common: Add notes about how MAC is generated

BastilleBSD · Jan 24, 2025 · 2c45c51 · 2c45c51
1 parent 10c8296
commit 2c45c51
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/usr/local/share/bastille/common.sh b/usr/local/share/bastille/common.sh
@@ -228,8 +228,9 @@ generate_static_mac() {
     local jail_name="${1}"
     local external_interface="${2}"
     local external_interface_mac="$(ifconfig ${external_interface} | grep ether | awk '{print $2}')"
-    # Use FreeBSD vendor prefix for jail MAC prefix
+    # Use FreeBSD vendor MAC prefix (58:9c:fc) for jail MAC prefix
     local macaddr_prefix="58:9c:fc"
+    # Use hash of interface+jailname for jail MAC suffix
     local macaddr_suffix="$(echo -n "${external_interface_mac}${jail_name}" | sed 's#:##g' | sha256 | cut -b -5 | sed 's/\([0-9a-fA-F][0-9a-fA-F]\)\([0-9a-fA-F][0-9a-fA-F]\)\([0-9a-fA-F]\)/\1:\2:\3/')"
     if [ -z "${macaddr_prefix}" ] || [ -z "${macaddr_suffix}" ]; then
         error_notify "Failed to generate MAC address."
@@ -364,4 +365,4 @@ checkyesno() {
         return 1
         ;;
     esac
-}
+}