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| /*!\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 |