1*23197Smckusick /* 2*23197Smckusick * Copyright (c) 1982 Regents of the University of California. 3*23197Smckusick * All rights reserved. The Berkeley software License Agreement 4*23197Smckusick * specifies the terms and conditions for redistribution. 5*23197Smckusick * 6*23197Smckusick * @(#)tcp_var.h 6.3 (Berkeley) 06/08/85 7*23197Smckusick */ 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 struct mbuf *t_ipopt; /* ip options */ 245092Swnj short t_maxseg; /* maximum segment size */ 255246Sroot char t_force; /* 1 if forcing out a byte */ 265067Swnj u_char t_flags; 275092Swnj #define TF_ACKNOW 0x01 /* ack peer immediately */ 285092Swnj #define TF_DELACK 0x02 /* ack, but try to delay it */ 295443Swnj #define TF_DONTKEEP 0x04 /* don't use keep-alives */ 305443Swnj #define TF_NOOPT 0x08 /* don't use tcp options */ 314881Swnj struct tcpiphdr *t_template; /* skeletal packet for transmit */ 325067Swnj struct inpcb *t_inpcb; /* back pointer to internet pcb */ 334808Swnj /* 345067Swnj * The following fields are used as in the protocol specification. 355067Swnj * See RFC783, Dec. 1981, page 21. 364808Swnj */ 375067Swnj /* send sequence variables */ 385067Swnj tcp_seq snd_una; /* send unacknowledged */ 395067Swnj tcp_seq snd_nxt; /* send next */ 405067Swnj tcp_seq snd_up; /* send urgent pointer */ 415067Swnj tcp_seq snd_wl1; /* window update seg seq number */ 425067Swnj tcp_seq snd_wl2; /* window update seg ack number */ 435067Swnj tcp_seq iss; /* initial send sequence number */ 445246Sroot u_short snd_wnd; /* send window */ 455067Swnj /* receive sequence variables */ 465246Sroot short rcv_wnd; /* receive window */ 475067Swnj tcp_seq rcv_nxt; /* receive next */ 485067Swnj tcp_seq rcv_up; /* receive urgent pointer */ 495067Swnj tcp_seq irs; /* initial receive sequence number */ 505067Swnj /* 515067Swnj * Additional variables for this implementation. 525067Swnj */ 535076Swnj /* receive variables */ 545076Swnj tcp_seq rcv_adv; /* advertised window */ 555067Swnj /* retransmit variables */ 565092Swnj tcp_seq snd_max; /* highest sequence number sent 5717359Skarels * used to recognize retransmits 5817359Skarels */ 5917359Skarels /* congestion control (for source quench) */ 6017359Skarels u_short snd_cwnd; /* congestion-controlled window */ 615166Swnj /* transmit timing stuff */ 625166Swnj short t_idle; /* inactivity time */ 635166Swnj short t_rtt; /* round trip time */ 645166Swnj tcp_seq t_rtseq; /* sequence number being timed */ 655166Swnj float t_srtt; /* smoothed round-trip time */ 665443Swnj /* out-of-band data */ 675443Swnj char t_oobflags; /* have some */ 685550Swnj char t_iobc; /* input character */ 695443Swnj #define TCPOOB_HAVEDATA 0x01 705067Swnj }; 714808Swnj 724881Swnj #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 734881Swnj #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 744881Swnj 754926Swnj struct tcpstat { 764926Swnj int tcps_badsum; 774926Swnj int tcps_badoff; 784926Swnj int tcps_hdrops; 794926Swnj int tcps_badsegs; 804926Swnj int tcps_unack; 814926Swnj }; 824926Swnj 834808Swnj #ifdef KERNEL 845067Swnj struct inpcb tcb; /* head of queue of active tcpcb's */ 855067Swnj struct tcpstat tcpstat; /* tcp statistics */ 864881Swnj struct tcpiphdr *tcp_template(); 8710398Ssam struct tcpcb *tcp_close(), *tcp_drop(); 8810398Ssam struct tcpcb *tcp_timers(), *tcp_disconnect(), *tcp_usrclosed(); 894808Swnj #endif 90