transmission/libtransmission/port-forwarding-upnp.cc

370 lines
11 KiB
C++

// This file Copyright © 2007-2023 Mnemosyne LLC.
// It may be used under GPLv2 (SPDX: GPL-2.0-only), GPLv3 (SPDX: GPL-3.0-only),
// or any future license endorsed by Mnemosyne LLC.
// License text can be found in the licenses/ folder.
#include <array>
#include <cerrno>
#include <chrono>
#include <future>
#include <mutex>
#include <string>
#include <thread>
#include <utility>
#include <fmt/core.h>
#include <fmt/format.h>
#ifdef SYSTEM_MINIUPNP
#include <miniupnpc/miniupnpc.h>
#include <miniupnpc/upnpcommands.h>
#else
#include <miniupnp/miniupnpc.h>
#include <miniupnp/upnpcommands.h>
#endif
#define LIBTRANSMISSION_PORT_FORWARDING_MODULE
#include "transmission.h"
#include "log.h"
#include "port-forwarding-upnp.h"
#include "port-forwarding.h"
#include "tr-assert.h"
#include "utils.h" // for _(), tr_strerror()
namespace
{
enum class UpnpState
{
Idle,
Failed,
WillDiscover, // next action is upnpDiscover()
Discovering, // currently making blocking upnpDiscover() call in a worker thread
WillMap, // next action is UPNP_AddPortMapping()
WillUnmap // next action is UPNP_DeletePortMapping()
};
} // namespace
struct tr_upnp
{
tr_upnp() = default;
tr_upnp(tr_upnp&&) = delete;
tr_upnp(tr_upnp const&) = delete;
tr_upnp& operator=(tr_upnp&&) = delete;
tr_upnp& operator=(tr_upnp const&) = delete;
~tr_upnp()
{
TR_ASSERT(!isMapped);
TR_ASSERT(
state == UpnpState::Idle || state == UpnpState::Failed || state == UpnpState::WillDiscover ||
state == UpnpState::Discovering);
FreeUPNPUrls(&urls);
}
bool hasDiscovered = false;
UPNPUrls urls = {};
IGDdatas data = {};
tr_port port;
std::string lanaddr;
bool isMapped = false;
UpnpState state = UpnpState::WillDiscover;
// Used to return the results of upnpDiscover() from a worker thread
// to be processed without blocking in tr_upnpPulse().
// This will be pending while the state is UpnpState::DISCOVERING.
std::optional<std::future<UPNPDev*>> discover_future;
};
namespace
{
constexpr auto port_fwd_state(UpnpState upnp_state, bool is_mapped)
{
switch (upnp_state)
{
case UpnpState::WillDiscover:
case UpnpState::Discovering:
return TR_PORT_UNMAPPED;
case UpnpState::WillMap:
return TR_PORT_MAPPING;
case UpnpState::WillUnmap:
return TR_PORT_UNMAPPING;
case UpnpState::Idle:
return is_mapped ? TR_PORT_MAPPED : TR_PORT_UNMAPPED;
default: // UpnpState::FAILED:
return TR_PORT_ERROR;
}
}
[[nodiscard]] UPNPDev* upnp_discover(int msec, char const* bindaddr)
{
UPNPDev* ret = nullptr;
auto have_err = bool{};
#if (MINIUPNPC_API_VERSION >= 8) /* adds ipv6 and error args */
int err = UPNPDISCOVER_SUCCESS;
#if (MINIUPNPC_API_VERSION >= 14) /* adds ttl */
ret = upnpDiscover(msec, bindaddr, nullptr, 0, 0, 2, &err);
#else
ret = upnpDiscover(msec, bindaddr, nullptr, 0, 0, &err);
