Added the feature of delayed packages

config/config.yaml

@@ -3,6 +3,20 @@ ports:
   udp: 5001
   ssh: 2222
 
+delays:
+  global:
+    min: 50    # milliseconds
+    max: 200   # milliseconds
+  per_port:
+    - port: 5000
+      min: 100
+      max: 300
+      protocols: ["tcp"]
+    - port: 5001
+      min: 75 
+      max: 150
+      protocols: ["udp"]
+
 rules_path: config/rules.yaml
 
 addresses: ["1.2.3.4", "5.4.3.2"]

delay/delay.go

@@ -0,0 +1,47 @@
+package delay
+
+import (
+	"math/rand"
+	"time"
+)
+
+type DelayRange struct {
+	Min int `yaml:"min"`
+	Max int `yaml:"max"`
+}
+
+type PortDelay struct {
+	Port      int      `yaml:"port"`
+	Min       int      `yaml:"min"`
+	Max       int      `yaml:"max"`
+	Protocols []string `yaml:"protocols"`
+}
+
+type DelayConfig struct {
+	Global  DelayRange  `yaml:"global"`
+	PerPort []PortDelay `yaml:"per_port"`
+}
+
+func NewDelayHandler(config DelayConfig) *DelayHandler {
+	return &DelayHandler{config: config}
+}
+
+type DelayHandler struct {
+	config DelayConfig
+}
+
+func (h *DelayHandler) GetDelay(port int, protocol string) time.Duration {
+	// Check port specific delay
+	for _, pd := range h.config.PerPort {
+		if pd.Port == port {
+			for _, p := range pd.Protocols {
+				if p == protocol {
+					return time.Duration(rand.Intn(pd.Max-pd.Min+1)+pd.Min) * time.Millisecond
+				}
+			}
+		}
+	}
+
+	// Fall back to global delay
+	return time.Duration(rand.Intn(h.config.Global.Max-h.config.Global.Min+1)+h.config.Global.Min) * time.Millisecond
+}

delay/delay_test.go

@@ -0,0 +1,55 @@
+package delay
+
+import (
+	"testing"
+	"time"
+)
+
+func TestDelayHandler(t *testing.T) {
+	config := DelayConfig{
+		Global: DelayRange{Min: 50, Max: 200},
+		PerPort: []PortDelay{
+			{
+				Port:      5000,
+				Min:       100,
+				Max:       300,
+				Protocols: []string{"tcp"},
+			},
+		},
+	}
+
+	handler := NewDelayHandler(config)
+
+	tests := []struct {
+		name     string
+		port     int
+		protocol string
+		minDelay time.Duration
+		maxDelay time.Duration
+	}{
+		{
+			name:     "TCP port 5000",
+			port:     5000,
+			protocol: "tcp",
+			minDelay: 100 * time.Millisecond,
+			maxDelay: 300 * time.Millisecond,
+		},
+		{
+			name:     "Global fallback",
+			port:     5001,
+			protocol: "udp",
+			minDelay: 50 * time.Millisecond,
+			maxDelay: 200 * time.Millisecond,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			delay := handler.GetDelay(tt.port, tt.protocol)
+			if delay < tt.minDelay || delay > tt.maxDelay {
+				t.Errorf("Delay %v outside expected range [%v, %v]",
+					delay, tt.minDelay, tt.maxDelay)
+			}
+		})
+	}
+}