A connection's two 16 KiB relay buffers lived inline in its slot, so every
connection that had moved a byte kept those pages resident even while idle.
They now come from one ObjectPool with two buffers per connection slot: a
connection leases a buffer while bytes wait in it and returns it when it
drains, and the LIFO free list hands the same warm pages to the next busy
connection. The pool covers every direction of every slot, so a lease never
fails and reads never wait on it.
With 1,000 idle connections, ss-server drops from 35.4 to 27.2 KiB per
connection on Linux (C: 26.2) and from 73.9 to 42.2 KiB on macOS. The slot
shrinks from 104 to 68 KiB.
FixedBuffer gains a user-provided constructor so that value-initialising one
(a pool lease, a variant alternative) no longer zero-fills its storage.
The test regex skipped file names with digits (test_aead2022_cpp.cpp,
test_base64_cpp.cpp); include them, fix the two optional accesses it then
reports, and build test_jconf with the strict warning set.
Convert acl, acl_literal, aead2022, base64, buffer, cache (legacy
reference), crypto, ipset, ipset_reference, json, netutils, ppbloom,
process, ref, ssurl and utils tests to test_helpers.hpp. ctest names are
unchanged; every assertion is kept. Build the ported sources with the
strict C++ warning set.
read_jconf now reads the file and builds the JSON tree in a scratch arena
that is released before it returns, and copies the parsed strings into one
process-lifetime arena instead of a malloc per string. parse_addr and the
config parser share one address splitter.
Port test_jconf to C++ and cover every field copied out of the parse tree,
a re-read, and the densest file the size limit accepts.
The unauthenticated stream ciphers (aes-*-cfb, aes-*-ctr, camellia-*-cfb,
chacha20, chacha20-ietf, salsa20) are gone from every build, together
with the SS_ENABLE_LEGACY option, the C++ stream codecs, their C test
oracle and the stream-only tests and configurations. A configuration
naming one of them, or RC4/table, now fails at startup with a message
pointing to an AEAD method, and test_cli checks that.
Shell completions list only the supported methods (and now include the
2022 ones), and the docs and the compatibility contract say the stream
ciphers were removed.
utils.cpp's \snippet aead.cpp and stream.cpp now live in src/crypto/,
which was not on Doxygen's EXAMPLE_PATH, so the man1 and HTML builds
failed. List the documentation sources explicitly instead of guessing
their extension.
ss-local, ss-tunnel and ss-redir only timed the upstream connect (as the
C relays did), so a client that never finished its SOCKS handshake, or a
stream whose peer vanished without a FIN, held a pool slot forever. With
the pool now a hard cap that pauses accepting when full, enough of them
stopped the listener for good. Every connection now starts with the idle
deadline, connected() re-arms it, and traffic refreshes it for all kinds
(the idle timeout keeps its 24 h floor, MIN_TCP_IDLE_TIMEOUT).
An evicted session keeps its pool slot until its socket's close callback
runs, so with pool capacity equal to the table's the acquire after an
eviction failed: a full table dropped new-session packets after evicting
a live session for nothing. The AEAD-2022 shared-session pool had the
same problem with entries still referenced by relay sessions.
heap_realloc returned NULL when a block outgrew the largest size class or
the budget, and libuv aborts when growing its watcher array fails: a poll
on fd 8190 or above (about 4,000 connections) killed the process.
Move the block to the system heap instead, as malloc and calloc already
do. test_heap_guard_cpp polls fd 16380 with the heaps installed.
docker/static: the C++ unit tests link the static libstdc++, whose error
paths need an unwinder that --rtlib=compiler-rt does not provide; link
llvm-libunwind. The programs themselves still need no C++ runtime.
docker/build: build in the default bundled mode with CMake instead of
against libev/udns (Alpine's Mbed TLS 4 is not supported by system
mode).
docs/performance.md compares master (C) with the C++ engine on macOS
arm64: zero heap allocations per connection or datagram (from 27-89),
TCP throughput within noise, and about 20 MiB more RSS at 1,000 open
connections from the inline per-connection buffers. docs/cpp-core.md
and CLAUDE.md now describe the finished layout.
Sizes the resolver's query pool, the last of the capacity settings the
no-heap-after-startup design calls for. Defaults are unchanged: the
connection limit (plus 64 on ss-server, which also resolves for its
statistics).
The C cache (now used only by the reference codecs) moves to
tests/reference and src/uthash.h is deleted. ACL rules and ss-manager's
servers are ListNodes on IntrusiveLists; destroying an element unlinks
it, so the free paths no longer have to remember to. core.h keeps only
ss_ip. test_rule is ported to C++ and also covers literal rules.
The programs now use only the C++ codecs. The C stream/AEAD/AEAD-2022
implementations stay as the reference the differential tests and the C
unit tests compare against. Key derivation and the cipher tables used by
the doc snippets move to src/crypto/keys.{hpp,cpp}.
ss-manager keeps its servers in an ss_list (at most MAX_PORT_NUM,
looked up only on control messages) instead of a uthash table, and
tests/test_manager.py covers add/ping/list/remove end to end.
