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, int out_verify,
  72                 int verify_mode);
  73 static void selector_init(tunala_selector_t *selector);
  74 static void selector_add_listener(tunala_selector_t *selector, int fd);
  75 static void selector_add_tunala(tunala_selector_t *selector, tunala_item_t *t);
  76 static int selector_select(tunala_selector_t *selector);
  77 /* This returns -1 for error, 0 for no new connections, or 1 for success, in
  78  * which case *newfd is populated. */
  79 static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd);
  80 static int tunala_world_new_item(tunala_world_t *world, int fd,
  81                 const unsigned char *ip, unsigned short port);
  82 static void tunala_world_del_item(tunala_world_t *world, unsigned int idx);
  83 static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item);
  84
  85 /*********************************************/
  86 /* MAIN FUNCTION (and its utility functions) */
  87 /*********************************************/
  88
  89 static const char *def_proxyhost = "127.0.0.1:443";
  90 static const char *def_listenhost = "127.0.0.1:8080";
  91 static int def_max_tunnels = 50;
  92 static const char *def_cacert = NULL;
  93 static const char *def_cert = NULL;
  94 static const char *def_key = NULL;
  95 static const char *def_engine_id = NULL;
  96 static int def_server_mode = 0;
  97 static const char *def_cipher_list = NULL;
  98 static int def_out_state = 0;
  99 static int def_out_verify = 0;
 100 static int def_verify_mode = 0;
 101
 102 static const char *helpstring =
 103         "\n'Tunala' (A tunneler with a New Zealand accent)\n"
 104         "Usage: tunala [options], where options are from;\n"
 105         "    -listen [host:]<port>  (default = 127.0.0.1:8080)\n"
 106         "    -proxy <host>:<port>   (default = 127.0.0.1:443)\n"
 107         "    -maxtunnels <num>      (default = 50)\n"
 108         "    -cacert <path|NULL>    (default = NULL)\n"
 109         "    -cert <path|NULL>      (default = NULL)\n"
 110         "    -key <path|NULL>       (default = whatever '-cert' is)\n"
 111         "    -engine <id|NULL>      (default = NULL)\n"
 112         "    -server <0|1>          (default = 0, ie. an SSL client)\n"
 113         "    -cipher <list>         (specifies cipher list to use)\n"
 114         "    -out_state             (prints SSL handshake states)\n"
 115         "    -out_verify            (prints certificate verification states)\n"
 116         "    -v_peer                (verify the peer certificate)\n"
 117         "    -v_strict              (do not continue if peer validation fails)\n"
 118         "    -v_once                (no verification in renegotiates)\n"
 119         "    -<h|help|?>            (displays this help screen)\n"
 120         "NB: It is recommended to specify a cert+key when operating as an\n"
 121         "SSL server. If you only specify '-cert', the same file must\n"
 122         "contain a matching private key.\n";
 123
 124 static int usage(const char *errstr, int isunknownarg)
 125 {
 126         if(isunknownarg)
 127                 fprintf(stderr, "Error: unknown argument '%s'\n", errstr);
 128         else
 129                 fprintf(stderr, "Error: %s\n", errstr);
 130         fprintf(stderr, "%s\n", helpstring);
 131         return 1;
 132 }
 133
 134 static int err_str0(const char *str0)
 135 {
 136         fprintf(stderr, str0);
 137         fprintf(stderr, "\n");
 138         return 1;
 139 }
 140
 141 static int err_str1(const char *str0, const char *str1)
 142 {
 143         fprintf(stderr, str0, str1);
 144         fprintf(stderr, "\n");
 145         return 1;
 146 }
 147
 148 static int parse_max_tunnels(const char *s, unsigned int *maxtunnels)
 149 {
 150         unsigned long l;
 151         char *temp;
 152         l = strtoul(s, &temp, 10);
 153         if((temp == s) || (*temp != '\0') || (l < 1) || (l > 1024)) {
 154                 fprintf(stderr, "Error, '%s' is an invalid value for "
 155                                 "maxtunnels\n", s);
 156                 return 0;
 157         }
 158         *maxtunnels = (unsigned int)l;
 159         return 1;
 160 }
