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 /* This struct is used exclusively for dataplane
  30  * interaction via a dataplane context.
  31  *
  32  * It is designed to mimic the netlink nexthop_grp
  33  * struct in include/linux/nexthop.h
  34  */
  35 struct nh_grp {
  36         uint32_t id;
  37         uint8_t weight;
  38 };
  39
  40 PREDECL_RBTREE_UNIQ(nhg_connected_tree);
  41
  42 /*
  43  * Hashtables contiaining entries found in `zebra_router`.
  44  */
  45
  46 struct nhg_hash_entry {
  47         uint32_t id;
  48         afi_t afi;
  49         vrf_id_t vrf_id;
  50         int type;
  51
  52         struct nexthop_group *nhg;
  53
  54         /* If this is not a group, it
  55          * will be a single nexthop
  56          * and must have an interface
  57          * associated with it.
  58          * Otherwise, this will be null.
  59          */
  60         struct interface *ifp;
  61
  62         uint32_t refcnt;
  63         uint32_t dplane_ref;
  64
  65         uint32_t flags;
  66
  67         /* Dependency tree for other entries.
  68          * For instance a group with two
  69          * nexthops will have two dependencies
  70          * pointing to those nhg_hash_entries.
  71          *
  72          * Using a rb tree here to make lookups
  73          * faster with ID's.
  74          */
  75         struct nhg_connected_tree_head nhg_depends, nhg_dependents;
  76 /*
  77  * Is this nexthop group valid, ie all nexthops are fully resolved.
  78  * What is fully resolved?  It's a nexthop that is either self contained
  79  * and correct( ie no recursive pointer ) or a nexthop that is recursively
  80  * resolved and correct.
  81  */
  82 #define NEXTHOP_GROUP_VALID (1 << 0)
  83 /*
  84  * Has this nexthop group been installed?  At this point in time, this
  85  * means that the data-plane has been told about this nexthop group
  86  * and it's possible usage by a route entry.
  87  */
  88 #define NEXTHOP_GROUP_INSTALLED (1 << 1)
  89 /*
  90  * Has the nexthop group been queued to be send to the FIB?
  91  * The NEXTHOP_GROUP_VALID flag should also be set by this point.
  92  */
  93 #define NEXTHOP_GROUP_QUEUED (1 << 2)
  94 /*
  95  * Is this a nexthop that is recursively resolved?
  96  */
  97 #define NEXTHOP_GROUP_RECURSIVE (1 << 3)
  98 /*
  99  * This is a nexthop group we got from the kernel, it is identical to
 100  * one we already have. (The kernel allows duplicate nexthops, we don't
 101  * since we hash on them). We are only tracking it in our ID table,
 102  * it is unusable by our created routes but may be used by routes we get
 103  * from the kernel. Therefore, it is unhashable.
 104  */
 105 #define NEXTHOP_GROUP_UNHASHABLE (1 << 4)
 106 };
 107
 108 /* Was this one we created, either this session or previously? */
 109 #define ZEBRA_NHG_CREATED(NHE) ((NHE->type) == ZEBRA_ROUTE_NHG)
 110
 111
 112 enum nhg_ctx_op_e {
 113         NHG_CTX_OP_NONE = 0,
 114         NHG_CTX_OP_NEW,
 115         NHG_CTX_OP_DEL,
 116 };
 117
 118 enum nhg_ctx_status {
 119         NHG_CTX_NONE = 0,
 120         NHG_CTX_QUEUED,
 121         NHG_CTX_REQUEUED,
 122         NHG_CTX_SUCCESS,
 123         NHG_CTX_FAILURE,
 124 };
 125
 126 /*
 127  * Context needed to queue nhg updates on the
 128  * work queue.
 129  */
 130 struct nhg_ctx {
 131
 132         /* Unique ID */
 133         uint32_t id;
 134
 135         vrf_id_t vrf_id;
 136         afi_t afi;
 137         /*
 138          * This should only every be ZEBRA_ROUTE_NHG unless we get a a kernel
 139          * created nexthop not made by us.
 140          */
 141         int type;
 142
 143         /* If its a group array, how many? */
 144         uint8_t count;
 145
 146         /* Its either a single nexthop or an array of ID's */
 147         union {
 148                 struct nexthop nh;
 149                 struct nh_grp grp[MULTIPATH_NUM];
 150         } u;
 151
 152         enum nhg_ctx_op_e op;
 153         enum nhg_ctx_status status;
 154 };
 155
 156 /* Global control to disable use of kernel nexthops, if available. We can't
 157  * force the kernel to support nexthop ids, of course, but we can disable
 158  * zebra's use of them, for testing e.g. By default, if the kernel supports
 159  * nexthop ids, zebra uses them.
