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construct/ircd/client.cc

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22 KiB
C++

// Matrix Construct
//
// Copyright (C) Matrix Construct Developers, Authors & Contributors
// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice is present in all copies. The
// full license for this software is available in the LICENSE file.
//
// client::settings conf::item's
//
ircd::conf::item<size_t>
ircd::client::settings::max_client
{
{ "name", "ircd.client.max_client" },
{ "default", 16384L },
};
ircd::conf::item<size_t>
ircd::client::settings::max_client_per_peer
{
{ "name", "ircd.client.max_client_per_peer" },
{ "default", 24L },
};
ircd::conf::item<size_t>
ircd::client::settings::stack_size
{
{ "name", "ircd.client.stack_size" },
{ "default", ssize_t(1_MiB) },
};
ircd::conf::item<size_t>
ircd::client::settings::pool_size
{
{
{ "name", "ircd.client.pool_size " },
{ "default", 64L },
}, []
{
using client = ircd::client;
client::pool.set(client::settings::pool_size);
}
};
/// Linkage for the default settings
decltype(ircd::client::settings)
ircd::client::settings
{};
//
// client::conf conf::item's
//
ircd::conf::item<ircd::seconds>
ircd::client::conf::async_timeout_default
{
{ "name", "ircd.client.conf.async_timeout" },
{ "default", 305L },
};
ircd::conf::item<ircd::seconds>
ircd::client::conf::request_timeout_default
{
{ "name", "ircd.client.conf.request_timeout" },
{ "default", 33L },
};
ircd::conf::item<size_t>
ircd::client::conf::header_max_size_default
{
{ "name", "ircd.client.conf.header_max_size" },
{ "default", ssize_t(8_KiB) },
};
/// Linkage for the default conf
decltype(ircd::client::default_conf)
ircd::client::default_conf
{};
decltype(ircd::client::log)
ircd::client::log
{
"client", 'C'
};
decltype(ircd::client::pool_opts)
ircd::client::pool_opts
{
size_t(settings.stack_size),
size_t(settings.pool_size),
};
/// The pool of request contexts. When a client makes a request it does so by acquiring
/// a stack from this pool. The request handling and response logic can then be written
/// in a synchronous manner as if each connection had its own thread.
decltype(ircd::client::pool)
ircd::client::pool
{
"client", pool_opts
};
/// A general semaphore for the client system; used for coarse operations
/// like waiting for all clients to disconnect / system shutdown et al.
decltype(ircd::client::dock)
ircd::client::dock;
decltype(ircd::client::ctr)
ircd::client::ctr
{};
// Linkage for the container of all active clients for iteration purposes.
template<>
decltype(ircd::util::instance_multimap<ircd::net::ipport, ircd::client, ircd::net::ipport::cmp_ip>::map)
ircd::util::instance_multimap<ircd::net::ipport, ircd::client, ircd::net::ipport::cmp_ip>::map
{};
//
// init
//
ircd::client::init::init()
{
spawn();
}
ircd::client::init::~init()
noexcept
{
const ctx::uninterruptible::nothrow ui;
terminate_all();
close_all();
wait_all();
log::debug
{
log, "All client contexts, connections, and requests are clear.",
};
assert(client::map.empty());
}
//
// util
//
void
ircd::client::spawn()
{
pool.add(size_t(settings.pool_size));
}
void
ircd::client::wait_all()
{
if(pool.active())
log::dwarning
{
log, "Waiting on %zu active of %zu client request contexts; %zu pending; %zu queued.",
pool.active(),
pool.size(),
pool.pending(),
pool.queued()
};
static const auto is_empty
{
[] { return client::map.empty(); }
};
while(!dock.wait_for(seconds(3), is_empty))
{
for(const auto &[remote, client] : client::map)
log::dwarning
{
log, "Waiting for client %s",
client->loghead(),
};
log::warning
{
log, "Waiting for %zu clients to close...",
client::map.size(),
};
}
log::debug
{
log, "Joining %zu active of %zu client request contexts; %zu pending; %zu queued",
pool.active(),
pool.size(),
pool.pending(),
pool.queued()
};
pool.join();
}
void
ircd::client::close_all()
{
if(!client::map.empty())
log::debug
{
log, "Closing %zu clients", client::map.size()
};
auto it(begin(client::map));
while(it != end(client::map))
{
auto c(shared_from(*it->second)); ++it; try
{
c->close(net::dc::RST, net::close_ignore);
}
catch(const std::exception &e)
{
log::derror
{
log, "Error disconnecting client @%p: %s", c.get(), e.what()
