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 tree 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         struct nhg_connected_tree_head nhg_depends, nhg_dependents;
  91
  92 /*
  93  * Is this nexthop group valid, ie all nexthops are fully resolved.
  94  * What is fully resolved?  It's a nexthop that is either self contained
  95  * and correct( ie no recursive pointer ) or a nexthop that is recursively
  96  * resolved and correct.
  97  */
  98 #define NEXTHOP_GROUP_VALID (1 << 0)
  99 /*
 100  * Has this nexthop group been installed?  At this point in time, this
 101  * means that the data-plane has been told about this nexthop group
 102  * and it's possible usage by a route entry.
 103  */
 104 #define NEXTHOP_GROUP_INSTALLED (1 << 1)
 105 /*
 106  * Has the nexthop group been queued to be send to the FIB?
 107  * The NEXTHOP_GROUP_VALID flag should also be set by this point.
 108  */
 109 #define NEXTHOP_GROUP_QUEUED (1 << 2)
 110 /*
 111  * Is this a nexthop that is recursively resolved?
 112  */
 113 #define NEXTHOP_GROUP_RECURSIVE (1 << 3)
 114
 115 /*
 116  * Backup nexthop support - identify groups that are backups for
 117  * another group.
 118  */
 119 #define NEXTHOP_GROUP_BACKUP (1 << 4)
 120
 121 /*
 122  * The NHG has been release by an upper level protocol via the
 123  * `zebra_nhg_proto_del()` API.
 124  *
 125  * We use this flag to track this state in case the NHG is still being used
 126  * by routes therefore holding their refcnts as well. Otherwise, the NHG will
 127  * be removed and uninstalled.
 128  *
 129  */
 130 #define NEXTHOP_GROUP_PROTO_RELEASED (1 << 5)
 131
 132 /*
 133  * Track FPM installation status..
 134  */
 135 #define NEXTHOP_GROUP_FPM (1 << 6)
 136 };
 137
 138 /* Upper 4 bits of the NHG are reserved for indicating the NHG type */
 139 #define NHG_ID_TYPE_POS 28
 140 enum nhg_type {
 141         NHG_TYPE_L3 = 0,
 142         NHG_TYPE_L2_NH, /* NHs in a L2 NHG used as a MAC/FDB dest */
 143         NHG_TYPE_L2,    /* L2 NHG used as a MAC/FDB dest */
 144 };
 145
 146 /* Was this one we created, either this session or previously? */
 147 #define ZEBRA_NHG_CREATED(NHE)                                                 \
 148         (((NHE->type) <= ZEBRA_ROUTE_MAX) && (NHE->type != ZEBRA_ROUTE_KERNEL))
 149
 150 /* Is this an NHE owned by zebra and not an upper level protocol? */
 151 #define ZEBRA_OWNED(NHE) (NHE->type == ZEBRA_ROUTE_NHG)
 152
 153 #define PROTO_OWNED(NHE) (NHE->id >= ZEBRA_NHG_PROTO_LOWER)
 154
 155 /*
 156  * Backup nexthops: this is a group object itself, so
 157  * that the backup nexthops can use the same code as a normal object.
 158  */
 159 struct nhg_backup_info {
 160         struct nhg_hash_entry *nhe;
 161 };
 162
 163 enum nhg_ctx_op_e {
 164         NHG_CTX_OP_NONE = 0,
 165         NHG_CTX_OP_NEW,
 166         NHG_CTX_OP_DEL,
 167 };
 168
 169 enum nhg_ctx_status {
 170         NHG_CTX_NONE = 0,
 171         NHG_CTX_QUEUED,
 172         NHG_CTX_REQUEUED,
 173         NHG_CTX_SUCCESS,
 174         NHG_CTX_FAILURE,
 175 };
 176
 177 /*
 178  * Context needed to queue nhg updates on the
 179  * work queue.
 180  */
 181 struct nhg_ctx {
 182
 183         /* Unique ID */
 184         uint32_t id;
 185
 186         vrf_id_t vrf_id;
 187         afi_t afi;
 188
 189         /*
 190          * This should only ever be ZEBRA_ROUTE_NHG unless we get a a kernel
 191          * created nexthop not made by us.
