bss_bio.c

OpenSSL 0.9.8k 最新版OpenSSL

	if (write_offset >= b->size)
		write_offset -= b->size;
	if (write_offset + num > b->size)
		/* no ring buffer wrap-around for non-copying interface
		 * (to fulfil the promise by BIO_ctrl_get_write_guarantee,
		 * BIO_nwrite may have to be called twice) */
		num = b->size - write_offset;

	if (buf != NULL)
		*buf = b->buf + write_offset;
	assert(write_offset + num <= b->size);

	return num;
	}

static ssize_t bio_nwrite(BIO *bio, char **buf, size_t num_)
	{
	struct bio_bio_st *b;
	ssize_t num, space;

	if (num_ > SSIZE_MAX)
		num = SSIZE_MAX;
	else
		num = (ssize_t)num_;

	space = bio_nwrite0(bio, buf);
	if (num > space)
		num = space;
	if (num <= 0)
		return num;
	b = bio->ptr;
	assert(b != NULL);
	b->len += num;
	assert(b->len <= b->size);

	return num;
	}


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_SET_WRITE_BUF_SIZE:
		if (b->peer)
			{
			BIOerr(BIO_F_BIO_CTRL, BIO_R_IN_USE);
			ret = 0;
			}
		else if (num == 0)
			{
			BIOerr(BIO_F_BIO_CTRL, BIO_R_INVALID_ARGUMENT);
			ret = 0;
			}
		else
			{
			size_t new_size = num;

			if (b->size != new_size)
				{
				if (b->buf) 
					{
					OPENSSL_free(b->buf);
					b->buf = NULL;
					}
				b->size = new_size;
				}
			ret = 1;
			}
		break;

	case BIO_C_GET_WRITE_BUF_SIZE:
		ret = (long) b->size;
		break;

	case BIO_C_MAKE_BIO_PAIR:
		{
		BIO *other_bio = ptr;
		
		if (bio_make_pair(bio, other_bio))
			ret = 1;
		else
			ret = 0;
		}
		break;
		
	case BIO_C_DESTROY_BIO_PAIR:
		/* Affects both BIOs in the pair -- call just once!
		 * Or let BIO_free(bio1); BIO_free(bio2); do the job. */
		bio_destroy_pair(bio);
		ret = 1;
		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;

	case BIO_C_NREAD0:
		/* prepare for non-copying read */
		ret = (long) bio_nread0(bio, ptr);
		break;
		
	case BIO_C_NREAD:
		/* non-copying read */
		ret = (long) bio_nread(bio, ptr, (size_t) num);
		break;
		
	case BIO_C_NWRITE0:
		/* prepare for non-copying write */
		ret = (long) bio_nwrite0(bio, ptr);
		break;

	case BIO_C_NWRITE:
		/* non-copying write */
		ret = (long) bio_nwrite(bio, ptr, (size_t) num);
		break;
		

	/* standard CTRL codes follow */

	case BIO_CTRL_RESET:
		if (b->buf != NULL)
			{
			b->len = 0;
			b->offset = 0;
			}
		ret = 0;
		break;		

	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:
		if (b->buf != NULL)
			ret = (long) b->len;
		else
			ret = 0;
		break;

	case BIO_CTRL_DUP:
		/* See BIO_dup_chain for circumstances we have to expect. */
		{
		BIO *other_bio = ptr;
		struct bio_bio_st *other_b;
		
		assert(other_bio != NULL);
		other_b = other_bio->ptr;
		assert(other_b != NULL);
		
		assert(other_b->buf == NULL); /* other_bio is always fresh */

		other_b->size = b->size;
		}

		ret = 1;
		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 int bio_puts(BIO *bio, const char *str)
	{
	return bio_write(bio, str, strlen(str));
	}


static int bio_make_pair(BIO *bio1, BIO *bio2)
	{
	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)
		{
		BIOerr(BIO_F_BIO_MAKE_PAIR, BIO_R_IN_USE);
		return 0;
		}
	
	if (b1->buf == NULL)
		{
		b1->buf = OPENSSL_malloc(b1->size);
		if (b1->buf == NULL)
			{
			BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
			return 0;
			}
		b1->len = 0;
		b1->offset = 0;
		}
	
	if (b2->buf == NULL)
		{
		b2->buf = OPENSSL_malloc(b2->size);
		if (b2->buf == NULL)
			{
			BIOerr(BIO_F_BIO_MAKE_PAIR, 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 void bio_destroy_pair(BIO *bio)
	{
	struct bio_bio_st *b = bio->ptr;

	if (b != NULL)
		{
		BIO *peer_bio = b->peer;

		if (peer_bio != NULL)
			{
			struct bio_bio_st *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;
			}
		}
	}
 

