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zebra_nhg.c
2050 lines (1718 loc) · 52.1 KB
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zebra_nhg.c
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/* Zebra Nexthop Group Code.
* Copyright (C) 2019 Cumulus Networks, Inc.
* Donald Sharp
* Stephen Worley
*
* This file is part of FRR.
*
* FRR is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* FRR is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with FRR; see the file COPYING. If not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#include <zebra.h>
#include "lib/nexthop.h"
#include "lib/nexthop_group_private.h"
#include "lib/routemap.h"
#include "lib/mpls.h"
#include "lib/jhash.h"
#include "lib/debug.h"
#include "zebra/connected.h"
#include "zebra/debug.h"
#include "zebra/zebra_router.h"
#include "zebra/zebra_nhg_private.h"
#include "zebra/zebra_rnh.h"
#include "zebra/zebra_routemap.h"
#include "zebra/zebra_memory.h"
#include "zebra/zserv.h"
#include "zebra/rt.h"
#include "zebra_errors.h"
#include "zebra_dplane.h"
#include "zebra/interface.h"
DEFINE_MTYPE_STATIC(ZEBRA, NHG, "Nexthop Group Entry");
DEFINE_MTYPE_STATIC(ZEBRA, NHG_CONNECTED, "Nexthop Group Connected");
DEFINE_MTYPE_STATIC(ZEBRA, NHG_CTX, "Nexthop Group Context");
/* id counter to keep in sync with kernel */
uint32_t id_counter;
/* */
static bool g_nexthops_enabled = true;
static struct nhg_hash_entry *depends_find(const struct nexthop *nh,
afi_t afi);
static void depends_add(struct nhg_connected_tree_head *head,
struct nhg_hash_entry *depend);
static struct nhg_hash_entry *
depends_find_add(struct nhg_connected_tree_head *head, struct nexthop *nh,
afi_t afi);
static struct nhg_hash_entry *
depends_find_id_add(struct nhg_connected_tree_head *head, uint32_t id);
static void depends_decrement_free(struct nhg_connected_tree_head *head);
static void nhg_connected_free(struct nhg_connected *dep)
{
XFREE(MTYPE_NHG_CONNECTED, dep);
}
static struct nhg_connected *nhg_connected_new(struct nhg_hash_entry *nhe)
{
struct nhg_connected *new = NULL;
new = XCALLOC(MTYPE_NHG_CONNECTED, sizeof(struct nhg_connected));
new->nhe = nhe;
return new;
}
void nhg_connected_tree_free(struct nhg_connected_tree_head *head)
{
struct nhg_connected *rb_node_dep = NULL;
if (!nhg_connected_tree_is_empty(head)) {
frr_each_safe(nhg_connected_tree, head, rb_node_dep) {
nhg_connected_tree_del(head, rb_node_dep);
nhg_connected_free(rb_node_dep);
}
}
}
bool nhg_connected_tree_is_empty(const struct nhg_connected_tree_head *head)
{
return nhg_connected_tree_count(head) ? false : true;
}
struct nhg_connected *
nhg_connected_tree_root(struct nhg_connected_tree_head *head)
{
return nhg_connected_tree_first(head);
}
void nhg_connected_tree_del_nhe(struct nhg_connected_tree_head *head,
struct nhg_hash_entry *depend)
{
struct nhg_connected lookup = {};
struct nhg_connected *remove = NULL;
lookup.nhe = depend;
/* Lookup to find the element, then remove it */
remove = nhg_connected_tree_find(head, &lookup);
remove = nhg_connected_tree_del(head, remove);
if (remove)
nhg_connected_free(remove);
}
void nhg_connected_tree_add_nhe(struct nhg_connected_tree_head *head,
struct nhg_hash_entry *depend)
{
struct nhg_connected *new = NULL;
new = nhg_connected_new(depend);
if (new)
nhg_connected_tree_add(head, new);
}
static void
nhg_connected_tree_decrement_ref(struct nhg_connected_tree_head *head)
{
struct nhg_connected *rb_node_dep = NULL;
frr_each_safe(nhg_connected_tree, head, rb_node_dep) {
