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 | static inline __be32 tipc_hdr_rps_key(struct tipc_basic_hdr *hdr) |
48 | { |
49 | u32 w0 = ntohl(hdr->w[0]); |
50 | bool keepalive_msg = (w0 & KEEPALIVE_MSG_MASK) == KEEPALIVE_MSG_MASK; |
51 | __be32 key; |
52 | |
53 | /* Return source node identity as key */ |
54 | if (likely(!keepalive_msg)) |
55 | return hdr->w[3]; |
56 | |
57 | /* Spread PROBE/PROBE_REPLY messages across the cores */ |
58 | get_random_bytes(buf: &key, len: sizeof(key)); |
59 | return key; |
60 | } |
61 | |
62 | #endif |
63 | |