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isisd: fix wrong next-hops from SPF

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The forwarding table was filled with wrong next-hops, and which is even
worse, it was done in a totally non-deterministic way.

The next-hop set for an IP prefix by isisd was the neighbor IS from
which the flooded LSP about the IP prefix was arrived. So, if an IS
received all the LSPs through its, say, eth0 interface, all entries
in the forwarding table contained the next IS reachable via eth0 as
the next-hop.

The solution is to propagate the correct next-hop further from node to
node as the SPF algorithm traverses the graph and selects the next
node to be added to the set of already covered nodes.

Also, the construction of the tentative node list (the nodes where the
shortest path is not known yet) was buggy: if a node was already a
member of this list with a certain path cost, and an alternative path
was found to it with a lower cost while processing a pseudo-node LSP,
it was not added to the list. This way, the path selected by isisd for
a certain prefix was the first one it encountered during the LSDB
processing.

Signed-off-by: Fritz Reichmann <fritz@reichmann.nl>
This commit is contained in:
Peter Szilagyi 2011-10-01 17:22:51 +04:00 committed by Denis Ovsienko
parent 907fd95e50
commit d034aa027e
3 changed files with 29 additions and 29 deletions
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1
isisd/isis_lsp.h
View file

@ -58,7 +58,6 @@ struct isis_lsp
#endif #endif
/* used for 60 second counting when rem_lifetime is zero */ /* used for 60 second counting when rem_lifetime is zero */
int age_out; int age_out;
struct isis_adjacency *adj;
/* FIXME: For now only topology LSP's use this. Is it helpful for others? */ /* FIXME: For now only topology LSP's use this. Is it helpful for others? */
struct isis_area *area; struct isis_area *area;
struct tlvs tlv_data; /* Simplifies TLV access */ struct tlvs tlv_data; /* Simplifies TLV access */

4
isisd/isis_pdu.c
View file

@ -1222,7 +1222,6 @@ dontcheckadj:
ntohs (hdr->pdu_len), lsp0, ntohs (hdr->pdu_len), lsp0,
circuit->area); circuit->area);
lsp->level = level; lsp->level = level;
lsp->adj = adj;
lsp_insert (lsp, circuit->area->lspdb[level - 1]); lsp_insert (lsp, circuit->area->lspdb[level - 1]);
/* ii */ /* ii */
ISIS_FLAGS_SET_ALL (lsp->SRMflags); ISIS_FLAGS_SET_ALL (lsp->SRMflags);
@ -1254,8 +1253,7 @@ dontcheckadj:
ISIS_CLEAR_FLAG (lsp->SSNflags, circuit); ISIS_CLEAR_FLAG (lsp->SSNflags, circuit);
} }
} }
if (lsp)
lsp->adj = adj;
return retval; return retval;
} }

