/* * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved. * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved. * * This code is derived from software contributed to The DragonFly Project * by Jeffrey M. Hsu. * * 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 DragonFly 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 COPYRIGHT HOLDERS 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 * COPYRIGHT HOLDERS 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. 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 * $FreeBSD: src/sys/netinet/tcp_var.h,v 1.56.2.13 2003/02/03 02:34:07 hsu Exp $ * $DragonFly: src/sys/netinet/tcp_var.h,v 1.42 2008/10/27 02:56:30 sephe Exp $ */ #ifndef _NETINET_TCP_VAR_H_ #define _NETINET_TCP_VAR_H_ #ifndef _NETINET_IN_PCB_H_ #include /* needed for in_conninfo, inp_gen_t */ #endif #ifndef _NETINET_TCP_H_ #include #endif /* * Kernel variables for tcp. */ extern int tcp_do_rfc1323; extern int tcp_low_rtobase; extern int tcp_do_sack; extern int tcp_do_smartsack; extern int tcp_aggregate_acks; /* TCP segment queue entry */ struct tseg_qent { LIST_ENTRY(tseg_qent) tqe_q; int tqe_len; /* TCP segment data length */ struct tcphdr *tqe_th; /* a pointer to tcp header */ struct mbuf *tqe_m; /* mbuf contains packet */ }; LIST_HEAD(tsegqe_head, tseg_qent); extern int tcp_reass_maxseg; extern int tcp_reass_qsize; #ifdef MALLOC_DECLARE MALLOC_DECLARE(M_TSEGQ); #endif struct tcptemp { u_char tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */ struct tcphdr tt_t; }; #define tcp6cb tcpcb /* for KAME src sync over BSD*'s */ struct raw_sackblock { /* covers [start, end) */ tcp_seq rblk_start; tcp_seq rblk_end; }; /* maximum number of SACK blocks that will fit in the TCP option space */ #define MAX_SACK_REPORT_BLOCKS 4 TAILQ_HEAD(sackblock_list, sackblock); struct scoreboard { int nblocks; struct sackblock_list sackblocks; tcp_seq lostseq; /* passed SACK lost test */ struct sackblock *lastfound; /* search hint */ struct sackblock *freecache; /* one slot free block cache */ }; struct netmsg_tcp_timer; /* * Tcp control block, one per tcp; fields: * Organized for 16 byte cacheline efficiency. */ struct tcpcb { struct tsegqe_head t_segq; int t_dupacks; /* consecutive dup acks recd */ int tt_cpu; /* sanity check the cpu */ struct tcp_callout *tt_rexmt; /* retransmit timer */ struct tcp_callout *tt_persist;/* retransmit persistence */ struct tcp_callout *tt_keep; /* keepalive */ struct tcp_callout *tt_2msl; /* 2*msl TIME_WAIT timer */ struct tcp_callout *tt_delack; /* delayed ACK timer */ struct netmsg_tcp_timer *tt_msg; /* timer message */ struct inpcb *t_inpcb; /* back pointer to internet pcb */ int t_state; /* state of this connection */ u_int t_flags; #define TF_ACKNOW 0x00000001 /* ack peer immediately */ #define TF_DELACK 0x00000002 /* ack, but try to delay it */ #define TF_NODELAY 0x00000004 /* don't delay packets to coalesce */ #define TF_NOOPT 0x00000008 /* don't use tcp options */ #define TF_SENTFIN 0x00000010 /* have sent FIN */ #define TF_REQ_SCALE 0x00000020 /* have/will request window scaling */ #define TF_RCVD_SCALE 0x00000040 /* other side has requested scaling */ #define TF_REQ_TSTMP 0x00000080 /* have/will request timestamps */ #define TF_RCVD_TSTMP 0x00000100 /* a timestamp was received in SYN */ #define TF_SACK_PERMITTED 0x00000200 /* other side said I could SACK */ #define TF_NEEDSYN 0x00000400 /* send SYN (implicit state) */ #define TF_NEEDFIN 0x00000800 /* send FIN (implicit state) */ #define TF_NOPUSH 0x00001000 /* don't push */ #define TF_LISTEN 0x00002000 /* listen(2) has been called */ #define TF_SIGNATURE 0x00004000 /* require MD5 digests (RFC2385) */ #define TF_UNUSED01 