zebra: new dplane action to set gre link interface

This action is initiated by nhrp and has been stubbed when
moving to zebra. Now, a netlink request is forged to set
the link interface of a gre interface if that gre interface
does not have already a link interface.

Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>

zebra/if_netlink.c

@@ -463,6 +463,46 @@ uint32_t kernel_get_speed(struct interface *ifp, int *error)
 	return get_iflink_speed(ifp, error);
 }
 
+static ssize_t
+netlink_gre_set_msg_encoder(struct zebra_dplane_ctx *ctx, void *buf,
+			    size_t buflen)
+{
+	struct {
+		struct nlmsghdr n;
+		struct ifinfomsg ifi;
+		char buf[];
+	} *req = buf;
+	uint32_t link_idx;
+	struct rtattr *rta_info, *rta_data;
+
+	if (buflen < sizeof(*req))
+		return 0;
+	memset(req, 0, sizeof(*req));
+
+	req->n.nlmsg_type =  RTM_NEWLINK;
+	req->n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
+	req->n.nlmsg_flags = NLM_F_REQUEST;
+
+	req->ifi.ifi_index = dplane_ctx_get_ifindex(ctx);
+	req->ifi.ifi_change = 0xFFFFFFFF;
+	link_idx = dplane_ctx_gre_get_link_ifindex(ctx);
+
+	rta_info = nl_attr_nest(&req->n, buflen, IFLA_LINKINFO);
+	if (!rta_info)
+		return 0;
+	if (!nl_attr_put(&req->n, buflen, IFLA_INFO_KIND, "gre", 3))
+		return 0;
+	rta_data = nl_attr_nest(&req->n, buflen, IFLA_INFO_DATA);
+	if (!rta_info)
+		return 0;
+	if (!nl_attr_put32(&req->n, buflen, IFLA_GRE_LINK, link_idx))
+		return 0;
+	nl_attr_nest_end(&req->n, rta_data);
+	nl_attr_nest_end(&req->n, rta_info);
+
+	return NLMSG_ALIGN(req->n.nlmsg_len);
+}
+
 static int netlink_extract_bridge_info(struct rtattr *link_data,
 				       struct zebra_l2info_bridge *bridge_info)
 {
@@ -524,9 +564,13 @@ static int netlink_extract_gre_info(struct rtattr *link_data,
 	if (!attr[IFLA_GRE_LINK]) {
 		if (IS_ZEBRA_DEBUG_KERNEL)
 			zlog_debug("IFLA_GRE_LINK missing from GRE IF message");
-	} else
+	} else {
 		gre_info->ifindex_link =
 			*(ifindex_t *)RTA_DATA(attr[IFLA_GRE_LINK]);
+		if (IS_ZEBRA_DEBUG_KERNEL)
+			zlog_debug("IFLA_GRE_LINK obtained is %u",
+				   gre_info->ifindex_link);
+	}
 	if (attr[IFLA_GRE_IKEY])
 		gre_info->ikey = *(uint32_t *)RTA_DATA(attr[IFLA_GRE_IKEY]);
 	if (attr[IFLA_GRE_OKEY])
@@ -986,6 +1030,20 @@ static int netlink_request_intf_addr(struct nlsock *netlink_cmd, int family,
 	return netlink_request(netlink_cmd, &req);
 }
 
+enum netlink_msg_status
+netlink_put_gre_set_msg(struct nl_batch *bth, struct zebra_dplane_ctx *ctx)
+{
+	enum dplane_op_e op;
+	enum netlink_msg_status ret;
+
+	op = dplane_ctx_get_op(ctx);
+	assert(op == DPLANE_OP_GRE_SET);
+
+	ret = netlink_batch_add_msg(bth, ctx, netlink_gre_set_msg_encoder, false);
+
+	return ret;
+}
+
 /* Interface lookup by netlink socket. */
 int interface_lookup_netlink(struct zebra_ns *zns)
 {

zebra/if_netlink.h

@@ -32,6 +32,9 @@ extern int netlink_interface_addr(struct nlmsghdr *h, ns_id_t ns_id,
 extern int netlink_link_change(struct nlmsghdr *h, ns_id_t ns_id, int startup);
 extern int interface_lookup_netlink(struct zebra_ns *zns);
 
+extern enum netlink_msg_status
+netlink_put_gre_set_msg(struct nl_batch *bth, struct zebra_dplane_ctx *ctx);
+
 extern enum netlink_msg_status
 netlink_put_address_update_msg(struct nl_batch *bth,
 			       struct zebra_dplane_ctx *ctx);

zebra/kernel_netlink.c

@@ -1360,6 +1360,9 @@ static enum netlink_msg_status nl_put_msg(struct nl_batch *bth,
 	case DPLANE_OP_IPSET_ENTRY_DELETE:
 		return FRR_NETLINK_ERROR;
 
