update_graphs

#!/bin/sh
# Copyright (c) 2022 Ashlen <eurydice@riseup.net>

# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.

# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

# update graphs with rrdtool(1)

err() {
	printf '%s\n' "$*" >&2
	exit 1
}

usage() {
	err "${PROGRAM_NAME} [-s] [type] [period] [rrddir] [savedir]

-s: swap colors for allowed incoming and outgoing traffic (by default,
    incoming traffic is green and outgoing traffic is blue). These defaults
    work for a router, but are inappropriate for a public-facing server that
    sends out data more than it receives it.

[type] can be: pf

[period] can be: day week month
Note that [period] can also take a number of hours as an integer.

[rrddir] is where the rrd files are found.
[savedir] is where the graphs are saved.

${PROGRAM_NAME} is meant to be a frontend for rrdtool(1) for rrd files
maintained by symux(1). ${PROGRAM_NAME} assumes that the rrd files in
rrddir for a particular type are named the same way that the 'datadir'
statement in symux.conf would name them."
}

# Restrict PERIOD length as to avoid too large an integer. 99999 hours is
# roughly 11 years which is more than enough for my use case.
check_period_length() {
	[ ${#PERIOD} -gt 5 ] || err 'PERIOD is restricted to five characters or less.'
}

gen_pf_graphs() {
	GRAPHS='pf-bits
pf-passed-packets
pf-dropped-packets
pf-state-inserts-removals
pf-state-searches'

	[ "${SWAPCOLORS}" = 'yes' ] && INCOLOR="${BLUE}" OUTCOLOR="${GREEN}"

	: "${INCOLOR:=${GREEN}}"
	: "${OUTCOLOR:=${BLUE}}"

	for graphname in ${GRAPHS}; do
		BASE_CMD="rrdtool graph "${SAVEDIR}/${graphname}-${PERIOD}.png" -s -${HOURS}hours"

		case "${graphname}" in
			'pf-bits')
				REST_OF_CMD="-t 'pf bits in/out (IPv4)' \
--vertical-label 'bits/s' \
'DEF:bytes_v4_in=${RRDDIR}/${TYPE}.rrd:bytes_v4_in:MAX' \
'DEF:bytes_v4_out=${RRDDIR}/${TYPE}.rrd:bytes_v4_out:MAX' \
'CDEF:bps_in=bytes_v4_in,8,*' \
'CDEF:bps_out=bytes_v4_out,8,*' \
'AREA:bps_in${INCOLOR}:in' \
'AREA:bps_out${OUTCOLOR}:out'"
				;;

			'pf-passed-packets')
				REST_OF_CMD="-t 'pf passed packets in/out (IPv4)' \
--vertical-label 'packets/s' \
'DEF:packets_v4_in_pass=${RRDDIR}/${TYPE}.rrd:packets_v4_in_pass:MAX' \
'DEF:packets_v4_out_pass=${RRDDIR}/${TYPE}.rrd:packets_v4_out_pass:MAX' \
'AREA:packets_v4_in_pass${INCOLOR}:in' \
'AREA:packets_v4_out_pass${OUTCOLOR}:out'"
				;;

			'pf-dropped-packets')
				REST_OF_CMD="-t 'pf dropped packets in/out (IPv4)' \
--vertical-label 'packets/s' \
'DEF:packets_v4_in_drop=${RRDDIR}/${TYPE}.rrd:packets_v4_in_drop:MAX' \
'DEF:packets_v4_out_drop=${RRDDIR}/${TYPE}.rrd:packets_v4_out_drop:MAX' \
'AREA:packets_v4_in_drop${RED}:in' \
'AREA:packets_v4_out_drop${YELLOW}:out'"
				;;

			'pf-state-inserts-removals')
				REST_OF_CMD="-t 'pf state inserts/removals' \
--vertical-label 'states/s' \
'DEF:states_inserts=${RRDDIR}/${TYPE}.rrd:states_inserts:MAX' \
'DEF:states_removals=${RRDDIR}/${TYPE}.rrd:states_removals:MAX' \
'AREA:states_inserts${GREEN}:inserts' \
'AREA:states_removals${RED}:removals'"
				;;

			'pf-state-searches')
				REST_OF_CMD="-t 'pf state searches' \
--vertical-label 'states/s' \
'DEF:states_searches=${RRDDIR}/${TYPE}.rrd:states_searches:MAX' \
'AREA:states_searches${RED}:searches'"
				;;

			*) err 'This should never happen.' ;;
		esac
		eval "${BASE_CMD} ${REST_OF_CMD}"
	done
}

command -v 'rrdtool' > /dev/null 2>&1 \
	|| err "rrdtool not found in PATH or not executable."

while getopts s opt; do
	case "${opt}" in
		's') SWAPCOLORS='yes' ;;
		*) usage ;;
	esac
done

shift $((OPTIND - 1))

readonly PROGRAM_NAME="${0##*/}"
[ -z "$*" ] && usage

readonly TYPE="$1"
readonly PERIOD="$2"
readonly RRDDIR="$3"
readonly SAVEDIR="$4"

case "${TYPE}" in
	'pf') : ;;
	*) err "\"${TYPE}\" isn't a valid type of statistic to graph." ;;
esac

# shellcheck disable=SC2086
case "${PERIOD}" in
	'day') readonly HOURS=24 ;;
	'week') readonly HOURS=168 ;;
	'month') readonly HOURS=672 ;;
	[0-9]*)
		check_period_length
		readonly HOURS=${PERIOD}
		;;
	*) err "\"${PERIOD}\" isn't a valid time period for graphing." ;;
esac

[ -n "${RRDDIR}" ] || err "${PROGRAM_NAME} needs a directory containing rrd files."
[ -d "${RRDDIR}" ] || err "\"${RRDDIR}\" isn't a directory."
[ -r "${RRDDIR}" ] || err "\"${RRDDIR}\" isn't readable."

[ -n "${SAVEDIR}" ] || err "${PROGRAM_NAME} needs a directory to save graphs in."
[ -d "${SAVEDIR}" ] || err "\"${SAVEDIR}\" isn't a directory."
[ -w "${SAVEDIR}" ] || err "\"${SAVEDIR}\" isn't writable."

[ -f "${RRDDIR}/${TYPE}.rrd" ] || err "\"${RRDDIR}/${TYPE}.rrd\" isn't a file."
[ -r "${RRDDIR}/${TYPE}.rrd" ] || err "\"${RRDDIR}/${TYPE}.rrd\" isn't readable."

readonly RED='#FF0000'
readonly GREEN='#00FF00'
readonly YELLOW='#FFFF00'
readonly BLUE='#0000FF'

case "${TYPE}" in
	'pf') gen_pf_graphs "$1" "$2" "$3" "$4" ;;
esac