0x00008000 /* unused */ #define TF_MORETOCOME 0x00010000 /* More data to be appended to sock */ #define TF_UNUSED00 0x00020000 /* unused */ #define TF_LASTIDLE 0x00040000 /* connection was previously idle */ #define TF_RXWIN0SENT 0x00080000 /* sent a receiver win 0 in response */ #define TF_FASTRECOVERY 0x00100000 /* in NewReno Fast Recovery */ #define TF_WASFRECOVERY 0x00200000 /* was in NewReno Fast Recovery */ #define TF_FIRSTACCACK 0x00400000 /* Look for 1st acceptable ACK. */ #define TF_FASTREXMT 0x00800000 /* Did Fast Retransmit. */ #define TF_EARLYREXMT 0x01000000 /* Did Early (Fast) Retransmit. */ #define TF_FORCE 0x02000000 /* Set if forcing out a byte */ #define TF_ONOUTPUTQ 0x04000000 /* on t_outputq list */ #define TF_DUPSEG 0x08000000 /* last seg a duplicate */ #define TF_ENCLOSESEG 0x10000000 /* enclosing SACK block */ #define TF_SACKLEFT 0x20000000 /* send SACK blocks from left side */ #define TF_KEEPALIVE 0x40000000 /* temporary keepalive */ #define TF_RXRESIZED 0x80000000 /* rcvbuf was resized */ tcp_seq snd_up; /* send urgent pointer */ u_long snd_last; /* time last data were sent */ tcp_seq snd_una; /* send unacknowledged */ tcp_seq snd_recover; /* for use with NewReno Fast Recovery */ tcp_seq snd_max; /* highest sequence number sent; * used to recognize retransmits */ tcp_seq snd_nxt; /* send next */ 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 */ tcp_seq irs; /* initial receive sequence number */ tcp_seq rcv_nxt; /* receive next */ tcp_seq rcv_adv; /* advertised window */ u_long rcv_wnd; /* receive window */ tcp_seq rcv_up; /* receive urgent pointer */ u_long snd_wnd; /* send window */ u_long snd_cwnd; /* congestion-controlled window */ u_long snd_wacked; /* bytes acked in one send window */ u_long snd_ssthresh; /* snd_cwnd size threshold for * for slow start exponential to * linear switch */ int t_rxtcur; /* current retransmit value (ticks) */ u_int t_maxseg; /* maximum segment size */ int t_srtt; /* smoothed round-trip time */ int t_rttvar; /* variance in round-trip time */ u_int t_maxopd; /* mss plus options */ u_long t_rcvtime; /* reception inactivity time */ u_long t_starttime; /* time connection was established */ int t_rtttime; /* round trip time */ tcp_seq t_rtseq; /* sequence number being timed */ int t_rxtshift; /* log(2) of rexmt exp. backoff */ u_int t_rttmin; /* minimum rtt allowed */ u_int t_rttbest; /* best rtt we've seen */ u_long t_rttupdated; /* number of times rtt sampled */ u_long max_sndwnd; /* largest window peer has offered */ int t_softerror; /* possible error not yet reported */ /* out-of-band data */ char t_oobflags; /* have some */ char t_iobc; /* input character */ #define TCPOOB_HAVEDATA 0x01 #define TCPOOB_HADDATA 0x02 /* 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; /* experimental */ u_long snd_cwnd_prev; /* cwnd prior to retransmit */ u_long snd_wacked_prev; /* prior bytes acked in send window */ u_long snd_ssthresh_prev; /* ssthresh prior to retransmit */ tcp_seq snd_recover_prev; /* snd_recover prior to retransmit */ u_long t_badrxtwin; /* window for retransmit recovery */ u_long t_rexmtTS; /* timestamp of last retransmit */ u_char snd_limited; /* segments limited transmitted */ tcp_seq rexmt_high; /* highest seq # retransmitted + 1 */ tcp_seq snd_max_rexmt; /* snd_max when rexmting snd_una */ struct scoreboard scb; /* sack scoreboard */ struct raw_sackblock reportblk; /* incoming segment or D-SACK block */ struct raw_sackblock encloseblk; int nsackhistory; struct raw_sackblock sackhistory[MAX_SACK_REPORT_BLOCKS]; /* reported */ TAILQ_ENTRY(tcpcb) t_outputq; /* tcp_output needed list */ /* bandwith limitation */ u_long snd_bandwidth; /* calculated bandwidth