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 #include <vnet/dpo/interface_rx_dpo.h>
  25 #include <vnet/dpo/mpls_disposition.h>
  26 #include <vnet/dpo/dvr_dpo.h>
  27 #include <vnet/dpo/drop_dpo.h>
  28
  29 #include <vnet/adj/adj.h>
  30 #include <vnet/adj/adj_mcast.h>
  31
  32 #include <vnet/fib/fib_path.h>
  33 #include <vnet/fib/fib_node.h>
  34 #include <vnet/fib/fib_table.h>
  35 #include <vnet/fib/fib_entry.h>
  36 #include <vnet/fib/fib_path_list.h>
  37 #include <vnet/fib/fib_internal.h>
  38 #include <vnet/fib/fib_urpf_list.h>
  39 #include <vnet/fib/mpls_fib.h>
  40 #include <vnet/udp/udp_encap.h>
  41 #include <vnet/bier/bier_fmask.h>
  42 #include <vnet/bier/bier_table.h>
  43 #include <vnet/bier/bier_imp.h>
  44 #include <vnet/bier/bier_disp_table.h>
  45
  46 /**
  47  * Enurmeration of path types
  48  */
  49 typedef enum fib_path_type_t_ {
  50     /**
  51      * Marker. Add new types after this one.
  52      */
  53     FIB_PATH_TYPE_FIRST = 0,
  54     /**
  55      * Attached-nexthop. An interface and a nexthop are known.
  56      */
  57     FIB_PATH_TYPE_ATTACHED_NEXT_HOP = FIB_PATH_TYPE_FIRST,
  58     /**
  59      * attached. Only the interface is known.
  60      */
  61     FIB_PATH_TYPE_ATTACHED,
  62     /**
  63      * recursive. Only the next-hop is known.
  64      */
  65     FIB_PATH_TYPE_RECURSIVE,
  66     /**
  67      * special. nothing is known. so we drop.
  68      */
  69     FIB_PATH_TYPE_SPECIAL,
  70     /**
  71      * exclusive. user provided adj.
  72      */
  73     FIB_PATH_TYPE_EXCLUSIVE,
  74     /**
  75      * deag. Link to a lookup adj in the next table
  76      */
  77     FIB_PATH_TYPE_DEAG,
  78     /**
  79      * interface receive.
  80      */
  81     FIB_PATH_TYPE_INTF_RX,
  82     /**
  83      * Path resolves via a UDP encap object.
  84      */
  85     FIB_PATH_TYPE_UDP_ENCAP,
  86     /**
  87      * receive. it's for-us.
  88      */
  89     FIB_PATH_TYPE_RECEIVE,
  90     /**
  91      * bier-imp. it's via a BIER imposition.
  92      */
  93     FIB_PATH_TYPE_BIER_IMP,
  94     /**
  95      * bier-fmask. it's via a BIER ECMP-table.
  96      */
  97     FIB_PATH_TYPE_BIER_TABLE,
  98     /**
  99      * bier-fmask. it's via a BIER f-mask.
 100      */
 101     FIB_PATH_TYPE_BIER_FMASK,
 102     /**
 103      * via a DVR.
 104      */
 105     FIB_PATH_TYPE_DVR,
 106     /**
 107      * Marker. Add new types before this one, then update it.
 108      */
 109     FIB_PATH_TYPE_LAST = FIB_PATH_TYPE_BIER_FMASK,
 110 } __attribute__ ((packed)) fib_path_type_t;
 111
 112 /**
 113  * The maximum number of path_types
 114  */
 115 #define FIB_PATH_TYPE_MAX (FIB_PATH_TYPE_LAST + 1)
 116
 117 #define FIB_PATH_TYPES {                                        \
 118     [FIB_PATH_TYPE_ATTACHED_NEXT_HOP] = "attached-nexthop",     \
 119     [FIB_PATH_TYPE_ATTACHED]          = "attached",             \
 120     [FIB_PATH_TYPE_RECURSIVE]         = "recursive",            \
 121     [FIB_PATH_TYPE_SPECIAL]           = "special",              \
 122     [FIB_PATH_TYPE_EXCLUSIVE]         = "exclusive",            \
 123     [FIB_PATH_TYPE_DEAG]              = "deag",                 \
 124     [FIB_PATH_TYPE_INTF_RX]           = "intf-rx",              \
 125     [FIB_PATH_TYPE_UDP_ENCAP]         = "udp-encap",            \
 126     [FIB_PATH_TYPE_RECEIVE]           = "receive",              \
 127     [FIB_PATH_TYPE_BIER_IMP]          = "bier-imp",             \
 128     [FIB_PATH_TYPE_BIER_TABLE]        = "bier-table",           \
 129     [FIB_PATH_TYPE_BIER_FMASK]        = "bier-fmask",           \
 130     [FIB_PATH_TYPE_DVR]               = "dvr",                  \
 131 }
 132
 133 #define FOR_EACH_FIB_PATH_TYPE(_item)           \
 134     for (_item = FIB_PATH_TYPE_FIRST;           \
 135          _item <= FIB_PATH_TYPE_LAST;           \
 136          _item++)
 137
 138 /**
 139  * Enurmeration of path operational (i.e. derived) attributes
 140  */
 141 typedef enum fib_path_oper_attribute_t_ {
 142     /**
 143      * Marker. Add new types after this one.
 144      */
 145     FIB_PATH_OPER_ATTRIBUTE_FIRST = 0,
 146     /**
 147      * The path forms part of a recursive loop.
 148      */
 149     FIB_PATH_OPER_ATTRIBUTE_RECURSIVE_LOOP = FIB_PATH_OPER_ATTRIBUTE_FIRST,
 150     /**
 151      * The path is resolved
 152      */
 153     FIB_PATH_OPER_ATTRIBUTE_RESOLVED,
 154     /**
 155      * The path is attached, despite what the next-hop may say.
 156      */
 157     FIB_PATH_OPER_ATTRIBUTE_ATTACHED,
 158     /**
 159      * The path has become a permanent drop.
 160      */
 161     FIB_PATH_OPER_ATTRIBUTE_DROP,
 162     /**
 163      * Marker. Add new types before this one, then update it.
 164      */
 165     FIB_PATH_OPER_ATTRIBUTE_LAST = FIB_PATH_OPER_ATTRIBUTE_DROP,
 166 } __attribute__ ((packed)) fib_path_oper_attribute_t;
 167
 168 /**
 169  * The maximum number of path operational attributes
 170  */
 171 #define FIB_PATH_OPER_ATTRIBUTE_MAX (FIB_PATH_OPER_ATTRIBUTE_LAST + 1)
 172
 173 #define FIB_PATH_OPER_ATTRIBUTES {                                      \
 174     [FIB_PATH_OPER_ATTRIBUTE_RECURSIVE_LOOP] = "recursive-loop",        \
 175     [FIB_PATH_OPER_ATTRIBUTE_RESOLVED]       = "resolved",              \
 176     [FIB_PATH_OPER_ATTRIBUTE_DROP]           = "drop",                  \
 177 }
 178
 179 #define FOR_EACH_FIB_PATH_OPER_ATTRIBUTE(_item) \
 180     for (_item = FIB_PATH_OPER_ATTRIBUTE_FIRST; \
 181          _item <= FIB_PATH_OPER_ATTRIBUTE_LAST; \
 182          _item++)
 183
 184 /**
 185  * Path flags from the attributes
 186  */
 187 typedef enum fib_path_oper_flags_t_ {
 188     FIB_PATH_OPER_FLAG_NONE = 0,
 189     FIB_PATH_OPER_FLAG_RECURSIVE_LOOP = (1 << FIB_PATH_OPER_ATTRIBUTE_RECURSIVE_LOOP),
 190     FIB_PATH_OPER_FLAG_DROP = (1 << FIB_PATH_OPER_ATTRIBUTE_DROP),
 191     FIB_PATH_OPER_FLAG_RESOLVED = (1 << FIB_PATH_OPER_ATTRIBUTE_RESOLVED),
 192     FIB_PATH_OPER_FLAG_ATTACHED = (1 << FIB_PATH_OPER_ATTRIBUTE_ATTACHED),
 193 } __attribute__ ((packed)) fib_path_oper_flags_t;
 194
 195 /**
 196  * A FIB path
 197  */
 198 typedef struct fib_path_t_ {
 199     /**
 200      * A path is a node in the FIB graph.
 201      */
 202     fib_node_t fp_node;
 203
 204     /**
 205      * The index of the path-list to which this path belongs
 206      */
 207     u32 fp_pl_index;
 208
 209     /**
 210      * This marks the start of the memory area used to hash
 211      * the path
 212      */
 213     STRUCT_MARK(path_hash_start);
 214
 215     /**
 216      * Configuration Flags
 217      */
 218     fib_path_cfg_flags_t fp_cfg_flags;
 219
 220     /**
 221      * The type of the path. This is the selector for the union
 222      */
 223     fib_path_type_t fp_type;
 224
 225     /**
 226      * The protocol of the next-hop, i.e. the address family of the
 227      * next-hop's address. We can't derive this from the address itself
 228      * since the address can be all zeros
 229      */
 230     dpo_proto_t fp_nh_proto;
 231
 232     /**
 233      * UCMP [unnormalised] weigth
 234      */
 235     u8 fp_weight;
 236
 237     /**
 238      * A path preference. 0 is the best.
 239      * Only paths of the best preference, that are 'up', are considered
 240      * for forwarding.
 241      */
 242     u8 fp_preference;
 243
 244     /**
 245      * per-type union of the data required to resolve the path
 246      */
 247     union {
 248         struct {
 249             /**
 250              * The next-hop
 251              */
 252             ip46_address_t fp_nh;
 253             /**
 254              * The interface
 255              */
 256             u32 fp_interface;
 257         } attached_next_hop;
 258         struct {
 259             /**
 260              * The interface
 261              */
 262             u32 fp_interface;
 263         } attached;
 264         struct {
 265             union
 266             {
 267                 /**
 268                  * The next-hop
 269                  */
 270                 ip46_address_t fp_ip;
 271                 struct {
 272                     /**
 273                      * The local label to resolve through.
 274                      */
 275                     mpls_label_t fp_local_label;
 276                     /**
 277                      * The EOS bit of the resolving label
 278                      */
 279                     mpls_eos_bit_t fp_eos;
 280                 };
 281             } fp_nh;
 282             union {
 283                 /**
 284                  * The FIB table index in which to find the next-hop.
 285                  */
 286                 fib_node_index_t fp_tbl_id;
 287                 /**
 288                  * The BIER FIB the fmask is in
 289                  */
 290                 index_t fp_bier_fib;
 291             };
 292         } recursive;
 293         struct {
 294             /**
 295              * BIER FMask ID
 296              */
 297             index_t fp_bier_fmask;
 298         } bier_fmask;
 299         struct {
 300             /**
 301              * The BIER table's ID
 302              */
 303             bier_table_id_t fp_bier_tbl;
 304         } bier_table;
 305         struct {
 306             /**
 307              * The BIER imposition object
 308              * this is part of the path's key, since the index_t
 309              * of an imposition object is the object's key.
 310              */
 311             index_t fp_bier_imp;
 312         } bier_imp;
 313         struct {
 314             /**
 315              * The FIB index in which to perfom the next lookup
 316              */
 317             fib_node_index_t fp_tbl_id;
 318             /**
 319              * The RPF-ID to tag the packets with
 320              */
 321             fib_rpf_id_t fp_rpf_id;
 322         } deag;
 323         struct {
 324         } special;
 325         struct {
 326             /**
 327              * The user provided 'exclusive' DPO
 328              */
 329             dpo_id_t fp_ex_dpo;
 330         } exclusive;
 331         struct {
 332             /**
 333              * The interface on which the local address is configured
 334              */
 335             u32 fp_interface;
 336             /**
 337              * The next-hop
 338              */
 339             ip46_address_t fp_addr;
 340         } receive;
 341         struct {
 342             /**
 343              * The interface on which the packets will be input.
 344              */
 345             u32 fp_interface;
 346         } intf_rx;
 347         struct {
 348             /**
 349              * The UDP Encap object this path resolves through
 350              */
 351             u32 fp_udp_encap_id;
 352         } udp_encap;
 353         struct {
 354             /**
 355              * The interface
 356              */
 357             u32 fp_interface;
 358         } dvr;
 359     };
 360     STRUCT_MARK(path_hash_end);
 361
 362     /**
 363      * Memebers in this last section represent information that is
 364      * dervied during resolution. It should not be copied to new paths
 365      * nor compared.
