This series is adding support to mount usb hostside exported 9pfs
filesystems via the usb gadget interface. It also includes a simple tool
(p9_fwd.py) to translate an tcp 9pfs transport and reuse it via the usb
interface.
+--------------------------+ | +--------------------------+
| 9PFS mounting client | | | 9PFS exporting server |
SW | | | | |
| (this:trans_usbg) | | |(e.g. diod or nfs-ganesha)|
+-------------^------------+ | +-------------^------------+
| | |
| | +------v------+
| | | p9_fwd.py |
| | +------^------+
| | |
------------------|------------------------------------|-------------
| | |
+-------------v------------+ | +-------------v------------+
| | | | |
HW | USB Device Controller <---------> USB Host Controller |
| | | | |
+--------------------------+ | +--------------------------+
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.
One use-case is to use it as an alternative to NFS root booting during
the development of embedded Linux devices.
Signed-off-by: Michael Grzeschik <[email protected]>
---
Changes in v2:
- improved the commit messages
- introduced an patch to move the header u_f.h to include/linux/usb to compile usb gadget functions treewide
- moved usbg gadget function to net/9p/
- adderessed several comments in function driver, like the cleanup path and kbuild errors
- improved the documentation in Documentation/filesystems/9p.rst
- Link to v1: https://lore.kernel.org/r/[email protected]
---
Michael Grzeschik (4):
usb: gadget: function: move u_f.h to include/linux/usb/
net/9p/usbg: Add new usb gadget function transport
usb: gadget: legacy: add 9pfs multi gadget
tools: usb: p9_fwd: add usb gadget packet forwarder script
Documentation/filesystems/9p.rst | 47 ++
drivers/usb/gadget/configfs.c | 2 +-
drivers/usb/gadget/function/f_fs.c | 2 +-
drivers/usb/gadget/function/f_hid.c | 2 +-
drivers/usb/gadget/function/f_loopback.c | 2 +-
drivers/usb/gadget/function/f_midi.c | 2 +-
drivers/usb/gadget/function/f_midi2.c | 2 +-
drivers/usb/gadget/function/f_sourcesink.c | 2 +-
drivers/usb/gadget/legacy/9pfs.c | 268 ++++++++
drivers/usb/gadget/legacy/Kconfig | 16 +
drivers/usb/gadget/legacy/Makefile | 2 +
drivers/usb/gadget/u_f.c | 2 +-
{drivers/usb/gadget => include/linux/usb}/u_f.h | 0
net/9p/Kconfig | 6 +
net/9p/Makefile | 4 +
net/9p/trans_usbg.c | 871 ++++++++++++++++++++++++
tools/usb/p9_fwd.py | 194 ++++++
17 files changed, 1416 insertions(+), 8 deletions(-)
---
base-commit: 41bccc98fb7931d63d03f326a746ac4d429c1dd3
change-id: 20240116-ml-topic-u9p-895274530eb1
Best regards,
--
Michael Grzeschik <[email protected]>
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 <[email protected]>
---
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.
+
+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("<I", data[:4])[0]
+ 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("<I", data[:4])[0]
+ 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()
--
2.39.2
Add the newly introduced 9pfs transport gadget interface with an new
multi composed gadget together with acm and eem.
When using this legacy module, it is also possible to
mount the 9PFS usb dir as root filesystem. Just follow the
instrucitons from Documentation/filesystems/9p.rst
Signed-off-by: Michael Grzeschik <[email protected]>
---
v1 -> v2:
- deleted the usbg 9pfs detailed instruction from commit message
- added depends on net for NET_9P dependency
---
drivers/usb/gadget/legacy/9pfs.c | 268 +++++++++++++++++++++++++++++++++++++
drivers/usb/gadget/legacy/Kconfig | 16 +++
drivers/usb/gadget/legacy/Makefile | 2 +
3 files changed, 286 insertions(+)
diff --git a/drivers/usb/gadget/legacy/9pfs.c b/drivers/usb/gadget/legacy/9pfs.c
new file mode 100644
index 0000000000000..3ac7f2e92c5a3
--- /dev/null
+++ b/drivers/usb/gadget/legacy/9pfs.c
@@ -0,0 +1,268 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * usb9pfs.c -- Gadget usb9pfs
+ *
+ * Copyright (C) 2023 Michael Grzeschik
+ */
+
+/*
+ * Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs usb
+ * transport to mount host filesystem via usb gadget. This driver will
+ * also add one ACM and NCM interface.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/usb/composite.h>
+#include <linux/netdevice.h>
+
+#include "u_eem.h"
+#include "u_ether.h"
+
+/*-------------------------------------------------------------------------*/
+USB_GADGET_COMPOSITE_OPTIONS();
+
+USB_ETHERNET_MODULE_PARAMETERS();
+
+/* Defines */
+
+#define DRIVER_VERSION_STR "v1.0"
+#define DRIVER_VERSION_NUM 0x1000
+
+#define DRIVER_DESC "Composite Gadget (9P + ACM + NCM)"
+
+/*-------------------------------------------------------------------------*/
+
+#define DRIVER_VENDOR_NUM 0x1d6b /* Linux Foundation */
+#define DRIVER_PRODUCT_NUM 0x0109 /* Linux-USB 9PFS Gadget */
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_device_descriptor device_desc = {
+ .bLength = sizeof(device_desc),
+ .bDescriptorType = USB_DT_DEVICE,
+
+ /* .bcdUSB = DYNAMIC */
+
+ .bDeviceClass = USB_CLASS_MISC,
+ .bDeviceSubClass = 2,
+ .bDeviceProtocol = 1,
+
+ /* .bMaxPacketSize0 = f(hardware) */
+
+ /* Vendor and product id can be overridden by module parameters. */
+ .idVendor = cpu_to_le16(DRIVER_VENDOR_NUM),
+ .idProduct = cpu_to_le16(DRIVER_PRODUCT_NUM),
+ /* .bcdDevice = f(hardware) */
+ /* .iManufacturer = DYNAMIC */
+ /* .iProduct = DYNAMIC */
+ /* NO SERIAL NUMBER */
+ /*.bNumConfigurations = DYNAMIC*/
+};
+
+static const struct usb_descriptor_header *otg_desc[2];
+
+static struct usb_string strings_dev[] = {
+ [USB_GADGET_MANUFACTURER_IDX].s = "",
+ [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
+ [USB_GADGET_SERIAL_IDX].s = "",
+ { } /* end of list */
+};
+
+static struct usb_gadget_strings stringtab_dev = {
+ .language = 0x0409, /* en-us */
+ .strings = strings_dev,
+};
+
+static struct usb_gadget_strings *dev_strings[] = {
+ &stringtab_dev,
+ NULL,
+};
+
+static struct usb_configuration cdc_driver_conf = {
+ .label = DRIVER_DESC,
+ .bConfigurationValue = 1,
+ /* .iConfiguration = DYNAMIC */
+ .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
+};
+
+static struct usb_function *f_9pfs;
+static struct usb_function_instance *fi_9pfs;
+
+static struct usb_function *f_acm;
+static struct usb_function_instance *fi_acm;
+
+static struct usb_function *f_eem;
+static struct usb_function_instance *fi_eem;
+
+static int cdc_do_config(struct usb_configuration *c)
+{
+ int ret;
+
+ if (gadget_is_otg(c->cdev->gadget)) {
+ c->descriptors = otg_desc;
+ c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+ }
+
+ f_9pfs = usb_get_function(fi_9pfs);
+ if (IS_ERR(f_9pfs))
+ return PTR_ERR(f_9pfs);
+
+ ret = usb_add_function(c, f_9pfs);
+ if (ret < 0)
+ goto err_func_9pfs;
+
+ f_acm = usb_get_function(fi_acm);
+ if (IS_ERR(f_acm)) {
+ ret = PTR_ERR(f_acm);
+ goto err_func_acm;
+ }
+
+ ret = usb_add_function(c, f_acm);
+ if (ret)
+ goto err_conf;
+
+ f_eem = usb_get_function(fi_eem);
+ if (IS_ERR(f_eem)) {
+ ret = PTR_ERR(f_eem);
+ goto err_eem;
+ }
+
+ ret = usb_add_function(c, f_eem);
+ if (ret)
+ goto err_run;
+
+ return 0;
+err_run:
+ usb_put_function(f_eem);
+err_eem:
+ usb_remove_function(c, f_acm);
+err_conf:
+ usb_put_function(f_acm);
+err_func_acm:
+ usb_remove_function(c, f_9pfs);
+err_func_9pfs:
+ usb_put_function(f_9pfs);
+ return ret;
+}
+
+static int usb9pfs_bind(struct usb_composite_dev *cdev)
+{
+ struct f_eem_opts *eem_opts = NULL;
+ int status;
+
+ fi_9pfs = usb_get_function_instance("usb9pfs");
+ if (IS_ERR(fi_9pfs)) {
+ if (PTR_ERR(fi_9pfs) == -ENOENT)
+ return -EPROBE_DEFER;
+ return PTR_ERR(fi_9pfs);
+ }
+
+ /* set up serial link layer */
+ fi_acm = usb_get_function_instance("acm");
+ if (IS_ERR(fi_acm)) {
+ if (PTR_ERR(fi_9pfs) == -ENOENT)
+ return -EPROBE_DEFER;
+ status = PTR_ERR(fi_acm);
+ goto err_conf_acm;
+ }
+
+ fi_eem = usb_get_function_instance("eem");
+ if (IS_ERR(fi_eem)) {
+ if (PTR_ERR(fi_9pfs) == -ENOENT)
+ return -EPROBE_DEFER;
+ status = PTR_ERR(fi_eem);
+ goto err_conf_eem;
+ }
+
+ eem_opts = container_of(fi_eem, struct f_eem_opts, func_inst);
+
+ gether_set_qmult(eem_opts->net, qmult);
+ if (!gether_set_host_addr(eem_opts->net, host_addr))
+ pr_info("using host ethernet address: %s", host_addr);
+ if (!gether_set_dev_addr(eem_opts->net, dev_addr))
+ pr_info("using self ethernet address: %s", dev_addr);
+
+ /* Allocate string descriptor numbers ... note that string
+ * contents can be overridden by the composite_dev glue.
