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|
// SPDX-License-Identifier: ISC
/* $OpenBSD$ */
/*
* Copyright (c) 2009 Michele Marchetto <michele@openbsd.org>
*/
#include <zebra.h>
#include "ldpd.h"
#include "ldpe.h"
#include "log.h"
#include "ldp_debug.h"
static int gen_init_prms_tlv(struct ibuf *, struct nbr *);
static int gen_cap_dynamic_tlv(struct ibuf *);
static int gen_cap_twcard_tlv(struct ibuf *, int);
static int gen_cap_unotif_tlv(struct ibuf *, int);
void
send_init(struct nbr *nbr)
{
struct ibuf *buf;
uint16_t size;
int err = 0;
debug_msg_send("initialization: lsr-id %pI4", &nbr->id);
size = LDP_HDR_SIZE + LDP_MSG_SIZE + SESS_PRMS_SIZE +
CAP_TLV_DYNAMIC_SIZE + CAP_TLV_TWCARD_SIZE + CAP_TLV_UNOTIF_SIZE;
if ((buf = ibuf_open(size)) == NULL)
fatal(__func__);
SET_FLAG(err, gen_ldp_hdr(buf, size));
size -= LDP_HDR_SIZE;
SET_FLAG(err, gen_msg_hdr(buf, MSG_TYPE_INIT, size));
SET_FLAG(err, gen_init_prms_tlv(buf, nbr));
SET_FLAG(err, gen_cap_dynamic_tlv(buf));
SET_FLAG(err, gen_cap_twcard_tlv(buf, 1));
SET_FLAG(err, gen_cap_unotif_tlv(buf, 1));
if (err) {
ibuf_free(buf);
return;
}
evbuf_enqueue(&nbr->tcp->wbuf, buf);
}
int
recv_init(struct nbr *nbr, char *buf, uint16_t len)
{
struct ldp_msg msg;
struct sess_prms_tlv sess;
uint16_t max_pdu_len;
int caps_rcvd = 0;
debug_msg_recv("initialization: lsr-id %pI4", &nbr->id);
memcpy(&msg, buf, sizeof(msg));
buf += LDP_MSG_SIZE;
len -= LDP_MSG_SIZE;
if (len < SESS_PRMS_SIZE) {
session_shutdown(nbr, S_BAD_MSG_LEN, msg.id, msg.type);
return (-1);
}
memcpy(&sess, buf, sizeof(sess));
if (ntohs(sess.length) != SESS_PRMS_LEN) {
session_shutdown(nbr, S_BAD_TLV_LEN, msg.id, msg.type);
return (-1);
}
if (ntohs(sess.proto_version) != LDP_VERSION) {
session_shutdown(nbr, S_BAD_PROTO_VER, msg.id, msg.type);
return (-1);
}
if (ntohs(sess.keepalive_time) < MIN_KEEPALIVE) {
session_shutdown(nbr, S_KEEPALIVE_BAD, msg.id, msg.type);
return (-1);
}
if (sess.lsr_id != ldp_rtr_id_get(leconf) ||
ntohs(sess.lspace_id) != 0) {
session_shutdown(nbr, S_NO_HELLO, msg.id, msg.type);
return (-1);
}
buf += SESS_PRMS_SIZE;
len -= SESS_PRMS_SIZE;
/* Optional Parameters */
while (len > 0) {
struct tlv tlv;
uint16_t tlv_type;
uint16_t tlv_len;
if (len < sizeof(tlv)) {
session_shutdown(nbr, S_BAD_TLV_LEN, msg.id, msg.type);
return (-1);
}
memcpy(&tlv, buf, TLV_HDR_SIZE);
tlv_type = ntohs(tlv.type);
tlv_len = ntohs(tlv.length);
if (tlv_len + TLV_HDR_SIZE > len) {
session_shutdown(nbr, S_BAD_TLV_LEN, msg.id, msg.type);
return (-1);
}
buf += TLV_HDR_SIZE;
len -= TLV_HDR_SIZE;
/*
* RFC 5561 - Section 6:
* "The S-bit of a Capability Parameter in an Initialization
* message MUST be 1 and SHOULD be ignored on receipt".
