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 /* For now, hard-coded as follows;
  88  * (a) We're like "tunala -listen 127.0.0.1:9001 -proxy 127.0.0.1:9002"
  89  * (b) We max out at 50 simultaneous tunnels, listening will stop while we have
  90  *     that many tunnels operating and will recommence as/when tunnels close.
  91  * (c) We are an SSL client proxy
  92  * (d) We use the "openssl" ENGINE
  93  * (e) We use the CA cert file "cacert.pem"
  94  * */
  95
  96 static const char *def_proxyhost = "127.0.0.1:443";
  97 static const char *def_listenhost = "127.0.0.1:8080";
  98 static int def_max_tunnels = 50;
  99 static const char *def_cacert = NULL;
 100 static const char *def_cert = NULL;
 101 static const char *def_key = NULL;
 102 static const char *def_engine_id = NULL;
 103 static int def_server_mode = 0;
 104
 105 static const char *helpstring =
 106         "\n'Tunala' (A tunneler with a New Zealand accent)\n"
 107         "Usage: tunala [options], where options are from;\n"
 108         "    -listen [host:]<port>  (default = 127.0.0.1:8080)\n"
 109         "    -proxy <host>:<port>   (default = 127.0.0.1:443)\n"
 110         "    -maxtunnels <num>      (default = 50)\n"
 111         "    -cacert <path|NULL>    (default = NULL)\n"
 112         "    -cert <path|NULL>      (default = NULL)\n"
 113         "    -key <path|NULL>       (default = whatever '-cert' is)\n"
 114         "    -engine <id|NULL>      (default = NULL)\n"
 115         "    -server <0|1>          (default = 0, ie. an SSL client)\n"
 116         "    -<h|help|?>            (displays this help screen)\n"
 117         "NB: It is recommended to specify a cert+key when operating as an\n"
 118         "SSL server. If you only specify '-cert', the same file must\n"
 119         "contain a matching private key.\n";
 120
 121 static int usage(const char *errstr, int isunknownarg)
 122 {
 123         if(isunknownarg)
 124                 fprintf(stderr, "Error: unknown argument '%s'\n", errstr);
 125         else
 126                 fprintf(stderr, "Error: %s\n", errstr);
 127         fprintf(stderr, "%s\n", helpstring);
 128         return 1;
 129 }
 130
 131 static int err_str0(const char *str0)
 132 {
 133         fprintf(stderr, str0);
 134         fprintf(stderr, "\n");
 135         return 1;
 136 }
 137
 138 static int err_str1(const char *str0, const char *str1)
 139 {
 140         fprintf(stderr, str0, str1);
 141         fprintf(stderr, "\n");
 142         return 1;
 143 }
 144
 145 static int parse_max_tunnels(const char *s, unsigned int *maxtunnels)
 146 {
 147         unsigned long l;
 148         char *temp;
 149         l = strtoul(s, &temp, 10);
 150         if((temp == s) || (*temp != '\0') || (l < 1) || (l > 1024)) {
 151                 fprintf(stderr, "Error, '%s' is an invalid value for "
 152                                 "maxtunnels\n", s);
 153                 return 0;
 154         }
 155         *maxtunnels = (unsigned int)l;
 156         return 1;
 157 }
 158
 159 static int parse_server_mode(const char *s, int *servermode)
 160 {
 161         unsigned long l;
 162         char *temp;
 163         l = strtoul(s, &temp, 10);
 164         if((temp == s) || (*temp != '\0') || (l > 1)) {
 165                 fprintf(stderr, "Error, '%s' is an invalid value for the "
 166                                 "server mode\n", s);
 167                 return 0;
 168         }
 169         *servermode = (int)l;
 170         return 1;
 171 }
 172
 173 int main(int argc, char *argv[])
 174 {
 175         unsigned int loop;
 176         int newfd;
 177         tunala_world_t world;
 178         tunala_item_t *t_item;
 179         unsigned char *proxy_ip;
 180         unsigned short proxy_port;
 181         /* Overridables */
 182         const char *proxyhost = def_proxyhost;
 183         const char *listenhost = def_listenhost;
 184         unsigned int max_tunnels = def_max_tunnels;
 185         const char *cacert = def_cacert;
 186         const char *cert = def_cert;
 187         const char *key = def_key;
 188         const char *engine_id = def_engine_id;
 189         int server_mode = def_server_mode;
 190
 191 /* Parse command-line arguments */
