crypto/bio/bss_acpt.c

   1 /*
   2  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdio.h>
  11 #include <errno.h>
  12 #include "bio_lcl.h"
  13
  14 #ifndef OPENSSL_NO_SOCK
  15
  16 typedef struct bio_accept_st {
  17     int state;
  18     int accept_family;
  19     int bind_mode;     /* Socket mode for BIO_listen */
  20     int accepted_mode; /* Socket mode for BIO_accept (set on accepted sock) */
  21     char *param_addr;
  22     char *param_serv;
  23
  24     int accept_sock;
  25
  26     BIO_ADDRINFO *addr_first;
  27     const BIO_ADDRINFO *addr_iter;
  28     BIO_ADDR cache_accepting_addr;   /* Useful if we asked for port 0 */
  29     char *cache_accepting_name, *cache_accepting_serv;
  30     BIO_ADDR cache_peer_addr;
  31     char *cache_peer_name, *cache_peer_serv;
  32
  33     BIO *bio_chain;
  34 } BIO_ACCEPT;
  35
  36 static int acpt_write(BIO *h, const char *buf, int num);
  37 static int acpt_read(BIO *h, char *buf, int size);
  38 static int acpt_puts(BIO *h, const char *str);
  39 static long acpt_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  40 static int acpt_new(BIO *h);
  41 static int acpt_free(BIO *data);
  42 static int acpt_state(BIO *b, BIO_ACCEPT *c);
  43 static void acpt_close_socket(BIO *data);
  44 static BIO_ACCEPT *BIO_ACCEPT_new(void);
  45 static void BIO_ACCEPT_free(BIO_ACCEPT *a);
  46
  47 # define ACPT_S_BEFORE                   1
  48 # define ACPT_S_GET_ADDR                 2
  49 # define ACPT_S_CREATE_SOCKET            3
  50 # define ACPT_S_LISTEN                   4
  51 # define ACPT_S_ACCEPT                   5
  52 # define ACPT_S_OK                       6
  53
  54 static const BIO_METHOD methods_acceptp = {
  55     BIO_TYPE_ACCEPT,
  56     "socket accept",
  57     /* TODO: Convert to new style write function */
  58     bwrite_conv,
  59     acpt_write,
  60     /* TODO: Convert to new style read function */
  61     bread_conv,
  62     acpt_read,
  63     acpt_puts,
  64     NULL,                       /* connect_gets,         */
  65     acpt_ctrl,
  66     acpt_new,
  67     acpt_free,
  68     NULL,                       /* connect_callback_ctrl */
  69 };
  70
  71 const BIO_METHOD *BIO_s_accept(void)
  72 {
  73     return &methods_acceptp;
  74 }
  75
  76 static int acpt_new(BIO *bi)
  77 {
  78     BIO_ACCEPT *ba;
  79
  80     bi->init = 0;
  81     bi->num = (int)INVALID_SOCKET;
  82     bi->flags = 0;
  83     if ((ba = BIO_ACCEPT_new()) == NULL)
  84         return 0;
  85     bi->ptr = (char *)ba;
  86     ba->state = ACPT_S_BEFORE;
  87     bi->shutdown = 1;
  88     return 1;
  89 }
  90
  91 static BIO_ACCEPT *BIO_ACCEPT_new(void)
  92 {
  93     BIO_ACCEPT *ret;
  94
  95     if ((ret = OPENSSL_zalloc(sizeof(*ret))) == NULL)
  96         return NULL;
  97     ret->accept_family = BIO_FAMILY_IPANY;
  98     ret->accept_sock = (int)INVALID_SOCKET;
  99     return ret;
 100 }
 101
