/* $NetBSD: tcp_var.h,v 1.190 2018/12/27 16:59:17 maxv 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
* 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.
*
* The views and conclusions contained in the software and documentation
* are those of the authors and should not be interpreted as representing
* official policies, either expressed or implied, of the US Naval
* 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_VAR_H_
#define _NETINET_TCP_VAR_H_
#if defined(_KERNEL_OPT)
#include "opt_inet.h"
#include "opt_mbuftrace.h"
#endif
/*
* TCP kernel structures and variables.
*/
#include <sys/callout.h>
#ifdef TCP_SIGNATURE
/*
* Defines which are needed by the xform_tcp module and tcp_[in|out]put
* for SADB verification and lookup.
*/
#define TCP_SIGLEN 16 /* length of computed digest in bytes */
#define TCP_KEYLEN_MIN 1 /* minimum length of TCP-MD5 key */
#define TCP_KEYLEN_MAX 80 /* maximum length of TCP-MD5 key */
/*
* Only a single SA per host may be specified at this time. An SPI is
* needed in order for the KEY_LOOKUP_SA() lookup to work.
*/
#define TCP_SIG_SPI 0x1000
#endif /* TCP_SIGNATURE */
/*
* Tcp+ip header, after ip options removed.
*/
struct tcpiphdr {
struct ipovly ti_i; /* overlaid ip structure */
struct tcphdr ti_t; /* tcp header */
} __packed;
#define ti_x1 ti_i.ih_x1
#define ti_pr ti_i.ih_pr
#define ti_len ti_i.ih_len
#define ti_src ti_i.ih_src
#define ti_dst ti_i.ih_dst
#define ti_sport ti_t.th_sport
#define ti_dport ti_t.th_dport
#define ti_seq ti_t.th_seq
#define ti_ack ti_t.th_ack
#define ti_x2 ti_t.th_x2
#define ti_off ti_t.th_off
#define ti_flags ti_t.th_flags
#define ti_win ti_t.th_win
#define ti_sum ti_t.th_sum
#define ti_urp ti_t.th_urp
/*
* SACK option block.
*/
struct sackblk {
tcp_seq left; /* Left edge of sack block. */
tcp_seq right; /* Right edge of sack block. */
};
TAILQ_HEAD(sackhead, sackhole);
struct sackhole {
tcp_seq start;
tcp_seq end;
tcp_seq rxmit;
TAILQ_ENTRY(sackhole) sackhole_q;
};
/*
* Tcp control block, one per tcp; fields:
*/
struct tcpcb {
int t_family; /* address family on the wire */
struct ipqehead segq; /* sequencing queue */
int t_segqlen; /* length of the above */
callout_t t_timer[TCPT_NTIMERS];/* tcp timers */
short t_state; /* state of this connection */
short t_rxtshift; /* log(2) of rexmt exp. backoff */
uint32_t t_rxtcur; /* current retransmit value */
short t_dupacks; /* consecutive dup acks recd */
/*
* t_partialacks:
* <0 not in fast recovery.
* ==0 in fast recovery. has not received partial acks
* >0 in fast recovery. has received partial acks
*/
short t_partialacks; /* partials acks during fast rexmit */
u_short t_peermss; /* peer's maximum segment size */
u_short t_ourmss; /* our's maximum segment size */
u_short t_segsz; /* current segment size in use */
char t_force; /* 1 if forcing out a byte */
u_int t_flags;
#define TF_ACKNOW 0x0001 /* ack peer immediately */
#define TF_DELACK 0x0002 /* ack, but try to delay it */
#define TF_NODELAY 0x0004 /* don't delay packets to coalesce */
#define TF_NOOPT 0x0008 /* don't use tcp options */
#define TF_REQ_SCALE 0x0020 /* have/will request window scaling */
#define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */
#define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */
#define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */
#define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */
#define TF_SYN_REXMT 0x0400 /* rexmit timer fired on SYN */
#define TF_WILL_SACK 0x0800 /* try to use SACK */
#define TF_REASSEMBLING 0x1000 /* we're busy reassembling */
#define TF_DEAD 0x2000 /* dead and to-be-released */
#define TF_PMTUD_PEND 0x4000 /* Path MTU Discovery pending */
#define TF_ECN_PERMIT 0x10000 /* other side said is ECN-ready */
#define TF_ECN_SND_CWR 0x20000 /* ECN CWR in queue */
#define TF_ECN_SND_ECE 0x40000 /* ECN ECE in queue */
#define TF_SIGNATURE 0x400000 /* require MD5 digests (RFC2385) */
struct mbuf *t_template; /* skeletal packet for transmit */
struct inpcb *t_inpcb; /* back pointer to internet pcb */
struct in6pcb *t_in6pcb; /* back pointer to internet pcb */
callout_t t_delack_ch; /* delayed ACK callout */
/*
* The following fields are used as in the protocol specification.
