git.cworth.org Git - ttt/blob - src/ttt-client.c

   1 /* ttt-client.c - client handling code for tic-tac-toe game server
   2  *
   3  * Copyright © 2005 Carl Worth
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2, or (at your option)
   8  * any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software Foundation,
  17  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18  *
  19  * Author: Carl Worth <cworth@cworth.org>
  20  */
  21
  22 #include "ttt-client.h"
  23
  24 #define YY_DECL int yylex (yyscan_t yyscanner, ttt_token_t *token)
  25
  26 #include "ttt-error.h"
  27 #include "ttt-lex.h"
  28 #include "ttt-server.h"
  29 #include "ttt-socket.h"
  30 #include "ttt-token.h"
  31
  32 struct _ttt_client {
  33     pthread_mutex_t mutex;
  34     pthread_t       thread;
  35
  36     ttt_server_t    *server;
  37     int             socket;
  38     yyscan_t        scanner;
  39
  40     char            **request_strings;
  41     int             num_request_strings;
  42
  43     char            *name;
  44     ttt_bool_t      registered;
  45     int             num_wins;
  46 };
  47
  48 typedef ttt_error_t (*ttt_command_func_t) (ttt_client_t *client,
  49                                            char **args,
  50                                            int num_args);
  51
  52 static ttt_error_t
  53 _ttt_client_execute_helo (ttt_client_t *client,
  54                           char         **args,
  55                           int          num_args);
  56
  57 static ttt_error_t
  58 _ttt_client_execute_who (ttt_client_t *client,
  59                          char         **args,
  60                          int          num_args);
  61
  62 static ttt_error_t
  63 _ttt_client_execute_message (ttt_client_t *client,
  64                              char         **args,
  65                              int          num_args);
  66
  67 static ttt_error_t
  68 _ttt_client_execute_help (ttt_client_t  *client,
  69                           char     **args,
  70                           int      num_args);
  71
  72 static ttt_error_t
  73 _ttt_client_execute_version (ttt_client_t  *client,
  74                              char          **args,
  75                              int           num_args);
  76
  77 static ttt_error_t
  78 _ttt_client_execute_quit (ttt_client_t *client,
  79                           char         **args,
  80                           int          num_args);
  81
  82 typedef struct _ttt_command_description {
  83     const char         *command;
  84     int                args_min;
  85     int                args_max;
  86     ttt_command_func_t execute;
  87     const char         *usage;
  88     const char         *description;
  89 } ttt_command_description_t;
  90
  91 ttt_command_description_t command_descriptions[] = {
  92     {"HELO",    1, 1, _ttt_client_execute_helo,
  93      "HELO <username>         ", "Register."},
  94
  95     {"HELP",    0, 1, _ttt_client_execute_help,
  96      "HELP <command>          ", "Display help for a command."},
  97
  98     {"MESSAGE", 1, 1, _ttt_client_execute_message,
  99      "MESSAGE <message>       ", "Send a message to everyone."},
 100
 101     {"QUIT",    0, 0, _ttt_client_execute_quit,
 102      "QUIT                    ", "Quit session."},
 103
 104     {"VERSION", 1, 1, _ttt_client_execute_version,
 105      "VERSION <client-version>", "Negotiate protocol version."},
 106
 107     {"WHO",     0, 0, _ttt_client_execute_who,
 108      "WHO                     ", "List registered users."}
 109 };
 110
 111 #define ARRAY_SIZE(arr) (sizeof(arr)/sizeof(arr[0]))
 112
 113 static ttt_error_t
 114 _ttt_client_execute_helo (ttt_client_t *client,
 115                           char         **args,
 116                           int          num_args)
 117 {
 118     ttt_error_t error;
 119     char *response;
 120     char *notice;
 121
 122     assert (num_args == 1);
 123
 124     ttt_client_set_name (client, args[0]);
 125
 126     error = ttt_server_register_client (client->server, client);
 127     if (error)
 128         return error;
 129     client->registered = TRUE;
 130
 131     xasprintf (&response, "HELO %s %s %s\r\n",
 132                client->name,
 133                ttt_server_get_host (client->server),
 134                ttt_server_get_port (client->server));
 135     ttt_client_send (client, response);
 136
 137     xasprintf (&notice, "NOTICE USER %s\r\n",
 138                client->name);
 139     ttt_server_broadcast (client->server, notice);
 140
 141     free (notice);
 142     free (response);
 143
 144     return TTT_ERROR_NONE;
 145 }
 146
 147 static ttt_error_t
 148 _ttt_client_execute_who (ttt_client_t *client,
 149                          char         **args,
 150                          int          num_args)
 151 {
 152     char *response;
 153
 154     assert (num_args == 0);
 155
 156     if (!client->registered)
 157         return TTT_ERROR_NO_NAME_SET;
 158
