C++ BIO_set_retry_read函數代碼示例

static int mem_read(BIO *b, char *out, int outl)
{
    int ret = -1;
    BUF_MEM *bm;

    bm = (BUF_MEM *)b->ptr;
    BIO_clear_retry_flags(b);
    ret = (outl >= 0 && (size_t)outl > bm->length) ? (int)bm->length : outl;
    if ((out != NULL) && (ret > 0)) {
        memcpy(out, bm->data, ret);
        bm->length -= ret;
        if (b->flags & BIO_FLAGS_MEM_RDONLY)
            bm->data += ret;
        else {
            memmove(&(bm->data[0]), &(bm->data[ret]), bm->length);
        }
    } else if (bm->length == 0) {
        ret = b->num;
        if (ret != 0)
            BIO_set_retry_read(b);
    }
    return (ret);
}

static int conn_read(BIO *bio, char *out, int out_len) {
  int ret = 0;
  BIO_CONNECT *data;

  data = (BIO_CONNECT *)bio->ptr;
  if (data->state != BIO_CONN_S_OK) {
    ret = conn_state(bio, data);
    if (ret <= 0) {
      return ret;
    }
  }

  bio_clear_socket_error();
  ret = recv(bio->num, out, out_len, 0);
  BIO_clear_retry_flags(bio);
  if (ret <= 0) {
    if (bio_fd_should_retry(ret)) {
      BIO_set_retry_read(bio);
    }
  }

  return ret;
}

static int dgram_read(BIO *b, char *out, int outl)
	{
	int ret=0;
	bio_dgram_data *data = (bio_dgram_data *)b->ptr;

	struct sockaddr peer;
	int peerlen = sizeof(peer);

	if (out != NULL)
		{
		clear_socket_error();
		memset(&peer, 0x00, peerlen);
		/* Last arg in recvfrom is signed on some platforms and
		 * unsigned on others. It is of type socklen_t on some
		 * but this is not universal. Cast to (void *) to avoid
		 * compiler warnings.
		 */
		dgram_adjust_rcv_timeout(b);
		ret=recvfrom(b->num,out,outl,0,&peer,(void *)&peerlen);

		if ( ! data->connected  && ret >= 0)
			BIO_ctrl(b, BIO_CTRL_DGRAM_SET_PEER, 0, &peer);

		BIO_clear_retry_flags(b);
		if (ret < 0)
			{
			if (BIO_dgram_should_retry(ret))
				{
				BIO_set_retry_read(b);
				data->_errno = get_last_socket_error();
				}
			}

		dgram_reset_rcv_timeout(b);
		}
	return(ret);
	}

static int nbiof_read (BIO * b, char *out, int outl)
{
    int ret = 0;

#if 1
    int num;

    unsigned char n;
#endif

    if (out == NULL)
        return (0);
    if (b->next_bio == NULL)
        return (0);

    BIO_clear_retry_flags (b);
#if 1
    RAND_pseudo_bytes (&n, 1);
    num = (n & 0x07);

    if (outl > num)
        outl = num;

    if (num == 0)
    {
        ret = -1;
        BIO_set_retry_read (b);
    }
    else
#endif
    {
        ret = BIO_read (b->next_bio, out, outl);
        if (ret < 0)
            BIO_copy_next_retry (b);
    }
    return (ret);
}

static int rdg_bio_read(BIO* bio, char* buf, int size)
{
	int status;
	rdpRdg* rdg = (rdpRdg*) BIO_get_data(bio);
	status = rdg_read_data_packet(rdg, (BYTE*) buf, size);

	if (status < 0)
	{
		BIO_clear_retry_flags(bio);
		return -1;
	}
	else if (status == 0)
	{
		BIO_set_retry_read(bio);
		WSASetLastError(WSAEWOULDBLOCK);
		return -1;
	}
	else
	{
		BIO_set_flags(bio, BIO_FLAGS_READ);
	}

	return status;
}

/* Called to extract data from the BIO. */
static int
bio_bufferevent_read(BIO *b, char *out, int outlen)
{
	int r = 0;
	struct evbuffer *input;

