zebra/zebra_nhg.h

   1 /* Zebra Nexthop Group header.
   2  * Copyright (C) 2019 Cumulus Networks, Inc.
   3  *                    Donald Sharp
   4  *                    Stephen Worley
   5  *
   6  * This file is part of FRR.
   7  *
   8  * FRR is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the
  10  * Free Software Foundation; either version 2, or (at your option) any
  11  * later version.
  12  *
  13  * FRR is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with FRR; see the file COPYING.  If not, write to the Free
  20  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  21  * 02111-1307, USA.
  22  */
  23 #ifndef __ZEBRA_NHG_H__
  24 #define __ZEBRA_NHG_H__
  25
  26 #include "lib/nexthop.h"
  27 #include "lib/nexthop_group.h"
  28
  29 #ifdef __cplusplus
  30 extern "C" {
  31 #endif
  32
  33 /* This struct is used exclusively for dataplane
  34  * interaction via a dataplane context.
  35  *
  36  * It is designed to mimic the netlink nexthop_grp
  37  * struct in include/linux/nexthop.h
  38  */
  39 struct nh_grp {
  40         uint32_t id;
  41         uint8_t weight;
  42 };
  43
  44 PREDECL_RBTREE_UNIQ(nhg_connected_tree);
  45
  46 /*
  47  * Hashtables containing nhg entries is in `zebra_router`.
  48  */
  49 struct nhg_hash_entry {
  50         uint32_t id;
  51         afi_t afi;
  52         vrf_id_t vrf_id;
  53
  54         /* Time since last update */
  55         time_t uptime;
  56
  57         /* Source protocol - zebra or another daemon */
  58         int type;
  59
  60         /* zapi instance and session id, for groups from other daemons */
  61         uint16_t zapi_instance;
  62         uint32_t zapi_session;
  63
  64         struct nexthop_group nhg;
  65
  66         /* If supported, a mapping of backup nexthops. */
  67         struct nhg_backup_info *backup_info;
  68
  69         /* If this is not a group, it
  70          * will be a single nexthop
  71          * and must have an interface
  72          * associated with it.
  73          * Otherwise, this will be null.
  74          */
  75         struct interface *ifp;
  76
  77         uint32_t refcnt;
  78         uint32_t dplane_ref;
  79
  80         uint32_t flags;
  81
  82         /* Dependency trees for other entries.
  83          * For instance a group with two
  84          * nexthops will have two dependencies
  85          * pointing to those nhg_hash_entries.
  86          *
  87          * Using a rb tree here to make lookups
  88          * faster with ID's.
  89          *
  90          * nhg_depends the RB tree of entries that this
  91          * group contains.
  92          *
  93          * nhg_dependents the RB tree of entries that
  94          * this group is being used by
  95          *
  96          * NHG id 3 with nexthops id 1/2
  97          * nhg(3)->nhg_depends has 1 and 2 in the tree
  98          * nhg(3)->nhg_dependents is empty
  99          *
 100          * nhg(1)->nhg_depends is empty
 101          * nhg(1)->nhg_dependents is 3 in the tree
 102          *
 103          * nhg(2)->nhg_depends is empty
 104          * nhg(3)->nhg_dependents is 3 in the tree
 105          */
 106         struct nhg_connected_tree_head nhg_depends, nhg_dependents;
 107
 108 /*
 109  * Is this nexthop group valid, ie all nexthops are fully resolved.
 110  * What is fully resolved?  It's a nexthop that is either self contained
 111  * and correct( ie no recursive pointer ) or a nexthop that is recursively
 112  * resolved and correct.
 113  */
 114 #define NEXTHOP_GROUP_VALID (1 << 0)
 115 /*
 116  * Has this nexthop group been installed?  At this point in time, this
 117  * means that the data-plane has been told about this nexthop group
 118  * and it's possible usage by a route entry.
