/*      $NetBSD: tcp_syncache.h,v 1.2 2022/09/20 10:12:18 ozaki-r Exp $ */

/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* 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 project 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 PROJECT 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 PROJECT 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.
*/

/*
*      @(#)COPYRIGHT   1.1 (NRL) 17 January 1995
*
* NRL grants permission for redistribution and use in source and binary
* forms, with or without modification, of the software and documentation
* created at NRL 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. All advertising materials mentioning features or use of this software
*    must display the following acknowledgements:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
*      This product includes software developed at the Information
*      Technology Division, US Naval Research Laboratory.
* 4. Neither the name of the NRL nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL 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 NRL 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
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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*
* The views and conclusions contained in the software and documentation
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* Research Laboratory (NRL).
*/

/*-
* Copyright (c) 1997, 1998, 1999, 2001, 2005 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
* This code is derived from software contributed to The NetBSD Foundation
* by Charles M. Hannum.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/

/*
* 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
*/

#ifndef _NETINET_TCP_SYNCACHE_H_
#define _NETINET_TCP_SYNCACHE_H_

#if defined(_KERNEL_OPT)
#include "opt_inet.h"
#include "opt_mbuftrace.h"
#endif

#ifdef _KERNEL
#include <sys/callout.h>
#include <sys/mbuf.h>
#include <sys/queue.h>

#include <net/route.h>

/*
* Data for the TCP compressed state engine.
*/
union syn_cache_sa {
       struct sockaddr sa;
       struct sockaddr_in sin;
#if 1 /*def INET6*/
       struct sockaddr_in6 sin6;
#endif
};

struct syn_cache {
       TAILQ_ENTRY(syn_cache) sc_bucketq;      /* link on bucket list */
       callout_t sc_timer;                     /* rexmt timer */
       struct route sc_route;
       long sc_win;                            /* advertised window */
       int sc_bucketidx;                       /* our bucket index */
       u_int32_t sc_hash;
       u_int32_t sc_timestamp;                 /* timestamp from SYN */
       u_int32_t sc_timebase;                  /* our local timebase */
       union syn_cache_sa sc_src;
       union syn_cache_sa sc_dst;
       tcp_seq sc_irs;
       tcp_seq sc_iss;
       u_int sc_rxtcur;                        /* current rxt timeout */
       u_int sc_rxttot;                        /* total time spend on queues */
       u_short sc_rxtshift;                    /* for computing backoff */
       u_short sc_flags;

#define SCF_UNREACH             0x0001          /* we've had an unreach error */
#define SCF_TIMESTAMP           0x0002          /* peer will do timestamps */
#define SCF_DEAD                0x0004          /* this entry to be released */
#define SCF_SACK_PERMIT         0x0008          /* peer will do SACK */
#define SCF_ECN_PERMIT          0x0010          /* peer will do ECN */
#define SCF_SIGNATURE   0x40                    /* send MD5 digests */

       struct mbuf *sc_ipopts;                 /* IP options */
       u_int16_t sc_peermaxseg;
       u_int16_t sc_ourmaxseg;
       u_int8_t sc_request_r_scale     : 4,
                sc_requested_s_scale   : 4;

       struct tcpcb *sc_tp;                    /* tcb for listening socket */
       LIST_ENTRY(syn_cache) sc_tpq;           /* list of entries by same tp */
};

struct syn_cache_head {
       TAILQ_HEAD(, syn_cache) sch_bucket;     /* bucket entries */
       u_short sch_length;                     /* # entries in bucket */
};

extern  int tcp_syn_bucket_limit;/* max entries per hash bucket */
extern  int tcp_syn_cache_limit; /* max entries for compressed state engine */
extern  u_long syn_cache_count;

int      syn_cache_add(struct sockaddr *, struct sockaddr *,
               struct tcphdr *, unsigned int, struct socket *,
               struct mbuf *, u_char *, int, struct tcp_opt_info *);
void     syn_cache_unreach(const struct sockaddr *, const struct sockaddr *,
          struct tcphdr *);
struct socket
       *syn_cache_get(struct sockaddr *, struct sockaddr *,
               struct tcphdr *, struct socket *so, struct mbuf *);
void     syn_cache_init(void);
void     syn_cache_insert(struct syn_cache *, struct tcpcb *);
void     syn_cache_reset(struct sockaddr *, struct sockaddr *,
               struct tcphdr *);
void     syn_cache_cleanup(struct tcpcb *);
#endif

#endif /* !_NETINET_TCP_SYNCACHE_H_ */