dup() and dup2() support for socket descriptors

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1884 42af7a65-404d-4744-a932-0658087f49c3

11 files changed, 503 insertions, 35 deletions

diff --git a/nuttx/net/Makefile b/nuttx/net/Makefile
index 7880a974e..8802e01d7 100644
--- a/nuttx/net/Makefile
+++ b/nuttx/net/Makefile
@@ -38,7 +38,7 @@
 ifeq ($(CONFIG_NET),y)
 SOCK_ASRCS	=
 SOCK_CSRCS	= socket.c bind.c connect.c sendto.c recv.c recvfrom.c \
-		  net_sockets.c net_close.c
+		  net_sockets.c net_close.c net_dup.c net_dup2.c net_clone.c
 
 ifeq ($(CONFIG_NET_TCP),y)
 SOCK_CSRCS	+= send.c listen.c accept.c 
diff --git a/nuttx/net/accept.c b/nuttx/net/accept.c
index a3a2e067e..a9701b2d5 100644
--- a/nuttx/net/accept.c
+++ b/nuttx/net/accept.c
@@ -149,6 +149,14 @@ static int accept_interrupt(struct uip_conn *listener, struct uip_conn *conn)
 
       pstate->acpt_newconn     = conn;
       pstate->acpt_result      = OK;
+
+      /* Set a reference of one on the new connection */
+
+      DEBUGASSERT(conn->crefs == 0);
+      conn->crefs              = 1;
+
+      /* Wake-up the waiting caller thread */
+
       sem_post(&pstate->acpt_sem);
 
       /* Stop any further callbacks */
@@ -405,7 +413,10 @@ int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen)
     }
   irqrestore(save);
 
-  /* Initialize the socket structure and mark the socket as connected */
+  /* Initialize the socket structure and mark the socket as connected.
+   * (The reference count on the new connection structure was set in the
+   * interrupt handler).
+   */
 
   pnewsock->s_type   = SOCK_STREAM;
   pnewsock->s_conn   = state.acpt_newconn;
diff --git a/nuttx/net/net_clone.c b/nuttx/net/net_clone.c
new file mode 100644
index 000000000..e23016073
--- /dev/null
+++ b/nuttx/net/net_clone.c
@@ -0,0 +1,117 @@
+/****************************************************************************
+ * net/net_clone.c
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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>
+#ifdef CONFIG_NET
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "net_internal.h"
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: net_clone
+ *
+ * Description:
+ *   Performs the low level, common portion of net_dup() and net_dup2()
+ *
+ ****************************************************************************/
+
+int net_clone(FAR struct socket *psock1, FAR struct socket *psock2)
+{
+  irqstate_t flags;
+  int ret = OK;
+
+  /* Parts of this operation need to be atomic */
+
+  flags = irqsave();
+
+  /* Duplicate the socket state */
+
+  psock2->s_type     = psock1->s_type;      /* Protocol type: Only SOCK_STREAM or SOCK_DGRAM */
+  psock2->s_flags    = psock1->s_flags;     /* See _SF_* definitions */
+#ifdef CONFIG_NET_SOCKOPTS
+  psock2->s_options  = psock1->s_options;   /* Selected socket options */
+#endif
+#ifndef CONFIG_DISABLE_CLOCK
+  psock2->s_rcvtimeo = psock1->s_rcvtimeo;  /* Receive timeout value (in deciseconds) */
+  psock2->s_sndtimeo = psock1->s_sndtimeo;  /* Send timeout value (in deciseconds) */
+#endif
+  psock2->s_conn     = psock1->s_conn;      /* UDP or TCP connection structure */
+
+  /* Increment the reference count on the connection */
+
+#ifdef CONFIG_NET_TCP
+  if (psock2->s_type == SOCK_STREAM)
+    {
+      struct uip_conn *conn = psock2->s_conn;
+      DEBUGASSERT(conn->crefs > 0);
+      conn->crefs++;
+    }
+  else
+#endif
+#ifdef CONFIG_NET_UDP
+  if (psock2->s_type == SOCK_DGRAM)
+    {
+      struct uip_udp_conn *conn = psock2->s_conn;
+      DEBUGASSERT(conn->crefs > 0);
+      conn->crefs++;
+    }
+  else
+#endif
+    {
+      ndbg("Unsupported type: %d\n", psock2->s_type);
+      ret = -EBADF;
+    }
+
+  irqrestore(flags);
+  return ret;
+}
+
+#endif /* CONFIG_NET */
+
+
diff --git a/nuttx/net/net_close.c b/nuttx/net/net_close.c
index 7ce1f9fa4..f8de0614a 100644
--- a/nuttx/net/net_close.c
+++ b/nuttx/net/net_close.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/net_close.c
  *
- *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -61,7 +61,7 @@ struct tcp_close_s
 {
   FAR struct socket         *cl_psock; /* Reference to the TCP socket */
   FAR struct uip_callback_s *cl_cb;    /* Reference to TCP callback instance */
-  sem_t                      cl_sem;   /* Semaphore signals disconnect completion */
+  sem_t                       cl_sem;   /* Semaphore signals disconnect completion */
 };
 #endif
 
