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|
/* $OpenBSD: labelmapping.c,v 1.31 2015/02/09 11:53:25 claudio Exp $ */
/*
* Copyright (c) 2009 Michele Marchetto <michele@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <net/if_dl.h>
#include <netmpls/mpls.h>
#include <unistd.h>
#include <errno.h>
#include <event.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include "ldpd.h"
#include "ldp.h"
#include "log.h"
#include "ldpe.h"
void gen_label_tlv(struct ibuf *, u_int32_t);
void gen_reqid_tlv(struct ibuf *, u_int32_t);
void gen_fec_tlv(struct ibuf *, struct in_addr, u_int8_t);
int tlv_decode_label(struct nbr *, struct ldp_msg *, char *, u_int16_t,
u_int32_t *);
int tlv_decode_fec_elm(struct nbr *, struct ldp_msg *, char *, u_int16_t,
u_int8_t *, u_int32_t *, u_int8_t *);
static void
enqueue_pdu(struct nbr *nbr, struct ibuf *buf, u_int16_t size)
{
struct ldp_hdr *ldp_hdr;
ldp_hdr = ibuf_seek(buf, 0, sizeof(struct ldp_hdr));
ldp_hdr->length = htons(size);
evbuf_enqueue(&nbr->tcp->wbuf, buf);
}
/* Generic function that handles all Label Message types */
void
send_labelmessage(struct nbr *nbr, u_int16_t type, struct mapping_head *mh)
{
struct ibuf *buf = NULL;
struct mapping_entry *me;
u_int16_t tlv_size, size = 0;
int first = 1;
while ((me = TAILQ_FIRST(mh)) != NULL) {
/* generate pdu */
if (first) {
if ((buf = ibuf_open(LDP_MAX_LEN)) == NULL)
fatal("send_labelmapping");
/* real size will be set up later */
gen_ldp_hdr(buf, 0);
size = LDP_HDR_PDU_LEN;
first = 0;
}
/* calculate size */
tlv_size = LDP_MSG_LEN + TLV_HDR_LEN + FEC_ELM_MIN_LEN +
PREFIX_SIZE(me->map.prefixlen);
if (type == MSG_TYPE_LABELMAPPING ||
me->map.flags & F_MAP_OPTLABEL)
tlv_size += LABEL_TLV_LEN;
if (me->map.flags & F_MAP_REQ_ID)
tlv_size += REQID_TLV_LEN;
/* maximum pdu length exceeded, we need a new ldp pdu */
if (size + tlv_size > LDP_MAX_LEN) {
enqueue_pdu(nbr, buf, size);
first = 1;
continue;
}
size += tlv_size;
/* append message and tlvs */
gen_msg_tlv(buf, type, tlv_size);
gen_fec_tlv(buf, me->map.prefix, me->map.prefixlen);
if (type == MSG_TYPE_LABELMAPPING ||
me->map.flags & F_MAP_OPTLABEL)
gen_label_tlv(buf, me->map.label);
if (me->map.flags & F_MAP_REQ_ID)
gen_reqid_tlv(buf, me->map.requestid);
TAILQ_REMOVE(mh, me, entry);
free(me);
}
enqueue_pdu(nbr, buf, size);
nbr_fsm(nbr, NBR_EVT_PDU_SENT);
}
/* Generic function that handles all Label Message types */
int
recv_labelmessage(struct nbr *nbr, char *buf, u_int16_t len, u_int16_t type)
{
struct ldp_msg lm;
struct tlv ft;
u_int32_t label, reqid = 0;
u_int8_t flags = 0;
int feclen, lbllen, tlen;
u_int8_t addr_type;
struct mapping_entry *me;
struct mapping_head mh;
bcopy(buf, &lm, sizeof(lm));
buf += sizeof(struct ldp_msg);
len -= sizeof(struct ldp_msg);
/* FEC TLV */
if (len < sizeof(ft)) {
session_shutdown(nbr, S_BAD_TLV_LEN, lm.msgid, lm.type);
return (-1);
}
bcopy(buf, &ft, sizeof(ft));
if (ntohs(ft.type) != TLV_TYPE_FEC) {
send_notification_nbr(nbr, S_MISS_MSG, lm.msgid, lm.type);
return (-1);
}
feclen = ntohs(ft.length);
if (feclen > len - TLV_HDR_LEN) {
session_shutdown(nbr, S_BAD_TLV_LEN, lm.msgid, lm.type);
return (-1);
}
buf += TLV_HDR_LEN; /* just advance to the end of the fec header */
len -= TLV_HDR_LEN;
TAILQ_INIT(&mh);
do {
me = calloc(1, sizeof(*me));
me->map.messageid = lm.msgid;
TAILQ_INSERT_HEAD(&mh, me, entry);
if ((tlen = tlv_decode_fec_elm(nbr, &lm, buf, feclen,
&addr_type, &me->map.prefix.s_addr, &me->map.prefixlen)) == -1)
goto err;
/*
* The Wildcard FEC Element can be used only in the
* Label Withdraw and Label Release messages.