 160  */
 161 void zebra_nhg_enable_kernel_nexthops(bool set);
 162 bool zebra_nhg_kernel_nexthops_enabled(void);
 163
 164 /**
 165  * NHE abstracted tree functions.
 166  * Use these where possible instead of the direct ones access ones.
 167  */
 168 struct nhg_hash_entry *zebra_nhg_alloc(void);
 169 void zebra_nhg_free(struct nhg_hash_entry *nhe);
 170 /* In order to clear a generic hash, we need a generic api, sigh. */
 171 void zebra_nhg_hash_free(void *p);
 172
 173 extern struct nhg_hash_entry *zebra_nhg_resolve(struct nhg_hash_entry *nhe);
 174
 175 extern unsigned int zebra_nhg_depends_count(const struct nhg_hash_entry *nhe);
 176 extern bool zebra_nhg_depends_is_empty(const struct nhg_hash_entry *nhe);
 177
 178 extern unsigned int
 179 zebra_nhg_dependents_count(const struct nhg_hash_entry *nhe);
 180 extern bool zebra_nhg_dependents_is_empty(const struct nhg_hash_entry *nhe);
 181
 182 /* Lookup ID, doesn't create */
 183 extern struct nhg_hash_entry *zebra_nhg_lookup_id(uint32_t id);
 184
 185 /* Hash functions */
 186 extern uint32_t zebra_nhg_hash_key(const void *arg);
 187 extern uint32_t zebra_nhg_id_key(const void *arg);
 188
 189 extern bool zebra_nhg_hash_equal(const void *arg1, const void *arg2);
 190 extern bool zebra_nhg_hash_id_equal(const void *arg1, const void *arg2);
 191
 192 /*
 193  * Process a context off of a queue.
 194  * Specifically this should be from
 195  * the rib meta queue.
 196  */
 197 extern int nhg_ctx_process(struct nhg_ctx *ctx);
 198
 199 /* Find via kernel nh creation */
 200 extern int zebra_nhg_kernel_find(uint32_t id, struct nexthop *nh,
 201                                  struct nh_grp *grp, uint8_t count,
 202                                  vrf_id_t vrf_id, afi_t afi, int type,
 203                                  int startup);
 204 /* Del via kernel */
 205 extern int zebra_nhg_kernel_del(uint32_t id, vrf_id_t vrf_id);
 206
 207 /* Find via route creation */
 208 extern struct nhg_hash_entry *
 209 zebra_nhg_rib_find(uint32_t id, struct nexthop_group *nhg, afi_t rt_afi);
 210
 211 /* Reference counter functions */
 212 extern void zebra_nhg_decrement_ref(struct nhg_hash_entry *nhe);
 213 extern void zebra_nhg_increment_ref(struct nhg_hash_entry *nhe);
 214
 215 /* Check validity of nhe, if invalid will update dependents as well */
 216 extern void zebra_nhg_check_valid(struct nhg_hash_entry *nhe);
 217
 218 /* Convert nhe depends to a grp context that can be passed around safely */
 219 extern uint8_t zebra_nhg_nhe2grp(struct nh_grp *grp, struct nhg_hash_entry *nhe,
 220                                  int size);
 221
 222 /* Dataplane install/uninstall */
 223 extern void zebra_nhg_install_kernel(struct nhg_hash_entry *nhe);
 224 extern void zebra_nhg_uninstall_kernel(struct nhg_hash_entry *nhe);
 225
 226 /* Forward ref of dplane update context type */
 227 struct zebra_dplane_ctx;
 228 extern void zebra_nhg_dplane_result(struct zebra_dplane_ctx *ctx);
 229
 230
 231 /* Sweet the nhg hash tables for old entries on restart */
 232 extern void zebra_nhg_sweep_table(struct hash *hash);
 233
 234 /* Nexthop resolution processing */
 235 struct route_entry; /* Forward ref to avoid circular includes */
 236 extern int nexthop_active_update(struct route_node *rn, struct route_entry *re);
 237
 238 #endif  /* __ZEBRA_NHG_H__ */