From e5d0158e4d2b555e980b5f15856e792376f40494 Mon Sep 17 00:00:00 2001
From: Daniel Czerwonk <daniel@dan-nrw.de>
Date: Sun, 1 Jul 2018 19:28:08 +0200
Subject: [PATCH] added implementation for IPv6 supernet calculation
---
net/ip_test.go | 12 ++++++++++
net/prefix.go | 33 +++++++++++++++++++++++++-
net/prefix_test.go | 59 ++++++++++++++++++++++++++++++++++++++++++----
3 files changed, 98 insertions(+), 6 deletions(-)
diff --git a/net/ip_test.go b/net/ip_test.go
index 03f78ec9..4720985f 100644
--- a/net/ip_test.go
+++ b/net/ip_test.go
@@ -312,6 +312,12 @@ func TestBitAtPosition(t *testing.T) {
position uint8
expected bool
}{
+ {
+ name: "IPv4: all ones -> 0",
+ input: IPv4FromOctets(255, 255, 255, 255),
+ position: 1,
+ expected: true,
+ },
{
name: "IPv4: Bit 8 from 1.0.0.0 -> 0",
input: IPv4FromOctets(10, 0, 0, 0),
@@ -348,6 +354,12 @@ func TestBitAtPosition(t *testing.T) {
position: 115,
expected: false,
},
+ {
+ name: "IPv6: all ones -> 1",
+ input: IPv6FromBlocks(0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF),
+ position: 1,
+ expected: true,
+ },
}
for _, test := range tests {
diff --git a/net/prefix.go b/net/prefix.go
index c4042024..f75c2004 100644
--- a/net/prefix.go
+++ b/net/prefix.go
@@ -89,7 +89,7 @@ func (pfx Prefix) GetSupernet(x Prefix) Prefix {
return pfx.supernetIPv4(x)
}
- panic("No IPv6 support yet!")
+ return pfx.supernetIPv6(x)
}
func (pfx Prefix) supernetIPv4(x Prefix) Prefix {
@@ -109,6 +109,37 @@ func (pfx Prefix) supernetIPv4(x Prefix) Prefix {
}
}
+func (pfx Prefix) supernetIPv6(x Prefix) Prefix {
+ maxPfxLen := min(pfx.pfxlen, x.pfxlen)
+
+ a := pfx.addr.BitAtPosition(1)
+ b := x.addr.BitAtPosition(1)
+ pfxLen := uint8(0)
+ mask := uint64(0)
+ for a == b && pfxLen < maxPfxLen {
+ a = pfx.addr.BitAtPosition(pfxLen + 2)
+ b = x.addr.BitAtPosition(pfxLen + 2)
+ pfxLen++
+
+ if pfxLen == 64 {
+ mask = 0
+ }
+
+ m := pfxLen % 64
+ mask = mask + uint64(1)<<(64-m)
+ }
+
+ if pfxLen == 0 {
+ return NewPfx(IPv6(0, 0), pfxLen)
+ }
+
+ if pfxLen > 64 {
+ return NewPfx(IPv6(pfx.addr.higher, pfx.addr.lower&mask), pfxLen)
+ }
+
+ return NewPfx(IPv6(pfx.addr.higher&mask, 0), pfxLen)
+}
+
func min(a uint8, b uint8) uint8 {
if a < b {
return a
diff --git a/net/prefix_test.go b/net/prefix_test.go
index d886a49e..4428a4e8 100644
--- a/net/prefix_test.go
+++ b/net/prefix_test.go
@@ -63,7 +63,7 @@ func TestGetSupernet(t *testing.T) {
expected Prefix
}{
{
- name: "Test 1",
+ name: "Supernet of 10.0.0.0 and 11.100.123.0 -> 10.0.0.0/7",
a: Prefix{
addr: IPv4FromOctets(10, 0, 0, 0),
pfxlen: 8,
@@ -78,7 +78,7 @@ func TestGetSupernet(t *testing.T) {
},
},
{
- name: "Test 2",
+ name: "Supernet of 10.0.0.0 and 192.168.0.0 -> 0.0.0.0/0",
a: Prefix{
addr: IPv4FromOctets(10, 0, 0, 0),
pfxlen: 8,
@@ -88,15 +88,64 @@ func TestGetSupernet(t *testing.T) {
pfxlen: 24,
},
expected: Prefix{
- addr: IPv4(0), // 0.0.0.0/0
+ addr: IPv4(0),
+ pfxlen: 0,
+ },
+ },
+ {
+ name: "Supernet of 2001:678:1e0:100:23::/64 and 2001:678:1e0:1ff::/64 -> 2001:678:1e0:100::/56",
+ a: Prefix{
+ addr: IPv6FromBlocks(0x2001, 0x678, 0x1e0, 0x100, 0x23, 0, 0, 0),
+ pfxlen: 64,
+ },
+ b: Prefix{
+ addr: IPv6FromBlocks(0x2001, 0x678, 0x1e0, 0x1ff, 0, 0, 0, 0),
+ pfxlen: 64,
+ },
+ expected: Prefix{
+ addr: IPv6FromBlocks(0x2001, 0x678, 0x1e0, 0x100, 0, 0, 0, 0),
+ pfxlen: 56,
+ },
+ },
+ {
+ name: "Supernet of 2001:678:1e0::/128 and 2001:678:1e0::1/128 -> 2001:678:1e0:100::/127",
+ a: Prefix{
+ addr: IPv6FromBlocks(0x2001, 0x678, 0x1e0, 0, 0, 0, 0, 0),
+ pfxlen: 128,
+ },
+ b: Prefix{
+ addr: IPv6FromBlocks(0x2001, 0x678, 0x1e0, 0, 0, 0, 0, 1),
+ pfxlen: 128,
+ },
+ expected: Prefix{
+ addr: IPv6FromBlocks(0x2001, 0x678, 0x1e0, 0, 0, 0, 0, 0),
+ pfxlen: 127,
+ },
+ },
+ {
+ name: "Supernet of all ones and all zeros -> ::/0",
+ a: Prefix{
+ addr: IPv6FromBlocks(0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF),
+ pfxlen: 128,
+ },
+ b: Prefix{
+ addr: IPv6(0, 0),
+ pfxlen: 128,
+ },
+ expected: Prefix{
+ addr: IPv6FromBlocks(0, 0, 0, 0, 0, 0, 0, 0),
pfxlen: 0,
},
},
}
+ t.Parallel()
+
for _, test := range tests {
- s := test.a.GetSupernet(test.b)
- assert.Equal(t, s, test.expected)
+ t.Run(test.name, func(t *testing.T) {
+ s := test.a.GetSupernet(test.b)
+ assert.Equal(t, test.expected, s)
+ })
}
}
--
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