lib/libcrypto/bio/bss_dgram.c

   1 /* $OpenBSD: bss_dgram.c,v 1.41 2015/07/20 23:15:28 doug Exp $ */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@OpenSSL.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59
  60 #include <sys/socket.h>
  61 #include <sys/time.h>
  62
  63 #include <netinet/in.h>
  64
  65 #include <errno.h>
  66 #include <netdb.h>
  67 #include <stdio.h>
  68 #include <string.h>
  69 #include <unistd.h>
  70
  71 #include <openssl/opensslconf.h>
  72
  73 #include <openssl/bio.h>
  74
  75 #ifndef OPENSSL_NO_DGRAM
  76
  77
  78 static int dgram_write(BIO *h, const char *buf, int num);
  79 static int dgram_read(BIO *h, char *buf, int size);
  80 static int dgram_puts(BIO *h, const char *str);
  81 static long dgram_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  82 static int dgram_new(BIO *h);
  83 static int dgram_free(BIO *data);
  84 static int dgram_clear(BIO *bio);
  85
  86
  87 static int BIO_dgram_should_retry(int s);
  88
  89 static BIO_METHOD methods_dgramp = {
  90         .type = BIO_TYPE_DGRAM,
  91         .name = "datagram socket",
  92         .bwrite = dgram_write,
  93         .bread = dgram_read,
  94         .bputs = dgram_puts,
  95         .ctrl = dgram_ctrl,
  96         .create = dgram_new,
  97         .destroy = dgram_free
  98 };
  99
 100
 101 typedef struct bio_dgram_data_st {
 102         union {
 103                 struct sockaddr sa;
 104                 struct sockaddr_in sa_in;
 105                 struct sockaddr_in6 sa_in6;
 106         } peer;
 107         unsigned int connected;
 108         unsigned int _errno;
 109         unsigned int mtu;
 110         struct timeval next_timeout;
 111         struct timeval socket_timeout;
 112 } bio_dgram_data;
 113
 114
 115 BIO_METHOD *
 116 BIO_s_datagram(void)
 117 {
 118         return (&methods_dgramp);
 119 }
 120
 121 BIO *
 122 BIO_new_dgram(int fd, int close_flag)
 123 {
 124         BIO *ret;
 125
 126         ret = BIO_new(BIO_s_datagram());
 127         if (ret == NULL)
 128                 return (NULL);
 129         BIO_set_fd(ret, fd, close_flag);
 130         return (ret);
 131 }
 132
 133 static int
 134 dgram_new(BIO *bi)
 135 {
 136         bio_dgram_data *data = NULL;
 137
 138         bi->init = 0;
 139         bi->num = 0;
 140         data = calloc(1, sizeof(bio_dgram_data));
 141         if (data == NULL)
 142                 return 0;
 143         bi->ptr = data;
 144
 145         bi->flags = 0;
 146         return (1);
 147 }
 148
 149 static int
 150 dgram_free(BIO *a)
 151 {
 152         bio_dgram_data *data;
 153
 154         if (a == NULL)
 155                 return (0);
 156         if (!dgram_clear(a))
 157                 return 0;
 158
 159         data = (bio_dgram_data *)a->ptr;
 160         free(data);
 161
 162         return (1);
 163 }
 164
 165 static int
 166 dgram_clear(BIO *a)
 167 {
 168         if (a == NULL)
 169                 return (0);
 170         if (a->shutdown) {
 171                 if (a->init) {
 172                         shutdown(a->num, SHUT_RDWR);
 173                         close(a->num);
 174                 }
 175                 a->init = 0;
 176                 a->flags = 0;
 177         }
 178         return (1);
 179 }
 180
 181 static void
 182 dgram_adjust_rcv_timeout(BIO *b)
 183 {
 184 #if defined(SO_RCVTIMEO)
 185         bio_dgram_data *data = (bio_dgram_data *)b->ptr;
 186
 187         /* Is a timer active? */
 188         if (data->next_timeout.tv_sec > 0 || data->next_timeout.tv_usec > 0) {
 189                 struct timeval timenow, timeleft;
 190
 191                 /* Read current socket timeout */
 192                 socklen_t sz = sizeof(data->socket_timeout);
 193                 if (getsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO,
 194                     &(data->socket_timeout), &sz) < 0) {
 195                         perror("getsockopt");
 196                 }
 197
 198                 /* Get current time */
 199                 gettimeofday(&timenow, NULL);
 200
 201                 /* Calculate time left until timer expires */
 202                 memcpy(&timeleft, &(data->next_timeout), sizeof(struct timeval));
 203                 timeleft.tv_sec -= timenow.tv_sec;
 204                 timeleft.tv_usec -= timenow.tv_usec;
 205                 if (timeleft.tv_usec < 0) {
 206                         timeleft.tv_sec--;
 207                         timeleft.tv_usec += 1000000;
 208                 }
 209
 210                 if (timeleft.tv_sec < 0) {
 211                         timeleft.tv_sec = 0;
 212                         timeleft.tv_usec = 1;
 213                 }
 214
 215                 /* Adjust socket timeout if next handhake message timer
 216                  * will expire earlier.
