feat: Added ftfp server implementation

src/tftp/error.rs

@@ -0,0 +1,20 @@
+use std::io;
+use std::string::FromUtf8Error;
+
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error("Invalid op code '{0}'")]
+    InvalidOpCode(u16),
+    #[error("Invalid error code '{0}'")]
+    InvalidErrorCode(u16),
+    #[error("Invalid mode '{0}'")]
+    InvalidMode(String),
+    #[error("String contains invalid characters")]
+    InvalidString(#[from] FromUtf8Error),
+    #[error("Unterminated string")]
+    UnterminatedString,
+    #[error("Io error: {0}")]
+    Io(#[from] io::Error),
+}