87     [FIB_PATH_TYPE_RECURSIVE]         = "recursive",            \
  88     [FIB_PATH_TYPE_SPECIAL]           = "special",              \
  89     [FIB_PATH_TYPE_EXCLUSIVE]         = "exclusive",            \
  90     [FIB_PATH_TYPE_DEAG]              = "deag",                 \
  91     [FIB_PATH_TYPE_RECEIVE]           = "receive",              \
  92 }
  93
  94 #define FOR_EACH_FIB_PATH_TYPE(_item) \
  95     for (_item = FIB_PATH_TYPE_FIRST; _item <= FIB_PATH_TYPE_LAST; _item++)
  96
  97 /**
  98  * Enurmeration of path operational (i.e. derived) attributes
  99  */
 100 typedef enum fib_path_oper_attribute_t_ {
 101     /**
 102      * Marker. Add new types after this one.
 103      */
 104     FIB_PATH_OPER_ATTRIBUTE_FIRST = 0,
 105     /**
 106      * The path forms part of a recursive loop.
 107      */
 108     FIB_PATH_OPER_ATTRIBUTE_RECURSIVE_LOOP = FIB_PATH_OPER_ATTRIBUTE_FIRST,
 109     /**
 110      * The path is resolved
 111      */
 112     FIB_PATH_OPER_ATTRIBUTE_RESOLVED,
 113     /**
 114      * The path is attached, despite what the next-hop may say.
 115      */
 116     FIB_PATH_OPER_ATTRIBUTE_ATTACHED,
 117     /**
 118      * The path has become a permanent drop.
 119      */
 120     FIB_PATH_OPER_ATTRIBUTE_DROP,
 121     /**
 122      * Marker. Add new types before this one, then update it.
 123      */
 124     FIB_PATH_OPER_ATTRIBUTE_LAST = FIB_PATH_OPER_ATTRIBUTE_DROP,
 125 } __attribute__ ((packed)) fib_path_oper_attribute_t;
 126
 127 /**
 128  * The maximum number of path operational attributes
 129  */
 130 #define FIB_PATH_OPER_ATTRIBUTE_MAX (FIB_PATH_OPER_ATTRIBUTE_LAST + 1)
 131
 132 #define FIB_PATH_OPER_ATTRIBUTES {                                      \
 133     [FIB_PATH_OPER_ATTRIBUTE_RECURSIVE_LOOP] = "recursive-loop",        \
 134     [FIB_PATH_OPER_ATTRIBUTE_RESOLVED]       = "resolved",              \
 135     [FIB_PATH_OPER_ATTRIBUTE_DROP]           = "drop",                  \
 136 }
 137
 138 #define FOR_EACH_FIB_PATH_OPER_ATTRIBUTE(_item) \
 139     for (_item = FIB_PATH_OPER_ATTRIBUTE_FIRST; \
 140          _item <= FIB_PATH_OPER_ATTRIBUTE_LAST; \
 141          _item++)
 142
 143 /**
 144  * Path flags from the attributes
 145  */
 146 typedef enum fib_path_oper_flags_t_ {
 147     FIB_PATH_OPER_FLAG_NONE = 0,
 148     FIB_PATH_OPER_FLAG_RECURSIVE_LOOP = (1 << FIB_PATH_OPER_ATTRIBUTE_RECURSIVE_LOOP),
 149     FIB_PATH_OPER_FLAG_DROP = (1 << FIB_PATH_OPER_ATTRIBUTE_DROP),
 150     FIB_PATH_OPER_FLAG_RESOLVED = (1 << FIB_PATH_OPER_ATTRIBUTE_RESOLVED),
 151     FIB_PATH_OPER_FLAG_ATTACHED = (1 << FIB_PATH_OPER_ATTRIBUTE_ATTACHED),
 152 } __attribute__ ((packed)) fib_path_oper_flags_t;
 153
 154 /**
 155  * A FIB path
 156  */
 157 typedef struct fib_path_t_ {
 158     /**
 159      * A path is a node in the FIB graph.
 160      */
 161     fib_node_t fp_node;
 162
 163     /**
 164      * The index of the path-list to which this path belongs
 165      */
 166     u32 fp_pl_index;
 167
 168     /**
 169      * This marks the start of the memory area used to hash
 170      * the path
 171      */
 172     STRUCT_MARK(path_hash_start);
 173
 174     /**
 175      * Configuration Flags
 176      */
 177     fib_path_cfg_flags_t fp_cfg_flags;
 178
 179     /**
 180      * The type of the path. This is the selector for the union
 181      */
 182     fib_path_type_t fp_type;
 183
 184     /**
 185      * The protocol of the next-hop, i.e. the address family of the
 186      * next-hop's address. We can't derive this from the address itself
 187      * since the address can be all zeros
 188      */
 189     fib_protocol_t fp_nh_proto;
 190
 191     /**
 192      * UCMP [unnormalised] weigt
 193      */
 194     u32 fp_weight;
 195
 196     /**
 197      * per-type union of the data required to resolve the path
 198      */
 199     union {
 200         struct {
 201             /**
 202              * The next-hop
 203              */
 204             ip46_address_t fp_nh;
 205             /**
 206              * The interface
 207              */
 208             u32 fp_interface;
 209         } attached_next_hop;
 210         struct {
 211             /**
 212              * The interface
 213              */
 214             u32 fp_interface;
 215         } attached;
 216         struct {
 217             union
 218             {
 219                 /**
 220                  * The next-hop
 221                  */
 222                 ip46_address_t fp_ip;
 223                 /**
 224                  * The local label to resolve through.
 225                  */
 226                 mpls_label_t fp_local_label;
 227             } fp_nh;
 228             /**
 229              * The FIB table index in which to find the next-hop.
 230              * This needs to be fixed. We should lookup the adjacencies in
 231              * a separate table of adjacencies, rather than from the FIB.
 232              * Two reasons I can think of:
 233              *   - consider:
 234              *       int ip addr Gig0 10.0.0.1/24
 235              *       ip route 10.0.0.2/32 via Gig1 192.168.1.2
 236              *       ip route 1.1.1.1/32 via Gig0 10.0.0.2
 237              *     this is perfectly valid.
 238              *     Packets addressed to 10.0.0.2 should be sent via Gig1.
 239              *     Packets address to 1.1.1.1 should be sent via Gig0.
 240              *    when we perform the adj resolution from the FIB for the path
 241              *    "via Gig0 10.0.0.2" the lookup will result in the route via Gig1
 242              *    and so we will pick up the adj via Gig1 - which was not what the
 243              *    operator wanted.
 244              *  - we can only return link-type IPv4 and so not the link-type MPLS.
 245              *    more on this in a later commit.
 246              *
 247              * The table ID should only belong to a recursive path and indicate
 248              * which FIB should be used to resolve the next-hop.
 249              */
 250             fib_node_index_t fp_tbl_id;
 251         } recursive;
 252         struct {
 253             /**
 254              * The FIB index in which to perfom the next lookup
 255              */
 256             fib_node_index_t fp_tbl_id;
 257         } deag;
 258         struct {
 259         } special;
 260         struct {
 261             /**
 262              * The user provided 'exclusive' DPO
 263              */
 264             dpo_id_t fp_ex_dpo;
 265         } exclusive;
 266         struct {
 267             /**
 268              * The interface on which the local address is configured
 269              */
 270             u32 fp_interface;
 271             /**
 272              * The next-hop
 273              */
 274             ip46_address_t fp_addr;
 275         } receive;
 276     };
 277     STRUCT_MARK(path_hash_end);
 278
 279     /**
 280      * Memebers in this last section represent information that is
 281      * dervied during resolution. It should not be copied to new paths
 282      * nor compared.
 283      */
 284
 285     /**
 286      * Operational Flags
 287      */
 288     fib_path_oper_flags_t fp_oper_flags;
 289
 290     /**
 291      * the resolving via fib. not part of the union, since it it not part
 292      * of the path's hash.
 293      */
 294     fib_node_index_t fp_via_fib;
 295
 296     /**
 297      * The Data-path objects through which this path resolves for IP.
 298      */
 299     dpo_id_t fp_dpo;
 300
 301     /**
 302      * the index of this path in the parent's child list.
