0401-580941-iptables_apply_update.patch

From dafbc722de7bf7445a7650e5fe0778ac798dcd18 Mon Sep 17 00:00:00 2001
From: Laurence J. Lane <ljlane@debian.org>
Subject: [PATCH] iptables: update iptables-apply to v1.1
Bug: http://bugs.debian.org/580941

This is GW's update to iptables-apply. It does a code
cleanup and adds two options: one runs a command and
the other writes the sucessful rules file.

I modified the script to use mktemp instead of tempfile. I also
fixed a couple of hyphens in the man page addition.

Signed-off-by: Laurence J. Lane <ljlane@debian.org>
---
 iptables-apply      |  310 ++++++++++++++++++++++++++++++++++++----------------
 iptables-apply.8.in |   48 +++++---
 2 files changed, 247 insertions(+), 111 deletions(-)

--- a/iptables/iptables-apply
+++ b/iptables/iptables-apply
@@ -1,174 +1,294 @@
 #!/bin/bash
-#
 # iptables-apply -- a safer way to update iptables remotely
 #
-# Copyright © Martin F. Krafft <madduck@madduck.net>
+# Usage:
+#   iptables-apply [-hV] [-t timeout] [-w savefile] {[rulesfile]|-c [runcmd]}
+#
+# Versions:
+#   * 1.0 Copyright 2006 Martin F. Krafft <madduck@madduck.net>
+#         Original version
+#   * 1.1 Copyright 2010 GW <gw.2010@tnode.com or http://gw.tnode.com/>
+#         Added parameter -c (run command)
+#         Added parameter -w (save successfully applied rules to file)
+#         Major code cleanup
+#
 # Released under the terms of the Artistic Licence 2.0
 #
 set -eu
 
-PROGNAME="${0##*/}";
-VERSION=1.0
+PROGNAME="${0##*/}"
+VERSION=1.1
+
+
+### Default settings
+
+DEF_TIMEOUT=10
+
+MODE=0  # apply rulesfile mode
+# MODE=1  # run command mode
+
+case "$PROGNAME" in
+	(*6*)
+		SAVE=ip6tables-save
+		RESTORE=ip6tables-restore
+		DEF_RULESFILE="/etc/network/ip6tables.up.rules"
+		DEF_SAVEFILE="$DEF_RULESFILE"
+		DEF_RUNCMD="/etc/network/ip6tables.up.run"
+		;;
+	(*)
+		SAVE=iptables-save
+		RESTORE=iptables-restore
+		DEF_RULESFILE="/etc/network/iptables.up.rules"
+		DEF_SAVEFILE="$DEF_RULESFILE"
+		DEF_RUNCMD="/etc/network/iptables.up.run"
+		;;
+esac
+
 
-TIMEOUT=10
+### Functions
 
-function blurb()
-{
-	cat <<-_eof
+function blurb() {
+	cat <<-__EOF__
 	$PROGNAME $VERSION -- a safer way to update iptables remotely
-	_eof
+	__EOF__
 }
 
-function copyright()
-{
-	cat <<-_eof
-	$PROGNAME is C Martin F. Krafft <madduck@madduck.net>.
-
-	The program has been published under the terms of the Artistic Licence 2.0
-	_eof
+function copyright() {
+	cat <<-__EOF__
+	$PROGNAME has been published under the terms of the Artistic Licence 2.0.
+
+	Original version - Copyright 2006 Martin F. Krafft <madduck@madduck.net>.
+	Version 1.1 - Copyright 2010 GW <gw.2010@tnode.com or http://gw.tnode.com/>.
+	__EOF__
 }
 