*/
switch (tlv_type) {
case TLV_TYPE_ATMSESSIONPAR:
session_shutdown(nbr, S_BAD_TLV_VAL, msg.id, msg.type);
return (-1);
case TLV_TYPE_FRSESSION:
session_shutdown(nbr, S_BAD_TLV_VAL, msg.id, msg.type);
return (-1);
case TLV_TYPE_DYNAMIC_CAP:
if (tlv_len != CAP_TLV_DYNAMIC_LEN) {
session_shutdown(nbr, S_BAD_TLV_LEN, msg.id, msg.type);
return (-1);
}
if (CHECK_FLAG(caps_rcvd, F_CAP_TLV_RCVD_DYNAMIC)) {
session_shutdown(nbr, S_BAD_TLV_VAL, msg.id, msg.type);
return (-1);
}
SET_FLAG(caps_rcvd, F_CAP_TLV_RCVD_DYNAMIC);
SET_FLAG(nbr->flags, F_NBR_CAP_DYNAMIC);
log_debug("%s: lsr-id %pI4 announced the Dynamic Capability Announcement capability", __func__,
&nbr->id);
break;
case TLV_TYPE_TWCARD_CAP:
if (tlv_len != CAP_TLV_TWCARD_LEN) {
session_shutdown(nbr, S_BAD_TLV_LEN, msg.id, msg.type);
return (-1);
}
if (CHECK_FLAG(caps_rcvd, F_CAP_TLV_RCVD_TWCARD)) {
session_shutdown(nbr, S_BAD_TLV_VAL, msg.id, msg.type);
return (-1);
}
SET_FLAG(caps_rcvd, F_CAP_TLV_RCVD_TWCARD);
SET_FLAG(nbr->flags, F_NBR_CAP_TWCARD);
log_debug("%s: lsr-id %pI4 announced the Typed Wildcard FEC capability", __func__, &nbr->id);
break;
case TLV_TYPE_UNOTIF_CAP:
if (tlv_len != CAP_TLV_UNOTIF_LEN) {
session_shutdown(nbr, S_BAD_TLV_LEN, msg.id, msg.type);
return (-1);
}
if (CHECK_FLAG(caps_rcvd, F_CAP_TLV_RCVD_UNOTIF)) {
session_shutdown(nbr, S_BAD_TLV_VAL, msg.id, msg.type);
return (-1);
}
SET_FLAG(caps_rcvd, F_CAP_TLV_RCVD_UNOTIF);
SET_FLAG(nbr->flags, F_NBR_CAP_UNOTIF);
log_debug("%s: lsr-id %pI4 announced the Unrecognized Notification capability", __func__,
&nbr->id);
break;
default:
if (!CHECK_FLAG(ntohs(tlv.type), UNKNOWN_FLAG))
send_notification_rtlvs(nbr, S_UNSSUPORTDCAP,
msg.id, msg.type, tlv_type, tlv_len, buf);
/* ignore unknown tlv */
break;
}
buf += tlv_len;
len -= tlv_len;
}
nbr->keepalive = MIN(nbr_get_keepalive(nbr->af, nbr->id),
ntohs(sess.keepalive_time));
max_pdu_len = ntohs(sess.max_pdu_len);
/*
* RFC 5036 - Section 3.5.3:
* "A value of 255 or less specifies the default maximum length of
* 4096 octets".
*/
if (max_pdu_len <= 255)
max_pdu_len = LDP_MAX_LEN;
nbr->max_pdu_len = MIN(max_pdu_len, LDP_MAX_LEN);
nbr_fsm(nbr, NBR_EVT_INIT_RCVD);
return (0);
}
void
send_capability(struct nbr *nbr, uint16_t capability, int enable)
{
struct ibuf *buf;
uint16_t size;
int err = 0;
log_debug("%s: lsr-id %pI4", __func__, &nbr->id);
size = LDP_HDR_SIZE + LDP_MSG_SIZE + CAP_TLV_DYNAMIC_SIZE;
if ((buf = ibuf_open(size)) == NULL)
fatal(__func__);
SET_FLAG(err, gen_ldp_hdr(buf, size));
size -= LDP_HDR_SIZE;
SET_FLAG(err, gen_msg_hdr(buf, MSG_TYPE_CAPABILITY, size));
switch (capability) {
case TLV_TYPE_TWCARD_CAP:
SET_FLAG(err, gen_cap_twcard_tlv(buf, enable));
break;
case TLV_TYPE_UNOTIF_CAP:
SET_FLAG(err, gen_cap_unotif_tlv(buf, enable));
break;
case TLV_TYPE_DYNAMIC_CAP:
/*
* RFC 5561 - Section 9:
* "An LDP speaker MUST NOT include the Dynamic Capability
* Announcement Parameter in Capability messages sent to
* its peers".
