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From: Lars Gunnarsson <gunnarsson.lars@gmail.com>
To: Valentina Manea <valentina.manea.m@gmail.com>,
	Shuah Khan <shuah@kernel.org>,
	linux-usb@vger.kernel.org
Subject: [PATCH v1 1/3] tools/usbip: support use case reconnect: prepare
Date: Wed, 6 Oct 2021 22:48:17 +0200	[thread overview]
Message-ID: <20211006204817.GA43927@dell-precision-T3610> (raw)

This patch implements an usb monitor into libusbip to await usb events,
example connect and disconnect.

Signed-off-by: Lars Gunnarsson <gunnarsson.lars@gmail.com>
---
 tools/usb/usbip/.gitignore             |   1 +
 tools/usb/usbip/libsrc/Makefile.am     |   3 +-
 tools/usb/usbip/libsrc/usbip_common.h  |   1 +
 tools/usb/usbip/libsrc/usbip_monitor.c | 147 +++++++++++++++++++++++++
 tools/usb/usbip/libsrc/usbip_monitor.h |  21 ++++
 5 files changed, 172 insertions(+), 1 deletion(-)
 create mode 100644 tools/usb/usbip/libsrc/usbip_monitor.c
 create mode 100644 tools/usb/usbip/libsrc/usbip_monitor.h

diff --git a/tools/usb/usbip/.gitignore b/tools/usb/usbip/.gitignore
index 597361a96dbb..6304adefb5e1 100644
--- a/tools/usb/usbip/.gitignore
+++ b/tools/usb/usbip/.gitignore
@@ -28,6 +28,7 @@ libsrc/libusbip_la-usbip_common.lo
 libsrc/libusbip_la-usbip_device_driver.lo
 libsrc/libusbip_la-usbip_host_common.lo
 libsrc/libusbip_la-usbip_host_driver.lo
+libsrc/libusbip_la-usbip_monitor.lo
 libsrc/libusbip_la-vhci_driver.lo
 src/usbip
 src/usbipd
diff --git a/tools/usb/usbip/libsrc/Makefile.am b/tools/usb/usbip/libsrc/Makefile.am
index dabd2c91d311..3e31e33729cf 100644
--- a/tools/usb/usbip/libsrc/Makefile.am
+++ b/tools/usb/usbip/libsrc/Makefile.am
@@ -8,4 +8,5 @@ libusbip_la_SOURCES := names.c names.h usbip_host_driver.c usbip_host_driver.h \
 		       usbip_device_driver.c usbip_device_driver.h \
 		       usbip_common.c usbip_common.h usbip_host_common.h \
 		       usbip_host_common.c vhci_driver.c vhci_driver.h \
-		       sysfs_utils.c sysfs_utils.h
+		       sysfs_utils.c sysfs_utils.h \
+		       usbip_monitor.c
diff --git a/tools/usb/usbip/libsrc/usbip_common.h b/tools/usb/usbip/libsrc/usbip_common.h
index 73a367a7fa10..13f1d4ca47c5 100644
--- a/tools/usb/usbip/libsrc/usbip_common.h
+++ b/tools/usb/usbip/libsrc/usbip_common.h
@@ -30,6 +30,7 @@
 
