Status: complete for the agreed modernization scope. Native MSVC remains an explicitly deferred milestone. Implementation branch: feature/self-contained-portable-c; review: #3050 (merged).
Keep C11 and the existing CLI, JSON configuration, ss:// parsing, SIP003 plugins, ACL blacklist/whitelist/outbound precedence, public shadowsocks.h API, legacy stream ciphers, AEAD and SIP022 TCP/UDP behavior in the compatibility profile. Removing regex or legacy ciphers is explicit opt-in, with configuration errors for unavailable functionality. Linux redirection/netfilter remains Linux-only.
- Baseline: fresh rebuild, unit/integration results, binary/dependency sizes, TCP and UDP throughput, and memory measurements.
- Required independent interoperability including TCP and UDP; missing peers fail the required CI job and are reported as skips in optional local runs.
- Target-scoped CMake, separate programs/static/shared library options, reliable dependency discovery, installation/export metadata and presets.
- Offline bundled dependency mode and source release archive; explicit system mode for distro packages; checksums, licenses, versions, update procedure.
- Remove libcork: address parsing, lists, hash maps, subprocess lifecycle.
- Remove libipset: bounded IPv4/IPv6 prefix storage with insertion/deletion; differential tests including holes inside larger networks.
- Vendor the small bloom filter and remove all three submodule requirements.
- Portability layer for sockets/errors, I/O, clocks, randomness and processes.
- Runtime CI: Linux glibc/musl, macOS, FreeBSD, Windows MinGW.
- Document MSVC/event-loop compatibility assessment as a later milestone.
- Minimal profile: no regex/plugins/manager/legacy stream ciphers.
- Crypto-only Mbed TLS configuration and evidence-backed provider assessment.
- Complete sanitizers/static analysis, compatibility and stress validation, release archive offline build, installed consumer, before/after report.
Base commit: 8fe386b. Its libcork checkout is 074e074b, different from the superproject gitlink; this was pre-existing local state. That checkout, libipset and libbloom are preserved and ignored locally. Fresh baseline builds use those same checkouts, with no modernization changes applied to baseline source. The fresh baseline passes all 13 original unit tests.
Requires CMake 3.20+, a C11 compiler, and a build executor. Presets use Ninja; manual configuration may use another generator.
cmake --preset system
cmake --build --preset system
ctest --preset system
Programs are in build-system/bin for either linkage mode. WITH_STATIC selects
static third-party dependencies; it does not promise a static libc or OS runtime.
SS_BUILD_EXECUTABLES, SS_BUILD_STATIC_LIBRARY and SS_BUILD_SHARED_LIBRARY control
outputs independently. Docs and platform shell tools are explicit opt-ins.
Bundled mode is the default and the bundled / minimal presets exercise it.
Maintainers stage the intended source files, then run
scripts/source_archive.py build-artifacts/shadowsocks-c.tar.gz.
The archive includes tracked working-tree contents (so uncommitted changes are
included); record the final commit with a published release and use a clean
checkout for publishing. No submodules are accepted in the archive.
The tests workflow runs actionlint 1.7.12 on GitHub Actions workflows and
Ruff 0.15.6 on Python scripts/tests (E9,F63,F7,F82: syntax errors, invalid
constructs and undefined names). Run the same checks locally:
actionlint -shellcheck= -pyflakes=
uvx --from ruff==0.15.6 ruff check --select E9,F63,F7,F82 tests scriptsProject C builds treat compiler warnings as errors. The separate clang-tidy-18 job analyzes project sources using the CMake compilation database and allows zero warnings. Tool failures and compiler errors also fail the job; complete diagnostics are uploaded even on failure. Vendored sources remain excluded.
Implementation validation at commit cdb192a passes the full platform matrix: Linux glibc x86-64/ARM64 and macOS full/minimal builds, real TCP/UDP relay, SIP003 cleanup (full profile), and relocated installed consumers. FreeBSD 14.3 passes compilation, unit/vendor tests, real TCP/UDP relay and installed consumers. Native Windows UCRT64 passes all 31 unit/vendor tests, six-method TCP/UDP relay, and installed static/shared consumers. Relay and consumer execution excludes MSYS2/toolchain DLL directories from PATH; binaries require only Windows system DLLs. Zig cross-builds also include both libraries and installed consumers.
Alpine/musl builds the release archive with networking and Python discovery disabled and passes all unit/vendor and TCP/UDP tests. Linux Valgrind, ASan/UBSan, coverage, required shadowsocks-rust interoperability, clang-tidy-18, and Debian package construction pass. Evidence: platform matrix, tests and analysis, system builds and packaging.
The same committed source archive also builds locally on Linux arm64 with networking and Python discovery disabled, passing all 31 unit/vendor tests and six-method TCP/UDP plus SIP003 tests. The source release itself needs no Git or Python to compile. Executable-only installation omits library metadata, and a minimal static-library-only build succeeds with the PCRE2 archive removed. The final documentation commit is rechecked by the same CI matrix before delivery.
