demos/tunala/tunala.c

   1 #if defined(NO_BUFFER) || defined(NO_IP) || defined(NO_OPENSSL)
   2 #error "Badness, NO_BUFFER, NO_IP or NO_OPENSSL is defined, turn them *off*"
   3 #endif
   4
   5 /* Include our bits'n'pieces */
   6 #include "tunala.h"
   7
   8
   9 /********************************************/
  10 /* Our local types that specify our "world" */
  11 /********************************************/
  12
  13 /* These represent running "tunnels". Eg. if you wanted to do SSL in a
  14  * "message-passing" scanario, the "int" file-descriptors might be replaced by
  15  * thread or process IDs, and the "select" code might be replaced by message
  16  * handling code. Whatever. */
  17 typedef struct _tunala_item_t {
  18         /* The underlying SSL state machine. This is a data-only processing unit
  19          * and we communicate with it by talking to its four "buffers". */
  20         state_machine_t sm;
  21         /* The file-descriptors for the "dirty" (encrypted) side of the SSL
  22          * setup. In actuality, this is typically a socket and both values are
  23          * identical. */
  24         int dirty_read, dirty_send;
  25         /* The file-descriptors for the "clean" (unencrypted) side of the SSL
  26          * setup. These could be stdin/stdout, a socket (both values the same),
  27          * or whatever you like. */
  28         int clean_read, clean_send;
  29 } tunala_item_t;
  30
  31 /* This structure is used as the data for running the main loop. Namely, in a
  32  * network format such as this, it is stuff for select() - but as pointed out,
  33  * when moving the real-world to somewhere else, this might be replaced by
  34  * something entirely different. It's basically the stuff that controls when
  35  * it's time to do some "work". */
  36 typedef struct _select_sets_t {
  37         int max; /* As required as the first argument to select() */
  38         fd_set reads, sends, excepts; /* As passed to select() */
  39 } select_sets_t;
  40 typedef struct _tunala_selector_t {
  41         select_sets_t last_selected; /* Results of the last select() */
  42         select_sets_t next_select; /* What we'll next select on */
  43 } tunala_selector_t;
  44
  45 /* This structure is *everything*. We do it to avoid the use of globals so that,
  46  * for example, it would be easier to shift things around between async-IO,
  47  * thread-based, or multi-fork()ed (or combinations thereof). */
  48 typedef struct _tunala_world_t {
  49         /* The file-descriptor we "listen" on for new connections */
  50         int listen_fd;
  51         /* The array of tunnels */
  52         tunala_item_t *tunnels;
  53         /* the number of tunnels in use and allocated, respectively */
  54         unsigned int tunnels_used, tunnels_size;
  55         /* Our outside "loop" context stuff */
  56         tunala_selector_t selector;
  57         /* Our SSL_CTX, which is configured as the SSL client or server and has
  58          * the various cert-settings and callbacks configured. */
  59         SSL_CTX *ssl_ctx;
  60         /* Simple flag with complex logic :-) Indicates whether we're an SSL
  61          * server or an SSL client. */
  62         int server_mode;
  63 } tunala_world_t;
  64
  65 /*****************************/
  66 /* Internal static functions */
  67 /*****************************/
  68
  69 static SSL_CTX *initialise_ssl_ctx(int server_mode, const char *engine_id,
  70                 const char *CAfile, const char *cert, const char *key);
  71 static void selector_init(tunala_selector_t *selector);
  72 static void selector_add_listener(tunala_selector_t *selector, int fd);
  73 static void selector_add_tunala(tunala_selector_t *selector, tunala_item_t *t);
  74 static int selector_select(tunala_selector_t *selector);
  75 /* This returns -1 for error, 0 for no new connections, or 1 for success, in
  76  * which case *newfd is populated. */
  77 static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd);
  78 static int tunala_world_new_item(tunala_world_t *world, int fd,
  79                 const unsigned char *ip, unsigned short port);
