/etc/network/if-pre-up.d/uml-utilities is in uml-utilities 20070815.1-2build1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | #!/bin/sh
test -x /usr/bin/tunctl || exit 0
test -n "${IF_TUNCTL_USER}" || exit 0
/usr/bin/tunctl -u "${IF_TUNCTL_USER}" -t "${IFACE}"
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