 303      */
 304     u32 fp_sibling;
 305 } fib_path_t;
 306
 307 /*
 308  * Array of strings/names for the path types and attributes
 309  */
 310 static const char *fib_path_type_names[] = FIB_PATH_TYPES;
 311 static const char *fib_path_oper_attribute_names[] = FIB_PATH_OPER_ATTRIBUTES;
 312 static const char *fib_path_cfg_attribute_names[]  = FIB_PATH_CFG_ATTRIBUTES;
 313
 314 /*
 315  * The memory pool from which we allocate all the paths
 316  */
 317 static fib_path_t *fib_path_pool;
 318
 319 /*
 320  * Debug macro
 321  */
 322 #ifdef FIB_DEBUG
 323 #define FIB_PATH_DBG(_p, _fmt, _args...)                        \
 324 {                                                               \
 325     u8 *_tmp = NULL;                                            \
 326     _tmp = fib_path_format(fib_path_get_index(_p), _tmp);       \
 327     clib_warning("path:[%d:%s]:" _fmt,                          \
 328                  fib_path_get_index(_p), _tmp,                  \
 329                  ##_args);                                      \
 330     vec_free(_tmp);                                             \
 331 }
 332 #else
 333 #define FIB_PATH_DBG(_p, _fmt, _args...)
 334 #endif
 335
 336 static fib_path_t *
 337 fib_path_get (fib_node_index_t index)
 338 {
 339     return (pool_elt_at_index(fib_path_pool, index));
 340 }
 341
 342 static fib_node_index_t
 343 fib_path_get_index (fib_path_t *path)
 344 {
 345     return (path - fib_path_pool);
 346 }
 347
 348 static fib_node_t *
 349 fib_path_get_node (fib_node_index_t index)
 350 {
 351     return ((fib_node_t*)fib_path_get(index));
 352 }
 353
 354 static fib_path_t*
 355 fib_path_from_fib_node (fib_node_t *node)
 356 {
 357 #if CLIB_DEBUG > 0
 358     ASSERT(FIB_NODE_TYPE_PATH == node->fn_type);
 359 #endif
 360     return ((fib_path_t*)node);
 361 }
 362
 363 u8 *
 364 format_fib_path (u8 * s, va_list * args)
 365 {
 366     fib_path_t *path = va_arg (*args, fib_path_t *);
 367     vnet_main_t * vnm = vnet_get_main();
 368     fib_path_oper_attribute_t oattr;
 369     fib_path_cfg_attribute_t cattr;
 370
 371     s = format (s, "      index:%d ", fib_path_get_index(path));
 372     s = format (s, "pl-index:%d ", path->fp_pl_index);
 373     s = format (s, "%U ", format_fib_protocol, path->fp_nh_proto);
 374     s = format (s, "weight=%d ", path->fp_weight);
 375     s = format (s, "%s: ", fib_path_type_names[path->fp_type]);
 376     if (FIB_PATH_OPER_FLAG_NONE != path->fp_oper_flags) {
 377         s = format(s, " oper-flags:");
 378         FOR_EACH_FIB_PATH_OPER_ATTRIBUTE(oattr) {
 379             if ((1<<oattr) & path->fp_oper_flags) {
 380                 s = format (s, "%s,", fib_path_oper_attribute_names[oattr]);
 381             }
 382         }
 383     }
 384     if (FIB_PATH_CFG_FLAG_NONE != path->fp_cfg_flags) {
 385         s = format(s, " cfg-flags:");
 386         FOR_EACH_FIB_PATH_CFG_ATTRIBUTE(cattr) {
 387             if ((1<<cattr) & path->fp_cfg_flags) {
 388                 s = format (s, "%s,", fib_path_cfg_attribute_names[cattr]);
 389             }
 390         }
 391     }
 392     s = format(s, "\n       ");
 393
 394     switch (path->fp_type)
 395     {
 396     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
 397         s = format (s, "%U", format_ip46_address,
 398                     &path->attached_next_hop.fp_nh,
 399                     IP46_TYPE_ANY);
 400         if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_DROP)
 401         {
 402             s = format (s, " if_index:%d", path->attached_next_hop.fp_interface);
 403         }
 404         else
 405         {
 406             s = format (s, " %U",
 407                         format_vnet_sw_interface_name,
 408                         vnm,
 409                         vnet_get_sw_interface(
 410                             vnm,
 411                             path->attached_next_hop.fp_interface));
 412             if (vnet_sw_interface_is_p2p(vnet_get_main(),
 413                                          path->attached_next_hop.fp_interface))
 414             {
 415                 s = format (s, " (p2p)");
 416             }
 417         }
 418         if (!dpo_id_is_valid(&path->fp_dpo))
 419         {
 420             s = format(s, "\n          unresolved");
 421         }
 422         else
 423         {
 424             s = format(s, "\n          %U",
 425                        format_dpo_id,
 426                        &path->fp_dpo, 13);
 427         }
 428         break;
 429     case FIB_PATH_TYPE_ATTACHED:
 430         if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_DROP)
 431         {
 432             s = format (s, " if_index:%d", path->attached_next_hop.fp_interface);
 433         }
 434         else
 435         {
 436             s = format (s, " %U",
 437                         format_vnet_sw_interface_name,
 438                         vnm,
 439                         vnet_get_sw_interface(
 440                             vnm,
 441                             path->attached.fp_interface));
 442         }
 443         break;
 444     case FIB_PATH_TYPE_RECURSIVE:
 445         if (FIB_PROTOCOL_MPLS == path->fp_nh_proto)
 446         {
 447             s = format (s, "via %U",
 448                         format_mpls_unicast_label,
 449                         path->recursive.fp_nh.fp_local_label);
 450         }
 451         else
 452         {
 453             s = format (s, "via %U",
 454                         format_ip46_address,
 455                         &path->recursive.fp_nh.fp_ip,
 456                         IP46_TYPE_ANY);
 457         }
 458         s = format (s, " in fib:%d",
 459                     path->recursive.fp_tbl_id,
 460                     path->fp_via_fib);
 461         s = format (s, " via-fib:%d", path->fp_via_fib);
 462         s = format (s, " via-dpo:[%U:%d]",
 463                     format_dpo_type, path->fp_dpo.dpoi_type,
 464                     path->fp_dpo.dpoi_index);
 465
 466         break;
 467     case FIB_PATH_TYPE_RECEIVE:
 468     case FIB_PATH_TYPE_SPECIAL:
 469     case FIB_PATH_TYPE_DEAG:
 470     case FIB_PATH_TYPE_EXCLUSIVE:
 471         if (dpo_id_is_valid(&path->fp_dpo))
 472         {
 473             s = format(s, "%U", format_dpo_id,
 474                        &path->fp_dpo, 2);
 475         }
 476         break;
 477     }
 478     return (s);
 479 }
 480
 481 u8 *
 482 fib_path_format (fib_node_index_t pi, u8 *s)
 483 {
 484     fib_path_t *path;
 485
 486     path = fib_path_get(pi);
 487     ASSERT(NULL != path);
 488
 489     return (format (s, "%U", format_fib_path, path));
 490 }
 491
 492 u8 *
 493 fib_path_adj_format (fib_node_index_t pi,
 494                      u32 indent,
 495                      u8 *s)
 496 {
 497     fib_path_t *path;
 498
 499     path = fib_path_get(pi);
 500     ASSERT(NULL != path);
 501
 502     if (!dpo_id_is_valid(&path->fp_dpo))
 503     {
 504         s = format(s, " unresolved");
 505     }
 506     else
 507     {
 508         s = format(s, "%U", format_dpo_id,
 509                    &path->fp_dpo, 2);
 510     }
 511
 512     return (s);
 513 }
 514
 515 /*
 516  * fib_path_last_lock_gone
 517  *
 518  * We don't share paths, we share path lists, so the [un]lock functions
 519  * are no-ops
 520  */
 521 static void
 522 fib_path_last_lock_gone (fib_node_t *node)
 523 {
 524     ASSERT(0);
 525 }
 526
 527 static const adj_index_t
 528 fib_path_attached_next_hop_get_adj (fib_path_t *path,
 529                                     vnet_link_t link)
 530 {
 531     if (vnet_sw_interface_is_p2p(vnet_get_main(),
 532                                  path->attached_next_hop.fp_interface))
 533     {
 534         /*
 535          * if the interface is p2p then the adj for the specific
 536          * neighbour on that link will never exist. on p2p links
 537          * the subnet address (the attached route) links to the
 538          * auto-adj (see below), we want that adj here too.