 366      */
 367
 368     /**
 369      * Operational Flags
 370      */
 371     fib_path_oper_flags_t fp_oper_flags;
 372
 373     union {
 374         /**
 375          * the resolving via fib. not part of the union, since it it not part
 376          * of the path's hash.
 377          */
 378         fib_node_index_t fp_via_fib;
 379         /**
 380          * the resolving bier-table
 381          */
 382         index_t fp_via_bier_tbl;
 383         /**
 384          * the resolving bier-fmask
 385          */
 386         index_t fp_via_bier_fmask;
 387     };
 388
 389     /**
 390      * The Data-path objects through which this path resolves for IP.
 391      */
 392     dpo_id_t fp_dpo;
 393
 394     /**
 395      * the index of this path in the parent's child list.
 396      */
 397     u32 fp_sibling;
 398 } fib_path_t;
 399
 400 /*
 401  * Array of strings/names for the path types and attributes
 402  */
 403 static const char *fib_path_type_names[] = FIB_PATH_TYPES;
 404 static const char *fib_path_oper_attribute_names[] = FIB_PATH_OPER_ATTRIBUTES;
 405 static const char *fib_path_cfg_attribute_names[]  = FIB_PATH_CFG_ATTRIBUTES;
 406
 407 /*
 408  * The memory pool from which we allocate all the paths
 409  */
 410 static fib_path_t *fib_path_pool;
 411
 412 /*
 413  * Debug macro
 414  */
 415 #ifdef FIB_DEBUG
 416 #define FIB_PATH_DBG(_p, _fmt, _args...)                        \
 417 {                                                               \
 418     u8 *_tmp = NULL;                                            \
 419     _tmp = fib_path_format(fib_path_get_index(_p), _tmp);       \
 420     clib_warning("path:[%d:%U]:" _fmt,                          \
 421                  fib_path_get_index(_p), format_fib_path, _p, 0,\
 422                  ##_args);                                      \
 423     vec_free(_tmp);                                             \
 424 }
 425 #else
 426 #define FIB_PATH_DBG(_p, _fmt, _args...)
 427 #endif
 428
 429 static fib_path_t *
 430 fib_path_get (fib_node_index_t index)
 431 {
 432     return (pool_elt_at_index(fib_path_pool, index));
 433 }
 434
 435 static fib_node_index_t
 436 fib_path_get_index (fib_path_t *path)
 437 {
 438     return (path - fib_path_pool);
 439 }
 440
 441 static fib_node_t *
 442 fib_path_get_node (fib_node_index_t index)
 443 {
 444     return ((fib_node_t*)fib_path_get(index));
 445 }
 446
 447 static fib_path_t*
 448 fib_path_from_fib_node (fib_node_t *node)
 449 {
 450     ASSERT(FIB_NODE_TYPE_PATH == node->fn_type);
 451     return ((fib_path_t*)node);
 452 }
 453
 454 u8 *
 455 format_fib_path (u8 * s, va_list * args)
 456 {
 457     fib_node_index_t path_index = va_arg (*args, fib_node_index_t);
 458     u32 indent = va_arg (*args, u32);
 459     vnet_main_t * vnm = vnet_get_main();
 460     fib_path_oper_attribute_t oattr;
 461     fib_path_cfg_attribute_t cattr;
 462     fib_path_t *path;
 463
 464     path = fib_path_get(path_index);
 465
 466     s = format (s, "%Upath:[%d] ", format_white_space, indent,
 467                 fib_path_get_index(path));
 468     s = format (s, "pl-index:%d ", path->fp_pl_index);
 469     s = format (s, "%U ", format_dpo_proto, path->fp_nh_proto);
 470     s = format (s, "weight=%d ", path->fp_weight);
 471     s = format (s, "pref=%d ", path->fp_preference);
 472     s = format (s, "%s: ", fib_path_type_names[path->fp_type]);
 473     if (FIB_PATH_OPER_FLAG_NONE != path->fp_oper_flags) {
 474         s = format(s, " oper-flags:");
 475         FOR_EACH_FIB_PATH_OPER_ATTRIBUTE(oattr) {
 476             if ((1<<oattr) & path->fp_oper_flags) {
 477                 s = format (s, "%s,", fib_path_oper_attribute_names[oattr]);
 478             }
 479         }
 480     }
 481     if (FIB_PATH_CFG_FLAG_NONE != path->fp_cfg_flags) {
 482         s = format(s, " cfg-flags:");
 483         FOR_EACH_FIB_PATH_CFG_ATTRIBUTE(cattr) {
 484             if ((1<<cattr) & path->fp_cfg_flags) {
 485                 s = format (s, "%s,", fib_path_cfg_attribute_names[cattr]);
 486             }
 487         }
 488     }
 489     s = format(s, "\n%U", format_white_space, indent+2);
 490
 491     switch (path->fp_type)
 492     {
 493     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
 494         s = format (s, "%U", format_ip46_address,
 495                     &path->attached_next_hop.fp_nh,
 496                     IP46_TYPE_ANY);
 497         if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_DROP)
 498         {
 499             s = format (s, " if_index:%d", path->attached_next_hop.fp_interface);
 500         }
 501         else
 502         {
 503             s = format (s, " %U",
 504                         format_vnet_sw_interface_name,
 505                         vnm,
 506                         vnet_get_sw_interface(
 507                             vnm,
 508                             path->attached_next_hop.fp_interface));
 509             if (vnet_sw_interface_is_p2p(vnet_get_main(),
 510                                          path->attached_next_hop.fp_interface))
 511             {
 512                 s = format (s, " (p2p)");
 513             }
 514         }
 515         if (!dpo_id_is_valid(&path->fp_dpo))
 516         {
 517             s = format(s, "\n%Uunresolved", format_white_space, indent+2);
 518         }
 519         else
 520         {
 521             s = format(s, "\n%U%U",
 522                        format_white_space, indent,
 523                        format_dpo_id,
 524                        &path->fp_dpo, 13);
 525         }
 526         break;
 527     case FIB_PATH_TYPE_ATTACHED:
 528         if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_DROP)
 529         {
 530             s = format (s, "if_index:%d", path->attached_next_hop.fp_interface);
 531         }
 532         else
 533         {
 534             s = format (s, " %U",
 535                         format_vnet_sw_interface_name,
 536                         vnm,
 537                         vnet_get_sw_interface(
 538                             vnm,
 539                             path->attached.fp_interface));
 540         }
 541         break;
 542     case FIB_PATH_TYPE_RECURSIVE:
 543         if (DPO_PROTO_MPLS == path->fp_nh_proto)
 544         {
 545             s = format (s, "via %U %U",
 546                         format_mpls_unicast_label,
 547                         path->recursive.fp_nh.fp_local_label,
 548                         format_mpls_eos_bit,
 549                         path->recursive.fp_nh.fp_eos);
 550         }
 551         else
 552         {
 553             s = format (s, "via %U",
 554                         format_ip46_address,
 555                         &path->recursive.fp_nh.fp_ip,
 556                         IP46_TYPE_ANY);
 557         }
 558         s = format (s, " in fib:%d",
 559                     path->recursive.fp_tbl_id,
 560                     path->fp_via_fib);
 561         s = format (s, " via-fib:%d", path->fp_via_fib);
 562         s = format (s, " via-dpo:[%U:%d]",
 563                     format_dpo_type, path->fp_dpo.dpoi_type,
 564                     path->fp_dpo.dpoi_index);
 565
 566         break;
 567     case FIB_PATH_TYPE_UDP_ENCAP:
 568         s = format (s, "UDP-encap ID:%d", path->udp_encap.fp_udp_encap_id);
 569         break;
 570     case FIB_PATH_TYPE_BIER_TABLE:
 571         s = format (s, "via bier-table:[%U}",
 572                     format_bier_table_id,
 573                     &path->bier_table.fp_bier_tbl);
 574         s = format (s, " via-dpo:[%U:%d]",
 575                     format_dpo_type, path->fp_dpo.dpoi_type,
 576                     path->fp_dpo.dpoi_index);
 577         break;
 578     case FIB_PATH_TYPE_BIER_FMASK:
 579         s = format (s, "via-fmask:%d", path->bier_fmask.fp_bier_fmask);
 580         s = format (s, " via-dpo:[%U:%d]",
 581                     format_dpo_type, path->fp_dpo.dpoi_type,
 582                     path->fp_dpo.dpoi_index);
 583         break;
 584     case FIB_PATH_TYPE_BIER_IMP:
 585         s = format (s, "via %U", format_bier_imp,
 586                     path->bier_imp.fp_bier_imp, 0, BIER_SHOW_BRIEF);
 587         break;
 588     case FIB_PATH_TYPE_DVR:
 589         s = format (s, " %U",
 590                     format_vnet_sw_interface_name,
 591                     vnm,
 592                     vnet_get_sw_interface(
 593                         vnm,
 594                         path->dvr.fp_interface));
 595         break;
 596     case FIB_PATH_TYPE_RECEIVE:
 597     case FIB_PATH_TYPE_INTF_RX:
 598     case FIB_PATH_TYPE_SPECIAL:
 599     case FIB_PATH_TYPE_DEAG:
 600     case FIB_PATH_TYPE_EXCLUSIVE:
 601         if (dpo_id_is_valid(&path->fp_dpo))
 602         {
 603             s = format(s, "%U", format_dpo_id,
 604                        &path->fp_dpo, indent+2);
 605         }
 606         break;
 607     }
 608     return (s);
 609 }
 610
 611 u8 *
 612 fib_path_format (fib_node_index_t pi, u8 *s)
 613 {
 614     fib_path_t *path;
 615
 616     path = fib_path_get(pi);
 617     ASSERT(NULL != path);
 618
 619     return (format (s, "%U", format_fib_path, path));
 620 }
 621
 622 /*
 623  * fib_path_last_lock_gone
 624  *
 625  * We don't share paths, we share path lists, so the [un]lock functions
 626  * are no-ops
 627  */
 628 static void
 629 fib_path_last_lock_gone (fib_node_t *node)
 630 {
 631     ASSERT(0);
 632 }
 633
 634 static const adj_index_t
 635 fib_path_attached_next_hop_get_adj (fib_path_t *path,
 636                                     vnet_link_t link)
 637 {
 638     if (vnet_sw_interface_is_p2p(vnet_get_main(),
 639                                  path->attached_next_hop.fp_interface))
 640     {
 641         /*
 642          * if the interface is p2p then the adj for the specific
 643          * neighbour on that link will never exist. on p2p links
 644          * the subnet address (the attached route) links to the
 645          * auto-adj (see below), we want that adj here too.
 646          */
 647         return (adj_nbr_add_or_lock(dpo_proto_to_fib(path->fp_nh_proto),
 648                                     link,
 649                                     &zero_addr,
 650                                     path->attached_next_hop.fp_interface));
 651     }
 652     else
 653     {
 654         return (adj_nbr_add_or_lock(dpo_proto_to_fib(path->fp_nh_proto),
 655                                     link,
 656                                     &path->attached_next_hop.fp_nh,
 657                                     path->attached_next_hop.fp_interface));
 658     }
 659 }
 660
 661 static void
 662 fib_path_attached_next_hop_set (fib_path_t *path)
 663 {
 664     /*
 665      * resolve directly via the adjacnecy discribed by the
 666      * interface and next-hop
 667      */
 668     dpo_set(&path->fp_dpo,
 669             DPO_ADJACENCY,
 670             path->fp_nh_proto,
 671             fib_path_attached_next_hop_get_adj(
 672                  path,
 673                  dpo_proto_to_link(path->fp_nh_proto)));
 674
 675     /*
 676      * become a child of the adjacency so we receive updates
 677      * when its rewrite changes
 678      */
 679     path->fp_sibling = adj_child_add(path->fp_dpo.dpoi_index,
 680                                      FIB_NODE_TYPE_PATH,
 681                                      fib_path_get_index(path));
 682
 683     if (!vnet_sw_interface_is_admin_up(vnet_get_main(),
 684                                       path->attached_next_hop.fp_interface) ||
 685         !adj_is_up(path->fp_dpo.dpoi_index))
 686     {
 687         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 688     }
 689 }
 690
 691 static const adj_index_t
 692 fib_path_attached_get_adj (fib_path_t *path,
 693                            vnet_link_t link)
 694 {
 695     if (vnet_sw_interface_is_p2p(vnet_get_main(),
 696                                  path->attached.fp_interface))
 697     {
 698         /*
 699          * point-2-point interfaces do not require a glean, since
 700          * there is nothing to ARP. Install a rewrite/nbr adj instead
 701          */
 702         return (adj_nbr_add_or_lock(dpo_proto_to_fib(path->fp_nh_proto),
 703                                     link,
 704                                     &zero_addr,
 705                                     path->attached.fp_interface));
 706     }
 707     else
 708     {
 709         return (adj_glean_add_or_lock(dpo_proto_to_fib(path->fp_nh_proto),
 710                                       link,
 711                                       path->attached.fp_interface,
 712                                       NULL));
 713     }
 714 }
 715
 716 /*
 717  * create of update the paths recursive adj
 718  */
 719 static void
 720 fib_path_recursive_adj_update (fib_path_t *path,
 721                                fib_forward_chain_type_t fct,
 722                                dpo_id_t *dpo)
 723 {
 724     dpo_id_t via_dpo = DPO_INVALID;
 725
 726     /*
 727      * get the DPO to resolve through from the via-entry
 728      */
 729     fib_entry_contribute_forwarding(path->fp_via_fib,
 730                                     fct,
 731                                     &via_dpo);
 732
 733
 734     /*
 735      * hope for the best - clear if restrictions apply.
