svn commit: r295546 - head/share/examples/jails
Devin Teske
dteske at FreeBSD.org
Thu Feb 11 21:28:36 UTC 2016
Author: dteske
Date: Thu Feb 11 21:28:34 2016
New Revision: 295546
URL: https://svnweb.freebsd.org/changeset/base/295546
Log:
Centralize MAC derivation formula
Modified:
head/share/examples/jails/jib
head/share/examples/jails/jng
Modified: head/share/examples/jails/jib
==============================================================================
--- head/share/examples/jails/jib Thu Feb 11 20:16:11 2016 (r295545)
+++ head/share/examples/jails/jib Thu Feb 11 21:28:34 2016 (r295546)
@@ -170,6 +170,91 @@ action_usage()
exit $FAILURE
}
+derive_mac()
+{
+ local OPTIND=1 OPTARG __flag
+ local __mac_num= __make_pair=
+ while getopts 2n: __flag; do
+ case "$__flag" in
+ 2) __make_pair=1 ;;
+ n) __mac_num=${OPTARG%%[^0-9]*} ;;
+ esac
+ done
+ shift $(( $OPTIND - 1 ))
+
+ if [ ! "$__mac_num" ]; then
+ eval __mac_num=\${_${iface}_num:--1}
+ __mac_num=$(( $__mac_num + 1 ))
+ eval _${iface}_num=\$__mac_num
+ fi
+
+ local __iface="$1" __name="$2" __var_to_set="$3" __var_to_set_b="$4"
+ local __iface_devid __new_devid __num __new_devid_b
+ #
+ # Calculate MAC address derived from given iface.
+ #
+ # The formula I'm using is ``NP:SS:SS:II:II:II'' where:
+ # + N denotes 4 bits used as a counter to support branching
+ # each parent interface up to 15 times under the same jail
+ # name (see S below).
+ # + P denotes the special nibble whose value, if one of
+ # 2, 6, A, or E (but usually 2) denotes a privately
+ # administered MAC address (while remaining routable).
+ # + S denotes 16 bits, the sum(1) value of the jail name.
+ # + I denotes bits that are inherited from parent interface.
+ #
+ # The S bits are a CRC-16 checksum of NAME, allowing the jail
+ # to change link numbers in ng_bridge(4) without affecting the
+ # MAC address. Meanwhile, if...
+ # + the jail NAME changes (e.g., it was duplicated and given
+ # a new name with no other changes)
+ # + the underlying network interface changes
+ # + the jail is moved to another host
+ # the MAC address will be recalculated to a new, similarly
+ # unique value preventing conflict.
+ #
+ __iface_devid=$( ifconfig $__iface ether | awk '/ether/,$0=$2' )
+ __new_devid=${__iface_devid#??:??:??}
+ # :II:II:II => S:II:II:II
+ __num=$( set -- `echo -n "$__name" | sum` && echo $1 )
+ __new_devid=$( printf %x $(( $__num & 15 )) )$__new_devid
+ # S:II:II:II => :SS:II:II:II
+ __num=$(( $__num >> 4 ))
+ __new_devid=:$( printf %x $(( $__num & 15 )) )$__new_devid
+ # :SS:II:II:II => S:SS:II:II:II
+ __num=$(( $__num >> 4 ))
+ __new_devid=$( printf %x $(( $__num & 15 )) )$__new_devid
+ # S:SS:II:II:II => :SS:SS:II:II:II
+ __new_devid=:$( printf %x $(( $__num & 15 )) )$__new_devid
+ # :SS:SS:II:II:II => P:SS:SS:II:II:II
+ case "$__iface_devid" in
+ ?2:*) __new_devid=a$__new_devid __new_devid_b=e$__new_devid ;;
+ ?[Ee]:*) __new_devid=2$__new_devid __new_devid_b=6$__new_devid ;;
+ *) __new_devid=2$__new_devid __new_devid_b=e$__new_devid
+ esac
+ # P:SS:SS:II:II:II => NP:SS:SS:II:II:II
+ __new_devid=$( printf %x $(( $__mac_num & 15 )) )$__new_devid
+ __new_devid_b=$( printf %x $(( $__mac_num & 15 )) )$__new_devid_b
+
+ #
+ # Return derivative MAC address(es)
+ #
+ if [ "$__make_pair" ]; then
+ if [ "$__var_to_set" -a "$__var_to_set_b" ]; then
+ eval $__var_to_set=\$__new_devid
+ eval $__var_to_set_b=\$__new_devid_b
+ else
+ echo $__new_devid $__new_devid_b
+ fi
+ else
+ if [ "$__var_to_set" ]; then
+ eval $__var_to_set=\$__new_devid
+ else
+ echo $__new_devid
+ fi
+ fi
+}
+
mustberoot_to_continue()
{
if [ "$( id -u )" -ne 0 ]; then
@@ -198,8 +283,7 @@ jib_addm()
mustberoot_to_continue
- local iface iface_devid eiface_devid
- local eiface_devid_a eiface_devid_b
+ local iface eiface_devid_a eiface_devid_b
local new num quad i=0
for iface in $*; do
@@ -231,79 +315,7 @@ jib_addm()
# 6. Set the MAC address of the new interface using a sensible
# algorithm to prevent conflicts on the network.
#
- # The formula I'm using is ``NP:SS:SS:II:II:II'' where:
- # + N denotes 4 bits used as a counter to support branching
- # each parent interface up to 15 times under the same jail
- # name (see S below).
