#2 DCC with reverse initiation functionality and NAT integration.

ICommand/Internal/dcc.cpp

@@ -19,20 +19,29 @@ void ICommandPriv::cmd_dcc(const std::string& command, const std::string& target
             const auto code = static_cast<int>(result.second);
             const auto errorStr = QString::fromStdString(IRCErrorToString(result.second));
             mdi.currentStatus()->printToActive(PrintType::ProgramInfo, QObject::tr("/DCC: Unable to initiate DCC Chat to %1 [%2 (%3)]")
-                    .arg( QString::fromStdString(target), errorStr, QString::number(code)) );
+                                                                       .arg( QString::fromStdString(target), errorStr, QString::number(code)) );
         }
         else {
-            const auto portno = result.first->port();
+            auto dcc = result.first;
+            const auto portno = dcc->isReversed() ? 0
+                                                  : dcc->port();
+
             auto* window = mdi.createDCCSubwindow(mdi.currentStatus(), IWin::Type::DCCChat, result.first, IRCPrefix(target));
-            window->print(PrintType::ProgramInfo, QObject::tr("Initiated CHAT with %1 on port %2")
-                                                    .arg( QString::fromStdString(target) )
-                                                    .arg(portno));
+
+            if (dcc->isReversed())
+                window->print(PrintType::ProgramInfo, QObject::tr("Initiating CHAT with %1, please wait...")
+                                                        .arg( QString::fromStdString(target) ));
+            else
+                window->print(PrintType::ProgramInfo, QObject::tr("Initiating CHAT with %1 on port %2, please wait...")
+                        .arg( QString::fromStdString(target) )
+                        .arg(portno));
 
             const auto myIp = findOwnIpAddress();
             const auto msg = fmt::format( "CHAT chat {} {}",
                                           normalIpToLong(myIp),
                                           portno
                                         );
+
             cmd_ctcp(target, "DCC", msg);
         }
     }

IRCClient/CMakeLists.txt

@@ -70,5 +70,12 @@ list(APPEND ${component}_PRIVATE
 )
 
 add_library(${component} STATIC ${${component}_SOURCES} ${${component}_COMMANDS} ${${component}_PRIVATE})
-target_link_libraries(${component} fmt crypto ssl)
+
+target_link_libraries(${component}
+    NATUtils
+    fmt
+    crypto
+    ssl
+)
+
 target_include_directories(${component} PRIVATE ${CMAKE_SOURCE_DIR})

IRCClient/DCC.cpp

@@ -7,6 +7,9 @@
 
 #include "DCC.h"
 #include "IRCBase.h"
+#include "NATUtils/PortMapping.h"
+#include "NATUtils/PublicAddress.h"
+#include "Utilities.h"
 #include <fmt/format.h>
 #include <iostream>
 
@@ -89,24 +92,46 @@ struct DCCPriv
         if (!ec) return; // No errors.
         std::cerr << fmt::format("'- DCC write error: {} ({})", SystemErrorToIRCError(ec), ec.message()) << std::endl;
     }
+
+    void startListener()
+    {
+        acceptor.open(endpoint.protocol());
+        acceptor.set_option(tcp::acceptor::reuse_address(true));
+        acceptor.bind(endpoint);
+        acceptor.listen(1);
+        acceptor.async_accept(socket, [this](const asio::error_code& ec){
+            if (ec == asio::error::operation_aborted)
+                return;
+
+            if (ec)
+                disconnected(ec);
+            else
+                connected(ec);
+        });
+    }
 };
 
 DCC::DCC(IRCBase& ircctx, asio::io_context& ioctx)
         : mp(std::make_unique<DCCPriv>(*this, ircctx, Direction::Initiator, ioctx, "", "0"))
 {
-    mp->acceptor.open(mp->endpoint.protocol());
-    mp->acceptor.set_option(tcp::acceptor::reuse_address(true));
-    mp->acceptor.bind(mp->endpoint);
-    mp->acceptor.listen(1);
-    mp->acceptor.async_accept(mp->socket, [this](const asio::error_code& ec){
-        if (ec == asio::error::operation_aborted)
-            return;
+    auto ipAddress = findOwnIpAddress();
+
+    mp->startListener(); // also acquires a port for us
+
+    if (isPrivateIp(ipAddress) && NATPortMapping::add(ipAddress, port(), port())) {
+        auto publicIp = NATPublicAddress::get();
+        if (publicIp.has_value()) {
+            ipAddress = longIpToNormal(*publicIp);
+        }
+        else {
+            NATPortMapping::remove(ipAddress, port(), port());
+            // Reset internal state, effectively stopping the listening.
+            // This DCC instance will be destroyed and replaced when we get a response with the port to use in reverse.
+            mp = std::make_unique<DCCPriv>(*this, ircctx, Direction::Initiator, ioctx, "", "0");
+        }
+    }
 
