To forward a remote usb device over usbip the following steps is required:
1. Execute "usbip bind" on remote end.
2. Execute "usbip attach" on local end.
These steps must be perfomed in above order and after usb device is plugged in.
If the usb device is unplugged on the remote end the steps above needs to be
performed again to establish the connection. This patch set implements a feature
to persistently forward devices on a given bus. When using flag "-p|--persistent"
on remot end, the USB device becomes exported when plugged in. When using flag
"-p|--persistent" on local end, the USB device becomes imported when available
on remote end. Thus it is only required to run the usbip command once on each
end, in any order, to persistently forward usb devices on a given bus.
This patch extends the command "usbip bind" with flag "-p|--persistent" to
monitor and export a devices on given busid when plugged in, instead of
returning an error if the device is not available. When the usb device is
unplugged, it will start monitor the given bus again.
Signed-off-by: Lars Gunnarsson <gunnarsson.lars@xxxxxxxxx>
---
v2: Change title, fix style warnings, improve feature description, refactor
cmdline flag usage.
Documentation/usb/usbip_protocol.rst | 5 ++
tools/usb/usbip/src/usbip_bind.c | 114 +++++++++++++++++++++------
2 files changed, 94 insertions(+), 25 deletions(-)
diff --git a/Documentation/usb/usbip_protocol.rst b/Documentation/usb/usbip_protocol.rst
index 0b8541fda4d8..2ed7d97278e8 100644
--- a/Documentation/usb/usbip_protocol.rst
+++ b/Documentation/usb/usbip_protocol.rst
@@ -9,6 +9,11 @@ The USB/IP protocol follows a server/client architecture. The server exports the
USB devices and the clients import them. The device driver for the exported
USB device runs on the client machine.
+Initially the server may choose to export any of its available USB devices,
+based on the busid. The device will remain exported until it's unplugged or
+unbound from the usbip driver. It is also possible to persistently export
+devices on a given bus by monitor when they are plugged in.
+
The client may ask for the list of the exported USB devices. To get the list the
client opens a TCP/IP connection to the server, and sends an OP_REQ_DEVLIST
packet on top of the TCP/IP connection (so the actual OP_REQ_DEVLIST may be sent
diff --git a/tools/usb/usbip/src/usbip_bind.c b/tools/usb/usbip/src/usbip_bind.c
index f1cf9225a69c..fd4ccbfce6c6 100644
--- a/tools/usb/usbip/src/usbip_bind.c
+++ b/tools/usb/usbip/src/usbip_bind.c
@@ -8,12 +8,14 @@
#include <errno.h>
#include <stdio.h>
+#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#include "usbip_common.h"
+#include "usbip_monitor.h"
#include "utils.h"
#include "usbip.h"
#include "sysfs_utils.h"
@@ -24,10 +26,17 @@ enum unbind_status {
UNBIND_ST_FAILED
};
+struct bind_options {
+ char *busid;
+ bool is_persistent;
+};
+
static const char usbip_bind_usage_string[] =
"usbip bind <args>\n"
- " -b, --busid=<busid> Bind " USBIP_HOST_DRV_NAME ".ko to device "
- "on <busid>\n";
+ " -b, --busid=<busid> Bind " USBIP_HOST_DRV_NAME ".ko to device\n"
+ " on <busid>\n"
+ " -p, --persistent Persistently monitor the given bus and\n"
+ " export USB devices plugged in\n";
void usbip_bind_usage(void)
{
@@ -127,29 +136,26 @@ static int unbind_other(char *busid)
return status;
}
-static int bind_device(char *busid)
+static const char *get_device_devpath(char *busid)
{
- int rc;
- struct udev *udev;
- struct udev_device *dev;
- const char *devpath;
+ struct udev *udev = udev_new();
+ const char *devpath = NULL;
+ struct udev_device *dev = udev_device_new_from_subsystem_sysname(udev, "usb", busid);
- /* Check whether the device with this bus ID exists. */
- udev = udev_new();
- dev = udev_device_new_from_subsystem_sysname(udev, "usb", busid);
- if (!dev) {
- err("device with the specified bus ID does not exist");
- return -1;
- }
- devpath = udev_device_get_devpath(dev);
+ if (dev)
+ devpath = udev_device_get_devpath(dev);
udev_unref(udev);
+ return devpath;
+}
- /* If the device is already attached to vhci_hcd - bail out */
- if (strstr(devpath, USBIP_VHCI_DRV_NAME)) {
- err("bind loop detected: device: %s is attached to %s\n",
- devpath, USBIP_VHCI_DRV_NAME);
- return -1;
- }
+static bool is_usb_connected(char *busid)
+{
+ return get_device_devpath(busid) != NULL;
+}
+
+static int bind_available_device(char *busid)
+{
+ int rc;
rc = unbind_other(busid);
if (rc == UNBIND_ST_FAILED) {
@@ -174,36 +180,94 @@ static int bind_device(char *busid)
return -1;
}
- info("bind device on busid %s: complete", busid);
+ info("device on busid %s: bind complete", busid);
return 0;
}
+static int bind_device(char *busid)
+{
+ const char *devpath = get_device_devpath(busid);
+
+ /* Check whether the device with this bus ID exists. */
+ if (!devpath) {
+ err("device with the specified bus ID does not exist");
+ return -1;
+ }
+
+ /* If the device is already attached to vhci_hcd - bail out */
+ if (strstr(devpath, USBIP_VHCI_DRV_NAME)) {
+ err("bind loop detected: device: %s is attached to %s\n",
+ devpath, USBIP_VHCI_DRV_NAME);
+ return -1;
+ }
+
+ return bind_available_device(busid);
+}
+
+static int bind_device_persistently(char *busid)
+{
+ int rc = 0;
+ bool already_connected = is_usb_connected(busid);
+ usbip_monitor_t *monitor = monitor = usbip_monitor_new();
+
+ usbip_monitor_set_busid(monitor, busid);
+ while (rc == 0) {
+ if (!already_connected) {
+ info("device on busid %s: monitor connect", busid);
+ usbip_monitor_await_usb_bind(monitor, USBIP_USB_DRV_NAME);
+ }
+ rc = bind_available_device(busid);
+ if (rc == 0) {
+ info("device on busid %s: monitor disconnect", busid);
+ usbip_monitor_await_usb_bind(monitor, USBIP_HOST_DRV_NAME);
+ usbip_monitor_await_usb_unbind(monitor);
+ }
+ already_connected = false;
+ }
+ usbip_monitor_delete(monitor);
+ return rc;
+}
+
int usbip_bind(int argc, char *argv[])
{
static const struct option opts[] = {
{ "busid", required_argument, NULL, 'b' },
+ { "persistent", no_argument, NULL, 'p' },
{ NULL, 0, NULL, 0 }
};
+ struct bind_options options = {};
int opt;
int ret = -1;
for (;;) {
- opt = getopt_long(argc, argv, "b:", opts, NULL);
+ opt = getopt_long(argc, argv, "b:p", opts, NULL);
if (opt == -1)
break;
switch (opt) {
case 'b':
- ret = bind_device(optarg);
- goto out;
+ options.busid = optarg;
+ break;
+ case 'p':
+ options.is_persistent = true;
+ break;
default:
goto err_out;
}
}
+ if (!options.busid)
+ goto err_out;
+
+ if (options.is_persistent)
+ ret = bind_device_persistently(options.busid);
+ else
+ ret = bind_device(options.busid);
+ goto out;
+
err_out:
usbip_bind_usage();
out:
--
2.25.1
