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-rw-r--r--src/network/dns_handler.cpp112
-rw-r--r--src/network/dns_handler.hpp62
-rw-r--r--src/network/dns_socket_handler.cpp45
-rw-r--r--src/network/dns_socket_handler.hpp46
-rw-r--r--src/network/socket_handler.hpp2
-rw-r--r--src/network/tcp_socket_handler.cpp166
-rw-r--r--src/network/tcp_socket_handler.hpp47
7 files changed, 469 insertions, 11 deletions
diff --git a/src/network/dns_handler.cpp b/src/network/dns_handler.cpp
new file mode 100644
index 0000000..45bf626
--- /dev/null
+++ b/src/network/dns_handler.cpp
@@ -0,0 +1,112 @@
+#include <config.h>
+#ifdef CARES_FOUND
+
+#include <network/dns_socket_handler.hpp>
+#include <network/tcp_socket_handler.hpp>
+#include <network/dns_handler.hpp>
+#include <network/poller.hpp>
+
+#include <algorithm>
+#include <stdexcept>
+
+DNSHandler DNSHandler::instance;
+
+using namespace std::string_literals;
+
+void on_hostname4_resolved(void* arg, int status, int, struct hostent* hostent)
+{
+ TCPSocketHandler* socket_handler = static_cast<TCPSocketHandler*>(arg);
+ socket_handler->on_hostname4_resolved(status, hostent);
+}
+
+void on_hostname6_resolved(void* arg, int status, int, struct hostent* hostent)
+{
+ TCPSocketHandler* socket_handler = static_cast<TCPSocketHandler*>(arg);
+ socket_handler->on_hostname6_resolved(status, hostent);
+}
+
+DNSHandler::DNSHandler()
+{
+ int ares_error;
+ if ((ares_error = ::ares_library_init(ARES_LIB_INIT_ALL)) != 0)
+ throw std::runtime_error("Failed to initialize c-ares lib: "s + ares_strerror(ares_error));
+ if ((ares_error = ::ares_init(&this->channel)) != ARES_SUCCESS)
+ throw std::runtime_error("Failed to initialize c-ares channel: "s + ares_strerror(ares_error));
+}
+
+ares_channel& DNSHandler::get_channel()
+{
+ return this->channel;
+}
+
+void DNSHandler::destroy()
+{
+ this->socket_handlers.clear();
+ ::ares_destroy(this->channel);
+ ::ares_library_cleanup();
+}
+
+void DNSHandler::gethostbyname(const std::string& name,
+ TCPSocketHandler* socket_handler, int family)
+{
+ socket_handler->free_cares_addrinfo();
+ if (family == AF_INET)
+ ::ares_gethostbyname(this->channel, name.data(), family,
+ &::on_hostname4_resolved, socket_handler);
+ else
+ ::ares_gethostbyname(this->channel, name.data(), family,
+ &::on_hostname6_resolved, socket_handler);
+}
+
+void DNSHandler::watch_dns_sockets(std::shared_ptr<Poller>& poller)
+{
+ fd_set readers;
+ fd_set writers;
+
+ FD_ZERO(&readers);
+ FD_ZERO(&writers);
+
+ int ndfs = ::ares_fds(this->channel, &readers, &writers);
+ // For each existing DNS socket, see if we are still supposed to watch it,
+ // if not then erase it
+ this->socket_handlers.erase(
+ std::remove_if(this->socket_handlers.begin(), this->socket_handlers.end(),
+ [&readers](const auto& dns_socket)
+ {
+ return !FD_ISSET(dns_socket->get_socket(), &readers);
+ }),
+ this->socket_handlers.end());
+
+ for (auto i = 0; i < ndfs; ++i)
+ {
+ bool read = FD_ISSET(i, &readers);
+ bool write = FD_ISSET(i, &writers);
+ // Look for the DNSSocketHandler with this fd
+ auto it = std::find_if(this->socket_handlers.begin(),
+ this->socket_handlers.end(),
+ [i](const auto& socket_handler)
+ {
+ return i == socket_handler->get_socket();
+ });
+ if (!read && !write) // No need to read or write to it
+ { // If found, erase it and stop watching it because it is not
+ // needed anymore
+ if (it != this->socket_handlers.end())
+ // The socket destructor removes it from the poller
+ this->socket_handlers.erase(it);
+ }
+ else // We need to write and/or read to it
+ { // If not found, create it because we need to watch it
+ if (it == this->socket_handlers.end())
+ {
+ this->socket_handlers.emplace_front(std::make_unique<DNSSocketHandler>(poller, i));
+ it = this->socket_handlers.begin();
+ }
+ poller->add_socket_handler(it->get());
+ if (write)
+ poller->watch_send_events(it->get());
+ }
+ }
+}
+
+#endif /* CARES_FOUND */
diff --git a/src/network/dns_handler.hpp b/src/network/dns_handler.hpp
new file mode 100644
index 0000000..ec5b2fa
