-/* ttt.c - client-server tic-tac-toe game
+/* ttt-server.c - tic-tac-toe game server
*
* Copyright © 2005 Carl Worth
*
* Author: Carl Worth <cworth@cworth.org>
*/
-#include "ttt.h"
+#include "ttt-server.h"
+
+#include "ttt-args.h"
+#include "ttt-client.h"
+#include "ttt-error.h"
#include "ttt-socket.h"
+struct _ttt_server {
+ pthread_mutex_t mutex;
+
+ const char *host;
+ const char *port;
+
+ ttt_client_t **clients;
+ int clients_size;
+ int num_clients;
+};
+
static void
-ttt_dispatch (int connected_socket)
+ttt_server_init (ttt_server_t *server, const char *host, const char *port)
+{
+ pthread_mutex_init (&server->mutex, NULL);
+
+ server->host = host;
+ server->port = port;
+
+ server->clients = NULL;
+ server->clients_size = 0;
+ server->num_clients = 0;
+}
+
+/* Exported: See ttt-server.h for documentation. */
+ttt_error_t
+ttt_server_register_client (ttt_server_t *server, ttt_client_t *client)
{
-#define BUF_SIZE 1024
+ int i;
+ ttt_error_t error = TTT_ERROR_NONE;
+ const char *username;
+
+ pthread_mutex_lock (&server->mutex);
+
+ username = ttt_client_get_username (client);
+
+ assert (username != NULL);
- while (1) {
- char buf[BUF_SIZE];
- int cnt;
- cnt = read (connected_socket, buf, BUF_SIZE);
- if (cnt == 0)
+ if (username[0] == '\0')
+ return TTT_ERROR_INVALID_NAME;
+
+ for (i = 0; i < server->num_clients; i++) {
+ if (strcmp (ttt_client_get_username (server->clients[i]), username) == 0) {
+ error = TTT_ERROR_INVALID_NAME;
+ goto CLEANUP_LOCK;
+ }
+ }
+
+ fprintf (stderr, "Client %s has joined.\r\n", username);
+
+ server->num_clients++;
+
+ if (server->num_clients > server->clients_size) {
+ if (server->clients_size == 0)
+ server->clients_size = 1;
+ else
+ server->clients_size *= 2;
+
+ server->clients = xrealloc (server->clients,
+ server->clients_size * sizeof (ttt_client_t *));
+ }
+
+ server->clients [server->num_clients - 1] = client;
+
+ CLEANUP_LOCK:
+ pthread_mutex_unlock (&server->mutex);
+
+ return error;
+}
+
+/* Exported: See ttt-server.h for documentation. */
+void
+ttt_server_unregister_client (ttt_server_t *server, ttt_client_t *client)
+{
+ int i;
+
+ pthread_mutex_lock (&server->mutex);
+
+ for (i = 0; i < server->num_clients; i++)
+ if (server->clients[i] == client)
break;
- write (0, buf, cnt);
- write (connected_socket, buf, cnt);
+
+ assert (i < server->num_clients);
+
+ printf ("Client %s has left.\r\n", ttt_client_get_username (client));
+
+ memmove (&server->clients[i], &server->clients[i+1],
+ (server->num_clients - i - 1) * sizeof (ttt_client_t *));
+
+ server->num_clients--;
+
+ pthread_mutex_unlock (&server->mutex);
+}
+
+/* Exported: See ttt-server.h for documentation. */
+void
+ttt_server_broadcast (ttt_server_t *server, const char *message)
+{
+ int i;
+
+ pthread_mutex_lock (&server->mutex);
+
+ for (i = 0; i < server->num_clients; i++)
+ ttt_client_send (server->clients[i], message);
+
+ pthread_mutex_unlock (&server->mutex);
+}
+
+/* Exported: See ttt-server.h for documentation. */
+const char*
+ttt_server_who (ttt_server_t *server)
+{
+ int i;
+ char *response;
+
+ pthread_mutex_lock (&server->mutex);
+
+ xasprintf (&response, "WHO");
+
+ for (i = 0; i < server->num_clients; i++)
+ xasprintf (&response, "%s %s",
+ response,
+ ttt_client_get_username (server->clients[i]));
+
+ xasprintf (&response, "%s\r\n", response);
+
+ pthread_mutex_unlock (&server->mutex);
+
+ return response;
+}
+
+/* Exported: See ttt-server.h for documentation. */
+ttt_error_t
+ttt_server_statistics (ttt_server_t *server, const char *username, char **response)
+{
+ ttt_bool_t usernamefound = FALSE;
+ const char *client_username;
+ int client_num_wins;
+ int i;
+
+ pthread_mutex_lock (&server->mutex);
+
+ for (i = 0; i < server->num_clients; i++) {
+ client_username = ttt_client_get_username (server->clients[i]);
+ if (strcasecmp (username, client_username) == 0) {
+ usernamefound = TRUE;
+ client_num_wins = ttt_client_get_num_wins (server->clients[i]);
+ xasprintf (response, "STATISTICS %s \"\r\n"
+ "TICTACTOE WINS %d\r\n\"\r\n",
+ client_username,
+ client_num_wins);
+ }
+ }
+
+ pthread_mutex_unlock (&server->mutex);
+
+ if (!usernamefound)
+ return TTT_ERROR_NO_USER;
+
+ return TTT_ERROR_NONE;
+}
+
+/* Exported: See ttt-server.h for documentation. */
+ttt_error_t
+ttt_server_verify_username (ttt_server_t *server, const char *username)
+{
+ ttt_bool_t usernamefound = FALSE;
+ const char *client_username;
+ int i;
+
+ pthread_mutex_lock (&server->mutex);
+
+ for (i = 0; i < server->num_clients; i++) {
+ client_username = ttt_client_get_username (server->clients[i]);
