Separation of concerns for protocol observations (#35)

* feat: creating sample Go module

* feat: example error handling

* refactor: random example communication message

* feat: example map data type (slice) & test cases

* Template for suggested experimental expectations (#24)

* feat: draft variable packet size experiment

* docs: new section for project replicability

* docs: markdown diagram (system control flow) + blockquote highlight

* refactor: utility to insights + diode collection script

* fix: text cache source location

* Delete `message` directory

* Delete `example` directory

* bump: latest Go milestone (minor release)

* Topic levels for MQTT (#27)

* feat: diode telemetry channel + updated configuration settings

* refactor: diode config settings & remove republish code

* feat: read file contents from text file

* feat: MQTT index, topic, payload, & checksum (example)

* feat: create new message counter via mutex

* feat: send file contents via MQTT telemetry topic

* nit: remove unused broker message contents

* refactor: message content of diode diagnostics

* docs: finalize project directory structure

* refactor: variables for testing content publisher

* feat: placeholder client + server (I/O)

* refactor: data diode settings & connection constants

* refactor: application constants with minimal error handling

* deps: remove outdated string metrics library

* docs: create B4-0144-355112.json (via Fend_B4_4.0.2.fw)

Source: #30

* refactor: diode test variables

* docs: mock external API for schema validation

* Mock system connection & message crafting (#34)

* bump: project requirements via upgrading direct dependencies

* feat: baseline for UUID + timestamp (MQTT)

* refactor: diode test binary logic + echo message

* feat: improve overall test coverage with republish contents

* refactor: content compontents for subscription overhaul

* fix: run all tests in current directory + subdirectories

* feat: MQTT test subscription + application (client/server)

* refactor: diode test command & server continuous stream

* fix: broken build with undefined import

* refactor: draft goroutine for server connection(s)

Makefile

@@ -1,10 +1,10 @@
 all: build
 
 build:
-	go build -o diode -ldflags="-X main.SemVer=0.0.8" diode.go
+	go build -o diode -ldflags="-X main.SemVer=0.0.9" diode.go
 
 test:
-	go test -v
+	go test -v ./...
 
 run:
 	go run diode.go

config/settings.yaml

@@ -8,6 +8,6 @@ output:
   port: 13337
   tls: false
 broker:
-  server: "test.mosquitto.org"
+  server: "localhost"
   port: 1883
   topic: "diode/telemetry"

diode.go

@@ -13,6 +13,7 @@ import (
 	"os"
 	"time"
 
+	analysis "github.com/acep-uaf/data-diode/insights"
 	utility "github.com/acep-uaf/data-diode/utility"
 	"github.com/urfave/cli/v2"
 	"gopkg.in/yaml.v2"
@@ -136,7 +137,7 @@ func main() {
 				Usage:   "Testing state synchronization via diode I/O",
 				Action: func(tCtx *cli.Context) error {
 					fmt.Println("----- TEST -----")
-					exampleContents(InputTextFile)
+					utility.RepublishContents(InputTextFile, mqttBrokerIP, mqttBrokerTopic, mqttBrokerPort)
 					return nil
 				},
 			},
@@ -156,8 +157,7 @@ func main() {
 				Usage:   "System benchmark analysis + report performance metrics",
 				Action: func(bCtx *cli.Context) error {
 					fmt.Println("----- BENCHMARKS -----")
-					// TODO: Perform specific benchmarks here...
-					// e.g. ping test, network throughput, system performance, disk I/O, memory usage
+					analysis.Pong()
 					return nil
 				},
 			},
@@ -167,7 +167,7 @@ func main() {
 				Usage:   "MQTT → TCP stream demo",
 				Action: func(mCtx *cli.Context) error {
 					fmt.Println("----- MQTT -----")
-					republishContents(InputTextFile, mqttBrokerIP, mqttBrokerTopic, mqttBrokerPort)
+					utility.Subscription(mqttBrokerIP, mqttBrokerPort, mqttBrokerTopic, targetServerIP, targetServerPort)
 					return nil
 				},
 			},

diode_test.go

@@ -1,33 +1,77 @@
 package main
 
 import (
+	"bytes"
 	"fmt"
+	"net"
 	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
 	"testing"
 
 	insights "github.com/acep-uaf/data-diode/insights"
+	"github.com/acep-uaf/data-diode/utility"
 )
 
 var (
-	BackupConfiguration = "config/B4-0144-355112.json"
-	SystemSettings      = "config/settings.yaml"
-	FileChecksum        = "477076c6fd8cf48ff2d0159b22bada27588c6fa84918d1c4fc20cd9ddd291dbd"
+	BackupConfiguration  = "config/B4-0144-355112.json"
+	SystemSettings       = "config/settings.yaml"
+	ProjectDocumentation = "docs/SOP.md"
+	FileChecksum         = "477076c6fd8cf48ff2d0159b22bada27588c6fa84918d1c4fc20cd9ddd291dbd"
+	SampleMessage        = "Hello, world."
+	InterfaceSize        = 1024
+	InterfaceProtocol    = "tcp"
+	InterfaceAddress     = "localhost:13337"
 )
 
