From patchwork Mon Apr 29 23:33:28 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Grzeschik X-Patchwork-Id: 13647857 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (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 32CE0199EA0 for ; Mon, 29 Apr 2024 23:33:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714433629; cv=none; b=NdDxZRLHX5i7yC12Pe3PHOvlMn8Szg+lgyrmuEoW1MHDItz76CpAu1nkqVqdhingbXoHkLes7EWKuz/dcKGQWy0HLDiGOsaNe4ZRUg3HnwYKcLzQpY/CKzs+e/QckZTqPGw00KJdfXat2OxZjTiZIrLdWKPfDwCuQR7fRMZqaD8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714433629; c=relaxed/simple; bh=L5KXeSk7hkGoHKgsy2k0u6Scx/cRO8oaI8swFnso1HU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=sDGlXGkROkOzFJjEVr5NK7E/IipliiYVUd+M99SURk76fvSkw/2WAWO2yv+xPwumbGpBT8pLjkN7U/e6p479cY4chH7GHYAeSLTOytTveNPmAbh9VOW5u7HRPr2Gsy0G6aHrzpjTLRnRfLfJczK1piCYZqj7isy4Ba0q6Ym3jFE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1s1aV3-0000Eu-9F; Tue, 30 Apr 2024 01:33:33 +0200 Received: from [2a0a:edc0:0:1101:1d::ac] (helo=dude04.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1s1aUy-00F42k-TS; Tue, 30 Apr 2024 01:33:28 +0200 Received: from localhost ([::1] helo=dude04.red.stw.pengutronix.de) by dude04.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1s1aUy-004m1K-1B; Tue, 30 Apr 2024 01:33:28 +0200 From: Michael Grzeschik Date: Tue, 30 Apr 2024 01:33:28 +0200 Subject: [PATCH v4 3/3] tools: usb: p9_fwd: add usb gadget packet forwarder script Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240116-ml-topic-u9p-v4-3-722ed28b0ade@pengutronix.de> References: <20240116-ml-topic-u9p-v4-0-722ed28b0ade@pengutronix.de> In-Reply-To: <20240116-ml-topic-u9p-v4-0-722ed28b0ade@pengutronix.de> To: 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, Michael Grzeschik X-Mailer: b4 0.12.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=9238; i=m.grzeschik@pengutronix.de; h=from:subject:message-id; bh=L5KXeSk7hkGoHKgsy2k0u6Scx/cRO8oaI8swFnso1HU=; b=owEBbQKS/ZANAwAKAb9pWET5cfSrAcsmYgBmMC5IzOy5QtvE9EU8qLRosOu243RGjfabVC9h2 6N5AOPIyoOJAjMEAAEKAB0WIQQV2+2Fpbqd6fvv0Gi/aVhE+XH0qwUCZjAuSAAKCRC/aVhE+XH0 q10PEACJ7Pk8MELvmIV9OzoDKwsXks8DgBMqfYPZmCROSnnQrSQDCoFerqB+kpXUeLRj3hkr51t oa99Rvursa6lfJq/v8Uzg3bzvHXojttKY/hU5DXa0LrMbhgLzDY82h2NQcSM4y+Hn/4CgZ0yRWv nqAoJtIjBZKzhBgZAHXCw8w514X2IPQqyEYB9PEFNuQNVqd2B7LRyLlcZu8E4elSIavPU0ZH54O OiQ9Q6xH9Uj1OI7aiLMVxPO1IDhdASh3icZGWnYwXHCHXSdJX63TJNJyhtcFoGEHfnKhl+34lNN XfSktj17zbGUv+uKLfvD8xvhXrZXZ1/rfJvCOzcG913tQJ3XDF/S+2gBIrwgN9c4+VKRXpzWKAQ 8EGKcVbFr65KOzKufk7ALYJQqPQwXC8zUGMCnGrA0fI9fv3oJabILx3WYHpg86DhEkv2Xggo1yu VZxco77hK7ocrOaA9oOQx5+i162OHGKVXzghhw4ZMFcQRI6sWTxpv/9+vU8ZLwks4e2MCXdlPSw 4tZKSSIXAu75DFMGRJnThX7A6l//xXE6h5c3gDQ0+ajuVa+PpxBw/28cOqc12oQEzUCAQ/7HxyQ ZeliTqS5ASAfnEUxYBOs1Y/GZNUPeVpfeXh8l/Ky0xfrwgOe45qNxDMQGmalDE1WWTcDFnEpNCM HmnMKj9am1XSXyw== X-Developer-Key: i=m.grzeschik@pengutronix.de; a=openpgp; fpr=957BC452CE953D7EA60CF4FC0BE9E3157A1E2C64 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: m.grzeschik@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-usb@vger.kernel.org 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 --- v3 -> v4: - v2 -> v3: - 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 10cf79dc287f8..2467f1ea4a150 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 is the tag associated by the usb gadget transport. It is defined by the configfs instance name. +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. + +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(" 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()