 192 next_arg:
 193         argc--; argv++;
 194         if(argc > 0) {
 195                 if(strcmp(*argv, "-listen") == 0) {
 196                         if(argc < 2)
 197                                 return usage("-listen requires an argument", 0);
 198                         argc--; argv++;
 199                         listenhost = *argv;
 200                         goto next_arg;
 201                 } else if(strcmp(*argv, "-proxy") == 0) {
 202                         if(argc < 2)
 203                                 return usage("-proxy requires an argument", 0);
 204                         argc--; argv++;
 205                         proxyhost = *argv;
 206                         goto next_arg;
 207                 } else if(strcmp(*argv, "-maxtunnels") == 0) {
 208                         if(argc < 2)
 209                                 return usage("-maxtunnels requires an argument", 0);
 210                         argc--; argv++;
 211                         if(!parse_max_tunnels(*argv, &max_tunnels))
 212                                 return 1;
 213                         goto next_arg;
 214                 } else if(strcmp(*argv, "-cacert") == 0) {
 215                         if(argc < 2)
 216                                 return usage("-cacert requires an argument", 0);
 217                         argc--; argv++;
 218                         if(strcmp(*argv, "NULL") == 0)
 219                                 cacert = NULL;
 220                         else
 221                                 cacert = *argv;
 222                         goto next_arg;
 223                 } else if(strcmp(*argv, "-cert") == 0) {
 224                         if(argc < 2)
 225                                 return usage("-cert requires an argument", 0);
 226                         argc--; argv++;
 227                         if(strcmp(*argv, "NULL") == 0)
 228                                 cert = NULL;
 229                         else
 230                                 cert = *argv;
 231                         goto next_arg;
 232                 } else if(strcmp(*argv, "-key") == 0) {
 233                         if(argc < 2)
 234                                 return usage("-key requires an argument", 0);
 235                         argc--; argv++;
 236                         if(strcmp(*argv, "NULL") == 0)
 237                                 key = NULL;
 238                         else
 239                                 key = *argv;
 240                         goto next_arg;
 241                 } else if(strcmp(*argv, "-engine") == 0) {
 242                         if(argc < 2)
 243                                 return usage("-engine requires an argument", 0);
 244                         argc--; argv++;
 245                         engine_id = *argv;
 246                         goto next_arg;
 247                 } else if(strcmp(*argv, "-server") == 0) {
 248                         if(argc < 2)
 249                                 return usage("-server requires an argument", 0);
 250                         argc--; argv++;
 251                         if(!parse_server_mode(*argv, &server_mode))
 252                                 return 1;
 253                         goto next_arg;
 254                 } else if((strcmp(*argv, "-h") == 0) ||
 255                                 (strcmp(*argv, "-help") == 0) ||
 256                                 (strcmp(*argv, "-?") == 0)) {
 257                         fprintf(stderr, "%s\n", helpstring);
 258                         return 0;
 259                 } else
 260                         return usage(*argv, 1);
 261         }
 262
 263         /* Initialise network stuff */
 264         if(!ip_initialise())
 265                 return err_str0("ip_initialise failed");
 266         err_str0("ip_initialise succeeded");
 267         /* Create the SSL_CTX */
 268         if((world.ssl_ctx = initialise_ssl_ctx(server_mode, engine_id,
 269                         cacert, cert, key)) == NULL)
 270                 return err_str1("initialise_ssl_ctx(engine_id=%s) failed",
 271                         (engine_id == NULL) ? "NULL" : engine_id);
