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                 const char *cipher_list, int out_state);
  72 static void selector_init(tunala_selector_t *selector);
  73 static void selector_add_listener(tunala_selector_t *selector, int fd);
  74 static void selector_add_tunala(tunala_selector_t *selector, tunala_item_t *t);
  75 static int selector_select(tunala_selector_t *selector);
  76 /* This returns -1 for error, 0 for no new connections, or 1 for success, in
  77  * which case *newfd is populated. */
  78 static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd);
  79 static int tunala_world_new_item(tunala_world_t *world, int fd,
  80                 const unsigned char *ip, unsigned short port);
  81 static void tunala_world_del_item(tunala_world_t *world, unsigned int idx);
  82 static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item);
  83
  84 /*********************************************/
  85 /* MAIN FUNCTION (and its utility functions) */
  86 /*********************************************/
  87
  88 static const char *def_proxyhost = "127.0.0.1:443";
  89 static const char *def_listenhost = "127.0.0.1:8080";
  90 static int def_max_tunnels = 50;
  91 static const char *def_cacert = NULL;
  92 static const char *def_cert = NULL;
  93 static const char *def_key = NULL;
  94 static const char *def_engine_id = NULL;
  95 static int def_server_mode = 0;
  96 static const char *def_cipher_list = NULL;
  97 static int def_out_state = 0;
  98
  99 static const char *helpstring =
 100         "\n'Tunala' (A tunneler with a New Zealand accent)\n"
 101         "Usage: tunala [options], where options are from;\n"
 102         "    -listen [host:]<port>  (default = 127.0.0.1:8080)\n"
 103         "    -proxy <host>:<port>   (default = 127.0.0.1:443)\n"
 104         "    -maxtunnels <num>      (default = 50)\n"
 105         "    -cacert <path|NULL>    (default = NULL)\n"
 106         "    -cert <path|NULL>      (default = NULL)\n"
 107         "    -key <path|NULL>       (default = whatever '-cert' is)\n"
 108         "    -engine <id|NULL>      (default = NULL)\n"
 109         "    -server <0|1>          (default = 0, ie. an SSL client)\n"
 110         "    -cipher <list>         (specifies cipher list to use)\n"
 111         "    -out_state             (prints SSL handshake states)\n"
 112         "    -<h|help|?>            (displays this help screen)\n"
 113         "NB: It is recommended to specify a cert+key when operating as an\n"
 114         "SSL server. If you only specify '-cert', the same file must\n"
 115         "contain a matching private key.\n";
 116
 117 static int usage(const char *errstr, int isunknownarg)
 118 {
 119         if(isunknownarg)
 120                 fprintf(stderr, "Error: unknown argument '%s'\n", errstr);
 121         else
 122                 fprintf(stderr, "Error: %s\n", errstr);
 123         fprintf(stderr, "%s\n", helpstring);
 124         return 1;
 125 }
 126
 127 static int err_str0(const char *str0)
 128 {
 129         fprintf(stderr, str0);
 130         fprintf(stderr, "\n");
 131         return 1;
 132 }
 133
 134 static int err_str1(const char *str0, const char *str1)
 135 {
 136         fprintf(stderr, str0, str1);
 137         fprintf(stderr, "\n");
 138         return 1;
 139 }
 140
 141 static int parse_max_tunnels(const char *s, unsigned int *maxtunnels)
 142 {
 143         unsigned long l;
 144         char *temp;
 145         l = strtoul(s, &temp, 10);
 146         if((temp == s) || (*temp != '\0') || (l < 1) || (l > 1024)) {
 147                 fprintf(stderr, "Error, '%s' is an invalid value for "
 148                                 "maxtunnels\n", s);
 149                 return 0;
 150         }
 151         *maxtunnels = (unsigned int)l;
 152         return 1;
 153 }
 154
 155 static int parse_server_mode(const char *s, int *servermode)
 156 {
 157         unsigned long l;
 158         char *temp;
 159         l = strtoul(s, &temp, 10);
 160         if((temp == s) || (*temp != '\0') || (l > 1)) {
 161                 fprintf(stderr, "Error, '%s' is an invalid value for the "
 162                                 "server mode\n", s);
 163                 return 0;
 164         }
 165         *servermode = (int)l;
 166         return 1;
 167 }
 168
 169 int main(int argc, char *argv[])
 170 {
 171         unsigned int loop;
 172         int newfd;
 173         tunala_world_t world;
 174         tunala_item_t *t_item;
 175         unsigned char *proxy_ip;
 176         unsigned short proxy_port;
 177         /* Overridables */
