1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1993, 1994, 1995 5 * The Regents of the University of California. 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 9 * are met: 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 name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95 32 * $FreeBSD$ 33 */ 34 35 #ifndef _NETINET_TCP_SYNCACHE_H_ 36 #define _NETINET_TCP_SYNCACHE_H_ 37 #ifdef _KERNEL 38 39 void syncache_init(void); 40 #ifdef VIMAGE 41 void syncache_destroy(void); 42 #endif 43 void syncache_unreach(struct in_conninfo *, tcp_seq, uint16_t); 44 int syncache_expand(struct in_conninfo *, struct tcpopt *, 45 struct tcphdr *, struct socket **, struct mbuf *, uint16_t); 46 struct socket * syncache_add(struct in_conninfo *, struct tcpopt *, 47 struct tcphdr *, struct inpcb *, struct socket *, struct mbuf *, 48 void *, void *, uint8_t, uint16_t); 49 void syncache_chkrst(struct in_conninfo *, struct tcphdr *, struct mbuf *, 50 uint16_t); 51 void syncache_badack(struct in_conninfo *, uint16_t); 52 int syncache_pcblist(struct sysctl_req *); 53 54 struct syncache { 55 TAILQ_ENTRY(syncache) sc_hash; 56 struct in_conninfo sc_inc; /* addresses */ 57 int sc_rxttime; /* retransmit time */ 58 u_int16_t sc_rxmits; /* retransmit counter */ 59 u_int16_t sc_port; /* remote UDP encaps port */ 60 u_int32_t sc_tsreflect; /* timestamp to reflect */ 61 u_int32_t sc_tsoff; /* ts offset w/ syncookies */ 62 u_int32_t sc_flowlabel; /* IPv6 flowlabel */ 63 tcp_seq sc_irs; /* seq from peer */ 64 tcp_seq sc_iss; /* our ISS */ 65 struct mbuf *sc_ipopts; /* source route */ 66 u_int16_t sc_peer_mss; /* peer's MSS */ 67 u_int16_t sc_wnd; /* advertised window */ 68 u_int8_t sc_ip_ttl; /* TTL / Hop Limit */ 69 u_int8_t sc_ip_tos; /* TOS / Traffic Class */ 70 u_int8_t sc_requested_s_scale:4, 71 sc_requested_r_scale:4; 72 u_int16_t sc_flags; 73 #if defined(TCP_OFFLOAD) || !defined(TCP_OFFLOAD_DISABLE) 74 struct toedev *sc_tod; /* entry added by this TOE */ 75 void *sc_todctx; /* TOE driver context */ 76 #endif 77 struct label *sc_label; /* MAC label reference */ 78 struct ucred *sc_cred; /* cred cache for jail checks */ 79 void *sc_tfo_cookie; /* for TCP Fast Open response */ 80 void *sc_pspare; /* TCP_SIGNATURE */ 81 u_int32_t sc_spare[2]; /* UTO */ 82 }; 83 84 /* 85 * Flags for the sc_flags field. 86 */ 87 #define SCF_NOOPT 0x01 /* no TCP options */ 88 #define SCF_WINSCALE 0x02 /* negotiated window scaling */ 89 #define SCF_TIMESTAMP 0x04 /* negotiated timestamps */ 90 /* MSS is implicit */ 91 #define SCF_UNREACH 0x10 /* icmp unreachable received */ 92 #define SCF_SIGNATURE 0x20 /* send MD5 digests */ 93 #define SCF_SACK 0x80 /* send SACK option */ 94 #define SCF_ECN_MASK 0x700 /* ECN codepoint mask */ 95 #define SCF_ECN 0x100 /* send ECN setup packet */ 96 #define SCF_ACE_N 0x400 /* send ACE non-ECT setup */ 97 #define SCF_ACE_0 0x500 /* send ACE ECT0 setup */ 98 #define SCF_ACE_1 0x600 /* send ACE ECT1 setup */ 99 #define SCF_ACE_CE 0x700 /* send ACE CE setup */ 100 101 struct syncache_head { 102 struct mtx sch_mtx; 103 TAILQ_HEAD(sch_head, syncache) sch_bucket; 104 struct callout sch_timer; 105 int sch_nextc; 106 u_int sch_length; 107 struct tcp_syncache *sch_sc; 108 time_t sch_last_overflow; 109 }; 110 111 #define SYNCOOKIE_SECRET_SIZE 16 112 #define SYNCOOKIE_LIFETIME 15 /* seconds */ 113 114 struct syncookie_secret { 115 volatile u_int oddeven; 116 uint8_t key[2][SYNCOOKIE_SECRET_SIZE]; 117 struct callout reseed; 118 u_int lifetime; 119 }; 120 121 #define TCP_SYNCACHE_PAUSE_TIME SYNCOOKIE_LIFETIME 122 #define TCP_SYNCACHE_MAX_BACKOFF 6 /* 16 minutes */ 123 124 struct tcp_syncache { 125 struct syncache_head *hashbase; 126 uma_zone_t zone; 127 u_int hashsize; 128 u_int hashmask; 129 u_int bucket_limit; 130 u_int cache_limit; 131 u_int rexmt_limit; 132 uint32_t hash_secret; 133 struct vnet *vnet; 134 struct syncookie_secret secret; 135 struct mtx pause_mtx; 136 struct callout pause_co; 137 time_t pause_until; 138 uint8_t pause_backoff; 139 volatile bool paused; 140 bool see_other; 141 }; 142 143 /* Internal use for the syncookie functions. */ 144 union syncookie { 145 uint8_t cookie; 146 struct { 147 uint8_t odd_even:1, 148 sack_ok:1, 149 wscale_idx:3, 150 mss_idx:3; 151 } flags; 152 }; 153 154 #endif /* _KERNEL */ 155 #endif /* !_NETINET_TCP_SYNCACHE_H_ */ 156