Merge pull request #422 from BernardXiong/master

Add lwIP/NAT, DHCP server and dlib(LIBC of IAR)

components/dfs/filesystems/devfs/devfs.c

@@ -131,6 +131,7 @@ int dfs_device_fs_close(struct dfs_fd *file)
 
 int dfs_device_fs_open(struct dfs_fd *file)
 {
+    rt_err_t result;
     rt_device_t device;
 
     if (file->flags & DFS_O_CREAT)
@@ -186,9 +187,16 @@ int dfs_device_fs_open(struct dfs_fd *file)
     if (device == RT_NULL)
         return -DFS_STATUS_ENODEV;
 
-    file->data = device;
-    
-    return DFS_STATUS_OK;
+    /* to open device */
+    result = rt_device_open(device, RT_DEVICE_OFLAG_RDWR);
+    if (result == RT_EOK || result == -RT_ENOSYS)
+    {
+        file->data = device;
+        return DFS_STATUS_OK;
+    }
+
+    /* open device failed. */
+    return -DFS_STATUS_EIO;
 }
 
 int dfs_device_fs_stat(struct dfs_filesystem *fs, const char *path, struct stat *st)

components/libc/SConscript

@@ -11,6 +11,8 @@ if GetDepend('RT_USING_LIBC'):
         objs = objs + SConscript('newlib/SConscript')
     elif rtconfig.PLATFORM == 'armcc':
         objs = objs + SConscript('armlibc/SConscript')
+    elif rtconfig.PLATFORM == 'iar':
+        objs = objs + SConscript('dlib/SConscript')
 else:
     if rtconfig.PLATFORM == 'gcc':
         objs = objs + SConscript('minilibc/SConscript')

components/libc/armlibc/stubs.c

@@ -13,7 +13,7 @@
  * Date           Author       Notes
  * 2012-11-23     Yihui        The first version
  * 2013-11-24     aozima       fixed _sys_read()/_sys_write() issues.
- * 2014-08-03     bernard      If using msh, use system() implementation 
+ * 2014-08-03     bernard      If using msh, use system() implementation
  *                             in msh.
  */
 
@@ -48,11 +48,11 @@ const char __stderr_name[] = "STDERR";
  */
 FILEHANDLE _sys_open(const char *name, int openmode)
 {
-#ifdef RT_USING_DFS    
+#ifdef RT_USING_DFS
     int fd;
     int mode = O_RDONLY;
 #endif
-    
+
     /* Register standard Input Output devices. */
     if (strcmp(name, __stdin_name) == 0)
         return (STDIN);
@@ -64,34 +64,34 @@ FILEHANDLE _sys_open(const char *name, int openmode)
 #ifndef RT_USING_DFS
     return -1;
 #else
-	/* Correct openmode from fopen to open */
-	if (openmode & OPEN_PLUS) 
-	{
-		if (openmode & OPEN_W) 
-		{
-			mode |= (O_RDWR | O_TRUNC | O_CREAT);
-		}
-		else if (openmode & OPEN_A) 
-		{
-			mode |= (O_RDWR | O_APPEND | O_CREAT);
-		}
-		else 
-			mode |= O_RDWR;				
-	}
-	else
-	{
-		if (openmode & OPEN_W) 
-		{
-			mode |= (O_WRONLY | O_TRUNC | O_CREAT);
-		}
-		else if (openmode & OPEN_A)
-		{					
+    /* Correct openmode from fopen to open */
+    if (openmode & OPEN_PLUS)
+    {
+        if (openmode & OPEN_W)
+        {
+            mode |= (O_RDWR | O_TRUNC | O_CREAT);
+        }
+        else if (openmode & OPEN_A)
+        {
+            mode |= (O_RDWR | O_APPEND | O_CREAT);
+        }
+        else
+            mode |= O_RDWR;
+    }
+    else
+    {
+        if (openmode & OPEN_W)
+        {
+            mode |= (O_WRONLY | O_TRUNC | O_CREAT);
+        }
+        else if (openmode & OPEN_A)
+        {
             mode |= (O_WRONLY | O_APPEND | O_CREAT);
-		}					
-	}
+        }
+    }
 