- # + P denotes the special nibble whose value, if one of
- # 2, 6, A, or E (but usually 2) denotes a privately
- # administered MAC address (while remaining routable).
- # + S denotes 16 bits, the sum(1) value of the jail name.
- # + I denotes bits that are inherited from parent interface.
- #
- # The S bits are a CRC-16 checksum of NAME, allowing the jail
- # to change the epair(4) generation order without affecting the
- # MAC address. Meanwhile, if...
- # + the jail NAME changes (e.g., it was duplicated and given
- # a new name with no other changes)
- # + the underlying network interface changes
- # + the jail is moved to another host
- # the MAC address will be recalculated to a new, similarly
- # unique value preventing conflict.
- #
- iface_devid=$( ifconfig $iface ether | awk '/ether/,$0=$2' )
- eiface_devid=${iface_devid#??:??:??}
- num=$( set -- `echo -n $name | sum` && echo $1 )
- quad=$(( $num & 15 ))
- case "$quad" in
- 10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
- 13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
- esac
- eiface_devid=$quad$eiface_devid
- num=$(( $num >> 4 ))
- quad=$(( $num & 15 ))
- case "$quad" in
- 10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
- 13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
- esac
- eiface_devid=$quad$eiface_devid
- num=$(( $num >> 4 ))
- quad=$(( $num & 15 ))
- case "$quad" in
- 10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
- 13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
- esac
- eiface_devid=$quad:$eiface_devid
- num=$(( $num >> 4 ))
- quad=$(( $num & 15 ))
- case "$quad" in
- 10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
- 13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
- esac
- case "$iface_devid" in
- ?[Ee]:*)
- eiface_devid_a=2:$quad$eiface_devid
- eiface_devid_b=6:$quad$eiface_devid
- ;;
- *)
- eiface_devid_a=2:$quad$eiface_devid
- eiface_devid_b=e:$quad$eiface_devid
- esac
- eval num=\$_${iface}_num
- if [ "$num" ]; then
- num=$(( $num + 1 ))
- eval _${iface}_num=$num
- else
- num=0
- local _${iface}_num=$num
- fi
- quad=$(( $num & 15 ))
- case "$quad" in
- 10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
- 13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
- esac
- eiface_devid_a=$quad$eiface_devid_a
- eiface_devid_b=$quad$eiface_devid_b
+ derive_mac -2 $iface "$name" eiface_devid_a eiface_devid_b
ifconfig "e${i}a_$name" ether $eiface_devid_a > /dev/null 2>&1
ifconfig "e${i}b_$name" ether $eiface_devid_b > /dev/null 2>&1
Modified: head/share/examples/jails/jng
==============================================================================
--- head/share/examples/jails/jng Thu Feb 11 20:16:11 2016 (r295545)
+++ head/share/examples/jails/jng Thu Feb 11 21:28:34 2016 (r295546)
@@ -172,6 +172,91 @@ action_usage()
exit $FAILURE
}
+derive_mac()
+{
+ local OPTIND=1 OPTARG __flag
+ local __mac_num= __make_pair=
+ while getopts 2n: __flag; do
+ case "$__flag" in
+ 2) __make_pair=1 ;;
+ n) __mac_num=${OPTARG%%[^0-9]*} ;;
+ esac
+ done
+ shift $(( $OPTIND - 1 ))
+
+ if [ ! "$__mac_num" ]; then
+ eval __mac_num=\${_${iface}_num:--1}
+ __mac_num=$(( $__mac_num + 1 ))
+ eval _${iface}_num=\$__mac_num
+ fi
+
+ local __iface="$1" __name="$2" __var_to_set="$3" __var_to_set_b="$4"
+ local __iface_devid __new_devid __num __new_devid_b
+ #
+ # Calculate MAC address derived from given iface.
+ #
+ # The formula I'm using is ``NP:SS:SS:II:II:II'' where:
+ # + N denotes 4 bits used as a counter to support branching
+ # each parent interface up to 15 times under the same jail
+ # name (see S below).
+ # + P denotes the special nibble whose value, if one of
+ # 2, 6, A, or E (but usually 2) denotes a privately
+ # administered MAC address (while remaining routable).
+ # + S denotes 16 bits, the sum(1) value of the jail name.
+ # + I denotes bits that are inherited from parent interface.
+ #
+ # The S bits are a CRC-16 checksum of NAME, allowing the jail
+ # to change link numbers in ng_bridge(4) without affecting the
+ # MAC address. Meanwhile, if...
+ # + the jail NAME changes (e.g., it was duplicated and given
+ # a new name with no other changes)
+ # + the underlying network interface changes
+ # + the jail is moved to another host
+ # the MAC address will be recalculated to a new, similarly
+ # unique value preventing conflict.
