.

AGENTS.md

@@ -0,0 +1,98 @@
+# CLAUDE.md
+
+This file provides guidance to AI Agents such as Claude Code or ChatGPT Codex when working with code in this repository.
+
+## General guidelines
+
+Use idiomatic Go as possible. Prefer simple code than complex.
+
+## Project Overview
+
+Gemserve is a simple Gemini protocol server written in Go that serves static files over TLS-encrypted connections. The Gemini protocol is a lightweight, privacy-focused alternative to HTTP designed for serving text-based content.
+
+### Development Commands
+
+```bash
+# Build, test, and format everything
+make
+
+# Run tests only
+make test
+
+# Build binaries to ./dist/ (gemserve, gemget, gembench)
+make build
+
+# Format code with gofumpt and gci
+make fmt
+
+# Run golangci-lint
+make lint
+
+# Run linter with auto-fix
+make lintfix
+
+# Clean build artifacts
+make clean
+
+# Run the server (after building)
+./dist/gemserve
+
+# Generate TLS certificates for development
+certs/generate.sh
+```
+
+### Architecture
+
+Core Components
+
+- **cmd/gemserve/gemserve.go**: Entry point with TLS server setup, signal handling, and graceful shutdown
+- **cmd/gemget/**: Gemini protocol client for fetching content
+- **cmd/gembench/**: Benchmarking tool for Gemini servers
+- **server/**: Request processing, file serving, and Gemini protocol response handling
+- **gemini/**: Gemini protocol implementation (URL parsing, status codes, path normalization)
+- **config/**: CLI-based configuration system
+- **lib/logging/**: Structured logging package with context-aware loggers
+- **lib/apperrors/**: Application error handling (fatal vs non-fatal errors)
+- **uid/**: Connection ID generation for logging (uses external vendor package)
+
+Key Patterns
+
+- **Security First**: All file operations use `filepath.IsLocal()` and path cleaning to prevent directory traversal
+- **Error Handling**: Uses structured errors via `lib/apperrors` package distinguishing fatal from non-fatal errors
+- **Logging**: Structured logging with configurable levels via internal logging package
+- **Testing**: Table-driven tests with parallel execution, heavy focus on security edge cases
+
+Request Flow
+
+1. TLS connection established on port 1965
+2. Read up to 1KB request (Gemini spec limit)
+3. Parse and normalize Gemini URL
+4. Validate path security (prevent traversal)
+5. Serve file or directory index with appropriate MIME type
+6. Send response with proper Gemini status codes
+
+Configuration
+
+Server configured via CLI flags:
+- `--listen`: Server address (default: localhost:1965)
+- `--root-path`: Directory to serve files from
+- `--dir-indexing`: Enable directory browsing (default: false)
+- `--log-level`: Logging verbosity (debug, info, warn, error; default: info)
+- `--response-timeout`: Response timeout in seconds (default: 30)
+- `--tls-cert`: TLS certificate file path (default: certs/server.crt)
+- `--tls-key`: TLS key file path (default: certs/server.key)
+- `--max-response-size`: Maximum response size in bytes (default: 5242880)
+
+Testing Strategy
+
+- **server/server_test.go**: Path security and file serving tests
+- **gemini/url_test.go**: URL parsing and normalization tests
+- Focus on security edge cases (Unicode, traversal attempts, malformed URLs)
+- Use parallel test execution for performance
+
+Security Considerations
+
+- All connections require TLS certificates (stored in certs/)
+- Path traversal protection is critical - test thoroughly when modifying file serving logic
+- Request size limited to 1KB per Gemini specification
+- Input validation on all URLs and paths