     fd = open(name, mode, 0);
-    if(fd < 0)
+    if (fd < 0)
         return -1;
     else
         return fd + STDERR + 1;
@@ -121,10 +121,10 @@ int _sys_close(FILEHANDLE fh)
  */
 int _sys_read(FILEHANDLE fh, unsigned char *buf, unsigned len, int mode)
 {
-#ifdef RT_USING_DFS    
+#ifdef RT_USING_DFS
     int size;
 #endif
-    
+
     if (fh == STDIN)
     {
         /* TODO */
@@ -138,7 +138,7 @@ int _sys_read(FILEHANDLE fh, unsigned char *buf, unsigned len, int mode)
     return 0;
 #else
     size = read(fh - STDERR - 1, buf, len);
-    if(size >= 0)
+    if (size >= 0)
         return len - size;
     else
         return -1;
@@ -159,7 +159,7 @@ int _sys_write(FILEHANDLE fh, const unsigned char *buf, unsigned len, int mode)
 #ifdef RT_USING_DFS
     int size;
 #endif
-    
+
     if ((fh == STDOUT) || (fh == STDERR))
     {
 #ifndef RT_USING_CONSOLE
@@ -170,18 +170,18 @@ int _sys_write(FILEHANDLE fh, const unsigned char *buf, unsigned len, int mode)
         console_device = rt_console_get_device();
         if (console_device != 0) rt_device_write(console_device, 0, buf, len);
 
-		return 0;
+        return 0;
 #endif
     }
 
-    if(fh == STDIN)
+    if (fh == STDIN)
         return -1;
 
 #ifndef RT_USING_DFS
     return 0;
 #else
     size = write(fh - STDERR - 1, buf, len);
-    if(size >= 0)
+    if (size >= 0)
         return len - size;
     else
         return -1;
@@ -270,6 +270,6 @@ int remove(const char *filename)
 int system(const char *string)
 {
     RT_ASSERT(0);
-    for(;;);
+    for (;;);
 }
 #endif

components/libc/dlib/README.md

@@ -0,0 +1,4 @@
+Dlib(IAR) porting for RT-Thread.
+
+Please define RT_USING_LIBC and compile RT-Thread with IAR compiler.
+

components/libc/dlib/SConscript

@@ -0,0 +1,15 @@
+from building import *
+import rtconfig
+
+src = Glob('*.c')
+cwd = GetCurrentDir()
+group = []
+
+CPPPATH = [cwd]
+CPPDEFINES = ['RT_USING_DLIBC']
+
+if rtconfig.PLATFORM == 'iar':
+    group = DefineGroup('dlib', src, depend = ['RT_USING_LIBC'], 
+        CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES)
+
+Return('group')

components/libc/dlib/environ.c

@@ -0,0 +1,25 @@
+/* File: environ.c
+ * this file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2015, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2015-01-28     Bernard      first version
+ */
+
+const char *__environ = "OS=RT-Thread";
+