 178         const char *proxyhost = def_proxyhost;
 179         const char *listenhost = def_listenhost;
 180         unsigned int max_tunnels = def_max_tunnels;
 181         const char *cacert = def_cacert;
 182         const char *cert = def_cert;
 183         const char *key = def_key;
 184         const char *engine_id = def_engine_id;
 185         int server_mode = def_server_mode;
 186         const char *cipher_list = def_cipher_list;
 187         int out_state = def_out_state;
 188
 189 /* Parse command-line arguments */
 190 next_arg:
 191         argc--; argv++;
 192         if(argc > 0) {
 193                 if(strcmp(*argv, "-listen") == 0) {
 194                         if(argc < 2)
 195                                 return usage("-listen requires an argument", 0);
 196                         argc--; argv++;
 197                         listenhost = *argv;
 198                         goto next_arg;
 199                 } else if(strcmp(*argv, "-proxy") == 0) {
 200                         if(argc < 2)
 201                                 return usage("-proxy requires an argument", 0);
 202                         argc--; argv++;
 203                         proxyhost = *argv;
 204                         goto next_arg;
 205                 } else if(strcmp(*argv, "-maxtunnels") == 0) {
 206                         if(argc < 2)
 207                                 return usage("-maxtunnels requires an argument", 0);
 208                         argc--; argv++;
 209                         if(!parse_max_tunnels(*argv, &max_tunnels))
 210                                 return 1;
 211                         goto next_arg;
 212                 } else if(strcmp(*argv, "-cacert") == 0) {
 213                         if(argc < 2)
 214                                 return usage("-cacert requires an argument", 0);
 215                         argc--; argv++;
 216                         if(strcmp(*argv, "NULL") == 0)
 217                                 cacert = NULL;
 218                         else
 219                                 cacert = *argv;
 220                         goto next_arg;
 221                 } else if(strcmp(*argv, "-cert") == 0) {
 222                         if(argc < 2)
 223                                 return usage("-cert requires an argument", 0);
 224                         argc--; argv++;
 225                         if(strcmp(*argv, "NULL") == 0)
 226                                 cert = NULL;
 227                         else
 228                                 cert = *argv;
 229                         goto next_arg;
 230                 } else if(strcmp(*argv, "-key") == 0) {
 231                         if(argc < 2)
 232                                 return usage("-key requires an argument", 0);
 233                         argc--; argv++;
 234                         if(strcmp(*argv, "NULL") == 0)
 235                                 key = NULL;
 236                         else
 237                                 key = *argv;
 238                         goto next_arg;
 239                 } else if(strcmp(*argv, "-engine") == 0) {
 240                         if(argc < 2)
 241                                 return usage("-engine requires an argument", 0);
 242                         argc--; argv++;
 243                         engine_id = *argv;
 244                         goto next_arg;
 245                 } else if(strcmp(*argv, "-server") == 0) {
 246                         if(argc < 2)
 247                                 return usage("-server requires an argument", 0);
 248                         argc--; argv++;
 249                         if(!parse_server_mode(*argv, &server_mode))
 250                                 return 1;
 251                         goto next_arg;
 252                 } else if(strcmp(*argv, "-cipher") == 0) {
 253                         if(argc < 2)
 254                                 return usage("-cipher requires an argument", 0);
 255                         argc--; argv++;
 256                         cipher_list = *argv;
 257                         goto next_arg;
 258                 } else if(strcmp(*argv, "-out_state") == 0) {
 259                         out_state = 1;
 260                         goto next_arg;
 261                 } else if((strcmp(*argv, "-h") == 0) ||
 262                                 (strcmp(*argv, "-help") == 0) ||
 263                                 (strcmp(*argv, "-?") == 0)) {
 264                         fprintf(stderr, "%s\n", helpstring);
 265                         return 0;
 266                 } else