CLAUDE.md

@@ -1,87 +0,0 @@
-# CLAUDE.md
-
-This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
-
-## Project Overview
-
-Gemserve is a simple Gemini protocol server written in Go that serves static files over TLS-encrypted connections. The Gemini protocol is a lightweight, privacy-focused alternative to HTTP designed for serving text-based content.
-
-## Development Commands
-
-```bash
-# Build, test, and format everything
-make
-
-# Run tests only
-make test
-
-# Build binary to ./dist/gemserve
-make build
-
-# Format code with gofumpt and gci
-make fmt
-
-# Run golangci-lint
-make lint
-
-# Run linter with auto-fix
-make lintfix
-
-# Clean build artifacts
-make clean
-
-# Run the server (after building)
-./dist/gemserve
-
-# Generate TLS certificates for development
-certs/generate.sh
-```
-
-## Architecture
-
-### Core Components
-
-- **main.go**: Entry point with TLS server setup, signal handling, and graceful shutdown
-- **server/**: Request processing, file serving, and Gemini protocol response handling
-- **gemini/**: Gemini protocol implementation (URL parsing, status codes, path normalization)
-- **config/**: CLI-based configuration system
-- **uid/**: Connection ID generation for logging
-
-### Key Patterns
-
-- **Security First**: All file operations use `filepath.IsLocal()` and path cleaning to prevent directory traversal
-- **Error Handling**: Uses structured errors with `xerrors` package for consistent error propagation
-- **Logging**: Structured logging with configurable levels via internal logging package
-- **Testing**: Table-driven tests with parallel execution, heavy focus on security edge cases
-
-### Request Flow
-
-1. TLS connection established on port 1965
-2. Read up to 1KB request (Gemini spec limit)
-3. Parse and normalize Gemini URL
-4. Validate path security (prevent traversal)
-5. Serve file or directory index with appropriate MIME type
-6. Send response with proper Gemini status codes
-
-## Configuration
-
-Server configured via CLI flags:
-- `--listen`: Server address (default: localhost:1965)
-- `--root-path`: Directory to serve files from
-- `--dir-indexing`: Enable directory browsing
-- `--log-level`: Logging verbosity
-- `--response-timeout`: Response timeout in seconds
-
-## Testing Strategy
-
-- **server/server_test.go**: Path security and file serving tests
-- **gemini/url_test.go**: URL parsing and normalization tests
-- Focus on security edge cases (Unicode, traversal attempts, malformed URLs)
-- Use parallel test execution for performance
-
-## Security Considerations
-
-- All connections require TLS certificates (stored in certs/)
-- Path traversal protection is critical - test thoroughly when modifying file serving logic
-- Request size limited to 1KB per Gemini specification
-- Input validation on all URLs and paths

CLAUDE.md

@@ -0,0 +1 @@
+./AGENTS.md

Makefile

@@ -34,7 +34,9 @@ lintfix: fmt
 
 build: clean
 	mkdir -p ./dist
-	go build -mod=vendor -o ./dist/gemserve ./main.go
+	go build -mod=vendor -o ./dist/gemserve ./cmd/gemserve/gemserve.go
+	go build -mod=vendor -o ./dist/gemget ./cmd/gemget/gemget.go
+	go build -mod=vendor -o ./dist/gembench ./cmd/gembench/gembench.go
 
 build-docker: build
 	docker build -t gemserve .

cmd/gembench/gembench.go

@@ -0,0 +1,180 @@
+package main
+
+import (
+	"context"
+	"crypto/tls"
+	"flag"
+	"fmt"
+	"io"
+	"log/slog"
+	"net/url"
+	"os"
+	"os/signal"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+
+	"gemserve/lib/logging"
+)
+
+func main() {
+	// Parse command-line flags
+	insecure := flag.Bool("insecure", false, "Skip TLS certificate verification")
+	totalConnections := flag.Int("total-connections", 250, "Total connections to make")
+	parallelism := flag.Int("parallelism", 10, "How many connections to run in parallel")
+	flag.Parse()
+
+	// Get the URL from arguments
+	args := flag.Args()
+	if len(args) != 1 {
+		fmt.Fprintf(os.Stderr, "Usage: gemget [--insecure] <gemini-url>\n")
+		os.Exit(1)
+	}
+
+	logging.SetupLogging(slog.LevelInfo)
+	logger := logging.Logger
+	ctx := logging.WithLogger(context.Background(), logger)
+
+	geminiURL := args[0]
+	host := validateUrl(geminiURL)
+	if host == "" {
+		logger.Error("Invalid URL.")
+		os.Exit(1)
+	}
+	start := time.Now()
+	err := benchmark(ctx, geminiURL, host, *insecure, *totalConnections, *parallelism)
+	if err != nil {
+		logger.Error(err.Error())
+		os.Exit(1)
+	}
+	end := time.Now()
+	tookMs := end.Sub(start).Milliseconds()
+	logger.Info("End.", "ms", tookMs)
+}
+
+var wg sync.WaitGroup
+
+type ctxKey int
+
+const ctxKeyJobIndex ctxKey = 1
+
+func benchmark(ctx context.Context, u string, h string, insecure bool, totalConnections int, parallelism int) error {
+	logger := logging.FromContext(ctx)
+	signals := make(chan os.Signal, 1)
+	signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM)
+	// Root context, used to cancel
+	// connections and graceful shutdown.
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	// Semaphore to limit concurrency.
+	// Goroutines put value to channel (acquire slot)
+	// and consume value from channel (release slot).
+	semaphore := make(chan struct{}, parallelism)
+
+loop:
+	for i := 0; i < totalConnections; i++ {
+		select {
+		case <-signals:
+			logger.Warn("Received SIGINT or SIGTERM signal, shutting down gracefully")
+			cancel()
+			break loop
+		case semaphore <- struct{}{}: // Acquire slot
+			wg.Add(1)
+			go func(jobIndex int) {
+				defer func() {
+					<-semaphore // Release slot
+					wg.Done()
+				}()
+				ctxWithValue := context.WithValue(ctx, ctxKeyJobIndex, jobIndex)
+				ctxWithTimeout, cancel := context.WithTimeout(ctxWithValue, 60*time.Second)
+				defer cancel()
+				err := connect(ctxWithTimeout, u, h, insecure)
+				if err != nil {
+					logger.Warn(fmt.Sprintf("%d error: %v", jobIndex, err))
+				}
+			}(i)
+		}
+	}
+	wg.Wait()
+	return nil
+}
+
+func validateUrl(u string) string {
+	// Parse the URL
+	parsedURL, err := url.Parse(u)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error parsing URL: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Ensure it's a gemini URL
+	if parsedURL.Scheme != "gemini" {
+		fmt.Fprintf(os.Stderr, "Error: URL must use gemini:// scheme\n")
+		os.Exit(1)
+	}
+
+	// Get host and port
+	host := parsedURL.Host
+	if !strings.Contains(host, ":") {
+		host = host + ":1965" // Default Gemini port
+	}
+
+	return host
+}
+
+func connect(ctx context.Context, url string, host string, insecure bool) error {
+	logger := logging.FromContext(ctx)
+	tlsConfig := &tls.Config{
+		InsecureSkipVerify: insecure,
+		MinVersion:         tls.VersionTLS12,
+	}
+
+	// Context checkpoint
+	if ctx.Err() != nil {
+		return nil
+	}
+
+	// Connect to the server
+	conn, err := tls.Dial("tcp", host, tlsConfig)
+	if err != nil {
+		return err
+	}
+
+	// Set connection deadline based on context
+	if deadline, ok := ctx.Deadline(); ok {
+		_ = conn.SetDeadline(deadline)
+	}
+
+	defer func() {
+		_ = conn.Close()
+	}()
+
+	// Context checkpoint
+	if ctx.Err() != nil {
+		return nil
+	}
+
+	// Send the request (URL + CRLF)
+	request := url + "\r\n"
+	_, err = conn.Write([]byte(request))
+	if err != nil {
+		return err
+	}
+
+	// Context checkpoint
+	if ctx.Err() != nil {
+		return nil
+	}
+
+	// Read and dump response
+	_, err = io.Copy(io.Discard, conn)
+	if err != nil {
+		return err
+	}
+
+	jobIndex := ctx.Value(ctxKeyJobIndex)
+	logger.Debug(fmt.Sprintf("%d done", jobIndex))
+	return nil
+}

