diff options
Diffstat (limited to 'src/rust/protover')
-rw-r--r-- | src/rust/protover/Cargo.toml | 6 | ||||
-rw-r--r-- | src/rust/protover/ffi.rs | 42 | ||||
-rw-r--r-- | src/rust/protover/lib.rs | 4 | ||||
-rw-r--r-- | src/rust/protover/protover.rs | 113 |
4 files changed, 85 insertions, 80 deletions
diff --git a/src/rust/protover/Cargo.toml b/src/rust/protover/Cargo.toml index 86301b8787..af1089c914 100644 --- a/src/rust/protover/Cargo.toml +++ b/src/rust/protover/Cargo.toml @@ -3,6 +3,9 @@ authors = ["The Tor Project"] version = "0.0.1" name = "protover" +[features] +testing = ["tor_log/testing"] + [dependencies] libc = "=0.2.39" @@ -18,6 +21,9 @@ path = "../tor_util" [dependencies.tor_allocate] path = "../tor_allocate" +[dependencies.tor_log] +path = "../tor_log" + [lib] name = "protover" path = "lib.rs" diff --git a/src/rust/protover/ffi.rs b/src/rust/protover/ffi.rs index 2ee0286ecf..a9d5013c6d 100644 --- a/src/rust/protover/ffi.rs +++ b/src/rust/protover/ffi.rs @@ -12,9 +12,6 @@ use std::ffi::CString; use protover::*; use smartlist::*; use tor_allocate::allocate_and_copy_string; -use tor_util::strings::byte_slice_is_c_like; -use tor_util::strings::empty_static_cstr; - /// Translate C enums to Rust Proto enums, using the integer value of the C /// enum to map to its associated Rust enum @@ -130,9 +127,11 @@ pub extern "C" fn protocol_list_supports_protocol_or_later( Err(_) => return 0, }; - let is_supported = - protover_string_supports_protocol_or_later( - protocol_list, protocol, version); + let is_supported = protover_string_supports_protocol_or_later( + protocol_list, + protocol, + version, + ); return if is_supported { 1 } else { 0 }; } @@ -143,18 +142,7 @@ pub extern "C" fn protocol_list_supports_protocol_or_later( pub extern "C" fn protover_get_supported_protocols() -> *const c_char { let supported: &'static CStr; - // If we're going to pass it to C, there cannot be any intermediate NUL - // bytes. An assert is okay here, since changing the const byte slice - // in protover.rs to contain a NUL byte somewhere in the middle would be a - // programming error. - assert!(byte_slice_is_c_like(SUPPORTED_PROTOCOLS)); - - // It's okay to unwrap the result of this function because - // we can see that the bytes we're passing into it 1) are valid UTF-8, - // 2) have no intermediate NUL bytes, and 3) are terminated with a NUL - // byte. - supported = CStr::from_bytes_with_nul(SUPPORTED_PROTOCOLS).unwrap(); - + supported = get_supported_protocols_cstr(); supported.as_ptr() } @@ -202,10 +190,9 @@ pub extern "C" fn protover_is_supported_here( #[no_mangle] pub extern "C" fn protover_compute_for_old_tor(version: *const c_char) -> *const c_char { let supported: &'static CStr; - let elder_protocols: &'static [u8]; let empty: &'static CStr; - empty = empty_static_cstr(); + empty = cstr!(""); if version.is_null() { return empty.as_ptr(); @@ -220,19 +207,6 @@ pub extern "C" fn protover_compute_for_old_tor(version: *const c_char) -> *const Err(_) => return empty.as_ptr(), }; - elder_protocols = compute_for_old_tor(&version); - - // If we're going to pass it to C, there cannot be any intermediate NUL - // bytes. An assert is okay here, since changing the const byte slice - // in protover.rs to contain a NUL byte somewhere in the middle would be a - // programming error. - assert!