#include // harmless on other platforms #define __USE_MINGW_ANSI_STDIO 1 #include #include "router.hpp" #include #ifndef _WIN32 #include #include #endif namespace llarp { namespace handlers { TunEndpoint::TunEndpoint(const std::string &nickname, llarp_router *r) : service::Endpoint(nickname, r) , m_UserToNetworkPktQueue(nickname + "_sendq", r->netloop, r->netloop) , m_NetworkToUserPktQueue(nickname + "_recvq", r->netloop, r->netloop) { tunif.user = this; tunif.netmask = DefaultTunNetmask; strncpy(tunif.ifaddr, DefaultTunSrcAddr, sizeof(tunif.ifaddr) - 1); strncpy(tunif.ifname, DefaultTunIfname, sizeof(tunif.ifname) - 1); tunif.tick = nullptr; tunif.before_write = &tunifBeforeWrite; tunif.recvpkt = &tunifRecvPkt; this->dll.ip_tracker = nullptr; this->dll.user = &r->hiddenServiceContext; // this->dll.callback = std::bind(&TunEndpoint::MapAddress, this); } bool TunEndpoint::SetOption(const std::string &k, const std::string &v) { if(k == "exit-node") { llarp::RouterID exitRouter; if(!HexDecode(v.c_str(), exitRouter, exitRouter.size())) { llarp::LogError(Name(), " bad exit router key: ", v); return false; } m_Exit.reset(new llarp::exit::BaseSession( exitRouter, std::bind(&TunEndpoint::QueueInboundPacketForExit, this, std::placeholders::_1), router, m_NumPaths, numHops)); llarp::LogInfo(Name(), " using exit at ", exitRouter); } if(k == "local-dns") { std::string resolverAddr = v; uint16_t dnsport = 53; auto pos = v.find(":"); if(pos != std::string::npos) { resolverAddr = v.substr(0, pos); dnsport = std::atoi(v.substr(pos + 1).c_str()); } m_LocalResolverAddr = llarp::Addr(resolverAddr, dnsport); llarp::LogInfo(Name(), " local dns set to ", m_LocalResolverAddr); } if(k == "upstream-dns") { std::string resolverAddr = v; uint16_t dnsport = 53; auto pos = v.find(":"); if(pos != std::string::npos) { resolverAddr = v.substr(0, pos); dnsport = std::atoi(v.substr(pos + 1).c_str()); } m_UpstreamDNSAddr = llarp::Addr(resolverAddr, dnsport); llarp::LogInfo(Name(), " upstream dns set to ", m_UpstreamDNSAddr); } if(k == "mapaddr") { auto pos = v.find(":"); if(pos == std::string::npos) { llarp::LogError("Cannot map address ", v, " invalid format, missing colon (:), expects " "address.loki:ip.address.goes.here"); return false; } service::Address addr; auto addr_str = v.substr(0, pos); if(!addr.FromString(addr_str)) { llarp::LogError(Name() + " cannot map invalid address ", addr_str); return false; } auto ip_str = v.substr(pos + 1); in_addr ip; if(inet_pton(AF_INET, ip_str.c_str(), &ip) != 1) { llarp::LogError("cannot map to invalid ip ", ip_str); return false; } return MapAddress(addr, huint32_t{ntohl(ip.s_addr)}); } if(k == "ifname") { strncpy(tunif.ifname, v.c_str(), sizeof(tunif.ifname) - 1); llarp::LogInfo(Name() + " setting ifname to ", tunif.ifname); return true; } if(k == "ifaddr") { std::string addr; auto pos = v.find("/"); if(pos != std::string::npos) { int num; std::string part = v.substr(pos + 1); #if defined(ANDROID) || defined(RPI) num = atoi(part.c_str()); #else num = std::stoi(part); #endif if(num > 0) { tunif.netmask = num; addr = v.substr(0, pos); } else { llarp::LogError("bad ifaddr value: ", v); return false; } } else { tunif.netmask = 32; addr = v; } llarp::LogInfo(Name() + " set ifaddr to ", addr, " with netmask ", tunif.netmask); strncpy(tunif.ifaddr, addr.c_str(), sizeof(tunif.ifaddr) - 1); // set up address in dotLokiLookup // llarp::Addr tunIp(tunif.ifaddr); llarp::huint32_t tunIpV4; tunIpV4.h = inet_addr(tunif.ifaddr); // related to dns_iptracker_setup_dotLokiLookup(&this->dll, tunIp); dns_iptracker_setup( this->dll.ip_tracker, tunIpV4); // claim GW IP to make sure it's not inuse return true; } return Endpoint::SetOption(k, v); } bool TunEndpoint::HasLocalIP(const huint32_t &ip) const { return m_IPToAddr.find(ip) != m_IPToAddr.end(); } bool TunEndpoint::QueueOutboundTraffic(llarp::net::IPv4Packet &&pkt) { return m_NetworkToUserPktQueue.EmplaceIf( [](llarp::net::IPv4Packet &) -> bool { return true; }, std::move(pkt)); } bool TunEndpoint::MapAddress(const service::Address &addr, huint32_t ip) { auto itr = m_IPToAddr.find(ip); if(itr != m_IPToAddr.end()) { // XXX is calling inet_ntoa safe in this context? it's MP-unsafe llarp::LogWarn(ip, " already mapped to ", service::Address(itr->second).ToString()); return false; } llarp::LogInfo(Name() + " map ", addr.ToString(), " to ", ip); m_IPToAddr.insert(std::make_pair(ip, addr.data())); m_AddrToIP.insert(std::make_pair(addr.data(), ip)); MarkIPActiveForever(ip); return true; } bool TunEndpoint::Start() { // do network isolation first if(!Endpoint::Start()) return false; #ifdef WIN32 return SetupNetworking(); #else if(!NetworkIsIsolated()) { llarp::LogInfo("Setting up global DNS IP tracker"); llarp::huint32_t tunIpV4; tunIpV4.h = inet_addr(tunif.ifaddr); dns_iptracker_setup_dotLokiLookup( &this->dll, tunIpV4); // just set ups dll to use global iptracker dns_iptracker_setup( this->dll.ip_tracker, tunIpV4); // claim GW IP to make sure it's not inuse // set up networking in currrent thread if we are not isolated if(!SetupNetworking()) return false; } else { llarp::LogInfo("Setting up per netns DNS IP tracker"); llarp::huint32_t tunIpV4; tunIpV4.h = inet_addr(tunif.ifaddr); llarp::Addr tunIp(tunif.ifaddr); this->dll.ip_tracker = new dns_iptracker; dns_iptracker_setup_dotLokiLookup( &this->dll, tunIpV4); // just set ups dll to use global iptracker dns_iptracker_setup( this->dll.ip_tracker, tunIpV4); // claim GW IP to make sure it's not inuse } // wait for result for network setup llarp::LogInfo("waiting for tun interface..."); return m_TunSetupResult.get_future().get(); #endif } bool TunEndpoint::SetupTun() { if(!llarp_ev_add_tun(EndpointNetLoop(), &tunif)) { llarp::LogError(Name(), " failed to set up tun interface"); return false; } struct addrinfo hint, *res = NULL; int ret; memset(&hint, '\0', sizeof hint); hint.ai_family = PF_UNSPEC; hint.ai_flags = AI_NUMERICHOST; ret = getaddrinfo(tunif.ifaddr, NULL, &hint, &res); if(ret) { llarp::LogError(Name(), " failed to set up tun interface, cant determine " "family from ", tunif.ifaddr); return false; } /* // output is in network byte order unsigned char buf[sizeof(struct in6_addr)]; int s = inet_pton(res->ai_family, tunif.ifaddr, buf); if (s <= 0) { llarp::LogError(Name(), " failed to set up tun interface, cant parse ", tunif.ifaddr); return false; } */ if(res->ai_family == AF_INET6) { llarp::LogError(Name(), " failed to set up tun interface, we don't support " "IPv6 format"); return false; } freeaddrinfo(res); struct in_addr addr; // network