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    Length: 3363 (0xd23)
    Types: TextFile
    Names: »connect.c«

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

TextFile

/* connect.c */

/*  BUG:  Should close sock after accepting. */

#include "externs.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <pwd.h>
#include <ctype.h>
/* typedef unsigned short uid_t; */     /* Needed on 4.2 */

connectport (opponent, port)
	char *opponent;
	int port;
{
	struct sockaddr_in addr;
	struct hostent *hishost, *myhost;
	struct passwd *mypasswd, *getpwuid();
	char *hishostname, *myhostname, *myname, *index(), *getpw(), *malloc();
	uid_t getuid();
	int i;

	if (hishostname = index (opponent, '@')) {
		hishostname [0] = '\0';        /* separate user and host */
		hishostname++;
	} else {
		hishostname = malloc (MAXBUFF);
		if (gethostname (hishostname, MAXBUFF) < 0)
			error ("gethostname in connectport");
	}
	myhostname = malloc (MAXBUFF);
	if (gethostname (myhostname, MAXBUFF) < 0)
		error ("gethostname in connectport");
	if ((myhost = (struct hostent *) gethostbyname(myhostname))
	    == (struct hostent *) NIL)
		error ("gethostname in connectport");
	strcpy (myhostname, myhost -> h_name);
	lowerstring (myhostname);
	if ((hishost = (struct hostent *) gethostbyname(hishostname))
	    == (struct hostent *) NIL)
		error ("gethostname in connectport");
	lowerstring (hishost -> h_name);
	mypasswd = getpwuid ((int) getuid());
	myname = mypasswd -> pw_name;
	if (iamserver == UNSET)
		if (i = strcmp (myname, opponent))
			iamserver = (i < 0);
		else if (i = strcmp (myhostname, hishost -> h_name))
			iamserver = (i < 0);
	if ((sock = socket (AF_INET, SOCK_STREAM, 0)) < 0)
		error ("socket in connectport");
	bzero ((char *) &addr, sizeof (addr));
	if (port == 0 && iamserver) {
		hashport (myhostname, &port);
		hashport (hishost -> h_name, &port);
		hashport (myname, &port);
		hashport (opponent, &port);
	}
	if (port == 0 && !iamserver) {
		hashport (hishost -> h_name, &port);
		hashport (myhostname, &port);
		hashport (opponent, &port);
		hashport (myname, &port);
	}
	port = port % 50021 + 10000;  /* 50021 is prime */
	addr.sin_family = AF_INET;
	addr.sin_port = htons ((u_short) port);
	if (iamserver) {
		if (bind (sock, /*(char *)*/ &addr, sizeof (addr)) < 0)
			if ((errno == EADDRINUSE || errno == ENOTCONN)
			&& iamserver == UNSET) {
				/* hope other player is server */
				iamserver = FALSE;
				close (sock);
				if ((sock = socket (AF_INET, SOCK_STREAM, 0))
				    < 0)
					error ("socket in connectport");
			} else
				error ("bind in connectport");
		if (iamserver && listen (sock, 1) < 0)
			error ("listen in connectport");
		while (iamserver
		&& (sock = accept (sock, (struct sockaddr_in *) NULL,
				   (int *) NULL)) < 0)
			if (errno != EINTR && errno != EBADF)
				error ("accept in connectport");
	}
	if (!iamserver) {
		bcopy (hishost->h_addr, (char *) &addr.sin_addr,
		       hishost->h_length);
		while (connect (sock, /*(char *)*/ &addr, sizeof (addr)) < 0)
			if ( errno == EINTR || errno == ECONNREFUSED) {
				close (sock);
				if ((sock = socket (AF_INET, SOCK_STREAM, 0))
				    < 0)
					error ("socket in connectport");
			} else
				error ("connect in connectport");
	}
}

hashport (s, port)
	char *s;
	int *port;
{
	while (*s)
		*port = ((*port < 0) | (*port << 1)) + *s++;
	*port &= ~0x80000000;	/* make *port nonnegative */
}

lowerstring (s)
	char *s;
{
	while (*s) {
		if (isupper (*s))
			*s = tolower (*s);
		s++;
	}
}