 736      */
 737     path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
 738
 739     /*
 740      * Validate any recursion constraints and over-ride the via
 741      * adj if not met
 742      */
 743     if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RECURSIVE_LOOP)
 744     {
 745         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 746         dpo_copy(&via_dpo, drop_dpo_get(path->fp_nh_proto));
 747     }
 748     else if (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_RESOLVE_HOST)
 749     {
 750         /*
 751          * the via FIB must be a host route.
 752          * note the via FIB just added will always be a host route
 753          * since it is an RR source added host route. So what we need to
 754          * check is whether the route has other sources. If it does then
 755          * some other source has added it as a host route. If it doesn't
 756          * then it was added only here and inherits forwarding from a cover.
 757          * the cover is not a host route.
 758          * The RR source is the lowest priority source, so we check if it
 759          * is the best. if it is there are no other sources.
 760          */
 761         if (fib_entry_get_best_source(path->fp_via_fib) >= FIB_SOURCE_RR)
 762         {
 763             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 764             dpo_copy(&via_dpo, drop_dpo_get(path->fp_nh_proto));
 765
 766             /*
 767              * PIC edge trigger. let the load-balance maps know
 768              */
 769             load_balance_map_path_state_change(fib_path_get_index(path));
 770         }
 771     }
 772     else if (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_RESOLVE_ATTACHED)
 773     {
 774         /*
 775          * RR source entries inherit the flags from the cover, so
 776          * we can check the via directly
 777          */
 778         if (!(FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags(path->fp_via_fib)))
 779         {
 780             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 781             dpo_copy(&via_dpo, drop_dpo_get(path->fp_nh_proto));
 782
 783             /*
 784              * PIC edge trigger. let the load-balance maps know
 785              */
 786             load_balance_map_path_state_change(fib_path_get_index(path));
 787         }
 788     }
 789     /*
 790      * check for over-riding factors on the FIB entry itself
 791      */
 792     if (!fib_entry_is_resolved(path->fp_via_fib))
 793     {
 794         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 795         dpo_copy(&via_dpo, drop_dpo_get(path->fp_nh_proto));
 796
 797         /*
 798          * PIC edge trigger. let the load-balance maps know
 799          */
 800         load_balance_map_path_state_change(fib_path_get_index(path));
 801     }
 802
 803     /*
 804      * If this path is contributing a drop, then it's not resolved
 805      */
 806     if (dpo_is_drop(&via_dpo) || load_balance_is_drop(&via_dpo))
 807     {
 808         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 809     }
 810
 811     /*
 812      * update the path's contributed DPO
 813      */
 814     dpo_copy(dpo, &via_dpo);
 815
 816     FIB_PATH_DBG(path, "recursive update:");
 817
 818     dpo_reset(&via_dpo);
 819 }
 820
 821 /*
 822  * re-evaulate the forwarding state for a via fmask path
 823  */
 824 static void
 825 fib_path_bier_fmask_update (fib_path_t *path,
 826                             dpo_id_t *dpo)
 827 {
 828     bier_fmask_contribute_forwarding(path->bier_fmask.fp_bier_fmask, dpo);
 829
 830     /*
 831      * if we are stakcing on the drop, then the path is not resolved
 832      */
 833     if (dpo_is_drop(dpo))
 834     {
 835         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 836     }
 837     else
 838     {
 839         path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
 840     }
 841 }
 842
 843 /*
 844  * fib_path_is_permanent_drop
 845  *
 846  * Return !0 if the path is configured to permanently drop,
 847  * despite other attributes.
 848  */
 849 static int
 850 fib_path_is_permanent_drop (fib_path_t *path)
 851 {
 852     return ((path->fp_cfg_flags & FIB_PATH_CFG_FLAG_DROP) ||
 853             (path->fp_oper_flags & FIB_PATH_OPER_FLAG_DROP));
 854 }
 855
 856 /*
 857  * fib_path_unresolve
 858  *
 859  * Remove our dependency on the resolution target
 860  */
 861 static void
 862 fib_path_unresolve (fib_path_t *path)
 863 {
 864     /*
 865      * the forced drop path does not need unresolving
 866      */
 867     if (fib_path_is_permanent_drop(path))
 868     {
 869         return;
 870     }
 871
 872     switch (path->fp_type)
 873     {
 874     case FIB_PATH_TYPE_RECURSIVE:
 875         if (FIB_NODE_INDEX_INVALID != path->fp_via_fib)
 876         {
 877             fib_prefix_t pfx;
 878
 879             fib_entry_get_prefix(path->fp_via_fib, &pfx);
 880             fib_entry_child_remove(path->fp_via_fib,
 881                                    path->fp_sibling);
 882             fib_table_entry_special_remove(path->recursive.fp_tbl_id,
 883                                            &pfx,
 884                                            FIB_SOURCE_RR);
 885             path->fp_via_fib = FIB_NODE_INDEX_INVALID;
 886         }
 887         break;
 888     case FIB_PATH_TYPE_BIER_FMASK:
 889         bier_fmask_child_remove(path->fp_via_bier_fmask,
 890                                 path->fp_sibling);
 891         break;
 892     case FIB_PATH_TYPE_BIER_IMP:
 893         bier_imp_unlock(path->fp_dpo.dpoi_index);
 894         break;
 895     case FIB_PATH_TYPE_BIER_TABLE:
 896         bier_table_ecmp_unlock(path->fp_via_bier_tbl);
 897         break;
 898     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
 899         adj_child_remove(path->fp_dpo.dpoi_index,
 900                          path->fp_sibling);
 901         adj_unlock(path->fp_dpo.dpoi_index);
 902         break;
 903     case FIB_PATH_TYPE_ATTACHED:
 904         adj_child_remove(path->fp_dpo.dpoi_index,
 905                          path->fp_sibling);
 906         adj_unlock(path->fp_dpo.dpoi_index);
 907         break;
 908     case FIB_PATH_TYPE_UDP_ENCAP:
 909         udp_encap_unlock_w_index(path->fp_dpo.dpoi_index);
 910         break;
 911     case FIB_PATH_TYPE_EXCLUSIVE:
 912         dpo_reset(&path->exclusive.fp_ex_dpo);
 913         break;
 914     case FIB_PATH_TYPE_SPECIAL:
 915     case FIB_PATH_TYPE_RECEIVE:
 916     case FIB_PATH_TYPE_INTF_RX:
 917     case FIB_PATH_TYPE_DEAG:
 918     case FIB_PATH_TYPE_DVR:
 919         /*
 920          * these hold only the path's DPO, which is reset below.
 921          */
 922         break;
 923     }
 924
 925     /*
 926      * release the adj we were holding and pick up the
 927      * drop just in case.
 928      */
 929     dpo_reset(&path->fp_dpo);
 930     path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
 931
 932     return;
 933 }
 934
 935 static fib_forward_chain_type_t
 936 fib_path_to_chain_type (const fib_path_t *path)
 937 {
 938     if (DPO_PROTO_MPLS == path->fp_nh_proto)
 939     {
 940         if (FIB_PATH_TYPE_RECURSIVE == path->fp_type &&
 941             MPLS_EOS == path->recursive.fp_nh.fp_eos)
 942         {
 943             return (FIB_FORW_CHAIN_TYPE_MPLS_EOS);
 944         }
 945         else
 946         {
 947             return (FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS);
 948         }
 949     }
 950     else
 951     {
 952         return (fib_forw_chain_type_from_dpo_proto(path->fp_nh_proto));
 953     }
 954 }
 955
 956 /*
 957  * fib_path_back_walk_notify
 958  *
 959  * A back walk has reach this path.
 960  */
 961 static fib_node_back_walk_rc_t
 962 fib_path_back_walk_notify (fib_node_t *node,
 963                            fib_node_back_walk_ctx_t *ctx)
 964 {
 965     fib_path_t *path;
 966
 967     path = fib_path_from_fib_node(node);
 968
 969     switch (path->fp_type)
 970     {
 971     case FIB_PATH_TYPE_RECURSIVE:
 972         if (FIB_NODE_BW_REASON_FLAG_EVALUATE & ctx->fnbw_reason)
 973         {
 974             /*
 975              * modify the recursive adjacency to use the new forwarding
 976              * of the via-fib.
 977              * this update is visible to packets in flight in the DP.
 978              */
 979             fib_path_recursive_adj_update(
 980                 path,
 981                 fib_path_to_chain_type(path),
 982                 &path->fp_dpo);
 983         }
 984         if ((FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE & ctx->fnbw_reason) ||
 985             (FIB_NODE_BW_REASON_FLAG_ADJ_DOWN   & ctx->fnbw_reason))
 986         {
 987             /*
 988              * ADJ updates (complete<->incomplete) do not need to propagate to
 989              * recursive entries.
 990              * The only reason its needed as far back as here, is that the adj
 991              * and the incomplete adj are a different DPO type, so the LBs need
 992              * to re-stack.
 993              * If this walk was quashed in the fib_entry, then any non-fib_path
 994              * children (like tunnels that collapse out the LB when they stack)
 995              * would not see the update.
 996              */
 997             return (FIB_NODE_BACK_WALK_CONTINUE);
 998         }
 999         break;
1000     case FIB_PATH_TYPE_BIER_FMASK:
1001         if (FIB_NODE_BW_REASON_FLAG_EVALUATE & ctx->fnbw_reason)
1002         {
1003             /*
1004              * update to use the BIER fmask's new forwading
1005              */
1006             fib_path_bier_fmask_update(path, &path->fp_dpo);
1007         }
1008         if ((FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE & ctx->fnbw_reason) ||
1009             (FIB_NODE_BW_REASON_FLAG_ADJ_DOWN   & ctx->fnbw_reason))
1010         {
1011             /*
1012              * ADJ updates (complete<->incomplete) do not need to propagate to
1013              * recursive entries.
1014              * The only reason its needed as far back as here, is that the adj
1015              * and the incomplete adj are a different DPO type, so the LBs need
1016              * to re-stack.
1017              * If this walk was quashed in the fib_entry, then any non-fib_path
1018              * children (like tunnels that collapse out the LB when they stack)
1019              * would not see the update.
1020              */
1021             return (FIB_NODE_BACK_WALK_CONTINUE);
1022         }
1023         break;
1024     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1025         /*
1026 FIXME comment
1027          * ADJ_UPDATE backwalk pass silently through here and up to
1028          * the path-list when the multipath adj collapse occurs.
1029          * The reason we do this is that the assumtption is that VPP
1030          * runs in an environment where the Control-Plane is remote
1031          * and hence reacts slowly to link up down. In order to remove
1032          * this down link from the ECMP set quickly, we back-walk.
1033          * VPP also has dedicated CPUs, so we are not stealing resources
1034          * from the CP to do so.