 539          */
 540         return (adj_nbr_add_or_lock(path->fp_nh_proto,
 541                                     link,
 542                                     &zero_addr,
 543                                     path->attached_next_hop.fp_interface));
 544     }
 545     else
 546     {
 547         return (adj_nbr_add_or_lock(path->fp_nh_proto,
 548                                     link,
 549                                     &path->attached_next_hop.fp_nh,
 550                                     path->attached_next_hop.fp_interface));
 551     }
 552 }
 553
 554 static void
 555 fib_path_attached_next_hop_set (fib_path_t *path)
 556 {
 557     /*
 558      * resolve directly via the adjacnecy discribed by the
 559      * interface and next-hop
 560      */
 561     dpo_set(&path->fp_dpo,
 562             DPO_ADJACENCY,
 563             fib_proto_to_dpo(path->fp_nh_proto),
 564             fib_path_attached_next_hop_get_adj(
 565                  path,
 566                  fib_proto_to_link(path->fp_nh_proto)));
 567
 568     /*
 569      * become a child of the adjacency so we receive updates
 570      * when its rewrite changes
 571      */
 572     path->fp_sibling = adj_child_add(path->fp_dpo.dpoi_index,
 573                                      FIB_NODE_TYPE_PATH,
 574                                      fib_path_get_index(path));
 575
 576     if (!vnet_sw_interface_is_admin_up(vnet_get_main(),
 577                                       path->attached_next_hop.fp_interface) ||
 578         !adj_is_up(path->fp_dpo.dpoi_index))
 579     {
 580         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 581     }
 582 }
 583
 584 /*
 585  * create of update the paths recursive adj
 586  */
 587 static void
 588 fib_path_recursive_adj_update (fib_path_t *path,
 589                                fib_forward_chain_type_t fct,
 590                                dpo_id_t *dpo)
 591 {
 592     dpo_id_t via_dpo = DPO_INVALID;
 593
 594     /*
 595      * get the DPO to resolve through from the via-entry
 596      */
 597     fib_entry_contribute_forwarding(path->fp_via_fib,
 598                                     fct,
 599                                     &via_dpo);
 600
 601
 602     /*
 603      * hope for the best - clear if restrictions apply.
 604      */
 605     path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
 606
 607     /*
 608      * Validate any recursion constraints and over-ride the via
 609      * adj if not met
 610      */
 611     if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RECURSIVE_LOOP)
 612     {
 613         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 614         dpo_copy(&via_dpo, drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
 615     }
 616     else if (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_RESOLVE_HOST)
 617     {
 618         /*
 619          * the via FIB must be a host route.
 620          * note the via FIB just added will always be a host route
 621          * since it is an RR source added host route. So what we need to
 622          * check is whether the route has other sources. If it does then
 623          * some other source has added it as a host route. If it doesn't
 624          * then it was added only here and inherits forwarding from a cover.
 625          * the cover is not a host route.
 626          * The RR source is the lowest priority source, so we check if it
 627          * is the best. if it is there are no other sources.
 628          */
 629         if (fib_entry_get_best_source(path->fp_via_fib) >= FIB_SOURCE_RR)
 630         {
 631             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 632             dpo_copy(&via_dpo, drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
 633
 634             /*
 635              * PIC edge trigger. let the load-balance maps know
 636              */
 637             load_balance_map_path_state_change(fib_path_get_index(path));
 638         }
 639     }
 640     else if (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_RESOLVE_ATTACHED)
 641     {
 642         /*
 643          * RR source entries inherit the flags from the cover, so
 644          * we can check the via directly
 645          */
 646         if (!(FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags(path->fp_via_fib)))
 647         {
 648             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 649             dpo_copy(&via_dpo, drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
 650
 651             /*
 652              * PIC edge trigger. let the load-balance maps know
 653              */
 654             load_balance_map_path_state_change(fib_path_get_index(path));
 655         }
 656     }
 657     /*
 658      * check for over-riding factors on the FIB entry itself
 659      */
 660     if (!fib_entry_is_resolved(path->fp_via_fib))
 661     {
 662         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 663         dpo_copy(&via_dpo, drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
 664
 665         /*
 666          * PIC edge trigger. let the load-balance maps know
 667          */
 668         load_balance_map_path_state_change(fib_path_get_index(path));
 669     }
 670
 671     /*
 672      * update the path's contributed DPO
 673      */
 674     dpo_copy(dpo, &via_dpo);
 675
 676     FIB_PATH_DBG(path, "recursive update: %U",
 677                  fib_get_lookup_main(path->fp_nh_proto),
 678                  &path->fp_dpo, 2);
 679
 680     dpo_reset(&via_dpo);
 681 }
 682
 683 /*
 684  * fib_path_is_permanent_drop
 685  *
 686  * Return !0 if the path is configured to permanently drop,
 687  * despite other attributes.
 688  */
 689 static int
 690 fib_path_is_permanent_drop (fib_path_t *path)
 691 {
 692     return ((path->fp_cfg_flags & FIB_PATH_CFG_FLAG_DROP) ||
 693             (path->fp_oper_flags & FIB_PATH_OPER_FLAG_DROP));
 694 }
 695
 696 /*
 697  * fib_path_unresolve
 698  *
 699  * Remove our dependency on the resolution target
 700  */
 701 static void
 702 fib_path_unresolve (fib_path_t *path)
 703 {
 704     /*
 705      * the forced drop path does not need unresolving
 706      */
 707     if (fib_path_is_permanent_drop(path))
 708     {
 709         return;
 710     }
 711
 712     switch (path->fp_type)
 713     {
 714     case FIB_PATH_TYPE_RECURSIVE:
 715         if (FIB_NODE_INDEX_INVALID != path->fp_via_fib)
 716         {
 717             fib_prefix_t pfx;
 718
 719             fib_entry_get_prefix(path->fp_via_fib, &pfx);
 720             fib_entry_child_remove(path->fp_via_fib,
 721                                    path->fp_sibling);
 722             fib_table_entry_special_remove(path->recursive.fp_tbl_id,
 723                                            &pfx,
 724                                            FIB_SOURCE_RR);
 725             path->fp_via_fib = FIB_NODE_INDEX_INVALID;
 726         }
 727         break;
 728     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
 729     case FIB_PATH_TYPE_ATTACHED:
 730         adj_child_remove(path->fp_dpo.dpoi_index,
 731                          path->fp_sibling);
 732         adj_unlock(path->fp_dpo.dpoi_index);
 733         break;
 734     case FIB_PATH_TYPE_EXCLUSIVE:
 735         dpo_reset(&path->exclusive.fp_ex_dpo);
 736         break;
 737     case FIB_PATH_TYPE_SPECIAL:
 738     case FIB_PATH_TYPE_RECEIVE:
 739     case FIB_PATH_TYPE_DEAG:
 740         /*
 741          * these hold only the path's DPO, which is reset below.
 742          */
 743         break;
 744     }
 745
 746     /*
 747      * release the adj we were holding and pick up the
 748      * drop just in case.
 749      */
 750     dpo_reset(&path->fp_dpo);
 751     path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 752
 753     return;
 754 }
 755
 756 static fib_forward_chain_type_t
 757 fib_path_proto_to_chain_type (fib_protocol_t proto)
 758 {
 759     switch (proto)
 760     {
 761     case FIB_PROTOCOL_IP4:
 762         return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
 763     case FIB_PROTOCOL_IP6:
 764         return (FIB_FORW_CHAIN_TYPE_UNICAST_IP6);
 765     case FIB_PROTOCOL_MPLS:
 766         return (FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS);
 767     }
 768     return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
 769 }
 770
 771 /*
 772  * fib_path_back_walk_notify
 773  *
 774  * A back walk has reach this path.
 775  */
 776 static fib_node_back_walk_rc_t
 777 fib_path_back_walk_notify (fib_node_t *node,
 778                            fib_node_back_walk_ctx_t *ctx)
 779 {
 780     fib_path_t *path;
 781
 782     path = fib_path_from_fib_node(node);
 783
 784     switch (path->fp_type)
 785     {
 786     case FIB_PATH_TYPE_RECURSIVE:
 787         if (FIB_NODE_BW_REASON_FLAG_EVALUATE & ctx->fnbw_reason)
 788         {
 789             /*
 790              * modify the recursive adjacency to use the new forwarding
 791              * of the via-fib.
 792              * this update is visible to packets in flight in the DP.
 793              */
 794             fib_path_recursive_adj_update(
 795                 path,
 796                 fib_path_proto_to_chain_type(path->fp_nh_proto),
 797                 &path->fp_dpo);
 798         }
 799         if ((FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE & ctx->fnbw_reason) ||
 800             (FIB_NODE_BW_REASON_FLAG_ADJ_DOWN   & ctx->fnbw_reason))
 801         {
 802             /*
 803              * ADJ updates (complete<->incomplete) do not need to propagate to
 804              * recursive entries.
 805              * The only reason its needed as far back as here, is that the adj
 806              * and the incomplete adj are a different DPO type, so the LBs need
 807              * to re-stack.
 808              * If this walk was quashed in the fib_entry, then any non-fib_path
 809              * children (like tunnels that collapse out the LB when they stack)
 810              * would not see the update.
