Local sockets: Add basic packet send logic

4 files changed, 296 insertions, 7 deletions

diff --git a/nuttx/net/local/Make.defs b/nuttx/net/local/Make.defs
index 35dc643cc..cd79ede8b 100644
--- a/nuttx/net/local/Make.defs
+++ b/nuttx/net/local/Make.defs
@@ -39,7 +39,7 @@ ifeq ($(CONFIG_NET_LOCAL),y)
 
 NET_CSRCS += local_conn.c local_connect.c local_release.c local_bind.c
 NET_CSRCS += local_listen.c local_accept.c local_fifo.c local_recvfrom.c
-NET_CSRCS += local_send.c local_sendto.c
+NET_CSRCS += local_send.c local_sendto.c local_utils.c
 
 # Include UDP build support
 
diff --git a/nuttx/net/local/local.h b/nuttx/net/local/local.h
index 275a658ac..dc733d15f 100644
--- a/nuttx/net/local/local.h
+++ b/nuttx/net/local/local.h
@@ -54,6 +54,18 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+/* Packet format in FIFO:
+ *
+ * 1. Sync bytes (7 at most)
+ * 2. End/Start byte
+ * 3. 16-bit packet length (in host order)
+ * 4. Packet data (in host order)
+ * 5. 16-bit checksum (in host order, includes packet length)
+ */
+
+#define LOCAL_SYNC_BYTE   0x42                /* Byte in sync sequence */
+#define LOCAL_END_BYTE    0xbd                /* End of sync seqence */
+
 /****************************************************************************
  * Public Type Definitions
  ****************************************************************************/
@@ -312,7 +324,7 @@ int psock_local_accept(FAR struct socket *psock, FAR struct sockaddr *addr,
  *   psock    An instance of the internal socket structure.
  *   buf      Data to send
  *   len      Length of data to send
- *   flags    Send flags
+ *   flags    Send flags (ignored for now)
  *
  * Return:
  *   On success, returns the number of characters sent.  On  error,
@@ -334,7 +346,7 @@ ssize_t psock_local_send(FAR struct socket *psock, FAR const void *buf,
  *   psock    A pointer to a NuttX-specific, internal socket structure
  *   buf      Data to send
  *   len      Length of data to send
- *   flags    Send flags
+ *   flags    Send flags (ignored for now)
  *   to       Address of recipient
  *   tolen    The length of the address structure
  *
@@ -365,7 +377,7 @@ ssize_t psock_local_sendto(FAR struct socket *psock, FAR const void *buf,
  *   psock    A pointer to a NuttX-specific, internal socket structure
  *   buf      Buffer to receive data
  *   len      Length of buffer
- *   flags    Receive flags
+ *   flags    Receive flags (ignored for now)
  *   from     Address of source (may be NULL)
  *   fromlen  The length of the address structure
  *
@@ -441,6 +453,61 @@ int local_open_server_rx(FAR struct local_conn_s *server);
 
 int local_open_server_tx(FAR struct local_conn_s *server);
 
+/****************************************************************************
+ * Name: local_chksum
+ *
+ * Description:
+ *   Compute a simple checksum over the packet data
+ *
+ * Parameters:
+ *   buf      Data to send
+ *   len      Length of data to send
+ *
+ * Return:
+ *   The 16-bit checksum (including the length)
+ *
+ ****************************************************************************/
+
+uint16_t local_chksum(FAR const uint8_t *buf, size_t len);
+
+/****************************************************************************
+ * Name: local_write
+ *
+ * Description:
+ *   Write a data on the write-only FIFO.
+ *
+ * Parameters:
+ *   fd       File descriptor or write-only FIFO.
+ *   buf      Data to send
+ *   len      Length of data to send
+ *
+ * Return:
+ *   On success, returns the number of characters sent.  On  error, a
+ *   negated errno value is returned.
+ *
+ ****************************************************************************/
+
+int local_write(int fd, FAR const uint8_t *buf, size_t len);
+
+/****************************************************************************
+ * Name: local_send_packet
+ *
+ * Description:
+ *   Write a packet on the write-only FIFO.
+ *
+ * Parameters:
+ *   fd       File descriptor or write-only FIFO.
+ *   buf      Data to send
+ *   len      Length of data to send
+ *
+ * Return:
+ *   Zero is returned on success; a negated errno value is returned on any
+ *   failure.
+ *
+ ****************************************************************************/
+
+int local_send_packet(int fd, FAR const uint8_t *buf, size_t len);
+
 #undef EXTERN
 #ifdef __cplusplus
 }
diff --git a/nuttx/net/local/local_send.c b/nuttx/net/local/local_send.c
index b0cb1d22f..74bf7f0a4 100644
--- a/nuttx/net/local/local_send.c
+++ b/nuttx/net/local/local_send.c
@@ -42,6 +42,8 @@
 
 #include <sys/types.h>
 #include <errno.h>
+#include <assert.h>
+#include <debug.h>
 