+ */
+ status = usb_string_ids_tab(cdev, strings_dev);
+ if (status < 0)
+ return status;
+
+ device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
+ device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
+ device_desc.iSerialNumber = strings_dev[USB_GADGET_SERIAL_IDX].id;
+
+ /* support OTG systems */
+ if (gadget_is_otg(cdev->gadget)) {
+ if (!otg_desc[0]) {
+ struct usb_descriptor_header *usb_desc;
+
+ usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
+ if (!usb_desc) {
+ status = -ENOMEM;
+ goto err_conf_otg;
+ }
+ usb_otg_descriptor_init(cdev->gadget, usb_desc);
+ otg_desc[0] = usb_desc;
+ otg_desc[1] = NULL;
+ }
+ }
+
+ status = usb_add_config(cdev, &cdc_driver_conf, cdc_do_config);
+ if (status)
+ goto err_free_otg_desc;
+
+ usb_ep_autoconfig_reset(cdev->gadget);
+ usb_composite_overwrite_options(cdev, &coverwrite);
+
+ dev_info(&cdev->gadget->dev, DRIVER_DESC " version: " DRIVER_VERSION_STR "\n");
+
+ return 0;
+
+err_free_otg_desc:
+ kfree(otg_desc[0]);
+ otg_desc[0] = NULL;
+err_conf_otg:
+ usb_put_function_instance(fi_eem);
+err_conf_eem:
+ usb_put_function_instance(fi_acm);
+err_conf_acm:
+ usb_put_function_instance(fi_9pfs);
+ return status;
+}
+
+static int usb9pfs_unbind(struct usb_composite_dev *cdev)
+{
+ if (!IS_ERR_OR_NULL(f_eem))
+ usb_put_function(f_eem);
+ usb_put_function_instance(fi_eem);
+ if (!IS_ERR_OR_NULL(f_acm))
+ usb_put_function(f_acm);
+ usb_put_function_instance(fi_acm);
+ if (!IS_ERR_OR_NULL(f_9pfs))
+ usb_put_function(f_9pfs);
+ usb_put_function_instance(fi_9pfs);
+ kfree(otg_desc[0]);
+ otg_desc[0] = NULL;
+
+ return 0;
+}
+
+static struct usb_composite_driver usb9pfs_driver = {
+ .name = "usb9pfs",
+ .dev = &device_desc,
+ .strings = dev_strings,
+ .max_speed = USB_SPEED_SUPER,
+ .bind = usb9pfs_bind,
+ .unbind = usb9pfs_unbind,
+};
+
+module_usb_composite_driver(usb9pfs_driver);
+
+MODULE_AUTHOR("Michael Grzeschik");
+MODULE_LICENSE("GPL");
diff --git a/drivers/usb/gadget/legacy/Kconfig b/drivers/usb/gadget/legacy/Kconfig
index 0a7b382fbe27c..8b2aab155e0cf 100644
--- a/drivers/usb/gadget/legacy/Kconfig
+++ b/drivers/usb/gadget/legacy/Kconfig
@@ -62,6 +62,22 @@ config USB_ZERO
Say "y" to link the driver statically, or "m" to build a
dynamically linked module called "g_zero".
+config USB_9PFS
+ tristate "Gadget 9PFS"
+ depends on NET
+ select USB_LIBCOMPOSITE
+ select USB_U_SERIAL
+ select USB_U_ETHER
+ select USB_F_ACM
+ select USB_F_EEM
+ select NET_9P_USBG
+ select NET_9P
+ help
+ 9PFS Transport Layer
+
+ Say "y" to link the driver statically, or "m" to build a
+ dynamically linked module called "g_9pfs".
+
config USB_ZERO_HNPTEST
bool "HNP Test Device"
depends on USB_ZERO && USB_OTG
diff --git a/drivers/usb/gadget/legacy/Makefile b/drivers/usb/gadget/legacy/Makefile
index 4d864bf82799d..99c098800d898 100644
--- a/drivers/usb/gadget/legacy/Makefile
+++ b/drivers/usb/gadget/legacy/Makefile
@@ -8,6 +8,7 @@ ccflags-y += -I$(srctree)/drivers/usb/gadget/udc/
ccflags-y += -I$(srctree)/drivers/usb/gadget/function/
g_zero-y := zero.o
+g_9pfs-y := 9pfs.o
g_audio-y := audio.o
g_ether-y := ether.o
g_serial-y := serial.o
@@ -26,6 +27,7 @@ g_acm_ms-y := acm_ms.o
g_tcm_usb_gadget-y := tcm_usb_gadget.o
obj-$(CONFIG_USB_ZERO) += g_zero.o
+obj-$(CONFIG_USB_9PFS) += g_9pfs.o
obj-$(CONFIG_USB_AUDIO) += g_audio.o
obj-$(CONFIG_USB_ETH) += g_ether.o
obj-$(CONFIG_USB_GADGETFS) += gadgetfs.o
--
2.39.2
Add the new gadget function for 9pfs transport. This function is
defining an simple 9pfs transport interface that consists of one in and
one out endpoint. The endpoints transmit and receive the 9pfs protocol
payload when mounting a 9p filesystem over usb.
Signed-off-by: Michael Grzeschik <[email protected]>
---
v1 -> v2:
- move the driver to net/9p/trans_usbg.c
- fixed the commit title
- fix %zu usage in p9_debug for size_t type
- define functions static that are only used localy
- return 0 in alloc_requests
- use id_alloc_max instead of ida_simple_get
- call ida_free in usb9pfs_free_func
- call kfree for usb9pfs->tag and usb9pfs in usb9pfs_free_func
- add MODULE_ALIAS_9P to load this module automatic when mounting
- improved the documentation
- added depends on USB_GADGET in Kconfig
---
Documentation/filesystems/9p.rst | 15 +
net/9p/Kconfig | 6 +
net/9p/Makefile | 4 +
net/9p/trans_usbg.c | 871 +++++++++++++++++++++++++++++++++++++++
4 files changed, 896 insertions(+)
diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst
index 1e0e0bb6fdf91..64439068a8fc5 100644
--- a/Documentation/filesystems/9p.rst
+++ b/Documentation/filesystems/9p.rst
@@ -53,6 +53,20 @@ mount points. Each 9P export is seen by the client as a virtio device with an
associated "mount_tag" property. Available mount tags can be
seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
+USBG Usage
+==========
+
+To mount a 9p FS on a USB Host accessible via the gadget at runtime::
+
+ mount -t 9p -o trans=usbg,aname=/path/to/fs <mount_tag> /mnt/9
+
+To mount a 9p FS on a USB Host accessible via the gadget as root filesystem::
+
+ root=<mount_tag> rootfstype=9p rootflags=trans=usbg,cache=loose,uname=root,access=0,dfltuid=0,dfltgid=0,aname=/path/to/rootfs
+
+where mount_tag is the tag associated by the usb gadget transport. The
+pattern is usb9pfs0, usb9pfs1, ...
+
Options
=======
@@ -68,6 +82,7 @@ Options
virtio connect to the next virtio channel available
(from QEMU with trans_virtio module)
rdma connect to a specified RDMA channel
+ usbg connect to a specified usb gadget channel
======== ============================================
uname=name user name to attempt mount as on the remote server. The
diff --git a/net/9p/Kconfig b/net/9p/Kconfig
index 00ebce9e5a657..c3d357eb8bb37 100644
--- a/net/9p/Kconfig
+++ b/net/9p/Kconfig
@@ -39,6 +39,12 @@ config NET_9P_XEN
This builds support for a transport for 9pfs between
two Xen domains.
