IOB: Add iob_clone()

2 files changed, 193 insertions, 3 deletions

diff --git a/nuttx/net/iob/Make.defs b/nuttx/net/iob/Make.defs
index f84d8f017..4f9a52c23 100644
--- a/nuttx/net/iob/Make.defs
+++ b/nuttx/net/iob/Make.defs
@@ -40,9 +40,9 @@ ifeq ($(CONFIG_NET_IOB),y)
 
 # Include IOB src files
 
-NET_CSRCS += iob_alloc.c iob_concat.c iob_copyin.c iob_copyout.c iob_free.c
-NET_CSRCS += iob_freeq.c iob_initialize.c iob_pack.c iob_trimhead.c
-NET_CSRCS += iob_trimtail.c
+NET_CSRCS += iob_alloc.c iob_clone.c iob_concat.c iob_copyin.c iob_copyout.c
+NET_CSRCS += iob_free.c iob_freeq.c iob_initialize.c iob_pack.c
+NET_CSRCS += iob_trimhead.c iob_trimtail.c
 
 # Include iob build support
 
diff --git a/nuttx/net/iob/iob_clone.c b/nuttx/net/iob/iob_clone.c
new file mode 100644
index 000000000..0ba98f9f2
--- /dev/null
+++ b/nuttx/net/iob/iob_clone.c
@@ -0,0 +1,190 @@
+/****************************************************************************
+ * net/iob1/iob_copy.c
+ *
+ *   Copyright (C) 2014 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 <string.h>
+#include <queue.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/net/iob.h>
+
+#include "iob.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifndef MIN
+#  define MIN(a,b) ((a) < (b) ? (a) : (b))
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: iob_clone
+ *
+ * Description:
+ *   Duplicate (and pack) the data in iob1 in iob2.  iob2 must be empty.
+ *
+ ****************************************************************************/
+
+int iob_clone(FAR struct iob_s *iob1, FAR struct iob_s *iob2)
+{
+  FAR uint8_t *src;
+  FAR uint8_t *dest;
+  unsigned int ncopy;
+  unsigned int avail1;
+  unsigned int avail2;
+  unsigned int offset1;
+  unsigned int offset2;
+
+  DEBUGASSERT(iob2->io_len == 0 && iob2->io_offset == 0 &&
+              iob2->io_pktlen == 0 && iob2->io_link.flink == NULL);
+
+  /* Copy the header information */
+
+  iob2->io_flags = iob1->io_flags;
+  iob2->io_pktlen = iob1->io_pktlen;
+  iob2->io_priv = iob1->io_priv;
+
+  /* Handle special case where there are empty buffers at the head
+   * the the list.
+   */
+
+  while (iob1->io_len <= 0)
+    {
+      iob1 = (FAR struct iob_s *)iob1->io_link.flink;
+    }
+
+  /* Pack each entry from iob1 to iob2 */
+
+  offset1 = 0;
+  offset2 = 0;
+
+  while (iob1)
+    {
+      /* Get the source I/O buffer pointer and the number of bytes to copy
+       * from this address.
+       */
+
+      src    = &iob1->io_data[iob1->io_offset + offset1];
+      avail1 = iob1->io_len - offset1;
+
+      /* Get the destination I/O buffer pointer and the number of bytes to
+       * copy to that address.
+       */
+
+      dest   = &iob2->io_data[offset2];
+      avail2 = CONFIG_IOB_BUFSIZE - offset2;
+
+      /* Copy the smaller of the two and update the srce and destination
+       * offsets.
+       */
+
+      ncopy = MIN(avail1, avail2);
+      memcpy(dest, src, ncopy);
+
+      offset1 += ncopy;
+      offset2 += ncopy;
+
+      /* Have we taken all of the data from the source I/O buffer? */
+
+      if (offset1 >= iob1->io_len)
+        {
+          /* Skip over empty entries in the chain (there should not be any
+           * but just to be safe).
+           */
+
+          do
+            {
+              /* Yes.. move to the next source I/O buffer */
+
+              iob1 = (FAR struct iob_s *)iob1->io_link.flink;
+            }
+          while (iob1->io_len <= 0);
+
+          /* Reset the offset to the beginning of the I/O buffer */
+
+          offset1 = 0;
+        }
+
+      /* Have we filled the destination I/O buffer? Is there more data to be
+       * transferred?
+       */
+
+       if (offset2 >= CONFIG_IOB_BUFSIZE && iob1 != NULL)
+        {
+          FAR struct iob_s *next;
+
+          /* Allocate new destination I/O buffer and hook it into the
+           * destination I/O buffer chain.
+           */
+
+          next = iob_alloc();
+          if (!next)
+            {
+              ndbg("Failed to allocate an I/O buffer/n");
+              return -ENOMEM;
+            }
+
+          iob2->io_link.flink = &next->io_link;
+          iob2 = next;
+          offset2 = 0;
+        }
+    }
+
+  return 0;
+}