From 40997c4a080f94148d06c41a9607536267efef15 Mon Sep 17 00:00:00 2001
From: Dirk Ziegelmeier <dirk@ziegelmeier.net>
Date: Mon, 29 Jan 2018 06:59:47 +0100
Subject: [PATCH] Apply (modified) patch #9552: tftp_cleanup() for cleanup and
 filename buffer zeroing to prevent filename bugs ... without the memset to
 zero out the filename

---
 src/apps/tftp/tftp_server.c         | 10 ++++++++++
 src/include/lwip/apps/tftp_server.h |  1 +
 2 files changed, 11 insertions(+)

diff --git a/src/apps/tftp/tftp_server.c b/src/apps/tftp/tftp_server.c
index 6da94d48..07f6170e 100644
--- a/src/apps/tftp/tftp_server.c
+++ b/src/apps/tftp/tftp_server.c
@@ -412,4 +412,14 @@ tftp_init(const struct tftp_context *ctx)
   return ERR_OK;
 }
 
+/** @ingroup tftp
+ * Deinitialize ("turn off") TFTP server.
+ */
+void tftp_cleanup(void)
+{
+  LWIP_ASSERT("Cleanup called on non-initialized TFTP", tftp_state.upcb != NULL);
+  udp_remove(tftp_state.upcb);
+  memset(&tftp_state, 0, sizeof(tftp_state));
+}
+
 #endif /* LWIP_UDP */
diff --git a/src/include/lwip/apps/tftp_server.h b/src/include/lwip/apps/tftp_server.h
index a27ed961..0a7fbee0 100644
--- a/src/include/lwip/apps/tftp_server.h
+++ b/src/include/lwip/apps/tftp_server.h
@@ -86,6 +86,7 @@ struct tftp_context {
 };
 
 err_t tftp_init(const struct tftp_context* ctx);
+void tftp_cleanup(void);
 
 #ifdef __cplusplus
 }