Freedom: Add maxSplit fragment option; Add applyTo noises option (XTLS#4998)

Author: patterniha

infra/conf/freedom.go

@@ -27,12 +27,14 @@ type Fragment struct {
 	Packets  string      `json:"packets"`
 	Length   *Int32Range `json:"length"`
 	Interval *Int32Range `json:"interval"`
+	MaxSplit *Int32Range `json:"maxSplit"`
 }
 
 type Noise struct {
-	Type   string      `json:"type"`
-	Packet string      `json:"packet"`
-	Delay  *Int32Range `json:"delay"`
+	Type    string      `json:"type"`
+	Packet  string      `json:"packet"`
+	Delay   *Int32Range `json:"delay"`
+	ApplyTo string      `json:"applyTo"`
 }
 
 // Build implements Buildable
@@ -108,6 +110,13 @@ func (c *FreedomConfig) Build() (proto.Message, error) {
 			config.Fragment.IntervalMin = uint64(c.Fragment.Interval.From)
 			config.Fragment.IntervalMax = uint64(c.Fragment.Interval.To)
 		}
+
+		{
+			if c.Fragment.MaxSplit != nil {
+				config.Fragment.MaxSplitMin = uint64(c.Fragment.MaxSplit.From)
+				config.Fragment.MaxSplitMax = uint64(c.Fragment.MaxSplit.To)
+			}
+		}
 	}
 
 	if c.Noise != nil {
@@ -193,5 +202,15 @@ func ParseNoise(noise *Noise) (*freedom.Noise, error) {
 		NConfig.DelayMin = uint64(noise.Delay.From)
 		NConfig.DelayMax = uint64(noise.Delay.To)
 	}
+	switch strings.ToLower(noise.ApplyTo) {
+	case "", "ip", "all":
+		NConfig.ApplyTo = "ip"
+	case "ipv4":
+		NConfig.ApplyTo = "ipv4"
+	case "ipv6":
+		NConfig.ApplyTo = "ipv6"
+	default:
+		return nil, errors.New("Invalid applyTo, only ip/ipv4/ipv6 are supported")
+	}
 	return NConfig, nil
 }

proxy/freedom/config.pb.go

@@ -19,13 +19,16 @@ message Fragment {
   uint64 length_max = 4;
   uint64 interval_min = 5;
   uint64 interval_max = 6;
+  uint64 max_split_min = 7;
+  uint64 max_split_max = 8;
 }
 message Noise {
   uint64 length_min = 1;
   uint64 length_max = 2;
   uint64 delay_min = 3;
   uint64 delay_max = 4;
   bytes packet = 5;
+  string apply_to = 6;
 }
 
 message Config {