*/
fatalx("send_capability: An LDP speaker MUST NOT include the Dynamic Capability Announcement Parameter");
break;
default:
fatalx("send_capability: unsupported capability");
break;
}
if (err) {
ibuf_free(buf);
return;
}
evbuf_enqueue(&nbr->tcp->wbuf, buf);
nbr_fsm(nbr, NBR_EVT_PDU_SENT);
nbr->stats.capability_sent++;
}
int
recv_capability(struct nbr *nbr, char *buf, uint16_t len)
{
struct ldp_msg msg;
int enable = 0;
int caps_rcvd = 0;
log_debug("%s: lsr-id %pI4", __func__, &nbr->id);
memcpy(&msg, buf, sizeof(msg));
buf += LDP_MSG_SIZE;
len -= LDP_MSG_SIZE;
/* Optional Parameters */
while (len > 0) {
struct tlv tlv;
uint16_t tlv_type;
uint16_t tlv_len;
uint8_t reserved;
if (len < sizeof(tlv)) {
session_shutdown(nbr, S_BAD_TLV_LEN, msg.id, msg.type);
return (-1);
}
memcpy(&tlv, buf, TLV_HDR_SIZE);
tlv_type = ntohs(tlv.type);
tlv_len = ntohs(tlv.length);
if (tlv_len + TLV_HDR_SIZE > len) {
session_shutdown(nbr, S_BAD_TLV_LEN, msg.id, msg.type);
return (-1);
}
buf += TLV_HDR_SIZE;
len -= TLV_HDR_SIZE;
switch (tlv_type) {
case TLV_TYPE_TWCARD_CAP:
if (tlv_len != CAP_TLV_TWCARD_LEN) {
session_shutdown(nbr, S_BAD_TLV_LEN, msg.id, msg.type);
return (-1);
}
if (CHECK_FLAG(caps_rcvd, F_CAP_TLV_RCVD_TWCARD)) {
session_shutdown(nbr, S_BAD_TLV_VAL, msg.id, msg.type);
return (-1);
}
SET_FLAG(caps_rcvd, F_CAP_TLV_RCVD_TWCARD);
memcpy(&reserved, buf, sizeof(reserved));
enable = reserved & STATE_BIT;
if (enable)
SET_FLAG(nbr->flags, F_NBR_CAP_TWCARD);
else
UNSET_FLAG(nbr->flags, F_NBR_CAP_TWCARD);
log_debug("%s: lsr-id %pI4 %s the Typed Wildcard FEC capability", __func__, &nbr->id,
(enable) ? "announced" : "withdrew");
break;
case TLV_TYPE_UNOTIF_CAP:
if (tlv_len != CAP_TLV_UNOTIF_LEN) {
session_shutdown(nbr, S_BAD_TLV_LEN, msg.id, msg.type);
return (-1);
}
if (CHECK_FLAG(caps_rcvd, F_CAP_TLV_RCVD_UNOTIF)) {
session_shutdown(nbr, S_BAD_TLV_VAL, msg.id, msg.type);
return (-1);
}
SET_FLAG(caps_rcvd, F_CAP_TLV_RCVD_UNOTIF);
memcpy(&reserved, buf, sizeof(reserved));
enable = reserved & STATE_BIT;
if (enable)
SET_FLAG(nbr->flags, F_NBR_CAP_UNOTIF);
else
UNSET_FLAG(nbr->flags, F_NBR_CAP_UNOTIF);
log_debug("%s: lsr-id %pI4 %s the Unrecognized Notification capability", __func__,
&nbr->id, (enable) ? "announced" : "withdrew");
break;
case TLV_TYPE_DYNAMIC_CAP:
/*
* RFC 5561 - Section 9:
* "An LDP speaker that receives a Capability message
* from a peer that includes the Dynamic Capability
* Announcement Parameter SHOULD silently ignore the
* parameter and process any other Capability Parameters
* in the message".
*/
fallthrough;
default:
if (!CHECK_FLAG(ntohs(tlv.type), UNKNOWN_FLAG))
send_notification_rtlvs(nbr, S_UNSSUPORTDCAP,
msg.id, msg.type, tlv_type, tlv_len, buf);
/* ignore unknown tlv */
break;
}
buf += tlv_len;
len -= tlv_len;
}
nbr_fsm(nbr, NBR_EVT_PDU_RCVD);
return (0);
}
static int
gen_init_prms_tlv(struct ibuf *buf, struct nbr *nbr)
{
struct sess_prms_tlv parms;
memset(&parms, 0, sizeof(parms));
parms.type = htons(TLV_TYPE_COMMONSESSION);
parms.length = htons(SESS_PRMS_LEN);
parms.proto_version = htons(LDP_VERSION);
parms.keepalive_time = htons(nbr_get_keepalive(nbr->af, nbr->id));
parms.reserved = 0;
parms.pvlim = 0;
parms.max_pdu_len = 0;
parms.lsr_id = nbr->id.s_addr;
parms.lspace_id = 0;
return (ibuf_add(buf, &parms, SESS_PRMS_SIZE));
}
static int
gen_cap_dynamic_tlv(struct ibuf *buf)
{
struct capability_tlv cap;
memset(&cap, 0, sizeof(cap));
cap.type = htons(TLV_TYPE_DYNAMIC_CAP);
cap.length = htons(CAP_TLV_DYNAMIC_LEN);
/* the S-bit is always 1 for the Dynamic Capability Announcement */
cap.reserved = STATE_BIT;
return (ibuf_add(buf, &cap, CAP_TLV_DYNAMIC_SIZE));
}
static int
gen_cap_twcard_tlv(struct ibuf *buf, int enable)
{
struct capability_tlv cap;
memset(&cap, 0, sizeof(cap));
cap.type = htons(TLV_TYPE_TWCARD_CAP);
cap.length = htons(CAP_TLV_TWCARD_LEN);
if (enable)
cap.reserved = STATE_BIT;
return (ibuf_add(buf, &cap, CAP_TLV_TWCARD_SIZE));
}
static int
gen_cap_unotif_tlv(struct ibuf *buf, int enable)
{
struct capability_tlv cap;
memset(&cap, 0, sizeof(cap));
cap.type = htons(TLV_TYPE_UNOTIF_CAP);
cap.length = htons(CAP_TLV_UNOTIF_LEN);
if (enable)
cap.reserved = STATE_BIT;
return (ibuf_add(buf, &cap, CAP_TLV_UNOTIF_SIZE));
}
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