  80 static void tunala_world_del_item(tunala_world_t *world, unsigned int idx);
  81 static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item);
  82
  83 /*********************************************/
  84 /* MAIN FUNCTION (and its utility functions) */
  85 /*********************************************/
  86
  87 static const char *def_proxyhost = "127.0.0.1:443";
  88 static const char *def_listenhost = "127.0.0.1:8080";
  89 static int def_max_tunnels = 50;
  90 static const char *def_cacert = NULL;
  91 static const char *def_cert = NULL;
  92 static const char *def_key = NULL;
  93 static const char *def_engine_id = NULL;
  94 static int def_server_mode = 0;
  95
  96 static const char *helpstring =
  97         "\n'Tunala' (A tunneler with a New Zealand accent)\n"
  98         "Usage: tunala [options], where options are from;\n"
  99         "    -listen [host:]<port>  (default = 127.0.0.1:8080)\n"
 100         "    -proxy <host>:<port>   (default = 127.0.0.1:443)\n"
 101         "    -maxtunnels <num>      (default = 50)\n"
 102         "    -cacert <path|NULL>    (default = NULL)\n"
 103         "    -cert <path|NULL>      (default = NULL)\n"
 104         "    -key <path|NULL>       (default = whatever '-cert' is)\n"
 105         "    -engine <id|NULL>      (default = NULL)\n"
 106         "    -server <0|1>          (default = 0, ie. an SSL client)\n"
 107         "    -<h|help|?>            (displays this help screen)\n"
 108         "NB: It is recommended to specify a cert+key when operating as an\n"
 109         "SSL server. If you only specify '-cert', the same file must\n"
 110         "contain a matching private key.\n";
 111
 112 static int usage(const char *errstr, int isunknownarg)
 113 {
 114         if(isunknownarg)
 115                 fprintf(stderr, "Error: unknown argument '%s'\n", errstr);
 116         else
 117                 fprintf(stderr, "Error: %s\n", errstr);
 118         fprintf(stderr, "%s\n", helpstring);
 119         return 1;
 120 }
 121
 122 static int err_str0(const char *str0)
 123 {
 124         fprintf(stderr, str0);
 125         fprintf(stderr, "\n");
 126         return 1;
 127 }
 128
 129 static int err_str1(const char *str0, const char *str1)
 130 {
 131         fprintf(stderr, str0, str1);
 132         fprintf(stderr, "\n");
 133         return 1;
 134 }
 135
 136 static int parse_max_tunnels(const char *s, unsigned int *maxtunnels)
 137 {
 138         unsigned long l;
 139         char *temp;
 140         l = strtoul(s, &temp, 10);
 141         if((temp == s) || (*temp != '\0') || (l < 1) || (l > 1024)) {
 142                 fprintf(stderr, "Error, '%s' is an invalid value for "
 143                                 "maxtunnels\n", s);
 144                 return 0;
 145         }
 146         *maxtunnels = (unsigned int)l;
 147         return 1;
 148 }
 149
 150 static int parse_server_mode(const char *s, int *servermode)
 151 {
 152         unsigned long l;
 153         char *temp;
 154         l = strtoul(s, &temp, 10);
 155         if((temp == s) || (*temp != '\0') || (l > 1)) {
 156                 fprintf(stderr, "Error, '%s' is an invalid value for the "
 157                                 "server mode\n", s);
 158                 return 0;
 159         }
 160         *servermode = (int)l;
 161         return 1;
 162 }
 163
 164 int main(int argc, char *argv[])
 165 {
 166         unsigned int loop;
 167         int newfd;
 168         tunala_world_t world;
 169         tunala_item_t *t_item;
 170         unsigned char *proxy_ip;
 171         unsigned short proxy_port;
 172         /* Overridables */
 173         const char *proxyhost = def_proxyhost;
 174         const char *listenhost = def_listenhost;
 175         unsigned int max_tunnels = def_max_tunnels;
 176         const char *cacert = def_cacert;
 177         const char *cert = def_cert;
 178         const char *key = def_key;
 179         const char *engine_id = def_engine_id;
 180         int server_mode = def_server_mode;
 181
 182 /* Parse command-line arguments */
 183 next_arg:
 184         argc--; argv++;
 185         if(argc > 0) {
 186                 if(strcmp(*argv, "-listen") == 0) {