-function about()
-{
+function about() {
 	blurb
 	echo
 	copyright
 }
 
-function usage()
-{
-	cat <<-_eof
-	Usage: $PROGNAME [options] ruleset
-
-	The script will try to apply a new ruleset (as output by iptables-save/read
-	by iptables-restore) to iptables, then prompt the user whether the changes
-	are okay. If the new ruleset cut the existing connection, the user will not
-	be able to answer affirmatively. In this case, the script rolls back to the
-	previous ruleset.
-
-	The following options may be specified, using standard conventions:
-
-	-t | --timeout	Specify the timeout in seconds (default: $TIMEOUT)
-	-V | --version	Display version information
-	-h | --help	Display this help text
-	_eof
+function usage() {
+	blurb
+	echo
+	cat <<-__EOF__
+	Usage:
+	  $PROGNAME [-hV] [-t timeout] [-w savefile] {[rulesfile]|-c [runcmd]}
+
+	The script will try to apply a new rulesfile (as output by iptables-save,
+	read by iptables-restore) or run a command to configure iptables and then
+	prompt the user whether the changes are okay. If the new iptables rules cut
+	the existing connection, the user will not be able to answer affirmatively.
+	In this case, the script rolls back to the previous working iptables rules
+	after the timeout expires.
+
+	Successfully applied rules can also be written to savefile and later used
+	to roll back to this state. This can be used to implement a store last good
+	configuration mechanism when experimenting with an iptables setup script:
+	  $PROGNAME -w $DEF_SAVEFILE -c $DEF_RUNCMD
+
+	When called as ip6tables-apply, the script will use ip6tables-save/-restore
+	and IPv6 default values instead. Default value for rulesfile is
+	'$DEF_RULESFILE'.
+
+	Options:
+
+	-t seconds, --timeout seconds
+	  Specify the timeout in seconds (default: $DEF_TIMEOUT).
+	-w savefile, --write savefile
+	  Specify the savefile where successfully applied rules will be written to
+	  (default if empty string is given: $DEF_SAVEFILE).
+	-c runcmd, --command runcmd
+	  Run command runcmd to configure iptables instead of applying a rulesfile
+	  (default: $DEF_RUNCMD).
+	-h, --help
+	  Display this help text.
+	-V, --version
+	  Display version information.
+
+	__EOF__
+}
+
+function checkcommands() {
+	for cmd in "${COMMANDS[@]}"; do
+		if ! command -v "$cmd" >/dev/null; then
+			echo "Error: needed command not found: $cmd" >&2
+			exit 127
+		fi
+	done
+}
+
+function revertrules() {
+	echo -n "Reverting to old iptables rules... "
+	"$RESTORE" <"$TMPFILE"
+	echo "done."
 }
 
-SHORTOPTS="t:Vh";
-LONGOPTS="timeout:,version,help";
+
+### Parsing and checking parameters
+
+TIMEOUT="$DEF_TIMEOUT"
+SAVEFILE=""
+
+SHORTOPTS="t:w:chV";
+LONGOPTS="timeout:,write:,command,help,version";
 
 OPTS=$(getopt -s bash -o "$SHORTOPTS" -l "$LONGOPTS" -n "$PROGNAME" -- "$@") || exit $?
 for opt in $OPTS; do
 	case "$opt" in
-		(-*) unset OPT_STATE;;
+		(-*)
+			unset OPT_STATE
+			;;
 		(*)
 			case "${OPT_STATE:-}" in
-				(SET_TIMEOUT)
-					eval TIMEOUT=$opt
-					case "$TIMEOUT" in
-						([0-9]*) :;;
-						(*)
-							echo "E: non-numeric timeout value." >&2
-							exit 1
-							;;
-					esac
+				(SET_TIMEOUT) eval TIMEOUT=$opt;;
+				(SET_SAVEFILE)
+					eval SAVEFILE=$opt
+					[ -z "$SAVEFILE" ] && SAVEFILE="$DEF_SAVEFILE"
 					;;
 			esac
 			;;
 	esac
 
 	case "$opt" in
+		(-t|--timeout) OPT_STATE="SET_TIMEOUT";;
+		(-w|--write) OPT_STATE="SET_SAVEFILE";;
+		(-c|--command) MODE=1;;
 		(-h|--help) usage >&2; exit 0;;
 		(-V|--version) about >&2; exit 0;;
-		(-t|--timeout) OPT_STATE=SET_TIMEOUT;;
 		(--) break;;
 	esac
 	shift
 done
 
-case "$PROGNAME" in
-	(*6*)
-		SAVE=ip6tables-save
-		RESTORE=ip6tables-restore
-		DEFAULT_FILE=/etc/network/ip6tables
-		;;
-	(*)
-		SAVE=iptables-save
-		RESTORE=iptables-restore
-		DEFAULT_FILE=/etc/network/iptables
-		;;
-esac
-
-FILE="${1:-$DEFAULT_FILE}";
-
-if [[ -z "$FILE" ]]; then
-	echo "E: missing file argument." >&2
+# Validate parameters
+if [ "$TIMEOUT" -ge 0 ] 2>/dev/null; then
+	TIMEOUT=$(($TIMEOUT))
+else
+	echo "Error: timeout must be a positive number" >&2
 	exit 1
 fi
 
-if [[ ! -r "$FILE" ]]; then
-	echo "E: cannot read $FILE" >&2
-	exit 2
+if [ -n "$SAVEFILE" -a -e "$SAVEFILE" -a ! -w "$SAVEFILE" ]; then
+	echo "Error: savefile not writable: $SAVEFILE" >&2
+	exit 8
 fi
 
