在sniffer.h库中获取VS C2664

Question

我正在开发一个数据包捕获程序。我从http http://libtins.github.io/examples/http-requests/上的一个libtins示例开始。

但VS提示a

C2664错误运算符'bool C2664 main:operator ()(Tins::Packet &) const'：无法将参数1从'Tins::PDU‘转换为'Tins::Packet &’packetSniff path- to -tins\sniffer.h 681

在sniffer.h的以下部分

try {
            // If the functor returns false, we're done
            #if TINS_IS_CXX11 && !defined(_MSC_VER)
            if (!Tins::Internals::invoke_loop_cb(function, *it)) {
                return;
            }
            //here
            #else
            if (!function(*it->pdu())) {
                return;
            }
            #endif
        }

我已经从首页http://libtins.github.io/构建并运行了这个示例

但是下面的代码会生成C2664

#define WIN32
#define TINS_STATIC
#define NOMINMAX
#pragma warning(disable : 4996)
#include <string>
#include <iostream>
#include <stdexcept>
#include <boost/regex.hpp>
#include <tins/tcp_ip/stream_follower.h>
#include <tins/sniffer.h>
#include <tins/tins.h>
#include "color.h"
#include <vector>
#include <sstream>

using std::string;
using std::cout;
using std::cerr;
using std::endl;
using std::exception;
using std::vector;
using std::wcout;
using std::stringstream;

using boost::regex;
using boost::match_results;

using Tins::Packet;
using Tins::Sniffer;
using Tins::SnifferConfiguration;
using Tins::TCPIP::Stream;
using Tins::TCPIP::StreamFollower;
using Tins::NetworkInterface;
using termcolor::on_red;
using termcolor::on_green;
using termcolor::reset;

// This example captures and follows TCP streams seen on port 80. It will
// wait until both the client and server send data and then apply a regex
// to both payloads, extrating some information and printing it.

// Don't buffer more than 3kb of data in either request/response
const size_t MAX_PAYLOAD = 3 * 1024;
// The regex to be applied on the request. This will extract the HTTP
// method being used, the request's path and the Host header value.
regex request_regex("([\\w]+) ([^ ]+).+\r\nHost: ([\\d\\w\\.-]+)\r\n");
// The regex to be applied on the response. This finds the response code.
regex response_regex("HTTP/[^ ]+ ([\\d]+)");

void on_server_data(Stream& stream) {
    match_results<Stream::payload_type::const_iterator> client_match;
    match_results<Stream::payload_type::const_iterator> server_match;
    const Stream::payload_type& client_payload = stream.client_payload();
    const Stream::payload_type& server_payload = stream.server_payload();
    // Run the regexes on client/server payloads
    bool valid = regex_search(server_payload.begin(), server_payload.end(),
        server_match, response_regex) &&
        regex_search(client_payload.begin(), client_payload.end(),
            client_match, request_regex);

    stringstream ss;
    for (char c : server_payload) {
        ss << c;
    }

    cout << on_green << "Server raw payload " <<
        ss.str() << reset << endl;

    // If we matched both the client and the server regexes
    if (valid) {
        // Extract all fields
        string method = string(client_match[1].first, client_match[1].second);
        string url = string(client_match[2].first, client_match[2].second);
        string host = string(client_match[3].first, client_match[3].second);
        string response_code = string(server_match[1].first, server_match[1].second);
        // Now print them
        cout << method << " http://" << host << url << " -> " << response_code << endl;

        // Once we've seen the first request on this stream, ignore it
        stream.ignore_client_data();
        stream.ignore_server_data();
    }

    // Just in case the server returns invalid data, stop at 3kb
    if (stream.server_payload().size() > MAX_PAYLOAD) {
        stream.ignore_server_data();
    }
}

void on_client_data(Stream& stream) {
    // Don't hold more than 3kb of data from the client's flow
    if (stream.client_payload().size() > MAX_PAYLOAD) {
        stream.ignore_client_data();
    }
}

void on_new_connection(Stream& stream) {
    stream.client_data_callback(&on_client_data);
    stream.server_data_callback(&on_server_data);
    // Don't automatically cleanup the stream's data, as we'll manage
    // the buffer ourselves and let it grow until we see a full request
    // and response
    stream.auto_cleanup_payloads(false);
}

int main(int argc, char* argv[]) {
    // First fetch all network interfaces
    vector<NetworkInterface> interfaces = NetworkInterface::all();
    // Now iterate them
    int i = 0;
    for (const NetworkInterface& iface : interfaces) {
        // First print the name (GUID)
        cout << i++ << ' ' << "Interface name: " << termcolor::on_red << iface.name() <<
            termcolor::on_cyan << ' ' << iface.addresses().ip_addr << termcolor::reset;

        // Now print the friendly name, a wstring that will contain something like 
        // "Local Area Connection 2"
        wcout << " (" << iface.friendly_name() << ")" << endl;
    }

    try {
        // Construct the sniffer configuration object
        SnifferConfiguration config;
        // Only capture TCP traffic sent from/to port 80
        config.set_filter("tcp port 5000");
        // Construct the sniffer we'll use
        Sniffer sniffer(interfaces[5].name(), config);

        wcout << on_green <<"Starting capture on interface " << 
            interfaces[5].friendly_name() << reset << endl;

        // Now construct the stream follower
        StreamFollower follower;
        // We just need to specify the callback to be executed when a new 
        // stream is captured. In this stream, you should define which callbacks
        // will be executed whenever new data is sent on that stream 
        // (see on_new_connection)
        follower.new_stream_callback(&on_new_connection);
        // Now start capturing. Every time there's a new packet, call 
        // follower.process_packet
        sniffer.sniff_loop([&](Packet& packet) {
            follower.process_packet(packet);
            return true;
        });
    }
    catch (exception& ex) {
        cerr << "Error: " << ex.what() << endl;
        return 1;
    }
}

Answer 1

根据sniffer.h中的代码，

try {
        // If the functor returns false, we're done
        #if TINS_IS_CXX11 && !defined(_MSC_VER)
        if (!Tins::Internals::invoke_loop_cb(function, *it)) {
            return;
        }
        //here
        #else
        if (!function(*it->pdu())) {
            return;
        }
        #endif
    }

当您使用VS进行编译时，默认情况下定义了宏_MSC_VER，并且您的代码将转到#else分支，因此它将使用PDU对象调用您的回调。为了避免这种情况，我建议您选择不同的编译器，或者查看他们专门针对MSVC的说明。

Answer 2

我最终找到了一个解决方案，将其传递给sniffer.h中的Tins::Packet &。

if (!function((Tins::Packet &)*it->pdu())) {
                return;
            }