feat(scanner): add subnet ping scan and TCP port scans for alive hosts

Introduce subnet scanning using CIDR prefix notation and perform TCP port scans
on each discovered alive host. The change replaces the full port scan with a
two-step process: first pinging the subnet to find active devices, then scanning
their open TCP ports.

.gitignore

@@ -2,3 +2,4 @@
 .xmake
 build
 compile_commands.json
+ignore

src/cli/portscan_cli.cpp

@@ -0,0 +1,28 @@
+#include "portscan_cli.hpp"
+#include <boost/program_options/value_semantic.hpp>
+#include <cassert>
+
+PortScanCli::PortScanCli()
+    : CliBase("Port Scanner Options")
+{
+}
+
+void PortScanCli::setupOptions()
+{
+    // clang-format off
+    desc_.add_options()
+        ("help,h",      "Show help")
+        ("ip,H",        withDefault(ip_, "<IPv4>"),      "Base IPv4 inside your LAN (e.g. 10.0.1.42)")
+        ("prefix,p",    withDefault(prefix_, "<0..32>"), "CIDR prefix length (e.g. 24)");
+    // clang-format on
+}
+
+int PortScanCli::getPrefix() const
+{
+    return vm_.at("prefix").as<int>();
+}
+
+std::string PortScanCli::getBaseIp() const
+{
+    return vm_.at("ip").as<std::string>();
+}

src/cli/portscan_cli.hpp

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "cli_base.hpp"
+#include "option_utils.hpp"
+#include <string>
+
+class PortScanCli : public CliBase, protected OptionUtils
+{
+  public:
+    PortScanCli();
+
+    int getPrefix() const;
+    std::string getBaseIp() const;
+
+  protected:
+    void setupOptions() override;
+
+  private:
+    int prefix_{24};
+    std::string ip_{"10.0.1.0"};
+};

src/common/aliases.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <boost/asio.hpp>
+#include <boost/asio/ip/address.hpp>
+#include <boost/program_options.hpp>
+#include <boost/system/error_code.hpp>
+
+// --- Error handling ---
+using ErrorCode = boost::system::error_code;
+
+// --- Asio types ---
+using IoContext = boost::asio::io_context;
+using SteadyTimer = boost::asio::steady_timer;
+
+// --- Ip types ---
+using IpAddress = boost::asio::ip::address;
+
+// --- TCP types ---
+using TcpSocket = boost::asio::ip::tcp::socket;
+using TcpAcceptor = boost::asio::ip::tcp::acceptor;
+using TcpEndpoint = boost::asio::ip::tcp::endpoint;
+
+// --- UDP types ---
+using UdpSocket = boost::asio::ip::udp::socket;
+using UdpEndpoint = boost::asio::ip::udp::endpoint;
+
+// --- Program options ---
+using OptionsDescription = boost::program_options::options_description;
+using VariablesMap = boost::program_options::variables_map;

src/common/cli_base.cpp

@@ -0,0 +1,34 @@
+#include "cli_base.hpp"
+#include <boost/program_options/parsers.hpp>
+#include <iostream>
+
+CliBase::CliBase(const std::string &title)
+    : desc_(title)
+    , help_(false)
+{
+}
+
+void CliBase::parse(int argc, char *argv[])
+{
+    using namespace boost::program_options;
+
+    setupOptions(); // must be first
+
+    parsed_options parsed = parse_command_line(argc, argv, desc_);
+    store(parsed, vm_);
+    notify(vm_);
+
+    if (vm_.count("help")) {
+        help_ = true;
+    }
+}
+
+bool CliBase::isHelp() const
+{
+    return help_;
+}
+
+void CliBase::printHelp() const
+{
+    std::cout << desc_ << "\n";
+}

