/* $OpenBSD: tcp_var.h,v 1.45 2003/02/12 14:41:08 jason Exp $ */ /* $NetBSD: tcp_var.h,v 1.17 1996/02/13 23:44:24 christos 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 */ #ifndef _NETINET_TCP_VAR_H_ #define _NETINET_TCP_VAR_H_ struct sackblk { tcp_seq start; /* start seq no. of sack block */ tcp_seq end; /* end seq no. */ }; struct sackhole { tcp_seq start; /* start seq no. of hole */ tcp_seq end; /* end seq no. */ int dups; /* number of dup(s)acks for this hole */ tcp_seq rxmit; /* next seq. no in hole to be retransmitted */ struct sackhole *next; /* next in list */ }; /* * Kernel variables for tcp. */ /* * Tcp control block, one per tcp; fields: */ struct tcpcb { struct ipqehead segq; /* sequencing queue */ struct timeout t_timer[TCPT_NTIMERS]; /* tcp timers */ short t_state; /* state of this connection */ 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_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_SIGNATURE 0x0400 /* require TCP MD5 signature */ #ifdef TCP_ECN #define TF_ECN_PERMIT 0x00008000 /* other side said I could ECN */ #define TF_RCVD_CE 0x00010000 /* send ECE in subsequent segs */ #define TF_SEND_CWR 0x00020000 /* send CWR in next seg */ #define TF_DISABLE_ECN 0x00040000 /* disable ECN for this connection */ #endif struct mbuf *t_template; /* skeletal packet for transmit */ struct inpcb *t_inpcb; /* back pointer to internet pcb */ struct timeout t_delack_to; /* delayed ACK callback */ /* * 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 */ #ifdef TCP_SACK int sack_disable; /* disable SACK for this connection */ int snd_numholes; /* number of holes seen by sender */ struct sackhole *snd_holes; /* linked list of holes (sorted) */ #if defined(TCP_SACK) && defined(TCP_FACK) tcp_seq snd_fack; /* for FACK congestion control */ u_long snd_awnd; /* snd_nxt - snd_fack + */ /* retransmitted data */ int retran_data; /* amount of outstanding retx. data */ #endif /* TCP_FACK */ #endif /* TCP_SACK */ #if defined(TCP_SACK) || defined(TCP_ECN) tcp_seq snd_last; /* for use in fast recovery */ #endif /* 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 */ #ifdef TCP_SACK tcp_seq rcv_laststart; /* start of last segment recd. */ tcp_seq rcv_lastend; /* end of ... */ tcp_seq rcv_lastsack; /* last seq number(+1) sack'd by rcv'r*/ int rcv_numsacks; /* # distinct sack blks present */ struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */ #endif /* * 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 */ u_short t_maxopd; /* mss plus options */ u_short t_peermss; /* peer's maximum segment size */ /* * 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 */ short t_srtt; /* smoothed round-trip time */ short t_rttvar; /* variance in round-trip time */ u_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 */ int pf; }; #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) #ifdef _KERNEL extern int tcp_delack_ticks; void tcp_delack(void *); #define TCP_INIT_DELACK(tp) \ timeout_set(&(tp)->t_delack_to, tcp_delack, tp) #define TCP_RESTART_DELACK(tp) \ timeout_add(&(tp)->t_delack_to, tcp_delack_ticks) #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; \ timeout_del(&(tp)->t_delack_to); \ } \ } while (/*CONSTCOND*/0) #endif /* _KERNEL */ /* * 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 8 /* multiplier for srtt; 3 bits frac. */ #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */ #define TCP_RTTVAR_SCALE 4 /* multiplier for rttvar; 2 bits */ #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 TCP_RTTVAR_SCALE * 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_int32_t tcps_connattempt; /* connections initiated */ u_int32_t tcps_accepts; /* connections accepted */ u_int32_t tcps_connects; /* connections established */ u_int32_t tcps_drops; /* connections dropped */ u_int32_t tcps_conndrops; /* embryonic connections dropped */ u_int32_t tcps_closed; /* conn. closed (includes drops) */ u_int32_t tcps_segstimed; /* segs where we tried to get rtt */ u_int32_t tcps_rttupdated; /* times we succeeded */ u_int32_t tcps_delack; /* delayed acks sent */ u_int32_t tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ u_int32_t tcps_rexmttimeo; /* retransmit timeouts */ u_int32_t tcps_persisttimeo; /* persist timeouts */ u_int32_t tcps_persistdrop; /* connections dropped in persist */ u_int32_t tcps_keeptimeo; /* keepalive timeouts */ u_int32_t tcps_keepprobe; /* keepalive probes sent */ u_int32_t tcps_keepdrops; /* connections dropped in keepalive */ u_int32_t tcps_sndtotal; /* total packets sent */ u_int32_t tcps_sndpack; /* data packets sent */ u_int64_t tcps_sndbyte; /* data bytes sent */ u_int32_t tcps_sndrexmitpack; /* data packets retransmitted */ u_int64_t tcps_sndrexmitbyte; /* data bytes retransmitted */ u_int64_t tcps_sndrexmitfast; /* Fast retransmits */ u_int32_t tcps_sndacks; /* ack-only packets sent */ u_int32_t tcps_sndprobe; /* window probes sent */ u_int32_t tcps_sndurg; /* packets sent with URG only */ u_int32_t tcps_sndwinup; /* window update-only packets sent */ u_int32_t tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ u_int32_t tcps_rcvtotal; /* total packets received */ u_int32_t tcps_rcvpack; /* packets received in sequence */ u_int64_t tcps_rcvbyte; /* bytes received in sequence */ u_int32_t tcps_rcvbadsum; /* packets received with ccksum errs */ u_int32_t tcps_rcvbadoff; /* packets received with bad offset */ u_int32_t tcps_rcvmemdrop; /* packets dropped for lack of memory */ u_int32_t tcps_rcvnosec; /* packets dropped for lack of ipsec */ u_int32_t tcps_rcvshort; /* packets received too short */ u_int32_t tcps_rcvduppack; /* duplicate-only packets received */ u_int64_t tcps_rcvdupbyte; /* duplicate-only bytes received */ u_int32_t tcps_rcvpartduppack; /* packets with some duplicate data */ u_int64_t tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ u_int32_t tcps_rcvoopack; /* out-of-order packets received */ u_int64_t tcps_rcvoobyte; /* out-of-order bytes received */ u_int32_t tcps_rcvpackafterwin; /* packets with data after window */ u_int64_t tcps_rcvbyteafterwin; /* bytes rcvd after window */ u_int32_t tcps_rcvafterclose; /* packets rcvd after "close" */ u_int32_t tcps_rcvwinprobe; /* rcvd window probe packets */ u_int32_t tcps_rcvdupack; /* rcvd duplicate acks */ u_int32_t tcps_rcvacktoomuch; /* rcvd acks for unsent data */ u_int32_t tcps_rcvackpack; /* rcvd ack packets */ u_int64_t tcps_rcvackbyte; /* bytes acked by rcvd acks */ u_int32_t tcps_rcvwinupd; /* rcvd window update packets */ u_int32_t tcps_pawsdrop; /* segments dropped due to PAWS */ u_int32_t tcps_predack; /* times hdr predict ok for acks */ u_int32_t tcps_preddat; /* times hdr predict ok for data pkts */ u_int32_t tcps_pcbhashmiss; /* input packets missing pcb hash */ u_int32_t tcps_noport; /* no socket on port */ u_int32_t tcps_badsyn; /* SYN packet with src==dst rcv'ed */ u_int32_t tcps_rcvbadsig; /* rcvd bad/missing TCP signatures */ u_int64_t tcps_rcvgoodsig; /* rcvd good TCP signatures */ u_int32_t tcps_inhwcsum; /* input hardware-checksummed packets */ u_int32_t tcps_outhwcsum; /* output hardware-checksummed packets */ /* ECN stats */ u_int32_t tcps_ecn_accepts; /* ecn connections accepted */ u_int32_t tcps_ecn_rcvece; /* # of rcvd ece */ u_int32_t tcps_ecn_rcvcwr; /* # of rcvd cwr */ u_int32_t tcps_ecn_rcvce; /* # of rcvd ce in ip header */ u_int32_t tcps_ecn_sndect; /* # of cwr sent */ u_int32_t tcps_ecn_sndece; /* # of ece sent */ u_int32_t tcps_ecn_sndcwr; /* # of cwr sent */ u_int32_t tcps_cwr_ecn; /* # of cwnd reduced by ecn */ u_int32_t tcps_cwr_frecovery; /* # of cwnd reduced by fastrecovery */ u_int32_t tcps_cwr_timeout; /* # of cwnd reduced by timeout */ }; /* * Names for TCP sysctl objects. */ #define TCPCTL_RFC1323 1 /* enable/disable RFC1323 timestamps/scaling */ #define TCPCTL_KEEPINITTIME 2 /* TCPT_KEEP value */ #define TCPCTL_KEEPIDLE 3 /* allow tcp_keepidle to be changed */ #define TCPCTL_KEEPINTVL 4 /* allow tcp_keepintvl to be changed */ #define TCPCTL_SLOWHZ 5 /* return kernel idea of PR_SLOWHZ */ #define TCPCTL_BADDYNAMIC 6 /* return bad dynamic port bitmap */ #define TCPCTL_RECVSPACE 7 /* receive buffer space */ #define TCPCTL_SENDSPACE 8 /* send buffer space */ #define TCPCTL_IDENT 9 /* get connection owner */ #define TCPCTL_SACK 10 /* selective acknowledgement, rfc 2018 */ #define TCPCTL_MSSDFLT 11 /* Default maximum segment size */ #define TCPCTL_RSTPPSLIMIT 12 /* RST pps limit */ #define TCPCTL_ACK_ON_PUSH 13 /* ACK immediately on PUSH */ #define TCPCTL_ECN 14 /* RFC3168 ECN */ #define TCPCTL_MAXID 15 #define TCPCTL_NAMES { \ { 0, 0 }, \ { "rfc1323", CTLTYPE_INT }, \ { "keepinittime", CTLTYPE_INT }, \ { "keepidle", CTLTYPE_INT }, \ { "keepintvl", CTLTYPE_INT }, \ { "slowhz", CTLTYPE_INT }, \ { "baddynamic", CTLTYPE_STRUCT }, \ { "recvspace", CTLTYPE_INT }, \ { "sendspace", CTLTYPE_INT }, \ { "ident", CTLTYPE_STRUCT }, \ { "sack", CTLTYPE_INT }, \ { "mssdflt", CTLTYPE_INT }, \ { "rstppslimit", CTLTYPE_INT }, \ { "ackonpush", CTLTYPE_INT }, \ { "ecn", CTLTYPE_INT }, \ } struct tcp_ident_mapping { struct sockaddr_storage faddr, laddr; int euid, ruid; }; #ifdef _KERNEL extern struct inpcbtable tcbtable; /* head of queue of active tcpcb's */ extern 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 maximum segment size */ extern int tcp_ack_on_push; /* ACK immediately on PUSH */ #ifdef TCP_SACK extern int tcp_do_sack; /* SACK enabled/disabled */ extern struct pool sackhl_pool; #endif extern int tcp_do_ecn; /* RFC3168 ECN enabled/disabled? */ int tcp_attach(struct socket *); void tcp_canceltimers(struct tcpcb *); struct tcpcb * tcp_close(struct tcpcb *); #if defined(INET6) && !defined(TCP6) void tcp6_ctlinput(int, struct sockaddr *, void *); #endif void *tcp_ctlinput(int, struct sockaddr *, void *); int tcp_ctloutput(int, struct socket *, int, int, struct mbuf **); struct tcpcb * tcp_disconnect(struct tcpcb *); struct tcpcb * tcp_drop(struct tcpcb *, int); void tcp_dooptions(struct tcpcb *, u_char *, int, struct tcphdr *, int *, u_int32_t *, u_int32_t *); void tcp_drain(void); void tcp_init(void); #if defined(INET6) && !defined(TCP6) int tcp6_input(struct mbuf **, int *, int); #endif void tcp_input(struct mbuf *, ...); int tcp_mss(struct tcpcb *, int); void tcp_mss_update(struct tcpcb *); void tcp_mtudisc(struct inpcb *, int); void tcp_mtudisc_increase(struct inpcb *, int); #ifdef INET6 void tcp6_mtudisc(struct inpcb *, int); void tcp6_mtudisc_callback(struct in6_addr *); #endif struct tcpcb * tcp_newtcpcb(struct inpcb *); void tcp_notify(struct inpcb *, int); int tcp_output(struct tcpcb *); void tcp_pulloutofband(struct socket *, u_int, struct mbuf *, int); void tcp_quench(struct inpcb *, int); int tcp_reass(struct tcpcb *, struct tcphdr *, struct mbuf *, int *); void tcp_rscale(struct tcpcb *, u_long); void tcp_respond(struct tcpcb *, caddr_t, struct mbuf *, tcp_seq, tcp_seq, int); void tcp_setpersist(struct tcpcb *); void tcp_slowtimo(void); struct mbuf * tcp_template(struct tcpcb *); void tcp_trace(int, int, struct tcpcb *, caddr_t, int, int); struct tcpcb * tcp_usrclosed(struct tcpcb *); int tcp_sysctl(int *, u_int, void *, size_t *, void *, size_t); #if defined(INET6) && !defined(TCP6) int tcp6_usrreq(struct socket *, int, struct mbuf *, struct mbuf *, struct mbuf *, struct proc *); #endif int tcp_usrreq(struct socket *, int, struct mbuf *, struct mbuf *, struct mbuf *); void tcp_xmit_timer(struct tcpcb *, int); void tcpdropoldhalfopen(struct tcpcb *, u_int16_t); #ifdef TCP_SACK int tcp_sack_option(struct tcpcb *,struct tcphdr *,u_char *,int); void tcp_update_sack_list(struct tcpcb *tp); void tcp_del_sackholes(struct tcpcb *, struct tcphdr *); void tcp_clean_sackreport(struct tcpcb *tp); void tcp_sack_adjust(struct tcpcb *tp); struct sackhole * tcp_sack_output(struct tcpcb *tp); int tcp_sack_partialack(struct tcpcb *, struct tcphdr *); #ifdef DEBUG void tcp_print_holes(struct tcpcb *tp); #endif #endif /* TCP_SACK */ #if defined(TCP_SACK) int tcp_newreno(struct tcpcb *, struct tcphdr *); u_long tcp_seq_subtract(u_long, u_long ); #endif /* TCP_SACK */ #ifdef TCP_SIGNATURE int tcp_signature_apply(caddr_t, caddr_t, unsigned int); #endif /* TCP_SIGNATURE */ void tcp_rndiss_init(void); tcp_seq tcp_rndiss_next(void); u_int16_t tcp_rndiss_encrypt(u_int16_t); #endif /* _KERNEL */ #endif /* _NETINET_TCP_VAR_H_ */