/************************************************************************
TTT.c
Castrated TTT server. No datagram queries, no timeouts. Assumes
completely well-behaved clients. Uses deprecated network address
translation.
Phil Kearns
April 12, 1998
Modified March, 2014
Adapted with GUI by Adam Carpenter - acarpent - acarpenter@email.wm.edu
Modified April 2017
*************************************************************************/
#include "common.h"
char board[9]; /* The tic-tac-toe board */
int main(int argc, char **argv)
{
int listener; /* fd for socket on which we get connection requests */
int Xfd, Ofd; /* fds for sockets onto VCs to clients */
struct sockaddr_in s1, Xaddr, Oaddr;
int length, sfile, i, moveto, result, Xresult, Oresult;
unsigned short lport;
int currentmove; /* 0->X, 1->O */
char hostid[128], Xhandle[32], Ohandle[32];
struct tttmsg outmsg, inmsg;
if (argc != 1) {
fprintf(stderr,"TTT:usage is TTT\n");
exit(1);
}
if ( (sfile = open(SFILE, O_RDWR|O_CREAT|O_TRUNC, 0644)) < 0) {
perror("TTT:sfile");
exit(1);
}
if (gethostname(hostid,128) < 0){
perror("TTT:gethostname");
exit(1);
}
i=0;
while (hostid[i] != '\0')
write(sfile,&hostid[i++], 1);
write(sfile,"\0", 1);
if ( (listener = socket( AF_INET, SOCK_STREAM, 0 )) < 0 ) {
perror("TTT:socket");
exit(1);
}
bzero((char *) &s1, sizeof(s1));
s1.sin_family = AF_INET;
s1.sin_addr.s_addr = INADDR_ANY; /* Any of this host's interfaces is OK. */
s1.sin_port = 0; /* bind() will gimme unique port. */
if (bind(listener, (struct sockaddr *)&s1, sizeof(s1)) < 0) {
perror("TTT:bind");
exit(1);
}
length = sizeof(s1);
if (getsockname(listener, (struct sockaddr *)&s1, (socklen_t *)&length) < 0) {
perror("TTT:getsockname");
exit(1);
}
lport = s1.sin_port;
write(sfile, &lport, sizeof(unsigned short));
close(sfile);
listen(listener,5);
length = sizeof(Xaddr);
if ((Xfd = accept(listener, (struct sockaddr *)&Xaddr, (socklen_t *)&length)) < 0) {
perror("TTT:accept X");
exit(1);
}
/* Send WHO to X */
bzero((char *)&outmsg, sizeof(outmsg));
outmsg.type = WHO;
putmsg(Xfd, &outmsg);
/* Await HANDLE from X */
bzero((char *)&inmsg, sizeof(inmsg));
getmsg(Xfd, &inmsg);
if (inmsg.type != HANDLE) protocol_error(HANDLE, &inmsg);
strncpy(Xhandle, inmsg.data, 31);
Xhandle[31] = '\0';
length = sizeof(Oaddr);
if ((Ofd = accept(listener, (struct sockaddr *)&Oaddr, (socklen_t *)&length)) < 0) {
perror("TTT:accept O");
exit(1);
}
/* Send WHO to O */
bzero((char *)&outmsg, sizeof(outmsg));
outmsg.type = WHO;
putmsg(Ofd, &outmsg);
/* Await HANDLE from O */
bzero((char *)&inmsg, sizeof(inmsg));
getmsg(Ofd, &inmsg);
if (inmsg.type != HANDLE) protocol_error(HANDLE, &inmsg);
strncpy(Ohandle, inmsg.data, 31);
Ohandle[31] = '\0';
/* WE HAVE A MATCH */
for(i=0; i<9; i++) board[i]=' ';
/* Send MATCH to X */
bzero((char *)&outmsg, sizeof(outmsg));
outmsg.type=MATCH;
strncpy(outmsg.data, Ohandle, 31);
outmsg.data[31] = '\0';
outmsg.board[0] = 'X';
putmsg(Xfd, &outmsg);
/* Send MATCH to O */
bzero((char *)&outmsg, sizeof(outmsg));
outmsg.type=MATCH;
strncpy(outmsg.data, Xhandle, 31);
outmsg.data[31] = '\0';
outmsg.board[0] = 'O';
putmsg(Ofd, &outmsg);
while(1) {
/* Send WHATMOVE to X */
bzero((char *)&outmsg, sizeof(outmsg));
outmsg.type=WHATMOVE;
for(i=0; i<9; i++) outmsg.board[i]=board[i];
putmsg(Xfd, &outmsg);
/* Await MOVE from X */
bzero((char *)&inmsg, sizeof(inmsg));
getmsg(Xfd, &inmsg);
// End the match if player X resigned.