 267                         return usage(*argv, 1);
 268         }
 269
 270         /* Initialise network stuff */
 271         if(!ip_initialise())
 272                 return err_str0("ip_initialise failed");
 273         err_str0("ip_initialise succeeded");
 274         /* Create the SSL_CTX */
 275         if((world.ssl_ctx = initialise_ssl_ctx(server_mode, engine_id,
 276                         cacert, cert, key, cipher_list, out_state)) == NULL)
 277                 return err_str1("initialise_ssl_ctx(engine_id=%s) failed",
 278                         (engine_id == NULL) ? "NULL" : engine_id);
 279         err_str1("initialise_ssl_ctx(engine_id=%s) succeeded",
 280                         (engine_id == NULL) ? "NULL" : engine_id);
 281         /* Create the listener */
 282         if((world.listen_fd = ip_create_listener(listenhost)) == -1)
 283                 return err_str1("ip_create_listener(%s) failed", listenhost);
 284         err_str1("ip_create_listener(%s) succeeded", listenhost);
 285         if(!ip_parse_address(proxyhost, &proxy_ip, &proxy_port, 0))
 286                 return err_str1("ip_parse_address(%s) failed", proxyhost);
 287         err_str1("ip_parse_address(%s) succeeded", proxyhost);
 288         fprintf(stderr, "Info - proxying to %d.%d.%d.%d:%d\n",
 289                         (int)proxy_ip[0], (int)proxy_ip[1],
 290                         (int)proxy_ip[2], (int)proxy_ip[3], (int)proxy_port);
 291         fprintf(stderr, "Info - set maxtunnels to %d\n", (int)max_tunnels);
 292         fprintf(stderr, "Info - set to operate as an SSL %s\n",
 293                         (server_mode ? "server" : "client"));
 294         /* Initialise the rest of the stuff */
 295         world.tunnels_used = world.tunnels_size = 0;
 296         world.tunnels = NULL;
 297         world.server_mode = server_mode;
 298         selector_init(&world.selector);
 299
 300 /* We're ready to loop */
 301 main_loop:
 302         /* Should we listen for *new* tunnels? */
 303         if(world.tunnels_used < max_tunnels)
 304                 selector_add_listener(&world.selector, world.listen_fd);
 305         /* We should add in our existing tunnels */
 306         for(loop = 0; loop < world.tunnels_used; loop++)
 307                 selector_add_tunala(&world.selector, world.tunnels + loop);
 308         /* Now do the select */
 309         switch(selector_select(&world.selector)) {
 310         case -1:
 311                 fprintf(stderr, "selector_select returned a badness error.\n");
 312                 abort();
 313         case 0:
 314                 fprintf(stderr, "Warn, selector_select returned 0 - signal??\n");
 315                 goto main_loop;
 316         default:
 317                 break;
 318         }
 319         /* Accept new connection if we should and can */
 320         if((world.tunnels_used < max_tunnels) && (selector_get_listener(
 321                                         &world.selector, world.listen_fd,
 322                                         &newfd) == 1)) {
 323                 /* We have a new connection */
 324                 if(!tunala_world_new_item(&world, newfd,
 325                                         proxy_ip, proxy_port))
 326                         fprintf(stderr, "tunala_world_new_item failed\n");
 327                 else
 328                         fprintf(stderr, "Info, new tunnel opened, now up to "
 329                                         "%d\n", world.tunnels_used);
 330         }
 331         /* Give each tunnel its moment, note the while loop is because it makes
 332          * the logic easier than with "for" to deal with an array that may shift
 333          * because of deletes. */
 334         loop = 0;
 335         t_item = world.tunnels;
 336         while(loop < world.tunnels_used) {
 337                 if(!tunala_item_io(&world.selector, t_item)) {
 338                         /* We're closing whether for reasons of an error or a
 339                          * natural close. Don't increment loop or t_item because
 340                          * the next item is moving to us! */
 341                         tunala_world_del_item(&world, loop);
 342                         fprintf(stderr, "Info, tunnel closed, down to %d\n",
 343                                         world.tunnels_used);
 344                 }
 345                 else {
 346                         /* Move to the next item */
 347                         loop++;
 348                         t_item++;
 349                 }
 350         }