zebra_nhg_decrement_ref(rb_node_dep->nhe);
}
}
static void
nhg_connected_tree_increment_ref(struct nhg_connected_tree_head *head)
{
struct nhg_connected *rb_node_dep = NULL;
frr_each(nhg_connected_tree, head, rb_node_dep) {
zebra_nhg_increment_ref(rb_node_dep->nhe);
}
}
struct nhg_hash_entry *zebra_nhg_resolve(struct nhg_hash_entry *nhe)
{
if (CHECK_FLAG(nhe->flags, NEXTHOP_GROUP_RECURSIVE)
&& !zebra_nhg_depends_is_empty(nhe)) {
nhe = nhg_connected_tree_root(&nhe->nhg_depends)->nhe;
return zebra_nhg_resolve(nhe);
}
return nhe;
}
unsigned int zebra_nhg_depends_count(const struct nhg_hash_entry *nhe)
{
return nhg_connected_tree_count(&nhe->nhg_depends);
}
bool zebra_nhg_depends_is_empty(const struct nhg_hash_entry *nhe)
{
return nhg_connected_tree_is_empty(&nhe->nhg_depends);
}
static void zebra_nhg_depends_del(struct nhg_hash_entry *from,
struct nhg_hash_entry *depend)
{
nhg_connected_tree_del_nhe(&from->nhg_depends, depend);
}
static void zebra_nhg_depends_init(struct nhg_hash_entry *nhe)
{
nhg_connected_tree_init(&nhe->nhg_depends);
}
unsigned int zebra_nhg_dependents_count(const struct nhg_hash_entry *nhe)
{
return nhg_connected_tree_count(&nhe->nhg_dependents);
}
bool zebra_nhg_dependents_is_empty(const struct nhg_hash_entry *nhe)
{
return nhg_connected_tree_is_empty(&nhe->nhg_dependents);
}
static void zebra_nhg_dependents_del(struct nhg_hash_entry *from,
struct nhg_hash_entry *dependent)
{
nhg_connected_tree_del_nhe(&from->nhg_dependents, dependent);
}
static void zebra_nhg_dependents_add(struct nhg_hash_entry *to,
struct nhg_hash_entry *dependent)
{
nhg_connected_tree_add_nhe(&to->nhg_dependents, dependent);
}
static void zebra_nhg_dependents_init(struct nhg_hash_entry *nhe)
{
nhg_connected_tree_init(&nhe->nhg_dependents);
}
/* Release this nhe from anything depending on it */
static void zebra_nhg_dependents_release(struct nhg_hash_entry *nhe)
{
struct nhg_connected *rb_node_dep = NULL;
frr_each_safe(nhg_connected_tree, &nhe->nhg_dependents, rb_node_dep) {
zebra_nhg_depends_del(rb_node_dep->nhe, nhe);
/* recheck validity of the dependent */
zebra_nhg_check_valid(rb_node_dep->nhe);
}
}
/* Release this nhe from anything that it depends on */
static void zebra_nhg_depends_release(struct nhg_hash_entry *nhe)
{
if (!zebra_nhg_depends_is_empty(nhe)) {
struct nhg_connected *rb_node_dep = NULL;
frr_each_safe(nhg_connected_tree, &nhe->nhg_depends,
rb_node_dep) {
zebra_nhg_dependents_del(rb_node_dep->nhe, nhe);
}
}
}
struct nhg_hash_entry *zebra_nhg_lookup_id(uint32_t id)
{
struct nhg_hash_entry lookup = {};
lookup.id = id;
return hash_lookup(zrouter.nhgs_id, &lookup);
}
static int zebra_nhg_insert_id(struct nhg_hash_entry *nhe)
{
if (hash_lookup(zrouter.nhgs_id, nhe)) {
flog_err(
EC_ZEBRA_NHG_TABLE_INSERT_FAILED,
"Failed inserting NHG id=%u into the ID hash table, entry already exists",
nhe->id);
return -1;
}
hash_get(zrouter.nhgs_id, nhe, hash_alloc_intern);
return 0;
}
static void zebra_nhg_set_if(struct nhg_hash_entry *nhe, struct interface *ifp)
{
nhe->ifp = ifp;
if_nhg_dependents_add(ifp, nhe);
}
static void
zebra_nhg_connect_depends(struct nhg_hash_entry *nhe,
struct nhg_connected_tree_head nhg_depends)
{
struct nhg_connected *rb_node_dep = NULL;
/* This has been allocated higher above in the stack. Could probably
* re-allocate and free the old stuff but just using the same memory
* for now. Otherwise, their might be a time trade-off for repeated
* alloc/frees as startup.