src/common/cli_base.hpp

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <boost/program_options/options_description.hpp>
+#include <boost/program_options/variables_map.hpp>
+#include <string>
+
+class CliBase
+{
+  public:
+    CliBase(const std::string &title);
+
+    virtual ~CliBase() = default;
+
+    // parse argc/argv
+    void parse(int argc, char *argv[]);
+
+    bool isHelp() const;
+    void printHelp() const;
+
+  protected:
+    // children add their specific options here
+    virtual void setupOptions() = 0;
+
+    boost::program_options::options_description desc_;
+    boost::program_options::variables_map vm_;
+    bool help_;
+};

src/common/logger.cpp

@@ -1,5 +1,4 @@
 #include "logger.hpp"
-
 #include <boost/date_time/posix_time/posix_time_io.hpp>
 
 void Logger::init(bool toConsole, const std::string_view filePath)

src/common/option_utils.hpp

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <boost/program_options.hpp>
+
+class OptionUtils
+{
+  public:
+    template <typename T>
+    using OptionValue = boost::program_options::typed_value<T> *;
+
+    template <typename T>
+    static OptionValue<T>
+    withDefault(const T &value, const char *name = nullptr);
+
+  protected:
+    OptionUtils() = default;
+    ~OptionUtils() = default;
+};
+
+#include "option_utils.tpp"

src/common/option_utils.tpp

@@ -0,0 +1,13 @@
+#pragma once
+#include "option_utils.hpp"
+
+template <typename T>
+OptionUtils::OptionValue<T>
+OptionUtils::withDefault(const T &value, const char *name)
+{
+    auto v = boost::program_options::value<T>()->default_value(value);
+    if (name) {
+        v->value_name(name); // Optional
+    }
+    return v;
+}

src/common/types/app/byte_buffer.hpp

@@ -1,7 +0,0 @@
-#pragma once
-
-#include <cstdint>
-#include <vector>
-
-// Alias for raw byte buffer
-using ByteBuffer = std::vector<std::uint8_t>;

src/common/types/app/chunk_index.hpp

@@ -1,6 +0,0 @@
-#pragma once
-
-#include <cstdint>
-
-// Sequential file chunk index
-using ChunkIndex = std::uint32_t;

src/common/types/app/file_size.hpp

@@ -1,6 +0,0 @@
-#pragma once
-
-#include <cstdint>
-
-// File total size in bytes
-using FileSize = std::uint64_t;

src/common/types/app/frame_length.hpp

@@ -1,6 +0,0 @@
-#pragma once
-
-#include <cstdint>
-
-// Wire length prefix type for a single framed message (big-endian on the wire)
-using FrameLength = std::uint32_t;

src/common/types/app/id.hpp

@@ -1,6 +0,0 @@
-#pragma once
-
-#include <cstdint>
-
-// Client, group, or message ID
-using Id = std::uint64_t;

src/common/types/deps/boost_asio.hpp

@@ -1,6 +0,0 @@
-#pragma once
-
-#include <boost/asio/io_context.hpp>
-
-// IO Context
-using IoContext = boost::asio::io_context;

src/common/types/deps/boost_asio_ip_tcp.hpp

@@ -1,9 +0,0 @@
-#pragma once
-
-#include <boost/asio/ip/tcp.hpp>
-
-// TCP
-using TcpSocket = boost::asio::ip::tcp::socket;
-using TcpAcceptor = boost::asio::ip::tcp::acceptor;
-using TcpEndpoint = boost::asio::ip::tcp::endpoint;
-using TcpResolver = boost::asio::ip::tcp::resolver;

src/common/types/deps/boost_asio_steady_timer.hpp

@@ -1,6 +0,0 @@
-#pragma once
-
-#include <boost/asio/steady_timer.hpp>
-
-// Timers
-using SteadyTimer = boost::asio::steady_timer;

src/common/types/deps/boost_system_error_code.hpp

@@ -1,6 +0,0 @@
-#pragma once
-
-#include <boost/system/error_code.hpp>
-
-// Error handling
-using ErrorCode = boost::system::error_code;

