1 /* ==================================================================== 2 * Copyright (c) 1998-2003 The OpenSSL Project. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in 13 * the documentation and/or other materials provided with the 14 * distribution. 15 * 16 * 3. All advertising materials mentioning features or use of this 17 * software must display the following acknowledgment: 18 * "This product includes software developed by the OpenSSL Project 19 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 20 * 21 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 22 * endorse or promote products derived from this software without 23 * prior written permission. For written permission, please contact 24 * openssl-core (at) openssl.org. 25 * 26 * 5. Products derived from this software may not be called "OpenSSL" 27 * nor may "OpenSSL" appear in their names without prior written 28 * permission of the OpenSSL Project. 29 * 30 * 6. Redistributions of any form whatsoever must retain the following 31 * acknowledgment: 32 * "This product includes software developed by the OpenSSL Project 33 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 34 * 35 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 36 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 38 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 41 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 42 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 44 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 46 * OF THE POSSIBILITY OF SUCH DAMAGE. 47 * ==================================================================== 48 * 49 * This product includes cryptographic software written by Eric Young 50 * (eay (at) cryptsoft.com). This product includes software written by Tim 51 * Hudson (tjh (at) cryptsoft.com). */ 52 53 #include <openssl/bio.h> 54 55 #include <assert.h> 56 57 #include <openssl/buf.h> 58 #include <openssl/err.h> 59 #include <openssl/mem.h> 60 61 62 struct bio_bio_st { 63 BIO *peer; /* NULL if buf == NULL. 64 * If peer != NULL, then peer->ptr is also a bio_bio_st, 65 * and its "peer" member points back to us. 66 * peer != NULL iff init != 0 in the BIO. */ 67 68 /* This is for what we write (i.e. reading uses peer's struct): */ 69 int closed; /* valid iff peer != NULL */ 70 size_t len; /* valid iff buf != NULL; 0 if peer == NULL */ 71 size_t offset; /* valid iff buf != NULL; 0 if len == 0 */ 72 size_t size; 73 char *buf; /* "size" elements (if != NULL) */ 74 75 size_t request; /* valid iff peer != NULL; 0 if len != 0, 76 * otherwise set by peer to number of bytes 77 * it (unsuccessfully) tried to read, 78 * never more than buffer space (size-len) warrants. */ 79 }; 80 81 static int bio_new(BIO *bio) { 82 struct bio_bio_st *b; 83 84 b = OPENSSL_malloc(sizeof *b); 85 if (b == NULL) { 86 return 0; 87 } 88 89 b->peer = NULL; 90 b->size = 17 * 1024; /* enough for one TLS record (just a default) */ 91 b->buf = NULL; 92 93 bio->ptr = b; 94 return 1; 95 } 96 97 static void bio_destroy_pair(BIO *bio) { 98 struct bio_bio_st *b = bio->ptr; 99 BIO *peer_bio; 100 struct bio_bio_st *peer_b; 101 102 if (b == NULL) { 103 return; 104 } 105 106 peer_bio = b->peer; 107 if (peer_bio == NULL) { 108 return; 109 } 110 111 peer_b = peer_bio->ptr; 112 113 assert(peer_b != NULL); 114 assert(peer_b->peer == bio); 115 116 peer_b->peer = NULL; 117 peer_bio->init = 0; 118 assert(peer_b->buf != NULL); 119 peer_b->len = 0; 120 peer_b->offset = 0; 121 122 b->peer = NULL; 123 bio->init = 0; 124 assert(b->buf != NULL); 125 b->len = 0; 126 b->offset = 0; 127 } 128 129 static int bio_free(BIO *bio) { 130 struct bio_bio_st *b; 131 132 if (bio == NULL) { 133 return 0; 134 } 135 b = bio->ptr; 136 137 assert(b != NULL); 138 139 if (b->peer) { 140 bio_destroy_pair(bio); 141 } 142 143 if (b->buf != NULL) { 144 OPENSSL_free(b->buf); 145 } 146 147 OPENSSL_free(b); 148 149 return 1; 150 } 151 152 static int bio_read(BIO *bio, char *buf, int size_) { 153 size_t size = size_; 154 size_t rest; 155 struct bio_bio_st *b, *peer_b; 156 157 BIO_clear_retry_flags(bio); 158 159 if (!bio->init) { 160 return 0; 161 } 162 163 b = bio->ptr; 164 assert(b != NULL); 165 assert(b->peer != NULL); 166 peer_b = b->peer->ptr; 167 assert(peer_b != NULL); 168 assert(peer_b->buf != NULL); 169 170 peer_b->request = 0; /* will be set in "retry_read" situation */ 171 172 if (buf == NULL || size == 0) { 173 return 0; 174 } 175 176 if (peer_b->len == 0) { 177 if (peer_b->closed) { 178 return 0; /* writer has closed, and no data is left */ 179 } else { 180 BIO_set_retry_read(bio); /* buffer is empty */ 181 if (size <= peer_b->size) { 182 peer_b->request = size; 183 } else { 184 /* don't ask for more than the peer can 185 * deliver in one write */ 186 peer_b->request = peer_b->size; 187 } 188 return -1; 189 } 190 } 191 192 /* we can read */ 193 if (peer_b->len < size) { 194 size = peer_b->len; 195 } 196 197 /* now read "size" bytes */ 198 rest = size; 199 200 assert(rest > 0); 201 /* one or two iterations */ 202 do { 203 size_t chunk; 204 205 assert(rest <= peer_b->len); 206 if (peer_b->offset + rest <= peer_b->size) { 207 chunk = rest; 208 } else { 209 /* wrap around ring buffer */ 210 chunk = peer_b->size - peer_b->offset; 211 } 212 assert(peer_b->offset + chunk <= peer_b->size); 213 214 memcpy(buf, peer_b->buf + peer_b->offset, chunk); 215 216 peer_b->len -= chunk; 217 if (peer_b->len) { 218 peer_b->offset += chunk; 219 assert(peer_b->offset <= peer_b->size); 220 if (peer_b->offset == peer_b->size) { 221 peer_b->offset = 0; 222 } 223 buf += chunk; 224 } else { 225 /* buffer now empty, no need to advance "buf" */ 226 assert(chunk == rest); 227 peer_b->offset = 0; 228 } 229 rest -= chunk; 230 } while (rest); 231 232 return size; 233 } 234 235 static int bio_write(BIO *bio, const char *buf, int num_) { 236 size_t num = num_; 237 size_t rest; 238 struct bio_bio_st *b; 239 240 BIO_clear_retry_flags(bio); 241 242 if (!bio->init || buf == NULL || num == 0) { 243 return 0; 244 } 245 246 b = bio->ptr; 247 assert(b != NULL); 248 assert(b->peer != NULL); 249 assert(b->buf != NULL); 250 251 b->request = 0; 252 if (b->closed) { 253 /* we already closed */ 254 OPENSSL_PUT_ERROR(BIO, bio_write, BIO_R_BROKEN_PIPE); 255 return -1; 256 } 257 258 assert(b->len <= b->size); 259 260 if (b->len == b->size) { 261 BIO_set_retry_write(bio); /* buffer is full */ 262 return -1; 263 } 264 265 /* we can write */ 266 if (num > b->size - b->len) { 267 num = b->size - b->len; 268 } 269 270 /* now write "num" bytes */ 271 rest = num; 272 273 assert(rest > 0); 274 /* one or two iterations */ 275 do { 276 size_t write_offset; 277 size_t chunk; 278 279 assert(b->len + rest <= b->size); 280 281 write_offset = b->offset + b->len; 282 if (write_offset >= b->size) { 283 write_offset -= b->size; 284 } 285 /* b->buf[write_offset] is the first byte we can write to. */ 286 287 if (write_offset + rest <= b->size) { 288 chunk = rest; 289 } else { 290 /* wrap around ring buffer */ 291 chunk = b->size - write_offset; 292 } 293 294 memcpy(b->buf + write_offset, buf, chunk); 295 296 b->len += chunk; 297 298 assert(b->len <= b->size); 299 300 rest -= chunk; 301 buf += chunk; 302 } while (rest); 303 304 return num; 305 } 306 307 static int bio_make_pair(BIO *bio1, BIO *bio2) { 308 struct bio_bio_st *b1, *b2; 309 310 assert(bio1 != NULL); 311 assert(bio2 != NULL); 312 313 b1 = bio1->ptr; 314 b2 = bio2->ptr; 315 316 if (b1->peer != NULL || b2->peer != NULL) { 317 OPENSSL_PUT_ERROR(BIO, bio_make_pair, BIO_R_IN_USE); 318 return 0; 319 } 320 321 if (b1->buf == NULL) { 322 b1->buf = OPENSSL_malloc(b1->size); 323 if (b1->buf == NULL) { 324 OPENSSL_PUT_ERROR(BIO, bio_make_pair, ERR_R_MALLOC_FAILURE); 325 return 0; 326 } 327 b1->len = 0; 328 b1->offset = 0; 329 } 330 331 if (b2->buf == NULL) { 332 b2->buf = OPENSSL_malloc(b2->size); 333 if (b2->buf == NULL) { 334 OPENSSL_PUT_ERROR(BIO, bio_make_pair, ERR_R_MALLOC_FAILURE); 335 return 0; 336 } 337 b2->len = 0; 338 b2->offset = 0; 339 } 340 341 b1->peer = bio2; 342 b1->closed = 0; 343 b1->request = 0; 344 b2->peer = bio1; 345 b2->closed = 0; 346 b2->request = 0; 347 348 bio1->init = 1; 349 bio2->init = 1; 350 351 return 1; 352 } 353 354 static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr) { 355 long ret; 356 struct bio_bio_st *b = bio->ptr; 357 358 assert(b != NULL); 359 360 switch (cmd) { 361 /* specific CTRL codes */ 362 363 case BIO_C_SET_BUFF_SIZE: 364 if (b->peer) { 365 OPENSSL_PUT_ERROR(BIO, bio_ctrl, BIO_R_IN_USE); 366 ret = 0; 367 } else if (num == 0) { 368 OPENSSL_PUT_ERROR(BIO, bio_ctrl, BIO_R_INVALID_ARGUMENT); 369 ret = 0; 370 } else { 371 size_t new_size = num; 372 373 if (b->size != new_size) { 374 if (b->buf) { 375 OPENSSL_free(b->buf); 376 b->buf = NULL; 377 } 378 b->size = new_size; 379 } 380 ret = 1; 381 } 382 break; 383 384 case BIO_C_GET_WRITE_BUF_SIZE: 385 ret = (long)b->size; 386 break; 387 388 case BIO_C_GET_WRITE_GUARANTEE: 389 /* How many bytes can the caller feed to the next write 390 * without having to keep any? */ 391 if (b->peer == NULL || b->closed) { 392 ret = 0; 393 } else { 394 ret = (long)b->size - b->len; 395 } 396 break; 397 398 case BIO_C_GET_READ_REQUEST: 399 /* If the peer unsuccessfully tried to read, how many bytes 400 * were