| #!/bin/bash |
| # Copyright 2021 Google LLC |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| |
| # List of options the script accepts. Trailing column means that the option |
| # requires an argument. |
| ARGUMENT_LIST=( |
| "help" |
| "product-id:" |
| "product-name:" |
| "host-mac:" |
| "bind-device:" |
| "dev-mac:" |
| "dev-type:" |
| "gadget-dir-name:" |
| "iface-name:" |
| ) |
| |
| print_usage() { |
| cat <<HELP |
| $0 [OPTIONS] [stop|start] |
| Create USB Gadget Configuration |
| --product-id USB Product Id for the gadget. |
| --product-name Product name string (en) for the gadget. |
| --host-mac MAC address of the host part of the connection. Optional. |
| --dev-mac MAC address of the device (gadget) part of the connection. Optional. |
| --dev-type Type of gadget to instantiate. Default: "eem" |
| --bind-device Name of the device to bind, as listed in /sys/class/udc/ |
| --gadget-dir-name Optional base name for gadget directory. Default: iface-name |
| --iface-name name of the network interface. |
| --help Print this help and exit. |
| HELP |
| } |
| |
| gadget_start() { |
| # Always provide a basic network configuration |
| mkdir -p /run/systemd/network || return |
| cat >/run/systemd/network/+-bmc-"${IFACE_NAME}".network <<EOF |
| [Match] |
| Name=${IFACE_NAME} |
| EOF |
| |
| # Add the gbmcbr configuration if this is a relevant device |
| if (( ID_VENDOR == 0x18d1 && ID_PRODUCT == 0x22b )); then |
| cat >>/run/systemd/network/+-bmc-"${IFACE_NAME}".network <<EOF |
| [Network] |
| Bridge=gbmcbr |
| [Bridge] |
| Cost=85 |
| EOF |
| fi |
| |
| # Ignore any failures due to systemd being unavailable at boot |
| networkctl reload || true |
| |
| local gadget_dir="${CONFIGFS_HOME}/usb_gadget/${GADGET_DIR_NAME}" |
| mkdir -p "${gadget_dir}" || return |
| echo "${ID_VENDOR}" >"${gadget_dir}/idVendor" || return |
| echo "${ID_PRODUCT}" >"${gadget_dir}/idProduct" || return |
| |
| local str_en_dir="${gadget_dir}/strings/0x409" |
| mkdir -p "${str_en_dir}" || return |
| echo "${STR_EN_VENDOR}" >"${str_en_dir}/manufacturer" || return |
| echo "${STR_EN_PRODUCT}" >"${str_en_dir}/product" || return |
| |
| local config_dir="${gadget_dir}/configs/c.1" |
| mkdir -p "${config_dir}" || return |
| echo 100 > "${config_dir}/MaxPower" || return |
| mkdir -p "${config_dir}/strings/0x409" || return |
| echo "${DEV_TYPE^^}" > "${config_dir}/strings/0x409/configuration" || return |
| |
| local func_dir="${gadget_dir}/functions/${DEV_TYPE}.${IFACE_NAME}" |
| mkdir -p "${func_dir}" || return |
| |
| if [[ -n $HOST_MAC_ADDR ]]; then |
| echo "${HOST_MAC_ADDR}" >"${func_dir}"/host_addr || return |
| fi |
| |
| if [[ -n $DEV_MAC_ADDR ]]; then |
| echo "${DEV_MAC_ADDR}" >"${func_dir}"/dev_addr || return |
| fi |
| |
| ln -s "${func_dir}" "${config_dir}" || return |
| |
