crypto/bio/bss_acpt.c

   1 /*
   2  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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         BIOerr(BIO_F_BIO_ACCEPT_NEW, ERR_R_MALLOC_FAILURE);
  97         return NULL;
  98     }
  99     ret->accept_family = BIO_FAMILY_IPANY;
 100     ret->accept_sock = (int)INVALID_SOCKET;
 101     return ret;
 102 }
 103
 104 static void BIO_ACCEPT_free(BIO_ACCEPT *a)
 105 {
 106     if (a == NULL)
 107         return;
 108     OPENSSL_free(a->param_addr);
 109     OPENSSL_free(a->param_serv);
 110     BIO_ADDRINFO_free(a->addr_first);
 111     OPENSSL_free(a->cache_accepting_name);
 112     OPENSSL_free(a->cache_accepting_serv);
 113     OPENSSL_free(a->cache_peer_name);
 114     OPENSSL_free(a->cache_peer_serv);
 115     BIO_free(a->bio_chain);
 116     OPENSSL_free(a);
 117 }
 118
 119 static void acpt_close_socket(BIO *bio)
 120 {
 121     BIO_ACCEPT *c;
 122
 123     c = (BIO_ACCEPT *)bio->ptr;
 124     if (c->accept_sock != (int)INVALID_SOCKET) {
 125         shutdown(c->accept_sock, 2);
 126         closesocket(c->accept_sock);
 127         c->accept_sock = (int)INVALID_SOCKET;
 128         bio->num = (int)INVALID_SOCKET;
 129     }
 130 }
 131
 132 static int acpt_free(BIO *a)
 133 {
 134     BIO_ACCEPT *data;
 135
 136     if (a == NULL)
 137         return 0;
 138     data = (BIO_ACCEPT *)a->ptr;
 139
 140     if (a->shutdown) {
 141         acpt_close_socket(a);
 142         BIO_ACCEPT_free(data);
 143         a->ptr = NULL;
 144         a->flags = 0;
 145         a->init = 0;
 146     }
 147     return 1;
 148 }
 149
 150 static int acpt_state(BIO *b, BIO_ACCEPT *c)
 151 {
 152     BIO *bio = NULL, *dbio;
 153     int s = -1, ret = -1;
 154
 155     for (;;) {
 156         switch (c->state) {
 157         case ACPT_S_BEFORE:
 158             if (c->param_addr == NULL && c->param_serv == NULL) {
 159                 BIOerr(BIO_F_ACPT_STATE, BIO_R_NO_ACCEPT_ADDR_OR_SERVICE_SPECIFIED);
 160                 ERR_add_error_data(4,
 161                                    "hostname=", c->param_addr,
 162                                    " service=", c->param_serv);
 163                 goto exit_loop;
 164             }
 165
 166             /* Because we're starting a new bind, any cached name and serv
 167              * are now obsolete and need to be cleaned out.
 168              * QUESTION: should this be done in acpt_close_socket() instead?
 169              */
 170             OPENSSL_free(c->cache_accepting_name);
 171             c->cache_accepting_name = NULL;
 172             OPENSSL_free(c->cache_accepting_serv);
 173             c->cache_accepting_serv = NULL;
 174             OPENSSL_free(c->cache_peer_name);
 175             c->cache_peer_name = NULL;
 176             OPENSSL_free(c->cache_peer_serv);
 177             c->cache_peer_serv = NULL;
 178
 179             c->state = ACPT_S_GET_ADDR;
 180             break;
 181
 182         case ACPT_S_GET_ADDR:
 183             {
 184                 int family = AF_UNSPEC;
 185                 switch (c->accept_family) {
 186                 case BIO_FAMILY_IPV6:
 187                     if (1) { /* This is a trick we use to avoid bit rot.
 188                               * at least the "else" part will always be
 189                               * compiled.