-        if (ec)
-            mp->disconnected(ec);
-        else
-            mp->connected(ec);
-    });
+    mp->ip = ipAddress;
 }
 
 DCC::DCC(IRCBase& ircctx, asio::io_context& ioctx, const std::string& ip, const std::string& port)
@@ -127,23 +152,50 @@ bool DCC::isPending() const
     return mp->pending;
 }
 
-IRCError DCC::accept()
+IRCError DCC::accept(const std::string& targetNickname)
 {
     if (mp->direction == Direction::Initiator)
         return IRCError::DCC_NotATarget; // Only usable if we are a Target...
 
-    mp->resolverResults = mp->resolver.resolve(mp->ip, mp->port);
-
-    asio::async_connect(mp->socket, mp->resolverResults,
-        [this](const asio::error_code& ec, const tcp::endpoint&) {
-            if (ec)
-                mp->disconnected(ec);
+    auto acceptNormally = [this] {
+        mp->resolverResults = mp->resolver.resolve(mp->ip, mp->port);
+
+        asio::async_connect(mp->socket, mp->resolverResults,
+                            [this](const asio::error_code& ec, const tcp::endpoint&) {
+                                if (ec)
+                                    mp->disconnected(ec);
+                                else
+                                    mp->connected(ec);
+                            });
+
+        mp->pending = false;
+        return IRCError::NoError;
+    };
+
+    auto acceptReversed = [this, &targetNickname] {
+        auto ipAddress = findOwnIpAddress();
+        mp->startListener();
+
+        if (isPrivateIp(ipAddress) && NATPortMapping::add(ipAddress, port(), port())) {
+            auto publicIp = NATPublicAddress::get();
+            if (publicIp.has_value())
+                ipAddress = longIpToNormal(*publicIp);
             else
-                mp->connected(ec);
-        });
+                NATPortMapping::remove(ipAddress, port(), port());
+        }
+
+        mp->ircctx.ctcpRequest(targetNickname, "DCC", fmt::format("CHAT chat {} {}",
+                                                                  normalIpToLong(ipAddress),
+                                                                  port()));
 
-    mp->pending = false;
-    return IRCError::NoError;
+        mp->pending = false;
+        return IRCError::NoError;
+    };
+
+    if (mp->port == "0")
+        return acceptReversed();
+    else
+        return acceptNormally();
 }
 
 void DCC::disconnect()
@@ -203,6 +255,11 @@ const std::string& DCC::ip() const
     return mp->ip;
 }
 
+bool DCC::isReversed() const
+{
+    return mp->port == "0";
+}
+
 void DCC::setCallbackRead(DCC::CallbackRead&& cb)
 {
     mp->cbRead = std::move(cb);

IRCClient/DCC.h

@@ -47,7 +47,7 @@ public:
     DCC(IRCBase& ircctx, asio::io_context& ioctx, const std::string& ip, const std::string& port);
 
     [[nodiscard]] bool isPending() const;
-    IRCError accept();
+    IRCError accept(const std::string& targetNickname);
 
     void disconnect();
 
@@ -59,9 +59,22 @@ public:
     const IRCBase& context() const;
 
     bool isConnected() const;
+
+    /*
+     * As initiator: Port to listen on.
+     * Reversed initiator: Always zero.
+     * As target: Port to connect to.
+    */
     uint16_t port() const;
+
+    /*
+     * As initiator: IP to listen on (published in CTCP DCC request)
+     * As target or reversed initiator: IP to connect to.
+    */
     const std::string& ip() const;
 
+    bool isReversed() const;
+
     /*
      * Callbacks used by 'users' of this class.
     */
@@ -84,7 +97,7 @@ protected:
     virtual void onDisconnected(IRCError e);
 
 private:
-        std::unique_ptr<DCCPriv> mp;
+    std::unique_ptr<DCCPriv> mp;
 };
 
 #endif // DCC_H

IRCClient/IRCBasePriv.h

@@ -24,8 +24,8 @@
 namespace {
 
 /* Debug/development options */
-constexpr bool DumpReadData = true;
-constexpr bool DumpWriteData = true;
+constexpr bool DumpReadData = false;
+constexpr bool DumpWriteData = false;
 
 const std::vector<std::string> V3Support {
     "account-notify",

IRCClient/Utilities.cpp

@@ -15,23 +15,6 @@
 namespace {
 constexpr auto DefaultIpAddress{ "127.0.0.1" };
 