	BIO_clear_retry_flags(b);

	if (!out)
		return 0;
	if (!BIO_get_data(b))
		return -1;

	input = bufferevent_get_input(BIO_get_data(b));
	if (evbuffer_get_length(input) == 0) {
		/* If there's no data to read, say so. */
		BIO_set_retry_read(b);
		return -1;
	} else {
		r = evbuffer_remove(input, out, outlen);
	}

	return r;
}

inline int memq_read (BIO *b, char *out, int size)
{
	MemQ *bmq = (MemQ*)b->ptr;
	int ret = -1;
	BIO_clear_retry_flags (b);
	if (!bmq->empty())
	{
		try {
			ret = (int)bmq->read((unsigned char *)out, (size_t)size);
		}
		catch (...)
		{
			BIOerr(BIO_F_MEM_READ, BIO_R_INVALID_ARGUMENT);
			return -1;
		}
	}
	else
	{
		ret = b->num;
		if (ret != 0)
			BIO_set_retry_read (b);
	}
	return ret;
}

/* Returns the amount read. */
static int bio_apr_socket_read(BIO *bio, char *in, int inlen)
{
    apr_size_t len = inlen;
    serv_ctx_t *serv_ctx = bio->ptr;
    apr_status_t status;

    BIO_clear_retry_flags(bio);

    status = apr_socket_recv(serv_ctx->client_sock, in, &len);
    serv_ctx->bio_read_status = status;
    serf__log_skt(TEST_VERBOSE, __FILE__, serv_ctx->client_sock,
                  "Read %d bytes from socket with status %d.\n", len, status);

    if (status == APR_EAGAIN) {
        BIO_set_retry_read(bio);
        if (len == 0)
            return -1;
    }

    if (SERF_BUCKET_READ_ERROR(status))
        return -1;

    return len;
}

static int tou_socket_read(BIO *b, char *out, int outl)
	{
	int ret=0;
#ifdef DEBUG_TOU_BIO
	fprintf(stderr, "tou_socket_read(%p,%p,%d)\n",b,out,outl);
#endif

	if (out != NULL)
		{
		clear_tou_socket_error(b->num);
		/* call tou library */
		ret=tou_read(b->num,out,outl);
		BIO_clear_retry_flags(b);
		if (ret <= 0)
			{
			if (BIO_tou_socket_should_retry(b->num, ret))
				BIO_set_retry_read(b);
			}
		}
#ifdef DEBUG_TOU_BIO
	fprintf(stderr, "tou_socket_read() = %d\n", ret);
#endif
	return(ret);
	}

void BIO_set_retry_read_shim(BIO *b) {
    BIO_set_retry_read(b);
}

//.........這裏部分代碼省略.........
        if (s->info_callback != NULL)
            cb = s->info_callback;
        else if (s->ctx->info_callback != NULL)
            cb = s->ctx->info_callback;

        if (cb != NULL) {
            j = (alert_level << 8) | alert_descr;
            cb(s, SSL_CB_READ_ALERT, j);
        }

        if (alert_level == SSL3_AL_WARNING) {
            s->s3.warn_alert = alert_descr;
            SSL3_RECORD_set_read(rr);

            s->rlayer.alert_count++;
            if (s->rlayer.alert_count == MAX_WARN_ALERT_COUNT) {
                SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
                         SSL_R_TOO_MANY_WARN_ALERTS);
                return -1;
            }

            if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
#ifndef OPENSSL_NO_SCTP
                /*
                 * With SCTP and streams the socket may deliver app data
                 * after a close_notify alert. We have to check this first so
                 * that nothing gets discarded.
                 */
                if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
                    BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
                    s->d1->shutdown_received = 1;
                    s->rwstate = SSL_READING;
                    BIO_clear_retry_flags(SSL_get_rbio(s));
                    BIO_set_retry_read(SSL_get_rbio(s));
                    return -1;
                }
#endif
                s->shutdown |= SSL_RECEIVED_SHUTDOWN;
                return 0;
            }
        } else if (alert_level == SSL3_AL_FATAL) {
            char tmp[16];

            s->rwstate = SSL_NOTHING;
            s->s3.fatal_alert = alert_descr;
            SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_DTLS1_READ_BYTES,
                     SSL_AD_REASON_OFFSET + alert_descr);
            BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
            ERR_add_error_data(2, "SSL alert number ", tmp);
            s->shutdown |= SSL_RECEIVED_SHUTDOWN;
            SSL3_RECORD_set_read(rr);
            SSL_CTX_remove_session(s->session_ctx, s->session);
            return 0;
        } else {
            SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_DTLS1_READ_BYTES,
                     SSL_R_UNKNOWN_ALERT_TYPE);
            return -1;
        }

        goto start;
    }

    if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
                                            * shutdown */
        s->rwstate = SSL_NOTHING;
        SSL3_RECORD_set_length(rr, 0);