1035          */
1036         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_UP & ctx->fnbw_reason)
1037         {
1038             if (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED)
1039             {
1040                 /*
1041                  * alreday resolved. no need to walk back again
1042                  */
1043                 return (FIB_NODE_BACK_WALK_CONTINUE);
1044             }
1045             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
1046         }
1047         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DOWN & ctx->fnbw_reason)
1048         {
1049             if (!(path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED))
1050             {
1051                 /*
1052                  * alreday unresolved. no need to walk back again
1053                  */
1054                 return (FIB_NODE_BACK_WALK_CONTINUE);
1055             }
1056             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
1057         }
1058         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DELETE & ctx->fnbw_reason)
1059         {
1060             /*
1061              * The interface this path resolves through has been deleted.
1062              * This will leave the path in a permanent drop state. The route
1063              * needs to be removed and readded (and hence the path-list deleted)
1064              * before it can forward again.
1065              */
1066             fib_path_unresolve(path);
1067             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_DROP;
1068         }
1069         if (FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE & ctx->fnbw_reason)
1070         {
1071             /*
1072              * restack the DPO to pick up the correct DPO sub-type
1073              */
1074             uword if_is_up;
1075             adj_index_t ai;
1076
1077             if_is_up = vnet_sw_interface_is_admin_up(
1078                            vnet_get_main(),
1079                            path->attached_next_hop.fp_interface);
1080
1081             ai = fib_path_attached_next_hop_get_adj(
1082                      path,
1083                      dpo_proto_to_link(path->fp_nh_proto));
1084
1085             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
1086             if (if_is_up && adj_is_up(ai))
1087             {
1088                 path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
1089             }
1090
1091             dpo_set(&path->fp_dpo, DPO_ADJACENCY, path->fp_nh_proto, ai);
1092             adj_unlock(ai);
1093
1094             if (!if_is_up)
1095             {
1096                 /*
1097                  * If the interface is not up there is no reason to walk
1098                  * back to children. if we did they would only evalute
1099                  * that this path is unresolved and hence it would
1100                  * not contribute the adjacency - so it would be wasted
1101                  * CPU time.
1102                  */
1103                 return (FIB_NODE_BACK_WALK_CONTINUE);
1104             }
1105         }
1106         if (FIB_NODE_BW_REASON_FLAG_ADJ_DOWN & ctx->fnbw_reason)
1107         {
1108             if (!(path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED))
1109             {
1110                 /*
1111                  * alreday unresolved. no need to walk back again
1112                  */
1113                 return (FIB_NODE_BACK_WALK_CONTINUE);
1114             }
1115             /*
1116              * the adj has gone down. the path is no longer resolved.
1117              */
1118             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
1119         }
1120         break;
1121     case FIB_PATH_TYPE_ATTACHED:
1122     case FIB_PATH_TYPE_DVR:
1123         /*
1124          * FIXME; this could schedule a lower priority walk, since attached
1125          * routes are not usually in ECMP configurations so the backwalk to
1126          * the FIB entry does not need to be high priority
1127          */
1128         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_UP & ctx->fnbw_reason)
1129         {
1130             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
1131         }
1132         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DOWN & ctx->fnbw_reason)
1133         {
1134             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
1135         }
1136         if (FIB_NODE_BW_REASON_FLAG_INTERFACE_DELETE & ctx->fnbw_reason)
1137         {
1138             fib_path_unresolve(path);
1139             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_DROP;
1140         }
1141         break;
1142     case FIB_PATH_TYPE_UDP_ENCAP:
1143     {
1144         dpo_id_t via_dpo = DPO_INVALID;
1145
1146         /*
1147          * hope for the best - clear if restrictions apply.
1148          */
1149         path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
1150
1151         udp_encap_contribute_forwarding(path->udp_encap.fp_udp_encap_id,
1152                                         path->fp_nh_proto,
1153                                         &via_dpo);
1154         /*
1155          * If this path is contributing a drop, then it's not resolved
1156          */
1157         if (dpo_is_drop(&via_dpo) || load_balance_is_drop(&via_dpo))
1158         {
1159             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
1160         }
1161
1162         /*
1163          * update the path's contributed DPO
1164          */
1165         dpo_copy(&path->fp_dpo, &via_dpo);
1166         dpo_reset(&via_dpo);
1167         break;
1168     }
1169     case FIB_PATH_TYPE_INTF_RX:
1170         ASSERT(0);
1171     case FIB_PATH_TYPE_DEAG:
1172         /*
1173          * FIXME When VRF delete is allowed this will need a poke.
1174          */
1175     case FIB_PATH_TYPE_SPECIAL:
1176     case FIB_PATH_TYPE_RECEIVE:
1177     case FIB_PATH_TYPE_EXCLUSIVE:
1178     case FIB_PATH_TYPE_BIER_TABLE:
1179     case FIB_PATH_TYPE_BIER_IMP:
1180         /*
1181          * these path types have no parents. so to be
1182          * walked from one is unexpected.
1183          */
1184         ASSERT(0);
1185         break;
1186     }
1187
1188     /*
1189      * propagate the backwalk further to the path-list
1190      */
1191     fib_path_list_back_walk(path->fp_pl_index, ctx);
1192
1193     return (FIB_NODE_BACK_WALK_CONTINUE);
1194 }
1195
1196 static void
1197 fib_path_memory_show (void)
1198 {
1199     fib_show_memory_usage("Path",
1200                           pool_elts(fib_path_pool),
1201                           pool_len(fib_path_pool),
1202                           sizeof(fib_path_t));
1203 }
1204
1205 /*
1206  * The FIB path's graph node virtual function table
1207  */
1208 static const fib_node_vft_t fib_path_vft = {
1209     .fnv_get = fib_path_get_node,
1210     .fnv_last_lock = fib_path_last_lock_gone,
1211     .fnv_back_walk = fib_path_back_walk_notify,
1212     .fnv_mem_show = fib_path_memory_show,
1213 };
1214
1215 static fib_path_cfg_flags_t
1216 fib_path_route_flags_to_cfg_flags (const fib_route_path_t *rpath)
1217 {
1218     fib_path_cfg_flags_t cfg_flags = FIB_PATH_CFG_FLAG_NONE;
1219
1220     if (rpath->frp_flags & FIB_ROUTE_PATH_RESOLVE_VIA_HOST)
1221         cfg_flags |= FIB_PATH_CFG_FLAG_RESOLVE_HOST;
1222     if (rpath->frp_flags & FIB_ROUTE_PATH_RESOLVE_VIA_ATTACHED)
1223         cfg_flags |= FIB_PATH_CFG_FLAG_RESOLVE_ATTACHED;
1224     if (rpath->frp_flags & FIB_ROUTE_PATH_LOCAL)
1225         cfg_flags |= FIB_PATH_CFG_FLAG_LOCAL;
1226     if (rpath->frp_flags & FIB_ROUTE_PATH_ATTACHED)
1227         cfg_flags |= FIB_PATH_CFG_FLAG_ATTACHED;
1228     if (rpath->frp_flags & FIB_ROUTE_PATH_INTF_RX)
1229         cfg_flags |= FIB_PATH_CFG_FLAG_INTF_RX;
1230     if (rpath->frp_flags & FIB_ROUTE_PATH_RPF_ID)
1231         cfg_flags |= FIB_PATH_CFG_FLAG_RPF_ID;
1232     if (rpath->frp_flags & FIB_ROUTE_PATH_EXCLUSIVE)
1233         cfg_flags |= FIB_PATH_CFG_FLAG_EXCLUSIVE;
1234     if (rpath->frp_flags & FIB_ROUTE_PATH_DROP)
1235         cfg_flags |= FIB_PATH_CFG_FLAG_DROP;
1236     if (rpath->frp_flags & FIB_ROUTE_PATH_SOURCE_LOOKUP)
1237         cfg_flags |= FIB_PATH_CFG_FLAG_DEAG_SRC;
1238
1239     return (cfg_flags);
1240 }
1241
1242 /*
1243  * fib_path_create
1244  *
1245  * Create and initialise a new path object.
1246  * return the index of the path.
1247  */
1248 fib_node_index_t
1249 fib_path_create (fib_node_index_t pl_index,
1250                  const fib_route_path_t *rpath)
1251 {
1252     fib_path_t *path;
1253
1254     pool_get(fib_path_pool, path);
1255     memset(path, 0, sizeof(*path));
1256
1257     fib_node_init(&path->fp_node,
1258                   FIB_NODE_TYPE_PATH);
1259
1260     dpo_reset(&path->fp_dpo);
1261     path->fp_pl_index = pl_index;
1262     path->fp_nh_proto = rpath->frp_proto;
1263     path->fp_via_fib = FIB_NODE_INDEX_INVALID;
1264     path->fp_weight = rpath->frp_weight;
1265     if (0 == path->fp_weight)
1266     {
1267         /*
1268          * a weight of 0 is a meaningless value. We could either reject it, and thus force
1269          * clients to always use 1, or we can accept it and fixup approrpiately.
1270          */
1271         path->fp_weight = 1;
1272     }
1273     path->fp_preference = rpath->frp_preference;
1274     path->fp_cfg_flags = fib_path_route_flags_to_cfg_flags(rpath);
1275
1276     /*
1277      * deduce the path's tpye from the parementers and save what is needed.
1278      */
1279     if (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_LOCAL)
1280     {
1281         path->fp_type = FIB_PATH_TYPE_RECEIVE;
1282         path->receive.fp_interface = rpath->frp_sw_if_index;
1283         path->receive.fp_addr = rpath->frp_addr;
1284     }
1285     else if (rpath->frp_flags & FIB_ROUTE_PATH_UDP_ENCAP)
1286     {
1287         path->fp_type = FIB_PATH_TYPE_UDP_ENCAP;
1288         path->udp_encap.fp_udp_encap_id = rpath->frp_udp_encap_id;
1289     }
1290     else if (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_INTF_RX)
1291     {
1292         path->fp_type = FIB_PATH_TYPE_INTF_RX;
1293         path->intf_rx.fp_interface = rpath->frp_sw_if_index;
1294     }
1295     else if (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_RPF_ID)
1296     {
1297         path->fp_type = FIB_PATH_TYPE_DEAG;
1298         path->deag.fp_tbl_id = rpath->frp_fib_index;
1299         path->deag.fp_rpf_id = rpath->frp_rpf_id;
1300     }
1301     else if (rpath->frp_flags & FIB_ROUTE_PATH_BIER_FMASK)
1302     {
1303         path->fp_type = FIB_PATH_TYPE_BIER_FMASK;
1304         path->bier_fmask.fp_bier_fmask = rpath->frp_bier_fmask;
1305     }
1306     else if (rpath->frp_flags & FIB_ROUTE_PATH_BIER_IMP)
1307     {
1308         path->fp_type = FIB_PATH_TYPE_BIER_IMP;
1309         path->bier_imp.fp_bier_imp = rpath->frp_bier_imp;
1310     }
1311     else if (rpath->frp_flags & FIB_ROUTE_PATH_BIER_TABLE)
1312     {
1313         path->fp_type = FIB_PATH_TYPE_BIER_TABLE;
1314         path->bier_table.fp_bier_tbl = rpath->frp_bier_tbl;
1315     }
1316     else if (rpath->frp_flags & FIB_ROUTE_PATH_DEAG)
1317     {
1318         path->fp_type = FIB_PATH_TYPE_DEAG;
1319         path->deag.fp_tbl_id = rpath->frp_fib_index;
1320     }
1321     else if (rpath->frp_flags & FIB_ROUTE_PATH_DVR)
1322     {
1323         path->fp_type = FIB_PATH_TYPE_DVR;
1324         path->dvr.fp_interface = rpath->frp_sw_if_index;
1325     }
1326     else if (~0 != rpath->frp_sw_if_index)
1327     {
1328         if (ip46_address_is_zero(&rpath->frp_addr))
1329         {
1330             path->fp_type = FIB_PATH_TYPE_ATTACHED;
1331             path->attached.fp_interface = rpath->frp_sw_if_index;
1332         }
1333         else
1334         {
1335             path->fp_type = FIB_PATH_TYPE_ATTACHED_NEXT_HOP;
1336             path->attached_next_hop.fp_interface = rpath->frp_sw_if_index;
1337             path->attached_next_hop.fp_nh = rpath->frp_addr;
1338         }
1339     }
1340     else
1341     {
1342         if (ip46_address_is_zero(&rpath->frp_addr))
1343         {
1344             if (~0 == rpath->frp_fib_index)
1345             {
1346                 path->fp_type = FIB_PATH_TYPE_SPECIAL;
1347             }
1348             else
1349             {
1350                 path->fp_type = FIB_PATH_TYPE_DEAG;
1351                 path->deag.fp_tbl_id = rpath->frp_fib_index;
1352                 path->deag.fp_rpf_id = ~0;
1353             }
1354         }
1355         else
1356         {
1357             path->fp_type = FIB_PATH_TYPE_RECURSIVE;
1358             if (DPO_PROTO_MPLS == path->fp_nh_proto)
1359             {
1360                 path->recursive.fp_nh.fp_local_label = rpath->frp_local_label;
1361                 path->recursive.fp_nh.fp_eos = rpath->frp_eos;
1362             }
1363             else
1364             {
1365                 path->recursive.fp_nh.fp_ip = rpath->frp_addr;
1366             }
1367             path->recursive.fp_tbl_id = rpath->frp_fib_index;
1368         }
1369     }
1370
1371     FIB_PATH_DBG(path, "create");
1372
1373     return (fib_path_get_index(path));
1374 }
1375
1376 /*
1377  * fib_path_create_special
1378  *
1379  * Create and initialise a new path object.
