otg service and helper

PKGBUILD

@@ -28,6 +28,7 @@ depends=(
 	python-raspberry-gpio
 	python-pyserial
 	python-setproctitle
+	python-psutil
 	python-systemd
 	python-dbus
 	python-pygments

configs/os/services/kvmd-otg.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=Pi-KVM - OTG setup
+After=systemd-modules-load.service
+Before=kvmd.service
+
+[Service]
+Type=oneshot
+ExecStart=/usr/bin/kvmd-otg start
+ExecStop=/usr/bin/kvmd-otg stop
+RemainAfterExit=true
+
+[Install]
+WantedBy=multi-user.target

kvmd/apps/__init__.py

@@ -241,6 +241,17 @@ def _get_config_scheme() -> Dict:
             },
         },
 
+        "otg": {
+            "gadget":        Option("pikvm"),
+            "vendor_id":     Option(0x1D6B, type=valid_number),  # Linux Foundation
+            "product_id":    Option(0x0104, type=valid_number),  # Multifunction Composite Gadget
+            "manufacturer":  Option("Pi-KVM"),
+            "product":       Option("Composite KVM Device"),
+            "serial_number": Option("CAFEBABE"),
+            "udc":           Option(""),
+            "acm":           Option(True, type=valid_bool),
+        },
+
         "ipmi": {
             "server": {
                 "host":    Option("::", type=valid_ip_or_host),

