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NetBSD/sys/netinet/tcp_var.h

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/* $NetBSD: tcp_var.h,v 1.22 1997/08/29 16:02:43 gwr Exp $ */
/*
* Copyright (c) 1982, 1986, 1993, 1994
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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 8.3 (Berkeley) 4/10/94
*/
/*
* Kernel variables for tcp.
*/
/*
* Tcp control block, one per tcp; fields:
*/
struct tcpcb {
struct ipqehead segq; /* sequencing queue */
short t_state; /* state of this connection */
short t_timer[TCPT_NTIMERS]; /* tcp timers */
short t_rxtshift; /* log(2) of rexmt exp. backoff */
short t_rxtcur; /* current retransmit value */
short t_dupacks; /* consecutive dup acks recd */
u_short t_maxseg; /* maximum segment size */
char t_force; /* 1 if forcing out a byte */
u_short 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_SENTFIN 0x0010 /* have sent FIN */
#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 */
struct tcpiphdr *t_template; /* skeletal packet for transmit */
struct inpcb *t_inpcb; /* back pointer to internet pcb */
/*
* The following fields are used as in the protocol specification.
* See RFC783, 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 */
/* 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 */
tcp_seq snd_max; /* highest sequence number sent;
* used to recognize retransmits
*/
/* 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
*/
/*
* transmit timing stuff. See below for scale of srtt and rttvar.
* "Variance" is actually smoothed difference.
*/
short t_idle; /* inactivity time */
short t_rtt; /* round trip time */
tcp_seq t_rtseq; /* sequence number being timed */
short t_srtt; /* smoothed round-trip time */
short t_rttvar; /* variance in round-trip time */
short 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 */
tcp_seq last_ack_sent;
/* TUBA stuff */
caddr_t t_tuba_pcb; /* next level down pcb for TCP over z */
};
/*
* 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;
};
/*
* This structure should not exceed 32 bytes.
* XXX On the Alpha, it's already 36-bytes, which rounds to 40.
* XXX Need to eliminate the pointer.
*/
struct syn_cache {
struct syn_cache *sc_next;
u_int32_t sc_tstmp : 1,
sc_hash : 31;
struct in_addr sc_src;
struct in_addr sc_dst;
tcp_seq sc_irs;
tcp_seq sc_iss;
u_int16_t sc_sport;
u_int16_t sc_dport;
u_int16_t sc_peermaxseg;
u_int8_t sc_timer;
u_int8_t sc_request_r_scale : 4,
sc_requested_s_scale : 4;
};
struct syn_cache_head {
struct syn_cache *sch_first; /* First entry in the bucket */
struct syn_cache *sch_last; /* Last entry in the bucket */
struct syn_cache_head *sch_headq; /* The next non-empty bucket */
int16_t sch_timer_sum; /* Total time in this bucket */
u_int16_t sch_length; /* @ # elements in bucket */
};
#define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb)
#define sototcpcb(so) (intotcpcb(sotoinpcb(so)))
/*
* The smoothed round-trip time and estimated variance
* are stored as fixed point numbers scaled by the values below.
* For convenience, these scales are also used in smoothing the average
* (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
* With these scales, srtt has 3 bits to the right of the binary point,
* and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
* binary point, and is smoothed with an ALPHA of 0.75.
*/
#define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */
#define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */
/*
* The initial retransmission should happen at rtt + 4 * rttvar.
* 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.
*/
#define TCP_REXMTVAL(tp) \
((((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) >> 2)
/*
* TCP statistics.
* Many of these should be kept per connection,
* but that's inconvenient at the moment.
*/
struct tcpstat {
u_long tcps_connattempt; /* connections initiated */
u_long tcps_accepts; /* connections accepted */
u_long tcps_connects; /* connections established */
u_long tcps_drops; /* connections dropped */
u_long tcps_conndrops; /* embryonic connections dropped */
u_long tcps_closed; /* conn. closed (includes drops) */
u_long tcps_segstimed; /* segs where we tried to get rtt */
u_long tcps_rttupdated; /* times we succeeded */
u_long tcps_delack; /* delayed acks sent */
u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
u_long tcps_rexmttimeo; /* retransmit timeouts */
u_long tcps_persisttimeo; /* persist timeouts */
u_long tcps_keeptimeo; /* keepalive timeouts */
u_long tcps_keepprobe; /* keepalive probes sent */
u_long tcps_keepdrops; /* connections dropped in keepalive */
u_long tcps_sndtotal; /* total packets sent */
u_long tcps_sndpack; /* data packets sent */
u_long tcps_sndbyte; /* data bytes sent */
u_long tcps_sndrexmitpack; /* data packets retransmitted */
u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
u_long tcps_sndacks; /* ack-only packets sent */
u_long tcps_sndprobe; /* window probes sent */
u_long tcps_sndurg; /* packets sent with URG only */
u_long tcps_sndwinup; /* window update-only packets sent */
u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
u_long tcps_rcvtotal; /* total packets received */
u_long tcps_rcvpack; /* packets received in sequence */
u_long tcps_rcvbyte; /* bytes received in sequence */
u_long tcps_rcvbadsum; /* packets received with ccksum errs */
