1 /* tcp_var.h 6.2 84/11/14 */ 2 3 /* 4 * Kernel variables for tcp. 5 */ 6 7 /* 8 * Tcp control block, one per tcp; fields: 9 */ 10 struct tcpcb { 11 struct tcpiphdr *seg_next; /* sequencing queue */ 12 struct tcpiphdr *seg_prev; 13 short t_state; /* state of this connection */ 14 short t_timer[TCPT_NTIMERS]; /* tcp timers */ 15 short t_rxtshift; /* log(2) of rexmt exp. backoff */ 16 struct mbuf *t_tcpopt; /* tcp options */ 17 struct mbuf *t_ipopt; /* ip options */ 18 short t_maxseg; /* maximum segment size */ 19 char t_force; /* 1 if forcing out a byte */ 20 u_char t_flags; 21 #define TF_ACKNOW 0x01 /* ack peer immediately */ 22 #define TF_DELACK 0x02 /* ack, but try to delay it */ 23 #define TF_DONTKEEP 0x04 /* don't use keep-alives */ 24 #define TF_NOOPT 0x08 /* don't use tcp options */ 25 struct tcpiphdr *t_template; /* skeletal packet for transmit */ 26 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 27 /* 28 * The following fields are used as in the protocol specification. 29 * See RFC783, Dec. 1981, page 21. 30 */ 31 /* send sequence variables */ 32 tcp_seq snd_una; /* send unacknowledged */ 33 tcp_seq snd_nxt; /* send next */ 34 tcp_seq snd_up; /* send urgent pointer */ 35 tcp_seq snd_wl1; /* window update seg seq number */ 36 tcp_seq snd_wl2; /* window update seg ack number */ 37 tcp_seq iss; /* initial send sequence number */ 38 u_short snd_wnd; /* send window */ 39 /* receive sequence variables */ 40 short rcv_wnd; /* receive window */ 41 tcp_seq rcv_nxt; /* receive next */ 42 tcp_seq rcv_up; /* receive urgent pointer */ 43 tcp_seq irs; /* initial receive sequence number */ 44 /* 45 * Additional variables for this implementation. 46 */ 47 /* receive variables */ 48 tcp_seq rcv_adv; /* advertised window */ 49 /* retransmit variables */ 50 tcp_seq snd_max; /* highest sequence number sent 51 * used to recognize retransmits 52 */ 53 /* congestion control (for source quench) */ 54 u_short snd_cwnd; /* congestion-controlled window */ 55 /* transmit timing stuff */ 56 short t_idle; /* inactivity time */ 57 short t_rtt; /* round trip time */ 58 tcp_seq t_rtseq; /* sequence number being timed */ 59 float t_srtt; /* smoothed round-trip time */ 60 /* out-of-band data */ 61 char t_oobflags; /* have some */ 62 char t_iobc; /* input character */ 63 #define TCPOOB_HAVEDATA 0x01 64 }; 65 66 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 67 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 68 69 struct tcpstat { 70 int tcps_badsum; 71 int tcps_badoff; 72 int tcps_hdrops; 73 int tcps_badsegs; 74 int tcps_unack; 75 }; 76 77 #ifdef KERNEL 78 struct inpcb tcb; /* head of queue of active tcpcb's */ 79 struct tcpstat tcpstat; /* tcp statistics */ 80 struct tcpiphdr *tcp_template(); 81 struct tcpcb *tcp_close(), *tcp_drop(); 82 struct tcpcb *tcp_timers(), *tcp_disconnect(), *tcp_usrclosed(); 83 #endif 84