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bird/proto/ospf/dbdes.c
Ondrej Zajicek (work) a30b9d2800 OSPF: Opaque LSAs and Router Information LSA
Add support for OSPFv2 Opaque LSAs (RFC 5250) and for Router Information
LSA (RFC 7770). The second part is here mainly for testing opaque LSAs.
2019-02-17 23:02:05 +01:00

506 lines
12 KiB
C

/*
* BIRD -- OSPF
*
* (c) 1999--2004 Ondrej Filip <feela@network.cz>
* (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2009--2014 CZ.NIC z.s.p.o.
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include "ospf.h"
struct ospf_dbdes2_packet
{
struct ospf_packet hdr;
union ospf_auth auth;
u16 iface_mtu;
u8 options;
u8 imms; /* I, M, MS bits */
u32 ddseq;
struct ospf_lsa_header lsas[];
};
struct ospf_dbdes3_packet
{
struct ospf_packet hdr;
u32 options;
u16 iface_mtu;
u8 padding;
u8 imms; /* I, M, MS bits */
u32 ddseq;
struct ospf_lsa_header lsas[];
};
static inline uint
ospf_dbdes_hdrlen(struct ospf_proto *p)
{
return ospf_is_v2(p) ?
sizeof(struct ospf_dbdes2_packet) : sizeof(struct ospf_dbdes3_packet);
}
static void
ospf_dbdes_body(struct ospf_proto *p, struct ospf_packet *pkt,
struct ospf_lsa_header **body, uint *count)
{
uint plen = ntohs(pkt->length);
uint hlen = ospf_dbdes_hdrlen(p);
*body = ((void *) pkt) + hlen;
*count = (plen - hlen) / sizeof(struct ospf_lsa_header);
}
static void
ospf_dump_dbdes(struct ospf_proto *p, struct ospf_packet *pkt)
{
struct ospf_lsa_header *lsas;
uint i, lsa_count;
u32 pkt_ddseq;
u16 pkt_iface_mtu;
u8 pkt_imms;
ASSERT(pkt->type == DBDES_P);
ospf_dump_common(p, pkt);
if (ospf_is_v2(p))
{
struct ospf_dbdes2_packet *ps = (void *) pkt;
pkt_iface_mtu = ntohs(ps->iface_mtu);
pkt_imms = ps->imms;
pkt_ddseq = ntohl(ps->ddseq);
}
else /* OSPFv3 */
{
struct ospf_dbdes3_packet *ps = (void *) pkt;
pkt_iface_mtu = ntohs(ps->iface_mtu);
pkt_imms = ps->imms;
pkt_ddseq = ntohl(ps->ddseq);
}
log(L_TRACE "%s: mtu %u", p->p.name, pkt_iface_mtu);
log(L_TRACE "%s: imms %s%s%s", p->p.name,
(pkt_imms & DBDES_I) ? "I " : "",
(pkt_imms & DBDES_M) ? "M " : "",
(pkt_imms & DBDES_MS) ? "MS" : "");
log(L_TRACE "%s: ddseq %u", p->p.name, pkt_ddseq);
ospf_dbdes_body(p, pkt, &lsas, &lsa_count);
for (i = 0; i < lsa_count; i++)
ospf_dump_lsahdr(p, lsas + i);
}
static void
ospf_prepare_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
{
struct ospf_iface *ifa = n->ifa;
struct ospf_packet *pkt;
uint length;
u16 iface_mtu = (ifa->type == OSPF_IT_VLINK) ? 0 : ifa->iface->mtu;
/* Update DBDES buffer */
if (n->ldd_bsize != ifa->tx_length)
{
mb_free(n->ldd_buffer);
n->ldd_buffer = mb_allocz(n->pool, ifa->tx_length);
n->ldd_bsize = ifa->tx_length;
}
pkt = n->ldd_buffer;
ospf_pkt_fill_hdr(ifa, pkt, DBDES_P);
if (ospf_is_v2(p))
{
struct ospf_dbdes2_packet *ps = (void *) pkt;
ps->iface_mtu = htons(iface_mtu);
