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 +++++----- libpod/network/subnet_test.go | 62 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+), 7 deletions(-) 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 } diff --git a/libpod/network/subnet_test.go b/libpod/network/subnet_test.go index 917c3be88..55b2443bd 100644 --- a/libpod/network/subnet_test.go +++ b/libpod/network/subnet_test.go @@ -33,3 +33,65 @@ func TestNextSubnet(t *testing.T) { }) } } + +func TestFirstIPInSubnet(t *testing.T) { + tests := []struct { + name string + args *net.IPNet + want net.IP + wantErr bool + }{ + {"class b", parseCIDR("192.168.0.0/16"), net.ParseIP("192.168.0.1"), false}, + {"class c", parseCIDR("192.168.1.0/24"), net.ParseIP("192.168.1.1"), false}, + {"cidr /23", parseCIDR("192.168.0.0/23"), net.ParseIP("192.168.0.1"), false}, + {"cidr /25", parseCIDR("192.168.1.0/25"), net.ParseIP("192.168.1.1"), false}, + {"cidr /26", parseCIDR("172.16.1.128/26"), net.ParseIP("172.16.1.129"), false}, + {"class a", parseCIDR("10.0.0.0/8"), net.ParseIP("10.0.0.1"), false}, + {"cidr /32", parseCIDR("192.168.255.4/32"), net.ParseIP("192.168.255.4"), false}, + {"cidr /31", parseCIDR("192.168.255.4/31"), net.ParseIP("192.168.255.5"), false}, + } + for _, tt := range tests { + test := tt + t.Run(test.name, func(t *testing.T) { + got, err := FirstIPInSubnet(test.args) + if (err != nil) != test.wantErr { + t.Errorf("FirstIPInSubnet() error = %v, wantErr %v", err, test.wantErr) + return + } + if !got.Equal(test.want) { + t.Errorf("FirstIPInSubnet() got = %v, want %v", got, test.want) + } + }) + } +} + +func TestLastIPInSubnet(t *testing.T) { + tests := []struct { + name string + args *net.IPNet + want net.IP + wantErr bool + }{ + {"class b", parseCIDR("192.168.0.0/16"), net.ParseIP("192.168.255.255"), false}, + {"class c", parseCIDR("192.168.1.0/24"), net.ParseIP("192.168.1.255"), false}, + {"cidr /23", parseCIDR("192.168.0.0/23"), net.ParseIP("192.168.1.255"), false}, + {"cidr /25", parseCIDR("192.168.1.0/25"), net.ParseIP("192.168.1.127"), false}, + {"cidr /26", parseCIDR("172.16.1.128/26"), net.ParseIP("172.16.1.191"), false}, + {"class a", parseCIDR("10.0.0.0/8"), net.ParseIP("10.255.255.255"), false}, + {"cidr /32", parseCIDR("192.168.255.4/32"), net.ParseIP("192.168.255.4"), false}, + {"cidr /31", parseCIDR("192.168.255.4/31"), net.ParseIP("192.168.255.5"), false}, + } + for _, tt := range tests { + test := tt + t.Run(test.name, func(t *testing.T) { + got, err := LastIPInSubnet(test.args) + if (err != nil) != test.wantErr { + t.Errorf("LastIPInSubnet() error = %v, wantErr %v", err, test.wantErr) + return + } + if !got.Equal(test.want) { + t.Errorf("LastIPInSubnet() got = %v, want %v", got, test.want) + } + }) + } +} -- cgit v1.2.3-54-g00ecf