mirror of
https://github.com/oxen-io/lokinet.git
synced 2024-10-29 11:05:43 +00:00
328 lines
11 KiB
C++
328 lines
11 KiB
C++
#include <llarp/dns_dotlokilookup.hpp>
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#include <llarp/handlers/tun.hpp>
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#include <llarp/service/context.hpp>
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std::string const default_chars =
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"abcdefghijklmnaoqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
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#include <random>
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std::string
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random_string(size_t len = 15, std::string const &allowed_chars = default_chars)
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{
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std::mt19937_64 gen{std::random_device()()};
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std::uniform_int_distribution< size_t > dist{0, allowed_chars.length() - 1};
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std::string ret;
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std::generate_n(std::back_inserter(ret), len,
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[&] { return allowed_chars[dist(gen)]; });
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return ret;
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}
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struct check_query_simple_request
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{
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const struct sockaddr *from; // source
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dnsd_question_request *request;
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};
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std::unordered_map< std::string, struct dnsd_query_hook_response * >
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loki_tld_lookup_cache;
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void
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llarp_dotlokilookup_checkQuery(void *u, uint64_t orig, uint64_t left)
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{
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if(left)
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return;
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// struct check_query_request *request = static_cast< struct
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// check_query_request * >(u);
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struct check_query_simple_request *qr =
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static_cast< struct check_query_simple_request * >(u);
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dotLokiLookup *dll = (dotLokiLookup *)qr->request->context->user;
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if(!dll)
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{
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llarp::LogError("DNSd dotLokiLookup is not configured");
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write404_dnss_response(qr->from, qr->request);
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delete qr;
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return;
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}
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// we do have result
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// if so send that
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// else
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// if we have a free private ip, send that
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llarp::service::Address addr;
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if(!addr.FromString(qr->request->question.name))
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{
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llarp::LogWarn("Could not base32 decode address: ",
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qr->request->question.name);
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write404_dnss_response(qr->from, qr->request);
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delete qr;
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return;
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}
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// cache hit
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auto itr = loki_tld_lookup_cache.find(addr.ToString());
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if(itr != loki_tld_lookup_cache.end())
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{
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llarp::LogDebug("Found in .loki lookup cache");
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writesend_dnss_response(itr->second->returnThis, qr->from, qr->request);
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delete qr;
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return;
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}
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struct dns_pointer *free_private = dns_iptracker_get_free(dll->ip_tracker);
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if(free_private)
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{
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// in_addr ip_address = ((sockaddr_in *)free_private->hostResult)->sin_addr;
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/*
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llarp::handlers::TunEndpoint *tunEndpoint =
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(llarp::handlers::TunEndpoint *)dll->user;
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if (!tunEndpoint)
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{
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llarp::LogWarn("dotLokiLookup user isnt a tunEndpoint: ", dll->user);
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return;
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}
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bool mapResult = tunEndpoint->MapAddress(addr,
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free_private->hostResult.tohl()); if(!mapResult)
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{
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delete qr;
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return;
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}
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*/
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llarp::service::Context *routerHiddenServiceContext =
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(llarp::service::Context *)dll->user;
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if(!routerHiddenServiceContext)
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{
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llarp::LogWarn("dotLokiLookup user isnt a service::Context: ", dll->user);
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write404_dnss_response(qr->from, qr->request);
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delete qr;
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return;
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}
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bool mapResult = routerHiddenServiceContext->MapAddressAll(
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addr, free_private->hostResult);
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if(!mapResult)
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{
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llarp::LogWarn("dotLokiLookup failed to map address");
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write404_dnss_response(qr->from, qr->request);
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delete qr;
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return;
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}
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// make a dnsd_query_hook_response for the cache
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dnsd_query_hook_response *response = new dnsd_query_hook_response;
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response->dontLookUp = true;
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response->dontSendResponse = false;
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// llarp::Addr test(*free_private->hostResult.getSockAddr());
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// llarp::LogInfo("IP Test: ", test);
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response->returnThis = free_private->hostResult;
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llarp::LogInfo("Saving ", qr->request->question.name);
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loki_tld_lookup_cache[qr->request->question.name] = response;
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// we can't delete response now...