 351         goto main_loop;
 352         /* Should never get here */
 353         abort();
 354         return 1;
 355 }
 356
 357 /****************/
 358 /* OpenSSL bits */
 359 /****************/
 360
 361 static SSL_CTX *initialise_ssl_ctx(int server_mode, const char *engine_id,
 362                 const char *CAfile, const char *cert, const char *key,
 363                 const char *cipher_list, int out_state)
 364 {
 365         SSL_CTX *ctx, *ret = NULL;
 366         SSL_METHOD *meth;
 367         ENGINE *e = NULL;
 368         FILE *fp = NULL;
 369         X509 *x509 = NULL;
 370         EVP_PKEY *pkey = NULL;
 371
 372         OpenSSL_add_ssl_algorithms();
 373         SSL_load_error_strings();
 374
 375         meth = (server_mode ? SSLv23_server_method() : SSLv23_client_method());
 376         if(meth == NULL)
 377                 goto err;
 378         if(engine_id) {
 379                 if((e = ENGINE_by_id(engine_id)) == NULL) {
 380                         fprintf(stderr, "Error obtaining '%s' engine, openssl "
 381                                         "errors follow\n", engine_id);
 382                         goto err;
 383                 }
 384                 if(!ENGINE_set_default(e, ENGINE_METHOD_ALL)) {
 385                         fprintf(stderr, "Error assigning '%s' engine, openssl "
 386                                         "errors follow\n", engine_id);
 387                         goto err;
 388                 }
 389                 ENGINE_free(e);
 390         }
 391         if((ctx = SSL_CTX_new(meth)) == NULL)
 392                 goto err;
 393         /* cacert */
 394         if(CAfile) {
 395                 if(!X509_STORE_load_locations(SSL_CTX_get_cert_store(ctx),
 396                                         CAfile, NULL)) {
 397                         fprintf(stderr, "Error loading CA cert(s) in '%s'\n",
 398                                         CAfile);
 399                         goto err;
 400                 }
 401                 fprintf(stderr, "Info, operating with CA cert(s) in '%s'\n",
 402                                 CAfile);
 403         } else
 404                 fprintf(stderr, "Info, operating without a CA cert(-list)\n");
 405         if(!SSL_CTX_set_default_verify_paths(ctx)) {
 406                 fprintf(stderr, "Error setting default verify paths\n");
 407                 goto err;
 408         }
 409         /* cert */
 410         if(cert) {
 411                 if((fp = fopen(cert, "r")) == NULL) {
 412                         fprintf(stderr, "Error opening cert file '%s'\n", cert);
 413                         goto err;
 414                 }
 415                 if(!PEM_read_X509(fp, &x509, NULL, NULL)) {
 416                         fprintf(stderr, "Error reading PEM cert from '%s'\n",
 417                                         cert);
 418                         goto err;
 419                 }
 420                 if(!SSL_CTX_use_certificate(ctx, x509)) {
 421                         fprintf(stderr, "Error, cert in '%s' can not be used\n",
 422                                         cert);
 423                         goto err;
 424                 }
 425                 fprintf(stderr, "Info, operating with cert in '%s'\n", cert);
 426                 fclose(fp);
 427                 fp = NULL;
 428                 /* If a cert was given without matching key, we assume the same
 429                  * file contains the required key. */
 430                 if(!key)
 431                         key = cert;
 432         } else
 433                 if(key) {
 434                         fprintf(stderr, "Error, can't specify a key without a "
 435                                         "corresponding certificate\n");
 436                         goto err;
 437                 }
 438         /* key */
 439         if(key) {
 440                 if((fp = fopen(key, "r")) == NULL) {
 441                         fprintf(stderr, "Error opening key file '%s'\n", key);
 442                         goto err;
 443                 }
 444                 if(!PEM_read_PrivateKey(fp, &pkey, NULL, NULL)) {
 445                         fprintf(stderr, "Error reading PEM key from '%s'\n",
 446                                         key);
 447                         goto err;
 448                 }
 449                 if(!SSL_CTX_use_PrivateKey(ctx, pkey)) {
 450                         fprintf(stderr, "Error, key in '%s' can not be used\n",
 451                                         key);
 452                         goto err;
 453                 }
