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NetBSD/usr.sbin/ldpd/tlv_stack.c

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/* $NetBSD: tlv_stack.c,v 1.4 2011/06/15 18:16:48 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 <kefren@NetBSD.org>
*
* 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 <arpa/inet.h>
#include <netmpls/mpls.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "ldp.h"
#include "ldp_errors.h"
#include "ldp_peer.h"
#include "tlv.h"
#include "socketops.h"
#include "pdu.h"
#include "label.h"
#include "mpls_interface.h"
#include "tlv_stack.h"
uint8_t ldp_ceil8(int);
uint8_t
ldp_ceil8(int x)
{
if (x % 8 == 0)
return x / 8;
return x / 8 + 1;
}
int
map_label(struct ldp_peer * p, struct fec_tlv * f, struct label_tlv * l)
{
int n;
struct prefix_tlv *pref;
struct in_addr inatmp;
if (ntohs(f->type) != TLV_FEC) {
debugp("Invalid FEC TLV !\n");
return LDP_E_BAD_FEC;
}
if (ntohs(l->type) != TLV_GENERIC_LABEL) {
debugp("Invalid LABEL TLV! (0x%.4X)\n", ntohs(l->type));
return LDP_E_BAD_LABEL;
}
/*
* Actually address field length is given only in length field in
* bits !
*/
n = ntohs(f->length);
if (!n)
return LDP_E_BAD_FEC;
debugp("Label %u for:\n", ntohl(l->label));
pref = (struct prefix_tlv *) & f[1];
/*
* Section 3.4.1
* Note that this version of LDP supports the use of multiple FEC
* Elements per FEC for the Label Mapping message only. The use of
* multiple FEC Elements in other messages is not permitted in this
* version, and is a subject for future study.
*/
for (; n > 0; pref = (struct prefix_tlv *) ((unsigned char *) pref +
ldp_ceil8(pref->prelen) + TLV_TYPE_LENGTH)) {
n -= ldp_ceil8(pref->prelen) + TLV_TYPE_LENGTH;
if (ntohs(pref->af) != LDP_AF_INET) {
debugp("BAD ADDRESS FAMILY (%d) ! (prefix type %d, "
"length %d)\n", ntohs(pref->af), pref->type,
pref->prelen);
return LDP_E_BAD_AF;
}
switch(pref->type) {
case FEC_PREFIX:
case FEC_HOST:
memset(&inatmp, 0, sizeof(struct in_addr));
memcpy(&inatmp, &pref->prefix, ldp_ceil8(pref->prelen));
debugp("Prefix/Host add: %s/%d\n", inet_ntoa(inatmp),
pref->prelen);
ldp_peer_add_mapping(p, &inatmp, pref->prelen,
ntohl(l->label));
/* Try to change RIB only if label is installed */
if (label_get_by_prefix(&inatmp, pref->prelen) != NULL)
mpls_add_label(p, NULL, &inatmp, pref->prelen,
ntohl(l->label), 1);
break;
case FEC_WILDCARD:
fatalp("LDP: Wildcard add from peer %s\n",
inet_ntoa(p->address));
return LDP_E_BAD_FEC;
default:
fatalp("Unknown FEC type %d\n", pref->type);
return LDP_E_BAD_FEC;
}
}
return LDP_E_OK;
}
int
withdraw_label(struct ldp_peer * p, struct fec_tlv * f)
{
int n;
struct prefix_tlv *pref;
struct in_addr inatmp;
struct label *lab;
if (ntohs(f->type) != TLV_FEC) {
debugp("Invalid FEC TLV !\n");
return LDP_E_BAD_FEC;
}
n = ntohs(f->length);
if (!n)
return LDP_E_BAD_FEC;
pref = (struct prefix_tlv *) & f[1];
