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    Length: 4229 (0x1085)
    Types: TextFile
    Names: »sockt.c«

└─⟦b20c6495f⟧ Bits:30007238 EUUGD18: Wien-båndet, efterår 1987
    └─⟦this⟧ »EUUGD18/General/Dots/sockt.c« 

TextFile

/* sockt.c */
/* All the stuff that deals with sockets is here */

#include "dots.h"
#include <sys/un.h>	/* unix domain sockets */
#include <errno.h>

#define SOCKNAME  "/tmp/dots"

#define namelen(sockt) (sizeof (sockt.sun_family) + strlen(sockt.sun_path))

int len;
static int (*oldint)(), (*oldquit)();
struct sockaddr_un sockt;

sockit(argc, argv)
char **argv;
{
    setbuf(stdout, (char *)NULL);

    mover = THEM;
    opponent = argv[2];
    Initial[THEM] = *opponent;

    (void) strcpy(sockt.sun_path, SOCKNAME);
    len = namelen(sockt);

    if ((sd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {	/* create a socket */
	oops("Socket error");
	return;
    }

    /* try to respond to a possible connection already established */
    while (connect(sd, (struct sockaddr *)&sockt, namelen(sockt)) == -1)
	/*
	 * check to see if we can't connect because of "correct" errors 
	 */
	if (errno != ENOENT) {	/* no such file or directory */
	    perror("connect on socket");
	    puts("Trying again...");
	    (void) close(sd);
	    sockit(argc, argv);
	} else {
	    mover = US;	/* challenger goes first */
	    if (!findem(argc, argv))
		return;
	    else
		break;
	}
    getsizes();		/* get the window sizes of both players */
    Dots(2);		/* we are connected and won't return */
}

/* send an invitation */

#include <sys/time.h>
struct itimerval waittime;
jmp_buf jmpbuf;

reinvite(sig)
{
    if (sig == SIGALRM) {
	printf("\nre");
	longjmp(jmpbuf, 1);
    }
    timerclear(&waittime.it_interval);
    timerclear(&waittime.it_value);
    (void) setitimer(ITIMER_REAL, &waittime, (struct itimerval *) 0);
    destroysocket();
    (void) signal(SIGINT, oldint);
    (void) signal(SIGQUIT, oldquit);
    longjmp(jmpbuf, 2);
}

invite(recipient)
FILE *recipient;
{
    int newsok;

    waittime.it_value.tv_sec = 30;
    waittime.it_value.tv_usec = 0;
    waittime.it_interval = waittime.it_value;

    /*
     * we're a server, so we give a name to the socket to the client knows
     * what to connect with. bind() is used to give a name to a socket. 
     */
    if (bind(sd, (struct sockaddr *)&sockt, len) == -1) {
	oops("Can't bind %s", SOCKNAME);
	return 0;
    }
    if (listen(sd, 5) == -1) {
	oops("Can't listen %s", SOCKNAME);
	return 0;
    }

    setbuf(recipient, (char *)NULL);

    /*
     * accept() will hang around and do nothing unless someone requests a
     * connection.  So, we wait..  signal again every 30 secs with setitmer 
     */
    (void) signal(SIGALRM, reinvite);
    oldint = signal(SIGINT, reinvite);
    oldquit = signal(SIGQUIT, reinvite);
    (void) setitimer(ITIMER_REAL, &waittime, (struct itimerval *) 0);
    if (setjmp(jmpbuf) == 2)
	return 0;
    printf("sending challenge...");
    fprintf(recipient, "Message from the \"dots\" game...\007\007\007\n");
    fprintf(recipient, "%s would like to play \"dots.\"\n", username);
    fprintf(recipient, "respond with \"dots 2 %s\"\n", username);

    while ((newsok = accept(sd, (struct sockaddr *)0, (int *)0)) == -1)
	if (errno != EINTR) {
	    oops("Can't accept %s", SOCKNAME);
	    return 0;
	} else
	    continue;

    timerclear(&waittime.it_interval);
    timerclear(&waittime.it_value);
    (void) setitimer(ITIMER_REAL, &waittime, (struct itimerval *) 0);
    (void) close(sd);
    sd = newsok;
    return 1;
}

 /* find lines and cols of the other guy */
getsizes()
{
    int their_lines, their_cols;

    do_twice {
	if (mover == US) {
	    (void) write(sd, (char *)&COLS, sizeof(int));
	    (void) write(sd, (char *)&LINES, sizeof(int));
	} else {
	    (void) read(sd, (char *)&their_cols, sizeof(int));
	    (void) read(sd, (char *)&their_lines, sizeof(int));
	}
	mover = !mover;
    }
    Length = min(COLS, their_cols) / 4;
    Width = min(LINES, their_lines) / 2 - 2;
    comptally = persontally = 0;
    xposit = 2, yposit = 1;
    y_start = 1 + (LINES - 2) / 2 - Width;
    x_start = 1 + COLS / 2 - Length * 2;

    (void) signal(SIGINT, oldint);
    (void) signal(SIGQUIT, oldquit);
}

destroysocket()
{
    if (!access(SOCKNAME, 0)) {
	if (shutdown(sd, 2) == -1)  /* dissallow further sends and recieves */
	    oops("shutdown failed cuz");
	if (unlink(SOCKNAME) == -1)
	    oops("Can't unlink %s", SOCKNAME);
    }
}