cmd/gemget/gemget.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"crypto/tls"
+	"flag"
+	"fmt"
+	"io"
+	"net/url"
+	"os"
+	"strings"
+)
+
+func main() {
+	// Parse command-line flags
+	insecure := flag.Bool("insecure", false, "Skip TLS certificate verification")
+	flag.Parse()
+
+	// Get the URL from arguments
+	args := flag.Args()
+	if len(args) != 1 {
+		fmt.Fprintf(os.Stderr, "Usage: gemget [--insecure] <gemini-url>\n")
+		os.Exit(1)
+	}
+
+	geminiURL := args[0]
+
+	host := validateUrl(geminiURL)
+
+	connect(geminiURL, host, *insecure)
+}
+
+func validateUrl(u string) string {
+	// Parse the URL
+	parsedURL, err := url.Parse(u)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error parsing URL: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Ensure it's a gemini URL
+	if parsedURL.Scheme != "gemini" {
+		fmt.Fprintf(os.Stderr, "Error: URL must use gemini:// scheme\n")
+		os.Exit(1)
+	}
+
+	// Get host and port
+	host := parsedURL.Host
+	if !strings.Contains(host, ":") {
+		host = host + ":1965" // Default Gemini port
+	}
+
+	return host
+}
+
+func connect(url string, host string, insecure bool) {
+	// Configure TLS
+	tlsConfig := &tls.Config{
+		InsecureSkipVerify: insecure,
+		MinVersion:         tls.VersionTLS12,
+	}
+
+	// Connect to the server
+	conn, err := tls.Dial("tcp", host, tlsConfig)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error connecting to server: %v\n", err)
+		os.Exit(1)
+	}
+	defer func() {
+		_ = conn.Close()
+	}()
+
+	// Send the request (URL + CRLF)
+	request := url + "\r\n"
+	_, err = conn.Write([]byte(request))
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error sending request: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Read and print the response to stdout
+	_, err = io.Copy(os.Stdout, conn)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error reading response: %v\n", err)
+		os.Exit(1)
+	}
+}

