Forgotten files.

.golangci.yaml

@@ -0,0 +1,12 @@
+run:
+  deadline: 5m
+linters:
+  enable-all: true
+  disable:
+    # Actually not really needed.
+    - gochecknoglobals
+linters-settings:
+  lll:
+    line-length: 420
+  gocyclo:
+    min-complexity: 40

commands/exported.go

@@ -0,0 +1,17 @@
+package commands
+
+import (
+	// stdlib
+	"log"
+
+	// local
+	"develop.pztrn.name/gonews/gonews/commands/greeting"
+	"develop.pztrn.name/gonews/gonews/commands/quit"
+)
+
+func Initialize() {
+	log.Println("Initializing commands...")
+
+	greeting.Initialize()
+	quit.Initialize()
+}

commands/greeting/exported.go

@@ -0,0 +1,23 @@
+package greeting
+
+import (
+	// stdlib
+	"log"
+
+	// local
+	"develop.pztrn.name/gonews/gonews/eventer"
+	"develop.pztrn.name/gonews/gonews/networker"
+)
+
+func Initialize() {
+	log.Println("Initializing greeting command...")
+
+	eventer.AddEventHandler(&eventer.EventHandler{
+		Command: "internal/greeting",
+		Handler: handler,
+	})
+}
+
+func handler(data interface{}) interface{} {
+	return &networker.Reply{Code: "201", Data: "NNTP server is ready, posting prohibited\r\n"}
+}

commands/quit/exported.go

@@ -0,0 +1,23 @@
+package quit
+
+import (
+	// stdlib
+	"log"
+
+	// local
+	"develop.pztrn.name/gonews/gonews/eventer"
+	"develop.pztrn.name/gonews/gonews/networker"
+)
+
+func Initialize() {
+	log.Println("Initializing quit command...")
+
+	eventer.AddEventHandler(&eventer.EventHandler{
+		Command: "commands/quit",
+		Handler: handler,
+	})
+}
+
+func handler(data interface{}) interface{} {
+	return &networker.Reply{Code: "205", Data: "NNTP Service exits normally\r\n"}
+}

configuration/config.go

@@ -0,0 +1,18 @@
+package configuration
+
+// Represents configuration file structure.
+type config struct {
+	// Network represents network stack configuration.
+	Network []Network `yaml:"network"`
+}
+
+type Network struct {
+	// Address represents address to bing in form of "ip:port".
+	Address string `yaml:"address"`
+	// Limit sets maximum simultaneous connections that can be
+	// processed by worker.
+	Limit int `yaml:"limit"`
+	// Type sets connection type. See networker for available
+	// types.
+	Type string `yaml:"type"`
+}

configuration/exported.go

@@ -0,0 +1,55 @@
+package configuration
+
+import (
+	// stdlib
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+
+	// other
+	"gopkg.in/yaml.v2"
+)
+
+var (
+	Cfg *config
+)
+
+// Initialize initializes package and parses configuration into struct.
+func Initialize() {
+	log.Println("Initializing configuration...")
+
+	pathRaw, found := os.LookupEnv("GONEWS_CONFIG")
+	if !found {
+		log.Fatalln("Failed to read configuration - no GONEWS_CONFIG environment variable defined.")
+	}
+
+	// Normalize path.
+	if strings.HasPrefix(pathRaw, "~") {
+		userHomeDir, err := os.UserHomeDir()
+		if err != nil {
+			log.Fatalln("Failed to obtain user's home directory path: " + err.Error())
+		}
+
+		pathRaw = strings.Replace(pathRaw, "~", userHomeDir, 1)
+	}
+	absPath, err1 := filepath.Abs(pathRaw)
+	if err1 != nil {
+		log.Fatalln("Failed to get absolute path for configuration file: " + err1.Error())
+	}
+
+	// Read and parse configuration file.
+	fileData, err2 := ioutil.ReadFile(absPath)
+	if err2 != nil {
+		log.Fatalln("Failed to read configuration file data: " + err2.Error())
+	}
+
+	Cfg = &config{}
+	err3 := yaml.Unmarshal(fileData, Cfg)
+	if err3 != nil {
+		log.Fatalln("Failed to parse configuration file: " + err3.Error())
+	}
+
+	log.Printf("Configuration file parsed: %+v\n", Cfg)
+}