*/
if (addr_type == FEC_WILDCARD) {
switch (type) {
case MSG_TYPE_LABELWITHDRAW:
case MSG_TYPE_LABELRELEASE:
me->map.flags |= F_MAP_WILDCARD;
break;
default:
session_shutdown(nbr, S_BAD_TLV_VAL, lm.msgid,
lm.type);
goto err;
break;
}
}
/*
* LDP supports the use of multiple FEC Elements per
* FEC for the Label Mapping message only.
*/
if (type != MSG_TYPE_LABELMAPPING &&
tlen != feclen) {
session_shutdown(nbr, S_BAD_TLV_VAL, lm.msgid,
lm.type);
goto err;
}
buf += tlen;
len -= tlen;
feclen -= tlen;
} while (feclen > 0);
/* Mandatory Label TLV */
if (type == MSG_TYPE_LABELMAPPING) {
lbllen = tlv_decode_label(nbr, &lm, buf, len, &label);
if (lbllen == -1)
goto err;
buf += lbllen;
len -= lbllen;
}
/* Optional Parameters */
while (len > 0) {
struct tlv tlv;
u_int32_t reqbuf, labelbuf;
if (len < sizeof(tlv)) {
session_shutdown(nbr, S_BAD_TLV_LEN, lm.msgid,
lm.type);
goto err;
}
bcopy(buf, &tlv, sizeof(tlv));
buf += TLV_HDR_LEN;
len -= TLV_HDR_LEN;
switch (ntohs(tlv.type)) {
case TLV_TYPE_LABELREQUEST:
switch (type) {
case MSG_TYPE_LABELMAPPING:
case MSG_TYPE_LABELABORTREQ:
if (ntohs(tlv.length) != 4) {
session_shutdown(nbr, S_BAD_TLV_LEN,
lm.msgid, lm.type);
goto err;
}
flags |= F_MAP_REQ_ID;
memcpy(&reqbuf, buf, sizeof(reqbuf));
reqid = ntohl(reqbuf);
break;
default:
/* ignore */
break;
}
break;
case TLV_TYPE_HOPCOUNT:
case TLV_TYPE_PATHVECTOR:
/* TODO just ignore for now */
break;
case TLV_TYPE_GENERICLABEL:
switch (type) {
case MSG_TYPE_LABELWITHDRAW:
case MSG_TYPE_LABELRELEASE:
if (ntohs(tlv.length) != 4) {
session_shutdown(nbr, S_BAD_TLV_LEN,
lm.msgid, lm.type);
goto err;
}
memcpy(&labelbuf, buf, sizeof(labelbuf));
label = ntohl(labelbuf);
flags |= F_MAP_OPTLABEL;
break;
default:
/* ignore */
break;
}
break;
case TLV_TYPE_ATMLABEL:
case TLV_TYPE_FRLABEL:
switch (type) {
case MSG_TYPE_LABELWITHDRAW:
case MSG_TYPE_LABELRELEASE:
/* unsupported */
session_shutdown(nbr, S_BAD_TLV_VAL, lm.msgid,
lm.type);
goto err;
break;
default:
/* ignore */
break;
}
break;
default:
if (!(ntohs(tlv.type) & UNKNOWN_FLAG)) {
send_notification_nbr(nbr, S_UNKNOWN_TLV,
lm.msgid, lm.type);
}
/* ignore unknown tlv */
break;
}
buf += ntohs(tlv.length);
len -= ntohs(tlv.length);
}
/* notify lde about the received message. */
while ((me = TAILQ_FIRST(&mh)) != NULL) {
int imsg_type = IMSG_NONE;
me->map.flags |= flags;
if (type == MSG_TYPE_LABELMAPPING ||
me->map.flags & F_MAP_OPTLABEL)
me->map.label = label;
if (me->map.flags & F_MAP_REQ_ID)
me->map.requestid = reqid;
switch (type) {
case MSG_TYPE_LABELMAPPING:
imsg_type = IMSG_LABEL_MAPPING;
break;
case MSG_TYPE_LABELREQUEST:
imsg_type = IMSG_LABEL_REQUEST;
break;
case MSG_TYPE_LABELWITHDRAW:
imsg_type = IMSG_LABEL_WITHDRAW;
break;
case MSG_TYPE_LABELRELEASE:
imsg_type = IMSG_LABEL_RELEASE;
break;
case MSG_TYPE_LABELABORTREQ:
imsg_type = IMSG_LABEL_ABORT;
break;
default:
break;
}
ldpe_imsg_compose_lde(imsg_type, nbr->peerid, 0, &me->map,
sizeof(struct map));
TAILQ_REMOVE(&mh, me, entry);
free(me);
}
return (ntohs(lm.length));
