summaryrefslogtreecommitdiff
path: root/src/rust/protover
diff options
context:
space:
mode:
Diffstat (limited to 'src/rust/protover')
-rw-r--r--src/rust/protover/ffi.rs63
-rw-r--r--src/rust/protover/lib.rs1
-rw-r--r--src/rust/protover/protover.rs133
3 files changed, 107 insertions, 90 deletions
diff --git a/src/rust/protover/ffi.rs b/src/rust/protover/ffi.rs
index 3eb22c933e..d724c102d3 100644
--- a/src/rust/protover/ffi.rs
+++ b/src/rust/protover/ffi.rs
@@ -12,6 +12,9 @@ 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
@@ -137,18 +140,22 @@ pub extern "C" fn protocol_list_supports_protocol_or_later(
/// Provide an interface for C to translate arguments and return types for
/// protover::get_supported_protocols
#[no_mangle]
-pub extern "C" fn protover_get_supported_protocols() -> *mut c_char {
- // Not handling errors when unwrapping as the content is controlled
- // and is an empty string
- let empty = CString::new("").unwrap();
-
- let supported = get_supported_protocols();
- let c_supported = match CString::new(supported) {
- Ok(n) => n,
- Err(_) => return empty.into_raw(),
- };
-
- c_supported.into_raw()
+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.as_ptr()
}
/// Provide an interface for C to translate arguments and return types for
@@ -193,15 +200,15 @@ pub extern "C" fn protover_is_supported_here(
/// Provide an interface for C to translate arguments and return types for
/// protover::compute_for_old_tor
#[no_mangle]
-pub extern "C" fn protover_compute_for_old_tor(
- version: *const c_char,
-) -> *mut c_char {
- // Not handling errors when unwrapping as the content is controlled
- // and is an empty string
- let empty = String::new();
+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();
if version.is_null() {
- return allocate_and_copy_string(&empty);
+ return empty.as_ptr();
}
// Require an unsafe block to read the version from a C string. The pointer
@@ -210,10 +217,22 @@ pub extern "C" fn protover_compute_for_old_tor(
let version = match c_str.to_str() {
Ok(n) => n,
- Err(_) => return allocate_and_copy_string(&empty),
+ Err(_) => return empty.as_ptr(),
};
- let supported = compute_for_old_tor(&version);
+ 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();
- allocate_and_copy_string(&supported)
+ supported.as_ptr()
}
diff --git a/src/rust/protover/lib.rs b/src/rust/protover/lib.rs
index 5a5dea4408..fe8c0f9bb2 100644
--- a/src/rust/protover/lib.rs
+++ b/src/rust/protover/lib.rs
@@ -26,6 +26,7 @@ extern crate libc;
extern crate smartlist;
extern crate external;
extern crate tor_allocate;
+extern crate tor_util;
mod protover;
pub mod ffi;
diff --git a/src/rust/protover/protover.rs b/src/rust/protover/protover.rs
index af0049a414..826f1b73f1 100644
--- a/src/rust/protover/protover.rs
+++ b/src/rust/protover/protover.rs
@@ -3,12 +3,15 @@
use external::c_tor_version_as_new_as;
+use std::str;
use std::str::FromStr;
use std::fmt;
use std::collections::{HashMap, HashSet};
use std::ops::Range;
use std::string::String;
+use tor_util::strings::NUL_BYTE;
+
/// The first version of Tor that included "proto" entries in its descriptors.
/// Authorities should use this to decide whether to guess proto lines.
///
@@ -22,21 +25,29 @@ 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: u32 = 500;
-/// Currently supported protocols and their versions
+/// 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`
-const SUPPORTED_PROTOCOLS: &'static [&'static str] = &[
- "Cons=1-2",
- "Desc=1-2",
- "DirCache=1-2",
- "HSDir=1-2",
- "HSIntro=3-4",
- "HSRend=1-2",
- "Link=1-4",
- "LinkAuth=1,3",
- "Microdesc=1-2",
- "Relay=1-2",
-];
+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.