* See RFC793, Dec. 1981, page 21.
*/
/* send sequence variables */
tcp_seq snd_una; /* send unacknowledged */
tcp_seq snd_nxt; /* send next */
tcp_seq snd_up; /* send urgent pointer */
tcp_seq snd_wl1; /* window update seg seq number */
tcp_seq snd_wl2; /* window update seg ack number */
tcp_seq iss; /* initial send sequence number */
u_long snd_wnd; /* send window */
/*
* snd_recover
* it's basically same as the "recover" variable in RFC 2852 (NewReno).
* when entering fast retransmit, it's set to snd_max.
* newreno uses this to detect partial ack.
* snd_high
* it's basically same as the "send_high" variable in RFC 2852 (NewReno).
* on each RTO, it's set to snd_max.
* newreno uses this to avoid false fast retransmits.
*/
tcp_seq snd_recover;
tcp_seq snd_high;
/* receive sequence variables */
u_long rcv_wnd; /* receive window */
tcp_seq rcv_nxt; /* receive next */
tcp_seq rcv_up; /* receive urgent pointer */
tcp_seq irs; /* initial receive sequence number */
/*
* Additional variables for this implementation.
*/
/* receive variables */
tcp_seq rcv_adv; /* advertised window */
/*
* retransmit variables
*
* snd_max
* the highest sequence number we've ever sent.
* used to recognize retransmits.
*/
tcp_seq snd_max;
/* congestion control (for slow start, source quench, retransmit after loss) */
u_long snd_cwnd; /* congestion-controlled window */
u_long snd_ssthresh; /* snd_cwnd size threshhold for
* for slow start exponential to
* linear switch
*/
/* auto-sizing variables */
u_int rfbuf_cnt; /* recv buffer autoscaling byte count */
uint32_t rfbuf_ts; /* recv buffer autoscaling timestamp */
/*
* transmit timing stuff. See below for scale of srtt and rttvar.
* "Variance" is actually smoothed difference.
*/
uint32_t t_rcvtime; /* time last segment received */
uint32_t t_rtttime; /* time we started measuring rtt */
tcp_seq t_rtseq; /* sequence number being timed */
int32_t t_srtt; /* smoothed round-trip time */
int32_t t_rttvar; /* variance in round-trip time */
uint32_t t_rttmin; /* minimum rtt allowed */
u_long max_sndwnd; /* largest window peer has offered */
/* out-of-band data */
char t_oobflags; /* have some */
char t_iobc; /* input character */
#define TCPOOB_HAVEDATA 0x01
#define TCPOOB_HADDATA 0x02
short t_softerror; /* possible error not yet reported */
/* RFC 1323 variables */
u_char snd_scale; /* window scaling for send window */
u_char rcv_scale; /* window scaling for recv window */
u_char request_r_scale; /* pending window scaling */
u_char requested_s_scale;
u_int32_t ts_recent; /* timestamp echo data */
u_int32_t ts_recent_age; /* when last updated */
u_int32_t ts_timebase; /* our timebase */
tcp_seq last_ack_sent;
/* RFC 3465 variables */
u_long t_bytes_acked; /* ABC "bytes_acked" parameter */
/* SACK stuff */
#define TCP_SACK_MAX 3
#define TCPSACK_NONE 0
#define TCPSACK_HAVED 1
u_char rcv_sack_flags; /* SACK flags. */
struct sackblk rcv_dsack_block; /* RX D-SACK block. */
struct ipqehead timeq; /* time sequenced queue. */
struct sackhead snd_holes; /* TX SACK holes. */
int snd_numholes; /* Number of TX SACK holes. */
tcp_seq rcv_lastsack; /* last seq number(+1) sack'd by rcv'r*/
tcp_seq sack_newdata; /* New data xmitted in this recovery
episode starts at this seq number*/