| # This only works on kernel 5.12+, we have to ignore failures for now |
| echo "$IFACE_NAME" >"${func_dir}"/ifname || true |
| |
| echo "${BIND_DEVICE}" >"${gadget_dir}"/UDC || return |
| # Try to reconfigure a few times in case we race with systemd-networkd |
| local start=$SECONDS |
| while (( SECONDS - start < 5 )); do |
| local ifname |
| ifname="$(<"${func_dir}"/ifname)" || return |
| [ "${IFACE_NAME}" = "$ifname" ] && break |
| ip link set dev "$ifname" down && \ |
| ip link set dev "$ifname" name "${IFACE_NAME}" && break |
| sleep 1 |
| done |
| ip link set dev "$IFACE_NAME" up || return |
| } |
| |
| gadget_stop() { |
| local gadget_dir="${CONFIGFS_HOME}/usb_gadget/${GADGET_DIR_NAME}" |
| rm -f "${gadget_dir}/configs/c.1/${DEV_TYPE}.${IFACE_NAME}" |
| rmdir "${gadget_dir}/functions/${DEV_TYPE}.${IFACE_NAME}" \ |
| "${gadget_dir}/configs/c.1/strings/0x409" \ |
| "${gadget_dir}/configs/c.1" \ |
| "${gadget_dir}/strings/0x409" \ |
| "${gadget_dir}" || true |
| |
| rm -f /run/systemd/network/+-bmc-"${IFACE_NAME}".network |
| networkctl reload || true |
| } |
| |
| opts="$(getopt \ |
| --longoptions "$(printf "%s," "${ARGUMENT_LIST[@]}")" \ |
| --name "$(basename "$0")" \ |
| --options "" \ |
| -- "$@" |
| )" |
| |
| eval set -- "$opts" |
| |
| CONFIGFS_HOME=${CONFIGFS_HOME:-/sys/kernel/config} |
| ID_VENDOR="0x18d1" # Google |
| ID_PRODUCT="" |
| STR_EN_VENDOR="Google" |
| STR_EN_PRODUCT="" |
| DEV_MAC_ADDR="" |
| DEV_TYPE="eem" |
| HOST_MAC_ADDR="" |
| BIND_DEVICE="" |
| ACTION="start" |
| GADGET_DIR_NAME="" |
| IFACE_NAME="" |
| while [[ $# -gt 0 ]]; do |
| case "$1" in |
| --product-id) |
| ID_PRODUCT=$2 |
| shift 2 |
| ;; |
| --product-name) |
| STR_EN_PRODUCT=$2 |
| shift 2 |
| ;; |
| --host-mac) |
| HOST_MAC_ADDR=$2 |
| shift 2 |
| ;; |
| --dev-mac) |
| DEV_MAC_ADDR=$2 |
| shift 2 |
| ;; |
| --dev-type) |
| DEV_TYPE=$2 |
| shift 2 |
| ;; |
| --bind-device) |
| BIND_DEVICE=$2 |
| shift 2 |
| ;; |
| --gadget-dir-name) |
| GADGET_DIR_NAME=$2 |
| shift 2 |
| ;; |
| --iface-name) |
| IFACE_NAME=$2 |
| shift 2 |
| ;; |
| --help) |
| print_usage |
| exit 0 |
| ;; |
| start) |
| ACTION="start" |
| shift 1 |
| break |
| ;; |
| stop) |
| ACTION="stop" |
| shift 1 |
| break |
| ;; |
| --) |
| shift 1 |
| ;; |
| *) |
| break |
| ;; |
| esac |
| done |
| |
| if [ -z "$GADGET_DIR_NAME" ]; then |
| GADGET_DIR_NAME="$IFACE_NAME" |
| fi |
| |
| if [[ $ACTION == "stop" ]]; then |
| gadget_stop |
| else |
| if [ -z "$ID_PRODUCT" ]; then |
| echo "Product ID is missing" >&2 |
| exit 1 |
| fi |
| |
| if [ -z "$IFACE_NAME" ]; then |
| echo "Interface name is missing" >&2 |
| exit 1 |
| fi |
| |
| if [ -z "$BIND_DEVICE" ]; then |
| echo "Bind device is missing" >&2 |
| exit 1 |
| fi |
| |
| rc=0 |
| gadget_start || rc=$? |
| (( rc == 0 )) || gadget_stop || true |
| exit $rc |
| fi |