src/core/local_ping_scanner.cpp

@@ -0,0 +1,103 @@
+#include "local_ping_scanner.hpp"
+#include "logger.hpp"
+#include <Poco/Net/ICMPClient.h>
+#include <boost/asio/ip/address_v4.hpp>
+#include <stdexcept>
+
+LocalPingScanner::LocalPingScanner(
+    const std::string &baseIp, int prefixLen, int timeoutMs
+)
+    : baseIp_(baseIp)
+    , prefixLen_(prefixLen)
+    , timeoutMs_(timeoutMs)
+{
+    if (prefixLen_ < 0 || prefixLen_ > 32) {
+        Logger::error("Invalid prefix length in LocalPingScanner constructor");
+        throw std::runtime_error("Bad prefix length");
+    }
+    if (timeoutMs_ <= 0) {
+        timeoutMs_ = 2000;
+    }
+}
+
+const std::vector<std::string> &LocalPingScanner::alive() const
+{
+    return alive_;
+}
+
+uint32_t LocalPingScanner::ipToU32(const std::string &ip)
+{
+    using namespace boost::asio::ip;
+    return static_cast<uint32_t>(make_address_v4(ip).to_uint());
+}
+
+std::string LocalPingScanner::u32ToIp(uint32_t v)
+{
+    using namespace boost::asio::ip;
+    return address_v4(v).to_string();
+}
+
+bool LocalPingScanner::pingHost(const std::string &ip) const
+{
+    try {
+        return Poco::Net::ICMPClient::pingIPv4(
+                   ip,
+                   /*repeat=*/1,
+                   /*dataSize=*/48,
+                   /*ttl=*/64,
+                   /*timeout=*/timeoutMs_
+               )
+               > 0;
+    } catch (const std::exception &ex) {
+        Logger::error(
+            std::string("Ping failed for host ") + ip + ": " + ex.what()
+        );
+        return false;
+    } catch (...) {
+        Logger::fatal(std::string("Unknown error pinging host ") + ip);
+        return false;
+    }
+}
+
+void LocalPingScanner::runImpl()
+{
+    alive_.clear();
+
+    const uint32_t base = ipToU32(baseIp_);
+    const uint32_t mask =
+        (prefixLen_ == 0) ? 0u : (0xFFFFFFFFu << (32 - prefixLen_));
+    const uint32_t network = base & mask;
+    const uint32_t broadcast = network | (~mask);
+
+    // No hosts when prefix is too tight (e.g., /32).
+    if (broadcast - network <= 2) {
+        return;
+    }
+
+    const std::string selfIp = u32ToIp(base);
+
+    for (uint32_t v = network + 1; v < broadcast; ++v) {
+        const std::string ipStr = u32ToIp(v);
+
+        if (ipStr == selfIp) {
+            continue;
+        }
+
+        if (pingHost(ipStr)) {
+            alive_.push_back(ipStr);
+        }
+    }
+}
+
+void LocalPingScanner::run()
+{
+    try {
+        runImpl();
+    } catch (const std::exception &ex) {
+        Logger::error(
+            std::string("Exception in LocalPingScanner::run: ") + ex.what()
+        );
+    } catch (...) {
+        Logger::fatal("Unknown exception in LocalPingScanner::run");
+    }
+}

src/core/local_ping_scanner.hpp

@@ -0,0 +1,26 @@
+#pragma once
+#include <cstdint>
+#include <string>
+#include <vector>
+
+class LocalPingScanner
+{
+  public:
+    LocalPingScanner(
+        const std::string &baseIp, int prefixLen, int timeoutMs = 2000
+    );
+
+    void run(); // blocking scan over subnet
+    const std::vector<std::string> &alive() const;
+
+  private:
+    static std::string u32ToIp(uint32_t v);
+    static uint32_t ipToU32(const std::string &ip);
+    bool pingHost(const std::string &ip) const;
+    void runImpl();
+
+    std::string baseIp_;
+    int prefixLen_;
+    int timeoutMs_;
+    std::vector<std::string> alive_;
+};