networker/connection.go

@@ -0,0 +1,94 @@
+package networker
+
+import (
+	// stdlib
+	"bufio"
+	"log"
+	"net"
+	"strings"
+
+	// local
+	"develop.pztrn.name/gonews/gonews/eventer"
+)
+
+// This function is a connection worker.
+func connectionWorker(conn net.Conn) {
+	remoteAddr := conn.RemoteAddr()
+	log.Printf("accepted connection from %v\n", conn.RemoteAddr())
+
+	defer func() {
+		err := conn.Close()
+		if err != nil {
+			log.Println("Failed to close connection from " + remoteAddr.String() + ": " + err.Error())
+		}
+		log.Println("Connection from " + remoteAddr.String() + " closed")
+	}()
+
+	// Create buffers.
+	r := bufio.NewReader(conn)
+	w := bufio.NewWriter(conn)
+	scanr := bufio.NewScanner(r)
+
+	// Send greeting.
+	greetingData, _ := eventer.LaunchEvent("internal/greeting", nil)
+	greetingReply := greetingData.(*Reply)
+
+	_, err := w.WriteString(greetingReply.Code + " " + greetingReply.Data)
+	if err != nil {
+		log.Println("Failed to write greeting for " + remoteAddr.String() + ": " + err.Error())
+		return
+	}
+	w.Flush()
+
+	// Start reading for commands.
+	// Every command can be represented as slice where first element
+	// is actual command and all next - parameters.
+	// By default we read only one line per iteration.
+	// ToDo: multiline data parser for posting.
+	for {
+		dataAppeared := scanr.Scan()
+		if !dataAppeared {
+			log.Println("Failed to read data from " + remoteAddr.String() + ": " + scanr.Err().Error())
+			break
+		}
+
+		log.Println("Got data: " + scanr.Text())
+
+		// ToDo: what if we'll upload binary data here?
+		// Not supported yet.
+		data := strings.Split(scanr.Text(), " ")
+		replyRaw, err := eventer.LaunchEvent("commands/"+data[0], data[1:])
+		if err != nil {
+			// We won't break here as this is just logging of appeared error.
+			log.Println("Error appeared while processing command '" + data[0] + "' for " + remoteAddr.String() + ": " + err.Error())
+		}
+
+		// We might have nil in reply, so we'll assume that passed command
+		// is unknown to us.
+		if replyRaw == nil {
+			_, err := w.WriteString(unknownCommandErrorCode + " " + unknownCommandErrorText + "\r\n")
+			if err != nil {
+				log.Println("Failed to write string to socket for " + remoteAddr.String() + ": " + err.Error())
+				break
+			}
+			w.Flush()
+			continue
+		}
+
+		// Every reply will be a reply struct.
+		reply := replyRaw.(*Reply)
+
+		_, err1 := w.WriteString(reply.Code + " " + reply.Data)
+		if err1 != nil {
+			log.Println("Failed to write string to socket for " + remoteAddr.String() + ": " + err1.Error())
+			break
+		}
+		w.Flush()
+
+		// Check for QUIT command.
+		if strings.ToLower(data[0]) == "quit" {
+			log.Println("QUIT command received, closing connection to " + remoteAddr.String())
+			break
+		}
+	}
+}

networker/errors.go

@@ -0,0 +1,6 @@
+package networker
+
+const (
+	unknownCommandErrorCode = "500"
+	unknownCommandErrorText = "Unknown command"
+)

networker/reply.go

@@ -0,0 +1,6 @@
+package networker
+
+type Reply struct {
+	Code string
+	Data string
+}

networker/server.go

@@ -0,0 +1,37 @@
+package networker
+
+import (
+	// stdlib
+	"log"
+	"net"
+
+	// local
+	"develop.pztrn.name/gonews/gonews/configuration"
+)
+
+// This function responsible for accepting incoming connections for
+// each address configuration.
+func startServer(config configuration.Network) {
+	log.Println("Starting server on " + config.Address + " (type: " + config.Type + ")")
+
+	l, err := net.Listen("tcp", config.Address)
+	if err != nil {
+		log.Fatalln("Failed to start TCP server on " + config.Address + ": " + err.Error())
+	}
+	defer func() {
+		err := l.Close()
+		if err != nil {
+			log.Println("Failed to close TCP server on " + config.Address + ": " + err.Error())
+		}
+	}()
+
+	for {
+		conn, err1 := l.Accept()
+		if err1 != nil {
+			log.Println("Failed to accept new incoming connection: " + err1.Error())
+			continue
+		}
+
+		go connectionWorker(conn)
+	}
+}