-/* 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"
-static ttt_status_t
-_sockaddr_init (struct sockaddr_in *addr,
- const char *host,
- const char *port)
+#include "ttt-args.h"
+#include "ttt-client.h"
+#include "ttt-error.h"
+#include "ttt-socket.h"
+
+struct _ttt_invite {
+ ttt_client_t *actor;
+ ttt_client_t *invitee;
+};
+
+struct _ttt_server {
+ pthread_mutex_t mutex;
+
+ const char *host;
+ const char *port;
+
+ ttt_client_t **clients;
+ int clients_size;
+ int num_clients;
+
+ ttt_invite_t **invites;
+ int invites_size;
+ int num_invites;
+};
+
+static void
+ttt_server_init (ttt_server_t *server, const char *host, const char *port)
{
- struct hostent *hostent;
- struct servent *servent;
- char *endptr;
- long port_long;
- uint16_t port_short;
+ pthread_mutex_init (&server->mutex, NULL);
- addr->sin_family = AF_INET;
+ server->host = host;
+ server->port = port;
- hostent = gethostbyname (host);
- if (hostent == NULL)
- {
- fprintf (stderr, "Error: Lookup failed for host %s: %s\n",
- host, hstrerror (h_errno));
- return TTT_STATUS_FAILURE;
+ server->clients = NULL;
+ server->clients_size = 0;
+ server->num_clients = 0;
+
+ server->invites = NULL;
+ server->invites_size = 0;
+ server->num_invites = 0;
+}
+
+/* Exported: See ttt-server.h for documentation. */
+ttt_error_t
+ttt_server_register_client (ttt_server_t *server, ttt_client_t *client)
+{
+ 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);
+
+ if (username[0] == '\0')
+ return TTT_ERROR_INVALID_NAME;
+
+ for (i = 0; i < server->num_clients; i++) {
+ if (strcasecmp (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 *));
}
- memcpy (&addr->sin_addr.s_addr, hostent->h_addr_list[0],
- sizeof (addr->sin_addr.s_addr));
- assert (*port != '\0');
- port_long = strtol (port, &endptr, 10);
- if (*endptr == '\0')
+ 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)
+{
+ ttt_invite_t *invite;
+ char *notice;
+ ttt_bool_t send_notice = FALSE;
+ int i;
+
+ pthread_mutex_lock (&server->mutex);
+
+ /* Auto-retract and decline pending notices */
+ /* Notices are sent after mutex unlock */
+ for (i = 0; i < server->num_invites; i++)
{
- /* Numeric port*/
- if (port_long <= 0 || port_long >= (1 << 16)) {
- fprintf (stderr, "Error: Port %ld out of range.\n", port_long);
- return TTT_STATUS_FAILURE;
+ invite = server->invites[i];
+ if ((invite->actor == client) || (invite->invitee == client))
+ {
+ send_notice = TRUE;
+ if (invite->actor == client)
+ xasprintf (¬ice, "%s" "NOTICE RETRACT %s %s\r\n",
+ notice,
+ ttt_client_get_username(invite->actor),
+ ttt_client_get_username(invite->invitee));
+ else
+ xasprintf (¬ice, "%s" "NOTICE DECLINE %s %s\r\n",
+ notice,
+ ttt_client_get_username(invite->invitee),
+ ttt_client_get_username(invite->actor));
+
+ memmove (&server->invites[i], &server->invites[i+1],
+ (server->num_invites - i - 1) * sizeof (ttt_invite_t *));
+ server->num_invites--;
+ i--;
}
- port_short = port_long;
- addr->sin_port = htons (port_short);
- } else {
- /* Named port */
- servent = getservbyname (port, "tcp");
- if (port == NULL) {
- fprintf (stderr, "Error: Lookup failed for port %s: %s\n",
- port, hstrerror (h_errno));
- return TTT_STATUS_FAILURE;
+ }
+
+ for (i = 0; i < server->num_clients; i++)
+ if (server->clients[i] == client)
+ break;
+
+ assert (i < server->num_clients);
+
+ fprintf (stderr, "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);
+
+ if (send_notice)
+ {
+ ttt_server_broadcast(server, notice);
+ free (notice);
+ }
+}
+
+/* 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_verify_username (ttt_server_t *server,
+ const char *username)
+{
+ ttt_client_t *client;
+
+ return ttt_server_get_client_from_username (server,
+ username,
+ &client);
+}
+
+/* Exported: See ttt-server.h for documentation. */
+ttt_error_t
+ttt_server_get_client_from_username (ttt_server_t *server,
+ const char *username,
+ ttt_client_t **client)
+{
+ 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;
+ *client = server->clients[i];
}
- addr->sin_port = servent->s_port;
}
- return TTT_STATUS_SUCCESS;
+ pthread_mutex_unlock (&server->mutex);
+
+ if (!usernamefound)
+ return TTT_ERROR_NO_USER;
+
+ return TTT_ERROR_NONE;
}
-static int
-_wait_for_connection (int listen_socket)
