Merge pull request #14034 from LabNConsulting/aceelindem/ospf_prefix_suppression

ospfd: Implement OSPF prefix-suppression as specified in RFC 6860

5 files changed, 146 insertions, 21 deletions

diff --git a/ospfd/ospf_interface.c b/ospfd/ospf_interface.c
index 72de19811..bdab672b4 100644
--- a/ospfd/ospf_interface.c
+++ b/ospfd/ospf_interface.c
@@ -600,6 +600,7 @@ void ospf_free_if_params(struct interface *ifp, struct in_addr addr)
 	    !OSPF_IF_PARAM_CONFIGURED(oip, auth_type) &&
 	    !OSPF_IF_PARAM_CONFIGURED(oip, if_area) &&
 	    !OSPF_IF_PARAM_CONFIGURED(oip, opaque_capable) &&
+	    !OSPF_IF_PARAM_CONFIGURED(oip, prefix_suppression) &&
 	    listcount(oip->auth_crypt) == 0) {
 		ospf_del_if_params(ifp, oip);
 		rn->info = NULL;
@@ -709,6 +710,8 @@ int ospf_if_new_hook(struct interface *ifp)
 	SET_IF_PARAM(IF_DEF_PARAMS(ifp), opaque_capable);
 	IF_DEF_PARAMS(ifp)->opaque_capable = OSPF_OPAQUE_CAPABLE_DEFAULT;
 
+	IF_DEF_PARAMS(ifp)->prefix_suppression = OSPF_PREFIX_SUPPRESSION_DEFAULT;
+
 	rc = ospf_opaque_new_if(ifp);
 	return rc;
 }
diff --git a/ospfd/ospf_interface.h b/ospfd/ospf_interface.h
index 38ec45c75..47b70f803 100644
--- a/ospfd/ospf_interface.h
+++ b/ospfd/ospf_interface.h
@@ -81,6 +81,9 @@ struct ospf_if_params {
 	/* Fast-Hellos */
 	DECLARE_IF_PARAM(uint8_t, fast_hello);
 
+	/* Prefix-Suppression */
+	DECLARE_IF_PARAM(bool, prefix_suppression);
+
 	/* Authentication data. */
 	uint8_t auth_simple[OSPF_AUTH_SIMPLE_SIZE + 1]; /* Simple password. */
 	uint8_t auth_simple__config : 1;
diff --git a/ospfd/ospf_lsa.c b/ospfd/ospf_lsa.c
index 27e7e0275..7ef983427 100644
--- a/ospfd/ospf_lsa.c
+++ b/ospfd/ospf_lsa.c
@@ -539,16 +539,23 @@ static int lsa_link_ptop_set(struct stream **s, struct ospf_interface *oi)
 		}
 
 	/* no need for a stub link for unnumbered interfaces */
-	if (oi->ptp_dmvpn
-	    || !CHECK_FLAG(oi->connected->flags, ZEBRA_IFA_UNNUMBERED)) {
-		/* Regardless of the state of the neighboring router, we must
-		   add a Type 3 link (stub network).
-		   N.B. Options 1 & 2 share basically the same logic. */
-		masklen2ip(oi->address->prefixlen, &mask);
-		id.s_addr = CONNECTED_PREFIX(oi->connected)->u.prefix4.s_addr
-			    & mask.s_addr;
-		links += link_info_set(s, id, mask, LSA_LINK_TYPE_STUB, 0,
-				       oi->output_cost);
+	if (OSPF_IF_PARAM(oi, prefix_suppression)) {
+		if (IS_DEBUG_OSPF(lsa, LSA_GENERATE))
+			zlog_debug("LSA[Type1]: Interface %s stub link omitted due prefix-suppression",
+				   oi->ifp->name);
+	} else {
+		if (oi->ptp_dmvpn ||
+		    !CHECK_FLAG(oi->connected->flags, ZEBRA_IFA_UNNUMBERED)) {
+			/* Regardless of the state of the neighboring router, we must
+			   add a Type 3 link (stub network).
+			   N.B. Options 1 & 2 share basically the same logic. */
+			masklen2ip(oi->address->prefixlen, &mask);
+			id.s_addr =
+				CONNECTED_PREFIX(oi->connected)->u.prefix4.s_addr &
+				mask.s_addr;
+			links += link_info_set(s, id, mask, LSA_LINK_TYPE_STUB,
+					       0, oi->output_cost);
+		}
 	}
 
 	return links;
@@ -563,10 +570,15 @@ static int lsa_link_broadcast_set(struct stream **s, struct ospf_interface *oi)
 