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// FIXME: flush cache to disk
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// on crash we'll need to bring up all the same IPs we assigned before...
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writesend_dnss_response(response->returnThis, qr->from, qr->request);
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delete qr;
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return;
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}
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// else
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llarp::LogInfo("Sending cname to delay");
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writecname_dnss_response(
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random_string(49, "abcdefghijklmnopqrstuvwxyz") + "bob.loki", qr->from,
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qr->request);
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delete qr;
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}
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std::vector< std::string >
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split(std::string str)
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{
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size_t pos = 0;
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std::string token;
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std::string s(str);
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std::vector< std::string > tokens;
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while((pos = s.find(".")) != std::string::npos)
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{
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token = s.substr(0, pos);
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// llarp::LogInfo("token [", token, "]");
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tokens.push_back(token);
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s.erase(0, pos + 1);
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}
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token = s.substr(0, pos);
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tokens.push_back(token);
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// llarp::LogInfo("token [", token, "]");
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return tokens;
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}
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struct reverse_handler_iter_context
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{
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std::string lName;
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const struct sockaddr *from;
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const struct dnsd_question_request *request;
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};
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bool
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ReverseHandlerIter(struct llarp::service::Context::endpoint_iter *endpointCfg)
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{
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reverse_handler_iter_context *context =
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(reverse_handler_iter_context *)endpointCfg->user;
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// llarp::LogInfo("context ", context->request->question.name);
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// llarp::LogInfo("Checking ", lName);
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llarp::handlers::TunEndpoint *tunEndpoint =
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(llarp::handlers::TunEndpoint *)endpointCfg->endpoint;
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if(!tunEndpoint)
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{
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llarp::LogError("No tunnel endpoint found");
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return true; // still continue
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}
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// llarp::LogInfo("for ", tunEndpoint->tunif.ifaddr);
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std::string checkStr(tunEndpoint->tunif.ifaddr);
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std::vector< std::string > tokensSearch = split(context->lName);
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std::vector< std::string > tokensCheck = split(checkStr);
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// well the tunif is just one ip on a network range...
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// support "b._dns-sd._udp.0.0.200.10.in-addr.arpa"
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size_t searchTokens = tokensSearch.size();
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std::string searchIp = tokensSearch[searchTokens - 3] + "."
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+ tokensSearch[searchTokens - 4] + "." + tokensSearch[searchTokens - 5]
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+ "." + tokensSearch[searchTokens - 6];
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std::string checkIp = tokensCheck[0] + "." + tokensCheck[1] + "."
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+ tokensCheck[2] + "." + tokensCheck[3];
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llarp::LogDebug(searchIp, " vs ", checkIp);
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llarp::IPRange range = llarp::iprange_ipv4(
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stoi(tokensCheck[0]), stoi(tokensCheck[1]), stoi(tokensCheck[2]),
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stoi(tokensCheck[3]), tunEndpoint->tunif.netmask); // create range
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// hack atm to work around limitations in ipaddr_ipv4_bits and llarp::IPRange
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llarp::huint32_t searchIPv4_fixed = llarp::ipaddr_ipv4_bits(
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stoi(tokensSearch[searchTokens - 6]),
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stoi(tokensSearch[searchTokens - 5]),
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stoi(tokensSearch[searchTokens - 4]),
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stoi(tokensSearch[searchTokens
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- 3])); // create ip (llarp::Addr is untrustworthy atm)
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llarp::huint32_t searchIPv4_search = llarp::ipaddr_ipv4_bits(
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stoi(tokensSearch[searchTokens - 3]),
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stoi(tokensSearch[searchTokens - 4]),
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stoi(tokensSearch[searchTokens - 5]),
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stoi(tokensSearch[searchTokens
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- 6])); // create ip (llarp::Addr is untrustworthy atm)
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// bool inRange = range.Contains(searchAddr.xtohl());
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bool inRange = range.Contains(searchIPv4_search);
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llarp::Addr searchAddr(searchIp);
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llarp::Addr checkAddr(checkIp);
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llarp::LogDebug(searchAddr, " vs ", range.ToString(), " = ",
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inRange ? "inRange" : "not match");
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if(inRange)
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{
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llarp::service::Address addr =
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tunEndpoint->ObtainAddrForIP(searchIPv4_fixed);
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if(addr.ToString()