+ if (strcasecmp (username, client_username) == 0)
+ usernamefound = TRUE;
}
+
+ pthread_mutex_unlock (&server->mutex);
+
+ if (!usernamefound)
+ return TTT_ERROR_NO_USER;
+
+ return TTT_ERROR_NONE;
+}
+
+/* Exported: See ttt-server.h for documentation. */
+const char*
+ttt_server_get_host (ttt_server_t *server)
+{
+ return server->host;
+}
+
+/* Exported: See ttt-server.h for documentation. */
+const char*
+ttt_server_get_port (ttt_server_t *server)
+{
+ return server->port;
}
static const char *WELCOME_MESSAGE =
-"Welcome to ttt-server. So far, this program is simply a demonstration\n"
-"of a TCP/IP server that handles one client at a time. The server is\n"
-"currently listening on:\n"
-"\n %s:%s\n"
-"\nTo test this program, simply connect a client to that host and port.\n"
-"For example:\n"
-"\n telnet %s %s\n"
-"\nOnce you have connected a client, the server will echo any characters\n"
-"it receives back to the client as well as to stdout.\n"
-"\nNote that to terminate the telnet client you type Control-], then\n"
-"<Enter>, then \"close\" (and <Enter>) at the \"telnet> \" prompt.\n"
-"\nHave fun!\n"
-"-Carl\n"
-"\nPS. The server handles only one client at a time, but multiple clients\n"
-"may be able to connect simultaneously. Subsequent clients will see no\n"
-"output from the server until all previous clients exit.\n"
-"\nExtending the server to fork a new process for each client would be a fun\n"
-"project for a motivated student (as would writing a custom client program).\n\n";
+"Welcome to ttt-server. The server is currently listening on:\r\n"
+"\r\n"
+" %s:%s\r\n"
+"\r\n"
+"To test this, simply connect one or more clients to that host and port.\r\n"
+"For example:\r\n"
+"\r\n"
+" telnet %s %s\r\n"
+"\r\n"
+"The TTTP (tic-tac-toe protocol) has been partially implemented.\r\n"
+"The following commands should work: HELO, HELP, MESSAGE, VERSION, QUIT, WHO.\r\n"
+"\r\n";
+
+static void
+_ttt_server_accept (void *closure, int client_socket)
+{
+ ttt_server_t *server = closure;
+
+ ttt_client_new (server, client_socket);
+}
+
+static void
+_detach_and_write_child_pid_to (const char *filename)
+{
+ pid_t pid;
+
+ /* Use the Unix double-fork trick to detach completely. See
+ * setsid(2) for some details as to why two forks are
+ * needed. */
+ pid = xfork ();
+ if (pid) {
+ /* First parent just exits */
+ exit (0);
+ }
+
+ chdir ("/");
+ setsid ();
+
+ pid = xfork ();
+ if (pid) {
+ /* Second parent exits after writing pid */
+ FILE *file = xfopen (filename, "w");
+ fprintf (file, "%d\n", pid);
+ fclose (file);
+ exit (0);
+ }
+
+ /* Final, detached child returns. */
+}
int
main (int argc, char **argv)
{
ttt_args_t args;
+ ttt_server_t server;
int socket;
ttt_args_parse (&args, argc, argv);
- if (args.log_file)
- xfreopen (args.log_file, "a", stderr);
+ if (args.log_file || args.detach) {
+ FILE *log_file;
+ /* In the detach case, we force redirection to a log file. */
+ if (args.log_file == NULL)
+ args.log_file = "/var/log/ttt-server.log";
+ log_file = fopen (args.log_file, "a");
+ if (log_file == NULL) {
+ printf ("Warning: Failed to open log file %s: %s.\n",
+ args.log_file, strerror (errno));
+ printf ("Logging will be disabled.\n");
+ xdup2 (1, 2);
+ } else {
+ xdup2 (fileno (log_file), 2);
+ }
+ }
+
+ if (args.detach)
+ _detach_and_write_child_pid_to (args.pid_file);
+
+ /* Now that we've setup logging and the pid file, drop any special
+ * permissions we might have if we were asked to do that. */
+ if (args.user) {
+ int ret;
+ struct passwd *pwd;
+ errno = 0;
+ pwd = getpwnam (args.user);
+ if (pwd == NULL) {
+ fprintf (stderr, "Error: Failed to lookup uid for %s: %s. Aborting.\n",
+ args.user,
+ errno == 0 ? "User not found" : strerror (errno));
+ exit (1);
+ }
+ ret = setuid (pwd->pw_uid);
+ if (ret == -1) {
+ fprintf (stderr, "Error: Failed to setuid to %d (%s): %s. Aborting.\n",
+ pwd->pw_uid, args.user, strerror (errno));
+ exit (1);
+ }
+ }
socket = ttt_socket_create_server (args.host, args.port);
- printf (WELCOME_MESSAGE, args.host, args.port, args.host, args.port);
+ if (args.detach) {
+ printf ("Server started listening on %s:%s\n", args.host, args.port);
+ fprintf (stderr, "Server started listening on %s:%s\n", args.host, args.port);
+ } else {
+ printf (WELCOME_MESSAGE, args.host, args.port, args.host, args.port);
+ }
+
+ fclose (stdout);
+ fclose (stdin);
+
+ ttt_server_init (&server, args.host, args.port);
while (1)
- ttt_socket_accept (socket, ttt_dispatch);
+ ttt_socket_accept (socket, _ttt_server_accept, &server);
/* We only reach here if something bad happened. */
return 1;
projects / ttt / blobdiff