ps->options = ifa->oa->options | OPT_O;
ps->imms = 0; /* Will be set later */
ps->ddseq = htonl(n->dds);
length = sizeof(struct ospf_dbdes2_packet);
}
else /* OSPFv3 */
{
struct ospf_dbdes3_packet *ps = (void *) pkt;
ps->options = htonl(ifa->oa->options);
ps->iface_mtu = htons(iface_mtu);
ps->padding = 0;
ps->imms = 0; /* Will be set later */
ps->ddseq = htonl(n->dds);
length = sizeof(struct ospf_dbdes3_packet);
}
/* Prepare DBDES body */
if (!(n->myimms & DBDES_I) && (n->myimms & DBDES_M))
{
struct ospf_lsa_header *lsas;
struct top_hash_entry *en;
uint i = 0, lsa_max;
ospf_dbdes_body(p, pkt, &lsas, &lsa_max);
en = (void *) s_get(&(n->dbsi));
while (i < lsa_max)
{
if (!SNODE_VALID(en))
{
n->myimms &= ~DBDES_M; /* Unset More bit */
break;
}
if ((en->lsa.age < LSA_MAXAGE) &&
lsa_flooding_allowed(en->lsa_type, en->domain, ifa) &&
lsa_is_acceptable(en->lsa_type, n, p))
{
lsa_hton_hdr(&(en->lsa), lsas + i);
i++;
}
en = SNODE_NEXT(en);
}
s_put(&(n->dbsi), SNODE en);
length += i * sizeof(struct ospf_lsa_header);
}
if (ospf_is_v2(p))
((struct ospf_dbdes2_packet *) pkt)->imms = n->myimms;
else
((struct ospf_dbdes3_packet *) pkt)->imms = n->myimms;
pkt->length = htons(length);
}
static void
ospf_do_send_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
{
struct ospf_iface *ifa = n->ifa;
OSPF_PACKET(ospf_dump_dbdes, n->ldd_buffer,
"DBDES packet sent to nbr %R on %s", n->rid, ifa->ifname);
sk_set_tbuf(ifa->sk, n->ldd_buffer);
ospf_send_to(ifa, n->ip);
sk_set_tbuf(ifa->sk, NULL);
}
/**
* ospf_send_dbdes - transmit database description packet
* @p: OSPF protocol instance
* @n: neighbor
*
* Sending of a database description packet is described in 10.8 of RFC 2328.
* Reception of each packet is acknowledged in the sequence number of another.
* When I send a packet to a neighbor I keep a copy in a buffer. If the neighbor
* does not reply, I don't create a new packet but just send the content
* of the buffer.
*/
void
ospf_send_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
{
/* RFC 2328 10.8 */
ASSERT((n->state == NEIGHBOR_EXSTART) || (n->state == NEIGHBOR_EXCHANGE));
if (n->ifa->oa->rt == NULL)
return;
ospf_prepare_dbdes(p, n);
ospf_do_send_dbdes(p, n);
}
void
ospf_rxmt_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
{
struct ospf_iface *ifa = n->ifa;
ASSERT(n->state > NEIGHBOR_EXSTART);
if (!n->ldd_buffer)
{
log(L_WARN "%s: No DBDES packet for retransmit", p->p.name);
STATS(bad_dbdes);
ospf_neigh_sm(n, INM_SEQMIS);
return;
}
/* Send last packet */
ospf_do_send_dbdes(p, n);
}
void
ospf_reset_ldd(struct ospf_proto *p UNUSED, struct ospf_neighbor *n)
{
mb_free(n->ldd_buffer);
n->ldd_buffer = NULL;
n->ldd_bsize = 0;
}
static int
ospf_process_dbdes(struct ospf_proto *p, struct ospf_packet *pkt, struct ospf_neighbor *n)
{
struct ospf_iface *ifa = n->ifa;
