--- /dev/null
+// Copyright (C) 2011 Internet Systems Consortium, Inc. ("ISC")
+//
+// 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 appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <unistd.h> // for some IPC/network system calls
+#include <errno.h>
+
+#include <boost/shared_array.hpp>
+
+#include <config.h>
+
+#include <log/dummylog.h>
+
+#include <asio.hpp>
+#include <asio/error.hpp>
+#include <asiolink/dummy_io_cb.h>
+#include <asiolink/udp_endpoint.h>
+#include <asiolink/udp_socket.h>
+#include "sync_udp_server.h"
+#include "logger.h"
+
+#include <dns/opcode.h>
+
+using namespace asio;
+using asio::ip::udp;
+using isc::log::dlog;
+
+using namespace std;
+using namespace isc::dns;
+using namespace isc::util;
+using namespace isc::asiolink;
+
+namespace isc {
+namespace asiodns {
+
+/*
+ * Some of the member variables here are shared_ptrs and some are
+ * auto_ptrs. There will be one instance of Data for the lifetime
+ * of packet. The variables that are state only for a single packet
+ * use auto_ptr, as it is more lightweight. In the case of shared
+ * configuration (eg. the callbacks, socket), we use shared_ptrs.
+ */
+struct SyncUDPServer::Data {
+ /*
+ * Constructors from parameters passed to UDPServer constructor.
+ * This instance will not be used to retrieve and answer the actual
+ * query, it will only hold parameters until we wait for the
+ * first packet. But we do initialize the socket in here.
+ */
+ Data(io_service& io_service, const ip::address& addr, const uint16_t port,
+ SimpleCallback* checkin, DNSLookup* lookup, DNSAnswer* answer) :
+ io_(io_service), done_(false),
+ checkin_callback_(checkin),lookup_callback_(lookup),
+ answer_callback_(answer)
+ {
+ // We must use different instantiations for v4 and v6;
+ // otherwise ASIO will bind to both
+ udp proto = addr.is_v4() ? udp::v4() : udp::v6();
+ socket_.reset(new udp::socket(io_service, proto));
+ socket_->set_option(socket_base::reuse_address(true));
+ if (addr.is_v6()) {
+ socket_->set_option(asio::ip::v6_only(true));
+ }
+ socket_->bind(udp::endpoint(addr, port));
+ }
+ Data(io_service& io_service, int fd, int af, SimpleCallback* checkin,
+ DNSLookup* lookup, DNSAnswer* answer) :
+ io_(io_service), done_(false),
+ checkin_callback_(checkin),lookup_callback_(lookup),
+ answer_callback_(answer)
+ {
+ if (af != AF_INET && af != AF_INET6) {
+ isc_throw(InvalidParameter, "Address family must be either AF_INET "
+ "or AF_INET6, not " << af);
+ }
+ LOG_DEBUG(logger, DBGLVL_TRACE_BASIC, ASIODNS_FD_ADD_UDP).arg(fd);
+ try {
+ socket_.reset(new udp::socket(io_service));
+ socket_->assign(af == AF_INET6 ? udp::v6() : udp::v4(), fd);
+ } catch (const std::exception& exception) {
+ // Whatever the thing throws, it is something from ASIO and we
+ // convert it
+ isc_throw(IOError, exception.what());
+ }
+ }
+
+ /*
+ * Copy constructor. Default one would probably do, but it is unnecessary
+ * to copy many of the member variables every time we fork to handle
+ * another packet.
+ *
+ * We also allocate data for receiving the packet here.
+ */
+ Data(const Data& other) :
+ io_(other.io_), socket_(other.socket_), done_(false),
+ checkin_callback_(other.checkin_callback_),
+ lookup_callback_(other.lookup_callback_),
+ answer_callback_(other.answer_callback_)
+ {
+ // Instantiate the data buffer and endpoint that will
+ // be used by the asynchronous receive call.