 217                  */
 218                 if ((data->socket_timeout.tv_sec == 0 &&
 219                     data->socket_timeout.tv_usec == 0) ||
 220                     (data->socket_timeout.tv_sec > timeleft.tv_sec) ||
 221                     (data->socket_timeout.tv_sec == timeleft.tv_sec &&
 222                     data->socket_timeout.tv_usec >= timeleft.tv_usec)) {
 223                         if (setsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO,
 224                             &timeleft, sizeof(struct timeval)) < 0) {
 225                                 perror("setsockopt");
 226                         }
 227                 }
 228         }
 229 #endif
 230 }
 231
 232 static void
 233 dgram_reset_rcv_timeout(BIO *b)
 234 {
 235 #if defined(SO_RCVTIMEO)
 236         bio_dgram_data *data = (bio_dgram_data *)b->ptr;
 237
 238         /* Is a timer active? */
 239         if (data->next_timeout.tv_sec > 0 || data->next_timeout.tv_usec > 0) {
 240                 if (setsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO,
 241                     &(data->socket_timeout), sizeof(struct timeval)) < 0) {
 242                         perror("setsockopt");
 243                 }
 244         }
 245 #endif
 246 }
 247
 248 static int
 249 dgram_read(BIO *b, char *out, int outl)
 250 {
 251         int ret = 0;
 252         bio_dgram_data *data = (bio_dgram_data *)b->ptr;
 253
 254         struct  {
 255                 socklen_t len;
 256                 union   {
 257                         struct sockaddr sa;
 258                         struct sockaddr_in sa_in;
 259                         struct sockaddr_in6 sa_in6;
 260                 } peer;
 261         } sa;
 262
 263         sa.len = sizeof(sa.peer);
 264
 265         if (out != NULL) {
 266                 errno = 0;
 267                 memset(&sa.peer, 0, sizeof(sa.peer));
 268                 dgram_adjust_rcv_timeout(b);
 269                 ret = recvfrom(b->num, out, outl, 0, &sa.peer.sa, &sa.len);
 270
 271                 if (! data->connected  && ret >= 0)
 272                         BIO_ctrl(b, BIO_CTRL_DGRAM_SET_PEER, 0, &sa.peer);
 273
 274                 BIO_clear_retry_flags(b);
 275                 if (ret < 0) {
 276                         if (BIO_dgram_should_retry(ret)) {
 277                                 BIO_set_retry_read(b);
 278                                 data->_errno = errno;
 279                         }
 280                 }
 281
 282                 dgram_reset_rcv_timeout(b);
 283         }
 284         return (ret);
 285 }
 286
 287 static int
 288 dgram_write(BIO *b, const char *in, int inl)
 289 {
 290         int ret;
 291         bio_dgram_data *data = (bio_dgram_data *)b->ptr;
 292         errno = 0;
 293
 294         if (data->connected)
 295                 ret = write(b->num, in, inl);
 296         else {
 297                 int peerlen = sizeof(data->peer);
 298
 299                 if (data->peer.sa.sa_family == AF_INET)
 300                         peerlen = sizeof(data->peer.sa_in);
 301                 else if (data->peer.sa.sa_family == AF_INET6)
 302                         peerlen = sizeof(data->peer.sa_in6);
 303                 ret = sendto(b->num, in, inl, 0, &data->peer.sa, peerlen);
 304         }
 305
 306         BIO_clear_retry_flags(b);
 307         if (ret <= 0) {
 308                 if (BIO_dgram_should_retry(ret)) {
 309                         BIO_set_retry_write(b);
 310
 311                         data->_errno = errno;
 312                         /*
 313                          * higher layers are responsible for querying MTU,
 314                          * if necessary
 315                          */
 316                 }
 317         }
 318         return (ret);
 319 }
 320
 321 static long
 322 dgram_ctrl(BIO *b, int cmd, long num, void *ptr)
 323 {
 324         long ret = 1;
 325         int *ip;
 326         struct sockaddr *to = NULL;
 327         bio_dgram_data *data = NULL;
 328 #if (defined(IP_MTU_DISCOVER) || defined(IP_MTU))
 329         int sockopt_val = 0;
 330         socklen_t sockopt_len;  /* assume that system supporting IP_MTU is
 331                                  * modern enough to define socklen_t */
 332         socklen_t addr_len;
 333         union   {
 334                 struct sockaddr sa;
 335                 struct sockaddr_in s4;
 336                 struct sockaddr_in6 s6;
 337         } addr;
 338 #endif
 339
 340         data = (bio_dgram_data *)b->ptr;
 341