 102 static void BIO_ACCEPT_free(BIO_ACCEPT *a)
 103 {
 104     if (a == NULL)
 105         return;
 106
 107     OPENSSL_free(a->param_addr);
 108     OPENSSL_free(a->param_serv);
 109     BIO_ADDRINFO_free(a->addr_first);
 110     OPENSSL_free(a->cache_accepting_name);
 111     OPENSSL_free(a->cache_accepting_serv);
 112     OPENSSL_free(a->cache_peer_name);
 113     OPENSSL_free(a->cache_peer_serv);
 114     BIO_free(a->bio_chain);
 115     OPENSSL_free(a);
 116 }
 117
 118 static void acpt_close_socket(BIO *bio)
 119 {
 120     BIO_ACCEPT *c;
 121
 122     c = (BIO_ACCEPT *)bio->ptr;
 123     if (c->accept_sock != (int)INVALID_SOCKET) {
 124         shutdown(c->accept_sock, 2);
 125         closesocket(c->accept_sock);
 126         c->accept_sock = (int)INVALID_SOCKET;
 127         bio->num = (int)INVALID_SOCKET;
 128     }
 129 }
 130
 131 static int acpt_free(BIO *a)
 132 {
 133     BIO_ACCEPT *data;
 134
 135     if (a == NULL)
 136         return 0;
 137     data = (BIO_ACCEPT *)a->ptr;
 138
 139     if (a->shutdown) {
 140         acpt_close_socket(a);
 141         BIO_ACCEPT_free(data);
 142         a->ptr = NULL;
 143         a->flags = 0;
 144         a->init = 0;
 145     }
 146     return 1;
 147 }
 148
 149 static int acpt_state(BIO *b, BIO_ACCEPT *c)
 150 {
 151     BIO *bio = NULL, *dbio;
 152     int s = -1, ret = -1;
 153
 154     for (;;) {
 155         switch (c->state) {
 156         case ACPT_S_BEFORE:
 157             if (c->param_addr == NULL && c->param_serv == NULL) {
 158                 BIOerr(BIO_F_ACPT_STATE, BIO_R_NO_ACCEPT_ADDR_OR_SERVICE_SPECIFIED);
 159                 ERR_add_error_data(4,
 160                                    "hostname=", c->param_addr,
 161                                    " service=", c->param_serv);
 162                 goto exit_loop;
 163             }
 164
 165             /* Because we're starting a new bind, any cached name and serv
 166              * are now obsolete and need to be cleaned out.
 167              * QUESTION: should this be done in acpt_close_socket() instead?
 168              */
 169             OPENSSL_free(c->cache_accepting_name);
 170             c->cache_accepting_name = NULL;
 171             OPENSSL_free(c->cache_accepting_serv);
 172             c->cache_accepting_serv = NULL;
 173             OPENSSL_free(c->cache_peer_name);
 174             c->cache_peer_name = NULL;
 175             OPENSSL_free(c->cache_peer_serv);
 176             c->cache_peer_serv = NULL;
 177
 178             c->state = ACPT_S_GET_ADDR;
 179             break;
 180
 181         case ACPT_S_GET_ADDR:
 182             {
 183                 int family = AF_UNSPEC;
 184                 switch (c->accept_family) {
 185                 case BIO_FAMILY_IPV6:
 186                     if (1) { /* This is a trick we use to avoid bit rot.
 187                               * at least the "else" part will always be
 188                               * compiled.