53
isisd/isis_spf.c
View file

@ -405,12 +405,13 @@ isis_spf_add2tent (struct isis_spftree *spftree, enum vertextype vtype,
if (adj) if (adj)
listnode_add (vertex->Adj_N, adj); listnode_add (vertex->Adj_N, adj);
#ifdef EXTREME_DEBUG #ifdef EXTREME_DEBUG
zlog_debug ("ISIS-Spf: add to TENT %s %s depth %d dist %d", zlog_debug ("ISIS-Spf: add to TENT %s %s depth %d dist %d",
vtype2string (vertex->type), vid2string (vertex, buff), vtype2string (vertex->type), vid2string (vertex, buff),
vertex->depth, vertex->d_N); vertex->depth, vertex->d_N);
#endif /* EXTREME_DEBUG */ #endif /* EXTREME_DEBUG */
listnode_add (spftree->tents, vertex);
if (list_isempty (spftree->tents)) if (list_isempty (spftree->tents))
{ {
listnode_add (spftree->tents, vertex); listnode_add (spftree->tents, vertex);
@ -549,7 +550,8 @@ process_N (struct isis_spftree *spftree, enum vertextype vtype, void *id,
*/ */
static int static int
isis_spf_process_lsp (struct isis_spftree *spftree, struct isis_lsp *lsp, isis_spf_process_lsp (struct isis_spftree *spftree, struct isis_lsp *lsp,
uint32_t cost, uint16_t depth, int family) uint32_t cost, uint16_t depth, int family,
struct isis_adjacency *adj)
{ {
struct listnode *node, *fragnode = NULL; struct listnode *node, *fragnode = NULL;
u_int16_t dist; u_int16_t dist;
@ -563,9 +565,6 @@ isis_spf_process_lsp (struct isis_spftree *spftree, struct isis_lsp *lsp,
struct ipv6_reachability *ip6reach; struct ipv6_reachability *ip6reach;
#endif /* HAVE_IPV6 */ #endif /* HAVE_IPV6 */
if (!lsp->adj)
return ISIS_WARNING;
if (lsp->tlv_data.nlpids == NULL || !speaks (lsp->tlv_data.nlpids, family)) if (lsp->tlv_data.nlpids == NULL || !speaks (lsp->tlv_data.nlpids, family))
return ISIS_OK; return ISIS_OK;
@ -591,7 +590,7 @@ lspfragloop:
vtype = LSP_PSEUDO_ID (is_neigh->neigh_id) ? VTYPE_PSEUDO_IS vtype = LSP_PSEUDO_ID (is_neigh->neigh_id) ? VTYPE_PSEUDO_IS
: VTYPE_NONPSEUDO_IS; : VTYPE_NONPSEUDO_IS;
process_N (spftree, vtype, (void *) is_neigh->neigh_id, dist, process_N (spftree, vtype, (void *) is_neigh->neigh_id, dist,
depth + 1, lsp->adj, family); depth + 1, adj, family);
} }
} }
if (lsp->tlv_data.te_is_neighs) if (lsp->tlv_data.te_is_neighs)
@ -607,7 +606,7 @@ lspfragloop:
vtype = LSP_PSEUDO_ID (te_is_neigh->neigh_id) ? VTYPE_PSEUDO_TE_IS vtype = LSP_PSEUDO_ID (te_is_neigh->neigh_id) ? VTYPE_PSEUDO_TE_IS
: VTYPE_NONPSEUDO_TE_IS; : VTYPE_NONPSEUDO_TE_IS;
process_N (spftree, vtype, (void *) te_is_neigh->neigh_id, dist, process_N (spftree, vtype, (void *) te_is_neigh->neigh_id, dist,
depth + 1, lsp->adj, family); depth + 1, adj, family);
} }
} }
if (family == AF_INET && lsp->tlv_data.ipv4_int_reachs) if (family == AF_INET && lsp->tlv_data.ipv4_int_reachs)
@ -621,7 +620,7 @@ lspfragloop:
prefix.u.prefix4 = ipreach->prefix; prefix.u.prefix4 = ipreach->prefix;
prefix.prefixlen = ip_masklen (ipreach->mask); prefix.prefixlen = ip_masklen (ipreach->mask);
process_N (spftree, vtype, (void *) &prefix, dist, depth + 1, process_N (spftree, vtype, (void *) &prefix, dist, depth + 1,
