feat(packet_sniffer): replace port scanner with packet sniffer

Captures network packets, extracts source/destination IPs, protocol type, and
ports. Masks IPs when enabled and logs details with protocol information.

src/cli/packet_sniffer_cli.cpp

@@ -0,0 +1,30 @@
+#include "packet_sniffer_cli.hpp"
+#include <boost/program_options/value_semantic.hpp>
+
+PacketSnifferCli::PacketSnifferCli()
+    : CliBase("Packet Sniffer Options")
+    , ip_("")
+{
+}
+
+void PacketSnifferCli::setupOptions()
+{
+    // clang-format off
+    desc_.add_options()
+        ("help,h",  "Show help")
+        ("ip,H",    withDefault(ip_, "<IP>"), "Local IPv4 to sniff (e.g. 192.168.1.42)")
+        ("mask,m",  boost::program_options::value<bool>()->default_value(false)->implicit_value(true),
+                    "Mask IP addresses in output (demo)");
+    // clang-format on
+}
+
+std::string PacketSnifferCli::getIp() const
+{
+    return vm_.at("ip").as<std::string>();
+}
+
+bool PacketSnifferCli::isMaskEnabled() const
+{
+    const auto it = vm_.find("mask");
+    return (it != vm_.end()) ? it->second.as<bool>() : false;
+}

src/cli/packet_sniffer_cli.hpp

@@ -1,15 +1,15 @@
 #pragma once
-
 #include "cli_base.hpp"
 #include "option_utils.hpp"
 #include <string>
 
-class PortScanCli : public CliBase, protected OptionUtils
+class PacketSnifferCli : public CliBase, protected OptionUtils
 {
   public:
-    PortScanCli();
+    PacketSnifferCli();
 
     std::string getIp() const;
+    bool isMaskEnabled() const;
 
   protected:
     void setupOptions() override;

src/cli/portscan_cli.cpp

@@ -1,26 +0,0 @@
-#include "portscan_cli.hpp"
-#include <boost/program_options/value_semantic.hpp>
-#include <cassert>
-
-PortScanCli::PortScanCli()
-    : CliBase("Port Scanner Options")
-    , ip_("")
-{
-}
-
-void PortScanCli::setupOptions()
-{
-    // clang-format off
-    desc_.add_options()
-        ("help,h",     "Show help")
-        ("ip,H",       withDefault(ip_, "<IP>"),    "Local IPv4 to scan");
-    // clang-format on
-}
-
-std::string PortScanCli::getIp() const
-{
-    if (vm_["ip"].empty() == 0) {
-        return "127.0.0.1";
-    }
-    return vm_.at("ip").as<std::string>();
-}

src/core/port_scanner.cpp

@@ -1,142 +0,0 @@
-#include "port_scanner.hpp"
-#include "logger.hpp"
-#include <boost/asio.hpp>
-#include <string>
-
-PortScanner::PortScanner(
-    const std::string &ip, const std::vector<uint16_t> &ports
-)
-    : ports_(ports)
-{
-    ErrorCode ec;
-    addr_ = boost::asio::ip::make_address(ip, ec);
-    ip_ok_ = !ec;
-
-    if (!ip_ok_) {
-        Logger::error(std::string("PortScanner: invalid IP: ") + ip);
-    } else {
-        Logger::debug(std::string("PortScanner: using IP: ") + ip);
-    }
-}
-
-void PortScanner::setTimeoutMs(int ms)
-{
-    if (ms > 0) {
-        timeout_ms_ = ms;
-        Logger::debug(
-            std::string("PortScanner: timeout set to ")
-            + std::to_string(timeout_ms_) + " ms"
-        );
-    }
-}
-
-void PortScanner::run()
-{
-    if (!ip_ok_) {
-        Logger::error("PortScanner::run - aborting: ip not ok");
-        return;
-    }
-    for (uint16_t p : ports_) {
-        if (probe(p)) {
-            Logger::info(std::to_string(p));
-        }
-    }
-}
-
-bool PortScanner::probe(uint16_t port)
-{
-    TcpSocket s(io_);
-    SteadyTimer t(io_);
-    auto ep = endpoint(port);
-
-    Logger::debug(
-        std::string("PortScanner::probe - probing port ") + std::to_string(port)
-    );
-
-    armTimer(t, s);
-    armConnect(s, ep);
-    runUntilDone();
-    cancelTimer(t);
-    drainLeftovers();
-    close(s);
-
-    if (ok_) {
-        Logger::debug(std::string("Port ") + std::to_string(port) + " is OPEN");
-    } else {
-        Logger::debug(
-            std::string("Port ") + std::to_string(port) + " is CLOSED/FILTERED"
-        );
-    }
-
-    return ok_;
-}
-
-TcpEndpoint PortScanner::endpoint(uint16_t port) const
-{
-    return TcpEndpoint(addr_, port);
-}
-
-void PortScanner::armTimer(SteadyTimer &t, TcpSocket &s)
-{
-    t.expires_after(std::chrono::milliseconds(timeout_ms_));
-
-    auto onTimeout = [&s](const ErrorCode &ec) {
-        if (!ec) {
-            Logger::debug("Timer expired -> cancelling socket");
-            s.cancel();
-        }
-    };
-
-    t.async_wait(onTimeout);
-}
-
-void PortScanner::armConnect(TcpSocket &s, const TcpEndpoint &ep)
-{
-    ok_ = false;
-    done_ = false;
-
-    auto onConnect = [this](const ErrorCode &ec) {
-        if (!ec) {
-            ok_ = true;
-            Logger::debug("async_connect succeeded");
-        } else {
-            ok_ = false;
-            Logger::debug(std::string("async_connect failed: ") + ec.message());
-        }
-        done_ = true;
-    };
-
-    s.async_connect(ep, onConnect);
-}
-
-void PortScanner::runUntilDone()
-{
-    io_.restart();
-    while (!done_ && io_.run_one()) {
-    }
-}
-
-void PortScanner::cancelTimer(SteadyTimer &t)
-{
-    ErrorCode ec;
-    t.cancel();
-    if (ec) {
-        Logger::warn(std::string("cancelTimer: ") + ec.message());
-    }
-}
-
-void PortScanner::drainLeftovers()
-{
-    io_.restart();
-    while (io_.run_one()) {
-        continue;
-    }
-}
-
-void PortScanner::close(TcpSocket &s)
-{
-    ErrorCode ig;
-    if (s.close(ig)) {
-        Logger::warn(std::string("close socket failed: ") + ig.message());
-    }
-}