cmd/gemserve/gemserve.go

@@ -0,0 +1,162 @@
+package main
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"net"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+	"time"
+
+	"gemserve/lib/apperrors"
+	"gemserve/lib/logging"
+
+	"gemserve/config"
+	"gemserve/server"
+
+	"git.antanst.com/antanst/uid"
+)
+
+func main() {
+	config.CONFIG = *config.GetConfig()
+	logging.SetupLogging(config.CONFIG.LogLevel)
+	logger := logging.Logger
+	ctx := logging.WithLogger(context.Background(), logger)
+	err := runApp(ctx)
+	if err != nil {
+		logger.Error("Fatal Error", "err", err)
+		panic(fmt.Sprintf("Fatal Error: %v", err))
+	}
+	os.Exit(0)
+}
+
+func runApp(ctx context.Context) error {
+	logger := logging.FromContext(ctx)
+	logger.Info("Starting up. Press Ctrl+C to exit")
+
+	listenAddr := config.CONFIG.ListenAddr
+
+	signals := make(chan os.Signal, 1)
+	signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM)
+
+	// Only this file should send to this channel.
+	// All external functions should return errors.
+	fatalErrors := make(chan error)
+
+	// Root context, used to cancel
+	// connections and graceful shutdown.
+	serverCtx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	// WaitGroup to track active connections
+	// in order to be able to wait until
+	// they are properly dropped
+	var wg sync.WaitGroup
+
+	// Spawn server on the background.
+	// Returned errors are considered fatal.
+	go func() {
+		err := startServer(serverCtx, listenAddr, &wg, fatalErrors)
+		if err != nil {
+			fatalErrors <- apperrors.NewFatalError(fmt.Errorf("server startup failed: %w", err))
+		}
+	}()
+
+	for {
+		select {
+		case <-signals:
+			logger.Warn("Received SIGINT or SIGTERM signal, shutting down gracefully")
+			cancel()
+			wg.Wait()
+			return nil
+		case fatalError := <-fatalErrors:
+			cancel()
+			wg.Wait()
+			return fatalError
+		}
+	}
+}
+
+func startServer(ctx context.Context, listenAddr string, wg *sync.WaitGroup, fatalErrors chan<- error) (err error) {
+	logger := logging.FromContext(ctx)
+
+	cert, err := tls.LoadX509KeyPair(config.CONFIG.TLSCert, config.CONFIG.TLSKey)
+	if err != nil {
+		return apperrors.NewFatalError(fmt.Errorf("failed to load TLS certificate/key: %w", err))
+	}
+
+	logger.Debug("Using TLS cert", "path", config.CONFIG.TLSCert)
+	logger.Debug("Using TLS key", "path", config.CONFIG.TLSKey)
+
+	tlsConfig := &tls.Config{
+		Certificates: []tls.Certificate{cert},
+		MinVersion:   tls.VersionTLS12,
+	}
+
+	listener, err := tls.Listen("tcp", listenAddr, tlsConfig)
+	if err != nil {
+		return apperrors.NewFatalError(err)
+	}
+
+	defer func(listener net.Listener) {
+		_ = listener.Close()
+	}(listener)
+
+	// If context is cancelled, close listener
+	// to unblock Accept() inside main loop.
+	go func() {
+		<-ctx.Done()
+		_ = listener.Close()
+	}()
+
+	logger.Info("Server listening", "address", listenAddr)
+
+	for {
+		conn, err := listener.Accept()
+		if err != nil {
+			if ctx.Err() != nil {
+				return nil
+			} // ctx cancellation
+			logger.Info("Failed to accept connection: %v", "error", err)
+			continue
+		}
+
+		// At this point we have a new connection.
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+
+			// Type assert the connection to TLS connection
+			tlsConn, ok := conn.(*tls.Conn)
+			if !ok {
+				logger.Error("Connection is not a TLS connection")
+				_ = conn.Close()
+				return
+			}
+
+			remoteAddr := conn.RemoteAddr().String()
+			connId := uid.UID()
+
+			// Create cancellable connection context
+			// with connection ID.
+			connLogger := logging.WithAttr(logger, "id", connId)
+			connLogger = logging.WithAttr(connLogger, "remoteAddr", remoteAddr)
+			connCtx := context.WithValue(ctx, server.CtxConnIdKey, connId)
+			connCtx = context.WithValue(connCtx, logging.CtxLoggerKey, connLogger)
+			connCtx, cancel := context.WithTimeout(connCtx, time.Duration(config.CONFIG.ResponseTimeout)*time.Second)
+			defer cancel()
+
+			err := server.HandleConnection(connCtx, tlsConn)
+			if err != nil {
+				if apperrors.IsFatal(err) {
+					fatalErrors <- err
+					return
+				}
+				connLogger.Info("Connection failed", "error", err)
+			}
+		}()
+	}
+}

config/config.go

@@ -17,6 +17,7 @@ type Config struct {
 	ListenAddr         string     // Address to listen on
 	TLSCert            string     // TLS certificate file
 	TLSKey             string     // TLS key file
+	MaxResponseSize    int        // Max response size in bytes
 }
 
 var CONFIG Config //nolint:gochecknoglobals
@@ -47,6 +48,7 @@ func GetConfig() *Config {
 	listen := flag.String("listen", "localhost:1965", "Address to listen on")
 	tlsCert := flag.String("tls-cert", "certs/server.crt", "TLS certificate file")
 	tlsKey := flag.String("tls-key", "certs/server.key", "TLS key file")
+	maxResponseSize := flag.Int("max-response-size", 5_242_880, "Max response size in bytes")
 
 	flag.Parse()
 