};
}
}
}
void
ircd::client::interrupt_all()
{
if(pool.active())
log::warning
{
log, "Interrupting %zu active of %zu client request contexts; %zu pending; %zu queued",
pool.active(),
pool.size(),
pool.pending(),
pool.queued()
};
pool.interrupt();
}
void
ircd::client::terminate_all()
{
if(pool.active())
log::warning
{
log, "Terminating %zu active of %zu client request contexts; %zu pending; %zu queued",
pool.active(),
pool.size(),
pool.pending(),
pool.queued()
};
pool.terminate();
}
void
ircd::client::create(net::listener &,
const std::shared_ptr<socket> &sock)
{
const auto client
{
std::make_shared<ircd::client>(sock)
};
client->async();
}
size_t
ircd::client::count(const net::ipport &remote)
{
return client::map.count(remote);
}
ircd::parse::read_closure
ircd::read_closure(client &client)
{
// Returns a function the parser can call when it wants more data
return [&client](char *&start, char *const &stop)
{
char *const got(start);
read(client, start, stop);
//std::cout << ">>>> " << std::distance(got, start) << std::endl;
//std::cout << string_view{got, start} << std::endl;
//std::cout << "----" << std::endl;
};
}
char *
ircd::read(client &client,
char *&start,
char *const &stop)
{
assert(client.sock);
auto &sock(*client.sock);
const mutable_buffer buf
{
start, stop
};
char *const base(start);
start += net::read(sock, buf);
return base;
}
const ircd::ipport &
ircd::local(const client &client)
{
return client.local;
}
const ircd::ipport &
ircd::remote(const client &client)
{
return client.it->first;
}
//
// async loop
//
namespace ircd
{
static bool handle_ec_default(client &, const error_code &);
static bool handle_ec_timeout(client &);
static bool handle_ec_short_read(client &);
static bool handle_ec_eof(client &);
static bool handle_ec(client &, const error_code &);
static void handle_client_request(std::shared_ptr<client>);
static void handle_client_ready(std::shared_ptr<client>, const error_code &ec);
}
/// This function is the basis for the client's request loop. We still use
/// an asynchronous pattern until there is activity on the socket (a request)
/// in which case the switch to synchronous mode is made by jumping into an
/// ircd::context drawn from the request pool. When the request is finished,
/// the client exits back into asynchronous mode until the next request is
/// received and rinse and repeat.
//
/// This sequence exists to avoid any possible c10k-style limitation imposed by
/// dedicating a context and its stack space to the lifetime of a connection.
/// This is similar to the thread-per-request pattern before async was in vogue.
///
/// This call returns immediately so we no longer block the current context and
/// its stack while waiting for activity on idle connections between requests.
bool
ircd::client::async()
{
assert(bool(this->sock));
assert(bool(this->conf));
auto &sock(*this->sock);
if(unlikely(sock.fini))
return false;
const auto &timeout
{
conf->async_timeout
};
const net::wait_opts opts
{
net::ready::READ, timeout
};
auto handler
{
std::bind(ircd::handle_client_ready, shared_from(*this), ph::_1)
};
// Re-purpose the request time counter into an async timer by marking it.
timer = ircd::timer{};
sock(opts, std::move(handler));
return true;
}
/// The client's socket is ready for reading. This intermediate handler
/// intercepts any errors otherwise dispatches the client to the request
/// pool to be married with a stack. Right here this handler is executing on
/// the main stack (not in any ircd::context).
///
/// The context the closure ends up getting is the next available from the
/// request pool, which may not be available immediately so this handler might
/// be queued for some time after this call returns.
void
ircd::handle_client_ready(std::shared_ptr<client> client,
const error_code &ec)
{
if(!handle_ec(*client, ec))
return;
auto handler
{
std::bind(ircd::handle_client_request, std::move(client))
};
if(client::pool.avail() == 0)
log::dwarning
{
client::log, "Client context pool exhausted. %zu requests queued.",
client::pool.queued()
};
client::pool(std::move(handler));
}
/// A request context has been dispatched and is now handling this client.
