Experimental Proxmark3 support via PM3 CLI

Author: AlbertMN

internal/api/websocket.go

@@ -36,7 +36,8 @@ type WSClient struct {
 	send        chan []byte
 	hub         *WSHub
 	mu          sync.Mutex
-	subscribed  map[string]bool // Track subscribed readers for auto-read
+	closed      bool                      // True when client is disconnected
+	subscribed  map[string]bool           // Track subscribed readers for auto-read
 	pollTickers map[string]*time.Ticker
 	lastUIDs    map[string]string // Track last seen UID per reader
 }
@@ -75,7 +76,10 @@ func (h *WSHub) Run() {
 			h.mu.Lock()
 			if _, ok := h.clients[client]; ok {
 				delete(h.clients, client)
+				client.mu.Lock()
+				client.closed = true
 				close(client.send)
+				client.mu.Unlock()
 			}
 			h.mu.Unlock()
 		case message := <-h.broadcast:
@@ -276,24 +280,50 @@ func (c *WSClient) handleMessage(msg WSMessage) {
 }
 
 func (c *WSClient) sendResponse(id string, msgType string, payload interface{}) {
+	c.mu.Lock()
+	if c.closed {
+		c.mu.Unlock()
+		return
+	}
+	c.mu.Unlock()
+
 	payloadBytes, _ := json.Marshal(payload)
 	response := WSMessage{
 		Type:    msgType,
 		ID:      id,
 		Payload: payloadBytes,
 	}
 	responseBytes, _ := json.Marshal(response)
-	c.send <- responseBytes
+
+	// Use non-blocking send to avoid panic if channel closes between check and send
+	select {
+	case c.send <- responseBytes:
+	default:
+		// Channel full or closed, drop the message
+	}
 }
 
 func (c *WSClient) sendError(id string, errMsg string) {
+	c.mu.Lock()
+	if c.closed {
+		c.mu.Unlock()
+		return
+	}
+	c.mu.Unlock()
+
 	response := WSMessage{
 		Type:  "error",
 		ID:    id,
 		Error: errMsg,
 	}
 	responseBytes, _ := json.Marshal(response)
-	c.send <- responseBytes
+
+	// Use non-blocking send to avoid panic if channel closes between check and send
+	select {
+	case c.send <- responseBytes:
+	default:
+		// Channel full or closed, drop the message
+	}
 }
 
 func (c *WSClient) handleListReaders(id string) {

internal/config/config.go

@@ -3,6 +3,7 @@ package config
 import (
 	"os"
 	"strconv"
+	"time"
 )
 
 const (
@@ -12,8 +13,18 @@ const (
 
 // Config holds the application configuration.
 type Config struct {
-	Host string
-	Port int
+	Host      string
+	Port      int
+	Proxmark3 Proxmark3Config
+}
+
+// Proxmark3Config holds Proxmark3-specific configuration.
+type Proxmark3Config struct {
+	Enabled        bool          // Enable Proxmark3 support (NFC_AGENT_PROXMARK3=1)
+	Path           string        // Custom path to pm3 binary (NFC_AGENT_PM3_PATH)
+	Port           string        // Specific serial port (NFC_AGENT_PM3_PORT)
+	PersistentMode bool          // Use persistent subprocess (NFC_AGENT_PM3_PERSISTENT, default: true)
+	IdleTimeout    time.Duration // Idle timeout before killing subprocess (NFC_AGENT_PM3_IDLE_TIMEOUT, default: 60s)
 }
 
 // Load reads configuration from environment variables with sensible defaults.
@@ -35,9 +46,34 @@ func Load() *Config {
 		cfg.Host = host
 	}
 
+	// Proxmark3 configuration
+	cfg.Proxmark3 = Proxmark3Config{
+		Enabled:        os.Getenv("NFC_AGENT_PROXMARK3") == "1",
+		Path:           os.Getenv("NFC_AGENT_PM3_PATH"),
+		Port:           os.Getenv("NFC_AGENT_PM3_PORT"),
+		PersistentMode: os.Getenv("NFC_AGENT_PM3_PERSISTENT") != "0", // Default ON
+		IdleTimeout:    parseIdleTimeout(os.Getenv("NFC_AGENT_PM3_IDLE_TIMEOUT")),
+	}
+
 	return cfg
 }
 
+// parseIdleTimeout parses the idle timeout from a string.
+// Returns 60s by default, -1 for "never" or "-1".
+func parseIdleTimeout(s string) time.Duration {
+	if s == "" {
+		return 60 * time.Second
+	}
+	if s == "-1" || s == "never" {
+		return -1 // Never timeout
+	}
+	d, err := time.ParseDuration(s)
+	if err != nil {
+		return 60 * time.Second
+	}
+	return d
+}
+
 // Address returns the formatted host:port address string.
 func (c *Config) Address() string {
 	return c.Host + ":" + strconv.Itoa(c.Port)