init xboard node

internal/kernel/kernel.go

@@ -0,0 +1,42 @@
+package kernel
+
+import (
+	"context"
+
+	"github.com/cedar2025/xboard-node/internal/panel"
+	"golang.org/x/time/rate"
+)
+
+// Kernel is the interface for proxy kernel backends (sing-box, xray, etc.)
+type Kernel interface {
+	// Name returns the kernel identifier (e.g. "sing-box")
+	Name() string
+	// ApplyConfig generates kernel config from panel data and (re)starts the process
+	ApplyConfig(nodeConfig *panel.NodeConfig, users []panel.User, certFile, keyFile string) error
+	// Stop gracefully stops the kernel process
+	Stop()
+	// IsRunning returns whether the kernel is currently active
+	IsRunning() bool
+	// GetConnections returns all active proxy connections
+	GetConnections(ctx context.Context) ([]Connection, error)
+	// CloseConnection terminates a specific connection by ID
+	CloseConnection(ctx context.Context, connID string) error
+	// SetSpeedLimitFunc configures optional per-user bandwidth throttling.
+	// The function resolves a user UUID to a *rate.Limiter (nil = unlimited).
+	// For sing-box, the limiter is embedded in the connection tracker wrapper
+	// so both byte counting and rate limiting happen in a single CountFunc
+	// callback, allowing splice/zero-copy paths.
+	SetSpeedLimitFunc(fn func(uuid string) *rate.Limiter)
+	// Reload hot-swaps the inbound users and routing rules without full kernel restart.
+	// Existing connections may be briefly interrupted, but routes/outbounds stay alive.
+	Reload(nodeConfig *panel.NodeConfig, users []panel.User, certFile, keyFile string) error
+}
+
+// Connection represents an active proxy connection reported by the kernel
+type Connection struct {
+	ID       string
+	UserID   int    // extracted user ID (0 if unknown)
+	Upload   int64  // cumulative upload bytes
+	Download int64  // cumulative download bytes
+	SourceIP string // client source IP (cleaned, no port/brackets)
+}