 189                               */
 190 #ifdef AF_INET6
 191                         family = AF_INET6;
 192                     } else {
 193 #endif
 194                         BIOerr(BIO_F_ACPT_STATE, BIO_R_UNAVAILABLE_IP_FAMILY);
 195                         goto exit_loop;
 196                     }
 197                     break;
 198                 case BIO_FAMILY_IPV4:
 199                     family = AF_INET;
 200                     break;
 201                 case BIO_FAMILY_IPANY:
 202                     family = AF_UNSPEC;
 203                     break;
 204                 default:
 205                     BIOerr(BIO_F_ACPT_STATE, BIO_R_UNSUPPORTED_IP_FAMILY);
 206                     goto exit_loop;
 207                 }
 208                 if (BIO_lookup(c->param_addr, c->param_serv, BIO_LOOKUP_SERVER,
 209                                family, SOCK_STREAM, &c->addr_first) == 0)
 210                     goto exit_loop;
 211             }
 212             if (c->addr_first == NULL) {
 213                 BIOerr(BIO_F_ACPT_STATE, BIO_R_LOOKUP_RETURNED_NOTHING);
 214                 goto exit_loop;
 215             }
 216             /* We're currently not iterating, but set this as preparation
 217              * for possible future development in that regard
 218              */
 219             c->addr_iter = c->addr_first;
 220             c->state = ACPT_S_CREATE_SOCKET;
 221             break;
 222
 223         case ACPT_S_CREATE_SOCKET:
 224             ret = BIO_socket(BIO_ADDRINFO_family(c->addr_iter),
 225                              BIO_ADDRINFO_socktype(c->addr_iter),
 226                              BIO_ADDRINFO_protocol(c->addr_iter), 0);
 227             if (ret == (int)INVALID_SOCKET) {
 228                 SYSerr(SYS_F_SOCKET, get_last_socket_error());
 229                 ERR_add_error_data(4,
 230                                    "hostname=", c->param_addr,
 231                                    " service=", c->param_serv);
 232                 BIOerr(BIO_F_ACPT_STATE, BIO_R_UNABLE_TO_CREATE_SOCKET);
 233                 goto exit_loop;
 234             }
 235             c->accept_sock = ret;
 236             b->num = ret;
 237             c->state = ACPT_S_LISTEN;
 238             break;
 239
 240         case ACPT_S_LISTEN:
 241             {
 242                 if (!BIO_listen(c->accept_sock,
 243                                 BIO_ADDRINFO_address(c->addr_iter),
 244                                 c->bind_mode)) {
 245                     BIO_closesocket(c->accept_sock);
 246                     goto exit_loop;
 247                 }
 248             }
 249
 250             {
 251                 union BIO_sock_info_u info;
 252
 253                 info.addr = &c->cache_accepting_addr;
 254                 if (!BIO_sock_info(c->accept_sock, BIO_SOCK_INFO_ADDRESS,
 255                                    &info)) {
 256                     BIO_closesocket(c->accept_sock);
 257                     goto exit_loop;
 258                 }
 259             }
 260
 261             c->cache_accepting_name =
 262                 BIO_ADDR_hostname_string(&c->cache_accepting_addr, 1);
 263             c->cache_accepting_serv =
 264                 BIO_ADDR_service_string(&c->cache_accepting_addr, 1);
 265             c->state = ACPT_S_ACCEPT;
 266             s = -1;
 267             ret = 1;
 268             goto end;
 269
 270         case ACPT_S_ACCEPT:
 271             if (b->next_bio != NULL) {
 272                 c->state = ACPT_S_OK;
 273                 break;
 274             }
 275             BIO_clear_retry_flags(b);
 276             b->retry_reason = 0;
 277
 278             OPENSSL_free(c->cache_peer_name);
 279             c->cache_peer_name = NULL;
 280             OPENSSL_free(c->cache_peer_serv);
 281             c->cache_peer_serv = NULL;
 282
 283             s = BIO_accept_ex(c->accept_sock, &c->cache_peer_addr,
 284                               c->accepted_mode);
 285
 286             /* If the returned socket is invalid, this might still be
 287              * retryable
 288              */
 289             if (s < 0) {
 290                 if (BIO_sock_should_retry(s)) {
 291                     BIO_set_retry_special(b);
 292                     b->retry_reason = BIO_RR_ACCEPT;
 293                     goto end;
 294                 }
 295             }
 296
 297             /* If it wasn't retryable, we fail */
 298             if (s < 0) {
 299                 ret = s;
 300                 goto exit_loop;
 301             }
 302
 303             bio = BIO_new_socket(s, BIO_CLOSE);
 304             if (bio == NULL)
 305                 goto exit_loop;
 306
 307             BIO_set_callback(bio, BIO_get_callback(b));
 308             BIO_set_callback_arg(bio, BIO_get_callback_arg(b));
 309
 310             /*
 311              * If the accept BIO has an bio_chain, we dup it and put the new
 312              * socket at the end.
