crypto/bio/bss_dgram.c

   1 /* crypto/bio/bio_dgram.c */
   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
  61 #include <stdio.h>
  62 #include <errno.h>
  63 #define USE_SOCKETS
  64 #include "cryptlib.h"
  65
  66 #include <openssl/bio.h>
  67 #ifndef OPENSSL_NO_DGRAM
  68
  69 #if defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS)
  70 #include <sys/timeb.h>
  71 #endif
  72
  73 #ifdef OPENSSL_SYS_LINUX
  74 #define IP_MTU      14 /* linux is lame */
  75 #endif
  76
  77 #ifdef WATT32
  78 #define sock_write SockWrite  /* Watt-32 uses same names */
  79 #define sock_read  SockRead
  80 #define sock_puts  SockPuts
  81 #endif
  82
  83 static int dgram_write(BIO *h, const char *buf, int num);
  84 static int dgram_read(BIO *h, char *buf, int size);
  85 static int dgram_puts(BIO *h, const char *str);
  86 static long dgram_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  87 static int dgram_new(BIO *h);
  88 static int dgram_free(BIO *data);
  89 static int dgram_clear(BIO *bio);
  90
  91 static int BIO_dgram_should_retry(int s);
  92
  93 static void get_current_time(struct timeval *t);
  94
  95 static BIO_METHOD methods_dgramp=
  96         {
  97         BIO_TYPE_DGRAM,
  98         "datagram socket",
  99         dgram_write,
 100         dgram_read,
 101         dgram_puts,
 102         NULL, /* dgram_gets, */
 103         dgram_ctrl,
 104         dgram_new,
 105         dgram_free,
 106         NULL,
 107         };
 108
 109 typedef struct bio_dgram_data_st
 110         {
 111         struct sockaddr peer;
 112         unsigned int connected;
 113         unsigned int _errno;
 114         unsigned int mtu;
 115         struct timeval next_timeout;
 116         struct timeval socket_timeout;
 117         } bio_dgram_data;
 118
 119 BIO_METHOD *BIO_s_datagram(void)
 120         {
 121         return(&methods_dgramp);
 122         }
 123
 124 BIO *BIO_new_dgram(int fd, int close_flag)
 125         {
 126         BIO *ret;
 127
 128         ret=BIO_new(BIO_s_datagram());
 129         if (ret == NULL) return(NULL);
 130         BIO_set_fd(ret,fd,close_flag);
 131         return(ret);
 132         }
 133
 134 static int dgram_new(BIO *bi)
 135         {
 136         bio_dgram_data *data = NULL;
 137
 138         bi->init=0;
 139         bi->num=0;
 140         data = OPENSSL_malloc(sizeof(bio_dgram_data));
 141         if (data == NULL)
 142                 return 0;
 143         memset(data, 0x00, sizeof(bio_dgram_data));
 144     bi->ptr = data;
 145
 146         bi->flags=0;
 147         return(1);
 148         }
 149
 150 static int dgram_free(BIO *a)
 151         {
 152         bio_dgram_data *data;
 153
 154         if (a == NULL) return(0);
 155         if ( ! dgram_clear(a))
 156                 return 0;
 157
 158         data = (bio_dgram_data *)a->ptr;
 159         if(data != NULL) OPENSSL_free(data);
 160
 161         return(1);
 162         }
 163
 164 static int dgram_clear(BIO *a)
 165         {
 166         if (a == NULL) return(0);
 167         if (a->shutdown)
 168                 {
 169                 if (a->init)
 170                         {
 171                         SHUTDOWN2(a->num);
 172                         }
 173                 a->init=0;
 174                 a->flags=0;
 175                 }
 176         return(1);
 177         }
 178
 179 static void dgram_adjust_rcv_timeout(BIO *b)
 180         {
 181 #if defined(SO_RCVTIMEO)
 182         bio_dgram_data *data = (bio_dgram_data *)b->ptr;
 183         int sz = sizeof(int);
 184
 185         /* Is a timer active? */
 186         if (data->next_timeout.tv_sec > 0 || data->next_timeout.tv_usec > 0)
 187                 {
 188                 struct timeval timenow, timeleft;
 189
 190                 /* Read current socket timeout */
 191 #ifdef OPENSSL_SYS_WINDOWS
 192                 int timeout;
 193                 if (getsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO,
 194                                            (void*)&timeout, &sz) < 0)
 195                         { perror("getsockopt"); }
 196                 else
 197                         {
