nosni/common.cpp

#include <stdio.h>
#include <string>
#include <string_view>
#include <unordered_map>
#include <optional>
#include <curlpp/cURLpp.hpp>
#include <curlpp/Easy.hpp>
#include <curlpp/Infos.hpp>
#include <curlpp/Options.hpp>


static
std::unordered_map<std::string, bool> cache;



static
std::optional<bool> cached_is_domain_blocked(const char *hostname) {
    auto fres = cache.find(hostname);
    if (fres != cache.end()) {
        return fres->second;
    }
    return {};
}

extern "C"
bool is_domain_blocked(const char *hostname) {
    bool fres;

    // Check cache first
    {
        auto fres = cached_is_domain_blocked(hostname);
        if (fres.has_value()) {
            return fres.value();
        }
    }

    // Use curlpp to check for HTTP != 200
    try {
        // Send request
		curlpp::Cleanup cleanup;
		curlpp::Easy req;
		req.setOpt<curlpp::options::Url>(std::string("http://")+hostname);
        req.setOpt<curlpp::options::NoBody>(true);
        req.setOpt<curlpp::options::Timeout>(6);
		req.perform();

        // Get status code
        auto status = curlpp::infos::ResponseCode::get(req);

        // Check result
        fres = status == 403;
	} catch (...) {
		fres = true;
	}

	// Store result in cache
	cache[hostname] = fres;

    // Debug result
    printf("Domain %s is%s\n", hostname, fres?" probably blocked":"n't blocked");

    // Return result
    return fres;
}