or 0 */ u_long snd_bwnd; /* bandwidth-controlled window */ int t_bw_rtttime; /* used for bandwidth calculation */ tcp_seq t_bw_rtseq; /* used for bandwidth calculation */ /* anti DoS counters */ u_long rcv_second; /* start of interval second */ u_long rcv_pps; /* received packets per second */ u_long rcv_byps; /* received bytes per second */ u_int32_t rfbuf_ts; /* recv buffer autoscaling timestamp */ int rfbuf_cnt; /* recv buffer autoscaling byte count */ int t_keepinit; /* time to establish connection */ int t_keepidle; /* time before keepalive probes begin */ int t_keepintvl; /* time between keepalive probes */ int t_keepcnt; /* maximum number of keepalive probes */ int t_maxidle; /* time to drop after starting probes */ int t_rxtsyn; /* time spent in SYN or SYN|ACK rexmt */ }; #define IN_FASTRECOVERY(tp) (tp->t_flags & TF_FASTRECOVERY) #define ENTER_FASTRECOVERY(tp) tp->t_flags |= TF_FASTRECOVERY #define EXIT_FASTRECOVERY(tp) tp->t_flags &= ~TF_FASTRECOVERY #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_ALLOCSA() lookup to work. */ #define TCP_SIG_SPI 0x1000 #endif /* TCP_SIGNATURE */ /* * TCP statistics. */ struct tcp_stats { 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_minmssdrops; /* average minmss too low drops */ 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_sndsackrtopack; /* packets sent by SACK after RTO */ u_long tcps_sndsackrtobyte; /* bytes sent by SACK after RTO */ u_long tcps_sndfastrexmit; /* Fast Retransmissions */ u_long tcps_sndearlyrexmit; /* early Fast Retransmissions */ u_long tcps_sndlimited; /* Limited Transmit packets */ u_long tcps_sndrtobad; /* spurious RTO retransmissions */ u_long tcps_sndfastrexmitbad; /* spurious Fast Retransmissions */ u_long tcps_sndearlyrexmitbad; /* spurious early Fast Retransmissions, a subset of tcps_sndfastrexmitbad */ u_long tcps_eifeldetected; /* Eifel-detected spurious rexmits */ u_long tcps_rttcantdetect; /* Eifel but not 1/2 RTT-detectable */ u_long tcps_rttdetected; /* RTT-detected spurious RTO rexmits */ 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_sndsackpack; /* packets sent by SACK recovery alg */ u_long tcps_sndsackbyte; /* bytes sent by SACK recovery */ u_long tcps_snduna3; /* re-retransmit snd_una on 3 new seg */ u_long tcps_snduna1; /* re-retransmit snd_una on 1 new seg */ u_long tcps_sndsackopt; /* SACK options sent */ u_long tcps_snddsackopt; /* D-SACK options sent */ u_long tcps_sndidle; /* sending idle detected */ 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_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 */ u_long tcps_rcvbadsackopt; /* rcvd illegal SACK options */ u_long tcps_sacksbupdate; /* times SACK scoreboard updated */ u_long tcps_sacksboverflow; /* times SACK scoreboard overflowed */ u_long tcps_sacksbreused; /* times SACK sb-block reused */ u_long tcps_sacksbfailed; /* times SACK sb update failed */ u_long tcps_sacksbfast; /* timee SACK sb-block uses cache */ u_long tcps_sc_added; /* entry added to syncache */ u_long tcps_sc_retransmitted; /* syncache entry was retransmitted */ u_long tcps_sc_dupsyn; /* duplicate SYN packet */ u_long tcps_sc_dropped; /* could not reply to packet */ u_long tcps_sc_completed; /* successful extraction of entry */ u_long tcps_sc_bucketoverflow; /* syncache per-bucket limit hit */ u_long tcps_sc_cacheoverflow; /* syncache cache limit hit */ u_long tcps_sc_reset; /* RST removed entry from syncache */ u_long tcps_sc_stale; /* timed out or listen socket gone */ u_long tcps_sc_aborted; /* syncache entry aborted */ u_long tcps_sc_badack; /* removed due to bad ACK */ u_long tcps_sc_unreach; /* ICMP unreachable received */ u_long tcps_sc_zonefail; /* zalloc() failed */ u_long