tcp_seq snd_fack; /* FACK TCP. Forward-most data held by
peer. */
/* CUBIC variables */
ulong snd_cubic_wmax; /* W_max */
ulong snd_cubic_wmax_last; /* Used for fast convergence */
ulong snd_cubic_ctime; /* Last congestion time */
/* pointer for syn cache entries*/
LIST_HEAD(, syn_cache) t_sc; /* list of entries by this tcb */
/* prediction of next mbuf when using large window sizes */
struct mbuf *t_lastm; /* last mbuf that data was sent from */
int t_inoff; /* data offset in previous mbuf */
int t_lastoff; /* last data address in mbuf chain */
int t_lastlen; /* last length read from mbuf chain */
/* Path-MTU discovery blackhole detection */
int t_mtudisc; /* perform mtudisc for this tcb */
/* Path-MTU Discovery Information */
u_int t_pmtud_mss_acked; /* MSS acked, lower bound for MTU */
u_int t_pmtud_mtu_sent; /* MTU used, upper bound for MTU */
tcp_seq t_pmtud_th_seq; /* TCP SEQ from ICMP payload */
u_int t_pmtud_nextmtu; /* Advertised Next-Hop MTU from ICMP */
u_short t_pmtud_ip_len; /* IP length from ICMP payload */
u_short t_pmtud_ip_hl; /* IP header length from ICMP payload */
uint8_t t_ecn_retries; /* # of ECN setup retries */
const struct tcp_congctl *t_congctl; /* per TCB congctl algorithm */
/* Keepalive per socket */
u_int t_keepinit;
u_int t_keepidle;
u_int t_keepintvl;
u_int t_keepcnt;
u_int t_maxidle; /* t_keepcnt * t_keepintvl */
u_int t_msl; /* MSL to use for this connexion */
/* maintain a few stats per connection: */
uint32_t t_rcvoopack; /* out-of-order packets received */
uint32_t t_sndrexmitpack; /* retransmit packets sent */
uint32_t t_sndzerowin; /* zero-window updates sent */
};
/*
* Macros to aid ECN TCP.
*/
#define TCP_ECN_ALLOWED(tp) (tp->t_flags & TF_ECN_PERMIT)
/*
* Macros to aid SACK/FACK TCP.
*/
#define TCP_SACK_ENABLED(tp) (tp->t_flags & TF_WILL_SACK)
#define TCP_FACK_FASTRECOV(tp) \
(TCP_SACK_ENABLED(tp) && \
(SEQ_GT(tp->snd_fack, tp->snd_una + tcprexmtthresh * tp->t_segsz)))
#ifdef _KERNEL
/*
* TCP reassembly queue locks.
*/
static __inline int tcp_reass_lock_try (struct tcpcb *)
__unused;
static __inline void tcp_reass_unlock (struct tcpcb *)
__unused;
static __inline int
tcp_reass_lock_try(struct tcpcb *tp)
{
int s;
/*
* Use splvm() -- we're blocking things that would cause
* mbuf allocation.
*/
s = splvm();
if (tp->t_flags & TF_REASSEMBLING) {
splx(s);
return (0);
}
tp->t_flags |= TF_REASSEMBLING;
splx(s);
return (1);
}
static __inline void
tcp_reass_unlock(struct tcpcb *tp)
{
int s;
s = splvm();
KASSERT((tp->t_flags & TF_REASSEMBLING) != 0);
tp->t_flags &= ~TF_REASSEMBLING;
splx(s);
}
#ifdef DIAGNOSTIC
#define TCP_REASS_LOCK(tp) \
do { \
if (tcp_reass_lock_try(tp) == 0) { \
printf("%s:%d: tcpcb %p reass already locked\n", \
__FILE__, __LINE__, tp); \
panic("tcp_reass_lock"); \
} \
} while (/*CONSTCOND*/ 0)
#define TCP_REASS_LOCK_CHECK(tp) \
do { \
if (((tp)->t_flags & TF_REASSEMBLING) == 0) { \
printf("%s:%d: tcpcb %p reass lock not held\n", \
__FILE__, __LINE__, tp); \
panic("tcp reass lock check"); \
} \
} while (/*CONSTCOND*/ 0)
#else
#define TCP_REASS_LOCK(tp) (void) tcp_reass_lock_try((tp))
#define TCP_REASS_LOCK_CHECK(tp) /* nothing */
#endif
#define TCP_REASS_UNLOCK(tp) tcp_reass_unlock((tp))
#endif /* _KERNEL */
/*
* Queue for delayed ACK processing.