+config NET_9P_USBG
+ bool "9P USB Gadget Transport"
+ depends on USB_GADGET
+ help
+ This builds support for a transport for 9pfs over
+ usb gadget.
config NET_9P_RDMA
depends on INET && INFINIBAND && INFINIBAND_ADDR_TRANS
diff --git a/net/9p/Makefile b/net/9p/Makefile
index 1df9b344c30bd..22794a451c3f7 100644
--- a/net/9p/Makefile
+++ b/net/9p/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
obj-$(CONFIG_NET_9P_XEN) += 9pnet_xen.o
obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o
obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
+obj-$(CONFIG_NET_9P_USBG) += 9pnet_usbg.o
9pnet-objs := \
mod.o \
@@ -23,3 +24,6 @@ obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
9pnet_rdma-objs := \
trans_rdma.o \
+
+9pnet_usbg-objs := \
+ trans_usbg.o \
diff --git a/net/9p/trans_usbg.c b/net/9p/trans_usbg.c
new file mode 100644
index 0000000000000..93d9606a806d8
--- /dev/null
+++ b/net/9p/trans_usbg.c
@@ -0,0 +1,871 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * trans_usbg.c - USB peripheral usb9pfs configuration driver and transport.
+ *
+ * Copyright (C) 2024 Michael Grzeschik <[email protected]>
+ */
+
+/* Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs
+ * transport to mount host exported filesystem via usb gadget.
+ */
+
+/* +--------------------------+ | +--------------------------+
+ * | 9PFS mounting client | | | 9PFS exporting server |
+ * SW | | | | |
+ * | (this:trans_usbg) | | |(e.g. diod or nfs-ganesha)|
+ * +-------------^------------+ | +-------------^------------+
+ * | | |
+ * ------------------|------------------------------------|-------------
+ * | | |
+ * +-------------v------------+ | +-------------v------------+
+ * | | | | |
+ * HW | USB Device Controller <---------> USB Host Controller |
+ * | | | | |
+ * +--------------------------+ | +--------------------------+
+ */
+
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/usb/composite.h>
+#include <linux/usb/u_f.h>
+
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+#include <net/9p/transport.h>
+
+#define DEFAULT_BUFLEN 16384
+
+struct f_usb9pfs {
+ struct p9_client *client;
+
+ struct p9_req_t *p9_tx_req;
+
+ struct list_head tx_req_list;
+
+ /* 9p request lock for en/dequeue */
+ spinlock_t lock;
+ /* usb request lock for en/dequeue */
+ spinlock_t req_lock;
+
+ struct usb_request *in_req;
+ struct usb_request *out_req;
+
+ struct usb_ep *in_ep;
+ struct usb_ep *out_ep;
+
+ unsigned int buflen;
+
+ bool inuse;
+ char *tag;
+
+ int index;
+
+ struct usb_function function;
+
+ struct list_head function_list;
+};
+
+static inline struct f_usb9pfs *func_to_usb9pfs(struct usb_function *f)
+{
+ return container_of(f, struct f_usb9pfs, function);
+}
+
+struct f_usb9pfs_opts {
+ struct usb_function_instance func_inst;
+ unsigned int buflen;
+
+ /* Read/write access to configfs attributes is handled by configfs.
+ *
+ * This is to protect the data from concurrent access by read/write
+ * and create symlink/remove symlink.
+ */
+ struct mutex lock;
+ int refcnt;
+};
+
+static DEFINE_IDA(usb9pfs_ida);
+static DEFINE_MUTEX(usb9pfs_ida_lock); /* protects access do usb9pfs_ida */
+
+static DEFINE_MUTEX(usb9pfs_lock);
+static struct list_head usbg_function_list;
+
+static int usb9pfs_tx_fill(struct f_usb9pfs *usb9pfs, struct usb_request *req,
+ gfp_t gfp_flags)
+{
+ struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
+ int retval = -ENOMEM;
+
+ if (!(usb9pfs->p9_tx_req->tc.size % usb9pfs->in_ep->maxpacket))
+ req->zero = 1;
+
+ req->buf = usb9pfs->p9_tx_req->tc.sdata;
+ req->length = usb9pfs->p9_tx_req->tc.size;
+
+ dev_dbg(&cdev->gadget->dev, "%s usb9pfs send --> %d/%d, zero: %d\n",
+ usb9pfs->in_ep->name, req->actual, req->length, req->zero);
+
+ retval = usb_ep_queue(usb9pfs->in_ep, req, gfp_flags);
+
+ dev_dbg(&cdev->gadget->dev, "tx submit --> %d\n", retval);
+
+ return retval;
+}
+
+static int usb9pfs_rx_fill(struct f_usb9pfs *usb9pfs, struct usb_request *req,
+ gfp_t gfp_flags)
+{
+ struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
+ int retval = -ENOMEM;
+
+ retval = usb_ep_queue(usb9pfs->out_ep, req, gfp_flags);
+
+ dev_dbg(&cdev->gadget->dev, "rx submit --> %d\n", retval);
+
+ return retval;
+}
+
+static int usb9pfs_transmit(struct f_usb9pfs *usb9pfs)
+{
+ struct p9_req_t *p9_req = NULL;
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(&usb9pfs->lock, flags);
+
+ if (usb9pfs->p9_tx_req) {
+ spin_unlock_irqrestore(&usb9pfs->lock, flags);
+ return -EBUSY;
+ }
+
+ p9_req = list_first_entry_or_null(&usb9pfs->tx_req_list, struct p9_req_t, req_list);
+ if (!p9_req) {
+ spin_unlock_irqrestore(&usb9pfs->lock, flags);
+ return -ENOENT;
+ }
+
+ list_del(&p9_req->req_list);
+
+ usb9pfs->p9_tx_req = p9_req;
+
+ p9_req_get(usb9pfs->p9_tx_req);
+
+ usb9pfs_tx_fill(usb9pfs, usb9pfs->in_req, GFP_ATOMIC);
+
+ spin_unlock_irqrestore(&usb9pfs->lock, flags);
+
+ return ret;
+}
+
+static void usb9pfs_tx_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct f_usb9pfs *usb9pfs = ep->driver_data;
+ struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
+
+ /* reset zero packages */
+ req->zero = 0;
+
+ dev_dbg(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
+ ep->name, req->status, req->actual, req->length);
+
+ switch (req->status) {
+ case 0: /* normal completion? */
+ spin_lock(&usb9pfs->req_lock);
+
+ WRITE_ONCE(usb9pfs->p9_tx_req->status, REQ_STATUS_SENT);
+
+ p9_req_put(usb9pfs->client, usb9pfs->p9_tx_req);
+
+ usb9pfs_rx_fill(usb9pfs, usb9pfs->out_req, GFP_ATOMIC);
+
+ spin_unlock(&usb9pfs->req_lock);
+
+ break;
+
+ default:
+ dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
+ ep->name, req->status, req->actual, req->length);
+ usb_ep_free_request(ep == usb9pfs->in_ep ?
+ usb9pfs->out_ep : usb9pfs->in_ep,
+ req->context);
+ free_ep_req(ep, req);
+ return;
+ }
+}
+
+static struct p9_req_t *usb9pfs_rx_header(struct f_usb9pfs *usb9pfs,
+ struct usb_request *req)
+{
+ struct p9_req_t *p9_rx_req;
+ struct p9_fcall rc;
+ int ret;
+
+ /* start by reading header */
+ rc.sdata = req->buf;
+ rc.offset = 0;
+ rc.capacity = P9_HDRSZ;
+ rc.size = P9_HDRSZ;
+
+ p9_debug(P9_DEBUG_TRANS, "mux %p got %zu bytes\n", usb9pfs,
+ rc.capacity - rc.offset);
+
+ ret = p9_parse_header(&rc, &rc.size, NULL, NULL, 0);
+ if (ret) {
+ p9_debug(P9_DEBUG_ERROR,
+ "error parsing header: %d\n", ret);
+ return NULL;
+ }
+
+ p9_debug(P9_DEBUG_TRANS,
+ "mux %p pkt: size: %d bytes tag: %d\n",
+ usb9pfs, rc.size, rc.tag);
+
+ p9_rx_req = p9_tag_lookup(usb9pfs->client, rc.tag);
+ if (!p9_rx_req || p9_rx_req->status != REQ_STATUS_SENT) {
+ p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", rc.tag);
+ return NULL;
+ }
+
+ if (rc.size > p9_rx_req->rc.capacity) {
+ p9_debug(P9_DEBUG_ERROR,
+ "requested packet size too big: %d for tag %d with capacity %zd\n",
+ rc.size, rc.tag, p9_rx_req->rc.capacity);
+ return NULL;
+ }
+
+ if (!p9_rx_req->rc.sdata) {
+ p9_debug(P9_DEBUG_ERROR,
+ "No recv fcall for tag %d (req %p), disconnecting!\n",
+ rc.tag, p9_rx_req);
+ p9_req_put(usb9pfs->client, p9_rx_req);
+ return NULL;
+ }
+
+ return p9_rx_req;
+}
+
+static void usb9pfs_rx_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct f_usb9pfs *usb9pfs = ep->driver_data;
+ struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
+ struct p9_req_t *p9_rx_req;
+ unsigned long flags;
+
+ switch (req->status) {
+ case 0: /* normal completion? */
+ spin_lock_irqsave(&usb9pfs->req_lock, flags);
+ p9_rx_req = usb9pfs_rx_header(usb9pfs, req);
+ if (!p9_rx_req) {
+ spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
+ goto free_req;
+ }
+
+ memcpy(p9_rx_req->rc.sdata, req->buf, req->actual);
+ p9_rx_req->rc.size = req->actual;
+
+ p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_RCVD);
+ p9_req_put(usb9pfs->client, p9_rx_req);
+
+ usb9pfs->p9_tx_req = NULL;
+
+ usb9pfs_transmit(usb9pfs);
+
+ spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
+
+ return;
+free_req:
+ default:
+ dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
+ ep->name, req->status, req->actual, req->length);
+ usb_ep_free_request(ep == usb9pfs->in_ep ?