 /* kernel module names */
 #define USBIP_CORE_MOD_NAME	"usbip-core"
+#define USBIP_USB_DRV_NAME	"usb"
 #define USBIP_HOST_DRV_NAME	"usbip-host"
 #define USBIP_DEVICE_DRV_NAME	"usbip-vudc"
 #define USBIP_VHCI_DRV_NAME	"vhci_hcd"
diff --git a/tools/usb/usbip/libsrc/usbip_monitor.c b/tools/usb/usbip/libsrc/usbip_monitor.c
new file mode 100644
index 000000000000..731d344f2965
--- /dev/null
+++ b/tools/usb/usbip/libsrc/usbip_monitor.c
@@ -0,0 +1,147 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/**
+ * Copyright (C) 2021 Lars Gunnarsson
+ */
+#include <libudev.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/poll.h>
+
+#include "usbip_monitor.h"
+
+static const size_t MAX_STRLEN = 32;
+
+struct usbip_monitor {
+	const char *busid;
+	struct udev *udev;
+	struct udev_monitor *udev_monitor;
+};
+
+usbip_monitor_t *usbip_monitor_new(void)
+{
+	usbip_monitor_t *monitor = NULL;
+	struct udev *udev = udev_new();
+
+	if (udev) {
+		struct udev_monitor *udev_monitor =
+			udev_monitor_new_from_netlink(udev, "udev");
+		udev_monitor_filter_add_match_subsystem_devtype(
+			udev_monitor,
+			/*subsystem=*/"usb",
+			/*devtype=*/"usb_device");
+		udev_monitor_enable_receiving(udev_monitor);
+		monitor = malloc(sizeof(struct usbip_monitor));
+		monitor->busid = NULL;
+		monitor->udev = udev;
+		monitor->udev_monitor = udev_monitor;
+	}
+	return monitor;
+}
+
+void usbip_monitor_delete(usbip_monitor_t *monitor)
+{
+	if (monitor) {
+		udev_monitor_unref(monitor->udev_monitor);
+		udev_unref(monitor->udev);
+		free(monitor);
+	}
+}
+
+void usbip_monitor_set_busid(usbip_monitor_t *monitor, const char *busid)
+{
+	monitor->busid = busid;
+}
+
+static struct udev_device *await_udev_event(const usbip_monitor_t *monitor)
+{
+	struct udev_device *dev = NULL;
+	int fd = udev_monitor_get_fd(monitor->udev_monitor);
+	const int timeout = -1;
+	const int nfds = 1; // number of file descriptors
+	struct pollfd pollfd[] = { { fd, POLLIN, 0 } };
+	int nfd = poll(pollfd, nfds, timeout);
+
+	if (nfd) {
+		dev = udev_monitor_receive_device(monitor->udev_monitor);
+	}
+	return dev;
+}
+
+static int optional_filter_busid(const char *busid, const char *udev_busid)
+{
+	int filter_match = 0;
+
+	if (busid) {
+		if (strncmp(busid, udev_busid, MAX_STRLEN) == 0) {
+			filter_match = 1;
+		}
+	} else {
+		filter_match = 1;
+	}
+	return filter_match;
+}
+
+static void await_usb_with_driver(const usbip_monitor_t *monitor,
+				  const char *driver, const char *action)
+{
+	while (1) {
+		struct udev_device *dev = await_udev_event(monitor);
+
+		if (dev) {
+			const char *udev_action = udev_device_get_action(dev);
+			const char *udev_driver = udev_device_get_driver(dev);
+			const char *udev_busid = udev_device_get_sysname(dev);
+
+			if (strncmp(udev_action, action, MAX_STRLEN) == 0 &&
+			    strncmp(udev_driver, driver, MAX_STRLEN) == 0) {
+				if (optional_filter_busid(monitor->busid,
+							  udev_busid)) {
+					break;
+				}
+			}
+			udev_device_unref(dev);
+		}
+	}
+}
+
+void usbip_monitor_await_usb_add(const usbip_monitor_t *monitor,
+				 const char *driver)
+{
+	await_usb_with_driver(monitor, driver, "add");
+}
+
+void usbip_monitor_await_usb_bind(const usbip_monitor_t *monitor,
+				  const char *driver)
+{
+	await_usb_with_driver(monitor, driver, "bind");
+}
+
+static void await_usb(const usbip_monitor_t *monitor, const char *action)
+{
+	while (1) {
+		struct udev_device *dev = await_udev_event(monitor);
+
+		if (dev) {
+			const char *udev_action = udev_device_get_action(dev);
+			const char *udev_busid = udev_device_get_sysname(dev);
+
+			if (strncmp(udev_action, action, MAX_STRLEN) == 0) {
+				if (optional_filter_busid(monitor->busid,
+							  udev_busid)) {
+					break;
+				}
+			}
+			udev_device_unref(dev);
+		}
+	}
+}
+
+void usbip_monitor_await_usb_unbind(const usbip_monitor_t *monitor)
+{
+	await_usb(monitor, "unbind");
+}
+
+void usbip_monitor_await_usb_delete(const usbip_monitor_t *monitor)
+{
+	await_usb(monitor, "delete");
+}
diff --git a/tools/usb/usbip/libsrc/usbip_monitor.h b/tools/usb/usbip/libsrc/usbip_monitor.h
new file mode 100644
index 000000000000..474b95c80452
--- /dev/null
+++ b/tools/usb/usbip/libsrc/usbip_monitor.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/**
+ * Copyright (C) 2021 Lars Gunnarsson
+ */
+#ifndef __USBIP_MONITOR_H
+#define __USBIP_MONITOR_H
+
+typedef struct usbip_monitor usbip_monitor_t;
+
+usbip_monitor_t *usbip_monitor_new(void);
+void usbip_monitor_delete(usbip_monitor_t *monitor);
+
+void usbip_monitor_set_busid(usbip_monitor_t *monitor, const char *busid);
+void usbip_monitor_await_usb_add(const usbip_monitor_t *monitor,
+				 const char *driver);
+void usbip_monitor_await_usb_bind(const usbip_monitor_t *monitor,
+				  const char *driver);
+void usbip_monitor_await_usb_unbind(const usbip_monitor_t *monitor);
+void usbip_monitor_await_usb_delete(const usbip_monitor_t *monitor);
+
+#endif /* __USBIP_MONITOR_H */
-- 
2.25.1


             reply	other threads:[~2021-10-06 20:48 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-06 20:48 Lars Gunnarsson [this message]
2021-10-06 23:37 ` [PATCH v1 1/3] tools/usbip: support use case reconnect: prepare Shuah Khan
2021-10-07 21:04   ` Lars Gunnarsson
2021-10-07  5:33 ` Greg KH

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