*/
#ifdef _KERNEL
extern int tcp_delack_ticks;
void tcp_delack(void *);
#define TCP_RESTART_DELACK(tp) \
callout_reset(&(tp)->t_delack_ch, tcp_delack_ticks, \
tcp_delack, tp)
#define TCP_SET_DELACK(tp) \
do { \
if (((tp)->t_flags & TF_DELACK) == 0) { \
(tp)->t_flags |= TF_DELACK; \
TCP_RESTART_DELACK(tp); \
} \
} while (/*CONSTCOND*/0)
#define TCP_CLEAR_DELACK(tp) \
do { \
if ((tp)->t_flags & TF_DELACK) { \
(tp)->t_flags &= ~TF_DELACK; \
callout_stop(&(tp)->t_delack_ch); \
} \
} while (/*CONSTCOND*/0)
#endif /* _KERNEL */
/*
* Compute the current timestamp for a connection.
*/
#define TCP_TIMESTAMP(tp) (tcp_now - (tp)->ts_timebase)
/*
* Handy way of passing around TCP option info.
*/
struct tcp_opt_info {
int ts_present;
u_int32_t ts_val;
u_int32_t ts_ecr;
u_int16_t maxseg;
};
#define TOF_SIGNATURE 0x0040 /* signature option present */
#define TOF_SIGLEN 0x0080 /* sigature length valid (RFC2385) */
/*
* 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 */
};
#define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb)
#ifdef INET6
#define in6totcpcb(ip) ((struct tcpcb *)(ip)->in6p_ppcb)
#endif
#ifndef INET6
#define sototcpcb(so) (intotcpcb(sotoinpcb(so)))
#else
#define sototcpcb(so) (((so)->so_proto->pr_domain->dom_family == AF_INET) \
? intotcpcb(sotoinpcb(so)) \
: in6totcpcb(sotoin6pcb(so)))
#endif
/*
* See RFC2988 for a discussion of RTO calculation; comments assume
* familiarity with that document.
*
* The smoothed round-trip time and estimated variance are stored as
* fixed point numbers. Historically, srtt was scaled by
* TCP_RTT_SHIFT bits, and rttvar by TCP_RTTVAR_SHIFT bits. Because
* the values coincide with the alpha and beta parameters suggested
* for RTO calculation (1/8 for srtt, 1/4 for rttvar), the combination
* of computing 1/8 of the new value and transforming it to the
* fixed-point representation required zero instructions. However,
* the storage representations no longer coincide with the alpha/beta
* shifts; instead, more fractional bits are present.
*
* The storage representation of srtt is 1/32 slow ticks, or 1/64 s.
* (The assumption that a slow tick is 500 ms should not be present in
* the code.)
*
* The storage representation of rttvar is 1/16 slow ticks, or 1/32 s.
* There may be some confusion about this in the code.
*
* For historical reasons, these scales are also used in smoothing the
* average (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
* This results in alpha of 0.125 and beta of 0.25, following RFC2988
* section 2.3
*
* XXX Change SHIFT values to LGWEIGHT and REP_SHIFT, and adjust
* the code to use the correct ones.
*/
#define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */
#define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */
/*
* Compute TCP retransmission timer, following RFC2988.
* This macro returns a value in slow timeout ticks.
*
* Section 2.2 requires that the RTO value be
* srtt + max(G, 4*RTTVAR)
* where G is the clock granularity.
*
* This comment has not necessarily been updated for the new storage
* representation:
*
* Because of the way we do the smoothing, srtt and rttvar
* will each average +1/2 tick of bias. When we compute
* the retransmit timer, we want 1/2 tick of rounding and
* 1 extra tick because of +-1/2 tick uncertainty in the
* firing of the timer. The bias will give us exactly the
* 1.5 tick we need. But, because the bias is
* statistical, we have to test that we don't drop below
* the minimum feasible timer (which is 2 ticks).
* This macro assumes that the value of 1<<TCP_RTTVAR_SHIFT
* is the same as the multiplier for rttvar.
*
* This macro appears to be wrong; it should be checking rttvar*4 in
* ticks and making sure we use 1 instead if rttvar*4 rounds to 0. It
* appears to be treating srtt as being in the old storage
* representation, resulting in a factor of 4 extra.
*/
#define TCP_REXMTVAL(tp) \
((((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) >> 2)
/*
* Compute the initial window for slow start.
*/
#define TCP_INITIAL_WINDOW(iw, segsz) \
uimin((iw) * (segsz), uimax(2 * (segsz), tcp_init_win_max[(iw)]))
/*
* TCP statistics.