 	/* Describe Type 3 Link. */
 	if (oi->state == ISM_Waiting) {
+		if (OSPF_IF_PARAM(oi, prefix_suppression)) {
+			if (IS_DEBUG_OSPF(lsa, LSA_GENERATE))
+				zlog_debug("LSA[Type1]: Interface %s stub link omitted due prefix-suppression",
+					   oi->ifp->name);
+			return 0;
+		}
 		if (IS_DEBUG_OSPF(lsa, LSA_GENERATE))
-			zlog_debug(
-				"LSA[Type1]: Interface %s is in state Waiting. Adding stub interface",
-				oi->ifp->name);
+			zlog_debug("LSA[Type1]: Interface %s is in state Waiting. Adding stub interface",
+				   oi->ifp->name);
 		masklen2ip(oi->address->prefixlen, &mask);
 		id.s_addr = oi->address->u.prefix4.s_addr & mask.s_addr;
 		return link_info_set(s, id, mask, LSA_LINK_TYPE_STUB, 0,
@@ -587,10 +599,15 @@ static int lsa_link_broadcast_set(struct stream **s, struct ospf_interface *oi)
 	}
 	/* Describe type 3 link. */
 	else {
+		if (OSPF_IF_PARAM(oi, prefix_suppression)) {
+			if (IS_DEBUG_OSPF(lsa, LSA_GENERATE))
+				zlog_debug("LSA[Type1]: Interface %s stub link omitted due prefix-suppression",
+					   oi->ifp->name);
+			return 0;
+		}
 		if (IS_DEBUG_OSPF(lsa, LSA_GENERATE))
-			zlog_debug(
-				"LSA[Type1]: Interface %s has no DR. Adding stub interface",
-				oi->ifp->name);
+			zlog_debug("LSA[Type1]: Interface %s has no DR. Adding stub interface",
+				   oi->ifp->name);
 		masklen2ip(oi->address->prefixlen, &mask);
 		id.s_addr = oi->address->u.prefix4.s_addr & mask.s_addr;
 		return link_info_set(s, id, mask, LSA_LINK_TYPE_STUB, 0,
@@ -603,7 +620,7 @@ static int lsa_link_loopback_set(struct stream **s, struct ospf_interface *oi)
 	struct in_addr id, mask;
 
 	/* Describe Type 3 Link. */
-	if (oi->state != ISM_Loopback)
+	if ((oi->state != ISM_Loopback) || OSPF_IF_PARAM(oi, prefix_suppression))
 		return 0;
 
 	mask.s_addr = 0xffffffff;
@@ -645,9 +662,15 @@ static int lsa_link_ptomp_set(struct stream **s, struct ospf_interface *oi)
 	struct in_addr id, mask;
 	uint16_t cost = ospf_link_cost(oi);
 
-	mask.s_addr = 0xffffffff;
-	id.s_addr = oi->address->u.prefix4.s_addr;
-	links += link_info_set(s, id, mask, LSA_LINK_TYPE_STUB, 0, 0);
+	if (OSPF_IF_PARAM(oi, prefix_suppression)) {
+		if (IS_DEBUG_OSPF(lsa, LSA_GENERATE))
+			zlog_debug("LSA[Type1]: Interface %s stub link omitted due prefix-suppression",
+				   oi->ifp->name);
+	} else {
+		mask.s_addr = 0xffffffff;
+		id.s_addr = oi->address->u.prefix4.s_addr;
+		links += link_info_set(s, id, mask, LSA_LINK_TYPE_STUB, 0, 0);
+	}
 
 	if (IS_DEBUG_OSPF(lsa, LSA_GENERATE))
 		zlog_debug("PointToMultipoint: running ptomultip_set");
@@ -1006,7 +1029,14 @@ static void ospf_network_lsa_body_set(struct stream *s,
 	struct route_node *rn;
 	struct ospf_neighbor *nbr;
 
-	masklen2ip(oi->address->prefixlen, &mask);
+	if (OSPF_IF_PARAM(oi, prefix_suppression)) {
+		mask.s_addr = 0xffffffff;
+		if (IS_DEBUG_OSPF(lsa, LSA_GENERATE))
+			zlog_debug("LSA[Type2]: Interface %s network mask set to host mask due prefix-suppression",
+				   oi->ifp->name);
+	} else {
+		masklen2ip(oi->address->prefixlen, &mask);
+	}
 	stream_put_ipv4(s, mask.s_addr);
 
 	/* The network-LSA lists those routers that are fully adjacent to
diff --git a/ospfd/ospf_route.c b/ospfd/ospf_route.c
index 3ffa7c0bb..170909fa9 100644
--- a/ospfd/ospf_route.c
+++ b/ospfd/ospf_route.c
@@ -463,6 +463,12 @@ void ospf_intra_add_transit(struct route_table *rt, struct vertex *v,
 	   the IP network number, which can be obtained by masking the
 	   Vertex ID (Link State ID) with its associated subnet mask (found
 	   in the body of the associated network-LSA). */
+	if (lsa->mask.s_addr == 0xffffffff) {
+		if (IS_DEBUG_OSPF_EVENT)
+			zlog_debug("Suppress installing LSA[Type2,%pI4] route due to host mask",
+				   &(lsa->header.id));
+		return;
+	}
 	p.family = AF_INET;
 	p.prefix = v->id;
 	p.prefixlen = ip_masklen(lsa->mask);
diff --git a/ospfd/ospf_vty.c b/ospfd/ospf_vty.c
index a23802719..d3dbd4821 100644
--- a/ospfd/ospf_vty.c
+++ b/ospfd/ospf_vty.c
@@ -4076,6 +4076,20 @@ static void show_ip_ospf_interface_sub(struct vty *vty, struct ospf *ospf,
 
 		ospf_interface_bfd_show(vty, ifp, json_interface_sub);
 
