1 files changed, 275 insertions, 0 deletions
diff --git a/ldpd/rlfa.c b/ldpd/rlfa.c
new file mode 100644
index 0000000..d898a13
--- /dev/null
+++ b/ldpd/rlfa.c
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020  NetDEF, Inc.
+ *                     Renato Westphal
+ */
+
+#include <zebra.h>
+
+#include "ldpd.h"
+#include "lde.h"
+#include "ldpe.h"
+#include "log.h"
+#include "ldp_debug.h"
+#include "rlfa.h"
+
+#include <lib/log.h>
+
+struct ldp_rlfa_node_head rlfa_node_tree;
+
+static int ldp_rlfa_client_compare(const struct ldp_rlfa_client *a,
+				   const struct ldp_rlfa_client *b)
+{
+	if (a->igp.vrf_id < b->igp.vrf_id)
+		return -1;
+	if (a->igp.vrf_id > b->igp.vrf_id)
+		return 1;
+
+	if (a->igp.protocol < b->igp.protocol)
+		return -1;
+	if (a->igp.protocol > b->igp.protocol)
+		return 1;
+
+	if (a->igp.isis.spf.tree_id < b->igp.isis.spf.tree_id)
+		return -1;
+	if (a->igp.isis.spf.tree_id > b->igp.isis.spf.tree_id)
+		return 1;
+
+	if (a->igp.isis.spf.level < b->igp.isis.spf.level)
+		return -1;
+	if (a->igp.isis.spf.level > b->igp.isis.spf.level)
+		return 1;
+
+	return 0;
+}
+RB_GENERATE(ldp_rlfa_client_head, ldp_rlfa_client, entry,
+	    ldp_rlfa_client_compare)
+
+static int ldp_rlfa_node_compare(const struct ldp_rlfa_node *a,
+				 const struct ldp_rlfa_node *b)
+{
+	if (ntohl(a->pq_address.s_addr) < ntohl(b->pq_address.s_addr))
+		return -1;
+	if (ntohl(a->pq_address.s_addr) > ntohl(b->pq_address.s_addr))
+		return 1;
+
+	return prefix_cmp(&a->destination, &b->destination);
+}
+RB_GENERATE(ldp_rlfa_node_head, ldp_rlfa_node, entry, ldp_rlfa_node_compare)
+
+struct ldp_rlfa_client *rlfa_client_new(struct ldp_rlfa_node *rnode,
+					struct zapi_rlfa_igp *igp)
+{
+	struct ldp_rlfa_client *rclient;
+
+	if ((rclient = calloc(1, sizeof(*rclient))) == NULL)
+		fatal(__func__);
+
+	rclient->igp = *igp;
+	rclient->node = rnode;
+	RB_INSERT(ldp_rlfa_client_head, &rnode->clients, rclient);
+
+	return rclient;
+}
+
+void rlfa_client_del(struct ldp_rlfa_client *rclient)
+{
+	struct ldp_rlfa_node *rnode = rclient->node;
+
+	RB_REMOVE(ldp_rlfa_client_head, &rnode->clients, rclient);
+	free(rclient);
+
+	/* Delete RLFA node if it's empty. */
+	if (RB_EMPTY(ldp_rlfa_client_head, &rnode->clients))
+		rlfa_node_del(rnode);
+}
+
+struct ldp_rlfa_client *rlfa_client_find(struct ldp_rlfa_node *rnode,
+					 struct zapi_rlfa_igp *igp)
+{
+	struct ldp_rlfa_client rclient;
+
+	rclient.igp = *igp;
+	return RB_FIND(ldp_rlfa_client_head, &rnode->clients, &rclient);
+}
+
+struct ldp_rlfa_node *rlfa_node_new(const struct prefix *destination,
+				    struct in_addr pq_address)
+{
+	struct ldp_rlfa_node *rnode;
+
+	if ((rnode = calloc(1, sizeof(*rnode))) == NULL)
+		fatal(__func__);
+
+	rnode->destination = *destination;
+	rnode->pq_address = pq_address;
+	rnode->pq_label = MPLS_INVALID_LABEL;
+	RB_INIT(ldp_rlfa_client_head, &rnode->clients);
+	RB_INSERT(ldp_rlfa_node_head, &rlfa_node_tree, rnode);
+
+	return rnode;
+}
+
+void rlfa_node_del(struct ldp_rlfa_node *rnode)
+{
+	/* Delete RLFA clients. */
+	while (!RB_EMPTY(ldp_rlfa_client_head, &rnode->clients)) {
+		struct ldp_rlfa_client *rclient;
+
+		rclient = RB_ROOT(ldp_rlfa_client_head, &rnode->clients);
+		rlfa_client_del(rclient);
+	}
+
+	RB_REMOVE(ldp_rlfa_node_head, &rlfa_node_tree, rnode);
+	free(rnode);
+}
+
+struct ldp_rlfa_node *rlfa_node_find(const struct prefix *destination,
+				     struct in_addr pq_address)
+{
+	struct ldp_rlfa_node rnode = {};
+
+	rnode.destination = *destination;
+	rnode.pq_address = pq_address;
+	return RB_FIND(ldp_rlfa_node_head, &rlfa_node_tree, &rnode);