+ data_.reset(new char[MAX_LENGTH]);
+ sender_.reset(new udp::endpoint());
+ }
+
+ // The ASIO service object
+ asio::io_service& io_;
+
+ // Class member variables which are dynamic, and changes to which
+ // need to accessible from both sides of a coroutine fork or from
+ // outside of the coroutine (i.e., from an asynchronous I/O call),
+ // should be declared here as pointers and allocated in the
+ // constructor or in the coroutine. This allows state information
+ // to persist when an individual copy of the coroutine falls out
+ // scope while waiting for an event, *so long as* there is another
+ // object that is referencing the same data. As a side-benefit, using
+ // pointers also reduces copy overhead for coroutine objects.
+ //
+ // Note: Currently these objects are allocated by "new" in the
+ // constructor, or in the function operator while processing a query.
+ // Repeated allocations from the heap for every incoming query is
+ // clearly a performance issue; this must be optimized in the future.
+ // The plan is to have a structure pre-allocate several "Data"
+ // objects which can be pulled off a free list and placed on an in-use
+ // list whenever a query comes in. This will serve the dual purpose
+ // of improving performance and guaranteeing that state information
+ // will *not* be destroyed when any one instance of the coroutine
+ // falls out of scope while waiting for an event.
+ //
+ // Socket used to for listen for queries. Created in the
+ // constructor and stored in a shared_ptr because socket objects
+ // are not copyable.
+ boost::shared_ptr<asio::ip::udp::socket> socket_;
+
+ // The ASIO-internal endpoint object representing the client
+ std::auto_ptr<asio::ip::udp::endpoint> sender_;
+
+ // \c IOMessage and \c Message objects to be passed to the
+ // DNS lookup and answer providers
+ std::auto_ptr<asiolink::IOMessage> io_message_;
+
+ // The original query as sent by the client
+ isc::dns::MessagePtr query_message_;
+
+ // The response message we are building
+ isc::dns::MessagePtr answer_message_;
+
+ // The buffer into which the response is written
+ isc::util::OutputBufferPtr respbuf_;
+
+ // The buffer into which the query packet is written
+ boost::shared_array<char> data_;
+
+ // State information that is entirely internal to a given instance
+ // of the coroutine can be declared here.
+ size_t bytes_;
+ bool done_;
+
+
+ // Callback functions provided by the caller
+ const SimpleCallback* checkin_callback_;
+ const DNSLookup* lookup_callback_;
+ const DNSAnswer* answer_callback_;
+
+ std::auto_ptr<IOEndpoint> peer_;
+ std::auto_ptr<IOSocket> iosock_;
+};
+
+/// The following functions implement the \c UDPServer class.
+///
+/// The constructor. It just creates new internal state object
+/// and lets it handle the initialization.
+SyncUDPServer::SyncUDPServer(io_service& io_service, const ip::address& addr,
+ const uint16_t port, SimpleCallback* checkin,
+ DNSLookup* lookup, DNSAnswer* answer) :
+ data_(new Data(io_service, addr, port, checkin, lookup, answer))
+{ }
+
+SyncUDPServer::SyncUDPServer(io_service& io_service, int fd, int af,
+ SimpleCallback* checkin, DNSLookup* lookup,
+ DNSAnswer* answer) :
+ data_(new Data(io_service, fd, af, checkin, lookup, answer))
+{ }
+
+/// The function operator is implemented with the "stackless coroutine"
+/// pattern; see internal/coroutine.h for details.
+void
+SyncUDPServer::operator()(asio::error_code ec, size_t length) {
+ /// Because the coroutine reentry block is implemented as
+ /// a switch statement, inline variable declarations are not
+ /// permitted. Certain variables used below can be declared here.
+
+ CORO_REENTER (this) {
+ do {
+ /*
+ * This is preparation for receiving a packet. We get a new
+ * state object for the lifetime of the next packet to come.
+ * It allocates the buffers to receive data into.
+ */
+ data_.reset(new Data(*data_));
+
+ do {
+ // Begin an asynchronous receive, then yield.
+ // When the receive event is posted, the coroutine
+ // will resume immediately after this point.