*/
nhe->nhg_depends = nhg_depends;
/* Attach backpointer to anything that it depends on */
zebra_nhg_dependents_init(nhe);
if (!zebra_nhg_depends_is_empty(nhe)) {
frr_each(nhg_connected_tree, &nhe->nhg_depends, rb_node_dep) {
zebra_nhg_dependents_add(rb_node_dep->nhe, nhe);
}
}
/* Add the ifp now if its not a group or recursive and has ifindex */
if (zebra_nhg_depends_is_empty(nhe) && nhe->nhg->nexthop
&& nhe->nhg->nexthop->ifindex) {
struct interface *ifp = NULL;
ifp = if_lookup_by_index(nhe->nhg->nexthop->ifindex,
nhe->nhg->nexthop->vrf_id);
if (ifp)
zebra_nhg_set_if(nhe, ifp);
else
flog_err(
EC_ZEBRA_IF_LOOKUP_FAILED,
"Zebra failed to lookup an interface with ifindex=%d in vrf=%u for NHE id=%u",
nhe->nhg->nexthop->ifindex,
nhe->nhg->nexthop->vrf_id, nhe->id);
}
}
struct nhg_hash_entry *zebra_nhg_alloc(void)
{
struct nhg_hash_entry *nhe;
nhe = XCALLOC(MTYPE_NHG, sizeof(struct nhg_hash_entry));
return nhe;
}
static struct nhg_hash_entry *zebra_nhg_copy(const struct nhg_hash_entry *copy,
uint32_t id)
{
struct nhg_hash_entry *nhe;
nhe = zebra_nhg_alloc();
nhe->id = id;
nhe->nhg = nexthop_group_new();
nexthop_group_copy(nhe->nhg, copy->nhg);
nhe->vrf_id = copy->vrf_id;
nhe->afi = copy->afi;
nhe->type = copy->type ? copy->type : ZEBRA_ROUTE_NHG;
nhe->refcnt = 0;
nhe->dplane_ref = zebra_router_get_next_sequence();
return nhe;
}
/* Allocation via hash handler */
static void *zebra_nhg_hash_alloc(void *arg)
{
struct nhg_hash_entry *nhe = NULL;
struct nhg_hash_entry *copy = arg;
nhe = zebra_nhg_copy(copy, copy->id);
/* Mark duplicate nexthops in a group at creation time. */
nexthop_group_mark_duplicates(nhe->nhg);
zebra_nhg_connect_depends(nhe, copy->nhg_depends);
zebra_nhg_insert_id(nhe);
return nhe;
}
uint32_t zebra_nhg_hash_key(const void *arg)
{
const struct nhg_hash_entry *nhe = arg;
uint32_t key = 0x5a351234;
key = jhash_3words(nhe->vrf_id, nhe->afi, nexthop_group_hash(nhe->nhg),
key);
return key;
}
uint32_t zebra_nhg_id_key(const void *arg)
{
const struct nhg_hash_entry *nhe = arg;
return nhe->id;
}
bool zebra_nhg_hash_equal(const void *arg1, const void *arg2)
{
const struct nhg_hash_entry *nhe1 = arg1;
const struct nhg_hash_entry *nhe2 = arg2;
struct nexthop *nexthop1;
struct nexthop *nexthop2;
/* No matter what if they equal IDs, assume equal */
