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@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@cryptsoft.com). This product includes software written by Tim
51 * Hudson (tjh@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
65struct 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
84static 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
98static 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
130static 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
150static 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
233static 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
305static 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
359static 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
454static 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
459static const BIO_METHOD *bio_s_bio(void) { return &methods_biop; }
460
461int 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
479size_t BIO_ctrl_get_read_request(BIO *bio) {
480 return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL);
481}
482
483size_t BIO_ctrl_get_write_guarantee(BIO *bio) {
484 return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL);
485}
486
487int BIO_shutdown_wr(BIO *bio) {
488 return BIO_ctrl(bio, BIO_C_SHUTDOWN_WR, 0, NULL);
489}
490