 454                 fprintf(stderr, "Info, operating with key in '%s'\n", key);
 455         } else
 456                 fprintf(stderr, "Info, operating without a cert or key\n");
 457
 458         /* cipher_list */
 459         if(cipher_list) {
 460                 if(!SSL_CTX_set_cipher_list(ctx, cipher_list)) {
 461                         fprintf(stderr, "Error setting cipher list '%s'\n",
 462                                         cipher_list);
 463                         goto err;
 464                 }
 465                 fprintf(stderr, "Info, set cipher list '%s'\n", cipher_list);
 466         } else
 467                 fprintf(stderr, "Info, operating with default cipher list\n");
 468
 469         /* out_state (output of SSL handshake states to screen). */
 470         if(out_state) {
 471                 SSL_CTX_set_info_callback(ctx, cb_ssl_info);
 472                 cb_ssl_info_set_output(stderr);
 473         }
 474
 475         /* Success! */
 476         ret = ctx;
 477 err:
 478         if(!ret) {
 479                 ERR_print_errors_fp(stderr);
 480                 if(ctx)
 481                         SSL_CTX_free(ctx);
 482         }
 483         if(fp)
 484                 fclose(fp);
 485         if(x509)
 486                 X509_free(x509);
 487         if(pkey)
 488                 EVP_PKEY_free(pkey);
 489         return ret;
 490 }
 491
 492 /*****************/
 493 /* Selector bits */
 494 /*****************/
 495
 496 static void selector_sets_init(select_sets_t *s)
 497 {
 498         s->max = 0;
 499         FD_ZERO(&s->reads);
 500         FD_ZERO(&s->sends);
 501         FD_ZERO(&s->excepts);
 502 }
 503 static void selector_init(tunala_selector_t *selector)
 504 {
 505         selector_sets_init(&selector->last_selected);
 506         selector_sets_init(&selector->next_select);
 507 }
 508
 509 #define SEL_EXCEPTS 0x00
 510 #define SEL_READS   0x01
 511 #define SEL_SENDS   0x02
 512 static void selector_add_raw_fd(tunala_selector_t *s, int fd, int flags)
 513 {
 514         FD_SET(fd, &s->next_select.excepts);
 515         if(flags & SEL_READS)
 516                 FD_SET(fd, &s->next_select.reads);
 517         if(flags & SEL_SENDS)
 518                 FD_SET(fd, &s->next_select.sends);
 519         /* Adjust "max" */
 520         if(s->next_select.max < (fd + 1))
 521                 s->next_select.max = fd + 1;
 522 }
 523
 524 static void selector_add_listener(tunala_selector_t *selector, int fd)
 525 {
 526         selector_add_raw_fd(selector, fd, SEL_READS);
 527 }
 528
 529 static void selector_add_tunala(tunala_selector_t *s, tunala_item_t *t)
 530 {
 531         /* Set clean read if sm.clean_in is not full */
 532         if(t->clean_read != -1) {
 533                 selector_add_raw_fd(s, t->clean_read,
 534                         (buffer_full(state_machine_get_buffer(&t->sm,
 535                                 SM_CLEAN_IN)) ? SEL_EXCEPTS : SEL_READS));
 536         }
 537         /* Set clean send if sm.clean_out is not empty */
 538         if(t->clean_send != -1) {
 539                 selector_add_raw_fd(s, t->clean_send,
 540                         (buffer_empty(state_machine_get_buffer(&t->sm,
 541                                 SM_CLEAN_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
 542         }
 543         /* Set dirty read if sm.dirty_in is not full */
 544         if(t->dirty_read != -1) {
 545                 selector_add_raw_fd(s, t->dirty_read,
 546                         (buffer_full(state_machine_get_buffer(&t->sm,
 547                                 SM_DIRTY_IN)) ? SEL_EXCEPTS : SEL_READS));
 548         }
 549         /* Set dirty send if sm.dirty_out is not empty */
 550         if(t->dirty_send != -1) {
 551                 selector_add_raw_fd(s, t->dirty_send,
 552                         (buffer_empty(state_machine_get_buffer(&t->sm,
 553                                 SM_DIRTY_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
 554         }
 555 }
 556
 557 static int selector_select(tunala_selector_t *selector)
 558 {
 559         memcpy(&selector->last_selected, &selector->next_select,
 560                         sizeof(select_sets_t));
 561         selector_sets_init(&selector->next_select);
 562         return select(selector->last_selected.max,
 563                         &selector->last_selected.reads,
 564                         &selector->last_selected.sends,
 565                         &selector->last_selected.excepts, NULL);
 566 }
 567
 568 /* This returns -1 for error, 0 for no new connections, or 1 for success, in
