/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1982, 1986, 1993, 1994, 1995
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)tcp_var.h 8.4 (Berkeley) 5/24/95
* $FreeBSD$
*/
#ifndef _NETINET_TCP_SYNCACHE_H_
#define _NETINET_TCP_SYNCACHE_H_
#ifdef _KERNEL
void syncache_init(void);
#ifdef VIMAGE
void syncache_destroy(void);
#endif
void syncache_unreach(struct in_conninfo *, tcp_seq);
int syncache_expand(struct in_conninfo *, struct tcpopt *,
struct tcphdr *, struct socket **, struct mbuf *);
int syncache_add(struct in_conninfo *, struct tcpopt *,
struct tcphdr *, struct inpcb *, struct socket **, struct mbuf *,
void *, void *);
void syncache_chkrst(struct in_conninfo *, struct tcphdr *, struct mbuf *);
void syncache_badack(struct in_conninfo *);
int syncache_pcblist(struct sysctl_req *req, int max_pcbs, int *pcbs_exported);
struct syncache {
TAILQ_ENTRY(syncache) sc_hash;
struct in_conninfo sc_inc; /* addresses */
int sc_rxttime; /* retransmit time */
u_int16_t sc_rxmits; /* retransmit counter */
u_int32_t sc_tsreflect; /* timestamp to reflect */
u_int32_t sc_tsoff; /* ts offset w/ syncookies */
u_int32_t sc_flowlabel; /* IPv6 flowlabel */
tcp_seq sc_irs; /* seq from peer */
tcp_seq sc_iss; /* our ISS */
struct mbuf *sc_ipopts; /* source route */
u_int16_t sc_peer_mss; /* peer's MSS */
u_int16_t sc_wnd; /* advertised window */
u_int8_t sc_ip_ttl; /* IPv4 TTL */
u_int8_t sc_ip_tos; /* IPv4 TOS */
u_int8_t sc_requested_s_scale:4,
sc_requested_r_scale:4;
u_int16_t sc_flags;
#if defined(TCP_OFFLOAD) || !defined(TCP_OFFLOAD_DISABLE)
struct toedev *sc_tod; /* entry added by this TOE */
void *sc_todctx; /* TOE driver context */
#endif
struct label *sc_label; /* MAC label reference */
struct ucred *sc_cred; /* cred cache for jail checks */
void *sc_tfo_cookie; /* for TCP Fast Open response */
void *sc_pspare; /* TCP_SIGNATURE */
u_int32_t sc_spare[2]; /* UTO */
};
/*
* Flags for the sc_flags field.
*/
#define SCF_NOOPT 0x01 /* no TCP options */
#define SCF_WINSCALE 0x02 /* negotiated window scaling */
#define SCF_TIMESTAMP 0x04 /* negotiated timestamps */
/* MSS is implicit */
#define SCF_UNREACH 0x10 /* icmp unreachable received */
#define SCF_SIGNATURE 0x20 /* send MD5 digests */
#define SCF_SACK 0x80 /* send SACK option */
#define SCF_ECN 0x100 /* send ECN setup packet */
struct syncache_head {
struct mtx sch_mtx;
TAILQ_HEAD(sch_head, syncache) sch_bucket;
struct callout sch_timer;
int sch_nextc;
u_int sch_length;
struct tcp_syncache *sch_sc;
time_t sch_last_overflow;
};
#define SYNCOOKIE_SECRET_SIZE 16
#define SYNCOOKIE_LIFETIME 15 /* seconds */
struct syncookie_secret {
volatile u_int oddeven;
uint8_t key[2][SYNCOOKIE_SECRET_SIZE];
struct callout reseed;
u_int lifetime;
};
struct tcp_syncache {
struct syncache_head *hashbase;
uma_zone_t zone;
u_int hashsize;
u_int hashmask;
u_int bucket_limit;
u_int cache_limit;
u_int rexmt_limit;
uint32_t hash_secret;
struct vnet *vnet;
struct syncookie_secret secret;
};
/* Internal use for the syncookie functions. */
union syncookie {
uint8_t cookie;
struct {
uint8_t odd_even:1,
sack_ok:1,
wscale_idx:3,
mss_idx:3;
} flags;
};
#endif /* _KERNEL */
#endif /* !_NETINET_TCP_SYNCACHE_H_ */