1380  * return the index of the path.
1381  */
1382 fib_node_index_t
1383 fib_path_create_special (fib_node_index_t pl_index,
1384                          dpo_proto_t nh_proto,
1385                          fib_path_cfg_flags_t flags,
1386                          const dpo_id_t *dpo)
1387 {
1388     fib_path_t *path;
1389
1390     pool_get(fib_path_pool, path);
1391     memset(path, 0, sizeof(*path));
1392
1393     fib_node_init(&path->fp_node,
1394                   FIB_NODE_TYPE_PATH);
1395     dpo_reset(&path->fp_dpo);
1396
1397     path->fp_pl_index = pl_index;
1398     path->fp_weight = 1;
1399     path->fp_preference = 0;
1400     path->fp_nh_proto = nh_proto;
1401     path->fp_via_fib = FIB_NODE_INDEX_INVALID;
1402     path->fp_cfg_flags = flags;
1403
1404     if (FIB_PATH_CFG_FLAG_DROP & flags)
1405     {
1406         path->fp_type = FIB_PATH_TYPE_SPECIAL;
1407     }
1408     else if (FIB_PATH_CFG_FLAG_LOCAL & flags)
1409     {
1410         path->fp_type = FIB_PATH_TYPE_RECEIVE;
1411         path->attached.fp_interface = FIB_NODE_INDEX_INVALID;
1412     }
1413     else
1414     {
1415         path->fp_type = FIB_PATH_TYPE_EXCLUSIVE;
1416         ASSERT(NULL != dpo);
1417         dpo_copy(&path->exclusive.fp_ex_dpo, dpo);
1418     }
1419
1420     return (fib_path_get_index(path));
1421 }
1422
1423 /*
1424  * fib_path_copy
1425  *
1426  * Copy a path. return index of new path.
1427  */
1428 fib_node_index_t
1429 fib_path_copy (fib_node_index_t path_index,
1430                fib_node_index_t path_list_index)
1431 {
1432     fib_path_t *path, *orig_path;
1433
1434     pool_get(fib_path_pool, path);
1435
1436     orig_path = fib_path_get(path_index);
1437     ASSERT(NULL != orig_path);
1438
1439     memcpy(path, orig_path, sizeof(*path));
1440
1441     FIB_PATH_DBG(path, "create-copy:%d", path_index);
1442
1443     /*
1444      * reset the dynamic section
1445      */
1446     fib_node_init(&path->fp_node, FIB_NODE_TYPE_PATH);
1447     path->fp_oper_flags     = FIB_PATH_OPER_FLAG_NONE;
1448     path->fp_pl_index  = path_list_index;
1449     path->fp_via_fib   = FIB_NODE_INDEX_INVALID;
1450     memset(&path->fp_dpo, 0, sizeof(path->fp_dpo));
1451     dpo_reset(&path->fp_dpo);
1452
1453     return (fib_path_get_index(path));
1454 }
1455
1456 /*
1457  * fib_path_destroy
1458  *
1459  * destroy a path that is no longer required
1460  */
1461 void
1462 fib_path_destroy (fib_node_index_t path_index)
1463 {
1464     fib_path_t *path;
1465
1466     path = fib_path_get(path_index);
1467
1468     ASSERT(NULL != path);
1469     FIB_PATH_DBG(path, "destroy");
1470
1471     fib_path_unresolve(path);
1472
1473     fib_node_deinit(&path->fp_node);
1474     pool_put(fib_path_pool, path);
1475 }
1476
1477 /*
1478  * fib_path_destroy
1479  *
1480  * destroy a path that is no longer required
1481  */
1482 uword
1483 fib_path_hash (fib_node_index_t path_index)
1484 {
1485     fib_path_t *path;
1486
1487     path = fib_path_get(path_index);
1488
1489     return (hash_memory(STRUCT_MARK_PTR(path, path_hash_start),
1490                         (STRUCT_OFFSET_OF(fib_path_t, path_hash_end) -
1491                          STRUCT_OFFSET_OF(fib_path_t, path_hash_start)),
1492                         0));
1493 }
1494
1495 /*
1496  * fib_path_cmp_i
1497  *
1498  * Compare two paths for equivalence.
1499  */
1500 static int
1501 fib_path_cmp_i (const fib_path_t *path1,
1502                 const fib_path_t *path2)
1503 {
1504     int res;
1505
1506     res = 1;
1507
1508     /*
1509      * paths of different types and protocol are not equal.
1510      * different weights and/or preference only are the same path.
1511      */
1512     if (path1->fp_type != path2->fp_type)
1513     {
1514         res = (path1->fp_type - path2->fp_type);
1515     }
1516     else if (path1->fp_nh_proto != path2->fp_nh_proto)
1517     {
1518         res = (path1->fp_nh_proto - path2->fp_nh_proto);
1519     }
1520     else
1521     {
1522         /*
1523          * both paths are of the same type.
1524          * consider each type and its attributes in turn.
1525          */
1526         switch (path1->fp_type)
1527         {
1528         case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1529             res = ip46_address_cmp(&path1->attached_next_hop.fp_nh,
1530                                    &path2->attached_next_hop.fp_nh);
1531             if (0 == res) {
1532                 res = (path1->attached_next_hop.fp_interface -
1533                        path2->attached_next_hop.fp_interface);
1534             }
1535             break;
1536         case FIB_PATH_TYPE_ATTACHED:
1537             res = (path1->attached.fp_interface -
1538                    path2->attached.fp_interface);
1539             break;
1540         case FIB_PATH_TYPE_RECURSIVE:
1541             res = ip46_address_cmp(&path1->recursive.fp_nh,
1542                                    &path2->recursive.fp_nh);
1543
1544             if (0 == res)
1545             {
1546                 res = (path1->recursive.fp_tbl_id - path2->recursive.fp_tbl_id);
1547             }
1548             break;
1549         case FIB_PATH_TYPE_BIER_FMASK:
1550             res = (path1->bier_fmask.fp_bier_fmask -
1551                    path2->bier_fmask.fp_bier_fmask);
1552             break;
1553         case FIB_PATH_TYPE_BIER_IMP:
1554             res = (path1->bier_imp.fp_bier_imp -
1555                    path2->bier_imp.fp_bier_imp);
1556             break;
1557         case FIB_PATH_TYPE_BIER_TABLE:
1558             res = bier_table_id_cmp(&path1->bier_table.fp_bier_tbl,
1559                                     &path2->bier_table.fp_bier_tbl);
1560             break;
1561         case FIB_PATH_TYPE_DEAG:
1562             res = (path1->deag.fp_tbl_id - path2->deag.fp_tbl_id);
1563             if (0 == res)
1564             {
1565                 res = (path1->deag.fp_rpf_id - path2->deag.fp_rpf_id);
1566             }
1567             break;
1568         case FIB_PATH_TYPE_INTF_RX:
1569             res = (path1->intf_rx.fp_interface - path2->intf_rx.fp_interface);
1570             break;
1571         case FIB_PATH_TYPE_UDP_ENCAP:
1572             res = (path1->udp_encap.fp_udp_encap_id - path2->udp_encap.fp_udp_encap_id);
1573             break;
1574         case FIB_PATH_TYPE_DVR:
1575             res = (path1->dvr.fp_interface - path2->dvr.fp_interface);
1576             break;
1577         case FIB_PATH_TYPE_SPECIAL:
1578         case FIB_PATH_TYPE_RECEIVE:
1579         case FIB_PATH_TYPE_EXCLUSIVE:
1580             res = 0;
1581             break;
1582         }
1583     }
1584     return (res);
1585 }
1586
1587 /*
1588  * fib_path_cmp_for_sort
1589  *
1590  * Compare two paths for equivalence. Used during path sorting.
1591  * As usual 0 means equal.
1592  */
1593 int
1594 fib_path_cmp_for_sort (void * v1,
1595                        void * v2)
1596 {
1597     fib_node_index_t *pi1 = v1, *pi2 = v2;
1598     fib_path_t *path1, *path2;
1599
1600     path1 = fib_path_get(*pi1);
1601     path2 = fib_path_get(*pi2);
1602
1603     /*
1604      * when sorting paths we want the highest preference paths
1605      * first, so that the choices set built is in prefernce order
1606      */
1607     if (path1->fp_preference != path2->fp_preference)
1608     {
1609         return (path1->fp_preference - path2->fp_preference);
1610     }
1611
1612     return (fib_path_cmp_i(path1, path2));
1613 }
1614
1615 /*
1616  * fib_path_cmp
1617  *
1618  * Compare two paths for equivalence.
1619  */
1620 int
1621 fib_path_cmp (fib_node_index_t pi1,
1622               fib_node_index_t pi2)
1623 {
1624     fib_path_t *path1, *path2;
1625
1626     path1 = fib_path_get(pi1);
1627     path2 = fib_path_get(pi2);
1628
1629     return (fib_path_cmp_i(path1, path2));
1630 }
1631
1632 int
1633 fib_path_cmp_w_route_path (fib_node_index_t path_index,
1634                            const fib_route_path_t *rpath)
1635 {
1636     fib_path_t *path;
1637     int res;
1638
1639     path = fib_path_get(path_index);
1640
1641     res = 1;
1642
1643     if (path->fp_weight != rpath->frp_weight)
1644     {
1645         res = (path->fp_weight - rpath->frp_weight);
1646     }
1647     else
1648     {
1649         /*
1650          * both paths are of the same type.
1651          * consider each type and its attributes in turn.
1652          */
1653         switch (path->fp_type)
1654         {
1655         case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1656             res = ip46_address_cmp(&path->attached_next_hop.fp_nh,
1657                                    &rpath->frp_addr);
1658             if (0 == res)
1659             {
1660                 res = (path->attached_next_hop.fp_interface -
1661                        rpath->frp_sw_if_index);
1662             }
1663             break;
1664         case FIB_PATH_TYPE_ATTACHED:
1665             res = (path->attached.fp_interface - rpath->frp_sw_if_index);
1666             break;
1667         case FIB_PATH_TYPE_RECURSIVE:
1668             if (DPO_PROTO_MPLS == path->fp_nh_proto)
1669             {
1670                 res = path->recursive.fp_nh.fp_local_label - rpath->frp_local_label;
1671
1672                 if (res == 0)
1673                 {
1674                     res = path->recursive.fp_nh.fp_eos - rpath->frp_eos;
1675                 }
1676             }
1677             else
1678             {
1679                 res = ip46_address_cmp(&path->recursive.fp_nh.fp_ip,
1680                                        &rpath->frp_addr);
1681             }
1682
1683             if (0 == res)
1684             {
1685                 res = (path->recursive.fp_tbl_id - rpath->frp_fib_index);
1686             }
1687             break;
1688         case FIB_PATH_TYPE_BIER_FMASK:
1689             res = (path->bier_fmask.fp_bier_fmask - rpath->frp_bier_fmask);
1690             break;
1691         case FIB_PATH_TYPE_BIER_IMP:
1692             res = (path->bier_imp.fp_bier_imp - rpath->frp_bier_imp);
1693             break;
1694         case FIB_PATH_TYPE_BIER_TABLE:
1695             res = bier_table_id_cmp(&path->bier_table.fp_bier_tbl,
1696                                     &rpath->frp_bier_tbl);
1697             break;
1698         case FIB_PATH_TYPE_INTF_RX:
1699             res = (path->intf_rx.fp_interface - rpath->frp_sw_if_index);
1700             break;
1701         case FIB_PATH_TYPE_UDP_ENCAP:
1702             res = (path->udp_encap.fp_udp_encap_id - rpath->frp_udp_encap_id);
1703             break;
1704         case FIB_PATH_TYPE_DEAG:
1705             res = (path->deag.fp_tbl_id - rpath->frp_fib_index);
1706             if (0 == res)
1707             {
1708                 res = (path->deag.fp_rpf_id - rpath->frp_rpf_id);
1709             }
1710             break;
1711         case FIB_PATH_TYPE_DVR:
1712             res = (path->dvr.fp_interface - rpath->frp_sw_if_index);
1713             break;
1714         case FIB_PATH_TYPE_SPECIAL:
1715         case FIB_PATH_TYPE_RECEIVE:
1716         case FIB_PATH_TYPE_EXCLUSIVE:
1717             res = 0;
1718             break;
1719         }
1720     }
1721     return (res);
1722 }
1723
1724 /*
1725  * fib_path_recursive_loop_detect
1726  *
1727  * A forward walk of the FIB object graph to detect for a cycle/loop. This
1728  * walk is initiated when an entry is linking to a new path list or from an old.
