lokinet/llarp/handlers/tun.cpp
Jeff Becker 80919a3b76
address feedback.
* use exceptions when fetching identity key instead of std::optional, will throw on fail
* fix up config options for endpoint auth and add better docs
* add llarp::serive::AuthType enum for controlling what kind of endpoint auth to use
2020-07-02 11:13:31 -04:00

1033 lines
29 KiB
C++

#include <algorithm>
#include "net/net.hpp"
// harmless on other platforms
#define __USE_MINGW_ANSI_STDIO 1
#include <handlers/tun.hpp>
#include <sys/types.h>
#ifndef _WIN32
#include <sys/socket.h>
#include <netdb.h>
#endif
#include <dns/dns.hpp>
#include <ev/ev.hpp>
#include <router/abstractrouter.hpp>
#include <service/context.hpp>
#include <service/endpoint_state.hpp>
#include <util/meta/memfn.hpp>
#include <util/thread/logic.hpp>
#include <nodedb.hpp>
#include <rpc/endpoint_rpc.hpp>
#include <util/str.hpp>
namespace llarp
{
namespace handlers
{
void
TunEndpoint::FlushToUser(std::function<bool(net::IPPacket&)> send)
{
// flush network to user
m_NetworkToUserPktQueue.Process(send);
}
bool
TunEndpoint::ShouldFlushNow(llarp_time_t now) const
{
static constexpr auto FlushInterval = 25ms;
return now >= m_LastFlushAt + FlushInterval;
}
void
TunEndpoint::tunifTick(llarp_tun_io* tun)
{
auto* self = static_cast<TunEndpoint*>(tun->user);
self->Flush();
}
TunEndpoint::TunEndpoint(AbstractRouter* r, service::Context* parent, bool lazyVPN)
: service::Endpoint(r, parent)
, m_UserToNetworkPktQueue("endpoint_sendq", r->netloop(), r->netloop())
, m_NetworkToUserPktQueue("endpoint_recvq", r->netloop(), r->netloop())
, m_Resolver(std::make_shared<dns::Proxy>(
r->netloop(), r->logic(), r->netloop(), r->logic(), this))
{
if (not lazyVPN)
{
tunif.reset(new llarp_tun_io());
std::fill(tunif->ifaddr, tunif->ifaddr + sizeof(tunif->ifaddr), 0);
std::fill(tunif->ifname, tunif->ifname + sizeof(tunif->ifname), 0);
tunif->netmask = 0;
tunif->get_fd_promise = nullptr;
tunif->user = this;
// eh this shouldn't do anything on windows anyway
tunif->tick = &tunifTick;
tunif->before_write = &tunifBeforeWrite;
tunif->recvpkt = &tunifRecvPkt;
}
}
util::StatusObject
TunEndpoint::ExtractStatus() const
{
auto obj = service::Endpoint::ExtractStatus();
obj["ifaddr"] = m_OurRange.ToString();
if (tunif)
{
obj["ifname"] = tunif->ifname;
}
std::vector<std::string> resolvers;
for (const auto& addr : m_UpstreamResolvers)
resolvers.emplace_back(addr.toString());
obj["ustreamResolvers"] = resolvers;
obj["localResolver"] = m_LocalResolverAddr.toString();
util::StatusObject ips{};
for (const auto& item : m_IPActivity)
{
util::StatusObject ipObj{{"lastActive", to_json(item.second)}};
std::string remoteStr;
AlignedBuffer<32> addr = m_IPToAddr.at(item.first);
if (m_SNodes.at(addr))
remoteStr = RouterID(addr.as_array()).ToString();
else
remoteStr = service::Address(addr.as_array()).ToString();
ipObj["remote"] = remoteStr;
std::string ipaddr = item.first.ToString();
ips[ipaddr] = ipObj;
}
obj["addrs"] = ips;
obj["ourIP"] = m_OurIP.ToString();
obj["nextIP"] = m_NextIP.ToString();
obj["maxIP"] = m_MaxIP.ToString();
return obj;
}
bool
TunEndpoint::Configure(const NetworkConfig& conf, const DnsConfig& dnsConf)
{
if (conf.m_reachable)
{
m_PublishIntroSet = true;
LogInfo(Name(), " setting to be reachable by default");
}
else
{
m_PublishIntroSet = false;
LogInfo(Name(), " setting to be not reachable by default");
}
if (conf.m_AuthType != service::AuthType::eAuthTypeNone)
{
std::string url, method;
if (conf.m_AuthUrl.has_value() and conf.m_AuthMethod.has_value())
{
url = *conf.m_AuthUrl;
method = *conf.m_AuthMethod;
}
auto auth = std::make_shared<rpc::EndpointAuthRPC>(
url, method, conf.m_AuthWhitelist, Router()->lmq(), shared_from_this());
auth->Start();
m_AuthPolicy = std::move(auth);
}
/*
* TODO: reinstate this option (it's not even clear what section this came from...)