 342         switch (cmd) {
 343         case BIO_CTRL_RESET:
 344                 num = 0;
 345         case BIO_C_FILE_SEEK:
 346                 ret = 0;
 347                 break;
 348         case BIO_C_FILE_TELL:
 349         case BIO_CTRL_INFO:
 350                 ret = 0;
 351                 break;
 352         case BIO_C_SET_FD:
 353                 dgram_clear(b);
 354                 b->num= *((int *)ptr);
 355                 b->shutdown = (int)num;
 356                 b->init = 1;
 357                 break;
 358         case BIO_C_GET_FD:
 359                 if (b->init) {
 360                         ip = (int *)ptr;
 361                         if (ip != NULL)
 362                                 *ip = b->num;
 363                         ret = b->num;
 364                 } else
 365                         ret = -1;
 366                 break;
 367         case BIO_CTRL_GET_CLOSE:
 368                 ret = b->shutdown;
 369                 break;
 370         case BIO_CTRL_SET_CLOSE:
 371                 b->shutdown = (int)num;
 372                 break;
 373         case BIO_CTRL_PENDING:
 374         case BIO_CTRL_WPENDING:
 375                 ret = 0;
 376                 break;
 377         case BIO_CTRL_DUP:
 378         case BIO_CTRL_FLUSH:
 379                 ret = 1;
 380                 break;
 381         case BIO_CTRL_DGRAM_CONNECT:
 382                 to = (struct sockaddr *)ptr;
 383                 switch (to->sa_family) {
 384                 case AF_INET:
 385                         memcpy(&data->peer, to, sizeof(data->peer.sa_in));
 386                         break;
 387                 case AF_INET6:
 388                         memcpy(&data->peer, to, sizeof(data->peer.sa_in6));
 389                         break;
 390                 default:
 391                         memcpy(&data->peer, to, sizeof(data->peer.sa));
 392                         break;
 393                 }
 394                 break;
 395                 /* (Linux)kernel sets DF bit on outgoing IP packets */
 396         case BIO_CTRL_DGRAM_MTU_DISCOVER:
 397 #if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
 398                 addr_len = (socklen_t)sizeof(addr);
 399                 memset((void *)&addr, 0, sizeof(addr));
 400                 if (getsockname(b->num, &addr.sa, &addr_len) < 0) {
 401                         ret = 0;
 402                         break;
 403                 }
 404                 switch (addr.sa.sa_family) {
 405                 case AF_INET:
 406                         sockopt_val = IP_PMTUDISC_DO;
 407                         ret = setsockopt(b->num, IPPROTO_IP, IP_MTU_DISCOVER,
 408                             &sockopt_val, sizeof(sockopt_val));
 409                         if (ret < 0)
 410                                 perror("setsockopt");
 411                         break;
 412 #if defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
 413                 case AF_INET6:
 414                         sockopt_val = IPV6_PMTUDISC_DO;
 415                         ret = setsockopt(b->num, IPPROTO_IPV6,
 416                             IPV6_MTU_DISCOVER, &sockopt_val,
 417                             sizeof(sockopt_val));
 418                         if (ret < 0)
 419                                 perror("setsockopt");
 420                         break;
 421 #endif
 422                 default:
 423                         ret = -1;
 424                         break;
 425                 }
 426 #else
 427                 ret = -1;
 428 #endif
 429                 break;
 430         case BIO_CTRL_DGRAM_QUERY_MTU:
 431 #if defined(IP_MTU)
 432                 addr_len = (socklen_t)sizeof(addr);
 433                 memset((void *)&addr, 0, sizeof(addr));
 434                 if (getsockname(b->num, &addr.sa, &addr_len) < 0) {
 435                         ret = 0;
 436                         break;
 437                 }
 438                 sockopt_len = sizeof(sockopt_val);
 439                 switch (addr.sa.sa_family) {
 440                 case AF_INET:
 441                         ret = getsockopt(b->num, IPPROTO_IP, IP_MTU,
 442                             &sockopt_val, &sockopt_len);
 443                         if (ret < 0 || sockopt_val < 0) {
 444                                 ret = 0;
 445                         } else {
 446                                 /* we assume that the transport protocol is UDP and no
 447                                  * IP options are used.
