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1 : : /* 2 : : * include/net/tipc.h: Include file for TIPC message header routines 3 : : * 4 : : * Copyright (c) 2017 Ericsson AB 5 : : * All rights reserved. 6 : : * 7 : : * Redistribution and use in source and binary forms, with or without 8 : : * modification, are permitted provided that the following conditions are met: 9 : : * 10 : : * 1. Redistributions of source code must retain the above copyright 11 : : * notice, this list of conditions and the following disclaimer. 12 : : * 2. Redistributions in binary form must reproduce the above copyright 13 : : * notice, this list of conditions and the following disclaimer in the 14 : : * documentation and/or other materials provided with the distribution. 15 : : * 3. Neither the names of the copyright holders nor the names of its 16 : : * contributors may be used to endorse or promote products derived from 17 : : * this software without specific prior written permission. 18 : : * 19 : : * Alternatively, this software may be distributed under the terms of the 20 : : * GNU General Public License ("GPL") version 2 as published by the Free 21 : : * Software Foundation. 22 : : * 23 : : * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 24 : : * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 : : * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 : : * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 27 : : * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 : : * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 : : * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 : : * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 : : * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 : : * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 : : * POSSIBILITY OF SUCH DAMAGE. 34 : : */ 35 : : 36 : : #ifndef _TIPC_HDR_H 37 : : #define _TIPC_HDR_H 38 : : 39 : : #include <linux/random.h> 40 : : 41 : : #define KEEPALIVE_MSG_MASK 0x0e080000 /* LINK_PROTOCOL + MSG_IS_KEEPALIVE */ 42 : : 43 : : struct tipc_basic_hdr { 44 : : __be32 w[4]; 45 : : }; 46 : : 47 : 0 : static inline __be32 tipc_hdr_rps_key(struct tipc_basic_hdr *hdr) 48 : : { 49 : 0 : u32 w0 = ntohl(hdr->w[0]); 50 : 0 : bool keepalive_msg = (w0 & KEEPALIVE_MSG_MASK) == KEEPALIVE_MSG_MASK; 51 : 0 : __be32 key; 52 : : 53 : : /* Return source node identity as key */ 54 [ # # ]: 0 : if (likely(!keepalive_msg)) 55 : 0 : return hdr->w[3]; 56 : : 57 : : /* Spread PROBE/PROBE_REPLY messages across the cores */ 58 : 0 : get_random_bytes(&key, sizeof(key)); 59 : 0 : return key; 60 : : } 61 : : 62 : : #endif