* Each counter is an unsigned 64-bit value.
*
* Many of these should be kept per connection, but that's inconvenient
* at the moment.
*/
#define TCP_STAT_CONNATTEMPT 0 /* connections initiated */
#define TCP_STAT_ACCEPTS 1 /* connections accepted */
#define TCP_STAT_CONNECTS 2 /* connections established */
#define TCP_STAT_DROPS 3 /* connections dropped */
#define TCP_STAT_CONNDROPS 4 /* embryonic connections dropped */
#define TCP_STAT_CLOSED 5 /* conn. closed (includes drops) */
#define TCP_STAT_SEGSTIMED 6 /* segs where we tried to get rtt */
#define TCP_STAT_RTTUPDATED 7 /* times we succeeded */
#define TCP_STAT_DELACK 8 /* delayed ACKs sent */
#define TCP_STAT_TIMEOUTDROP 9 /* conn. dropped in rxmt timeout */
#define TCP_STAT_REXMTTIMEO 10 /* retransmit timeouts */
#define TCP_STAT_PERSISTTIMEO 11 /* persist timeouts */
#define TCP_STAT_KEEPTIMEO 12 /* keepalive timeouts */
#define TCP_STAT_KEEPPROBE 13 /* keepalive probes sent */
#define TCP_STAT_KEEPDROPS 14 /* connections dropped in keepalive */
#define TCP_STAT_PERSISTDROPS 15 /* connections dropped in persist */
#define TCP_STAT_CONNSDRAINED 16 /* connections drained due to memory
shortage */
#define TCP_STAT_PMTUBLACKHOLE 17 /* PMTUD blackhole detected */
#define TCP_STAT_SNDTOTAL 18 /* total packets sent */
#define TCP_STAT_SNDPACK 19 /* data packlets sent */
#define TCP_STAT_SNDBYTE 20 /* data bytes sent */
#define TCP_STAT_SNDREXMITPACK 21 /* data packets retransmitted */
#define TCP_STAT_SNDREXMITBYTE 22 /* data bytes retransmitted */
#define TCP_STAT_SNDACKS 23 /* ACK-only packets sent */
#define TCP_STAT_SNDPROBE 24 /* window probes sent */
#define TCP_STAT_SNDURG 25 /* packets sent with URG only */
#define TCP_STAT_SNDWINUP 26 /* window update-only packets sent */
#define TCP_STAT_SNDCTRL 27 /* control (SYN|FIN|RST) packets sent */
#define TCP_STAT_RCVTOTAL 28 /* total packets received */
#define TCP_STAT_RCVPACK 29 /* packets received in sequence */
#define TCP_STAT_RCVBYTE 30 /* bytes received in sequence */
#define TCP_STAT_RCVBADSUM 31 /* packets received with cksum errs */
#define TCP_STAT_RCVBADOFF 32 /* packets received with bad offset */
#define TCP_STAT_RCVMEMDROP 33 /* packets dropped for lack of memory */
#define TCP_STAT_RCVSHORT 34 /* packets received too short */
#define TCP_STAT_RCVDUPPACK 35 /* duplicate-only packets received */
#define TCP_STAT_RCVDUPBYTE 36 /* duplicate-only bytes received */
#define TCP_STAT_RCVPARTDUPPACK 37 /* packets with some duplicate data */
#define TCP_STAT_RCVPARTDUPBYTE 38 /* dup. bytes in part-dup. packets */
#define TCP_STAT_RCVOOPACK 39 /* out-of-order packets received */
#define TCP_STAT_RCVOOBYTE 40 /* out-of-order bytes received */
#define TCP_STAT_RCVPACKAFTERWIN 41 /* packets with data after window */
#define TCP_STAT_RCVBYTEAFTERWIN 42 /* bytes received after window */
#define TCP_STAT_RCVAFTERCLOSE 43 /* packets received after "close" */
#define TCP_STAT_RCVWINPROBE 44 /* rcvd window probe packets */
#define TCP_STAT_RCVDUPACK 45 /* rcvd duplicate ACKs */
#define TCP_STAT_RCVACKTOOMUCH 46 /* rcvd ACKs for unsent data */
#define TCP_STAT_RCVACKPACK 47 /* rcvd ACK packets */
#define TCP_STAT_RCVACKBYTE 48 /* bytes ACKed by rcvd ACKs */
#define TCP_STAT_RCVWINUPD 49 /* rcvd window update packets */
