[LTP] [RFC PATCH v7 02/11] network/stress: Add library test_net_stress.sh

[Petr Vorel]

> On 07/25/2017 05:52 PM, Petr Vorel wrote:
> >> On 07/25/2017 12:57 PM, Petr Vorel wrote:
> >>> Hi Alexey,
> >>>>> +export OCTET_3_IPV4_UNUSED=${OCTET_3_IPV4_UNUSED:-23} # x.x.N.x
> >>>>> +export OCTET_4_LHOST_IPV4_HOST_UNUSED=${OCTET_4_LHOST_IPV4_HOST_UNUSED:-2} # x.x.x.N
> >>>>> +export OCTET_4_RHOST_IPV4_HOST_UNUSED=${OCTET_4_RHOST_IPV4_HOST_UNUSED:-1} # x.x.x.N
> >>>>> +export LHOST_IPV4_HOST_UNUSED="${OCTET_3_IPV4_UNUSED}.${OCTET_4_LHOST_IPV4_HOST_UNUSED}"
> >>>>> +export RHOST_IPV4_HOST_UNUSED="${OCTET_3_IPV4_UNUSED}.${OCTET_4_RHOST_IPV4_HOST_UNUSED}"
> >>>>> +export LHOST_IPV4_UNUSED="${IPV4_NET16_UNUSED}.$LHOST_IPV4_HOST_UNUSED"
> >>>>> +export RHOST_IPV4_UNUSED="${IPV4_NET16_UNUSED}.$RHOST_IPV4_HOST_UNUSED"
> >>>>> +
> >>>>> +export OCTET_3_IPV6_UNUSED="${OCTET_3_IPV6_UNUSED:-:0}"
> >>>>> +export OCTET_4_LHOST_IPV6_HOST_UNUSED=${OCTET_4_LHOST_IPV6_HOST_UNUSED:-2}
> >>>>> +export OCTET_4_RHOST_IPV6_HOST_UNUSED=${OCTET_4_RHOST_IPV6_HOST_UNUSED:-1}
> >>>>> +export LHOST_IPV6_HOST_UNUSED="${OCTET_3_IPV6_UNUSED}:${OCTET_4_LHOST_IPV6_HOST_UNUSED}"
> >>>>> +export RHOST_IPV6_HOST_UNUSED="${OCTET_3_IPV6_UNUSED}:${OCTET_4_RHOST_IPV6_HOST_UNUSED}"
> >>>>> +export LHOST_IPV6_UNUSED="${IPV6_NET32_UNUSED}:$LHOST_IPV6_HOST_UNUSED"
> >>>>> +export RHOST_IPV6_UNUSED="${IPV6_NET32_UNUSED}:$RHOST_IPV6_HOST_UNUSED"
> >>>> Hmm, what is the purpose of adding these variables to the library?
> >>>> Why someone would need to redefine any of them?
> >>> I thought someone might appreciate ability to full control of IP
> >>> addresses, but you're right it's probably useless.
> >>> If you don't mind, I'll keep {L,R}HOST_IPV{4,6}_UNUSED variables as they are used in many scripts
> >>> (DRY approach) and delete the rest of variables.

> >> What about adding a new function similar to tst_ipaddr()?
> >> tst_ipaddr_un(), tst_ipaddr_new(), etc.? Probably we would need to add
> >> some optional counter parameter along with lhost/rhost...
> > How about this?

> > tst_ipaddr_un()
> > {
> > 	local type="${1:-lhost}"
> > 	local counter="${2:-1}"
> > 	local host net max_counter max_net max_host tmp

> > 	[ "$TST_IPV6" ] && max_net=65536 || max_net=256
> > 	max_host=$((max_net - 2))
> > 	max_counter=$((max_host * max_net / 2))

> > 	if [ $counter -gt $max_counter ]; then
> > 		tst_resm TCONF "'$counter' higher than max counter limit '$max_counter'"
> > 	fi

> I guess we can safely omit this check.
OK.


> > 	tmp=$((counter * 2))
> > 	[ "$type" = "rhost" ] && tmp=$((tmp - 1))

> > 	host=$((tmp % max_host))
> > 	net=$((tmp / max_host))
> > 	[ $host -eq 0 ] && { host=$max_host; net=$((net - 1)); }

> > 	if [ "$TST_IPV6" ]; then
> > 		echo "${IPV6_NET32_UNUSED}::$(printf %x:%x ${net} ${host})"
> > 	else
> > 		echo "${IPV4_NET16_UNUSED}.${net}.${host}"
> > 	fi
> > }

> Looks good to me.
Thanks. It will be all in v8. I'd like to send it ASAP as I'm on holiday since next week
for two weeks.

> > And if we want to work with more than last octet, we might appreciate to be able to
> > specify (optionally) third octet as well ($net variable).
> > Scripts which could benefit from it are at least:
> > if-{addr,route}-addlarge, route4-change-if.
Do we want to get rid of direct usage of IPV4_NET16_UNUSED and IPV6_NET32_UNUSED (at least
in most of the scripts) and use tst_ipaddr_un()? I'm not sure if this is useful, but, as I
wrote before, tests in if-{addr,route}-addlarge, route4-change-if require change in third
octet.

So how about this (I also added security check, even it's close to impossible that will be
needed):

# Get IP address of unused network
# tst_ipaddr_un [TYPE] [COUNTER] [OCTET_3]
# TYPE: { lhost | rhost }; Default value is 'lhost'.
# COUNTER: Integer value; Default is 1.
# OCTET_3: Specify third octet; Default is calculated from counter.
tst_ipaddr_un()
{
	local type="${1:-lhost}"
	local counter="${2:-1}"
	local octet_3="${3:-}"
	local host net max_net max_host tmp

	[ "$TST_IPV6" ] && max_net=65536 || max_net=256
	max_host=$((max_net - 2))

	tmp=$((counter * 2))
	[ "$type" = "rhost" ] && tmp=$((tmp - 1))

	host=$((tmp % max_host))
	net=$((tmp / max_host))
	[ $host -eq 0 ] && { host=$max_host; net=$((net - 1)); }

	[ -n "$octet_3" ] && net=$octet_3

	[ $host -gt $max_host ] && host=$max_host
	[ $net -gt $max_net ] && net=$max_net

	if [ "$TST_IPV6" ]; then
		echo "${IPV6_NET32_UNUSED}::$(printf %x:%x ${net} ${host})"
	else
		echo "${IPV4_NET16_UNUSED}.${net}.${host}"
	fi
}


Kind regards,
Petr