 161
 162 static int parse_server_mode(const char *s, int *servermode)
 163 {
 164         unsigned long l;
 165         char *temp;
 166         l = strtoul(s, &temp, 10);
 167         if((temp == s) || (*temp != '\0') || (l > 1)) {
 168                 fprintf(stderr, "Error, '%s' is an invalid value for the "
 169                                 "server mode\n", s);
 170                 return 0;
 171         }
 172         *servermode = (int)l;
 173         return 1;
 174 }
 175
 176 int main(int argc, char *argv[])
 177 {
 178         unsigned int loop;
 179         int newfd;
 180         tunala_world_t world;
 181         tunala_item_t *t_item;
 182         unsigned char *proxy_ip;
 183         unsigned short proxy_port;
 184         /* Overridables */
 185         const char *proxyhost = def_proxyhost;
 186         const char *listenhost = def_listenhost;
 187         unsigned int max_tunnels = def_max_tunnels;
 188         const char *cacert = def_cacert;
 189         const char *cert = def_cert;
 190         const char *key = def_key;
 191         const char *engine_id = def_engine_id;
 192         int server_mode = def_server_mode;
 193         const char *cipher_list = def_cipher_list;
 194         int out_state = def_out_state;
 195         int out_verify = def_out_verify;
 196         int verify_mode = def_verify_mode;
 197
 198 /* Parse command-line arguments */
 199 next_arg:
 200         argc--; argv++;
 201         if(argc > 0) {
 202                 if(strcmp(*argv, "-listen") == 0) {
 203                         if(argc < 2)
 204                                 return usage("-listen requires an argument", 0);
 205                         argc--; argv++;
 206                         listenhost = *argv;
 207                         goto next_arg;
 208                 } else if(strcmp(*argv, "-proxy") == 0) {
 209                         if(argc < 2)
 210                                 return usage("-proxy requires an argument", 0);
 211                         argc--; argv++;
 212                         proxyhost = *argv;
 213                         goto next_arg;
 214                 } else if(strcmp(*argv, "-maxtunnels") == 0) {
 215                         if(argc < 2)
 216                                 return usage("-maxtunnels requires an argument", 0);
 217                         argc--; argv++;
 218                         if(!parse_max_tunnels(*argv, &max_tunnels))
 219                                 return 1;
 220                         goto next_arg;
 221                 } else if(strcmp(*argv, "-cacert") == 0) {
 222                         if(argc < 2)
 223                                 return usage("-cacert requires an argument", 0);
 224                         argc--; argv++;
 225                         if(strcmp(*argv, "NULL") == 0)
 226                                 cacert = NULL;
 227                         else
 228                                 cacert = *argv;
 229                         goto next_arg;
 230                 } else if(strcmp(*argv, "-cert") == 0) {
 231                         if(argc < 2)
 232                                 return usage("-cert requires an argument", 0);
 233                         argc--; argv++;
 234                         if(strcmp(*argv, "NULL") == 0)
 235                                 cert = NULL;
 236                         else
 237                                 cert = *argv;
 238                         goto next_arg;
 239                 } else if(strcmp(*argv, "-key") == 0) {
 240                         if(argc < 2)
 241                                 return usage("-key requires an argument", 0);
 242                         argc--; argv++;
 243                         if(strcmp(*argv, "NULL") == 0)
 244                                 key = NULL;
 245                         else
 246                                 key = *argv;
 247                         goto next_arg;
 248                 } else if(strcmp(*argv, "-engine") == 0) {
 249                         if(argc < 2)
 250                                 return usage("-engine requires an argument", 0);
 251                         argc--; argv++;
 252                         engine_id = *argv;