+type TCP struct {
+	ClientTargetIP      string
+	ClientTargetPort    int
+	ServerTargetIP      string
+	ServerPort          int
+	ServerSocketTimeout int
+}
+
 func TestAPI(t *testing.T) {
 	jsonFile, err := os.Open(BackupConfiguration)
 
+	schema := "CAMIO.2024.1.0"
+	version := filepath.Base(jsonFile.Name())
+
+	// FIXME: Cross reference the JSON contents, schema version, & configuration file?
+	fmt.Println(version, schema)
+
 	if err != nil {
 		t.Errorf("[?] %s via %s", err, jsonFile.Name())
 	}
 }
 
 func TestCLI(t *testing.T) {
-	got := "diode"
-	want := "diode"
+	binary := exec.Command("go", "build", "-o", "diode")
+	buildErr := binary.Run()
+	if buildErr != nil {
+		t.Fatalf("[!] Failed to build CLI binary: %v", buildErr)
+	}
 
-	if got != want {
-		t.Errorf("got %q, want %q", got, want)
+	cmd := exec.Command("./diode")
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	err := cmd.Run()
+	if err != nil {
+		t.Fatalf("[!] Failed to execute CLI command: %v", err)
+	}
+
+	expectation := "diode: try 'diode --help' for more information"
+	reality := strings.TrimSpace(stdout.String())
+	if reality != expectation {
+		t.Errorf("[?] Expected output: %q, but got: %q", expectation, reality)
+	}
+
+	if stderr.Len() > 0 {
+		t.Errorf("[?] Unexpected error output: %q", stderr.String())
 	}
 }
 
@@ -43,10 +87,99 @@ func TestFileContents(t *testing.T) {
 	want := FileChecksum
 
 	if got != want {
-		t.Errorf("got %q, want %q", got, want)
+		t.Errorf(">> got %q, want %q", got, want)
+	}
+}
+
+func TestBinaryContents(t *testing.T) {
+	// TODO: Implement the following:
+	// - Craft a text message containing binary data + checksum.
+	// - Ensure transmission across data diode without corrupted information.
+	// - Check for uuenconding and base64 encoding / delimiters.
+
+	sample := []byte(SampleMessage)
+
+	if len(sample) == 0 {
+		t.Errorf("[!] No binary contents...")
+	}
+}
+
+func TestEchoMessage(t *testing.T) {
+	go func() {
+		listener, err := net.Listen(InterfaceProtocol, InterfaceAddress)
+		if err != nil {
+			t.Errorf("[!] Failed to start TCP server: %v", err)
+		}
+		defer listener.Close()
+
+		conn, err := listener.Accept()
+		if err != nil {
+			t.Errorf("[!] Failed to accept connection: %v", err)
+		}
+		defer conn.Close()
+
+		buf := make([]byte, InterfaceSize)
+		n, err := conn.Read(buf)
+		if err != nil {
+			t.Errorf("[!] Failed to read message: %v", err)
+		}
+
+		_, err = conn.Write(buf[:n])
+		if err != nil {
+			t.Errorf("[!] Failed to write message: %v", err)
+		}
+	}()
+
+	// TODO: Mock the TCP client/server to simulate the transmission of data.
+
+	conn, err := net.Dial(InterfaceProtocol, InterfaceAddress)
+	if err != nil {
+		t.Fatalf("[!] Failed to connect to TCP server: %v", err)
+	}
+	defer conn.Close()
+
+	message := SampleMessage
+	_, err = conn.Write([]byte(message))
+	if err != nil {
+		t.Fatalf("[!] Failed to send message: %v", err)
+	}
+
+	buf := make([]byte, len(message))
+	n, err := conn.Read(buf)
+	if err != nil {
+		t.Fatalf("[!] Failed to read echoed message: %v", err)
+	}
+
+	match := string(buf[:n])
+	if match != message {
+		t.Errorf("[!] Echoed message does not match original message: got %q, want %q", match, message)
 	}
 }
 
 func TestRepublishContents(t *testing.T) {
-	// TODO: Mock the MQTT client.
+	location := ProjectDocumentation
+	broker := "localhost"
+	topic := "test/message"
+	port := 1883
+
+	// TODO: Mock the MQTT connection.
+
+	utility.RepublishContents(location, broker, topic, port)
+
+	if len(location) == 0 {
+		t.Errorf("[!] No location specified...")
+	}
+
+	if len(broker) == 0 {
+		t.Errorf("[!] No broker specified...")
+	}
+
+	if len(topic) == 0 {
+		t.Errorf("[!] No topic specified...")
+	}
+
+	if port == 0 {
+		t.Errorf("[!] No port specified...")
+	}
 }
+

