/* $NetBSD: label.c,v 1.11 2013/07/31 06:58:23 kefren Exp $ */

/*-
* Copyright (c) 2010 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Mihai Chelaru <[email protected]>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

#include <netmpls/mpls.h>

#include <assert.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>

#include "ldp.h"
#include "tlv_stack.h"
#include "mpls_routes.h"
#include "label.h"
#include "ldp_errors.h"

static int labels_compare(void*, const void*, const void*);

int min_label = MIN_LABEL, max_label = MAX_LABEL;

static rb_tree_t labels_tree;
static const rb_tree_ops_t tree_ops = {
       .rbto_compare_nodes = labels_compare,
       .rbto_compare_key = labels_compare,
       .rbto_node_offset = offsetof(struct label, lbtree),
       .rbto_context = NULL
};

void
label_init()
{

       rb_tree_init(&labels_tree, &tree_ops);
}

static int
labels_compare(void *context, const void *node1, const void *node2)
{
       const struct label *l1 = node1, *l2 = node2;
       int ret;

       if (__predict_false(l1->so_dest.sa.sa_family !=
           l2->so_dest.sa.sa_family))
               return l1->so_dest.sa.sa_family > l2->so_dest.sa.sa_family ?
                   1 : -1;

       assert(l1->so_dest.sa.sa_len == l2->so_dest.sa.sa_len);
       assert(l1->so_pref.sa.sa_len == l2->so_pref.sa.sa_len);

       if ((ret = memcmp(&l1->so_dest.sa, &l2->so_dest.sa,
           l1->so_dest.sa.sa_len)) != 0)
               return ret;
       else
               return memcmp(&l1->so_pref.sa, &l2->so_pref.sa,
                   l1->so_pref.sa.sa_len);
}

/*
* if binding == 0 it receives a free one
*/
struct label   *
label_add(const union sockunion * so_dest, const union sockunion * so_pref,
         const union sockunion * so_gate, uint32_t binding,
         const struct ldp_peer * p, uint32_t label, bool host)
{
       struct label   *l;
       char    spreftmp[INET_ADDRSTRLEN];

       l = calloc(1, sizeof(*l));

       if (!l) {
               fatalp("label_add: malloc problem\n");
               return NULL;
       }

       assert(so_dest);
       assert(so_pref);
       assert(so_dest->sa.sa_family == so_pref->sa.sa_family);
       assert(label_get(so_dest, so_pref) == NULL);

       memcpy(&l->so_dest, so_dest, so_dest->sa.sa_len);
       memcpy(&l->so_pref, so_pref, so_pref->sa.sa_len);

       if (so_gate)
               memcpy(&l->so_gate, so_gate, so_gate->sa.sa_len);
       if (binding)
               l->binding = binding;
       else
               l->binding = get_free_local_label();
       l->p = p;
       l->label = label;
       l->host = host;

       if (rb_tree_insert_node(&labels_tree, l) != l)
               fatalp("label already in tree");

       strlcpy(spreftmp, satos(&so_pref->sa), INET_ADDRSTRLEN);
       warnp("[label_add] added binding %d for %s/%s\n", l->binding,
           satos(&so_dest->sa), spreftmp);

       send_label_tlv_to_all(&(so_dest->sa),
           from_union_to_cidr(so_pref), l->binding);
       return l;
}

/* Unlink a label */
void
label_del(struct label * l)
{
       warnp("[label_del] deleted binding %d for %s\n", l->binding,
          satos(&l->so_dest.sa));
       rb_tree_remove_node(&labels_tree, l);
       free(l);
}

/*
* Delete or Reuse the old IPv4 route, delete MPLS route
* readd = REATT_INET_CHANGE -> delete and recreate the INET route
* readd = REATT_INET_DEL -> deletes INET route
* readd = REATT_INET_NODEL -> doesn't touch the INET route
*/
void
label_reattach_route(struct label *l, int readd)
{

       warnp("[label_reattach_route] binding %d deleted\n",
               l->binding);

