diff options
Diffstat (limited to 'louloulibs/network/tcp_socket_handler.cpp')
| -rw-r--r-- | louloulibs/network/tcp_socket_handler.cpp | 501 |
1 files changed, 501 insertions, 0 deletions
diff --git a/louloulibs/network/tcp_socket_handler.cpp b/louloulibs/network/tcp_socket_handler.cpp new file mode 100644 index 0000000..5420b1c --- /dev/null +++ b/louloulibs/network/tcp_socket_handler.cpp @@ -0,0 +1,501 @@ +#include <network/tcp_socket_handler.hpp> +#include <network/dns_handler.hpp> + +#include <utils/timed_events.hpp> +#include <utils/scopeguard.hpp> +#include <network/poller.hpp> + +#include <logger/logger.hpp> +#include <sys/socket.h> +#include <sys/types.h> +#include <stdexcept> +#include <unistd.h> +#include <errno.h> +#include <cstring> +#include <fcntl.h> + +#ifdef BOTAN_FOUND +# include <botan/hex.h> +# include <botan/tls_exceptn.h> + +Botan::AutoSeeded_RNG TCPSocketHandler::rng; +Botan::TLS::Policy TCPSocketHandler::policy; +Botan::TLS::Session_Manager_In_Memory TCPSocketHandler::session_manager(TCPSocketHandler::rng); + +#endif + +#ifndef UIO_FASTIOV +# define UIO_FASTIOV 8 +#endif + +using namespace std::string_literals; +using namespace std::chrono_literals; + +namespace ph = std::placeholders; + +TCPSocketHandler::TCPSocketHandler(std::shared_ptr<Poller> poller): + SocketHandler(poller, -1), + use_tls(false), + connected(false), + connecting(false), + hostname_resolution_failed(false) +#ifdef BOTAN_FOUND + ,credential_manager(this) +#endif +{} + +TCPSocketHandler::~TCPSocketHandler() +{ + this->close(); +} + + +void TCPSocketHandler::init_socket(const struct addrinfo* rp) +{ + if (this->socket != -1) + ::close(this->socket); + if ((this->socket = ::socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol)) == -1) + throw std::runtime_error("Could not create socket: "s + strerror(errno)); + // Bind the socket to a specific address, if specified + if (!this->bind_addr.empty()) + { + // Convert the address from string format to a sockaddr that can be + // used in bind() + struct addrinfo* result; + int err = ::getaddrinfo(this->bind_addr.data(), nullptr, nullptr, &result); + if (err != 0 || !result) + log_error("Failed to bind socket to ", this->bind_addr, ": ", + gai_strerror(err)); + else + { + utils::ScopeGuard sg([result](){ freeaddrinfo(result); }); + struct addrinfo* rp; + int bind_error = 0; + for (rp = result; rp; rp = rp->ai_next) + { + if ((bind_error = ::bind(this->socket, + reinterpret_cast<const struct sockaddr*>(rp->ai_addr), + rp->ai_addrlen)) == 0) + break; + } + if (!rp) + log_error("Failed to bind socket to ", this->bind_addr, ": ", + strerror(bind_error)); + else + log_info("Socket successfully bound to ", this->bind_addr); + } + } + int optval = 1; + if (::setsockopt(this->socket, SOL_SOCKET, SO_KEEPALIVE, &optval, sizeof(optval)) == -1) + log_warning("Failed to enable TCP keepalive on socket: ", strerror(errno)); + // Set the socket on non-blocking mode. This is useful to receive a EAGAIN + // error when connect() would block, to not block the whole process if a + // remote is not responsive. + const int existing_flags = ::fcntl(this->socket, F_GETFL, 0); + if ((existing_flags == -1) || + (::fcntl(this->socket, F_SETFL, existing_flags | O_NONBLOCK) == -1)) + throw std::runtime_error("Could not initialize socket: "s + strerror(errno)); +} + +void TCPSocketHandler::connect(const std::string& address, const std::string& port, const bool tls) +{ + this->address = address; + this->port = port; + this->use_tls = tls; + + utils::ScopeGuard sg; + + struct addrinfo* addr_res; + + if (!this->connecting) + { + // Get the addrinfo from getaddrinfo (or ares_gethostbyname), only if + // this is the first call of this function. + if (!this->resolver.is_resolved()) + { + log_info("Trying to connect to ", address, ":", port); + // Start the asynchronous process of resolving the hostname. Once + // the addresses have been found and `resolved` has been set to true + // (but connecting will still be false), TCPSocketHandler::connect() + // needs to be called, again. + this->resolver.resolve(address, port, + [this](const struct addrinfo*) + { + log_debug("Resolution success, calling connect() again"); + this->connect(); + }, + [this](const char*) + { + log_debug("Resolution failed, calling connect() again"); + this->connect(); + }); + return; + } + else + { + // The c-ares resolved the hostname and the available addresses + // where saved in the cares_addrinfo linked list. Now, just use + // this list to try to connect. + addr_res = this->resolver.get_result().get(); + if (!addr_res) + { + this->hostname_resolution_failed = true; + const auto msg = this->resolver.get_error_message(); + this->close(); + this->on_connection_failed(msg); + return ; + } + } + } + else + { // This function is called again, use the saved addrinfo structure, + // instead of re-doing the whole getaddrinfo process. + addr_res = &this->addrinfo; + } + + for (struct addrinfo* rp = addr_res; rp; rp = rp->ai_next) + { + if (!this->connecting) + { + try { + this->init_socket(rp); + } + catch (const std::runtime_error& error) { + log_error("Failed to init socket: ", error.what()); + break; + } + } + + this->display_resolved_ip(rp); + + if (::connect(this->socket, rp->ai_addr, rp->ai_addrlen) == 0 + || errno == EISCONN) + { + log_info("Connection success."); + TimedEventsManager::instance().cancel("connection_timeout"s + + std::to_string(this->socket)); + this->poller->add_socket_handler(this); + this->connected = true; + this->connecting = false; +#ifdef BOTAN_FOUND + if (this->use_tls) + this->start_tls(); +#endif + this->on_connected(); + return ; + } + else if (errno == EINPROGRESS || errno == EALREADY) + { // retry this process later, when the socket + // is ready to be written on. + this->connecting = true; + this->poller->add_socket_handler(this); + this->poller->watch_send_events(this); + // Save the addrinfo structure, to use it on the next call + this->ai_addrlen = rp->ai_addrlen; + memcpy(&this->ai_addr, rp->ai_addr, this->ai_addrlen); + memcpy(&this->addrinfo, rp, sizeof(struct addrinfo)); + this->addrinfo.ai_addr = reinterpret_cast<struct sockaddr*>(&this->ai_addr); + this->addrinfo.ai_next = nullptr; + // If the connection has not succeeded or failed in 5s, we consider + // it to have failed + TimedEventsManager::instance().add_event( + TimedEvent(std::chrono::steady_clock::now() + 5s, + std::bind(&TCPSocketHandler::on_connection_timeout, this), + "connection_timeout"s + std::to_string(this->socket))); + return ; + } + log_info("Connection failed:", strerror(errno)); + } + log_error("All connection attempts failed."); + this->close(); + this->on_connection_failed(strerror(errno)); + return ; +} + +void TCPSocketHandler::on_connection_timeout() +{ + this->close(); + this->on_connection_failed("connection timed out"); +} + +void TCPSocketHandler::connect() +{ + this->connect(this->address, this->port, this->use_tls); +} + +void TCPSocketHandler::on_recv() +{ +#ifdef BOTAN_FOUND + if (this->use_tls) + this->tls_recv(); + else +#endif + this->plain_recv(); +} + +void TCPSocketHandler::plain_recv() +{ + static constexpr size_t