bird/proto/ospf/lsupd.c
2011-09-03 21:31:26 +02:00

742 lines
18 KiB
C

/*
* BIRD -- OSPF
*
* (c) 2000--2004 Ondrej Filip <feela@network.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include "ospf.h"
struct ospf_lsupd_packet
{
struct ospf_packet ospf_packet;
u32 lsano; /* Number of LSA's */
};
/* Beware of unaligned access */
void ospf_dump_lsahdr(struct proto *p, struct ospf_lsa_header *lsa_n)
{
struct ospf_lsa_header lsa;
ntohlsah(lsa_n, &lsa);
log(L_TRACE "%s: LSA Type: %04x, Id: %R, Rt: %R, Age: %u, Seq: %08x, Sum: %04x",
p->name, lsa.type, lsa.id, lsa.rt, lsa.age, lsa.sn, lsa.checksum);
}
void ospf_dump_common(struct proto *p, struct ospf_packet *op)
{
log(L_TRACE "%s: length %d", p->name, ntohs(op->length));
log(L_TRACE "%s: router %R", p->name, ntohl(op->routerid));
}
static void ospf_dump_lsupd(struct proto *p, struct ospf_lsupd_packet *pkt)
{
struct ospf_packet *op = &pkt->ospf_packet;
ASSERT(op->type == LSUPD_P);
ospf_dump_common(p, op);
/* We know that ntohs(op->length) >= sizeof(struct ospf_lsa_header) */
u8 *pbuf= (u8 *) pkt;
unsigned int offset = sizeof(struct ospf_lsupd_packet);
unsigned int bound = ntohs(op->length) - sizeof(struct ospf_lsa_header);
unsigned int i, j, lsalen;
j = ntohl(pkt->lsano);
for (i = 0; i < j; i++)
{
if (offset > bound)
{
log(L_TRACE "%s: LSA invalid", p->name);
return;
}
struct ospf_lsa_header *lsa = (void *) (pbuf + offset);
ospf_dump_lsahdr(p, lsa);
lsalen = ntohs(lsa->length);
offset += lsalen;
if (((lsalen % 4) != 0) || (lsalen <= sizeof(struct ospf_lsa_header)))
{
log(L_TRACE "%s: LSA invalid", p->name);
return;
}
}
}
#ifdef OSPFv2
int
ospf_lsa_flooding_allowed(struct ospf_lsa_header *lsa, u32 domain, struct ospf_iface *ifa)
{
if (lsa->type == LSA_T_EXT)
{
if (ifa->type == OSPF_IT_VLINK)
return 0;
if (!oa_is_ext(ifa->oa))
return 0;
return 1;
}
else
return ifa->oa->areaid == domain;
}
#else /* OSPFv3 */
static int
unknown_lsa_type(struct ospf_lsa_header *lsa)
{
switch (lsa->type)
{
case LSA_T_RT:
case LSA_T_NET:
case LSA_T_SUM_NET:
case LSA_T_SUM_RT:
case LSA_T_EXT:
case LSA_T_NSSA:
case LSA_T_LINK:
case LSA_T_PREFIX:
return 0;
default:
return 1;
}
}
int
ospf_lsa_flooding_allowed(struct ospf_lsa_header *lsa, u32 domain, struct ospf_iface *ifa)
{
u32 scope = LSA_SCOPE(lsa);
/* 4.5.2 (Case 2) */
if (unknown_lsa_type(lsa) && !(lsa->type & LSA_UBIT))
scope = LSA_SCOPE_LINK;
switch (scope)
{
case LSA_SCOPE_LINK:
return ifa->iface->index == domain;
case LSA_SCOPE_AREA:
return ifa->oa->areaid == domain;
case LSA_SCOPE_AS:
if (ifa->type == OSPF_IT_VLINK)
return 0;
if (!oa_is_ext(ifa->oa))
return 0;
return 1;
default:
log(L_ERR "LSA with invalid scope");
return 0;
}
}
#endif
/**
* ospf_lsupd_flood - send received or generated lsa to the neighbors
* @po: OSPF protocol
* @n: neighbor than sent this lsa (or NULL if generated)
* @hn: LSA header followed by lsa body in network endianity (may be NULL)
* @hh: LSA header in host endianity (must be filled)
* @domain: domain of LSA (must be filled)
* @rtl: add this LSA into retransmission list
*
*
* return value - was the LSA flooded back?