 272         err_str1("initialise_ssl_ctx(engine_id=%s) succeeded",
 273                         (engine_id == NULL) ? "NULL" : engine_id);
 274         /* Create the listener */
 275         if((world.listen_fd = ip_create_listener(listenhost)) == -1)
 276                 return err_str1("ip_create_listener(%s) failed", listenhost);
 277         err_str1("ip_create_listener(%s) succeeded", listenhost);
 278         if(!ip_parse_address(proxyhost, &proxy_ip, &proxy_port, 0))
 279                 return err_str1("ip_parse_address(%s) failed", proxyhost);
 280         err_str1("ip_parse_address(%s) succeeded", proxyhost);
 281         fprintf(stderr, "Info - proxying to %d.%d.%d.%d:%d\n",
 282                         (int)proxy_ip[0], (int)proxy_ip[1],
 283                         (int)proxy_ip[2], (int)proxy_ip[3], (int)proxy_port);
 284         fprintf(stderr, "Info - set maxtunnels to %d\n", (int)max_tunnels);
 285         fprintf(stderr, "Info - set to operate as an SSL %s\n",
 286                         (server_mode ? "server" : "client"));
 287         /* Initialise the rest of the stuff */
 288         world.tunnels_used = world.tunnels_size = 0;
 289         world.tunnels = NULL;
 290         world.server_mode = server_mode;
 291         selector_init(&world.selector);
 292
 293 /* We're ready to loop */
 294 main_loop:
 295         /* Should we listen for *new* tunnels? */
 296         if(world.tunnels_used < max_tunnels)
 297                 selector_add_listener(&world.selector, world.listen_fd);
 298         /* We should add in our existing tunnels */
 299         for(loop = 0; loop < world.tunnels_used; loop++)
 300                 selector_add_tunala(&world.selector, world.tunnels + loop);
 301         /* Now do the select */
 302         switch(selector_select(&world.selector)) {
 303         case -1:
 304                 fprintf(stderr, "selector_select returned a badness error.\n");
 305                 abort();
 306         case 0:
 307                 fprintf(stderr, "Warn, selector_select return 0 - signal??\n");
 308                 goto main_loop;
 309         default:
 310                 break;
 311         }
 312         /* Accept new connection if we should and can */
 313         if((world.tunnels_used < max_tunnels) && (selector_get_listener(
 314                                         &world.selector, world.listen_fd,
 315                                         &newfd) == 1)) {
 316                 /* We have a new connection */
 317                 if(!tunala_world_new_item(&world, newfd,
 318                                         proxy_ip, proxy_port)) {
 319                         fprintf(stderr, "tunala_world_new_item failed\n");
 320                         abort();
 321                 }
 322                 fprintf(stderr, "Info, new tunnel opened, now up to %d\n",
 323                                 world.tunnels_used);
 324         }
 325         /* Give each tunnel its moment, note the while loop is because it makes
 326          * the logic easier than with "for" to deal with an array that may shift
 327          * because of deletes. */
 328         loop = 0;
 329         t_item = world.tunnels;
 330         while(loop < world.tunnels_used) {
 331                 if(!tunala_item_io(&world.selector, t_item)) {
 332                         /* We're closing whether for reasons of an error or a
 333                          * natural close. Don't increment loop or t_item because
 334                          * the next item is moving to us! */
 335                         tunala_world_del_item(&world, loop);
 336                         fprintf(stderr, "Info, tunnel closed, down to %d\n",
 337                                         world.tunnels_used);
 338                 }
 339                 else {
 340                         /* Move to the next item */
 341                         loop++;
 342                         t_item++;
 343                 }
 344         }
 345         goto main_loop;
 346         /* Should never get here */
 347         abort();
 348         return 1;
 349 }
 350
 351 /****************/
 352 /* OpenSSL bits */
 353 /****************/
 354
 355 static SSL_CTX *initialise_ssl_ctx(int server_mode, const char *engine_id,