 187                         if(argc < 2)
 188                                 return usage("-listen requires an argument", 0);
 189                         argc--; argv++;
 190                         listenhost = *argv;
 191                         goto next_arg;
 192                 } else if(strcmp(*argv, "-proxy") == 0) {
 193                         if(argc < 2)
 194                                 return usage("-proxy requires an argument", 0);
 195                         argc--; argv++;
 196                         proxyhost = *argv;
 197                         goto next_arg;
 198                 } else if(strcmp(*argv, "-maxtunnels") == 0) {
 199                         if(argc < 2)
 200                                 return usage("-maxtunnels requires an argument", 0);
 201                         argc--; argv++;
 202                         if(!parse_max_tunnels(*argv, &max_tunnels))
 203                                 return 1;
 204                         goto next_arg;
 205                 } else if(strcmp(*argv, "-cacert") == 0) {
 206                         if(argc < 2)
 207                                 return usage("-cacert requires an argument", 0);
 208                         argc--; argv++;
 209                         if(strcmp(*argv, "NULL") == 0)
 210                                 cacert = NULL;
 211                         else
 212                                 cacert = *argv;
 213                         goto next_arg;
 214                 } else if(strcmp(*argv, "-cert") == 0) {
 215                         if(argc < 2)
 216                                 return usage("-cert requires an argument", 0);
 217                         argc--; argv++;
 218                         if(strcmp(*argv, "NULL") == 0)
 219                                 cert = NULL;
 220                         else
 221                                 cert = *argv;
 222                         goto next_arg;
 223                 } else if(strcmp(*argv, "-key") == 0) {
 224                         if(argc < 2)
 225                                 return usage("-key requires an argument", 0);
 226                         argc--; argv++;
 227                         if(strcmp(*argv, "NULL") == 0)
 228                                 key = NULL;
 229                         else
 230                                 key = *argv;
 231                         goto next_arg;
 232                 } else if(strcmp(*argv, "-engine") == 0) {
 233                         if(argc < 2)
 234                                 return usage("-engine requires an argument", 0);
 235                         argc--; argv++;
 236                         engine_id = *argv;
 237                         goto next_arg;
 238                 } else if(strcmp(*argv, "-server") == 0) {
 239                         if(argc < 2)
 240                                 return usage("-server requires an argument", 0);
 241                         argc--; argv++;
 242                         if(!parse_server_mode(*argv, &server_mode))
 243                                 return 1;
 244                         goto next_arg;
 245                 } else if((strcmp(*argv, "-h") == 0) ||
 246                                 (strcmp(*argv, "-help") == 0) ||
 247                                 (strcmp(*argv, "-?") == 0)) {
 248                         fprintf(stderr, "%s\n", helpstring);
 249                         return 0;
 250                 } else
 251                         return usage(*argv, 1);
 252         }
 253
 254         /* Initialise network stuff */
 255         if(!ip_initialise())
 256                 return err_str0("ip_initialise failed");
 257         err_str0("ip_initialise succeeded");
 258         /* Create the SSL_CTX */
 259         if((world.ssl_ctx = initialise_ssl_ctx(server_mode, engine_id,
 260                         cacert, cert, key)) == NULL)
 261                 return err_str1("initialise_ssl_ctx(engine_id=%s) failed",
 262                         (engine_id == NULL) ? "NULL" : engine_id);
 263         err_str1("initialise_ssl_ctx(engine_id=%s) succeeded",
 264                         (engine_id == NULL) ? "NULL" : engine_id);