kvmd/apps/otg/__init__.py

@@ -0,0 +1,182 @@
+# ========================================================================== #
+#                                                                            #
+#    KVMD - The main Pi-KVM daemon.                                          #
+#                                                                            #
+#    Copyright (C) 2018  Maxim Devaev <mdevaev@gmail.com>                    #
+#                                                                            #
+#    This program is free software: you can redistribute it and/or modify    #
+#    it under the terms of the GNU General Public License as published by    #
+#    the Free Software Foundation, either version 3 of the License, or       #
+#    (at your option) any later version.                                     #
+#                                                                            #
+#    This program is distributed in the hope that it will be useful,         #
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of          #
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           #
+#    GNU General Public License for more details.                            #
+#                                                                            #
+#    You should have received a copy of the GNU General Public License       #
+#    along with this program.  If not, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+# ========================================================================== #
+
+
+from os import listdir
+from os import mkdir
+from os import makedirs
+from os import symlink
+from os import rmdir
+from os import unlink
+from os.path import join
+
+import argparse
+
+from typing import List
+from typing import Optional
+
+from ...yamlconf import Section
+
+from ...validators import ValidatorError
+
+from .. import init
+
+
+# =====
+def _write(path: str, text: str) -> None:
+    with open(path, "w") as param_file:
+        param_file.write(text)
+
+
+def _find_udc(udc: str) -> str:
+    udcs = sorted(listdir("/sys/class/udc"))
+    if not udc:
+        if len(udcs) == 0:
+            raise RuntimeError("Can't find any UDC")
+        udc = udcs[0]
+    elif udc not in udcs:
+        raise RuntimeError(f"Can't find selected UDC: {udc}")
+    return udc
+
+
+def _check_config(config: Section) -> None:
+    if (
+        not config.otg.acm
+        and config.kvmd.hid.type != "otg"
+        and config.kvmd.msd.type != "otg"
+    ):
+        raise RuntimeError("Nothing to do")
+
+
+def _cmd_start(config: Section) -> None:
+    # https://www.kernel.org/doc/Documentation/usb/gadget_configfs.txt
+    # https://www.isticktoit.net/?p=1383
+
+    _check_config(config)
+
+    udc = _find_udc(config.otg.udc)
+
+    gadget_path = join("/sys/kernel/config/usb_gadget", config.otg.gadget)
+    mkdir(gadget_path)
+
+    _write(join(gadget_path, "idVendor"), f"0x{config.otg.vendor_id:X}")
+    _write(join(gadget_path, "idProduct"), f"0x{config.otg.product_id:X}")
+    _write(join(gadget_path, "bcdDevice"), "0x0100")
+    _write(join(gadget_path, "bcdUSB"), "0x0200")
+
+    lang_path = join(gadget_path, "strings/0x409")
+    mkdir(lang_path)
+    _write(join(lang_path, "manufacturer"), config.otg.manufacturer)
+    _write(join(lang_path, "product"), config.otg.product)
+    _write(join(lang_path, "serialnumber"), config.otg.serial_number)
+
+    config_path = join(gadget_path, "configs/c.1")
+    makedirs(join(config_path, "strings/0x409"))
+    _write(join(gadget_path, "configs/c.1/strings/0x409/configuration"), "Config 1: ECM network")
+    _write(join(gadget_path, "configs/c.1/MaxPower"), "250")
+
+    if config.otg.acm:
+        func_path = join(gadget_path, "functions/acm.usb0")
+        mkdir(func_path)
+        symlink(func_path, join(config_path, "acm.usb0"))
+
+    if config.kvmd.hid.type == "otg":
+        func_path = join(gadget_path, "functions/hid.usb0")
+        mkdir(func_path)
+        _write(join(func_path, "protocol"), "1")
+        _write(join(func_path, "subclass"), "1")
+        _write(join(func_path, "report_length"), "1")
+        with open(join(func_path, "report_desc"), "wb") as report_file:
+            report_file.write(
+                b"\x05\x01\x09\x06\xa1\x01\x05\x07\x19\xe0\x29\xe7\x15\x00"
+                b"\x25\x01\x75\x01\x95\x08\x81\x02\x95\x01\x75\x08\x81\x03"
+                b"\x95\x05\x75\x01\x05\x08\x19\x01\x29\x05\x91\x02\x95\x01"
+                b"\x75\x03\x91\x03\x95\x06\x75\x08\x15\x00\x25\x65\x05\x07"
+                b"\x19\x00\x29\x65\x81\x00\xc0"
+            )
+        symlink(func_path, join(config_path, "hid.usb0"))
+
+    if config.kvmd.msd.type == "otg":
+        func_path = join(gadget_path, "functions/mass_storage.usb0")
+        mkdir(func_path)
+        _write(join(func_path, "stall"), "0")
+        _write(join(func_path, "lun.0/cdrom"), "1")
+        _write(join(func_path, "lun.0/ro"), "1")
+        _write(join(func_path, "lun.0/removable"), "1")
+        _write(join(func_path, "lun.0/nofua"), "0")
+        symlink(func_path, join(config_path, "mass_storage.usb0"))
+
+    _write(join(gadget_path, "UDC"), udc)
+
+
+def _cmd_stop(config: Section) -> None:
+    # https://www.kernel.org/doc/Documentation/usb/gadget_configfs.txt
+
+    _check_config(config)
+
+    gadget_path = join("/sys/kernel/config/usb_gadget", config.otg.gadget)
+
+    _write(join(gadget_path, "UDC"), "")
+
+    config_path = join(gadget_path, "configs/c.1")
+    for func in listdir(config_path):
+        if func.endswith(".usb0"):
+            unlink(join(config_path, func))
+    rmdir(join(config_path, "strings/0x409"))
+    rmdir(config_path)
+
+    funcs_path = join(gadget_path, "functions")
+    for func in listdir(funcs_path):
+        if func.endswith(".usb0"):
+            rmdir(join(funcs_path, func))
+
+    rmdir(join(gadget_path, "strings/0x409"))
+    rmdir(gadget_path)
+
+
+# =====
+def main(argv: Optional[List[str]]=None) -> None:
+    (parent_parser, argv, config) = init(
+        add_help=False,
+        argv=argv,
+        load_hid=True,
+        load_atx=True,
+        load_msd=True,
+    )
+    parser = argparse.ArgumentParser(
+        prog="kvmd-otg",
+        description="Control KVMD OTG device",
+        parents=[parent_parser],
+    )
+    parser.set_defaults(cmd=(lambda *_: parser.print_help()))
+    subparsers = parser.add_subparsers()
+
+    cmd_start_parser = subparsers.add_parser("start", help="Start OTG")
+    cmd_start_parser.set_defaults(cmd=_cmd_start)
+
+    cmd_stop_parser = subparsers.add_parser("stop", help="Stop OTG")
+    cmd_stop_parser.set_defaults(cmd=_cmd_stop)
+
+    options = parser.parse_args(argv[1:])
+    try:
+        options.cmd(config)
+    except ValidatorError as err:
+        raise SystemExit(str(err))

kvmd/apps/otg/__main__.py

@@ -0,0 +1,24 @@
+# ========================================================================== #
+#                                                                            #
+#    KVMD - The main Pi-KVM daemon.                                          #
+#                                                                            #
+#    Copyright (C) 2018  Maxim Devaev <mdevaev@gmail.com>                    #
+#                                                                            #
+#    This program is free software: you can redistribute it and/or modify    #
+#    it under the terms of the GNU General Public License as published by    #
+#    the Free Software Foundation, either version 3 of the License, or       #
+#    (at your option) any later version.                                     #
+#                                                                            #
+#    This program is distributed in the hope that it will be useful,         #
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of          #
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           #
+#    GNU General Public License for more details.                            #
+#                                                                            #
+#    You should have received a copy of the GNU General Public License       #
+#    along with this program.  If not, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+# ========================================================================== #
+
+
+from . import main
+main()

