As per feedback from the netdev community, we change the buffer overflow protection algorithm in receiving sockets so that it always respects the nominal upper limit set in sk_rcvbuf. Instead of scaling up from a small sk_rcvbuf value, which leads to violation of the configured sk_rcvbuf limit, we now calculate the weighted per-message limit by scaling down from a much bigger value, still in the same field, according to the importance priority of the received message. To allow for administrative tunability of the socket receive buffer size, we create a tipc_rmem sysctl variable to allow the user to configure an even bigger value via sysctl command. It is a size of three (min/default/max) to be consistent with things like tcp_rmem. By default, the value initialized in tipc_rmem[1] is equal to the receive socket size needed by a TIPC_CRITICAL_IMPORTANCE message. This value is also set as the default value of sk_rcvbuf. Originally-by: Jon Maloy <jon.maloy@ericsson.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Jon Maloy <jon.maloy@ericsson.com> [Ying: added sysctl variation to Jon's original patch] Signed-off-by: Ying Xue <ying.xue@windriver.com> [PG: don't compile sysctl.c if not config'd; add Documentation] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			64 lines
		
	
	
	
		
			2.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			64 lines
		
	
	
	
		
			2.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
 | 
						|
 * net/tipc/sysctl.c: sysctl interface to TIPC subsystem
 | 
						|
 *
 | 
						|
 * Copyright (c) 2013, Wind River Systems
 | 
						|
 * All rights reserved.
 | 
						|
 *
 | 
						|
 * Redistribution and use in source and binary forms, with or without
 | 
						|
 * modification, are permitted provided that the following conditions are met:
 | 
						|
 *
 | 
						|
 * 1. Redistributions of source code must retain the above copyright
 | 
						|
 *    notice, this list of conditions and the following disclaimer.
 | 
						|
 * 2. Redistributions in binary form must reproduce the above copyright
 | 
						|
 *    notice, this list of conditions and the following disclaimer in the
 | 
						|
 *    documentation and/or other materials provided with the distribution.
 | 
						|
 * 3. Neither the names of the copyright holders nor the names of its
 | 
						|
 *    contributors may be used to endorse or promote products derived from
 | 
						|
 *    this software without specific prior written permission.
 | 
						|
 *
 | 
						|
 * Alternatively, this software may be distributed under the terms of the
 | 
						|
 * GNU General Public License ("GPL") version 2 as published by the Free
 | 
						|
 * Software Foundation.
 | 
						|
 *
 | 
						|
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 | 
						|
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 | 
						|
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 | 
						|
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 | 
						|
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 | 
						|
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 | 
						|
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 | 
						|
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 | 
						|
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 | 
						|
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 | 
						|
 * POSSIBILITY OF SUCH DAMAGE.
 | 
						|
 */
 | 
						|
 | 
						|
#include "core.h"
 | 
						|
 | 
						|
#include <linux/sysctl.h>
 | 
						|
 | 
						|
static struct ctl_table_header *tipc_ctl_hdr;
 | 
						|
 | 
						|
static struct ctl_table tipc_table[] = {
 | 
						|
	{
 | 
						|
		.procname	= "tipc_rmem",
 | 
						|
		.data		= &sysctl_tipc_rmem,
 | 
						|
		.maxlen		= sizeof(sysctl_tipc_rmem),
 | 
						|
		.mode		= 0644,
 | 
						|
		.proc_handler	= proc_dointvec,
 | 
						|
	},
 | 
						|
	{}
 | 
						|
};
 | 
						|
 | 
						|
int tipc_register_sysctl(void)
 | 
						|
{
 | 
						|
	tipc_ctl_hdr = register_net_sysctl(&init_net, "net/tipc", tipc_table);
 | 
						|
	if (tipc_ctl_hdr == NULL)
 | 
						|
		return -ENOMEM;
 | 
						|
	return 0;
 | 
						|
}
 | 
						|
 | 
						|
void tipc_unregister_sysctl(void)
 | 
						|
{
 | 
						|
	unregister_net_sysctl_table(tipc_ctl_hdr);
 | 
						|
}
 |