#endif
have_err = err != UPNPDISCOVER_SUCCESS;
#else
ret = upnpDiscover(msec, bindaddr, nullptr, 0);
have_err = ret == nullptr;
#endif
if (have_err)
{
tr_logAddDebug(fmt::format("upnpDiscover failed: {} ({})", tr_strerror(errno), errno));
}
return ret;
}
[[nodiscard]] int get_specific_port_mapping_entry(tr_upnp const* handle, char const* proto)
{
auto int_client = std::array<char, 16>{};
auto int_port = std::array<char, 16>{};
auto const port_str = fmt::format(FMT_STRING("{:d}"), handle->port.host());
#if (MINIUPNPC_API_VERSION >= 10) /* adds remoteHost arg */
int const err = UPNP_GetSpecificPortMappingEntry(
handle->urls.controlURL,
handle->data.first.servicetype,
port_str.c_str(),
proto,
nullptr /*remoteHost*/,
std::data(int_client),
std::data(int_port),
nullptr /*desc*/,
nullptr /*enabled*/,
nullptr /*duration*/);
#elif (MINIUPNPC_API_VERSION >= 8) /* adds desc, enabled and leaseDuration args */
int const err = UPNP_GetSpecificPortMappingEntry(
handle->urls.controlURL,
handle->data.first.servicetype,
port_str.c_str(),
proto,
std::data(int_client),
std::data(int_port),
nullptr /*desc*/,
nullptr /*enabled*/,
nullptr /*duration*/);
#else
int const err = UPNP_GetSpecificPortMappingEntry(
handle->urls.controlURL,
handle->data.first.servicetype,
port_str.c_str(),
proto,
std::data(int_client),
std::data(int_port));
#endif
return err;
}
[[nodiscard]] int upnp_add_port_mapping(tr_upnp const* handle, char const* proto, tr_port port, char const* desc)
{
int const old_errno = errno;
errno = 0;
auto const port_str = fmt::format(FMT_STRING("{:d}"), port.host());
#if (MINIUPNPC_API_VERSION >= 8)
int const err = UPNP_AddPortMapping(
handle->urls.controlURL,
handle->data.first.servicetype,
port_str.c_str(),
port_str.c_str(),
handle->lanaddr.c_str(),
desc,
proto,
nullptr,
nullptr);
#else
int const err = UPNP_AddPortMapping(
handle->urls.controlURL,
handle->data.first.servicetype,
port_str.c_str(),
port_str.c_str(),
handle->lanaddr.c_str(),
desc,
proto,
nullptr);
#endif
if (err != 0)
{
tr_logAddDebug(fmt::format("{} Port forwarding failed with error {}: {} ({})", proto, err, tr_strerror(errno), errno));
}
errno = old_errno;
return err;
}
void tr_upnpDeletePortMapping(tr_upnp const* handle, char const* proto, tr_port port)
{
auto const port_str = fmt::format(FMT_STRING("{:d}"), port.host());
UPNP_DeletePortMapping(handle->urls.controlURL, handle->data.first.servicetype, port_str.c_str(), proto, nullptr);
}
enum
{
UPNP_IGD_NONE = 0,
UPNP_IGD_VALID_CONNECTED = 1,
UPNP_IGD_VALID_NOT_CONNECTED = 2,
UPNP_IGD_INVALID = 3
};
auto* discover_thread_func(std::string bindaddr) // NOLINT performance-unnecessary-value-param
{
// If multicastif is not NULL, it will be used instead of the default
// multicast interface for sending SSDP discover packets.