tcps_sc_sendcookie; /* SYN cookie sent */ u_long tcps_sc_recvcookie; /* SYN cookie received */ }; #ifdef _KERNEL #if defined(SMP) #define tcpstat tcpstats_percpu[mycpuid] #else #define tcpstat tcpstats_percpu[0] #endif struct sockopt; extern struct tcp_stats tcpstats_percpu[MAXCPU]; static const int tcprexmtthresh = 3; #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_flags; /* which options are present */ #define TOF_TS 0x0001 /* timestamp */ #define TOF_MSS 0x0010 #define TOF_SCALE 0x0020 #define TOF_SACK_PERMITTED 0x0040 #define TOF_SACK 0x0080 #define TOF_SIGNATURE 0x0100 /* signature option present */ #define TOF_SIGLEN 0x0200 /* sigature length valid (RFC2385) */ u_int32_t to_tsval; u_int32_t to_tsecr; u_int16_t to_mss; u_int8_t to_requested_s_scale; u_int8_t to_nsackblocks; struct raw_sackblock *to_sackblocks; }; struct syncache { inp_gen_t sc_inp_gencnt; /* pointer check */ struct tcpcb *sc_tp; /* tcb for listening socket */ struct mbuf *sc_ipopts; /* source route */ struct in_conninfo sc_inc; /* addresses */ #define sc_route sc_inc.inc_route #define sc_route6 sc_inc.inc6_route u_int32_t sc_tsrecent; tcp_seq sc_irs; /* seq from peer */ tcp_seq sc_iss; /* our ISS */ u_long sc_rxttime; /* retransmit time */ u_int16_t sc_rxtslot; /* retransmit counter */ u_int16_t sc_peer_mss; /* peer's MSS */ u_int16_t sc_wnd; /* advertised window */ u_int8_t sc_requested_s_scale:4, sc_request_r_scale:4; u_int8_t sc_flags; #define SCF_NOOPT 0x01 /* no TCP options */ #define SCF_WINSCALE 0x02 /* negotiated window scaling */ #define SCF_TIMESTAMP 0x04 /* negotiated timestamps */ #define SCF_UNUSED 0x08 /* unused */ #define SCF_UNREACH 0x10 /* icmp unreachable received */ #define SCF_SACK_PERMITTED 0x20 /* saw SACK permitted option */ #define SCF_SIGNATURE 0x40 /* send MD5 digests */ #define SCF_MARKER 0x80 /* not a real entry */ int sc_rxtused; /* time spent in SYN|ACK rxt */ TAILQ_ENTRY(syncache) sc_hash; TAILQ_ENTRY(syncache) sc_timerq; }; struct syncache_head { TAILQ_HEAD(, syncache) sch_bucket; u_int sch_length; }; #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) \ max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)) \ + (tp)->t_rttvar) >> TCP_DELTA_SHIFT) /* * TCB structure exported to user-land via sysctl(3). * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been * included. Not all of our clients do. */ #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_) struct xtcpcb { size_t xt_len; struct inpcb xt_inp; struct tcpcb xt_tp; struct xsocket xt_socket; u_quad_t xt_alignment_hack; }; #endif /* * Names for TCP sysctl objects */ #define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */ /* 2 was TCPCTL_DO_RFC1644 */ #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 /* timeout for establishing syn */ #define TCPCTL_PCBLIST 11 /* list of all outstanding PCBs */ #define TCPCTL_DELACKTIME 12 /* time before sending delayed ACK */ #define TCPCTL_V6MSSDFLT 13 /* MSS default for IPv6 */ #define TCPCTL_MAXID 14 #define TCPCTL_NAMES { \ { 0, 0 }, \ { "rfc1323", CTLTYPE_INT }, \ { "reserved", CTLTYPE_INT}, /* was rfc1644 */ \ { "mssdflt", CTLTYPE_INT }, \ { "stats", CTLTYPE_STRUCT }, \ { "rttdflt", CTLTYPE_INT }, \ { "keepidle", CTLTYPE_INT }, \ { "keepintvl", CTLTYPE_INT }, \ { "sendspace", CTLTYPE_INT }, \ { "recvspace", CTLTYPE_INT }, \ { "keepinit", CTLTYPE_INT }, \ { "pcblist", CTLTYPE_STRUCT }, \ { "delacktime", CTLTYPE_INT }, \ { "v6mssdflt", CTLTYPE_INT }, \ } #ifdef _KERNEL #ifdef SYSCTL_DECL SYSCTL_DECL(_net_inet_tcp); #endif #define TCP_DO_SACK(tp) ((tp)->t_flags & TF_SACK_PERMITTED) #define TCP_SACK_BLKEND(len, thflags) \ ((len) + (((thflags) & TH_FIN) != 0)) TAILQ_HEAD(tcpcbackqhead,tcpcb); extern struct