-COMMANDS=(tempfile "$SAVE" "$RESTORE")
+case "$MODE" in
+	(1)
+		# Treat parameter as runcmd (run command mode)
+		RUNCMD="${1:-$DEF_RUNCMD}"
+		if [ ! -x "$RUNCMD" ]; then
+			echo "Error: runcmd not executable: $RUNCMD" >&2
+			exit 6
+		fi
 
-for cmd in "${COMMANDS[@]}"; do
-	if ! command -v $cmd >/dev/null; then
-		echo "E: command not found: $cmd" >&2
-		exit 127
-	fi
-done
+		# Needed commands
+		COMMANDS=(mktemp "$SAVE" "$RESTORE" "$RUNCMD")
+		checkcommands
+		;;
+	(*)
+		# Treat parameter as rulesfile (apply rulesfile mode)
+		RULESFILE="${1:-$DEF_RULESFILE}";
+		if [ ! -r "$RULESFILE" ]; then
+			echo "Error: rulesfile not readable: $RULESFILE" >&2
+			exit 2
+		fi
 
-umask 0700
+		# Needed commands
+		COMMANDS=(mktemp "$SAVE" "$RESTORE")
+		checkcommands
+		;;
+esac
 
-TMPFILE=$(tempfile -p iptap)
+
+### Begin work
+
+# Store old iptables rules to temporary file
+TMPFILE=`mktemp /tmp/$PROGNAME-XXXXXXXX`
 trap "rm -f $TMPFILE" EXIT HUP INT QUIT ILL TRAP ABRT BUS \
 		      FPE USR1 SEGV USR2 PIPE ALRM TERM
 
 if ! "$SAVE" >"$TMPFILE"; then
+	# An error occured
 	if ! grep -q ipt /proc/modules 2>/dev/null; then
-		echo "E: iptables support lacking from the kernel." >&2
+		echo "Error: iptables support lacking from the kernel" >&2
 		exit 3
 	else
-		echo "E: unknown error saving current iptables ruleset." >&2
+		echo "Error: unknown error saving old iptables rules: $TMPFILE" >&2
 		exit 4
 	fi
 fi
 
+# Legacy to stop the fail2ban daemon if present
 [ -x /etc/init.d/fail2ban ] && /etc/init.d/fail2ban stop
 
-echo -n "Applying new ruleset... "
-if ! "$RESTORE" <"$FILE"; then
-	echo "failed."
-	echo "E: unknown error applying new iptables ruleset." >&2
-	exit 5
-else
-	echo "done."
-fi
+# Configure iptables
+case "$MODE" in
+	(1)
+		# Run command in background and kill it if it times out
+		echo -n "Running command '$RUNCMD'... "
+		"$RUNCMD" &
+		CMD_PID=$!
+		( sleep "$TIMEOUT"; kill "$CMD_PID" 2>/dev/null; exit 0 ) &
+		CMDTIMEOUT_PID=$!
+		if ! wait "$CMD_PID"; then
+			echo "failed."
+			echo "Error: unknown error running command: $RUNCMD" >&2
+			revertrules
+			exit 7
+		else
+			echo "done."
+		fi
+		;;
+	(*)
+		# Apply iptables rulesfile
+		echo -n "Applying new iptables rules from '$RULESFILE'... "
+		if ! "$RESTORE" <"$RULESFILE"; then
+			echo "failed."
+			echo "Error: unknown error applying new iptables rules: $RULESFILE" >&2
+			revertrules
+			exit 5
+		else
+			echo "done."
+		fi
+		;;
+esac
 
+# Prompt user for confirmation
 echo -n "Can you establish NEW connections to the machine? (y/N) "
 
-read -n1 -t "${TIMEOUT:-15}" ret 2>&1 || :
+read -n1 -t "$TIMEOUT" ret 2>&1 || :
 case "${ret:-}" in
 	(y*|Y*)
+		# Success
 		echo
+
+		if [ ! -z "$SAVEFILE" ]; then
+			# Write successfully applied rules to the savefile
+			echo "Writing successfully applied rules to '$SAVEFILE'..."
+			if ! "$SAVE" >"$SAVEFILE"; then
+				echo "Error: unknown error writing successfully applied rules: $SAVEFILE" >&2
+				exit 9
+			fi
+		fi
+
 		echo "... then my job is done. See you next time."
 		;;
 	(*)
-		if [[ -z "${ret:-}" ]]; then
-			echo "apparently not..."
+		# Failed
+		echo
+		if [ -z "${ret:-}" ]; then
+			echo "Timeout! Something happened (or did not). Better play it safe..."
 		else
-			echo
+			echo "No affirmative response! Better play it safe..."
 		fi
-		echo "Timeout. Something happened (or did not). Better play it safe..."
-		echo -n "Reverting to old ruleset... "
-		"$RESTORE" <"$TMPFILE";
-		echo "done."
+		revertrules
 		exit 255
 		;;
 esac
 
