zebra: ZEBRA_ROUTE_ADD supports seg6local route (step1)

With this patch, zclient can intall seg6local rotues whem
they set properties nh_seg6local_{action,ctx} on struct nexthop
and set ZEBRA_FLAG_SEG6LOCAL_ROUTE on zapi_route's flag.

Signed-off-by: Hiroki Shirokura <slank.dev@gmail.com>

zebra/rt_netlink.c

@@ -22,9 +22,18 @@
 
 #ifdef HAVE_NETLINK
 
+/* The following definition is to workaround an issue in the Linux kernel
+ * header files with redefinition of 'struct in6_addr' in both
+ * netinet/in.h and linux/in6.h.
+ * Reference - https://sourceware.org/ml/libc-alpha/2013-01/msg00599.html
+ */
+#define _LINUX_IN6_H
+
 #include <net/if_arp.h>
 #include <linux/lwtunnel.h>
 #include <linux/mpls_iptunnel.h>
+#include <linux/seg6_iptunnel.h>
+#include <linux/seg6_local.h>
 #include <linux/neighbour.h>
 #include <linux/rtnetlink.h>
 #include <linux/nexthop.h>
@@ -38,6 +47,8 @@
 #include "if.h"
 #include "log.h"
 #include "prefix.h"
+#include "plist.h"
+#include "plist_int.h"
 #include "connected.h"
 #include "table.h"
 #include "memory.h"
@@ -1262,6 +1273,52 @@ static bool _netlink_route_build_singlepath(const struct prefix *p,
 					      sizeof(label_buf)))
 		return false;
 
+	if (nexthop->nh_seg6local_ctx) {
+		struct rtattr *nest;
+		const struct seg6local_context *ctx;
+
+		ctx = nexthop->nh_seg6local_ctx;
+		nl_attr_put16(nlmsg, req_size, RTA_ENCAP_TYPE,
+			      LWTUNNEL_ENCAP_SEG6_LOCAL);
+
+		nest = nl_attr_nest(nlmsg, req_size, RTA_ENCAP);
+		switch (nexthop->nh_seg6local_action) {
+		case ZEBRA_SEG6_LOCAL_ACTION_END:
+			nl_attr_put32(nlmsg, req_size, SEG6_LOCAL_ACTION,
+				      SEG6_LOCAL_ACTION_END);
+			break;
+		case ZEBRA_SEG6_LOCAL_ACTION_END_X:
+			nl_attr_put32(nlmsg, req_size, SEG6_LOCAL_ACTION,
+				      SEG6_LOCAL_ACTION_END_X);
+			nl_attr_put(nlmsg, req_size, SEG6_LOCAL_NH6, &ctx->nh6,
+				    sizeof(struct in6_addr));
+			break;
+		case ZEBRA_SEG6_LOCAL_ACTION_END_T:
+			nl_attr_put32(nlmsg, req_size, SEG6_LOCAL_ACTION,
+				      SEG6_LOCAL_ACTION_END_T);
+			nl_attr_put32(nlmsg, req_size, SEG6_LOCAL_TABLE,
+				      ctx->table);
+			break;
+		case ZEBRA_SEG6_LOCAL_ACTION_END_DX4:
+			nl_attr_put32(nlmsg, req_size, SEG6_LOCAL_ACTION,
+				      SEG6_LOCAL_ACTION_END_DX4);
+			nl_attr_put(nlmsg, req_size, SEG6_LOCAL_NH4, &ctx->nh4,
+				    sizeof(struct in_addr));
+			break;
+		case ZEBRA_SEG6_LOCAL_ACTION_END_DT6:
+			nl_attr_put32(nlmsg, req_size, SEG6_LOCAL_ACTION,
+				      SEG6_LOCAL_ACTION_END_DT6);
+			nl_attr_put32(nlmsg, req_size, SEG6_LOCAL_TABLE,
+				      ctx->table);
+			break;
+		default:
+			zlog_err("%s: unsupport seg6local behaviour action=%u",
+				 __func__, nexthop->nh_seg6local_action);
+			break;
+		}
+		nl_attr_nest_end(nlmsg, nest);
+	}
+
 	if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_ONLINK))
 		rtmsg->rtm_flags |= RTNH_F_ONLINK;
 
@@ -2256,6 +2313,67 @@ ssize_t netlink_nexthop_msg_encode(uint16_t cmd,
 				nl_attr_nest_end(&req->n, nest);
 			}
 