if (nhe1->id && nhe2->id && (nhe1->id == nhe2->id))
return true;
if (nhe1->vrf_id != nhe2->vrf_id)
return false;
if (nhe1->afi != nhe2->afi)
return false;
/* Nexthops should be sorted */
for (nexthop1 = nhe1->nhg->nexthop, nexthop2 = nhe2->nhg->nexthop;
nexthop1 || nexthop2;
nexthop1 = nexthop1->next, nexthop2 = nexthop2->next) {
if (nexthop1 && !nexthop2)
return false;
if (!nexthop1 && nexthop2)
return false;
/*
* We have to check the active flag of each individual one,
* not just the overall active_num. This solves the special case
* issue of a route with a nexthop group with one nexthop
* resolving to itself and thus marking it inactive. If we
* have two different routes each wanting to mark a different
* nexthop inactive, they need to hash to two different groups.
*
* If we just hashed on num_active, they would hash the same
* which is incorrect.
*
* ex)
* 1.1.1.0/24
* -> 1.1.1.1 dummy1 (inactive)
* -> 1.1.2.1 dummy2
*
* 1.1.2.0/24
* -> 1.1.1.1 dummy1
* -> 1.1.2.1 dummy2 (inactive)
*
* Without checking each individual one, they would hash to
* the same group and both have 1.1.1.1 dummy1 marked inactive.
*
*/
if (CHECK_FLAG(nexthop1->flags, NEXTHOP_FLAG_ACTIVE)
!= CHECK_FLAG(nexthop2->flags, NEXTHOP_FLAG_ACTIVE))
return false;
if (!nexthop_same(nexthop1, nexthop2))
return false;
}
return true;
}
bool zebra_nhg_hash_id_equal(const void *arg1, const void *arg2)
{
const struct nhg_hash_entry *nhe1 = arg1;
const struct nhg_hash_entry *nhe2 = arg2;
return nhe1->id == nhe2->id;
}
static int zebra_nhg_process_grp(struct nexthop_group *nhg,
struct nhg_connected_tree_head *depends,
struct nh_grp *grp, uint8_t count)
{
nhg_connected_tree_init(depends);
for (int i = 0; i < count; i++) {
struct nhg_hash_entry *depend = NULL;
/* We do not care about nexthop_grp.weight at
* this time. But we should figure out
* how to adapt this to our code in
* the future.
*/
depend = depends_find_id_add(depends, grp[i].id);
if (!depend) {
flog_err(
EC_ZEBRA_NHG_SYNC,
"Received Nexthop Group from the kernel with a dependent Nexthop ID (%u) which we do not have in our table",
grp[i].id);
return -1;
}
/*
* If this is a nexthop with its own group
* dependencies, add them as well. Not sure its
* even possible to have a group within a group
* in the kernel.
