summaryrefslogtreecommitdiff
path: root/src/rust/protover/protover.rs
diff options
context:
space:
mode:
Diffstat (limited to 'src/rust/protover/protover.rs')
-rw-r--r--src/rust/protover/protover.rs113
1 files changed, 67 insertions, 46 deletions
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)]
7apu2bq3rhoylwmucxizk54afw5jyda7pho4j5zdcqpwkufke7zdzwad.onion