components/libc/dlib/rmtx.c

@@ -0,0 +1,74 @@
+/*
+ * File      : rmtx.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2015, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2015-01-28     Bernard      first version
+ */
+#include <rtthread.h>
+#include <yfuns.h>
+
+/*
+ * for IAR compiler, we recommand to define _DLIB_THREAD_SUPPORT
+ * as 2 for dlib multi-thread support.
+ */
+
+#if _DLIB_THREAD_SUPPORT
+typedef void* _Rmtx;
+void _Mtxinit(_Rmtx *m)
+{
+    rt_mutex_t mutex;
+
+    RT_ASSERT(m != RT_NULL);
+    
+    mutex = (rt_mutex_t)m;
+    rt_mutex_init(mutex, "iarMtx", RT_IPC_FLAG_FIFO);
+}
+
+void _Mtxdst(_Rmtx *m)
+{
+    rt_mutex_t mutex;
+
+    RT_ASSERT(m != RT_NULL);
+
+    mutex = (rt_mutex_t)m;
+    rt_mutex_detach(mutex);
+}
+
+void _Mtxlock(_Rmtx *m)
+{
+    rt_mutex_t mutex;
+
+    RT_ASSERT(m != RT_NULL);
+
+    mutex = (rt_mutex_t)m;
+    rt_mutex_take(mutex, RT_WAITING_FOREVER);
+}
+
+void _Mtxunlock(_Rmtx *m)
+{
+    rt_mutex_t mutex;
+
+    RT_ASSERT(m != RT_NULL);
+
+    mutex = (rt_mutex_t)m;
+    rt_mutex_release(mutex);
+}
+#endif
+

components/libc/dlib/syscall_close.c

@@ -0,0 +1,43 @@
+/*
+ * File      : syscall_close.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2015, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2015-01-28     Bernard      first version
+ */
+#include <rtthread.h>
+#ifdef RT_USING_DFS
+#include <dfs_posix.h>
+#endif
+#include <yfuns.h>
+
+#pragma module_name = "?__close"
+int __close(int handle)
+{
+    if (handle == _LLIO_STDOUT ||
+        handle == _LLIO_STDERR ||
+        handle == _LLIO_STDIN)
+        return _LLIO_ERROR;
+
+#ifdef RT_USING_DFS
+    return close(handle);
+#else
+    return 0;
+#endif
+}

components/libc/dlib/syscall_lseek.c

@@ -0,0 +1,43 @@
+/*
+ * File      : syscall_lseek.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2015, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2015-01-28     Bernard      first version
+ */
+#include <rtthread.h>
+#ifdef RT_USING_DFS
+#include <dfs_posix.h>
+#endif
+#include <yfuns.h>
+
+#pragma module_name = "?__lseek"
+long __lseek(int handle, long offset, int whence)
+{
+    if (handle == _LLIO_STDOUT ||
+        handle == _LLIO_STDERR ||
+        handle == _LLIO_STDIN)
+        return _LLIO_ERROR;
+
+#ifdef RT_USING_DFS
+    return lseek(handle, offset, whence);
+#else
+    return _LLIO_ERROR;
+#endif
+}

components/libc/dlib/syscall_mem.c

@@ -0,0 +1,44 @@
+/*
+ * File      : syscall_mem.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2015, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2015-01-28     Bernard      first version
+ */
+#include <rtthread.h>
+
+void *malloc(rt_size_t n)
+{
+    return rt_malloc(n);
+}
+
+void *realloc(void *rmem, rt_size_t newsize)
+{
+    return rt_realloc(rmem, newsize);
+}
+
+void *calloc(rt_size_t nelem, rt_size_t elsize)
+{
+	return rt_calloc(nelem, elsize);
+}
+
+void free(void *rmem)
+{
+    rt_free(rmem);
+}