*/
copy_nexthops(&nhg->nexthop, depend->nhg->nexthop, NULL);
}
return 0;
}
static void handle_recursive_depend(struct nhg_connected_tree_head *nhg_depends,
struct nexthop *nh, afi_t afi)
{
struct nhg_hash_entry *depend = NULL;
struct nexthop_group resolved_ng = {};
resolved_ng.nexthop = nh;
depend = zebra_nhg_rib_find(0, &resolved_ng, afi);
depends_add(nhg_depends, depend);
}
static bool zebra_nhg_find(struct nhg_hash_entry **nhe, uint32_t id,
struct nexthop_group *nhg,
struct nhg_connected_tree_head *nhg_depends,
vrf_id_t vrf_id, afi_t afi, int type)
{
struct nhg_hash_entry lookup = {};
uint32_t old_id_counter = id_counter;
bool created = false;
bool recursive = false;
/*
* If it has an id at this point, we must have gotten it from the kernel
*/
lookup.id = id ? id : ++id_counter;
lookup.type = type ? type : ZEBRA_ROUTE_NHG;
lookup.nhg = nhg;
lookup.vrf_id = vrf_id;
if (lookup.nhg->nexthop->next) {
/* Groups can have all vrfs and AF's in them */
lookup.afi = AFI_UNSPEC;
lookup.vrf_id = 0;
} else {
switch (lookup.nhg->nexthop->type) {
case (NEXTHOP_TYPE_IFINDEX):
case (NEXTHOP_TYPE_BLACKHOLE):
/*
* This switch case handles setting the afi different
* for ipv4/v6 routes. Ifindex/blackhole nexthop
* objects cannot be ambiguous, they must be Address
* Family specific. If we get here, we will either use
* the AF of the route, or the one we got passed from
* here from the kernel.
*/
lookup.afi = afi;
break;
case (NEXTHOP_TYPE_IPV4_IFINDEX):
case (NEXTHOP_TYPE_IPV4):
lookup.afi = AFI_IP;
break;
case (NEXTHOP_TYPE_IPV6_IFINDEX):
case (NEXTHOP_TYPE_IPV6):
lookup.afi = AFI_IP6;
break;
}
}
if (id)
(*nhe) = zebra_nhg_lookup_id(id);
else
(*nhe) = hash_lookup(zrouter.nhgs, &lookup);
/* If it found an nhe in our tables, this new ID is unused */
if (*nhe)
id_counter = old_id_counter;
if (!(*nhe)) {
/* Only hash/lookup the depends if the first lookup
* fails to find something. This should hopefully save a
* lot of cycles for larger ecmp sizes.
*/
if (nhg_depends)
/* If you don't want to hash on each nexthop in the
* nexthop group struct you can pass the depends
* directly. Kernel-side we do this since it just looks
* them up via IDs.
*/
lookup.nhg_depends = *nhg_depends;
else {
if (nhg->nexthop->next) {
zebra_nhg_depends_init(&lookup);
/* If its a group, create a dependency tree */
struct nexthop *nh = NULL;
for (nh = nhg->nexthop; nh; nh = nh->next)
depends_find_add(&lookup.nhg_depends,
nh, afi);
} else if (CHECK_FLAG(nhg->nexthop->flags,
NEXTHOP_FLAG_RECURSIVE)) {
zebra_nhg_depends_init(&lookup);
handle_recursive_depend(&lookup.nhg_depends,
nhg->nexthop->resolved,
afi);
recursive = true;
}
}
(*nhe) = hash_get(zrouter.nhgs, &lookup, zebra_nhg_hash_alloc);
created = true;
if (recursive)
SET_FLAG((*nhe)->flags, NEXTHOP_GROUP_RECURSIVE);
}
return created;
}
/* Find/create a single nexthop */
static struct nhg_hash_entry *
zebra_nhg_find_nexthop(uint32_t id, struct nexthop *nh, afi_t afi, int type)
{
struct nhg_hash_entry *nhe = NULL;
struct nexthop_group nhg = {};
vrf_id_t vrf_id = !vrf_is_backend_netns() ? VRF_DEFAULT : nh->vrf_id;
nexthop_group_add_sorted(&nhg, nh);
zebra_nhg_find(&nhe, id, &nhg, NULL, vrf_id, afi, type);
return nhe;
}
static uint32_t nhg_ctx_get_id(const struct nhg_ctx *ctx)
{
return ctx->id;
}
static void nhg_ctx_set_status(struct nhg_ctx *ctx, enum nhg_ctx_status status)
{
ctx->status = status;
}
static enum nhg_ctx_status nhg_ctx_get_status(const struct nhg_ctx *ctx)