 811              */
 812             return (FIB_NODE_BACK_WALK_CONTINUE);
 813         }
 814         break;
 815     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
 816         /*
 817 FIXME comment
 818          * ADJ_UPDATE backwalk pass silently through here and up to
 819          * the path-list when the multipath adj collapse occurs.
 820          * The reason we do this is that the assumtption is that VPP
 821          * runs in an environment where the Control-Plane is remote
 822          * and hence reacts slowly to link up down. In order to remove
 823          * this down link from the ECMP set quickly, we back-walk.
 824          * VPP also has dedicated CPUs, so we are not stealing resources
 825          * from the CP to do so.
 826          */
 827         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_UP & ctx->fnbw_reason)
 828         {
 829             if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED)
 830             {
 831                 /*
 832                  * alreday resolved. no need to walk back again
 833                  */
 834                 return (FIB_NODE_BACK_WALK_CONTINUE);
 835             }
 836             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
 837         }
 838         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DOWN & ctx->fnbw_reason)
 839         {
 840             if (!(path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED))
 841             {
 842                 /*
 843                  * alreday unresolved. no need to walk back again
 844                  */
 845                 return (FIB_NODE_BACK_WALK_CONTINUE);
 846             }
 847             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 848         }
 849         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DELETE & ctx->fnbw_reason)
 850         {
 851             /*
 852              * The interface this path resolves through has been deleted.
 853              * This will leave the path in a permanent drop state. The route
 854              * needs to be removed and readded (and hence the path-list deleted)
 855              * before it can forward again.
 856              */
 857             fib_path_unresolve(path);
 858             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_DROP;
 859         }
 860         if (FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE & ctx->fnbw_reason)
 861         {
 862             /*
 863              * restack the DPO to pick up the correct DPO sub-type
 864              */
 865             uword if_is_up;
 866             adj_index_t ai;
 867
 868             if_is_up = vnet_sw_interface_is_admin_up(
 869                            vnet_get_main(),
 870                            path->attached_next_hop.fp_interface);
 871
 872             ai = fib_path_attached_next_hop_get_adj(
 873                      path,
 874                      fib_proto_to_link(path->fp_nh_proto));
 875
 876             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 877             if (if_is_up && adj_is_up(ai))
 878             {
 879                 path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
 880             }
 881
 882             dpo_set(&path->fp_dpo, DPO_ADJACENCY,
 883                     fib_proto_to_dpo(path->fp_nh_proto),
 884                     ai);
 885             adj_unlock(ai);
 886
 887             if (!if_is_up)
 888             {
 889                 /*
 890                  * If the interface is not up there is no reason to walk
 891                  * back to children. if we did they would only evalute
 892                  * that this path is unresolved and hence it would
 893                  * not contribute the adjacency - so it would be wasted
 894                  * CPU time.
 895                  */
 896                 return (FIB_NODE_BACK_WALK_CONTINUE);
 897             }
 898         }
 899         if (FIB_NODE_BW_REASON_FLAG_ADJ_DOWN & ctx->fnbw_reason)
 900         {
 901             if (!(path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED))
 902             {
 903                 /*
 904                  * alreday unresolved. no need to walk back again
 905                  */
 906                 return (FIB_NODE_BACK_WALK_CONTINUE);
 907             }
 908             /*
 909              * the adj has gone down. the path is no longer resolved.
 910              */
 911             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 912         }
 913         break;
 914     case FIB_PATH_TYPE_ATTACHED:
 915         /*
 916          * FIXME; this could schedule a lower priority walk, since attached
 917          * routes are not usually in ECMP configurations so the backwalk to
 918          * the FIB entry does not need to be high priority
 919          */
 920         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_UP & ctx->fnbw_reason)
 921         {
 922             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
 923         }
 924         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DOWN & ctx->fnbw_reason)
 925         {
 926             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 927         }
 928         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DELETE & ctx->fnbw_reason)
 929         {
 930             fib_path_unresolve(path);
 931             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_DROP;
 932         }
 933         break;
 934     case FIB_PATH_TYPE_DEAG:
 935         /*
 936          * FIXME When VRF delete is allowed this will need a poke.
 937          */
 938     case FIB_PATH_TYPE_SPECIAL:
 939     case FIB_PATH_TYPE_RECEIVE:
 940     case FIB_PATH_TYPE_EXCLUSIVE:
 941         /*
 942          * these path types have no parents. so to be
 943          * walked from one is unexpected.
 944          */
 945         ASSERT(0);
 946         break;
 947     }
 948
 949     /*
 950      * propagate the backwalk further to the path-list
 951      */
 952     fib_path_list_back_walk(path->fp_pl_index, ctx);
 953
 954     return (FIB_NODE_BACK_WALK_CONTINUE);
 955 }
 956
 957 static void
 958 fib_path_memory_show (void)
 959 {
 960     fib_show_memory_usage("Path",
 961                           pool_elts(fib_path_pool),
 962                           pool_len(fib_path_pool),
 963                           sizeof(fib_path_t));
 964 }
 965
 966 /*
 967  * The FIB path's graph node virtual function table
 968  */
 969 static const fib_node_vft_t fib_path_vft = {
 970     .fnv_get = fib_path_get_node,
 971     .fnv_last_lock = fib_path_last_lock_gone,
 972     .fnv_back_walk = fib_path_back_walk_notify,
 973     .fnv_mem_show = fib_path_memory_show,
 974 };
 975
 976 static fib_path_cfg_flags_t
 977 fib_path_route_flags_to_cfg_flags (const fib_route_path_t *rpath)
 978 {
 979     fib_path_cfg_flags_t cfg_flags = FIB_PATH_CFG_FLAG_NONE;
 980
 981     if (rpath->frp_flags & FIB_ROUTE_PATH_RESOLVE_VIA_HOST)
 982         cfg_flags |= FIB_PATH_CFG_FLAG_RESOLVE_HOST;
 983     if (rpath->frp_flags & FIB_ROUTE_PATH_RESOLVE_VIA_ATTACHED)
 984         cfg_flags |= FIB_PATH_CFG_FLAG_RESOLVE_ATTACHED;
 985     if (rpath->frp_flags & FIB_ROUTE_PATH_LOCAL)
 986         cfg_flags |= FIB_PATH_CFG_FLAG_LOCAL;
 987     if (rpath->frp_flags & FIB_ROUTE_PATH_ATTACHED)
 988         cfg_flags |= FIB_PATH_CFG_FLAG_ATTACHED;
 989
 990     return (cfg_flags);
 991 }
 992
 993 /*
 994  * fib_path_create
 995  *
 996  * Create and initialise a new path object.
 997  * return the index of the path.
 998  */
 999 fib_node_index_t
1000 fib_path_create (fib_node_index_t pl_index,
1001                  fib_protocol_t nh_proto,
1002                  fib_path_cfg_flags_t flags,
1003                  const fib_route_path_t *rpath)
1004 {
1005     fib_path_t *path;
1006
1007     pool_get(fib_path_pool, path);
1008     memset(path, 0, sizeof(*path));
1009
1010     fib_node_init(&path->fp_node,
1011                   FIB_NODE_TYPE_PATH);
1012
1013     dpo_reset(&path->fp_dpo);
1014     path->fp_pl_index = pl_index;
1015     path->fp_nh_proto = nh_proto;
1016     path->fp_via_fib = FIB_NODE_INDEX_INVALID;
1017     path->fp_weight = rpath->frp_weight;
1018     if (0 == path->fp_weight)
1019     {
1020         /*
1021          * a weight of 0 is a meaningless value. We could either reject it, and thus force
1022          * clients to always use 1, or we can accept it and fixup approrpiately.
1023          */
1024         path->fp_weight = 1;
1025     }
1026     path->fp_cfg_flags = flags;
1027     path->fp_cfg_flags |= fib_path_route_flags_to_cfg_flags(rpath);
1028
1029     /*
1030      * deduce the path's tpye from the parementers and save what is needed.