+	case DPLANE_OP_GRE_SET:
+		return netlink_put_gre_set_msg(bth, ctx);
+
 	case DPLANE_OP_NONE:
 		return FRR_NETLINK_ERROR;
 	}

zebra/rt.h

@@ -81,9 +81,6 @@ extern int mpls_kernel_init(void);
 extern uint32_t kernel_get_speed(struct interface *ifp, int *error);
 extern int kernel_get_ipmr_sg_stats(struct zebra_vrf *zvrf, void *mroute);
 
-extern int kernel_configure_if_link(struct interface *ifp,
-				    struct interface *link_ifp, ns_id_t ns_id);
-
 /*
  * Southbound Initialization routines to get initial starting
  * state.

zebra/rt_netlink.c

@@ -3890,14 +3890,6 @@ netlink_put_neigh_update_msg(struct nl_batch *bth, struct zebra_dplane_ctx *ctx)
 				     false);
 }
 
-int kernel_configure_if_link(struct interface *ifp,
-			     struct interface *link_ifp,
-			     ns_id_t ns_id)
-{
-	/* TODO */
-	return 0;
-}
-
 /*
  * MPLS label forwarding table change via netlink interface, using dataplane
  * context information.

zebra/rt_socket.c

@@ -394,12 +394,6 @@ enum zebra_dplane_result kernel_mac_update_ctx(struct zebra_dplane_ctx *ctx)
 	return ZEBRA_DPLANE_REQUEST_SUCCESS;
 }
 
-int kernel_configure_if_link(struct interface *ifp, struct interface *link_ifp,
-			     ns_id_t ns_id)
-{
-	return 0;
-}
-
 extern int kernel_interface_set_master(struct interface *master,
 				       struct interface *slave)
 {

zebra/zapi_msg.c

@@ -3435,22 +3435,40 @@ static inline void zebra_gre_source_set(ZAPI_HANDLER_ARGS)
 	vrf_id_t link_vrf_id;
 	struct interface *ifp;
 	struct interface *ifp_link;
-	ns_id_t ns_id;
 	vrf_id_t vrf_id = zvrf->vrf->vrf_id;
+	struct zebra_if *zif, *gre_zif;
+	struct zebra_l2info_gre *gre_info;
 
 	s = msg;
 	STREAM_GETL(s, idx);
 	ifp  = if_lookup_by_index(idx, vrf_id);
 	STREAM_GETL(s, link_idx);
 	STREAM_GETL(s, link_vrf_id);
+
 	ifp_link  = if_lookup_by_index(link_idx, link_vrf_id);
 	if (!ifp_link || !ifp) {
 		zlog_warn("GRE (index %u, VRF %u) or GRE link interface (index %u, VRF %u) not found, when setting GRE params",
 			  idx, vrf_id, link_idx, link_vrf_id);
 		return;
 	}
-	ns_id = zvrf->zns->ns_id;
-	kernel_configure_if_link(ifp, ifp_link, ns_id);
+
+	if (!IS_ZEBRA_IF_GRE(ifp))
+		return;
+
+	gre_zif = (struct zebra_if *)ifp->info;
+	zif = (struct zebra_if *)ifp_link->info;
+	if (!zif || !gre_zif)
+		return;
+
+	gre_info = &zif->l2info.gre;
+	if (!gre_info)
+		return;
+
+	/* if gre link already set */
+	if (gre_zif->link && gre_zif->link == ifp_link)
+		return;
+
+	dplane_gre_set(ifp, ifp_link);
 
  stream_failure:
 	return;

zebra/zebra_dplane.c

@@ -271,6 +271,9 @@ struct dplane_rule_info {
 	struct dplane_ctx_rule old;
 };
 
+struct dplane_gre_ctx {
+	uint32_t link_ifindex;
+};
 /*
  * The context block used to exchange info about route updates across
  * the boundary between the zebra main context (and pthread) and the
@@ -327,6 +330,7 @@ struct zebra_dplane_ctx {
 			struct zebra_pbr_ipset_info info;
 		} ipset_entry;
 		struct dplane_neigh_table neightable;
+		struct dplane_gre_ctx gre;
 	} u;
 
 	/* Namespace info, used especially for netlink kernel communication */
@@ -469,6 +473,9 @@ static struct zebra_dplane_globals {
 	_Atomic uint32_t dg_neightable_in;
 	_Atomic uint32_t dg_neightable_errors;
 