{
return ctx->status;
}
static void nhg_ctx_set_op(struct nhg_ctx *ctx, enum nhg_ctx_op_e op)
{
ctx->op = op;
}
static enum nhg_ctx_op_e nhg_ctx_get_op(const struct nhg_ctx *ctx)
{
return ctx->op;
}
static vrf_id_t nhg_ctx_get_vrf_id(const struct nhg_ctx *ctx)
{
return ctx->vrf_id;
}
static int nhg_ctx_get_type(const struct nhg_ctx *ctx)
{
return ctx->type;
}
static int nhg_ctx_get_afi(const struct nhg_ctx *ctx)
{
return ctx->afi;
}
static struct nexthop *nhg_ctx_get_nh(struct nhg_ctx *ctx)
{
return &ctx->u.nh;
}
static uint8_t nhg_ctx_get_count(const struct nhg_ctx *ctx)
{
return ctx->count;
}
static struct nh_grp *nhg_ctx_get_grp(struct nhg_ctx *ctx)
{
return ctx->u.grp;
}
static struct nhg_ctx *nhg_ctx_new()
{
struct nhg_ctx *new = NULL;
new = XCALLOC(MTYPE_NHG_CTX, sizeof(struct nhg_ctx));
return new;
}
static void nhg_ctx_free(struct nhg_ctx **ctx)
{
struct nexthop *nh;
if (ctx == NULL)
return;
assert((*ctx) != NULL);
if (nhg_ctx_get_count(*ctx))
goto done;
nh = nhg_ctx_get_nh(*ctx);
nexthop_del_labels(nh);
done:
XFREE(MTYPE_NHG_CTX, *ctx);
*ctx = NULL;
}
static struct nhg_ctx *nhg_ctx_init(uint32_t id, struct nexthop *nh,
struct nh_grp *grp, vrf_id_t vrf_id,
afi_t afi, int type, uint8_t count)
{
struct nhg_ctx *ctx = NULL;
ctx = nhg_ctx_new();
ctx->id = id;
ctx->vrf_id = vrf_id;
ctx->afi = afi;
ctx->type = type;
ctx->count = count;
if (count)
/* Copy over the array */
memcpy(&ctx->u.grp, grp, count * sizeof(struct nh_grp));
else if (nh)
ctx->u.nh = *nh;
return ctx;
}
static bool zebra_nhg_contains_unhashable(struct nhg_hash_entry *nhe)
{
struct nhg_connected *rb_node_dep = NULL;
frr_each(nhg_connected_tree, &nhe->nhg_depends, rb_node_dep) {
if (CHECK_FLAG(rb_node_dep->nhe->flags,
NEXTHOP_GROUP_UNHASHABLE))
return true;
}
return false;
}
static void zebra_nhg_set_unhashable(struct nhg_hash_entry *nhe)
{
SET_FLAG(nhe->flags, NEXTHOP_GROUP_UNHASHABLE);
SET_FLAG(nhe->flags, NEXTHOP_GROUP_INSTALLED);
flog_warn(
EC_ZEBRA_DUPLICATE_NHG_MESSAGE,
"Nexthop Group with ID (%d) is a duplicate, therefore unhashable, ignoring",
nhe->id);
}
static void zebra_nhg_set_valid(struct nhg_hash_entry *nhe)
{
struct nhg_connected *rb_node_dep;
SET_FLAG(nhe->flags, NEXTHOP_GROUP_VALID);
frr_each(nhg_connected_tree, &nhe->nhg_dependents, rb_node_dep)
zebra_nhg_set_valid(rb_node_dep->nhe);
}
static void zebra_nhg_set_invalid(struct nhg_hash_entry *nhe)
{
struct nhg_connected *rb_node_dep;
UNSET_FLAG(nhe->flags, NEXTHOP_GROUP_VALID);
/* Update validity of nexthops depending on it */
frr_each(nhg_connected_tree, &nhe->nhg_dependents, rb_node_dep)
zebra_nhg_check_valid(rb_node_dep->nhe);
}
void zebra_nhg_check_valid(struct nhg_hash_entry *nhe)
{
struct nhg_connected *rb_node_dep = NULL;
bool valid = false;
/* If anthing else in the group is valid, the group is valid */
frr_each(nhg_connected_tree, &nhe->nhg_depends, rb_node_dep) {
if (CHECK_FLAG(rb_node_dep->nhe->flags, NEXTHOP_GROUP_VALID)) {
valid = true;
goto done;
}
}
done:
if (valid)
zebra_nhg_set_valid(nhe);
else
zebra_nhg_set_invalid(nhe);
}
static void zebra_nhg_release(struct nhg_hash_entry *nhe)
{
/* Remove it from any lists it may be on */
zebra_nhg_depends_release(nhe);
zebra_nhg_dependents_release(nhe);
if (nhe->ifp)
if_nhg_dependents_del(nhe->ifp, nhe);
/*
* If its unhashable, we didn't store it here and have to be
* sure we don't clear one thats actually being used.
