From 70e7acdb23715298624d123f7cc7c9dbcdf0465c Mon Sep 17 00:00:00 2001 From: Paul Holzinger Date: Mon, 23 Nov 2020 11:41:40 +0100 Subject: Fix ip-range for classless subnet masks The `LastIPInSubnet` function worked only for classful subnet masks (e.g. /8, /16, /24). For non standard subnet masks this returned the wrong ip address. This works now for all subnet mask. A unit test is added to ensure this. Signed-off-by: Paul Holzinger --- libpod/network/subnet.go | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'libpod/network/subnet.go') diff --git a/libpod/network/subnet.go b/libpod/network/subnet.go index 90f0cdfce..120038e57 100644 --- a/libpod/network/subnet.go +++ b/libpod/network/subnet.go @@ -54,14 +54,10 @@ func LastIPInSubnet(addr *net.IPNet) (net.IP, error) { //nolint:interfacer ones, bits := cidr.Mask.Size() if ones == bits { - return FirstIPInSubnet(cidr) + return cidr.IP, nil } - hostStart := ones / 8 - // Handle the first host byte - cidr.IP[hostStart] |= 0xff & cidr.Mask[hostStart] - // Fill the rest with ones - for i := hostStart; i < len(cidr.IP); i++ { - cidr.IP[i] = 0xff + for i := range cidr.IP { + cidr.IP[i] = cidr.IP[i] | ^cidr.Mask[i] } return cidr.IP, nil } @@ -73,6 +69,10 @@ func FirstIPInSubnet(addr *net.IPNet) (net.IP, error) { //nolint:interfacer if err != nil { return nil, err } + ones, bits := cidr.Mask.Size() + if ones == bits { + return cidr.IP, nil + } cidr.IP[len(cidr.IP)-1]++ return cidr.IP, nil } -- cgit v1.2.3-54-g00ecf