diff options
Diffstat (limited to 'isisd/isis_bfd.c')
| -rw-r--r-- | isisd/isis_bfd.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/isisd/isis_bfd.c b/isisd/isis_bfd.c new file mode 100644 index 0000000..5e24e35 --- /dev/null +++ b/isisd/isis_bfd.c @@ -0,0 +1,219 @@ +// 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); +} |