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 7.3 (Berkeley) 06/30/87 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 struct mbuf *t_tcpopt; /* tcp options */ 23 u_short t_maxseg; /* maximum segment size */ 24 char t_force; /* 1 if forcing out a byte */ 25 u_char t_flags; 26 #define TF_ACKNOW 0x01 /* ack peer immediately */ 27 #define TF_DELACK 0x02 /* ack, but try to delay it */ 28 #define TF_NODELAY 0x04 /* don't delay packets to coalesce */ 29 #define TF_NOOPT 0x08 /* don't use tcp options */ 30 #define TF_SENTFIN 0x10 /* have sent FIN */ 31 struct tcpiphdr *t_template; /* skeletal packet for transmit */ 32 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 33 /* 34 * The following fields are used as in the protocol specification. 35 * See RFC783, Dec. 1981, page 21. 36 */ 37 /* send sequence variables */ 38 tcp_seq snd_una; /* send unacknowledged */ 39 tcp_seq snd_nxt; /* send next */ 40 tcp_seq snd_up; /* send urgent pointer */ 41 tcp_seq snd_wl1; /* window update seg seq number */ 42 tcp_seq snd_wl2; /* window update seg ack number */ 43 tcp_seq iss; /* initial send sequence number */ 44 u_short snd_wnd; /* send window */ 45 /* receive sequence variables */ 46 u_short rcv_wnd; /* receive window */ 47 tcp_seq rcv_nxt; /* receive next */ 48 tcp_seq rcv_up; /* receive urgent pointer */ 49 tcp_seq irs; /* initial receive sequence number */ 50 /* 51 * Additional variables for this implementation. 52 */ 53 /* receive variables */ 54 tcp_seq rcv_adv; /* advertised window */ 55 /* retransmit variables */ 56 tcp_seq snd_max; /* highest sequence number sent 57 * used to recognize retransmits 58 */ 59 /* congestion control (for source quench) */ 60 u_short snd_cwnd; /* congestion-controlled window */ 61 /* 62 * transmit timing stuff. 63 * srtt and rttvar are stored as fixed point; for convenience in smoothing, 64 * srtt has 3 bits to the right of the binary point, rttvar has 2. 65 */ 66 short t_idle; /* inactivity time */ 67 short t_rtt; /* round trip time */ 68 u_short max_rcvd; /* most peer has sent into window */ 69 tcp_seq t_rtseq; /* sequence number being timed */ 70 short t_srtt; /* smoothed round-trip time */ 71 short t_rttvar; /* variance in round-trip time */ 72 u_short max_sndwnd; /* largest window peer has offered */ 73 /* out-of-band data */ 74 char t_oobflags; /* have some */ 75 char t_iobc; /* input character */ 76 #define TCPOOB_HAVEDATA 0x01 77 #define TCPOOB_HADDATA 0x02 78 }; 79 80 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 81 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 82 83 /* 84 * TCP statistics. 85 * Many of these should be kept per connection, 86 * but that's inconvenient at the moment. 87 */ 88 struct tcpstat { 89 u_long tcps_connattempt; /* connections initiated */ 90 u_long tcps_accepts; /* connections accepted */ 91 u_long tcps_connects; /* connections established */ 92 u_long tcps_drops; /* connections dropped */ 93 u_long tcps_conndrops; /* embryonic connections dropped */ 94 u_long tcps_closed; /* conn. closed (includes drops) */ 95 u_long tcps_segstimed; /* segs where we tried to get rtt */ 96 u_long tcps_rttupdated; /* times we succeeded */ 97 u_long tcps_delack; /* delayed acks sent */ 98 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ 99 u_long tcps_rexmttimeo; /* retransmit timeouts */ 100 u_long tcps_persisttimeo; /* persist timeouts */ 101 u_long tcps_keeptimeo; /* keepalive timeouts */ 102 u_long tcps_keepprobe; /* keepalive probes sent */ 103 u_long tcps_keepdrops; /* connections dropped in keepalive */ 104 105 u_long tcps_sndtotal; /* total packets sent */ 106 u_long tcps_sndpack; /* data packets sent */ 107 u_long tcps_sndbyte; /* data bytes sent */ 108 u_long tcps_sndrexmitpack; /* data packets retransmitted */ 109 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */ 110 u_long tcps_sndacks; /* ack-only packets sent */ 111 u_long tcps_sndprobe; /* window probes sent */ 112 u_long tcps_sndurg; /* packets sent with URG only */ 113 u_long tcps_sndwinup; /* window update-only packets sent */ 114 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ 115 116 u_long tcps_rcvtotal; /* total packets received */ 117 u_long tcps_rcvpack; /* packets received in sequence */ 118 u_long tcps_rcvbyte; /* bytes received in sequence */ 119 u_long tcps_rcvbadsum; /* packets received with ccksum errs */ 120 u_long tcps_rcvbadoff; /* packets received with bad offset */ 121 u_long tcps_rcvshort; /* packets received too short */ 122 u_long tcps_rcvduppack; /* duplicate-only packets received */ 123 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */ 124 u_long tcps_rcvpartduppack; /* packets with some duplicate data */ 125 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ 126 u_long tcps_rcvoopack; /* out-of-order packets received */ 127 u_long tcps_rcvoobyte; /* out-of-order bytes received */ 128 u_long tcps_rcvpackafterwin; /* packets with data after window */ 129 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */ 130 u_long tcps_rcvafterclose; /* packets rcvd after "close" */ 131 u_long tcps_rcvwinprobe; /* rcvd window probe packets */ 132 u_long tcps_rcvdupack; /* rcvd duplicate acks */ 133 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */ 134 u_long tcps_rcvackpack; /* rcvd ack packets */ 135 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */ 136 u_long tcps_rcvwinupd; /* rcvd window update packets */ 137 }; 138 139 #ifdef KERNEL 140 struct inpcb tcb; /* head of queue of active tcpcb's */ 141 struct tcpstat tcpstat; /* tcp statistics */ 142 struct tcpiphdr *tcp_template(); 143 struct tcpcb *tcp_close(), *tcp_drop(); 144 struct tcpcb *tcp_timers(), *tcp_disconnect(), *tcp_usrclosed(); 145 #endif 146