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 || peer_b->zero_copy_read_lock) {
    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);

    memcpy(buf, peer_b->buf + peer_b->offset, chunk);

    peer_b->len -= chunk;
    /* If zero_copy_write_lock == 1 we must advance the offset even if buffer
     * becomes empty, to make sure write_offset = (offset + len) % size
     * does not change. */
    if (peer_b->len || peer_b->zero_copy_write_lock) {
      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;
}

int bio_ber_get_header(BIO *bio, BIO_BER_CTX *ctx)
	{
	char buf[64];
	int i,j,n;
	int ret;
	unsigned char *p;
	unsigned long length
	int tag;
	int class;
	long max;

	BIO_clear_retry_flags(b);

	/* Pack the buffer down if there is a hole at the front */
	if (ctx->buf_off != 0)
		{
		p=ctx->buf;
		j=ctx->buf_off;
		n=ctx->buf_len-j;
		for (i=0; i<n; i++)
			{
			p[0]=p[j];
			p++;
			}
		ctx->buf_len-j;
		ctx->buf_off=0;
		}

	/* If there is more room, read some more data */
	i=BER_BUF_SIZE-ctx->buf_len;
	if (i)
		{
		i=BIO_read(bio->next_bio,&(ctx->buf[ctx->buf_len]),i);
		if (i <= 0)
			{
			BIO_copy_next_retry(b);
			return(i);
			}
		else
			ctx->buf_len+=i;
		}

	max=ctx->buf_len;
	p=ctx->buf;
	ret=ASN1_get_object(&p,&length,&tag,&class,max);

	if (ret & 0x80)
		{
		if ((ctx->buf_len < BER_BUF_SIZE) &&
			(ERR_GET_REASON(ERR_peek_error()) == ASN1_R_TOO_LONG))
			{
			ERR_clear_error(); /* clear the error */
			BIO_set_retry_read(b);
			}
		return(-1);
		}

	/* We have no error, we have a header, so make use of it */

	if ((ctx->tag  >= 0) && (ctx->tag != tag))
		{
		BIOerr(BIO_F_BIO_BER_GET_HEADER,BIO_R_TAG_MISMATCH);
		sprintf(buf,"tag=%d, got %d",ctx->tag,tag);
		ERR_add_error_data(1,buf);
		return(-1);
		}
	if (ret & 0x01)
	if (ret & V_ASN1_CONSTRUCTED)
	}

static int ssl_read(BIO *b, char *buf, size_t size, size_t *readbytes)
{
    int ret = 1;
    BIO_SSL *sb;
    SSL *ssl;
    int retry_reason = 0;
    int r = 0;

    if (buf == NULL)
        return 0;
    sb = BIO_get_data(b);
    ssl = sb->ssl;

    BIO_clear_retry_flags(b);

    ret = ssl_read_internal(ssl, buf, size, readbytes);

    switch (SSL_get_error(ssl, ret)) {
    case SSL_ERROR_NONE:
        if (sb->renegotiate_count > 0) {
            sb->byte_count += *readbytes;
            if (sb->byte_count > sb->renegotiate_count) {
                sb->byte_count = 0;
                sb->num_renegotiates++;
                SSL_renegotiate(ssl);
                r = 1;
            }
        }
        if ((sb->renegotiate_timeout > 0) && (!r)) {
            unsigned long tm;

            tm = (unsigned long)time(NULL);
            if (tm > sb->last_time + sb->renegotiate_timeout) {
                sb->last_time = tm;
                sb->num_renegotiates++;
                SSL_renegotiate(ssl);
            }
        }

        break;
    case SSL_ERROR_WANT_READ:
        BIO_set_retry_read(b);
        break;
    case SSL_ERROR_WANT_WRITE:
        BIO_set_retry_write(b);
        break;
    case SSL_ERROR_WANT_X509_LOOKUP:
        BIO_set_retry_special(b);
        retry_reason = BIO_RR_SSL_X509_LOOKUP;
        break;
    case SSL_ERROR_WANT_ACCEPT:
        BIO_set_retry_special(b);
        retry_reason = BIO_RR_ACCEPT;
        break;
    case SSL_ERROR_WANT_CONNECT:
        BIO_set_retry_special(b);
        retry_reason = BIO_RR_CONNECT;
        break;
    case SSL_ERROR_SYSCALL:
    case SSL_ERROR_SSL:
    case SSL_ERROR_ZERO_RETURN:
    default:
        break;
    }

    BIO_set_retry_reason(b, retry_reason);

    return ret;
}

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);
	do /* one or two iterations */
		{
		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);

		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;
	}