inpcbinfo tcbinfo[]; extern struct tcpcbackqhead tcpcbackq[]; extern int tcp_mssdflt; /* XXX */ extern int tcp_minmss; extern int tcp_delack_enabled; extern int path_mtu_discovery; union netmsg; int tcp_addrcpu(in_addr_t faddr, in_port_t fport, in_addr_t laddr, in_port_t lport); struct lwkt_port * tcp_addrport(in_addr_t faddr, in_port_t fport, in_addr_t laddr, in_port_t lport); struct lwkt_port *tcp_addrport0(void); void tcp_canceltimers (struct tcpcb *); struct tcpcb * tcp_close (struct tcpcb *); void tcp_ctlinput(union netmsg *); void tcp_ctloutput(union netmsg *); struct tcpcb * tcp_drop (struct tcpcb *, int); void tcp_drain (void); void tcp_fasttimo (void); void tcp_init (void); void tcp_thread_init (void); int tcp_input (struct mbuf **, int *, int); void tcp_mss (struct tcpcb *, int); int tcp_mssopt (struct tcpcb *); void tcp_drop_syn_sent (struct inpcb *, int); void tcp_mtudisc (struct inpcb *, int); struct tcpcb * tcp_newtcpcb (struct inpcb *); int tcp_output (struct tcpcb *); void tcp_quench (struct inpcb *, int); void tcp_respond (struct tcpcb *, void *, struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int); struct rtentry * tcp_rtlookup (struct in_conninfo *); int tcp_sack_bytes_below(struct scoreboard *scb, tcp_seq seq); void tcp_sack_destroy(struct scoreboard *scb); void tcp_sack_cleanup(struct scoreboard *scb); void tcp_sack_report_cleanup(struct tcpcb *tp); int tcp_sack_ndsack_blocks(struct raw_sackblock *blocks, const int numblocks, tcp_seq snd_una); void tcp_sack_fill_report(struct tcpcb *tp, u_char *opt, u_int *plen); boolean_t tcp_sack_has_sacked(struct scoreboard *scb, u_int amount); void tcp_sack_tcpcb_init(struct tcpcb *tp); uint32_t tcp_sack_compute_pipe(struct tcpcb *tp); boolean_t tcp_sack_nextseg(struct tcpcb *tp, tcp_seq *nextrexmt, uint32_t *len, boolean_t *losdup); #ifdef later void tcp_sack_revert_scoreboard(struct scoreboard *scb, tcp_seq snd_una, u_int maxseg); void tcp_sack_save_scoreboard(struct scoreboard *scb); #endif void tcp_sack_skip_sacked(struct scoreboard *scb, tcp_seq *prexmt); void tcp_sack_update_scoreboard(struct tcpcb *tp, struct tcpopt *to); void tcp_save_congestion_state(struct tcpcb *tp); void tcp_revert_congestion_state(struct tcpcb *tp); void tcp_setpersist (struct tcpcb *); struct tcptemp *tcp_maketemplate (struct tcpcb *); void tcp_freetemplate (struct tcptemp *); void tcp_fillheaders (struct tcpcb *, void *, void *); struct lwkt_port * tcp_soport(struct socket *, struct sockaddr *, struct mbuf **); struct lwkt_port * tcp_ctlport(int, struct sockaddr *, void *); struct tcpcb * tcp_timers (struct tcpcb *, int); void tcp_trace (short, short, struct tcpcb *, void *, struct tcphdr *, int); void tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq); u_long tcp_initial_window(struct tcpcb *tp); void tcp_timer_keep_activity(struct tcpcb *tp, int thflags); void syncache_init(void); void syncache_unreach(struct in_conninfo *, struct tcphdr *); int syncache_expand(struct in_conninfo *, struct tcphdr *, struct socket **, struct mbuf *); int syncache_add(struct in_conninfo *, struct tcpopt *, struct tcphdr *, struct socket *, struct mbuf *); void syncache_chkrst(struct in_conninfo *, struct tcphdr *); void syncache_badack(struct in_conninfo *); void syncache_destroy(struct tcpcb *tp); #ifdef TCP_SIGNATURE int tcpsignature_apply(void *fstate, void *data, unsigned int len); int tcpsignature_compute(struct mbuf *m, int len, int tcpoptlen, u_char *buf, u_int direction); #endif /* TCP_SIGNATURE */ extern struct pr_usrreqs tcp_usrreqs; extern u_long tcp_sendspace; extern u_long tcp_recvspace; tcp_seq tcp_new_isn (struct tcpcb *); #endif /* _KERNEL */ #endif /* _NETINET_TCP_VAR_H_ */