@@ -71,5 +73,6 @@ func GetConfig() *Config {
 		ListenAddr:         *listen,
 		TLSCert:            *tlsCert,
 		TLSKey:             *tlsKey,
+		MaxResponseSize:    *maxResponseSize,
 	}
 }

gemini/statusCodes.go

@@ -6,8 +6,7 @@ const (
 	// Input group
 	StatusInputExpected          = 10
 	StatusInputExpectedSensitive = 11
-
-	StatusSuccess = 20
+	StatusSuccess                = 20
 
 	// Redirect group
 	StatusRedirectTemporary = 30

lib/logging/logging.go

@@ -6,14 +6,12 @@ import (
 	"os"
 	"path/filepath"
 
-	"gemserve/config"
-
 	"github.com/lmittmann/tint"
 )
 
-type contextKey int
+type contextKey string
 
-const loggerKey contextKey = 0
+const CtxLoggerKey contextKey = "logger"
 
 var (
 	programLevel *slog.LevelVar = new(slog.LevelVar) // Info by default
@@ -21,19 +19,23 @@ var (
 )
 
 func WithLogger(ctx context.Context, logger *slog.Logger) context.Context {
-	return context.WithValue(ctx, loggerKey, logger)
+	return context.WithValue(ctx, CtxLoggerKey, logger)
+}
+
+func WithAttr(logger *slog.Logger, attrName string, attrValue interface{}) *slog.Logger {
+	return logger.With(attrName, attrValue)
 }
 
 func FromContext(ctx context.Context) *slog.Logger {
-	if logger, ok := ctx.Value(loggerKey).(*slog.Logger); ok {
+	if logger, ok := ctx.Value(CtxLoggerKey).(*slog.Logger); ok {
 		return logger
 	}
 	// Return default logger instead of panicking
 	return slog.Default()
 }
 
-func SetupLogging() {
-	programLevel.Set(config.CONFIG.LogLevel)
+func SetupLogging(logLevel slog.Level) {
+	programLevel.Set(logLevel)
 	// With coloring (uses external package)
 	opts := &tint.Options{
 		AddSource: true,