 356                 const char *CAfile, const char *cert, const char *key)
 357 {
 358         SSL_CTX *ctx, *ret = NULL;
 359         SSL_METHOD *meth;
 360         ENGINE *e = NULL;
 361         FILE *fp = NULL;
 362         X509 *x509 = NULL;
 363         EVP_PKEY *pkey = NULL;
 364
 365         OpenSSL_add_ssl_algorithms();
 366         SSL_load_error_strings();
 367
 368         meth = (server_mode ? SSLv23_server_method() : SSLv23_client_method());
 369         if(meth == NULL)
 370                 goto err;
 371         if(engine_id) {
 372                 if((e = ENGINE_by_id(engine_id)) == NULL) {
 373                         fprintf(stderr, "Error obtaining '%s' engine, openssl "
 374                                         "errors follow\n", engine_id);
 375                         goto err;
 376                 }
 377                 if(!ENGINE_set_default(e, ENGINE_METHOD_ALL)) {
 378                         fprintf(stderr, "Error assigning '%s' engine, openssl "
 379                                         "errors follow\n", engine_id);
 380                         goto err;
 381                 }
 382                 ENGINE_free(e);
 383         }
 384         if((ctx = SSL_CTX_new(meth)) == NULL)
 385                 goto err;
 386         /* cacert */
 387         if(CAfile) {
 388                 if(!X509_STORE_load_locations(SSL_CTX_get_cert_store(ctx),
 389                                         CAfile, NULL)) {
 390                         fprintf(stderr, "Error loading CA cert(s) in '%s'\n",
 391                                         CAfile);
 392                         goto err;
 393                 }
 394                 fprintf(stderr, "Info, operating with CA cert(s) in '%s'\n",
 395                                 CAfile);
 396         } else
 397                 fprintf(stderr, "Info, operating without a CA cert(-list)\n");
 398         if(!SSL_CTX_set_default_verify_paths(ctx)) {
 399                 fprintf(stderr, "Error setting default verify paths\n");
 400                 goto err;
 401         }
 402         /* cert */
 403         if(cert) {
 404                 if((fp = fopen(cert, "r")) == NULL) {
 405                         fprintf(stderr, "Error opening cert file '%s'\n", cert);
 406                         goto err;
 407                 }
 408                 if(!PEM_read_X509(fp, &x509, NULL, NULL)) {
 409                         fprintf(stderr, "Error reading PEM cert from '%s'\n",
 410                                         cert);
 411                         goto err;
 412                 }
 413                 if(!SSL_CTX_use_certificate(ctx, x509)) {
 414                         fprintf(stderr, "Error, cert in '%s' can not be used\n",
 415                                         cert);
 416                         goto err;
 417                 }
 418                 fprintf(stderr, "Info, operating with cert in '%s'\n", cert);
 419                 fclose(fp);
 420                 fp = NULL;
 421                 /* If a cert was given without matching key, we assume the same
 422                  * file contains the required key. */
 423                 if(!key)
 424                         key = cert;
 425         } else
 426                 if(key) {
 427                         fprintf(stderr, "Error, can't specify a key without a "
 428                                         "corresponding certificate\n");
 429                         goto err;
 430                 }
 431         /* key */
 432         if(key) {
 433                 if((fp = fopen(key, "r")) == NULL) {
 434                         fprintf(stderr, "Error opening key file '%s'\n", key);
 435                         goto err;
 436                 }
 437                 if(!PEM_read_PrivateKey(fp, &pkey, NULL, NULL)) {
 438                         fprintf(stderr, "Error reading PEM key from '%s'\n",
 439                                         key);
 440                         goto err;
 441                 }
 442                 if(!SSL_CTX_use_PrivateKey(ctx, pkey)) {
 443                         fprintf(stderr, "Error, key in '%s' can not be used\n",
 444                                         key);