@@ -222,33 +222,75 @@ int net_close(int sockfd)
       goto errout;
     }
 
-  /* Perform uIP side of the close depending on the protocol type */
+  /* We perform the uIP close operation only if this is the last count on the socket.
+   * (actually, I think the socket crefs only takes the values 0 and 1 right now).
+   */
 
-  switch (psock->s_type)
+  if (psock->s_crefs <= 1)
     {
-#ifdef CONFIG_NET_TCP
-      case SOCK_STREAM:
+      /* Perform uIP side of the close depending on the protocol type */
+
+      switch (psock->s_type)
         {
-          struct uip_conn *conn = psock->s_conn;
-          uip_unlisten(conn);          /* No longer accepting connections */
-          netclose_disconnect(psock);  /* Break any current connections */
-          uip_tcpfree(conn);           /* Free uIP resources */
-        }
-        break;
+#ifdef CONFIG_NET_TCP
+          case SOCK_STREAM:
+            {
+              struct uip_conn *conn = psock->s_conn;
+
+              /* Is this the last reference to the connection structure (there
+               * could be more if the socket was dup'ed.
+               */
+
+              if (conn->crefs <= 1)
+                {
+                  /* Yes... free the connection structure */
+
+                 uip_unlisten(conn);          /* No longer accepting connections */
+                  netclose_disconnect(psock);  /* Break any current connections */
+                  uip_tcpfree(conn);           /* Free uIP resources */
+                }
+              else
+                {
+                  /* No.. Just decrement the reference count */
+
+                  conn->crefs--;
+                }
+            }
+            break;
 #endif
 
 #ifdef CONFIG_NET_UDP
-      case SOCK_DGRAM:
-        uip_udpfree(psock->s_conn);    /* Free uIP resources */
-        break;
+          case SOCK_DGRAM:
+            {
+              struct uip_udp_conn *conn = psock->s_conn;
+
+              /* Is this the last reference to the connection structure (there
+               * could be more if the socket was dup'ed.
+               */
+
+              if (conn->crefs <= 1)
+                {
+                  /* Yes... free the connection structure */
+
+                  uip_udpfree(psock->s_conn);    /* Free uIP resources */
+                }
+              else
+                {
+                  /* No.. Just decrement the reference count */
+
+                  conn->crefs--;
+                }
+            }
+            break;
 #endif
 
-      default:
-        err = EBADF;
-        goto errout;
+          default:
+            err = EBADF;
+            goto errout;
+        }
     }
 
-  /* Then release the socket structure containing the connection */
+  /* Then release our reference on the socket structure containing the connection */
 