main.go

@@ -1,273 +0,0 @@
-package main
-
-import (
-	"bytes"
-	"context"
-	"crypto/tls"
-	"errors"
-	"fmt"
-	"io"
-	"net"
-	"os"
-	"os/signal"
-	"strings"
-	"sync"
-	"syscall"
-	"time"
-
-	"gemserve/lib/apperrors"
-	"gemserve/lib/logging"
-
-	"gemserve/config"
-	"gemserve/gemini"
-	"gemserve/server"
-
-	"git.antanst.com/antanst/uid"
-)
-
-func main() {
-	config.CONFIG = *config.GetConfig()
-	logging.SetupLogging()
-	logger := logging.Logger
-	ctx := logging.WithLogger(context.Background(), logger)
-	err := runApp(ctx)
-	if err != nil {
-		logger.Error(fmt.Sprintf("Fatal Error: %v", err))
-		panic(fmt.Sprintf("Fatal Error: %v", err))
-	}
-	os.Exit(0)
-}
-
-func runApp(ctx context.Context) error {
-	logger := logging.FromContext(ctx)
-	logger.Info("Starting up. Press Ctrl+C to exit")
-
-	listenAddr := config.CONFIG.ListenAddr
-
-	signals := make(chan os.Signal, 1)
-	signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM)
-
-	fatalErrors := make(chan error)
-
-	// Root server context, used to cancel
-	// connections and graceful shutdown.
-	serverCtx, cancel := context.WithCancel(ctx)
-	defer cancel()
-
-	// WaitGroup to track active connections
-	var wg sync.WaitGroup
-
-	// Spawn server on the background.
-	// Returned errors are considered fatal.
-	go func() {
-		err := startServer(serverCtx, listenAddr, &wg, fatalErrors)
-		if err != nil {
-			fatalErrors <- apperrors.NewFatalError(fmt.Errorf("server startup failed: %w", err))
-		}
-	}()
-
-	for {
-		select {
-		case <-signals:
-			logger.Warn("Received SIGINT or SIGTERM signal, shutting down gracefully")
-			cancel()
-			wg.Wait()
-			return nil
-		case fatalError := <-fatalErrors:
-			cancel()
-			wg.Wait()
-			return fatalError
-		}
-	}
-}
-
-func startServer(ctx context.Context, listenAddr string, wg *sync.WaitGroup, fatalErrors chan<- error) (err error) {
-	logger := logging.FromContext(ctx)
-
-	cert, err := tls.LoadX509KeyPair(config.CONFIG.TLSCert, config.CONFIG.TLSKey)
-	if err != nil {
-		return apperrors.NewFatalError(fmt.Errorf("failed to load TLS certificate/key: %w", err))
-	}
-
-	logger.Debug("Using TLS cert", "path", config.CONFIG.TLSCert)
-	logger.Debug("Using TLS key", "path", config.CONFIG.TLSKey)
-
-	tlsConfig := &tls.Config{
-		Certificates: []tls.Certificate{cert},
-		MinVersion:   tls.VersionTLS12,
-	}
-
-	listener, err := tls.Listen("tcp", listenAddr, tlsConfig)
-	if err != nil {
-		return apperrors.NewFatalError(err)
-	}
-
-	defer func(listener net.Listener) {
-		_ = listener.Close()
-	}(listener)
-
-	// If context is cancelled, close listener
-	// to unblock Accept() inside main loop.
-	go func() {
-		<-ctx.Done()
-		_ = listener.Close()
-	}()
-
-	logger.Info("Server listening", "address", listenAddr)
-
-	for {
-		conn, err := listener.Accept()
-		if err != nil {
-			if ctx.Err() != nil {
-				return nil
-			} // ctx cancellation
-			logger.Info("Failed to accept connection: %v", "error", err)
-			continue
-		}
-
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
-
-			// Type assert the connection to TLS connection
-			tlsConn, ok := conn.(*tls.Conn)
-			if !ok {
-				logger.Error("Connection is not a TLS connection")
-				_ = conn.Close()
-				return
-			}
-
-			remoteAddr := conn.RemoteAddr().String()
-			connId := uid.UID()
-
-			// Create a timeout context for this connection
-			connCtx, cancel := context.WithTimeout(ctx, time.Duration(config.CONFIG.ResponseTimeout)*time.Second)
-			defer cancel()
-
-			err := handleConnection(connCtx, tlsConn, connId, remoteAddr)
-			if err != nil {
-				if apperrors.IsFatal(err) {
-					fatalErrors <- err
-					return
-				}
-				logger.Info("Connection failed", "id", connId, "remoteAddr", remoteAddr, "error", err)
-			}
-		}()
-	}
-}
-
-func closeConnection(conn *tls.Conn) error {
-	err := conn.CloseWrite()
-	if err != nil {
-		return apperrors.NewNetworkError(fmt.Errorf("failed to close TLS connection: %w", err))
-	}
-	err = conn.Close()
-	if err != nil {
-		return apperrors.NewNetworkError(fmt.Errorf("failed to close connection: %w", err))
-	}
-	return nil
-}
-
-func handleConnection(ctx context.Context, conn *tls.Conn, connId string, remoteAddr string) (err error) {
-	logger := logging.FromContext(ctx)
-	start := time.Now()
-	var outputBytes []byte
-
-	// Set connection deadline based on context
-	if deadline, ok := ctx.Deadline(); ok {
-		_ = conn.SetDeadline(deadline)
-	}
-
-	defer func(conn *tls.Conn) {
-		end := time.Now()
-		tookMs := end.Sub(start).Milliseconds()
-		var responseHeader string
-
-		// On non-errors, just log response and close connection.
-		if err == nil {
-			// Log non-erroneous responses
-			if i := bytes.Index(outputBytes, []byte{'\r'}); i >= 0 {
-				responseHeader = string(outputBytes[:i])
-			}
-			logger.Info("Response", "connId", connId, "remoteAddr", remoteAddr, "responseHeader", responseHeader, "ms", tookMs)
-			_ = closeConnection(conn)
-			return
-		}
-
-		// Handle context cancellation/timeout
-		if errors.Is(err, context.DeadlineExceeded) {
-			logger.Info("Connection timeout", "id", connId, "remoteAddr", remoteAddr, "ms", tookMs)
-			responseHeader = fmt.Sprintf("%d Request timeout", gemini.StatusCGIError)
-			_, _ = conn.Write([]byte(responseHeader + "\r\n"))
-			_ = closeConnection(conn)
-			return
-		}
-		if errors.Is(err, context.Canceled) {
-			logger.Info("Connection cancelled", "id", connId, "remoteAddr", remoteAddr, "ms", tookMs)
-			_ = closeConnection(conn)
-			return
-		}
-
-		var code int
-		var responseMsg string
-		if apperrors.IsFatal(err) {
-			_ = closeConnection(conn)
-			return
-		}
-		if apperrors.IsGeminiError(err) {
-			code = apperrors.GetStatusCode(err)
-			responseMsg = "server error"
-		} else {
-			code = gemini.StatusPermanentFailure
-			responseMsg = "server error"
-		}
-		responseHeader = fmt.Sprintf("%d %s", code, responseMsg)
-		_, _ = conn.Write([]byte(responseHeader + "\r\n"))
-		_ = closeConnection(conn)
-	}(conn)
-
-	// Check context before starting
-	if err := ctx.Err(); err != nil {
-		return err
-	}
-
-	// Gemini is supposed to have a 1kb limit
-	// on input requests.
-	buffer := make([]byte, 1025)
-
-	n, err := conn.Read(buffer)
-	if err != nil && err != io.EOF {
-		return apperrors.NewGeminiError(fmt.Errorf("failed to read connection data: %w", err), gemini.StatusBadRequest)
-	}
-	if n == 0 {
-		return apperrors.NewGeminiError(fmt.Errorf("client did not send data"), gemini.StatusBadRequest)
-	}
-	if n > 1024 {
-		return apperrors.NewGeminiError(fmt.Errorf("client request size %d > 1024 bytes", n), gemini.StatusBadRequest)
-	}
-
-	// Check context after read
-	if err := ctx.Err(); err != nil {
-		return err
-	}
-
-	dataBytes := buffer[:n]
-	dataString := string(dataBytes)
-
-	logger.Info("Request", "id", connId, "remoteAddr", remoteAddr, "data", strings.TrimSpace(dataString), "size", len(dataBytes))
-	outputBytes, err = server.GenerateResponse(ctx, conn, connId, dataString)
-	if err != nil {
-		return err
-	}
-
-	// Check context before write
-	if err := ctx.Err(); err != nil {
-		return err
-	}
-
-	_, err = conn.Write(outputBytes)
-	if err != nil {
-		return err
-	}
-	return nil
-}