 198                         data->socket_timeout.tv_sec = timeout / 1000;
 199                         data->socket_timeout.tv_usec = (timeout % 1000) * 1000;
 200                         }
 201 #else
 202                 if ( getsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO,
 203                                                 &(data->socket_timeout), (void *)&sz) < 0)
 204                         { perror("getsockopt"); }
 205 #endif
 206
 207                 /* Get current time */
 208                 get_current_time(&timenow);
 209
 210                 /* Calculate time left until timer expires */
 211                 memcpy(&timeleft, &(data->next_timeout), sizeof(struct timeval));
 212                 timeleft.tv_sec -= timenow.tv_sec;
 213                 timeleft.tv_usec -= timenow.tv_usec;
 214                 if (timeleft.tv_usec < 0)
 215                         {
 216                         timeleft.tv_sec--;
 217                         timeleft.tv_usec += 1000000;
 218                         }
 219
 220                 if (timeleft.tv_sec < 0)
 221                         {
 222                         timeleft.tv_sec = 0;
 223                         timeleft.tv_usec = 1;
 224                         }
 225
 226                 /* Adjust socket timeout if next handhake message timer
 227                  * will expire earlier.
 228                  */
 229                 if ((data->socket_timeout.tv_sec == 0 && data->socket_timeout.tv_usec == 0) ||
 230                         (data->socket_timeout.tv_sec > timeleft.tv_sec) ||
 231                         (data->socket_timeout.tv_sec == timeleft.tv_sec &&
 232                          data->socket_timeout.tv_usec >= timeleft.tv_usec))
 233                         {
 234 #ifdef OPENSSL_SYS_WINDOWS
 235                         timeout = timeleft.tv_sec * 1000 + timeleft.tv_usec / 1000;
 236                         if (setsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO,
 237                                                    (void*)&timeout, sizeof(timeout)) < 0)
 238                                 { perror("setsockopt"); }
 239 #else
 240                         if ( setsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO, &timeleft,
 241                                                         sizeof(struct timeval)) < 0)
 242                                 { perror("setsockopt"); }
 243 #endif
 244                         }
 245                 }
 246 #endif
 247         }
 248
 249 static void dgram_reset_rcv_timeout(BIO *b)
 250         {
 251 #if defined(SO_RCVTIMEO)
 252         bio_dgram_data *data = (bio_dgram_data *)b->ptr;
 253
 254         /* Is a timer active? */
 255         if (data->next_timeout.tv_sec > 0 || data->next_timeout.tv_usec > 0)
 256                 {
 257 #ifdef OPENSSL_SYS_WINDOWS
 258                 int timeout = data->socket_timeout.tv_sec * 1000 +
 259                                           data->socket_timeout.tv_usec / 1000;
 260                 if (setsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO,
 261                                            (void*)&timeout, sizeof(timeout)) < 0)
 262                         { perror("setsockopt"); }
 263 #else
 264                 if ( setsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO, &(data->socket_timeout),
 265                                                 sizeof(struct timeval)) < 0)
 266                         { perror("setsockopt"); }
 267 #endif
 268                 }
 269 #endif
 270         }
 271
 272 static int dgram_read(BIO *b, char *out, int outl)
 273         {
 274         int ret=0;
 275         bio_dgram_data *data = (bio_dgram_data *)b->ptr;
 276
 277         struct sockaddr peer;
 278         int peerlen = sizeof(peer);
 279
 280         if (out != NULL)
 281                 {
 282                 clear_socket_error();
 283                 memset(&peer, 0x00, peerlen);
 284                 /* Last arg in recvfrom is signed on some platforms and
 285                  * unsigned on others. It is of type socklen_t on some
 286                  * but this is not universal. Cast to (void *) to avoid
 287                  * compiler warnings.