*/
int
ospf_lsupd_flood(struct proto_ospf *po,
struct ospf_neighbor *n, struct ospf_lsa_header *hn,
struct ospf_lsa_header *hh, u32 domain, int rtl)
{
struct ospf_iface *ifa;
struct ospf_neighbor *nn;
struct top_hash_entry *en;
struct proto *p = &po->proto;
int ret, retval = 0;
/* pg 148 */
WALK_LIST(ifa, po->iface_list)
{
if (ifa->stub)
continue;
if (! ospf_lsa_flooding_allowed(hh, domain, ifa))
continue;
DBG("Wanted to flood LSA: Type: %u, ID: %R, RT: %R, SN: 0x%x, Age %u\n",
hh->type, hh->id, hh->rt, hh->sn, hh->age);
ret = 0;
WALK_LIST(nn, ifa->neigh_list)
{
/* 13.3 (1a) */
if (nn->state < NEIGHBOR_EXCHANGE)
continue;
/* 13.3 (1b) */
if (nn->state < NEIGHBOR_FULL)
{
if ((en = ospf_hash_find_header(nn->lsrqh, domain, hh)) != NULL)
{
DBG("That LSA found in lsreq list for neigh %R\n", nn->rid);
switch (lsa_comp(hh, &en->lsa))
{
case CMP_OLDER:
continue;
break;
case CMP_SAME:
s_rem_node(SNODE en);
if (en->lsa_body != NULL)
mb_free(en->lsa_body);
en->lsa_body = NULL;
DBG("Removing from lsreq list for neigh %R\n", nn->rid);
ospf_hash_delete(nn->lsrqh, en);
if (EMPTY_SLIST(nn->lsrql))
ospf_neigh_sm(nn, INM_LOADDONE);
continue;
break;
case CMP_NEWER:
s_rem_node(SNODE en);
if (en->lsa_body != NULL)
mb_free(en->lsa_body);
en->lsa_body = NULL;
DBG("Removing from lsreq list for neigh %R\n", nn->rid);
ospf_hash_delete(nn->lsrqh, en);
if (EMPTY_SLIST(nn->lsrql))
ospf_neigh_sm(nn, INM_LOADDONE);
break;
default:
bug("Bug in lsa_comp?");
}
}
}
/* 13.3 (1c) */
if (nn == n)
continue;
/* 13.3 (1d) */
if (rtl)
{
/* In OSPFv3, there should be check whether receiving router understand
that type of LSA (for LSA types with U-bit == 0). But as we does not support
any optional LSA types, this is not needed yet */
if ((en = ospf_hash_find_header(nn->lsrth, domain, hh)) == NULL)
{
en = ospf_hash_get_header(nn->lsrth, domain, hh);
}
else
{
s_rem_node(SNODE en);
}
s_add_tail(&nn->lsrtl, SNODE en);
memcpy(&en->lsa, hh, sizeof(struct ospf_lsa_header));
DBG("Adding that LSA for flood to %I\n", nn->ip);
}
else
{
if ((en = ospf_hash_find_header(nn->lsrth, domain, hh)) != NULL)
{
s_rem_node(SNODE en);
ospf_hash_delete(nn->lsrth, en);
}
}
ret = 1;
}
if (ret == 0)
continue; /* pg 150 (2) */
if (n && (n->ifa == ifa))
{
if ((n->rid == ifa->drid) || n->rid == ifa->bdrid)
continue; /* pg 150 (3) */
if (ifa->state == OSPF_IS_BACKUP)
continue; /* pg 150 (4) */
retval = 1;
}
{
u16 len, age;
struct ospf_lsupd_packet *pk;
struct ospf_packet *op;
struct ospf_lsa_header *lh;
pk = ospf_tx_buffer(ifa);
op = &pk->ospf_packet;
ospf_pkt_fill_hdr(ifa, pk, LSUPD_P);
pk->lsano = htonl(1);
lh = (struct ospf_lsa_header *) (pk + 1);