go.mod

@@ -4,13 +4,14 @@ go 1.22.1
 
 require (
 	github.com/eclipse/paho.mqtt.golang v1.4.3
+	github.com/google/uuid v1.6.0
 	github.com/olekukonko/tablewriter v0.0.5
 	github.com/urfave/cli/v2 v2.27.1
 	gopkg.in/yaml.v2 v2.4.0
 )
 
 require (
-	github.com/cpuguy83/go-md2man/v2 v2.0.3 // indirect
+	github.com/cpuguy83/go-md2man/v2 v2.0.4 // indirect
 	github.com/gorilla/websocket v1.5.1 // indirect
 	github.com/mattn/go-runewidth v0.0.15 // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect

go.sum

@@ -1,7 +1,9 @@
-github.com/cpuguy83/go-md2man/v2 v2.0.3 h1:qMCsGGgs+MAzDFyp9LpAe1Lqy/fY/qCovCm0qnXZOBM=
-github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/cpuguy83/go-md2man/v2 v2.0.4 h1:wfIWP927BUkWJb2NmU/kNDYIBTh/ziUX91+lVfRxZq4=
+github.com/cpuguy83/go-md2man/v2 v2.0.4/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/eclipse/paho.mqtt.golang v1.4.3 h1:2kwcUGn8seMUfWndX0hGbvH8r7crgcJguQNCyp70xik=
 github.com/eclipse/paho.mqtt.golang v1.4.3/go.mod h1:CSYvoAlsMkhYOXh/oKyxa8EcBci6dVkLCbo5tTC1RIE=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gorilla/websocket v1.5.1 h1:gmztn0JnHVt9JZquRuzLw3g4wouNVzKL15iLr/zn/QY=
 github.com/gorilla/websocket v1.5.1/go.mod h1:x3kM2JMyaluk02fnUJpQuwD2dCS5NDG2ZHL0uE0tcaY=
 github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=

insights/benchmark.go

@@ -8,6 +8,21 @@ import (
 	"time"
 )
 
+func Pong() bool {
+	location := "https://example.com/"
+
+	resp, err := http.Get(location)
+
+	if err != nil {
+		return false
+	}
+	defer resp.Body.Close()
+
+	println(">> Status: ", resp.Status)
+
+	return true
+}
+
 func Checksum() [32]byte {
 	location := "https://www.gutenberg.org/cache/epub/84/pg84.txt"
 

utility/application.go

@@ -87,7 +87,6 @@ func StartPlaceholderClient(host string, port int) {
 
 func StartPlaceholderServer(host string, port int) {
 	listener, err := net.Listen(CONN_TYPE, fmt.Sprintf("%s:%d", host, port))
-
 	if err != nil {
 		fmt.Println(">> [!] Error listening: ", err.Error())
 		return
@@ -100,30 +99,35 @@ func StartPlaceholderServer(host string, port int) {
 		fmt.Println(">> Server waiting for connection...")
 
 		conn, err := listener.Accept()
-
 		if err != nil {
 			fmt.Println(">> [!] Error accepting: ", err.Error())
 			return
 		}
 
 		fmt.Println(">> Server accepted connection from: ", conn.RemoteAddr())
 
-		for {
-			data := make([]byte, SAMPLE)
-			_, err := conn.Read(data)
-			if err != nil {
-				fmt.Println(">> [!] Error receiving data: ", err.Error())
-				break
-			}
+		go func(conn net.Conn) {
+			defer conn.Close()
 
-			fmt.Printf(">> Received data: %s\n", string(data))
+			for {
+				data := make([]byte, SAMPLE)
+				bytesRead, err := conn.Read(data)
+				if err != nil {
+					fmt.Println(">> [!] Error receiving data: ", err.Error())
+					if err.Error() == "EOF" {
+						fmt.Println(">> Connection closed by client.")
+						return
+					}
+				}
 
-			_, err = conn.Write([]byte(ACKNOWLEDGEMENT))
+				fmt.Printf(">> Received data: %s\n", string(data[:bytesRead]))
 
-			if err != nil {
-				fmt.Println(">> [!] Error sending ACK: ", err.Error())
-				return
+				_, err = conn.Write([]byte(ACKNOWLEDGEMENT))
+				if err != nil {
+					fmt.Println(">> [!] Error sending ACK: ", err.Error())
+					return
+				}
 			}
-		}
+		}(conn)
 	}
 }

utility/application_test.go

@@ -0,0 +1,21 @@
+package utility
+
+import "testing"
+
+func TestClient(t *testing.T) {
+	got := "server"
+	want := "client"
+
+	if got != want {
+		t.Errorf("got %q, want %q", got, want)
+	}
+}
+
+func TestServer(t *testing.T) {
+	got := "client"
+	want := "server"
+
+	if got != want {
+		t.Errorf("got %q, want %q", got, want)
+	}
+}