Commit Graph
4 Commits
Author SHA1 Message Date
Max Lv 0fb282245c C++20 port 8/14: allocation-free stream cipher codecs (#3072)
* Add allocation-free C++ stream cipher codecs

src/crypto/stream.hpp implements the legacy stream methods this build
supports (AES CFB/CTR, Camellia CFB, Salsa20, ChaCha20, ChaCha20-IETF)
as value types. The AES and Camellia contexts are held by value through
Mbed TLS's block-cipher APIs instead of an allocated
mbedtls_cipher_context_t, and the libsodium ciphers track their
keystream position, finishing partial 64-byte blocks from a stack block
instead of the padding copies stream.cpp makes.

test_crypto_stream_cpp runs TCP streams (with fragments that split
keystream blocks) and UDP packets between the C and C++
implementations in both directions for all twelve methods and checks
IV replay; alloc_steady_crypto_stream requires zero allocations for new
connections and packets.

* Document the crypto codecs, cache rewrite and allocation progress

* Include <algorithm> for std::min in test_crypto_stream_cpp.cpp

* Do not memcpy from an empty span in the stream decoder

An empty read before the IV arrived passed a null source to memcpy,
which UBSan reports (and the ASan CI job turns into a failure).

* Include C++ headers before crypto.h in test_crypto_stream_cpp.cpp

crypto.h defines min/max macros for the C sources; libstdc++ headers
included after it fail to parse.
2026-10-15 10:00:37 +08:00
Max Lv 8c3390887e Add the C++ event layer over libuv (#3069)
src/event/loop.hpp wraps uv_loop/poll/timer/signal/async handles that
live by value inside their owner and dispatch to an owner member
function chosen at compile time. A Poll owns its socket and carries
read and write interest on one handle, closing the descriptor in
libuv's close callback. CloseGroup collects the asynchronous closes of
an owner's handles and reports completion afterwards, which is how
pooled owners implement AsyncClosable. DeadlineList drives the idle
timeouts of many owners from one timer.

test_event_cpp covers readiness, closing a peer from inside a
callback, recycling a pooled owner only after its handles closed,
repeating timers, deadline ordering and cross-thread wakeups.
2026-10-15 09:54:56 +08:00
Max Lv 384810efce C++20 port 2/14: compile the leaf modules as C++ (#3066)
* Make headers and leaf modules compile as C++

Wrap the declarations of every project header in extern "C" (after the
system includes, which must keep C++ linkage), so converted modules and
the remaining C files agree on linkage.

In the leaf modules, cast allocator and memchr results explicitly,
rename identifiers called new, replace the getpwnam_r VLA with the
fixed 16 KiB buffer the loop already capped itself at, and make the
rlimit initialiser conversion explicit. All of this is still valid C.

* Compile the leaf modules as C++

Rename base64, json, ipset, process, ppbloom, rule, ssurl and cache from
.c to .cpp without touching their contents, and update the CMake source
lists, debian/copyright and the docs.

Ported code keeps -Wall; -Wextra is now opt-in through
ss_strict_warnings() for code written as C++ (the core tests).
check_no_heap.py gains a ratchet baseline for the converted modules,
which still allocate the way the C code did. A new check_cxx_runtime
test verifies with nm that the programs and libshadowsocks-c.a still
need no C++ runtime library, so C consumers are unaffected.

* Fix the Windows branches of process.cpp for C++

Cast allocator results and the thread argument explicitly and
value-initialise JOBOBJECT_EXTENDED_LIMIT_INFORMATION with {}. Found by
the zig x86_64-windows-gnu cross build.

* Keep clang-tidy clean for the converted modules

Once the C headers are included from C++ translation units,
bugprone-dynamic-static-initializers reports each extern variable
declaration in them; none is defined in a header, so disable the check.
Mark the two bounded memchr searches in ssurl.cpp, which
bugprone-not-null-terminated-result misreads as string copies.

* check_cxx_runtime: ignore glibc symbol versions

nm on glibc prints __cxa_atexit@GLIBC_2.2.5, which the allowlist for the
libc-provided __cxa_atexit/__cxa_finalize did not match.

* Keep GCC's C++-only warnings off for modules converted from C

GCC's C++ -Wall includes -Wsign-compare and -Wclass-memaccess, which C's
-Wall does not, so the converted modules failed -Werror on GCC (Linux,
UCRT64) although nothing in them changed. They keep the warning set they
were written against; code under ss_strict_warnings() re-enables both.
2026-10-15 09:48:18 +08:00
Max Lv bcb3731968 C++20 port 1/14: build, ownership core and allocation audit (#3065)
* Enable C++20 alongside C11 in the build

Add CXX to the project with C++20 (no extensions) and build C++ sources
with -Wextra -fno-exceptions -fno-rtti -fno-threadsafe-statics on top of
the existing warning flags. Give every toolchain a C++ compiler: the zig
Windows toolchain, the static macOS/Windows CI jobs, the static musl
image (clang++ plus libstdc++ headers) and the RPM spec.

* Add C++20 ownership and allocation core

Header-only primitives for the no-heap-after-startup design:
Result/Status, Region, ObjectPool with PoolPtr (std::unique_ptr with a
pool deleter), generation-checked Handle and asynchronous close support,
intrusive RefPtr, FixedBuffer, MonotonicArena, FixedHashMap and FixedLru,
IntrusiveList, and a bounded FixedHeap for third-party allocator hooks.

Unit tests cover each primitive (test_core_*). scripts/check_no_heap.py
rejects heap allocation in C++ sources under src/ and runs as a ctest.
clang-tidy now also analyses C++ sources and the core headers.

* Add heap allocation audit for relayed connections

alloc_counter is a preloadable malloc counter (glibc, macOS) that writes
a snapshot on SIGUSR2. measure_alloc.py warms ss-local and ss-server up,
snapshots both, relays more connections and reports allocations per
connection. It runs report-only as the alloc_audit_report ctest.
interop.peers() now yields the started processes.

* Document the C++20 port and allocation baseline

docs/cpp-core.md describes the language profile, the core primitives,
the phase plan and the measured C baseline (77-89 allocations per
connection in ss-server, 27-39 in ss-local). The compatibility contract
now keeps the C11 public header instead of a C11 code base. CLAUDE.md
drops stale libev, submodule and gnu99 references.

* Fix CI for the C++ core: libstdc++ headers, static unwinder, newer clang

- docker/static: Alpine's libstdc++ headers come with g++, and the C++
  tests' static libstdc++ needs an unwinder that compiler-rt lacks; add
  g++ and llvm-libunwind.
- FixedBuffer: drop the unused kCapacity (clang-tidy 18 reports it as a
  dynamically initialized header static).
- ss-server on Windows: manager_addr was only read in POSIX-only code,
  which newer clang rejects (-Wunused-but-set-global); say that the
  option is ignored there.

* CI: allow running the test and build workflows by hand

Stacked PRs target their parent branch, which these workflows do not
trigger on; workflow_dispatch lets each layer run the full matrix.

* CI: let clang-tidy ignore GCC-only warning flags

The compile database comes from a GCC build, whose flags (for example
-Wno-class-memaccess) clang-tidy does not know and reports as errors.
2026-10-15 09:45:54 +08:00