Add a framework for top an tailing config files with DHCP data and a method for cleaning them.

1 files changed, 68 insertions, 1 deletions

diff --git a/dhcpcd-run-hooks.in b/dhcpcd-run-hooks.in
index 94d9dfc4..ecd9aa98 100644
--- a/dhcpcd-run-hooks.in
+++ b/dhcpcd-run-hooks.in
@@ -1,7 +1,71 @@
 #!/bin/sh
 # dhcpcd client configuration script 
 
-# Handy functions for our hooks to use
+# Handy variables functions for our hooks to use
+signature_base="# Generated by dhcpcd for interface "
+signature="${signature_base}${interface}"
+signature_base_end="# End of dhcpcd content for interface "
+signature_end="${signature_base_end}${interface}"
+
+# Clean a configuration file of our current signature and stale ones
+clean_conf()
+{
+	local cf=$1 cft="$1.tmp" x= m1= m2=
+
+	if [ -f "${cf}" ]; then
+		# Remove our old entry
+		m1="^${signature}$"
+		m2="^${signature_end}$"
+		rm -f "${cft}" "${cft}.tmp"
+		sed "/${m1}/,/${m2}/d" "${cf}" > "${cft}"
+		# Remove stale entries
+		m1="^${siganture_base} "
+		for x in $(sed -n "s/${m1}//p" "${cft}"); do
+			if [ ! -s /var/run/dhcpcd-${x}.pid ]; then
+				m1="^${signtaure_base}${x}$"
+				m2="^${signature_base_end} ${x}$"
+				sed "/${m1}/,/${m2}/d" "${cft}" >"${cft}".tmp
+				mv -f "${cft}".tmp "${cft}"
+			fi
+		done
+		# If files are identical then don't replace and return 1
+		# to show that no cleaning took place
+		if type cmp >/dev/null 2>&1; then
+			cmp -s "${cf}" "${cft}"
+		elif type diff >/dev/null 2>&1; then
+			diff -q "${cf}" "${cft}" >/dev/null
+		else
+			false
+		fi
+		if [ $? -eq 0 ]; then
+			rm -f "${cft}"
+			return 1
+		fi
+		mv -f "${cft}" "${cf}"
+		return 0
+	fi
+}
+
+# Append our config to the end of a file, surrouned by our signature
+append_conf()
+{
+	echo "${signature}" >> "$1"
+	echo "$2" >> "$1"
+	echo "${signature_end}" >> "$1"
+}
+
+# Prepend our config to the start of a file, surrouned by our signature
+prepend_conf()
+{
+	rm -f "$1.${interface}"
+	echo "${signature}" > "$1.${interface}"
+	echo "$2" >> "$1.${interface}"
+	echo "${signature_end}" >> "$1.${interface}"
+	cat "$1" >> "$1.${interface}"
+	mv -f "$1.${interface}" "$1"
+}
+
+# Save a config file
 save_conf()
 {
 	if [ -f "$1" ]; then
@@ -9,6 +73,8 @@ save_conf()
 		mv -f "$1" "$1"-pre."${interface}"
 	fi
 }
+
+# Restore a config file
 restore_conf()
 {
 	[ -f "$1"-pre."${interface}" ] || return 1
@@ -16,6 +82,7 @@ restore_conf()
 	mv -f "$1"-pre."${interface}" "$1"
 }
 
+
 # We source each script into this one so that scripts run earlier can
 # remove variables from the environment so later scripts don't see them.
 # Thus, the user can create their dhcpcd.hook script to configure