--- /dev/null
+++ b/src/network/dns_handler.hpp
@@ -0,0 +1,62 @@
+#ifndef DNS_HANDLER_HPP_INCLUDED
+#define DNS_HANDLER_HPP_INCLUDED
+
+#include <config.h>
+#ifdef CARES_FOUND
+
+class TCPSocketHandler;
+class Poller;
+class DNSSocketHandler;
+
+# include <ares.h>
+# include <memory>
+# include <string>
+# include <list>
+
+void on_hostname4_resolved(void* arg, int status, int, struct hostent* hostent);
+void on_hostname6_resolved(void* arg, int status, int, struct hostent* hostent);
+
+/**
+ * Class managing DNS resolution. It should only be statically instanciated
+ * once in SocketHandler. It manages ares channel and calls various
+ * functions of that library.
+ */
+
+class DNSHandler
+{
+public:
+ DNSHandler();
+ ~DNSHandler() = default;
+ void gethostbyname(const std::string& name, TCPSocketHandler* socket_handler,
+ int family);
+ /**
+ * Call ares_fds to know what fd needs to be watched by the poller, create
+ * or destroy DNSSocketHandlers depending on the result.
+ */
+ void watch_dns_sockets(std::shared_ptr<Poller>& poller);
+ /**
+ * Destroy and stop watching all the DNS sockets. Then de-init the channel
+ * and library.
+ */
+ void destroy();
+ ares_channel& get_channel();
+
+ static DNSHandler instance;
+
+private:
+ /**
+ * The list of sockets that needs to be watched, according to the last
+ * call to ares_fds. DNSSocketHandlers are added to it or removed from it
+ * in the watch_dns_sockets() method
+ */
+ std::list<std::unique_ptr<DNSSocketHandler>> socket_handlers;
+ ares_channel channel;
+
+ DNSHandler(const DNSHandler&) = delete;
+ DNSHandler(DNSHandler&&) = delete;
+ DNSHandler& operator=(const DNSHandler&) = delete;
+ DNSHandler& operator=(DNSHandler&&) = delete;
+};
+
+#endif /* CARES_FOUND */
+#endif /* DNS_HANDLER_HPP_INCLUDED */
diff --git a/src/network/dns_socket_handler.cpp b/src/network/dns_socket_handler.cpp
new file mode 100644
index 0000000..6563894
--- /dev/null
+++ b/src/network/dns_socket_handler.cpp
@@ -0,0 +1,45 @@
+#include <config.h>
+#ifdef CARES_FOUND
+
+#include <network/dns_socket_handler.hpp>
+#include <network/dns_handler.hpp>
+#include <network/poller.hpp>
+
+#include <ares.h>
+
+DNSSocketHandler::DNSSocketHandler(std::shared_ptr<Poller> poller,
+ const socket_t socket):
+ SocketHandler(poller, socket)
+{
+}
+
+DNSSocketHandler::~DNSSocketHandler()
+{
+}
+
+void DNSSocketHandler::connect()
+{
+}
+
+void DNSSocketHandler::on_recv()
+{
+ // always stop watching send and read events. We will re-watch them if the
+ // next call to ares_fds tell us to
+ this->poller->remove_socket_handler(this->socket);
+ ::ares_process_fd(DNSHandler::instance.get_channel(), this->socket, ARES_SOCKET_BAD);
+}
+
+void DNSSocketHandler::on_send()
+{
+ // always stop watching send and read events. We will re-watch them if the
+ // next call to ares_fds tell us to
+ this->poller->remove_socket_handler(this->socket);
+ ::ares_process_fd(DNSHandler::instance.get_channel(), ARES_SOCKET_BAD, this->socket);
+}
+
+bool DNSSocketHandler::is_connected() const
+{
+ return true;
+}
+
+#endif /* CARES_FOUND */
diff --git a/src/network/dns_socket_handler.hpp b/src/network/dns_socket_handler.hpp
new file mode 100644
index 0000000..beb47d9
--- /dev/null
+++ b/src/network/dns_socket_handler.hpp
@@ -0,0 +1,46 @@
+#ifndef DNS_SOCKET_HANDLER_HPP
+# define DNS_SOCKET_HANDLER_HPP
+
+#include <config.h>
+#ifdef CARES_FOUND
+
+#include <network/socket_handler.hpp>
+#include <ares.h>
+
+/**
+ * Manage a socket returned by ares_fds. We do not create, open or close the
+ * socket ourself: this is done by c-ares. We just call ares_process_fd()
+ * with the correct parameters, depending on what can be done on that socket
+ * (Poller reported it to be writable or readeable)
+ */
+
+class DNSSocketHandler: public SocketHandler
+{
+public:
+ explicit DNSSocketHandler(std::shared_ptr<Poller> poller, const socket_t socket);
+ ~DNSSocketHandler();
+ /**
+ * Just call dns_process_fd, c-ares will do its work of send()ing or
+ * recv()ing the data it wants on that socket.
