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 #include <string.h> 57 58 #include <openssl/buf.h> 59 #include <openssl/err.h> 60 #include <openssl/mem.h> 61 62 #include "../internal.h" 63 64 65 struct bio_bio_st { 66 BIO *peer; // NULL if buf == NULL. 67 // If peer != NULL, then peer->ptr is also a bio_bio_st, 68 // and its "peer" member points back to us. 69 // peer != NULL iff init != 0 in the BIO. 70 71 // This is for what we write (i.e. reading uses peer's struct): 72 int closed; // valid iff peer != NULL 73 size_t len; // valid iff buf != NULL; 0 if peer == NULL 74 size_t offset; // valid iff buf != NULL; 0 if len == 0 75 size_t size; 76 uint8_t *buf; // "size" elements (if != NULL) 77 78 size_t request; // valid iff peer != NULL; 0 if len != 0, 79 // otherwise set by peer to number of bytes 80 // it (unsuccessfully) tried to read, 81 // never more than buffer space (size-len) warrants. 82 }; 83 84 static int bio_new(BIO *bio) { 85 struct bio_bio_st *b; 86 87 b = OPENSSL_malloc(sizeof *b); 88 if (b == NULL) { 89 return 0; 90 } 91 OPENSSL_memset(b, 0, sizeof(struct bio_bio_st)); 92 93 b->size = 17 * 1024; // enough for one TLS record (just a default) 94 bio->ptr = b; 95 return 1; 96 } 97 98 static void bio_destroy_pair(BIO *bio) { 99 struct bio_bio_st *b = bio->ptr; 100 BIO *peer_bio; 101 struct bio_bio_st *peer_b; 102 103 if (b == NULL) { 104 return; 105 } 106 107 peer_bio = b->peer; 108 if (peer_bio == NULL) { 109 return; 110 } 111 112 peer_b = peer_bio->ptr; 113 114 assert(peer_b != NULL); 115 assert(peer_b->peer == bio); 116 117 peer_b->peer = NULL; 118 peer_bio->init = 0; 119 assert(peer_b->buf != NULL); 120 peer_b->len = 0; 121 peer_b->offset = 0; 122 123 b->peer = NULL; 124 bio->init = 0; 125 assert(b->buf != NULL); 126 b->len = 0; 127 b->offset = 0; 128 } 129 130 static int bio_free(BIO *bio) { 131 struct bio_bio_st *b; 132 133 if (bio == NULL) { 134 return 0; 135 } 136 b = bio->ptr; 137 138 assert(b != NULL); 139 140 if (b->peer) { 141 bio_destroy_pair(bio); 142 } 143 144 OPENSSL_free(b->buf); 145 OPENSSL_free(b); 146 147 return 1; 148 } 149 150 static int bio_read(BIO *bio, char *buf, int size_) { 151 size_t size = size_; 152 size_t rest; 153 struct bio_bio_st *b, *peer_b; 154 155 BIO_clear_retry_flags(bio); 156 157 if (!bio->init) { 158 return 0; 159 } 160 161 b = bio->ptr; 162 assert(b != NULL); 163 assert(b->peer != NULL); 164 peer_b = b->peer->ptr; 165 assert(peer_b != NULL); 166 assert(peer_b->buf != NULL); 167 168 peer_b->request = 0; // will be set in "retry_read" situation 169 170 if (buf == NULL || size == 0) { 171 return 0; 172 } 173 174 if (peer_b->len == 0) { 175 if (peer_b->closed) { 176 return 0; // writer has closed, and no data is left 177 } else { 178 BIO_set_retry_read(bio); // buffer is empty 179 if (size <= peer_b->size) { 180 peer_b->request = size; 181 } else { 182 // don't ask for more than the peer can 183 // deliver in one write 184 peer_b->request = peer_b->size; 185 } 186 return -1; 187 } 188 } 189 190 // we can read 191 if (peer_b->len < size) { 192 size = peer_b->len; 193 } 194 195 // now read "size" bytes 196 rest = size; 197 198 assert(rest > 0); 199 // one or two iterations 