src/core/port_scanner.hpp

@@ -1,37 +0,0 @@
-#pragma once
-#include "aliases.hpp"
-#include <boost/asio.hpp>
-#include <cstdint>
-#include <string>
-#include <vector>
-
-class PortScanner
-{
-  public:
-    PortScanner(const std::string &ip, const std::vector<uint16_t> &ports);
-
-    void setTimeoutMs(int ms);
-
-    void run();
-
-  private:
-    bool probe(uint16_t port);
-    TcpEndpoint endpoint(uint16_t port) const;
-
-    void armTimer(SteadyTimer &t, TcpSocket &s);
-    void armConnect(TcpSocket &s, const TcpEndpoint &ep);
-    void runUntilDone();
-    void cancelTimer(SteadyTimer &t);
-    void drainLeftovers();
-    void close(TcpSocket &s);
-
-  private:
-    IoContext io_;
-    IpAddress addr_;
-    std::vector<uint16_t> ports_;
-
-    int timeout_ms_{300};
-    bool ip_ok_{false};
-    bool ok_{false};
-    bool done_{false};
-};

src/core/sniffer.cpp

@@ -0,0 +1,135 @@
+#include "sniffer.hpp"
+#include "logger.hpp"
+#include <tins/tins.h>
+
+Sniffer::Sniffer(std::string localIp, bool maskIp)
+    : ip_(std::move(localIp))
+    , mask_(maskIp)
+{
+}
+
+int Sniffer::run()
+{
+    const auto ifaceName = resolveIfaceNameByIp(ip_);
+
+    Tins::SnifferConfiguration cfg;
+    cfg.set_promisc_mode(true);
+    cfg.set_immediate_mode(true);
+
+    Tins::Sniffer sniffer(ifaceName, cfg);
+
+    auto running = [this] { return !stop_.load(std::memory_order_relaxed); };
+
+    auto handler = [&](Tins::PDU &pdu) -> bool {
+        if (!running())
+            return false;
+
+        std::string src, dst;
+        const char *type = "OTHER";
+        uint16_t sport = 0, dport = 0;
+
+        if (auto *arp = pdu.find_pdu<Tins::ARP>()) {
+            src = arp->sender_ip_addr().to_string();
+            dst = arp->target_ip_addr().to_string();
+            type = "ARP";
+        } else if (auto *ip4 = pdu.find_pdu<Tins::IP>()) {
+            src = ip4->src_addr().to_string();
+            dst = ip4->dst_addr().to_string();
+
+            if (auto *tcp = pdu.find_pdu<Tins::TCP>()) {
+                type = "TCP";
+                sport = tcp->sport();
+                dport = tcp->dport();
+            } else if (auto *udp = pdu.find_pdu<Tins::UDP>()) {
+                type = "UDP";
+                sport = udp->sport();
+                dport = udp->dport();
+            } else if (pdu.find_pdu<Tins::ICMP>()) {
+                type = "ICMP";
+            } else {
+                type = "IP";
+            }
+        } else if (auto *ip6 = pdu.find_pdu<Tins::IPv6>()) {
+            src = ip6->src_addr().to_string();
+            dst = ip6->dst_addr().to_string();
+
+            if (auto *tcp = pdu.find_pdu<Tins::TCP>()) {
+                type = "TCP";
+                sport = tcp->sport();
+                dport = tcp->dport();
+            } else if (auto *udp = pdu.find_pdu<Tins::UDP>()) {
+                type = "UDP";
+                sport = udp->sport();
+                dport = udp->dport();
+            } else if (pdu.find_pdu<Tins::ICMPv6>()) {
+                type = "ICMPv6";
+            } else {
+                type = "IPv6";
+            }
+        } else {
+            Logger::info("(unknown src) -> (unknown dst) [OTHER]");
+            return running();
+        }
+
+        if (mask_) {
+            src = hideHalf(src);
+            dst = hideHalf(dst);
+        }
+
+        printLine(src, dst, type, sport, dport);
+        return running();
+    };
+
+    sniffer.sniff_loop(handler);
+    return 0;
+}
+
+void Sniffer::stop()
+{
+    stop_.store(true, std::memory_order_relaxed);
+}
+
+std::string Sniffer::hideHalf(const std::string &s) const
+{
+    if (s.empty()) {
+        return s;
+    }
+
+    const size_t n = s.size();
+    const size_t hide = n / 2;
+    const size_t keep = n - hide;
+    std::string out = s.substr(0, keep);
+    out.append(hide, '*');
+
+    return out;
+}
+
+std::string Sniffer::resolveIfaceNameByIp(const std::string &ip)
+{
+    const Tins::IPv4Address want(ip);
+    for (const auto &iface : Tins::NetworkInterface::all()) {
+        const auto info = iface.addresses(); // .ip_addr/.netmask/...
+        if (info.ip_addr == want) {
+            return iface.name();
+        }
+    }
+    throw std::runtime_error("Interface with IP " + ip + " not found");
+}
+
+void Sniffer::printLine(
+    const std::string &src,
+    const std::string &dst,
+    const char *type,
+    uint16_t sport,
+    uint16_t dport
+)
+{
+    if (sport || dport) {
+        Logger::info(
+            std::string(src) + ":" + std::to_string(sport) + " -> " + dst + ":"
+            + std::to_string(dport) + " [" + type + "]"
+        );
+    } else {
+        Logger::info(std::string(src) + " -> " + dst + " [" + type + "]");
+    }
+}