+		if (use_json) {
+			json_object_boolean_add(json_interface_sub,
+						"prefixSuppression",
+						OSPF_IF_PARAM(oi,
+							      prefix_suppression));
+			json_object_boolean_add(json_oi, "prefixSuppression",
+						OSPF_IF_PARAM(oi,
+							      prefix_suppression));
+		} else {
+			if (OSPF_IF_PARAM(oi, prefix_suppression))
+				vty_out(vty,
+					"  Suppress advertisement of interface IP prefix\n");
+		}
+
 		/* OSPF Authentication information */
 		ospf_interface_auth_show(vty, oi, json_interface_sub, use_json);
 
@@ -9865,6 +9879,56 @@ DEFPY(ip_ospf_capability_opaque, ip_ospf_capability_opaque_addr_cmd,
 }
 
 
+DEFPY(ip_ospf_prefix_suppression, ip_ospf_prefix_suppression_addr_cmd,
+      "[no] ip ospf prefix-suppression [A.B.C.D]$ip_addr", NO_STR
+      "IP Information\n"
+      "OSPF interface commands\n"
+      "Supress OSPF prefix advertisement on this interface\n"
+      "Address of interface\n")
+{
+	VTY_DECLVAR_CONTEXT(interface, ifp);
+	struct route_node *rn;
+	bool prefix_suppression_change;
+	struct ospf_if_params *params;
+
+	params = IF_DEF_PARAMS(ifp);
+
+	if (ip_addr.s_addr != INADDR_ANY) {
+		params = ospf_get_if_params(ifp, ip_addr);
+		ospf_if_update_params(ifp, ip_addr);
+	}
+
+	prefix_suppression_change = (params->prefix_suppression == (bool)no);
+	params->prefix_suppression = (no) ? false : true;
+	if (params->prefix_suppression != OSPF_PREFIX_SUPPRESSION_DEFAULT)
+		SET_IF_PARAM(params, prefix_suppression);
+	else {
+		UNSET_IF_PARAM(params, prefix_suppression);
+		if (params != IF_DEF_PARAMS(ifp)) {
+			ospf_free_if_params(ifp, ip_addr);
+			ospf_if_update_params(ifp, ip_addr);
+		}
+	}
+
+	/*
+	 * If there is a change to the prefix suppression, update the Router-LSA.
+	 */
+	if (prefix_suppression_change) {
+		for (rn = route_top(IF_OIFS(ifp)); rn; rn = route_next(rn)) {
+			struct ospf_interface *oi = rn->info;
+
+			if (oi && (oi->state > ISM_Down) &&
+			    (ip_addr.s_addr == INADDR_ANY ||
+			     IPV4_ADDR_SAME(&oi->address->u.prefix4, &ip_addr))) {
+				(void)ospf_router_lsa_update_area(oi->area);
+				if (oi->state == ISM_DR)
+					ospf_network_lsa_update(oi);
+			}
+		}
+	}
+	return CMD_SUCCESS;
+}
+
 DEFUN (ospf_max_metric_router_lsa_admin,
        ospf_max_metric_router_lsa_admin_cmd,
        "max-metric router-lsa administrative",
@@ -12285,6 +12349,22 @@ static int config_write_interface_one(struct vty *vty, struct vrf *vrf)
 				vty_out(vty, "\n");
 			}
 
+			/* prefix-suppression print. */
+			if (OSPF_IF_PARAM_CONFIGURED(params,
+						     prefix_suppression) &&
+			    params->prefix_suppression !=
+				    OSPF_PREFIX_SUPPRESSION_DEFAULT) {
+				if (params->prefix_suppression == false)
+					vty_out(vty,
+						" no ip ospf prefix-suppression");
+				else
+					vty_out(vty,
+						" ip ospf prefix-suppression");
+				if (params != IF_DEF_PARAMS(ifp) && rn)
+					vty_out(vty, " %pI4", &rn->p.u.prefix4);
+				vty_out(vty, "\n");
+			}
+
 			while (1) {
 				if (rn == NULL)
 					rn = route_top(IF_OIFS_PARAMS(ifp));
@@ -13097,6 +13177,9 @@ static void ospf_vty_if_init(void)
 	/* "ip ospf capability opaque" commands. */
 	install_element(INTERFACE_NODE, &ip_ospf_capability_opaque_addr_cmd);
 
+	/* "ip ospf prefix-suppression" commands. */
+	install_element(INTERFACE_NODE, &ip_ospf_prefix_suppression_addr_cmd);
+
 	/* These commands are compatibitliy for previous version. */
 	install_element(INTERFACE_NODE, &ospf_authentication_key_cmd);
 	install_element(INTERFACE_NODE, &ospf_message_digest_key_cmd);