1 files changed, 144 insertions, 0 deletions
diff --git a/client/quake/net.go b/client/quake/net.go
new file mode 100644
index 0000000..16c9016
--- /dev/null
+++ b/client/quake/net.go
@@ -0,0 +1,144 @@
+package quake
+
+import (
+	"errors"
+	"net"
+	"syscall"
+	"time"
+
+	"github.com/osm/quake/common/sequencer"
+	"github.com/osm/quake/packet"
+	"github.com/osm/quake/packet/clc"
+	"github.com/osm/quake/packet/command"
+	"github.com/osm/quake/packet/command/connect"
+	"github.com/osm/quake/packet/command/getchallenge"
+	"github.com/osm/quake/packet/command/ip"
+	"github.com/osm/quake/packet/svc"
+)
+
+func (c *Client) Connect(addrPort string) error {
+	addr, err := net.ResolveUDPAddr("udp", addrPort)
+	if err != nil {
+		return err
+	}
+
+	conn, err := net.DialUDP("udp", nil, addr)
+	if err != nil {
+		return err
+	}
+	c.conn = conn
+
+	c.sendChallenge()
+
+	buf := make([]byte, 1024*64)
+	for {
+
+		var isReadTimeout bool
+		var incomingSeq uint32
+		var incomingAck uint32
+		var packet packet.Packet
+		var cmds []command.Command
+
+		if err := c.conn.SetReadDeadline(
+			time.Now().Add(time.Millisecond * c.readDeadline),
+		); err != nil {
+			c.logger.Printf("unable to set read deadline, %v\n", err)
+		}
+
+		n, _, err := c.conn.ReadFromUDP(buf)
+		if err != nil {
+			if errors.Is(err, syscall.ECONNREFUSED) {
+				c.logger.Printf("lost connection - reconnecting in 5 seqonds")
+				time.Sleep(time.Second * 5)
+				c.sendChallenge()
+				continue
+			}
+
+			if err, ok := err.(net.Error); ok && err.Timeout() {
+				isReadTimeout = true
+				goto process
+			}
+
+			c.logger.Printf("unexpected read error, %v", err)
+			continue
+		}
+
+		packet, err = svc.Parse(c.ctx, buf[:n])
+		if err != nil {
+			c.logger.Printf("error when parsing server data, %v", err)
+			continue
+		}
+
+		switch p := packet.(type) {
+		case *svc.Connectionless:
+			cmds = []command.Command{p.Command}
+		case *svc.GameData:
+			cmds = p.Commands
+			incomingSeq = p.Seq
+			incomingAck = p.Ack
+
+		}
+
+		for _, h := range c.handlers {
+			cmds = append(cmds, h(packet)...)
+		}
+	process:
+		c.processCommands(incomingSeq, incomingAck, cmds, isReadTimeout)
+	}
+}
+
+func (c *Client) processCommands(
+	incomingSeq, incomingAck uint32,
+	serverCmds []command.Command,
+	isReadTmeout bool,
+) {
+	var cmds []command.Command
+
+	for _, serverCmd := range serverCmds {
+		for _, cmd := range c.handleServerCommand(serverCmd) {
+			switch cmd := cmd.(type) {
+			case *connect.Command, *ip.Command:
+				if _, err := c.conn.Write(
+					(&clc.Connectionless{Command: cmd}).Bytes(),
+				); err != nil {
+					c.logger.Printf("unable to send connectionless command, %v\n", err)
+				}
+			default:
+				cmds = append(cmds, cmd)
+			}
+		}
+	}
+
+	if c.seq.GetState() <= sequencer.Handshake {
+		return
+	}
+
+	c.cmdsMu.Lock()
+	outSeq, outAck, outCmds, err := c.seq.Process(incomingSeq, incomingAck, append(c.cmds, cmds...))
+	c.cmds = []command.Command{}
+	c.cmdsMu.Unlock()
+
+	if err == sequencer.ErrRateLimit {
+		return
+	}
+
+	if _, err := c.conn.Write((&clc.GameData{
+		Seq:      outSeq,
+		Ack:      outAck,
+		QPort:    c.qPort,
+		Commands: append(outCmds, c.getMove(outSeq)),
+	}).Bytes()); err != nil {
+		c.logger.Printf("unable to send game data, %v\n", err)
+	}
+}
+
+func (c *Client) sendChallenge() {
+	c.seq.Reset()
+	c.seq.SetState(sequencer.Handshake)
+	c.readDeadline = connectReadDeadline
+	if _, err := c.conn.Write(
+		(&clc.Connectionless{Command: &getchallenge.Command{}}).Bytes(),
+	); err != nil {
+		c.logger.Printf("unable to send challenge, %v\n", err)
+	}
+}