Add Snell protocol. Refactor MASQUE HTTP/2, Fair Queue. Update XHTTP, OpenVPN, Sudoku, Fallback. Fixes

transport/openvpn/push.go

@@ -10,16 +10,17 @@ import (
 const PushRequest = "PUSH_REQUEST"
 
 type PushReply struct {
-	Raw       string
-	Prefixes  []netip.Prefix
-	DNS       []netip.Addr
-	PeerID    uint32
-	Cipher    string
-	Ping      uint32
-	MTU       uint32
-	CompLZO   bool
-	Redirect  bool
-	BlockIPv6 bool
+	Raw         string
+	Prefixes    []netip.Prefix
+	DNS         []netip.Addr
+	PeerID      uint32
+	Cipher      string
+	Ping        uint32
+	PingRestart uint32
+	MTU         uint32
+	CompLZO     bool
+	Redirect    bool
+	BlockIPv6   bool
 }
 
 func ParsePushReply(message string) (*PushReply, error) {
@@ -81,6 +82,12 @@ func ParsePushReply(message string) (*PushReply, error) {
 					reply.Ping = uint32(v)
 				}
 			}
+		case "ping-restart":
+			if len(fields) >= 2 {
+				if v, err := strconv.ParseUint(fields[1], 10, 32); err == nil {
+					reply.PingRestart = uint32(v)
+				}
+			}
 		case "tun-mtu":
 			if len(fields) >= 2 {
 				if v, err := strconv.ParseUint(fields[1], 10, 32); err == nil {
@@ -113,27 +120,44 @@ func splitPushOptions(message string) []string {
 	return out
 }
 
-func parseIPv4Ifconfig(address, mask string) (netip.Prefix, error) {
+func parseIPv4Ifconfig(address, maskOrPeer string) (netip.Prefix, error) {
 	addr, err := netip.ParseAddr(address)
 	if err != nil {
 		return netip.Prefix{}, fmt.Errorf("parse pushed ipv4 address %q: %w", address, err)
 	}
-	maskAddr, err := netip.ParseAddr(mask)
+	maskAddr, err := netip.ParseAddr(maskOrPeer)
 	if err != nil {
-		return netip.Prefix{}, fmt.Errorf("parse pushed ipv4 mask %q: %w", mask, err)
+		return netip.Prefix{}, fmt.Errorf("parse pushed ipv4 mask %q: %w", maskOrPeer, err)
 	}
 	if !addr.Is4() || !maskAddr.Is4() {
 		return netip.Prefix{}, fmt.Errorf("openvpn ifconfig requires ipv4 address and mask")
 	}
-	maskBytes := maskAddr.As4()
+
+	if ones, ok := ipv4MaskSize(maskAddr); ok {
+		return netip.PrefixFrom(addr, ones), nil
+	}
+
+	// Some servers, including SoftEther/VPNGate in net30/p2p mode, push
+	// "ifconfig <local> <remote>" rather than "ifconfig <local> <netmask>".
+	// Use a host prefix for that local tunnel address.
+	return netip.PrefixFrom(addr, 32), nil
+}
+
+func ipv4MaskSize(mask netip.Addr) (int, bool) {
+	maskBytes := mask.As4()
 	ones := 0
+	seenZero := false
 	for _, b := range maskBytes {
 		for i := 7; i >= 0; i-- {
 			if b&(1<<i) == 0 {
-				return netip.PrefixFrom(addr, ones), nil
+				seenZero = true
+				continue
+			}
+			if seenZero {
+				return 0, false
 			}
 			ones++
 		}
 	}
-	return netip.PrefixFrom(addr, ones), nil
+	return ones, true
 }