/// This function is executing on that ircd::ctx stack. client::main() will
/// now be called and synchronous programming is possible. Afterward, the
/// client will release this ctx and its stack and fall back to async mode
/// or die.
void
ircd::handle_client_request(std::shared_ptr<client> client)
try
{
// The ircd::ctx now handling this request is referenced and accessible
// in client for the duration of this handling.
assert(ctx::current);
assert(!client->reqctx);
client->reqctx = ctx::current;
client->ready_count++;
const unwind reset{[&client]
{
assert(bool(client));
assert(client->reqctx);
assert(client->reqctx == ctx::current);
client->reqctx = nullptr;
if(client::pool.avail() <= 1)
client::dock.notify_all();
}};
#ifdef RB_DEBUG
timer timer;
log::debug
{
client::log, "%s enter",
client->loghead()
};
#endif
if(!client->main())
{
client->close(net::dc::SSL_NOTIFY).wait();
return;
}
#ifdef RB_DEBUG
thread_local char buf[64];
log::debug
{
client::log, "%s leave %s",
client->loghead(),
pretty(buf, timer.at<microseconds>(), true)
};
#endif
client->async();
}
catch(const std::exception &e)
{
log::error
{
client::log, "%s fault :%s",
client->loghead(),
e.what()
};
}
bool
ircd::handle_ec(client &client,
const error_code &ec)
{
using std::errc;
using boost::asio::error::get_ssl_category;
using boost::asio::error::get_misc_category;
if(unlikely(run::level != run::level::RUN && !ec))
{
log::dwarning
{
client::log, "%s refusing client request in runlevel %s",
client.loghead(),
reflect(run::level)
};
client.close(net::dc::RST, net::close_ignore);
return false;
}
if(system_category(ec)) switch(ec.value())
{
case 0: return true;
case int(errc::operation_canceled): return false;
case int(errc::timed_out): return handle_ec_timeout(client);
default: return handle_ec_default(client, ec);
}
else if(ec.category() == get_ssl_category()) switch(uint8_t(ec.value()))
{
#ifdef SSL_R_SHORT_READ
case SSL_R_SHORT_READ: return handle_ec_short_read(client);
#endif
default: return handle_ec_default(client, ec);
}
else if(ec == net::eof)
return handle_ec_eof(client);
else
return handle_ec_default(client, ec);
}
/// The client indicated they will not be sending the data we have been
/// waiting for. The proper behavior now is to initiate a clean shutdown.
bool
ircd::handle_ec_eof(client &client)
try
{
log::debug
{
client::log, "%s end of file",
client.loghead()
};
client.close(net::dc::SSL_NOTIFY, net::close_ignore);
return false;
}
catch(const std::exception &e)
{
log::error
{
client::log, "%s end of file :%s",
client.loghead(),
e.what()
};
return false;
}
/// The client terminated the connection, likely improperly, and SSL
/// is informing us with an opportunity to prevent truncation attacks.
/// Best behavior here is to just close the sd.
bool
ircd::handle_ec_short_read(client &client)
try
{
log::dwarning
{
client::log, "%s short_read",
client.loghead()
};
client.close(net::dc::RST, net::close_ignore);
return false;
}
catch(const std::exception &e)
{
log::error
{
client::log, "%s short_read :%s",
client.loghead(),
e.what()
};
return false;
}
/// The net:: system determined the client timed out because we set a timer
/// on the socket waiting for data which never arrived. The client may very
/// well still be there, so the best thing to do is to attempt a clean
/// disconnect.
bool
ircd::handle_ec_timeout(client &client)
try
{
assert(bool(client.sock));
log::debug
{
client::log, "%s disconnecting after inactivity timeout",
client.loghead()
};
client.close(net::dc::SSL_NOTIFY, net::close_ignore);
return false;
}
catch(const std::exception &e)
{
log::derror
{
client::log, "%s timeout :%s",
client.loghead(),
e.what()
};
return false;
}
/// Unknown/untreated error. Probably not worth attempting a clean shutdown
/// so a hard / immediate disconnect given instead.
bool
ircd::handle_ec_default(client &client,
const error_code &ec)
{
thread_local char buf[256];
log::derror
{
client::log, "%s :%s",
client.loghead(),
string(buf, ec)
};
client.close(net::dc::RST, net::close_ignore);
return false;
}
//
// client
//
ircd::client::client(std::shared_ptr<socket> sock)
:instance_multimap{[&sock]
() -> net::ipport
{
assert(bool(sock));
const auto &ep(sock->remote());
return { ep.address(), ep.port() };
}()}
,head_buffer
{
conf->header_max_size
}
,sock
{
std::move(sock)
}
,local
{
net::local_ipport(*this->sock)
}
{
assert(size(head_buffer) >= 8_KiB);
}
ircd::client::~client()
noexcept try
{
dock.notify_all();
//assert(!sock || !connected(*sock));
}
catch(const std::exception &e)
{
log::critical
{
log, "~client(%p): %s",
this,
e.what()
};
return;
}
/// Client main loop.