+	_Atomic uint32_t dg_gre_set_in;
+	_Atomic uint32_t dg_gre_set_errors;
+
 	/* Dataplane pthread */
 	struct frr_pthread *dg_pthread;
 
@@ -713,6 +720,9 @@ static void dplane_ctx_free_internal(struct zebra_dplane_ctx *ctx)
 			}
 			list_delete(&ctx->u.iptable.interface_name_list);
 		}
+		break;
+	case DPLANE_OP_GRE_SET:
+		break;
 	}
 }
 
@@ -979,6 +989,10 @@ const char *dplane_op2str(enum dplane_op_e op)
 	case DPLANE_OP_NEIGH_TABLE_UPDATE:
 		ret = "NEIGH_TABLE_UPDATE";
 		break;
+
+	case DPLANE_OP_GRE_SET:
+		ret = "GRE_SET";
+		break;
 	}
 
 	return ret;
@@ -1772,6 +1786,15 @@ uint32_t dplane_ctx_neigh_get_update_flags(const struct zebra_dplane_ctx *ctx)
 	return ctx->u.neigh.update_flags;
 }
 
+/* Accessor for GRE set */
+uint32_t
+dplane_ctx_gre_get_link_ifindex(const struct zebra_dplane_ctx *ctx)
+{
+	DPLANE_CTX_VALID(ctx);
+
+	return ctx->u.gre.link_ifindex;
+}
+
 /* Accessors for PBR rule information */
 int dplane_ctx_rule_get_sock(const struct zebra_dplane_ctx *ctx)
 {
@@ -4125,6 +4148,67 @@ dplane_pbr_ipset_entry_delete(struct zebra_pbr_ipset_entry *ipset)
 	return ipset_entry_update_internal(DPLANE_OP_IPSET_ENTRY_DELETE, ipset);
 }
 
+/*
+ * Common helper api for GRE set
+ */
+enum zebra_dplane_result
+dplane_gre_set(struct interface *ifp, struct interface *ifp_link)
+{
+	enum zebra_dplane_result result = ZEBRA_DPLANE_REQUEST_FAILURE;
+	struct zebra_dplane_ctx *ctx;
+	enum dplane_op_e op = DPLANE_OP_GRE_SET;
+	int ret;
+	struct zebra_ns *zns;
+
+	ctx = dplane_ctx_alloc();
+
+	if (!ifp)
+		return result;
+
+	if (IS_ZEBRA_DEBUG_DPLANE_DETAIL) {
+		zlog_debug("init dplane ctx %s: if %s link %s%s",
+			   dplane_op2str(op), ifp->name,
+			   ifp_link ? "set" : "unset", ifp_link ?
+			   ifp_link->name : "");
+	}
+
+	ctx->zd_op = op;
+	ctx->zd_status = ZEBRA_DPLANE_REQUEST_SUCCESS;
+	zns = zebra_ns_lookup(ifp->vrf_id);
+	if (!zns)
+		return result;
+	dplane_ctx_ns_init(ctx, zns, false);
+
+	dplane_ctx_set_ifname(ctx, ifp->name);
+	ctx->zd_vrf_id = ifp->vrf_id;
+	ctx->zd_ifindex = ifp->ifindex;
+	if (ifp_link)
+		ctx->u.gre.link_ifindex = ifp_link->ifindex;
+	else
+		ctx->u.gre.link_ifindex = 0;
+
+	ctx->zd_status = ZEBRA_DPLANE_REQUEST_SUCCESS;
+
+	/* Enqueue context for processing */
+	ret = dplane_update_enqueue(ctx);
+
+	/* Update counter */
+	atomic_fetch_add_explicit(&zdplane_info.dg_gre_set_in, 1,
+				  memory_order_relaxed);
+
+	if (ret == AOK)
+		result = ZEBRA_DPLANE_REQUEST_QUEUED;
+	else {
+		atomic_fetch_add_explicit(
+			&zdplane_info.dg_gre_set_errors, 1,
+			memory_order_relaxed);
+		if (ctx)
+			dplane_ctx_free(&ctx);
+		result = ZEBRA_DPLANE_REQUEST_FAILURE;
+	}
+	return result;
+}
+
 /*
  * Handler for 'show dplane'
  */
@@ -4234,6 +4318,13 @@ int dplane_show_helper(struct vty *vty, bool detailed)
 				    memory_order_relaxed);
 	vty_out(vty, "Neighbor Table updates:       %"PRIu64"\n", incoming);
 	vty_out(vty, "Neighbor Table errors:        %"PRIu64"\n", errs);
+
+	incoming = atomic_load_explicit(&zdplane_info.dg_gre_set_in,
+					memory_order_relaxed);
+	errs = atomic_load_explicit(&zdplane_info.dg_gre_set_errors,
+				    memory_order_relaxed);
+	vty_out(vty, "GRE set updates:       %"PRIu64"\n", incoming);
+	vty_out(vty, "GRE set errors:        %"PRIu64"\n", errs);
 	return CMD_SUCCESS;
 }
 