+ usb9pfs->out_ep : usb9pfs->in_ep,
+ req->context);
+ free_ep_req(ep, req);
+ return;
+ }
+
+ p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_ERROR);
+}
+
+static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
+{
+ int value;
+
+ value = usb_ep_disable(ep);
+ if (value < 0)
+ dev_info(&cdev->gadget->dev, "disable %s --> %d\n", ep->name, value);
+}
+
+static void disable_endpoints(struct usb_composite_dev *cdev,
+ struct usb_ep *in, struct usb_ep *out,
+ struct usb_ep *iso_in, struct usb_ep *iso_out)
+{
+ disable_ep(cdev, in);
+ disable_ep(cdev, out);
+}
+
+static void disable_usb9pfs(struct f_usb9pfs *usb9pfs)
+{
+ struct usb_composite_dev *cdev;
+
+ cdev = usb9pfs->function.config->cdev;
+ disable_endpoints(cdev, usb9pfs->in_ep, usb9pfs->out_ep, NULL, NULL);
+ dev_dbg(&cdev->gadget->dev, "%s disabled\n", usb9pfs->function.name);
+}
+
+static inline struct usb_request *usb9pfs_alloc_ep_req(struct usb_ep *ep, int len)
+{
+ return alloc_ep_req(ep, len);
+}
+
+static int alloc_requests(struct usb_composite_dev *cdev,
+ struct f_usb9pfs *usb9pfs)
+{
+ usb9pfs->in_req = usb_ep_alloc_request(usb9pfs->in_ep, GFP_ATOMIC);
+ if (!usb9pfs->in_req)
+ goto fail;
+
+ usb9pfs->out_req = usb9pfs_alloc_ep_req(usb9pfs->out_ep, usb9pfs->buflen);
+ if (!usb9pfs->out_req)
+ goto fail_in;
+
+ usb9pfs->in_req->complete = usb9pfs_tx_complete;
+ usb9pfs->out_req->complete = usb9pfs_rx_complete;
+
+ /* length will be set in complete routine */
+ usb9pfs->in_req->context = usb9pfs;
+ usb9pfs->out_req->context = usb9pfs;
+
+ return 0;
+
+fail_in:
+ usb_ep_free_request(usb9pfs->in_ep, usb9pfs->in_req);
+fail:
+ return 0;
+}
+
+static int enable_endpoint(struct usb_composite_dev *cdev,
+ struct f_usb9pfs *usb9pfs, struct usb_ep *ep)
+{
+ int result;
+
+ result = config_ep_by_speed(cdev->gadget, &usb9pfs->function, ep);
+ if (result)
+ goto out;
+
+ result = usb_ep_enable(ep);
+ if (result < 0)
+ goto out;
+
+ ep->driver_data = usb9pfs;
+
+ result = 0;
+
+out:
+ return result;
+}
+
+static int
+enable_usb9pfs(struct usb_composite_dev *cdev, struct f_usb9pfs *usb9pfs)
+{
+ int result = 0;
+
+ result = enable_endpoint(cdev, usb9pfs, usb9pfs->in_ep);
+ if (result)
+ goto out;
+
+ result = enable_endpoint(cdev, usb9pfs, usb9pfs->out_ep);
+ if (result)
+ goto disable_in;
+
+ result = alloc_requests(cdev, usb9pfs);
+ if (result)
+ goto disable_out;
+
+ dev_dbg(&cdev->gadget->dev, "%s enabled\n", usb9pfs->function.name);
+ return 0;
+
+disable_out:
+ usb_ep_disable(usb9pfs->out_ep);
+disable_in:
+ usb_ep_disable(usb9pfs->in_ep);
+out:
+ return result;
+}
+
+static int p9_usbg_create(struct p9_client *client, const char *devname, char *args)
+{
+ struct usb_composite_dev *cdev;
+ struct f_usb9pfs *usb9pfs;
+ struct f_usb9pfs *tmp;
+ struct usb_function *f;
+ int ret = -ENOENT;
+ int found = 0;
+
+ if (!devname)
+ return -EINVAL;
+
+ mutex_lock(&usb9pfs_lock);
+ list_for_each_entry_safe(usb9pfs, tmp, &usbg_function_list, function_list) {
+ if (!usb9pfs->tag)
+ continue;
+ if (!strncmp(devname, usb9pfs->tag, strlen(devname))) {
+ if (!usb9pfs->inuse) {
+ usb9pfs->inuse = true;
+ found = 1;
+ break;
+ }
+ ret = -EBUSY;
+ break;
+ }
+ }
+ mutex_unlock(&usb9pfs_lock);
+
+ if (!found) {
+ pr_err("no channels available for device %s\n", devname);
+ return ret;
+ }
+
+ INIT_LIST_HEAD(&usb9pfs->tx_req_list);
+
+ spin_lock_init(&usb9pfs->lock);
+ spin_lock_init(&usb9pfs->req_lock);
+
+ f = &usb9pfs->function;
+ cdev = f->config->cdev;
+
+ client->trans = (void *)usb9pfs;
+ client->status = Connected;
+ usb9pfs->client = client;
+
+ client->trans_mod->maxsize = usb9pfs->buflen;
+
+ disable_usb9pfs(usb9pfs);
+
+ return enable_usb9pfs(cdev, usb9pfs);
+}
+
+static void p9_usbg_close(struct p9_client *client)
+{
+ struct f_usb9pfs *usb9pfs = client->trans;
+
+ disable_usb9pfs(usb9pfs);
+}
+
+static int p9_usbg_request(struct p9_client *client, struct p9_req_t *p9_req)
+{
+ struct f_usb9pfs *usb9pfs = client->trans;
+ unsigned long flags;
+
+ spin_lock_irqsave(&usb9pfs->lock, flags);
+ list_add_tail(&p9_req->req_list, &usb9pfs->tx_req_list);
+ spin_unlock_irqrestore(&usb9pfs->lock, flags);
+
+ spin_lock_irqsave(&usb9pfs->req_lock, flags);
+ usb9pfs_transmit(usb9pfs);
+ spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
+
+ return 0;
+}
+
+/* We don't currently allow canceling of requests */
+static int p9_usbg_cancel(struct p9_client *client, struct p9_req_t *req)
+{
+ return 1;
+}
+
+static struct p9_trans_module p9_usbg_trans = {
+ .name = "usbg",
+ .create = p9_usbg_create,
+ .close = p9_usbg_close,
+ .request = p9_usbg_request,
+ .cancel = p9_usbg_cancel,
+ .owner = THIS_MODULE,
+};
+
+/*-------------------------------------------------------------------------*/
+
+#define USB_PROTOCOL_9PFS 0x09
+
+static struct usb_interface_descriptor usb9pfs_intf = {
+ .bLength = sizeof(usb9pfs_intf),
+ .bDescriptorType = USB_DT_INTERFACE,
+
+ .bNumEndpoints = 2,
+ .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
+ .bInterfaceSubClass = USB_SUBCLASS_VENDOR_SPEC,
+ .bInterfaceProtocol = USB_PROTOCOL_9PFS,
+
+ /* .iInterface = DYNAMIC */
+};
+
+/* full speed support: */
+
+static struct usb_endpoint_descriptor fs_usb9pfs_source_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor fs_usb9pfs_sink_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_descriptor_header *fs_usb9pfs_descs[] = {
+ (struct usb_descriptor_header *)&usb9pfs_intf,
+ (struct usb_descriptor_header *)&fs_usb9pfs_sink_desc,
+ (struct usb_descriptor_header *)&fs_usb9pfs_source_desc,
+ NULL,
+};
+
+/* high speed support: */
+
+static struct usb_endpoint_descriptor hs_usb9pfs_source_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor hs_usb9pfs_sink_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *hs_usb9pfs_descs[] = {
+ (struct usb_descriptor_header *)&usb9pfs_intf,
+ (struct usb_descriptor_header *)&hs_usb9pfs_source_desc,
+ (struct usb_descriptor_header *)&hs_usb9pfs_sink_desc,
+ NULL,
+};
+
+/* super speed support: */
+
+static struct usb_endpoint_descriptor ss_usb9pfs_source_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor ss_usb9pfs_source_comp_desc = {
+ .bLength = USB_DT_SS_EP_COMP_SIZE,
+ .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+ .bMaxBurst = 0,
+ .bmAttributes = 0,
+ .wBytesPerInterval = 0,
+};
+
+static struct usb_endpoint_descriptor ss_usb9pfs_sink_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor ss_usb9pfs_sink_comp_desc = {
+ .bLength = USB_DT_SS_EP_COMP_SIZE,
+ .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+ .bMaxBurst = 0,
+ .bmAttributes = 0,
+ .wBytesPerInterval = 0,
+};
+
+static struct usb_descriptor_header *ss_usb9pfs_descs[] = {
+ (struct usb_descriptor_header *)&usb9pfs_intf,
+ (struct usb_descriptor_header *)&ss_usb9pfs_source_desc,
+ (struct usb_descriptor_header *)&ss_usb9pfs_source_comp_desc,
+ (struct usb_descriptor_header *)&ss_usb9pfs_sink_desc,
+ (struct usb_descriptor_header *)&ss_usb9pfs_sink_comp_desc,
+ NULL,
+};
+
+/* function-specific strings: */
