diff options
Diffstat (limited to 'src/vnet/fib/fib_bfd.c')
| -rw-r--r-- | src/vnet/fib/fib_bfd.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/src/vnet/fib/fib_bfd.c b/src/vnet/fib/fib_bfd.c new file mode 100644 index 00000000..734ee8cc --- /dev/null +++ b/src/vnet/fib/fib_bfd.c @@ -0,0 +1,196 @@ +/* + * 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/fib/fib_entry_delegate.h> +#include <vnet/fib/fib_entry.h> +#include <vnet/fib/fib_table.h> +#include <vnet/fib/fib_walk.h> + +static fib_bfd_state_t +fib_bfd_bfd_state_to_fib (bfd_state_e bstate) +{ + switch (bstate) + { + case BFD_STATE_up: + return (FIB_BFD_STATE_UP); + case BFD_STATE_down: + case BFD_STATE_admin_down: + case BFD_STATE_init: + return (FIB_BFD_STATE_DOWN); + } + return (FIB_BFD_STATE_DOWN); +} + +static void +fib_bfd_update_walk (fib_node_index_t fei) +{ + /* + * initiate a backwalk of dependent children + * to notify of the state change of this entry. + */ + fib_node_back_walk_ctx_t ctx = { + .fnbw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE, + }; + fib_walk_sync(FIB_NODE_TYPE_ENTRY, fei, &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 +fib_bfd_notify (bfd_listen_event_e event, + const bfd_session_t *session) +{ + fib_entry_delegate_t *fed; + const bfd_udp_key_t *key; + fib_node_index_t fei; + + if (BFD_HOP_TYPE_MULTI != 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; + + fib_prefix_t pfx = { + .fp_addr = key->peer_addr, + .fp_proto = (ip46_address_is_ip4 (&key->peer_addr) ? + FIB_PROTOCOL_IP4: + FIB_PROTOCOL_IP6), + .fp_len = (ip46_address_is_ip4 (&key->peer_addr) ? + 32: + 128), + }; + + /* + * get the FIB entry + */ + fei = fib_table_lookup_exact_match(key->fib_index, &pfx); + + switch (event) + { + case BFD_LISTEN_EVENT_CREATE: + /* + * The creation of a new session + */ + if ((FIB_NODE_INDEX_INVALID != fei) && + (fed = fib_entry_delegate_get(fib_entry_get(fei), + FIB_ENTRY_DELEGATE_BFD))) + { + /* + * already got state for this entry + */ + } + else + { + /* + * source and lock the entry. add the delegate + */ + fei = fib_table_entry_special_add(key->fib_index, + &pfx, + FIB_SOURCE_RR, + FIB_ENTRY_FLAG_NONE); + fib_entry_lock(fei); + + fed = fib_entry_delegate_find_or_add(fib_entry_get(fei), + FIB_ENTRY_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. + */ + fed->fd_bfd_state = FIB_BFD_STATE_UP; + } + break; + + case BFD_LISTEN_EVENT_UPDATE: + /* + * state change up/dowm and + */ + ASSERT(FIB_NODE_INDEX_INVALID != fei); + + fed = fib_entry_delegate_get(fib_entry_get(fei), + FIB_ENTRY_DELEGATE_BFD); + + if (NULL != fed) + { + fed->fd_bfd_state = fib_bfd_bfd_state_to_fib(session->local_state); + fib_bfd_update_walk(fei); + } + /* + * else + * no BFD state + */ + break; + + case BFD_LISTEN_EVENT_DELETE: + /* + * session has been removed. + */ + if (FIB_NODE_INDEX_INVALID == fei) + { + /* + * no FIB entry + */ + } + else if (fib_entry_delegate_get(fib_entry_get(fei), + FIB_ENTRY_DELEGATE_BFD)) + { + /* + * has an associated BFD tracking delegate + * usource the entry and remove the BFD tracking deletgate + */ + fib_entry_delegate_remove(fib_entry_get(fei), + FIB_ENTRY_DELEGATE_BFD); + fib_bfd_update_walk(fei); + + fib_table_entry_special_remove(key->fib_index, + &pfx, + FIB_SOURCE_RR); + fib_entry_unlock(fei); + } + /* + * else + * no BFD associated state + */ + break; + } +} + +static clib_error_t * +fib_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(fib_bfd_notify); + + return (error); +} + +VLIB_INIT_FUNCTION (fib_bfd_main_init); |