*
if (k == "isolate-network" && IsTrueValue(v.c_str()))
{
#if defined(__linux__)
LogInfo(Name(), " isolating network...");
if (!SpawnIsolatedNetwork())
{
LogError(Name(), " failed to spawn isolated network");
return false;
}
LogInfo(Name(), " booyeah network isolation succeeded");
return true;
#else
LogError(Name(), " network isolation is not supported on your platform");
return false;
#endif
}
*/
/*
* TODO: this is currently defined for [router] / RouterConfig, but is clearly an [endpoint]
* option. either move it to [endpoint] or plumb RouterConfig through
*
if (k == "strict-connect")
{
RouterID connect;
if (!connect.FromString(v))
{
LogError(Name(), " invalid snode for strict-connect: ", v);
return false;
}
RouterContact rc;
if (!m_router->nodedb()->Get(connect, rc))
{
LogError(
Name(), " we don't have the RC for ", v, " so we can't use it in strict-connect");
return false;
}
for (const auto& ai : rc.addrs)
{
m_StrictConnectAddrs.emplace_back(ai);
LogInfo(Name(), " added ", m_StrictConnectAddrs.back(), " to strict connect");
}
return true;
}
*/
m_LocalResolverAddr = dnsConf.m_bind;
m_UpstreamResolvers = dnsConf.m_upstreamDNS;
for (const auto& item : conf.m_mapAddrs)
{
if (not MapAddress(item.second, item.first, false))
return false;
}
std::string ifname = conf.m_ifname;
if (tunif)
{
if (ifname.length() >= sizeof(tunif->ifname))
{
llarp::LogError(Name() + " ifname '", ifname, "' is too long");
return false;
}
strncpy(tunif->ifname, ifname.c_str(), sizeof(tunif->ifname) - 1);
llarp::LogInfo(Name() + " setting ifname to ", tunif->ifname);
m_OurRange = conf.m_ifaddr;
m_UseV6 = not m_OurRange.IsV4();
tunif->netmask = m_OurRange.HostmaskBits();
const auto addr = m_OurRange.BaseAddressString();
llarp::LogInfo(Name() + " set ifaddr to ", addr, " with netmask ", tunif->netmask);
strncpy(tunif->ifaddr, addr.c_str(), sizeof(tunif->ifaddr) - 1);
}
return Endpoint::Configure(conf, dnsConf);
}
bool
TunEndpoint::HasLocalIP(const huint128_t& ip) const
{
return m_IPToAddr.find(ip) != m_IPToAddr.end();
}
bool
TunEndpoint::QueueOutboundTraffic(llarp::net::IPPacket&& pkt)
{
return m_NetworkToUserPktQueue.EmplaceIf(
[](llarp::net::IPPacket&) -> bool { return true; }, std::move(pkt));
}
void
TunEndpoint::Flush()
{
FlushSend();
Pump(Now());
}
static bool
is_random_snode(const dns::Message& msg)
{
return msg.questions[0].IsName("random.snode");
}
static bool
is_localhost_loki(const dns::Message& msg)
{
return msg.questions[0].IsName("localhost.loki");
}
template <>
bool
TunEndpoint::FindAddrForIP(service::Address& addr, huint128_t ip)
{
auto itr = m_IPToAddr.find(ip);
if (itr != m_IPToAddr.end() and not m_SNodes[itr->second])
{
addr = service::Address(itr->second.as_array());
return true;
}
return false;
}
template <>
bool
TunEndpoint::FindAddrForIP(RouterID& addr, huint128_t ip)
{
auto itr = m_IPToAddr.find(ip);
if (itr != m_IPToAddr.end() and m_SNodes[itr->second])
{
addr = RouterID(itr->second.as_array());
return true;
}
return false;
}
static dns::Message&
clear_dns_message(dns::Message& msg)
{
msg.authorities.resize(0);
msg.additional.resize(0);
msg.answers.resize(0);
msg.hdr_fields &= ~dns::flags_RCODENameError;
return msg;
}
bool
TunEndpoint::HandleHookedDNSMessage(dns::Message msg, std::function<void(dns::Message)> reply)
{
auto ReplyToSNodeDNSWhenReady = [self = this, reply = reply](
RouterID snode, auto msg, bool isV6) -> bool {
return self->EnsurePathToSNode(snode, [=](const RouterID&, exit::BaseSession_ptr s) {
self->SendDNSReply(snode, s, msg, reply, true, isV6);