1031      */
1032     if (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_LOCAL)
1033     {
1034         path->fp_type = FIB_PATH_TYPE_RECEIVE;
1035         path->receive.fp_interface = rpath->frp_sw_if_index;
1036         path->receive.fp_addr = rpath->frp_addr;
1037     }
1038     else if (~0 != rpath->frp_sw_if_index)
1039     {
1040         if (ip46_address_is_zero(&rpath->frp_addr))
1041         {
1042             path->fp_type = FIB_PATH_TYPE_ATTACHED;
1043             path->attached.fp_interface = rpath->frp_sw_if_index;
1044         }
1045         else
1046         {
1047             path->fp_type = FIB_PATH_TYPE_ATTACHED_NEXT_HOP;
1048             path->attached_next_hop.fp_interface = rpath->frp_sw_if_index;
1049             path->attached_next_hop.fp_nh = rpath->frp_addr;
1050         }
1051     }
1052     else
1053     {
1054         if (ip46_address_is_zero(&rpath->frp_addr))
1055         {
1056             if (~0 == rpath->frp_fib_index)
1057             {
1058                 path->fp_type = FIB_PATH_TYPE_SPECIAL;
1059             }
1060             else
1061             {
1062                 path->fp_type = FIB_PATH_TYPE_DEAG;
1063                 path->deag.fp_tbl_id = rpath->frp_fib_index;
1064             }
1065         }
1066         else
1067         {
1068             path->fp_type = FIB_PATH_TYPE_RECURSIVE;
1069             if (FIB_PROTOCOL_MPLS == path->fp_nh_proto)
1070             {
1071                 path->recursive.fp_nh.fp_local_label = rpath->frp_local_label;
1072             }
1073             else
1074             {
1075                 path->recursive.fp_nh.fp_ip = rpath->frp_addr;
1076             }
1077             path->recursive.fp_tbl_id = rpath->frp_fib_index;
1078         }
1079     }
1080
1081     FIB_PATH_DBG(path, "create");
1082
1083     return (fib_path_get_index(path));
1084 }
1085
1086 /*
1087  * fib_path_create_special
1088  *
1089  * Create and initialise a new path object.
1090  * return the index of the path.
1091  */
1092 fib_node_index_t
1093 fib_path_create_special (fib_node_index_t pl_index,
1094                          fib_protocol_t nh_proto,
1095                          fib_path_cfg_flags_t flags,
1096                          const dpo_id_t *dpo)
1097 {
1098     fib_path_t *path;
1099
1100     pool_get(fib_path_pool, path);
1101     memset(path, 0, sizeof(*path));
1102
1103     fib_node_init(&path->fp_node,
1104                   FIB_NODE_TYPE_PATH);
1105     dpo_reset(&path->fp_dpo);
1106
1107     path->fp_pl_index = pl_index;
1108     path->fp_weight = 1;
1109     path->fp_nh_proto = nh_proto;
1110     path->fp_via_fib = FIB_NODE_INDEX_INVALID;
1111     path->fp_cfg_flags = flags;
1112
1113     if (FIB_PATH_CFG_FLAG_DROP & flags)
1114     {
1115         path->fp_type = FIB_PATH_TYPE_SPECIAL;
1116     }
1117     else if (FIB_PATH_CFG_FLAG_LOCAL & flags)
1118     {
1119         path->fp_type = FIB_PATH_TYPE_RECEIVE;
1120         path->attached.fp_interface = FIB_NODE_INDEX_INVALID;
1121     }
1122     else
1123     {
1124         path->fp_type = FIB_PATH_TYPE_EXCLUSIVE;
1125         ASSERT(NULL != dpo);
1126         dpo_copy(&path->exclusive.fp_ex_dpo, dpo);
1127     }
1128
1129     return (fib_path_get_index(path));
1130 }
1131
1132 /*
1133  * fib_path_copy
1134  *
1135  * Copy a path. return index of new path.
1136  */
1137 fib_node_index_t
1138 fib_path_copy (fib_node_index_t path_index,
1139                fib_node_index_t path_list_index)
1140 {
1141     fib_path_t *path, *orig_path;
1142
1143     pool_get(fib_path_pool, path);
1144
1145     orig_path = fib_path_get(path_index);
1146     ASSERT(NULL != orig_path);
1147
1148     memcpy(path, orig_path, sizeof(*path));
1149
1150     FIB_PATH_DBG(path, "create-copy:%d", path_index);
1151
1152     /*
1153      * reset the dynamic section
1154      */
1155     fib_node_init(&path->fp_node, FIB_NODE_TYPE_PATH);
1156     path->fp_oper_flags     = FIB_PATH_OPER_FLAG_NONE;
1157     path->fp_pl_index  = path_list_index;
1158     path->fp_via_fib   = FIB_NODE_INDEX_INVALID;
1159     memset(&path->fp_dpo, 0, sizeof(path->fp_dpo));
1160     dpo_reset(&path->fp_dpo);
1161
1162     return (fib_path_get_index(path));
1163 }
1164
1165 /*
1166  * fib_path_destroy
1167  *
1168  * destroy a path that is no longer required
1169  */
1170 void
1171 fib_path_destroy (fib_node_index_t path_index)
1172 {
1173     fib_path_t *path;
1174
1175     path = fib_path_get(path_index);
1176
1177     ASSERT(NULL != path);
1178     FIB_PATH_DBG(path, "destroy");
1179
1180     fib_path_unresolve(path);
1181
1182     fib_node_deinit(&path->fp_node);
1183     pool_put(fib_path_pool, path);
1184 }
1185
1186 /*
1187  * fib_path_destroy
1188  *
1189  * destroy a path that is no longer required
1190  */
1191 uword
1192 fib_path_hash (fib_node_index_t path_index)
1193 {
1194     fib_path_t *path;
1195
1196     path = fib_path_get(path_index);
1197
1198     return (hash_memory(STRUCT_MARK_PTR(path, path_hash_start),
1199                         (STRUCT_OFFSET_OF(fib_path_t, path_hash_end) -
1200                          STRUCT_OFFSET_OF(fib_path_t, path_hash_start)),
1201                         0));
1202 }
1203
1204 /*
1205  * fib_path_cmp_i
1206  *
1207  * Compare two paths for equivalence.
1208  */
1209 static int
1210 fib_path_cmp_i (const fib_path_t *path1,
1211                 const fib_path_t *path2)
1212 {
1213     int res;
1214
1215     res = 1;
1216
1217     /*
1218      * paths of different types and protocol are not equal.
1219      * different weights only are the same path.
1220      */
1221     if (path1->fp_type != path2->fp_type)
1222     {
1223         res = (path1->fp_type - path2->fp_type);
1224     }
1225     else if (path1->fp_nh_proto != path2->fp_nh_proto)
1226     {
1227         res = (path1->fp_nh_proto - path2->fp_nh_proto);
1228     }
1229     else
1230     {
1231         /*
1232          * both paths are of the same type.
1233          * consider each type and its attributes in turn.
1234          */
1235         switch (path1->fp_type)
1236         {
1237         case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1238             res = ip46_address_cmp(&path1->attached_next_hop.fp_nh,
1239                                    &path2->attached_next_hop.fp_nh);
1240             if (0 == res) {
1241                 res = vnet_sw_interface_compare(
1242                           vnet_get_main(),
1243                           path1->attached_next_hop.fp_interface,
1244                           path2->attached_next_hop.fp_interface);
1245             }
1246             break;
1247         case FIB_PATH_TYPE_ATTACHED:
1248             res = vnet_sw_interface_compare(
1249                       vnet_get_main(),
1250                       path1->attached.fp_interface,
1251                       path2->attached.fp_interface);
1252             break;
1253         case FIB_PATH_TYPE_RECURSIVE:
1254             res = ip46_address_cmp(&path1->recursive.fp_nh,
1255                                    &path2->recursive.fp_nh);
1256
1257             if (0 == res)
1258             {
1259                 res = (path1->recursive.fp_tbl_id - path2->recursive.fp_tbl_id);
1260             }
1261             break;
1262         case FIB_PATH_TYPE_DEAG:
1263             res = (path1->deag.fp_tbl_id - path2->deag.fp_tbl_id);
1264             break;
1265         case FIB_PATH_TYPE_SPECIAL:
1266         case FIB_PATH_TYPE_RECEIVE:
1267         case FIB_PATH_TYPE_EXCLUSIVE:
1268             res = 0;
1269             break;
1270         }
1271     }
1272     return (res);
1273 }
1274
1275 /*
1276  * fib_path_cmp_for_sort
1277  *
1278  * Compare two paths for equivalence. Used during path sorting.
1279  * As usual 0 means equal.
1280  */
1281 int
1282 fib_path_cmp_for_sort (void * v1,
1283                        void * v2)
1284 {
1285     fib_node_index_t *pi1 = v1, *pi2 = v2;
1286     fib_path_t *path1, *path2;
1287
1288     path1 = fib_path_get(*pi1);
1289     path2 = fib_path_get(*pi2);
1290
1291     return (fib_path_cmp_i(path1, path2));
1292 }
1293
1294 /*
1295  * fib_path_cmp
1296  *
1297  * Compare two paths for equivalence.