*/
if (!CHECK_FLAG(nhe->flags, NEXTHOP_GROUP_UNHASHABLE))
hash_release(zrouter.nhgs, nhe);
hash_release(zrouter.nhgs_id, nhe);
}
static void zebra_nhg_handle_uninstall(struct nhg_hash_entry *nhe)
{
zebra_nhg_release(nhe);
zebra_nhg_free(nhe);
}
static void zebra_nhg_handle_install(struct nhg_hash_entry *nhe)
{
/* Update validity of groups depending on it */
struct nhg_connected *rb_node_dep;
frr_each_safe(nhg_connected_tree, &nhe->nhg_dependents, rb_node_dep)
zebra_nhg_set_valid(rb_node_dep->nhe);
}
/*
* The kernel/other program has changed the state of a nexthop object we are
* using.
*/
static void zebra_nhg_handle_kernel_state_change(struct nhg_hash_entry *nhe,
bool is_delete)
{
if (nhe->refcnt) {
flog_err(
EC_ZEBRA_NHG_SYNC,
"Kernel %s a nexthop group with ID (%u) that we are still using for a route, sending it back down",
(is_delete ? "deleted" : "updated"), nhe->id);
UNSET_FLAG(nhe->flags, NEXTHOP_GROUP_INSTALLED);
zebra_nhg_install_kernel(nhe);
} else
zebra_nhg_handle_uninstall(nhe);
}
static int nhg_ctx_process_new(struct nhg_ctx *ctx)
{
struct nexthop_group *nhg = NULL;
struct nhg_connected_tree_head nhg_depends = {};
struct nhg_hash_entry *lookup = NULL;
struct nhg_hash_entry *nhe = NULL;
uint32_t id = nhg_ctx_get_id(ctx);
uint8_t count = nhg_ctx_get_count(ctx);
vrf_id_t vrf_id = nhg_ctx_get_vrf_id(ctx);
int type = nhg_ctx_get_type(ctx);
afi_t afi = nhg_ctx_get_afi(ctx);
lookup = zebra_nhg_lookup_id(id);
if (lookup) {
/* This is already present in our table, hence an update
* that we did not initate.
*/
zebra_nhg_handle_kernel_state_change(lookup, false);
return 0;
}
if (nhg_ctx_get_count(ctx)) {
nhg = nexthop_group_new();
if (zebra_nhg_process_grp(nhg, &nhg_depends,
nhg_ctx_get_grp(ctx), count)) {
depends_decrement_free(&nhg_depends);
nexthop_group_delete(&nhg);
return -ENOENT;
}
if (!zebra_nhg_find(&nhe, id, nhg, &nhg_depends, vrf_id, type,
afi))
depends_decrement_free(&nhg_depends);
/* These got copied over in zebra_nhg_alloc() */
nexthop_group_delete(&nhg);
} else
nhe = zebra_nhg_find_nexthop(id, nhg_ctx_get_nh(ctx), afi,
type);
if (nhe) {
if (id != nhe->id) {
struct nhg_hash_entry *kernel_nhe = NULL;
/* Duplicate but with different ID from
* the kernel
*/
/* The kernel allows duplicate nexthops
* as long as they have different IDs.
