Unverified Commit 88204f91 authored by Isis Lovecruft's avatar Isis Lovecruft
Browse files

rust: Implement error types for Rust protover implementation. 

This will allow us to do actual error handling intra-crate in a more
rusty manner, e.g. propogating errors in match statements, conversion
between error types, logging messages, etc.

 * FIXES part of #24031: https://bugs.torproject.org/24031.
parent 961d2ad5

src/rust/protover/errors.rs

0 → 100644
+43 −0
Original line number Diff line number Diff line 
// Copyright (c) 2018, The Tor Project, Inc.

// Copyright (c) 2018, isis agora lovecruft

// See LICENSE for licensing information



//! Various errors which may occur during protocol version parsing.



use std::fmt;

use std::fmt::Display;



/// All errors which may occur during protover parsing routines.

#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]

#[allow(missing_docs)] // See Display impl for error descriptions

pub enum ProtoverError {

    Overlap,

    LowGreaterThanHigh,

    Unparseable,

    ExceedsMax,

    ExceedsExpansionLimit,

    UnknownProtocol,

    ExceedsNameLimit,

}



/// Descriptive error messages for `ProtoverError` variants.

impl Display for ProtoverError {

    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {

        match *self {

            ProtoverError::Overlap

                => write!(f, "Two or more (low, high) protover ranges would overlap once expanded."),

            ProtoverError::LowGreaterThanHigh

                => write!(f, "The low in a (low, high) protover range was greater than high."),

            ProtoverError::Unparseable

                => write!(f, "The protover string was unparseable."),

            ProtoverError::ExceedsMax

                => write!(f, "The high in a (low, high) protover range exceeds u32::MAX."),

            ProtoverError::ExceedsExpansionLimit

                => write!(f, "The protover string would exceed the maximum expansion limit."),

            ProtoverError::UnknownProtocol

                => write!(f, "A protocol in the protover string we attempted to parse is unknown."),

            ProtoverError::ExceedsNameLimit

                => write!(f, "An unrecognised protocol name was too long."),

        }

    }

}

src/rust/protover/lib.rs

+3 −0
Original line number Diff line number Diff line
@@ -22,12 +22,15 @@ 
//! protocols to develop independently, without having to claim compatibility

//! with specific versions of Tor.



#[deny(missing_docs)]



extern crate libc;

extern crate smartlist;

extern crate external;

extern crate tor_allocate;

extern crate tor_util;



pub mod errors;

mod protover;

pub mod ffi;

src/rust/protover/protover.rs

+4 −2
Original line number Diff line number Diff line
@@ -13,6 +13,8 @@ use std::u32; 


use tor_util::strings::NUL_BYTE;



use errors::ProtoverError;



/// The first version of Tor that included "proto" entries in its descriptors.

/// Authorities should use this to decide whether to guess proto lines.

///
@@ -78,7 +80,7 @@ impl fmt::Display for Proto { 
///

/// C_RUST_COUPLED: src/or/protover.c `PROTOCOL_NAMES`

impl FromStr for Proto {

    type Err = &'static str;

    type Err = ProtoverError;



    fn from_str(s: &str) -> Result<Self, Self::Err> {

        match s {
@@ -92,7 +94,7 @@ impl FromStr for Proto { 
            "LinkAuth" => Ok(Proto::LinkAuth),

            "Microdesc" => Ok(Proto::Microdesc),

            "Relay" => Ok(Proto::Relay),

            _ => Err("Not a valid protocol type"),

            _ => Err(ProtoverError::UnknownProtocol),

        }

    }

}