Import lwIP contrib rep

... from http://git.savannah.gnu.org/cgit/lwip/lwip-contrib.git/ into contrib/ subdir, STABLE-2_1_0_RELEASE tag
lwIP contrib is now officially frozen
TODO: Fix build

contrib/examples/tftp/tftp_example.c

@@ -0,0 +1,91 @@
+/*
+ * 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.
+ * 
+ * Author: Dirk Ziegelmeier <dziegel@gmx.de>
+ *
+ */
+
+#include <stdio.h>
+
+#include "lwip/apps/tftp_server.h"
+#include "tftp_example.h"
+
+#if LWIP_UDP
+
+static void*
+tftp_open(const char* fname, const char* mode, u8_t is_write)
+{
+  LWIP_UNUSED_ARG(mode);
+  
+  if (is_write) {
+    return (void*)fopen(fname, "wb");
+  } else {
+    return (void*)fopen(fname, "rb");
+  }
+}
+
+static void 
+tftp_close(void* handle)
+{
+  fclose((FILE*)handle);
+}
+
+static int
+tftp_read(void* handle, void* buf, int bytes)
+{
+  int ret = fread(buf, 1, bytes, (FILE*)handle);
+  if (ret <= 0) {
+    return -1;
+  }
+  return ret;
+}
+
+static int
+tftp_write(void* handle, struct pbuf* p)
+{
+  while (p != NULL) {
+    if (fwrite(p->payload, 1, p->len, (FILE*)handle) != (size_t)p->len) {
+      return -1;
+    }
+    p = p->next;
+  }
+  
+  return 0;
+}
+
+static const struct tftp_context tftp = {
+  tftp_open,
+  tftp_close,
+  tftp_read,
+  tftp_write
+};
+
+void
+tftp_example_init(void)
+{
+  tftp_init(&tftp);
+}
+
+#endif /* LWIP_UDP */

contrib/examples/tftp/tftp_example.h

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+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+/* 
+ * File:   tftp_example.h
+ * Author: dziegel
+ *
+ * Created on February 17, 2018, 3:43 PM
+ */
+
+#ifndef TFTP_EXAMPLE_H
+#define TFTP_EXAMPLE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void tftp_example_init(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* TFTP_EXAMPLE_H */
+