@@ -4680,6 +4771,12 @@ static void kernel_dplane_log_detail(struct zebra_dplane_ctx *ctx)
 			   dplane_ctx_get_ifname(ctx),
 			   family2str(dplane_ctx_neightable_get_family(ctx)));
 		break;
+	case DPLANE_OP_GRE_SET:
+		zlog_debug("Dplane gre set op %s, ifp %s, link %u",
+			   dplane_op2str(dplane_ctx_get_op(ctx)),
+			   dplane_ctx_get_ifname(ctx),
+			   ctx->u.gre.link_ifindex);
+		break;
 	}
 }
 
@@ -4808,6 +4905,12 @@ static void kernel_dplane_handle_result(struct zebra_dplane_ctx *ctx)
 				memory_order_relaxed);
 		break;
 
+	case DPLANE_OP_GRE_SET:
+		if (res != ZEBRA_DPLANE_REQUEST_SUCCESS)
+			atomic_fetch_add_explicit(
+				&zdplane_info.dg_gre_set_errors, 1,
+				memory_order_relaxed);
+		break;
 	/* Ignore 'notifications' - no-op */
 	case DPLANE_OP_SYS_ROUTE_ADD:
 	case DPLANE_OP_SYS_ROUTE_DELETE:

zebra/zebra_dplane.h

@@ -171,6 +171,7 @@ enum dplane_op_e {
 	DPLANE_OP_NEIGH_IP_DELETE,
 
 	DPLANE_OP_NEIGH_TABLE_UPDATE,
+	DPLANE_OP_GRE_SET,
 };
 
 /*
@@ -527,6 +528,10 @@ dplane_ctx_neightable_get_mcast_probes(const struct zebra_dplane_ctx *ctx);
 uint32_t
 dplane_ctx_neightable_get_ucast_probes(const struct zebra_dplane_ctx *ctx);
 
+/* Accessor for GRE set */
+uint32_t
+dplane_ctx_gre_get_link_ifindex(const struct zebra_dplane_ctx *ctx);
+
 /* Namespace info - esp. for netlink communication */
 const struct zebra_dplane_info *dplane_ctx_get_ns(
 	const struct zebra_dplane_ctx *ctx);
@@ -695,6 +700,12 @@ enum zebra_dplane_result dplane_neigh_table_update(const struct interface *ifp,
 						   const uint32_t ucast_probes,
 						   const uint32_t mcast_probes);
 
+/*
+ * Enqueue a GRE set
+ */
+enum zebra_dplane_result
+dplane_gre_set(struct interface *ifp, struct interface *ifp_link);
+
 /* Forward ref of zebra_pbr_rule */
 struct zebra_pbr_rule;
 

zebra/zebra_errors.h

@@ -134,6 +134,7 @@ enum zebra_log_refs {
 	EC_ZEBRA_DUPLICATE_NHG_MESSAGE,
 	EC_ZEBRA_VRF_MISCONFIGURED,
 	EC_ZEBRA_ES_CREATE,
+	EC_ZEBRA_GRE_SET_UPDATE,
 };
 
 void zebra_error_init(void);

zebra/zebra_nhg.c

@@ -2965,6 +2965,7 @@ void zebra_nhg_dplane_result(struct zebra_dplane_ctx *ctx)
 	case DPLANE_OP_IPSET_ENTRY_ADD:
 	case DPLANE_OP_IPSET_ENTRY_DELETE:
 	case DPLANE_OP_NEIGH_TABLE_UPDATE:
+	case DPLANE_OP_GRE_SET:
 		break;
 	}
 

zebra/zebra_rib.c

@@ -4062,6 +4062,7 @@ static int rib_process_dplane_results(struct thread *thread)
 			case DPLANE_OP_NEIGH_DISCOVER:
 			case DPLANE_OP_BR_PORT_UPDATE:
 			case DPLANE_OP_NEIGH_TABLE_UPDATE:
+			case DPLANE_OP_GRE_SET:
 			case DPLANE_OP_NONE:
 				/* Don't expect this: just return the struct? */
 				dplane_ctx_fini(&ctx);