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 * __FBSDID("$FreeBSD$"); 28 */ 29 30 /* 31 * Seven entry's is carefully choosen to 32 * fit in one cache line. We can easily 33 * change this to 15 (but it gets very 34 * little extra filtering). To change it 35 * to be larger than 15 would require either 36 * sf_bits becoming a uint32_t and then you 37 * could go to 31.. or change it to a full 38 * bitstring.. It is really doubtful you 39 * will get much benefit beyond 7, in testing 40 * there was a small amount but very very small. 41 */ 42 #define SACK_FILTER_BLOCKS 7 43 44 struct sack_filter { 45 tcp_seq sf_ack; 46 uint16_t sf_bits; 47 uint8_t sf_cur; 48 uint8_t sf_used; 49 struct sackblk sf_blks[SACK_FILTER_BLOCKS]; 50 }; 51 #ifdef _KERNEL 52 void sack_filter_clear(struct sack_filter *sf, tcp_seq seq); 53 int sack_filter_blks(struct sack_filter *sf, struct sackblk *in, int numblks, 54 tcp_seq th_ack); 55 void sack_filter_reject(struct sack_filter *sf, struct sackblk *in); 56 #endif 57 #endif 58