byte order if(inet_aton(tunif.ifaddr, &addr) == 0) { llarp::LogError(Name(), " failed to set up tun interface, cant parse ", tunif.ifaddr); return false; } llarp::Addr lAddr(tunif.ifaddr); m_OurIP = lAddr.xtohl(); m_NextIP = m_OurIP; auto xmask = netmask_ipv4_bits(tunif.netmask); m_MaxIP = m_OurIP ^ (~xmask); llarp::LogInfo(Name(), " set ", tunif.ifname, " to have address ", lAddr); llarp::LogInfo(Name(), " allocated up to ", m_MaxIP); return true; } bool TunEndpoint::SetupNetworking() { llarp::LogInfo("Set Up networking for ", Name()); bool result = SetupTun(); #ifndef WIN32 m_TunSetupResult.set_value( result); // now that NT has tun, we don't need the CPP guard #endif if(!NetworkIsIsolated()) { // need to check to see if we have more than one hidden service // well we'll only use the primary // FIXME: detect number of hidden services llarp::LogWarn( "Only utilizing first hidden service for .loki look ups"); // because we can't find to the tun interface because we don't want it // accessible on lokinet we can only bind one to loopback, and we can't // really utilize anything other than port 53 we can't bind to our // public interface, don't want it exploitable maybe we could detect if // you have a private interface } llarp::LogInfo("TunDNS set up ", m_LocalResolverAddr, " to ", m_UpstreamDNSAddr); if(!llarp_dnsd_init(&this->dnsd, EndpointLogic(), EndpointNetLoop(), m_LocalResolverAddr, m_UpstreamDNSAddr)) { llarp::LogError("Couldnt init dns daemon"); } // configure hook for .loki lookup dnsd.intercept = &llarp_dotlokilookup_handler; // set dotLokiLookup (this->dll) configuration dnsd.user = &this->dll; return result; } void TunEndpoint::Tick(llarp_time_t now) { // call tun code in endpoint logic in case of network isolation //llarp_logic_queue_job(EndpointLogic(), {this, handleTickTun}); FlushSend(); Endpoint::Tick(now); } void TunEndpoint::FlushSend() { m_UserToNetworkPktQueue.Process([&](net::IPv4Packet &pkt) { auto itr = m_IPToAddr.find(pkt.dst()); if(itr == m_IPToAddr.end()) { if(m_Exit) { pkt.UpdateIPv4PacketOnDst({0}, pkt.dst()); m_Exit->SendUpstreamTraffic(std::move(pkt)); } else llarp::LogWarn(Name(), " has no endpoint for ", pkt.dst()); return true; } // prepare packet for insertion into network // this includes clearing IP addresses, recalculating checksums, etc pkt.UpdateIPv4PacketOnSrc(); if(!SendToOrQueue(itr->second.data(), pkt.Buffer(), service::eProtocolTraffic)) { llarp::LogWarn(Name(), " did not flush packets"); } return true; }); } bool TunEndpoint::ProcessDataMessage(service::ProtocolMessage *msg) { // llarp::LogInfo("got packet from ", msg->sender.Addr()); auto themIP = ObtainIPForAddr(msg->sender.Addr().data()); // llarp::LogInfo("themIP ", themIP); auto usIP = m_OurIP; auto buf = llarp::Buffer(msg->payload); if(m_NetworkToUserPktQueue.EmplaceIf( [buf, themIP, usIP](net::IPv4Packet &pkt) -> bool { // load if(!pkt.Load(buf)) return false; // filter out: // - packets smaller than minimal IPv4 header // - non-IPv4 packets // - packets with weird src/dst addresses // (0.0.0.0/8 but not 0.0.0.0) // - packets with 0 src but non-0 dst and oposite auto hdr = pkt.Header(); if(pkt.sz < sizeof(*hdr) || hdr->version != 4 || (hdr->saddr != 0 && *(byte_t *)&(hdr->saddr) == 0) || (hdr->daddr != 0 && *(byte_t *)&(hdr->daddr) == 0) || ((hdr->saddr == 0) != (hdr->daddr == 0))) { return false; } // update packet to use proper addresses, recalc checksums pkt.UpdateIPv4PacketOnDst(themIP, usIP); return true; })) llarp::LogDebug(Name(), " handle data message ", msg->payload.size(), " bytes from ", themIP); return true; } huint32_t TunEndpoint::GetIfAddr() const { return m_OurIP; } huint32_t TunEndpoint::ObtainIPForAddr(const byte_t *a) { llarp_time_t now = Now(); huint32_t nextIP = {0}; AlignedBuffer< 32 > ident(a); { // previously allocated address auto itr = m_AddrToIP.find(ident); if(itr != m_AddrToIP.end()) { // mark ip active MarkIPActive(itr->second); return itr->second; } } // allocate new address if(m_NextIP < m_MaxIP) { do { nextIP = ++m_NextIP; } while(m_IPToAddr.find(nextIP) != m_IPToAddr.end() && m_NextIP < m_MaxIP); if(nextIP < m_MaxIP) { m_AddrToIP[ident] = nextIP; m_IPToAddr[nextIP] = ident; llarp::LogInfo(Name(), " mapped ", ident, " to ", nextIP); MarkIPActive(nextIP); return nextIP; } } // we are full // expire least active ip // TODO: prevent DoS std::pair< huint32_t, llarp_time_t > oldest = {huint32_t{0}, 0}; // find oldest entry auto itr = m_IPActivity.begin(); while(itr != m_IPActivity.end()) { if(itr->second <= now) { if((now - itr->second) > oldest.second) { oldest.first = itr->first; oldest.second = itr->second; } } ++itr; } // remap address m_IPToAddr[oldest.first] = ident; m_AddrToIP[ident] = oldest.first; nextIP = oldest.first; // mark ip active m_IPActivity[nextIP] = std::max(m_IPActivity[nextIP], now); return nextIP; } bool TunEndpoint::HasRemoteForIP(huint32_t ip) const { return m_IPToAddr.find(ip) != m_IPToAddr.end(); } void TunEndpoint::MarkIPActive(huint32_t ip) { m_IPActivity[ip] = std::max(Now(), m_IPActivity[ip]); } void TunEndpoint::MarkIPActiveForever(huint32_t ip) { m_IPActivity[ip] = std::numeric_limits< uint64_t >::max(); } void TunEndpoint::handleTickTun(void *u) { TunEndpoint *self = static_cast< TunEndpoint * >(u); self->TickTun(self->Now()); } void TunEndpoint::TickTun(__attribute__((unused)) llarp_time_t now) { // called in the isolated thread } void TunEndpoint::tunifBeforeWrite(llarp_tun_io *tun) { // called in the isolated network thread TunEndpoint *self = static_cast< TunEndpoint * >(tun->user); self->m_NetworkToUserPktQueue.Process([tun](net::IPv4Packet &pkt) { if(!llarp_ev_tun_async_write(tun, pkt.buf, pkt.sz)) llarp::LogWarn("packet dropped"); }); if(self->m_UserToNetworkPktQueue.Size()) llarp_logic_queue_job(self->RouterLogic(), {self, &handleNetSend}); } void TunEndpoint::handleNetSend(void *user) { TunEndpoint *self = static_cast< TunEndpoint * >(user); self->FlushSend(); } void TunEndpoint::tunifRecvPkt(llarp_tun_io *tun, const void *buf, ssize_t sz) { // called for every packet read from user in isolated network thread TunEndpoint *self = static_cast< TunEndpoint * >(tun->user); llarp::LogDebug("got pkt ", sz, " bytes"); if(!self->m_UserToNetworkPktQueue.EmplaceIf( [buf, sz](net::IPv4Packet &pkt) -> bool { return pkt.Load(llarp::InitBuffer(buf, sz)) && pkt.Header()->version == 4; })) { llarp::LogInfo("Failed to parse ipv4 packet"); llarp::DumpBuffer(llarp::InitBuffer(buf, sz)); } } TunEndpoint::~TunEndpoint() { } } // namespace handlers } // namespace llarp