ref: 2cdc6577ef8a251bf1740439cf5bfc47050dab41
dir: /third_party/boringssl/src/crypto/bio/pair.c/
/* ====================================================================
* Copyright (c) 1998-2003 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com). */
#include <openssl/bio.h>
#include <assert.h>
#include <string.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include "../internal.h"
struct bio_bio_st {
BIO *peer; // NULL if buf == NULL.
// If peer != NULL, then peer->ptr is also a bio_bio_st,
// and its "peer" member points back to us.
// peer != NULL iff init != 0 in the BIO.
// This is for what we write (i.e. reading uses peer's struct):
int closed; // valid iff peer != NULL
size_t len; // valid iff buf != NULL; 0 if peer == NULL
size_t offset; // valid iff buf != NULL; 0 if len == 0
size_t size;
uint8_t *buf; // "size" elements (if != NULL)
size_t request; // valid iff peer != NULL; 0 if len != 0,
// otherwise set by peer to number of bytes
// it (unsuccessfully) tried to read,
// never more than buffer space (size-len) warrants.
};
static int bio_new(BIO *bio) {
struct bio_bio_st *b;
b = OPENSSL_malloc(sizeof *b);
if (b == NULL) {
return 0;
}
OPENSSL_memset(b, 0, sizeof(struct bio_bio_st));
b->size = 17 * 1024; // enough for one TLS record (just a default)
bio->ptr = b;
return 1;
}
static void bio_destroy_pair(BIO *bio) {
struct bio_bio_st *b = bio->ptr;
BIO *peer_bio;
struct bio_bio_st *peer_b;
if (b == NULL) {
return;
}
peer_bio = b->peer;
if (peer_bio == NULL) {
return;
}
peer_b = peer_bio->ptr;
assert(peer_b != NULL);
assert(peer_b->peer == bio);
peer_b->peer = NULL;
peer_bio->init = 0;
assert(peer_b->buf != NULL);
peer_b->len = 0;
peer_b->offset = 0;
b->peer = NULL;
bio->init = 0;
assert(b->buf != NULL);
b->len = 0;
b->offset = 0;
}
static int bio_free(BIO *bio) {
struct bio_bio_st *b = bio->ptr;
assert(b != NULL);
if (b->peer) {
bio_destroy_pair(bio);
}
OPENSSL_free(b->buf);
OPENSSL_free(b);
return 1;
}
static int bio_read(BIO *bio, char *buf, int size_) {
size_t size = size_;
size_t rest;
struct bio_bio_st *b, *peer_b;
BIO_clear_retry_flags(bio);
if (!bio->init) {
return 0;
}
b = bio->ptr;
assert(b != NULL);
assert(b->peer != NULL);
peer_b = b->peer->ptr;
assert(peer_b != NULL);
assert(peer_b->buf != NULL);
peer_b->request = 0; // will be set in "retry_read" situation
if (buf == NULL || size == 0) {
return 0;
}
if (peer_b->len == 0) {
if (peer_b->closed) {
return 0; // writer has closed, and no data is left
} else {
BIO_set_retry_read(bio); // buffer is empty
if (size <= peer_b->size) {
peer_b->request = size;
} else {
// don't ask for more than the peer can
// deliver in one write
peer_b->request = peer_b->size;
}
return -1;
}
}
// we can read
if (peer_b->len < size) {
size = peer_b->len;
}
// now read "size" bytes
rest = size;
assert(rest > 0);
// one or two iterations
do {
size_t chunk;
assert(rest <= peer_b->len);
if (peer_b->offset + rest <= peer_b->size) {
chunk = rest;
} else {
// wrap around ring buffer
chunk = peer_b->size - peer_b->offset;
}
assert(peer_b->offset + chunk <= peer_b->size);
OPENSSL_memcpy(buf, peer_b->buf + peer_b->offset, chunk);
peer_b->len -= chunk;
if (peer_b->len) {
peer_b->offset += chunk;
assert(peer_b->offset <= peer_b->size);
if (peer_b->offset == peer_b->size) {
peer_b->offset = 0;
}
buf += chunk;
} else {
// buffer now empty, no need to advance "buf"
assert(chunk == rest);
peer_b->offset = 0;
}
rest -= chunk;
} while (rest);
return size;
}
static int bio_write(BIO *bio, const char *buf, int num_) {
size_t num = num_;
size_t rest;
struct bio_bio_st *b;
BIO_clear_retry_flags(bio);
if (!bio->init || buf == NULL || num == 0) {
return 0;
}
b = bio->ptr;
assert(b != NULL);
assert(b->peer != NULL);
assert(b->buf != NULL);
b->request = 0;
if (b->closed) {
// we already closed
OPENSSL_PUT_ERROR(BIO, BIO_R_BROKEN_PIPE);
return -1;
}
assert(b->len <= b->size);
if (b->len == b->size) {
BIO_set_retry_write(bio); // buffer is full
return -1;
}
// we can write
if (num > b->size - b->len) {
num = b->size - b->len;
}
// now write "num" bytes
rest = num;
assert(rest > 0);
// one or two iterations
do {
size_t write_offset;
size_t chunk;
assert(b->len + rest <= b->size);
write_offset = b->offset + b->len;
if (write_offset >= b->size) {
write_offset -= b->size;
}
// b->buf[write_offset] is the first byte we can write to.