 265         /* Create the listener */
 266         if((world.listen_fd = ip_create_listener(listenhost)) == -1)
 267                 return err_str1("ip_create_listener(%s) failed", listenhost);
 268         err_str1("ip_create_listener(%s) succeeded", listenhost);
 269         if(!ip_parse_address(proxyhost, &proxy_ip, &proxy_port, 0))
 270                 return err_str1("ip_parse_address(%s) failed", proxyhost);
 271         err_str1("ip_parse_address(%s) succeeded", proxyhost);
 272         fprintf(stderr, "Info - proxying to %d.%d.%d.%d:%d\n",
 273                         (int)proxy_ip[0], (int)proxy_ip[1],
 274                         (int)proxy_ip[2], (int)proxy_ip[3], (int)proxy_port);
 275         fprintf(stderr, "Info - set maxtunnels to %d\n", (int)max_tunnels);
 276         fprintf(stderr, "Info - set to operate as an SSL %s\n",
 277                         (server_mode ? "server" : "client"));
 278         /* Initialise the rest of the stuff */
 279         world.tunnels_used = world.tunnels_size = 0;
 280         world.tunnels = NULL;
 281         world.server_mode = server_mode;
 282         selector_init(&world.selector);
 283
 284 /* We're ready to loop */
 285 main_loop:
 286         /* Should we listen for *new* tunnels? */
 287         if(world.tunnels_used < max_tunnels)
 288                 selector_add_listener(&world.selector, world.listen_fd);
 289         /* We should add in our existing tunnels */
 290         for(loop = 0; loop < world.tunnels_used; loop++)
 291                 selector_add_tunala(&world.selector, world.tunnels + loop);
 292         /* Now do the select */
 293         switch(selector_select(&world.selector)) {
 294         case -1:
 295                 fprintf(stderr, "selector_select returned a badness error.\n");
 296                 abort();
 297         case 0:
 298                 fprintf(stderr, "Warn, selector_select return 0 - signal??\n");
 299                 goto main_loop;
 300         default:
 301                 break;
 302         }
 303         /* Accept new connection if we should and can */
 304         if((world.tunnels_used < max_tunnels) && (selector_get_listener(
 305                                         &world.selector, world.listen_fd,
 306                                         &newfd) == 1)) {
 307                 /* We have a new connection */
 308                 if(!tunala_world_new_item(&world, newfd,
 309                                         proxy_ip, proxy_port)) {
 310                         fprintf(stderr, "tunala_world_new_item failed\n");
 311                         abort();
 312                 }
 313                 fprintf(stderr, "Info, new tunnel opened, now up to %d\n",
 314                                 world.tunnels_used);
 315         }
 316         /* Give each tunnel its moment, note the while loop is because it makes
 317          * the logic easier than with "for" to deal with an array that may shift
 318          * because of deletes. */
 319         loop = 0;
 320         t_item = world.tunnels;
 321         while(loop < world.tunnels_used) {
 322                 if(!tunala_item_io(&world.selector, t_item)) {
 323                         /* We're closing whether for reasons of an error or a
 324                          * natural close. Don't increment loop or t_item because
 325                          * the next item is moving to us! */
 326                         tunala_world_del_item(&world, loop);
 327                         fprintf(stderr, "Info, tunnel closed, down to %d\n",
 328                                         world.tunnels_used);
 329                 }
 330                 else {
 331                         /* Move to the next item */
 332                         loop++;
 333                         t_item++;
 334                 }
 335         }
 336         goto main_loop;
 337         /* Should never get here */
 338         abort();
 339         return 1;
 340 }
 341
 342 /****************/
 343 /* OpenSSL bits */
 344 /****************/
 345
 346 static SSL_CTX *initialise_ssl_ctx(int server_mode, const char *engine_id,
 347                 const char *CAfile, const char *cert, const char *key)
