1 #ifndef __sack_filter_h__ 2 #define __sack_filter_h__ 3 /*- 4 * Copyright (c) 2017-9 Netflix, Inc. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 /* 29 * Seven entry's is carefully choosen to 30 * fit in one cache line. We can easily 31 * change this to 15 (but it gets very 32 * little extra filtering). To change it 33 * to be larger than 15 would require either 34 * sf_bits becoming a uint32_t and then you 35 * could go to 31.. or change it to a full 36 * bitstring.. It is really doubtful you 37 * will get much benefit beyond 7, in testing 38 * there was a small amount but very very small. 39 */ 40 #define SACK_FILTER_BLOCKS 7 41 42 struct sack_filter { 43 tcp_seq sf_ack; 44 uint16_t sf_bits; 45 uint8_t sf_cur; 46 uint8_t sf_used; 47 struct sackblk sf_blks[SACK_FILTER_BLOCKS]; 48 }; 49 #ifdef _KERNEL 50 void sack_filter_clear(struct sack_filter *sf, tcp_seq seq); 51 int sack_filter_blks(struct sack_filter *sf, struct sackblk *in, int numblks, 52 tcp_seq th_ack); 53 void sack_filter_reject(struct sack_filter *sf, struct sackblk *in); 54 static inline uint8_t sack_filter_blks_used(struct sack_filter *sf) 55 { 56 return (sf->sf_used); 57 } 58 59 #endif 60 #endif 61