+}
+
+void lde_rlfa_client_send(struct ldp_rlfa_client *rclient)
+{
+	struct ldp_rlfa_node		*rnode = rclient->node;
+	struct zapi_rlfa_response	 rlfa_labels = {};
+	struct fec			 fec;
+	struct fec_node			*fn;
+	struct fec_nh			*fnh;
+	int				 i = 0;
+
+	/* Fill in inner label (allocated by PQ node). */
+	rlfa_labels.igp = rclient->igp;
+	rlfa_labels.destination = rnode->destination;
+	rlfa_labels.pq_label = rnode->pq_label;
+
+	/* Fill in outer label(s) (allocated by the nexthop routers). */
+	fec.type = FEC_TYPE_IPV4;
+	fec.u.ipv4.prefix = rnode->pq_address;
+	fec.u.ipv4.prefixlen = IPV4_MAX_BITLEN;
+	fn = (struct fec_node *)fec_find(&ft, &fec);
+	if (!fn)
+		return;
+	LIST_FOREACH(fnh, &fn->nexthops, entry) {
+		if (fnh->remote_label == NO_LABEL)
+			continue;
+
+		rlfa_labels.nexthops[i].family = fnh->af;
+		switch (fnh->af) {
+		case AF_INET:
+			rlfa_labels.nexthops[i].gate.ipv4 = fnh->nexthop.v4;
+			break;
+		case AF_INET6:
+			rlfa_labels.nexthops[i].gate.ipv6 = fnh->nexthop.v6;
+			break;
+		default:
+			continue;
+		}
+		rlfa_labels.nexthops[i].label = fnh->remote_label;
+		i++;
+	}
+	rlfa_labels.nexthop_num = i;
+
+	lde_imsg_compose_parent(IMSG_RLFA_LABELS, 0, &rlfa_labels,
+				sizeof(rlfa_labels));
+}
+
+void lde_rlfa_label_update(const struct fec *fec)
+{
+	struct ldp_rlfa_node *rnode;
+
+	if (fec->type != FEC_TYPE_IPV4
+	    || fec->u.ipv4.prefixlen != IPV4_MAX_BITLEN)
+		return;
+
+	/*
+	 * TODO: use an rb-tree lookup to restrict the iteration to the RLFAs
+	 * that were effectivelly affected by the label update.
+	 */
+	RB_FOREACH (rnode, ldp_rlfa_node_head, &rlfa_node_tree) {
+		struct ldp_rlfa_client *rclient;
+
+		if (!IPV4_ADDR_SAME(&rnode->pq_address, &fec->u.ipv4.prefix))
+			continue;
+
+		RB_FOREACH (rclient, ldp_rlfa_client_head, &rnode->clients)
+			lde_rlfa_client_send(rclient);
+	}
+}
+
+void lde_rlfa_check(struct ldp_rlfa_client *rclient)
+{
+	struct lde_nbr *ln;
+	struct lde_map *me;
+	struct fec fec;
+	union ldpd_addr pq_address = {};
+
+	pq_address.v4 = rclient->node->pq_address;
+	ln = lde_nbr_find_by_addr(AF_INET, &pq_address);
+	if (!ln)
+		return;
+
+	lde_prefix2fec(&rclient->node->destination, &fec);
+	me = (struct lde_map *)fec_find(&ln->recv_map, &fec);
+	if (!me)
+		return;
+
+	rclient->node->pq_label = me->map.label;
+	lde_rlfa_client_send(rclient);
+}
+
+/*
+ * Check if there's any registered RLFA client for this prefix/neighbor (PQ
+ * node) and notify about the updated label.
+ */
+void lde_rlfa_update_clients(struct fec *fec, struct lde_nbr *ln,
+			     uint32_t label)
+{
+	struct prefix		 rlfa_dest;
+	struct ldp_rlfa_node	*rnode;
+
+	lde_fec2prefix(fec, &rlfa_dest);
+	rnode = rlfa_node_find(&rlfa_dest, ln->id);
+	if (rnode) {
+		struct ldp_rlfa_client *rclient;
+
+		rnode->pq_label = label;
+		RB_FOREACH (rclient, ldp_rlfa_client_head, &rnode->clients)
+			lde_rlfa_client_send(rclient);
+	} else
+		lde_rlfa_label_update(fec);
+}
+
+void ldpe_rlfa_init(struct ldp_rlfa_client *rclient)
+{
+	struct tnbr *tnbr;
+	union ldpd_addr pq_address = {};
+
+	pq_address.v4 = rclient->node->pq_address;
+	tnbr = tnbr_find(leconf, AF_INET, &pq_address);
+	if (tnbr == NULL) {
+		tnbr = tnbr_new(AF_INET, &pq_address);
+		tnbr_update(tnbr);
+		RB_INSERT(tnbr_head, &leconf->tnbr_tree, tnbr);
+	}
+
+	tnbr->rlfa_count++;
+}
+
+void ldpe_rlfa_exit(struct ldp_rlfa_client *rclient)
+{
+	struct tnbr *tnbr;
+	union ldpd_addr pq_address = {};
+
+	pq_address.v4 = rclient->node->pq_address;
+	tnbr = tnbr_find(leconf, AF_INET, &pq_address);
+	if (tnbr) {
+		tnbr->rlfa_count--;
+		tnbr_check(leconf, tnbr);
+	}
+}