if (inmsg.type == RESIGNED) {
bzero((char *)&outmsg, sizeof(outmsg));
outmsg.type=ABORT;
putmsg(Ofd, &outmsg);
exit(0);
}
else if (inmsg.type != MOVE) {
protocol_error(MOVE, &inmsg);
}
currentmove = 0; /* X's move being reported*/
moveto = inmsg.res & 0xF;
if (board[moveto] != ' ') {
fprintf(stderr, "TTT: invalid move\n");
exit(1);
}
board[moveto] = 'X';
if ((result = check_board(currentmove)) != 0) break;
/* Send WHATMOVE to O */
bzero((char *)&outmsg, sizeof(outmsg));
outmsg.type=WHATMOVE;
for(i=0; i<9; i++) outmsg.board[i]=board[i];
putmsg(Ofd, &outmsg);
/* Await MOVE from O */
bzero((char *)&inmsg, sizeof(inmsg));
getmsg(Ofd, &inmsg);
// End the match if player O resigned.
if (inmsg.type == RESIGNED) {
bzero((char *)&outmsg, sizeof(outmsg));
outmsg.type=ABORT;
putmsg(Xfd, &outmsg);
exit(0);
}
else if (inmsg.type != MOVE) {
protocol_error(MOVE, &inmsg);
}
if (inmsg.type != MOVE) protocol_error(MOVE, &inmsg);
currentmove = 1; /* O's move being reported*/
moveto = inmsg.res & 0xF;
if (board[moveto] != ' ') {
fprintf(stderr, "TTT: invalid move\n");
exit(1);
}
board[moveto] = 'O';
if ((result = check_board(currentmove)) != 0) break;
} /* while */
/* Match is over, report the result to both clients */
if (result == 2) {
Xresult = Oresult = 'D';
}
else { /* result must be 1, we have a winner */
if (currentmove == 0) { Xresult = 'W'; Oresult = 'L';}
else { Xresult = 'L'; Oresult = 'W';}
}
/* Send RESULT to X */
bzero((char *)&outmsg, sizeof(outmsg));
outmsg.type = RESULT;
outmsg.res = Xresult;
for(i=0; i<9; i++) outmsg.board[i]=board[i];
putmsg(Xfd, &outmsg);
/* Send RESULT to O */
bzero((char *)&outmsg, sizeof(outmsg));
outmsg.type = RESULT;
outmsg.res = Oresult;
for(i=0; i<9; i++) outmsg.board[i]=board[i];
putmsg(Ofd, &outmsg);
/* The game is finished */
return(0);
}
/************************************************************************
check_board() returns 0 if no winner
1 if winner
2 if draw
Brute force.
************************************************************************/
int
check_board(player)
int player; /* X is 0, O is 1 */
{
char match;
int i,spaces;
match = (player?'O':'X');
if (((board[0] == match) && (board[1] == match) && (board[2] == match)) ||
((board[3] == match) && (board[4] == match) && (board[5] == match)) ||
((board[6] == match) && (board[7] == match) && (board[8] == match)) ||
((board[0] == match) && (board[3] == match) && (board[6] == match)) ||
((board[1] == match) && (board[4] == match) && (board[7] == match)) ||
((board[2] == match) && (board[5] == match) && (board[8] == match)) ||
((board[0] == match) && (board[4] == match) && (board[8] == match)) ||
((board[2] == match) && (board[4] == match) && (board[6] == match))) return 1;
spaces = 0;
for(i=0; i<9; i++)
if (board[i] == ' ') {
spaces++;
break;
}
if (!spaces) return 2;
return 0;
}
void
dump_board(s,board)
FILE *s;
char board[];
{
fprintf(s,"%c | %c | %c\n", board[0], board[1], board[2]);
fprintf(s,"----------\n");
fprintf(s,"%c | %c | %c\n", board[3], board[4], board[5]);
fprintf(s,"----------\n");
fprintf(s,"%c | %c | %c\n", board[6], board[7], board[8]);
}
