/* $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 #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<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_ */