+ */
+ void on_recv() override final;
+ void on_send() override final;
+ /**
+ * Do nothing, because we are always considered to be connected, since the
+ * connection is done by c-ares and not by us.
+ */
+ void connect() override final;
+ /**
+ * Always true, see the comment for connect()
+ */
+ bool is_connected() const override final;
+
+private:
+ DNSSocketHandler(const DNSSocketHandler&) = delete;
+ DNSSocketHandler(DNSSocketHandler&&) = delete;
+ DNSSocketHandler& operator=(const DNSSocketHandler&) = delete;
+ DNSSocketHandler& operator=(DNSSocketHandler&&) = delete;
+};
+
+#endif // CARES_FOUND
+#endif // DNS_SOCKET_HANDLER_HPP
diff --git a/src/network/socket_handler.hpp b/src/network/socket_handler.hpp
index 9a894a4..0858474 100644
--- a/src/network/socket_handler.hpp
+++ b/src/network/socket_handler.hpp
@@ -1,6 +1,7 @@
#ifndef SOCKET_HANDLER_HPP
# define SOCKET_HANDLER_HPP
+#include <config.h>
#include <memory>
class Poller;
@@ -19,6 +20,7 @@ public:
virtual void on_send() = 0;
virtual void connect() = 0;
virtual bool is_connected() const = 0;
+
socket_t get_socket() const
{ return this->socket; }
diff --git a/src/network/tcp_socket_handler.cpp b/src/network/tcp_socket_handler.cpp
index 1d1eaa7..e9984e3 100644
--- a/src/network/tcp_socket_handler.cpp
+++ b/src/network/tcp_socket_handler.cpp
@@ -1,4 +1,5 @@
#include <network/tcp_socket_handler.hpp>
+#include <network/dns_handler.hpp>
#include <utils/timed_events.hpp>
#include <utils/scopeguard.hpp>
@@ -42,8 +43,22 @@ TCPSocketHandler::TCPSocketHandler(std::shared_ptr<Poller> poller):
use_tls(false),
connected(false),
connecting(false)
+#ifdef CARES_FOUND
+ ,resolved(false),
+ resolved4(false),
+ resolved6(false),
+ cares_addrinfo(nullptr),
+ cares_error()
+#endif
{}
+TCPSocketHandler::~TCPSocketHandler()
+{
+#ifdef CARES_FOUND
+ this->free_cares_addrinfo();
+#endif
+}
+
void TCPSocketHandler::init_socket(const struct addrinfo* rp)
{
if ((this->socket = ::socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol)) == -1)
@@ -72,9 +87,35 @@ void TCPSocketHandler::connect(const std::string& address, const std::string& po
if (!this->connecting)
{
+ // Get the addrinfo from getaddrinfo (or ares_gethostbyname), only if
+ // this is the first call of this function.
+#ifdef CARES_FOUND
+ if (!this->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.