 348 {
 349         SSL_CTX *ctx, *ret = NULL;
 350         SSL_METHOD *meth;
 351         ENGINE *e = NULL;
 352         FILE *fp = NULL;
 353         X509 *x509 = NULL;
 354         EVP_PKEY *pkey = NULL;
 355
 356         OpenSSL_add_ssl_algorithms();
 357         SSL_load_error_strings();
 358
 359         meth = (server_mode ? SSLv23_server_method() : SSLv23_client_method());
 360         if(meth == NULL)
 361                 goto err;
 362         if(engine_id) {
 363                 if((e = ENGINE_by_id(engine_id)) == NULL) {
 364                         fprintf(stderr, "Error obtaining '%s' engine, openssl "
 365                                         "errors follow\n", engine_id);
 366                         goto err;
 367                 }
 368                 if(!ENGINE_set_default(e, ENGINE_METHOD_ALL)) {
 369                         fprintf(stderr, "Error assigning '%s' engine, openssl "
 370                                         "errors follow\n", engine_id);
 371                         goto err;
 372                 }
 373                 ENGINE_free(e);
 374         }
 375         if((ctx = SSL_CTX_new(meth)) == NULL)
 376                 goto err;
 377         /* cacert */
 378         if(CAfile) {
 379                 if(!X509_STORE_load_locations(SSL_CTX_get_cert_store(ctx),
 380                                         CAfile, NULL)) {
 381                         fprintf(stderr, "Error loading CA cert(s) in '%s'\n",
 382                                         CAfile);
 383                         goto err;
 384                 }
 385                 fprintf(stderr, "Info, operating with CA cert(s) in '%s'\n",
 386                                 CAfile);
 387         } else
 388                 fprintf(stderr, "Info, operating without a CA cert(-list)\n");
 389         if(!SSL_CTX_set_default_verify_paths(ctx)) {
 390                 fprintf(stderr, "Error setting default verify paths\n");
 391                 goto err;
 392         }
 393         /* cert */
 394         if(cert) {
 395                 if((fp = fopen(cert, "r")) == NULL) {
 396                         fprintf(stderr, "Error opening cert file '%s'\n", cert);
 397                         goto err;
 398                 }
 399                 if(!PEM_read_X509(fp, &x509, NULL, NULL)) {
 400                         fprintf(stderr, "Error reading PEM cert from '%s'\n",
 401                                         cert);
 402                         goto err;
 403                 }
 404                 if(!SSL_CTX_use_certificate(ctx, x509)) {
 405                         fprintf(stderr, "Error, cert in '%s' can not be used\n",
 406                                         cert);
 407                         goto err;
 408                 }
 409                 fprintf(stderr, "Info, operating with cert in '%s'\n", cert);
 410                 fclose(fp);
 411                 fp = NULL;
 412                 /* If a cert was given without matching key, we assume the same
 413                  * file contains the required key. */
 414                 if(!key)
 415                         key = cert;
 416         } else
 417                 if(key) {
 418                         fprintf(stderr, "Error, can't specify a key without a "
 419                                         "corresponding certificate\n");
 420                         goto err;
 421                 }
 422         /* key */
 423         if(key) {
 424                 if((fp = fopen(key, "r")) == NULL) {
 425                         fprintf(stderr, "Error opening key file '%s'\n", key);
 426                         goto err;
 427                 }
 428                 if(!PEM_read_PrivateKey(fp, &pkey, NULL, NULL)) {
 429                         fprintf(stderr, "Error reading PEM key from '%s'\n",
 430                                         key);
 431                         goto err;
 432                 }
 433                 if(!SSL_CTX_use_PrivateKey(ctx, pkey)) {
 434                         fprintf(stderr, "Error, key in '%s' can not be used\n",
 435                                         key);
 436                         goto err;
 437                 }
