usr/src/sys/netinet/tcp_fsm.h

/*      tcp_fsm.h       4.4     81/11/08        */

/*
 * TCP FSM definitions.
 *
 * The TCP is conceptually a finite state machine with 13 states
 * and 9 inputs.  The states and inputs are defined here, as well
 * as an array which is used in network profiling to keep event
 * counters on the state transitions.  The actual state transitions
 * occur on input to the tcp machine (tcp_input.c) and when user
 * requests are made (tcp_states.c).
 *
 * This TCP machine has two more states than suggested in RFC 793,
 * the extra states being L_SYN_RCVD and RCV_WAIT.
 *
 * EXPLAIN THE EXTRA STATES!!!
 */

/*
 * States
 */
#define TCP_NSTATES     14

#define EFAILEC         -1              /* new state for failure, internally */
#define SAME            0               /* no state change, internally */
#define LISTEN          1               /* listening for connection */
#define SYN_SENT        2               /* active, have sent syn */
#define SYN_RCVD        3
#define L_SYN_RCVD      4
#define ESTAB           5               /* established */
#define FIN_W1          6               /* have closed and sent fin */
#define FIN_W2          7               /* have closed and rcvd ack of fin */
#define TIME_WAIT       8               /* in 2*msl quiet wait after close */
#define CLOSE_WAIT      9               /* rcvd fin, waiting for UCLOSE */
#define CLOSING         10              /* closed xchd FIN; await FIN ACK */
#define LAST_ACK        11              /* had fin and UCLOSE; await FIN ACK */
#define RCV_WAIT        12              /* waiting for user to drain data */
#define CLOSED          13              /* closed */

/*
 * Inputs to fsm.
 */
#define TCP_NINPUTS     10

#define IUOPENA         0               /* active open by user */
#define INRECV          1               /* segment received from net */
#define IUOPENR         2               /* passive open by user */
#define IUCLOSE         3               /* close by user */
#define ISTIMER         4               /* tcp timer expired */
#define IURECV          5               /* user read data; adjust window */
#define IUSEND          6               /* user sending data */
#define IUABORT         7               /* user aborts connection */
#define INCLEAR         8               /* network clear */
#define INSEND          9               /* send by tcp to remote peer */

#ifdef KPROF
int     acounts[TCP_NSTATES][TCP_NINPUTS];
#endif

#ifdef TCPSTATES
char *tcpstates[] = {
        "SAME",         "LISTEN",       "SYN_SENT",     "SYN_RCVD",
        "L_SYN_RCVD",   "ESTAB",        "FIN_W1",       "FIN_W2",
        "TIME_WAIT",    "CLOSE_WAIT",   "CLOSING",      "LAST_ACK",
        "RCV_WAIT",     "CLOSED"
};
char *tcpinputs[] = {
        "BAD",          "UOPENA",       "NRECV",        "UOPENR",
        "UCLOSE",       "STIMER",       "URECV",        "USEND",
        "UABORT",       "NCLEAR",       "NSEND",
};
char *tcptimers[] = { "INIT", "REXMT", "REXMTTL", "PERSIST", "FINACK" };
#endif