+			if (nh->nh_seg6local_ctx) {
+				uint32_t action;
+				uint16_t encap;
+				struct rtattr *nest;
+				const struct seg6local_context *ctx;
+
+				req->nhm.nh_family = AF_INET6;
+				action = nh->nh_seg6local_action;
+				ctx = nh->nh_seg6local_ctx;
+				encap = LWTUNNEL_ENCAP_SEG6_LOCAL;
+				nl_attr_put(&req->n, buflen, NHA_ENCAP_TYPE,
+					    &encap, sizeof(uint16_t));
+
+				nest = nl_attr_nest(&req->n, buflen,
+						    NHA_ENCAP | NLA_F_NESTED);
+				switch (action) {
+				case SEG6_LOCAL_ACTION_END:
+					nl_attr_put32(&req->n, buflen,
+						      SEG6_LOCAL_ACTION,
+						      SEG6_LOCAL_ACTION_END);
+					break;
+				case SEG6_LOCAL_ACTION_END_X:
+					nl_attr_put32(&req->n, buflen,
+						      SEG6_LOCAL_ACTION,
+						      SEG6_LOCAL_ACTION_END_X);
+					nl_attr_put(&req->n, buflen,
+						    SEG6_LOCAL_NH6, &ctx->nh6,
+						    sizeof(struct in6_addr));
+					break;
+				case SEG6_LOCAL_ACTION_END_T:
+					nl_attr_put32(&req->n, buflen,
+						      SEG6_LOCAL_ACTION,
+						      SEG6_LOCAL_ACTION_END_T);
+					nl_attr_put32(&req->n, buflen,
+						      SEG6_LOCAL_TABLE,
+						      ctx->table);
+					break;
+				case SEG6_LOCAL_ACTION_END_DX4:
+					nl_attr_put32(&req->n, buflen,
+						      SEG6_LOCAL_ACTION,
+						      SEG6_LOCAL_ACTION_END_DX4);
+					nl_attr_put(&req->n, buflen,
+						    SEG6_LOCAL_NH4, &ctx->nh4,
+						    sizeof(struct in_addr));
+					break;
+				case SEG6_LOCAL_ACTION_END_DT6:
+					nl_attr_put32(&req->n, buflen,
+						      SEG6_LOCAL_ACTION,
+						      SEG6_LOCAL_ACTION_END_DT6);
+					nl_attr_put32(&req->n, buflen,
+						      SEG6_LOCAL_TABLE,
+						      ctx->table);
+					break;
+				default:
+					zlog_err("%s: unsupport seg6local behaviour action=%u",
+						 __func__, action);
+					break;
+				}
+				nl_attr_nest_end(&req->n, nest);
+			}
+
 nexthop_done:
 
 			if (IS_ZEBRA_DEBUG_KERNEL)

zebra/zapi_msg.c

@@ -1747,6 +1747,18 @@ static bool zapi_read_nexthops(struct zserv *client, struct prefix *p,
 					   &api_nh->labels[0]);
 		}
 
+		if (CHECK_FLAG(flags, ZEBRA_FLAG_SEG6LOCAL_ROUTE)
+		    && api_nh->type != NEXTHOP_TYPE_BLACKHOLE) {
+			if (IS_ZEBRA_DEBUG_RECV)
+				zlog_debug("%s: adding seg6local action %s",
+					   __func__,
+					   seg6local_action2str(
+						   api_nh->seg6local_action));
+
+			nexthop_add_seg6local(nexthop, api_nh->seg6local_action,
+					      &api_nh->seg6local_ctx);
+		}
+
 		if (IS_ZEBRA_DEBUG_RECV) {
 			labelbuf[0] = '\0';
 			nhbuf[0] = '\0';

zebra/zebra_nhg.c

@@ -1007,6 +1007,7 @@ void nhg_ctx_free(struct nhg_ctx **ctx)
 	nh = nhg_ctx_get_nh(*ctx);
 
 	nexthop_del_labels(nh);
+	nexthop_del_seg6local(nh);
 
 done:
 	XFREE(MTYPE_NHG_CTX, *ctx);
@@ -1377,6 +1378,7 @@ static struct nhg_hash_entry *depends_find_singleton(const struct nexthop *nh,
 
 	/* The copy may have allocated labels; free them if necessary. */
 	nexthop_del_labels(&lookup);
+	nexthop_del_seg6local(&lookup);
 
 	if (IS_ZEBRA_DEBUG_NHG_DETAIL)
 		zlog_debug("%s: nh %pNHv => %p (%u)",

zebra/zebra_vty.c

@@ -653,6 +653,15 @@ static void show_route_nexthop_helper(struct vty *vty,
 				       sizeof(buf), 1));
 	}
 
+	if (nexthop->nh_seg6local_ctx) {
+		seg6local_context2str(buf, sizeof(buf),
+				      nexthop->nh_seg6local_ctx,
+				      nexthop->nh_seg6local_action);
+		vty_out(vty, ", seg6local %s %s",
+			seg6local_action2str(nexthop->nh_seg6local_action),
+			buf);
+	}
+
 	if (nexthop->weight)
 		vty_out(vty, ", weight %u", nexthop->weight);
 
@@ -675,6 +684,7 @@ static void show_nexthop_json_helper(json_object *json_nexthop,
 	char buf[SRCDEST2STR_BUFFER];
 	json_object *json_labels = NULL;
 	json_object *json_backups = NULL;
+	json_object *json_seg6local = NULL;
 	int i;
 
 	json_object_int_add(json_nexthop, "flags",
@@ -852,6 +862,15 @@ static void show_nexthop_json_helper(json_object *json_nexthop,
 	if (nexthop->srte_color)
 		json_object_int_add(json_nexthop, "srteColor",
 				    nexthop->srte_color);
+
+	if (nexthop->nh_seg6local_ctx) {
+		json_seg6local = json_object_new_object();
+		json_object_string_add(
+			json_seg6local, "action",
+			seg6local_action2str(nexthop->nh_seg6local_action));
+		json_object_object_add(json_nexthop, "seg6local",
+				       json_seg6local);
+	}
 }
 
 static void vty_show_ip_route(struct vty *vty, struct route_node *rn,