 253                         goto next_arg;
 254                 } else if(strcmp(*argv, "-server") == 0) {
 255                         if(argc < 2)
 256                                 return usage("-server requires an argument", 0);
 257                         argc--; argv++;
 258                         if(!parse_server_mode(*argv, &server_mode))
 259                                 return 1;
 260                         goto next_arg;
 261                 } else if(strcmp(*argv, "-cipher") == 0) {
 262                         if(argc < 2)
 263                                 return usage("-cipher requires an argument", 0);
 264                         argc--; argv++;
 265                         cipher_list = *argv;
 266                         goto next_arg;
 267                 } else if(strcmp(*argv, "-out_state") == 0) {
 268                         out_state = 1;
 269                         goto next_arg;
 270                 } else if(strcmp(*argv, "-out_verify") == 0) {
 271                         out_verify = 1;
 272                         goto next_arg;
 273                 } else if(strcmp(*argv, "-v_peer") == 0) {
 274                         verify_mode |= SSL_VERIFY_PEER;
 275                         goto next_arg;
 276                 } else if(strcmp(*argv, "-v_strict") == 0) {
 277                         verify_mode |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
 278                         goto next_arg;
 279                 } else if(strcmp(*argv, "-v_once") == 0) {
 280                         verify_mode |= SSL_VERIFY_CLIENT_ONCE;
 281                         goto next_arg;
 282                 } else if((strcmp(*argv, "-h") == 0) ||
 283                                 (strcmp(*argv, "-help") == 0) ||
 284                                 (strcmp(*argv, "-?") == 0)) {
 285                         fprintf(stderr, "%s\n", helpstring);
 286                         return 0;
 287                 } else
 288                         return usage(*argv, 1);
 289         }
 290
 291         /* Initialise network stuff */
 292         if(!ip_initialise())
 293                 return err_str0("ip_initialise failed");
 294         err_str0("ip_initialise succeeded");
 295         /* Create the SSL_CTX */
 296         if((world.ssl_ctx = initialise_ssl_ctx(server_mode, engine_id,
 297                         cacert, cert, key, cipher_list, out_state, out_verify,
 298                         verify_mode)) == NULL)
 299                 return err_str1("initialise_ssl_ctx(engine_id=%s) failed",
 300                         (engine_id == NULL) ? "NULL" : engine_id);
 301         err_str1("initialise_ssl_ctx(engine_id=%s) succeeded",
 302                         (engine_id == NULL) ? "NULL" : engine_id);
 303         /* Create the listener */
 304         if((world.listen_fd = ip_create_listener(listenhost)) == -1)
 305                 return err_str1("ip_create_listener(%s) failed", listenhost);
 306         err_str1("ip_create_listener(%s) succeeded", listenhost);
 307         if(!ip_parse_address(proxyhost, &proxy_ip, &proxy_port, 0))
 308                 return err_str1("ip_parse_address(%s) failed", proxyhost);
 309         err_str1("ip_parse_address(%s) succeeded", proxyhost);
 310         fprintf(stderr, "Info - proxying to %d.%d.%d.%d:%d\n",
 311                         (int)proxy_ip[0], (int)proxy_ip[1],
 312                         (int)proxy_ip[2], (int)proxy_ip[3], (int)proxy_port);
 313         fprintf(stderr, "Info - set maxtunnels to %d\n", (int)max_tunnels);
 314         fprintf(stderr, "Info - set to operate as an SSL %s\n",
 315                         (server_mode ? "server" : "client"));
 316         /* Initialise the rest of the stuff */
 317         world.tunnels_used = world.tunnels_size = 0;
 318         world.tunnels = NULL;
 319         world.server_mode = server_mode;
 320         selector_init(&world.selector);
 321
 322 /* We're ready to loop */
 323 main_loop:
 324         /* Should we listen for *new* tunnels? */
 325         if(world.tunnels_used < max_tunnels)
 326                 selector_add_listener(&world.selector, world.listen_fd);
