[LTP] [RFC PATCH v8 01/11] lib/test_net.sh: Add unused IP address helper functions

[Alexey Kodanev]

Hi Petr,
On 22.08.2017 20:18, Petr Vorel wrote:
> Hi Alexey,
>
> again, thank you for your review!
>
>>> +# Get IP address of unused network, specified by 3rd and 4th octet.
>>> +# This is useful when 3rd and/or 4th octet are needed to be defined.
>>> +# tst_ipaddr_un_ip [OCTET_3] [OCTET_4]
>> 3rd and 4th octet are only meaningful for IPv4, what about 'net_id' and
>> 'host_id' instead?
> OK, no problem.
>
>>> +# OCTET_3: Integer or hex value of 3rd octet; Default value is 0.
>>> +# OCTET_4: Integer or hex value of 4th octet; Default value is 0.
>>> +tst_ipaddr_un_ip()
>>> +{
>>> +	local octet_3="${1:-0}"
>>> +	local octet_4="${2:-0}"
>>> +	local max
>>> +
>>> +	[ "$TST_IPV6" ] && max=65535 || max=255
>>> +
>>> +	if [ "$TST_IPV6" ]; then
>>> +		octet_3=$(printf %d $octet_3)
>>> +		octet_4=$(printf %d $octet_4)
>>> +	fi
>>> +
>>> +	[ $octet_3 -lt 0 ] && octet_3=0
>>> +	[ $octet_4 -lt 0 ] && octet_4=1
>>> +	[ $octet_3 -gt $max ] && octet_3=$max
>>> +	[ $octet_4 -gt $max ] && octet_4=$max
>>> +
>>> +	if [ "$TST_IPV6" ]; then
>>> +		[ $octet_3 -gt 0 ] && octet_3="$(printf %x $octet_3)" || octet_3=
>>> +		[ $octet_4 -gt 0 -o "$octet_3" ] && octet_4="$(printf %x $octet_4)" || octet_4=
>>> +		[ "$octet_3" -a "$octet_4" ] && octet_4=":$octet_4"
>>> +		echo "${IPV6_NET32_UNUSED}::${octet_3}${octet_4}"
>> '${octet_3}${octet_4}' - if max is 65K, it's 4 bytes, ':' missed?
> Not sure if I get what you mean, I don't see missing ':'

Sorry,  now I see that you added it here:

[ "$octet_3" -a "$octet_4" ] && octet_4=":$octet_4"

>
> $ TST_IPV6=6 tst_ipaddr_un_ip 65535
> fd00:23::ffff:0
>
> $ TST_IPV6=6 tst_ipaddr_un_ip 65535 65535
> fd00:23::ffff:ffff
>
> $ TST_IPV6=6 tst_ipaddr_un_ip 0 65535
> fd00:23::ffff
>
> But I'll use new version based on move one parameter before '::', as you suggested (see
> bellow).
>
>
>> I assume this is needed for getting subnets/routes, in most cases we would
>> have 64-bit netmask that's why I would move one parameter before '::'
>> echo "${IPV6_NET32_UNUSED}:${octet_3}::${octet_4}"
> Right, changed:
> if [ "$TST_IPV6" ]; then
> 	[ $host_id -gt 0 ] && host_id="$(printf %x $host_id)" || host_id=
> 	[ $net_id -gt 0 ] && net_id="$(printf %x $net_id)" || net_id=
> 	[ "$net_id" ] && net_id=":$net_id"
> 	echo "${IPV6_NET32_UNUSED}${net_id}::${host_id}"
> else
> 	echo "${IPV4_NET16_UNUSED}.${net_id}.${host_id}"
> fi
> i.e. don't print ':0', when host_id == 0 and don't print '0' at the end when host_id == 0.
> I give up optimizations when IPV6_NET32_UNUSED contain ':' at the end (it shouldn't contain
> it anyway).
>
>
>> Can we have getopts in a single function to prevent code duplication?
> OK, rewritten into single function:
> # Get IP address of unused network, specified by either by type and
> # counter or by net and host.
> # tst_ipaddr_un -cCOUNTER [TYPE]
> # tst_ipaddr_un [NET_ID] [HOST_ID]
> # TYPE: { lhost | rhost }; Default value is 'lhost'.
> # COUNTER: Integer value for counting HOST_ID and NET_ID. Default is 1.
> # NET_ID: Integer or hex value of net. For IPv4 is 3rd octet, for IPv6 is 3rd
> # hextet. Default value is 0.
> # HOST_ID: Integer or hex value of host. For IPv4 is 4th octet, for IPv6 is the
> # last hextet. Default value is 0.
> tst_ipaddr_un()
> {
> 	local counter host_id net_id max_host_id max_net_id tmp type
> 	local OPTIND
>
> 	while getopts "c:" opt; do
> 		case $opt in
> 			c) counter="$OPTARG";;
> 		esac
> 	done
> 	shift $(($OPTIND - 1))
>
> 	[ "$TST_IPV6" ] && max_net_id=65535 || max_net_id=255
>
> 	if [ "$counter" ]; then

What about handling the case here when no parameter specified or only
the type?

-    if [ "$counter" ]; then
+    if [ $# -eq 0 -o "$1" = "rhost" ]; then


Thanks,
Alexey