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Revision 693c56491fb720087437a635e6eaf440659b922f authored by Jon Paul Maloy on 22 December 2016, 12:22:29 UTC, committed by David S. Miller on 23 December 2016, 22:53:47 UTC 
tipc: don't send FIN message from connectionless socket
 
In commit 6f00089c7372 ("tipc: remove SS_DISCONNECTING state") the
check for socket type is in the wrong place, causing a closing socket
to always send out a FIN message even when the socket was never
connected. This is normally harmless, since the destination node for
such messages most often is zero, and the message will be dropped, but
it is still a wrong and confusing behavior.

We fix this in this commit.

Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent e252536
Raw File
custom_method.c 
/*
 * custom_method.c - debugfs interface for customizing ACPI control method
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/uaccess.h>
#include <linux/debugfs.h>
#include <linux/acpi.h>

#include "internal.h"

#define _COMPONENT		ACPI_SYSTEM_COMPONENT
ACPI_MODULE_NAME("custom_method");
MODULE_LICENSE("GPL");

static struct dentry *cm_dentry;

/* /sys/kernel/debug/acpi/custom_method */

static ssize_t cm_write(struct file *file, const char __user * user_buf,
			size_t count, loff_t *ppos)
{
	static char *buf;
	static u32 max_size;
	static u32 uncopied_bytes;

	struct acpi_table_header table;
	acpi_status status;

	if (!(*ppos)) {
		/* parse the table header to get the table length */
		if (count <= sizeof(struct acpi_table_header))
			return -EINVAL;
		if (copy_from_user(&table, user_buf,
				   sizeof(struct acpi_table_header)))
			return -EFAULT;
		uncopied_bytes = max_size = table.length;
		buf = kzalloc(max_size, GFP_KERNEL);
		if (!buf)
			return -ENOMEM;
	}

	if (buf == NULL)
		return -EINVAL;

	if ((*ppos > max_size) ||
	    (*ppos + count > max_size) ||
	    (*ppos + count < count) ||
	    (count > uncopied_bytes))
		return -EINVAL;

	if (copy_from_user(buf + (*ppos), user_buf, count)) {
		kfree(buf);
		buf = NULL;
		return -EFAULT;
	}

	uncopied_bytes -= count;
	*ppos += count;

	if (!uncopied_bytes) {
		status = acpi_install_method(buf);
		kfree(buf);
		buf = NULL;
		if (ACPI_FAILURE(status))
			return -EINVAL;
		add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
	}

	return count;
}

static const struct file_operations cm_fops = {
	.write = cm_write,
	.llseek = default_llseek,
};

static int __init acpi_custom_method_init(void)
{
	if (acpi_debugfs_dir == NULL)
		return -ENOENT;

	cm_dentry = debugfs_create_file("custom_method", S_IWUSR,
					acpi_debugfs_dir, NULL, &cm_fops);
	if (cm_dentry == NULL)
		return -ENODEV;

	return 0;
}

static void __exit acpi_custom_method_exit(void)
{
	if (cm_dentry)
		debugfs_remove(cm_dentry);
 }

module_init(acpi_custom_method_init);
module_exit(acpi_custom_method_exit);
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