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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 "fib_entry.h"
#include "fib_entry_src.h"
#include "fib_path_list.h"
#include "fib_table.h"
#include "fib_entry_cover.h"
#include "fib_attached_export.h"
/**
* Source initialisation Function
*/
static void
fib_entry_src_adj_init (fib_entry_src_t *src)
{
src->adj.fesa_cover = FIB_NODE_INDEX_INVALID;
src->adj.fesa_sibling = FIB_NODE_INDEX_INVALID;
}
static void
fib_entry_src_adj_path_swap (fib_entry_src_t *src,
const fib_entry_t *entry,
fib_path_list_flags_t pl_flags,
const fib_route_path_t *paths)
{
src->fes_pl = fib_path_list_create(pl_flags, paths);
}
static void
fib_entry_src_adj_remove (fib_entry_src_t *src)
{
src->fes_pl = FIB_NODE_INDEX_INVALID;
}
/*
* Source activate.
* Called when the source is the new longer best source on the entry
*/
static int
fib_entry_src_adj_activate (fib_entry_src_t *src,
const fib_entry_t *fib_entry)
{
fib_entry_t *cover;
/*
* find the covering prefix. become a dependent thereof.
* there should always be a cover, though it may be the default route.
*/
src->adj.fesa_cover = fib_table_get_less_specific(fib_entry->fe_fib_index,
&fib_entry->fe_prefix);
ASSERT(FIB_NODE_INDEX_INVALID != src->adj.fesa_cover);
ASSERT(fib_entry_get_index(fib_entry) != src->adj.fesa_cover);
cover = fib_entry_get(src->adj.fesa_cover);
ASSERT(cover != fib_entry);
src->adj.fesa_sibling =
fib_entry_cover_track(cover,
fib_entry_get_index(fib_entry));
/*
* if the cover is attached on the same interface as this adj source then
* install the FIB entry via the adj. otherwise install a drop.
* This prevents ARP/ND entries that on interface X that do not belong
* on X's subnet from being added to the FIB. To do so would allow
* nefarious gratuitous ARP requests from attracting traffic to the sender.
*
* and yes, I really do mean attached and not connected.
* this abomination;
* ip route add 10.0.0.0/24 Eth0
* is attached. and we want adj-fibs to install on Eth0.
*/
if (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover))
{
u32 cover_itf = fib_entry_get_resolving_interface(src->adj.fesa_cover);
u32 adj_itf = fib_path_list_get_resolving_interface(src->fes_pl);
if (cover_itf == adj_itf)
{
return (1);
}
else
{
/*
* if the interface the adj is on is unnumbered to the
* cover's, then allow that too.
*/
vnet_sw_interface_t *swif;
swif = vnet_get_sw_interface (vnet_get_main(), adj_itf);
if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED &&
cover_itf == swif->unnumbered_sw_if_index)
{
return (1);
}
}
}
return (0);
}
/*
* Source Deactivate.
* Called when the source is no longer best source on the entry
*/
static void
fib_entry_src_adj_deactivate (fib_entry_src_t *src,
const fib_entry_t *fib_entry)
{
fib_entry_t *cover;
/*
* remove the depednecy on the covering entry
*/
ASSERT(FIB_NODE_INDEX_INVALID != src->adj.fesa_cover);
cover = fib_entry_get(src->adj.fesa_cover);
fib_entry_cover_untrack(cover, src->adj.fesa_sibling);
/*
* tell the cover this entry no longer needs exporting
*/
fib_attached_export_covered_removed(cover, fib_entry_get_index(fib_entry));
src->adj.fesa_cover = FIB_NODE_INDEX_INVALID;
}
static u8*
fib_entry_src_adj_format (fib_entry_src_t *src,
u8* s)
{
return (format(s, "cover:%d", src->adj.fesa_cover));
}
static void
fib_entry_src_adj_installed (fib_entry_src_t *src,
const fib_entry_t *fib_entry)
{
/*
* The adj source now rules! poke our cover to get exported
*/
fib_entry_t *cover;
ASSERT(FIB_NODE_INDEX_INVALID != src->adj.fesa_cover);
cover = fib_entry_get(src->adj.fesa_cover);
fib_attached_export_covered_added(cover,
fib_entry_get_index(fib_entry));
}
static fib_entry_src_cover_res_t
fib_entry_src_adj_cover_change (fib_entry_src_t *src,
const fib_entry_t *fib_entry)
{
fib_entry_src_cover_res_t res = {
.install = !0,
.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
};
fib_entry_src_adj_deactivate(src, fib_entry);
res.install = fib_entry_src_adj_activate(src, fib_entry);
if (res.install) {
/*
* ADJ fib can install
*/
res.bw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
}
return (res);
}
/*
* fib_entry_src_adj_cover_update
*/
static fib_entry_src_cover_res_t
fib_entry_src_adj_cover_update (fib_entry_src_t *src,
const fib_entry_t *fib_entry)
{
/*
* the cover has updated, i.e. its forwarding or flags
* have changed. do'nt decativate/activate here, since this
* prefix is updated during the covers walk.
*/
fib_entry_src_cover_res_t res = {
.install = !0,
.bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
};
fib_entry_t *cover;
ASSERT(FIB_NODE_INDEX_INVALID != src->adj.fesa_cover);
cover = fib_entry_get(src->adj.fesa_cover);
res.install = (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover));
return (res);
}
const static fib_entry_src_vft_t adj_src_vft = {
.fesv_init = fib_entry_src_adj_init,
.fesv_path_swap = fib_entry_src_adj_path_swap,
.fesv_remove = fib_entry_src_adj_remove,
.fesv_activate = fib_entry_src_adj_activate,
.fesv_deactivate = fib_entry_src_adj_deactivate,
.fesv_format = fib_entry_src_adj_format,
.fesv_installed = fib_entry_src_adj_installed,
.fesv_cover_change = fib_entry_src_adj_cover_change,
.fesv_cover_update = fib_entry_src_adj_cover_update,
};
void
fib_entry_src_adj_register (void)
{
fib_entry_src_register(FIB_SOURCE_ADJ, &adj_src_vft);
}
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