(byte_slice_is_c_like(elder_protocols)); - - // It's okay to unwrap the result of this function because - // we can see that the bytes we're passing into it 1) are valid UTF-8, - // 2) have no intermediate NUL bytes, and 3) are terminated with a NUL - // byte. - supported = CStr::from_bytes_with_nul(elder_protocols).unwrap_or(empty); - + supported = compute_for_old_tor(&version); supported.as_ptr() } diff --git a/src/rust/protover/lib.rs b/src/rust/protover/lib.rs index fe8c0f9bb2..d1d49d2a59 100644 --- a/src/rust/protover/lib.rs +++ b/src/rust/protover/lib.rs @@ -26,8 +26,12 @@ extern crate libc; extern crate smartlist; extern crate external; extern crate tor_allocate; +#[macro_use] extern crate tor_util; +#[macro_use] +extern crate tor_log; + mod protover; pub mod ffi; diff --git a/src/rust/protover/protover.rs b/src/rust/protover/protover.rs index e5dc69b9a0..fd1f41d780 100644 --- a/src/rust/protover/protover.rs +++ b/src/rust/protover/protover.rs @@ -1,17 +1,17 @@ // Copyright (c) 2016-2017, The Tor Project, Inc. */ // See LICENSE for licensing information */ -use external::c_tor_version_as_new_as; - use std::str; use std::str::FromStr; +use std::ffi::CStr; use std::fmt; use std::collections::{HashMap, HashSet}; use std::ops::Range; use std::string::String; use std::u32; -use tor_util::strings::NUL_BYTE; +use tor_log::{LogSeverity, LogDomain}; +use external::c_tor_version_as_new_as; /// The first version of Tor that included "proto" entries in its descriptors. /// Authorities should use this to decide whether to guess proto lines. @@ -26,30 +26,6 @@ const FIRST_TOR_VERSION_TO_ADVERTISE_PROTOCOLS: &'static str = "0.2.9.3-alpha"; /// C_RUST_COUPLED: src/or/protover.c `MAX_PROTOCOLS_TO_EXPAND` const MAX_PROTOCOLS_TO_EXPAND: usize = (1<<16); -/// Currently supported protocols and their versions, as a byte-slice. -/// -/// # Warning -/// -/// This byte-slice ends in a NUL byte. This is so that we can directly convert -/// it to an `&'static CStr` in the FFI code, in order to hand the static string -/// to C in a way that is compatible with C static strings. -/// -/// Rust code which wishes to accesses this string should use -/// `protover::get_supported_protocols()` instead. -/// -/// C_RUST_COUPLED: src/or/protover.c `protover_get_supported_protocols` -pub(crate) const SUPPORTED_PROTOCOLS: &'static [u8] = - b"Cons=1-2 \ - Desc=1-2 \ - DirCache=1-2 \ - HSDir=1-2 \ - HSIntro=3-4 \ - HSRend=1-2 \ - Link=1-5 \ - LinkAuth=1,3 \ - Microdesc=1-2 \ - Relay=1-2\0"; - /// Known subprotocols in Tor. Indicates which subprotocol a relay supports. /// /// C_RUST_COUPLED: src/or/protover.h `protocol_type_t` @@ -97,21 +73,51 @@ impl FromStr for Proto { } } -/// Get the string representation of current supported protocols +/// Get a CStr representation of current supported protocols, for +/// passing to C, or for converting to a `&str` for Rust. /// /// # Returns /// -/// A `String` whose value is the existing protocols supported by tor. +/// An `&'static CStr` whose value is the existing protocols supported by tor. /// Returned data is in the format as follows: /// /// "HSDir=1-1 LinkAuth=1" /// -pub fn get_supported_protocols() -> &'static str { - // The `len() - 1` is to remove the NUL byte. - // The `unwrap` is safe becauase we SUPPORTED_PROTOCOLS is under - // our control. - str::from_utf8(&SUPPORTED_PROTOCOLS[..SUPPORTED_PROTOCOLS.len() - 1]) - .unwrap_or("") +/// # Note +/// +/// Rust code can use the `&'static CStr` as a normal `&'a str` by +/// calling `protover::get_supported_protocols`. +/// +// C_RUST_COUPLED: src/or/protover.c `protover_get_supported_protocols` +pub(crate) fn get_supported_protocols_cstr() -> &'static CStr { + cstr!