 288                  */
 289                 dgram_adjust_rcv_timeout(b);
 290                 ret=recvfrom(b->num,out,outl,0,&peer,(void *)&peerlen);
 291
 292                 if ( ! data->connected  && ret >= 0)
 293                         BIO_ctrl(b, BIO_CTRL_DGRAM_SET_PEER, 0, &peer);
 294
 295                 BIO_clear_retry_flags(b);
 296                 if (ret < 0)
 297                         {
 298                         if (BIO_dgram_should_retry(ret))
 299                                 {
 300                                 BIO_set_retry_read(b);
 301                                 data->_errno = get_last_socket_error();
 302                                 }
 303                         }
 304
 305                 dgram_reset_rcv_timeout(b);
 306                 }
 307         return(ret);
 308         }
 309
 310 static int dgram_write(BIO *b, const char *in, int inl)
 311         {
 312         int ret;
 313         bio_dgram_data *data = (bio_dgram_data *)b->ptr;
 314         clear_socket_error();
 315
 316     if ( data->connected )
 317         ret=writesocket(b->num,in,inl);
 318     else
 319 #if defined(NETWARE_CLIB) && defined(NETWARE_BSDSOCK)
 320         ret=sendto(b->num, (char *)in, inl, 0, &data->peer, sizeof(data->peer));
 321 #else
 322         ret=sendto(b->num, in, inl, 0, &data->peer, sizeof(data->peer));
 323 #endif
 324
 325         BIO_clear_retry_flags(b);
 326         if (ret <= 0)
 327                 {
 328                 if (BIO_dgram_should_retry(ret))
 329                         {
 330                         BIO_set_retry_write(b);
 331                         data->_errno = get_last_socket_error();
 332
 333 #if 0 /* higher layers are responsible for querying MTU, if necessary */
 334                         if ( data->_errno == EMSGSIZE)
 335                                 /* retrieve the new MTU */
 336                                 BIO_ctrl(b, BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 337 #endif
 338                         }
 339                 }
 340         return(ret);
 341         }
 342
 343 static long dgram_ctrl(BIO *b, int cmd, long num, void *ptr)
 344         {
 345         long ret=1;
 346         int *ip;
 347         struct sockaddr *to = NULL;
 348         bio_dgram_data *data = NULL;
 349 #if defined(IP_MTU_DISCOVER) || defined(IP_MTU)
 350         long sockopt_val = 0;
 351         unsigned int sockopt_len = 0;
 352 #endif
 353 #ifdef OPENSSL_SYS_LINUX
 354         socklen_t addr_len;
 355         struct sockaddr_storage addr;
 356 #endif
 357
 358         data = (bio_dgram_data *)b->ptr;
 359
 360         switch (cmd)
 361                 {
 362         case BIO_CTRL_RESET:
 363                 num=0;
 364         case BIO_C_FILE_SEEK:
 365                 ret=0;
 366                 break;
 367         case BIO_C_FILE_TELL:
 368         case BIO_CTRL_INFO:
 369                 ret=0;
 370                 break;
 371         case BIO_C_SET_FD:
 372                 dgram_clear(b);
 373                 b->num= *((int *)ptr);
 374                 b->shutdown=(int)num;
 375                 b->init=1;
 376                 break;
 377         case BIO_C_GET_FD:
 378                 if (b->init)
 379                         {
 380                         ip=(int *)ptr;
 381                         if (ip != NULL) *ip=b->num;
 382                         ret=b->num;
 383                         }
 384                 else
 385                         ret= -1;
 386                 break;
 387         case BIO_CTRL_GET_CLOSE:
 388                 ret=b->shutdown;
 389                 break;
 390         case BIO_CTRL_SET_CLOSE:
 391                 b->shutdown=(int)num;
 392                 break;
 393         case BIO_CTRL_PENDING:
 394         case BIO_CTRL_WPENDING:
 395                 ret=0;
 396                 break;
 397         case BIO_CTRL_DUP:
 398         case BIO_CTRL_FLUSH:
 399                 ret=1;
 400                 break;
