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Separate the DNS resolution logic from the TCP communication logic

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fix #3137
This commit is contained in:
Florent Le Coz
2015-10-15 04:32:02 +02:00
parent 1aa2c2d857
commit aa340e1c5e
7 changed files with 463 additions and 246 deletions
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louloulibs/network/tcp_socket_handler.cpp
+20 -182
View File
@@ -11,13 +11,9 @@
#include <stdexcept>
#include <unistd.h>
#include <errno.h>
#include <netdb.h>
#include <cstring>
#include <fcntl.h>
#include <iostream>
#include <arpa/inet.h>
#ifdef BOTAN_FOUND
# include <botan/hex.h>
# include <botan/tls_exceptn.h>
@@ -43,24 +39,9 @@ TCPSocketHandler::TCPSocketHandler(std::shared_ptr<Poller> poller):
use_tls(false),
connected(false),
connecting(false),
#ifdef CARES_FOUND
resolving(false),
resolved(false),
resolved4(false),
resolved6(false),
cares_addrinfo(nullptr),
cares_error(),
#endif
hostname_resolution_failed(false)
{}
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)
@@ -91,17 +72,24 @@ void TCPSocketHandler::connect(const std::string& address, const std::string& po
{
// Get the addrinfo from getaddrinfo (or ares_gethostbyname), only if
// this is the first call of this function.
#ifdef CARES_FOUND
if (!this->resolved)
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->resolving = true;
DNSHandler::instance.gethostbyname(address, this, AF_INET6);
DNSHandler::instance.gethostbyname(address, this, AF_INET);
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
@@ -109,39 +97,16 @@ void TCPSocketHandler::connect(const std::string& address, const std::string& po
// 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;
addr_res = this->resolver.get_result().get();
if (!addr_res)
{
this->hostname_resolution_failed = true;
const auto msg = this->cares_error;
const auto msg = this->resolver.get_error_message();
this->close();
this->on_connection_failed(msg);
return ;
}
}
#else
log_info("Trying to connect to " << address << ":" << port);
struct addrinfo hints;
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_flags = 0;
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = 0;
const int res = ::getaddrinfo(address.c_str(), port.c_str(), &hints, &addr_res);
if (res != 0)
{
log_warning("getaddrinfo failed: "s + gai_strerror(res));
this->hostname_resolution_failed = true;
this->close();
this->on_connection_failed(gai_strerror(res));
return ;
}
// 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,
@@ -335,30 +300,18 @@ void TCPSocketHandler::close()
}
this->connected = false;
this->connecting = false;
#ifdef CARES_FOUND
this->resolving = false;
this->resolved = false;
this->resolved4 = false;
this->resolved6 = false;
this->free_cares_addrinfo();
this->cares_error.clear();
#endif
this->in_buf.clear();
this->out_buf.clear();
this->port.clear();
this->resolver.clear();
}
void TCPSocketHandler::display_resolved_ip(struct addrinfo* rp) const
{
char buf[INET6_ADDRSTRLEN];
if (rp->ai_family == AF_INET)
log_debug("Connecting to IP address " << ::inet_ntop(rp->ai_family,
&reinterpret_cast<sockaddr_in*>(rp->ai_addr)->sin_addr,
buf, sizeof(buf)));
log_debug("Trying IPv4 address " << addr_to_string(rp));
else if (rp->ai_family == AF_INET6)
log_debug("Connecting to IPv6 address " << ::inet_ntop(rp->ai_family,
&reinterpret_cast<sockaddr_in6*>(rp->ai_addr)->sin6_addr,
buf, sizeof(buf)));
log_debug("Trying IPv6 address " << addr_to_string(rp));
}
void TCPSocketHandler::send_data(std::string&& data)
@@ -399,11 +352,7 @@ bool TCPSocketHandler::is_connected() const
bool TCPSocketHandler::is_connecting() const
{
#ifdef CARES_FOUND
return this->connecting || this->resolving;
#else
return this->connecting;
#endif
return this->connecting || this->resolver.is_resolving();
}
void* TCPSocketHandler::get_receive_buffer(const size_t) const
@@ -506,122 +455,11 @@ void TCPSocketHandler::on_tls_activated()
}
void Permissive_Credentials_Manager::verify_certificate_chain(const std::string& type,
const std::string& purported_hostname,
const std::vector<Botan::X509_Certificate>&)
const std::string& purported_hostname,
const std::vector<Botan::X509_Certificate>&)
{ // TODO: Offer the admin to disallow connection on untrusted
// certificates
log_debug("Checking remote certificate (" << type << ") for hostname " << purported_hostname);
}
#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->resolving = false;
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->resolving = false;
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