src/core/port_scanner.cpp

@@ -0,0 +1,126 @@
+#include "port_scanner.hpp"
+#include "logger.hpp"
+#include <algorithm>
+
+PortScanner::PortScanner(std::string ip, int timeoutMs)
+    : ip_(std::move(ip))
+    , timeoutMs_(timeoutMs)
+{
+    if (timeoutMs_ <= 0) {
+        timeoutMs_ = 250;
+    }
+}
+
+PortScanner::Probe::Probe(IoContext &io, uint16_t p)
+    : port(p)
+    , socket(io)
+    , timer(io)
+{
+}
+
+const std::vector<uint16_t> &PortScanner::openPorts() const
+{
+    return openPorts_;
+}
+
+void PortScanner::run()
+{
+    openPorts_.clear();
+    nextPort_ = kFirstPort;
+    outstanding_ = 0;
+    active_.clear();
+
+    while (outstanding_ < kMaxConcurrency && nextPort_ <= kLastPort) {
+        startNext();
+    }
+
+    io_.run();
+}
+
+void PortScanner::startNext()
+{
+    if (nextPort_ > kLastPort) {
+        return;
+    }
+
+    const uint16_t port = static_cast<uint16_t>(nextPort_);
+    nextPort_ += 1;
+
+    startProbe(port);
+}
+
+void PortScanner::startProbe(uint16_t port)
+{
+    // Lifetime of Probe is managed in 'active_' until probe finishes.
+    auto prPtr = std::make_unique<Probe>(io_, port);
+    Probe *pr = prPtr.get();
+    active_.push_back(std::move(prPtr));
+
+    outstanding_ += 1;
+
+    {
+        using namespace boost::asio::ip;
+
+        TcpEndpoint ep(make_address_v4(ip_), port);
+
+        pr->timer.expires_after(std::chrono::milliseconds(timeoutMs_));
+
+        auto onTimer = [pr](const ErrorCode &ec) {
+            // Cancel socket on timeout; completion will run onConnect with
+            // ec=operation_aborted.
+            if (!ec) {
+                pr->socket.cancel();
+            }
+        };
+
+        auto onAsyncConnect = [this, pr](const ErrorCode &ec) {
+            onConnect(pr, ec);
+        };
+
+        pr->timer.async_wait(onTimer);
+        pr->socket.async_connect(ep, onAsyncConnect);
+    }
+}
+
+void PortScanner::onConnect(Probe *pr, const ErrorCode &ec)
+{
+    pr->timer.cancel();
+
+    // Open if connect succeeded; REFUSED means closed but host is alive.
+    if (!ec) {
+        openPorts_.push_back(pr->port);
+        Logger::info(std::string("Open port: ") + std::to_string(pr->port));
+    }
+
+    ErrorCode ignored;
+    pr->socket.close(ignored);
+
+    finishProbe(pr);
+}
+
+void PortScanner::finishProbe(Probe *pr)
+{
+    if (outstanding_ > 0) {
+        outstanding_ -= 1;
+    }
+
+    // Remove 'pr' from active_ (active_ size <= kMaxConcurrency, linear
+    // erase is fine).
+    auto it = std::find_if(
+        active_.begin(), active_.end(), [pr](const std::unique_ptr<Probe> &u) {
+            return u.get() == pr;
+        }
+    );
+    if (it != active_.end()) {
+        active_.erase(it);
+    }
+
+    if (nextPort_ <= kLastPort) {
+        startNext();
+    }
+
+    if (outstanding_ == 0 && nextPort_ > kLastPort) {
+        io_.stop();
+        return;
+    }
+}

