zebra: When using Nexthop groups, use v6 RR semantics

The nexthop group route replace operation was made consistent across all versions of the kernel. A v6 route replacement does not need to do a delete than add when using nexthop groups Signed-off-by: Donald Sharp <[email protected]>
donaldsharp · Nov 6, 2023 · 7e1b56b · 7e1b56b
1 parent 7fe9333
commit 7e1b56b
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Showing 2 changed files with 17 additions and 3 deletions.
diff --git a/zebra/rt_netlink.c b/zebra/rt_netlink.c
@@ -2209,7 +2209,8 @@ ssize_t netlink_route_multipath_msg_encode(int cmd, struct zebra_dplane_ctx *ctx
 	req->n.nlmsg_flags = NLM_F_CREATE | NLM_F_REQUEST;
 
 	if (((cmd == RTM_NEWROUTE) &&
-	     ((p->family == AF_INET) || zrouter.v6_rr_semantics)) ||
+	     ((p->family == AF_INET) || kernel_nexthops_supported() ||
+	      zrouter.v6_rr_semantics)) ||
 	    force_rr)
 		req->n.nlmsg_flags |= NLM_F_REPLACE;
 
@@ -3095,7 +3096,8 @@ netlink_put_route_update_msg(struct nl_batch *bth, struct zebra_dplane_ctx *ctx)
 	} else if (dplane_ctx_get_op(ctx) == DPLANE_OP_ROUTE_INSTALL) {
 		cmd = RTM_NEWROUTE;
 	} else if (dplane_ctx_get_op(ctx) == DPLANE_OP_ROUTE_UPDATE) {
-		if (p->family == AF_INET || zrouter.v6_rr_semantics) {
+		if (p->family == AF_INET || kernel_nexthops_supported() ||
+		    zrouter.v6_rr_semantics) {
 			/* Single 'replace' operation */
 
 			/*

diff --git a/zebra/zebra_vty.c b/zebra/zebra_vty.c
@@ -4028,6 +4028,17 @@ static int config_write_protocol(struct vty *vty)
 	return 1;
 }
 
+static inline bool zebra_vty_v6_rr_semantics_used(void)
+{
+	if (zebra_nhg_kernel_nexthops_enabled())
+		return true;
+
+	if (zrouter.v6_rr_semantics)
+		return true;
+
+	return false;
+}
+
 DEFUN (show_zebra,
        show_zebra_cmd,
        "show zebra",
@@ -4048,7 +4059,8 @@ DEFUN (show_zebra,
 	ttable_add_row(table, "EVPN|%s", is_evpn_enabled() ? "On" : "Off");
 	ttable_add_row(table, "Kernel socket buffer size|%d", rcvbufsize);
 	ttable_add_row(table, "v6 Route Replace Semantics|%s",
-		       zrouter.v6_rr_semantics ? "Replace" : "Delete then Add");
+		       zebra_vty_v6_rr_semantics_used() ? "Replace"
+							: "Delete then Add");
 
 #ifdef GNU_LINUX
 	if (!vrf_is_backend_netns())