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- /****************************************************************************
- * mm/iob/iob_copyin.c
- *
- * Copyright (C) 2014, 2016-2018 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * 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. Neither the name NuttX nor the names of its contributors may be
- * used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS 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
- * COPYRIGHT OWNER OR 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.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <stdint.h>
- #include <string.h>
- #include <errno.h>
- #include <assert.h>
- #include <debug.h>
- #include <nuttx/mm/iob.h>
- #include "iob.h"
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: iob_copyin_internal
- *
- * Description:
- * Copy data 'len' bytes from a user buffer into the I/O buffer chain,
- * starting at 'offset', extending the chain as necessary.
- *
- * Returned Value:
- * The number of uncopied bytes left if >= 0 OR a negative error code.
- *
- ****************************************************************************/
- static int iob_copyin_internal(FAR struct iob_s *iob, FAR const uint8_t *src,
- unsigned int len, unsigned int offset,
- bool throttled, bool can_block,
- enum iob_user_e consumerid)
- {
- FAR struct iob_s *head = iob;
- FAR struct iob_s *next;
- FAR uint8_t *dest;
- unsigned int ncopy;
- unsigned int avail;
- unsigned int total = len;
- iobinfo("iob=%p len=%u offset=%u\n", iob, len, offset);
- DEBUGASSERT(iob && src);
- /* The offset must applied to data that is already in the I/O buffer chain */
- if (offset > iob->io_pktlen)
- {
- ioberr("ERROR: offset is past the end of data: %u > %u\n",
- offset, iob->io_pktlen);
- return -ESPIPE;
- }
- /* Skip to the I/O buffer containing the data offset */
- while (offset > iob->io_len)
- {
- offset -= iob->io_len;
- iob = iob->io_flink;
- }
- /* Then loop until all of the I/O data is copied from the user buffer */
- while (len > 0)
- {
- next = iob->io_flink;
- /* Get the destination I/O buffer address and the amount of data
- * available from that address.
- */
- dest = &iob->io_data[iob->io_offset + offset];
- avail = iob->io_len - offset;
- iobinfo("iob=%p avail=%u len=%u next=%p\n", iob, avail, len, next);
- /* Will the rest of the copy fit into this buffer, overwriting
- * existing data.
- */
- if (len > avail)
- {
- /* No.. Is this the last buffer in the chain? */
- if (next)
- {
- /* No.. clip to size that will overwrite. We cannot
- * extend the length of an I/O block in mid-chain.
- */
- ncopy = avail;
- }
- else
- {
- unsigned int maxlen;
- unsigned int newlen;
- /* Yes.. We can extend this buffer to the up to the very end. */
- maxlen = CONFIG_IOB_BUFSIZE - iob->io_offset;
- /* This is the new buffer length that we need. Of course,
- * clipped to the maximum possible size in this buffer.
- */
- newlen = len + offset;
- if (newlen > maxlen)
- {
- newlen = maxlen;
- }
- /* Set the new length and increment the packet length */
- head->io_pktlen += (newlen - iob->io_len);
- iob->io_len = newlen;
- /* Set the new number of bytes to copy */
- ncopy = newlen - offset;
- }
- }
- else
- {
- /* Yes.. Copy all of the remaining bytes */
- ncopy = len;
- }
- /* Copy from the user buffer to the I/O buffer. */
- memcpy(dest, src, ncopy);
- iobinfo("iob=%p Copy %u bytes new len=%u\n",
- iob, ncopy, iob->io_len);
- /* Adjust the total length of the copy and the destination address in
- * the user buffer.
- */
- len -= ncopy;
- src += ncopy;
- /* Skip to the next I/O buffer in the chain. First, check if we
- * are at the end of the buffer chain.
- */
- if (len > 0 && !next)
- {
- /* Yes.. allocate a new buffer.
- *
- * Copy as many bytes as possible. Block if we're allowed.
- */
- if (can_block)
- {
- next = iob_alloc(throttled, consumerid);
- }
- else
- {
- next = iob_tryalloc(throttled, consumerid);
- }
- if (next == NULL)
- {
- ioberr("ERROR: Failed to allocate I/O buffer\n");
- return -ENOMEM;
- }
- /* Add the new, empty I/O buffer to the end of the buffer chain. */
- iob->io_flink = next;
- iobinfo("iob=%p added to the chain\n", iob);
- }
- iob = next;
- offset = 0;
- }
- return total;
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: iob_copyin
- *
- * Description:
- * Copy data 'len' bytes from a user buffer into the I/O buffer chain,
- * starting at 'offset', extending the chain as necessary.
- *
- ****************************************************************************/
- int iob_copyin(FAR struct iob_s *iob, FAR const uint8_t *src,
- unsigned int len, unsigned int offset, bool throttled,
- enum iob_user_e consumerid)
- {
- return iob_copyin_internal(iob, src, len, offset, throttled, true, consumerid);
- }
- /****************************************************************************
- * Name: iob_trycopyin
- *
- * Description:
- * Copy data 'len' bytes from a user buffer into the I/O buffer chain,
- * starting at 'offset', extending the chain as necessary BUT without
- * waiting if buffers are not available.
- *
- ****************************************************************************/
- int iob_trycopyin(FAR struct iob_s *iob, FAR const uint8_t *src,
- unsigned int len, unsigned int offset, bool throttled,
- enum iob_user_e consumerid)
- {
- return iob_copyin_internal(iob, src, len, offset, throttled, false, consumerid);
- }
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