 119  */
 120 #define NEXTHOP_GROUP_INSTALLED (1 << 1)
 121 /*
 122  * Has the nexthop group been queued to be send to the FIB?
 123  * The NEXTHOP_GROUP_VALID flag should also be set by this point.
 124  */
 125 #define NEXTHOP_GROUP_QUEUED (1 << 2)
 126 /*
 127  * Is this a nexthop that is recursively resolved?
 128  */
 129 #define NEXTHOP_GROUP_RECURSIVE (1 << 3)
 130
 131 /*
 132  * Backup nexthop support - identify groups that are backups for
 133  * another group.
 134  */
 135 #define NEXTHOP_GROUP_BACKUP (1 << 4)
 136
 137 /*
 138  * The NHG has been release by an upper level protocol via the
 139  * `zebra_nhg_proto_del()` API.
 140  *
 141  * We use this flag to track this state in case the NHG is still being used
 142  * by routes therefore holding their refcnts as well. Otherwise, the NHG will
 143  * be removed and uninstalled.
 144  *
 145  */
 146 #define NEXTHOP_GROUP_PROTO_RELEASED (1 << 5)
 147
 148 /*
 149  * Track FPM installation status..
 150  */
 151 #define NEXTHOP_GROUP_FPM (1 << 6)
 152 };
 153
 154 /* Upper 4 bits of the NHG are reserved for indicating the NHG type */
 155 #define NHG_ID_TYPE_POS 28
 156 enum nhg_type {
 157         NHG_TYPE_L3 = 0,
 158         NHG_TYPE_L2_NH, /* NHs in a L2 NHG used as a MAC/FDB dest */
 159         NHG_TYPE_L2,    /* L2 NHG used as a MAC/FDB dest */
 160 };
 161
 162 /* Was this one we created, either this session or previously? */
 163 #define ZEBRA_NHG_CREATED(NHE)                                                 \
 164         (((NHE->type) <= ZEBRA_ROUTE_MAX) && (NHE->type != ZEBRA_ROUTE_KERNEL))
 165
 166 /* Is this an NHE owned by zebra and not an upper level protocol? */
 167 #define ZEBRA_OWNED(NHE) (NHE->type == ZEBRA_ROUTE_NHG)
 168
 169 #define PROTO_OWNED(NHE) (NHE->id >= ZEBRA_NHG_PROTO_LOWER)
 170
 171 /*
 172  * Backup nexthops: this is a group object itself, so
 173  * that the backup nexthops can use the same code as a normal object.
 174  */
 175 struct nhg_backup_info {
 176         struct nhg_hash_entry *nhe;
 177 };
 178
 179 enum nhg_ctx_op_e {
 180         NHG_CTX_OP_NONE = 0,
 181         NHG_CTX_OP_NEW,
 182         NHG_CTX_OP_DEL,
 183 };
 184
 185 enum nhg_ctx_status {
 186         NHG_CTX_NONE = 0,
 187         NHG_CTX_QUEUED,
 188         NHG_CTX_REQUEUED,
 189         NHG_CTX_SUCCESS,
 190         NHG_CTX_FAILURE,
 191 };
 192
 193 /*
 194  * Context needed to queue nhg updates on the
 195  * work queue.
 196  */
 197 struct nhg_ctx {
 198
 199         /* Unique ID */
 200         uint32_t id;
 201
 202         vrf_id_t vrf_id;
 203         afi_t afi;
 204
 205         /*
 206          * This should only ever be ZEBRA_ROUTE_NHG unless we get a a kernel
 207          * created nexthop not made by us.
 208          */
 209         int type;
 210
 211         /* If its a group array, how many? */
 212         uint8_t count;
 213
 214         /* Its either a single nexthop or an array of ID's */
 215         union {
 216                 struct nexthop nh;
 217                 struct nh_grp grp[MULTIPATH_NUM];
 218         } u;
 219
 220         enum nhg_ctx_op_e op;
 221         enum nhg_ctx_status status;
 222 };
 223
 224 /* Global control to disable use of kernel nexthops, if available. We can't
 225  * force the kernel to support nexthop ids, of course, but we can disable
 226  * zebra's use of them, for testing e.g. By default, if the kernel supports
 227  * nexthop ids, zebra uses them.
