From df10e201eb26edcdbfe75d8e1757f29db49126a2 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Wed, 17 Apr 2013 15:36:57 +0000 Subject: [PATCH] mac80211: rework mac address allocation If the first byte is available in the address mask, use only that one - set the local bit and xor it with the id << 2. This ensures that there are no hardware BSSID & BSSID-mask conflicts with devices that have almost the same MAC address with just a small offset. The MAC address conflict has been observed in a deployment with some devices from the same batch when running with multiple interfaces. If only some bits of the last byte are available, xor the id onto the last MAC address byte (relevant mostly for Ralink devices). In other cases (should not happen at this point), use the previous MAC address offset calculation but without the local bit. Signed-off-by: Felix Fietkau SVN-Revision: 36353 --- package/mac80211/files/lib/wifi/mac80211.sh | 34 +++++++++++++++------ 1 file changed, 24 insertions(+), 10 deletions(-) diff --git a/package/mac80211/files/lib/wifi/mac80211.sh b/package/mac80211/files/lib/wifi/mac80211.sh index 4c214e84c5..bb97211428 100644 --- a/package/mac80211/files/lib/wifi/mac80211.sh +++ b/package/mac80211/files/lib/wifi/mac80211.sh @@ -270,19 +270,33 @@ get_freq() { } mac80211_generate_mac() { - local off="$1" - local mac="$2" + local id="$1" + local ref="$2" local mask="$3" - local oIFS="$IFS"; IFS=":"; set -- $mac; IFS="$oIFS" - local b2mask=0x00 - [ $off -gt 0 ] && - [ "$mask" = "00:00:00:00:00:00" -o $(( 0x${mask%%:*} & 0x2 )) -gt 0 ] && b2mask=0x02 + [ "$mask" = "00:00:00:00:00:00" ] && mask="ff:ff:ff:ff:ff:ff"; + local oIFS="$IFS"; IFS=":"; set -- $mask; IFS="$oIFS" - printf "%02x:%s:%s:%s:%02x:%02x" \ - $(( 0x$1 | $b2mask )) $2 $3 $4 \ - $(( (0x$5 + ($off / 0x100)) % 0x100 )) \ - $(( (0x$6 + $off) % 0x100 )) + local mask1=$1 + local mask6=$6 + + local oIFS="$IFS"; IFS=":"; set -- $ref; IFS="$oIFS" + [ "$((0x$mask1))" -gt 0 ] && { + b1=$(((0x$1 | 0x2) ^ ($id << 2))) + printf "%02x:%s:%s:%s:%s:%s" $b1 $2 $3 $4 $5 $6 + return + } + + [ "$((0x$mask6))" -lt 255 ] && { + printf "%s:%s:%s:%s:%s:%02x" $1 $2 $3 $4 $5 $(( 0x$6 ^ $id )) + return + } + + off2=$(( (0x$6 + $id) / 0x100 )) + printf "%s:%s:%s:%s:%02x:%02x" \ + $1 $2 $3 $4 \ + $(( (0x$5 + $off2) % 0x100 )) \ + $(( (0x$6 + $id) % 0x100 )) } enable_mac80211() { -- 2.25.1