 438                 fprintf(stderr, "Info, operating with key in '%s'\n", key);
 439         } else
 440                 fprintf(stderr, "Info, operating without a cert or key\n");
 441
 442         /* Success! */
 443         ret = ctx;
 444 err:
 445         if(!ret) {
 446                 ERR_print_errors_fp(stderr);
 447                 if(ctx)
 448                         SSL_CTX_free(ctx);
 449         }
 450         if(fp)
 451                 fclose(fp);
 452         if(x509)
 453                 X509_free(x509);
 454         if(pkey)
 455                 EVP_PKEY_free(pkey);
 456         return ret;
 457 }
 458
 459 /*****************/
 460 /* Selector bits */
 461 /*****************/
 462
 463 static void selector_sets_init(select_sets_t *s)
 464 {
 465         s->max = 0;
 466         FD_ZERO(&s->reads);
 467         FD_ZERO(&s->sends);
 468         FD_ZERO(&s->excepts);
 469 }
 470 static void selector_init(tunala_selector_t *selector)
 471 {
 472         selector_sets_init(&selector->last_selected);
 473         selector_sets_init(&selector->next_select);
 474 }
 475
 476 #define SEL_EXCEPTS 0x00
 477 #define SEL_READS   0x01
 478 #define SEL_SENDS   0x02
 479 static void selector_add_raw_fd(tunala_selector_t *s, int fd, int flags)
 480 {
 481         FD_SET(fd, &s->next_select.excepts);
 482         if(flags & SEL_READS)
 483                 FD_SET(fd, &s->next_select.reads);
 484         if(flags & SEL_SENDS)
 485                 FD_SET(fd, &s->next_select.sends);
 486         /* Adjust "max" */
 487         if(s->next_select.max < (fd + 1))
 488                 s->next_select.max = fd + 1;
 489 }
 490
 491 static void selector_add_listener(tunala_selector_t *selector, int fd)
 492 {
 493         selector_add_raw_fd(selector, fd, SEL_READS);
 494 }
 495
 496 static void selector_add_tunala(tunala_selector_t *s, tunala_item_t *t)
 497 {
 498         /* Set clean read if sm.clean_in is not full */
 499         if(t->clean_read != -1) {
 500                 selector_add_raw_fd(s, t->clean_read,
 501                         (buffer_full(state_machine_get_buffer(&t->sm,
 502                                 SM_CLEAN_IN)) ? SEL_EXCEPTS : SEL_READS));
 503         }
 504         /* Set clean send if sm.clean_out is not empty */
 505         if(t->clean_send != -1) {
 506                 selector_add_raw_fd(s, t->clean_send,
 507                         (buffer_empty(state_machine_get_buffer(&t->sm,
 508                                 SM_CLEAN_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
 509         }
 510         /* Set dirty read if sm.dirty_in is not full */
 511         if(t->dirty_read != -1) {
 512                 selector_add_raw_fd(s, t->dirty_read,
 513                         (buffer_full(state_machine_get_buffer(&t->sm,
 514                                 SM_DIRTY_IN)) ? SEL_EXCEPTS : SEL_READS));
 515         }
 516         /* Set dirty send if sm.dirty_out is not empty */
 517         if(t->dirty_send != -1) {
 518                 selector_add_raw_fd(s, t->dirty_send,
 519                         (buffer_empty(state_machine_get_buffer(&t->sm,
 520                                 SM_DIRTY_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
 521         }
 522 }
 523
 524 static int selector_select(tunala_selector_t *selector)
 525 {
 526         memcpy(&selector->last_selected, &selector->next_select,
 527                         sizeof(select_sets_t));
 528         selector_sets_init(&selector->next_select);
 529         return select(selector->last_selected.max,
 530                         &selector->last_selected.reads,
 531                         &selector->last_selected.sends,
 532                         &selector->last_selected.excepts, NULL);
 533 }
 534
 535 /* This returns -1 for error, 0 for no new connections, or 1 for success, in
 536  * which case *newfd is populated. */
 537 static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd)
 538 {
 539         if(FD_ISSET(fd, &selector->last_selected.excepts))
 540                 return -1;
 541         if(!FD_ISSET(fd, &selector->last_selected.reads))
 542                 return 0;
 543         if((*newfd = ip_accept_connection(fd)) == -1)