+ CORO_YIELD data_->socket_->async_receive_from(
+ buffer(data_->data_.get(), MAX_LENGTH), *data_->sender_,
+ *this);
+
+ // Abort on fatal errors
+ // TODO: add log
+ if (ec) {
+ using namespace asio::error;
+ if (ec.value() != would_block && ec.value() != try_again &&
+ ec.value() != interrupted) {
+ return;
+ }
+ }
+
+ } while (ec || length == 0);
+
+ data_->bytes_ = length;
+
+ /*
+ * We fork the coroutine now. One (the child) will keep
+ * the current state and handle the packet, then die and
+ * drop ownership of the state. The other (parent) will just
+ * go into the loop again and replace the current state with
+ * a new one for a new object.
+ *
+ * Actually, both of the coroutines will be a copy of this
+ * one, but that's just internal implementation detail.
+ */
+ CORO_FORK data_->io_.post(SyncUDPServer(*this));
+ } while (is_parent());
+
+ // Create an \c IOMessage object to store the query.
+ //
+ // (XXX: It would be good to write a factory function
+ // that would quickly generate an IOMessage object without
+ // all these calls to "new".)
+ data_->peer_.reset(new UDPEndpoint(*data_->sender_));
+
+ // The UDP socket class has been extended with asynchronous functions
+ // and takes as a template parameter a completion callback class. As
+ // UDPServer does not use these extended functions (only those defined
+ // in the IOSocket base class) - but needs a UDPSocket to get hold of
+ // the underlying Boost UDP socket - DummyIOCallback is used. This
+ // provides the appropriate operator() but is otherwise functionless.
+ data_->iosock_.reset(
+ new UDPSocket<DummyIOCallback>(*data_->socket_));
+
+ data_->io_message_.reset(new IOMessage(data_->data_.get(),
+ data_->bytes_, *data_->iosock_, *data_->peer_));
+
+ // Perform any necessary operations prior to processing an incoming
+ // query (e.g., checking for queued configuration messages).
+ //
+ // (XXX: it may be a performance issue to check in for every single
+ // incoming query; we may wish to throttle this in the future.)
+ if (data_->checkin_callback_ != NULL) {
+ (*data_->checkin_callback_)(*data_->io_message_);
+ }
+
+ // If we don't have a DNS Lookup provider, there's no point in
+ // continuing; we exit the coroutine permanently.
+ if (data_->lookup_callback_ == NULL) {
+ CORO_YIELD return;
+ }
+
+ // Instantiate objects that will be needed by the
+ // asynchronous DNS lookup and/or by the send call.
+ data_->respbuf_.reset(new OutputBuffer(0));
+ data_->query_message_.reset(new Message(Message::PARSE));
+ data_->answer_message_.reset(new Message(Message::RENDER));
+
+ // Schedule a DNS lookup, and yield. When the lookup is
+ // finished, the coroutine will resume immediately after
+ // this point.
+ CORO_YIELD data_->io_.post(AsyncLookup<SyncUDPServer>(*this));
+
+ // The 'done_' flag indicates whether we have an answer
+ // to send back. If not, exit the coroutine permanently.
+ if (!data_->done_) {
+ CORO_YIELD return;
+ }
+
+ // Call the DNS answer provider to render the answer into
+ // wire format
+ (*data_->answer_callback_)(*data_->io_message_, data_->query_message_,
+ data_->answer_message_, data_->respbuf_);
+
+ // Begin an asynchronous send, and then yield. When the
+ // send completes, we will resume immediately after this point
+ // (though we have nothing further to do, so the coroutine
+ // will simply exit at that time).
+ CORO_YIELD data_->socket_->async_send_to(
+ buffer(data_->respbuf_->getData(), data_->respbuf_->getLength()),
+ *data_->sender_, *this);
+ }
+}
+
+/// Call the DNS lookup provider. (Expected to be called by the
+/// AsyncLookup<UDPServer> handler.)