 445                         goto err;
 446                 }
 447                 fprintf(stderr, "Info, operating with key in '%s'\n", key);
 448         } else
 449                 fprintf(stderr, "Info, operating without a cert or key\n");
 450
 451         /* Success! */
 452         ret = ctx;
 453 err:
 454         if(!ret) {
 455                 ERR_print_errors_fp(stderr);
 456                 if(ctx)
 457                         SSL_CTX_free(ctx);
 458         }
 459         if(fp)
 460                 fclose(fp);
 461         if(x509)
 462                 X509_free(x509);
 463         if(pkey)
 464                 EVP_PKEY_free(pkey);
 465         return ret;
 466 }
 467
 468 /*****************/
 469 /* Selector bits */
 470 /*****************/
 471
 472 static void selector_sets_init(select_sets_t *s)
 473 {
 474         s->max = 0;
 475         FD_ZERO(&s->reads);
 476         FD_ZERO(&s->sends);
 477         FD_ZERO(&s->excepts);
 478 }
 479 static void selector_init(tunala_selector_t *selector)
 480 {
 481         selector_sets_init(&selector->last_selected);
 482         selector_sets_init(&selector->next_select);
 483 }
 484
 485 #define SEL_EXCEPTS 0x00
 486 #define SEL_READS   0x01
 487 #define SEL_SENDS   0x02
 488 static void selector_add_raw_fd(tunala_selector_t *s, int fd, int flags)
 489 {
 490         FD_SET(fd, &s->next_select.excepts);
 491         if(flags & SEL_READS)
 492                 FD_SET(fd, &s->next_select.reads);
 493         if(flags & SEL_SENDS)
 494                 FD_SET(fd, &s->next_select.sends);
 495         /* Adjust "max" */
 496         if(s->next_select.max < (fd + 1))
 497                 s->next_select.max = fd + 1;
 498 }
 499
 500 static void selector_add_listener(tunala_selector_t *selector, int fd)
 501 {
 502         selector_add_raw_fd(selector, fd, SEL_READS);
 503 }
 504
 505 static void selector_add_tunala(tunala_selector_t *s, tunala_item_t *t)
 506 {
 507         /* Set clean read if sm.clean_in is not full */
 508         if(t->clean_read != -1) {
 509                 selector_add_raw_fd(s, t->clean_read,
 510                         (buffer_full(state_machine_get_buffer(&t->sm,
 511                                 SM_CLEAN_IN)) ? SEL_EXCEPTS : SEL_READS));
 512         }
 513         /* Set clean send if sm.clean_out is not empty */
 514         if(t->clean_send != -1) {
 515                 selector_add_raw_fd(s, t->clean_send,
 516                         (buffer_empty(state_machine_get_buffer(&t->sm,
 517                                 SM_CLEAN_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
 518         }
 519         /* Set dirty read if sm.dirty_in is not full */
 520         if(t->dirty_read != -1) {
 521                 selector_add_raw_fd(s, t->dirty_read,
 522                         (buffer_full(state_machine_get_buffer(&t->sm,
 523                                 SM_DIRTY_IN)) ? SEL_EXCEPTS : SEL_READS));
 524         }
 525         /* Set dirty send if sm.dirty_out is not empty */
 526         if(t->dirty_send != -1) {
 527                 selector_add_raw_fd(s, t->dirty_send,
 528                         (buffer_empty(state_machine_get_buffer(&t->sm,
 529                                 SM_DIRTY_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
 530         }
 531 }
 532
 533 static int selector_select(tunala_selector_t *selector)
 534 {
 535         memcpy(&selector->last_selected, &selector->next_select,
 536                         sizeof(select_sets_t));
 537         selector_sets_init(&selector->next_select);
 538         return select(selector->last_selected.max,
 539                         &selector->last_selected.reads,
 540                         &selector->last_selected.sends,
 541                         &selector->last_selected.excepts, NULL);
 542 }
 543
 544 /* This returns -1 for error, 0 for no new connections, or 1 for success, in
 545  * which case *newfd is populated. */
 546 static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd)
 547 {
 548         if(FD_ISSET(fd, &selector->last_selected.excepts))
 549                 return -1;
 550         if(!FD_ISSET(fd, &selector->last_selected.reads))
 551                 return 0;