struct ospf_lsa_header *lsas, lsa;
struct top_hash_entry *en, *req;
const char *err_dsc = NULL;
u32 lsa_type, lsa_domain;
uint i, lsa_count;
ospf_dbdes_body(p, pkt, &lsas, &lsa_count);
for (i = 0; i < lsa_count; i++)
{
lsa_ntoh_hdr(lsas + i, &lsa);
lsa_get_type_domain(&lsa, ifa, &lsa_type, &lsa_domain);
/* RFC 2328 10.6 and RFC 5340 4.2.2 */
if (!lsa_type)
DROP1(bad_dbdes, "LSA of unknown type");
if (!oa_is_ext(ifa->oa) && (LSA_SCOPE(lsa_type) == LSA_SCOPE_AS))
DROP1(bad_dbdes, "LSA with AS scope in stub area");
/* Errata 3746 to RFC 2328 - rt-summary-LSAs forbidden in stub areas */
if (!oa_is_ext(ifa->oa) && (lsa_type == LSA_T_SUM_RT))
DROP1(bad_dbdes, "rt-summary-LSA in stub area");
/* Not explicitly mentioned in RFC 5340 4.2.2 but makes sense */
if (LSA_SCOPE(lsa_type) == LSA_SCOPE_RES)
DROP1(bad_dbdes, "LSA with invalid scope");
en = ospf_hash_find(p->gr, lsa_domain, lsa.id, lsa.rt, lsa_type);
if (!en || (lsa_comp(&lsa, &(en->lsa)) == CMP_NEWER))
{
/* This should be splitted to ospf_lsa_lsrq_up() */
req = ospf_hash_get(n->lsrqh, lsa_domain, lsa.id, lsa.rt, lsa_type);
if (!SNODE_VALID(req))
s_add_tail(&n->lsrql, SNODE req);
if (!SNODE_VALID(n->lsrqi))
n->lsrqi = req;
req->lsa = lsa;
req->lsa_body = LSA_BODY_DUMMY;
if (!tm_active(n->lsrq_timer))
tm_start(n->lsrq_timer, 0);
}
}
return 0;
drop:
LOG_LSA1("Bad LSA (Type: %04x, Id: %R, Rt: %R) in DBDES", lsa_type, lsa.id, lsa.rt);
LOG_LSA2(" received from nbr %R on %s - %s", n->rid, ifa->ifname, err_dsc);
ospf_neigh_sm(n, INM_SEQMIS);
return -1;
}
void
ospf_receive_dbdes(struct ospf_packet *pkt, struct ospf_iface *ifa,
struct ospf_neighbor *n)
{
struct ospf_proto *p = ifa->oa->po;
const char *err_dsc = NULL;
u32 rcv_ddseq, rcv_options;
u16 rcv_iface_mtu;
u8 rcv_imms;
uint plen, err_val = 0;
/* RFC 2328 10.6 */
plen = ntohs(pkt->length);
if (plen < ospf_dbdes_hdrlen(p))
{
LOG_PKT("Bad DBDES packet from nbr %R on %s - %s (%u)", n->rid, ifa->ifname, "too short", plen);
STATS2(bad_pkt, dropped);
return;
}
OSPF_PACKET(ospf_dump_dbdes, pkt, "DBDES packet received from nbr %R on %s", n->rid, ifa->ifname);
ospf_neigh_sm(n, INM_HELLOREC);
if (ospf_is_v2(p))
{
struct ospf_dbdes2_packet *ps = (void *) pkt;
rcv_iface_mtu = ntohs(ps->iface_mtu);
rcv_options = ps->options;
rcv_imms = ps->imms;
rcv_ddseq = ntohl(ps->ddseq);
}
else /* OSPFv3 */
{
struct ospf_dbdes3_packet *ps = (void *) pkt;
rcv_options = ntohl(ps->options);
rcv_iface_mtu = ntohs(ps->iface_mtu);
rcv_imms = ps->imms;
rcv_ddseq = ntohl(ps->ddseq);
}
/* Reject packets with non-matching MTU */
if ((ifa->type != OSPF_IT_VLINK) &&
(rcv_iface_mtu != ifa->iface->mtu) &&
(rcv_iface_mtu != 0) && (ifa->iface->mtu != 0))
{
LOG_PKT("MTU mismatch with nbr %R on %s (remote %d, local %d)",
n->rid, ifa->ifname, rcv_iface_mtu, ifa->iface->mtu);
STATS2(bad_dbdes, dropped);
return;
}
switch (n->state)