 401         case BIO_CTRL_DGRAM_CONNECT:
 402                 to = (struct sockaddr *)ptr;
 403 #if 0
 404                 if (connect(b->num, to, sizeof(struct sockaddr)) < 0)
 405                         { perror("connect"); ret = 0; }
 406                 else
 407                         {
 408 #endif
 409                         memcpy(&(data->peer),to, sizeof(struct sockaddr));
 410 #if 0
 411                         }
 412 #endif
 413                 break;
 414                 /* (Linux)kernel sets DF bit on outgoing IP packets */
 415         case BIO_CTRL_DGRAM_MTU_DISCOVER:
 416 #ifdef OPENSSL_SYS_LINUX
 417                 addr_len = (socklen_t)sizeof(struct sockaddr_storage);
 418                 memset((void *)&addr, 0, sizeof(struct sockaddr_storage));
 419                 if (getsockname(b->num, (void *)&addr, &addr_len) < 0)
 420                         {
 421                         ret = 0;
 422                         break;
 423                         }
 424                 sockopt_len = sizeof(sockopt_val);
 425                 switch (addr.ss_family)
 426                         {
 427                 case AF_INET:
 428                         sockopt_val = IP_PMTUDISC_DO;
 429                         if ((ret = setsockopt(b->num, IPPROTO_IP, IP_MTU_DISCOVER,
 430                                 &sockopt_val, sizeof(sockopt_val))) < 0)
 431                                 perror("setsockopt");
 432                         break;
 433                 case AF_INET6:
 434                         sockopt_val = IPV6_PMTUDISC_DO;
 435                         if ((ret = setsockopt(b->num, IPPROTO_IPV6, IPV6_MTU_DISCOVER,
 436                                 &sockopt_val, sizeof(sockopt_val))) < 0)
 437                                 perror("setsockopt");
 438                         break;
 439                 default:
 440                         ret = -1;
 441                         break;
 442                         }
 443                 ret = -1;
 444 #else
 445                 break;
 446 #endif
 447         case BIO_CTRL_DGRAM_QUERY_MTU:
 448 #ifdef OPENSSL_SYS_LINUX
 449                 addr_len = (socklen_t)sizeof(struct sockaddr_storage);
 450                 memset((void *)&addr, 0, sizeof(struct sockaddr_storage));
 451                 if (getsockname(b->num, (void *)&addr, &addr_len) < 0)
 452                         {
 453                         ret = 0;
 454                         break;
 455                         }
 456                 sockopt_len = sizeof(sockopt_val);
 457                 switch (addr.ss_family)
 458                         {
 459                 case AF_INET:
 460                         if ((ret = getsockopt(b->num, IPPROTO_IP, IP_MTU, (void *)&sockopt_val,
 461                                 &sockopt_len)) < 0 || sockopt_val < 0)
 462                                 {
 463                                 ret = 0;
 464                                 }
 465                         else
 466                                 {
 467                                 /* we assume that the transport protocol is UDP and no
 468                                  * IP options are used.
 469                                  */
 470                                 data->mtu = sockopt_val - 8 - 20;
 471                                 ret = data->mtu;
 472                                 }
 473                         break;
 474                 case AF_INET6:
 475                         if ((ret = getsockopt(b->num, IPPROTO_IPV6, IPV6_MTU, (void *)&sockopt_val,
 476                                 &sockopt_len)) < 0 || sockopt_val < 0)
 477                                 {
 478                                 ret = 0;
 479                                 }
 480                         else
 481                                 {
 482                                 /* we assume that the transport protocol is UDP and no
 483                                  * IPV6 options are used.