/* Copy LSA into the packet */
if (hn)
{
memcpy(lh, hn, ntohs(hn->length));
}
else
{
u8 *help;
struct top_hash_entry *en;
htonlsah(hh, lh);
help = (u8 *) (lh + 1);
en = ospf_hash_find_header(po->gr, domain, hh);
htonlsab(en->lsa_body, help, hh->length - sizeof(struct ospf_lsa_header));
}
len = sizeof(struct ospf_lsupd_packet) + ntohs(lh->length);
age = ntohs(lh->age);
age += ifa->inftransdelay;
if (age > LSA_MAXAGE)
age = LSA_MAXAGE;
lh->age = htons(age);
op->length = htons(len);
OSPF_PACKET(ospf_dump_lsupd, pk, "LSUPD packet flooded via %s", ifa->iface->name);
switch (ifa->type)
{
case OSPF_IT_BCAST:
if ((ifa->state == OSPF_IS_BACKUP) || (ifa->state == OSPF_IS_DR))
ospf_send_to(ifa, AllSPFRouters);
else
ospf_send_to(ifa, AllDRouters);
break;
case OSPF_IT_NBMA:
if ((ifa->state == OSPF_IS_BACKUP) || (ifa->state == OSPF_IS_DR))
ospf_send_to_agt(ifa, NEIGHBOR_EXCHANGE);
else
ospf_send_to_bdr(ifa);
break;
case OSPF_IT_PTP:
ospf_send_to(ifa, AllSPFRouters);
break;
case OSPF_IT_PTMP:
ospf_send_to_agt(ifa, NEIGHBOR_EXCHANGE);
break;
case OSPF_IT_VLINK:
ospf_send_to(ifa, ifa->vip);
break;
default:
bug("Bug in ospf_lsupd_flood()");
}
}
}
return retval;
}
void /* I send all I received in LSREQ */
ospf_lsupd_send_list(struct ospf_neighbor *n, list * l)
{
struct ospf_area *oa = n->ifa->oa;
struct proto *p = &oa->po->proto;
struct l_lsr_head *lsr;
struct top_hash_entry *en;
struct ospf_lsupd_packet *pkt;
u32 len, len2, lsano;
char *buf;
pkt = ospf_tx_buffer(n->ifa);
buf = (void *) pkt;
lsr = HEAD(*l);
while(NODE_NEXT(lsr))
{
/* Prepare the packet */
ospf_pkt_fill_hdr(n->ifa, pkt, LSUPD_P);
len = sizeof(struct ospf_lsupd_packet);
lsano = 0;
/* Fill the packet with LSAs */
while(NODE_NEXT(lsr))
{
u32 domain = ospf_lsa_domain(lsr->lsh.type, n->ifa);
en = ospf_hash_find(oa->po->gr, domain, lsr->lsh.id, lsr->lsh.rt, lsr->lsh.type);
if (en == NULL)
{
/* Probably flushed LSA, this should not happen */
log(L_WARN "OSPF: LSA disappeared (Type: %04x, Id: %R, Rt: %R)",
lsr->lsh.type, lsr->lsh.id, lsr->lsh.rt);
lsr = NODE_NEXT(lsr);
continue;
}
len2 = len + en->lsa.length;
if (len2 > ospf_pkt_maxsize(n->ifa))
{
/* The packet if full, stop adding LSAs and sent it */
if (lsano > 0)
break;
/* LSA is larger than MTU, check buffer size */
if (len2 > ospf_pkt_bufsize(n->ifa))
{
/* Cannot fit in a tx buffer, skip that */
log(L_WARN "OSPF: LSA too large to send (Type: %04x, Id: %R, Rt: %R)",
lsr->lsh.type, lsr->lsh.id, lsr->lsh.rt);
lsr = NODE_NEXT(lsr);
continue;
}
}
/* Copy the LSA to the packet */
htonlsah(&(en->lsa), (struct ospf_lsa_header *) (buf + len));
htonlsab(en->lsa_body, buf + len + sizeof(struct ospf_lsa_header),
