123197Smckusick /* 223197Smckusick * Copyright (c) 1982 Regents of the University of California. 323197Smckusick * All rights reserved. The Berkeley software License Agreement 423197Smckusick * specifies the terms and conditions for redistribution. 523197Smckusick * 6*25894Skarels * @(#)tcp_var.h 6.6 (Berkeley) 01/13/86 723197Smckusick */ 84808Swnj 94808Swnj /* 104808Swnj * Kernel variables for tcp. 114808Swnj */ 124808Swnj 134808Swnj /* 145166Swnj * Tcp control block, one per tcp; fields: 154808Swnj */ 164881Swnj struct tcpcb { 175076Swnj struct tcpiphdr *seg_next; /* sequencing queue */ 185076Swnj struct tcpiphdr *seg_prev; 195246Sroot short t_state; /* state of this connection */ 205092Swnj short t_timer[TCPT_NTIMERS]; /* tcp timers */ 215166Swnj short t_rxtshift; /* log(2) of rexmt exp. backoff */ 225092Swnj struct mbuf *t_tcpopt; /* tcp options */ 235092Swnj short t_maxseg; /* maximum segment size */ 245246Sroot char t_force; /* 1 if forcing out a byte */ 255067Swnj u_char t_flags; 26*25894Skarels #define TF_ACKNOW 0x01 /* ack peer immediately */ 27*25894Skarels #define TF_DELACK 0x02 /* ack, but try to delay it */ 28*25894Skarels #define TF_NODELAY 0x04 /* don't delay packets to coalesce */ 29*25894Skarels #define TF_NOOPT 0x08 /* don't use tcp options */ 304881Swnj struct tcpiphdr *t_template; /* skeletal packet for transmit */ 315067Swnj struct inpcb *t_inpcb; /* back pointer to internet pcb */ 324808Swnj /* 335067Swnj * The following fields are used as in the protocol specification. 345067Swnj * See RFC783, Dec. 1981, page 21. 354808Swnj */ 365067Swnj /* send sequence variables */ 375067Swnj tcp_seq snd_una; /* send unacknowledged */ 385067Swnj tcp_seq snd_nxt; /* send next */ 395067Swnj tcp_seq snd_up; /* send urgent pointer */ 405067Swnj tcp_seq snd_wl1; /* window update seg seq number */ 415067Swnj tcp_seq snd_wl2; /* window update seg ack number */ 425067Swnj tcp_seq iss; /* initial send sequence number */ 435246Sroot u_short snd_wnd; /* send window */ 445067Swnj /* receive sequence variables */ 45*25894Skarels u_short rcv_wnd; /* receive window */ 465067Swnj tcp_seq rcv_nxt; /* receive next */ 475067Swnj tcp_seq rcv_up; /* receive urgent pointer */ 485067Swnj tcp_seq irs; /* initial receive sequence number */ 495067Swnj /* 505067Swnj * Additional variables for this implementation. 515067Swnj */ 525076Swnj /* receive variables */ 535076Swnj tcp_seq rcv_adv; /* advertised window */ 545067Swnj /* retransmit variables */ 555092Swnj tcp_seq snd_max; /* highest sequence number sent 5617359Skarels * used to recognize retransmits 5717359Skarels */ 5817359Skarels /* congestion control (for source quench) */ 5917359Skarels u_short snd_cwnd; /* congestion-controlled window */ 605166Swnj /* transmit timing stuff */ 615166Swnj short t_idle; /* inactivity time */ 625166Swnj short t_rtt; /* round trip time */ 6324822Skarels u_short max_rcvd; /* most peer has sent into window */ 645166Swnj tcp_seq t_rtseq; /* sequence number being timed */ 655166Swnj float t_srtt; /* smoothed round-trip time */ 6625262Skarels u_short max_sndwnd; /* largest window peer has offered */ 675443Swnj /* out-of-band data */ 685443Swnj char t_oobflags; /* have some */ 695550Swnj char t_iobc; /* input character */ 705443Swnj #define TCPOOB_HAVEDATA 0x01 7124822Skarels #define TCPOOB_HADDATA 0x02 725067Swnj }; 734808Swnj 744881Swnj #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 754881Swnj #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 764881Swnj 774926Swnj struct tcpstat { 784926Swnj int tcps_badsum; 794926Swnj int tcps_badoff; 804926Swnj int tcps_hdrops; 814926Swnj int tcps_badsegs; 824926Swnj int tcps_unack; 834926Swnj }; 844926Swnj 854808Swnj #ifdef KERNEL 865067Swnj struct inpcb tcb; /* head of queue of active tcpcb's */ 875067Swnj struct tcpstat tcpstat; /* tcp statistics */ 884881Swnj struct tcpiphdr *tcp_template(); 8910398Ssam struct tcpcb *tcp_close(), *tcp_drop(); 9010398Ssam struct tcpcb *tcp_timers(), *tcp_disconnect(), *tcp_usrclosed(); 914808Swnj #endif 92