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 32 #ifndef _NETINET_TCP_SYNCACHE_H_ 33 #define _NETINET_TCP_SYNCACHE_H_ 34 #ifdef _KERNEL 35 36 void syncache_init(void); 37 #ifdef VIMAGE 38 void syncache_destroy(void); 39 #endif 40 void syncache_unreach(struct in_conninfo *, tcp_seq, uint16_t); 41 int syncache_expand(struct in_conninfo *, struct tcpopt *, 42 struct tcphdr *, struct socket **, struct mbuf *, uint16_t); 43 struct socket * syncache_add(struct in_conninfo *, struct tcpopt *, 44 struct tcphdr *, struct inpcb *, struct socket *, struct mbuf *, 45 void *, void *, uint8_t, uint16_t); 46 void syncache_chkrst(struct in_conninfo *, struct tcphdr *, struct mbuf *, 47 uint16_t); 48 void syncache_badack(struct in_conninfo *, uint16_t); 49 int syncache_pcblist(struct sysctl_req *); 50 51 struct syncache { 52 TAILQ_ENTRY(syncache) sc_hash; 53 struct in_conninfo sc_inc; /* addresses */ 54 int sc_rxttime; /* retransmit time */ 55 u_int16_t sc_rxmits; /* retransmit counter */ 56 u_int16_t sc_port; /* remote UDP encaps port */ 57 u_int32_t sc_tsreflect; /* timestamp to reflect */ 58 u_int32_t sc_tsoff; /* ts offset w/ syncookies */ 59 u_int32_t sc_flowlabel; /* IPv6 flowlabel */ 60 tcp_seq sc_irs; /* seq from peer */ 61 tcp_seq sc_iss; /* our ISS */ 62 struct mbuf *sc_ipopts; /* source route */ 63 u_int16_t sc_peer_mss; /* peer's MSS */ 64 u_int16_t sc_wnd; /* advertised window */ 65 u_int8_t sc_ip_ttl; /* TTL / Hop Limit */ 66 u_int8_t sc_ip_tos; /* TOS / Traffic Class */ 67 u_int8_t sc_requested_s_scale:4, 68 sc_requested_r_scale:4; 69 u_int16_t sc_flags; 70 #if defined(TCP_OFFLOAD) || !defined(TCP_OFFLOAD_DISABLE) 71 struct toedev *sc_tod; /* entry added by this TOE */ 72 void *sc_todctx; /* TOE driver context */ 73 #endif 74 struct label *sc_label; /* MAC label reference */ 75 struct ucred *sc_cred; /* cred cache for jail checks */ 76 void *sc_tfo_cookie; /* for TCP Fast Open response */ 77 void *sc_pspare; /* TCP_SIGNATURE */ 78 u_int32_t sc_spare[2]; /* UTO */ 79 }; 80 81 /* 82 * Flags for the sc_flags field. 83 */ 84 #define SCF_NOOPT 0x01 /* no TCP options */ 85 #define SCF_WINSCALE 0x02 /* negotiated window scaling */ 86 #define SCF_TIMESTAMP 0x04 /* negotiated timestamps */ 87 /* MSS is implicit */ 88 #define SCF_UNREACH 0x10 /* icmp unreachable received */ 89 #define SCF_SIGNATURE 0x20 /* send MD5 digests */ 90 #define SCF_SACK 0x80 /* send SACK option */ 91 #define SCF_ECN_MASK 0x700 /* ECN codepoint mask */ 92 #define SCF_ECN 0x100 /* send ECN setup packet */ 93 #define SCF_ACE_N 0x400 /* send ACE non-ECT setup */ 94 #define SCF_ACE_0 0x500 /* send ACE ECT0 setup */ 95 #define SCF_ACE_1 0x600 /* send ACE ECT1 setup */ 96 #define SCF_ACE_CE 0x700 /* send ACE CE setup */ 97 98 struct syncache_head { 99 struct mtx sch_mtx; 100 TAILQ_HEAD(sch_head, syncache) sch_bucket; 101 struct callout sch_timer; 102 int sch_nextc; 103 u_int sch_length; 104 struct tcp_syncache *sch_sc; 105 time_t sch_last_overflow; 106 }; 107 108 #define SYNCOOKIE_SECRET_SIZE 16 109 #define SYNCOOKIE_LIFETIME 15 /* seconds */ 110 111 struct syncookie_secret { 112 volatile u_int oddeven; 113 uint8_t key[2][SYNCOOKIE_SECRET_SIZE]; 114 struct callout reseed; 115 u_int lifetime; 116 }; 117 118 #define TCP_SYNCACHE_PAUSE_TIME SYNCOOKIE_LIFETIME 119 #define TCP_SYNCACHE_MAX_BACKOFF 6 /* 16 minutes */ 120 121 struct tcp_syncache { 122 struct syncache_head *hashbase; 123 uma_zone_t zone; 124 u_int hashsize; 125 u_int hashmask; 126 u_int bucket_limit; 127 u_int cache_limit; 128 u_int rexmt_limit; 129 uint32_t hash_secret; 130 struct vnet *vnet; 131 struct syncookie_secret secret; 132 struct mtx pause_mtx; 133 struct callout pause_co; 134 time_t pause_until; 135 uint8_t pause_backoff; 136 volatile bool paused; 137 bool see_other; 138 }; 139 140 /* Internal use for the syncookie functions. */ 141 union syncookie { 142 uint8_t cookie; 143 struct { 144 uint8_t odd_even:1, 145 sack_ok:1, 146 wscale_idx:3, 147 mss_idx:3; 148 } flags; 149 }; 150 151 #endif /* _KERNEL */ 152 #endif /* !_NETINET_TCP_SYNCACHE_H_ */ 153