1. docker
  2. Commit 90a6e310fe4c70b99f9fa5c8d8615e2382edba0b
Browse code

Add an helper function to check if two network overlaps. Also add unit tests for this function

Guillaume J. Charmes authored on 2013/04/04 06:53:54
Showing 2 changed files
network.go
History View file @ 90a6e31
... ... 
@@ -29,6 +29,19 @@ func networkRange(network *net.IPNet) (net.IP, net.IP) {
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 	return firstIP, lastIP
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 }
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+// Detects overlap between one IPNet and another
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+func networkOverlaps(netX *net.IPNet, netY *net.IPNet) bool {
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+	firstIP, _ := networkRange(netX)
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+	if netY.Contains(firstIP) {
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+		return true
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+	}
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+	firstIP, _ = networkRange(netY)
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+	if netX.Contains(firstIP) {
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+		return true
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+	}
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+	return false
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+}
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+
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 // Converts a 4 bytes IP into a 32 bit integer
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 func ipToInt(ip net.IP) int32 {
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 	return int32(binary.BigEndian.Uint32(ip.To4()))
network_test.go
History View file @ 90a6e31
... ... 
@@ -217,3 +217,38 @@ func assertIPEquals(t *testing.T, ip1, ip2 net.IP) {
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 		t.Fatalf("Expected IP %s, got %s", ip1, ip2)
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 	}
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 }
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+
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+func AssertOverlap(CIDRx string, CIDRy string, t *testing.T) {
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+	_, netX, _ := net.ParseCIDR(CIDRx)
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+	_, netY, _ := net.ParseCIDR(CIDRy)
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+	if !networkOverlaps(netX, netY) {
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+		t.Errorf("%v and %v should overlap", netX, netY)
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+	}
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+}
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+
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+func AssertNoOverlap(CIDRx string, CIDRy string, t *testing.T) {
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+	_, netX, _ := net.ParseCIDR(CIDRx)
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+	_, netY, _ := net.ParseCIDR(CIDRy)
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+	if networkOverlaps(netX, netY) {
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+		t.Errorf("%v and %v should not overlap", netX, netY)
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+	}
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+}
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+
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+func TestNetworkOverlaps(t *testing.T) {
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+	//netY starts at same IP and ends within netX
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+	AssertOverlap("172.16.0.1/24", "172.16.0.1/25", t)
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+	//netY starts within netX and ends at same IP
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+	AssertOverlap("172.16.0.1/24", "172.16.0.128/25", t)
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+	//netY starts and ends within netX
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+	AssertOverlap("172.16.0.1/24", "172.16.0.64/25", t)
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+	//netY starts at same IP and ends outside of netX
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+	AssertOverlap("172.16.0.1/24", "172.16.0.1/23", t)
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+	//netY starts before and ends at same IP of netX
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+	AssertOverlap("172.16.1.1/24", "172.16.0.1/23", t)
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+	//netY starts before and ends outside of netX
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+	AssertOverlap("172.16.1.1/24", "172.16.0.1/23", t)
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+	//netY starts and ends before netX
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+	AssertNoOverlap("172.16.1.1/25", "172.16.0.1/24", t)
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+	//netX starts and ends before netY
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+	AssertNoOverlap("172.16.1.1/25", "172.16.2.1/24", t)
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+}