1 /* 2 * Copyright (c) 1982, 1986 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that this notice is preserved and that due credit is given 7 * to the University of California at Berkeley. The name of the University 8 * may not be used to endorse or promote products derived from this 9 * software without specific prior written permission. This software 10 * is provided ``as is'' without express or implied warranty. 11 * 12 * @(#)tcp_var.h 7.6 (Berkeley) 12/07/87 13 */ 14 15 /* 16 * Kernel variables for tcp. 17 */ 18 19 /* 20 * Tcp control block, one per tcp; fields: 21 */ 22 struct tcpcb { 23 struct tcpiphdr *seg_next; /* sequencing queue */ 24 struct tcpiphdr *seg_prev; 25 short t_state; /* state of this connection */ 26 short t_timer[TCPT_NTIMERS]; /* tcp timers */ 27 short t_rxtshift; /* log(2) of rexmt exp. backoff */ 28 short t_rxtcur; /* current retransmit value */ 29 short t_dupacks; /* consecutive dup acks recd */ 30 u_short t_maxseg; /* maximum segment size */ 31 char t_force; /* 1 if forcing out a byte */ 32 u_char t_flags; 33 #define TF_ACKNOW 0x01 /* ack peer immediately */ 34 #define TF_DELACK 0x02 /* ack, but try to delay it */ 35 #define TF_NODELAY 0x04 /* don't delay packets to coalesce */ 36 #define TF_NOOPT 0x08 /* don't use tcp options */ 37 #define TF_SENTFIN 0x10 /* have sent FIN */ 38 struct tcpiphdr *t_template; /* skeletal packet for transmit */ 39 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 40 /* 41 * The following fields are used as in the protocol specification. 42 * See RFC783, Dec. 1981, page 21. 43 */ 44 /* send sequence variables */ 45 tcp_seq snd_una; /* send unacknowledged */ 46 tcp_seq snd_nxt; /* send next */ 47 tcp_seq snd_up; /* send urgent pointer */ 48 tcp_seq snd_wl1; /* window update seg seq number */ 49 tcp_seq snd_wl2; /* window update seg ack number */ 50 tcp_seq iss; /* initial send sequence number */ 51 u_short snd_wnd; /* send window */ 52 /* receive sequence variables */ 53 u_short rcv_wnd; /* receive window */ 54 tcp_seq rcv_nxt; /* receive next */ 55 tcp_seq rcv_up; /* receive urgent pointer */ 56 tcp_seq irs; /* initial receive sequence number */ 57 /* 58 * Additional variables for this implementation. 59 */ 60 /* receive variables */ 61 tcp_seq rcv_adv; /* advertised window */ 62 /* retransmit variables */ 63 tcp_seq snd_max; /* highest sequence number sent 64 * used to recognize retransmits 65 */ 66 /* congestion control (for slow start, source quench, retransmit after loss) */ 67 u_short snd_cwnd; /* congestion-controlled window */ 68 u_short snd_ssthresh; /* snd_cwnd size threshhold for 69 * for slow start exponential to 70 * linear switch */ 71 /* 72 * transmit timing stuff. 73 * srtt and rttvar are stored as fixed point; for convenience in smoothing, 74 * srtt has 3 bits to the right of the binary point, rttvar has 2. 75 * "Variance" is actually smoothed difference. 76 */ 77 short t_idle; /* inactivity time */ 78 short t_rtt; /* round trip time */ 79 tcp_seq t_rtseq; /* sequence number being timed */ 80 short t_srtt; /* smoothed round-trip time */ 81 short t_rttvar; /* variance in round-trip time */ 82 u_short max_rcvd; /* most peer has sent into window */ 83 u_short max_sndwnd; /* largest window peer has offered */ 84 /* out-of-band data */ 85 char t_oobflags; /* have some */ 86 char t_iobc; /* input character */ 87 #define TCPOOB_HAVEDATA 0x01 88 #define TCPOOB_HADDATA 0x02 89 }; 90 91 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 92 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 93 94 /* 95 * TCP statistics. 96 * Many of these should be kept per connection, 97 * but that's inconvenient at the moment. 98 */ 99 struct tcpstat { 100 u_long tcps_connattempt; /* connections initiated */ 101 u_long tcps_accepts; /* connections accepted */ 102 u_long tcps_connects; /* connections established */ 103 u_long tcps_drops; /* connections dropped */ 104 u_long tcps_conndrops; /* embryonic connections dropped */ 105 u_long tcps_closed; /* conn. closed (includes drops) */ 106 u_long tcps_segstimed; /* segs where we tried to get rtt */ 107 u_long tcps_rttupdated; /* times we succeeded */ 108 u_long tcps_delack; /* delayed acks sent */ 109 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ 110 u_long tcps_rexmttimeo; /* retransmit timeouts */ 111 u_long tcps_persisttimeo; /* persist timeouts */ 112 u_long tcps_keeptimeo; /* keepalive timeouts */ 113 u_long tcps_keepprobe; /* keepalive probes sent */ 114 u_long tcps_keepdrops; /* connections dropped in keepalive */ 115 116 u_long tcps_sndtotal; /* total packets sent */ 117 u_long tcps_sndpack; /* data packets sent */ 118 u_long tcps_sndbyte; /* data bytes sent */ 119 u_long tcps_sndrexmitpack; /* data packets retransmitted */ 120 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */ 121 u_long tcps_sndacks; /* ack-only packets sent */ 122 u_long tcps_sndprobe; /* window probes sent */ 123 u_long tcps_sndurg; /* packets sent with URG only */ 124 u_long tcps_sndwinup; /* window update-only packets sent */ 125 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ 126 127 u_long tcps_rcvtotal; /* total packets received */ 128 u_long tcps_rcvpack; /* packets received in sequence */ 129 u_long tcps_rcvbyte; /* bytes received in sequence */ 130 u_long tcps_rcvbadsum; /* packets received with ccksum errs */ 131 u_long tcps_rcvbadoff; /* packets received with bad offset */ 132 u_long tcps_rcvshort; /* packets received too short */ 133 u_long tcps_rcvduppack; /* duplicate-only packets received */ 134 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */ 135 u_long tcps_rcvpartduppack; /* packets with some duplicate data */ 136 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ 137 u_long tcps_rcvoopack; /* out-of-order packets received */ 138 u_long tcps_rcvoobyte; /* out-of-order bytes received */ 139 u_long tcps_rcvpackafterwin; /* packets with data after window */ 140 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */ 141 u_long tcps_rcvafterclose; /* packets rcvd after "close" */ 142 u_long tcps_rcvwinprobe; /* rcvd window probe packets */ 143 u_long tcps_rcvdupack; /* rcvd duplicate acks */ 144 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */ 145 u_long tcps_rcvackpack; /* rcvd ack packets */ 146 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */ 147 u_long tcps_rcvwinupd; /* rcvd window update packets */ 148 }; 149 150 #ifdef KERNEL 151 struct inpcb tcb; /* head of queue of active tcpcb's */ 152 struct tcpstat tcpstat; /* tcp statistics */ 153 struct tcpiphdr *tcp_template(); 154 struct tcpcb *tcp_close(), *tcp_drop(); 155 struct tcpcb *tcp_timers(), *tcp_disconnect(), *tcp_usrclosed(); 156 #endif 157