 190                               */
 191 #ifdef AF_INET6
 192                         family = AF_INET6;
 193                     } else {
 194 #endif
 195                         BIOerr(BIO_F_ACPT_STATE, BIO_R_UNAVAILABLE_IP_FAMILY);
 196                         goto exit_loop;
 197                     }
 198                     break;
 199                 case BIO_FAMILY_IPV4:
 200                     family = AF_INET;
 201                     break;
 202                 case BIO_FAMILY_IPANY:
 203                     family = AF_UNSPEC;
 204                     break;
 205                 default:
 206                     BIOerr(BIO_F_ACPT_STATE, BIO_R_UNSUPPORTED_IP_FAMILY);
 207                     goto exit_loop;
 208                 }
 209                 if (BIO_lookup(c->param_addr, c->param_serv, BIO_LOOKUP_SERVER,
 210                                family, SOCK_STREAM, &c->addr_first) == 0)
 211                     goto exit_loop;
 212             }
 213             if (c->addr_first == NULL) {
 214                 BIOerr(BIO_F_ACPT_STATE, BIO_R_LOOKUP_RETURNED_NOTHING);
 215                 goto exit_loop;
 216             }
 217             /* We're currently not iterating, but set this as preparation
 218              * for possible future development in that regard
 219              */
 220             c->addr_iter = c->addr_first;
 221             c->state = ACPT_S_CREATE_SOCKET;
 222             break;
 223
 224         case ACPT_S_CREATE_SOCKET:
 225             ret = BIO_socket(BIO_ADDRINFO_family(c->addr_iter),
 226                              BIO_ADDRINFO_socktype(c->addr_iter),
 227                              BIO_ADDRINFO_protocol(c->addr_iter), 0);
 228             if (ret == (int)INVALID_SOCKET) {
 229                 SYSerr("socket", get_last_socket_error());
 230                 ERR_add_error_data(4,
 231                                    "hostname=", c->param_addr,
 232                                    " service=", c->param_serv);
 233                 BIOerr(BIO_F_ACPT_STATE, BIO_R_UNABLE_TO_CREATE_SOCKET);
 234                 goto exit_loop;
 235             }
 236             c->accept_sock = ret;
 237             b->num = ret;
 238             c->state = ACPT_S_LISTEN;
 239             break;
 240
 241         case ACPT_S_LISTEN:
 242             {
 243                 if (!BIO_listen(c->accept_sock,
 244                                 BIO_ADDRINFO_address(c->addr_iter),
 245                                 c->bind_mode)) {
 246                     BIO_closesocket(c->accept_sock);
 247                     goto exit_loop;
 248                 }
 249             }
 250
 251             {
 252                 union BIO_sock_info_u info;
 253
 254                 info.addr = &c->cache_accepting_addr;
 255                 if (!BIO_sock_info(c->accept_sock, BIO_SOCK_INFO_ADDRESS,
 256                                    &info)) {
 257                     BIO_closesocket(c->accept_sock);
 258                     goto exit_loop;
 259                 }
 260             }
 261
 262             c->cache_accepting_name =
 263                 BIO_ADDR_hostname_string(&c->cache_accepting_addr, 1);
 264             c->cache_accepting_serv =
 265                 BIO_ADDR_service_string(&c->cache_accepting_addr, 1);
 266             c->state = ACPT_S_ACCEPT;
 267             s = -1;
 268             ret = 1;
 269             goto end;
 270
 271         case ACPT_S_ACCEPT:
 272             if (b->next_bio != NULL) {
 273                 c->state = ACPT_S_OK;
 274                 break;
 275             }
 276             BIO_clear_retry_flags(b);
 277             b->retry_reason = 0;
 278
 279             OPENSSL_free(c->cache_peer_name);
 280             c->cache_peer_name = NULL;
 281             OPENSSL_free(c->cache_peer_serv);
 282             c->cache_peer_serv = NULL;
 283
 284             s = BIO_accept_ex(c->accept_sock, &c->cache_peer_addr,
 285                               c->accepted_mode);
 286
 287             /* If the returned socket is invalid, this might still be
 288              * retryable
 289              */
 290             if (s < 0) {
 291                 if (BIO_sock_should_retry(s)) {
 292                     BIO_set_retry_special(b);
 293                     b->retry_reason = BIO_RR_ACCEPT;
 294                     goto end;
 295                 }
 296             }
 297
 298             /* If it wasn't retryable, we fail */
 299             if (s < 0) {
 300                 ret = s;
 301                 goto exit_loop;
 302             }
 303
 304             bio = BIO_new_socket(s, BIO_CLOSE);
 305             if (bio == NULL)
 306                 goto exit_loop;
 307
 308             BIO_set_callback(bio, BIO_get_callback(b));
 309             BIO_set_callback_arg(bio, BIO_get_callback_arg(b));
 310
 311             /*
 312              * If the accept BIO has an bio_chain, we dup it and put the new
 313              * socket at the end.
