#!/bin/bash

# This script aims to make the use of the fiu_run_preload library a little
# easier by providing a more friendly user interface, and abstracting the
# environment variables used to communicate with it.

# default remote control over named pipes prefix
FIFO_PREFIX="${TMPDIR:-/tmp}/fiu-ctrl"

# default library path to look for preloader libraries
PLIBPATH="@@PREFIX@@/lib"

# the enable string to pass to the preload library (via the FIU_ENABLE
# environment variable)
ENABLE=""

# additional preloader libraries to use
PRELOAD_LIBS=""


HELP_MSG="
Usage: fiu-run [options] program [arguments]

The following options are supported:

  -e fpname	Enable the given failure point name.
  -p prob	... with the given probability (defaults to 100%).
  -u failnum	... and this failnum (must be != 0) (defaults to 1).
  -i failinfo	... and this failinfo (defaults to 0).
  -x		Use POSIX libfiu preload library, allows simulate failures in
		the POSIX and C standard library functions.
  -f ctrlpath	Enable remote control over named pipes with the given path as
		base name, the process id will be appended (defaults to
		\"$FIFO_PREFIX\", set to \"\" to disable).
  -l path	Path where to find the libfiu preload libraries, defaults to
		$PLIBPATH (which is usually correct).

The -p, -u and -i options must come after the -e they affect.

For example:

  fiu-run -x -e 'posix/io/*' -p 25 -e libc/mm/malloc -p 5 ls -l

will run \"ls -l\" enabling all failure points that begin with 'posix/io/'
with a 25% of probability to fail, and the failure point libc/mm/malloc with a
5% of probability to fail.
"


#
# Parse the options
#

if [ $# -lt 1 ]; then
	echo "$HELP_MSG"
	exit 1
fi

function opts_reset() {
	# variables to store what we know so far; after a new name is found
	# the old one is added to $ENABLE
	NAME=""
	PROB=-1
	FAILNUM=1
	FAILINFO=0
}

opts_reset;
while getopts "+e:p:u:i:f:l:xh" opt; do
	case $opt in
	e)
		# add the current one, if any
		if [ "$NAME" != "" ]; then
			ENABLE="$ENABLE:$NAME,$PROB,$FAILNUM,$FAILINFO"
			opts_reset;
		fi
		NAME="$OPTARG"
		;;
	p)
		PROB="$OPTARG"
		;;
	u)
		FAILNUM="$OPTARG"
		;;
	i)
		FAILINFO="$OPTARG"
		;;
	f)
		FIFO_PREFIX="$OPTARG"
		;;
	l)
		PLIBPATH="$OPTARG"
		;;
	x)
		PRELOAD_LIBS="$PRELOAD_LIBS $PLIBPATH/fiu_posix_preload.so"
		;;
	h|*)
		echo "$HELP_MSG"
		exit 1
		;;
	esac;
done

# add leftovers
if [ "$NAME" != "" ]; then
	ENABLE="$ENABLE:$NAME,$PROB,$FAILNUM,$FAILINFO"
	opts_reset;
fi

# eat the parameters we already processed
shift $(( $OPTIND - 1 ))


#
# Run the application
#

export FIU_ENABLE="$ENABLE"
export FIU_CTRL_FIFO="$FIFO_PREFIX"
export LD_PRELOAD="$PLIBPATH/fiu_run_preload.so $PRELOAD_LIBS"
exec "$@"