200 do { 201 size_t chunk; 202 203 assert(rest <= peer_b->len); 204 if (peer_b->offset + rest <= peer_b->size) { 205 chunk = rest; 206 } else { 207 // wrap around ring buffer 208 chunk = peer_b->size - peer_b->offset; 209 } 210 assert(peer_b->offset + chunk <= peer_b->size); 211 212 OPENSSL_memcpy(buf, peer_b->buf + peer_b->offset, chunk); 213 214 peer_b->len -= chunk; 215 if (peer_b->len) { 216 peer_b->offset += chunk; 217 assert(peer_b->offset <= peer_b->size); 218 if (peer_b->offset == peer_b->size) { 219 peer_b->offset = 0; 220 } 221 buf += chunk; 222 } else { 223 // buffer now empty, no need to advance "buf" 224 assert(chunk == rest); 225 peer_b->offset = 0; 226 } 227 rest -= chunk; 228 } while (rest); 229 230 return size; 231 } 232 233 static int bio_write(BIO *bio, const char *buf, int num_) { 234 size_t num = num_; 235 size_t rest; 236 struct bio_bio_st *b; 237 238 BIO_clear_retry_flags(bio); 239 240 if (!bio->init || buf == NULL || num == 0) { 241 return 0; 242 } 243 244 b = bio->ptr; 245 assert(b != NULL); 246 assert(b->peer != NULL); 247 assert(b->buf != NULL); 248 249 b->request = 0; 250 if (b->closed) { 251 // we already closed 252 OPENSSL_PUT_ERROR(BIO, BIO_R_BROKEN_PIPE); 253 return -1; 254 } 255 256 assert(b->len <= b->size); 257 258 if (b->len == b->size) { 259 BIO_set_retry_write(bio); // buffer is full 260 return -1; 261 } 262 263 // we can write 264 if (num > b->size - b->len) { 265 num = b->size - b->len; 266 } 267 268 // now write "num" bytes 269 rest = num; 270 271 assert(rest > 0); 272 // one or two iterations 273 do { 274 size_t write_offset; 275 size_t chunk; 276 277 assert(b->len + rest <= b->size); 278 279 write_offset = b->offset + b->len; 280 if (write_offset >= b->size) { 281 write_offset -= b->size; 282 } 283 // b->buf[write_offset] is the first byte we can write to. 284 285 if (write_offset + rest <= b->size) { 286 chunk = rest; 287 } else { 288 // wrap around ring buffer 289 chunk = b->size - write_offset; 290 } 291 292 OPENSSL_memcpy(b->buf + write_offset, buf, chunk); 293 294 b->len += chunk; 295 296 assert(b->len <= b->size); 297 298 rest -= chunk; 299 buf += chunk; 300 } while (rest); 301 302 return num; 303 } 304 305 static int bio_make_pair(BIO *bio1, BIO *bio2, size_t writebuf1_len, 306 size_t writebuf2_len) { 307 struct bio_bio_st *b1, *b2; 308 309 assert(bio1 != NULL); 310 assert(bio2 != NULL); 311 312 b1 = bio1->ptr; 313 b2 = bio2->ptr; 314 315 if (b1->peer != NULL || b2->peer != NULL) { 316 OPENSSL_PUT_ERROR(BIO, BIO_R_IN_USE); 317 return 0; 318 } 319 320 if (b1->buf == NULL) { 321 if (writebuf1_len) { 322 b1->size = writebuf1_len; 323 } 324 b1->buf = OPENSSL_malloc(b1->size); 325 if (b1->buf == NULL) { 326 OPENSSL_PUT_ERROR(BIO, ERR_R_MALLOC_FAILURE); 327 return 0; 328 } 329 b1->len = 0; 330 b1->offset = 0; 331 } 332 333 if (b2->buf == NULL) { 334 if (writebuf2_len) { 335 b2->size = writebuf2_len; 336 } 337 b2->buf = OPENSSL_malloc(b2->size); 338 if (b2->buf == NULL) { 339 OPENSSL_PUT_ERROR(BIO, ERR_R_MALLOC_FAILURE); 340 return 0; 341 } 342 b2->len = 0; 343 b2->offset = 0; 344 } 345 346 b1->peer = bio2; 347 b1->closed = 0; 348 b1->request = 0; 349 b2->peer = bio1; 350 b2->closed = 0; 