From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from madrid.collaboradmins.com (madrid.collaboradmins.com [46.235.227.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7FD896F061; Fri, 1 Mar 2024 14:26:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.235.227.194 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709303191; cv=none; b=JsBHhQAAG5/4adLGso/GvCY9C6enxVQ+90J8XUIEWqyHoIE1jG6OyERz+2onY0C+He1Eo3akQLsThRuwCHhQLVmP+Ur368NWX4xfsphudLaLZeLW2gi4IdHCM+plFUNikXNxnjrHY7B+2pTugF7+eJbKIcS1wiY2tzj0wVpeVUM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709303191; c=relaxed/simple; bh=xLLbFCitdEhU1RvTDI817HAwsCfV863rjSvWqc1GrrE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Tjw0MJXf3QzX1YMsO1pHpKoHuCSeW1nsNJ3wQa7l57POMVBrIRrxj9CYMhSBj9N2p+WVlxuMpCcLolysYEjuJMKeseAI0DMpbbCsMZK4dPvxl/TWMOjoJMEwlnx//v5CQovuDOPOUWLGNTufAXi+ocF9hi/vzBY8MU5QN/Ou1zs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=uAXwPk0s; arc=none smtp.client-ip=46.235.227.194 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="uAXwPk0s" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1709303186; bh=xLLbFCitdEhU1RvTDI817HAwsCfV863rjSvWqc1GrrE=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=uAXwPk0saTLazKJAQuPEkQzPgl1s3PhwwVTT5ddGZAev8koH47hMrAPhPdSxuaqig MNgfj54ywMgabYr+bxWA82k8m+YZiegNgvbOXmEA7LyEg4wpzAtlmSV4HXPhfPL9ur UovwRsOV8WEBSBzTn5W7dhl5hOc0xsUktzPLVI5nh7NBx8+b7D+dgte4CdZdvh3H3B b3zCpcVaOnqUEgqdLS6qa77R9BdsZKbx9g73i0xmjpOQq/ljsmkmBwdVQjiXItog9p 90KfHsbPe+v4kS4GEeE0EosemQNZHA16178Vlr73hg27RJ7EIN5gtp59X7ndChTjrw dbXmiVrAJWGoA== Received: from [100.95.196.182] (cola.collaboradmins.com [195.201.22.229]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: andrzej.p) by madrid.collaboradmins.com (Postfix) with ESMTPSA id 094ED37803EE; Fri, 1 Mar 2024 14:26:25 +0000 (UTC) Message-ID: <0d2fc837-a7b4-4d6f-9359-f2b64fe16f92@collabora.com> Date: Fri, 1 Mar 2024 15:26:24 +0100 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 4/4] tools: usb: p9_fwd: add usb gadget packet forwarder script Content-Language: en-US To: Michael Grzeschik , Eric Van Hensbergen , Latchesar Ionkov , Dominique Martinet , Christian Schoenebeck , Jonathan Corbet , Greg Kroah-Hartman Cc: v9fs@lists.linux.dev, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, kernel@pengutronix.de References: <20240116-ml-topic-u9p-v2-0-b46cbf592962@pengutronix.de> <20240116-ml-topic-u9p-v2-4-b46cbf592962@pengutronix.de> From: Andrzej Pietrasiewicz In-Reply-To: <20240116-ml-topic-u9p-v2-4-b46cbf592962@pengutronix.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi Michael, W dniu 2.02.2024 o 01:05, Michael Grzeschik pisze: > This patch is adding an small python tool to forward 9pfs requests > from the USB gadget to an existing 9pfs TCP server. Since currently all > 9pfs servers lack support for the usb transport this tool is an useful > helper to get started. > > Refer the Documentation section "USBG Example" in > Documentation/filesystems/9p.rst on how to use it. > > Signed-off-by: Michael Grzeschik > > --- > v1 -> v2: > - added usbg 9pfs detailed instructions to 9p.rst doc > --- > Documentation/filesystems/9p.rst | 32 +++++++ > tools/usb/p9_fwd.py | 194 +++++++++++++++++++++++++++++++++++++++ > 2 files changed, 226 insertions(+) > > diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst > index 64439068a8fc5..264265c72ba67 100644 > --- a/Documentation/filesystems/9p.rst > +++ b/Documentation/filesystems/9p.rst > @@ -67,6 +67,38 @@ To mount a 9p FS on a USB Host accessible via the gadget as root filesystem:: > where mount_tag is the tag associated by the usb gadget transport. The > pattern is usb9pfs0, usb9pfs1, ... > > +USBG Example > +============ > + > +The USB host exports a filesystem, while the gadget on the USB device > +side makes it mountable. > + > +Diod (9pfs server) and the forwarder are on the development host, where > +the root filesystem is actually stored. The gadget is initialized during > +boot (or later) on the embedded board. Then the forwarder will find it > +on the USB bus and start forwarding requests. > + > +In this case the 9p requests come from the device and are handled by the > +host. The reason is that USB device ports are normally not available on > +PCs, so a connection in the other direction would not work. > + > +When using the usbg transport, for now there is no native usb host > +service capable to handle the requests from the gadget driver. For > +this we have to use the extra python tool p9_fwd.py from tools/usb. > + > +Just start the 9pfs capable network server like diod/nfs-ganesha e.g.: > + > + $ diod -f -n -d 0 -S -l 0.0.0.0:9999 -e $PWD > + > +Then start the python transport: > + > + $ python $kernel_dir/tools/usb/p9_fwd.py -p 9999 > + > +After that the gadget driver can be used as described above. Hmm... The "described above" portion refers to . How do I get my if I run diod combined with p9_fwd.py? Regards, Andrzej > + > +One use-case is to use it as an alternative to NFS root booting during > +the development of embedded Linux devices. > + > Options > ======= > > diff --git a/tools/usb/p9_fwd.py b/tools/usb/p9_fwd.py > new file mode 100755 > index 0000000000000..95208df11abef > --- /dev/null > +++ b/tools/usb/p9_fwd.py > @@ -0,0 +1,194 @@ > +#!/usr/bin/env python3 > +# SPDX-License-Identifier: GPL-2.0 > + > +import argparse > +import errno > +import logging > +import socket > +import struct > +import sys > +import time > + > +import usb.core > +import usb.util > + > + > +class Forwarder: > + HEXDUMP_FILTER = ( > + "".join(chr(x).isprintable() and chr(x) or "." for x in range(128)) + "." * 128 > + ) > + > + @staticmethod > + def _log_hexdump(data): > + if not logging.root.isEnabledFor(logging.TRACE): > + return > + L = 16 > + for c in range(0, len(data), L): > + chars = data[c : c + L] > + dump = " ".join(f"{x:02x}" for x in chars) > + printable = "".join(HEXDUMP_FILTER[x] for x in chars) > + line = f"{c:08x} {dump:{L*3}s} |{printable:{L}s}|" > + logging.root.log(logging.TRACE, "%s", line) > + > + def __init__(self, server): > + self.stats = { > + "c2s packets": 0, > + "c2s bytes": 0, > + "s2c packets": 0, > + "s2c bytes": 0, > + } > + self.stats_logged = time.monotonic() > + > + dev = usb.core.find(idVendor=0x1D6B, idProduct=0x0109) > + if dev is None: > + raise ValueError("Device not found") > + > + logging.info(f"found device: {dev.bus}/{dev.address}") > + > + # dev.set_configuration() is not necessary since g_multi has only one > + usb9pfs = None > + # g_multi adds 9pfs as last interface > + cfg = dev.get_active_configuration() > + for intf in cfg: > + # we have to detach the usb-storage driver from multi gadget since > + # stall option could be set, which will lead to spontaneous port > + # resets and our transfers will run dead > + if intf.bInterfaceClass == 0x08: > + if dev.is_kernel_driver_active(intf.bInterfaceNumber): > + dev.detach_kernel_driver(intf.bInterfaceNumber) > + > + if ( > + intf.bInterfaceClass == 0xFF > + and intf.bInterfaceSubClass == 0xFF > + and intf.bInterfaceProtocol == 0x09 > + ): > + usb9pfs = intf > + if usb9pfs is None: > + raise ValueError("Interface not found") > + > + logging.info(f"claiming