u_long tcps_rcvbadoff; /* packets received with bad offset */
u_long tcps_rcvmemdrop; /* packets dropped for lack of memory */
u_long tcps_rcvshort; /* packets received too short */
u_long tcps_rcvduppack; /* duplicate-only packets received */
u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
u_long tcps_rcvpartduppack; /* packets with some duplicate data */
u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
u_long tcps_rcvoopack; /* out-of-order packets received */
u_long tcps_rcvoobyte; /* out-of-order bytes received */
u_long tcps_rcvpackafterwin; /* packets with data after window */
u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
u_long tcps_rcvafterclose; /* packets rcvd after "close" */
u_long tcps_rcvwinprobe; /* rcvd window probe packets */
u_long tcps_rcvdupack; /* rcvd duplicate acks */
u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
u_long tcps_rcvackpack; /* rcvd ack packets */
u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
u_long tcps_rcvwinupd; /* rcvd window update packets */
u_long tcps_pawsdrop; /* segments dropped due to PAWS */
u_long tcps_predack; /* times hdr predict ok for acks */
u_long tcps_preddat; /* times hdr predict ok for data pkts */
u_long tcps_pcbhashmiss; /* input packets missing pcb hash */
u_long tcps_noport; /* no socket on port */
u_long tcps_badsyn; /* received ack for which we have
no SYN in compressed state */
/* These statistics deal with the SYN cache. */
u_long tcps_sc_added; /* # of entries added */
u_long tcps_sc_completed; /* # of connections completed */
u_long tcps_sc_timed_out; /* # of entries timed out */
u_long tcps_sc_overflowed; /* # dropped due to overflow */
u_long tcps_sc_reset; /* # dropped due to RST */
u_long tcps_sc_unreach; /* # dropped due to ICMP unreach */
u_long tcps_sc_bucketoverflow; /* # dropped due to bucket overflow */
u_long tcps_sc_aborted; /* # of entries aborted (no mem) */
u_long tcps_sc_dupesyn; /* # of duplicate SYNs received */
u_long tcps_sc_dropped; /* # of SYNs dropped (no route/mem) */
u_long tcps_sc_collisions; /* # of hash collisions */
};
/*
* 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 */
#define TCPCTL_SYN_CACHE_INTER 7 /* interval of comp. state timer */
#define TCPCTL_MAXID 8
#define TCPCTL_NAMES { \
{ 0, 0 }, \
{ "rfc1323", CTLTYPE_INT }, \
{ "sendspace", CTLTYPE_INT }, \
{ "recvspace", CTLTYPE_INT }, \
{ "mssdflt", CTLTYPE_INT }, \
{ "syn_cache_limit", CTLTYPE_INT }, \
{ "syn_bucket_limit", CTLTYPE_INT }, \
{ "syn_cache_interval", CTLTYPE_INT },\
}
#ifdef _KERNEL
struct inpcbtable tcbtable; /* head of queue of active tcpcb's */
struct tcpstat tcpstat; /* tcp statistics */
u_int32_t tcp_now; /* for RFC 1323 timestamps */
extern int tcp_do_rfc1323; /* enabled/disabled? */
extern int tcp_mssdflt; /* default seg size */
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_syn_cache_interval; /* compressed state timer */
extern int tcp_syn_cache_size;
extern int tcp_syn_cache_timeo;
extern struct syn_cache_head tcp_syn_cache[], *tcp_syn_cache_first;
extern u_long syn_cache_count;
int tcp_attach __P((struct socket *));
void tcp_canceltimers __P((struct tcpcb *));
struct tcpcb *
tcp_close __P((struct tcpcb *));
void *tcp_ctlinput __P((int, struct sockaddr *, void *));
int tcp_ctloutput __P((int, struct socket *, int, int, struct mbuf **));
struct tcpcb *
tcp_disconnect __P((struct tcpcb *));
struct tcpcb *
tcp_drop __P((struct tcpcb *, int));
void tcp_dooptions __P((struct tcpcb *,
u_char *, int, struct tcpiphdr *, struct tcp_opt_info *));
void tcp_drain __P((void));
void tcp_fasttimo __P((void));
void tcp_init __P((void));
void tcp_input __P((struct mbuf *, ...));
int tcp_mss __P((struct tcpcb *, u_int));
struct tcpcb *
tcp_newtcpcb __P((struct inpcb *));
void tcp_notify __P((struct inpcb *, int));
int tcp_output __P((struct tcpcb *));
void tcp_pulloutofband __P((struct socket *,
struct tcpiphdr *, struct mbuf *));
void tcp_quench __P((struct inpcb *, int));
int tcp_reass __P((struct tcpcb *, struct tcpiphdr *, struct mbuf *));
int tcp_respond __P((struct tcpcb *,
struct tcpiphdr *, struct mbuf *, tcp_seq, tcp_seq, int));
void tcp_setpersist __P((struct tcpcb *));
void tcp_slowtimo __P((void));
struct tcpiphdr *
tcp_template __P((struct tcpcb *));
struct tcpcb *
tcp_timers __P((struct tcpcb *, int));
void tcp_trace __P((int, int, struct tcpcb *, struct tcpiphdr *, int));
struct tcpcb *
tcp_usrclosed __P((struct tcpcb *));
int tcp_sysctl __P((int *, u_int, void *, size_t *, void *, size_t));
int tcp_usrreq __P((struct socket *,
int, struct mbuf *, struct mbuf *, struct mbuf *, struct proc *));
void tcp_xmit_timer __P((struct tcpcb *, int));
int syn_cache_add __P((struct socket *, struct mbuf *, u_char *,
int, struct tcp_opt_info *));
void syn_cache_unreach __P((struct ip *, struct tcphdr *));
struct socket *
syn_cache_get __P((struct socket *so, struct mbuf *));
void syn_cache_insert __P((struct syn_cache *, struct syn_cache ***,
struct syn_cache_head **));
struct syn_cache *
syn_cache_lookup __P((struct tcpiphdr *, struct syn_cache ***,
struct syn_cache_head **));
void syn_cache_reset __P((struct tcpiphdr *));
int syn_cache_respond __P((struct syn_cache *, struct mbuf *,
register struct tcpiphdr *, long, u_long));
void syn_cache_timer __P((int));
#endif
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