 484                                  */
 485                                 data->mtu = sockopt_val - 8 - 40;
 486                                 ret = data->mtu;
 487                                 }
 488                         break;
 489                 default:
 490                         ret = 0;
 491                         break;
 492                         }
 493 #else
 494                 ret = 0;
 495 #endif
 496                 break;
 497         case BIO_CTRL_DGRAM_GET_MTU:
 498                 return data->mtu;
 499                 break;
 500         case BIO_CTRL_DGRAM_SET_MTU:
 501                 data->mtu = num;
 502                 ret = num;
 503                 break;
 504         case BIO_CTRL_DGRAM_SET_CONNECTED:
 505                 to = (struct sockaddr *)ptr;
 506
 507                 if ( to != NULL)
 508                         {
 509                         data->connected = 1;
 510                         memcpy(&(data->peer),to, sizeof(struct sockaddr));
 511                         }
 512                 else
 513                         {
 514                         data->connected = 0;
 515                         memset(&(data->peer), 0x00, sizeof(struct sockaddr));
 516                         }
 517                 break;
 518     case BIO_CTRL_DGRAM_GET_PEER:
 519         to = (struct sockaddr *) ptr;
 520
 521         memcpy(to, &(data->peer), sizeof(struct sockaddr));
 522                 ret = sizeof(struct sockaddr);
 523         break;
 524     case BIO_CTRL_DGRAM_SET_PEER:
 525         to = (struct sockaddr *) ptr;
 526
 527         memcpy(&(data->peer), to, sizeof(struct sockaddr));
 528         break;
 529         case BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT:
 530                 memcpy(&(data->next_timeout), ptr, sizeof(struct timeval));
 531                 break;
 532 #if defined(SO_RCVTIMEO)
 533         case BIO_CTRL_DGRAM_SET_RECV_TIMEOUT:
 534 #ifdef OPENSSL_SYS_WINDOWS
 535                 {
 536                 struct timeval *tv = (struct timeval *)ptr;
 537                 int timeout = tv->tv_sec * 1000 + tv->tv_usec/1000;
 538                 if (setsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO,
 539                         (void*)&timeout, sizeof(timeout)) < 0)
 540                         { perror("setsockopt"); ret = -1; }
 541                 }
 542 #else
 543                 if ( setsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO, ptr,
 544                         sizeof(struct timeval)) < 0)
 545                         { perror("setsockopt"); ret = -1; }
 546 #endif
 547                 break;
 548         case BIO_CTRL_DGRAM_GET_RECV_TIMEOUT:
 549 #ifdef OPENSSL_SYS_WINDOWS
 550                 {
 551                 int timeout, sz = sizeof(timeout);
 552                 struct timeval *tv = (struct timeval *)ptr;
 553                 if (getsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO,
 554                         (void*)&timeout, &sz) < 0)
 555                         { perror("getsockopt"); ret = -1; }
 556                 else
 557                         {
 558                         tv->tv_sec = timeout / 1000;
 559                         tv->tv_usec = (timeout % 1000) * 1000;
 560                         ret = sizeof(*tv);
 561                         }
 562                 }
 563 #else
 564                 if ( getsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO,
 565                         ptr, (void *)&ret) < 0)
 566                         { perror("getsockopt"); ret = -1; }
 567 #endif
 568                 break;
 569 #endif
 570 #if defined(SO_SNDTIMEO)
 571         case BIO_CTRL_DGRAM_SET_SEND_TIMEOUT:
 572 #ifdef OPENSSL_SYS_WINDOWS
 573                 {
 574                 struct timeval *tv = (struct timeval *)ptr;
 575                 int timeout = tv->tv_sec * 1000 + tv->tv_usec/1000;
 576                 if (setsockopt(b->num, SOL_SOCKET, SO_SNDTIMEO,
 577                         (void*)&timeout, sizeof(timeout)) < 0)
 578                         { perror("setsockopt"); ret = -1; }
 579                 }
 580 #else
 581                 if ( setsockopt(b->num, SOL_SOCKET, SO_SNDTIMEO, ptr,
 582                         sizeof(struct timeval)) < 0)
 583                         { perror("setsockopt"); ret = -1; }
 584 #endif
 585                 break;
 586         case BIO_CTRL_DGRAM_GET_SEND_TIMEOUT:
 587 #ifdef OPENSSL_SYS_WINDOWS