server/server.go

@@ -1,9 +1,12 @@
 package server
 
 import (
+	"bytes"
 	"context"
 	"crypto/tls"
+	"errors"
 	"fmt"
+	"io"
 	"net"
 	"net/url"
 	"os"
@@ -11,6 +14,7 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"time"
 	"unicode/utf8"
 
 	"gemserve/lib/apperrors"
@@ -22,11 +26,27 @@ import (
 	"github.com/gabriel-vasile/mimetype"
 )
 
+type contextKey string
+
+const CtxConnIdKey contextKey = "connId"
+
 type ServerConfig interface {
 	DirIndexingEnabled() bool
 	RootPath() string
 }
 
+func CloseConnection(conn *tls.Conn) error {
+	err := conn.CloseWrite()
+	if err != nil {
+		return apperrors.NewNetworkError(fmt.Errorf("failed to close TLS connection: %w", err))
+	}
+	err = conn.Close()
+	if err != nil {
+		return apperrors.NewNetworkError(fmt.Errorf("failed to close connection: %w", err))
+	}
+	return nil
+}
+
 func checkRequestURL(url *gemini.URL) error {
 	if !utf8.ValidString(url.String()) {
 		return apperrors.NewGeminiError(fmt.Errorf("invalid URL"), gemini.StatusBadRequest)
@@ -45,13 +65,19 @@ func checkRequestURL(url *gemini.URL) error {
 		return apperrors.NewGeminiError(fmt.Errorf("invalid server listen port: %w", err), gemini.StatusBadRequest)
 	}
 	if url.Port != listenPort {
-		return apperrors.NewGeminiError(fmt.Errorf("failed to parse URL: %w", err), gemini.StatusProxyRequestRefused)
+		return apperrors.NewGeminiError(fmt.Errorf("port mismatch"), gemini.StatusProxyRequestRefused)
 	}
 	return nil
 }
 
-func GenerateResponse(ctx context.Context, conn *tls.Conn, connId string, input string) ([]byte, error) {
+func GenerateResponse(ctx context.Context, conn *tls.Conn, input string) ([]byte, error) {
 	logger := logging.FromContext(ctx)
+	connId := ctx.Value(CtxConnIdKey).(string)
+
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+
 	trimmedInput := strings.TrimSpace(input)
 	// url will have a cleaned and normalized path after this
 	url, err := gemini.ParseURL(trimmedInput, "", true)
@@ -80,12 +106,15 @@ func GenerateResponse(ctx context.Context, conn *tls.Conn, connId string, input
 
 	// Handle directory.
 	if info.IsDir() {
-		return generateResponseDir(localPath)
+		return generateResponseDir(ctx, localPath)
 	}
-	return generateResponseFile(localPath)
+	return generateResponseFile(ctx, localPath)
 }
 