+void
+SyncUDPServer::asyncLookup() {
+ (*data_->lookup_callback_)(*data_->io_message_,
+ data_->query_message_, data_->answer_message_, data_->respbuf_, this);
+}
+
+/// Stop the UDPServer
+void
+SyncUDPServer::stop() {
+ /// Using close instead of cancel, because cancel
+ /// will only cancel the asynchornized event already submitted
+ /// to io service, the events post to io service after
+ /// cancel still can be scheduled by io service, if
+ /// the socket is cloesed, all the asynchronized event
+ /// for it won't be scheduled by io service not matter it is
+ /// submit to io serice before or after close call. And we will
+ //. get bad_descriptor error
+ data_->socket_->close();
+}
+
+/// Post this coroutine on the ASIO service queue so that it will
+/// resume processing where it left off. The 'done' parameter indicates
+/// whether there is an answer to return to the client.
+void
+SyncUDPServer::resume(const bool done) {
+ data_->done_ = done;
+ data_->io_.post(*this);
+}
+
+bool
+SyncUDPServer::hasAnswer() {
+ return (data_->done_);
+}
+
+} // namespace asiodns
+} // namespace isc
--- /dev/null
+// Copyright (C) 2011 Internet Systems Consortium, Inc. ("ISC")
+//
+// 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 appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#ifndef __SYNC_UDP_SERVER_H
+#define __SYNC_UDP_SERVER_H 1
+
+#ifndef ASIO_HPP
+#error "asio.hpp must be included before including this, see asiolink.h as to why"
+#endif
+
+#include <asiolink/simple_callback.h>
+#include <asiodns/dns_answer.h>
+#include <asiodns/dns_lookup.h>
+#include <asiodns/dns_server.h>
+
+#include <coroutine.h>
+
+namespace isc {
+namespace asiodns {
+
+//
+// Asynchronous UDP server coroutine
+//
+///
+/// \brief This class implements the coroutine to handle UDP
+/// DNS query event. As such, it is both a \c DNSServer and
+/// a \c coroutine
+///
+class SyncUDPServer : public virtual DNSServer, public virtual coroutine {
+public:
+ /// \brief Constructor
+ /// \param io_service the asio::io_service to work with
+ /// \param addr the IP address to listen for queries on
+ /// \param port the port to listen for queries on
+ /// \param checkin the callbackprovider for non-DNS events
+ /// \param lookup the callbackprovider for DNS lookup events
+ /// \param answer the callbackprovider for DNS answer events
+ explicit SyncUDPServer(asio::io_service& io_service,
+ const asio::ip::address& addr, const uint16_t port,
+ isc::asiolink::SimpleCallback* checkin = NULL,
+ DNSLookup* lookup = NULL,
+ DNSAnswer* answer = NULL);
+
+ /// \brief Constructor
+ /// \param io_service the asio::io_service to work with
+ /// \param fd the file descriptor of opened UDP socket
+ /// \param af address family, either AF_INET or AF_INET6
+ /// \param checkin the callbackprovider for non-DNS events
+ /// \param lookup the callbackprovider for DNS lookup events
+ /// \param answer the callbackprovider for DNS answer events
+ /// \throw isc::InvalidParameter if af is neither AF_INET nor AF_INET6
+ /// \throw isc::asiolink::IOError when a low-level error happens, like the
+ /// fd is not a valid descriptor.
+ SyncUDPServer(asio::io_service& io_service, int fd, int af,
+ isc::asiolink::SimpleCallback* checkin = NULL,
+ DNSLookup* lookup = NULL, DNSAnswer* answer = NULL);
+
+ /// \brief The function operator
+ void operator()(asio::error_code ec = asio::error_code(),
+ size_t length = 0);
+
+ /// \brief Calls the lookup callback
+ void asyncLookup();
+
+ /// \brief Stop the running server
+ /// \note once the server stopped, it can't restart
+ void stop();
+
+ /// \brief Resume operation
+ ///
+ /// \param done Set this to true if the lookup action is done and
+ /// we have an answer
+ void resume(const bool done);
+
+ /// \brief Check if we have an answer
+ ///
+ /// \return true if we have an answer
+ bool hasAnswer();
+
+ /// \brief Returns the coroutine state value
+ ///
+ /// \return the coroutine state value
+ int value() { return (get_value()); }
+
+ /// \brief Clones the object
+ ///
+ /// \return a newly allocated copy of this object
+ DNSServer* clone() {
+ SyncUDPServer* s = new SyncUDPServer(*this);
+ return (s);
+ }
+
+private:
+ enum { MAX_LENGTH = 4096 };
+
+ /**
+ * \brief Internal state and data.