+ DNSHandler::instance.gethostbyname(address, this, AF_INET6);
+ DNSHandler::instance.gethostbyname(address, this, AF_INET);
+ 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->cares_addrinfo;
+ if (!addr_res)
+ {
+ this->close();
+ this->on_connection_failed(this->cares_error);
+ return ;
+ }
+ }
+#else
log_info("Trying to connect to " << address << ":" << port);
- // Get the addrinfo from getaddrinfo, only if this is the first call
- // of this function.
struct addrinfo hints;
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_flags = 0;
@@ -94,6 +135,7 @@ void TCPSocketHandler::connect(const std::string& address, const std::string& po
// Make sure the alloced structure is always freed at the end of the
// function
sg.add_callback([&addr_res](){ freeaddrinfo(addr_res); });
+#endif
}
else
{ // This function is called again, use the saved addrinfo structure,
@@ -144,9 +186,9 @@ void TCPSocketHandler::connect(const std::string& address, const std::string& po
// 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)));
+ 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));
@@ -321,7 +363,11 @@ bool TCPSocketHandler::is_connected() const
bool TCPSocketHandler::is_connecting() const
{
+#ifdef CARES_FOUND
+ return this->connecting || !this->resolved;
+#else
return this->connecting;
+#endif
}
void* TCPSocketHandler::get_receive_buffer(const size_t) const
@@ -413,4 +459,114 @@ void TCPSocketHandler::on_tls_activated()
{
this->send_data("");
}
+
#endif // BOTAN_FOUND
+
+#ifdef CARES_FOUND
+
+void TCPSocketHandler::on_hostname4_resolved(int status, struct hostent* hostent)
+{
+ this->resolved4 = true;
+ if (status == ARES_SUCCESS)
+ this->fill_ares_addrinfo4(hostent);
+ else
+ this->cares_error = ::ares_strerror(status);
+
+ if (this->resolved4 && this->resolved6)
+ {
+ this->resolved = true;
+ this->connect();
+ }
+}
+
+void TCPSocketHandler::on_hostname6_resolved(int status, struct hostent* hostent)
+{
+ this->resolved6 = true;
+ if (status == ARES_SUCCESS)
+ this->fill_ares_addrinfo6(hostent);
+ else
+ this->cares_error = ::ares_strerror(status);
+
+ if (this->resolved4 && this->resolved6)
+ {
+ this->resolved = true;
+ this->connect();
+ }
+}
+
+void TCPSocketHandler::fill_ares_addrinfo4(const struct hostent* hostent)
+{
+ struct addrinfo* prev = this->cares_addrinfo;
+ struct in_addr** address = reinterpret_cast<struct in_addr**>(hostent->h_addr_list);
+
+ while (*address)
+ {
+ // Create a new addrinfo list element, and fill it
+ struct addrinfo* current = new struct addrinfo;
+ current->ai_flags = 0;
+ current->ai_family = hostent->h_addrtype;
+ current->ai_socktype = SOCK_STREAM;
+ current->ai_protocol = 0;
+ current->ai_addrlen = sizeof(struct sockaddr_in);
+
+ struct sockaddr_in* addr = new struct sockaddr_in;
+ addr->sin_family = hostent->h_addrtype;
+ addr->sin_port = htons(strtoul(this->port.data(), nullptr, 10));
+ addr->sin_addr.s_addr = (*address)->s_addr;
+
+ current->ai_addr = reinterpret_cast<struct sockaddr*>(addr);
+ current->ai_next = nullptr;
+ current->ai_canonname = nullptr;
+
+ current->ai_next = prev;
+ this->cares_addrinfo = current;
+ prev = current;
+ ++address;
+ }
+}
+
+void TCPSocketHandler::fill_ares_addrinfo6(const struct hostent* hostent)
+{
+ struct addrinfo* prev = this->cares_addrinfo;
+ struct in6_addr** address = reinterpret_cast<struct in6_addr**>(hostent->h_addr_list);
+
+ while (*address)
+ {
+ // Create a new addrinfo list element, and fill it
+ struct addrinfo* current = new struct addrinfo;
+ current->ai_flags = 0;
+ current->ai_family = hostent->h_addrtype;
+ current->ai_socktype = SOCK_STREAM;
+ current->ai_protocol = 0;
+ current->ai_addrlen = sizeof(struct sockaddr_in6);
+
+ struct sockaddr_in6* addr = new struct sockaddr_in6;
+ addr->sin6_family = hostent->h_addrtype;
+ addr->sin6_port = htons(strtoul(this->port.data(), nullptr, 10));
