The doctests for src/rust/crypto don't compile for multiple reasons,
including some missing exports and incorrect identifier paths. Fixes
bug 26415; bugfix on 0.3.4.1-alpha.
We need this trick because some of our Rust tests depend on our C
code, which in turn depend on other native libraries, which thereby
pulls a whole mess of our build system into "cargo test".
To solve this, we add a build script (build.rs) to set most of the
options that we want based on the contents of config.rust. Some
options can't be set, and need to go to the linker directly: we use
a linker replacement (link_rust.sh) for these. Both config.rust and
link_rust.sh are generated by autoconf for us.
This patch on its own should enough to make the crypto test build,
but not necessarily enough to make it pass.
* REFACTORS `UnvalidatedProtoEntry::from_str` to place the bulk of the
splitting/parsing logic in to a new
`UnvalidatedProtoEntry::parse_protocol_and_version_str()` method (so that
both `from_str()` and `from_str_any_len()` can call it.)
* ADD a new `UnvalidatedProtoEntry::from_str_any_len()` method in order to
maintain compatibility with consensus methods older than 29.
* ADD a limit on the number of characters in a protocol name.
* FIXES part of #25517: https://bugs.torproject.org/25517
* REFACTORS `UnvalidatedProtoEntry::from_str` to place the bulk of the
splitting/parsing logic in to a new
`UnvalidatedProtoEntry::parse_protocol_and_version_str()` method (so that
both `from_str()` and `from_str_any_len()` can call it.)
* ADD a new `UnvalidatedProtoEntry::from_str_any_len()` method in order to
maintain compatibility with consensus methods older than 29.
* ADD a limit on the number of characters in a protocol name.
* FIXES part of #25517: https://bugs.torproject.org/25517
Previously, the limit for MAX_PROTOCOLS_TO_EXPAND was actually being applied
in Rust to the maximum number of version (total, for all subprotocols).
Whereas in C, it was being applied to the number of subprotocols that were
allowed. This changes the Rust to match C's behaviour.
The behaviours still do not match, unsurprisingly, but now we know where a
primary difference is: the Rust is validating version ranges more than the C,
so in the C it's possible to call protover_all_supported on a ridiculous
version range like "Sleen=0-4294967294" because the C uses
MAX_PROTOCOLS_TO_EXPAND to count the number of *subprotocols* whereas the Rust
uses it to count the total number of *versions* of all subprotocols.
During code review and discussion with Chelsea Komlo, she pointed out
that protover::compute_for_old_tor() was a public function whose
return type was `&'static CStr`. We both agree that C-like parts of
APIs should:
1. not be exposed publicly (to other Rust crates),
2. only be called in the appropriate FFI code,
3. not expose types which are meant for FFI code (e.g. `*mut char`,
`CString`, `*const c_int`, etc.) to the pure-Rust code of other
crates.
4. FFI code (e.g. things in `ffi.rs` modules) should _never_ be called
from pure-Rust, not even from other modules in its own crate
(i.e. do not call `protover::ffi::*` from anywhere in
`protover::protoset::*`, etc).
With that in mind, this commit makes the following changes:
* CHANGE `protover::compute_for_old_tor()` to be
visible only at the `pub(crate)` level.
* RENAME `protover::compute_for_old_tor()` to
`protover::compute_for_old_tor_cstr()` to reflect the last change.
* ADD a new `protover::compute_for_old_tor()` function wrapper which
is public and intended for other Rust code to use, which returns a
`&str`.
It was changed to take borrows instead of taking ownership.
* REFACTOR `protover::ffi::protover_is_supported_here()` to use changed method
signature on `protover::is_supported_here()`.
This includes a subtle difference in behaviour to the previous Rust
implementation, where, for each vote that we're computing over, if a single one
fails to parse, we skip it. This now matches the current behaviour in the C
implementation.
* REFACTOR `protover::ffi::protover_compute_vote()` to use
new types and methods.
This includes a subtle difference in behaviour, as in 4258f1e18, where we return
(matching the C impl's return behaviour) earlier than before if parsing failed,
saving us computation in parsing the versions into a
protover::protoset::ProtoSet.
* REFACTOR `protover::ffi::protover_list_supports_protocol_or_later()` to use
new types and methods.
This includes a subtle difference in behaviour, as in 4258f1e18, where we return
(matching the C impl's return behaviour) earlier than before if parsing failed,
saving us computation in parsing the versions into a
protover::protoset::ProtoSet.
* REFACTOR `protover::ffi::protover_list_supports_protocol()` to use new types
and methods.
This includes differences in behaviour to before, which should now more closely
match the C version:
- If parsing a protover `char*` from C, and the string is not parseable, this
function will return 1 early, which matches the C behaviour when protocols
are unparseable. Previously, we would parse it and its version numbers
simultaneously, i.e. there was no fail early option, causing us to spend more
time unnecessarily parsing versions.
* REFACTOR `protover::ffi::protover_all_supported()` to use new types and
methods.
