p2p/netutil: new package for network utilities

The new package contains three things for now:

- IP network list parsing and matching
- The WSAEMSGSIZE workaround, which is duplicated in p2p/discover and
  p2p/discv5.

1 files changed, 173 insertions, 0 deletions

diff --git a/p2p/netutil/net_test.go b/p2p/netutil/net_test.go
new file mode 100644
index 000000000..1ee1fcb4d
--- /dev/null
+++ b/p2p/netutil/net_test.go
@@ -0,0 +1,173 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package netutil
+
+import (
+	"net"
+	"reflect"
+	"testing"
+
+	"github.com/davecgh/go-spew/spew"
+)
+
+func TestParseNetlist(t *testing.T) {
+	var tests = []struct {
+		input    string
+		wantErr  error
+		wantList *Netlist
+	}{
+		{
+			input:    "",
+			wantList: &Netlist{},
+		},
+		{
+			input:    "127.0.0.0/8",
+			wantErr:  nil,
+			wantList: &Netlist{{IP: net.IP{127, 0, 0, 0}, Mask: net.CIDRMask(8, 32)}},
+		},
+		{
+			input:   "127.0.0.0/44",
+			wantErr: &net.ParseError{Type: "CIDR address", Text: "127.0.0.0/44"},
+		},
+		{
+			input: "127.0.0.0/16, 23.23.23.23/24,",
+			wantList: &Netlist{
+				{IP: net.IP{127, 0, 0, 0}, Mask: net.CIDRMask(16, 32)},
+				{IP: net.IP{23, 23, 23, 0}, Mask: net.CIDRMask(24, 32)},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		l, err := ParseNetlist(test.input)
+		if !reflect.DeepEqual(err, test.wantErr) {
+			t.Errorf("%q: got error %q, want %q", test.input, err, test.wantErr)
+			continue
+		}
+		if !reflect.DeepEqual(l, test.wantList) {
+			spew.Dump(l)
+			spew.Dump(test.wantList)
+			t.Errorf("%q: got %v, want %v", test.input, l, test.wantList)
+		}
+	}
+}
+
+func TestNilNetListContains(t *testing.T) {
+	var list *Netlist
+	checkContains(t, list.Contains, nil, []string{"1.2.3.4"})
+}
+
+func TestIsLAN(t *testing.T) {
+	checkContains(t, IsLAN,
+		[]string{ // included
+			"0.0.0.0",
+			"0.2.0.8",
+			"127.0.0.1",
+			"10.0.1.1",
+			"10.22.0.3",
+			"172.31.252.251",
+			"192.168.1.4",
+			"fe80::f4a1:8eff:fec5:9d9d",
+			"febf::ab32:2233",
+			"fc00::4",
+		},
+		[]string{ // excluded
+			"192.0.2.1",
+			"1.0.0.0",
+			"172.32.0.1",
+			"fec0::2233",
+		},
+	)
+}
+
+func TestIsSpecialNetwork(t *testing.T) {
+	checkContains(t, IsSpecialNetwork,
+		[]string{ // included
+			"192.0.2.1",
+			"192.0.2.44",
+			"2001:db8:85a3:8d3:1319:8a2e:370:7348",
+			"255.255.255.255",
+			"224.0.0.22", // IPv4 multicast
+			"ff05::1:3",  // IPv6 multicast
+		},
+		[]string{ // excluded
+			"192.0.3.1",
+			"1.0.0.0",
+			"172.32.0.1",
+			"fec0::2233",
+		},
+	)
+}
+
+func checkContains(t *testing.T, fn func(net.IP) bool, inc, exc []string) {
+	for _, s := range inc {
+		if !fn(parseIP(s)) {
+			t.Error("returned false for included address", s)
+		}
+	}
+	for _, s := range exc {
+		if fn(parseIP(s)) {
+			t.Error("returned true for excluded address", s)
+		}
+	}
+}
+
+func parseIP(s string) net.IP {
+	ip := net.ParseIP(s)
+	if ip == nil {
+		panic("invalid " + s)
+	}
+	return ip
+}
+
+func TestCheckRelayIP(t *testing.T) {
+	tests := []struct {
+		sender, addr string
+		want         error
+	}{
+		{"127.0.0.1", "0.0.0.0", errUnspecified},
+		{"192.168.0.1", "0.0.0.0", errUnspecified},
+		{"23.55.1.242", "0.0.0.0", errUnspecified},
+		{"127.0.0.1", "255.255.255.255", errSpecial},
+		{"192.168.0.1", "255.255.255.255", errSpecial},
+		{"23.55.1.242", "255.255.255.255", errSpecial},
+		{"192.168.0.1", "127.0.2.19", errLoopback},
+		{"23.55.1.242", "192.168.0.1", errLAN},
+
+		{"127.0.0.1", "127.0.2.19", nil},
+		{"127.0.0.1", "192.168.0.1", nil},
+		{"127.0.0.1", "23.55.1.242", nil},
+		{"192.168.0.1", "192.168.0.1", nil},
+		{"192.168.0.1", "23.55.1.242", nil},
+		{"23.55.1.242", "23.55.1.242", nil},
+	}
+
+	for _, test := range tests {
+		err := CheckRelayIP(parseIP(test.sender), parseIP(test.addr))
+		if err != test.want {
+			t.Errorf("%s from %s: got %q, want %q", test.addr, test.sender, err, test.want)
+		}
+	}
+}
+
+func BenchmarkCheckRelayIP(b *testing.B) {
+	sender := parseIP("23.55.1.242")
+	addr := parseIP("23.55.1.2")
+	for i := 0; i < b.N; i++ {
+		CheckRelayIP(sender, addr)
+	}
+}