src/core/sniffer.hpp

@@ -0,0 +1,32 @@
+#pragma once
+#include <atomic>
+#include <cstdint>
+#include <string>
+
+class Sniffer
+{
+  public:
+    explicit Sniffer(std::string localIp, bool maskIp = false);
+
+    Sniffer(const Sniffer &) = delete;
+    Sniffer &operator=(const Sniffer &) = delete;
+
+    std::string hideHalf(const std::string &s) const;
+
+    int run();
+    void stop();
+
+  private:
+    static std::string resolveIfaceNameByIp(const std::string &ip);
+    static void printLine(
+        const std::string &src,
+        const std::string &dst,
+        const char *type,
+        uint16_t sport = 0,
+        uint16_t dport = 0
+    );
+
+    std::string ip_;
+    std::atomic<bool> stop_{false};
+    bool mask_{false};
+};

src/main.cpp

@@ -1,38 +1,26 @@
-#include "cli_base.hpp"
 #include "logger.hpp"
-#include "port_scanner.hpp"
-#include "portscan_cli.hpp"
+#include "packet_sniffer_cli.hpp"
+#include "sniffer.hpp"
+#include <exception>
 
-#include <string>
-#include <vector>
-
-static std::vector<uint16_t> allPorts()
-{
-    std::vector<uint16_t> v;
-    v.reserve(65535);
-    for (uint32_t p = 1; p <= 65535; ++p) {
-        v.push_back(static_cast<uint16_t>(p));
-    }
-    return v;
-}
-
-int main(int argc, char **argv)
+int main(int argc, char *argv[])
 {
     Logger::init(true);
+    try {
+        PacketSnifferCli cli;
+        cli.parse(argc, argv);
+        if (cli.isHelp()) {
+            cli.printHelp();
+            return 0;
+        }
 
-    PortScanCli cli;
-    cli.parse(argc, argv);
-    if (cli.isHelp()) {
-        cli.printHelp();
-        return 0;
+        Sniffer sniffer(cli.getIp(), cli.isMaskEnabled());
+        return sniffer.run();
+    } catch (const std::exception &ex) {
+        Logger::fatal(ex.what());
+        return 1;
+    } catch (...) {
+        Logger::fatal("unknown error");
+        return 1;
     }
-
-    const std::string ip = cli.getIp();
-    auto ports = allPorts();
-
-    Logger::info("Starting full port scan (1..65535)...");
-    PortScanner scanner(ip, ports);
-    scanner.run();
-    Logger::info("Scan completed.");
-    return 0;
 }

xmake.lua

@@ -10,10 +10,12 @@ add_requires("cmake::Boost", {
     },
 })
 
-target "port_scanner"
+add_requires("cmake::libtins", { alias = "libtins", system = true })
+
+target "packet_sniffer"
 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"
+    add_packages("boost", "libtins")
 end