-uint32_t ipStrToInt(const std::string& ip)
-{
-    std::stringstream ss(ip);
-    std::string p;
-    std::vector<unsigned> parts;
-    while (getline(ss, p, '.'))
-        parts.emplace_back(std::stoul(p));
-
-    uint32_t ret = parts[0];
-    for (int i = 1; i < 4; ++i) {
-        ret <<= 8u;
-        ret |= parts[i];
-    }
-
-    return ret;
-}
-
 std::string getIpFromSecondToken(const std::string& input)
 {
     if (input.empty())
@@ -127,24 +110,41 @@ bool singleWildcardMatch(const std::string& str, const std::string& wc)
     return !(hasLeft && hasRight && leftEnd == rightBegin);
 }
 
+std::string longIpToNormal(std::uint32_t longip)
+{
+    unsigned ip = longip;
+    unsigned a = (ip & 0xFF000000u) >> 24u;
+    unsigned b = (ip & 0x00FF0000u) >> 16u;
+    unsigned c = (ip & 0x0000FF00u) >> 8u;
+    unsigned d = ip & 0x000000FFu;
+    return fmt::format("{}.{}.{}.{}", a, b, c, d);
+}
+
 std::string longIpToNormal(const std::string& longip)
 {
     try {
-        unsigned ip = std::stoul(longip);
-        unsigned a = (ip & 0xFF000000u) >> 24u;
-        unsigned b = (ip & 0x00FF0000u) >> 16u;
-        unsigned c = (ip & 0x0000FF00u) >> 8u;
-        unsigned d = ip & 0x000000FFu;
-        return fmt::format("{}.{}.{}.{}", a, b, c, d);
+        return longIpToNormal( std::stoul(longip) );
     }
     catch (...) {
         return "0.0.0.0";
     }
 }
 
-std::string normalIpToLong(const std::string& normalip)
+std::uint32_t normalIpToLong(const std::string& normalip)
 {
-    return std::to_string(ipStrToInt(normalip));
+    std::stringstream ss(normalip);
+    std::string p;
+    std::vector<unsigned> parts;
+    while (getline(ss, p, '.'))
+        parts.emplace_back(std::stoul(p));
+
+    uint32_t ret = parts[0];
+    for (int i = 1; i < 4; ++i) {
+        ret <<= 8u;
+        ret |= parts[i];
+    }
+
+    return ret;
 }
 
 std::string concatenateModes(const std::unordered_map<char, std::string>& modes)
@@ -292,7 +292,7 @@ bool isPrivateIp(const std::string& ip)
      * Class C: 192.168.0.0 - 192.168.255.255
     */
 
-    const auto intip{ ipStrToInt(ip) };
+    const auto intip{ normalIpToLong(ip) };
 
     const auto classIp{ (intip & 0xFF000000) >> 24 };
 

IRCClient/Utilities.h

@@ -8,6 +8,7 @@
 #ifndef IRCUTILITIES_H
 #define IRCUTILITIES_H
 
+#include <cstdint>
 #include <unordered_map>
 #include <string>
 #include <algorithm>
@@ -16,8 +17,9 @@ constexpr char CTCPflag { 0x01 };
 
 std::pair<std::string,std::string> FormatCTCPLine(std::string line);
 bool singleWildcardMatch(const std::string& str, const std::string& wc);
+std::string longIpToNormal(std::uint32_t longip);
 std::string longIpToNormal(const std::string& longip);
-std::string normalIpToLong(const std::string& normalip);
+std::uint32_t normalIpToLong(const std::string& normalip);
 std::string concatenateModes(const std::unordered_map<char, std::string>& modes);
 bool strEquals(const std::string& l, const std::string& r);
 std::string toBase64(const std::string& input);

IWin/IWinDCCChat.cpp

@@ -6,12 +6,13 @@
 */
 
 #include "IWinDCCChat.h"
+#include "IWinStatus.h"
 #include <IRCClient/IRCBase.h>
 #include <QMessageBox>
 #include <iostream>
 