 159     response = xstrdup (ttt_server_who (client->server));
 160     ttt_client_send (client, response);
 161
 162     free (response);
 163
 164     return TTT_ERROR_NONE;
 165 }
 166
 167 static ttt_error_t
 168 _ttt_client_execute_message (ttt_client_t  *client,
 169                              char          **args,
 170                              int           num_args)
 171 {
 172     char *response;
 173     char *notice;
 174
 175     assert (num_args == 1);
 176
 177     if (!client->registered)
 178         return TTT_ERROR_NO_NAME_SET;
 179
 180     xasprintf (&response, "MESSAGE\r\n");
 181     ttt_client_send (client, response);
 182
 183     xasprintf (&notice, "NOTICE MESSAGE %s \"%s\"\r\n",
 184               client->name,
 185               args[0]);
 186     ttt_server_broadcast (client->server, notice);
 187
 188     free (notice);
 189     free (response);
 190
 191     return TTT_ERROR_NONE;
 192 }
 193
 194 static ttt_error_t
 195 _ttt_client_execute_help (ttt_client_t  *client,
 196                           char     **args,
 197                           int      num_args)
 198 {
 199     char *response;
 200     char *command;
 201     ttt_command_description_t *desc;
 202     int i;
 203     ttt_bool_t is_command = FALSE;
 204
 205     if (num_args == 0) {
 206         xasprintf (&response, "HELP \"\r\n"
 207                    "Available Commands:\r\n");
 208         for (i = 0; i < ARRAY_SIZE(command_descriptions); i++) {
 209             desc = &command_descriptions[i];
 210             xasprintf (&response, "%s\r\n  %s - %s\r\n",
 211                        response,
 212                        desc->usage,
 213                        desc->description);
 214         }
 215         xasprintf (&response, "%s\"\r\n", response);
 216     } else {
 217         command = args[0];
 218         for (i = 0; i < strlen (command); i++)
 219             command[i] = toupper (command[i]);
 220         for (i = 0; i < ARRAY_SIZE(command_descriptions); i++) {
 221             desc = &command_descriptions[i];
 222             if (strcmp (desc->command, command) == 0) {
 223                 is_command = TRUE;
 224                 xasprintf (&response, "HELP %s \"\r\n"
 225                            "%s\r\n"
 226                            "\r\n"
 227                            "Usage:\r\n"
 228                            "  %s\r\n"
 229                            "\"\r\n",
 230                            desc->command,
 231                            desc->description,
 232                            desc->usage);
 233                 /* XXX: Add detailed help. */
 234             }
 235         }
 236     }
 237
 238     if ((num_args == 1) && (!is_command))
 239         return TTT_ERROR_SYNTAX;
 240
 241     ttt_client_send (client, response);
 242
 243     free (response);
 244     return TTT_ERROR_NONE;
 245 }
 246
 247 static ttt_error_t
 248 _ttt_client_execute_version (ttt_client_t  *client,
 249                              char          **args,
 250                              int           num_args)
 251 {
 252     char *response;
 253
 254     assert (num_args == 1);
 255
 256     /* XXX: Argument is being ignored.
 257        This is not completely implemented. */
 258
 259     xasprintf (&response, "VERSION 1\r\n");
 260     ttt_client_send (client, response);
 261
 262     free (response);
 263     return TTT_ERROR_NONE;
 264 }
 265
 266 static ttt_error_t
 267 _ttt_client_execute_quit (ttt_client_t *client,
 268                           char         **args,
 269                           int          num_args)
 270 {
 271     char *notice;
 272
 273     assert (num_args == 0);
 274
 275     if (!client->registered)
 276         return TTT_ERROR_QUIT_REQUESTED;
 277
 278     xasprintf (&notice, "NOTICE QUIT %s\r\n",
 279                client->name);
 280     ttt_server_broadcast (client->server, notice);
 281
 282     free (notice);
 283
 284     return TTT_ERROR_QUIT_REQUESTED;
 285 }
 286
 287 static void
 288 _free_request (ttt_client_t *client);
 289
 290 static void
 291 _ttt_client_init (ttt_client_t  *client,
 292                   ttt_server_t  *server,
 293                   int            socket)
 294 {
 295     FILE *file;
 296
 297     pthread_mutex_init (&client->mutex, NULL);
 298
 299     client->server = server;
 300     client->socket = socket;
 301
 302     file = xfdopen (socket, "r");
 303     yylex_init (&client->scanner);
 304     yyset_in (file, client->scanner);
 305
 306     client->request_strings = NULL;
 307     client->num_request_strings = 0;
 308
 309     client->name = NULL;
 310     client->registered = FALSE;
 311     client->num_wins = 0;
 312 }
 313
 314 static void
 315 _ttt_client_fini (ttt_client_t *client)
 316 {
 317     pthread_mutex_lock (&client->mutex);
 318
 319     if (client->registered)
 320         ttt_server_unregister_client (client->server, client);
 321
 322     free (client->name);
 323     client->name = NULL;
 324
 325     yylex_destroy (client->scanner);