components/libc/dlib/syscall_open.c

@@ -0,0 +1,88 @@
+/*
+* File      : syscall_open.c
+* This file is part of RT-Thread RTOS
+* COPYRIGHT (C) 2006 - 2015, RT-Thread Development Team
+*
+*  This program is free software; you can redistribute it and/or modify
+*  it under the terms of the GNU General Public License as published by
+*  the Free Software Foundation; either version 2 of the License, or
+*  (at your option) any later version.
+*
+*  This program is distributed in the hope that it will be useful,
+*  but WITHOUT ANY WARRANTY; without even the implied warranty of
+*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*  GNU General Public License for more details.
+*
+*  You should have received a copy of the GNU General Public License along
+*  with this program; if not, write to the Free Software Foundation, Inc.,
+*  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*
+* Change Logs:
+* Date           Author       Notes
+* 2015-01-28     Bernard      first version
+*/
+
+#include <rtthread.h>
+#include <yfuns.h>
+#ifdef RT_USING_DFS
+#include <dfs_posix.h>
+#endif
+
+#pragma module_name = "?__open"
+
+int __open(const char *filename, int mode)
+{
+#ifndef RT_USING_DFS
+  return -1;
+#else
+  int handle;
+  int open_mode = O_RDONLY;
+  
+  if (mode & _LLIO_CREAT)
+  {
+    open_mode |= O_CREAT;
+    
+    /* Check what we should do with it if it exists. */
+    if (mode & _LLIO_APPEND)
+    {
+      /* Append to the existing file. */
+      open_mode |= O_APPEND;
+    }
+    
+    if (mode & _LLIO_TRUNC)
+    {
+      /* Truncate the existsing file. */
+      open_mode |= O_TRUNC;
+    }
+  }
+  
+  if (mode & _LLIO_TEXT)
+  {
+    /* we didn't support text mode */
+  }
+  
+  switch (mode & _LLIO_RDWRMASK)
+  {
+  case _LLIO_RDONLY:
+    break;
+    
+  case _LLIO_WRONLY:
+    open_mode |= O_WRONLY;
+    break;
+    
+  case _LLIO_RDWR:
+    /* The file should be opened for both reads and writes. */
+    open_mode |= O_RDWR;
+    break;
+    
+  default:
+    return -1;
+  }
+  
+  handle = open(filename, open_mode, 0);
+  if (handle < 0)
+    return -1;
+  
+  return handle + _LLIO_STDERR + 1;
+#endif
+}

components/libc/dlib/syscall_read.c

@@ -0,0 +1,53 @@
+/*
+ * File      : syscall_read.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2015, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2015-01-28     Bernard      first version
+ */
+
+#include <rtthread.h>
+#ifdef RT_USING_DFS
+#include <dfs_posix.h>
+#endif
+#include <yfuns.h>
+
+#pragma module_name = "?__read"
+size_t __read(int handle, unsigned char *buf, size_t len)
+{
+#ifdef RT_USING_DFS
+    int size;
+#endif
+
+    if (handle == _LLIO_STDIN)
+    {
+        /* TODO */
+        return 0;
+    }
+
+    if ((handle == _LLIO_STDOUT) || (handle == _LLIO_STDERR))
+        return _LLIO_ERROR;
+
+#ifndef RT_USING_DFS
+    return _LLIO_ERROR;
+#else
+    size = read(handle - _LLIO_STDERR - 1, buf, len);
+    return size;
+#endif
+}

components/libc/dlib/syscall_remove.c

@@ -0,0 +1,38 @@
+/*
+ * File      : syscall_remove.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2015, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2015-01-28     Bernard      first version
+ */
+#include <rtthread.h>
+#ifdef RT_USING_DFS
+#include <dfs_file.h>
+#endif
+#include <yfuns.h>
+
+#pragma module_name = "?remove"
+int remove(const char *val)
+{
+#ifdef RT_USING_DFS
+    dfs_file_unlink(val);
+#endif
+
+    return 0;
+}

components/libc/dlib/syscall_write.c

@@ -0,0 +1,62 @@
+/*
+ * File      : syscall_write.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2015, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2015-01-28     Bernard      first version
+ */
+
+#include <rtthread.h>
+#ifdef RT_USING_DFS
+#include <dfs_posix.h>
+#endif
+#include <yfuns.h>
+
+#pragma module_name = "?__write"
+
+size_t __write(int handle, const unsigned char *buf, size_t len)
+{
+#ifdef RT_USING_DFS
+    int size;
+#endif
+
+    if ((handle == _LLIO_STDOUT) || (handle == _LLIO_STDERR))
+    {
+#ifndef RT_USING_CONSOLE
+        return _LLIO_ERROR;
+#else
+        rt_device_t console_device;
+
+        console_device = rt_console_get_device();
+        if (console_device != 0) rt_device_write(console_device, 0, buf, len);
+
+        return len;
+#endif
+    }
+
+    if (handle == _LLIO_STDIN) return -1;
+
+#ifndef RT_USING_DFS
+    return _LLIO_ERROR;
+#else
+    size = write(handle - _LLIO_STDERR - 1, buf, len);
+    return size;
+#endif
+}
+

