[#622] pkg/network: Add multiaddress validation

Validation checks:
1. if address can be parsed by network package;
2. if address contains correct amount of protocols;
3. if address's protocols are in correct order.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

pkg/network/validation_test.go

@@ -0,0 +1,64 @@
+package network
+
+import (
+	"testing"
+
+	"github.com/nspcc-dev/neofs-api-go/pkg/netmap"
+	"github.com/stretchr/testify/require"
+)
+
+type testCase struct {
+	input string
+	err   error
+}
+
+func TestVerifyMultiAddress_Order(t *testing.T) {
+	testCases := []testCase{
+		{
+			input: "/ip4/1.2.3.4/tcp/80",
+			err:   nil,
+		},
+		{
+			input: "/ip6/1.2.3.4/tcp/80",
+			err:   nil,
+		},
+		{
+			input: "/dns4/1.2.3.4/tcp/80",
+			err:   nil,
+		},
+		{
+			input: "/dns4/1.2.3.4/tcp/80/tls",
+			err:   nil,
+		},
+		{
+			input: "/tls/dns4/1.2.3.4/tcp/80",
+			err:   errUnsupportedNetworkProtocol,
+		},
+		{
+			input: "/dns4/1.2.3.4/tls/tcp/80",
+			err:   errUnsupportedTransportProtocol,
+		},
+		{
+			input: "/dns4/1.2.3.4/tcp/80/wss",
+			err:   errUnsupportedPresentationProtocol,
+		},
+	}
+
+	for _, test := range testCases {
+		ni := constructNodeInfo(test.input)
+
+		if test.err != nil {
+			require.EqualError(t, test.err, VerifyMultiAddress(ni).Error())
+		} else {
+			require.NoError(t, VerifyMultiAddress(ni))
+		}
+	}
+}
+
+func constructNodeInfo(address string) *netmap.NodeInfo {
+	ni := new(netmap.NodeInfo)
+
+	ni.SetAddress(address)
+
+	return ni
+}