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Diffstat (limited to 'sys/netinet/tcp_var.h')
| -rw-r--r-- | sys/netinet/tcp_var.h | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h new file mode 100644 index 0000000..8a8e751 --- /dev/null +++ b/sys/netinet/tcp_var.h @@ -0,0 +1,278 @@ +/* + * 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 + */ + +/* + * Kernel variables for tcp. + */ + +/* + * Tcp control block, one per tcp; fields: + */ +struct tcpcb { + struct tcpiphdr *seg_next; /* sequencing queue */ + struct tcpiphdr *seg_prev; + short t_state; /* state of this connection */ + short t_timer[TCPT_NTIMERS]; /* tcp timers */ + 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_short 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 */ + + 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 threshhold for + * for slow start exponential to + * linear switch + */ +/* + * transmit timing stuff. See below for scale of srtt and rttvar. + * "Variance" is actually smoothed difference. + */ + short t_idle; /* inactivity time */ + short t_rtt; /* round trip time */ + 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_long ts_recent; /* timestamp echo data */ + u_long 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 */ +}; + +#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 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) + +/* 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; +}; + +#ifdef KERNEL +struct inpcb tcb; /* head of queue of active tcpcb's */ +struct tcpstat tcpstat; /* tcp statistics */ +u_long tcp_now; /* for RFC 1323 timestamps */ + +int tcp_attach __P((struct socket *)); +void tcp_canceltimers __P((struct tcpcb *)); +struct tcpcb * + tcp_close __P((struct tcpcb *)); +void tcp_ctlinput __P((int, struct sockaddr *, struct ip *)); +int tcp_ctloutput __P((int, struct socket *, int, int, struct mbuf **)); +struct tcpcb * + tcp_disconnect __P((struct tcpcb *)); +struct tcpcb * + tcp_drop __P((struct tcpcb *, int)); +void tcp_dooptions __P((struct tcpcb *, + u_char *, int, struct tcpiphdr *, int *, u_long *, u_long *)); +void tcp_drain __P((void)); +void tcp_fasttimo __P((void)); +void tcp_init __P((void)); +void tcp_input __P((struct mbuf *, int)); +int tcp_mss __P((struct tcpcb *, u_int)); +struct tcpcb * + tcp_newtcpcb __P((struct inpcb *)); +void tcp_notify __P((struct inpcb *, int)); +int tcp_output __P((struct tcpcb *)); +void tcp_pulloutofband __P((struct socket *, + struct tcpiphdr *, struct mbuf *)); +void tcp_quench __P((struct inpcb *, int)); +int tcp_reass __P((struct tcpcb *, struct tcpiphdr *, struct mbuf *)); +void tcp_respond __P((struct tcpcb *, + struct tcpiphdr *, struct mbuf *, u_long, u_long, int)); +void tcp_setpersist __P((struct tcpcb *)); +void tcp_slowtimo __P((void)); +struct tcpiphdr * + tcp_template __P((struct tcpcb *)); +struct tcpcb * + tcp_timers __P((struct tcpcb *, int)); +void tcp_trace __P((int, int, struct tcpcb *, struct tcpiphdr *, int)); +struct tcpcb * + tcp_usrclosed __P((struct tcpcb *)); +int tcp_usrreq __P((struct socket *, + int, struct mbuf *, struct mbuf *, struct mbuf *)); +void tcp_xmit_timer __P((struct tcpcb *, int)); +#endif |