1729  * The entry vector passed contains all the FIB entrys that are children of this
1730  * path (it is all the entries encountered on the walk so far). If this vector
1731  * contains the entry this path resolve via, then a loop is about to form.
1732  * The loop must be allowed to form, since we need the dependencies in place
1733  * so that we can track when the loop breaks.
1734  * However, we MUST not produce a loop in the forwarding graph (else packets
1735  * would loop around the switch path until the loop breaks), so we mark recursive
1736  * paths as looped so that they do not contribute forwarding information.
1737  * By marking the path as looped, an etry such as;
1738  *    X/Y
1739  *     via a.a.a.a (looped)
1740  *     via b.b.b.b (not looped)
1741  * can still forward using the info provided by b.b.b.b only
1742  */
1743 int
1744 fib_path_recursive_loop_detect (fib_node_index_t path_index,
1745                                 fib_node_index_t **entry_indicies)
1746 {
1747     fib_path_t *path;
1748
1749     path = fib_path_get(path_index);
1750
1751     /*
1752      * the forced drop path is never looped, cos it is never resolved.
1753      */
1754     if (fib_path_is_permanent_drop(path))
1755     {
1756         return (0);
1757     }
1758
1759     switch (path->fp_type)
1760     {
1761     case FIB_PATH_TYPE_RECURSIVE:
1762     {
1763         fib_node_index_t *entry_index, *entries;
1764         int looped = 0;
1765         entries = *entry_indicies;
1766
1767         vec_foreach(entry_index, entries) {
1768             if (*entry_index == path->fp_via_fib)
1769             {
1770                 /*
1771                  * the entry that is about to link to this path-list (or
1772                  * one of this path-list's children) is the same entry that
1773                  * this recursive path resolves through. this is a cycle.
1774                  * abort the walk.
1775                  */
1776                 looped = 1;
1777                 break;
1778             }
1779         }
1780
1781         if (looped)
1782         {
1783             FIB_PATH_DBG(path, "recursive loop formed");
1784             path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RECURSIVE_LOOP;
1785
1786             dpo_copy(&path->fp_dpo, drop_dpo_get(path->fp_nh_proto));
1787         }
1788         else
1789         {
1790             /*
1791              * no loop here yet. keep forward walking the graph.
1792              */
1793             if (fib_entry_recursive_loop_detect(path->fp_via_fib, entry_indicies))
1794             {
1795                 FIB_PATH_DBG(path, "recursive loop formed");
1796                 path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RECURSIVE_LOOP;
1797             }
1798             else
1799             {
1800                 FIB_PATH_DBG(path, "recursive loop cleared");
1801                 path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RECURSIVE_LOOP;
1802             }
1803         }
1804         break;
1805     }
1806     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1807     case FIB_PATH_TYPE_ATTACHED:
1808     case FIB_PATH_TYPE_SPECIAL:
1809     case FIB_PATH_TYPE_DEAG:
1810     case FIB_PATH_TYPE_DVR:
1811     case FIB_PATH_TYPE_RECEIVE:
1812     case FIB_PATH_TYPE_INTF_RX:
1813     case FIB_PATH_TYPE_UDP_ENCAP:
1814     case FIB_PATH_TYPE_EXCLUSIVE:
1815     case FIB_PATH_TYPE_BIER_FMASK:
1816     case FIB_PATH_TYPE_BIER_TABLE:
1817     case FIB_PATH_TYPE_BIER_IMP:
1818         /*
1819          * these path types cannot be part of a loop, since they are the leaves
1820          * of the graph.
1821          */
1822         break;
1823     }
1824
1825     return (fib_path_is_looped(path_index));
1826 }
1827
1828 int
1829 fib_path_resolve (fib_node_index_t path_index)
1830 {
1831     fib_path_t *path;
1832
1833     path = fib_path_get(path_index);
1834
1835     /*
1836      * hope for the best.
1837      */
1838     path->fp_oper_flags |= FIB_PATH_OPER_FLAG_RESOLVED;
1839
1840     /*
1841      * the forced drop path resolves via the drop adj
1842      */
1843     if (fib_path_is_permanent_drop(path))
1844     {
1845         dpo_copy(&path->fp_dpo, drop_dpo_get(path->fp_nh_proto));
1846         path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
1847         return (fib_path_is_resolved(path_index));
1848     }
1849
1850     switch (path->fp_type)
1851     {
1852     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
1853         fib_path_attached_next_hop_set(path);
1854         break;
1855     case FIB_PATH_TYPE_ATTACHED:
1856         /*
1857          * path->attached.fp_interface
1858          */
1859         if (!vnet_sw_interface_is_admin_up(vnet_get_main(),
1860                                            path->attached.fp_interface))
1861         {
1862             path->fp_oper_flags &= ~FIB_PATH_OPER_FLAG_RESOLVED;
1863         }
1864         dpo_set(&path->fp_dpo,
1865                 DPO_ADJACENCY,
1866                 path->fp_nh_proto,
1867                 fib_path_attached_get_adj(path,
1868                                           dpo_proto_to_link(path->fp_nh_proto)));
1869
1870         /*
1871          * become a child of the adjacency so we receive updates
1872          * when the interface state changes
1873          */
1874         path->fp_sibling = adj_child_add(path->fp_dpo.dpoi_index,
1875                                          FIB_NODE_TYPE_PATH,
1876                                          fib_path_get_index(path));
1877         break;
1878     case FIB_PATH_TYPE_RECURSIVE:
1879     {
1880         /*
1881          * Create a RR source entry in the table for the address
1882          * that this path recurses through.
1883          * This resolve action is recursive, hence we may create
1884          * more paths in the process. more creates mean maybe realloc
1885          * of this path.
1886          */
1887         fib_node_index_t fei;
1888         fib_prefix_t pfx;
1889
1890         ASSERT(FIB_NODE_INDEX_INVALID == path->fp_via_fib);
1891
1892         if (DPO_PROTO_MPLS == path->fp_nh_proto)
1893         {
1894             fib_prefix_from_mpls_label(path->recursive.fp_nh.fp_local_label,
1895                                        path->recursive.fp_nh.fp_eos,
1896                                        &pfx);
1897         }
1898         else
1899         {
1900             fib_prefix_from_ip46_addr(&path->recursive.fp_nh.fp_ip, &pfx);
1901         }
1902
1903         fei = fib_table_entry_special_add(path->recursive.fp_tbl_id,
1904                                           &pfx,
1905                                           FIB_SOURCE_RR,
1906                                           FIB_ENTRY_FLAG_NONE);
1907
1908         path = fib_path_get(path_index);
1909         path->fp_via_fib = fei;
1910
1911         /*
1912          * become a dependent child of the entry so the path is
1913          * informed when the forwarding for the entry changes.
1914          */
1915         path->fp_sibling = fib_entry_child_add(path->fp_via_fib,
1916                                                FIB_NODE_TYPE_PATH,
1917                                                fib_path_get_index(path));
1918
1919         /*
1920          * create and configure the IP DPO
1921          */
1922         fib_path_recursive_adj_update(
1923             path,
1924             fib_path_to_chain_type(path),
1925             &path->fp_dpo);
1926
1927         break;
1928     }
1929     case FIB_PATH_TYPE_BIER_FMASK:
1930     {
1931         /*
1932          * become a dependent child of the entry so the path is
1933          * informed when the forwarding for the entry changes.
1934          */
1935         path->fp_sibling = bier_fmask_child_add(path->bier_fmask.fp_bier_fmask,
1936                                                 FIB_NODE_TYPE_PATH,
1937                                                 fib_path_get_index(path));
1938
1939         path->fp_via_bier_fmask = path->bier_fmask.fp_bier_fmask;
1940         fib_path_bier_fmask_update(path, &path->fp_dpo);
1941
1942         break;
1943     }
1944     case FIB_PATH_TYPE_BIER_IMP:
1945         bier_imp_lock(path->bier_imp.fp_bier_imp);
1946         bier_imp_contribute_forwarding(path->bier_imp.fp_bier_imp,
1947                                        DPO_PROTO_IP4,
1948                                        &path->fp_dpo);
1949         break;
1950     case FIB_PATH_TYPE_BIER_TABLE:
1951     {
1952         /*
1953          * Find/create the BIER table to link to
1954          */
1955         ASSERT(FIB_NODE_INDEX_INVALID == path->fp_via_bier_tbl);
1956
1957         path->fp_via_bier_tbl =
1958             bier_table_ecmp_create_and_lock(&path->bier_table.fp_bier_tbl);
1959
1960         bier_table_contribute_forwarding(path->fp_via_bier_tbl,
1961                                          &path->fp_dpo);
1962         break;
1963     }
1964     case FIB_PATH_TYPE_SPECIAL:
1965         /*
1966          * Resolve via the drop
1967          */
1968         dpo_copy(&path->fp_dpo, drop_dpo_get(path->fp_nh_proto));
1969         break;
1970     case FIB_PATH_TYPE_DEAG:
1971     {
1972         if (DPO_PROTO_BIER == path->fp_nh_proto)
1973         {
1974             bier_disp_table_contribute_forwarding(path->deag.fp_tbl_id,
1975                                                   &path->fp_dpo);
1976         }
1977         else
1978         {
1979             /*
1980              * Resolve via a lookup DPO.
1981              * FIXME. control plane should add routes with a table ID
1982              */
1983             lookup_input_t input;
1984             lookup_cast_t cast;
1985
1986             cast = (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_RPF_ID ?
1987                     LOOKUP_MULTICAST :
1988                     LOOKUP_UNICAST);
1989             input = (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_DEAG_SRC ?
1990                      LOOKUP_INPUT_SRC_ADDR :
1991                      LOOKUP_INPUT_DST_ADDR);
1992
1993             lookup_dpo_add_or_lock_w_fib_index(path->deag.fp_tbl_id,
1994                                                path->fp_nh_proto,
1995                                                cast,
1996                                                input,
1997                                                LOOKUP_TABLE_FROM_CONFIG,
1998                                                &path->fp_dpo);
1999         }
2000         break;
2001     }
2002     case FIB_PATH_TYPE_DVR:
2003         dvr_dpo_add_or_lock(path->attached.fp_interface,
2004                             path->fp_nh_proto,
2005                             &path->fp_dpo);
2006         break;
2007     case FIB_PATH_TYPE_RECEIVE:
2008         /*
2009          * Resolve via a receive DPO.
2010          */
2011         receive_dpo_add_or_lock(path->fp_nh_proto,
2012                                 path->receive.fp_interface,
2013                                 &path->receive.fp_addr,
2014                                 &path->fp_dpo);
2015         break;
2016     case FIB_PATH_TYPE_UDP_ENCAP:
2017         udp_encap_lock(path->udp_encap.fp_udp_encap_id);
2018         udp_encap_contribute_forwarding(path->udp_encap.fp_udp_encap_id,
2019                                         path->fp_nh_proto,
2020                                         &path->fp_dpo);
2021         break;
2022     case FIB_PATH_TYPE_INTF_RX: {
2023         /*
2024          * Resolve via a receive DPO.