-IWinDCCChat::IWinDCCChat(std::shared_ptr<DCC> dcc_, const QString& targetNickname)
-    : IWin(IWin::Type::DCCChat, nullptr)
+IWinDCCChat::IWinDCCChat(IWinStatus* statusParent, std::shared_ptr<DCC> dcc_, const QString& targetNickname)
+    : IWin(IWin::Type::DCCChat, statusParent)
     , dcc(std::move(dcc_))
 {
     setButtonText(targetNickname);
@@ -32,9 +33,7 @@ IWinDCCChat::IWinDCCChat(std::shared_ptr<DCC> dcc_, const QString& targetNicknam
     connect(input, &ILineEdit::newLine,
             this, &IWinDCCChat::newLine);
 
-    dcc->setCallbackConnected([this]{ onConnected(); });
-    dcc->setCallbackDisconnected([this](IRCError e){ onDisconnected(e); });
-    dcc->setCallbackRead([this](const DCC::ByteString& data, std::size_t length){ onRead(data, length); });
+    setupCallbacks();
 }
 
 bool IWinDCCChat::printWithCustomTime(const QDateTime& timestamp, PrintType ptype, const QString& text)
@@ -51,10 +50,23 @@ void IWinDCCChat::refreshWindowTitle()
 void IWinDCCChat::acceptAsTarget()
 {
     const auto ip = QString::fromStdString(dcc->ip());
-    const auto port = QString::number(dcc->port());
-    print(PrintType::ProgramInfo, tr("Connecting to %1:%2...").arg(ip, port));
 
-    dcc->accept();
+    if (dcc->isReversed()) {
+        print(PrintType::ProgramInfo, tr("Waiting for participant..."));
+    }
+    else {
+        const auto port = QString::number(dcc->port());
+        print(PrintType::ProgramInfo, tr("Connecting to %1:%2...").arg(ip, port));
+    }
+
+    dcc->accept(getButtonText().toStdString());
+}
+
+void IWinDCCChat::setupCallbacks()
+{
+    dcc->setCallbackConnected([this]{ onConnected(); });
+    dcc->setCallbackDisconnected([this](IRCError e){ onDisconnected(e); });
+    dcc->setCallbackRead([this](const DCC::ByteString& data, std::size_t length){ onRead(data, length); });
 }
 
 void IWinDCCChat::closeEvent(QCloseEvent* evt)
@@ -139,3 +151,11 @@ void IWinDCCChat::disconnectFromDCC()
 {
     dcc->disconnect();
 }
+
+void IWinDCCChat::initiateReversed(std::shared_ptr<DCC> dcc_)
+{
+    reverseInitiatePending = false;
+    dcc = std::move(dcc_);
+    setupCallbacks();
+    dcc->accept(getButtonText().toStdString());
+}

IWin/IWinDCCChat.h

@@ -15,22 +15,28 @@
 #include <QCloseEvent>
 #include <memory>
 
+class IWinStatus;
+
 class IWinDCCChat : public IWin
 {
     Q_OBJECT
 
 public:
-    IWinDCCChat(std::shared_ptr<DCC> dcc_, const QString& targetNickname);
+    IWinDCCChat(IWinStatus* statusParent, std::shared_ptr<DCC> dcc_, const QString& targetNickname);
 
     bool printWithCustomTime(const QDateTime& timestamp, PrintType ptype, const QString& text) override;
     void refreshWindowTitle() override;
     void clear() override { view->resetView(); }
 
     void acceptAsTarget();
-
     void disconnectFromDCC();
 
+    void markReverseInitiatePending() { reverseInitiatePending = true; }
+    bool isReverseInitiatePending() const { return reverseInitiatePending; }
+    void initiateReversed(std::shared_ptr<DCC> dcc_);
+
 private:
+    void setupCallbacks();
     void closeEvent(QCloseEvent* evt) override;
     void onConnected();
     void onDisconnected(IRCError e);
@@ -43,6 +49,7 @@ private:
     ILineEdit* input;
     QString lineBuffer;
 
+    bool reverseInitiatePending{ false };
     std::shared_ptr<DCC> dcc;
 };
 

IdealIRC/IdealIRC.cpp

@@ -8,7 +8,10 @@
 #include "IdealIRC.h"
 #include "ui_IdealIRC.h"
 #include "config.h"
+
 #include "IWin/IWinStatus.h"
+#include "IWin/IWinDCCChat.h"
+
 #include <ConfigMgr.h>
 #include <QDebug>
 #include <QDir>
@@ -367,14 +370,36 @@ void IdealIRC::onStatusWindowCreated(IWinStatus* window)
         }
     });
 