components/libc/dlib/syscalls.h

@@ -0,0 +1,23 @@
+/* File: syscalls.h
+ * this file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2015, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2015-01-28     Bernard      first version
+ */
+

components/net/lwip-1.4.1/src/core/ipv4/ip.c

@@ -312,6 +312,11 @@ ip_input(struct pbuf *p, struct netif *inp)
   int check_ip_src=1;
 #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
 
+#if IP_NAT
+  extern u8_t ip_nat_input(struct pbuf *p);
+  extern u8_t ip_nat_out(struct pbuf *p);
+#endif
+
   IP_STATS_INC(ip.recv);
   snmp_inc_ipinreceives();
 
@@ -487,15 +492,30 @@ ip_input(struct pbuf *p, struct netif *inp)
 
   /* packet not for us? */
   if (netif == NULL) {
+#if IP_FORWARD || IP_NAT
+    u8_t taken = 0;
+#endif /* IP_FORWARD || IP_NAT */
     /* packet not for us, route or discard */
     LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip_input: packet not for us.\n"));
-#if IP_FORWARD
+#if IP_FORWARD || IP_NAT
     /* non-broadcast packet? */
-    if (!ip_addr_isbroadcast(&current_iphdr_dest, inp)) {
-      /* try to forward IP packet on (other) interfaces */
-      ip_forward(p, iphdr, inp);
-    } else
+    if (!ip_addr_isbroadcast(&(iphdr->dest), inp)) {
+#if IP_NAT
+      /* check if we want to perform NAT with this packet. */
+      taken = ip_nat_out(p);
+      if (!taken)
+#endif /* IP_NAT */
+      {
+#if IP_FORWARD
+        /* try to forward IP packet on (other) interfaces */
+        if (ip_forward(p, iphdr, inp) != NULL) {
+          taken = 1;
+        }
 #endif /* IP_FORWARD */
+      }
+    }
+    if (!taken)
+#endif /* IP_FORWARD || IP_NAT */
     {
       snmp_inc_ipinaddrerrors();
       snmp_inc_ipindiscards();
@@ -553,6 +573,13 @@ ip_input(struct pbuf *p, struct netif *inp)
   current_netif = inp;
   current_header = iphdr;
 
+#if IP_NAT
+  if (!ip_addr_isbroadcast(&(iphdr->dest), inp) &&
+      (ip_nat_input(p) != 0)) {
+     LWIP_DEBUGF(IP_DEBUG, ("ip_input: packet consumed by nat layer\n"));
+  } else
+#endif /* IP_NAT */
+
 #if LWIP_RAW
   /* raw input did not eat the packet? */
   if (raw_input(p, inp) == 0)

components/net/lwip-1.4.1/src/lwipopts.h

@@ -161,6 +161,12 @@
  */
 #define SYS_LIGHTWEIGHT_PROT        (NO_SYS==0)
 
+#ifdef LWIP_USING_NAT
+#define IP_NAT                      1
+#else
+#define IP_NAT                      0
+#endif
+
 /* ---------- TCP options ---------- */
 #ifdef RT_LWIP_TCP
 #define LWIP_TCP                    1

components/net/lwip_dhcpd/SConscript

@@ -0,0 +1,10 @@
+from building import *
+
+cwd = GetCurrentDir()
+src = Glob('*.c')
+
+CPPPATH = [cwd]
+
+group = DefineGroup('LwIP', src, depend = ['RT_USING_LWIP', 'LWIP_USING_DHCPD'], CPPPATH = CPPPATH)
+
+Return('group')

