A TLS sendData() failing with SSL_ERROR_WANT_READ (mid-handshake
application data, or a post-handshake session ticket exchange) has
nothing to do with write-readiness, but resetSocket() kept re-arming
EPOLLWRNORM anyway - an already-writable TCP socket fires that
immediately, so the retry loop spun the CPU as fast as it could
until the connection was eventually dropped, without ever reading
the peer's first command. Confirmed via a 15GB+ debug log from one
stuck connection. sendNeedsRead() lets Socket now tell the
difference and wait for a real EPOLLIN instead of busy-retrying.
Thread/EPoll lifecycle:
- Thread::~Thread() now actually joins/frees its worker thread (was
empty - the OS thread kept running against already-freed EPoll/Socket
objects on any early teardown, a confirmed "double free" crash)
- EPoll::~EPoll() calls stop() if never explicitly stopped, for the
same reason
- epoll_wait() now uses a 1s timeout instead of blocking forever, so a
worker thread can actually notice isStopping() and let itself be
joined
- EPoll::processCommand() iterated threads by value, silently
double-freeing the real vector's Thread the moment each copy went
out of scope
- ThreadScope gained onThreadStart()/onThreadEnd() hooks (actually
wired up now - the constructor that was supposed to store the scope
discarded it) for per-thread C-library init (e.g. MySQL client)
Socket/TCPSocket/TLS:
- Socket::writeSocket(): give up and shut down a connection after 50
consecutive zero-progress sends instead of retrying forever -
SSL_ERROR_WANT_READ on a write needs a READ to make progress, but
resetSocket() re-arms EPOLLWRNORM regardless, which an
already-writable TCP socket satisfies immediately - a real stuck
connection generated 55GB, then 12.9GB of debug log this way before
being caught
- Socket::writeSocket() now honors sendData()'s actual return value
(previously discarded, entry popped unconditionally after one call) -
a large response could get silently truncated past what fit in one
write()/SSL_write() call
- TLS::registerSocket()/sendData()/receiveData(): `initialized` now
only goes true once SSL_set_fd() has actually succeeded, and
sendData()/receiveData() check it first - fixes a real SIGSEGV where
a new session's own queued greeting could reach SSL_write() on a
different epoll thread before this session's handshake setup had run
- TCPServer::connectionRequest() now performs the TLS handshake ON THE
ACCEPTED SESSION, not the listening server itself (was building SSL
state on the wrong object, leaving every session's own `ssl`
uninitialized)
- TCPServer::receiveData() always uses the plain (non-TLS) read path -
the listening socket is never itself a TLS peer
- TCPSocket's block-mode literal reading used an unset `blockLength`
field instead of `blockSize`, and could busy-spin forever on a
multi-packet literal
- TCPSocket line scanning replaced an unbounded strcspn() (assumes a
NUL-terminated buffer; read past a non-NUL-terminated receive buffer
into adjacent heap memory) with a bounds-checked memchr() scan
Protocol/session handling:
- CommandList::processRequest() now case-folds the command keyword
before lookup - SMTP/POP3/IMAP commands are spec-required to be
case-insensitive; a client sending "Mail From:" instead of
"MAIL FROM:" previously failed to dispatch at all
- TCPSession::protocol() no longer drops blank lines while a handler
has grabbed input (e.g. __SMTP_DATA reading a message body, an IMAP
APPEND literal) - those handlers depend on seeing blank lines as
real content, not commands; this silently corrupted any message body
containing a blank line
- TCPSession's uuid alias fixed: streaming a raw uuid_t via operator<<
triggered libstdc++'s unsigned-char* overload (strlen() on 16 binary
bytes, a real stack-buffer-overflow read), and `alias` pointed at a
stack-local that was already destroyed by the time the constructor
returned
- INotify::processEvent() only treats event->name as a NUL-terminated
string when event->len > 0 (per inotify(7)) instead of unconditional
strlen() on a field the kernel doesn't guarantee is even present -
a confirmed heap-buffer-overflow read that had been misdiagnosed as
a MySQL thread-safety issue
Brad Arant