X-Git-Url: https://git.cworth.org/git?p=ttt;a=blobdiff_plain;f=src%2Fttt-server.c;h=4b29cf2f774d277dc14dd5bc675f4b5a9a25df6d;hp=a248fa1a789b0a22f20db04551f0f531aaf472d5;hb=df6ad6c8658a9f3a537a070a89a067c5ae598fcc;hpb=2cd70db8433cc9d02a4ca784190260889c835198

diff --git a/src/ttt-server.c b/src/ttt-server.c
index a248fa1..4b29cf2 100644
--- a/src/ttt-server.c
+++ b/src/ttt-server.c
@@ -1,4 +1,4 @@
-/* ttt.c - client-server tic-tac-toe game
+/* ttt-server.c - tic-tac-toe game server
  *
  * Copyright © 2005 Carl Worth
  *
@@ -19,158 +19,437 @@
  * 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 (&notice, "%s" "NOTICE RETRACT %s %s\r\n",
+			   notice,
+			   ttt_client_get_username(invite->actor),
+			   ttt_client_get_username(invite->invitee));
+	    else
+		xasprintf (&notice, "%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 args_first;
-    int listen_socket, connected_socket;
-    struct sockaddr_in addr;
+    ttt_server_t server;
+    int socket;
 
-    ttt_args_parse (&args, argc, argv, &args_first);
+    ttt_args_parse (&args, argc, argv);
 
-    listen_socket = xsocket (PF_INET, SOCK_STREAM, 0);
-
-#define HOST "localhost"
-#define PORT "5534"
+    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, HOST, 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, HOST, PORT, HOST, 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;
 }