2025          */
2026         interface_rx_dpo_add_or_lock(path->fp_nh_proto,
2027                                      path->intf_rx.fp_interface,
2028                                      &path->fp_dpo);
2029         break;
2030     }
2031     case FIB_PATH_TYPE_EXCLUSIVE:
2032         /*
2033          * Resolve via the user provided DPO
2034          */
2035         dpo_copy(&path->fp_dpo, &path->exclusive.fp_ex_dpo);
2036         break;
2037     }
2038
2039     return (fib_path_is_resolved(path_index));
2040 }
2041
2042 u32
2043 fib_path_get_resolving_interface (fib_node_index_t path_index)
2044 {
2045     fib_path_t *path;
2046
2047     path = fib_path_get(path_index);
2048
2049     switch (path->fp_type)
2050     {
2051     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
2052         return (path->attached_next_hop.fp_interface);
2053     case FIB_PATH_TYPE_ATTACHED:
2054         return (path->attached.fp_interface);
2055     case FIB_PATH_TYPE_RECEIVE:
2056         return (path->receive.fp_interface);
2057     case FIB_PATH_TYPE_RECURSIVE:
2058         if (fib_path_is_resolved(path_index))
2059         {
2060             return (fib_entry_get_resolving_interface(path->fp_via_fib));
2061         }
2062         break;
2063     case FIB_PATH_TYPE_DVR:
2064         return (path->dvr.fp_interface);
2065     case FIB_PATH_TYPE_INTF_RX:
2066     case FIB_PATH_TYPE_UDP_ENCAP:
2067     case FIB_PATH_TYPE_SPECIAL:
2068     case FIB_PATH_TYPE_DEAG:
2069     case FIB_PATH_TYPE_EXCLUSIVE:
2070     case FIB_PATH_TYPE_BIER_FMASK:
2071     case FIB_PATH_TYPE_BIER_TABLE:
2072     case FIB_PATH_TYPE_BIER_IMP:
2073         break;
2074     }
2075     return (~0);
2076 }
2077
2078 index_t
2079 fib_path_get_resolving_index (fib_node_index_t path_index)
2080 {
2081     fib_path_t *path;
2082
2083     path = fib_path_get(path_index);
2084
2085     switch (path->fp_type)
2086     {
2087     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
2088     case FIB_PATH_TYPE_ATTACHED:
2089     case FIB_PATH_TYPE_RECEIVE:
2090     case FIB_PATH_TYPE_INTF_RX:
2091     case FIB_PATH_TYPE_SPECIAL:
2092     case FIB_PATH_TYPE_DEAG:
2093     case FIB_PATH_TYPE_DVR:
2094     case FIB_PATH_TYPE_EXCLUSIVE:
2095         break;
2096     case FIB_PATH_TYPE_UDP_ENCAP:
2097         return (path->udp_encap.fp_udp_encap_id);
2098     case FIB_PATH_TYPE_RECURSIVE:
2099         return (path->fp_via_fib);
2100     case FIB_PATH_TYPE_BIER_FMASK:
2101         return (path->bier_fmask.fp_bier_fmask);
2102    case FIB_PATH_TYPE_BIER_TABLE:
2103        return (path->fp_via_bier_tbl);
2104    case FIB_PATH_TYPE_BIER_IMP:
2105        return (path->bier_imp.fp_bier_imp);
2106     }
2107     return (~0);
2108 }
2109
2110 adj_index_t
2111 fib_path_get_adj (fib_node_index_t path_index)
2112 {
2113     fib_path_t *path;
2114
2115     path = fib_path_get(path_index);
2116
2117     ASSERT(dpo_is_adj(&path->fp_dpo));
2118     if (dpo_is_adj(&path->fp_dpo))
2119     {
2120         return (path->fp_dpo.dpoi_index);
2121     }
2122     return (ADJ_INDEX_INVALID);
2123 }
2124
2125 u16
2126 fib_path_get_weight (fib_node_index_t path_index)
2127 {
2128     fib_path_t *path;
2129
2130     path = fib_path_get(path_index);
2131
2132     ASSERT(path);
2133
2134     return (path->fp_weight);
2135 }
2136
2137 u16
2138 fib_path_get_preference (fib_node_index_t path_index)
2139 {
2140     fib_path_t *path;
2141
2142     path = fib_path_get(path_index);
2143
2144     ASSERT(path);
2145
2146     return (path->fp_preference);
2147 }
2148
2149 u32
2150 fib_path_get_rpf_id (fib_node_index_t path_index)
2151 {
2152     fib_path_t *path;
2153
2154     path = fib_path_get(path_index);
2155
2156     ASSERT(path);
2157
2158     if (FIB_PATH_CFG_FLAG_RPF_ID & path->fp_cfg_flags)
2159     {
2160         return (path->deag.fp_rpf_id);
2161     }
2162
2163     return (~0);
2164 }
2165
2166 /**
2167  * @brief Contribute the path's adjacency to the list passed.
2168  * By calling this function over all paths, recursively, a child
2169  * can construct its full set of forwarding adjacencies, and hence its
2170  * uRPF list.
2171  */
2172 void
2173 fib_path_contribute_urpf (fib_node_index_t path_index,
2174                           index_t urpf)
2175 {
2176     fib_path_t *path;
2177
2178     path = fib_path_get(path_index);
2179
2180     /*
2181      * resolved and unresolved paths contribute to the RPF list.
2182      */
2183     switch (path->fp_type)
2184     {
2185     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
2186         fib_urpf_list_append(urpf, path->attached_next_hop.fp_interface);
2187         break;
2188
2189     case FIB_PATH_TYPE_ATTACHED:
2190         fib_urpf_list_append(urpf, path->attached.fp_interface);
2191         break;
2192
2193     case FIB_PATH_TYPE_RECURSIVE:
2194         if (FIB_NODE_INDEX_INVALID != path->fp_via_fib &&
2195             !fib_path_is_looped(path_index))
2196         {
2197             /*
2198              * there's unresolved due to constraints, and there's unresolved
2199              * due to ain't got no via. can't do nowt w'out via.
2200              */
2201             fib_entry_contribute_urpf(path->fp_via_fib, urpf);
2202         }
2203         break;
2204
2205     case FIB_PATH_TYPE_EXCLUSIVE:
2206     case FIB_PATH_TYPE_SPECIAL:
2207     {
2208         /*
2209          * these path types may link to an adj, if that's what
2210          * the clinet gave
2211          */
2212         u32 rpf_sw_if_index;
2213
2214         rpf_sw_if_index = dpo_get_urpf(&path->fp_dpo);
2215
2216         if (~0 != rpf_sw_if_index)
2217         {
2218             fib_urpf_list_append(urpf, rpf_sw_if_index);
2219         }
2220         break;
2221     }
2222     case FIB_PATH_TYPE_DVR:
2223         fib_urpf_list_append(urpf, path->dvr.fp_interface);
2224         break;
2225     case FIB_PATH_TYPE_DEAG:
2226     case FIB_PATH_TYPE_RECEIVE:
2227     case FIB_PATH_TYPE_INTF_RX:
2228     case FIB_PATH_TYPE_UDP_ENCAP:
2229     case FIB_PATH_TYPE_BIER_FMASK:
2230     case FIB_PATH_TYPE_BIER_TABLE:
2231     case FIB_PATH_TYPE_BIER_IMP:
2232         /*
2233          * these path types don't link to an adj
2234          */
2235         break;
2236     }
2237 }
2238
2239 void
2240 fib_path_stack_mpls_disp (fib_node_index_t path_index,
2241                           dpo_proto_t payload_proto,
2242                           fib_mpls_lsp_mode_t mode,
2243                           dpo_id_t *dpo)
2244 {
2245     fib_path_t *path;
2246
2247     path = fib_path_get(path_index);
2248
2249     ASSERT(path);
2250
2251     switch (path->fp_type)
2252     {
2253     case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
2254     {
2255         dpo_id_t tmp = DPO_INVALID;
2256
2257         dpo_copy(&tmp, dpo);
2258
2259         mpls_disp_dpo_create(payload_proto, ~0, mode, &tmp, dpo);
2260         dpo_reset(&tmp);
2261         break;
2262     }
2263     case FIB_PATH_TYPE_DEAG:
2264     {
2265         dpo_id_t tmp = DPO_INVALID;
2266
2267         dpo_copy(&tmp, dpo);
2268
2269         mpls_disp_dpo_create(payload_proto,
2270                              path->deag.fp_rpf_id,
2271                              mode, &tmp, dpo);
2272         dpo_reset(&tmp);
2273         break;
2274     }
2275     case FIB_PATH_TYPE_RECEIVE:
2276     case FIB_PATH_TYPE_ATTACHED:
2277     case FIB_PATH_TYPE_RECURSIVE:
2278     case FIB_PATH_TYPE_INTF_RX:
2279     case FIB_PATH_TYPE_UDP_ENCAP:
2280     case FIB_PATH_TYPE_EXCLUSIVE:
2281     case FIB_PATH_TYPE_SPECIAL:
2282     case FIB_PATH_TYPE_BIER_FMASK:
2283     case FIB_PATH_TYPE_BIER_TABLE:
2284     case FIB_PATH_TYPE_BIER_IMP:
2285     case FIB_PATH_TYPE_DVR:
2286         break;
2287     }
2288 }
2289
2290 void
2291 fib_path_contribute_forwarding (fib_node_index_t path_index,
2292                                 fib_forward_chain_type_t fct,
2293                                 dpo_id_t *dpo)
2294 {
2295     fib_path_t *path;
2296
2297     path = fib_path_get(path_index);
2298
2299     ASSERT(path);
2300     ASSERT(FIB_FORW_CHAIN_TYPE_MPLS_EOS != fct);
2301
2302     FIB_PATH_DBG(path, "contribute");
2303
2304     /*
2305      * The DPO stored in the path was created when the path was resolved.
2306      * This then represents the path's 'native' protocol; IP.
2307      * For all others will need to go find something else.
2308      */
2309     if (fib_path_to_chain_type(path) == fct)
2310     {
2311         dpo_copy(dpo, &path->fp_dpo);
2312     }
2313     else
2314     {
2315         switch (path->fp_type)
2316         {
2317         case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
2318             switch (fct)
2319             {
2320             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
2321             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
2322             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
2323             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
2324             case FIB_FORW_CHAIN_TYPE_ETHERNET:
2325             case FIB_FORW_CHAIN_TYPE_NSH:
2326             {
2327                 adj_index_t ai;
2328
2329                 /*
2330                  * get a appropriate link type adj.
