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