 448                                  */
 449                                 data->mtu = sockopt_val - 8 - 20;
 450                                 ret = data->mtu;
 451                         }
 452                         break;
 453 #if defined(IPV6_MTU)
 454                 case AF_INET6:
 455                         ret = getsockopt(b->num, IPPROTO_IPV6, IPV6_MTU,
 456                             &sockopt_val, &sockopt_len);
 457                         if (ret < 0 || sockopt_val < 0) {
 458                                 ret = 0;
 459                         } else {
 460                                 /* we assume that the transport protocol is UDP and no
 461                                  * IPV6 options are used.
 462                                  */
 463                                 data->mtu = sockopt_val - 8 - 40;
 464                                 ret = data->mtu;
 465                         }
 466                         break;
 467 #endif
 468 default:
 469                         ret = 0;
 470                         break;
 471                 }
 472 #else
 473                 ret = 0;
 474 #endif
 475                 break;
 476         case BIO_CTRL_DGRAM_GET_FALLBACK_MTU:
 477                 switch (data->peer.sa.sa_family) {
 478                 case AF_INET:
 479                         ret = 576 - 20 - 8;
 480                         break;
 481                 case AF_INET6:
 482 #ifdef IN6_IS_ADDR_V4MAPPED
 483                         if (IN6_IS_ADDR_V4MAPPED(&data->peer.sa_in6.sin6_addr))
 484                                 ret = 576 - 20 - 8;
 485                         else
 486 #endif
 487                                 ret = 1280 - 40 - 8;
 488                         break;
 489                 default:
 490                         ret = 576 - 20 - 8;
 491                         break;
 492                 }
 493                 break;
 494         case BIO_CTRL_DGRAM_GET_MTU:
 495                 return data->mtu;
 496                 break;
 497         case BIO_CTRL_DGRAM_SET_MTU:
 498                 data->mtu = num;
 499                 ret = num;
 500                 break;
 501         case BIO_CTRL_DGRAM_SET_CONNECTED:
 502                 to = (struct sockaddr *)ptr;
 503
 504                 if (to != NULL) {
 505                         data->connected = 1;
 506                         switch (to->sa_family) {
 507                         case AF_INET:
 508                                 memcpy(&data->peer, to, sizeof(data->peer.sa_in));
 509                                 break;
 510                         case AF_INET6:
 511                                 memcpy(&data->peer, to, sizeof(data->peer.sa_in6));
 512                                 break;
 513                         default:
 514                                 memcpy(&data->peer, to, sizeof(data->peer.sa));
 515                                 break;
 516                         }
 517                 } else {
 518                         data->connected = 0;
 519                         memset(&(data->peer), 0, sizeof(data->peer));
 520                 }
 521                 break;
 522         case BIO_CTRL_DGRAM_GET_PEER:
 523                 switch (data->peer.sa.sa_family) {
 524                 case AF_INET:
 525                         ret = sizeof(data->peer.sa_in);
 526                         break;
 527                 case AF_INET6:
 528                         ret = sizeof(data->peer.sa_in6);
 529                         break;
 530                 default:
 531                         ret = sizeof(data->peer.sa);
 532                         break;
 533                 }
 534                 if (num == 0 || num > ret)
 535                         num = ret;
 536                 memcpy(ptr, &data->peer, (ret = num));
 537                 break;
 538         case BIO_CTRL_DGRAM_SET_PEER:
 539                 to = (struct sockaddr *) ptr;
 540                 switch (to->sa_family) {
 541                 case AF_INET:
