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/*
* 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);
}
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