       /* No gateway ? */
       if (l->so_gate.sa.sa_len == 0)
               return;

       if (readd == REATT_INET_CHANGE) {
               /* Delete the tagged route and re-add IPv4 route */
               delete_route(&l->so_dest,
                   l->host ? NULL : &l->so_pref, NO_FREESO);
               add_route(&l->so_dest,
                   l->host ? NULL : &l->so_pref, &l->so_gate,
                   NULL, NULL, NO_FREESO, RTM_READD);
       } else if (readd == REATT_INET_DEL)
               delete_route(&l->so_dest, l->host ? NULL : &l->so_pref,
                   NO_FREESO);

       /* Deletes the MPLS route */
       if (l->binding >= min_label)
               delete_route(make_mpls_union(l->binding), NULL, FREESO);

       l->binding = MPLS_LABEL_IMPLNULL;
       l->p = NULL;
       l->label = 0;
}
/*
* Get a label by dst and pref
*/
struct label*
label_get(const union sockunion *sodest, const union sockunion *sopref)
{
       struct label l;

       memset(&l, 0, sizeof(l));
       memcpy(&l.so_dest, sodest, sodest->sa.sa_len);
       memcpy(&l.so_pref, sopref, sopref->sa.sa_len);

       return rb_tree_find_node(&labels_tree, &l);
}

/*
* Find all labels that points to a peer
* and reattach them to IPv4
*/
void
label_reattach_all_peer_labels(const struct ldp_peer *p, int readd)
{
       struct label   *l;

       RB_TREE_FOREACH(l, &labels_tree)
               if (l->p == p)
                       label_reattach_route(l, readd);
}

/*
* Find all labels that points to a peer
* and delete them
*/
void
del_all_peer_labels(const struct ldp_peer * p, int readd)
{
       struct label   *l, *lnext;

       RB_TREE_FOREACH(l, &labels_tree) {
back_delete:
               if(l->p != p)
                       continue;
               label_reattach_route(l, readd);
               lnext = rb_tree_iterate(&labels_tree, l, RB_DIR_RIGHT);
               label_del(l);
               if (lnext == NULL)
                       break;
               l = lnext;
               goto back_delete;
       }
}

/*
* Finds a label by its binding and deletes it
*/
void
label_del_by_binding(uint32_t binding, int readd)
{
       struct label   *l;

       RB_TREE_FOREACH(l, &labels_tree)
               if ((uint32_t)l->binding == binding) {
                       label_reattach_route(l, readd);
                       label_del(l);
                       break;
               }
}

/*
* For Compatibility with old bindinds code
*/
struct label*
label_get_by_prefix(const struct sockaddr *a, int prefixlen)
{
       const union sockunion *so_dest;
       union sockunion *so_pref;
       struct label *l;

       so_dest = (const union sockunion *)a;
       so_pref = from_cidr_to_union(prefixlen);

       l = label_get(so_dest, so_pref);

       free(so_pref);

       return l;
}

/*
* Get a free binding
*/
uint32_t
get_free_local_label()
{
       struct label *l;
       int lbl;

       for (lbl = min_label; lbl <= max_label; lbl++) {
               RB_TREE_FOREACH(l, &labels_tree)
                       if (l->binding == lbl)
                               break;
               if (l == NULL)
                       return lbl;
       }
       return 0;
}

/*
* Announce peers that a label has changed its binding
* by withdrawing it and reannouncing it
*/
void
announce_label_change(struct label *l)
{
       send_withdraw_tlv_to_all(&(l->so_dest.sa),
               from_union_to_cidr(&(l->so_pref)));
       send_label_tlv_to_all(&(l->so_dest.sa),
               from_union_to_cidr(&(l->so_pref)),
               l->binding);
}

void
label_check_assoc(struct ldp_peer *p)
{
       struct label *l;
       struct ldp_peer_address *wp;

       RB_TREE_FOREACH(l, &labels_tree)
               if (l->p == NULL && l->so_gate.sa.sa_family != 0)
                       SLIST_FOREACH(wp, &p->ldp_peer_address_head, addresses)
                               if (sockaddr_cmp(&l->so_gate.sa,
                                   &wp->address.sa) == 0) {
                                       l->p = p;
                                       l->label = MPLS_LABEL_IMPLNULL;
                                       break;
                               }
}

struct label *
label_get_right(struct label *l)
{
       if (l == NULL)
               return RB_TREE_MIN(&labels_tree);
       else
               return rb_tree_iterate(&labels_tree, l, RB_DIR_RIGHT);
}

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