 544                 return -1;
 545         return 1;
 546 }
 547
 548 /************************/
 549 /* "Tunala" world stuff */
 550 /************************/
 551
 552 static int tunala_world_make_room(tunala_world_t *world)
 553 {
 554         unsigned int newsize;
 555         tunala_item_t *newarray;
 556
 557         if(world->tunnels_used < world->tunnels_size)
 558                 return 1;
 559         newsize = (world->tunnels_size == 0 ? 16 :
 560                         ((world->tunnels_size * 3) / 2));
 561         if((newarray = malloc(newsize * sizeof(tunala_item_t))) == NULL)
 562                 return 0;
 563         memset(newarray, 0, newsize * sizeof(tunala_item_t));
 564         if(world->tunnels_used > 0)
 565                 memcpy(newarray, world->tunnels,
 566                         world->tunnels_used * sizeof(tunala_item_t));
 567         if(world->tunnels_size > 0)
 568                 free(world->tunnels);
 569         /* migrate */
 570         world->tunnels = newarray;
 571         world->tunnels_size = newsize;
 572         return 1;
 573 }
 574
 575 static int tunala_world_new_item(tunala_world_t *world, int fd,
 576                 const unsigned char *ip, unsigned short port)
 577 {
 578         tunala_item_t *item;
 579         int newfd;
 580
 581         if(!tunala_world_make_room(world))
 582                 return 0;
 583         item = world->tunnels + (world->tunnels_used++);
 584         state_machine_init(&item->sm);
 585         item->clean_read = item->clean_send =
 586                 item->dirty_read = item->dirty_send = -1;
 587         if((newfd = ip_create_connection_split(ip, port)) == -1)
 588                 goto err;
 589         /* Which way round? If we're a server, "fd" is the dirty side and the
 590          * connection we open is the clean one. For a client, it's the other way
 591          * around. */
 592         if(world->server_mode) {
 593                 item->dirty_read = item->dirty_send = fd;
 594                 item->clean_read = item->clean_send = newfd;
 595         } else {
 596                 item->clean_read = item->clean_send = fd;
 597                 item->dirty_read = item->dirty_send = newfd;
 598         }
 599         state_machine_set_SSL(&item->sm, SSL_new(world->ssl_ctx),
 600                         world->server_mode);
 601         return 1;
 602 err:
 603         state_machine_close(&item->sm);
 604         return 0;
 605
 606 }
 607
 608 static void tunala_world_del_item(tunala_world_t *world, unsigned int idx)
 609 {
 610         tunala_item_t *item = world->tunnels + idx;
 611         if(item->clean_read != -1)
 612                 close(item->clean_read);
 613         if(item->clean_send != item->clean_read)
 614                 close(item->clean_send);
 615         item->clean_read = item->clean_send = -1;
 616         if(item->dirty_read != -1)
 617                 close(item->dirty_read);
 618         if(item->dirty_send != item->dirty_read)
 619                 close(item->dirty_send);
 620         item->dirty_read = item->dirty_send = -1;
 621         state_machine_close(&item->sm);
 622         /* OK, now we fix the item array */
 623         if(idx + 1 < world->tunnels_used)
 624                 /* We need to scroll entries to the left */
 625                 memmove(world->tunnels + idx,
 626                                 world->tunnels + (idx + 1),
 627                                 (world->tunnels_used - (idx + 1)) *
 628                                         sizeof(tunala_item_t));
 629         world->tunnels_used--;
 630 }
 631
 632 static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item)
 633 {
 634         int c_r, c_s, d_r, d_s; /* Four boolean flags */
 635
 636         /* Take ourselves out of the gene-pool if there was an except */
 637         if((item->clean_read != -1) && FD_ISSET(item->clean_read,
 638                                 &selector->last_selected.excepts))
 639                 return 0;
 640         if((item->clean_send != -1) && FD_ISSET(item->clean_send,
 641                                 &selector->last_selected.excepts))
 642                 return 0;