 327         /* We should add in our existing tunnels */
 328         for(loop = 0; loop < world.tunnels_used; loop++)
 329                 selector_add_tunala(&world.selector, world.tunnels + loop);
 330         /* Now do the select */
 331         switch(selector_select(&world.selector)) {
 332         case -1:
 333                 fprintf(stderr, "selector_select returned a badness error.\n");
 334                 abort();
 335         case 0:
 336                 fprintf(stderr, "Warn, selector_select returned 0 - signal??\n");
 337                 goto main_loop;
 338         default:
 339                 break;
 340         }
 341         /* Accept new connection if we should and can */
 342         if((world.tunnels_used < max_tunnels) && (selector_get_listener(
 343                                         &world.selector, world.listen_fd,
 344                                         &newfd) == 1)) {
 345                 /* We have a new connection */
 346                 if(!tunala_world_new_item(&world, newfd,
 347                                         proxy_ip, proxy_port))
 348                         fprintf(stderr, "tunala_world_new_item failed\n");
 349                 else
 350                         fprintf(stderr, "Info, new tunnel opened, now up to "
 351                                         "%d\n", world.tunnels_used);
 352         }
 353         /* Give each tunnel its moment, note the while loop is because it makes
 354          * the logic easier than with "for" to deal with an array that may shift
 355          * because of deletes. */
 356         loop = 0;
 357         t_item = world.tunnels;
 358         while(loop < world.tunnels_used) {
 359                 if(!tunala_item_io(&world.selector, t_item)) {
 360                         /* We're closing whether for reasons of an error or a
 361                          * natural close. Don't increment loop or t_item because
 362                          * the next item is moving to us! */
 363                         tunala_world_del_item(&world, loop);
 364                         fprintf(stderr, "Info, tunnel closed, down to %d\n",
 365                                         world.tunnels_used);
 366                 }
 367                 else {
 368                         /* Move to the next item */
 369                         loop++;
 370                         t_item++;
 371                 }
 372         }
 373         goto main_loop;
 374         /* Should never get here */
 375         abort();
 376         return 1;
 377 }
 378
 379 /****************/
 380 /* OpenSSL bits */
 381 /****************/
 382
 383 static SSL_CTX *initialise_ssl_ctx(int server_mode, const char *engine_id,
 384                 const char *CAfile, const char *cert, const char *key,
 385                 const char *cipher_list, int out_state, int out_verify,
 386                 int verify_mode)
 387 {
 388         SSL_CTX *ctx, *ret = NULL;
 389         SSL_METHOD *meth;
 390         ENGINE *e = NULL;
 391         FILE *fp = NULL;
 392         X509 *x509 = NULL;
 393         EVP_PKEY *pkey = NULL;
 394
 395         OpenSSL_add_ssl_algorithms();
 396         SSL_load_error_strings();
 397
 398         meth = (server_mode ? SSLv23_server_method() : SSLv23_client_method());
 399         if(meth == NULL)
 400                 goto err;
 401         if(engine_id) {
 402                 if((e = ENGINE_by_id(engine_id)) == NULL) {
 403                         fprintf(stderr, "Error obtaining '%s' engine, openssl "
 404                                         "errors follow\n", engine_id);
 405                         goto err;
 406                 }
 407                 if(!ENGINE_set_default(e, ENGINE_METHOD_ALL)) {
 408                         fprintf(stderr, "Error assigning '%s' engine, openssl "
 409                                         "errors follow\n", engine_id);
 410                         goto err;
 411                 }
 412                 ENGINE_free(e);
 413         }
 414         if((ctx = SSL_CTX_new(meth)) == NULL)
 415                 goto err;
 416         /* cacert */
 417         if(CAfile) {
 418                 if(!X509_STORE_load_locations(SSL_CTX_get_cert_store(ctx),