 228  */
 229 void zebra_nhg_enable_kernel_nexthops(bool set);
 230 bool zebra_nhg_kernel_nexthops_enabled(void);
 231
 232 /* Global control for zebra to only use proto-owned nexthops */
 233 void zebra_nhg_set_proto_nexthops_only(bool set);
 234 bool zebra_nhg_proto_nexthops_only(void);
 235
 236 /* Global control for use of activated backups for recursive resolution. */
 237 void zebra_nhg_set_recursive_use_backups(bool set);
 238 bool zebra_nhg_recursive_use_backups(void);
 239
 240 /**
 241  * NHE abstracted tree functions.
 242  * Use these where possible instead of direct access.
 243  */
 244 struct nhg_hash_entry *zebra_nhg_alloc(void);
 245 void zebra_nhg_free(struct nhg_hash_entry *nhe);
 246 /* In order to clear a generic hash, we need a generic api, sigh. */
 247 void zebra_nhg_hash_free(void *p);
 248
 249 /* Init an nhe, for use in a hash lookup for example. There's some fuzziness
 250  * if the nhe represents only a single nexthop, so we try to capture that
 251  * variant also.
 252  */
 253 void zebra_nhe_init(struct nhg_hash_entry *nhe, afi_t afi,
 254                     const struct nexthop *nh);
 255
 256 /*
 257  * Shallow copy of 'orig', into new/allocated nhe.
 258  */
 259 struct nhg_hash_entry *zebra_nhe_copy(const struct nhg_hash_entry *orig,
 260                                       uint32_t id);
 261
 262 /* Allocate, free backup nexthop info objects */
 263 struct nhg_backup_info *zebra_nhg_backup_alloc(void);
 264 void zebra_nhg_backup_free(struct nhg_backup_info **p);
 265
 266 struct nexthop_group *zebra_nhg_get_backup_nhg(struct nhg_hash_entry *nhe);
 267
 268 extern struct nhg_hash_entry *zebra_nhg_resolve(struct nhg_hash_entry *nhe);
 269
 270 extern unsigned int zebra_nhg_depends_count(const struct nhg_hash_entry *nhe);
 271 extern bool zebra_nhg_depends_is_empty(const struct nhg_hash_entry *nhe);
 272
 273 extern unsigned int
 274 zebra_nhg_dependents_count(const struct nhg_hash_entry *nhe);
 275 extern bool zebra_nhg_dependents_is_empty(const struct nhg_hash_entry *nhe);
 276
 277 /* Lookup ID, doesn't create */
 278 extern struct nhg_hash_entry *zebra_nhg_lookup_id(uint32_t id);
 279
 280 /* Hash functions */
 281 extern uint32_t zebra_nhg_hash_key(const void *arg);
 282 extern uint32_t zebra_nhg_id_key(const void *arg);
 283
 284 extern bool zebra_nhg_hash_equal(const void *arg1, const void *arg2);
 285 extern bool zebra_nhg_hash_id_equal(const void *arg1, const void *arg2);
 286
 287 /*
 288  * Process a context off of a queue.
 289  * Specifically this should be from
 290  * the rib meta queue.
