| /* | 
 |  * include/net/tipc.h: Include file for TIPC message header routines | 
 |  * | 
 |  * Copyright (c) 2017 Ericsson AB | 
 |  * 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. | 
 |  */ | 
 |  | 
 | #ifndef _TIPC_HDR_H | 
 | #define _TIPC_HDR_H | 
 |  | 
 | #include <linux/random.h> | 
 |  | 
 | #define KEEPALIVE_MSG_MASK 0x0e080000  /* LINK_PROTOCOL + MSG_IS_KEEPALIVE */ | 
 |  | 
 | struct tipc_basic_hdr { | 
 | 	__be32 w[4]; | 
 | }; | 
 |  | 
 | static inline __be32 tipc_hdr_rps_key(struct tipc_basic_hdr *hdr) | 
 | { | 
 | 	u32 w0 = ntohl(hdr->w[0]); | 
 | 	bool keepalive_msg = (w0 & KEEPALIVE_MSG_MASK) == KEEPALIVE_MSG_MASK; | 
 | 	__be32 key; | 
 |  | 
 | 	/* Return source node identity as key */ | 
 | 	if (likely(!keepalive_msg)) | 
 | 		return hdr->w[3]; | 
 |  | 
 | 	/* Spread PROBE/PROBE_REPLY messages across the cores */ | 
 | 	get_random_bytes(&key, sizeof(key)); | 
 | 	return key; | 
 | } | 
 |  | 
 | #endif |