 #include <nuttx/net/net.h>
 
@@ -61,7 +63,7 @@
  *   psock    An instance of the internal socket structure.
  *   buf      Data to send
  *   len      Length of data to send
- *   flags    Send flags
+ *   flags    Send flags (ignored for now)
  *
  * Return:
  *   On success, returns the number of characters sent.  On  error,
@@ -73,8 +75,23 @@
 ssize_t psock_local_send(FAR struct socket *psock, FAR const void *buf,
                          size_t len, int flags)
 {
-#warning Missing logic
-  return -ENOSYS;
+  FAR struct local_conn_s *peer;
+
+  DEBUGASSERT(psock && psock->s_conn && buf);
+  peer = (FAR struct local_conn_s *)psock->s_conn;
+
+  /* Verify that this is a connected peer socket and that it has opened the
+   * outgoing FIFO for write-only access.
+   */
+
+  if (peer->lc_type != LOCAL_STATE_CONNECTED ||
+      peer->lc_outfd < 0)
+    {
+      ndbg("ERROR: not connected\n");
+      return -ENOTCONN;
+    }
+
+  return local_send_packet(peer->lc_outfd, (FAR uint8_t *)buf, len);
 }
 
 #endif /* CONFIG_NET && CONFIG_NET_LOCAL */
diff --git a/nuttx/net/local/local_utils.c b/nuttx/net/local/local_utils.c
new file mode 100644
index 000000000..5b69b650b
--- /dev/null
+++ b/nuttx/net/local/local_utils.c
@@ -0,0 +1,205 @@
+/****************************************************************************
+ * net/local/local_utils.c
+ *
+ *   Copyright (C) 2015 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>
+#if defined(CONFIG_NET) && defined(CONFIG_NET_LOCAL)
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <errno.h>
+#include <assert.h>
+#include <debug.h>
+
+#include "local/local.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define LOCAL_PREAMBLE_SIZE 8
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const uint8_t g_preamble[LOCAL_PREAMBLE_SIZE] =
+{
+  LOCAL_SYNC_BYTE, LOCAL_SYNC_BYTE, LOCAL_SYNC_BYTE, LOCAL_SYNC_BYTE,
+  LOCAL_SYNC_BYTE, LOCAL_SYNC_BYTE, LOCAL_SYNC_BYTE, LOCAL_END_BYTE
+};
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: local_chksum
+ *
+ * Description:
+ *   Compute a simple checksum over the packet data
+ *
+ * Parameters:
+ *   buf      Data to send
+ *   len      Length of data to send
+ *
+ * Return:
+ *   The 16-bit checksum (including the length)
+ *
+ ****************************************************************************/
+
+uint16_t local_chksum(FAR const uint8_t *buf, size_t len)
+{
+  uint16_t chksum;
+  int i;
+
+  DEBUGASSERT(buf && len <= 0xffff);
+
+  chksum = (len & 0xff)  + ((len >> 8) & 0xff);
+  for (i = 0; i < len; i++)
+    {
+      chksum += *buf++;
+    }
+
+  return chksum;
+}
+
+/****************************************************************************
+ * Name: local_write
+ *
+ * Description:
+ *   Write a data on the write-only FIFO.
+ *
+ * Parameters:
+ *   fd       File descriptor or write-only FIFO.
+ *   buf      Data to send
+ *   len      Length of data to send
+ *
+ * Return:
+ *   Zero is returned on success; a negated errno value is returned on any
+ *   failure.
+ *
+ ****************************************************************************/
+
+int local_write(int fd, FAR const uint8_t *buf, size_t len)
+{
+  ssize_t nwritten;
+
+  while (len > 0)
+    {
+      nwritten = write(fd, buf, len);
+      if (nwritten < 0)
+        {
+          int errcode = errno;
+          DEBUGASSERT(errcode > 0);
+
+          if (errcode != EINTR)
+            {
+              ndbg("ERROR: Write failed: %d\n", errcode);
+              return -errcode;
+            }
+
+          nvdbg("Ignoring signal\n");
+        }
+      else
+        {
+          DEBUGASSERT(nwritten > 0 && nwritten <= len);
+          len -= nwritten;
+          buf += nwritten;
+        }
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: local_send_packet
+ *
+ * Description:
+ *   Write a packet on the write-only FIFO.
+ *
+ * Parameters:
+ *   fd       File descriptor or write-only FIFO.
+ *   buf      Data to send
+ *   len      Length of data to send
+ *
+ * Return:
+ *   Zero is returned on success; a negated errno value is returned on any
+ *   failure.
+ *
+ ****************************************************************************/
+
+int local_send_packet(int fd, FAR const uint8_t *buf, size_t len)
+{
+  uint16_t len16;
+  uint16_t chksum;
+  int ret;
+
+  /* Compute the checksum over the packet data (including the length) */
+
+  chksum = local_chksum(buf, len);
+
+  /* Send the packet preamble */
+
+  ret = local_write(fd, g_preamble, LOCAL_PREAMBLE_SIZE);
+  if (ret == OK)
+    {
+      /* Send the packet length */
+
+      len16 = len;
+      ret = local_write(fd, (FAR const uint8_t *)&len16, sizeof(uint16_t));
+      if(ret == OK)
+        {
+          /* Send the packet data */
+
+          ret = local_write(fd, buf, len);
+          if (ret == OK)
+            {
+              /* Send the checksum */
+
+              ret = local_write(fd, (FAR const uint8_t *)&chksum,
+                                sizeof(uint16_t));
+            }
+        }
+    }
+
+  return ret;
+}
+
+#endif /* CONFIG_NET && CONFIG_NET_LOCAL */