+ ::memcpy(addr->sin6_addr.s6_addr, (*address)->s6_addr, 16);
+ addr->sin6_flowinfo = 0;
+ addr->sin6_scope_id = 0;
+
+ current->ai_addr = reinterpret_cast<struct sockaddr*>(addr);
+ current->ai_next = nullptr;
+ current->ai_canonname = nullptr;
+
+ current->ai_next = prev;
+ this->cares_addrinfo = current;
+ prev = current;
+ ++address;
+ }
+}
+
+void TCPSocketHandler::free_cares_addrinfo()
+{
+ while (this->cares_addrinfo)
+ {
+ delete this->cares_addrinfo->ai_addr;
+ auto next = this->cares_addrinfo->ai_next;
+ delete this->cares_addrinfo;
+ this->cares_addrinfo = next;
+ }
+}
+
+#endif // CARES_FOUND
diff --git a/src/network/tcp_socket_handler.hpp b/src/network/tcp_socket_handler.hpp
index 6d4bbe4..7f10cff 100644
--- a/src/network/tcp_socket_handler.hpp
+++ b/src/network/tcp_socket_handler.hpp
@@ -17,6 +17,10 @@
#include "config.h"
+#ifdef CARES_FOUND
+# include <ares.h>
+#endif
+
#ifdef BOTAN_FOUND
# include <botan/botan.h>
# include <botan/tls_client.h>
@@ -44,7 +48,7 @@ public:
class TCPSocketHandler: public SocketHandler
{
protected:
- ~TCPSocketHandler() {}
+ ~TCPSocketHandler();
public:
explicit TCPSocketHandler(std::shared_ptr<Poller> poller);
@@ -54,16 +58,16 @@ public:
* start_tls() when the connection succeeds.
*/
void connect(const std::string& address, const std::string& port, const bool tls);
- void connect();
+ void connect() override final;
/**
* Reads raw data from the socket. And pass it to parse_in_buffer()
* If we are using TLS on this connection, we call tls_recv()
*/
- void on_recv();
+ void on_recv() override final;
/**
* Write as much data from out_buf as possible, in the socket.
*/
- void on_send();
+ void on_send() override final;
/**
* Add the given data to out_buf and tell our poller that we want to be
* notified when a send event is ready.
@@ -107,9 +111,19 @@ public:
* The size argument is the size of the last chunk of data that was added to the buffer.
*/
virtual void parse_in_buffer(const size_t size) = 0;
- bool is_connected() const;
+ bool is_connected() const override final;
bool is_connecting() const;
+#ifdef CARES_FOUND
+ void on_hostname4_resolved(int status, struct hostent* hostent);
+ void on_hostname6_resolved(int status, struct hostent* hostent);
+
+ void free_cares_addrinfo();
+
+ void fill_ares_addrinfo4(const struct hostent* hostent);
+ void fill_ares_addrinfo6(const struct hostent* hostent);
+#endif
+
private:
/**
* Initialize the socket with the parameters contained in the given
@@ -185,7 +199,7 @@ private:
*/
std::list<std::string> out_buf;
/**
- * Keep the details of the addrinfo the triggered a EINPROGRESS error when
+ * Keep the details of the addrinfo that triggered a EINPROGRESS error when
* connect()ing to it, to reuse it directly when connect() is called
* again.
*/
@@ -225,6 +239,27 @@ protected:
bool connected;
bool connecting;
+#ifdef CARES_FOUND
+ /**
+ * Whether or not the DNS resolution was successfully done
+ */
+ bool resolved;
+ bool resolved4;
+ bool resolved6;
+ /**
+ * When using c-ares to resolve the host asynchronously, we need the
+ * c-ares callback to fill a structure (a struct addrinfo, for
+ * compatibility with getaddrinfo and the rest of the code that works when
+ * c-ares is not used) with all returned values (for example an IPv6 and
+ * an IPv4). The next call of connect() will then try all these values
+ * (exactly like we do with the result of getaddrinfo) and save the one
+ * that worked (or returned EINPROGRESS) in the other struct addrinfo (see
+ * the members addrinfo, ai_addrlen, and ai_addr).
+ */
+ struct addrinfo* cares_addrinfo;
+ std::string cares_error;
+#endif // CARES_FOUND
+
private:
TCPSocketHandler(const TCPSocketHandler&) = delete;
TCPSocketHandler(TCPSocketHandler&&) = delete;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-05 19:25:49 +0000