(possibly) Added UDP linker capabilities

2021-09-21 06:25:37 -05:00
parent 1be4378071
commit b7fd4ec7d8
3 changed files with 28 additions and 17 deletions
@@ -0,0 +1,188 @@
+package main
+
+import (
+	"bufio"
+	"errors"
+	"io"
+	"log"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type link struct {
+	addr     string
+	linkType string
+}
+
+func linker() {
+	links, err := parseConf()
+	if err != nil {
+		log.Println("Error while trying to parse config file:", err, "tcp linker signing off")
+		quitChan <- "tcp conf"
+		return
+	} else if links == nil {
+		log.Println("No values in config file or file not present (/etc/darkstorm-server.conf). tcp linker signing off")
+		quitChan <- "tcp conf"
+		return
+	}
+	fails := make(map[int]int) //logs how many fails per 5 seconds
+	failChan := make(chan int, 20)
+	open := make(map[int]bool)
+	for port, addr := range links {
+		open[port] = true
+		go createLink(port, addr, failChan)
+	}
+failWaiting:
+	for portFail := <-failChan; ; portFail = <-failChan {
+		if fails[portFail] == 0 {
+			go func() {
+				time.Sleep(5 * time.Second)
+				fails[portFail] = 0
+			}()
+		} else if fails[portFail] == 4 {
+			log.Println("Port", portFail, "has failed 5 time is as many seconds. Not restarting port...")
+			open[portFail] = false
+			for _, b := range open {
+				if b {
+					continue failWaiting
+				}
+			}
+			log.Println("All ports dead. Attempting restart...")
+			quitChan <- "tcp err"
+			return
+		}
+		fails[portFail]++
+		log.Println("Restarting linking for port", portFail)
+		go createLink(portFail, links[portFail], failChan)
+	}
+
+}
+
+func createLink(port int, l link, failChan chan int) {
+	log.Println("Linking", port, "to", l.addr, "with type", l.linkType)
+	listen, err := net.Listen(l.linkType, ":"+strconv.Itoa(port))
+	if err != nil {
+		log.Println("Error while trying to listen to port ", port, ":", err)
+		failChan <- port
+		return
+	}
+	defer listen.Close()
+	for {
+		con, err := listen.Accept()
+		if err != nil {
+			log.Println("Error while trying to accept connection to port ", port, ":", err)
+			failChan <- port
+			return
+		}
+		err = copyConn(con, l)
+		if err != nil {
+			log.Println("Error while trying copy data from port", port, "to address", l.addr, ":", err)
+			failChan <- port
+			return
+		}
+	}
+}
+
+func parseConf() (links map[int]link, err error) {
+	conf, err := os.Open("/etc/darkstorm-server.conf")
+	if os.IsNotExist(err) {
+		return nil, nil
+	} else if err != nil {
+		return nil, err
+	}
+	lineNum := 0
+	links = make(map[int]link)
+	rdr := bufio.NewReader(conf)
+	multilineComment := false
+	var line string
+	for {
+		if line == "" {
+			lineNum++
+			line, err = rdr.ReadString('\n')
+			if err != nil && line == "" {
+				break
+			} else if line == "" {
+				continue
+			}
+		}
+		startCom, endCom := strings.Index(line, "/*"), strings.Index(line, "*/")
+		if multilineComment {
+			if endCom != -1 {
+				line = line[endCom:]
+			} else {
+				continue
+			}
+		}
+		if startCom != -1 {
+			if endCom != -1 {
+				line = line[:startCom] + line[endCom:]
+				continue
+			}
+			line = line[:startCom]
+			multilineComment = true
+		}
+		if strings.Contains(line, "//") {
+			line = line[:strings.Index(line, "//")]
+		}
+		line = strings.ReplaceAll(line, "\t", " ")
+		for strings.Contains(line, "  ") {
+			line = strings.Replace(line, "  ", " ", -1)
+		}
+		line = strings.TrimSpace(line)
+		if line == "" {
+			continue
+		}
+		split := strings.Split(line, " ")
+		if len(split) < 2 || len(split) > 3 {
+			return nil, errors.New("invalid line #" + strconv.Itoa(lineNum))
+		}
+		var l link
+		if len(split) == 3 {
+		} else {
+			l.linkType = "tcp"
+		}
+		var i int
+		i, err = strconv.Atoi(split[0])
+		if err != nil {
+			return nil, errors.New("invalid line #" + strconv.Itoa(lineNum))
+		}
+		links[i] = l
+		line = ""
+	}
+	err = nil
+	if len(links) == 0 {
+		return nil, nil
+	}
+	return
+}
+
+func copyConn(src net.Conn, l link) error {
+	dst, err := net.Dial(l.linkType, l.addr)
+	if err != nil {
+		log.Println("Erro while dialing", l.addr)
+		return err
+	}
+
+	done := make(chan struct{})
+
+	go func() {
+		defer src.Close()
+		defer dst.Close()
+		io.Copy(dst, src)
+		done <- struct{}{}
+	}()
+
+	go func() {
+		defer src.Close()
+		defer dst.Close()
+		io.Copy(src, dst)
+		done <- struct{}{}
+	}()
+
+	<-done
+	<-done
+	return nil
+}