#define TCP_STAT_PAWSDROP 50 /* segments dropped due to PAWS */
#define TCP_STAT_PREDACK 51 /* times hdr predict OK for ACKs */
#define TCP_STAT_PREDDAT 52 /* times hdr predict OK for data pkts */
#define TCP_STAT_PCBHASHMISS 53 /* input packets missing PCB hash */
#define TCP_STAT_NOPORT 54 /* no socket on port */
#define TCP_STAT_BADSYN 55 /* received ACK for which we have
no SYN in compressed state */
#define TCP_STAT_DELAYED_FREE 56 /* delayed pool_put() of tcpcb */
#define TCP_STAT_SC_ADDED 57 /* # of sc entries added */
#define TCP_STAT_SC_COMPLETED 58 /* # of sc connections completed */
#define TCP_STAT_SC_TIMED_OUT 59 /* # of sc entries timed out */
#define TCP_STAT_SC_OVERFLOWED 60 /* # of sc drops due to overflow */
#define TCP_STAT_SC_RESET 61 /* # of sc drops due to RST */
#define TCP_STAT_SC_UNREACH 62 /* # of sc drops due to ICMP unreach */
#define TCP_STAT_SC_BUCKETOVERFLOW 63 /* # of sc drops due to bucket ovflow */
#define TCP_STAT_SC_ABORTED 64 /* # of sc entries aborted (no mem) */
#define TCP_STAT_SC_DUPESYN 65 /* # of duplicate SYNs received */
#define TCP_STAT_SC_DROPPED 66 /* # of SYNs dropped (no route/mem) */
#define TCP_STAT_SC_COLLISIONS 67 /* # of sc hash collisions */
#define TCP_STAT_SC_RETRANSMITTED 68 /* # of sc retransmissions */
#define TCP_STAT_SC_DELAYED_FREE 69 /* # of delayed pool_put()s */
#define TCP_STAT_SELFQUENCH 70 /* # of ENOBUFS we get on output */
#define TCP_STAT_BADSIG 71 /* # of drops due to bad signature */
#define TCP_STAT_GOODSIG 72 /* # of packets with good signature */
#define TCP_STAT_ECN_SHS 73 /* # of successful ECN handshakes */
#define TCP_STAT_ECN_CE 74 /* # of packets with CE bit */
#define TCP_STAT_ECN_ECT 75 /* # of packets with ECT(0) bit */
#define TCP_NSTATS 76
/*
* Names for TCP sysctl objects.
*/
#define TCPCTL_RFC1323 1 /* RFC1323 timestamps/scaling */
#define TCPCTL_SENDSPACE 2 /* default send buffer */
#define TCPCTL_RECVSPACE 3 /* default recv buffer */
#define TCPCTL_MSSDFLT 4 /* default seg size */
#define TCPCTL_SYN_CACHE_LIMIT 5 /* max size of comp. state engine */
#define TCPCTL_SYN_BUCKET_LIMIT 6 /* max size of hash bucket */
#if 0 /*obsoleted*/
#define TCPCTL_SYN_CACHE_INTER 7 /* interval of comp. state timer */
#endif
#define TCPCTL_INIT_WIN 8 /* initial window */
#define TCPCTL_MSS_IFMTU 9 /* mss from interface, not in_maxmtu */
#define TCPCTL_SACK 10 /* RFC2018 selective acknowledgement */
#define TCPCTL_WSCALE 11 /* RFC1323 window scaling */
#define TCPCTL_TSTAMP 12 /* RFC1323 timestamps */
#if 0 /*obsoleted*/
#define TCPCTL_COMPAT_42 13 /* 4.2BSD TCP bug work-arounds */
#endif
#define TCPCTL_CWM 14 /* Congestion Window Monitoring */
#define TCPCTL_CWM_BURSTSIZE 15 /* burst size allowed by CWM */
#define TCPCTL_ACK_ON_PUSH 16 /* ACK immediately on PUSH */
#define TCPCTL_KEEPIDLE 17 /* keepalive idle time */
#define TCPCTL_KEEPINTVL 18 /* keepalive probe interval */
#define TCPCTL_KEEPCNT 19 /* keepalive count */
#define TCPCTL_SLOWHZ 20 /* PR_SLOWHZ (read-only) */
#define TCPCTL_NEWRENO 21 /* NewReno Congestion Control */
#define TCPCTL_LOG_REFUSED 22 /* Log refused connections */
#if 0 /*obsoleted*/
#define TCPCTL_RSTRATELIMIT 23 /* RST rate limit */
#endif
#define TCPCTL_RSTPPSLIMIT 24 /* RST pps limit */
#define TCPCTL_DELACK_TICKS 25 /* # ticks to delay ACK */