 542                         memcpy(&data->peer, to, sizeof(data->peer.sa_in));
 543                         break;
 544                 case AF_INET6:
 545                         memcpy(&data->peer, to, sizeof(data->peer.sa_in6));
 546                         break;
 547                 default:
 548                         memcpy(&data->peer, to, sizeof(data->peer.sa));
 549                         break;
 550                 }
 551                 break;
 552         case BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT:
 553                 memcpy(&(data->next_timeout), ptr, sizeof(struct timeval));
 554                 break;
 555 #if defined(SO_RCVTIMEO)
 556         case BIO_CTRL_DGRAM_SET_RECV_TIMEOUT:
 557                 if (setsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO, ptr,
 558                     sizeof(struct timeval)) < 0) {
 559                         perror("setsockopt");
 560                         ret = -1;
 561                 }
 562                 break;
 563         case BIO_CTRL_DGRAM_GET_RECV_TIMEOUT:
 564                 {
 565                         socklen_t sz = sizeof(struct timeval);
 566                         if (getsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO,
 567                             ptr, &sz) < 0) {
 568                                 perror("getsockopt");
 569                                 ret = -1;
 570                         } else
 571                                 ret = sz;
 572                 }
 573                 break;
 574 #endif
 575 #if defined(SO_SNDTIMEO)
 576         case BIO_CTRL_DGRAM_SET_SEND_TIMEOUT:
 577                 if (setsockopt(b->num, SOL_SOCKET, SO_SNDTIMEO, ptr,
 578                     sizeof(struct timeval)) < 0) {
 579                         perror("setsockopt");
 580                         ret = -1;
 581                 }
 582                 break;
 583         case BIO_CTRL_DGRAM_GET_SEND_TIMEOUT:
 584                 {
 585                         socklen_t sz = sizeof(struct timeval);
 586                         if (getsockopt(b->num, SOL_SOCKET, SO_SNDTIMEO,
 587                             ptr, &sz) < 0) {
 588                                 perror("getsockopt");
 589                                 ret = -1;
 590                         } else
 591                                 ret = sz;
 592                 }
 593                 break;
 594 #endif
 595         case BIO_CTRL_DGRAM_GET_SEND_TIMER_EXP:
 596                 /* fall-through */
 597         case BIO_CTRL_DGRAM_GET_RECV_TIMER_EXP:
 598                 if (data->_errno == EAGAIN) {
 599                         ret = 1;
 600                         data->_errno = 0;
 601                 } else
 602                         ret = 0;
 603                 break;
 604 #ifdef EMSGSIZE
 605         case BIO_CTRL_DGRAM_MTU_EXCEEDED:
 606                 if (data->_errno == EMSGSIZE) {
 607                         ret = 1;
 608                         data->_errno = 0;
 609                 } else
 610                         ret = 0;
 611                 break;
 612 #endif
 613         default:
 614                 ret = 0;
 615                 break;
 616         }
 617         return (ret);
 618 }
 619
 620 static int
 621 dgram_puts(BIO *bp, const char *str)
 622 {
 623         int n, ret;
 624
 625         n = strlen(str);
 626         ret = dgram_write(bp, str, n);
 627         return (ret);
 628 }
 629
 630
 631 static int
 632 BIO_dgram_should_retry(int i)
 633 {
 634         int err;
 635
 636         if ((i == 0) || (i == -1)) {
 637                 err = errno;
 638                 return (BIO_dgram_non_fatal_error(err));
 639         }
 640         return (0);
 641 }
 642
 643 int
 644 BIO_dgram_non_fatal_error(int err)
 645 {
 646         switch (err) {
 647         case EINTR:
 648         case EAGAIN:
 649         case EINPROGRESS:
 650         case EALREADY:
 651                 return (1);
 652         default:
 653                 break;
 654         }
 655         return (0);
 656 }
 657
 658 #endif