});
};
auto ReplyToLokiDNSWhenReady = [self = this, reply = reply](
service::Address addr, auto msg, bool isV6) -> bool {
using service::Address;
using service::OutboundContext;
if (self->HasAddress(addr))
{
const auto ip = self->ObtainIPForAddr(addr, false);
msg->AddINReply(ip, isV6);
reply(*msg);
return true;
}
return self->EnsurePathToService(
addr,
[=](const Address&, OutboundContext* ctx) {
self->SendDNSReply(addr, ctx, msg, reply, false, isV6);
},
2s);
};
std::string qname;
if (msg.answers.size() > 0)
{
const auto& answer = msg.answers[0];
if (answer.HasCNameForTLD(".snode"))
{
dns::Name_t qname;
llarp_buffer_t buf(answer.rData);
if (not dns::DecodeName(&buf, qname, true))
return false;
RouterID addr;
if (not addr.FromString(qname))
return false;
auto replyMsg = std::make_shared<dns::Message>(clear_dns_message(msg));
return ReplyToSNodeDNSWhenReady(addr, std::move(replyMsg), false);
}
else if (answer.HasCNameForTLD(".loki"))
{
dns::Name_t qname;
llarp_buffer_t buf(answer.rData);
if (not dns::DecodeName(&buf, qname, true))
return false;
service::Address addr;
if (not addr.FromString(qname))
return false;
auto replyMsg = std::make_shared<dns::Message>(clear_dns_message(msg));
return ReplyToLokiDNSWhenReady(addr, replyMsg, false);
}
}
if (msg.questions.size() != 1)
{
llarp::LogWarn("bad number of dns questions: ", msg.questions.size());
return false;
}
qname = msg.questions[0].Name();
if (msg.questions[0].qtype == dns::qTypeMX)
{
// mx record
service::Address addr;
if (addr.FromString(qname, ".loki") || addr.FromString(qname, ".snode")
|| is_random_snode(msg) || is_localhost_loki(msg))
msg.AddMXReply(qname, 1);
else
msg.AddNXReply();
reply(msg);
}
else if (msg.questions[0].qtype == dns::qTypeCNAME)
{
if (is_random_snode(msg))
{
RouterID random;
if (Router()->GetRandomGoodRouter(random))
{
msg.AddCNAMEReply(random.ToString(), 1);
}
else
msg.AddNXReply();
}
else if (is_localhost_loki(msg))
{
size_t counter = 0;
context->ForEachService(
[&](const std::string&, const std::shared_ptr<service::Endpoint>& service) -> bool {
const service::Address addr = service->GetIdentity().pub.Addr();
msg.AddCNAMEReply(addr.ToString(), 1);
++counter;
return true;
});
if (counter == 0)
msg.AddNXReply();
}
else
msg.AddNXReply();
reply(msg);
}
else if (msg.questions[0].qtype == dns::qTypeA || msg.questions[0].qtype == dns::qTypeAAAA)
{
const bool isV6 = msg.questions[0].qtype == dns::qTypeAAAA;
const bool isV4 = msg.questions[0].qtype == dns::qTypeA;
llarp::service::Address addr;
if (isV6 && !SupportsV6())
{ // empty reply but not a NXDOMAIN so that client can retry IPv4
msg.AddNSReply("localhost.loki.");
}
// on MacOS this is a typeA query
else if (is_random_snode(msg))
{
RouterID random;
if (Router()->GetRandomGoodRouter(random))
{
msg.AddCNAMEReply(random.ToString(), 1);
return ReplyToSNodeDNSWhenReady(random, std::make_shared<dns::Message>(msg), isV6);
}
else
msg.AddNXReply();
}
else if (is_localhost_loki(msg))
{
size_t counter = 0;
context->ForEachService(
[&](const std::string&, const std::shared_ptr<service::Endpoint>& service) -> bool {
if (!service->HasIfAddr())
return true;
huint128_t ip = service->GetIfAddr();
if (ip.h)
{
msg.AddINReply(ip, isV6);
++counter;
}
return true;
});
if (counter == 0)
msg.AddNXReply();
}
else if (addr.FromString(qname, ".loki"))
{
if (isV4 && SupportsV6())
{
msg.hdr_fields |= dns::flags_QR | dns::flags_AA | dns::flags_RA;
}
else
{
return ReplyToLokiDNSWhenReady(addr, std::make_shared<dns::Message>(msg), isV6);
}
}
else if (addr.FromString(qname, ".snode"))