 419                                         CAfile, NULL)) {
 420                         fprintf(stderr, "Error loading CA cert(s) in '%s'\n",
 421                                         CAfile);
 422                         goto err;
 423                 }
 424                 fprintf(stderr, "Info, operating with CA cert(s) in '%s'\n",
 425                                 CAfile);
 426         } else
 427                 fprintf(stderr, "Info, operating without a CA cert(-list)\n");
 428         if(!SSL_CTX_set_default_verify_paths(ctx)) {
 429                 fprintf(stderr, "Error setting default verify paths\n");
 430                 goto err;
 431         }
 432         /* cert */
 433         if(cert) {
 434                 if((fp = fopen(cert, "r")) == NULL) {
 435                         fprintf(stderr, "Error opening cert file '%s'\n", cert);
 436                         goto err;
 437                 }
 438                 if(!PEM_read_X509(fp, &x509, NULL, NULL)) {
 439                         fprintf(stderr, "Error reading PEM cert from '%s'\n",
 440                                         cert);
 441                         goto err;
 442                 }
 443                 if(!SSL_CTX_use_certificate(ctx, x509)) {
 444                         fprintf(stderr, "Error, cert in '%s' can not be used\n",
 445                                         cert);
 446                         goto err;
 447                 }
 448                 fprintf(stderr, "Info, operating with cert in '%s'\n", cert);
 449                 fclose(fp);
 450                 fp = NULL;
 451                 /* If a cert was given without matching key, we assume the same
 452                  * file contains the required key. */
 453                 if(!key)
 454                         key = cert;
 455         } else
 456                 if(key) {
 457                         fprintf(stderr, "Error, can't specify a key without a "
 458                                         "corresponding certificate\n");
 459                         goto err;
 460                 }
 461         /* key */
 462         if(key) {
 463                 if((fp = fopen(key, "r")) == NULL) {
 464                         fprintf(stderr, "Error opening key file '%s'\n", key);
 465                         goto err;
 466                 }
 467                 if(!PEM_read_PrivateKey(fp, &pkey, NULL, NULL)) {
 468                         fprintf(stderr, "Error reading PEM key from '%s'\n",
 469                                         key);
 470                         goto err;
 471                 }
 472                 if(!SSL_CTX_use_PrivateKey(ctx, pkey)) {
 473                         fprintf(stderr, "Error, key in '%s' can not be used\n",
 474                                         key);
 475                         goto err;
 476                 }
 477                 fprintf(stderr, "Info, operating with key in '%s'\n", key);
 478         } else
 479                 fprintf(stderr, "Info, operating without a cert or key\n");
 480
 481         /* cipher_list */
 482         if(cipher_list) {
 483                 if(!SSL_CTX_set_cipher_list(ctx, cipher_list)) {
 484                         fprintf(stderr, "Error setting cipher list '%s'\n",
 485                                         cipher_list);
 486                         goto err;
 487                 }
 488                 fprintf(stderr, "Info, set cipher list '%s'\n", cipher_list);
 489         } else
 490                 fprintf(stderr, "Info, operating with default cipher list\n");
 491
 492         /* out_state (output of SSL handshake states to screen). */
 493         if(out_state)
 494                 cb_ssl_info_set_output(stderr);
 495
 496         /* out_verify & verify_mode */
 497         if(out_verify)
 498                 cb_ssl_verify_set_output(stderr);
 499
 500         /* Success! */
 501         SSL_CTX_set_info_callback(ctx, cb_ssl_info);
 502         SSL_CTX_set_verify(ctx, verify_mode, cb_ssl_verify);
 503         ret = ctx;
 504 err:
 505         if(!ret) {
 506                 ERR_print_errors_fp(stderr);
 507                 if(ctx)
 508                         SSL_CTX_free(ctx);
 509         }