 552         if((*newfd = ip_accept_connection(fd)) == -1)
 553                 return -1;
 554         return 1;
 555 }
 556
 557 /************************/
 558 /* "Tunala" world stuff */
 559 /************************/
 560
 561 static int tunala_world_make_room(tunala_world_t *world)
 562 {
 563         unsigned int newsize;
 564         tunala_item_t *newarray;
 565
 566         if(world->tunnels_used < world->tunnels_size)
 567                 return 1;
 568         newsize = (world->tunnels_size == 0 ? 16 :
 569                         ((world->tunnels_size * 3) / 2));
 570         if((newarray = malloc(newsize * sizeof(tunala_item_t))) == NULL)
 571                 return 0;
 572         memset(newarray, 0, newsize * sizeof(tunala_item_t));
 573         if(world->tunnels_used > 0)
 574                 memcpy(newarray, world->tunnels,
 575                         world->tunnels_used * sizeof(tunala_item_t));
 576         if(world->tunnels_size > 0)
 577                 free(world->tunnels);
 578         /* migrate */
 579         world->tunnels = newarray;
 580         world->tunnels_size = newsize;
 581         return 1;
 582 }
 583
 584 static int tunala_world_new_item(tunala_world_t *world, int fd,
 585                 const unsigned char *ip, unsigned short port)
 586 {
 587         tunala_item_t *item;
 588         int newfd;
 589
 590         if(!tunala_world_make_room(world))
 591                 return 0;
 592         item = world->tunnels + (world->tunnels_used++);
 593         state_machine_init(&item->sm);
 594         item->clean_read = item->clean_send =
 595                 item->dirty_read = item->dirty_send = -1;
 596         if((newfd = ip_create_connection_split(ip, port)) == -1)
 597                 goto err;
 598         /* Which way round? If we're a server, "fd" is the dirty side and the
 599          * connection we open is the clean one. For a client, it's the other way
 600          * around. */
 601         if(world->server_mode) {
 602                 item->dirty_read = item->dirty_send = fd;
 603                 item->clean_read = item->clean_send = newfd;
 604         } else {
 605                 item->clean_read = item->clean_send = fd;
 606                 item->dirty_read = item->dirty_send = newfd;
 607         }
 608         state_machine_set_SSL(&item->sm, SSL_new(world->ssl_ctx),
 609                         world->server_mode);
 610         return 1;
 611 err:
 612         state_machine_close(&item->sm);
 613         return 0;
 614
 615 }
 616
 617 static void tunala_world_del_item(tunala_world_t *world, unsigned int idx)
 618 {
 619         tunala_item_t *item = world->tunnels + idx;
 620         if(item->clean_read != -1)
 621                 close(item->clean_read);
 622         if(item->clean_send != item->clean_read)
 623                 close(item->clean_send);
 624         item->clean_read = item->clean_send = -1;
 625         if(item->dirty_read != -1)
 626                 close(item->dirty_read);
 627         if(item->dirty_send != item->dirty_read)
 628                 close(item->dirty_send);
 629         item->dirty_read = item->dirty_send = -1;
 630         state_machine_close(&item->sm);
 631         /* OK, now we fix the item array */
 632         if(idx + 1 < world->tunnels_used)
 633                 /* We need to scroll entries to the left */
 634                 memmove(world->tunnels + idx,
 635                                 world->tunnels + (idx + 1),
 636                                 (world->tunnels_used - (idx + 1)) *
 637                                         sizeof(tunala_item_t));
 638         world->tunnels_used--;
 639 }
 640
 641 static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item)
 642 {
 643         int c_r, c_s, d_r, d_s; /* Four boolean flags */
 644
 645         /* Take ourselves out of the gene-pool if there was an except */
 646         if((item->clean_read != -1) && FD_ISSET(item->clean_read,
 647                                 &selector->last_selected.excepts))
 648                 return 0;
 649         if((item->clean_send != -1) && FD_ISSET(item->clean_send,
 650                                 &selector->last_selected.excepts))
