1*17359Skarels /* tcp_var.h 6.2 84/11/14 */ 24808Swnj 34808Swnj /* 44808Swnj * Kernel variables for tcp. 54808Swnj */ 64808Swnj 74808Swnj /* 85166Swnj * Tcp control block, one per tcp; fields: 94808Swnj */ 104881Swnj struct tcpcb { 115076Swnj struct tcpiphdr *seg_next; /* sequencing queue */ 125076Swnj struct tcpiphdr *seg_prev; 135246Sroot short t_state; /* state of this connection */ 145092Swnj short t_timer[TCPT_NTIMERS]; /* tcp timers */ 155166Swnj short t_rxtshift; /* log(2) of rexmt exp. backoff */ 165092Swnj struct mbuf *t_tcpopt; /* tcp options */ 175092Swnj struct mbuf *t_ipopt; /* ip options */ 185092Swnj short t_maxseg; /* maximum segment size */ 195246Sroot char t_force; /* 1 if forcing out a byte */ 205067Swnj u_char t_flags; 215092Swnj #define TF_ACKNOW 0x01 /* ack peer immediately */ 225092Swnj #define TF_DELACK 0x02 /* ack, but try to delay it */ 235443Swnj #define TF_DONTKEEP 0x04 /* don't use keep-alives */ 245443Swnj #define TF_NOOPT 0x08 /* don't use tcp options */ 254881Swnj struct tcpiphdr *t_template; /* skeletal packet for transmit */ 265067Swnj struct inpcb *t_inpcb; /* back pointer to internet pcb */ 274808Swnj /* 285067Swnj * The following fields are used as in the protocol specification. 295067Swnj * See RFC783, Dec. 1981, page 21. 304808Swnj */ 315067Swnj /* send sequence variables */ 325067Swnj tcp_seq snd_una; /* send unacknowledged */ 335067Swnj tcp_seq snd_nxt; /* send next */ 345067Swnj tcp_seq snd_up; /* send urgent pointer */ 355067Swnj tcp_seq snd_wl1; /* window update seg seq number */ 365067Swnj tcp_seq snd_wl2; /* window update seg ack number */ 375067Swnj tcp_seq iss; /* initial send sequence number */ 385246Sroot u_short snd_wnd; /* send window */ 395067Swnj /* receive sequence variables */ 405246Sroot short rcv_wnd; /* receive window */ 415067Swnj tcp_seq rcv_nxt; /* receive next */ 425067Swnj tcp_seq rcv_up; /* receive urgent pointer */ 435067Swnj tcp_seq irs; /* initial receive sequence number */ 445067Swnj /* 455067Swnj * Additional variables for this implementation. 465067Swnj */ 475076Swnj /* receive variables */ 485076Swnj tcp_seq rcv_adv; /* advertised window */ 495067Swnj /* retransmit variables */ 505092Swnj tcp_seq snd_max; /* highest sequence number sent 51*17359Skarels * used to recognize retransmits 52*17359Skarels */ 53*17359Skarels /* congestion control (for source quench) */ 54*17359Skarels u_short snd_cwnd; /* congestion-controlled window */ 555166Swnj /* transmit timing stuff */ 565166Swnj short t_idle; /* inactivity time */ 575166Swnj short t_rtt; /* round trip time */ 585166Swnj tcp_seq t_rtseq; /* sequence number being timed */ 595166Swnj float t_srtt; /* smoothed round-trip time */ 605443Swnj /* out-of-band data */ 615443Swnj char t_oobflags; /* have some */ 625550Swnj char t_iobc; /* input character */ 635443Swnj #define TCPOOB_HAVEDATA 0x01 645067Swnj }; 654808Swnj 664881Swnj #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 674881Swnj #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 684881Swnj 694926Swnj struct tcpstat { 704926Swnj int tcps_badsum; 714926Swnj int tcps_badoff; 724926Swnj int tcps_hdrops; 734926Swnj int tcps_badsegs; 744926Swnj int tcps_unack; 754926Swnj }; 764926Swnj 774808Swnj #ifdef KERNEL 785067Swnj struct inpcb tcb; /* head of queue of active tcpcb's */ 795067Swnj struct tcpstat tcpstat; /* tcp statistics */ 804881Swnj struct tcpiphdr *tcp_template(); 8110398Ssam struct tcpcb *tcp_close(), *tcp_drop(); 8210398Ssam struct tcpcb *tcp_timers(), *tcp_disconnect(), *tcp_usrclosed(); 834808Swnj #endif 84