 291  */
 292 extern int nhg_ctx_process(struct nhg_ctx *ctx);
 293 void nhg_ctx_free(struct nhg_ctx **ctx);
 294
 295 /* Find via kernel nh creation */
 296 extern int zebra_nhg_kernel_find(uint32_t id, struct nexthop *nh,
 297                                  struct nh_grp *grp, uint8_t count,
 298                                  vrf_id_t vrf_id, afi_t afi, int type,
 299                                  int startup);
 300 /* Del via kernel */
 301 extern int zebra_nhg_kernel_del(uint32_t id, vrf_id_t vrf_id);
 302
 303 /* Find an nhe based on a nexthop_group */
 304 extern struct nhg_hash_entry *zebra_nhg_rib_find(uint32_t id,
 305                                                  struct nexthop_group *nhg,
 306                                                  afi_t rt_afi, int type);
 307
 308 /* Find an nhe based on a route's nhe, used during route creation */
 309 struct nhg_hash_entry *
 310 zebra_nhg_rib_find_nhe(struct nhg_hash_entry *rt_nhe, afi_t rt_afi);
 311
 312
 313 /**
 314  * Functions for Add/Del/Replace via protocol NHG creation.
 315  *
 316  * The NHEs will not be hashed. They will only be present in the
 317  * ID table and therefore not sharable.
 318  *
 319  * It is the owning protocols job to manage these.
 320  */
 321
 322 /*
 323  * Add NHE. If already exists, Replace.
 324  *
 325  * Returns allocated NHE on success, otherwise NULL.
 326  */
 327 struct nhg_hash_entry *zebra_nhg_proto_add(uint32_t id, int type,
 328                                            uint16_t instance, uint32_t session,
 329                                            struct nexthop_group *nhg,
 330                                            afi_t afi);
 331
 332 /*
 333  * Del NHE.
 334  *
 335  * Returns deleted NHE on success, otherwise NULL.
 336  *
 337  * Caller must decrement ref with zebra_nhg_decrement_ref() when done.
 338  */
 339 struct nhg_hash_entry *zebra_nhg_proto_del(uint32_t id, int type);
 340
 341 /*
 342  * Remove specific by proto NHGs.
 343  *
 344  * Called after client disconnect.
 345  *
 346  */
 347 unsigned long zebra_nhg_score_proto(int type);
 348
 349 /* Reference counter functions */
 350 extern void zebra_nhg_decrement_ref(struct nhg_hash_entry *nhe);
 351 extern void zebra_nhg_increment_ref(struct nhg_hash_entry *nhe);
 352
 353 /* Check validity of nhe, if invalid will update dependents as well */
 354 extern void zebra_nhg_check_valid(struct nhg_hash_entry *nhe);
 355
 356 /* Convert nhe depends to a grp context that can be passed around safely */
 357 extern uint8_t zebra_nhg_nhe2grp(struct nh_grp *grp, struct nhg_hash_entry *nhe,
 358                                  int size);
 359
 360 /* Dataplane install/uninstall */
 361 extern void zebra_nhg_install_kernel(struct nhg_hash_entry *nhe);
 362 extern void zebra_nhg_uninstall_kernel(struct nhg_hash_entry *nhe);
 363
 364 /* Forward ref of dplane update context type */
 365 struct zebra_dplane_ctx;
 366 extern void zebra_nhg_dplane_result(struct zebra_dplane_ctx *ctx);
 367
 368
 369 /* Sweep the nhg hash tables for old entries on restart */
 370 extern void zebra_nhg_sweep_table(struct hash *hash);
 371
 372 /*
 373  * We are shutting down but the nexthops should be kept
 374  * as that -r has been specified and we don't want to delete
 375  * the routes unintentionally
 376  */
 377 extern void zebra_nhg_mark_keep(void);
 378
 379 /* Nexthop resolution processing */
 380 struct route_entry; /* Forward ref to avoid circular includes */
 381 extern int nexthop_active_update(struct route_node *rn, struct route_entry *re);
 382
 383 #ifdef _FRR_ATTRIBUTE_PRINTFRR
 384 #pragma FRR printfrr_ext "%pNG" (const struct nhg_hash_entry *)
 385 #endif
 386
 387 #ifdef __cplusplus
 388 }
 389 #endif
 390
 391 #endif  /* __ZEBRA_NHG_H__ */