create Client in main package

client.go

@@ -0,0 +1,102 @@
+package quic
+
+import (
+	"bytes"
+	"math/rand"
+	"net"
+	"time"
+
+	"github.com/lucas-clemente/quic-go/protocol"
+	"github.com/lucas-clemente/quic-go/qerr"
+	"github.com/lucas-clemente/quic-go/utils"
+)
+
+// A Client of QUIC
+type Client struct {
+	addr *net.UDPAddr
+	conn *net.UDPConn
+
+	connectionID protocol.ConnectionID
+	version      protocol.VersionNumber
+
+	session *Session
+}
+
+// NewClient makes a new client
+func NewClient(addr *net.UDPAddr) (*Client, error) {
+	conn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: generate cryptographically secure random ConnectionID
+	rand.Seed(time.Now().UTC().UnixNano())
+	connectionID := protocol.ConnectionID(rand.Int63())
+
+	client := &Client{
+		addr:         addr,
+		conn:         conn,
+		version:      protocol.Version36,
+		connectionID: connectionID,
+	}
+
+	streamCallback := func(session *Session, stream utils.Stream) {}
+
+	client.session, err = newClientSession(conn, addr, client.version, client.connectionID, streamCallback, client.closeCallback)
+	if err != nil {
+		return nil, err
+	}
+
+	return client, nil
+}
+
+// Listen listens
+func (c *Client) Listen() {
+	go c.session.run()
+
+	for {
+		data := getPacketBuffer()
+		data = data[:protocol.MaxPacketSize]
+
+		n, _, err := c.conn.ReadFromUDP(data)
+		utils.Debugf("%d", n)
+		if err != nil {
+			panic(err)
+		}
+		data = data[:n]
+
+		err = c.handlePacket(data)
+		if err != nil {
+			utils.Errorf("error handling packet: %s", err.Error())
+		}
+	}
+}
+
+func (c *Client) handlePacket(packet []byte) error {
+	if protocol.ByteCount(len(packet)) > protocol.MaxPacketSize {
+		return qerr.PacketTooLarge
+	}
+
+	rcvTime := time.Now()
+
+	r := bytes.NewReader(packet)
+
+	hdr, err := ParsePublicHeader(r)
+	if err != nil {
+		return qerr.Error(qerr.InvalidPacketHeader, err.Error())
+	}
+	hdr.Raw = packet[:len(packet)-r.Len()]
+
+	c.session.handlePacket(&receivedPacket{
+		remoteAddr:   c.addr,
+		publicHeader: hdr,
+		data:         packet[len(packet)-r.Len():],
+		rcvTime:      rcvTime,
+	})
+	return nil
+}
+
+func (c *Client) closeCallback(id protocol.ConnectionID) {
+	utils.Infof("Connection %x closed.", id)
+	c.conn.Close()
+}