if (ntohs(pref->af) != LDP_AF_INET) {
debugp("BAD ADDRESS FAMILY (%d)! (prefix type %d, length %d)\n",
ntohs(pref->af), pref->type, pref->prelen);
return LDP_E_BAD_AF;
}
switch(pref->type) {
case FEC_PREFIX:
case FEC_HOST:
memset(&inatmp, 0, sizeof(struct in_addr));
memcpy(&inatmp, &pref->prefix, ldp_ceil8(pref->prelen));
debugp("Prefix/Host withdraw: %s/%d\n", inet_ntoa(inatmp),
pref->prelen);
/* Delete mapping */
ldp_peer_delete_mapping(p, &inatmp, pref->prelen);
/* Get label, see if we're pointing to this peer
* if so, send withdraw, reattach IP route and announce
* POP Label
*/
lab = label_get_by_prefix(&inatmp, pref->prelen);
if ((lab) && (lab->p == p)) {
change_local_label(lab, MPLS_LABEL_IMPLNULL);
label_reattach_route(lab, LDP_READD_CHANGE);
}
break;
case FEC_WILDCARD:
fatalp("LDP neighbour %s: Wildcard withdraw !!!\n",
inet_ntoa(p->address));
ldp_peer_delete_mapping(p, NULL, 0);
label_reattach_all_peer_labels(p, LDP_READD_CHANGE);
break;
default:
fatalp("Unknown FEC type %d\n", pref->type);
return LDP_E_BAD_FEC;
}
return LDP_E_OK;
}
/*
* In case of label redraw, reuse the same buffer to send label release
* Simply replace type and message id
*/
void
prepare_release(struct tlv * v)
{
struct label_map_tlv *t;
t = (struct label_map_tlv *) v;
t->type = htons(LDP_LABEL_RELEASE);
t->messageid = htonl(get_message_id());
}
/* Sends a label mapping */
void
send_label_tlv(struct ldp_peer * peer, struct in_addr * addr,
uint8_t prefixlen, uint32_t label, struct label_request_tlv *lrt)
{
struct label_map_tlv *lmt;
struct fec_tlv *fec;
struct prefix_tlv *p;
struct label_tlv *l;
/*
* Ok, so we have label map tlv that contains fec tlvs and label tlv
* but fec tlv contains prefix or host tlvs and prefix or host tlvs
* contains the network. After that we may have optional parameters
* Got it ?
*/
lmt = malloc(
sizeof(struct label_map_tlv) +
sizeof(struct fec_tlv) +
sizeof(struct prefix_tlv) - sizeof(struct in_addr) +
ldp_ceil8(prefixlen) +
sizeof(struct label_tlv) +
/* Label request optional parameter */
(lrt != NULL ? sizeof(struct label_request_tlv) : 0) );
if (!lmt) {
fatalp("send_label_tlv: malloc problem\n");
return;
}
lmt->type = htons(LDP_LABEL_MAPPING);
lmt->length = htons(sizeof(struct label_map_tlv) - TLV_TYPE_LENGTH
+ sizeof(struct fec_tlv)
+ sizeof(struct prefix_tlv) - sizeof(struct in_addr) +
ldp_ceil8(prefixlen)
+ sizeof(struct label_tlv) +
+ (lrt != NULL ? sizeof(struct label_request_tlv) : 0));
lmt->messageid = htonl(get_message_id());
/* FEC TLV */
fec = (struct fec_tlv *) & lmt[1];
fec->type = htons(TLV_FEC);
fec->length = htons(sizeof(struct fec_tlv) - TLV_TYPE_LENGTH
+ sizeof(struct prefix_tlv) - sizeof(struct in_addr) +
ldp_ceil8(prefixlen));
/* Now let's do the even a dirtier job: PREFIX TLV */
p = (struct prefix_tlv *) & fec[1];
/* Cisco and Juniper don't support FEC type HOST
* so everything is FEC_PREFIX..