#define TCPCTL_INIT_WIN_LOCAL 26 /* initial window for local nets */
#define TCPCTL_IDENT 27 /* rfc 931 identd */
#define TCPCTL_ACKDROPRATELIMIT 28 /* SYN/RST -> ACK rate limit */
#define TCPCTL_LOOPBACKCKSUM 29 /* do TCP checksum on loopback */
#define TCPCTL_STATS 30 /* TCP statistics */
#define TCPCTL_DEBUG 31 /* TCP debug sockets */
#define TCPCTL_DEBX 32 /* # of tcp debug sockets */
#define TCPCTL_DROP 33 /* drop tcp connection */
#define TCPCTL_MSL 34 /* Max Segment Life */
#ifdef _KERNEL
extern struct inpcbtable tcbtable; /* head of queue of active tcpcb's */
extern const struct pr_usrreqs tcp_usrreqs;
extern u_int32_t tcp_now; /* for RFC 1323 timestamps */
extern int tcp_do_rfc1323; /* enabled/disabled? */
extern int tcp_do_sack; /* SACK enabled/disabled? */
extern int tcp_do_win_scale; /* RFC1323 window scaling enabled/disabled? */
extern int tcp_do_timestamps; /* RFC1323 timestamps enabled/disabled? */
extern int tcp_mssdflt; /* default seg size */
extern int tcp_minmss; /* minimal seg size */
extern int tcp_msl; /* max segment life */
extern int tcp_init_win; /* initial window */
extern int tcp_init_win_local; /* initial window for local nets */
extern int tcp_init_win_max[11];/* max sizes for values of tcp_init_win_* */
extern int tcp_mss_ifmtu; /* take MSS from interface, not in_maxmtu */
extern int tcp_cwm; /* enable Congestion Window Monitoring */
extern int tcp_cwm_burstsize; /* burst size allowed by CWM */
extern int tcp_ack_on_push; /* ACK immediately on PUSH */
extern int tcp_syn_cache_limit; /* max entries for compressed state engine */
extern int tcp_syn_bucket_limit;/* max entries per hash bucket */
extern int tcp_log_refused; /* log refused connections */
extern int tcp_do_ecn; /* TCP ECN enabled/disabled? */
extern int tcp_ecn_maxretries; /* Max ECN setup retries */
extern int tcp_do_rfc1948; /* ISS by cryptographic hash */
extern int tcp_sack_tp_maxholes; /* Max holes per connection. */
extern int tcp_sack_globalmaxholes; /* Max holes per system. */
extern int tcp_sack_globalholes; /* Number of holes present. */
extern int tcp_do_abc; /* RFC3465 ABC enabled/disabled? */
extern int tcp_abc_aggressive; /* 1: L=2*SMSS 0: L=1*SMSS */
extern int tcp_msl_enable; /* enable TIME_WAIT truncation */
extern int tcp_msl_loop; /* MSL for loopback */
extern int tcp_msl_local; /* MSL for 'local' */
extern int tcp_msl_remote; /* MSL otherwise */
extern int tcp_msl_remote_threshold; /* RTT threshold */
extern int tcp_rttlocal; /* Use RTT to decide who's 'local' */
extern int tcp4_vtw_enable;
extern int tcp6_vtw_enable;
extern int tcp_vtw_was_enabled;
extern int tcp_vtw_entries;
extern int tcp_rst_ppslim;
extern int tcp_ackdrop_ppslim;
extern int tcp_syn_cache_size;
extern struct syn_cache_head tcp_syn_cache[];
extern u_long syn_cache_count;
#ifdef MBUFTRACE
extern struct mowner tcp_rx_mowner;
extern struct mowner tcp_tx_mowner;
extern struct mowner tcp_reass_mowner;
extern struct mowner tcp_sock_mowner;
extern struct mowner tcp_sock_rx_mowner;
extern struct mowner tcp_sock_tx_mowner;
extern struct mowner tcp_mowner;
#endif
extern int tcp_do_autorcvbuf;
extern int tcp_autorcvbuf_inc;
extern int tcp_autorcvbuf_max;
extern int tcp_do_autosndbuf;
extern int tcp_autosndbuf_inc;
extern int tcp_autosndbuf_max;