{
if (isV4 && SupportsV6())
{
msg.hdr_fields |= dns::flags_QR | dns::flags_AA | dns::flags_RA;
}
else
{
return ReplyToSNodeDNSWhenReady(
addr.as_array(), std::make_shared<dns::Message>(msg), isV6);
}
}
else
msg.AddNXReply();
reply(msg);
}
else if (msg.questions[0].qtype == dns::qTypePTR)
{
// reverse dns
huint128_t ip = {0};
if (!dns::DecodePTR(msg.questions[0].qname, ip))
{
msg.AddNXReply();
reply(msg);
return true;
}
RouterID snodeAddr;
if (FindAddrForIP(snodeAddr, ip))
{
msg.AddAReply(snodeAddr.ToString());
reply(msg);
return true;
}
service::Address lokiAddr;
if (FindAddrForIP(lokiAddr, ip))
{
msg.AddAReply(lokiAddr.ToString());
reply(msg);
return true;
}
msg.AddNXReply();
reply(msg);
return true;
}
else
{
msg.AddNXReply();
reply(msg);
}
return true;
}
void
TunEndpoint::ResetInternalState()
{
service::Endpoint::ResetInternalState();
}
bool
TunEndpoint::SupportsV6() const
{
return m_UseV6;
}
// FIXME: pass in which question it should be addressing
bool
TunEndpoint::ShouldHookDNSMessage(const dns::Message& msg) const
{
llarp::service::Address addr;
if (msg.questions.size() == 1)
{
/// hook every .loki
if (msg.questions[0].HasTLD(".loki"))
return true;
/// hook every .snode
if (msg.questions[0].HasTLD(".snode"))
return true;
// hook any ranges we own
if (msg.questions[0].qtype == llarp::dns::qTypePTR)
{
huint128_t ip = {0};
if (!dns::DecodePTR(msg.questions[0].qname, ip))
return false;
return m_OurRange.Contains(ip);
}
}
for (const auto& answer : msg.answers)
{
if (answer.HasCNameForTLD(".loki"))
return true;
if (answer.HasCNameForTLD(".snode"))
return true;
}
return false;
}
bool
TunEndpoint::MapAddress(const service::Address& addr, huint128_t ip, bool SNode)
{
auto itr = m_IPToAddr.find(ip);
if (itr != m_IPToAddr.end())
{
llarp::LogWarn(
ip, " already mapped to ", service::Address(itr->second.as_array()).ToString());
return false;
}
llarp::LogInfo(Name() + " map ", addr.ToString(), " to ", ip);
m_IPToAddr[ip] = addr;
m_AddrToIP[addr] = ip;
m_SNodes[addr] = SNode;
MarkIPActiveForever(ip);
return true;
}
bool
TunEndpoint::Start()
{
if (!Endpoint::Start())
{
llarp::LogWarn("Couldn't start endpoint");
return false;
}
return SetupNetworking();
}
bool
TunEndpoint::IsSNode() const
{
// TODO : implement me
return false;
}
bool
TunEndpoint::SetupTun()
{
lazy_vpn vpn;
huint32_t ip;
auto loop = EndpointNetLoop();
if (tunif == nullptr)
{
llarp::LogInfo(Name(), " waiting for vpn to start");
vpn = m_LazyVPNPromise.get_future().get();
vpnif = vpn.io;
if (vpnif == nullptr)
{
llarp::LogError(Name(), " failed to recieve vpn interface");
return false;
}
llarp::LogInfo(Name(), " got vpn interface");
auto self = shared_from_this();
// function to queue a packet to send to vpn interface
auto sendpkt = [self](net::IPPacket& pkt) -> bool {
// drop if no endpoint
auto impl = self->GetVPNImpl();
// drop if no vpn interface
if (impl == nullptr)
return true;
// drop if queue to vpn not enabled
if (not impl->reader.queue.enabled())
return true;
// drop if queue to vpn full
if (impl->reader.queue.full())
return true;
// queue to reader
impl->reader.queue.pushBack(pkt);
return false;
};
// event loop ticker
auto ticker = [self, sendpkt]() {
TunEndpoint* ep = self.get();
const bool running = not ep->IsStopped();
auto impl = ep->GetVPNImpl();
if (impl)
{
/// get packets from vpn
while (not impl->writer.queue.empty())
{
// queue it to be sent over lokinet
auto pkt = impl->writer.queue.popFront();
if (running)
ep->m_UserToNetworkPktQueue.Emplace(pkt);
}
}