en->lsa.length - sizeof(struct ospf_lsa_header));
len = len2;
lsano++;
lsr = NODE_NEXT(lsr);
}
if (lsano == 0)
break;
/* Send the packet */
pkt->lsano = htonl(lsano);
pkt->ospf_packet.length = htons(len);
OSPF_PACKET(ospf_dump_lsupd, pkt, "LSUPD packet sent to %I via %s",
n->ip, n->ifa->iface->name);
ospf_send_to(n->ifa, n->ip);
}
}
void
ospf_lsupd_receive(struct ospf_packet *ps_i, struct ospf_iface *ifa,
struct ospf_neighbor *n)
{
struct ospf_neighbor *ntmp;
struct proto_ospf *po = ifa->oa->po;
struct proto *p = &po->proto;
unsigned int i, max, sendreq = 1;
unsigned int size = ntohs(ps_i->length);
if (size < (sizeof(struct ospf_lsupd_packet) + sizeof(struct ospf_lsa_header)))
{
log(L_ERR "OSPF: Bad LSUPD packet from %I - too short (%u B)", n->ip, size);
return;
}
struct ospf_lsupd_packet *ps = (void *) ps_i;
OSPF_PACKET(ospf_dump_lsupd, ps, "LSUPD packet received from %I via %s", n->ip, ifa->iface->name);
if (n->state < NEIGHBOR_EXCHANGE)
{
OSPF_TRACE(D_PACKETS, "Received lsupd in lesser state than EXCHANGE from (%I)", n->ip);
return;
}
ospf_neigh_sm(n, INM_HELLOREC); /* Questionable */
unsigned int offset = sizeof(struct ospf_lsupd_packet);
unsigned int bound = size - sizeof(struct ospf_lsa_header);
max = ntohl(ps->lsano);
for (i = 0; i < max; i++)
{
struct ospf_lsa_header lsatmp;
struct top_hash_entry *lsadb;
if (offset > bound)
{
log(L_WARN "Received lsupd from %I is too short!", n->ip);
ospf_neigh_sm(n, INM_BADLSREQ);
return;
}
struct ospf_lsa_header *lsa = (void *) (((u8 *) ps) + offset);
unsigned int lsalen = ntohs(lsa->length);
offset += lsalen;
if ((offset > size) || ((lsalen % 4) != 0) ||
(lsalen <= sizeof(struct ospf_lsa_header)))
{
log(L_WARN "Received LSA from %I with bad length", n->ip);
ospf_neigh_sm(n, INM_BADLSREQ);
break;
}
/* pg 143 (1) */
u16 chsum = lsa->checksum;
if (chsum != lsasum_check(lsa, NULL))
{
log(L_WARN "Received bad lsa checksum from %I: %x %x", n->ip, chsum, lsa->checksum);
continue;
}
#ifdef OSPFv2
/* pg 143 (2) */
if ((lsa->type == 0) || (lsa->type == 6) || (lsa->type > LSA_T_NSSA))
{
log(L_WARN "Unknown LSA type from %I", n->ip);
continue;
}
/* pg 143 (3) */
if ((lsa->type == LSA_T_EXT) && !oa_is_ext(ifa->oa))
{
log(L_WARN "Received External LSA in stub area from %I", n->ip);
continue;
}
#else /* OSPFv3 */
/* 4.5.1 (2) */
if ((LSA_SCOPE(lsa) == LSA_SCOPE_AS) && !oa_is_ext(ifa->oa))
{
log(L_WARN "Received LSA with AS scope in stub area from %I", n->ip);
continue;
}
/* 4.5.1 (3) */
if ((LSA_SCOPE(lsa) == LSA_SCOPE_RES))
{
log(L_WARN "Received LSA with invalid scope from %I", n->ip);
continue;
}
#endif
ntohlsah(lsa, &lsatmp);
