Initial Stuff

README.md

@@ -1,2 +1,5 @@
-# darkstorm-server
-Experimenting with a Go server for personal uses
+# Darkstorm Server
+
+Experimenting with a Go server for personal uses. Combines a simple website server with a tcp forwarder.
+
+Configure which ports go to which addresses via /etc/darkstorm-server.conf in the form `port address`.

go.mod

@@ -0,0 +1,3 @@
+module github.com/CalebQ42/darkstorm-server
+
+go 1.17

main.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"log"
+	"time"
+)
+
+var quitChan chan string = make(chan string)
+
+func main() {
+	go tcpLinker()
+	go webserver()
+	for failure := <-quitChan; ; failure = <-quitChan {
+		switch failure {
+		case "tcp conf":
+			continue
+		case "tcp err":
+			go tcpLinkerRestart()
+		case "web arg":
+			continue
+		case "web err":
+			go websiteRestart()
+		}
+	}
+}
+
+func tcpLinkerRestart() {
+	log.Println("TCP linker failed. Restarting in 5 seconds...")
+	time.Sleep(5 * time.Second)
+	log.Println("Restarting tcp linker")
+	tcpLinker()
+}
+
+func websiteRestart() {
+	log.Println("Website failed. Restarting in 5 seconds...")
+	time.Sleep(5 * time.Second)
+	log.Println("Restarting website")
+	webserver()
+}

tcp.go

@@ -0,0 +1,136 @@
+package main
+
+import (
+	"bufio"
+	"errors"
+	"io"
+	"log"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+func tcpLinker() {
+	links, err := parseConf()
+	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
+	} else if err != nil {
+		log.Println("Error while trying to parse config file:", err)
+		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 link(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 link(portFail, links[portFail], failChan)
+	}
+
+}
+
+func link(port int, addr string, failChan chan int) {
+	listen, err := net.Listen("tcp", ":"+strconv.Itoa(port))
+	defer listen.Close()
+	if err != nil {
+		log.Println("Error while trying to listen to port ", port, ":", err)
+		failChan <- port
+		return
+	}
+	for {
+		con, err := listen.Accept()
+		defer con.Close()
+		if err != nil {
+			log.Println("Error while trying to accept connection to port ", port, ":", err)
+			failChan <- port
+			return
+		}
+		ext, err := net.Dial("tcp", addr)
+		defer ext.Close()
+		if err != nil {
+			log.Println("Error while trying to dial", addr, ":", err)
+			failChan <- port
+			return
+		}
+		_, err = io.Copy(ext, con)
+		if err != nil {
+			log.Println("Error while trying to copy data to", addr, ":", err)
+			failChan <- port
+			return
+		}
+		_, err = io.Copy(con, ext)
+		if err != nil {
+			log.Println("Error while trying to copy data to port", port, ":", err)
+			failChan <- port
+			return
+		}
+	}
+}
+
+func parseConf() (links map[int]string, err error) {
+	conf, err := os.Open("/etc/darkstorm-server.conf")
+	if os.IsNotExist(err) {
+		return nil, nil
+	}
+	lineNum := 0
+	links = make(map[int]string)
+	rdr := bufio.NewReader(conf)
+	for {
+		lineNum++
+		var origLine string
+		origLine, err = rdr.ReadString('\n')
+		if err != nil {
+			break
+		}
+		line := strings.ReplaceAll(origLine, "\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 {
+			return nil, errors.New("invalid line #" + strconv.Itoa(lineNum))
+		}
+		var i int
+		i, err = strconv.Atoi(split[0])
+		if err != nil {
+			return nil, errors.New("invalid line #" + strconv.Itoa(lineNum))
+		}
+		links[i] = split[1]
+	}
+	err = nil
+	if len(links) > 0 {
+		return nil, nil
+	}
+	return
+}

web.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"flag"
+	"log"
+	"net/http"
+)
+
+func webserver() {
+	flag.Parse()
+	path := flag.Arg(0)
+	keyPath := flag.Arg(0)
+	if path == "" {
+		log.Println("No argument given for website file path. website signing off...")
+		quitChan <- "web arg"
+		return
+	} else if keyPath == "" {
+		log.Println("No argument given for key files. website signing off...")
+		quitChan <- "web arg"
+		return
+	}
+	http.Handle("/", http.FileServer(http.Dir(path)))
+	err := http.ListenAndServeTLS(":443", keyPath+"/cert.pem", keyPath+"/key.pem", nil)
+	log.Println("Error while serving website:", err)
+	quitChan <- "web err"
+}