char const* multicastif = std::empty(bindaddr) ? nullptr : bindaddr.c_str();
return upnp_discover(2000, multicastif);
}
template<typename T>
bool is_future_ready(std::future<T> const& future)
{
return future.wait_for(std::chrono::seconds(0)) == std::future_status::ready;
}
} // namespace
// ---
tr_upnp* tr_upnpInit()
{
return new tr_upnp();
}
void tr_upnpClose(tr_upnp* handle)
{
delete handle;
}
tr_port_forwarding_state tr_upnpPulse(tr_upnp* handle, tr_port port, bool is_enabled, bool do_port_check, std::string bindaddr)
{
if (is_enabled && handle->state == UpnpState::WillDiscover)
{
TR_ASSERT(!handle->discover_future);
auto task = std::packaged_task<UPNPDev*(std::string)>{ discover_thread_func };
handle->discover_future = task.get_future();
handle->state = UpnpState::Discovering;
std::thread(std::move(task), std::move(bindaddr)).detach();
}
if (is_enabled && handle->state == UpnpState::Discovering && handle->discover_future &&
is_future_ready(*handle->discover_future))
{
auto* const devlist = handle->discover_future->get();
handle->discover_future.reset();
FreeUPNPUrls(&handle->urls);
auto lanaddr = std::array<char, TR_ADDRSTRLEN>{};
if (UPNP_GetValidIGD(devlist, &handle->urls, &handle->data, std::data(lanaddr), std::size(lanaddr) - 1) ==
UPNP_IGD_VALID_CONNECTED)
{
tr_logAddInfo(fmt::format(_("Found Internet Gateway Device '{url}'"), fmt::arg("url", handle->urls.controlURL)));
tr_logAddInfo(fmt::format(_("Local Address is '{address}'"), fmt::arg("address", lanaddr.data())));
handle->state = UpnpState::Idle;
handle->hasDiscovered = true;
handle->lanaddr = std::data(lanaddr);
}
else
{
handle->state = UpnpState::Failed;
tr_logAddDebug(fmt::format("UPNP_GetValidIGD failed: {} ({})", tr_strerror(errno), errno));
tr_logAddDebug("If your router supports UPnP, please make sure UPnP is enabled!");
}
freeUPNPDevlist(devlist);
}
if ((handle->state == UpnpState::Idle) && (handle->isMapped) && (!is_enabled || handle->port != port))
{
handle->state = UpnpState::WillUnmap;
}
if (is_enabled && handle->isMapped && do_port_check &&
((get_specific_port_mapping_entry(handle, "TCP") != UPNPCOMMAND_SUCCESS) ||
(get_specific_port_mapping_entry(handle, "UDP") != UPNPCOMMAND_SUCCESS)))
{
tr_logAddInfo(fmt::format(_("Port {port} is not forwarded"), fmt::arg("port", handle->port.host())));
handle->isMapped = false;
}
if (handle->state == UpnpState::WillUnmap)
{
tr_upnpDeletePortMapping(handle, "TCP", handle->port);
tr_upnpDeletePortMapping(handle, "UDP", handle->port);
tr_logAddInfo(fmt::format(
_("Stopping port forwarding through '{url}', service '{type}'"),
fmt::arg("url", handle->urls.controlURL),
fmt::arg("type", handle->data.first.servicetype)));
handle->isMapped = false;
handle->state = UpnpState::Idle;
handle->port = {};
}
if ((handle->state == UpnpState::Idle) && is_enabled && !handle->isMapped)
{
handle->state = UpnpState::WillMap;
}
if (handle->state == UpnpState::WillMap)
{
errno = 0;
if (handle->urls.controlURL == nullptr)
{
handle->isMapped = false;
}
else
{
auto const desc = fmt::format(FMT_STRING("Transmission at {:d}"), port.host());
int const err_tcp = upnp_add_port_mapping(handle, "TCP", port, desc.c_str());
int const err_udp = upnp_add_port_mapping(handle, "UDP", port, desc.c_str());
handle->isMapped = err_tcp == 0 || err_udp == 0;
}
tr_logAddDebug(fmt::format(
_("Port forwarding through '{url}', service '{type}'. (local address: {address}:{port})"),
fmt::arg("url", handle->urls.controlURL),
fmt::arg("type", handle->data.first.servicetype),
fmt::arg("address", handle->lanaddr),
fmt::arg("port", port.host())));
if (handle->isMapped)
{
tr_logAddInfo(fmt::format(_("Port {port} is forwarded"), fmt::arg("port", port.host())));
handle->port = port;
handle->state = UpnpState::Idle;
}
else
{
tr_logAddInfo(_("If your router supports UPnP, please make sure UPnP is enabled!"));
handle->port = {};
handle->state = UpnpState::Failed;
}
}
return port_fwd_state(handle->state, handle->isMapped);
}