requested? (As with BIO_CTRL_PENDING, that number 401 * can usually be treated as boolean.) */ 402 ret = (long)b->request; 403 break; 404 405 case BIO_C_RESET_READ_REQUEST: 406 /* Reset request. (Can be useful after read attempts 407 * at the other side that are meant to be non-blocking, 408 * e.g. when probing SSL_read to see if any data is 409 * available.) */ 410 b->request = 0; 411 ret = 1; 412 break; 413 414 case BIO_C_SHUTDOWN_WR: 415 /* similar to shutdown(..., SHUT_WR) */ 416 b->closed = 1; 417 ret = 1; 418 break; 419 420 /* standard CTRL codes follow */ 421 422 case BIO_CTRL_RESET: 423 if (b->buf != NULL) { 424 b->len = 0; 425 b->offset = 0; 426 } 427 ret = 0; 428 break; 429 430 case BIO_CTRL_GET_CLOSE: 431 ret = bio->shutdown; 432 break; 433 434 case BIO_CTRL_SET_CLOSE: 435 bio->shutdown = (int)num; 436 ret = 1; 437 break; 438 439 case BIO_CTRL_PENDING: 440 if (b->peer != NULL) { 441 struct bio_bio_st *peer_b = b->peer->ptr; 442 ret = (long)peer_b->len; 443 } else { 444 ret = 0; 445 } 446 break; 447 448 case BIO_CTRL_WPENDING: 449 ret = 0; 450 if (b->buf != NULL) { 451 ret = (long)b->len; 452 } 453 break; 454 455 case BIO_CTRL_FLUSH: 456 ret = 1; 457 break; 458 459 case BIO_CTRL_EOF: { 460 BIO *other_bio = ptr; 461 462 if (other_bio) { 463 struct bio_bio_st *other_b = other_bio->ptr; 464 assert(other_b != NULL); 465 ret = other_b->len == 0 && other_b->closed; 466 } else { 467 ret = 1; 468 } 469 } break; 470 471 default: 472 ret = 0; 473 } 474 return ret; 475 } 476 477 static int bio_puts(BIO *bio, const char *str) { 478 return bio_write(bio, str, strlen(str)); 479 } 480 481 int BIO_new_bio_pair(BIO **bio1_p, size_t writebuf1, BIO **bio2_p, 482 size_t writebuf2) { 483 BIO *bio1 = NULL, *bio2 = NULL; 484 long r; 485 int ret = 0; 486 487 bio1 = BIO_new(BIO_s_bio()); 488 if (bio1 == NULL) { 489 goto err; 490 } 491 bio2 = BIO_new(BIO_s_bio()); 492 if (bio2 == NULL) { 493 goto err; 494 } 495 496 if (writebuf1) { 497 r = BIO_set_write_buffer_size(bio1, writebuf1); 498 if (!r) { 499 goto err; 500 } 501 } 502 if (writebuf2) { 503 r = BIO_set_write_buffer_size(bio2, writebuf2); 504 if (!r) { 505 goto err; 506 } 507 } 508 509 if (!bio_make_pair(bio1, bio2)) { 510 goto err; 511 } 512 ret = 1; 513 514 err: 515 if (ret == 0) { 516 if (bio1) { 517 BIO_free(bio1); 518 bio1 = NULL; 519 } 520 if (bio2) { 521 BIO_free(bio2); 522 bio2 = NULL; 523 } 524 } 525 526 *bio1_p = bio1; 527 *bio2_p = bio2; 528 return ret; 529 } 530 531 static const BIO_METHOD methods_biop = { 532 BIO_TYPE_BIO, "BIO pair", bio_write, bio_read, 533 bio_puts, NULL /* no bio_gets */, bio_ctrl, bio_new, 534 bio_free, NULL /* no bio_callback_ctrl */ 535 }; 536 537 const BIO_METHOD *BIO_s_bio(void) { return &methods_biop; } 538 539 size_t BIO_ctrl_get_read_request(BIO *bio) { 540 return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL); 541 } 542 543 size_t BIO_ctrl_get_write_guarantee(BIO *bio) { 544 return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL); 545 } 546 547 int BIO_shutdown_wr(BIO *bio) { 548 return BIO_ctrl(bio, BIO_C_SHUTDOWN_WR, 0, NULL); 549 } 550