 192          */
 193         int type;
 194
 195         /* If its a group array, how many? */
 196         uint8_t count;
 197
 198         /* Its either a single nexthop or an array of ID's */
 199         union {
 200                 struct nexthop nh;
 201                 struct nh_grp grp[MULTIPATH_NUM];
 202         } u;
 203
 204         enum nhg_ctx_op_e op;
 205         enum nhg_ctx_status status;
 206 };
 207
 208 /* Global control to disable use of kernel nexthops, if available. We can't
 209  * force the kernel to support nexthop ids, of course, but we can disable
 210  * zebra's use of them, for testing e.g. By default, if the kernel supports
 211  * nexthop ids, zebra uses them.
 212  */
 213 void zebra_nhg_enable_kernel_nexthops(bool set);
 214 bool zebra_nhg_kernel_nexthops_enabled(void);
 215
 216 /* Global control for zebra to only use proto-owned nexthops */
 217 void zebra_nhg_set_proto_nexthops_only(bool set);
 218 bool zebra_nhg_proto_nexthops_only(void);
 219
 220 /* Global control for use of activated backups for recursive resolution. */
 221 void zebra_nhg_set_recursive_use_backups(bool set);
 222 bool zebra_nhg_recursive_use_backups(void);
 223
 224 /**
 225  * NHE abstracted tree functions.
 226  * Use these where possible instead of direct access.
 227  */
 228 struct nhg_hash_entry *zebra_nhg_alloc(void);
 229 void zebra_nhg_free(struct nhg_hash_entry *nhe);
 230 /* In order to clear a generic hash, we need a generic api, sigh. */
 231 void zebra_nhg_hash_free(void *p);
 232
 233 /* Init an nhe, for use in a hash lookup for example. There's some fuzziness
 234  * if the nhe represents only a single nexthop, so we try to capture that
 235  * variant also.
 236  */
 237 void zebra_nhe_init(struct nhg_hash_entry *nhe, afi_t afi,
 238                     const struct nexthop *nh);
 239
 240 /*
 241  * Shallow copy of 'orig', into new/allocated nhe.
 242  */
 243 struct nhg_hash_entry *zebra_nhe_copy(const struct nhg_hash_entry *orig,
 244                                       uint32_t id);
 245
 246 /* Allocate, free backup nexthop info objects */
 247 struct nhg_backup_info *zebra_nhg_backup_alloc(void);
 248 void zebra_nhg_backup_free(struct nhg_backup_info **p);
 249
 250 struct nexthop_group *zebra_nhg_get_backup_nhg(struct nhg_hash_entry *nhe);
 251
 252 extern struct nhg_hash_entry *zebra_nhg_resolve(struct nhg_hash_entry *nhe);
 253
 254 extern unsigned int zebra_nhg_depends_count(const struct nhg_hash_entry *nhe);
 255 extern bool zebra_nhg_depends_is_empty(const struct nhg_hash_entry *nhe);
 256
 257 extern unsigned int
 258 zebra_nhg_dependents_count(const struct nhg_hash_entry *nhe);
 259 extern bool zebra_nhg_dependents_is_empty(const struct nhg_hash_entry *nhe);
 260
 261 /* Lookup ID, doesn't create */
 262 extern struct nhg_hash_entry *zebra_nhg_lookup_id(uint32_t id);
 263
 264 /* Hash functions */
 265 extern uint32_t zebra_nhg_hash_key(const void *arg);
 266 extern uint32_t zebra_nhg_id_key(const void *arg);
 267
 268 extern bool zebra_nhg_hash_equal(const void *arg1, const void *arg2);
 269 extern bool zebra_nhg_hash_id_equal(const void *arg1, const void *arg2);
 270
 271 /*
 272  * Process a context off of a queue.
 273  * Specifically this should be from
 274  * the rib meta queue.
