/* * 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 <vlib/vlib.h> #include <vnet/ip/format.h> #include <vnet/ip/lookup.h> #include <vnet/adj/adj.h> #include <vnet/dpo/drop_dpo.h> #include "fib_entry_src.h" #include "fib_entry_src_rr.h" #include "fib_entry_cover.h" #include "fib_entry.h" #include "fib_table.h" /* * Source initialisation Function */ static void fib_entry_src_interpose_init (fib_entry_src_t *src) { src->u.interpose.fesi_cover = FIB_NODE_INDEX_INVALID; src->u.interpose.fesi_sibling = FIB_NODE_INDEX_INVALID; } /* * Source deinitialisation Function */ static void fib_entry_src_interpose_deinit (fib_entry_src_t *src) { ASSERT(src->u.interpose.fesi_cover == FIB_NODE_INDEX_INVALID); src->u.interpose.fesi_cover = FIB_NODE_INDEX_INVALID; src->u.interpose.fesi_sibling = FIB_NODE_INDEX_INVALID; dpo_reset(&src->u.interpose.fesi_dpo); } static fib_entry_src_t * fib_entry_src_rr_get_next_best (const fib_entry_src_t *src, const fib_entry_t *fib_entry) { fib_entry_src_t *next_src, *best_src = NULL; fib_source_t source; FOR_EACH_SRC_ADDED(fib_entry, next_src, source, ({ /* * skip to the next best source after this one */ switch (fib_source_cmp(source, src->fes_src)) { case FIB_SOURCE_CMP_BETTER: case FIB_SOURCE_CMP_EQUAL: continue; case FIB_SOURCE_CMP_WORSE: best_src = next_src; goto out; } })); out: return (best_src); } /* * Source activation. Called when the source is the new best source on the entry */ static int fib_entry_src_interpose_activate (fib_entry_src_t *src, const fib_entry_t *fib_entry) { fib_entry_src_t *best_src; fib_node_index_t old_pl; fib_entry_t *cover; old_pl = src->fes_pl; src->fes_pl = FIB_NODE_INDEX_INVALID; /* * The goal here is to find a path-list that will contribute forwarding * for the entry. * First check this entry for other sources that have a path-list */ best_src = fib_entry_src_rr_get_next_best(src, fib_entry); if (NULL != best_src) { const fib_entry_src_vft_t *vft; best_src->fes_flags |= FIB_ENTRY_SRC_FLAG_CONTRIBUTING; vft = fib_entry_src_get_vft(best_src); /* * there is another source for this entry. activate it so it * can provide forwarding */ if (NULL != vft->fesv_activate) { if (vft->fesv_activate(best_src, fib_entry)) { /* * next best source activated ok, use its path list */ src->fes_pl = best_src->fes_pl; } else { /* * the best source won't install so will use a drop */ dpo_proto_t dproto; dproto = fib_proto_to_dpo(fib_entry->fe_prefix.fp_proto); src->fes_pl = fib_path_list_create_special(dproto, FIB_PATH_LIST_FLAG_DROP, drop_dpo_get(dproto)); } } else { /* * next best source does not require activation, use its path list */ src->fes_pl = best_src->fes_pl; } } else { /* * find the covering prefix. become a dependent thereof. * for IP there should always be a cover, though it may be the default route. * For MPLS there is never a cover. */ if (FIB_PROTOCOL_MPLS == fib_entry->fe_prefix.fp_proto) { src->fes_pl = fib_path_list_create_special(DPO_PROTO_MPLS, FIB_PATH_LIST_FLAG_DROP, NULL); } else { src->u.interpose.fesi_cover = fib_table_get_less_specific(fib_entry->fe_fib_index, &fib_entry->fe_prefix); ASSERT(FIB_NODE_INDEX_INVALID != src->u.interpose.fesi_cover); cover = fib_entry_get(src->u.interpose.fesi_cover); src->u.interpose.fesi_sibling = fib_entry_cover_track(cover, fib_entry_get_index(fib_entry)); /* * if the cover is attached then install an attached-host path * (like an adj-fib). Otherwise inherit the forwarding from the cover */ if (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover)) { fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover); } else { fib_entry_src_rr_use_covers_pl(src, fib_entry, cover); } } } fib_path_list_unlock(old_pl); fib_path_list_lock(src->fes_pl); /* * return go for install */ return (!0); } /** * Source Deactivate. * Called when the source is no longer best source on the entry */ static void fib_entry_src_interpose_deactivate (fib_entry_src_t *src, const fib_entry_t *fib_entry) { fib_entry_t *cover; if (FIB_NODE_INDEX_INVALID != src->u.interpose.fesi_cover) { /* * remove the dependency on the covering entry, if that's * what was contributing the path-list */ cover = fib_entry_get(src->u.interpose.fesi_cover); fib_entry_cover_untrack(cover, src->u.interpose.fesi_sibling); src->u.interpose.fesi_cover = FIB_NODE_INDEX_INVALID; } else { fib_entry_src_t *best_src; best_src = fib_entry_src_rr_get_next_best(src, fib_entry); if (best_src) { best_src->fes_flags &= ~FIB_ENTRY_SRC_FLAG_CONTRIBUTING; /* * there is another source for this entry. activate it so it * can provide forwarding */ FIB_ENTRY_SRC_VFT_INVOKE(fib_entry, best_src, fesv_deactivate, (best_src, fib_entry)); } } fib_path_list_unlock(src->fes_pl); src->fes_pl = FIB_NODE_INDEX_INVALID; src->fes_entry_flags &= ~FIB_ENTRY_FLAGS_RR_INHERITED; } static int fib_entry_src_interpose_reactivate (fib_entry_src_t *src, const fib_entry_t *fib_entry) { fib_entry_src_interpose_deactivate(src, fib_entry); return (fib_entry_src_interpose_activate(src, fib_entry)); } static fib_entry_src_cover_res_t fib_entry_src_interpose_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, }; if (FIB_NODE_INDEX_INVALID == src->u.interpose.fesi_cover) { /* * the source may be added, but it is not active * if it is not tracking the cover. */ return (res); } /* * this function is called when this entry's cover has a more specific * entry inserted beneath it. That does not necessarily mean that this * entry is covered by the new prefix. check that */ if (src->u.interpose.fesi_cover != fib_table_get_less_specific(fib_entry->fe_fib_index, &fib_entry->fe_prefix)) { fib_entry_src_interpose_deactivate(src, fib_entry); fib_entry_src_interpose_activate(src, fib_entry); /* * dependent children need to re-resolve to the new forwarding info */ res.bw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE; } return (res); } static void fib_entry_src_interpose_add (fib_entry_src_t *src, const fib_entry_t *entry, fib_entry_flag_t flags, dpo_proto_t proto, const dpo_id_t *dpo) { dpo_copy(&src->u.interpose.fesi_dpo, dpo); } static void fib_entry_src_interpose_remove (fib_entry_src_t *src) { dpo_reset(&src->u.interpose.fesi_dpo); } static void fib_entry_src_interpose_set_data (fib_entry_src_t *src, const fib_entry_t *fib_entry, const void *data) { const dpo_id_t *dpo = data; dpo_copy(&src->u.interpose.fesi_dpo, dpo); } /** * Contribute forwarding to interpose in the chain */ const dpo_id_t* fib_entry_src_interpose_contribute(const fib_entry_src_t *src, const fib_entry_t *fib_entry) { return (&src->u.interpose.fesi_dpo); } static void fib_entry_src_interpose_copy (const fib_entry_src_t *orig_src, const fib_entry_t *fib_entry, fib_entry_src_t *copy_src) { copy_src->u.interpose.fesi_cover = orig_src->u.interpose.fesi_cover; if (FIB_NODE_INDEX_INVALID != copy_src->u.interpose.fesi_cover) { fib_entry_t *cover; cover = fib_entry_get(orig_src->u.interpose.fesi_cover); copy_src->u.interpose.fesi_sibling = fib_entry_cover_track(cover, fib_entry_get_index(fib_entry)); } dpo_copy(©_src->u.interpose.fesi_dpo, &orig_src->u.interpose.fesi_dpo); } static void fib_entry_src_interpose_flag_change (fib_entry_src_t *src, const fib_entry_t *fib_entry, fib_entry_flag_t new_flags) { if (!(new_flags & FIB_ENTRY_FLAG_INTERPOSE)) { /* * stop tracking the source contributing forwarding * and reset the interposer DPO */ fib_entry_src_interpose_deactivate(src, fib_entry); fib_entry_src_interpose_deinit(src); } } static u8* fib_entry_src_interpose_format (fib_entry_src_t *src, u8* s) { s = format(s, " cover:%d interpose:\n%U%U", src->u.interpose.fesi_cover, format_white_space, 6, format_dpo_id, &src->u.interpose.fesi_dpo, 8); return (s); } const static fib_entry_src_vft_t interpose_src_vft = { .fesv_init = fib_entry_src_interpose_init, .fesv_deinit = fib_entry_src_interpose_deinit, .fesv_activate = fib_entry_src_interpose_activate, .fesv_reactivate = fib_entry_src_interpose_reactivate, .fesv_deactivate = fib_entry_src_interpose_deactivate, .fesv_cover_change = fib_entry_src_interpose_cover_change, .fesv_cover_update = fib_entry_src_rr_cover_update, .fesv_format = fib_entry_src_interpose_format, .fesv_add = fib_entry_src_interpose_add, .fesv_remove = fib_entry_src_interpose_remove, .fesv_contribute_interpose = fib_entry_src_interpose_contribute, .fesv_set_data = fib_entry_src_interpose_set_data, .fesv_copy = fib_entry_src_interpose_copy, .fesv_flags_change = fib_entry_src_interpose_flag_change, }; void fib_entry_src_interpose_register (void) { fib_entry_src_behaviour_register(FIB_SOURCE_BH_INTERPOSE, &interpose_src_vft); }