From 7e4b7c797aedd8ca17aa921d235120eff101f787 Mon Sep 17 00:00:00 2001 From: Devin Teske Date: Thu, 11 Feb 2016 21:28:34 +0000 Subject: [PATCH] Centralize MAC derivation formula --- share/examples/jails/jib | 162 +++++++++++++++++++++------------------ share/examples/jails/jng | 157 ++++++++++++++++++++----------------- 2 files changed, 175 insertions(+), 144 deletions(-) diff --git a/share/examples/jails/jib b/share/examples/jails/jib index a93d2f2ed22f..68a95627b71f 100755 --- a/share/examples/jails/jib +++ b/share/examples/jails/jib @@ -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 diff --git a/share/examples/jails/jng b/share/examples/jails/jng index ee850ea5cadc..6c25539bdb58 100755 --- a/share/examples/jails/jng +++ b/share/examples/jails/jng @@ -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