interface:\n{usb9pfs}") > + usb.util.claim_interface(dev, usb9pfs.bInterfaceNumber) > + ep_out = usb.util.find_descriptor( > + usb9pfs, > + custom_match=lambda e: usb.util.endpoint_direction(e.bEndpointAddress) > + == usb.util.ENDPOINT_OUT, > + ) > + assert ep_out is not None > + ep_in = usb.util.find_descriptor( > + usb9pfs, > + custom_match=lambda e: usb.util.endpoint_direction(e.bEndpointAddress) > + == usb.util.ENDPOINT_IN, > + ) > + assert ep_in is not None > + logging.info(f"interface claimed") > + > + self.ep_out = ep_out > + self.ep_in = ep_in > + self.dev = dev > + > + # create and connect socket > + self.s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) > + self.s.connect(server) > + > + logging.info(f"connected to server") > + > + def c2s(self): > + """forward a request from the USB client to the TCP server""" > + data = None > + while data is None: > + try: > + logging.log(logging.TRACE, "c2s: reading") > + data = self.ep_in.read(self.ep_in.wMaxPacketSize) > + except usb.core.USBTimeoutError: > + logging.log(logging.TRACE, "c2s: reading timed out") > + continue > + except usb.core.USBError as e: > + if e.errno == errno.EIO: > + logging.debug("c2s: reading failed with %s, retrying", repr(e)) > + time.sleep(0.5) > + continue > + else: > + logging.error("c2s: reading failed with %s, aborting", repr(e)) > + raise > + size = struct.unpack(" + while len(data) < size: > + data += self.ep_in.read(size - len(data)) > + logging.log(logging.TRACE, "c2s: writing") > + self._log_hexdump(data) > + self.s.send(data) > + logging.debug("c2s: forwarded %i bytes", size) > + self.stats["c2s packets"] += 1 > + self.stats["c2s bytes"] += size > + > + def s2c(self): > + """forward a response from the TCP server to the USB client""" > + logging.log(logging.TRACE, "s2c: reading") > + data = self.s.recv(4) > + size = struct.unpack(" + while len(data) < size: > + data += self.s.recv(size - len(data)) > + logging.log(logging.TRACE, "s2c: writing") > + self._log_hexdump(data) > + while data: > + written = self.ep_out.write(data) > + assert written > 0 > + data = data[written:] > + if size % self.ep_out.wMaxPacketSize == 0: > + logging.log(logging.TRACE, "sending zero length packet") > + self.ep_out.write(b"") > + logging.debug("s2c: forwarded %i bytes", size) > + self.stats["s2c packets"] += 1 > + self.stats["s2c bytes"] += size > + > + def log_stats(self): > + logging.info("statistics:") > + for k, v in self.stats.items(): > + logging.info(f" {k+':':14s} {v}") > + > + def log_stats_interval(self, interval=5): > + if (time.monotonic() - self.stats_logged) < interval: > + return > + > + self.log_stats() > + self.stats_logged = time.monotonic() > + > + > +def main(): > + parser = argparse.ArgumentParser( > + description="Forward 9PFS requests from USB to TCP", > + ) > + > + parser.add_argument( > + "-s", "--server", type=str, default="127.0.0.1", help="server hostname" > + ) > + parser.add_argument("-p", "--port", type=int, default=564, help="server port") > + parser.add_argument("-v", "--verbose", action="count", default=0) > + > + args = parser.parse_args() > + > + logging.TRACE = logging.DEBUG - 5 > + logging.addLevelName(logging.TRACE, "TRACE") > + > + if args.verbose >= 2: > + level = logging.TRACE > + elif args.verbose: > + level = logging.DEBUG > + else: > + level = logging.INFO > + logging.basicConfig( > + level=level, format="%(asctime)-15s %(levelname)-8s %(message)s" > + ) > + > + f = Forwarder(server=(args.server, args.port)) > + > + try: > + while True: > + f.c2s() > + f.s2c() > + f.log_stats_interval() > + finally: > + f.log_stats() > + > + > +if __name__ == "__main__": > + main() >