lsp->adj, family); adj, family);
} }
} }
@ -636,7 +635,7 @@ lspfragloop:
prefix.u.prefix4 = ipreach->prefix; prefix.u.prefix4 = ipreach->prefix;
prefix.prefixlen = ip_masklen (ipreach->mask); prefix.prefixlen = ip_masklen (ipreach->mask);
process_N (spftree, vtype, (void *) &prefix, dist, depth + 1, process_N (spftree, vtype, (void *) &prefix, dist, depth + 1,
lsp->adj, family); adj, family);
} }
} }
if (family == AF_INET && lsp->tlv_data.te_ipv4_reachs) if (family == AF_INET && lsp->tlv_data.te_ipv4_reachs)
@ -651,7 +650,7 @@ lspfragloop:
te_ipv4_reach->control); te_ipv4_reach->control);
prefix.prefixlen = (te_ipv4_reach->control & 0x3F); prefix.prefixlen = (te_ipv4_reach->control & 0x3F);
process_N (spftree, vtype, (void *) &prefix, dist, depth + 1, process_N (spftree, vtype, (void *) &prefix, dist, depth + 1,
lsp->adj, family); adj, family);
} }
} }
#ifdef HAVE_IPV6 #ifdef HAVE_IPV6
@ -668,7 +667,7 @@ lspfragloop:
memcpy (&prefix.u.prefix6.s6_addr, ip6reach->prefix, memcpy (&prefix.u.prefix6.s6_addr, ip6reach->prefix,
PSIZE (ip6reach->prefix_len)); PSIZE (ip6reach->prefix_len));
process_N (spftree, vtype, (void *) &prefix, dist, depth + 1, process_N (spftree, vtype, (void *) &prefix, dist, depth + 1,
lsp->adj, family); adj, family);
} }
} }
#endif /* HAVE_IPV6 */ #endif /* HAVE_IPV6 */
@ -691,7 +690,8 @@ lspfragloop:
static int static int
isis_spf_process_pseudo_lsp (struct isis_spftree *spftree, isis_spf_process_pseudo_lsp (struct isis_spftree *spftree,
struct isis_lsp *lsp, uint16_t cost, struct isis_lsp *lsp, uint16_t cost,
uint16_t depth, int family) uint16_t depth, int family,
struct isis_adjacency *adj)
{ {
struct listnode *node, *fragnode = NULL; struct listnode *node, *fragnode = NULL;
struct is_neigh *is_neigh; struct is_neigh *is_neigh;
@ -715,13 +715,13 @@ pseudofragloop:
/* Two way connectivity */ /* Two way connectivity */
if (!memcmp (is_neigh->neigh_id, isis->sysid, ISIS_SYS_ID_LEN)) if (!memcmp (is_neigh->neigh_id, isis->sysid, ISIS_SYS_ID_LEN))
continue; continue;
if (isis_find_vertex if ((depth > 0 || isis_find_vertex
(spftree->tents, (void *) is_neigh->neigh_id, vtype) == NULL (spftree->tents, (void *) is_neigh->neigh_id, vtype) == NULL)
&& isis_find_vertex (spftree->paths, (void *) is_neigh->neigh_id, && isis_find_vertex (spftree->paths, (void *) is_neigh->neigh_id,
vtype) == NULL) vtype) == NULL)
{ {
/* C.2.5 i) */ /* C.2.5 i) */
isis_spf_add2tent (spftree, vtype, is_neigh->neigh_id, lsp->adj, isis_spf_add2tent (spftree, vtype, is_neigh->neigh_id, adj,
cost, depth, family); cost, depth, family);
} }
} }
@ -733,13 +733,13 @@ pseudofragloop:
/* Two way connectivity */ /* Two way connectivity */
if (!memcmp (te_is_neigh->neigh_id, isis->sysid, ISIS_SYS_ID_LEN)) if (!memcmp (te_is_neigh->neigh_id, isis->sysid, ISIS_SYS_ID_LEN))
continue; continue;
if (isis_find_vertex if ((depth > 0 || isis_find_vertex
(spftree->tents, (void *) te_is_neigh->neigh_id, vtype) == NULL (spftree->tents, (void *) te_is_neigh->neigh_id, vtype) == NULL)