 588                 {
 589                 int timeout, sz = sizeof(timeout);
 590                 struct timeval *tv = (struct timeval *)ptr;
 591                 if (getsockopt(b->num, SOL_SOCKET, SO_SNDTIMEO,
 592                         (void*)&timeout, &sz) < 0)
 593                         { perror("getsockopt"); ret = -1; }
 594                 else
 595                         {
 596                         tv->tv_sec = timeout / 1000;
 597                         tv->tv_usec = (timeout % 1000) * 1000;
 598                         ret = sizeof(*tv);
 599                         }
 600                 }
 601 #else
 602                 if ( getsockopt(b->num, SOL_SOCKET, SO_SNDTIMEO,
 603                         ptr, (void *)&ret) < 0)
 604                         { perror("getsockopt"); ret = -1; }
 605 #endif
 606                 break;
 607 #endif
 608         case BIO_CTRL_DGRAM_GET_SEND_TIMER_EXP:
 609                 /* fall-through */
 610         case BIO_CTRL_DGRAM_GET_RECV_TIMER_EXP:
 611 #ifdef OPENSSL_SYS_WINDOWS
 612                 if ( data->_errno == WSAETIMEDOUT)
 613 #else
 614                 if ( data->_errno == EAGAIN)
 615 #endif
 616                         {
 617                         ret = 1;
 618                         data->_errno = 0;
 619                         }
 620                 else
 621                         ret = 0;
 622                 break;
 623 #ifdef EMSGSIZE
 624         case BIO_CTRL_DGRAM_MTU_EXCEEDED:
 625                 if ( data->_errno == EMSGSIZE)
 626                         {
 627                         ret = 1;
 628                         data->_errno = 0;
 629                         }
 630                 else
 631                         ret = 0;
 632                 break;
 633 #endif
 634         default:
 635                 ret=0;
 636                 break;
 637                 }
 638         return(ret);
 639         }
 640
 641 static int dgram_puts(BIO *bp, const char *str)
 642         {
 643         int n,ret;
 644
 645         n=strlen(str);
 646         ret=dgram_write(bp,str,n);
 647         return(ret);
 648         }
 649
 650 static int BIO_dgram_should_retry(int i)
 651         {
 652         int err;
 653
 654         if ((i == 0) || (i == -1))
 655                 {
 656                 err=get_last_socket_error();
 657
 658 #if defined(OPENSSL_SYS_WINDOWS)
 659         /* If the socket return value (i) is -1
 660          * and err is unexpectedly 0 at this point,
 661          * the error code was overwritten by
 662          * another system call before this error
 663          * handling is called.
 664          */
 665 #endif
 666
 667                 return(BIO_dgram_non_fatal_error(err));
 668                 }
 669         return(0);
 670         }
 671
 672 int BIO_dgram_non_fatal_error(int err)
 673         {
 674         switch (err)
 675                 {
 676 #if defined(OPENSSL_SYS_WINDOWS)
 677 # if defined(WSAEWOULDBLOCK)
 678         case WSAEWOULDBLOCK:
 679 # endif
 680
 681 # if 0 /* This appears to always be an error */
 682 #  if defined(WSAENOTCONN)
 683         case WSAENOTCONN:
 684 #  endif
 685 # endif
 686 #endif
 687
 688 #ifdef EWOULDBLOCK
 689 # ifdef WSAEWOULDBLOCK
 690 #  if WSAEWOULDBLOCK != EWOULDBLOCK
 691         case EWOULDBLOCK:
 692 #  endif
 693 # else
 694         case EWOULDBLOCK:
 695 # endif
 696 #endif
 697
 698 #ifdef EINTR
 699         case EINTR:
 700 #endif
 701
 702 #ifdef EAGAIN
 703 #if EWOULDBLOCK != EAGAIN
 704         case EAGAIN:
 705 # endif
 706 #endif
 707
 708 #ifdef EPROTO
 709         case EPROTO:
 710 #endif
 711
 712 #ifdef EINPROGRESS
 713         case EINPROGRESS:
 714 #endif
 715
 716 #ifdef EALREADY
 717         case EALREADY:
 718 #endif
 719
 720                 return(1);
 721                 /* break; */
 722         default:
 723                 break;
 724                 }
 725         return(0);
 726         }
 727
 728 static void get_current_time(struct timeval *t)
 729         {
 730 #ifdef OPENSSL_SYS_WIN32
 731         struct _timeb tb;
 732         _ftime(&tb);
 733         t->tv_sec = (long)tb.time;
 734         t->tv_usec = (long)tb.millitm * 1000;
 735 #elif defined(OPENSSL_SYS_VMS)
 736         struct timeb tb;
 737         ftime(&tb);
 738         t->tv_sec = (long)tb.time;
 739         t->tv_usec = (long)tb.millitm * 1000;
 740 #else
 741         gettimeofday(t, NULL);
 742 #endif
 743         }
 744
 745 #endif