if (write_offset + rest <= b->size) {
chunk = rest;
} else {
// wrap around ring buffer
chunk = b->size - write_offset;
}
OPENSSL_memcpy(b->buf + write_offset, buf, chunk);
b->len += chunk;
assert(b->len <= b->size);
rest -= chunk;
buf += chunk;
} while (rest);
return num;
}
static int bio_make_pair(BIO *bio1, BIO *bio2, size_t writebuf1_len,
size_t writebuf2_len) {
struct bio_bio_st *b1, *b2;
assert(bio1 != NULL);
assert(bio2 != NULL);
b1 = bio1->ptr;
b2 = bio2->ptr;
if (b1->peer != NULL || b2->peer != NULL) {
OPENSSL_PUT_ERROR(BIO, BIO_R_IN_USE);
return 0;
}
if (b1->buf == NULL) {
if (writebuf1_len) {
b1->size = writebuf1_len;
}
b1->buf = OPENSSL_malloc(b1->size);
if (b1->buf == NULL) {
OPENSSL_PUT_ERROR(BIO, ERR_R_MALLOC_FAILURE);
return 0;
}
b1->len = 0;
b1->offset = 0;
}
if (b2->buf == NULL) {
if (writebuf2_len) {
b2->size = writebuf2_len;
}
b2->buf = OPENSSL_malloc(b2->size);
if (b2->buf == NULL) {
OPENSSL_PUT_ERROR(BIO, ERR_R_MALLOC_FAILURE);
return 0;
}
b2->len = 0;
b2->offset = 0;
}
b1->peer = bio2;
b1->closed = 0;
b1->request = 0;
b2->peer = bio1;
b2->closed = 0;
b2->request = 0;
bio1->init = 1;
bio2->init = 1;
return 1;
}
static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr) {
long ret;
struct bio_bio_st *b = bio->ptr;
assert(b != NULL);
switch (cmd) {
// specific CTRL codes
case BIO_C_GET_WRITE_BUF_SIZE:
ret = (long)b->size;
break;
case BIO_C_GET_WRITE_GUARANTEE:
// How many bytes can the caller feed to the next write
// without having to keep any?
if (b->peer == NULL || b->closed) {
ret = 0;
} else {
ret = (long)b->size - b->len;
}
break;
case BIO_C_GET_READ_REQUEST:
// If the peer unsuccessfully tried to read, how many bytes
// were requested? (As with BIO_CTRL_PENDING, that number
// can usually be treated as boolean.)
ret = (long)b->request;
break;
case BIO_C_RESET_READ_REQUEST:
// Reset request. (Can be useful after read attempts
// at the other side that are meant to be non-blocking,
// e.g. when probing SSL_read to see if any data is
// available.)
b->request = 0;
ret = 1;
break;
case BIO_C_SHUTDOWN_WR:
// similar to shutdown(..., SHUT_WR)
b->closed = 1;
ret = 1;
break;
// standard CTRL codes follow
case BIO_CTRL_GET_CLOSE:
ret = bio->shutdown;
break;
case BIO_CTRL_SET_CLOSE:
bio->shutdown = (int)num;
ret = 1;
break;
case BIO_CTRL_PENDING:
if (b->peer != NULL) {
struct bio_bio_st *peer_b = b->peer->ptr;
ret = (long)peer_b->len;
} else {
ret = 0;
}
break;
case BIO_CTRL_WPENDING:
ret = 0;
if (b->buf != NULL) {
ret = (long)b->len;
}
break;
case BIO_CTRL_FLUSH:
ret = 1;
break;
case BIO_CTRL_EOF: {
BIO *other_bio = ptr;
if (other_bio) {
struct bio_bio_st *other_b = other_bio->ptr;
assert(other_b != NULL);
ret = other_b->len == 0 && other_b->closed;
} else {
ret = 1;
}
} break;
default:
ret = 0;
}
return ret;
}
static const BIO_METHOD methods_biop = {
BIO_TYPE_BIO, "BIO pair", bio_write, bio_read, NULL /* puts */,
NULL /* gets */, bio_ctrl, bio_new, bio_free, NULL /* callback_ctrl */,
};
static const BIO_METHOD *bio_s_bio(void) { return &methods_biop; }
int BIO_new_bio_pair(BIO** bio1_p, size_t writebuf1_len,
BIO** bio2_p, size_t writebuf2_len) {
BIO *bio1 = BIO_new(bio_s_bio());
BIO *bio2 = BIO_new(bio_s_bio());
if (bio1 == NULL || bio2 == NULL ||
!bio_make_pair(bio1, bio2, writebuf1_len, writebuf2_len)) {
BIO_free(bio1);
BIO_free(bio2);
*bio1_p = NULL;
*bio2_p = NULL;
return 0;
}
*bio1_p = bio1;
*bio2_p = bio2;
return 1;
}
size_t BIO_ctrl_get_read_request(BIO *bio) {
return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL);
}
size_t BIO_ctrl_get_write_guarantee(BIO *bio) {
return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL);
}
int BIO_shutdown_wr(BIO *bio) {
return BIO_ctrl(bio, BIO_C_SHUTDOWN_WR, 0, NULL);
}