*
* if (prefixlen == 32) p->type = FEC_HOST; else
*/
p->type = FEC_PREFIX;
p->af = htons(LDP_AF_INET);
p->prelen = prefixlen;
memcpy(&p->prefix, addr, ldp_ceil8(prefixlen));
/* LABEL TLV */
l = (struct label_tlv *) ((unsigned char *) p +
sizeof(struct prefix_tlv) - sizeof(struct in_addr) +
ldp_ceil8(prefixlen));
l->type = htons(TLV_GENERIC_LABEL);
l->length = htons(sizeof(l->label));
l->label = htonl(label);
/* Label request optional parameter */
if (lrt)
memcpy(((char*)l) + TLV_TYPE_LENGTH + ntohs(l->length),
lrt, htons(lrt->length) + TLV_TYPE_LENGTH);
/* Wow, seems we're ready */
send_tlv(peer, (struct tlv *) lmt);
free(lmt);
}
void
send_label_tlv_to_all(struct in_addr * addr, uint8_t prefixlen, uint32_t label)
{
struct ldp_peer *p;
SLIST_FOREACH(p, &ldp_peer_head, peers)
send_label_tlv(p, addr, prefixlen, label, NULL);
}
/*
* Send all local labels to a peer
*/
void
send_all_bindings(struct ldp_peer * peer)
{
struct label *l;
SLIST_FOREACH(l, &label_head, labels)
send_label_tlv(peer, &((struct sockaddr_in*)(&l->so_dest))->sin_addr,
from_union_to_cidr(&l->so_pref), l->binding, NULL);
}
/* Sends a label WITHDRAW */
void
send_withdraw_tlv(struct ldp_peer * peer, struct in_addr * addr,
uint8_t prefixlen)
{
struct label_map_tlv *lmt;
struct fec_tlv *fec;
struct prefix_tlv *p;
/*
* Ok, so we have label map tlv that contains fec tlvs but fec tlv
* contains prefix or host tlvs and prefix or host tlvs contains the
* network. Yes, we don't have to announce label here
*/
lmt = malloc(sizeof(struct label_map_tlv)
+ sizeof(struct fec_tlv)
+ sizeof(struct prefix_tlv) - sizeof(struct in_addr) +
ldp_ceil8(prefixlen));
if (!lmt) {
fatalp("send_withdraw_tlv: malloc problem\n");
return;
}
lmt->type = htons(LDP_LABEL_WITHDRAW);
lmt->length = htons(sizeof(struct label_map_tlv) - TLV_TYPE_LENGTH
+ sizeof(struct fec_tlv)
+ sizeof(struct prefix_tlv) - sizeof(struct in_addr) +
ldp_ceil8(prefixlen));
lmt->messageid = htonl(get_message_id());
/* FEC TLV */
fec = (struct fec_tlv *) & lmt[1];
fec->type = htons(TLV_FEC);
fec->length = htons(sizeof(struct fec_tlv) - TLV_TYPE_LENGTH
+ sizeof(struct prefix_tlv) - sizeof(struct in_addr) +
ldp_ceil8(prefixlen));
/* Now the even dirtier job: PREFIX TLV */
p = (struct prefix_tlv *) & fec[1];
/* See above comment
*
* if (prefixlen == 32) p->type = FEC_HOST; else
*/
p->type = FEC_PREFIX;
p->af = htons(LDP_AF_INET);
p->prelen = prefixlen;
memcpy(&p->prefix, addr, ldp_ceil8(prefixlen));
/* Wow, seems we're ready */
send_tlv(peer, (struct tlv *) lmt);
free(lmt);
}
void
send_withdraw_tlv_to_all(struct in_addr * addr, uint8_t prefixlen)
{
struct ldp_peer *p;
SLIST_FOREACH(p, &ldp_peer_head, peers)
send_withdraw_tlv(p, addr, prefixlen);
}
int
request_respond(struct ldp_peer *p, struct label_map_tlv *lmt,
struct fec_tlv *fec)
{
struct prefix_tlv *pref;
struct in_addr inatmp;
struct label *lab;
struct label_request_tlv lrm;
if (ntohs(fec->type) != TLV_FEC || fec->length == 0) {
debugp("Invalid FEC TLV !\n");
return LDP_E_BAD_FEC;
}
pref = (struct prefix_tlv *) (fec + 1);
if (ntohs(pref->af) != LDP_AF_INET) {
debugp("request_respond: Bad address family\n");
return LDP_E_BAD_AF;
}
switch (pref->type) {
case FEC_PREFIX:
case FEC_HOST:
memset(&inatmp, 0, sizeof(struct in_addr));
memcpy(&inatmp, &pref->prefix, ldp_ceil8(pref->prelen));
debugp("Prefix/Host request: %s/%d\n", inet_ntoa(inatmp),
pref->prelen);
lab = label_get_by_prefix(&inatmp, pref->prelen);
if (!lab)
return LDP_E_NO_SUCH_ROUTE;
lrm.type = htons(TLV_LABEL_REQUEST);
lrm.length = htons(sizeof(uint32_t));
lrm.messageid = lmt->messageid;
send_label_tlv(p, &inatmp, pref->prelen, lab->binding, &lrm);
break;
case FEC_WILDCARD:
/*
* Section 3.4.1
* To be used only in the Label Withdraw and Label Release
*/
/* Fallthrough */
default:
fatalp("Invalid FEC type\n");
return LDP_E_BAD_FEC;
}
return LDP_E_OK;
}
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