 643         if((item->dirty_read != -1) && FD_ISSET(item->dirty_read,
 644                                 &selector->last_selected.excepts))
 645                 return 0;
 646         if((item->dirty_send != -1) && FD_ISSET(item->dirty_send,
 647                                 &selector->last_selected.excepts))
 648                 return 0;
 649         /* Grab our 4 IO flags */
 650         c_r = c_s = d_r = d_s = 0;
 651         if(item->clean_read != -1)
 652                 c_r = FD_ISSET(item->clean_read, &selector->last_selected.reads);
 653         if(item->clean_send != -1)
 654                 c_s = FD_ISSET(item->clean_send, &selector->last_selected.sends);
 655         if(item->dirty_read != -1)
 656                 d_r = FD_ISSET(item->dirty_read, &selector->last_selected.reads);
 657         if(item->dirty_send != -1)
 658                 d_s = FD_ISSET(item->dirty_send, &selector->last_selected.sends);
 659         /* If no IO has happened for us, skip needless data looping */
 660         if(!c_r && !c_s && !d_r && !d_s)
 661                 return 1;
 662         if(c_r)
 663                 c_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
 664                                 SM_CLEAN_IN), item->clean_read) <= 0);
 665         if(c_s)
 666                 c_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
 667                                 SM_CLEAN_OUT), item->clean_send) <= 0);
 668         if(d_r)
 669                 d_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
 670                                 SM_DIRTY_IN), item->dirty_read) <= 0);
 671         if(d_s)
 672                 d_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
 673                                 SM_DIRTY_OUT), item->dirty_send) <= 0);
 674         /* If any of the flags is non-zero, that means they need closing */
 675         if(c_r) {
 676                 close(item->clean_read);
 677                 if(item->clean_send == item->clean_read)
 678                         item->clean_send = -1;
 679                 item->clean_read = -1;
 680         }
 681         if(c_s) {
 682                 close(item->clean_send);
 683                 if(item->clean_send == item->clean_read)
 684                         item->clean_read = -1;
 685                 item->clean_send = -1;
 686         }
 687         if(d_r) {
 688                 close(item->dirty_read);
 689                 if(item->dirty_send == item->dirty_read)
 690                         item->dirty_send = -1;
 691                 item->dirty_read = -1;
 692         }
 693         if(d_s) {
 694                 close(item->dirty_send);
 695                 if(item->dirty_send == item->dirty_read)
 696                         item->dirty_read = -1;
 697                 item->dirty_send = -1;
 698         }
 699         /* This function name is attributed to the term donated by David
 700          * Schwartz on openssl-dev, message-ID:
 701          * <NCBBLIEPOCNJOAEKBEAKEEDGLIAA.davids@webmaster.com>. :-) */
 702         if(!state_machine_churn(&item->sm))
 703                 /* If the SSL closes, it will also zero-out the _in buffers
 704                  * and will in future process just outgoing data. As and
 705                  * when the outgoing data has gone, it will return zero
 706                  * here to tell us to bail out. */
 707                 return 0;
 708         /* Otherwise, we return zero if both sides are dead. */
 709         if(((item->clean_read == -1) || (item->clean_send == -1)) &&
 710                         ((item->dirty_read == -1) || (item->dirty_send == -1)))
 711                 return 0;
 712         /* If only one side closed, notify the SSL of this so it can take
 713          * appropriate action. */
 714         if((item->clean_read == -1) || (item->clean_send == -1)) {
 715                 if(!state_machine_close_clean(&item->sm))
 716                         return 0;
 717         }
 718         if((item->dirty_read == -1) || (item->dirty_send == -1)) {
 719                 if(state_machine_close_dirty(&item->sm))
 720                         return 0;
 721         }
 722         return 1;
 723 }
 724