+static struct usb_string strings_usb9pfs[] = {
+ [0].s = "usb9pfs input to output",
+ { } /* end of list */
+};
+
+static struct usb_gadget_strings stringtab_usb9pfs = {
+ .language = 0x0409, /* en-us */
+ .strings = strings_usb9pfs,
+};
+
+static struct usb_gadget_strings *usb9pfs_strings[] = {
+ &stringtab_usb9pfs,
+ NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int usb9pfs_func_bind(struct usb_configuration *c,
+ struct usb_function *f)
+{
+ struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
+ struct usb_composite_dev *cdev = c->cdev;
+ int ret;
+ int id;
+
+ /* allocate interface ID(s) */
+ id = usb_interface_id(c, f);
+ if (id < 0)
+ return id;
+ usb9pfs_intf.bInterfaceNumber = id;
+
+ id = usb_string_id(cdev);
+ if (id < 0)
+ return id;
+ strings_usb9pfs[0].id = id;
+ usb9pfs_intf.iInterface = id;
+
+ /* allocate endpoints */
+ usb9pfs->in_ep = usb_ep_autoconfig(cdev->gadget,
+ &fs_usb9pfs_source_desc);
+ if (!usb9pfs->in_ep)
+ goto autoconf_fail;
+
+ usb9pfs->out_ep = usb_ep_autoconfig(cdev->gadget,
+ &fs_usb9pfs_sink_desc);
+ if (!usb9pfs->out_ep)
+ goto autoconf_fail;
+
+ /* support high speed hardware */
+ hs_usb9pfs_source_desc.bEndpointAddress =
+ fs_usb9pfs_source_desc.bEndpointAddress;
+ hs_usb9pfs_sink_desc.bEndpointAddress = fs_usb9pfs_sink_desc.bEndpointAddress;
+
+ /* support super speed hardware */
+ ss_usb9pfs_source_desc.bEndpointAddress =
+ fs_usb9pfs_source_desc.bEndpointAddress;
+ ss_usb9pfs_sink_desc.bEndpointAddress = fs_usb9pfs_sink_desc.bEndpointAddress;
+
+ ret = usb_assign_descriptors(f, fs_usb9pfs_descs, hs_usb9pfs_descs,
+ ss_usb9pfs_descs, ss_usb9pfs_descs);
+ if (ret)
+ return ret;
+
+ dev_dbg(&cdev->gadget->dev, "%s speed %s: IN/%s, OUT/%s\n",
+ (gadget_is_superspeed(c->cdev->gadget) ? "super" :
+ (gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full")),
+ f->name, usb9pfs->in_ep->name, usb9pfs->out_ep->name);
+ return 0;
+
+autoconf_fail:
+ ERROR(cdev, "%s: can't autoconfigure on %s\n",
+ f->name, cdev->gadget->name);
+ return -ENODEV;
+}
+
+static void usb9pfs_free_func(struct usb_function *f)
+{
+ struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
+ struct f_usb9pfs_opts *opts;
+
+ ida_free(&usb9pfs_ida, usb9pfs->index);
+ kfree(usb9pfs->tag);
+ kfree(usb9pfs);
+
+ opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst);
+
+ mutex_lock(&opts->lock);
+ opts->refcnt--;
+ mutex_unlock(&opts->lock);
+
+ usb_free_all_descriptors(f);
+}
+
+static int usb9pfs_set_alt(struct usb_function *f,
+ unsigned int intf, unsigned int alt)
+{
+ return 0;
+}
+
+static void usb9pfs_disable(struct usb_function *f)
+{
+}
+
+static struct usb_function *usb9pfs_alloc(struct usb_function_instance *fi)
+{
+ struct f_usb9pfs_opts *usb9pfs_opts;
+ struct f_usb9pfs *usb9pfs;
+
+ usb9pfs = kzalloc(sizeof(*usb9pfs), GFP_KERNEL);
+ if (!usb9pfs)
+ return ERR_PTR(-ENOMEM);
+
+ usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst);
+
+ mutex_lock(&usb9pfs_opts->lock);
+ usb9pfs_opts->refcnt++;
+ mutex_unlock(&usb9pfs_opts->lock);
+
+ usb9pfs->buflen = usb9pfs_opts->buflen;
+
+ usb9pfs->function.name = "usb9pfs";
+ usb9pfs->function.bind = usb9pfs_func_bind;
+ usb9pfs->function.set_alt = usb9pfs_set_alt;
+ usb9pfs->function.disable = usb9pfs_disable;
+ usb9pfs->function.strings = usb9pfs_strings;
+
+ usb9pfs->function.free_func = usb9pfs_free_func;
+
+ mutex_lock(&usb9pfs_ida_lock);
+
+ usb9pfs->index = ida_alloc_max(&usb9pfs_ida, U8_MAX, GFP_KERNEL);
+ if (usb9pfs->index < 0) {
+ struct usb_function *ret = ERR_PTR(usb9pfs->index);
+
+ kfree(usb9pfs);
+ mutex_unlock(&usb9pfs_ida_lock);
+ return ret;
+ }
+
+ mutex_unlock(&usb9pfs_ida_lock);
+
+ usb9pfs->tag = kasprintf(GFP_KERNEL, "%s%d", usb9pfs->function.name,
+ usb9pfs->index);
+
+ INIT_LIST_HEAD(&usb9pfs->function_list);
+
+ mutex_lock(&usb9pfs_lock);
+ list_add_tail(&usb9pfs->function_list, &usbg_function_list);
+ mutex_unlock(&usb9pfs_lock);
+
+ return &usb9pfs->function;
+}
+
+static inline struct f_usb9pfs_opts *to_f_usb9pfs_opts(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct f_usb9pfs_opts,
+ func_inst.group);
+}
+
+static void usb9pfs_attr_release(struct config_item *item)
+{
+ struct f_usb9pfs_opts *usb9pfs_opts = to_f_usb9pfs_opts(item);
+
+ usb_put_function_instance(&usb9pfs_opts->func_inst);
+}
+
+static struct configfs_item_operations usb9pfs_item_ops = {
+ .release = usb9pfs_attr_release,
+};
+
+static ssize_t f_usb9pfs_opts_buflen_show(struct config_item *item, char *page)
+{
+ struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item);
+ int result;
+
+ mutex_lock(&opts->lock);
+ result = sprintf(page, "%d\n", opts->buflen);
+ mutex_unlock(&opts->lock);
+
+ return result;
+}
+
+static ssize_t f_usb9pfs_opts_buflen_store(struct config_item *item,
+ const char *page, size_t len)
+{
+ struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item);
+ int ret;
+ u32 num;
+
+ mutex_lock(&opts->lock);
+ if (opts->refcnt) {
+ ret = -EBUSY;
+ goto end;
+ }
+
+ ret = kstrtou32(page, 0, &num);
+ if (ret)
+ goto end;
+
+ opts->buflen = num;
+ ret = len;
+end:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+CONFIGFS_ATTR(f_usb9pfs_opts_, buflen);
+
+static struct configfs_attribute *usb9pfs_attrs[] = {
+ &f_usb9pfs_opts_attr_buflen,
+ NULL,
+};
+
+static const struct config_item_type usb9pfs_func_type = {
+ .ct_item_ops = &usb9pfs_item_ops,
+ .ct_attrs = usb9pfs_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static void usb9pfs_free_instance(struct usb_function_instance *fi)
+{
+ struct f_usb9pfs_opts *usb9pfs_opts;
+
+ usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst);
+ kfree(usb9pfs_opts);
+}
+
+static struct usb_function_instance *usb9pfs_alloc_instance(void)
+{
+ struct f_usb9pfs_opts *usb9pfs_opts;
+
+ usb9pfs_opts = kzalloc(sizeof(*usb9pfs_opts), GFP_KERNEL);
+ if (!usb9pfs_opts)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_init(&usb9pfs_opts->lock);
+
+ usb9pfs_opts->func_inst.free_func_inst = usb9pfs_free_instance;
+
+ usb9pfs_opts->buflen = DEFAULT_BUFLEN;
+
+ config_group_init_type_name(&usb9pfs_opts->func_inst.group, "",
+ &usb9pfs_func_type);
+
+ return &usb9pfs_opts->func_inst;
+}
+DECLARE_USB_FUNCTION(usb9pfs, usb9pfs_alloc_instance, usb9pfs_alloc);
+
+static int __init usb9pfs_modinit(void)
+{
+ int ret;
+
+ INIT_LIST_HEAD(&usbg_function_list);
+
+ ret = usb_function_register(&usb9pfsusb_func);
+ if (!ret)
+ v9fs_register_trans(&p9_usbg_trans);
+
+ return ret;
+}
+
+static void __exit usb9pfs_modexit(void)
+{
+ usb_function_unregister(&usb9pfsusb_func);
+ v9fs_unregister_trans(&p9_usbg_trans);
+}
+
+module_init(usb9pfs_modinit);
+module_exit(usb9pfs_modexit);
+
+MODULE_ALIAS_9P("usbg");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("USB gadget 9pfs transport");
+MODULE_AUTHOR("Michael Grzeschik");
--
2.39.2
On Fri, Feb 02, 2024 at 01:05:12AM +0100, Michael Grzeschik wrote:
> Add the newly introduced 9pfs transport gadget interface with an new
> multi composed gadget together with acm and eem.
