meta-google: gbmc-ncsi-config: Allow BMC address assignment

We need to allow BMC address assignment so that we can deprecate the
impersonation assignment we are currently performing on the BMC.

Change-Id: Ia153d0a5692876ef2c36b71230d597e51904d467
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/meta-google/recipes-google/ncsi/files/gbmc-ncsi-nft.sh.in b/meta-google/recipes-google/ncsi/files/gbmc-ncsi-nft.sh.in
index 074ec57..1f3ba25 100644
--- a/meta-google/recipes-google/ncsi/files/gbmc-ncsi-nft.sh.in
+++ b/meta-google/recipes-google/ncsi/files/gbmc-ncsi-nft.sh.in
@@ -36,6 +36,13 @@
 
   local ip6="$gbmc_ncsi_nft_lastip6"
   if [ -n "$ip6" ]; then
+    # Normalize the provided ipv6 address to the impersonated ipv6 address
+    local ip6_bytes=()
+    ip_to_bytes ip6_bytes "$ip6"
+    for (( i=8; i<16; ++i )); do
+      ip6_bytes[$i]=0
+    done
+    ip6="$(ip_bytes_to_str ip6_bytes)"
     contents+="        ip6 daddr $ip6/128 goto ncsi_legacy_input"$'\n'
   fi