351 b2->request = 0; 352 353 bio1->init = 1; 354 bio2->init = 1; 355 356 return 1; 357 } 358 359 static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr) { 360 long ret; 361 struct bio_bio_st *b = bio->ptr; 362 363 assert(b != NULL); 364 365 switch (cmd) { 366 // specific CTRL codes 367 368 case BIO_C_GET_WRITE_BUF_SIZE: 369 ret = (long)b->size; 370 break; 371 372 case BIO_C_GET_WRITE_GUARANTEE: 373 // How many bytes can the caller feed to the next write 374 // without having to keep any? 375 if (b->peer == NULL || b->closed) { 376 ret = 0; 377 } else { 378 ret = (long)b->size - b->len; 379 } 380 break; 381 382 case BIO_C_GET_READ_REQUEST: 383 // If the peer unsuccessfully tried to read, how many bytes 384 // were requested? (As with BIO_CTRL_PENDING, that number 385 // can usually be treated as boolean.) 386 ret = (long)b->request; 387 break; 388 389 case BIO_C_RESET_READ_REQUEST: 390 // Reset request. (Can be useful after read attempts 391 // at the other side that are meant to be non-blocking, 392 // e.g. when probing SSL_read to see if any data is 393 // available.) 394 b->request = 0; 395 ret = 1; 396 break; 397 398 case BIO_C_SHUTDOWN_WR: 399 // similar to shutdown(..., SHUT_WR) 400 b->closed = 1; 401 ret = 1; 402 break; 403 404 // standard CTRL codes follow 405 406 case BIO_CTRL_GET_CLOSE: 407 ret = bio->shutdown; 408 break; 409 410 case BIO_CTRL_SET_CLOSE: 411 bio->shutdown = (int)num; 412 ret = 1; 413 break; 414 415 case BIO_CTRL_PENDING: 416 if (b->peer != NULL) { 417 struct bio_bio_st *peer_b = b->peer->ptr; 418 ret = (long)peer_b->len; 419 } else { 420 ret = 0; 421 } 422 break; 423 424 case BIO_CTRL_WPENDING: 425 ret = 0; 426 if (b->buf != NULL) { 427 ret = (long)b->len; 428 } 429 break; 430 431 case BIO_CTRL_FLUSH: 432 ret = 1; 433 break; 434 435 case BIO_CTRL_EOF: { 436 BIO *other_bio = ptr; 437 438 if (other_bio) { 439 struct bio_bio_st *other_b = other_bio->ptr; 440 assert(other_b != NULL); 441 ret = other_b->len == 0 && other_b->closed; 442 } else { 443 ret = 1; 444 } 445 } break; 446 447 default: 448 ret = 0; 449 } 450 return ret; 451 } 452 453 454 static const BIO_METHOD methods_biop = { 455 BIO_TYPE_BIO, "BIO pair", bio_write, bio_read, NULL /* puts */, 456 NULL /* gets */, bio_ctrl, bio_new, bio_free, NULL /* callback_ctrl */, 457 }; 458 459 static const BIO_METHOD *bio_s_bio(void) { return &methods_biop; } 460 461 int BIO_new_bio_pair(BIO** bio1_p, size_t writebuf1_len, 462 BIO** bio2_p, size_t writebuf2_len) { 463 BIO *bio1 = BIO_new(bio_s_bio()); 464 BIO *bio2 = BIO_new(bio_s_bio()); 465 if (bio1 == NULL || bio2 == NULL || 466 !bio_make_pair(bio1, bio2, writebuf1_len, writebuf2_len)) { 467 BIO_free(bio1); 468 BIO_free(bio2); 469 *bio1_p = NULL; 470 *bio2_p = NULL; 471 return 0; 472 } 473 474 *bio1_p = bio1; 475 *bio2_p = bio2; 476 return 1; 477 } 478 479 size_t BIO_ctrl_get_read_request(BIO *bio) { 480 return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL); 481 } 482 483 size_t BIO_ctrl_get_write_guarantee(BIO *bio) { 484 return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL); 485 } 486 487 int BIO_shutdown_wr(BIO *bio) { 488 return BIO_ctrl(bio, BIO_C_SHUTDOWN_WR, 0, NULL); 489 } 490