 510         if(fp)
 511                 fclose(fp);
 512         if(x509)
 513                 X509_free(x509);
 514         if(pkey)
 515                 EVP_PKEY_free(pkey);
 516         return ret;
 517 }
 518
 519 /*****************/
 520 /* Selector bits */
 521 /*****************/
 522
 523 static void selector_sets_init(select_sets_t *s)
 524 {
 525         s->max = 0;
 526         FD_ZERO(&s->reads);
 527         FD_ZERO(&s->sends);
 528         FD_ZERO(&s->excepts);
 529 }
 530 static void selector_init(tunala_selector_t *selector)
 531 {
 532         selector_sets_init(&selector->last_selected);
 533         selector_sets_init(&selector->next_select);
 534 }
 535
 536 #define SEL_EXCEPTS 0x00
 537 #define SEL_READS   0x01
 538 #define SEL_SENDS   0x02
 539 static void selector_add_raw_fd(tunala_selector_t *s, int fd, int flags)
 540 {
 541         FD_SET(fd, &s->next_select.excepts);
 542         if(flags & SEL_READS)
 543                 FD_SET(fd, &s->next_select.reads);
 544         if(flags & SEL_SENDS)
 545                 FD_SET(fd, &s->next_select.sends);
 546         /* Adjust "max" */
 547         if(s->next_select.max < (fd + 1))
 548                 s->next_select.max = fd + 1;
 549 }
 550
 551 static void selector_add_listener(tunala_selector_t *selector, int fd)
 552 {
 553         selector_add_raw_fd(selector, fd, SEL_READS);
 554 }
 555
 556 static void selector_add_tunala(tunala_selector_t *s, tunala_item_t *t)
 557 {
 558         /* Set clean read if sm.clean_in is not full */
 559         if(t->clean_read != -1) {
 560                 selector_add_raw_fd(s, t->clean_read,
 561                         (buffer_full(state_machine_get_buffer(&t->sm,
 562                                 SM_CLEAN_IN)) ? SEL_EXCEPTS : SEL_READS));
 563         }
 564         /* Set clean send if sm.clean_out is not empty */
 565         if(t->clean_send != -1) {
 566                 selector_add_raw_fd(s, t->clean_send,
 567                         (buffer_empty(state_machine_get_buffer(&t->sm,
 568                                 SM_CLEAN_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
 569         }
 570         /* Set dirty read if sm.dirty_in is not full */
 571         if(t->dirty_read != -1) {
 572                 selector_add_raw_fd(s, t->dirty_read,
 573                         (buffer_full(state_machine_get_buffer(&t->sm,
 574                                 SM_DIRTY_IN)) ? SEL_EXCEPTS : SEL_READS));
 575         }
 576         /* Set dirty send if sm.dirty_out is not empty */
 577         if(t->dirty_send != -1) {
 578                 selector_add_raw_fd(s, t->dirty_send,
 579                         (buffer_empty(state_machine_get_buffer(&t->sm,
 580                                 SM_DIRTY_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
 581         }
 582 }
 583
 584 static int selector_select(tunala_selector_t *selector)
 585 {
 586         memcpy(&selector->last_selected, &selector->next_select,
 587                         sizeof(select_sets_t));
 588         selector_sets_init(&selector->next_select);
 589         return select(selector->last_selected.max,
 590                         &selector->last_selected.reads,
 591                         &selector->last_selected.sends,
 592                         &selector->last_selected.excepts, NULL);
 593 }
 594
 595 /* This returns -1 for error, 0 for no new connections, or 1 for success, in
 596  * which case *newfd is populated. */
 597 static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd)
 598 {
 599         if(FD_ISSET(fd, &selector->last_selected.excepts))
 600                 return -1;
 601         if(!FD_ISSET(fd, &selector->last_selected.reads))
 602                 return 0;
 603         if((*newfd = ip_accept_connection(fd)) == -1)
 604                 return -1;
 605         return 1;
 606 }
 607
 608 /************************/
 609 /* "Tunala" world stuff */
 610 /************************/
 611
 612 static int tunala_world_make_room(tunala_world_t *world)
 613 {
 614         unsigned int newsize;
 615         tunala_item_t *newarray;
 616
 617         if(world->tunnels_used < world->tunnels_size)
 618                 return 1;
