1 1.6 riastrad /* $NetBSD: ratelimit.h,v 1.6 2022/04/09 23:44:25 riastradh Exp $ */ 2 1.2 riastrad 3 1.2 riastrad /*- 4 1.2 riastrad * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 1.2 riastrad * All rights reserved. 6 1.2 riastrad * 7 1.2 riastrad * This code is derived from software contributed to The NetBSD Foundation 8 1.2 riastrad * by Taylor R. Campbell. 9 1.2 riastrad * 10 1.2 riastrad * Redistribution and use in source and binary forms, with or without 11 1.2 riastrad * modification, are permitted provided that the following conditions 12 1.2 riastrad * are met: 13 1.2 riastrad * 1. Redistributions of source code must retain the above copyright 14 1.2 riastrad * notice, this list of conditions and the following disclaimer. 15 1.2 riastrad * 2. Redistributions in binary form must reproduce the above copyright 16 1.2 riastrad * notice, this list of conditions and the following disclaimer in the 17 1.2 riastrad * documentation and/or other materials provided with the distribution. 18 1.2 riastrad * 19 1.2 riastrad * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.2 riastrad * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.2 riastrad * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.2 riastrad * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.2 riastrad * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.2 riastrad * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.2 riastrad * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.2 riastrad * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.2 riastrad * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.2 riastrad * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.2 riastrad * POSSIBILITY OF SUCH DAMAGE. 30 1.2 riastrad */ 31 1.2 riastrad 32 1.2 riastrad #ifndef _LINUX_RATELIMIT_H_ 33 1.2 riastrad #define _LINUX_RATELIMIT_H_ 34 1.2 riastrad 35 1.3 riastrad #include <sys/atomic.h> 36 1.3 riastrad #include <sys/stdbool.h> 37 1.3 riastrad #include <sys/time.h> 38 1.3 riastrad 39 1.4 riastrad #define ratelimit_state linux_ratelimit_state 40 1.4 riastrad 41 1.4 riastrad struct ratelimit_state { 42 1.5 riastrad volatile int missed; 43 1.5 riastrad 44 1.3 riastrad volatile unsigned rl_lock; 45 1.3 riastrad struct timeval rl_lasttime; 46 1.3 riastrad int rl_curpps; 47 1.3 riastrad unsigned rl_maxpps; 48 1.3 riastrad }; 49 1.3 riastrad 50 1.5 riastrad enum { 51 1.5 riastrad RATELIMIT_MSG_ON_RELEASE, 52 1.5 riastrad }; 53 1.5 riastrad 54 1.3 riastrad /* 55 1.3 riastrad * XXX Assumes hz=100 so this works in static initializers, and/or 56 1.3 riastrad * hopes the caller just uses DEFAULT_RATELIMIT_INTERVAL and doesn't 57 1.3 riastrad * mention hz. 58 1.3 riastrad */ 59 1.3 riastrad #define DEFAULT_RATELIMIT_INTERVAL (5*100) 60 1.3 riastrad #define DEFAULT_RATELIMIT_BURST 10 61 1.3 riastrad 62 1.3 riastrad #define DEFINE_RATELIMIT_STATE(n, i, b) \ 63 1.4 riastrad struct ratelimit_state n = { \ 64 1.5 riastrad .missed = 0, \ 65 1.3 riastrad .rl_lock = 0, \ 66 1.3 riastrad .rl_lasttime = { .tv_sec = 0, .tv_usec = 0 }, \ 67 1.3 riastrad .rl_curpps = 0, \ 68 1.3 riastrad .rl_maxpps = (b)/((i)/100), \ 69 1.3 riastrad } 70 1.3 riastrad 71 1.5 riastrad static inline void 72 1.5 riastrad ratelimit_state_init(struct ratelimit_state *r, int interval, int burst) 73 1.5 riastrad { 74 1.5 riastrad 75 1.5 riastrad memset(r, 0, sizeof(*r)); 76 1.5 riastrad r->rl_maxpps = burst/(interval/hz); 77 1.5 riastrad } 78 1.5 riastrad 79 1.5 riastrad static inline void 80 1.5 riastrad ratelimit_set_flags(struct ratelimit_state *r, unsigned long flags) 81 1.5 riastrad { 82 1.5 riastrad } 83 1.5 riastrad 84 1.3 riastrad static inline bool 85 1.4 riastrad __ratelimit(struct ratelimit_state *r) 86 1.3 riastrad { 87 1.3 riastrad int ok; 88 1.3 riastrad 89 1.6 riastrad if (atomic_swap_uint(&r->rl_lock, 1)) { 90 1.5 riastrad ok = false; 91 1.5 riastrad goto out; 92 1.5 riastrad } 93 1.6 riastrad membar_acquire(); 94 1.3 riastrad ok = ppsratecheck(&r->rl_lasttime, &r->rl_curpps, r->rl_maxpps); 95 1.6 riastrad atomic_store_release(&r->rl_lock, 0); 96 1.3 riastrad 97 1.5 riastrad out: if (!ok) 98 1.5 riastrad atomic_store_relaxed(&r->missed, 1); 99 1.3 riastrad return ok; 100 1.3 riastrad } 101 1.3 riastrad 102 1.2 riastrad #endif /* _LINUX_RATELIMIT_H_ */ 103
Indexes created Sat Sep 20 22:09:52 GMT 2025