Implement proper LSA ID generation.
This commit is contained in:
Ondrej Zajicek
parent
9f0ba7b1c7
commit
d82fc18d75
5 changed files with 106 additions and 13 deletions
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@ -37,6 +37,7 @@ struct fib_node {
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byte pxlen;
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byte flags; /* User-defined */
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byte x0, x1; /* User-defined */
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u32 uid; /* Unique ID based on hash */
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ip_addr prefix; /* In host order */
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};
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@ -172,6 +172,28 @@ fib_find(struct fib *f, ip_addr *a, int len)
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return e;
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}
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/*
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int
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fib_histogram(struct fib *f)
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{
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log(L_WARN "Histogram dump start %d %d", f->hash_size, f->entries);
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int i, j;
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struct fib_node *e;
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for (i = 0; i < f->hash_size; i++)
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{
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j = 0;
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for (e = f->hash_table[i]; e != NULL; e = e->next)
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j++;
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if (j > 0)
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log(L_WARN "Histogram line %d: %d", i, j);
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}
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log(L_WARN "Histogram dump end");
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}
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*/
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/**
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* fib_get - find or create a FIB node
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* @f: FIB to work with
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@ -187,6 +209,7 @@ fib_get(struct fib *f, ip_addr *a, int len)
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unsigned int h = ipa_hash(*a);
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struct fib_node **ee = f->hash_table + (h >> f->hash_shift);
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struct fib_node *g, *e = *ee;
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u32 uid = h << 16;
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while (e && (e->pxlen != len || !ipa_equal(*a, e->prefix)))
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e = e->next;
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@ -196,17 +219,31 @@ fib_get(struct fib *f, ip_addr *a, int len)
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if (len < 0 || len > BITS_PER_IP_ADDRESS || !ip_is_prefix(*a,len))
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bug("fib_get() called for invalid address");
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#endif
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while ((g = *ee) && g->uid < uid)
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ee = &g->next;
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while ((g = *ee) && g->uid == uid)
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{
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ee = &g->next;
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uid++;
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}
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if ((uid >> 16) != h)
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log(L_ERR "FIB hash table chains are too long");
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// log (L_WARN "FIB_GET %I %x %x", *a, h, uid);
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e = sl_alloc(f->fib_slab);
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e->prefix = *a;
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e->pxlen = len;
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while ((g = *ee) && ipa_hash(g->prefix) < h)
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ee = &g->next;
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e->next = *ee;
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e->uid = uid;
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*ee = e;
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e->readers = NULL;
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f->init(e);
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if (f->entries++ > f->entries_max)
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fib_rehash(f, HASH_HI_STEP);
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return e;
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}
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@ -605,7 +605,9 @@ ospf_reconfigure(struct proto *p, struct proto_config *c)
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struct area_net_config *anc;
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struct area_net *an;
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po->rfc1583 = new->rfc1583;
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if (po->rfc1583 != new->rfc1583)
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return 0;
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schedule_rtcalc(po);
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po->tick = new->tick;
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@ -18,7 +18,7 @@ static void ospf_ext_spf(struct proto_ospf *po);
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static void rt_sync(struct proto_ospf *po);
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/* In ospf_area->rtr we store paths to routers, but we use RID (and not IP address)
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as index, so we need to encapsulate RID to IP addresss */
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as index, so we need to encapsulate RID to IP address */
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#ifdef OSPFv2
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#define ipa_from_rid(x) _MI(x)
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#else /* OSPFv3 */
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@ -30,11 +30,64 @@ void flush_prefix_net_lsa(struct ospf_iface *ifa);
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#define ipa_to_rid(x) _I3(x)
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#endif
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/* FIXME very ugly hack */
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#ifdef OSPFv2
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#define ipa_to_lsaid(x) _I(x)
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static inline u32
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fibnode_to_lsaid(struct proto_ospf *po, struct fib_node *fn)
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{
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/* We have to map IP prefixes to u32 in such manner that resulting
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u32 interpreted as IP address is a member of given
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prefix. Therefore, /32 prefix have to be mapped on itself.