///
/// Before main(), the client had been sitting in async mode waiting for
/// socket activity. Once activity with data was detected indicating a request,
/// the client was dispatched to the request pool where it is paired to an
/// ircd::ctx with a stack. main() is then invoked on that ircd::ctx stack.
/// Nothing from the socket has been read into userspace before main().
///
/// This function parses requests off the socket in a loop until there are no
/// more requests or there is a fatal error. The ctx will "block" to wait for
/// more data off the socket during the middle of a request until the request
/// timeout is reached. main() will not "block" to wait for more data after a
/// request; it will simply `return true` which puts this client back into
/// async mode and relinquishes this stack. returning false will disconnect
/// the client rather than putting it back into async mode.
///
/// Normal exceptions do not pass below main() therefor anything unhandled is an
/// internal server error and the client is disconnected. The exception handler
/// here though is executing on a request ctx stack, and we can choose to take
/// advantage of that; in contrast to the handle_ec() switch which handles
/// errors on the main/callback stack and must be asynchronous.
///
bool
ircd::client::main()
try
{
parse::buffer pb{head_buffer};
parse::capstan pc{pb, read_closure(*this)}; do
{
if(!handle_request(pc))
return false;
// After the request, the head and content has been read off the socket
// and the capstan has advanced to the end of the content. The catch is
// that reading off the socket could have read too much, bleeding into
// the next request. This is rare, but pb.remove() will memmove() the
// bleed back to the beginning of the head buffer for the next loop.
pb.remove();
}
while(pc.unparsed());
return true;
}
catch(const std::system_error &e)
{
return handle_ec(*this, e.code());
}
catch(const ctx::interrupted &e)
{
log::warning
{
log, "%s request interrupted :%s",
loghead(),
e.what()
};
close(net::dc::SSL_NOTIFY, net::close_ignore);
return false;
}
catch(const std::exception &e)
{
log::critical
{
log, "%s :%s",
loghead(),
e.what()
};
return false;
}
catch(const ctx::terminated &)
{
close(net::dc::RST, net::close_ignore);
throw;
}
/// Handle a single request within the client main() loop.
///
/// This function returns false if the main() loop should exit
/// and thus disconnect the client. It should return true in most
/// cases even for lightly erroneous requests that won't affect
/// the next requests on the tape.
///
/// This function is timed. The timeout will prevent a client from
/// sending a partial request and leave us waiting for the rest.
bool
ircd::client::handle_request(parse::capstan &pc)
try
{
timer = ircd::timer{};
++request_count;
// This timeout covers the reception of a complete HTTP head. If the
// head was fragmented and has not entirely arrived yet this function
// will block this request context below. The timeout limits that.
net::scope_timeout timeout
{
*sock, conf->request_timeout
};
// This is the first read off the wire. The headers are entirely read and
// the tape is advanced.
const http::request::head head{pc};
head_length = pc.parsed - data(head_buffer);
content_consumed = std::min(pc.unparsed(), head.content_length);
pc.parsed += content_consumed;
assert(pc.parsed <= pc.read);
// The resource being sought will have its own specific timeout, or none
// at all. This timeout is now canceled to not conflict. Note that the
// time spent so far is still being accumulated by client.timer.
timeout.cancel();
log::debug
{
resource::log, "%s HTTP %s `%s' content-length:%zu have:%zu",
loghead(),
head.method,
head.path,
head.content_length,
content_consumed
};
// Sets values in this->client::request based on everything we know from
// the head for this scope. This gets updated again in the resource::
// unit for their scope with more data including the content.
