1 files changed, 82 insertions, 0 deletions
diff --git a/ifupdown/if-pre-up b/ifupdown/if-pre-up
new file mode 100755
index 0000000..97d091f
--- /dev/null
+++ b/ifupdown/if-pre-up
@@ -0,0 +1,82 @@
+#!/bin/sh
+
+set -eu
+
+get_iface_opts()
+{
+	local opts_start_cb="${1}"
+	local opt_cb="${2}"
+	local opts_end_cb="${3}"
+	local script=
+	local opts=
+	local opt=
+
+	script="$(printf '
+		/^iface[ \t][ \t]*%s/,/^[^ \t]/{
+			/^$/q;
+			s/^[ \t][ \t]*%s-//p;
+		}
+		' "${IFACE}" "${0##*/}")"
+
+	opts="$(sed -n "${script}" /var/run/net-ifaces)"
+	if [ "x${opts}" = 'x' ]; then
+		return 0
+	fi
+
+	${opts_start_cb}
+	while read -r opt; do
+		${opt_cb} ${opt}
+	done <<-EOF
+		${opts}
+		EOF
+	${opts_end_cb}
+
+	return 0
+}
+
+wpa_opts_start_cb()
+{
+	exec 3>"/var/run/wpa_supplicant.${IFACE}.conf"
+	printf 'ctrl_interface=DIR=/var/run/wpa_supplicant\ncountry=US\n\n' >&3
+	printf 'network={\n' >&3
+}
+
+wpa_opt_cb()
+{
+	local field="${1}"
+	shift 1
+	local value="${*}"
+
+	field="$(printf '%s\n' "${field}" | tr '-' '_')"
+	case "${field}" in
+		ssid)
+			if printf '%s\n' "${value}" | grep -q '[^0-9A-Fa-f:]'
+			then
+				if [ "x${value#\"}" = "x${value}" ]; then
+					value="\"${value}\""
+				fi
+			fi
+			;;
+		psk)
+			if printf '%s\n' "${value}" | grep -q '[^0-9A-Fa-f]'
+			then
+				if [ "x${value#\"}" = "x${value}" ]; then
+					value="\"${value}\""
+				fi
+			fi
+			;;
+	esac
+	printf '\t%s=%s\n' "${field}" "${value}" >&3
+}
+
+wpa_opts_end_cb()
+{
+	printf '}\n' >&3
+	exec &3>-
+	wpa_supplicant -B -s -Dnl80211 -i"${IFACE}" \
+		-c"/var/run/wpa_supplicant.${IFACE}.conf"
+}
+
+if [ "x${IFACE#wlan}" != "x${IFACE}" ]; then
+	get_iface_opts wpa_opts_start_cb wpa_opt_cb wpa_opts_end
+fi