("Cons=1-2 \ + Desc=1-2 \ + DirCache=1-2 \ + HSDir=1-2 \ + HSIntro=3-4 \ + HSRend=1-2 \ + Link=1-5 \ + LinkAuth=1,3 \ + Microdesc=1-2 \ + Relay=1-2") +} + +/// Get a string representation of current supported protocols. +/// +/// # Returns +/// +/// An `&'a str` whose value is the existing protocols supported by tor. +/// Returned data is in the format as follows: +/// +/// "HSDir=1-1 LinkAuth=1" +pub fn get_supported_protocols<'a>() -> &'a str { + let supported_cstr: &'static CStr = get_supported_protocols_cstr(); + let supported: &str = match supported_cstr.to_str() { + Ok(x) => x, + Err(_) => "", + }; + + supported } pub struct SupportedProtocols(HashMap<Proto, Versions>); @@ -220,7 +226,6 @@ impl Versions { } } - /// Parse the subprotocol type and its version numbers. /// /// # Inputs @@ -274,6 +279,20 @@ fn get_proto_and_vers<'a>( fn contains_only_supported_protocols(proto_entry: &str) -> bool { let (name, mut vers) = match get_proto_and_vers(proto_entry) { Ok(n) => n, + Err("Too many versions to expand") => { + tor_log_msg!( + LogSeverity::Warn, + LogDomain::Net, + "get_versions", + "When expanding a protocol list from an authority, I \ + got too many protocols. This is possibly an attack or a bug, \ + unless the Tor network truly has expanded to support over {} \ + different subprotocol versions. The offending string was: {}", + MAX_PROTOCOLS_TO_EXPAND, + proto_entry + ); + return false; + } Err(_) => return false, }; @@ -754,7 +773,7 @@ pub fn is_supported_here(proto: Proto, vers: Version) -> bool { /// /// # Returns /// -/// A `&'static [u8]` encoding a list of protocol names and supported +/// A `&'static CStr` encoding a list of protocol names and supported /// versions. The string takes the following format: /// /// "HSDir=1-1 LinkAuth=1" @@ -763,27 +782,29 @@ pub fn is_supported_here(proto: Proto, vers: Version) -> bool { /// only for tor versions older than FIRST_TOR_VERSION_TO_ADVERTISE_PROTOCOLS. /// /// C_RUST_COUPLED: src/rust/protover.c `compute_for_old_tor` -pub fn compute_for_old_tor(version: &str) -> &'static [u8] { +pub fn compute_for_old_tor(version: &str) -> &'static CStr { + let empty: &'static CStr = cstr!(""); + if c_tor_version_as_new_as(version, FIRST_TOR_VERSION_TO_ADVERTISE_PROTOCOLS) { - return NUL_BYTE; + return empty; } if c_tor_version_as_new_as(version, "0.2.9.1-alpha") { - return b"Cons=1-2 Desc=1-2 DirCache=1 HSDir=1 HSIntro=3 HSRend=1-2 \ - Link=1-4 LinkAuth=1 Microdesc=1-2 Relay=1-2\0"; + return cstr!("Cons=1-2 Desc=1-2 DirCache=1 HSDir=1 HSIntro=3 HSRend=1-2 \ + Link=1-4 LinkAuth=1 Microdesc=1-2 Relay=1-2"); } if c_tor_version_as_new_as(version, "0.2.7.5") { - return b"Cons=1-2 Desc=1-2 DirCache=1 HSDir=1 HSIntro=3 HSRend=1 \ - Link=1-4 LinkAuth=1 Microdesc=1-2 Relay=1-2\0"; + return cstr!("Cons=1-2 Desc=1-2 DirCache=1 HSDir=1 HSIntro=3 HSRend=1 \ + Link=1-4 LinkAuth=1 Microdesc=1-2 Relay=1-2"); } if c_tor_version_as_new_as(version, "0.2.4.19") { - return b"Cons=1 Desc=1 DirCache=1 HSDir=1 HSIntro=3 HSRend=1 \ - Link=1-4 LinkAuth=1 Microdesc=1 Relay=1-2\0"; + return cstr!("Cons=1 Desc=1 DirCache=1 HSDir=1 HSIntro=3 HSRend=1 \ + Link=1-4 LinkAuth=1 Microdesc=1 Relay=1-2"); } - NUL_BYTE + empty } #[cfg(test)] |