DBG("Update Type: %u ID: %R RT: %R, Sn: 0x%08x Age: %u, Sum: %u\n",
lsatmp.type, lsatmp.id, lsatmp.rt, lsatmp.sn, lsatmp.age, lsatmp.checksum);
/* FIXME domain should be link id for unknown LSA types with zero Ubit */
u32 domain = ospf_lsa_domain(lsatmp.type, ifa);
lsadb = ospf_hash_find_header(po->gr, domain, &lsatmp);
#ifdef LOCAL_DEBUG
if (lsadb)
DBG("I have Type: %u ID: %R RT: %R, Sn: 0x%08x Age: %u, Sum: %u\n",
lsadb->lsa.type, lsadb->lsa.id, lsadb->lsa.rt,
lsadb->lsa.sn, lsadb->lsa.age, lsadb->lsa.checksum);
#endif
/* pg 143 (4) */
if ((lsatmp.age == LSA_MAXAGE) && (lsadb == NULL) && can_flush_lsa(po))
{
ospf_lsack_enqueue(n, lsa, ACKL_DIRECT);
continue;
}
/* pg 144 (5) */
if ((lsadb == NULL) || (lsa_comp(&lsatmp, &lsadb->lsa) == CMP_NEWER))
{
struct ospf_iface *ift = NULL;
int self = (lsatmp.rt == po->router_id);
DBG("PG143(5): Received LSA is newer\n");
#ifdef OSPFv2
/* 13.4 - check self-originated LSAs of NET type */
if ((!self) && (lsatmp.type == LSA_T_NET))
{
struct ospf_iface *nifa;
WALK_LIST(nifa, po->iface_list)
{
if (!nifa->iface)
continue;
if (ipa_equal(nifa->addr->ip, ipa_from_u32(lsatmp.id)))
{
self = 1;
break;
}
}
}
#endif
/* pg 145 (5f) - premature aging of self originated lsa */
if (self)
{
if ((lsatmp.age == LSA_MAXAGE) && (lsatmp.sn == LSA_MAXSEQNO))
{
ospf_lsack_enqueue(n, lsa, ACKL_DIRECT);
continue;
}
OSPF_TRACE(D_EVENTS, "Received old self-originated LSA (Type: %04x, Id: %R, Rt: %R)",
lsatmp.type, lsatmp.id, lsatmp.rt);
if (lsadb)
{
OSPF_TRACE(D_EVENTS, "Reflooding new self-originated LSA with newer sequence number");
lsadb->lsa.sn = lsatmp.sn + 1;
lsadb->lsa.age = 0;
lsadb->inst_t = now;
lsadb->ini_age = 0;
lsasum_calculate(&lsadb->lsa, lsadb->lsa_body);
ospf_lsupd_flood(po, NULL, NULL, &lsadb->lsa, domain, 1);
}
else
{
OSPF_TRACE(D_EVENTS, "Premature aging it");
lsatmp.age = LSA_MAXAGE;
lsatmp.sn = LSA_MAXSEQNO;
lsa->age = htons(LSA_MAXAGE);
lsa->sn = htonl(LSA_MAXSEQNO);
lsasum_check(lsa, (lsa + 1)); /* It also calculates chsum! */
lsatmp.checksum = ntohs(lsa->checksum);
ospf_lsupd_flood(po, NULL, lsa, &lsatmp, domain, 0);
}
continue;
}
/* pg 144 (5a) */
if (lsadb && ((now - lsadb->inst_t) <= MINLSARRIVAL)) /* FIXME: test for flooding? */
{
OSPF_TRACE(D_EVENTS, "Skipping LSA received in less that MINLSARRIVAL");
sendreq = 0;
continue;
}
/* Remove old from all ret lists */
/* pg 144 (5c) */
/* Must be done before (5b), otherwise it also removes the new entries from (5b) */
if (lsadb)
WALK_LIST(ift, po->iface_list)
WALK_LIST(ntmp, ift->neigh_list)
{
struct top_hash_entry *en;
if (ntmp->state > NEIGHBOR_EXSTART)
if ((en = ospf_hash_find_header(ntmp->lsrth, domain, &lsadb->lsa)) != NULL)