 314              */
 315             if (c->bio_chain != NULL) {
 316                 if ((dbio = BIO_dup_chain(c->bio_chain)) == NULL)
 317                     goto exit_loop;
 318                 if (!BIO_push(dbio, bio))
 319                     goto exit_loop;
 320                 bio = dbio;
 321             }
 322             if (BIO_push(b, bio) == NULL)
 323                 goto exit_loop;
 324
 325             c->cache_peer_name =
 326                 BIO_ADDR_hostname_string(&c->cache_peer_addr, 1);
 327             c->cache_peer_serv =
 328                 BIO_ADDR_service_string(&c->cache_peer_addr, 1);
 329             c->state = ACPT_S_OK;
 330             bio = NULL;
 331             ret = 1;
 332             goto end;
 333
 334         case ACPT_S_OK:
 335             if (b->next_bio == NULL) {
 336                 c->state = ACPT_S_ACCEPT;
 337                 break;
 338             }
 339             ret = 1;
 340             goto end;
 341
 342         default:
 343             ret = 0;
 344             goto end;
 345         }
 346     }
 347
 348   exit_loop:
 349     if (bio != NULL)
 350         BIO_free(bio);
 351     else if (s >= 0)
 352         BIO_closesocket(s);
 353   end:
 354     return ret;
 355 }
 356
 357 static int acpt_read(BIO *b, char *out, int outl)
 358 {
 359     int ret = 0;
 360     BIO_ACCEPT *data;
 361
 362     BIO_clear_retry_flags(b);
 363     data = (BIO_ACCEPT *)b->ptr;
 364
 365     while (b->next_bio == NULL) {
 366         ret = acpt_state(b, data);
 367         if (ret <= 0)
 368             return ret;
 369     }
 370
 371     ret = BIO_read(b->next_bio, out, outl);
 372     BIO_copy_next_retry(b);
 373     return ret;
 374 }
 375
 376 static int acpt_write(BIO *b, const char *in, int inl)
 377 {
 378     int ret;
 379     BIO_ACCEPT *data;
 380
 381     BIO_clear_retry_flags(b);
 382     data = (BIO_ACCEPT *)b->ptr;
 383
 384     while (b->next_bio == NULL) {
 385         ret = acpt_state(b, data);
 386         if (ret <= 0)
 387             return ret;
 388     }
 389
 390     ret = BIO_write(b->next_bio, in, inl);
 391     BIO_copy_next_retry(b);
 392     return ret;
 393 }
 394
 395 static long acpt_ctrl(BIO *b, int cmd, long num, void *ptr)
 396 {
 397     int *ip;
 398     long ret = 1;
 399     BIO_ACCEPT *data;
 400     char **pp;
 401
 402     data = (BIO_ACCEPT *)b->ptr;
 403
 404     switch (cmd) {
 405     case BIO_CTRL_RESET:
 406         ret = 0;
 407         data->state = ACPT_S_BEFORE;
 408         acpt_close_socket(b);
 409         BIO_ADDRINFO_free(data->addr_first);
 410         data->addr_first = NULL;
 411         b->flags = 0;
 412         break;
 413     case BIO_C_DO_STATE_MACHINE:
 414         /* use this one to start the connection */
 415         ret = (long)acpt_state(b, data);
 416         break;
 417     case BIO_C_SET_ACCEPT:
 418         if (ptr != NULL) {
 419             if (num == 0) {
 420                 char *hold_serv = data->param_serv;
 421                 /* We affect the hostname regardless.  However, the input
 422                  * string might contain a host:service spec, so we must
 423                  * parse it, which might or might not affect the service
 424                  */
 425                 OPENSSL_free(data->param_addr);
 426                 data->param_addr = NULL;
 427                 ret = BIO_parse_hostserv(ptr,
 428                                          &data->param_addr,
 429                                          &data->param_serv,
 430                                          BIO_PARSE_PRIO_SERV);
 431                 if (hold_serv != data->param_serv)
 432                     OPENSSL_free(hold_serv);
 433                 b->init = 1;
 434             } else if (num == 1) {
 435                 OPENSSL_free(data->param_serv);