   sockfd_release(sockfd);
   return OK;
diff --git a/nuttx/net/net_dup.c b/nuttx/net/net_dup.c
new file mode 100644
index 000000000..f4ee15abe
--- /dev/null
+++ b/nuttx/net/net_dup.c
@@ -0,0 +1,134 @@
+/****************************************************************************
+ * net/net_dup.c
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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 <sys/types.h>
+#include <sys/socket.h>
+#include <sched.h>
+#include <errno.h>
+#include <debug.h>
+
+#include "net_internal.h"
+
+#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: net_dup OR dup
+ *
+ * Description:
+ *   Clone a socket descriptor to an arbitray descriptor number.  If file
+ *   descriptors are implemented, then this is called by dup() for the case
+ *   of socket file descriptors.  If file descriptors are not implemented,
+ *   then this function IS dup().
+ *
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTOR > 0
+int net_dup(int sockfd)
+#else
+int dup(int sockfd)
+#endif
+{
+  FAR struct socket *psock1 = sockfd_socket(sockfd);
+  FAR struct socket *psock2;
+  int sockfd2;
+  int err;
+  int ret;
+
+  /* Lock the scheduler throughout the following */
+
+  sched_lock();
+
+  /* Get the socket structure underlying sockfd */
+
+  psock1 = sockfd_socket(sockfd);
+ 
+ /* Verify that the sockfd corresponds to valid, allocated socket */
+
+  if (!psock1 || psock1->s_crefs <= 0)
+    {
+      err = EBADF;
+      goto errout;
+    }
+
+  /* Allocate a new socket descriptor */
+
+  sockfd2 = sockfd_allocate();
+  if (sockfd2 < 0)
+    {
+      err = ENFILE;
+      goto errout;
+    }
+
+  /* Get the socket structure underlying the new descriptor */
+
+  psock2 = sockfd_socket(sockfd2);
+  if (!psock2)
+    {
+      err = ENOSYS; /* should not happen */
+      goto errout;
+    }
+
+  /* Duplicate the socket state */
+
+  ret = net_clone(psock1, psock2);
+  if (ret < 0)
+    {
+      err = -ret;
+      goto errout;
+ 
+    }
+
+  sched_unlock();
+  return sockfd2;
+
+errout:
+  sched_unlock();
+  errno = err;
+  return ERROR;
+}
+
+#endif /* defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0 */
+
+
diff --git a/nuttx/net/net_dup2.c b/nuttx/net/net_dup2.c
new file mode 100644
index 000000000..8992ec226
--- /dev/null
+++ b/nuttx/net/net_dup2.c
@@ -0,0 +1,126 @@
+/****************************************************************************
+ * net/net_dup2.c
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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 <sys/types.h>
+#include <sys/socket.h>
+#include <sched.h>
+#include <errno.h>
+#include <debug.h>
+
+#include "net_internal.h"
+
+#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: net_dup2
+ *
+ * Description:
+ *   Clone a socket descriptor to an arbitray descriptor number.  If file
+ *   descriptors are implemented, then this is called by dup2() for the case
+ *   of socket file descriptors.  If file descriptors are not implemented,
+ *   then this function IS dup2().
+ *
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTOR > 0
+int net_dup2(int sockfd1, int sockfd2)
+#else
+int dup2(int sockfd1, int sockfd2)
+#endif
+{
+  FAR struct socket *psock1;
+  FAR struct socket *psock2;
+  int err;
+  int ret;
+
+  /* Lock the scheduler throughout the following */
+
+  sched_lock();
+
+  /* Get the socket structures underly both descriptors */
+
+  psock1 = sockfd_socket(sockfd1);
+  psock2 = sockfd_socket(sockfd2);
+
+  /* Verify that the sockfd1 and sockfd2 both refer to valid socket
+   * descriptors and that sockfd2 corresponds to allocated socket
+   */
+
+  if (!psock1 || !psock2 || psock1->s_crefs <= 0)
+    {
+      err = EBADF;
+      goto errout;
+    }
+
+  /* If sockfd2 also valid, allocated socket, then we will have to
+   * close it!
+   */
+
+  if (psock2->s_crefs > 0)
+    {
+      net_close(sockfd2);
+    }
+
+  /* Duplicate the socket state */
+
+  ret = net_clone(psock1, psock2);
+  if (ret < 0)
+    {
+      err = -ret;
+      goto errout;
+    }
+
+  sched_unlock();
+  return OK;
+
+errout:
+  sched_unlock();
+  errno = err;
+  return ERROR;
+}
+
+#endif /* CONFIG_NET && CONFIG_NSOCKET_DESCRIPTORS > 0 */
+
+
diff --git a/nuttx/net/net_internal.h b/nuttx/net/net_internal.h
index ebef372f9..ea3fdd5a6 100644
--- a/nuttx/net/net_internal.h
+++ b/nuttx/net/net_internal.h
@@ -1,7 +1,7 @@
 /****************************************************************************
- * net/net-internal.h
+ * net/net_internal.h
  *
- *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -142,7 +142,7 @@ extern "C" {
 #define EXTERN extern
 #endif
 
-/* net-sockets.c *************************************************************/
+/* net_sockets.c *************************************************************/
 
 EXTERN int  sockfd_allocate(void);
 EXTERN void sockfd_release(int sockfd);
@@ -156,38 +156,42 @@ EXTERN socktimeo_t net_timeval2dsec(struct timeval *tv);
 EXTERN void net_dsec2timeval(uint16 dsec, struct timeval *tv);
 #endif
 
-/* net-register.c ************************************************************/
+/* net_clone.c ***************************************************************/
+
+EXTERN int net_clone(FAR struct socket *psock1, FAR struct socket *psock2);
+
+/* net_register.c ************************************************************/
 
 #if CONFIG_NSOCKET_DESCRIPTORS > 0
 EXTERN void netdev_semtake(void);
 # define netdev_semgive() sem_post(&g_netdev_sem)
 #endif
 
-/* net-findbyname.c **********************************************************/
+/* net_findbyname.c **********************************************************/
 
 #if CONFIG_NSOCKET_DESCRIPTORS > 0
 EXTERN FAR struct uip_driver_s *netdev_findbyname(const char *ifname);
 #endif
 
-/* net-findbyaddr.c **********************************************************/
+/* net_findbyaddr.c **********************************************************/
 