struct secasvar;
void tcp_canceltimers(struct tcpcb *);
struct tcpcb *
tcp_close(struct tcpcb *);
int tcp_isdead(struct tcpcb *);
#ifdef INET6
void *tcp6_ctlinput(int, const struct sockaddr *, void *);
#endif
void *tcp_ctlinput(int, const struct sockaddr *, void *);
int tcp_ctloutput(int, struct socket *, struct sockopt *);
struct tcpcb *
tcp_disconnect1(struct tcpcb *);
struct tcpcb *
tcp_drop(struct tcpcb *, int);
#ifdef TCP_SIGNATURE
int tcp_signature_apply(void *, void *, u_int);
struct secasvar *tcp_signature_getsav(struct mbuf *);
int tcp_signature(struct mbuf *, struct tcphdr *, int, struct secasvar *,
char *);
#endif
void tcp_drain(void);
void tcp_drainstub(void);
void tcp_established(struct tcpcb *);
void tcp_init(void);
void tcp_init_common(unsigned);
#ifdef INET6
int tcp6_input(struct mbuf **, int *, int);
#endif
void tcp_input(struct mbuf *, int, int);
u_int tcp_hdrsz(struct tcpcb *);
u_long tcp_mss_to_advertise(const struct ifnet *, int);
void tcp_mss_from_peer(struct tcpcb *, int);
void tcp_tcpcb_template(void);
struct tcpcb *
tcp_newtcpcb(int, void *);
void tcp_notify(struct inpcb *, int);
#ifdef INET6
void tcp6_notify(struct in6pcb *, int);
#endif
u_int tcp_optlen(struct tcpcb *);
int tcp_output(struct tcpcb *);
void tcp_pulloutofband(struct socket *,
struct tcphdr *, struct mbuf *, int);
void tcp_quench(struct inpcb *);
#ifdef INET6
void tcp6_quench(struct in6pcb *);
#endif
void tcp_mtudisc(struct inpcb *, int);
#ifdef INET6
void tcp6_mtudisc_callback(struct in6_addr *);
#endif
void tcpipqent_init(void);
struct ipqent *tcpipqent_alloc(void);
void tcpipqent_free(struct ipqent *);
int tcp_respond(struct tcpcb *, struct mbuf *, struct mbuf *,
struct tcphdr *, tcp_seq, tcp_seq, int);
void tcp_rmx_rtt(struct tcpcb *);
void tcp_setpersist(struct tcpcb *);
#ifdef TCP_SIGNATURE
int tcp_signature_compute(struct mbuf *, struct tcphdr *, int, int,
int, u_char *, u_int);
#endif
void tcp_fasttimo(void);
struct mbuf *
tcp_template(struct tcpcb *);
void tcp_trace(short, short, struct tcpcb *, struct mbuf *, int);
struct tcpcb *
tcp_usrclosed(struct tcpcb *);
void tcp_usrreq_init(void);
void tcp_xmit_timer(struct tcpcb *, uint32_t);
tcp_seq tcp_new_iss(struct tcpcb *, tcp_seq);
tcp_seq tcp_new_iss1(void *, void *, u_int16_t, u_int16_t, size_t,
tcp_seq);
void tcp_sack_init(void);
void tcp_new_dsack(struct tcpcb *, tcp_seq, u_int32_t);
void tcp_sack_option(struct tcpcb *, const struct tcphdr *,
const u_char *, int);
void tcp_del_sackholes(struct tcpcb *, const struct tcphdr *);
void tcp_free_sackholes(struct tcpcb *);
void tcp_sack_adjust(struct tcpcb *tp);
struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt);
int tcp_sack_numblks(const struct tcpcb *);
#define TCP_SACK_OPTLEN(nblks) ((nblks) * 8 + 2 + 2)
void tcp_statinc(u_int);
void tcp_statadd(u_int, uint64_t);
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 *);
struct syn_cache *syn_cache_lookup(const struct sockaddr *, const struct sockaddr *,
struct syn_cache_head **);
void syn_cache_reset(struct sockaddr *, struct sockaddr *,
struct tcphdr *);
int syn_cache_respond(struct syn_cache *);
void syn_cache_cleanup(struct tcpcb *);
int tcp_input_checksum(int, struct mbuf *, const struct tcphdr *, int, int,
int);
#endif
#endif /* !_NETINET_TCP_VAR_H_ */