+# Legacy to start the fail2ban daemon again
 [ -x /etc/init.d/fail2ban ] && /etc/init.d/fail2ban start
 
 exit 0
--- a/iptables/iptables-apply.8.in
+++ b/iptables/iptables-apply.8.in
@@ -1,6 +1,6 @@
 .\"     Title: iptables-apply
-.\"    Author: Martin F. Krafft
-.\"      Date: Jun 04, 2006
+.\"    Author: Martin F. Krafft, GW
+.\"      Date: May 10, 2010
 .\"
 .TH IPTABLES\-APPLY 8 "" "@PACKAGE_STRING@" "@PACKAGE_STRING@"
 .\" disable hyphenation
@@ -8,23 +8,37 @@
 .SH NAME
 iptables-apply \- a safer way to update iptables remotely
 .SH SYNOPSIS
-\fBiptables\-apply\fP [\-\fBhV\fP] [\fB-t\fP \fItimeout\fP] \fIruleset\-file\fP
+\fBiptables\-apply\fP [\-\fBhV\fP] [\fB-t\fP \fItimeout\fP] [\fB-w\fP \fIsavefile\fP] {[\fIrulesfile]|-c [runcmd]}\fP
 .SH "DESCRIPTION"
 .PP
-iptables\-apply will try to apply a new ruleset (as output by
-iptables\-save/read by iptables\-restore) to iptables, then prompt the
-user whether the changes are okay. If the new ruleset cut the existing
-connection, the user will not be able to answer affirmatively. In this
-case, the script rolls back to the previous ruleset after the timeout
-expired. The timeout can be set with \fB\-t\fP.
-.PP
-When called as \fBip6tables\-apply\fP, the script will use
-ip6tables\-save/\-restore instead.
+iptables\-apply will try to apply a new rulesfile (as output by
+iptables-save, read by iptables-restore) or run a command to configure
+iptables and then prompt the user whether the changes are okay. If the
+new iptables rules cut the existing connection, the user will not be
+able to answer affirmatively. In this case, the script rolls back to
+the previous working iptables rules after the timeout expires.
+.PP
+Successfully applied rules can also be written to savefile and later used
+to roll back to this state. This can be used to implement a store last good
+configuration mechanism when experimenting with an iptables setup script:
+iptables-apply \-w /etc/network/iptables.up.rules \-c /etc/network/iptables.up.run
+.PP
+When called as ip6tables\-apply, the script will use
+ip6tables\-save/\-restore and IPv6 default values instead. Default
+value for rulesfile is '/etc/network/iptables.up.rules'.
 .SH OPTIONS
 .TP
 \fB\-t\fP \fIseconds\fR, \fB\-\-timeout\fP \fIseconds\fR
-Sets the timeout after which the script will roll back to the previous
-ruleset.
+Sets the timeout in seconds after which the script will roll back
+to the previous ruleset (default: 10).
+.TP
+\fB\-w\fP \fIsavefile\fR, \fB\-\-write\fP \fIsavefile\fR
+Specify the savefile where successfully applied rules will be written to
+(default if empty string is given: /etc/network/iptables.up.rules).
+.TP
+\fB\-c\fP \fIruncmd\fR, \fB\-\-command\fP \fIruncmd\fR
+Run command runcmd to configure iptables instead of applying a rulesfile
+(default: /etc/network/iptables.up.run).
 .TP
 \fB\-h\fP, \fB\-\-help\fP
 Display usage information.
@@ -36,9 +50,11 @@
 \fBiptables-restore\fP(8), \fBiptables-save\fP(8), \fBiptables\fR(8).
 .SH LEGALESE
 .PP
-iptables\-apply is copyright by Martin F. Krafft.
+Original iptables-apply - Copyright 2006 Martin F. Krafft <madduck@madduck.net>.
+Version 1.1 - Copyright 2010 GW <gw.2010@tnode.com or http://gw.tnode.com/>.
 .PP
-This manual page was written by Martin F. Krafft <madduck@madduck.net>
+This manual page was written by Martin F. Krafft <madduck@madduck.net> and
+extended by GW <gw.2010@tnode.com or http://gw.tnode.com/>.
 .PP
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the Artistic License 2.0.