 569  * which case *newfd is populated. */
 570 static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd)
 571 {
 572         if(FD_ISSET(fd, &selector->last_selected.excepts))
 573                 return -1;
 574         if(!FD_ISSET(fd, &selector->last_selected.reads))
 575                 return 0;
 576         if((*newfd = ip_accept_connection(fd)) == -1)
 577                 return -1;
 578         return 1;
 579 }
 580
 581 /************************/
 582 /* "Tunala" world stuff */
 583 /************************/
 584
 585 static int tunala_world_make_room(tunala_world_t *world)
 586 {
 587         unsigned int newsize;
 588         tunala_item_t *newarray;
 589
 590         if(world->tunnels_used < world->tunnels_size)
 591                 return 1;
 592         newsize = (world->tunnels_size == 0 ? 16 :
 593                         ((world->tunnels_size * 3) / 2));
 594         if((newarray = malloc(newsize * sizeof(tunala_item_t))) == NULL)
 595                 return 0;
 596         memset(newarray, 0, newsize * sizeof(tunala_item_t));
 597         if(world->tunnels_used > 0)
 598                 memcpy(newarray, world->tunnels,
 599                         world->tunnels_used * sizeof(tunala_item_t));
 600         if(world->tunnels_size > 0)
 601                 free(world->tunnels);
 602         /* migrate */
 603         world->tunnels = newarray;
 604         world->tunnels_size = newsize;
 605         return 1;
 606 }
 607
 608 static int tunala_world_new_item(tunala_world_t *world, int fd,
 609                 const unsigned char *ip, unsigned short port)
 610 {
 611         tunala_item_t *item;
 612         int newfd;
 613         SSL *new_ssl = NULL;
 614
 615         if(!tunala_world_make_room(world))
 616                 return 0;
 617         if((new_ssl = SSL_new(world->ssl_ctx)) == NULL) {
 618                 fprintf(stderr, "Error creating new SSL\n");
 619                 ERR_print_errors_fp(stderr);
 620                 return 0;
 621         }
 622         item = world->tunnels + (world->tunnels_used++);
 623         state_machine_init(&item->sm);
 624         item->clean_read = item->clean_send =
 625                 item->dirty_read = item->dirty_send = -1;
 626         if((newfd = ip_create_connection_split(ip, port)) == -1)
 627                 goto err;
 628         /* Which way round? If we're a server, "fd" is the dirty side and the
 629          * connection we open is the clean one. For a client, it's the other way
 630          * around. */
 631         if(world->server_mode) {
 632                 item->dirty_read = item->dirty_send = fd;
 633                 item->clean_read = item->clean_send = newfd;
 634         } else {
 635                 item->clean_read = item->clean_send = fd;
 636                 item->dirty_read = item->dirty_send = newfd;
 637         }
 638         /* We use the SSL's "app_data" to indicate a call-back induced "kill" */
 639         SSL_set_app_data(new_ssl, NULL);
 640         if(!state_machine_set_SSL(&item->sm, new_ssl, world->server_mode))
 641                 goto err;
 642         return 1;
 643 err:
 644         tunala_world_del_item(world, world->tunnels_used - 1);
 645         return 0;
 646
 647 }
 648
 649 static void tunala_world_del_item(tunala_world_t *world, unsigned int idx)
 650 {
 651         tunala_item_t *item = world->tunnels + idx;
 652         if(item->clean_read != -1)
 653                 close(item->clean_read);
 654         if(item->clean_send != item->clean_read)
 655                 close(item->clean_send);
 656         item->clean_read = item->clean_send = -1;
 657         if(item->dirty_read != -1)
 658                 close(item->dirty_read);
 659         if(item->dirty_send != item->dirty_read)
 660                 close(item->dirty_send);
 661         item->dirty_read = item->dirty_send = -1;
 662         state_machine_close(&item->sm);
 663         /* OK, now we fix the item array */
 664         if(idx + 1 < world->tunnels_used)
 665                 /* We need to scroll entries to the left */
 666                 memmove(world->tunnels + idx,
 667                                 world->tunnels + (idx + 1),
 668                                 (world->tunnels_used - (idx + 1)) *
 669                                         sizeof(tunala_item_t));
 670         world->tunnels_used--;
 671 }
 672
 673 static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item)
 674 {
 675         int c_r, c_s, d_r, d_s; /* Four boolean flags */
 676
 677         /* Take ourselves out of the gene-pool if there was an except */