+ *
+ * We use the pimple design pattern, but not because we need to hide
+ * internal data. This class and whole header is for private use anyway.
+ * It turned out that SyncUDPServer is copied a lot, because it is a coroutine.
+ * This way the overhead of copying is lower, we copy only one shared
+ * pointer instead of about 10 of them.
+ */
+ struct Data;
+ boost::shared_ptr<Data> data_;
+};
+
+} // namespace asiodns
+} // namespace isc
+#endif // __SYNC_UDP_SERVER_H
#include <asiolink/io_endpoint.h>
#include <asiolink/io_error.h>
#include <asiodns/udp_server.h>
+#include <asiodns/sync_udp_server.h>
#include <asiodns/tcp_server.h>
#include <asiodns/dns_answer.h>
#include <asiodns/dns_lookup.h>
// two servers, UDP client will only communicate with UDP server, same for TCP
// client
//
-// This is only the active part of the test. We run the test case twice, once
+// This is only the active part of the test. We run the test case four times, once
// for each type of initialization (once when giving it the address and port,
-// once when giving the file descriptor), to ensure it works both ways exactly
-// the same.
+// once when giving the file descriptor) multiplied by once for each type of UDP
+// server (UDPServer and SyncUDPServer), to ensure it works exactly the same.
template<class UDPServerClass>
class DNSServerTestBase : public::testing::Test {
protected:
};
// Initialization by the file descriptor
-class FdInit : public DNSServerTestBase<UDPServer> {
+template<class UDPServerClass>
+class FdInit : public DNSServerTestBase<UDPServerClass> {
private:
// Opens the file descriptor for us
// It uses the low-level C api, as it seems to be the easiest way to get
void SetUp() {
const int fdUDP(getFd(SOCK_DGRAM));
ASSERT_NE(-1, fdUDP) << strerror(errno);
- udp_server_ = new UDPServer(service, fdUDP, AF_INET6, checker_,
- lookup_, answer_);
+ this->udp_server_ = new UDPServerClass(this->service, fdUDP, AF_INET6,
+ this->checker_, this->lookup_,
+ this->answer_);
const int fdTCP(getFd(SOCK_STREAM));
ASSERT_NE(-1, fdTCP) << strerror(errno);
- tcp_server_ = new TCPServer(service, fdTCP, AF_INET6, checker_,
- lookup_, answer_);
+ this->tcp_server_ = new TCPServer(this->service, fdTCP, AF_INET6,
+ this->checker_, this->lookup_,
+ this->answer_);
}
};
template<class Parent>
class DNSServerTest : public Parent { };
-// TODO: Add the new SyncUDPServer class here. This might need some changes,
-// as it is not as generic, though
-typedef ::testing::Types<AddrPortInit<UDPServer>, FdInit> ServerTypes;
+typedef ::testing::Types<AddrPortInit<UDPServer>, AddrPortInit<SyncUDPServer>,
+ FdInit<UDPServer>, FdInit<SyncUDPServer> >
+ ServerTypes;
TYPED_TEST_CASE(DNSServerTest, ServerTypes);
-typedef ::testing::Types<UDPServer> UDPServerTypes;
+typedef ::testing::Types<UDPServer, SyncUDPServer> UDPServerTypes;
TYPED_TEST_CASE(DNSServerTestBase, UDPServerTypes);
template<class UDPServerClass>
projects / thirdparty / kea.git / commitdiff