-    connect(&(window->getConnection()), &IRC::DCCRequested, this, &IdealIRC::onDCCRequested);
+    connect(&(window->getConnection()), &IRC::DCCRequested, [this,window](const std::shared_ptr<DCC>& dcc, const IRCPrefix& sender, const QString& type, const QString& message) {
+        onDCCRequested(*window, dcc, sender, type, message);
+    });
 }
 
-void IdealIRC::onDCCRequested(const std::shared_ptr<DCC>& dcc, const IRCPrefix& sender, const QString& type, const QString& message)
+void IdealIRC::onDCCRequested(const IWinStatus& statusParent, const std::shared_ptr<DCC>& dcc, const IRCPrefix& sender, const QString& type, const QString& message)
 {
-    // TODO check type and message together... DCC SEND would use 'message' to hold filename and size
-    dccQueryDlg.addQuery(sender, type, dcc);
-    dccQueryDlg.show();
+    /*
+     * Need to check any DCC windows already open in the given status parent of the inbound DCC for pending reverses.
+     * Then compare for any matching pending reverses with this inbound DCC.
+    */
+    auto dccChatList = MdiManager::instance().childrenOf(&statusParent, IWin::Type::DCCChat);
+    bool requestHandled{ false };
+    for (auto* subwin : dccChatList) {
+        auto* dccwin = dynamic_cast<IWinDCCChat*>(subwin);
+        if (!dccwin) {
+            qWarning() << "Unable to cast a window marked as type DCCChat!?";
+            continue;
+        }
+
+        if (QString::fromStdString(sender.toString()) == dccwin->getButtonText() && dccwin->isReverseInitiatePending()) {
+            requestHandled = true;
+            dccwin->initiateReversed(dcc);
+        }
+    }
+
+    if (!requestHandled) {
+        dccQueryDlg.addQuery(sender, type, dcc);
+        dccQueryDlg.show();
+    }
 }
 
 void IdealIRC::on_actionConnect_triggered()

IdealIRC/IdealIRC.h

@@ -35,7 +35,7 @@ public:
 
 private slots:
     void onStatusWindowCreated(IWinStatus* window);
-    void onDCCRequested(const std::shared_ptr<DCC>& dcc, const IRCPrefix& sender, const QString& type, const QString& message);
+    void onDCCRequested(const IWinStatus& statusParent, const std::shared_ptr<DCC>& dcc, const IRCPrefix& sender, const QString& type, const QString& message);
     void on_actionConnect_triggered();
     void on_actionOptions_triggered();
     void on_actionAbout_IdealIRC_triggered();

IdealIRC/MdiManager.cpp

@@ -109,17 +109,26 @@ IWin* MdiManager::createSubwindow(IWin* parent, const QString& buttonText, IWin:
     return createSubwindowCommons(parent, basePtr, buttonText, iconPath, activate, buttonHighlight);
 }
 
-IWin* MdiManager::createDCCSubwindow(IWin* parent, IWin::Type windowType, std::shared_ptr<DCC> dcc, const IRCPrefix& target)
+IWin* MdiManager::createDCCSubwindow(IWin* parent, IWin::Type windowType, const std::shared_ptr<DCC>& dcc, const IRCPrefix& target)
 {
     IWin* basePtr{ nullptr };
+    IWinStatus* statusParent{ nullptr };
     QString iconPath;
     auto targetNickname{ QString::fromStdString(target.toString()) };
 
+    if (parent && parent->getType() == IWin::Type::Status)
+        statusParent = dynamic_cast<IWinStatus*>(parent);
+
     switch (windowType) {
-        case IWin::Type::DCCChat:
-            basePtr = new IWinDCCChat(std::move(dcc), targetNickname);
+        case IWin::Type::DCCChat: {
+            auto* winPtr = new IWinDCCChat(statusParent, dcc, targetNickname);
+            if (dcc->isReversed())
+                winPtr->markReverseInitiatePending();
+
+            basePtr = winPtr;
             iconPath = ":/Icons/private.png";
             break;
+        }
 
         default:
             break;

IdealIRC/MdiManager.h

@@ -34,7 +34,7 @@ public:
     static MdiManager& instance();
 
     IWin* createSubwindow(IWin* parent, const QString& buttonText, IWin::Type windowType, bool activate = true, Highlight buttonHighlight = HL_None);
-    IWin* createDCCSubwindow(IWin* parent, IWin::Type windowType, std::shared_ptr<DCC> dcc, const IRCPrefix& target);
+    IWin* createDCCSubwindow(IWin* parent, IWin::Type windowType, const std::shared_ptr<DCC>& dcc, const IRCPrefix& target);
     IWin* currentWindow() const;
     IWinStatus* currentStatus() const;