Address classification now uses inet_pton consistently with socket conversion; malformed dotted addresses previously accepted by libcork but rejected by inet_pton are no longer classified as IP literals. Full and suffix ACL rules are explicit additions; normal regex remains available by default. Legacy methods unavailable in Mbed TLS 3 (such as RC4) are not resurrected. Crypto providers remain libsodium plus the reduced Mbed TLS primitive set: AES-128/192-GCM, software AES fallback, MD5/SHA1 compatibility derivation, and legacy AES/Camellia stream modes prevent a transparent libsodium-only switch. See https://doc.libsodium.org/secret-key_cryptography/aead/aes-256-gcm and https://shadowsocks.org/doc/sip022.html for the provider and protocol contracts.
- Fresh base-commit build (8fe386b) passes all 13 original unit tests, using the preserved dependency checkouts described above. Both its system-shared and static-dependency programs were rebuilt for size comparisons.
- macOS full bundled: 31 tests; minimal: 29 tests. System dependencies: 17 tests.
- ASan + UBSan: all 17 project tests and six-method TCP/UDP SIP003 tests pass.
- Clang-tidy: zero warnings/errors with Homebrew LLVM; project compiler warnings remain errors. CI additionally uses its existing pinned clang-tidy-18 check.
- IP-set differential test: 1,028,000 comparisons against the original libipset, including randomized full-width IPv4/IPv6 insertion/deletion and membership.
- Linux x86-64 musl: 31 unit/vendor tests and all six TCP/UDP relay cases pass in containers with networking disabled. The preinstalled cross compiler intermittently crashed under CPU emulation; incremental retries completed.
- Installed bundled static/shared consumers run after relocation. Installed system-mode static/shared consumers also link and run. System static exports require the exact Mbed TLS version used at build time to avoid an ABI mismatch.
- Windows x86-64: programs, both libraries, all tests and installed consumers cross-compile with Zig. Native UCRT64 execution and installed consumers pass with runtime DLL lookup restricted to the installation and Windows system paths.
- SIP003 fixture: real TCP forwarding, UDP bypass, and child cleanup pass through the actual programs. DNS cancellation covers outstanding A/AAAA requests, exactly-once callbacks/free callbacks and reinitialization after shutdown.
MSVC is an explicitly deferred milestone, not a supported build today. MinGW-w64
supplies the POSIX compatibility headers/functions (unistd.h, getopt,
ssize_t, string helpers) used throughout the existing CLI. Native MSVC needs
those interfaces isolated, compiler-specific flags in the libsodium adapter,
libuv/Win32 build verification and export/import validation. CMake now rejects
MSVC early with the supported UCRT64/Zig alternatives. Removing the event loop
or inventing replacement crypto implementations is outside this modernization.
Retain libsodium plus Mbed TLS crypto primitives. The bundled Mbed TLS config omits TLS, X.509, certificate parsing and handshake machinery; it retains only cipher/hash primitives needed by protocol compatibility. Libsodium alone cannot replace AES-128-GCM, software AES fallback, MD5/SHA1 compatibility derivation and legacy stream modes. PCRE2 is absent in the minimal profile. This removes three submodule dependencies and reduces what is built without replacing audited cryptographic algorithms with project-specific implementations.
See measurements and tradeoffs for reproducible local results.
The static-macos and static-windows jobs use Clang, bundled dependencies and
SS_BUILD_SHARED_LIBRARY=OFF. They run unit/vendor tests, relocate the installed
static library, build its consumer, and exercise the installed TCP/UDP programs.
The macOS job also exercises SIP003. tests/check_static_runtime.py rejects
non-system dylibs and DLLs (including Windows delay imports) in every installed
program and the static consumer. Windows runtime tests exclude toolchain DLL
paths. Windows uses the native MSYS2 CLANG64 environment.
macOS and Windows retain their OS libraries; static builds on these platforms
mean no separately distributed project, crypto, event-loop or toolchain shared
libraries. The static-linux job builds the Clang/musl Dockerfile, which also
links libc statically and rejects ELF interpreters and NEEDED entries. All
three jobs publish the tested installations as workflow artifacts.
Libuv 1.52.1 replaces libev in bundled builds; system builds use the distro's libuv. Windows uses libuv's IOCP-backed AFD socket polling and macOS uses kqueue. The internal event API supports independent read/write watchers on one socket, including stopping/freeing watchers during callbacks. Handles close separately from application objects. Native tests exercise 256 descriptors and verify the IOCP handle or kqueue descriptor on the corresponding platform.
c-ares drives asynchronous A/AAAA lookups for TCP/UDP destinations and client hostname ACL bypass, with a dynamically sized DNS watcher list. Manager hostname updates also use this resolver. Runtime calls to the numeric-address helper cannot fall back to blocking DNS. Initial configuration/listener/proxy-address resolution remains synchronous before serving traffic. Tests use a local delayed DNS server to verify both address families, NXDOMAIN, cancellation, exactly-once callbacks, and timer progress while requests wait. Hostname ACL integration uses an unreachable proxy upstream so successful transfers prove direct resolution.
The project is named shadowsocks-c. New library outputs are
libshadowsocks-c, and CMake/pkg-config consumers use shadowsocks-c.
shadowsocks.h, its ABI version, and all ss-* commands remain stable.
Legacy library filenames are installed as relative symlinks on Unix and copies
on Windows; find_package(shadowsocks-libev) and the old pkg-config name resolve
to the new library. Private dependency archives and license files install under
shadowsocks-c. Source archives and the main manual use the new name.
Existing configuration paths, Debian package identifiers and service names remain compatible. GitHub URLs retain the current repository location.