>
> When using this legacy module, it is also possible to
> mount the 9PFS usb dir as root filesystem. Just follow the
> instrucitons from Documentation/filesystems/9p.rst
Why are we adding new "legacy" gadgets? What's wrong with the "correct"
api instead? You need a lot of justification here to add something to
an api we want to one day just delete.
And can you wrap your changelog at 72 columns?
>
> Signed-off-by: Michael Grzeschik <[email protected]>
>
> ---
> v1 -> v2:
> - deleted the usbg 9pfs detailed instruction from commit message
> - added depends on net for NET_9P dependency
> ---
> drivers/usb/gadget/legacy/9pfs.c | 268 +++++++++++++++++++++++++++++++++++++
> drivers/usb/gadget/legacy/Kconfig | 16 +++
> drivers/usb/gadget/legacy/Makefile | 2 +
> 3 files changed, 286 insertions(+)
>
> diff --git a/drivers/usb/gadget/legacy/9pfs.c b/drivers/usb/gadget/legacy/9pfs.c
> new file mode 100644
> index 0000000000000..3ac7f2e92c5a3
> --- /dev/null
> +++ b/drivers/usb/gadget/legacy/9pfs.c
> @@ -0,0 +1,268 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * usb9pfs.c -- Gadget usb9pfs
> + *
> + * Copyright (C) 2023 Michael Grzeschik
> + */
> +
> +/*
> + * Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs usb
> + * transport to mount host filesystem via usb gadget. This driver will
> + * also add one ACM and NCM interface.
Why "also"? What are those interfaces going to be used for and what do
they have to do with 9pfs?
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/err.h>
> +#include <linux/usb/composite.h>
> +#include <linux/netdevice.h>
> +
> +#include "u_eem.h"
> +#include "u_ether.h"
> +
> +/*-------------------------------------------------------------------------*/
> +USB_GADGET_COMPOSITE_OPTIONS();
> +
> +USB_ETHERNET_MODULE_PARAMETERS();
> +
> +/* Defines */
> +
> +#define DRIVER_VERSION_STR "v1.0"
> +#define DRIVER_VERSION_NUM 0x1000
> +
> +#define DRIVER_DESC "Composite Gadget (9P + ACM + NCM)"
> +
> +/*-------------------------------------------------------------------------*/
> +
> +#define DRIVER_VENDOR_NUM 0x1d6b /* Linux Foundation */
> +#define DRIVER_PRODUCT_NUM 0x0109 /* Linux-USB 9PFS Gadget */
> +
> +/*-------------------------------------------------------------------------*/
> +
> +static struct usb_device_descriptor device_desc = {
> + .bLength = sizeof(device_desc),
> + .bDescriptorType = USB_DT_DEVICE,
> +
> + /* .bcdUSB = DYNAMIC */
> +
> + .bDeviceClass = USB_CLASS_MISC,
> + .bDeviceSubClass = 2,
> + .bDeviceProtocol = 1,
> +
> + /* .bMaxPacketSize0 = f(hardware) */
> +
> + /* Vendor and product id can be overridden by module parameters. */
> + .idVendor = cpu_to_le16(DRIVER_VENDOR_NUM),
> + .idProduct = cpu_to_le16(DRIVER_PRODUCT_NUM),
> + /* .bcdDevice = f(hardware) */
> + /* .iManufacturer = DYNAMIC */
> + /* .iProduct = DYNAMIC */
> + /* NO SERIAL NUMBER */
> + /*.bNumConfigurations = DYNAMIC*/
> +};
> +
> +static const struct usb_descriptor_header *otg_desc[2];
> +
> +static struct usb_string strings_dev[] = {
> + [USB_GADGET_MANUFACTURER_IDX].s = "",
> + [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
> + [USB_GADGET_SERIAL_IDX].s = "",
> + { } /* end of list */
> +};
> +
> +static struct usb_gadget_strings stringtab_dev = {
> + .language = 0x0409, /* en-us */
> + .strings = strings_dev,
> +};
> +
> +static struct usb_gadget_strings *dev_strings[] = {
> + &stringtab_dev,
> + NULL,
> +};
> +
> +static struct usb_configuration cdc_driver_conf = {
> + .label = DRIVER_DESC,
> + .bConfigurationValue = 1,
> + /* .iConfiguration = DYNAMIC */
> + .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
> +};
> +
> +static struct usb_function *f_9pfs;
> +static struct usb_function_instance *fi_9pfs;
> +
> +static struct usb_function *f_acm;
> +static struct usb_function_instance *fi_acm;
> +
> +static struct usb_function *f_eem;
> +static struct usb_function_instance *fi_eem;
> +
> +static int cdc_do_config(struct usb_configuration *c)
> +{
> + int ret;
> +
> + if (gadget_is_otg(c->cdev->gadget)) {
> + c->descriptors = otg_desc;
> + c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
> + }
> +
> + f_9pfs = usb_get_function(fi_9pfs);
> + if (IS_ERR(f_9pfs))
> + return PTR_ERR(f_9pfs);
> +
> + ret = usb_add_function(c, f_9pfs);
> + if (ret < 0)
> + goto err_func_9pfs;
> +
> + f_acm = usb_get_function(fi_acm);
> + if (IS_ERR(f_acm)) {
> + ret = PTR_ERR(f_acm);
> + goto err_func_acm;
> + }
> +
> + ret = usb_add_function(c, f_acm);
> + if (ret)
> + goto err_conf;
> +
> + f_eem = usb_get_function(fi_eem);
> + if (IS_ERR(f_eem)) {
> + ret = PTR_ERR(f_eem);
> + goto err_eem;
> + }
> +
> + ret = usb_add_function(c, f_eem);
> + if (ret)
> + goto err_run;
> +
> + return 0;
> +err_run:
> + usb_put_function(f_eem);
> +err_eem:
> + usb_remove_function(c, f_acm);
> +err_conf:
> + usb_put_function(f_acm);
> +err_func_acm:
> + usb_remove_function(c, f_9pfs);
> +err_func_9pfs:
> + usb_put_function(f_9pfs);
> + return ret;
> +}
> +
> +static int usb9pfs_bind(struct usb_composite_dev *cdev)
> +{
> + struct f_eem_opts *eem_opts = NULL;
> + int status;
> +
> + fi_9pfs = usb_get_function_instance("usb9pfs");
> + if (IS_ERR(fi_9pfs)) {
> + if (PTR_ERR(fi_9pfs) == -ENOENT)
> + return -EPROBE_DEFER;
> + return PTR_ERR(fi_9pfs);
> + }
> +
> + /* set up serial link layer */
> + fi_acm = usb_get_function_instance("acm");
> + if (IS_ERR(fi_acm)) {
> + if (PTR_ERR(fi_9pfs) == -ENOENT)
> + return -EPROBE_DEFER;
> + status = PTR_ERR(fi_acm);
> + goto err_conf_acm;
> + }
> +
> + fi_eem = usb_get_function_instance("eem");
> + if (IS_ERR(fi_eem)) {
> + if (PTR_ERR(fi_9pfs) == -ENOENT)
> + return -EPROBE_DEFER;
> + status = PTR_ERR(fi_eem);
> + goto err_conf_eem;
> + }
> +
> + eem_opts = container_of(fi_eem, struct f_eem_opts, func_inst);
> +
> + gether_set_qmult(eem_opts->net, qmult);
> + if (!gether_set_host_addr(eem_opts->net, host_addr))
> + pr_info("using host ethernet address: %s", host_addr);
> + if (!gether_set_dev_addr(eem_opts->net, dev_addr))
> + pr_info("using self ethernet address: %s", dev_addr);
> +
> + /* Allocate string descriptor numbers ... note that string
> + * contents can be overridden by the composite_dev glue.
