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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IS-IS Rout(e)ing protocol - BFD support
* Copyright (C) 2018 Christian Franke
*/
#include <zebra.h>
#include "zclient.h"
#include "nexthop.h"
#include "bfd.h"
#include "lib_errors.h"
#include "isisd/isis_bfd.h"
#include "isisd/isis_zebra.h"
#include "isisd/isis_common.h"
#include "isisd/isis_constants.h"
#include "isisd/isis_adjacency.h"
#include "isisd/isis_circuit.h"
#include "isisd/isisd.h"
#include "isisd/fabricd.h"
DEFINE_MTYPE_STATIC(ISISD, BFD_SESSION, "ISIS BFD Session");
static void adj_bfd_cb(struct bfd_session_params *bsp,
const struct bfd_session_status *bss, void *arg)
{
struct isis_adjacency *adj = arg;
if (IS_DEBUG_BFD)
zlog_debug(
"ISIS-BFD: BFD changed status for adjacency %s old %s new %s",
isis_adj_name(adj),
bfd_get_status_str(bss->previous_state),
bfd_get_status_str(bss->state));
if (bss->state == BFD_STATUS_DOWN
&& bss->previous_state == BFD_STATUS_UP) {
adj->circuit->area->bfd_signalled_down = true;
isis_adj_state_change(&adj, ISIS_ADJ_DOWN,
"bfd session went down");
}
}
static void bfd_handle_adj_down(struct isis_adjacency *adj)
{
bfd_sess_free(&adj->bfd_session);
}
static void bfd_handle_adj_up(struct isis_adjacency *adj)
{
struct isis_circuit *circuit = adj->circuit;
int family;
union g_addr dst_ip;
union g_addr src_ip;
struct list *local_ips;
struct prefix *local_ip;
if (!circuit->bfd_config.enabled) {
if (IS_DEBUG_BFD)
zlog_debug(
"ISIS-BFD: skipping BFD initialization on adjacency with %s because BFD is not enabled for the circuit",
isis_adj_name(adj));
goto out;
}
/* If IS-IS IPv6 is configured wait for IPv6 address to be programmed
* before starting up BFD
*/
if (circuit->ipv6_router
&& (listcount(circuit->ipv6_link) == 0
|| adj->ll_ipv6_count == 0)) {
if (IS_DEBUG_BFD)
zlog_debug(
"ISIS-BFD: skipping BFD initialization on adjacency with %s because IPv6 is enabled but not ready",
isis_adj_name(adj));
return;
}
/*
* If IS-IS is enabled for both IPv4 and IPv6 on the circuit, prefer
* creating a BFD session over IPv6.
*/
if (circuit->ipv6_router && adj->ll_ipv6_count) {
family = AF_INET6;
dst_ip.ipv6 = adj->ll_ipv6_addrs[0];
local_ips = circuit->ipv6_link;
if (list_isempty(local_ips)) {
if (IS_DEBUG_BFD)
zlog_debug(
"ISIS-BFD: skipping BFD initialization: IPv6 enabled and no local IPv6 addresses");
goto out;
}
local_ip = listgetdata(listhead(local_ips));
src_ip.ipv6 = local_ip->u.prefix6;
} else if (circuit->ip_router && adj->ipv4_address_count) {
family = AF_INET;
dst_ip.ipv4 = adj->ipv4_addresses[0];
local_ips = fabricd_ip_addrs(adj->circuit);
if (!local_ips || list_isempty(local_ips)) {
if (IS_DEBUG_BFD)
zlog_debug(
"ISIS-BFD: skipping BFD initialization: IPv4 enabled and no local IPv4 addresses");
goto out;
}
local_ip = listgetdata(listhead(local_ips));
src_ip.ipv4 = local_ip->u.prefix4;
} else
goto out;
if (adj->bfd_session == NULL)
adj->bfd_session = bfd_sess_new(adj_bfd_cb, adj);
bfd_sess_set_timers(adj->bfd_session, BFD_DEF_DETECT_MULT,
BFD_DEF_MIN_RX, BFD_DEF_MIN_TX);
if (family == AF_INET)
bfd_sess_set_ipv4_addrs(adj->bfd_session, &src_ip.ipv4,
&dst_ip.ipv4);
else
bfd_sess_set_ipv6_addrs(adj->bfd_session, &src_ip.ipv6,
&dst_ip.ipv6);
bfd_sess_set_interface(adj->bfd_session, adj->circuit->interface->name);
bfd_sess_set_vrf(adj->bfd_session,
adj->circuit->interface->vrf->vrf_id);
bfd_sess_set_profile(adj->bfd_session, circuit->bfd_config.profile);
bfd_sess_install(adj->bfd_session);
return;
out:
bfd_handle_adj_down(adj);
}
static int bfd_handle_adj_state_change(struct isis_adjacency *adj)
{
if (adj->adj_state == ISIS_ADJ_UP)
bfd_handle_adj_up(adj);
else
bfd_handle_adj_down(adj);
return 0;
}
static void bfd_adj_cmd(struct isis_adjacency *adj)
{
if (adj->adj_state == ISIS_ADJ_UP && adj->circuit->bfd_config.enabled)
bfd_handle_adj_up(adj);
else
bfd_handle_adj_down(adj);
}
void isis_bfd_circuit_cmd(struct isis_circuit *circuit)
{
switch (circuit->circ_type) {
case CIRCUIT_T_BROADCAST:
for (int level = ISIS_LEVEL1; level <= ISIS_LEVEL2; level++) {
struct list *adjdb = circuit->u.bc.adjdb[level - 1];
struct listnode *node;
struct isis_adjacency *adj;
if (!adjdb)
continue;
for (ALL_LIST_ELEMENTS_RO(adjdb, node, adj))
bfd_adj_cmd(adj);
}
break;
case CIRCUIT_T_P2P:
if (circuit->u.p2p.neighbor)
bfd_adj_cmd(circuit->u.p2p.neighbor);
break;
default:
break;
}
}
static int bfd_handle_adj_ip_enabled(struct isis_adjacency *adj, int family,
bool global)
{
if (family != AF_INET6 || global)
return 0;
if (adj->bfd_session)
return 0;
if (adj->adj_state != ISIS_ADJ_UP)
return 0;
bfd_handle_adj_up(adj);
return 0;
}
static int bfd_handle_circuit_add_addr(struct isis_circuit *circuit)
{
struct isis_adjacency *adj;
struct listnode *node;
if (circuit->area == NULL)
return 0;
for (ALL_LIST_ELEMENTS_RO(circuit->area->adjacency_list, node, adj)) {
if (adj->bfd_session)
continue;
if (adj->adj_state != ISIS_ADJ_UP)
continue;
bfd_handle_adj_up(adj);
}
return 0;
}
void isis_bfd_init(struct event_loop *tm)
{
bfd_protocol_integration_init(zclient, tm);
hook_register(isis_adj_state_change_hook, bfd_handle_adj_state_change);
hook_register(isis_adj_ip_enabled_hook, bfd_handle_adj_ip_enabled);
hook_register(isis_circuit_add_addr_hook, bfd_handle_circuit_add_addr);
}
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