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All received prefixes have to be mapped on different u32s.
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We have an assumption that if there is nontrivial (non-/32)
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network prefix, then there is not /32 prefix for the first
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and the last IP address of the network (these are usually
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reserved, therefore it is not an important restriction).
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The network prefix is mapped to the first or the last
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IP address in the manner that disallow collisions - we
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use IP address that cannot be used by parent prefix.
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For example:
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192.168.0.0/24 maps to 192.168.0.255
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192.168.1.0/24 maps to 192.168.1.0
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because 192.168.0.0 and 192.168.1.255 might be used by
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192.168.0.0/23 .
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This is not compatible with older RFC 1583, so we have an option
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to the RFC 1583 compatible assignment (that always uses the first
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address) which disallows subnetting.
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Appendig E of RFC 2328 suggests different algorithm, that tries
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to maximize both compatibility and subnetting. But as it is not
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possible to have both reliably and the suggested algorithm was
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unnecessary complicated and it does crazy things like changing
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LSA ID for a network because different network appeared, we
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choose a different way. */
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u32 id = _I(fn->prefix);
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if ((po->rfc1583) || (fn->pxlen == 0) || (fn->pxlen == 32))
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return id;
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if (id & (1 << (32 - fn->pxlen)))
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return id;
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else
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return id | ~u32_mkmask(fn->pxlen);
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}
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#else /* OSPFv3 */
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#define ipa_to_lsaid(x) _I0(x) ^ _I1(x) ^ _I2(x) ^ _I3(x)
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static inline u32
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fibnode_to_lsaid(struct proto_ospf *po, struct fib_node *fn)
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{
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/* In OSPFv3, it is simpler. There is not a requirement
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for membership of the result in input network, so we
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just use hash-based unique ID. */
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return fn->uid;
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}
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#endif
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@ -660,8 +713,7 @@ originate_sum_lsa(struct ospf_area *oa, struct fib_node *fn, int type, int metri
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if (type == ORT_NET)
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{
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/* FIXME proper handling of LSA IDs and check for the same network */
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lsa.id = ipa_to_lsaid(fn->prefix);
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lsa.id = fibnode_to_lsaid(po, fn);
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lsa.type = LSA_T_SUM_NET;
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}
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else
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@ -710,8 +762,7 @@ flush_sum_lsa(struct ospf_area *oa, struct fib_node *fn, int type)
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lsa.rt = rid;
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if (type == ORT_NET)
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{
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/* FIXME proper handling of LSA IDs and check for the same network */
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lsa.id = ipa_to_lsaid(fn->prefix);
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lsa.id = fibnode_to_lsaid(po, fn);
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lsa.type = LSA_T_SUM_NET;
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}
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else
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@ -721,6 +772,8 @@ flush_sum_lsa(struct ospf_area *oa, struct fib_node *fn, int type)
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lsa.type = LSA_T_SUM_RT;
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}
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/* FIXME check for the same network */
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if ((en = ospf_hash_find_header(po->gr, oa->areaid, &lsa)) != NULL)
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{
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struct ospf_lsa_sum *sum = en->lsa_body;
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@ -892,7 +945,7 @@ originate_ext_lsa(net * n, rte * e, struct proto_ospf *po,
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#endif
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/* FIXME proper handling of LSA IDs and check for the same network */
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lsa.id = ipa_to_lsaid(n->n.prefix);
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lsa.id = fibnode_to_lsaid(po, &n->n);
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if ((en = ospf_hash_find_header(po->gr, 0, &lsa)) != NULL)
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{
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@ -927,7 +980,7 @@ flush_ext_lsa(net *n, struct proto_ospf *po)
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n->n.prefix, n->n.pxlen);
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/* FIXME proper handling of LSA IDs and check for the same network */
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u32 lsaid = ipa_to_lsaid(n->n.prefix);
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u32 lsaid = fibnode_to_lsaid(po, &n->n);
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if (en = ospf_hash_find(po->gr, 0, lsaid, rid, LSA_T_EXT))
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{
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