{
s_rem_node(SNODE en);
ospf_hash_delete(ntmp->lsrth, en);
}
}
/* pg 144 (5b) */
if (ospf_lsupd_flood(po, n, lsa, &lsatmp, domain, 1) == 0)
{
DBG("Wasn't flooded back\n"); /* ps 144(5e), pg 153 */
if (ifa->state == OSPF_IS_BACKUP)
{
if (ifa->drid == n->rid)
ospf_lsack_enqueue(n, lsa, ACKL_DELAY);
}
else
ospf_lsack_enqueue(n, lsa, ACKL_DELAY);
}
if ((lsatmp.age == LSA_MAXAGE) && (lsatmp.sn == LSA_MAXSEQNO)
&& lsadb && can_flush_lsa(po))
{
flush_lsa(lsadb, po);
schedule_rtcalc(po);
continue;
} /* FIXME lsack? */
/* pg 144 (5d) */
void *body = mb_alloc(p->pool, lsatmp.length - sizeof(struct ospf_lsa_header));
ntohlsab(lsa + 1, body, lsatmp.length - sizeof(struct ospf_lsa_header));
/* We will do validation check after flooding and
acknowledging given LSA to minimize problems
when communicating with non-validating peer */
if (lsa_validate(&lsatmp, body) == 0)
{
log(L_WARN "Received invalid LSA from %I", n->ip);
mb_free(body);
continue;
}
lsadb = lsa_install_new(po, &lsatmp, domain, body);
DBG("New LSA installed in DB\n");
#ifdef OSPFv3
/* Events 6,7 from RFC5340 4.4.3. */
if ((lsatmp.type == LSA_T_LINK) &&
(ifa->state == OSPF_IS_DR))
schedule_net_lsa(ifa);
#endif
continue;
}
/* FIXME pg145 (6) */
/* pg145 (7) */
if (lsa_comp(&lsatmp, &lsadb->lsa) == CMP_SAME)
{
struct top_hash_entry *en;
DBG("PG145(7) Got the same LSA\n");
if ((en = ospf_hash_find_header(n->lsrth, lsadb->domain, &lsadb->lsa)) != NULL)
{
/* pg145 (7a) */
s_rem_node(SNODE en);
ospf_hash_delete(n->lsrth, en);
if (ifa->state == OSPF_IS_BACKUP)
{
if (n->rid == ifa->drid)
ospf_lsack_enqueue(n, lsa, ACKL_DELAY);
}
}
else
{
/* pg145 (7b) */
ospf_lsack_enqueue(n, lsa, ACKL_DIRECT);
}
sendreq = 0;
continue;
}
/* pg145 (8) */
if ((lsadb->lsa.age == LSA_MAXAGE) && (lsadb->lsa.sn == LSA_MAXSEQNO))
{
continue;
}
{
list l;
struct l_lsr_head ll;
init_list(&l);
ll.lsh.id = lsadb->lsa.id;
ll.lsh.rt = lsadb->lsa.rt;
ll.lsh.type = lsadb->lsa.type;
add_tail(&l, NODE & ll);
ospf_lsupd_send_list(n, &l);
}
}
/* Send direct LSAs */
ospf_lsack_send(n, ACKL_DIRECT);
if (sendreq && (n->state == NEIGHBOR_LOADING))
{
ospf_lsreq_send(n); /* Ask for another part of neighbor's database */
}
}
void
ospf_lsupd_flush_nlsa(struct proto_ospf *po, struct top_hash_entry *en)
{
struct ospf_lsa_header *lsa = &en->lsa;
struct proto *p = &po->proto;
lsa->age = LSA_MAXAGE;
lsa->sn = LSA_MAXSEQNO;
lsasum_calculate(lsa, en->lsa_body);
OSPF_TRACE(D_EVENTS, "Premature aging self originated lsa!");
OSPF_TRACE(D_EVENTS, "Type: %04x, Id: %R, Rt: %R", lsa->type, lsa->id, lsa->rt);
ospf_lsupd_flood(po, NULL, NULL, lsa, en->domain, 0);
}