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Diffstat (limited to 'src/vnet/adj/adj_bfd.c')
| -rw-r--r-- | src/vnet/adj/adj_bfd.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/vnet/adj/adj_bfd.c b/src/vnet/adj/adj_bfd.c new file mode 100644 index 00000000..3d294c46 --- /dev/null +++ b/src/vnet/adj/adj_bfd.c @@ -0,0 +1,184 @@ +/* + * Copyright (c) 2016 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <vnet/bfd/bfd_main.h> + +#include <vnet/adj/adj_delegate.h> +#include <vnet/adj/adj_nbr.h> +#include <vnet/fib/fib_walk.h> + +static adj_bfd_state_t +adj_bfd_bfd_state_to_fib (bfd_state_e bstate) +{ + switch (bstate) + { + case BFD_STATE_up: + return (ADJ_BFD_STATE_UP); + case BFD_STATE_down: + case BFD_STATE_admin_down: + case BFD_STATE_init: + return (ADJ_BFD_STATE_DOWN); + } + return (ADJ_BFD_STATE_DOWN); +} + +static void +adj_bfd_update_walk (adj_index_t ai) +{ + /* + * initiate a backwalk of dependent children + * to notify of the state change of this adj. + */ + fib_node_back_walk_ctx_t ctx = { + .fnbw_reason = FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE, + }; + fib_walk_sync(FIB_NODE_TYPE_ADJ, ai, &ctx); +} + +/** + * @brief Callback function registered with BFD module to receive notifications + * of the CRUD of BFD sessions + * would be static but for the fact it's called from the unit-tests + */ +void +adj_bfd_notify (bfd_listen_event_e event, + const bfd_session_t *session) +{ + const bfd_udp_key_t *key; + fib_protocol_t fproto; + adj_delegate_t *aed; + adj_index_t ai; + + if (BFD_HOP_TYPE_SINGLE != session->hop_type) + { + /* + * multi-hop BFD sessions attach directly to the FIB entry + * single-hop adj to the associate adjacency. + */ + return; + } + + key = &session->udp.key; + + fproto = (ip46_address_is_ip4 (&key->peer_addr) ? + FIB_PROTOCOL_IP4: + FIB_PROTOCOL_IP6); + + /* + * find the adj that corresponds to the BFD session. + */ + ai = adj_nbr_add_or_lock(fproto, + fib_proto_to_link(fproto), + &key->peer_addr, + key->sw_if_index); + + switch (event) + { + case BFD_LISTEN_EVENT_CREATE: + /* + * The creation of a new session + */ + if ((ADJ_INDEX_INVALID != ai) && + (aed = adj_delegate_get(adj_get(ai), + ADJ_DELEGATE_BFD))) + { + /* + * already got state for this adj + */ + } + else + { + /* + * lock the adj. add the delegate. + * Lockinging the adj prevents it being removed and thus maintains + * the BFD derived states + */ + adj_lock(ai); + + aed = adj_delegate_find_or_add(adj_get(ai), ADJ_DELEGATE_BFD); + + /* + * pretend the session is up and skip the walk. + * If we set it down then we get traffic loss on new children. + * if we walk then we lose traffic for existing children. Wait + * for the first BFD UP/DOWN before we let the session's state + * influence forwarding. + */ + aed->ad_bfd_state = ADJ_BFD_STATE_UP; + aed->ad_bfd_index = session->bs_idx; + } + break; + + case BFD_LISTEN_EVENT_UPDATE: + /* + * state change up/dowm and + */ + aed = adj_delegate_get(adj_get(ai), ADJ_DELEGATE_BFD); + + if (NULL != aed) + { + aed->ad_bfd_state = adj_bfd_bfd_state_to_fib(session->local_state); + adj_bfd_update_walk(ai); + } + /* + * else + * not an adj with BFD state + */ + break; + + case BFD_LISTEN_EVENT_DELETE: + /* + * session has been removed. + */ + + if (adj_delegate_get(adj_get(ai), ADJ_DELEGATE_BFD)) + { + /* + * has an associated BFD tracking delegate + * remove the BFD tracking deletgate, update children, then + * unlock the adj + */ + adj_delegate_remove(adj_get(ai), ADJ_DELEGATE_BFD); + + adj_bfd_update_walk(ai); + adj_unlock(ai); + } + /* + * else + * no BFD associated state + */ + break; + } + + /* + * unlock match of the add-or-lock at the start + */ + adj_unlock(ai); +} + +static clib_error_t * +adj_bfd_main_init (vlib_main_t * vm) +{ + clib_error_t * error = NULL; + + if ((error = vlib_call_init_function (vm, bfd_main_init))) + return (error); + + bfd_register_listener(adj_bfd_notify); + + return (error); +} + +VLIB_INIT_FUNCTION (adj_bfd_main_init); |