 678         if((item->clean_read != -1) && FD_ISSET(item->clean_read,
 679                                 &selector->last_selected.excepts))
 680                 return 0;
 681         if((item->clean_send != -1) && FD_ISSET(item->clean_send,
 682                                 &selector->last_selected.excepts))
 683                 return 0;
 684         if((item->dirty_read != -1) && FD_ISSET(item->dirty_read,
 685                                 &selector->last_selected.excepts))
 686                 return 0;
 687         if((item->dirty_send != -1) && FD_ISSET(item->dirty_send,
 688                                 &selector->last_selected.excepts))
 689                 return 0;
 690         /* Grab our 4 IO flags */
 691         c_r = c_s = d_r = d_s = 0;
 692         if(item->clean_read != -1)
 693                 c_r = FD_ISSET(item->clean_read, &selector->last_selected.reads);
 694         if(item->clean_send != -1)
 695                 c_s = FD_ISSET(item->clean_send, &selector->last_selected.sends);
 696         if(item->dirty_read != -1)
 697                 d_r = FD_ISSET(item->dirty_read, &selector->last_selected.reads);
 698         if(item->dirty_send != -1)
 699                 d_s = FD_ISSET(item->dirty_send, &selector->last_selected.sends);
 700         /* If no IO has happened for us, skip needless data looping */
 701         if(!c_r && !c_s && !d_r && !d_s)
 702                 return 1;
 703         if(c_r)
 704                 c_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
 705                                 SM_CLEAN_IN), item->clean_read) <= 0);
 706         if(c_s)
 707                 c_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
 708                                 SM_CLEAN_OUT), item->clean_send) <= 0);
 709         if(d_r)
 710                 d_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
 711                                 SM_DIRTY_IN), item->dirty_read) <= 0);
 712         if(d_s)
 713                 d_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
 714                                 SM_DIRTY_OUT), item->dirty_send) <= 0);
 715         /* If any of the flags is non-zero, that means they need closing */
 716         if(c_r) {
 717                 close(item->clean_read);
 718                 if(item->clean_send == item->clean_read)
 719                         item->clean_send = -1;
 720                 item->clean_read = -1;
 721         }
 722         if(c_s && (item->clean_send != -1)) {
 723                 close(item->clean_send);
 724                 if(item->clean_send == item->clean_read)
 725                         item->clean_read = -1;
 726                 item->clean_send = -1;
 727         }
 728         if(d_r) {
 729                 close(item->dirty_read);
 730                 if(item->dirty_send == item->dirty_read)
 731                         item->dirty_send = -1;
 732                 item->dirty_read = -1;
 733         }
 734         if(d_s && (item->dirty_send != -1)) {
 735                 close(item->dirty_send);
 736                 if(item->dirty_send == item->dirty_read)
 737                         item->dirty_read = -1;
 738                 item->dirty_send = -1;
 739         }
 740         /* This function name is attributed to the term donated by David
 741          * Schwartz on openssl-dev, message-ID:
 742          * <NCBBLIEPOCNJOAEKBEAKEEDGLIAA.davids@webmaster.com>. :-) */
 743         if(!state_machine_churn(&item->sm))
 744                 /* If the SSL closes, it will also zero-out the _in buffers
 745                  * and will in future process just outgoing data. As and
 746                  * when the outgoing data has gone, it will return zero
 747                  * here to tell us to bail out. */
 748                 return 0;
 749         /* Otherwise, we return zero if both sides are dead. */
 750         if(((item->clean_read == -1) || (item->clean_send == -1)) &&
 751                         ((item->dirty_read == -1) || (item->dirty_send == -1)))
 752                 return 0;
 753         /* If only one side closed, notify the SSL of this so it can take
 754          * appropriate action. */
 755         if((item->clean_read == -1) || (item->clean_send == -1)) {
 756                 if(!state_machine_close_clean(&item->sm))
 757                         return 0;
 758         }
 759         if((item->dirty_read == -1) || (item->dirty_send == -1)) {
 760                 if(state_machine_close_dirty(&item->sm))
 761                         return 0;
 762         }
 763         return 1;
 764 }
 765