2331                  */
2332                 ai = fib_path_attached_next_hop_get_adj(
2333                          path,
2334                          fib_forw_chain_type_to_link_type(fct));
2335                 dpo_set(dpo, DPO_ADJACENCY,
2336                         fib_forw_chain_type_to_dpo_proto(fct), ai);
2337                 adj_unlock(ai);
2338
2339                 break;
2340             }
2341             case FIB_FORW_CHAIN_TYPE_MCAST_IP4:
2342             case FIB_FORW_CHAIN_TYPE_MCAST_IP6:
2343             case FIB_FORW_CHAIN_TYPE_BIER:
2344                 break;
2345             }
2346             break;
2347         case FIB_PATH_TYPE_RECURSIVE:
2348             switch (fct)
2349             {
2350             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
2351             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
2352             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
2353             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
2354             case FIB_FORW_CHAIN_TYPE_MCAST_IP4:
2355             case FIB_FORW_CHAIN_TYPE_MCAST_IP6:
2356             case FIB_FORW_CHAIN_TYPE_BIER:
2357                 fib_path_recursive_adj_update(path, fct, dpo);
2358                 break;
2359             case FIB_FORW_CHAIN_TYPE_ETHERNET:
2360             case FIB_FORW_CHAIN_TYPE_NSH:
2361                 ASSERT(0);
2362                 break;
2363             }
2364             break;
2365         case FIB_PATH_TYPE_BIER_TABLE:
2366             switch (fct)
2367             {
2368             case FIB_FORW_CHAIN_TYPE_BIER:
2369                 bier_table_contribute_forwarding(path->fp_via_bier_tbl, dpo);
2370                 break;
2371             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
2372             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
2373             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
2374             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
2375             case FIB_FORW_CHAIN_TYPE_MCAST_IP4:
2376             case FIB_FORW_CHAIN_TYPE_MCAST_IP6:
2377             case FIB_FORW_CHAIN_TYPE_ETHERNET:
2378             case FIB_FORW_CHAIN_TYPE_NSH:
2379                 ASSERT(0);
2380                 break;
2381             }
2382             break;
2383         case FIB_PATH_TYPE_BIER_FMASK:
2384             switch (fct)
2385             {
2386             case FIB_FORW_CHAIN_TYPE_BIER:
2387                 fib_path_bier_fmask_update(path, dpo);
2388                 break;
2389             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
2390             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
2391             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
2392             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
2393             case FIB_FORW_CHAIN_TYPE_MCAST_IP4:
2394             case FIB_FORW_CHAIN_TYPE_MCAST_IP6:
2395             case FIB_FORW_CHAIN_TYPE_ETHERNET:
2396             case FIB_FORW_CHAIN_TYPE_NSH:
2397                 ASSERT(0);
2398                 break;
2399             }
2400             break;
2401         case FIB_PATH_TYPE_BIER_IMP:
2402             bier_imp_contribute_forwarding(path->bier_imp.fp_bier_imp,
2403                                            fib_forw_chain_type_to_dpo_proto(fct),
2404                                            dpo);
2405             break;
2406         case FIB_PATH_TYPE_DEAG:
2407             switch (fct)
2408             {
2409             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
2410                 lookup_dpo_add_or_lock_w_table_id(MPLS_FIB_DEFAULT_TABLE_ID,
2411                                                   DPO_PROTO_MPLS,
2412                                                   LOOKUP_UNICAST,
2413                                                   LOOKUP_INPUT_DST_ADDR,
2414                                                   LOOKUP_TABLE_FROM_CONFIG,
2415                                                   dpo);
2416                 break;
2417             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
2418             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
2419             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
2420                 dpo_copy(dpo, &path->fp_dpo);
2421                 break;
2422             case FIB_FORW_CHAIN_TYPE_MCAST_IP4:
2423             case FIB_FORW_CHAIN_TYPE_MCAST_IP6:
2424             case FIB_FORW_CHAIN_TYPE_BIER:
2425                 break;
2426             case FIB_FORW_CHAIN_TYPE_ETHERNET:
2427             case FIB_FORW_CHAIN_TYPE_NSH:
2428                 ASSERT(0);
2429                 break;
2430             }
2431             break;
2432         case FIB_PATH_TYPE_EXCLUSIVE:
2433             dpo_copy(dpo, &path->exclusive.fp_ex_dpo);
2434             break;
2435         case FIB_PATH_TYPE_ATTACHED:
2436             switch (fct)
2437             {
2438             case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS:
2439             case FIB_FORW_CHAIN_TYPE_UNICAST_IP4:
2440             case FIB_FORW_CHAIN_TYPE_UNICAST_IP6:
2441             case FIB_FORW_CHAIN_TYPE_MPLS_EOS:
2442             case FIB_FORW_CHAIN_TYPE_ETHERNET:
2443             case FIB_FORW_CHAIN_TYPE_NSH:
2444             case FIB_FORW_CHAIN_TYPE_BIER:
2445                 {
2446                     adj_index_t ai;
2447
2448                     /*
2449                      * get a appropriate link type adj.
2450                      */
2451                     ai = fib_path_attached_get_adj(
2452                             path,
2453                             fib_forw_chain_type_to_link_type(fct));
2454                     dpo_set(dpo, DPO_ADJACENCY,
2455                             fib_forw_chain_type_to_dpo_proto(fct), ai);
2456                     adj_unlock(ai);
2457                     break;
2458                 }
2459             case FIB_FORW_CHAIN_TYPE_MCAST_IP4:
2460             case FIB_FORW_CHAIN_TYPE_MCAST_IP6:
2461                 {
2462                     adj_index_t ai;
2463
2464                     /*
2465                      * Create the adj needed for sending IP multicast traffic
2466                      */
2467                     ai = adj_mcast_add_or_lock(dpo_proto_to_fib(path->fp_nh_proto),
2468                                                fib_forw_chain_type_to_link_type(fct),
2469                                                path->attached.fp_interface);
2470                     dpo_set(dpo, DPO_ADJACENCY,
2471                             fib_forw_chain_type_to_dpo_proto(fct),
2472                             ai);
2473                     adj_unlock(ai);
2474                 }
2475                 break;
2476             }
2477             break;
2478         case FIB_PATH_TYPE_INTF_RX:
2479             /*
2480              * Create the adj needed for sending IP multicast traffic
2481              */
2482             interface_rx_dpo_add_or_lock(fib_forw_chain_type_to_dpo_proto(fct),
2483                                          path->attached.fp_interface,
2484                                          dpo);
2485             break;
2486         case FIB_PATH_TYPE_UDP_ENCAP:
2487             udp_encap_contribute_forwarding(path->udp_encap.fp_udp_encap_id,
2488                                             path->fp_nh_proto,
2489                                             dpo);
2490             break;
2491         case FIB_PATH_TYPE_RECEIVE:
2492         case FIB_PATH_TYPE_SPECIAL:
2493         case FIB_PATH_TYPE_DVR:
2494             dpo_copy(dpo, &path->fp_dpo);
2495             break;
2496         }
2497     }
2498 }
2499
2500 load_balance_path_t *
2501 fib_path_append_nh_for_multipath_hash (fib_node_index_t path_index,
2502                                        fib_forward_chain_type_t fct,
2503                                        load_balance_path_t *hash_key)
2504 {
2505     load_balance_path_t *mnh;
2506     fib_path_t *path;
2507
2508     path = fib_path_get(path_index);
2509
2510     ASSERT(path);
2511
2512     if (fib_path_is_resolved(path_index))
2513     {
2514         vec_add2(hash_key, mnh, 1);
2515
2516         mnh->path_weight = path->fp_weight;
2517         mnh->path_index = path_index;
2518         fib_path_contribute_forwarding(path_index, fct, &mnh->path_dpo);
2519     }
2520
2521     return (hash_key);
2522 }
2523
2524 int
2525 fib_path_is_recursive_constrained (fib_node_index_t path_index)
2526 {
2527     fib_path_t *path;
2528
2529     path = fib_path_get(path_index);
2530
2531     return ((FIB_PATH_TYPE_RECURSIVE == path->fp_type) &&
2532             ((path->fp_cfg_flags & FIB_PATH_CFG_FLAG_RESOLVE_ATTACHED) ||
2533              (path->fp_cfg_flags & FIB_PATH_CFG_FLAG_RESOLVE_HOST)));
2534 }
2535
2536 int
2537 fib_path_is_exclusive (fib_node_index_t path_index)
2538 {
2539     fib_path_t *path;
2540
2541     path = fib_path_get(path_index);
2542
2543     return (FIB_PATH_TYPE_EXCLUSIVE == path->fp_type);
2544 }
2545
2546 int
2547 fib_path_is_deag (fib_node_index_t path_index)
2548 {
2549     fib_path_t *path;
2550
2551     path = fib_path_get(path_index);
2552
2553     return (FIB_PATH_TYPE_DEAG == path->fp_type);
2554 }
2555
2556 int
2557 fib_path_is_resolved (fib_node_index_t path_index)
2558 {
2559     fib_path_t *path;
2560
2561     path = fib_path_get(path_index);
2562
2563     return (dpo_id_is_valid(&path->fp_dpo) &&
2564             (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RESOLVED) &&
2565             !fib_path_is_looped(path_index) &&
2566             !fib_path_is_permanent_drop(path));
2567 }
2568
2569 int
2570 fib_path_is_looped (fib_node_index_t path_index)
2571 {
2572     fib_path_t *path;
2573
2574     path = fib_path_get(path_index);
2575
2576     return (path->fp_oper_flags & FIB_PATH_OPER_FLAG_RECURSIVE_LOOP);
2577 }
2578
2579 fib_path_list_walk_rc_t
2580 fib_path_encode (fib_node_index_t path_list_index,
2581                  fib_node_index_t path_index,
2582                  void *ctx)
2583 {
2584     fib_route_path_encode_t **api_rpaths = ctx;
2585     fib_route_path_encode_t *api_rpath;
2586     fib_path_t *path;
2587
2588     path = fib_path_get(path_index);
2589     if (!path)
2590       return (FIB_PATH_LIST_WALK_CONTINUE);
2591     vec_add2(*api_rpaths, api_rpath, 1);
2592     api_rpath->rpath.frp_weight = path->fp_weight;
2593     api_rpath->rpath.frp_preference = path->fp_preference;
2594     api_rpath->rpath.frp_proto = path->fp_nh_proto;
2595     api_rpath->rpath.frp_sw_if_index = ~0;
2596     api_rpath->dpo = path->fp_dpo;
2597
2598     switch (path->fp_type)
2599       {
2600       case FIB_PATH_TYPE_RECEIVE:
2601         api_rpath->rpath.frp_addr = path->receive.fp_addr;
2602         api_rpath->rpath.frp_sw_if_index = path->receive.fp_interface;
2603         break;
2604       case FIB_PATH_TYPE_ATTACHED:
2605         api_rpath->rpath.frp_sw_if_index = path->attached.fp_interface;
2606         break;
2607       case FIB_PATH_TYPE_ATTACHED_NEXT_HOP:
2608         api_rpath->rpath.frp_sw_if_index = path->attached_next_hop.fp_interface;
2609         api_rpath->rpath.frp_addr = path->attached_next_hop.fp_nh;
2610         break;
2611       case FIB_PATH_TYPE_BIER_FMASK:
2612         api_rpath->rpath.frp_bier_fmask = path->bier_fmask.fp_bier_fmask;
2613         break;
2614       case FIB_PATH_TYPE_SPECIAL:
2615         break;
2616       case FIB_PATH_TYPE_DEAG:
2617         api_rpath->rpath.frp_fib_index = path->deag.fp_tbl_id;
2618         break;
2619       case FIB_PATH_TYPE_RECURSIVE:
2620         api_rpath->rpath.frp_addr = path->recursive.fp_nh.fp_ip;
2621         break;
2622       case FIB_PATH_TYPE_DVR:
2623           api_rpath->rpath.frp_sw_if_index = path->dvr.fp_interface;
2624           api_rpath->rpath.frp_flags |= FIB_ROUTE_PATH_DVR;
2625           break;
2626       case FIB_PATH_TYPE_UDP_ENCAP:
2627           api_rpath->rpath.frp_udp_encap_id = path->udp_encap.fp_udp_encap_id;
2628           api_rpath->rpath.frp_flags |= FIB_ROUTE_PATH_UDP_ENCAP;
2629           break;
2630       default:
2631         break;
2632       }
2633
2634     return (FIB_PATH_LIST_WALK_CONTINUE);
2635 }
2636
2637 dpo_proto_t
2638 fib_path_get_proto (fib_node_index_t path_index)
2639 {
2640     fib_path_t *path;
2641
2642     path = fib_path_get(path_index);
2643
2644     return (path->fp_nh_proto);
2645 }
2646
2647 void
2648 fib_path_module_init (void)
2649 {
2650     fib_node_register_type (FIB_NODE_TYPE_PATH, &fib_path_vft);
2651 }
2652
2653 static clib_error_t *
2654 show_fib_path_command (vlib_main_t * vm,
2655                         unformat_input_t * input,
2656                         vlib_cli_command_t * cmd)
2657 {
2658     fib_node_index_t pi;
2659     fib_path_t *path;
2660
2661     if (unformat (input, "%d", &pi))
2662     {
2663         /*
2664          * show one in detail
2665          */
2666         if (!pool_is_free_index(fib_path_pool, pi))
2667         {
2668             path = fib_path_get(pi);
2669             u8 *s = format(NULL, "%U", format_fib_path, pi, 1);
2670             s = format(s, "children:");
2671             s = fib_node_children_format(path->fp_node.fn_children, s);
2672             vlib_cli_output (vm, "%s", s);
2673             vec_free(s);
2674         }
2675         else
2676         {
2677             vlib_cli_output (vm, "path %d invalid", pi);
2678         }
2679     }
2680     else
2681     {
2682         vlib_cli_output (vm, "FIB Paths");
2683         pool_foreach_index (pi, fib_path_pool,
2684         ({
2685             vlib_cli_output (vm, "%U", format_fib_path, pi, 0);
2686         }));
2687     }
2688
2689     return (NULL);
2690 }
2691
2692 VLIB_CLI_COMMAND (show_fib_path, static) = {
2693   .path = "show fib paths",
2694   .function = show_fib_path_command,
2695   .short_help = "show fib paths",
2696 };