/* Exported convenience functions */
int BIO_new_bio_pair(BIO **bio1_p, size_t writebuf1,
	BIO **bio2_p, size_t writebuf2)
	 {
	 BIO *bio1 = NULL, *bio2 = NULL;
	 long r;
	 int ret = 0;

	 bio1 = BIO_new(BIO_s_bio());
	 if (bio1 == NULL)
		 goto err;
	 bio2 = BIO_new(BIO_s_bio());
	 if (bio2 == NULL)
		 goto err;

	 if (writebuf1)
		 {
		 r = BIO_set_write_buf_size(bio1, writebuf1);
		 if (!r)
			 goto err;
		 }
	 if (writebuf2)
		 {
		 r = BIO_set_write_buf_size(bio2, writebuf2);
		 if (!r)
			 goto err;
		 }

	 r = BIO_make_bio_pair(bio1, bio2);
	 if (!r)
		 goto err;
	 ret = 1;

 err:
	 if (ret == 0)
		 {
		 if (bio1)
			 {
			 BIO_free(bio1);
			 bio1 = NULL;
			 }
		 if (bio2)
			 {
			 BIO_free(bio2);
			 bio2 = NULL;
			 }
		 }

	 *bio1_p = bio1;
	 *bio2_p = bio2;
	 return ret;
	 }

size_t BIO_ctrl_get_write_guarantee(BIO *bio)
	{
	return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL);
	}

size_t BIO_ctrl_get_read_request(BIO *bio)
	{
	return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL);
	}

int BIO_ctrl_reset_read_request(BIO *bio)
	{
	return (BIO_ctrl(bio, BIO_C_RESET_READ_REQUEST, 0, NULL) != 0);
	}


/* BIO_nread0/nread/nwrite0/nwrite are available only for BIO pairs for now
 * (conceivably some other BIOs could allow non-copying reads and writes too.)
 */
int BIO_nread0(BIO *bio, char **buf)
	{
	long ret;

	if (!bio->init)
		{
		BIOerr(BIO_F_BIO_NREAD0, BIO_R_UNINITIALIZED);
		return -2;
		}

	ret = BIO_ctrl(bio, BIO_C_NREAD0, 0, buf);
	if (ret > INT_MAX)
		return INT_MAX;
	else
		return (int) ret;
	}

int BIO_nread(BIO *bio, char **buf, int num)
	{
	int ret;

	if (!bio->init)
		{
		BIOerr(BIO_F_BIO_NREAD, BIO_R_UNINITIALIZED);
		return -2;
		}

	ret = (int) BIO_ctrl(bio, BIO_C_NREAD, num, buf);
	if (ret > 0)
		bio->num_read += ret;
	return ret;
	}

int BIO_nwrite0(BIO *bio, char **buf)
	{
	long ret;

	if (!bio->init)
		{
		BIOerr(BIO_F_BIO_NWRITE0, BIO_R_UNINITIALIZED);
		return -2;
		}

	ret = BIO_ctrl(bio, BIO_C_NWRITE0, 0, buf);
	if (ret > INT_MAX)
		return INT_MAX;
	else
		return (int) ret;
	}

int BIO_nwrite(BIO *bio, char **buf, int num)
	{
	int ret;

	if (!bio->init)
		{
		BIOerr(BIO_F_BIO_NWRITE, BIO_R_UNINITIALIZED);
		return -2;
		}

	ret = BIO_ctrl(bio, BIO_C_NWRITE, num, buf);
	if (ret > 0)
		bio->num_write += ret;
	return ret;
	}