 #if CONFIG_NSOCKET_DESCRIPTORS > 0
 EXTERN FAR struct uip_driver_s *netdev_findbyaddr(const uip_ipaddr_t *raddr);
 #endif
 
-/* net-txnotify.c ************************************************************/
+/* net_txnotify.c ************************************************************/
 
 #if CONFIG_NSOCKET_DESCRIPTORS > 0
 EXTERN void netdev_txnotify(const uip_ipaddr_t *raddr);
 #endif
 
-/* net-count.c ***************************************************************/
+/* net_count.c ***************************************************************/
 
 #if CONFIG_NSOCKET_DESCRIPTORS > 0
 EXTERN int netdev_count(void);
 #endif
 
-/* net-arptimer.c ************************************************************/
+/* net_arptimer.c ************************************************************/
 
 EXTERN void arptimer_init(void);
 
diff --git a/nuttx/net/socket.c b/nuttx/net/socket.c
index 161866272..fddff2ccc 100644
--- a/nuttx/net/socket.c
+++ b/nuttx/net/socket.c
@@ -43,6 +43,7 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <errno.h>
+#include <assert.h>
 #include <debug.h>
 
 #include "net_internal.h"
@@ -155,13 +156,43 @@ int socket(int domain, int type, int protocol)
     {
 #ifdef CONFIG_NET_TCP
       case SOCK_STREAM:
-        psock->s_conn = uip_tcpalloc();
+        {
+          /* Allocate the TCP connection structure and save in the new
+           * socket instance.
+           */
+
+          struct uip_conn *conn = uip_tcpalloc();
+          psock->s_conn = conn;
+
+          /* Set the reference count on the connection structure.  This
+           * reference count will be increment only if the socket is
+           * dup'ed
+           */
+
+          DEBUGASSERT(conn->crefs == 0);
+          conn->crefs = 1;
+        }
         break;
 #endif
 
 #ifdef CONFIG_NET_UDP
       case SOCK_DGRAM:
-        psock->s_conn = uip_udpalloc();
+        {
+          /* Allocate the UDP connection structure and save in the new
+           * socket instance.
+           */
+
+          struct uip_udp_conn *conn = uip_udpalloc();
+          psock->s_conn = conn;
+
+          /* Set the reference count on the connection structure.  This
+           * reference count will be increment only if the socket is
+           * dup'ed
+           */
+
+          DEBUGASSERT(conn->crefs == 0);
+          conn->crefs = 1;
+        }
         break;
 #endif
 
diff --git a/nuttx/net/uip/uip_tcpbacklog.c b/nuttx/net/uip/uip_tcpbacklog.c
index 1eecdf9ad..e27c70a51 100644
--- a/nuttx/net/uip/uip_tcpbacklog.c
+++ b/nuttx/net/uip/uip_tcpbacklog.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/uip/uip_tcpbacklog.c
  *
- *   Copyright (C) 2008 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -68,7 +68,7 @@
  *
  * Description:
  *   Called from the listen() logic to setup the backlog as specified in the
- *   the listen arguments *.
+ *   the listen arguments.
  *
  * Assumptions:
  *   Called from normal user code. Interrupts may be disabled.
@@ -213,7 +213,7 @@ int uip_backlogdestroy(FAR struct uip_conn *conn)
  *
  * Description:
  *  Called uip_listen when a new connection is made with a listener socket
- *  but when there is not accept() in place to receive the connection.  This
+ *  but when there is no accept() in place to receive the connection.  This
  *  function adds the new connection to the backlog.
  *
  * Assumptions:
diff --git a/nuttx/net/uip/uip_tcpconn.c b/nuttx/net/uip/uip_tcpconn.c
index af61bab46..12451a47f 100644
--- a/nuttx/net/uip/uip_tcpconn.c
+++ b/nuttx/net/uip/uip_tcpconn.c
@@ -294,6 +294,7 @@ void uip_tcpfree(struct uip_conn *conn)
    * operation.
    */
 
+  DEBUGASSERT(conn->crefs == 0);
   flags = irqsave();
 
   /* UIP_ALLOCATED means that that the connection is not in the active list
diff --git a/nuttx/net/uip/uip_udpconn.c b/nuttx/net/uip/uip_udpconn.c
index ce23d2504..061f7dd78 100644
--- a/nuttx/net/uip/uip_udpconn.c
+++ b/nuttx/net/uip/uip_udpconn.c
@@ -271,6 +271,8 @@ void uip_udpfree(struct uip_udp_conn *conn)
    * is protected by a semaphore (that behaves like a mutex).
    */
 
+  DEBUGASSERT(conn->crefs == 0);
+
   _uip_semtake(&g_free_sem);
   conn->lport = 0;
   dq_addlast(&conn->node, &g_free_udp_connections);