///
@@ -94,36 +105,17 @@ impl FromStr for Proto {
///
/// "HSDir=1-1 LinkAuth=1"
///
-pub fn get_supported_protocols() -> String {
- SUPPORTED_PROTOCOLS.join(" ")
+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()
}
pub struct SupportedProtocols(HashMap<Proto, Versions>);
impl SupportedProtocols {
- /// # Examples
- ///
- /// ```
- /// use protover::SupportedProtocols;
- ///
- /// let supported_protocols = SupportedProtocols::from_proto_entries_string(
- /// "HSDir=1-2 HSIntro=3-4"
- /// );
- /// ```
- pub fn from_proto_entries_string(
- proto_entries: &str,
- ) -> Result<Self, &'static str> {
- Self::from_proto_entries(proto_entries.split(" "))
- }
-
- /// ```
- /// use protover::SupportedProtocols;
- ///
- /// let supported_protocols = SupportedProtocols::from_proto_entries([
- /// "HSDir=1-2",
- /// "HSIntro=3-4",
- /// ].iter());
- /// ```
pub fn from_proto_entries<I, S>(protocol_strs: I) -> Result<Self, &'static str>
where
I: Iterator<Item = S>,
@@ -137,19 +129,30 @@ impl SupportedProtocols {
Ok(SupportedProtocols(parsed))
}
- /// Translates supported tor versions from a string into a HashMap, which
- /// is useful when looking up a specific subprotocol.
+ /// Translates a string representation of a protocol list to a
+ /// SupportedProtocols instance.
///
- /// # Returns
+ /// # Examples
///
- /// A `Result` whose `Ok` value is a `HashMap<Proto, <Version>>` holding all
- /// subprotocols and versions currently supported by tor.
+ /// ```
+ /// use protover::SupportedProtocols;
///
- /// The returned `Result`'s `Err` value is an `&'static str` with a
- /// description of the error.
+ /// let supported_protocols = SupportedProtocols::from_proto_entries_string(
+ /// "HSDir=1-2 HSIntro=3-4"
+ /// );
+ /// ```
+ pub fn from_proto_entries_string(
+ proto_entries: &str,
+ ) -> Result<Self, &'static str> {
+ Self::from_proto_entries(proto_entries.split(" "))
+ }
+
+ /// Translate the supported tor versions from a string into a
+ /// HashMap, which is useful when looking up a specific
+ /// subprotocol.
///
fn tor_supported() -> Result<Self, &'static str> {
- Self::from_proto_entries(SUPPORTED_PROTOCOLS.iter().map(|n| *n))
+ Self::from_proto_entries_string(get_supported_protocols())
}
}
@@ -646,7 +649,7 @@ pub fn compute_vote(
}
let mut final_output: HashMap<String, String> =
- HashMap::with_capacity(SUPPORTED_PROTOCOLS.len());
+ HashMap::with_capacity(get_supported_protocols().split(" ").count());
// Go through and remove verstions that are less than the threshold
for (protocol, versions) in all_count {
@@ -705,7 +708,7 @@ fn write_vote_to_string(vote: &HashMap<String, String>) -> String {
/// ```
/// use protover::*;
///
-/// let is_supported = is_supported_here(Proto::Link, 5);
+/// let is_supported = is_supported_here(Proto::Link, 10);
/// assert_eq!(false, is_supported);
///
/// let is_supported = is_supported_here(Proto::Link, 1);
@@ -730,12 +733,12 @@ pub fn is_supported_here(proto: Proto, vers: Version) -> bool {
///
/// # Inputs
///
-/// * `version`, a string comprised of "[0-9,-]"
+/// * `version`, a string comprised of "[0-9a-z.-]"
///
/// # Returns
///
-/// A `String` whose value is series of pairs, comprising of the protocol name
-/// and versions that it supports. The string takes the following format:
+/// A `&'static [u8]` encoding a list of protocol names and supported
+/// versions. The string takes the following format:
///
/// "HSDir=1-1 LinkAuth=1"
///
@@ -743,33 +746,27 @@ 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) -> String {
- if c_tor_version_as_new_as(
- version,
- FIRST_TOR_VERSION_TO_ADVERTISE_PROTOCOLS,
- )
- {
- return String::new();
+pub fn compute_for_old_tor(version: &str) -> &'static [u8] {
+ if c_tor_version_as_new_as(version, FIRST_TOR_VERSION_TO_ADVERTISE_PROTOCOLS) {
+ return NUL_BYTE;
}
if c_tor_version_as_new_as(version, "0.2.9.1-alpha") {
- let ret = "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";
- return String::from(ret);
+ 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";
}
if c_tor_version_as_new_as(version, "0.2.7.5") {
- let ret = "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";
- return String::from(ret);
+ 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";
}
if c_tor_version_as_new_as(version, "0.2.4.19") {
- let ret = "Cons=1 Desc=1 DirCache=1 HSDir=1 HSIntro=3 HSRend=1 \
- Link=1-4 LinkAuth=1 Microdesc=1 Relay=1-2";
- return String::from(ret);
+ 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";
}
- String::new()
+
+ NUL_BYTE
}
#[cfg(test)]
7apu2bq3rhoylwmucxizk54afw5jyda7pho4j5zdcqpwkufke7zdzwad.onion