 326     shutdown (client->socket, SHUT_RDWR);
 327
 328     _free_request (client);
 329
 330     pthread_mutex_unlock (&client->mutex);
 331
 332     pthread_mutex_destroy (&client->mutex);
 333 }
 334
 335 /* XXX: The memory management for the request strings is pretty cheesy. */
 336 static void
 337 _append_to_request (ttt_client_t        *client,
 338                     const char          *string)
 339 {
 340     client->num_request_strings++;
 341     client->request_strings =
 342         xrealloc (client->request_strings,
 343                   client->num_request_strings * sizeof (char *));
 344
 345     client->request_strings[client->num_request_strings - 1] = xstrdup (string);
 346 }
 347
 348 static void
 349 _free_request (ttt_client_t *client)
 350 {
 351     int i;
 352
 353     for (i = 0; i < client->num_request_strings; i++)
 354         free (client->request_strings[i]);
 355
 356     free (client->request_strings);
 357
 358     client->request_strings = NULL;
 359     client->num_request_strings = 0;
 360 }
 361
 362 static ttt_status_t
 363 _read_request (ttt_client_t *client)
 364 {
 365     ttt_token_t token;
 366     ttt_token_type_t token_type;
 367
 368     _free_request (client);
 369
 370     while (1) {
 371         token_type = yylex (client->scanner, &token);
 372         /* Yes, EOF in two different enums is pretty ugly. */
 373         if (token_type == TTT_TOKEN_TYPE_EOF)
 374             return TTT_STATUS_EOF;
 375
 376         if (token_type == TTT_TOKEN_TYPE_NEWLINE) {
 377             if (client->num_request_strings)
 378                 return TTT_STATUS_SUCCESS;
 379             else
 380                 continue;
 381         }
 382
 383         assert (token_type == TTT_TOKEN_TYPE_STRING);
 384
 385         _append_to_request (client, token.u.string);
 386
 387         free (token.u.string);
 388     }
 389 }
 390
 391 static ttt_error_t
 392 _execute_request (ttt_client_t *client)
 393 {
 394     int i;
 395
 396     char *command = client->request_strings[0];
 397     int num_args = client->num_request_strings-1;
 398     ttt_command_description_t *desc;
 399
 400     for (i = 0; i < strlen (command); i++)
 401         command[i] = toupper (command[i]);
 402
 403     for (i = 0; i < ARRAY_SIZE(command_descriptions); i++) {
 404         desc = &command_descriptions[i];
 405         if (strcmp (command, desc->command) == 0) {
 406             if ((num_args < desc->args_min) || (num_args > desc->args_max))
 407                 return TTT_ERROR_SYNTAX;
 408             return (desc->execute) (client,
 409                                     &client->request_strings[1],
 410                                     num_args);
 411         }
 412     }
 413
 414     return TTT_ERROR_COMMAND;
 415 }
 416
 417 static void *
 418 _handle_requests_thread (void *closure)
 419 {
 420     ttt_status_t status;
 421     ttt_error_t error;
 422     ttt_client_t *client = closure;
 423
 424     while (1) {
 425
 426         status = _read_request (client);
 427         if (status == TTT_STATUS_EOF)
 428             break;
 429         if (status)
 430             ASSERT_NOT_REACHED;
 431
 432         error = _execute_request (client);
 433         if (error == TTT_ERROR_QUIT_REQUESTED)
 434             break;
 435         if (error)
 436             ttt_client_send (client, ttt_error_string (error));
 437     }
 438
 439     _ttt_client_fini (client);
 440     free (client);
 441
 442     return (void *) 0;
 443 }
 444
 445 /* Exported: See ttt-client.h for documentation. */
 446 void
 447 ttt_client_new (void *closure, int client_socket)
 448 {
 449     ttt_server_t *server = closure;
 450     ttt_client_t *client;
 451     int err;
 452
 453     client = xmalloc (sizeof (ttt_client_t));
 454
 455     _ttt_client_init (client, server, client_socket);
 456
 457     err = pthread_create (&client->thread, NULL,
 458                           _handle_requests_thread, client);
 459     if (err != 0) {
 460         fprintf (stderr, "Error: pthread_create failed: %s. Aborting.\r\n",
 461                  strerror (err));
 462         exit (1);
 463     }
 464 }
 465
 466 /* Exported: See ttt-client.h for documentation. */
 467 void
 468 ttt_client_send (ttt_client_t *client, const char *message)
 469 {
 470     pthread_mutex_lock (&client->mutex);
 471
 472     ttt_socket_write (client->socket, message, strlen (message));
 473
 474     pthread_mutex_unlock (&client->mutex);
 475 }
 476
 477 /* Exported: See ttt-client.h for documentation. */
 478 const char*
 479 ttt_client_get_name (ttt_client_t *client)
 480 {
 481     return client->name;
 482 }
 483
 484 /* Exported: See ttt-client.h for documentation. */
 485 void
 486 ttt_client_set_name (ttt_client_t *client, const char *name)
 487 {
 488     free (client->name);
 489     client->name = xstrdup (name);
 490 }
 491
 492 /* Exported: See ttt-client.h for documentation. */
 493 int
 494 ttt_client_get_num_wins (ttt_client_t *client)
 495 {
 496     return client->num_wins;
 497 }