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-rw-r--r--src/network/tcp_client_socket_handler.cpp261
1 files changed, 261 insertions, 0 deletions
diff --git a/src/network/tcp_client_socket_handler.cpp b/src/network/tcp_client_socket_handler.cpp
new file mode 100644
index 0000000..35f2446
--- /dev/null
+++ b/src/network/tcp_client_socket_handler.cpp
@@ -0,0 +1,261 @@
+#include <network/tcp_client_socket_handler.hpp>
+#include <utils/timed_events.hpp>
+#include <utils/scopeguard.hpp>
+#include <network/poller.hpp>
+
+#include <logger/logger.hpp>
+
+#include <cstring>
+#include <unistd.h>
+#include <fcntl.h>
+
+using namespace std::string_literals;
+
+TCPClientSocketHandler::TCPClientSocketHandler(std::shared_ptr<Poller>& poller):
+ TCPSocketHandler(poller),
+ hostname_resolution_failed(false),
+ connected(false),
+ connecting(false)
+{}
+
+TCPClientSocketHandler::~TCPClientSocketHandler()
+{
+ this->close();
+}
+
+void TCPClientSocketHandler::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 + std::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;
+ struct addrinfo hints{};
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_flags = AI_NUMERICHOST;
+ hints.ai_family = AF_UNSPEC;
+ int err = ::getaddrinfo(this->bind_addr.data(), nullptr, &hints, &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;
+ for (rp = result; rp; rp = rp->ai_next)
+ {
+ if ((::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(errno));
+ 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 + std::strerror(errno));
+}
+
+void TCPClientSocketHandler::connect(const std::string& address, const std::string& port, const bool tls)
+{
+ this->address = address;
+ this->port = port;
+ this->use_tls = tls;
+
+ struct addrinfo* addr_res;
+
+ if (!this->connecting)
+ {
+ // Get the addrinfo from getaddrinfo (or using udns), 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), TCPClientSocketHandler::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 DNS resolver resolved the hostname and the available addresses
+ // where saved in the 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(this->address, this->port);
+#endif
+ this->connection_date = std::chrono::system_clock::now();
+
+ // Get our local TCP port and store it
+ this->local_port = static_cast<uint16_t>(-1);
+ if (rp->ai_family == AF_INET6)
+ {
+ struct sockaddr_in6 a{};
+ socklen_t l = sizeof(a);
+ if (::getsockname(this->socket, (struct sockaddr*)&a, &l) != -1)
+ this->local_port = ntohs(a.sin6_port);
+ }
+ else if (rp->ai_family == AF_INET)
+ {
+ struct sockaddr_in a{};
+ socklen_t l = sizeof(a);
+ if (::getsockname(this->socket, (struct sockaddr*)&a, &l) != -1)
+ this->local_port = ntohs(a.sin_port);
+ }
+
+ log_debug("Local port: ", this->local_port, ", and remote port: ", this->port);
+
+ 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(&TCPClientSocketHandler::on_connection_timeout, this),
+ "connection_timeout"s + std::to_string(this->socket)));
+ return ;
+ }
+ log_info("Connection failed:", std::strerror(errno));
+ }
+ log_error("All connection attempts failed.");
+ this->close();
+ this->on_connection_failed(std::strerror(errno));
+ return ;
+}
+
+void TCPClientSocketHandler::on_connection_timeout()
+{
+ this->close();
+ this->on_connection_failed("connection timed out");
+}
+
+void TCPClientSocketHandler::connect()
+{
+ this->connect(this->address, this->port, this->use_tls);
+}
+
+void TCPClientSocketHandler::close()
+{
+ TimedEventsManager::instance().cancel("connection_timeout"s +
+ std::to_string(this->socket));
+
+ TCPSocketHandler::close();
+
+ this->connected = false;
+ this->connecting = false;
+ this->port.clear();
+ this->resolver.clear();
+}
+
+void TCPClientSocketHandler::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));
+}
+
+bool TCPClientSocketHandler::is_connected() const
+{
+ return this->connected;
+}
+
+bool TCPClientSocketHandler::is_connecting() const
+{
+ return this->connecting || this->resolver.is_resolving();
+}
+
+std::string TCPClientSocketHandler::get_port() const
+{
+ return this->port;
+}
+
+bool TCPClientSocketHandler::match_port_pairt(const uint16_t local, const uint16_t remote) const
+{
+ const auto remote_port = static_cast<uint16_t>(std::stoi(this->port));
+ return this->is_connected() && local == this->local_port && remote == remote_port;
+}