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Diffstat (limited to 'src/vnet/fib/fib_path_ext.c')
| -rw-r--r-- | src/vnet/fib/fib_path_ext.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/src/vnet/fib/fib_path_ext.c b/src/vnet/fib/fib_path_ext.c new file mode 100644 index 00000000000..f75b5626c04 --- /dev/null +++ b/src/vnet/fib/fib_path_ext.c @@ -0,0 +1,231 @@ +/* + * 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/mpls/mpls.h> +#include <vnet/dpo/mpls_label_dpo.h> +#include <vnet/dpo/load_balance.h> +#include <vnet/dpo/drop_dpo.h> + +#include <vnet/fib/fib_path_ext.h> +#include <vnet/fib/fib_entry_src.h> +#include <vnet/fib/fib_path.h> +#include <vnet/fib/fib_path_list.h> +#include <vnet/fib/fib_internal.h> + +u8 * +format_fib_path_ext (u8 * s, va_list * args) +{ + fib_path_ext_t *path_ext; + u32 ii; + + path_ext = va_arg (*args, fib_path_ext_t *); + + s = format(s, "path:%d labels:", + path_ext->fpe_path_index); + for (ii = 0; ii < vec_len(path_ext->fpe_path.frp_label_stack); ii++) + { + s = format(s, "%U ", + format_mpls_unicast_label, + path_ext->fpe_path.frp_label_stack[ii]); + } + return (s); +} + +int +fib_path_ext_cmp (fib_path_ext_t *path_ext, + const fib_route_path_t *rpath) +{ + return (fib_route_path_cmp(&path_ext->fpe_path, rpath)); +} + +static int +fib_path_ext_match (fib_node_index_t pl_index, + fib_node_index_t path_index, + void *ctx) +{ + fib_path_ext_t *path_ext = ctx; + + if (!fib_path_cmp_w_route_path(path_index, + &path_ext->fpe_path)) + { + path_ext->fpe_path_index = path_index; + return (0); + } + // keep going + return (1); +} + +void +fib_path_ext_resolve (fib_path_ext_t *path_ext, + fib_node_index_t path_list_index) +{ + /* + * Find the path on the path list that this is an extension for + */ + path_ext->fpe_path_index = FIB_NODE_INDEX_INVALID; + fib_path_list_walk(path_list_index, + fib_path_ext_match, + path_ext); +} + +void +fib_path_ext_init (fib_path_ext_t *path_ext, + fib_node_index_t path_list_index, + const fib_route_path_t *rpath) +{ + path_ext->fpe_path = *rpath; + path_ext->fpe_path_index = FIB_NODE_INDEX_INVALID; + + fib_path_ext_resolve(path_ext, path_list_index); +} + +/** + * @brief Return true if the label stack is implicit null + */ +static int +fib_path_ext_is_imp_null (fib_path_ext_t *path_ext) +{ + return ((1 == vec_len(path_ext->fpe_label_stack)) && + (MPLS_IETF_IMPLICIT_NULL_LABEL == path_ext->fpe_label_stack[0])); +} + +load_balance_path_t * +fib_path_ext_stack (fib_path_ext_t *path_ext, + const fib_entry_t *entry, + fib_forward_chain_type_t child_fct, + load_balance_path_t *nhs) +{ + fib_forward_chain_type_t parent_fct; + load_balance_path_t *nh; + + if (!fib_path_is_resolved(path_ext->fpe_path_index)) + return (nhs); + + /* + * Since we are stacking this path-extension, it must have a valid out + * label. From the chain type request by the child, determine what + * chain type we will request from the parent. + */ + switch (child_fct) + { + case FIB_FORW_CHAIN_TYPE_MPLS_EOS: + { + /* + * The EOS chain is a tricky since, when the path has an imp NULL one cannot know + * the adjacency to link to without knowing what the packets payload protocol + * will be once the label is popped. + */ + if (fib_path_ext_is_imp_null(path_ext)) + { + parent_fct = fib_entry_chain_type_fixup(entry, child_fct); + } + else + { + /* + * we have a label to stack. packets will thus be labelled when + * they encounter the child, ergo, non-eos. + */ + parent_fct = FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS; + } + break; + } + case FIB_FORW_CHAIN_TYPE_UNICAST_IP4: + case FIB_FORW_CHAIN_TYPE_UNICAST_IP6: + if (fib_path_ext_is_imp_null(path_ext)) + { + /* + * implicit-null label for the eos or IP chain, need to pick up + * the IP adj + */ + parent_fct = child_fct; + } + else + { + /* + * we have a label to stack. packets will thus be labelled when + * they encounter the child, ergo, non-eos. + */ + parent_fct = FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS; + } + break; + case FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS: + parent_fct = child_fct; + break; + default: + return (nhs); + break; + } + + dpo_id_t via_dpo = DPO_INVALID; + + /* + * The next object in the graph after the imposition of the label + * will be the DPO contributed by the path through which the packets + * are to be sent. We stack the MPLS Label DPO on this path DPO + */ + fib_path_contribute_forwarding(path_ext->fpe_path_index, + parent_fct, + &via_dpo); + + if (dpo_is_drop(&via_dpo) || + load_balance_is_drop(&via_dpo)) + { + /* + * don't stack a path extension on a drop. doing so will create + * a LB bucket entry on drop, and we will lose a percentage of traffic. + */ + } + else + { + vec_add2(nhs, nh, 1); + nh->path_weight = fib_path_get_weight(path_ext->fpe_path_index); + nh->path_index = path_ext->fpe_path_index; + dpo_copy(&nh->path_dpo, &via_dpo); + + /* + * The label is stackable for this chain type + * construct the mpls header that will be imposed in the data-path + */ + if (!fib_path_ext_is_imp_null(path_ext)) + { + /* + * we use the parent protocol for the label so that + * we pickup the correct MPLS imposition nodes to do + * ip[46] processing. + */ + dpo_proto_t chain_proto; + mpls_eos_bit_t eos; + index_t mldi; + + eos = (child_fct == FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS ? + MPLS_NON_EOS : + MPLS_EOS); + chain_proto = fib_forw_chain_type_to_dpo_proto(child_fct); + + mldi = mpls_label_dpo_create(path_ext->fpe_label_stack, + eos, 255, 0, + chain_proto, + &nh->path_dpo); + + dpo_set(&nh->path_dpo, + DPO_MPLS_LABEL, + chain_proto, + mldi); + } + } + dpo_reset(&via_dpo); + + return (nhs); +} |