> + */
> + status = usb_string_ids_tab(cdev, strings_dev);
> + if (status < 0)
> + return status;
> +
> + device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
> + device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
> + device_desc.iSerialNumber = strings_dev[USB_GADGET_SERIAL_IDX].id;
> +
> + /* support OTG systems */
> + if (gadget_is_otg(cdev->gadget)) {
> + if (!otg_desc[0]) {
> + struct usb_descriptor_header *usb_desc;
> +
> + usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
> + if (!usb_desc) {
> + status = -ENOMEM;
> + goto err_conf_otg;
> + }
> + usb_otg_descriptor_init(cdev->gadget, usb_desc);
> + otg_desc[0] = usb_desc;
> + otg_desc[1] = NULL;
> + }
> + }
> +
> + status = usb_add_config(cdev, &cdc_driver_conf, cdc_do_config);
> + if (status)
> + goto err_free_otg_desc;
> +
> + usb_ep_autoconfig_reset(cdev->gadget);
> + usb_composite_overwrite_options(cdev, &coverwrite);
> +
> + dev_info(&cdev->gadget->dev, DRIVER_DESC " version: " DRIVER_VERSION_STR "\n");
When drivers are working properly, they are quiet.
thanks,
greg k-h
On Sat, Feb 17, 2024 at 04:59:28PM +0100, Greg Kroah-Hartman wrote:
>On Fri, Feb 02, 2024 at 01:05:12AM +0100, Michael Grzeschik wrote:
>> Add the newly introduced 9pfs transport gadget interface with an new
>> multi composed gadget together with acm and eem.
>>
>> When using this legacy module, it is also possible to
>> mount the 9PFS usb dir as root filesystem. Just follow the
>> instrucitons from Documentation/filesystems/9p.rst
>
>Why are we adding new "legacy" gadgets? What's wrong with the "correct"
>api instead? You need a lot of justification here to add something to
>an api we want to one day just delete.
Without the legacy gadget there is no real solution to mount
the 9pfs via the gadget as rootfs. The "correct" api is configfs
which will need the user to have some filesystem to mount it to.
There is the relatively new concept of bootconfig which sounds
promising to describe an complete configfs tree from system boot.
However this is some future talk for now, so we would like to
stick with the legacy setup to be able to mount the 9pfs rootfs.
I will improve the commit message to make this clear.
>And can you wrap your changelog at 72 columns?
Sure
>
>>
>> Signed-off-by: Michael Grzeschik <[email protected]>
>>
>> ---
>> v1 -> v2:
>> - deleted the usbg 9pfs detailed instruction from commit message
>> - added depends on net for NET_9P dependency
>> ---
>> drivers/usb/gadget/legacy/9pfs.c | 268 +++++++++++++++++++++++++++++++++++++
>> drivers/usb/gadget/legacy/Kconfig | 16 +++
>> drivers/usb/gadget/legacy/Makefile | 2 +
>> 3 files changed, 286 insertions(+)
>>
>> diff --git a/drivers/usb/gadget/legacy/9pfs.c b/drivers/usb/gadget/legacy/9pfs.c
>> new file mode 100644
>> index 0000000000000..3ac7f2e92c5a3
>> --- /dev/null
>> +++ b/drivers/usb/gadget/legacy/9pfs.c
>> @@ -0,0 +1,268 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * usb9pfs.c -- Gadget usb9pfs
>> + *
>> + * Copyright (C) 2023 Michael Grzeschik
>> + */
>> +
>> +/*
>> + * Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs usb
>> + * transport to mount host filesystem via usb gadget. This driver will
>> + * also add one ACM and NCM interface.
>
>Why "also"? What are those interfaces going to be used for and what do
>they have to do with 9pfs?
They are not necessary to be used with 9pfs. But since we introduce an
new legacy module which is fully claiming the UDC, it would make sense
to leave the other endpoints unavailable but instead add some common
interfaces like ecm and acm.
I will also improve the comment and the commit message to point this
out.
>> + */
>> +
>> +#include <linux/kernel.h>
>> +#include <linux/slab.h>
>> +#include <linux/device.h>
>> +#include <linux/module.h>
>> +#include <linux/err.h>
>> +#include <linux/usb/composite.h>
>> +#include <linux/netdevice.h>
>> +
>> +#include "u_eem.h"
>> +#include "u_ether.h"
>> +
>> +/*-------------------------------------------------------------------------*/
>> +USB_GADGET_COMPOSITE_OPTIONS();
>> +
>> +USB_ETHERNET_MODULE_PARAMETERS();
>> +
>> +/* Defines */
>> +
>> +#define DRIVER_VERSION_STR "v1.0"
>> +#define DRIVER_VERSION_NUM 0x1000
>> +
>> +#define DRIVER_DESC "Composite Gadget (9P + ACM + NCM)"
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +#define DRIVER_VENDOR_NUM 0x1d6b /* Linux Foundation */
>> +#define DRIVER_PRODUCT_NUM 0x0109 /* Linux-USB 9PFS Gadget */
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +static struct usb_device_descriptor device_desc = {
>> + .bLength = sizeof(device_desc),
>> + .bDescriptorType = USB_DT_DEVICE,
>> +
>> + /* .bcdUSB = DYNAMIC */
>> +
>> + .bDeviceClass = USB_CLASS_MISC,
>> + .bDeviceSubClass = 2,
>> + .bDeviceProtocol = 1,
>> +
>> + /* .bMaxPacketSize0 = f(hardware) */
>> +
>> + /* Vendor and product id can be overridden by module parameters. */
>> + .idVendor = cpu_to_le16(DRIVER_VENDOR_NUM),
>> + .idProduct = cpu_to_le16(DRIVER_PRODUCT_NUM),
>> + /* .bcdDevice = f(hardware) */
>> + /* .iManufacturer = DYNAMIC */
>> + /* .iProduct = DYNAMIC */
>> + /* NO SERIAL NUMBER */
>> + /*.bNumConfigurations = DYNAMIC*/
>> +};
>> +
>> +static const struct usb_descriptor_header *otg_desc[2];
>> +
>> +static struct usb_string strings_dev[] = {
>> + [USB_GADGET_MANUFACTURER_IDX].s = "",
>> + [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
>> + [USB_GADGET_SERIAL_IDX].s = "",
>> + { } /* end of list */
>> +};
>> +
>> +static struct usb_gadget_strings stringtab_dev = {
>> + .language = 0x0409, /* en-us */
>> + .strings = strings_dev,
>> +};
>> +
>> +static struct usb_gadget_strings *dev_strings[] = {
>> + &stringtab_dev,
>> + NULL,
>> +};
>> +
>> +static struct usb_configuration cdc_driver_conf = {
>> + .label = DRIVER_DESC,
>> + .bConfigurationValue = 1,
>> + /* .iConfiguration = DYNAMIC */
>> + .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
>> +};
>> +
>> +static struct usb_function *f_9pfs;
>> +static struct usb_function_instance *fi_9pfs;
>> +
>> +static struct usb_function *f_acm;
>> +static struct usb_function_instance *fi_acm;
>> +
>> +static struct usb_function *f_eem;
>> +static struct usb_function_instance *fi_eem;
>> +
>> +static int cdc_do_config(struct usb_configuration *c)
>> +{
>> + int ret;
>> +
>> + if (gadget_is_otg(c->cdev->gadget)) {
>> + c->descriptors = otg_desc;
>> + c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
>> + }
>> +
>> + f_9pfs = usb_get_function(fi_9pfs);
>> + if (IS_ERR(f_9pfs))
>> + return PTR_ERR(f_9pfs);
>> +
>> + ret = usb_add_function(c, f_9pfs);
>> + if (ret < 0)
>> + goto err_func_9pfs;
>> +
>> + f_acm = usb_get_function(fi_acm);
>> + if (IS_ERR(f_acm)) {
>> + ret = PTR_ERR(f_acm);
>> + goto err_func_acm;
>> + }
>> +
>> + ret = usb_add_function(c, f_acm);
>> + if (ret)
>> + goto err_conf;
>> +
>> + f_eem = usb_get_function(fi_eem);
>> + if (IS_ERR(f_eem)) {
>> + ret = PTR_ERR(f_eem);
>> + goto err_eem;
>> + }
>> +
>> + ret = usb_add_function(c, f_eem);
>> + if (ret)
>> + goto err_run;
>> +
>> + return 0;
>> +err_run:
>> + usb_put_function(f_eem);
>> +err_eem:
>> + usb_remove_function(c, f_acm);
>> +err_conf:
>> + usb_put_function(f_acm);
>> +err_func_acm:
>> + usb_remove_function(c, f_9pfs);
>> +err_func_9pfs:
>> + usb_put_function(f_9pfs);
>> + return ret;
>> +}
>> +
>> +static int usb9pfs_bind(struct usb_composite_dev *cdev)
>> +{
>> + struct f_eem_opts *eem_opts = NULL;
>> + int status;
>> +
>> + fi_9pfs = usb_get_function_instance("usb9pfs");
>> + if (IS_ERR(fi_9pfs)) {
>> + if (PTR_ERR(fi_9pfs) == -ENOENT)
>> + return -EPROBE_DEFER;
>> + return PTR_ERR(fi_9pfs);
>> + }
>> +
>> + /* set up serial link layer */
>> + fi_acm = usb_get_function_instance("acm");
>> + if (IS_ERR(fi_acm)) {
>> + if (PTR_ERR(fi_9pfs) == -ENOENT)
>> + return -EPROBE_DEFER;
>> + status = PTR_ERR(fi_acm);
>> + goto err_conf_acm;
>> + }
>> +
>> + fi_eem = usb_get_function_instance("eem");
>> + if (IS_ERR(fi_eem)) {
>> + if (PTR_ERR(fi_9pfs) == -ENOENT)
>> + return -EPROBE_DEFER;
>> + status = PTR_ERR(fi_eem);
>> + goto err_conf_eem;
>> + }
>> +
>> + eem_opts = container_of(fi_eem, struct f_eem_opts, func_inst);
>> +
>> + gether_set_qmult(eem_opts->net, qmult);
>> + if (!gether_set_host_addr(eem_opts->net, host_addr))
>> + pr_info("using host ethernet address: %s", host_addr);
>> + if (!gether_set_dev_addr(eem_opts->net, dev_addr))
>> + pr_info("using self ethernet address: %s", dev_addr);
>> +
>> + /* Allocate string descriptor numbers ... note that string
>> + * contents can be overridden by the composite_dev glue.
