#!/bin/bash
apt-get install bridge-utils
rmmod g_mass_storage


# 定义USB Gadget的根目录
GADGET_ROOT="/sys/kernel/config/usb_gadget/nanopi"

# *** 重要：请根据你的实际情况修改这个值！ ***
# 你可以通过运行 'ls /sys/class/udc/' 命令来查看可用的 UDC 设备名称。
# 常见的名称有：musb-hdrc.0, musb-hdrc.4.auto, ci_hdrc.0, 20a00000.usb
UDC_DEVICE="musb-hdrc.4.auto"

# 确保脚本以root权限运行
if [ "$(id -u)" -ne 0 ]; then
    echo "This script must be run as root. Please run with 'sudo'."
    exit 1
fi

echo "--------------------------------------"
echo "Configuring USB Gadget for RNDIS Only"
echo "--------------------------------------"

# 1. 卸载并清理旧的 gadget 配置 (可选，但推荐在测试时使用以确保干净状态)
if [ -d "${GADGET_ROOT}" ]; then
    echo "Disabling existing gadget '${GADGET_ROOT##*/}'..."
    # 尝试解绑当前的 UDC (如果已经绑定)
    # 这需要先进入 gadget 目录，然后才能 echo "" > UDC
    if [ -f "${GADGET_ROOT}/UDC" ]; then
        current_udc=$(cat "${GADGET_ROOT}/UDC")
        if [ -n "$current_udc" ]; then
            echo "Unbinding ${current_udc} from previous gadget..."
            echo "" > "${GADGET_ROOT}/UDC" # 解绑 UDC
            sleep 1
        fi
    fi
    rm -rf "${GADGET_ROOT}" # 删除所有旧的配置
    echo "Old gadget configuration removed."
    sleep 1
fi

# 2. 进入 gadget 根目录并创建
echo "Creating new gadget configuration at ${GADGET_ROOT}..."
mkdir -p "${GADGET_ROOT}"
cd "${GADGET_ROOT}" || { echo "ERROR: Failed to cd to ${GADGET_ROOT}. Exiting."; exit 1; }

# 3. 设置设备描述符
echo "Setting device descriptors..."
echo 0x0955 > idVendor     # FriendlyElec's Vendor ID (or your preferred)
echo 0x7020 > idProduct    # Product ID for NanoPi-NEO-Core (or your preferred)
echo 0x0100 > bcdDevice    # Device Version 1.0 (0x0100)
echo 0x0200 > bcdUSB       # USB 2.0 (0x0200)

# RNDIS 复合设备通常使用特定的设备类/子类/协议
echo 0xEF > bDeviceClass     # Miscellaneous Device Class
echo 0x02 > bDeviceSubClass # Common Class
echo 0x01 > bDeviceProtocol # Interface Association Descriptor (IAD)

# 4. 设置字符串描述符
echo "Setting string descriptors (Manufacturer, Product, Serial)..."
mkdir -p strings/0x409 # English (0x409)

# 获取设备树中的序列号，如果没有则使用默认值
if [ -f /proc/device-tree/serial-number ]; then
    serialnumber="$(cat /proc/device-tree/serial-number|tr -d '\000')"
else
    serialnumber="1234567890ABCD" # Default serial number
fi
echo "${serialnumber}" > strings/0x409/serialnumber
echo "FriendlyElec" > strings/0x409/manufacturer
echo "NanoPi-NEO-Core" > strings/0x409/product

# 5. 创建配置 c.1
echo "Creating configuration 'c.1'..."
cfg="configs/c.1"
mkdir -p "${cfg}/strings/0x409"
echo 0x80 > "${cfg}/bmAttributes" # Self-powered
echo 250 > "${cfg}/MaxPower"     # Max power consumption (250mA)
echo "RNDIS Ethernet" > "${cfg}/strings/0x409/configuration" # Configuration description

# 6. 配置 RNDIS 功能
echo "Enabling RNDIS function (rndis.usb0)..."
func_rndis="functions/rndis.usb0"
mkdir -p "${func_rndis}"
ln -sf "${func_rndis}" "${cfg}" # Link RNDIS function to configuration c.1

# RNDIS OS Descriptors for Windows auto-detection
echo "Setting RNDIS OS Descriptors..."
echo 1 > os_desc/use
echo 0xcd > os_desc/b_vendor_code
echo MSFT100 > os_desc/qw_sign
echo "RNDIS" > "${func_rndis}/os_desc/interface.rndis/compatible_id"
echo "5162001" > "${func_rndis}/os_desc/interface.rndis/sub_compatible_id"
ln -sf "${cfg}" os_desc # Link configuration c.1 to os_desc

# 7. 绑定到 UDC 以激活 Gadget
echo "Activating USB Gadget on UDC: ${UDC_DEVICE}..."
# Check if UDC device exists in /sys/class/udc/
if [ -e "/sys/class/udc/${UDC_DEVICE}" ]; then
    echo "${UDC_DEVICE}" > UDC
    echo "USB Gadget successfully activated."
else
    echo "ERROR: UDC device '${UDC_DEVICE}' not found in /sys/class/udc/."
    echo "       Please check your UDC_DEVICE variable and 'ls /sys/class/udc/' output."
    exit 1
fi

# 8. 配置 RNDIS 网络接口
echo "Configuring RNDIS network interface (usb0)..."
NET_IP="192.168.55.1"
NET_MASK="255.255.255.0"

# 等待 usb0 接口出现
echo "Waiting for 'usb0' interface to appear..."
interface_ready=0
for i in $(seq 1 10); do # 等待最多10秒
    if ip link show usb0 &> /dev/null; then
        echo "'usb0' interface found."
        interface_ready=1
        break
    fi
    sleep 1
done

if [ "$interface_ready" -eq 0 ]; then
    echo "ERROR: 'usb0' interface did not appear after 10 seconds. RNDIS network configuration failed."
    echo "       Check kernel modules (g_ether, usb_f_rndis) and dmesg for errors."
    exit 1
fi

# 检查并安装 bridge-utils (如果需要)
if ! command -v brctl &> /dev/null; then
    echo "WARNING: 'brctl' command not found. Please install 'bridge-utils' package."
    echo "         (e.g., 'sudo apt install bridge-utils' on Debian/Ubuntu)"
    # 如果没有 brctl，尝试直接配置 usb0 接口，但不推荐
    echo "Attempting to configure 'usb0' directly (without bridge)..."
    ifconfig usb0 "${NET_IP}" netmask "${NET_MASK}" up
    echo "RNDIS network configured to ${NET_IP} on usb0 directly."
else
    # 清理旧的桥接设备 (如果存在)
    if ip link show zzbr0 &> /dev/null; then
        echo "Removing existing bridge 'zzbr0'..."
        brctl delbr zzbr0
    fi

    brctl addbr zzbr0 # 创建一个名为 zzbr0 的网络桥接
    ifconfig zzbr0 "${NET_IP}" netmask "${NET_MASK}" up # 配置桥接接口的IP地址
    brctl addif zzbr0 usb0 # 将 RNDIS 接口 usb0 添加到桥接
    ifconfig usb0 up # 确保 usb0 接口被激活

    echo "RNDIS network configured to ${NET_IP} on 'zzbr0' (bridging 'usb0')."
fi

echo "--------------------------------------"
echo "USB Gadget RNDIS setup complete."
echo "Connect your device to a PC."
echo "--------------------------------------"

exit 0