The loop is created before the programs fork into the background, and
kqueue/epoll descriptors do not survive fork(), so ss-server -f (which
ss-manager always uses) died as soon as it ran. Call uv_loop_fork() in
the child.
Each program's loop, signals, plugin watcher and stats timer now go
through ss::event::Program (src/event/program.hpp), held on main()'s
stack; ss-manager uses it too. ss-server resolves the manager address
with the relay resolver. With no C caller left, ss_event.cpp/.h,
resolv.cpp/.h and their C tests go; test_resolver_cpp.cpp replaces the
resolver tests against the same delayed local DNS server, and ss_ev is
now an interface target over libuv.
<shadowsocks/control.h> starts ss-local on a library-owned thread,
stops it from any thread through a libuv async handle and waits for it;
<shadowsocks/shadowsocks.hpp> wraps that in a move-only, header-only
shadowsocks::LocalServer whose destructor stops and waits. The library
exports only C symbols, shadowsocks.h is unchanged, and the shared
library version becomes 2.1.0 (SOVERSION 2). test_local_api_cpp covers
the lifecycle; the installed-package consumer gains a C++ program.
The TCP connection pool and the UDP session table are sized from these
options (or max_connections / max_udp_sessions in the configuration
file) at startup instead of fixed constants; the DNS query pool follows
the connection limit. test_limits.py checks that a connection beyond
the limit is refused and that accepting resumes once one closes.
GCC enables -Wsign-compare with -Wall for C++ (clang does not), which
turned a few signed/unsigned comparisons in base64, netutils, server and
manager into errors; udp.cpp needed <ctime>.
The programs point libuv, c-ares and Mbed TLS (MBEDTLS_PLATFORM_MEMORY in
the bundled build) at their own FixedHeap before anything runs, mark the
end of startup with heap_seal(), and in verbose mode report heap use and
any allocation after it at exit. The library build keeps the host's
allocator.
measure_alloc.py gains --udp, and the alloc_steady_programs_* tests now
fail on any malloc per relayed TCP connection (by name and by address)
or UDP association, for every cipher family.
musl's CMSG_NXTHDR compares a size_t with a ptrdiff_t, which Clang's
-Wsign-compare rejects in C++. Call it from one helper that suppresses
the warning there.
ss-redir's TCP side moves onto the relay engine (per-listener TOS for the
DSCP ports). src/relay/udp replaces udprelay.cpp: sessions keyed by
client address own their upstream socket and live in a fixed LRU,
AEAD-2022 server sessions are shared through RefPtr between the
session-ID table and the relays using them, and datagrams waiting for
DNS sit in pool slots. Packets are received into and built in
relay-owned buffers instead of a 64 KiB allocation per datagram. The
programs no longer call crypto_init(); Method sets up libsodium and the
replay filter.
crypto.h's min/max macros broke <algorithm> in C++ sources that include
it first, netutils.h's linux/tcp.h clashed with the netinet/tcp.h libuv
includes, and GCC rejects memcpy into crypto_t. Apple clang accepted all
three.
The request header, outbound ACL, target resolution through the relay's
resolver, the anti-probing stop stage and the manager traffic counters
are engine code now; the connmark-to-TOS tracker becomes a pair of relay
hooks. server.cpp keeps option parsing, nftables and the stats timer.
The SOCKS5 handshake, the ACL bypass decision (with its own resolver for
host-name rules) and the short wait for a first payload are now engine
code; local.cpp keeps only option parsing and startup. The library entry
points start the same engine.
One engine (src/relay/tcp) for the four TCP relays: connections live in a
fixed pool owned through PoolPtr, handshake, cipher state and buffers are
inline, timeouts are intrusive deadline lists on one timer and DNS answers
come back through generation-checked handles. A full pool refuses new
connections and pauses accepting until a slot frees.
ss-tunnel is the first user; its hand-written relay callbacks are gone.
tests/tunnel_interop.py covers every method against ss-server and
shadowsocks-rust.
Queries live in pool slots with their first A and AAAA answer inline,
c-ares sockets are watched from a fixed table, and answers reach the
waiter through a callback plus opaque words instead of a back-pointer.
resolv.cpp keeps the C API as a shim. The event Loop can now adopt the
ss_event loop, and a Poll can stop watching a socket it does not own.
TCP request/response streams with the salt echo between the two
directions, an exact-match salt pool on FixedLru, and UDP packets sealed
and opened in place with caller-owned session state. Differentially
tested against aead2022.cpp in both roles; the steady phase allocates
nothing.
The session table and the relay contexts each hold a reference; evicting a
session from the full table no longer frees memory a relay still uses.
Ported from the parked fix/aead2022-udp-session-eviction work.
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.
Max Lv