>> + */
>> + status = usb_string_ids_tab(cdev, strings_dev);
>> + if (status < 0)
>> + return status;
>> +
>> + device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
>> + device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
>> + device_desc.iSerialNumber = strings_dev[USB_GADGET_SERIAL_IDX].id;
>> +
>> + /* support OTG systems */
>> + if (gadget_is_otg(cdev->gadget)) {
>> + if (!otg_desc[0]) {
>> + struct usb_descriptor_header *usb_desc;
>> +
>> + usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
>> + if (!usb_desc) {
>> + status = -ENOMEM;
>> + goto err_conf_otg;
>> + }
>> + usb_otg_descriptor_init(cdev->gadget, usb_desc);
>> + otg_desc[0] = usb_desc;
>> + otg_desc[1] = NULL;
>> + }
>> + }
>> +
>> + status = usb_add_config(cdev, &cdc_driver_conf, cdc_do_config);
>> + if (status)
>> + goto err_free_otg_desc;
>> +
>> + usb_ep_autoconfig_reset(cdev->gadget);
>> + usb_composite_overwrite_options(cdev, &coverwrite);
>> +
>> + dev_info(&cdev->gadget->dev, DRIVER_DESC " version: " DRIVER_VERSION_STR "\n");
>
>When drivers are working properly, they are quiet.
Right, I will fix that.
Thanks,
Michael
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
On Mon, Feb 19, 2024 at 02:48:43AM +0100, Michael Grzeschik wrote:
> On Sat, Feb 17, 2024 at 04:59:28PM +0100, Greg Kroah-Hartman wrote:
> > On Fri, Feb 02, 2024 at 01:05:12AM +0100, Michael Grzeschik wrote:
> > > Add the newly introduced 9pfs transport gadget interface with an new
> > > multi composed gadget together with acm and eem.
> > >
> > > When using this legacy module, it is also possible to
> > > mount the 9PFS usb dir as root filesystem. Just follow the
> > > instrucitons from Documentation/filesystems/9p.rst
> >
> > Why are we adding new "legacy" gadgets? What's wrong with the "correct"
> > api instead? You need a lot of justification here to add something to
> > an api we want to one day just delete.
>
> Without the legacy gadget there is no real solution to mount
> the 9pfs via the gadget as rootfs. The "correct" api is configfs
> which will need the user to have some filesystem to mount it to.
That's what your initramfs is for. Why can't you just use that?
> There is the relatively new concept of bootconfig which sounds
> promising to describe an complete configfs tree from system boot.
Great, but until that happens, again, just use initramfs.
> However this is some future talk for now, so we would like to
> stick with the legacy setup to be able to mount the 9pfs rootfs.
I'd prefer to NOT add new legacy gadget drivers, and do everything
possible to delete them all from the tree "soon".
> > > +/*
> > > + * Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs usb
> > > + * transport to mount host filesystem via usb gadget. This driver will
> > > + * also add one ACM and NCM interface.
> >
> > Why "also"? What are those interfaces going to be used for and what do
> > they have to do with 9pfs?
>
> They are not necessary to be used with 9pfs. But since we introduce an
> new legacy module which is fully claiming the UDC, it would make sense
> to leave the other endpoints unavailable but instead add some common
> interfaces like ecm and acm.
But if no one needs/wants them, why make this complex? Again, configfs
can handle the composition of this if you need it, which is why that
"new" interface was created.
thanks,
greg k-h
On Mon, Feb 19, 2024 at 09:13:03AM +0100, Greg Kroah-Hartman wrote:
>On Mon, Feb 19, 2024 at 02:48:43AM +0100, Michael Grzeschik wrote:
>> On Sat, Feb 17, 2024 at 04:59:28PM +0100, Greg Kroah-Hartman wrote:
>> > On Fri, Feb 02, 2024 at 01:05:12AM +0100, Michael Grzeschik wrote:
>> > > Add the newly introduced 9pfs transport gadget interface with an new
>> > > multi composed gadget together with acm and eem.
>> > >
>> > > When using this legacy module, it is also possible to
>> > > mount the 9PFS usb dir as root filesystem. Just follow the
>> > > instrucitons from Documentation/filesystems/9p.rst
>> >
>> > Why are we adding new "legacy" gadgets? What's wrong with the "correct"
>> > api instead? You need a lot of justification here to add something to
>> > an api we want to one day just delete.
>>
>> Without the legacy gadget there is no real solution to mount
>> the 9pfs via the gadget as rootfs. The "correct" api is configfs
>> which will need the user to have some filesystem to mount it to.
>
>That's what your initramfs is for. Why can't you just use that?
Because out of convenience and to make it just work as simple as
nfsrootfs. With this we now need to maintain an full initramfs,
that has to come from somewhere.
>> There is the relatively new concept of bootconfig which sounds
>> promising to describe an complete configfs tree from system boot.
>
>Great, but until that happens, again, just use initramfs.
Hmm, okay.
>> However this is some future talk for now, so we would like to
>> stick with the legacy setup to be able to mount the 9pfs rootfs.
>
>I'd prefer to NOT add new legacy gadget drivers, and do everything
>possible to delete them all from the tree "soon".
When you mean this "soon" is in the near future, you are probably right
then.
>> > > +/*
>> > > + * Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs usb
>> > > + * transport to mount host filesystem via usb gadget. This driver will
>> > > + * also add one ACM and NCM interface.
>> >
>> > Why "also"? What are those interfaces going to be used for and what do
>> > they have to do with 9pfs?
>>
>> They are not necessary to be used with 9pfs. But since we introduce an
>> new legacy module which is fully claiming the UDC, it would make sense
>> to leave the other endpoints unavailable but instead add some common
>> interfaces like ecm and acm.
>
>But if no one needs/wants them, why make this complex? Again, configfs
>can handle the composition of this if you need it, which is why that
>"new" interface was created.
Okay, What about the rest of the series? Can you just skip this patch
then for? Or do you want me to send the series again without this
legacy driver. There are no dependencies to this in that series.
Michael
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
On Mon, Feb 19, 2024 at 09:02:54PM +0100, Michael Grzeschik wrote:
> Okay, What about the rest of the series? Can you just skip this patch
> then for? Or do you want me to send the series again without this
> legacy driver. There are no dependencies to this in that series.
I don't remember what the rest of this series was, it is long gone from
my review queue :(
So yes, please resend.
thanks,
greg k-h
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 <[email protected]>
>
> ---
> 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 <mount_tag>. How do I get my
<mount_tag> 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("<I", data[:4])[0]
> + 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("<I", data[:4])[0]
> + 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()
>
On Fri, Mar 01, 2024 at 03:26:24PM +0100, Andrzej Pietrasiewicz wrote:
>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 <[email protected]>
>>
>>---
>>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 <mount_tag>. How do I get my
><mount_tag> if I run diod combined with p9_fwd.py?
The mount_tag is decribing the instance of the usb gadget. So, when you
are describing only one gadget this will always be usb9pfs0.
The tools diod and p9_fwd.py don't need any mount_tag information.
9PFS can be sometimes a bit confusing, in regards of what shall be
mounted where. The filesystem path that should be shared by 9pfs
is always represented with the "aname" property.
Regards,
Michael
>>+
>>+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("<I", data[:4])[0]
>>+ 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("<I", data[:4])[0]
>>+ 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()
>>
>
>
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