tftp: added example for tftp client

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>

contrib/examples/example_app/lwipcfg.h.example

@@ -66,6 +66,7 @@
  * otherwise the raw api server will be used. */
 /*#define LWIP_TCPECHO_APP_NETCONN   */
 #define LWIP_TFTP_APP                 0
+#define LWIP_TFTP_CLIENT_APP          0
 #define LWIP_UDPECHO_APP              0
 #define LWIP_LWIPERF_APP              0
 

contrib/examples/example_app/lwipcfg.h.travis

@@ -62,6 +62,7 @@
  * otherwise the raw api server will be used. */
 /*#define LWIP_TCPECHO_APP_NETCONN   */
 #define LWIP_TFTP_APP                 1
+#define LWIP_TFTP_CLIENT_APP          1
 #define LWIP_UDPECHO_APP              1
 #define LWIP_LWIPERF_APP              1
 

contrib/examples/example_app/test.c

@@ -576,7 +576,10 @@ apps_init(void)
   sntp_example_init();
 #endif
 #if LWIP_TFTP_APP
-  tftp_example_init();
+  tftp_example_init_server();
+#endif
+#if LWIP_TFTP_CLIENT_APP
+  tftp_example_init_client();
 #endif
 #if LWIP_LWIPERF_APP
   lwiperf_example_init();

contrib/examples/tftp/tftp_example.c

@@ -29,6 +29,7 @@
 
 #include <stdio.h>
 
+#include "lwip/apps/tftp_client.h"
 #include "lwip/apps/tftp_server.h"
 #include "tftp_example.h"
 
@@ -36,16 +37,43 @@
 
 #if LWIP_UDP
 
+/* Define a base directory for TFTP access
+ * ATTENTION: This code does NOT check for sandboxing,
+ * i.e. '..' in paths is not checked! */
+#ifndef LWIP_TFTP_EXAMPLE_BASE_DIR
+#define LWIP_TFTP_EXAMPLE_BASE_DIR ""
+#endif
+
+/* Define this to a file to get via tftp client */
+#ifndef LWIP_TFTP_EXAMPLE_CLIENT_FILENAME
+#define LWIP_TFTP_EXAMPLE_CLIENT_FILENAME "test.bin"
+#endif
+
+/* Define this to a server IP string */
+#ifndef LWIP_TFTP_EXAMPLE_CLIENT_REMOTEIP
+#define LWIP_TFTP_EXAMPLE_CLIENT_REMOTEIP "192.168.0.1"
+#endif
+
+static char full_filename[256];
+
+static void *
+tftp_open_file(const char* fname, u8_t is_write)
+{
+  snprintf(full_filename, sizeof(full_filename), "%s%s", LWIP_TFTP_EXAMPLE_BASE_DIR, fname);
+  full_filename[sizeof(full_filename)-1] = 0;
+
+  if (is_write) {
+    return (void*)fopen(full_filename, "wb");
+  } else {
+    return (void*)fopen(full_filename, "rb");
+  }
+}
+
 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");
-  }
+  return tftp_open_file(fname, is_write);
 }
 
 static void
@@ -100,9 +128,28 @@ static const struct tftp_context tftp = {
 };
 
 void
-tftp_example_init(void)
+tftp_example_init_server(void)
 {
   tftp_init_server(&tftp);
 }
 
+void
+tftp_example_init_client(void)
+{
+  void *f;
+  err_t err;
+  ip_addr_t srv;
+  int ret = ipaddr_aton(LWIP_TFTP_EXAMPLE_CLIENT_REMOTEIP, &srv);
+  LWIP_ASSERT("ipaddr_aton failed", ret == 1);
+
+  err = tftp_init_client(&tftp);
+  LWIP_ASSERT("tftp_init_client failed", err == ERR_OK);
+
+  f = tftp_open_file(LWIP_TFTP_EXAMPLE_CLIENT_FILENAME, 1);
+  LWIP_ASSERT("failed to create file", f != NULL);
+
+  err = tftp_get(f, &srv, TFTP_PORT, LWIP_TFTP_EXAMPLE_CLIENT_FILENAME, TFTP_MODE_OCTET);
+  LWIP_ASSERT("tftp_get failed", err == ERR_OK);
+}
+
 #endif /* LWIP_UDP */

contrib/examples/tftp/tftp_example.h

@@ -18,7 +18,8 @@
 extern "C" {
 #endif
 
-void tftp_example_init(void);
+void tftp_example_init_server(void);
+void tftp_example_init_client(void);
 
 #ifdef __cplusplus
 }