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basic.go
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basic.go
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package ultraviolet
import (
"errors"
"log"
"net"
"os"
"strings"
"time"
"github.com/realDragonium/Ultraviolet/core"
"github.com/realDragonium/Ultraviolet/mc"
)
var (
ConnTimeoutDuration = 5 * time.Second
)
type API interface {
Run(addr string)
Close()
}
func ProcessRequest(reqData core.RequestData, servers core.ServerCatalog) (action core.ServerAction, pk mc.Packet, err error) {
server, err := LookupServer(reqData, servers)
if err != nil {
if errors.Is(err, core.ErrNoServerFound) && reqData.Type == mc.Status {
pk = servers.DefaultStatus()
}
return
}
action = server.ConnAction(reqData)
switch action {
case core.VERIFY_CONN:
pk = servers.VerifyConn()
case core.STATUS:
pk = server.Status()
}
return
}
func ReadStuff(conn net.Conn) (reqData core.RequestData, err error) {
conn.SetDeadline(time.Now().Add(ConnTimeoutDuration))
mcConn := mc.NewMcConn(conn)
handshakePacket, err := mcConn.ReadPacket()
if errors.Is(err, os.ErrDeadlineExceeded) {
err = core.ErrClientToSlow
return
} else if err != nil {
return
}
handshake, err := mc.UnmarshalServerBoundHandshake(handshakePacket)
if err != nil {
log.Printf("error while parsing handshake: %v", err)
}
reqType := mc.RequestState(handshake.NextState)
if reqType == mc.UnknownState {
err = core.ErrNotValidHandshake
return
}
packet, err := mcConn.ReadPacket()
if errors.Is(err, os.ErrDeadlineExceeded) {
err = core.ErrClientToSlow
return
} else if err != nil {
return
}
conn.SetDeadline(time.Time{})
serverAddr := strings.ToLower(handshake.ParseServerAddress())
reqData = core.RequestData{
Type: reqType,
ServerAddr: serverAddr,
Addr: conn.RemoteAddr(),
Handshake: handshake,
}
if reqType == mc.Login {
loginStart, err := mc.UnmarshalServerBoundLoginStart(packet)
if err != nil {
log.Printf("error while parsing login packet: %v", err)
return reqData, err
}
reqData.Username = string(loginStart.Name)
}
return reqData, nil
}
func LookupServer(req core.RequestData, servers core.ServerCatalog) (core.Server, error) {
return servers.Find(req.ServerAddr)
}
func SendResponse(conn net.Conn, pk mc.Packet, withPing bool) error {
conn.SetDeadline(time.Now().Add(ConnTimeoutDuration))
mcConn := mc.NewMcConn(conn)
if err := mcConn.WritePacket(pk); err != nil {
return err
}
if withPing {
pingPacket, err := mcConn.ReadPacket()
if err != nil {
return err
}
mcConn.WritePacket(pingPacket)
}
return nil
}
func FullRun(conn net.Conn, servers core.ServerCatalog) error {
reqData, err := ReadStuff(conn)
if err != nil {
return err
}
server, err := LookupServer(reqData, servers)
if errors.Is(err, core.ErrNoServerFound) && reqData.Type == mc.Status {
return SendResponse(conn, servers.DefaultStatus(), true)
} else if err != nil {
log.Printf("got error: %v", err)
return conn.Close()
}
return ProcessServer(conn, server, reqData)
}
func ProcessServer(conn net.Conn, server core.Server, reqData core.RequestData) error {
action := server.ConnAction(reqData)
if action == core.PROXY {
go ProxyConnection(conn, server, reqData)
return nil
}
defer conn.Close()
var responsePk mc.Packet
switch action {
// TOOD: Figure this one out
// case core.VERIFY_CONN:
// responsePk = servers.VerifyConn()
case core.STATUS:
responsePk = server.Status()
case core.CLOSE:
return nil
}
return SendResponse(conn, responsePk, action == core.STATUS)
}
func ProxyConnection(client net.Conn, server core.Server, reqData core.RequestData) (err error) {
serverConn, err := server.CreateConn(reqData)
if err != nil {
return
}
go func() {
pipe(serverConn, client)
client.Close()
}()
go func() {
pipe(client, serverConn)
serverConn.Close()
}()
return
}
func pipe(c1, c2 net.Conn) {
buffer := make([]byte, 0xffff)
for {
n, err := c1.Read(buffer)
if err != nil {
return
}
_, err = c2.Write(buffer[:n])
if err != nil {
return
}
}
}