1298  */
1299 int
1300 fib_path_cmp (fib_node_index_t pi1,
1301               fib_node_index_t pi2)
1302 {
1303     fib_path_t *path1, *path2;
1304
1305     path1 = fib_path_get(pi1);
1306     path2 = fib_path_get(pi2);
1307
1308     return (fib_path_cmp_i(path1, path2));
1309 }
1310
1311 int
1312 fib_path_cmp_w_route_path (fib_node_index_t path_index,
1313                            const fib_route_path_t *rpath)
1314 {
1315     fib_path_t *path;
1316     int res;
1317
1318     path = fib_path_get(path_index);
1319
1320     res = 1;
1321
1322     if (path->fp_weight != rpath->frp_weight)
1323     {
1324         res = (path->fp_weight - rpath->frp_weight);
1325     }
1326     else
1327     {
1328         /*
1329          * both paths are of the same type.
1330          * consider each type and its attributes in turn.
1331          */
1332         switch (path->fp_type)
1333         {
1334         case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1335             res = ip46_address_cmp(&path->attached_next_hop.fp_nh,
1336                                    &rpath->frp_addr);
1337             if (0 == res)
1338             {
1339                 res = vnet_sw_interface_compare(
1340                           vnet_get_main(),
1341                           path->attached_next_hop.fp_interface,
1342                           rpath->frp_sw_if_index);
1343             }
1344             break;
1345         case FIB_PATH_TYPE_ATTACHED:
1346             res = vnet_sw_interface_compare(
1347                       vnet_get_main(),
1348                       path->attached.fp_interface,
1349                       rpath->frp_sw_if_index);
1350             break;
1351         case FIB_PATH_TYPE_RECURSIVE:
1352             if (FIB_PROTOCOL_MPLS == path->fp_nh_proto)
1353             {
1354                 res = path->recursive.fp_nh.fp_local_label - rpath->frp_local_label;
1355             }
1356             else
1357             {
1358                 res = ip46_address_cmp(&path->recursive.fp_nh.fp_ip,
1359                                        &rpath->frp_addr);
1360             }
1361
1362             if (0 == res)
1363             {
1364                 res = (path->recursive.fp_tbl_id - rpath->frp_fib_index);
1365             }
1366             break;
1367         case FIB_PATH_TYPE_DEAG:
1368             res = (path->deag.fp_tbl_id - rpath->frp_fib_index);
1369             break;
1370         case FIB_PATH_TYPE_SPECIAL:
1371         case FIB_PATH_TYPE_RECEIVE:
1372         case FIB_PATH_TYPE_EXCLUSIVE:
1373             res = 0;
1374             break;
1375         }
1376     }
1377     return (res);
1378 }
1379
1380 /*
1381  * fib_path_recursive_loop_detect
1382  *
1383  * A forward walk of the FIB object graph to detect for a cycle/loop. This
1384  * walk is initiated when an entry is linking to a new path list or from an old.
1385  * The entry vector passed contains all the FIB entrys that are children of this
1386  * path (it is all the entries encountered on the walk so far). If this vector
1387  * contains the entry this path resolve via, then a loop is about to form.
1388  * The loop must be allowed to form, since we need the dependencies in place
1389  * so that we can track when the loop breaks.
1390  * However, we MUST not produce a loop in the forwarding graph (else packets
1391  * would loop around the switch path until the loop breaks), so we mark recursive
1392  * paths as looped so that they do not contribute forwarding information.
1393  * By marking the path as looped, an etry such as;
1394  *    X/Y
1395  *     via a.a.a.a (looped)
1396  *     via b.b.b.b (not looped)
1397  * can still forward using the info provided by b.b.b.b only
1398  */
1399 int
1400 fib_path_recursive_loop_detect (fib_node_index_t path_index,
1401                                 fib_node_index_t **entry_indicies)
1402 {
1403     fib_path_t *path;
1404
1405     path = fib_path_get(path_index);
1406
1407     /*
1408      * the forced drop path is never looped, cos it is never resolved.
1409      */
1410     if (fib_path_is_permanent_drop(path))
1411     {
1412         return (0);
1413     }
1414
1415     switch (path->fp_type)
1416     {
1417     case FIB_PATH_TYPE_RECURSIVE:
1418     {
1419         fib_node_index_t *entry_index, *entries;
1420         int looped = 0;
1421         entries = *entry_indicies;
1422
1423         vec_foreach(entry_index, entries) {
1424             if (*entry_index == path->fp_via_fib)
1425             {
1426                 /*
1427                  * the entry that is about to link to this path-list (or
1428                  * one of this path-list's children) is the same entry that
1429                  * this recursive path resolves through. this is a cycle.
1430                  * abort the walk.
1431                  */
1432                 looped = 1;
1433                 break;
1434             }
1435         }
1436
1437         if (looped)
1438         {
1439             FIB_PATH_DBG(path, "recursive loop formed");
1440             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RECURSIVE_LOOP;
1441
1442             dpo_copy(&path->fp_dpo,
1443                     drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
1444         }
1445         else
1446         {
1447             /*
1448              * no loop here yet. keep forward walking the graph.
1449              */
1450             if (fib_entry_recursive_loop_detect(path->fp_via_fib, entry_indicies))
1451             {
1452                 FIB_PATH_DBG(path, "recursive loop formed");
1453                 path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RECURSIVE_LOOP;
1454             }
1455             else
1456             {
1457                 FIB_PATH_DBG(path, "recursive loop cleared");
1458                 path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RECURSIVE_LOOP;
1459             }
1460         }
1461         break;
1462     }
1463     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1464     case FIB_PATH_TYPE_ATTACHED:
1465     case FIB_PATH_TYPE_SPECIAL:
1466     case FIB_PATH_TYPE_DEAG:
1467     case FIB_PATH_TYPE_RECEIVE:
1468     case FIB_PATH_TYPE_EXCLUSIVE:
1469         /*
1470          * these path types cannot be part of a loop, since they are the leaves
1471          * of the graph.
1472          */
1473         break;
1474     }
1475
1476     return (fib_path_is_looped(path_index));
1477 }
1478
1479 int
1480 fib_path_resolve (fib_node_index_t path_index)
1481 {
1482     fib_path_t *path;
1483
1484     path = fib_path_get(path_index);
1485
1486     /*
1487      * hope for the best.
1488      */
1489     path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
1490
1491     /*
1492      * the forced drop path resolves via the drop adj
1493      */
1494     if (fib_path_is_permanent_drop(path))
1495     {
1496         dpo_copy(&path->fp_dpo,
1497                  drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
1498         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
1499         return (fib_path_is_resolved(path_index));
1500     }
1501
1502     switch (path->fp_type)
1503     {
1504     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1505         fib_path_attached_next_hop_set(path);
1506         break;
1507     case FIB_PATH_TYPE_ATTACHED:
1508         /*
1509          * path->attached.fp_interface
1510          */
1511         if (!vnet_sw_interface_is_admin_up(vnet_get_main(),
1512                                            path->attached.fp_interface))
1513         {
1514             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
1515         }
1516         if (vnet_sw_interface_is_p2p(vnet_get_main(),
1517                                      path->attached.fp_interface))
1518         {
1519             /*
1520              * point-2-point interfaces do not require a glean, since
1521              * there is nothing to ARP. Install a rewrite/nbr adj instead
1522              */
1523             dpo_set(&path->fp_dpo,
1524                     DPO_ADJACENCY,
1525                     fib_proto_to_dpo(path->fp_nh_proto),
1526                     adj_nbr_add_or_lock(
1527                         path->fp_nh_proto,
1528                         fib_proto_to_link(path->fp_nh_proto),
1529                         &zero_addr,
1530                         path->attached.fp_interface));
1531         }
1532         else
1533         {
1534             dpo_set(&path->fp_dpo,
1535                     DPO_ADJACENCY_GLEAN,
1536                     fib_proto_to_dpo(path->fp_nh_proto),
1537                     adj_glean_add_or_lock(path->fp_nh_proto,
1538                                           path->attached.fp_interface,
1539                                           NULL));
1540         }
1541         /*
1542          * become a child of the adjacency so we receive updates
1543          * when the interface state changes
1544          */
1545         path->fp_sibling = adj_child_add(path->fp_dpo.dpoi_index,
1546                                          FIB_NODE_TYPE_PATH,
1547                                          fib_path_get_index(path));
1548
1549         break;
1550     case FIB_PATH_TYPE_RECURSIVE:
1551     {
1552         /*
1553          * Create a RR source entry in the table for the address
1554          * that this path recurses through.
1555          * This resolve action is recursive, hence we may create
1556          * more paths in the process. more creates mean maybe realloc
1557          * of this path.