components/net/lwip_dhcpd/dhcp_server.h

@@ -0,0 +1,36 @@
+/*
+ * File      : dhcp_server.h
+ *             A simple DHCP server implementation
+ *
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2013-2015, Shanghai Real-Thread Technology Co., Ltd
+ * http://www.rt-thread.com
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2013-01-30     aozima       the first version
+ * 2013-08-08     aozima       support different network segments.
+ * 2015-01-30     bernard      release to RT-Thread RTOS.
+ */
+
+#ifndef DHCPV4_SERVER_H__
+#define DHCPV4_SERVER_H__
+
+void dhcpd_start(char* netif_name);
+
+#endif
+

components/net/lwip_nat/README.md

@@ -0,0 +1,19 @@
+lwIP NAT componenent
+
+If you want to use lwIP NAT componenent, please define LWIP_USING_NAT in rtconfig.h. 
+
+In this case the network 213.129.231.168/29 is nat'ed when packets are sent to the 
+destination network 10.0.0.0/24 (untypical example - most users will have the other 
+way around).
+
+Use following code to add a NAT entry: 
+
+  ip_nat_entry_t nat_entry;
+ 
+  nat_entry.out_if = (struct netif *)&emac_if1;
+  nat_entry.in_if = (struct netif *)&emac_if2;
+  IP4_ADDR(&nat_entry.source_net, 213, 129, 231, 168);
+  IP4_ADDR(&nat_entry.source_netmask, 255, 255, 255, 248);
+  IP4_ADDR(&nat_entry.dest_net, 10, 0, 0, 0);
+  IP4_ADDR(&nat_entry.source_netmask, 255, 0, 0, 0);
+  ip_nat_add(&_nat_entry);

components/net/lwip_nat/SConscript

@@ -0,0 +1,10 @@
+from building import *
+
+cwd = GetCurrentDir()
+src = Glob('*.c')
+
+CPPPATH = [cwd]
+
+group = DefineGroup('LwIP', src, depend = ['RT_USING_LWIP', 'LWIP_USING_NAT'], CPPPATH = CPPPATH)
+
+Return('group')

components/net/lwip_nat/ipv4_nat.h

@@ -0,0 +1,103 @@
+/**
+ * NAT - NAT implementation for lwIP supporting TCP/UDP and ICMP.
+ * Copyright (c) 2009 Christian Walter, ?Embedded Solutions, Vienna 2009.
+ *
+ * Copyright (c) 2010 lwIP project ;-)
+ * All rights reserved.
+ *
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ */
+
+/*
+ * File      : ipv4_nat.h
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2015, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2015-01-26     Hichard      porting to RT-Thread
+ * 2015-01-27     Bernard      code cleanup for lwIP in RT-Thread
+ */
+
+#ifndef __LWIP_NAT_H__
+#define __LWIP_NAT_H__
+
+#include <rtthread.h>
+
+#ifdef LWIP_USING_NAT
+
+#include "lwip/err.h"
+#include "lwip/ip_addr.h"
+#include "lwip/opt.h"
+
+/** Timer interval at which to call ip_nat_tmr() */
+#define LWIP_NAT_TMR_INTERVAL_SEC        (30*1000)
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+struct netif;
+struct pbuf;
+
+typedef struct ip_nat_entry
+{
+  ip_addr_t    source_net;
+  ip_addr_t    source_netmask;
+  ip_addr_t    dest_net;
+  ip_addr_t    dest_netmask;
+  struct netif *out_if;
+  struct netif *in_if;
+} ip_nat_entry_t;
+
+void  ip_nat_init(void);
+void  ip_nat_tmr(void);
+u8_t  ip_nat_input(struct pbuf *p);
+u8_t  ip_nat_out(struct pbuf *p);
+
+err_t ip_nat_add(const ip_nat_entry_t *new_entry);
+void  ip_nat_remove(const ip_nat_entry_t *remove_entry);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* IP_NAT */
+
+#endif /* __LWIP_NAT_H__ */