kvmd/apps/otgmsd/__init__.py

@@ -0,0 +1,71 @@
+#!/usr/bin/env python3
+# ========================================================================== #
+#                                                                            #
+#    KVMD - The main Pi-KVM daemon.                                          #
+#                                                                            #
+#    Copyright (C) 2018  Maxim Devaev <mdevaev@gmail.com>                    #
+#                                                                            #
+#    This program is free software: you can redistribute it and/or modify    #
+#    it under the terms of the GNU General Public License as published by    #
+#    the Free Software Foundation, either version 3 of the License, or       #
+#    (at your option) any later version.                                     #
+#                                                                            #
+#    This program is distributed in the hope that it will be useful,         #
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of          #
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           #
+#    GNU General Public License for more details.                            #
+#                                                                            #
+#    You should have received a copy of the GNU General Public License       #
+#    along with this program.  If not, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+# ========================================================================== #
+
+
+import os
+import signal
+import errno
+import argparse
+
+import psutil
+
+
+# =====
+def _set_msd_image(gadget: str, path: str) -> None:
+    lun_file_path = os.path.join("/sys/kernel/config/usb_gadget", gadget, "functions/mass_storage.usb0/lun.0/file")
+    try:
+        with open(lun_file_path, "w") as lun_file:
+            lun_file.write(path + "\n")
+    except OSError as err:
+        if err.errno == errno.EBUSY:
+            raise SystemExit(f"Can't change image because device is locked: {str(err)}")
+        raise
+
+
+def _reset_msd() -> None:
+    # https://github.com/torvalds/linux/blob/3039fadf2bfdc104dc963820c305778c7c1a6229/drivers/usb/gadget/function/f_mass_storage.c#L2924
+    found = False
+    for proc in psutil.process_iter():
+        attrs = proc.as_dict(attrs=["name", "exe", "pid"])
+        if attrs.get("name") == "file-storage" and not attrs.get("exe"):
+            try:
+                proc.send_signal(signal.SIGUSR1)
+                found = True
+            except Exception as err:
+                SystemExit(f"Can't send SIGUSR1 to MSD kernel thread with pid={attrs['pid']}: {str(err)}")
+    if not found:
+        raise SystemExit("Can't find MSD kernel thread")
+
+
+# =====
+def main() -> None:
+    parser = argparse.ArgumentParser(description="KVMD OTG MSD Helper")
+    parser.add_argument("--reset", action="store_true", help="Send SIGUSR1 to MSD kernel thread")
+    parser.add_argument("--set-image", dest="image_path", default=None, help="Change active image path")
+    parser.add_argument("--gadget", default="pikvm", help="USB gadget name")
+    options = parser.parse_args()
+
+    if options.reset:
+        _reset_msd()
+
+    if options.image_path is not None:
+        _set_msd_image(options.gadget, options.image_path)

kvmd/apps/otgmsd/__main__.py

@@ -0,0 +1,24 @@
+# ========================================================================== #
+#                                                                            #
+#    KVMD - The main Pi-KVM daemon.                                          #
+#                                                                            #
+#    Copyright (C) 2018  Maxim Devaev <mdevaev@gmail.com>                    #
+#                                                                            #
+#    This program is free software: you can redistribute it and/or modify    #
+#    it under the terms of the GNU General Public License as published by    #
+#    the Free Software Foundation, either version 3 of the License, or       #
+#    (at your option) any later version.                                     #
+#                                                                            #
+#    This program is distributed in the hope that it will be useful,         #
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of          #
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           #
+#    GNU General Public License for more details.                            #
+#                                                                            #
+#    You should have received a copy of the GNU General Public License       #
+#    along with this program.  If not, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+# ========================================================================== #
+
+
+from . import main
+main()

setup.py

@@ -86,6 +86,8 @@ def main() -> None:
             "kvmd.plugins.msd",
             "kvmd.apps",
             "kvmd.apps.kvmd",
+            "kvmd.apps.otg",
+            "kvmd.apps.otgmsd",
             "kvmd.apps.htpasswd",
             "kvmd.apps.cleanup",
             "kvmd.apps.ipmi",
@@ -104,6 +106,8 @@ def main() -> None:
         entry_points={
             "console_scripts": [
                 "kvmd = kvmd.apps.kvmd:main",
+                "kvmd-otg = kvmd.apps.otg:main",
+                "kvmd-otg-msd = kvmd.apps.otgmsd:main",
                 "kvmd-htpasswd = kvmd.apps.htpasswd:main",
                 "kvmd-cleanup = kvmd.apps.cleanup:main",
                 "kvmd-ipmi = kvmd.apps.ipmi:main",

testenv/Dockerfile

@@ -18,6 +18,7 @@ RUN pacman -Syu --noconfirm \
 		python-tox \
 		python-systemd \
 		python-dbus \
+		python-psutil \
 		python-mako \
 		nginx-mainline \
 		socat \