+ #
+ __iface_devid=$( ifconfig $__iface ether | awk '/ether/,$0=$2' )
+ __new_devid=${__iface_devid#??:??:??}
+ # :II:II:II => S:II:II:II
+ __num=$( set -- `echo -n "$__name" | sum` && echo $1 )
+ __new_devid=$( printf %x $(( $__num & 15 )) )$__new_devid
+ # S:II:II:II => :SS:II:II:II
+ __num=$(( $__num >> 4 ))
+ __new_devid=:$( printf %x $(( $__num & 15 )) )$__new_devid
+ # :SS:II:II:II => S:SS:II:II:II
+ __num=$(( $__num >> 4 ))
+ __new_devid=$( printf %x $(( $__num & 15 )) )$__new_devid
+ # S:SS:II:II:II => :SS:SS:II:II:II
+ __new_devid=:$( printf %x $(( $__num & 15 )) )$__new_devid
+ # :SS:SS:II:II:II => P:SS:SS:II:II:II
+ case "$__iface_devid" in
+ ?2:*) __new_devid=a$__new_devid __new_devid_b=e$__new_devid ;;
+ ?[Ee]:*) __new_devid=2$__new_devid __new_devid_b=6$__new_devid ;;
+ *) __new_devid=2$__new_devid __new_devid_b=e$__new_devid
+ esac
+ # P:SS:SS:II:II:II => NP:SS:SS:II:II:II
+ __new_devid=$( printf %x $(( $__mac_num & 15 )) )$__new_devid
+ __new_devid_b=$( printf %x $(( $__mac_num & 15 )) )$__new_devid_b
+
+ #
+ # Return derivative MAC address(es)
+ #
+ if [ "$__make_pair" ]; then
+ if [ "$__var_to_set" -a "$__var_to_set_b" ]; then
+ eval $__var_to_set=\$__new_devid
+ eval $__var_to_set_b=\$__new_devid_b
+ else
+ echo $__new_devid $__new_devid_b
+ fi
+ else
+ if [ "$__var_to_set" ]; then
+ eval $__var_to_set=\$__new_devid
+ else
+ echo $__new_devid
+ fi
+ fi
+}
+
mustberoot_to_continue()
{
if [ "$( id -u )" -ne 0 ]; then
@@ -201,7 +286,7 @@ jng_bridge()
mustberoot_to_continue
- local iface iface_devid eiface eiface_devid
+ local iface eiface eiface_devid
local new num quad i=0
for iface in $*; do
@@ -262,74 +347,8 @@ jng_bridge()
# 6. Set the MAC address of the new interface using a sensible
# algorithm to prevent conflicts on the network.
#
- # The formula I'm using is ``NP:SS:SS:II:II:II'' where:
- # + N denotes 4 bits used as a counter to support branching
- # each parent interface up to 15 times under the same jail
- # name (see S below).
- # + P denotes the special nibble whose value, if one of
- # 2, 6, A, or E (but usually 2) denotes a privately
- # administered MAC address (while remaining routable).
- # + S denotes 16 bits, the sum(1) value of the jail name.
- # + I denotes bits that are inherited from parent interface.
- #
- # The S bits are a CRC-16 checksum of NAME, allowing the jail
- # to change link numbers in ng_bridge(4) without affecting the
- # MAC address. Meanwhile, if...
- # + the jail NAME changes (e.g., it was duplicated and given
- # a new name with no other changes)
- # + the underlying network interface changes
- # + the jail is moved to another host
- # the MAC address will be recalculated to a new, similarly
- # unique value preventing conflict.
- #
- iface_devid=$( ifconfig $iface ether | awk '/ether/,$0=$2' )
- eiface_devid=${iface_devid#??:??:??}
- num=$( set -- `echo -n $name | sum` && echo $1 )
- quad=$(( $num & 15 ))
- case "$quad" in
- 10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
- 13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
- esac
- eiface_devid=$quad$eiface_devid
- num=$(( $num >> 4 ))
- quad=$(( $num & 15 ))
- case "$quad" in
- 10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
- 13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
- esac
- eiface_devid=$quad$eiface_devid
- num=$(( $num >> 4 ))
- quad=$(( $num & 15 ))
- case "$quad" in
- 10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
- 13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
- esac
- eiface_devid=$quad:$eiface_devid
- num=$(( $num >> 4 ))
- quad=$(( $num & 15 ))
- case "$quad" in
- 10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
- 13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
- esac
- case "$iface_devid" in
- ?2:*) eiface_devid=a:$quad$eiface_devid ;;
- *) eiface_devid=2:$quad$eiface_devid
- esac
- eval num=\$_${iface}_num
- if [ "$num" ]; then
- num=$(( $num + 1 ))
- eval _${iface}_num=$num
- else
- num=0
- local _${iface}_num=$num
- fi
- quad=$(( $num & 15 ))
- case "$quad" in
- 10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
- 13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
- esac
- eiface_devid=$quad$eiface_devid
- ifconfig $eiface ether $eiface_devid > /dev/null 2>&1
+ derive_mac $iface "$name" eiface_devid
+ ifconfig $eiface ether $eiface_devid
i=$(( $i + 1 )) # on to next ng{i}_name
done # for iface
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