const scope_restore request
{
this->request, resource::request
{
head, string_view{} // no content considered yet
}
};
bool ret
{
resource_request(head)
};
if(ret && iequals(head.connection, "close"_sv))
ret = false;
return ret;
}
catch(const ctx::interrupted &e)
{
throw;
}
catch(const std::system_error &e)
{
static const auto operation_canceled
{
make_error_code(std::errc::operation_canceled)
};
if(e.code() != operation_canceled)
throw;
if(!sock || sock->fini)
return false;
const ctx::exception_handler eh;
resource::response
{
*this, http::REQUEST_TIMEOUT, {}, 0L, {}
};
return false;
}
catch(const http::error &e)
{
log::derror
{
resource::log, "%s HTTP %u %s :%s",
loghead(),
uint(e.code),
http::status(e.code),
e.content
};
if(!sock || sock->fini)
return false;
const ctx::exception_handler eh;
resource::response
{
*this, e.content, "text/html; charset=utf-8", e.code, e.headers
};
return false;
}
bool
ircd::client::resource_request(const http::request::head &head)
try
{
auto &resource
{
// throws HTTP 404 if not found.
ircd::resource::find(head.path)
};
auto &method
{
// throws HTTP 405 if not found.
resource[head.method]
};
const string_view content_partial
{
data(head_buffer) + head_length, content_consumed
};
method(*this, head, content_partial);
discard_unconsumed(head);
return true;
}
catch(const ctx::interrupted &)
{
throw;
}
catch(const std::system_error &)
{
throw;
}
catch(const http::error &e)
{
const ctx::exception_handler eh;
if(!empty(e.content))
log::derror
{
log, "%s HTTP %u `%s' %s :%s",
loghead(),
uint(e.code),
head.uri,
http::status(e.code),
e.content
};
if(!sock || sock->fini)
return false;
resource::response
{
*this, e.content, "text/html; charset=utf-8", e.code, e.headers
};
switch(e.code)
{
// These codes are "unrecoverable" errors and no more HTTP can be
// conducted with this tape. The client must be disconnected.
case http::BAD_REQUEST:
case http::REQUEST_TIMEOUT:
case http::PAYLOAD_TOO_LARGE:
case http::INTERNAL_SERVER_ERROR:
return false;
// These codes are "recoverable" and allow the next HTTP request in
// a pipeline to take place.
default:
discard_unconsumed(head);
return true;
}
}
catch(const std::exception &e)
{
const ctx::exception_handler eh;
log::error
{
log, "%s HTTP 500 Internal Error `%s' :%s",
loghead(),
head.uri,
e.what()
};
if(!sock || sock->fini)
return false;
resource::response
{
*this, e.what(), "text/html; charset=utf-8", http::INTERNAL_SERVER_ERROR
};
return false;
}
void
ircd::client::discard_unconsumed(const http::request::head &head)
{
if(unlikely(!sock))
return;
const size_t unconsumed
{
head.content_length - content_consumed
};
if(!unconsumed)
return;
log::debug
{
log, "%s discarding %zu unconsumed of %zu bytes content...",
loghead(),
unconsumed,
head.content_length
};
content_consumed += net::discard_all(*sock, unconsumed);
assert(content_consumed == head.content_length);
}
ircd::ctx::future<void>
ircd::client::close(const net::close_opts &opts)
{
return likely(sock) && !sock->fini?
net::close(*sock, opts):
ctx::already;
}
void
ircd::client::close(const net::close_opts &opts,
net::close_callback callback)
{
if(!sock)
return;
if(sock->fini)
return callback({});
net::close(*sock, opts, std::move(callback));
}
size_t
ircd::client::write_all(const const_buffer &buf)
{
if(unlikely(!sock))
throw std::system_error
{
make_error_code(std::errc::bad_file_descriptor)
};
if(unlikely(sock->fini))
throw std::system_error
{
make_error_code(std::errc::not_connected)
};
return net::write_all(*sock, buf);
}
/// Returns a string_view to a static (tls) buffer containing common
/// information used to prefix log calls for this client: i.e id, remote
/// address, etc. This is meant to be used as the first argument to all log
/// calls apropos this client and should not be held over a context switch
/// as there is only one static buffer.
ircd::string_view
ircd::client::loghead()
const
{
thread_local char buf[512];
thread_local char rembuf[128];
thread_local char locbuf[128];
return fmt::sprintf
{
buf, "socket:%lu local:%s remote:%s client:%lu req:%lu:%lu",
sock? net::id(*sock) : -1UL,
string(locbuf, ircd::local(*this)),
string(rembuf, ircd::remote(*this)),
id,
ready_count,
request_count
};
}