 619         newsize = (world->tunnels_size == 0 ? 16 :
 620                         ((world->tunnels_size * 3) / 2));
 621         if((newarray = malloc(newsize * sizeof(tunala_item_t))) == NULL)
 622                 return 0;
 623         memset(newarray, 0, newsize * sizeof(tunala_item_t));
 624         if(world->tunnels_used > 0)
 625                 memcpy(newarray, world->tunnels,
 626                         world->tunnels_used * sizeof(tunala_item_t));
 627         if(world->tunnels_size > 0)
 628                 free(world->tunnels);
 629         /* migrate */
 630         world->tunnels = newarray;
 631         world->tunnels_size = newsize;
 632         return 1;
 633 }
 634
 635 static int tunala_world_new_item(tunala_world_t *world, int fd,
 636                 const unsigned char *ip, unsigned short port)
 637 {
 638         tunala_item_t *item;
 639         int newfd;
 640         SSL *new_ssl = NULL;
 641
 642         if(!tunala_world_make_room(world))
 643                 return 0;
 644         if((new_ssl = SSL_new(world->ssl_ctx)) == NULL) {
 645                 fprintf(stderr, "Error creating new SSL\n");
 646                 ERR_print_errors_fp(stderr);
 647                 return 0;
 648         }
 649         item = world->tunnels + (world->tunnels_used++);
 650         state_machine_init(&item->sm);
 651         item->clean_read = item->clean_send =
 652                 item->dirty_read = item->dirty_send = -1;
 653         if((newfd = ip_create_connection_split(ip, port)) == -1)
 654                 goto err;
 655         /* Which way round? If we're a server, "fd" is the dirty side and the
 656          * connection we open is the clean one. For a client, it's the other way
 657          * around. */
 658         if(world->server_mode) {
 659                 item->dirty_read = item->dirty_send = fd;
 660                 item->clean_read = item->clean_send = newfd;
 661         } else {
 662                 item->clean_read = item->clean_send = fd;
 663                 item->dirty_read = item->dirty_send = newfd;
 664         }
 665         /* We use the SSL's "app_data" to indicate a call-back induced "kill" */
 666         SSL_set_app_data(new_ssl, NULL);
 667         if(!state_machine_set_SSL(&item->sm, new_ssl, world->server_mode))
 668                 goto err;
 669         return 1;
 670 err:
 671         tunala_world_del_item(world, world->tunnels_used - 1);
 672         return 0;
 673
 674 }
 675
 676 static void tunala_world_del_item(tunala_world_t *world, unsigned int idx)
 677 {
 678         tunala_item_t *item = world->tunnels + idx;
 679         if(item->clean_read != -1)
 680                 close(item->clean_read);
 681         if(item->clean_send != item->clean_read)
 682                 close(item->clean_send);
 683         item->clean_read = item->clean_send = -1;
 684         if(item->dirty_read != -1)
 685                 close(item->dirty_read);
 686         if(item->dirty_send != item->dirty_read)
 687                 close(item->dirty_send);
 688         item->dirty_read = item->dirty_send = -1;
 689         state_machine_close(&item->sm);
 690         /* OK, now we fix the item array */
 691         if(idx + 1 < world->tunnels_used)
 692                 /* We need to scroll entries to the left */
 693                 memmove(world->tunnels + idx,
 694                                 world->tunnels + (idx + 1),
 695                                 (world->tunnels_used - (idx + 1)) *
 696                                         sizeof(tunala_item_t));
 697         world->tunnels_used--;
 698 }
 699
 700 static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item)
 701 {
 702         int c_r, c_s, d_r, d_s; /* Four boolean flags */
 703
 704         /* Take ourselves out of the gene-pool if there was an except */
 705         if((item->clean_read != -1) && FD_ISSET(item->clean_read,
 706                                 &selector->last_selected.excepts))
 707                 return 0;
 708         if((item->clean_send != -1) && FD_ISSET(item->clean_send,
 709                                 &selector->last_selected.excepts))
 710                 return 0;
 711         if((item->dirty_read != -1) && FD_ISSET(item->dirty_read,