 313              */
 314             if (c->bio_chain != NULL) {
 315                 if ((dbio = BIO_dup_chain(c->bio_chain)) == NULL)
 316                     goto exit_loop;
 317                 if (!BIO_push(dbio, bio))
 318                     goto exit_loop;
 319                 bio = dbio;
 320             }
 321             if (BIO_push(b, bio) == NULL)
 322                 goto exit_loop;
 323
 324             c->cache_peer_name =
 325                 BIO_ADDR_hostname_string(&c->cache_peer_addr, 1);
 326             c->cache_peer_serv =
 327                 BIO_ADDR_service_string(&c->cache_peer_addr, 1);
 328             c->state = ACPT_S_OK;
 329             bio = NULL;
 330             ret = 1;
 331             goto end;
 332
 333         case ACPT_S_OK:
 334             if (b->next_bio == NULL) {
 335                 c->state = ACPT_S_ACCEPT;
 336                 break;
 337             }
 338             ret = 1;
 339             goto end;
 340
 341         default:
 342             ret = 0;
 343             goto end;
 344         }
 345     }
 346
 347   exit_loop:
 348     if (bio != NULL)
 349         BIO_free(bio);
 350     else if (s >= 0)
 351         BIO_closesocket(s);
 352   end:
 353     return ret;
 354 }
 355
 356 static int acpt_read(BIO *b, char *out, int outl)
 357 {
 358     int ret = 0;
 359     BIO_ACCEPT *data;
 360
 361     BIO_clear_retry_flags(b);
 362     data = (BIO_ACCEPT *)b->ptr;
 363
 364     while (b->next_bio == NULL) {
 365         ret = acpt_state(b, data);
 366         if (ret <= 0)
 367             return ret;
 368     }
 369
 370     ret = BIO_read(b->next_bio, out, outl);
 371     BIO_copy_next_retry(b);
 372     return ret;
 373 }
 374
 375 static int acpt_write(BIO *b, const char *in, int inl)
 376 {
 377     int ret;
 378     BIO_ACCEPT *data;
 379
 380     BIO_clear_retry_flags(b);
 381     data = (BIO_ACCEPT *)b->ptr;
 382
 383     while (b->next_bio == NULL) {
 384         ret = acpt_state(b, data);
 385         if (ret <= 0)
 386             return ret;
 387     }
 388
 389     ret = BIO_write(b->next_bio, in, inl);
 390     BIO_copy_next_retry(b);
 391     return ret;
 392 }
 393
 394 static long acpt_ctrl(BIO *b, int cmd, long num, void *ptr)
 395 {
 396     int *ip;
 397     long ret = 1;
 398     BIO_ACCEPT *data;
 399     char **pp;
 400
 401     data = (BIO_ACCEPT *)b->ptr;
 402
 403     switch (cmd) {
 404     case BIO_CTRL_RESET:
 405         ret = 0;
 406         data->state = ACPT_S_BEFORE;
 407         acpt_close_socket(b);
 408         BIO_ADDRINFO_free(data->addr_first);
 409         data->addr_first = NULL;
 410         b->flags = 0;
 411         break;
 412     case BIO_C_DO_STATE_MACHINE:
 413         /* use this one to start the connection */
 414         ret = (long)acpt_state(b, data);
 415         break;
 416     case BIO_C_SET_ACCEPT:
 417         if (ptr != NULL) {
 418             if (num == 0) {
 419                 char *hold_serv = data->param_serv;
 420                 /* We affect the hostname regardless.  However, the input
 421                  * string might contain a host:service spec, so we must
 422                  * parse it, which might or might not affect the service
 423                  */
 424                 OPENSSL_free(data->param_addr);
 425                 data->param_addr = NULL;
 426                 ret = BIO_parse_hostserv(ptr,
 427                                          &data->param_addr,
 428                                          &data->param_serv,
 429                                          BIO_PARSE_PRIO_SERV);
 430                 if (hold_serv != data->param_serv)
 431                     OPENSSL_free(hold_serv);
 432                 b->init = 1;
 433             } else if (num == 1) {
 434                 OPENSSL_free(data->param_serv);