err:
mapping_list_clr(&mh);
return (-1);
}
/* Other TLV related functions */
void
gen_label_tlv(struct ibuf *buf, u_int32_t label)
{
struct label_tlv lt;
lt.type = htons(TLV_TYPE_GENERICLABEL);
lt.length = htons(sizeof(label));
lt.label = htonl(label);
ibuf_add(buf, <, sizeof(lt));
}
int
tlv_decode_label(struct nbr *nbr, struct ldp_msg *lm, char *buf,
u_int16_t len, u_int32_t *label)
{
struct label_tlv lt;
if (len < sizeof(lt)) {
session_shutdown(nbr, S_BAD_TLV_LEN, lm->msgid, lm->type);
return (-1);
}
bcopy(buf, <, sizeof(lt));
if (!(ntohs(lt.type) & TLV_TYPE_GENERICLABEL)) {
send_notification_nbr(nbr, S_MISS_MSG, lm->msgid, lm->type);
return (-1);
}
switch (htons(lt.type)) {
case TLV_TYPE_GENERICLABEL:
if (ntohs(lt.length) != sizeof(lt) - TLV_HDR_LEN) {
session_shutdown(nbr, S_BAD_TLV_LEN, lm->msgid,
lm->type);
return (-1);
}
*label = ntohl(lt.label);
if (*label > MPLS_LABEL_MAX ||
(*label <= MPLS_LABEL_RESERVED_MAX &&
*label != MPLS_LABEL_IPV4NULL &&
*label != MPLS_LABEL_IMPLNULL)) {
session_shutdown(nbr, S_BAD_TLV_VAL, lm->msgid,
lm->type);
return (-1);
}
break;
case TLV_TYPE_ATMLABEL:
case TLV_TYPE_FRLABEL:
default:
/* unsupported */
session_shutdown(nbr, S_BAD_TLV_VAL, lm->msgid, lm->type);
return (-1);
}
return (sizeof(lt));
}
void
gen_reqid_tlv(struct ibuf *buf, u_int32_t reqid)
{
struct reqid_tlv rt;
rt.type = htons(TLV_TYPE_LABELREQUEST);
rt.length = htons(sizeof(reqid));
rt.reqid = htonl(reqid);
ibuf_add(buf, &rt, sizeof(rt));
}
void
gen_fec_tlv(struct ibuf *buf, struct in_addr prefix, u_int8_t prefixlen)
{
struct tlv ft;
u_int8_t type;
u_int16_t family;
u_int8_t len;
len = PREFIX_SIZE(prefixlen);
ft.type = htons(TLV_TYPE_FEC);
ft.length = htons(sizeof(type) + sizeof(family) + sizeof(prefixlen) +
len);
ibuf_add(buf, &ft, sizeof(ft));
type = FEC_PREFIX;
family = htons(FEC_IPV4);
ibuf_add(buf, &type, sizeof(type));
ibuf_add(buf, &family, sizeof(family));
ibuf_add(buf, &prefixlen, sizeof(prefixlen));
if (len)
ibuf_add(buf, &prefix, len);
}
int
tlv_decode_fec_elm(struct nbr *nbr, struct ldp_msg *lm, char *buf,
u_int16_t len, u_int8_t *type, u_int32_t *prefix, u_int8_t *prefixlen)
{
u_int16_t family, off = 0;
*type = *buf;
off += sizeof(u_int8_t);
if (*type == FEC_WILDCARD) {
if (len == 0)
return (off);
else {
session_shutdown(nbr, S_BAD_TLV_VAL, lm->msgid,
lm->type);
return (-1);
}
}
if (*type != FEC_PREFIX) {
send_notification_nbr(nbr, S_UNKNOWN_FEC, lm->msgid, lm->type);
return (-1);
}
if (len < FEC_ELM_MIN_LEN) {
session_shutdown(nbr, S_BAD_TLV_LEN, lm->msgid, lm->type);
return (-1);
}
bcopy(buf + off, &family, sizeof(family));
off += sizeof(family);
if (family != htons(FEC_IPV4)) {
send_notification_nbr(nbr, S_UNSUP_ADDR, lm->msgid, lm->type);
return (-1);
}
*prefixlen = buf[off];
off += sizeof(u_int8_t);
if (len < off + PREFIX_SIZE(*prefixlen)) {
session_shutdown(nbr, S_BAD_TLV_LEN, lm->msgid, lm->type);
return (-1);
}
*prefix = 0;
bcopy(buf + off, prefix, PREFIX_SIZE(*prefixlen));
return (off + PREFIX_SIZE(*prefixlen));
}
|