From 0ee4784d0cf92e399727efb92a1d8469e33d43b0 Mon Sep 17 00:00:00 2001
From: Simon Goldschmidt <goldsimon@gmx.de>
Date: Wed, 17 Oct 2018 21:37:46 +0200
Subject: [PATCH] tftp client: pass 'mode' as an enum, not as a string constant

---
 src/apps/tftp/tftp.c                | 27 +++++++++++++++++++++++----
 src/include/lwip/apps/tftp_client.h | 10 ++++++++--
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/src/apps/tftp/tftp.c b/src/apps/tftp/tftp.c
index 3c175a6a..dc41085c 100644
--- a/src/apps/tftp/tftp.c
+++ b/src/apps/tftp/tftp.c
@@ -503,26 +503,45 @@ void tftp_cleanup(void)
   memset(&tftp_state, 0, sizeof(tftp_state));
 }
 
+const char *
+mode_to_string(enum tftp_transfer_mode mode)
+{
+  if (mode == TFTP_MODE_OCTET) {
+    return "octet";
+  }
+  if (mode == TFTP_MODE_NETASCII) {
+    return "netascii";
+  }
+  if (mode == TFTP_MODE_BINARY) {
+    return "binary";
+  }
+  return NULL;
+}
+
 err_t
-tftp_get(void* handle, const ip_addr_t *addr, u16_t port, const char* fname, const char* mode)
+tftp_get(void* handle, const ip_addr_t *addr, u16_t port, const char* fname, enum tftp_transfer_mode mode)
 {
   LWIP_ERROR("TFTP client is not enabled (tftp_init)", (tftp_state.tftp_mode & LWIP_TFTP_MODE_CLIENT) != 0, return ERR_VAL);
+  LWIP_ERROR("tftp_get: invalid file name", fname != NULL, return ERR_VAL);
+  LWIP_ERROR("tftp_get: invalid mode", mode <= TFTP_MODE_BINARY, return ERR_VAL);
 
   tftp_state.handle = handle;
   tftp_state.blknum = 1;
   tftp_state.mode_write = 1; /* We want to receive data */
-  return send_request(addr, port, TFTP_RRQ, fname, mode);
+  return send_request(addr, port, TFTP_RRQ, fname, mode_to_string(mode));
 }
 
 err_t
-tftp_put(void* handle, const ip_addr_t *addr, u16_t port, const char* fname, const char* mode)
+tftp_put(void* handle, const ip_addr_t *addr, u16_t port, const char* fname, enum tftp_transfer_mode mode)
 {
   LWIP_ERROR("TFTP client is not enabled (tftp_init)", (tftp_state.tftp_mode & LWIP_TFTP_MODE_CLIENT) != 0, return ERR_VAL);
+  LWIP_ERROR("tftp_put: invalid file name", fname != NULL, return ERR_VAL);
+  LWIP_ERROR("tftp_put: invalid mode", mode <= TFTP_MODE_BINARY, return ERR_VAL);
 
   tftp_state.handle = handle;
   tftp_state.blknum = 1;
   tftp_state.mode_write = 0; /* We want to send data */
-  return send_request(addr, port, TFTP_WRQ, fname, mode);
+  return send_request(addr, port, TFTP_WRQ, fname, mode_to_string(mode));
 }
 
 #endif /* LWIP_UDP */
diff --git a/src/include/lwip/apps/tftp_client.h b/src/include/lwip/apps/tftp_client.h
index c65364ee..24dbda6a 100644
--- a/src/include/lwip/apps/tftp_client.h
+++ b/src/include/lwip/apps/tftp_client.h
@@ -37,8 +37,14 @@
 
 #include "lwip/apps/tftp_common.h"
 
+enum tftp_transfer_mode {
+  TFTP_MODE_OCTET,
+  TFTP_MODE_NETASCII,
+  TFTP_MODE_BINARY /* used in old versions only */
+};
+
 err_t tftp_init_client(const struct tftp_context* ctx);
-err_t tftp_get(void* handle, const ip_addr_t *addr, u16_t port, const char* fname, const char* mode);
-err_t tftp_put(void* handle, const ip_addr_t *addr, u16_t port, const char* fname, const char* mode);
+err_t tftp_get(void* handle, const ip_addr_t *addr, u16_t port, const char* fname, enum tftp_transfer_mode mode);
+err_t tftp_put(void* handle, const ip_addr_t *addr, u16_t port, const char* fname, enum tftp_transfer_mode mode);
 
 #endif /* LWIP_HDR_APPS_TFTP_CLIENT_H */