{
case NEIGHBOR_DOWN:
case NEIGHBOR_ATTEMPT:
case NEIGHBOR_2WAY:
OSPF_TRACE(D_PACKETS, "DBDES packet ignored - lesser state than ExStart");
return;
case NEIGHBOR_INIT:
ospf_neigh_sm(n, INM_2WAYREC);
if (n->state != NEIGHBOR_EXSTART)
return;
/* fallthrough */
case NEIGHBOR_EXSTART:
if (((rcv_imms & DBDES_IMMS) == DBDES_IMMS) &&
(n->rid > p->router_id) &&
(plen == ospf_dbdes_hdrlen(p)))
{
/* I'm slave! */
n->dds = rcv_ddseq;
n->ddr = rcv_ddseq;
n->options = rcv_options;
n->myimms &= ~DBDES_MS;
n->imms = rcv_imms;
tm_stop(n->dbdes_timer);
ospf_neigh_sm(n, INM_NEGDONE);
ospf_send_dbdes(p, n);
break;
}
if (!(rcv_imms & DBDES_I) &&
!(rcv_imms & DBDES_MS) &&
(n->rid < p->router_id) &&
(n->dds == rcv_ddseq))
{
/* I'm master! */
n->options = rcv_options;
n->ddr = rcv_ddseq - 1; /* It will be set corectly a few lines down */
n->imms = rcv_imms;
ospf_neigh_sm(n, INM_NEGDONE);
/* Continue to the NEIGHBOR_EXCHANGE case */
}
else
{
DBG("%s: Nothing happend to %I (imms=%d)\n", p->name, n->ip, rcv_imms);
break;
}
case NEIGHBOR_EXCHANGE:
if ((rcv_imms == n->imms) &&
(rcv_options == n->options) &&
(rcv_ddseq == n->ddr))
goto duplicate;
if ((rcv_imms & DBDES_MS) != (n->imms & DBDES_MS))
DROP(bad_dbdes, "MS-bit mismatch", rcv_imms);
if (rcv_imms & DBDES_I)
DROP(bad_dbdes, "I-bit mismatch", rcv_imms);
if (rcv_options != n->options)
DROP(bad_dbdes, "options mismatch", rcv_options);
n->ddr = rcv_ddseq;
n->imms = rcv_imms;
if (n->myimms & DBDES_MS)
{
/* MASTER */
if (rcv_ddseq != n->dds)
DROP(bad_dbdes, "DD sequence number mismatch", rcv_ddseq);
n->dds++;
if (ospf_process_dbdes(p, pkt, n) < 0)
return;
if (!(n->myimms & DBDES_M) && !(n->imms & DBDES_M))
{
tm_stop(n->dbdes_timer);
ospf_reset_ldd(p, n);
ospf_neigh_sm(n, INM_EXDONE);
break;
}
ospf_send_dbdes(p, n);
tm_start(n->dbdes_timer, n->ifa->rxmtint S);
}
else
{
/* SLAVE */
if (rcv_ddseq != (n->dds + 1))
DROP(bad_dbdes, "DD sequence number mismatch", rcv_ddseq);
n->ddr = rcv_ddseq;
n->dds = rcv_ddseq;
if (ospf_process_dbdes(p, pkt, n) < 0)
return;
ospf_send_dbdes(p, n);
if (!(n->myimms & DBDES_M) && !(n->imms & DBDES_M))
{
/* Use dbdes timer to postpone freeing of Last DBDES packet buffer */
tm_start(n->dbdes_timer, n->ifa->deadint S);
ospf_neigh_sm(n, INM_EXDONE);
}
}
break;
case NEIGHBOR_LOADING:
case NEIGHBOR_FULL:
if ((rcv_imms == n->imms) &&
(rcv_options == n->options) &&
(rcv_ddseq == n->ddr))
goto duplicate;
DROP(bad_dbdes, "too late for DD exchange", n->state);
default:
bug("Undefined interface state");
}
return;
duplicate:
OSPF_TRACE(D_PACKETS, "DBDES packet is duplicate");
/* Slave should retransmit DBDES packet */
if (!(n->myimms & DBDES_MS))
ospf_rxmt_dbdes(p, n);
return;
drop:
LOG_PKT("Bad DBDES packet from nbr %R on %s - %s (%u)",
n->rid, ifa->ifname, err_dsc, err_val);
ospf_neigh_sm(n, INM_SEQMIS);
return;
}