 712                                 &selector->last_selected.excepts))
 713                 return 0;
 714         if((item->dirty_send != -1) && FD_ISSET(item->dirty_send,
 715                                 &selector->last_selected.excepts))
 716                 return 0;
 717         /* Grab our 4 IO flags */
 718         c_r = c_s = d_r = d_s = 0;
 719         if(item->clean_read != -1)
 720                 c_r = FD_ISSET(item->clean_read, &selector->last_selected.reads);
 721         if(item->clean_send != -1)
 722                 c_s = FD_ISSET(item->clean_send, &selector->last_selected.sends);
 723         if(item->dirty_read != -1)
 724                 d_r = FD_ISSET(item->dirty_read, &selector->last_selected.reads);
 725         if(item->dirty_send != -1)
 726                 d_s = FD_ISSET(item->dirty_send, &selector->last_selected.sends);
 727         /* If no IO has happened for us, skip needless data looping */
 728         if(!c_r && !c_s && !d_r && !d_s)
 729                 return 1;
 730         if(c_r)
 731                 c_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
 732                                 SM_CLEAN_IN), item->clean_read) <= 0);
 733         if(c_s)
 734                 c_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
 735                                 SM_CLEAN_OUT), item->clean_send) <= 0);
 736         if(d_r)
 737                 d_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
 738                                 SM_DIRTY_IN), item->dirty_read) <= 0);
 739         if(d_s)
 740                 d_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
 741                                 SM_DIRTY_OUT), item->dirty_send) <= 0);
 742         /* If any of the flags is non-zero, that means they need closing */
 743         if(c_r) {
 744                 close(item->clean_read);
 745                 if(item->clean_send == item->clean_read)
 746                         item->clean_send = -1;
 747                 item->clean_read = -1;
 748         }
 749         if(c_s && (item->clean_send != -1)) {
 750                 close(item->clean_send);
 751                 if(item->clean_send == item->clean_read)
 752                         item->clean_read = -1;
 753                 item->clean_send = -1;
 754         }
 755         if(d_r) {
 756                 close(item->dirty_read);
 757                 if(item->dirty_send == item->dirty_read)
 758                         item->dirty_send = -1;
 759                 item->dirty_read = -1;
 760         }
 761         if(d_s && (item->dirty_send != -1)) {
 762                 close(item->dirty_send);
 763                 if(item->dirty_send == item->dirty_read)
 764                         item->dirty_read = -1;
 765                 item->dirty_send = -1;
 766         }
 767         /* This function name is attributed to the term donated by David
 768          * Schwartz on openssl-dev, message-ID:
 769          * <NCBBLIEPOCNJOAEKBEAKEEDGLIAA.davids@webmaster.com>. :-) */
 770         if(!state_machine_churn(&item->sm))
 771                 /* If the SSL closes, it will also zero-out the _in buffers
 772                  * and will in future process just outgoing data. As and
 773                  * when the outgoing data has gone, it will return zero
 774                  * here to tell us to bail out. */
 775                 return 0;
 776         /* Otherwise, we return zero if both sides are dead. */
 777         if(((item->clean_read == -1) || (item->clean_send == -1)) &&
 778                         ((item->dirty_read == -1) || (item->dirty_send == -1)))
 779                 return 0;
 780         /* If only one side closed, notify the SSL of this so it can take
 781          * appropriate action. */
 782         if((item->clean_read == -1) || (item->clean_send == -1)) {
 783                 if(!state_machine_close_clean(&item->sm))
 784                         return 0;
 785         }
 786         if((item->dirty_read == -1) || (item->dirty_send == -1)) {
 787                 if(state_machine_close_dirty(&item->sm))
 788                         return 0;
 789         }
 790         return 1;
 791 }
 792