first commit

internal/usbip/vhci.go

@@ -0,0 +1,168 @@
+//go:build linux
+
+package usbip
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+const vhciBasePath = "/sys/devices/platform/vhci_hcd.0"
+
+// VHCIPort represents a virtual USB port on the VHCI controller
+type VHCIPort struct {
+	Hub       string // "hs" or "ss"
+	Port      int
+	Status    int
+	Speed     int
+	DevID     uint32
+	SocketFD  int
+	LocalBusID string
+}
+
+// VHCI status constants
+const (
+	VDevStNull        = 0x04
+	VDevStNotAssigned = 0x05
+	VDevStUsed        = 0x06
+	VDevStError       = 0x07
+)
+
+// ReadVHCIStatus reads the current VHCI port status
+func ReadVHCIStatus() ([]VHCIPort, error) {
+	// Try status file directly, then status.0, status.1, etc.
+	var allPorts []VHCIPort
+
+	paths := []string{
+		filepath.Join(vhciBasePath, "status"),
+	}
+
+	// Check for multi-controller status files
+	for i := 0; i < 16; i++ {
+		p := filepath.Join(vhciBasePath, fmt.Sprintf("status.%d", i))
+		if _, err := os.Stat(p); err == nil {
+			paths = append(paths, p)
+		} else {
+			break
+		}
+	}
+
+	for _, path := range paths {
+		ports, err := parseStatusFile(path)
+		if err != nil {
+			continue
+		}
+		allPorts = append(allPorts, ports...)
+	}
+
+	if len(allPorts) == 0 {
+		return nil, fmt.Errorf("vhci-hcd module not loaded or no ports found (check: modprobe vhci-hcd)")
+	}
+
+	return allPorts, nil
+}
+
+func parseStatusFile(path string) ([]VHCIPort, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	lines := strings.Split(strings.TrimSpace(string(data)), "\n")
+	var ports []VHCIPort
+
+	for _, line := range lines {
+		line = strings.TrimSpace(line)
+		// Skip header lines
+		if strings.HasPrefix(line, "hub") || strings.HasPrefix(line, "prt") || line == "" {
+			continue
+		}
+
+		fields := strings.Fields(line)
+		if len(fields) < 7 {
+			continue
+		}
+
+		port := VHCIPort{Hub: fields[0]}
+
+		if v, err := strconv.Atoi(fields[1]); err == nil {
+			port.Port = v
+		}
+		if v, err := strconv.Atoi(fields[2]); err == nil {
+			port.Status = v
+		}
+		if v, err := strconv.Atoi(fields[3]); err == nil {
+			port.Speed = v
+		}
+		if v, err := strconv.ParseUint(fields[4], 16, 32); err == nil {
+			port.DevID = uint32(v)
+		}
+		if v, err := strconv.Atoi(fields[5]); err == nil {
+			port.SocketFD = v
+		}
+		port.LocalBusID = fields[6]
+
+		ports = append(ports, port)
+	}
+
+	return ports, nil
+}
+
+// FindFreePort finds an available VHCI port for the given speed
+func FindFreePort(speed uint32) (int, error) {
+	ports, err := ReadVHCIStatus()
+	if err != nil {
+		return -1, err
+	}
+
+	// Determine desired hub type based on speed
+	wantHub := "hs" // high-speed and below
+	if speed >= SpeedSuper {
+		wantHub = "ss" // super-speed
+	}
+
+	for _, port := range ports {
+		if port.Status == VDevStNull && port.Hub == wantHub {
+			return port.Port, nil
+		}
+	}
+
+	return -1, fmt.Errorf("no free VHCI port available for hub type %s", wantHub)
+}
+
+// AttachDevice writes to the VHCI attach file to create a virtual USB device.
+// sockfd must be a valid TCP socket file descriptor connected to the USB/IP server.
+func AttachDevice(port int, sockfd int, devID uint32, speed uint32) error {
+	attachPath := filepath.Join(vhciBasePath, "attach")
+
+	// Format: "<port> <sockfd> <devid> <speed>"
+	data := fmt.Sprintf("%d %d %d %d", port, sockfd, devID, speed)
+
+	if err := os.WriteFile(attachPath, []byte(data), 0); err != nil {
+		return fmt.Errorf("writing to VHCI attach: %w", err)
+	}
+
+	return nil
+}
+
+// DetachDevice writes to the VHCI detach file to remove a virtual USB device
+func DetachDevice(port int) error {
+	detachPath := filepath.Join(vhciBasePath, "detach")
+
+	data := fmt.Sprintf("%d", port)
+
+	if err := os.WriteFile(detachPath, []byte(data), 0); err != nil {
+		return fmt.Errorf("writing to VHCI detach: %w", err)
+	}
+
+	return nil
+}
+
+// IsVHCIAvailable checks if the vhci-hcd kernel module is loaded
+func IsVHCIAvailable() bool {
+	_, err := os.Stat(vhciBasePath)
+	return err == nil
+}