buf_size = 4096; + char buf[buf_size]; + void* recv_buf = this->get_receive_buffer(buf_size); + + if (recv_buf == nullptr) + recv_buf = buf; + + const ssize_t size = this->do_recv(recv_buf, buf_size); + + if (size > 0) + { + if (buf == recv_buf) + { + // data needs to be placed in the in_buf string, because no buffer + // was provided to receive that data directly. The in_buf buffer + // will be handled in parse_in_buffer() + this->in_buf += std::string(buf, size); + } + this->parse_in_buffer(size); + } +} + +ssize_t TCPSocketHandler::do_recv(void* recv_buf, const size_t buf_size) +{ + ssize_t size = ::recv(this->socket, recv_buf, buf_size, 0); + if (0 == size) + { + this->on_connection_close(""); + this->close(); + } + else if (-1 == size) + { + if (this->connecting) + log_warning("Error connecting: ", strerror(errno)); + else + log_warning("Error while reading from socket: ", strerror(errno)); + // Remember if we were connecting, or already connected when this + // happened, because close() sets this->connecting to false + const auto were_connecting = this->connecting; + this->close(); + if (were_connecting) + this->on_connection_failed(strerror(errno)); + else + this->on_connection_close(strerror(errno)); + } + return size; +} + +void TCPSocketHandler::on_send() +{ + struct iovec msg_iov[UIO_FASTIOV] = {}; + struct msghdr msg{nullptr, 0, + msg_iov, + 0, nullptr, 0, 0}; + for (const std::string& s: this->out_buf) + { + // unconsting the content of s is ok, sendmsg will never modify it + msg_iov[msg.msg_iovlen].iov_base = const_cast<char*>(s.data()); + msg_iov[msg.msg_iovlen].iov_len = s.size(); + if (++msg.msg_iovlen == UIO_FASTIOV) + break; + } + ssize_t res = ::sendmsg(this->socket, &msg, MSG_NOSIGNAL); + if (res < 0) + { + log_error("sendmsg failed: ", strerror(errno)); + this->on_connection_close(strerror(errno)); + this->close(); + } + else + { + // remove all the strings that were successfully sent. + for (auto it = this->out_buf.begin(); + it != this->out_buf.end();) + { + if (static_cast<size_t>(res) >= (*it).size()) + { + res -= (*it).size(); + it = this->out_buf.erase(it); + } + else + { + // If one string has partially been sent, we use substr to + // crop it + if (res > 0) + (*it) = (*it).substr(res, std::string::npos); + break; + } + } + if (this->out_buf.empty()) + this->poller->stop_watching_send_events(this); + } +} + +void TCPSocketHandler::close() +{ + TimedEventsManager::instance().cancel("connection_timeout"s + + std::to_string(this->socket)); + if (this->connected || this->connecting) + this->poller->remove_socket_handler(this->get_socket()); + if (this->socket != -1) + { + ::close(this->socket); + this->socket = -1; + } + this->connected = false; + this->connecting = false; + this->in_buf.clear(); + this->out_buf.clear(); + this->port.clear(); + this->resolver.clear(); +} + +void TCPSocketHandler::display_resolved_ip(struct addrinfo* rp) const +{ + if (rp->ai_family == AF_INET) + log_debug("Trying IPv4 address ", addr_to_string(rp)); + else if (rp->ai_family == AF_INET6) + log_debug("Trying IPv6 address ", addr_to_string(rp)); +} + +void TCPSocketHandler::send_data(std::string&& data) +{ +#ifdef BOTAN_FOUND + if (this->use_tls) + try { + this->tls_send(std::move(data)); + } catch (const Botan::TLS::TLS_Exception& e) { + this->on_connection_close("TLS error: "s + e.what()); + this->close(); + return ; + } + else +#endif + this->raw_send(std::move(data)); +} + +void TCPSocketHandler::raw_send(std::string&& data) +{ + if (data.empty()) + return ; + this->out_buf.emplace_back(std::move(data)); + if (this->connected) + this->poller->watch_send_events(this); +} + +void TCPSocketHandler::send_pending_data() +{ + if (this->connected && !this->out_buf.empty()) + this->poller->watch_send_events(this); +} + +bool TCPSocketHandler::is_connected() const +{ + return this->connected; +} + +bool TCPSocketHandler::is_connecting() const +{ + return this->connecting || this->resolver.is_resolving(); +} + +void* TCPSocketHandler::get_receive_buffer(const size_t) const +{ + return nullptr; +} + +#ifdef BOTAN_FOUND +void TCPSocketHandler::start_tls() +{ + Botan::TLS::Server_Information server_info(this->address, "irc", std::stoul(this->port)); + this->tls = std::make_unique<Botan::TLS::Client>( + std::bind(&TCPSocketHandler::tls_output_fn, this, ph::_1, ph::_2), + std::bind(&TCPSocketHandler::tls_data_cb, this, ph::_1, ph::_2), + std::bind(&TCPSocketHandler::tls_alert_cb, this, ph::_1, ph::_2, ph::_3), + std::bind(&TCPSocketHandler::tls_handshake_cb, this, ph::_1), + session_manager, this->credential_manager, policy, + rng, server_info, Botan::TLS::Protocol_Version::latest_tls_version()); +} + +void TCPSocketHandler::tls_recv() +{ + static constexpr size_t buf_size = 4096; + char recv_buf[buf_size]; + + const ssize_t size = this->do_recv(recv_buf, buf_size); + if (size > 0) + { + const bool was_active = this->tls->is_active(); + try { + this->tls->received_data(reinterpret_cast<const Botan::byte*>(recv_buf), + static_cast<size_t>(size)); + } catch (const Botan::TLS::TLS_Exception& e) { + // May happen if the server sends malformed TLS data (buggy server, + // or more probably we are just connected to a server that sends + // plain-text) + this->on_connection_close("TLS error: "s + e.what()); + this->close(); + return ; + } + if (!was_active && this->tls->is_active()) + this->on_tls_activated(); + } +} + +void TCPSocketHandler::tls_send(std::string&& data) +{ + // We may not be connected yet, or the tls session has + // not yet been negociated + if (this->tls && this->tls->is_active()) + { + const bool was_active = this->tls->is_active(); + if (!this->pre_buf.empty()) + { + this->tls->send(reinterpret_cast<const Botan::byte*>(this->pre_buf.data()), + this->pre_buf.size()); + this->pre_buf = ""; + } + if (!data.empty()) + this->tls->send(reinterpret_cast<const Botan::byte*>(data.data()), + data.size()); + if (!was_active && this->tls->is_active()) + this->on_tls_activated(); + } + else + this->pre_buf += data; +} + +void TCPSocketHandler::tls_data_cb(const Botan::byte* data, size_t size) +{ + this->in_buf += std::string(reinterpret_cast<const char*>(data), + size); + if (!this->in_buf.empty()) + this->parse_in_buffer(size); +} + +void TCPSocketHandler::tls_output_fn(const Botan::byte* data, size_t size) +{ + this->raw_send(std::string(reinterpret_cast<const char*>(data), size)); +} + +void TCPSocketHandler::tls_alert_cb(Botan::TLS::Alert alert, const Botan::byte*, size_t) +{ + log_debug("tls_alert: ", alert.type_string()); +} + +bool TCPSocketHandler::tls_handshake_cb(const Botan::TLS::Session& session) +{ + log_debug("Handshake with ", session.server_info().hostname(), " complete.", + " Version: ", session.version().to_string(), + " using ", session.ciphersuite().to_string()); + if (!session.session_id().empty()) + log_debug("Session ID ", Botan::hex_encode(session.session_id())); + if (!session.session_ticket().empty()) + log_debug("Session ticket ", Botan::hex_encode(session.session_ticket())); + return true; +} + +void TCPSocketHandler::on_tls_activated() +{ + this->send_data({}); +} + +#endif // BOTAN_FOUND |