&& isis_find_vertex (spftree->paths, (void *) te_is_neigh->neigh_id, && isis_find_vertex (spftree->paths, (void *) te_is_neigh->neigh_id,
vtype) == NULL) vtype) == NULL)
{ {
/* C.2.5 i) */ /* C.2.5 i) */
isis_spf_add2tent (spftree, vtype, te_is_neigh->neigh_id, lsp->adj, isis_spf_add2tent (spftree, vtype, te_is_neigh->neigh_id, adj,
cost, depth, family); cost, depth, family);
} }
} }
@ -860,9 +860,6 @@ isis_spf_preload_tent (struct isis_spftree *spftree,
lsp = lsp_search (lsp_id, area->lspdb[level - 1]); lsp = lsp_search (lsp_id, area->lspdb[level - 1]);
if (!lsp) if (!lsp)
zlog_warn ("No lsp found for IS adjacency"); zlog_warn ("No lsp found for IS adjacency");
/* else {
isis_spf_process_lsp (spftree, lsp, vertex->d_N, 1, family);
} */
break; break;
case ISIS_SYSTYPE_UNKNOWN: case ISIS_SYSTYPE_UNKNOWN:
default: default:
@ -885,14 +882,14 @@ isis_spf_preload_tent (struct isis_spftree *spftree,
{ {
zlog_warn ("ISIS-Spf: No adjacency found for DR"); zlog_warn ("ISIS-Spf: No adjacency found for DR");
} }
if (lsp == NULL || lsp->lsp_header->rem_lifetime == 0) else if (lsp == NULL || lsp->lsp_header->rem_lifetime == 0)
{ {
zlog_warn ("ISIS-Spf: No lsp found for DR"); zlog_warn ("ISIS-Spf: No lsp found for DR");
} }
else else
{ {
isis_spf_process_pseudo_lsp (spftree, lsp, isis_spf_process_pseudo_lsp (spftree, lsp,
circuit->te_metric[level - 1], 0, family); circuit->te_metric[level - 1], 0, family, adj);
} }
} }
@ -982,6 +979,7 @@ isis_run_spf (struct isis_area *area, int level, int family)
struct isis_spftree *spftree = NULL; struct isis_spftree *spftree = NULL;
u_char lsp_id[ISIS_SYS_ID_LEN + 2]; u_char lsp_id[ISIS_SYS_ID_LEN + 2];
struct isis_lsp *lsp; struct isis_lsp *lsp;
struct isis_adjacency *adj = NULL;
struct route_table *table = NULL; struct route_table *table = NULL;
struct route_node *rode; struct route_node *rode;
struct isis_route_info *rinfo; struct isis_route_info *rinfo;
@ -1042,6 +1040,11 @@ isis_run_spf (struct isis_area *area, int level, int family)
if (vertex->type == VTYPE_PSEUDO_IS || if (vertex->type == VTYPE_PSEUDO_IS ||
vertex->type == VTYPE_NONPSEUDO_IS) vertex->type == VTYPE_NONPSEUDO_IS)
{ {
if (listcount(vertex->Adj_N) == 0) {
continue;
}
adj = listgetdata(vertex->Adj_N->head);
memcpy (lsp_id, vertex->N.id, ISIS_SYS_ID_LEN + 1); memcpy (lsp_id, vertex->N.id, ISIS_SYS_ID_LEN + 1);
LSP_FRAGMENT (lsp_id) = 0; LSP_FRAGMENT (lsp_id) = 0;
lsp = lsp_search (lsp_id, area->lspdb[level - 1]); lsp = lsp_search (lsp_id, area->lspdb[level - 1]);
@ -1050,13 +1053,13 @@ isis_run_spf (struct isis_area *area, int level, int family)
if (LSP_PSEUDO_ID (lsp_id)) if (LSP_PSEUDO_ID (lsp_id))
{ {
isis_spf_process_pseudo_lsp (spftree, lsp, vertex->d_N, isis_spf_process_pseudo_lsp (spftree, lsp, vertex->d_N,
vertex->depth, family); vertex->depth, family, adj);
} }
else else
{ {
isis_spf_process_lsp (spftree, lsp, vertex->d_N, isis_spf_process_lsp (spftree, lsp, vertex->d_N,
vertex->depth, family); vertex->depth, family, adj);
} }
} }
else else