 651                 return 0;
 652         if((item->dirty_read != -1) && FD_ISSET(item->dirty_read,
 653                                 &selector->last_selected.excepts))
 654                 return 0;
 655         if((item->dirty_send != -1) && FD_ISSET(item->dirty_send,
 656                                 &selector->last_selected.excepts))
 657                 return 0;
 658         /* Grab our 4 IO flags */
 659         c_r = c_s = d_r = d_s = 0;
 660         if(item->clean_read != -1)
 661                 c_r = FD_ISSET(item->clean_read, &selector->last_selected.reads);
 662         if(item->clean_send != -1)
 663                 c_s = FD_ISSET(item->clean_send, &selector->last_selected.sends);
 664         if(item->dirty_read != -1)
 665                 d_r = FD_ISSET(item->dirty_read, &selector->last_selected.reads);
 666         if(item->dirty_send != -1)
 667                 d_s = FD_ISSET(item->dirty_send, &selector->last_selected.sends);
 668         /* If no IO has happened for us, skip needless data looping */
 669         if(!c_r && !c_s && !d_r && !d_s)
 670                 return 1;
 671         if(c_r)
 672                 c_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
 673                                 SM_CLEAN_IN), item->clean_read) <= 0);
 674         if(c_s)
 675                 c_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
 676                                 SM_CLEAN_OUT), item->clean_send) <= 0);
 677         if(d_r)
 678                 d_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
 679                                 SM_DIRTY_IN), item->dirty_read) <= 0);
 680         if(d_s)
 681                 d_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
 682                                 SM_DIRTY_OUT), item->dirty_send) <= 0);
 683         /* If any of the flags is non-zero, that means they need closing */
 684         if(c_r) {
 685                 close(item->clean_read);
 686                 if(item->clean_send == item->clean_read)
 687                         item->clean_send = -1;
 688                 item->clean_read = -1;
 689         }
 690         if(c_s) {
 691                 close(item->clean_send);
 692                 if(item->clean_send == item->clean_read)
 693                         item->clean_read = -1;
 694                 item->clean_send = -1;
 695         }
 696         if(d_r) {
 697                 close(item->dirty_read);
 698                 if(item->dirty_send == item->dirty_read)
 699                         item->dirty_send = -1;
 700                 item->dirty_read = -1;
 701         }
 702         if(d_s) {
 703                 close(item->dirty_send);
 704                 if(item->dirty_send == item->dirty_read)
 705                         item->dirty_read = -1;
 706                 item->dirty_send = -1;
 707         }
 708         /* This function name is attributed to the term donated by David
 709          * Schwartz on openssl-dev, message-ID:
 710          * <NCBBLIEPOCNJOAEKBEAKEEDGLIAA.davids@webmaster.com>. :-) */
 711         if(!state_machine_churn(&item->sm))
 712                 /* If the SSL closes, it will also zero-out the _in buffers
 713                  * and will in future process just outgoing data. As and
 714                  * when the outgoing data has gone, it will return zero
 715                  * here to tell us to bail out. */
 716                 return 0;
 717         /* Otherwise, we return zero if both sides are dead. */
 718         if(((item->clean_read == -1) || (item->clean_send == -1)) &&
 719                         ((item->dirty_read == -1) || (item->dirty_send == -1)))
 720                 return 0;
 721         /* If only one side closed, notify the SSL of this so it can take
 722          * appropriate action. */
 723         if((item->clean_read == -1) || (item->clean_send == -1)) {
 724                 if(!state_machine_close_clean(&item->sm))
 725                         return 0;
 726         }
 727         if((item->dirty_read == -1) || (item->dirty_send == -1)) {
 728                 if(state_machine_close_dirty(&item->sm))
 729                         return 0;
 730         }
 731         return 1;
 732 }
 733