1558          */
1559         fib_node_index_t fei;
1560         fib_prefix_t pfx;
1561
1562         ASSERT(FIB_NODE_INDEX_INVALID == path->fp_via_fib);
1563
1564         if (FIB_PROTOCOL_MPLS == path->fp_nh_proto)
1565         {
1566             fib_prefix_from_mpls_label(path->recursive.fp_nh.fp_local_label, &pfx);
1567         }
1568         else
1569         {
1570             fib_prefix_from_ip46_addr(&path->recursive.fp_nh.fp_ip, &pfx);
1571         }
1572
1573         fei = fib_table_entry_special_add(path->recursive.fp_tbl_id,
1574                                           &pfx,
1575                                           FIB_SOURCE_RR,
1576                                           FIB_ENTRY_FLAG_NONE,
1577                                           ADJ_INDEX_INVALID);
1578
1579         path = fib_path_get(path_index);
1580         path->fp_via_fib = fei;
1581
1582         /*
1583          * become a dependent child of the entry so the path is
1584          * informed when the forwarding for the entry changes.
1585          */
1586         path->fp_sibling = fib_entry_child_add(path->fp_via_fib,
1587                                                FIB_NODE_TYPE_PATH,
1588                                                fib_path_get_index(path));
1589
1590         /*
1591          * create and configure the IP DPO
1592          */
1593         fib_path_recursive_adj_update(
1594             path,
1595             fib_path_proto_to_chain_type(path->fp_nh_proto),
1596             &path->fp_dpo);
1597
1598         break;
1599     }
1600     case FIB_PATH_TYPE_SPECIAL:
1601         /*
1602          * Resolve via the drop
1603          */
1604         dpo_copy(&path->fp_dpo,
1605                  drop_dpo_get(fib_proto_to_dpo(path->fp_nh_proto)));
1606         break;
1607     case FIB_PATH_TYPE_DEAG:
1608         /*
1609          * Resolve via a lookup DPO.
1610          * FIXME. control plane should add routes with a table ID
1611          */
1612         lookup_dpo_add_or_lock_w_fib_index(path->deag.fp_tbl_id,
1613                                           fib_proto_to_dpo(path->fp_nh_proto),
1614                                           LOOKUP_INPUT_DST_ADDR,
1615                                           LOOKUP_TABLE_FROM_CONFIG,
1616                                           &path->fp_dpo);
1617         break;
1618     case FIB_PATH_TYPE_RECEIVE:
1619         /*
1620          * Resolve via a receive DPO.
1621          */
1622         receive_dpo_add_or_lock(fib_proto_to_dpo(path->fp_nh_proto),
1623                                 path->receive.fp_interface,
1624                                 &path->receive.fp_addr,
1625                                 &path->fp_dpo);
1626         break;
1627     case FIB_PATH_TYPE_EXCLUSIVE:
1628         /*
1629          * Resolve via the user provided DPO
1630          */
1631         dpo_copy(&path->fp_dpo, &path->exclusive.fp_ex_dpo);
1632         break;
1633     }
1634
1635     return (fib_path_is_resolved(path_index));
1636 }
1637
1638 u32
1639 fib_path_get_resolving_interface (fib_node_index_t path_index)
1640 {
1641     fib_path_t *path;
1642
1643     path = fib_path_get(path_index);
1644
1645     switch (path->fp_type)
1646     {
1647     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1648         return (path->attached_next_hop.fp_interface);
1649     case FIB_PATH_TYPE_ATTACHED:
1650         return (path->attached.fp_interface);
1651     case FIB_PATH_TYPE_RECEIVE:
1652         return (path->receive.fp_interface);
1653     case FIB_PATH_TYPE_RECURSIVE:
1654         return (fib_entry_get_resolving_interface(path->fp_via_fib));
1655     case FIB_PATH_TYPE_SPECIAL:
1656     case FIB_PATH_TYPE_DEAG:
1657     case FIB_PATH_TYPE_EXCLUSIVE:
1658         break;
1659     }
1660     return (~0);
1661 }
1662
1663 adj_index_t
1664 fib_path_get_adj (fib_node_index_t path_index)
1665 {
1666     fib_path_t *path;
1667
1668     path = fib_path_get(path_index);
1669
1670     ASSERT(dpo_is_adj(&path->fp_dpo));
1671     if (dpo_is_adj(&path->fp_dpo))
1672     {
1673         return (path->fp_dpo.dpoi_index);
1674     }
1675     return (ADJ_INDEX_INVALID);
1676 }
1677
1678 int
1679 fib_path_get_weight (fib_node_index_t path_index)
1680 {
1681     fib_path_t *path;
1682
1683     path = fib_path_get(path_index);
1684
1685     ASSERT(path);
1686
1687     return (path->fp_weight);
1688 }
1689
1690 /**
1691  * @brief Contribute the path's adjacency to the list passed.
1692  * By calling this function over all paths, recursively, a child
1693  * can construct its full set of forwarding adjacencies, and hence its
1694  * uRPF list.
1695  */
1696 void
1697 fib_path_contribute_urpf (fib_node_index_t path_index,
1698                           index_t urpf)
1699 {
1700     fib_path_t *path;
1701
1702     path = fib_path_get(path_index);
1703
1704     /*
1705      * resolved and unresolved paths contribute to the RPF list.
1706      */
1707     switch (path->fp_type)
1708     {
1709     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1710         fib_urpf_list_append(urpf, path->attached_next_hop.fp_interface);
1711         break;
1712
1713     case FIB_PATH_TYPE_ATTACHED:
1714         fib_urpf_list_append(urpf, path->attached.fp_interface);
1715         break;
1716
1717     case FIB_PATH_TYPE_RECURSIVE:
1718         if (FIB_NODE_INDEX_INVALID != path->fp_via_fib)
1719         {
1720             /*
1721              * there's unresolved due to constraints, and there's unresolved
1722              * due to ain't go no via. can't do nowt w'out via.
1723              */
1724             fib_entry_contribute_urpf(path->fp_via_fib, urpf);
1725         }
1726         break;
1727
1728     case FIB_PATH_TYPE_EXCLUSIVE:
1729     case FIB_PATH_TYPE_SPECIAL:
1730         /*
1731          * these path types may link to an adj, if that's what
1732          * the clinet gave
1733          */
1734         if (dpo_is_adj(&path->fp_dpo))
1735         {
1736             ip_adjacency_t *adj;
1737
1738             adj = adj_get(path->fp_dpo.dpoi_index);
1739
1740             fib_urpf_list_append(urpf, adj->rewrite_header.sw_if_index);
1741         }
1742         break;
1743
1744     case FIB_PATH_TYPE_DEAG:
1745     case FIB_PATH_TYPE_RECEIVE:
1746         /*
1747          * these path types don't link to an adj
1748          */
1749         break;
1750     }
1751 }
1752
1753 void
1754 fib_path_contribute_forwarding (fib_node_index_t path_index,
1755                                 fib_forward_chain_type_t fct,
1756                                 dpo_id_t *dpo)
1757 {
1758     fib_path_t *path;
1759
1760     path = fib_path_get(path_index);
1761
1762     ASSERT(path);
1763     ASSERT(FIB_FORW_CHAIN_TYPE_MPLS_EOS != fct);
1764
1765     FIB_PATH_DBG(path, "contribute");
1766
1767     /*
1768      * The DPO stored in the path was created when the path was resolved.
1769      * This then represents the path's 'native' protocol; IP.
1770      * For all others will need to go find something else.
1771      */
1772     if (fib_path_proto_to_chain_type(path->fp_nh_proto) == fct)
1773     {
1774         dpo_copy(dpo, &path->fp_dpo);
1775     }
1776     else
1777     {
1778         switch (path->fp_type)
1779         {
1780         case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1781             switch (fct)
1782             {
1783             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
1784             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
1785             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
1786             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
1787             case FIB_FORW_CHAIN_TYPE_ETHERNET:
1788             case FIB_FORW_CHAIN_TYPE_NSH:
1789             {
1790                 adj_index_t ai;
1791
1792                 /*
1793                  * get a appropriate link type adj.