 275  */
 276 extern int nhg_ctx_process(struct nhg_ctx *ctx);
 277
 278 /* Find via kernel nh creation */
 279 extern int zebra_nhg_kernel_find(uint32_t id, struct nexthop *nh,
 280                                  struct nh_grp *grp, uint8_t count,
 281                                  vrf_id_t vrf_id, afi_t afi, int type,
 282                                  int startup);
 283 /* Del via kernel */
 284 extern int zebra_nhg_kernel_del(uint32_t id, vrf_id_t vrf_id);
 285
 286 /* Find an nhe based on a nexthop_group */
 287 extern struct nhg_hash_entry *zebra_nhg_rib_find(uint32_t id,
 288                                                  struct nexthop_group *nhg,
 289                                                  afi_t rt_afi, int type);
 290
 291 /* Find an nhe based on a route's nhe, used during route creation */
 292 struct nhg_hash_entry *
 293 zebra_nhg_rib_find_nhe(struct nhg_hash_entry *rt_nhe, afi_t rt_afi);
 294
 295
 296 /**
 297  * Functions for Add/Del/Replace via protocol NHG creation.
 298  *
 299  * The NHEs will not be hashed. They will only be present in the
 300  * ID table and therefore not sharable.
 301  *
 302  * It is the owning protocols job to manage these.
 303  */
 304
 305 /*
 306  * Add NHE. If already exists, Replace.
 307  *
 308  * Returns allocated NHE on success, otherwise NULL.
 309  */
 310 struct nhg_hash_entry *zebra_nhg_proto_add(uint32_t id, int type,
 311                                            uint16_t instance, uint32_t session,
 312                                            struct nexthop_group *nhg,
 313                                            afi_t afi);
 314
 315 /*
 316  * Del NHE.
 317  *
 318  * Returns deleted NHE on success, otherwise NULL.
 319  *
 320  * Caller must decrement ref with zebra_nhg_decrement_ref() when done.
 321  */
 322 struct nhg_hash_entry *zebra_nhg_proto_del(uint32_t id, int type);
 323
 324 /*
 325  * Remove specific by proto NHGs.
 326  *
 327  * Called after client disconnect.
 328  *
 329  */
 330 unsigned long zebra_nhg_score_proto(int type);
 331
 332 /* Reference counter functions */
 333 extern void zebra_nhg_decrement_ref(struct nhg_hash_entry *nhe);
 334 extern void zebra_nhg_increment_ref(struct nhg_hash_entry *nhe);
 335
 336 /* Check validity of nhe, if invalid will update dependents as well */
 337 extern void zebra_nhg_check_valid(struct nhg_hash_entry *nhe);
 338
 339 /* Convert nhe depends to a grp context that can be passed around safely */
 340 extern uint8_t zebra_nhg_nhe2grp(struct nh_grp *grp, struct nhg_hash_entry *nhe,
 341                                  int size);
 342
 343 /* Dataplane install/uninstall */
 344 extern void zebra_nhg_install_kernel(struct nhg_hash_entry *nhe);
 345 extern void zebra_nhg_uninstall_kernel(struct nhg_hash_entry *nhe);
 346
 347 /* Forward ref of dplane update context type */
 348 struct zebra_dplane_ctx;
 349 extern void zebra_nhg_dplane_result(struct zebra_dplane_ctx *ctx);
 350
 351
 352 /* Sweep the nhg hash tables for old entries on restart */
 353 extern void zebra_nhg_sweep_table(struct hash *hash);
 354
 355 /*
 356  * We are shutting down but the nexthops should be kept
 357  * as that -r has been specified and we don't want to delete
 358  * the routes unintentionally
 359  */
 360 extern void zebra_nhg_mark_keep(void);
 361
 362 /* Nexthop resolution processing */
 363 struct route_entry; /* Forward ref to avoid circular includes */
 364 extern int nexthop_active_update(struct route_node *rn, struct route_entry *re);
 365
 366 #ifdef __cplusplus
 367 }
 368 #endif
 369
 370 #endif  /* __ZEBRA_NHG_H__ */