From dc61e3b7ffdc2e3873af238a9100d44ee685578c Mon Sep 17 00:00:00 2001 From: Sungbo Eo Date: Sat, 25 Jan 2020 23:06:07 +0900 Subject: base-files: add functions to set or clear bit in MAC address Some devices (e.g. Arduino Yun) need bitwise operations during MAC address setup. This commit adds generalized versions of macaddr_setbit_la(), which are helpful when manipulating a single bit in a MAC address. Signed-off-by: Sungbo Eo --- package/base-files/files/lib/functions/system.sh | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) (limited to 'package/base-files/files/lib/functions') diff --git a/package/base-files/files/lib/functions/system.sh b/package/base-files/files/lib/functions/system.sh index c7aa7bf75c..f3c901ff79 100644 --- a/package/base-files/files/lib/functions/system.sh +++ b/package/base-files/files/lib/functions/system.sh @@ -152,10 +152,26 @@ macaddr_geteui() { echo ${mac:9:2}$sep${mac:12:2}$sep${mac:15:2} } -macaddr_setbit_la() { +macaddr_setbit() { + local mac=$1 + local bit=${2:-0} + + [ $bit -gt 0 -a $bit -le 48 ] || return + + printf "%012x" $(( 0x${mac//:/} | 2**(48-bit) )) | sed -e 's/\(.\{2\}\)/\1:/g' -e 's/:$//' +} + +macaddr_unsetbit() { local mac=$1 + local bit=${2:-0} + + [ $bit -gt 0 -a $bit -le 48 ] || return - printf "%02x:%s" $((0x${mac%%:*} | 0x02)) ${mac#*:} + printf "%012x" $(( 0x${mac//:/} & ~(2**(48-bit)) )) | sed -e 's/\(.\{2\}\)/\1:/g' -e 's/:$//' +} + +macaddr_setbit_la() { + macaddr_setbit $1 7 } macaddr_2bin() { -- cgit v1.2.3