--- /dev/null
+/*!\file netinet/tcp_var.h
+ * Internal TCP structures and statistics.
+ */
+
+/*
+ * 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. 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 8.4 (Berkeley) 5/24/95
+ * $Id: tcp_var.h,v 1.36 1996/09/13 23:54:03 pst Exp $
+ */
+
+#ifndef __NETINET_TCP_VAR_H
+#define __NETINET_TCP_VAR_H
+
+/*
+ * Kernel variables for tcp.
+ */
+
+#ifdef TCP_AUTO
+ /* AUTO_RCV_HITHRESH flush reassembly queue, drop incoming packets
+ */
+ #define AUTO_RCV_HITHRESH (u_long)(0.95 * NMBCLUSTERS)
+
+ /* AUTO_RCV_LOWTHRESH drop incoming packets
+ */
+ #define AUTO_RCV_LOWTHRESH (u_long)(0.9 * NMBCLUSTERS)
+
+ /* AUTO_SND_THRESH reduce so_snd.sb_hiwat by acked
+ */
+ #define AUTO_SND_THRESH (u_long)(0.50 * NMBCLUSTERS)
+#endif
+
+#if defined(TCP_SACK) || defined(TCP_FACK)
+#include <netinet/tcp_scor.h>
+
+struct sackblock {
+ tcp_seq start;
+ tcp_seq end;
+ };
+#endif
+
+/*
+ * Tcp control block, one per tcp; fields:
+ */
+struct tcpcb {
+ struct tcpiphdr *seg_next; /* sequencing queue */
+ struct tcpiphdr *seg_prev;
+ /* !! struct ipqehead segq; */ /* sequencing queue */
+ int t_state; /* state of this connection */
+ int t_timer[TCPT_NTIMERS]; /* tcp timers */
+ int t_rxtshift; /* log(2) of rexmt exp. backoff */
+ int t_rxtcur; /* current retransmit value */
+#ifdef TCP_FACK
+ short t_padd; /* filler to preserve alignment */
+#else
+ short t_dupacks; /* consecutive dup acks recd */
+#endif
+ u_int t_maxseg; /* maximum segment size */
+ u_int t_maxopd; /* mss plus options */
+ int 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_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 */
+#define TF_NEEDSYN 0x0400 /* send SYN (implicit state) */
+#define TF_NEEDFIN 0x0800 /* send FIN (implicit state) */
+#define TF_NOPUSH 0x1000 /* don't push */
+#define TF_REQ_CC 0x2000 /* have/will request CC */
+#define TF_RCVD_CC 0x4000 /* a CC was received in SYN */
+#define TF_SENDCCNEW 0x8000 /* send CCnew instead of CC in SYN */
+
+ 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 threshold for
+ * for slow start exponential to
+ * linear switch
+ */
+/*
+ * transmit timing stuff. See below for scale of srtt and rttvar.
+ * "Variance" is actually smoothed difference.
+ */
+ u_int t_idle; /* inactivity time */
+ int t_rtt; /* round trip time */
+ tcp_seq t_rtseq; /* sequence number being timed */
+ int t_srtt; /* smoothed round-trip time */
+ int t_rttvar; /* variance in round-trip time */
+ u_int 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
+ int 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_long ts_recent; /* timestamp echo data */
+ u_long ts_recent_age; /* when last updated */
+ tcp_seq last_ack_sent;
+/* RFC 1644 variables */
+ tcp_cc cc_send; /* send connection count */
+ tcp_cc cc_recv; /* receive connection count */
+ u_long t_duration; /* connection duration */
+
+/* TUBA stuff */
+ caddr_t t_tuba_pcb; /* next level down pcb for TCP over z */
+/* More RTT stuff */
+ u_long t_rttupdated; /* number of times rtt sampled */
+
+#if defined(TCP_FACK) || defined(TCP_AUTO)
+ u_short t_alt_flags; /* experimental flags */
+#define TAF_SACK_SEEN 0x0001 /* other side can send SACKs */
+#define TAF_RECOVERY 0x0002 /* We are recovering from a lost segment */
+#define TAF_RATEHALF 0x0004 /* We are reducing the window during recovery */
+#define TAF_REPAIRED 0x0008 /* We have retransmitted something */
+#define TAF_WHOLD 0x0010 /* we are in the window hold state */
+#define TAF_TOGGLE 0x0020 /* divide by 2 toggle */
+#define TAF_AUTO_OFF 0x0040 /* autotuning is forced off */
+#endif
+
+#if defined(TCP_SACK) || defined(TCP_FACK)
+#define SACK_LIST_LEN 10
+
+/* Needed for SACK and FACK: */
+ struct sackblock sack_list[SACK_LIST_LEN]; /* Hack, keep 5 most recent SACKs */
+ struct scoreboard scrb;
+ int snd_retran_data;
+ tcp_seq recover;
+#endif
+#ifdef TCP_SACK
+ int pipe;
+#endif
+#ifdef TCP_FACK
+ tcp_seq snd_fack;
+#define TCP_FACK_REXMTTHRESH 3 /* number of SACKs before retransmitting a block */
+ u_long lothresh; /* recovery window floor */
+ u_long hithresh; /* maximum window following recovery */
+#endif
+};
+
+/*
+ * Structure to hold TCP options that are only used during segment
+ * processing (in tcp_input), but not held in the tcpcb.