 436                 data->param_serv = BUF_strdup(ptr);
 437                 b->init = 1;
 438             } else if (num == 2) {
 439                 data->bind_mode |= BIO_SOCK_NONBLOCK;
 440             } else if (num == 3) {
 441                 BIO_free(data->bio_chain);
 442                 data->bio_chain = (BIO *)ptr;
 443             } else if (num == 4) {
 444                 data->accept_family = *(int *)ptr;
 445             }
 446         } else {
 447             if (num == 2) {
 448                 data->bind_mode &= ~BIO_SOCK_NONBLOCK;
 449             }
 450         }
 451         break;
 452     case BIO_C_SET_NBIO:
 453         if (num != 0)
 454             data->accepted_mode |= BIO_SOCK_NONBLOCK;
 455         else
 456             data->accepted_mode &= ~BIO_SOCK_NONBLOCK;
 457         break;
 458     case BIO_C_SET_FD:
 459         b->num = *((int *)ptr);
 460         data->accept_sock = b->num;
 461         data->state = ACPT_S_ACCEPT;
 462         b->shutdown = (int)num;
 463         b->init = 1;
 464         break;
 465     case BIO_C_GET_FD:
 466         if (b->init) {
 467             ip = (int *)ptr;
 468             if (ip != NULL)
 469                 *ip = data->accept_sock;
 470             ret = data->accept_sock;
 471         } else
 472             ret = -1;
 473         break;
 474     case BIO_C_GET_ACCEPT:
 475         if (b->init) {
 476             if (num == 0 && ptr != NULL) {
 477                 pp = (char **)ptr;
 478                 *pp = data->cache_accepting_name;
 479             } else if (num == 1 && ptr != NULL) {
 480                 pp = (char **)ptr;
 481                 *pp = data->cache_accepting_serv;
 482             } else if (num == 2 && ptr != NULL) {
 483                 pp = (char **)ptr;
 484                 *pp = data->cache_peer_name;
 485             } else if (num == 3 && ptr != NULL) {
 486                 pp = (char **)ptr;
 487                 *pp = data->cache_peer_serv;
 488             } else if (num == 4) {
 489                 switch (BIO_ADDRINFO_family(data->addr_iter)) {
 490 #ifdef AF_INET6
 491                 case AF_INET6:
 492                     ret = BIO_FAMILY_IPV6;
 493                     break;
 494 #endif
 495                 case AF_INET:
 496                     ret = BIO_FAMILY_IPV4;
 497                     break;
 498                 case 0:
 499                     ret = data->accept_family;
 500                     break;
 501                 default:
 502                     ret = -1;
 503                     break;
 504                 }
 505             } else
 506                 ret = -1;
 507         } else
 508             ret = -1;
 509         break;
 510     case BIO_CTRL_GET_CLOSE:
 511         ret = b->shutdown;
 512         break;
 513     case BIO_CTRL_SET_CLOSE:
 514         b->shutdown = (int)num;
 515         break;
 516     case BIO_CTRL_PENDING:
 517     case BIO_CTRL_WPENDING:
 518         ret = 0;
 519         break;
 520     case BIO_CTRL_FLUSH:
 521         break;
 522     case BIO_C_SET_BIND_MODE:
 523         data->bind_mode = (int)num;
 524         break;
 525     case BIO_C_GET_BIND_MODE:
 526         ret = (long)data->bind_mode;
 527         break;
 528     case BIO_CTRL_DUP:
 529         break;
 530
 531     default:
 532         ret = 0;
 533         break;
 534     }
 535     return ret;
 536 }
 537
 538 static int acpt_puts(BIO *bp, const char *str)
 539 {
 540     int n, ret;
 541
 542     n = strlen(str);
 543     ret = acpt_write(bp, str, n);
 544     return ret;
 545 }
 546
 547 BIO *BIO_new_accept(const char *str)
 548 {
 549     BIO *ret;
 550
 551     ret = BIO_new(BIO_s_accept());
 552     if (ret == NULL)
 553         return NULL;
 554     if (BIO_set_accept_name(ret, str))
 555         return ret;
 556     BIO_free(ret);
 557     return NULL;
 558 }
 559
 560 #endif