Release v0.1.0

vendor/github.com/lightninglabs/neutrino/banman/codec.go

@@ -0,0 +1,83 @@
+package banman
+
+import (
+	"io"
+	"net"
+)
+
+// ipType represents the different types of IP addresses supported by the
+// BanStore interface.
+type ipType = byte
+
+const (
+	// ipv4 represents an IP address of type IPv4.
+	ipv4 ipType = 0
+
+	// ipv6 represents an IP address of type IPv6.
+	ipv6 ipType = 1
+)
+
+// encodeIPNet serializes the IP network into the given reader.
+func encodeIPNet(w io.Writer, ipNet *net.IPNet) error {
+	// Determine the appropriate IP type for the IP address contained in the
+	// network.
+	var (
+		ip     []byte
+		ipType ipType
+	)
+	switch {
+	case ipNet.IP.To4() != nil:
+		ip = ipNet.IP.To4()
+		ipType = ipv4
+	case ipNet.IP.To16() != nil:
+		ip = ipNet.IP.To16()
+		ipType = ipv6
+	default:
+		return ErrUnsupportedIP
+	}
+
+	// Write the IP type first in order to properly identify it when
+	// deserializing it, followed by the IP itself and its mask.
+	if _, err := w.Write([]byte{ipType}); err != nil {
+		return err
+	}
+	if _, err := w.Write(ip); err != nil {
+		return err
+	}
+	if _, err := w.Write([]byte(ipNet.Mask)); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// decodeIPNet deserialized an IP network from the given reader.
+func decodeIPNet(r io.Reader) (*net.IPNet, error) {
+	// Read the IP address type and determine whether it is supported.
+	var ipType [1]byte
+	if _, err := r.Read(ipType[:]); err != nil {
+		return nil, err
+	}
+
+	var ipLen int
+	switch ipType[0] {
+	case ipv4:
+		ipLen = net.IPv4len
+	case ipv6:
+		ipLen = net.IPv6len
+	default:
+		return nil, ErrUnsupportedIP
+	}
+
+	// Once we have the type and its corresponding length, attempt to read
+	// it and its mask.
+	ip := make([]byte, ipLen)
+	if _, err := r.Read(ip[:]); err != nil {
+		return nil, err
+	}
+	mask := make([]byte, ipLen)
+	if _, err := r.Read(mask[:]); err != nil {
+		return nil, err
+	}
+	return &net.IPNet{IP: ip, Mask: mask}, nil
+}