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== "yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy.loki")
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{
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write404_dnss_response(context->from,
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(dnsd_question_request *)context->request);
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}
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else
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{
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writesend_dnss_revresponse(addr.ToString(), context->from,
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(dnsd_question_request *)context->request);
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}
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return false;
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}
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return true; // we don't do anything with the result yet
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}
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dnsd_query_hook_response *
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llarp_dotlokilookup_handler(std::string name, const struct sockaddr *from,
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struct dnsd_question_request *const request)
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{
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dnsd_query_hook_response *response = new dnsd_query_hook_response;
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response->dontLookUp = false;
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response->dontSendResponse = false;
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response->returnThis = nullptr;
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llarp::LogDebug("Hooked ", name);
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std::string lName = name;
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std::transform(lName.begin(), lName.end(), lName.begin(), ::tolower);
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// llarp::LogDebug("Transformed ", lName);
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// 253.0.200.10.in-addr.arpa
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if(lName.find(".in-addr.arpa") != std::string::npos)
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{
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// llarp::LogDebug("Checking ", lName);
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dotLokiLookup *dll = (dotLokiLookup *)request->context->user;
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llarp::service::Context *routerHiddenServiceContext =
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(llarp::service::Context *)dll->user;
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if(!routerHiddenServiceContext)
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{
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llarp::LogWarn("dotLokiLookup user isnt a service::Context: ", dll->user);
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return response;
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}
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// llarp::LogDebug("Starting rev iter for ", lName);
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// which range?
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// for each tun interface
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struct reverse_handler_iter_context context;
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context.lName = lName;
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context.from = from;
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context.request = request;
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struct llarp::service::Context::endpoint_iter i;
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i.user = &context;
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i.index = 0;
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i.visit = &ReverseHandlerIter;
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bool res = routerHiddenServiceContext->iterate(i);
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if(!res)
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{
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llarp::LogInfo("Reverse is ours");
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response->dontSendResponse = true; // should have already sent it
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}
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else
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{
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llarp::LogInfo("Reverse is not ours");
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}
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}
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else if((lName.length() > 5 && lName.substr(lName.length() - 5, 5) == ".loki")
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|| (lName.length() > 6
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&& lName.substr(lName.length() - 6, 6) == ".loki."))
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{
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llarp::LogInfo("Detect Loki Lookup for ", lName);
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auto cache_check = loki_tld_lookup_cache.find(lName);
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if(cache_check != loki_tld_lookup_cache.end())
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{
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// was in cache
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llarp::LogInfo("Reused address from LokiLookupCache");
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// FIXME: avoid the response allocation if you could
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delete response;
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return cache_check->second;
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}
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// decode string into HS addr
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llarp::service::Address addr;
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if(!addr.FromString(lName))
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{
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llarp::LogWarn("Could not base32 decode address");
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response->dontLookUp = true; // will return nullptr which will give a 404
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return response;
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}
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llarp::LogDebug("Base32 decoded address ", addr);
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// start path build early (if you're looking it up, you're probably going to
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// use it)
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// main_router_prefetch(ctx, addr);
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// schedule future response
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check_query_simple_request *qr = new check_query_simple_request;
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qr->from = from;
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qr->request = request;
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// nslookup on osx is about 5 sec before a retry, 2s on linux
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llarp_logic_call_later(request->context->client.logic,
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{2000, qr, &llarp_dotlokilookup_checkQuery});
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response->dontSendResponse = true; // will send it shortly
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}
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return response;
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}
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