From 81da833c5b947e3814968f3d4b481a617772af0c Mon Sep 17 00:00:00 2001
From: Sander Speetjens <sander.speetjens@gmail.com>
Date: Thu, 9 Nov 2023 18:07:47 +0100
Subject: [PATCH] TFTP

Fix error of not writing the index.txt correctly
---
 project/Core/Src/tftp.c | 32 ++++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/project/Core/Src/tftp.c b/project/Core/Src/tftp.c
index 61ba699..70423df 100644
--- a/project/Core/Src/tftp.c
+++ b/project/Core/Src/tftp.c
@@ -13,7 +13,28 @@ extern struct llfs_data_file* llfs_root;
 static llfs_file_t virt_file[2] = {
     {.name = "index.txt", .data = "test", .len = 4},
     {.name = "virtImage.raw", .data = "test", .len = 4}
-    }; 
+    };
+
+int str_cat_str(char* dest, int dest_size, const char* src) {
+    int dest_len = strlen(dest);
+    int src_len = strlen(src);
+    if (dest_len + src_len > dest_size) {
+        return -1;
+    }
+    memcpy(dest + dest_len, src, src_len);
+    return 0;
+}
+
+int str_cat(char* dest, int dest_size, char c)
+{
+    int dest_len = strlen(dest);
+    if (dest_len + 1 > dest_size) {
+        return -1;
+    }
+    dest[dest_len] = c;
+    dest[dest_len + 1] = '\0';
+    return 0;
+}
 
 /**
  * @brief tftp helper functions
@@ -72,10 +93,13 @@ int tftp_read(void* handle, void* buf, int bytes) {
 
     if (file == &virt_file[0]) {
         const struct llfs_data_file* root = llfs_root;
-        snprintf(buf, bytes, "%s\n", virt_file[0].name);
-        snprintf(buf, bytes, "%s\n", virt_file[1].name);
+        str_cat_str(buf, bytes, virt_file[0].name);
+        str_cat(buf, bytes, '\n');
+        str_cat_str(buf, bytes, virt_file[1].name);
+        str_cat(buf, bytes, '\n');
         while(root != NULL) {
-            snprintf(buf, bytes, "%s\n", root->name);
+            str_cat(buf, bytes, root->name);
+            str_cat(buf, bytes, '\n');
             file = root->next;
         }
     } else if (file == &virt_file[1]) {