src/core/port_scanner.hpp

@@ -0,0 +1,43 @@
+#pragma once
+#include "aliases.hpp"
+#include <cstdint>
+#include <memory>
+#include <string>
+#include <vector>
+
+class PortScanner
+{
+  public:
+    explicit PortScanner(std::string ip, int timeoutMs = 250);
+
+    void run(); // blocking scan
+    const std::vector<uint16_t> &openPorts() const;
+
+  private:
+    struct Probe {
+        uint16_t port{0};
+        TcpSocket socket;
+        SteadyTimer timer;
+
+        Probe(IoContext &io, uint16_t p);
+    };
+
+    void startNext();
+    void startProbe(uint16_t port);
+    void onConnect(Probe *pr, const ErrorCode &ec);
+    void finishProbe(Probe *pr);
+
+    // Fixed settings
+    static constexpr uint16_t kFirstPort = 1;
+    static constexpr uint16_t kLastPort = 65535;
+    static constexpr std::size_t kMaxConcurrency = 256;
+
+    // State
+    std::string ip_;
+    IoContext io_;
+    std::vector<uint16_t> openPorts_;
+    std::vector<std::unique_ptr<Probe>> active_; // <= kMaxConcurrency
+    uint32_t nextPort_{kFirstPort};
+    std::size_t outstanding_{0};
+    int timeoutMs_;
+};

src/main.cpp

@@ -1,16 +1,61 @@
-#include <boost/asio.hpp>
+#include "local_ping_scanner.hpp"
-#include <iostream>
+#include "logger.hpp"
+#include "port_scanner.hpp"
+#include "portscan_cli.hpp"
+#include <string>
 
-int main()
+int main(int argc, char **argv)
 {
-    std::cout << "Hello, Boost + C++23 + xmake!\n";
+    Logger::init(true);
 
-    boost::asio::io_context io;
+    PortScanCli cli;
-    boost::asio::steady_timer timer(io, std::chrono::seconds(1));
+    cli.parse(argc, argv);
-    timer.async_wait([](const boost::system::error_code &) {
+    if (cli.isHelp()) {
-        std::cout << "Timer fired after 1 second!\n";
+        cli.printHelp();
-    });
+        return 0;
+    }
+
+    const std::string baseIp = cli.getBaseIp();
+
+    const int prefix = cli.getPrefix();
+    if (prefix < 0 || prefix > 32) {
+        Logger::fatal("Prefix must be in range 0..32\n");
+        return 2;
+    }
+
+    LocalPingScanner scanner(baseIp, prefix);
+    Logger::info(std::format("Scanning subnet: {}/{}", baseIp, prefix));
+
+    scanner.run();
+
+    const auto &alive = scanner.alive();
+    if (alive.empty()) {
+        Logger::info("No alive hosts found.\n");
+        return 0;
+    }
+
+    std::cout << "Alive hosts:\n";
+    for (const auto &ip : alive) {
+        std::cout << "  " << ip << "\n";
+    }
+
+    // For each alive host, run full TCP port scan
+    for (const auto &ip : alive) {
+        std::cout << "Scanning ports on " << ip << " ...\n";
+
+        PortScanner ps(ip);
+        ps.run();
+
+        const auto &open = ps.openPorts();
+        if (open.empty()) {
+            std::cout << "  No open TCP ports found on " << ip << "\n";
+        } else {
+            std::cout << "  Open ports on " << ip << ":\n";
+            for (uint16_t port : open) {
+                std::cout << "    " << port << "\n";
+            }
+        }
+    }
 
-    io.run();
     return 0;
 }

xmake.lua

@@ -2,16 +2,26 @@ set_languages "c++23"
 
 add_rules("plugin.compile_commands.autoupdate", { outputdir = "." })
 
-add_requires("boost", {
+add_requires("cmake::Boost", {
-    system = true, -- sudo pacman -S boost
+    alias = "boost",
-
+    system = true,
     configs = {
-        all = false,
+        components = { "program_options", "log" },
-        system = true, -- asio
     },
 })
 
-target "app"
+add_requires("cmake::Poco", {
-set_kind "binary"
+    alias = "poco",
-add_files "src/*.cpp"
+    system = true,
-add_links "boost_system"
+    configs = {
+        components = { "Net", "Foundation" },
+    },
+})
+
+target "port_scanner"
+do
+    set_kind "binary"
+    add_files("src/main.cpp", "src/cli/*.cpp", "src/common/*.cpp", "src/core/*.cpp")
+    add_includedirs("src", "src/cli", "src/common", "src/core", { public = true })
+    add_packages("boost", "poco")
+end