+/* Exported: See ttt-server.h for documentation. */
+ttt_error_t
+ttt_server_add_invite (ttt_server_t *server,
+ ttt_client_t *actor,
+ ttt_client_t *invitee)
{
- fd_set read_set;
- int num_selected;
- int flags, err;
- int connected_socket;
+ ttt_invite_t *invite;
+
+ pthread_mutex_lock (&server->mutex);
+
+ invite = xmalloc (sizeof (ttt_invite_t));
- FD_ZERO (&read_set);
- FD_SET (listen_socket, &read_set);
+ invite->actor = actor;
+ invite->invitee = invitee;
- while (1) {
- num_selected = select (listen_socket + 1,
- &read_set, NULL, NULL,
- NULL);
+ server->num_invites++;
- flags = fcntl (listen_socket, F_GETFL);
- flags |= O_NONBLOCK;
- xfcntl (listen_socket, F_SETFL, flags);
+ if (server->num_invites > server->invites_size) {
+ if (server->invites_size == 0)
+ server->invites_size = 1;
+ else
+ server->invites_size *= 2;
- connected_socket = accept (listen_socket, 0, 0);
- err = errno;
+ server->invites = xrealloc (server->invites,
+ server->invites_size * sizeof (ttt_invite_t *));
+ }
+
+ server->invites[server->num_invites - 1] = invite;
- flags &= ~O_NONBLOCK;
- xfcntl (listen_socket, F_SETFL, flags);
+ pthread_mutex_unlock (&server->mutex);
- if (connected_socket != -1)
- return connected_socket;
+ return TTT_ERROR_NONE;
+}
- if (err == EWOULDBLOCK || err == EAGAIN)
- continue;
+/* Exported: See ttt-server.h for documentation. */
+ttt_error_t
+ttt_server_remove_invite (ttt_server_t *server,
+ ttt_client_t *actor,
+ ttt_client_t *invitee)
+{
+ ttt_invite_t *invite;
+ ttt_error_t error;
+ int i;
- fprintf (stderr, "Error: accept failed: %s. Aborting.\n",
- strerror (err));
- exit (1);
+ pthread_mutex_lock (&server->mutex);
+
+ error = TTT_ERROR_NO_INVITE;
+ for (i = 0; i < server->num_invites; i++)
+ {
+ invite = server->invites[i];
+ if ((invite->actor == actor) && (invite->invitee == invitee))
+ {
+ error = TTT_ERROR_NONE;
+ break;
+ }
}
+
+ if (error)
+ goto CLEANUP_LOCK;
+
+ assert (i < server->num_invites);
+
+ memmove (&server->invites[i], &server->invites[i+1],
+ (server->num_invites - i - 1) * sizeof (ttt_invite_t *));
+
+ server->num_invites--;
+
+ CLEANUP_LOCK:
+ pthread_mutex_unlock (&server->mutex);
+
+ return error;
+}
+
+/* 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 one-shot TCP/IP server. The server is 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. By one-shot, I mean that the server will only accept a connection\n"
-"from a single client, and the server will exit when that client disconnects\n"
-"To test the server again, you will need to manually restart it again.\n"
-"Extending the server to start listening again, or to handle multiple\n"
-"clients simultaneously would both be fun projects for a motivated\n"
-"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, INVITE, ACCEPT, RETRACT, DECLINE, MESSAGE, STATISTICS, QUIT, VERSION, 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;
- int listen_socket, connected_socket;
- struct sockaddr_in addr;
+ ttt_server_t server;
+ int socket;
ttt_args_parse (&args, argc, argv);
- if (args.log_file)
- stderr = xfreopen (args.log_file, "a", stderr);
-
- listen_socket = xsocket (PF_INET, SOCK_STREAM, 0);
+ 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);
+ }
+ }
- _sockaddr_init (&addr, args.host, args.port);
+ if (args.detach)
+ _detach_and_write_child_pid_to (args.pid_file);
-#ifdef SO_REUSEADDR
- {
- int one = 1;
- setsockopt (listen_socket, SOL_SOCKET,
- SO_REUSEADDR, (char *) &one, sizeof (int));
+ /* 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);
+ }
}
-#endif
-
- xbind (listen_socket, (struct sockaddr *) &addr, sizeof (addr));
- xlisten (listen_socket, SOMAXCONN);
+ 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);
+ }
- connected_socket = _wait_for_connection (listen_socket);
+ fclose (stdout);
+ fclose (stdin);
-#define BUF_SIZE 1024
+ ttt_server_init (&server, args.host, args.port);
- while (1) {
- char buf[BUF_SIZE];
- int cnt;
- cnt = read (connected_socket, buf, BUF_SIZE);
- if (cnt == 0)
- break;
- write (0, buf, cnt);
- write (connected_socket, buf, cnt);
- }
+ while (1)
+ ttt_socket_accept (socket, _ttt_server_accept, &server);
- return 0;
+ /* We only reach here if something bad happened. */
+ return 1;
}