 435                 data->param_serv = BUF_strdup(ptr);
 436                 b->init = 1;
 437             } else if (num == 2) {
 438                 data->bind_mode |= BIO_SOCK_NONBLOCK;
 439             } else if (num == 3) {
 440                 BIO_free(data->bio_chain);
 441                 data->bio_chain = (BIO *)ptr;
 442             } else if (num == 4) {
 443                 data->accept_family = *(int *)ptr;
 444             }
 445         } else {
 446             if (num == 2) {
 447                 data->bind_mode &= ~BIO_SOCK_NONBLOCK;
 448             }
 449         }
 450         break;
 451     case BIO_C_SET_NBIO:
 452         if (num != 0)
 453             data->accepted_mode |= BIO_SOCK_NONBLOCK;
 454         else
 455             data->accepted_mode &= ~BIO_SOCK_NONBLOCK;
 456         break;
 457     case BIO_C_SET_FD:
 458         b->num = *((int *)ptr);
 459         data->accept_sock = b->num;
 460         data->state = ACPT_S_ACCEPT;
 461         b->shutdown = (int)num;
 462         b->init = 1;
 463         break;
 464     case BIO_C_GET_FD:
 465         if (b->init) {
 466             ip = (int *)ptr;
 467             if (ip != NULL)
 468                 *ip = data->accept_sock;
 469             ret = data->accept_sock;
 470         } else
 471             ret = -1;
 472         break;
 473     case BIO_C_GET_ACCEPT:
 474         if (b->init) {
 475             if (num == 0 && ptr != NULL) {
 476                 pp = (char **)ptr;
 477                 *pp = data->cache_accepting_name;
 478             } else if (num == 1 && ptr != NULL) {
 479                 pp = (char **)ptr;
 480                 *pp = data->cache_accepting_serv;
 481             } else if (num == 2 && ptr != NULL) {
 482                 pp = (char **)ptr;
 483                 *pp = data->cache_peer_name;
 484             } else if (num == 3 && ptr != NULL) {
 485                 pp = (char **)ptr;
 486                 *pp = data->cache_peer_serv;
 487             } else if (num == 4) {
 488                 switch (BIO_ADDRINFO_family(data->addr_iter)) {
 489 #ifdef AF_INET6
 490                 case AF_INET6:
 491                     ret = BIO_FAMILY_IPV6;
 492                     break;
 493 #endif
 494                 case AF_INET:
 495                     ret = BIO_FAMILY_IPV4;
 496                     break;
 497                 case 0:
 498                     ret = data->accept_family;
 499                     break;
 500                 default:
 501                     ret = -1;
 502                     break;
 503                 }
 504             } else
 505                 ret = -1;
 506         } else
 507             ret = -1;
 508         break;
 509     case BIO_CTRL_GET_CLOSE:
 510         ret = b->shutdown;
 511         break;
 512     case BIO_CTRL_SET_CLOSE:
 513         b->shutdown = (int)num;
 514         break;
 515     case BIO_CTRL_PENDING:
 516     case BIO_CTRL_WPENDING:
 517         ret = 0;
 518         break;
 519     case BIO_CTRL_FLUSH:
 520         break;
 521     case BIO_C_SET_BIND_MODE:
 522         data->bind_mode = (int)num;
 523         break;
 524     case BIO_C_GET_BIND_MODE:
 525         ret = (long)data->bind_mode;
 526         break;
 527     case BIO_CTRL_DUP:
 528         break;
 529
 530     default:
 531         ret = 0;
 532         break;
 533     }
 534     return ret;
 535 }
 536
 537 static int acpt_puts(BIO *bp, const char *str)
 538 {
 539     int n, ret;
 540
 541     n = strlen(str);
 542     ret = acpt_write(bp, str, n);
 543     return ret;
 544 }
 545
 546 BIO *BIO_new_accept(const char *str)
 547 {
 548     BIO *ret;
 549
 550     ret = BIO_new(BIO_s_accept());
 551     if (ret == NULL)
 552         return NULL;
 553     if (BIO_set_accept_name(ret, str))
 554         return ret;
 555     BIO_free(ret);
 556     return NULL;
 557 }
 558
 559 #endif