1794                  */
1795                 ai = fib_path_attached_next_hop_get_adj(
1796                          path,
1797                          fib_forw_chain_type_to_link_type(fct));
1798                 dpo_set(dpo, DPO_ADJACENCY,
1799                         fib_forw_chain_type_to_dpo_proto(fct), ai);
1800                 adj_unlock(ai);
1801
1802                 break;
1803             }
1804             case FIB_FORW_CHAIN_TYPE_MCAST_IP4:
1805             case FIB_FORW_CHAIN_TYPE_MCAST_IP6:
1806             break;
1807             }
1808             break;
1809         case FIB_PATH_TYPE_RECURSIVE:
1810             switch (fct)
1811             {
1812             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
1813             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
1814             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
1815             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
1816                 fib_path_recursive_adj_update(path, fct, dpo);
1817                 break;
1818             case FIB_FORW_CHAIN_TYPE_MCAST_IP4:
1819             case FIB_FORW_CHAIN_TYPE_MCAST_IP6:
1820             case FIB_FORW_CHAIN_TYPE_ETHERNET:
1821             case FIB_FORW_CHAIN_TYPE_NSH:
1822                 ASSERT(0);
1823                 break;
1824             }
1825             break;
1826         case FIB_PATH_TYPE_DEAG:
1827             switch (fct)
1828             {
1829             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
1830                 lookup_dpo_add_or_lock_w_table_id(MPLS_FIB_DEFAULT_TABLE_ID,
1831                                                   DPO_PROTO_MPLS,
1832                                                   LOOKUP_INPUT_DST_ADDR,
1833                                                   LOOKUP_TABLE_FROM_CONFIG,
1834                                                   dpo);
1835                 break;
1836             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
1837             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
1838             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
1839                 dpo_copy(dpo, &path->fp_dpo);
1840                 break;
1841             case FIB_FORW_CHAIN_TYPE_MCAST_IP4:
1842             case FIB_FORW_CHAIN_TYPE_MCAST_IP6:
1843             case FIB_FORW_CHAIN_TYPE_ETHERNET:
1844             case FIB_FORW_CHAIN_TYPE_NSH:
1845                 ASSERT(0);
1846                 break;
1847             }
1848             break;
1849         case FIB_PATH_TYPE_EXCLUSIVE:
1850             dpo_copy(dpo, &path->exclusive.fp_ex_dpo);
1851             break;
1852         case FIB_PATH_TYPE_ATTACHED:
1853             switch (fct)
1854             {
1855             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
1856             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
1857             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
1858             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
1859             case FIB_FORW_CHAIN_TYPE_ETHERNET:
1860             case FIB_FORW_CHAIN_TYPE_NSH:
1861                 break;
1862             case FIB_FORW_CHAIN_TYPE_MCAST_IP4:
1863             case FIB_FORW_CHAIN_TYPE_MCAST_IP6:
1864                 {
1865                     adj_index_t ai;
1866
1867                     /*
1868                      * Create the adj needed for sending IP multicast traffic
1869                      */
1870                     ai = adj_mcast_add_or_lock(path->fp_nh_proto,
1871                                                fib_forw_chain_type_to_link_type(fct),
1872                                                path->attached.fp_interface);
1873                     dpo_set(dpo, DPO_ADJACENCY_MCAST,
1874                             fib_forw_chain_type_to_dpo_proto(fct),
1875                             ai);
1876                     adj_unlock(ai);
1877                 }
1878                 break;
1879             }
1880             break;
1881         case FIB_PATH_TYPE_RECEIVE:
1882         case FIB_PATH_TYPE_SPECIAL:
1883             dpo_copy(dpo, &path->fp_dpo);
1884             break;
1885         }
1886     }
1887 }
1888
1889 load_balance_path_t *
1890 fib_path_append_nh_for_multipath_hash (fib_node_index_t path_index,
1891                                        fib_forward_chain_type_t fct,
1892                                        load_balance_path_t *hash_key)
1893 {
1894     load_balance_path_t *mnh;
1895     fib_path_t *path;
1896
1897     path = fib_path_get(path_index);
1898
1899     ASSERT(path);
1900
1901     if (fib_path_is_resolved(path_index))
1902     {
1903         vec_add2(hash_key, mnh, 1);
1904
1905         mnh->path_weight = path->fp_weight;
1906         mnh->path_index = path_index;
1907         fib_path_contribute_forwarding(path_index, fct, &mnh->path_dpo);
1908     }
1909
1910     return (hash_key);
1911 }
1912
1913 int
1914 fib_path_is_recursive (fib_node_index_t path_index)
1915 {
1916     fib_path_t *path;
1917
1918     path = fib_path_get(path_index);
1919
1920     return (FIB_PATH_TYPE_RECURSIVE == path->fp_type);
1921 }
1922
1923 int
1924 fib_path_is_exclusive (fib_node_index_t path_index)
1925 {
1926     fib_path_t *path;
1927
1928     path = fib_path_get(path_index);
1929
1930     return (FIB_PATH_TYPE_EXCLUSIVE == path->fp_type);
1931 }
1932
1933 int
1934 fib_path_is_deag (fib_node_index_t path_index)
1935 {
1936     fib_path_t *path;
1937
1938     path = fib_path_get(path_index);
1939
1940     return (FIB_PATH_TYPE_DEAG == path->fp_type);
1941 }
1942
1943 int
1944 fib_path_is_resolved (fib_node_index_t path_index)
1945 {
1946     fib_path_t *path;
1947
1948     path = fib_path_get(path_index);
1949
1950     return (dpo_id_is_valid(&path->fp_dpo) &&
1951             (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED) &&
1952             !fib_path_is_looped(path_index) &&
1953             !fib_path_is_permanent_drop(path));
1954 }
1955
1956 int
1957 fib_path_is_looped (fib_node_index_t path_index)
1958 {
1959     fib_path_t *path;
1960
1961     path = fib_path_get(path_index);
1962
1963     return (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RECURSIVE_LOOP);
1964 }
1965
1966 int
1967 fib_path_encode (fib_node_index_t path_list_index,
1968                  fib_node_index_t path_index,
1969                  void *ctx)
1970 {
1971     fib_route_path_encode_t **api_rpaths = ctx;
1972     fib_route_path_encode_t *api_rpath;
1973     fib_path_t *path;
1974
1975     path = fib_path_get(path_index);
1976     if (!path)
1977       return (0);
1978     vec_add2(*api_rpaths, api_rpath, 1);
1979     api_rpath->rpath.frp_weight = path->fp_weight;
1980     api_rpath->rpath.frp_proto = path->fp_nh_proto;
1981     api_rpath->rpath.frp_sw_if_index = ~0;
1982     api_rpath->dpo = path->exclusive.fp_ex_dpo;
1983     switch (path->fp_type)
1984       {
1985       case FIB_PATH_TYPE_RECEIVE:
1986         api_rpath->rpath.frp_addr = path->receive.fp_addr;
1987         api_rpath->rpath.frp_sw_if_index = path->receive.fp_interface;
1988         break;
1989       case FIB_PATH_TYPE_ATTACHED:
1990         api_rpath->rpath.frp_sw_if_index = path->attached.fp_interface;
1991         break;
1992       case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1993         api_rpath->rpath.frp_sw_if_index = path->attached_next_hop.fp_interface;
1994         api_rpath->rpath.frp_addr = path->attached_next_hop.fp_nh;
1995         break;
1996       case FIB_PATH_TYPE_SPECIAL:
1997         break;
1998       case FIB_PATH_TYPE_DEAG:
1999         break;
2000       case FIB_PATH_TYPE_RECURSIVE:
2001         api_rpath->rpath.frp_addr = path->recursive.fp_nh.fp_ip;
2002         break;
2003       default:
2004         break;
2005       }
2006     return (1);
2007 }
2008
2009 fib_protocol_t
2010 fib_path_get_proto (fib_node_index_t path_index)
2011 {
2012     fib_path_t *path;
2013
2014     path = fib_path_get(path_index);
2015
2016     return (path->fp_nh_proto);
2017 }
2018
2019 void
2020 fib_path_module_init (void)
2021 {
2022     fib_node_register_type (FIB_NODE_TYPE_PATH, &fib_path_vft);
2023 }
2024
2025 static clib_error_t *
2026 show_fib_path_command (vlib_main_t * vm,
2027                         unformat_input_t * input,
2028                         vlib_cli_command_t * cmd)
2029 {
2030     fib_node_index_t pi;
2031     fib_path_t *path;
2032
2033     if (unformat (input, "%d", &pi))
2034     {
2035         /*
2036          * show one in detail
2037          */
2038         if (!pool_is_free_index(fib_path_pool, pi))
2039         {
2040             path = fib_path_get(pi);
2041             u8 *s = fib_path_format(pi, NULL);
2042             s = format(s, "children:");
2043             s = fib_node_children_format(path->fp_node.fn_children, s);
2044             vlib_cli_output (vm, "%s", s);
2045             vec_free(s);
2046         }
2047         else
2048         {
2049             vlib_cli_output (vm, "path %d invalid", pi);
2050         }
2051     }
2052     else
2053     {
2054         vlib_cli_output (vm, "FIB Paths");
2055         pool_foreach(path, fib_path_pool,
2056         ({
2057             vlib_cli_output (vm, "%U", format_fib_path, path);
2058         }));
2059     }
2060
2061     return (NULL);
2062 }
2063
2064 VLIB_CLI_COMMAND (show_fib_path, static) = {
2065   .path = "show fib paths",
2066   .function = show_fib_path_command,
2067   .short_help = "show fib paths",
2068 };