* We are ignoring those to prevent
* syncing problems with the kernel
* changes.
*
* We maintain them *ONLY* in the ID hash table to
* track them and set the flag to indicated
* their attributes are unhashable.
*/
kernel_nhe = zebra_nhg_copy(nhe, id);
zebra_nhg_insert_id(kernel_nhe);
zebra_nhg_set_unhashable(kernel_nhe);
} else if (zebra_nhg_contains_unhashable(nhe)) {
/* The group we got contains an unhashable/duplicated
* depend, so lets mark this group as unhashable as well
* and release it from the non-ID hash.
*/
hash_release(zrouter.nhgs, nhe);
zebra_nhg_set_unhashable(nhe);
} else {
/* It actually created a new nhe */
SET_FLAG(nhe->flags, NEXTHOP_GROUP_VALID);
SET_FLAG(nhe->flags, NEXTHOP_GROUP_INSTALLED);
}
} else {
flog_err(
EC_ZEBRA_TABLE_LOOKUP_FAILED,
"Zebra failed to find or create a nexthop hash entry for ID (%u)",
id);
return -1;
}
return 0;
}
static int nhg_ctx_process_del(struct nhg_ctx *ctx)
{
struct nhg_hash_entry *nhe = NULL;
uint32_t id = nhg_ctx_get_id(ctx);
nhe = zebra_nhg_lookup_id(id);
if (!nhe) {
flog_warn(
EC_ZEBRA_BAD_NHG_MESSAGE,
"Kernel delete message received for nexthop group ID (%u) that we do not have in our ID table",
id);
return -1;
}
zebra_nhg_handle_kernel_state_change(nhe, true);
return 0;
}
static void nhg_ctx_fini(struct nhg_ctx **ctx)
{
/*
* Just freeing for now, maybe do something more in the future
* based on flag.
*/
nhg_ctx_free(ctx);
}
static int queue_add(struct nhg_ctx *ctx)
{
/* If its queued or already processed do nothing */
if (nhg_ctx_get_status(ctx) == NHG_CTX_QUEUED)
return 0;
if (rib_queue_nhg_add(ctx)) {
nhg_ctx_set_status(ctx, NHG_CTX_FAILURE);
return -1;
}
nhg_ctx_set_status(ctx, NHG_CTX_QUEUED);
return 0;
}
int nhg_ctx_process(struct nhg_ctx *ctx)
{
int ret = 0;
switch (nhg_ctx_get_op(ctx)) {
case NHG_CTX_OP_NEW:
ret = nhg_ctx_process_new(ctx);
if (nhg_ctx_get_count(ctx) && ret == -ENOENT
&& nhg_ctx_get_status(ctx) != NHG_CTX_REQUEUED) {
/**
* We have entered a situation where we are
* processing a group from the kernel
* that has a contained nexthop which
* we have not yet processed.
*
* Re-enqueue this ctx to be handled exactly one
* more time (indicated by the flag).
*
* By the time we get back to it, we
* should have processed its depends.
*/
nhg_ctx_set_status(ctx, NHG_CTX_NONE);
if (queue_add(ctx) == 0) {
nhg_ctx_set_status(ctx, NHG_CTX_REQUEUED);
return 0;
}
}
break;
case NHG_CTX_OP_DEL:
ret = nhg_ctx_process_del(ctx);
case NHG_CTX_OP_NONE:
break;
}
nhg_ctx_set_status(ctx, (ret ? NHG_CTX_FAILURE : NHG_CTX_SUCCESS));
nhg_ctx_fini(&ctx);