-func generateResponseFile(localPath string) ([]byte, error) {
+func generateResponseFile(ctx context.Context, localPath string) ([]byte, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
 	data, err := os.ReadFile(localPath)
 	if err != nil {
 		return nil, apperrors.NewGeminiError(fmt.Errorf("failed to access path: %w", err), gemini.StatusNotFound)
@@ -102,7 +131,10 @@ func generateResponseFile(localPath string) ([]byte, error) {
 	return response, nil
 }
 
-func generateResponseDir(localPath string) (output []byte, err error) {
+func generateResponseDir(ctx context.Context, localPath string) (output []byte, err error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
 	entries, err := os.ReadDir(localPath)
 	if err != nil {
 		return nil, apperrors.NewGeminiError(fmt.Errorf("failed to access path: %w", err), gemini.StatusNotFound)
@@ -127,7 +159,7 @@ func generateResponseDir(localPath string) (output []byte, err error) {
 		return response, nil
 	}
 	filePath := filepath.Join(localPath, "index.gmi")
-	return generateResponseFile(filePath)
+	return generateResponseFile(ctx, filePath)
 }
 
 func calculateLocalPath(input string, basePath string) (string, error) {
@@ -155,3 +187,110 @@ func calculateLocalPath(input string, basePath string) (string, error) {
 	filePath = path.Join(basePath, localPath)
 	return filePath, nil
 }
+
+func HandleConnection(ctx context.Context, conn *tls.Conn) (err error) {
+	logger := logging.FromContext(ctx)
+	start := time.Now()
+	var outputBytes []byte
+
+	// Set connection deadline based on context
+	if deadline, ok := ctx.Deadline(); ok {
+		_ = conn.SetDeadline(deadline)
+	}
+
+	defer func(conn *tls.Conn) {
+		end := time.Now()
+		tookMs := end.Sub(start).Milliseconds()
+		var responseHeader string
+
+		// On non-errors, just log response and close connection.
+		if err == nil {
+			// Log non-erroneous responses
+			if i := bytes.Index(outputBytes, []byte{'\r'}); i >= 0 {
+				responseHeader = string(outputBytes[:i])
+			}
+			logger.Debug("Response", "responseHeader", responseHeader, "ms", tookMs)
+			_ = CloseConnection(conn)
+			return
+		}
+
+		// Handle context cancellation/timeout
+		if errors.Is(err, context.DeadlineExceeded) {
+			logger.Info("Connection timeout", "ms", tookMs)
+			responseHeader = fmt.Sprintf("%d Request timeout", gemini.StatusCGIError)
+			_, _ = conn.Write([]byte(responseHeader + "\r\n"))
+			_ = CloseConnection(conn)
+			return
+		}
+		if errors.Is(err, context.Canceled) {
+			logger.Info("Connection cancelled", "ms", tookMs)
+			_ = CloseConnection(conn)
+			return
+		}
+
+		var code int
+		var responseMsg string
+		if apperrors.IsFatal(err) {
+			_ = CloseConnection(conn)
+			return
+		}
+		if apperrors.IsGeminiError(err) {
+			code = apperrors.GetStatusCode(err)
+			responseMsg = "server error"
+		} else {
+			code = gemini.StatusPermanentFailure
+			responseMsg = "server error"
+		}
+		responseHeader = fmt.Sprintf("%d %s", code, responseMsg)
+		_, _ = conn.Write([]byte(responseHeader + "\r\n"))
+		_ = CloseConnection(conn)
+	}(conn)
+
+	// Check context before starting
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+
+	// Gemini is supposed to have a 1kb limit
+	// on input requests.
+	buffer := make([]byte, 1025)
+
+	n, err := conn.Read(buffer)
+	if err != nil && err != io.EOF {
+		return apperrors.NewGeminiError(fmt.Errorf("failed to read connection data: %w", err), gemini.StatusBadRequest)
+	}
+	if n == 0 {
+		return apperrors.NewGeminiError(fmt.Errorf("client did not send data"), gemini.StatusBadRequest)
+	}
+	if n > 1024 {
+		return apperrors.NewGeminiError(fmt.Errorf("client request size %d > 1024 bytes", n), gemini.StatusBadRequest)
+	}
+
+	// Check context after read
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+
+	dataBytes := buffer[:n]
+	dataString := string(dataBytes)
+
+	logger.Info("Request", "data", strings.TrimSpace(dataString), "size", len(dataBytes))
+	outputBytes, err = GenerateResponse(ctx, conn, dataString)
+	if len(outputBytes) > config.CONFIG.MaxResponseSize {
+		return apperrors.NewGeminiError(fmt.Errorf("max response size reached"), gemini.StatusTemporaryFailure)
+	}
+	if err != nil {
+		return err
+	}
+
+	// Check context before write
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+
+	_, err = conn.Write(outputBytes)
+	if err != nil {
+		return err
+	}
+	return nil
+}