+ * It's basically used to reduce the number of parameters
+ * to tcp_dooptions.
+ */
+struct tcpopt {
+ u_long to_flag; /* which options are present */
+#define TOF_TS 0x0001 /* timestamp */
+#define TOF_CC 0x0002 /* CC and CCnew are exclusive */
+#define TOF_CCNEW 0x0004
+#define TOF_CCECHO 0x0008
+ u_long to_tsval;
+ u_long to_tsecr;
+ tcp_cc to_cc; /* holds CC or CCnew */
+ tcp_cc to_ccecho;
+};
+
+/*
+ * The TAO cache entry which is stored in the protocol family specific
+ * portion of the route metrics.
+ */
+struct rmxp_tao {
+ tcp_cc tao_cc; /* latest CC in valid SYN */
+ tcp_cc tao_ccsent; /* latest CC sent to peer */
+ u_short tao_mssopt; /* peer's cached MSS */
+#ifdef notyet
+ u_short tao_flags; /* cache status flags */
+#define TAOF_DONT 0x0001 /* peer doesn't understand rfc1644 */
+#define TAOF_OK 0x0002 /* peer does understand rfc1644 */
+#define TAOF_UNDEF 0 /* we don't know yet */
+#endif /* notyet */
+};
+#define rmx_taop(r) ((struct rmxp_tao *)(r).rmx_filler)
+
+#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_SCALE 32 /* multiplier for srtt; 3 bits frac. */
+#define TCP_RTT_SHIFT 5 /* shift for srtt; 3 bits frac. */
+#define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */
+#define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */
+#define TCP_DELTA_SHIFT 2 /* see tcp_input.c */
+
+/*
+ * 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 version of the macro adapted from a paper by Lawrence
+ * Brakmo and Larry Peterson which outlines a problem caused
+ * by insufficient precision in the original implementation,
+ * which results in inappropriately large RTO values for very
+ * fast networks.
+ */
+#define TCP_REXMTVAL(tp) \
+ ((((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)) \
+ + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
+
+/* XXX
+ * We want to avoid doing m_pullup on incoming packets but that
+ * means avoiding dtom on the tcp reassembly code. That in turn means
+ * keeping an mbuf pointer in the reassembly queue (since we might
+ * have a cluster). As a quick hack, the source & destination
+ * port numbers (which are no longer needed once we've located the
+ * tcpcb) are overlayed with an mbuf pointer.
+ */
+#define REASS_MBUF(ti) (*(struct mbuf **)&((ti)->ti_t))
+
+/*
+ * 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_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_pcbcachemiss;
+ u_long tcps_cachedrtt; /* times cached RTT in route updated */
+ u_long tcps_cachedrttvar; /* times cached rttvar updated */
+ u_long tcps_cachedssthresh; /* times cached ssthresh updated */
+ u_long tcps_usedrtt; /* times RTT initialized from route */
+ u_long tcps_usedrttvar; /* times RTTVAR initialized from rt */
+ u_long tcps_usedssthresh; /* times ssthresh initialized from rt*/
+ u_long tcps_persistdrop; /* timeout in persist state */
+ u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */
+ u_long tcps_mturesent; /* resends due to MTU discovery */
+ u_long tcps_listendrop; /* listen queue overflows */
+
+#ifdef TCP_FACK
+ /* NOTE: This may break some programs that rely on this structure
+ * being fixed length.
+ */
+ u_long tcps_fack_recovery; /* fack: recovery episodes */
+ u_long tcps_fack_sndpack; /* fack: data packets sent */
+ u_long tcps_fack_sndbyte; /* fack: data bytes sent */
+ u_long tcps_fack_sndrexmitpack;/* fack: data packets retransmitted */
+ u_long tcps_fack_sndrexmitbyte;/* fack: data bytes retransmitted */
+#endif
+};
+
+/*
+ * Names for TCP sysctl objects
+ */
+#define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */
+#define TCPCTL_DO_RFC1644 2 /* use RFC-1644 extensions */
+#define TCPCTL_MSSDFLT 3 /* MSS default */
+#define TCPCTL_STATS 4 /* statistics (read-only) */
+#define TCPCTL_RTTDFLT 5 /* default RTT estimate */
+#define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */
+#define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */
+#define TCPCTL_SENDSPACE 8 /* send buffer space */
+#define TCPCTL_RECVSPACE 9 /* receive buffer space */
+#define TCPCTL_KEEPINIT 10 /* receive buffer space */
+#define TCPCTL_MAXID 11
+
+#define TCPCTL_NAMES { \
+ { 0, 0 }, \
+ { "rfc1323", CTLTYPE_INT }, \
+ { "rfc1644", CTLTYPE_INT }, \
+ { "mssdflt", CTLTYPE_INT }, \
+ { "stats", CTLTYPE_STRUCT }, \
+ { "rttdflt", CTLTYPE_INT }, \
+ { "keepidle", CTLTYPE_INT }, \
+ { "keepintvl", CTLTYPE_INT }, \
+ { "sendspace", CTLTYPE_INT }, \
+ { "recvspace", CTLTYPE_INT }, \
+ { "keepinit", CTLTYPE_INT }, \
+}
+
+#endif
projects / oftp / blobdiff