1 /* 2 * Copyright (c) 1982, 1986 Regents of the University of California. 3 * All rights reserved. The Berkeley software License Agreement 4 * specifies the terms and conditions for redistribution. 5 * 6 * @(#)tcp_var.h 7.5 (Berkeley) 09/04/87 7 */ 8 9 /* 10 * Kernel variables for tcp. 11 */ 12 13 /* 14 * Tcp control block, one per tcp; fields: 15 */ 16 struct tcpcb { 17 struct tcpiphdr *seg_next; /* sequencing queue */ 18 struct tcpiphdr *seg_prev; 19 short t_state; /* state of this connection */ 20 short t_timer[TCPT_NTIMERS]; /* tcp timers */ 21 short t_rxtshift; /* log(2) of rexmt exp. backoff */ 22 short t_rxtcur; /* current retransmit value */ 23 short t_dupacks; /* consecutive dup acks recd */ 24 u_short t_maxseg; /* maximum segment size */ 25 char t_force; /* 1 if forcing out a byte */ 26 u_char t_flags; 27 #define TF_ACKNOW 0x01 /* ack peer immediately */ 28 #define TF_DELACK 0x02 /* ack, but try to delay it */ 29 #define TF_NODELAY 0x04 /* don't delay packets to coalesce */ 30 #define TF_NOOPT 0x08 /* don't use tcp options */ 31 #define TF_SENTFIN 0x10 /* have sent FIN */ 32 struct tcpiphdr *t_template; /* skeletal packet for transmit */ 33 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 34 /* 35 * The following fields are used as in the protocol specification. 36 * See RFC783, Dec. 1981, page 21. 37 */ 38 /* send sequence variables */ 39 tcp_seq snd_una; /* send unacknowledged */ 40 tcp_seq snd_nxt; /* send next */ 41 tcp_seq snd_up; /* send urgent pointer */ 42 tcp_seq snd_wl1; /* window update seg seq number */ 43 tcp_seq snd_wl2; /* window update seg ack number */ 44 tcp_seq iss; /* initial send sequence number */ 45 u_short snd_wnd; /* send window */ 46 /* receive sequence variables */ 47 u_short rcv_wnd; /* receive window */ 48 tcp_seq rcv_nxt; /* receive next */ 49 tcp_seq rcv_up; /* receive urgent pointer */ 50 tcp_seq irs; /* initial receive sequence number */ 51 /* 52 * Additional variables for this implementation. 53 */ 54 /* receive variables */ 55 tcp_seq rcv_adv; /* advertised window */ 56 /* retransmit variables */ 57 tcp_seq snd_max; /* highest sequence number sent 58 * used to recognize retransmits 59 */ 60 /* congestion control (for slow start, source quench, retransmit after loss) */ 61 u_short snd_cwnd; /* congestion-controlled window */ 62 u_short snd_ssthresh; /* snd_cwnd size threshhold for 63 * for slow start exponential to 64 * linear switch */ 65 /* 66 * transmit timing stuff. 67 * srtt and rttvar are stored as fixed point; for convenience in smoothing, 68 * srtt has 3 bits to the right of the binary point, rttvar has 2. 69 * "Variance" is actually smoothed difference. 70 */ 71 short t_idle; /* inactivity time */ 72 short t_rtt; /* round trip time */ 73 tcp_seq t_rtseq; /* sequence number being timed */ 74 short t_srtt; /* smoothed round-trip time */ 75 short t_rttvar; /* variance in round-trip time */ 76 u_short max_rcvd; /* most peer has sent into window */ 77 u_short max_sndwnd; /* largest window peer has offered */ 78 /* out-of-band data */ 79 char t_oobflags; /* have some */ 80 char t_iobc; /* input character */ 81 #define TCPOOB_HAVEDATA 0x01 82 #define TCPOOB_HADDATA 0x02 83 }; 84 85 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 86 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 87 88 /* 89 * TCP statistics. 90 * Many of these should be kept per connection, 91 * but that's inconvenient at the moment. 92 */ 93 struct tcpstat { 94 u_long tcps_connattempt; /* connections initiated */ 95 u_long tcps_accepts; /* connections accepted */ 96 u_long tcps_connects; /* connections established */ 97 u_long tcps_drops; /* connections dropped */ 98 u_long tcps_conndrops; /* embryonic connections dropped */ 99 u_long tcps_closed; /* conn. closed (includes drops) */ 100 u_long tcps_segstimed; /* segs where we tried to get rtt */ 101 u_long tcps_rttupdated; /* times we succeeded */ 102 u_long tcps_delack; /* delayed acks sent */ 103 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ 104 u_long tcps_rexmttimeo; /* retransmit timeouts */ 105 u_long tcps_persisttimeo; /* persist timeouts */ 106 u_long tcps_keeptimeo; /* keepalive timeouts */ 107 u_long tcps_keepprobe; /* keepalive probes sent */ 108 u_long tcps_keepdrops; /* connections dropped in keepalive */ 109 110 u_long tcps_sndtotal; /* total packets sent */ 111 u_long tcps_sndpack; /* data packets sent */ 112 u_long tcps_sndbyte; /* data bytes sent */ 113 u_long tcps_sndrexmitpack; /* data packets retransmitted */ 114 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */ 115 u_long tcps_sndacks; /* ack-only packets sent */ 116 u_long tcps_sndprobe; /* window probes sent */ 117 u_long tcps_sndurg; /* packets sent with URG only */ 118 u_long tcps_sndwinup; /* window update-only packets sent */ 119 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ 120 121 u_long tcps_rcvtotal; /* total packets received */ 122 u_long tcps_rcvpack; /* packets received in sequence */ 123 u_long tcps_rcvbyte; /* bytes received in sequence */ 124 u_long tcps_rcvbadsum; /* packets received with ccksum errs */ 125 u_long tcps_rcvbadoff; /* packets received with bad offset */ 126 u_long tcps_rcvshort; /* packets received too short */ 127 u_long tcps_rcvduppack; /* duplicate-only packets received */ 128 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */ 129 u_long tcps_rcvpartduppack; /* packets with some duplicate data */ 130 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ 131 u_long tcps_rcvoopack; /* out-of-order packets received */ 132 u_long tcps_rcvoobyte; /* out-of-order bytes received */ 133 u_long tcps_rcvpackafterwin; /* packets with data after window */ 134 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */ 135 u_long tcps_rcvafterclose; /* packets rcvd after "close" */ 136 u_long tcps_rcvwinprobe; /* rcvd window probe packets */ 137 u_long tcps_rcvdupack; /* rcvd duplicate acks */ 138 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */ 139 u_long tcps_rcvackpack; /* rcvd ack packets */ 140 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */ 141 u_long tcps_rcvwinupd; /* rcvd window update packets */ 142 }; 143 144 #ifdef KERNEL 145 struct inpcb tcb; /* head of queue of active tcpcb's */ 146 struct tcpstat tcpstat; /* tcp statistics */ 147 struct tcpiphdr *tcp_template(); 148 struct tcpcb *tcp_close(), *tcp_drop(); 149 struct tcpcb *tcp_timers(), *tcp_disconnect(), *tcp_usrclosed(); 150 #endif 151