// process packets queued from vpn
if (running)
{
ep->Flush();
ep->FlushToUser(sendpkt);
}
// if impl has a tick function call it
if (impl && impl->parent && impl->parent->tick)
impl->parent->tick(impl->parent);
};
if (not loop->add_ticker(ticker))
{
llarp::LogError(Name(), " failed to add vpn to event loop");
if (vpnif->injected)
vpnif->injected(vpnif, false);
return false;
}
}
else
{
if (!llarp_ev_add_tun(loop.get(), tunif.get()))
{
llarp::LogError(
Name(), " failed to set up tun interface: ", tunif->ifaddr, " on ", tunif->ifname);
return false;
}
}
const char* ifname;
const char* ifaddr;
unsigned char netmask;
if (tunif)
{
ifname = tunif->ifname;
ifaddr = tunif->ifaddr;
netmask = tunif->netmask;
}
else
{
ifname = vpn.info.ifname;
ifaddr = vpn.info.ifaddr;
netmask = vpn.info.netmask;
}
if (ip.FromString(ifaddr))
{
m_OurIP = net::ExpandV4(ip);
m_OurRange.netmask_bits = netmask_ipv6_bits(netmask + 96);
}
else if (m_OurIP.FromString(ifaddr))
{
m_OurRange.netmask_bits = netmask_ipv6_bits(netmask);
m_UseV6 = true;
}
else
{
LogError(Name(), " invalid interface address given, ifaddr=", ifaddr);
if (vpnif && vpnif->injected)
vpnif->injected(vpnif, false);
return false;
}
m_NextIP = m_OurIP;
m_OurRange.addr = m_OurIP;
m_MaxIP = m_OurRange.HighestAddr();
llarp::LogInfo(Name(), " set ", ifname, " to have address ", m_OurIP);
llarp::LogInfo(Name(), " allocated up to ", m_MaxIP, " on range ", m_OurRange);
const service::Address ourAddr = m_Identity.pub.Addr();
if (not MapAddress(ourAddr, GetIfAddr(), false))
{
return false;
}
if (m_OnUp)
{
m_OnUp->NotifyAsync(NotifyParams());
}
if (vpnif && vpnif->injected)
{
vpnif->injected(vpnif, true);
}
return HasAddress(ourAddr);
}
std::unordered_map<std::string, std::string>
TunEndpoint::NotifyParams() const
{
auto env = Endpoint::NotifyParams();
env.emplace("IP_ADDR", m_OurIP.ToString());
env.emplace("IF_ADDR", m_OurRange.ToString());
if (tunif)
env.emplace("IF_NAME", tunif->ifname);
std::string strictConnect;
for (const auto& addr : m_StrictConnectAddrs)
strictConnect += addr.toString() + " ";
env.emplace("STRICT_CONNECT_ADDRS", strictConnect);
return env;
}
bool
TunEndpoint::SetupNetworking()
{
llarp::LogInfo("Set Up networking for ", Name());
if (!SetupTun())
{
llarp::LogError(Name(), " failed to set up network interface");
return false;
}
if (!m_Resolver->Start(m_LocalResolverAddr, m_UpstreamResolvers))
{
// downgrade DNS server failure to a warning
llarp::LogWarn(Name(), " failed to start dns server");
// return false;
}
return true;
}
void
TunEndpoint::Tick(llarp_time_t now)
{
Endpoint::Tick(now);
}
bool
TunEndpoint::Stop()
{
return llarp::service::Endpoint::Stop();
}
void
TunEndpoint::FlushSend()
{
m_UserToNetworkPktQueue.Process([&](net::IPPacket& pkt) {
std::function<bool(const llarp_buffer_t&)> sendFunc;
huint128_t dst, src;
if (pkt.IsV4())
{
dst = pkt.dst4to6();
src = pkt.src4to6();
}
else
{
dst = pkt.dstv6();
src = pkt.srcv6();
}
auto itr = m_IPToAddr.find(dst);
if (itr == m_IPToAddr.end())
{
const auto exits = m_ExitMap.FindAll(dst);
if (IsBogon(dst) or exits.empty())
{
// send icmp unreachable
const auto icmp = pkt.MakeICMPUnreachable();
if (icmp.has_value())
{
HandleWriteIPPacket(icmp->ConstBuffer(), dst, src);
}
}
else
{
const auto addr = *exits.begin();
pkt.ZeroSourceAddress();
MarkAddressOutbound(addr);
EnsurePathToService(
addr,
[addr, pkt, self = this](service::Address, service::OutboundContext*) {
self->SendToServiceOrQueue(addr, pkt.ConstBuffer(), service::eProtocolExit);
},
1s);
}
return;
}
if (m_SNodes.at(itr->second))
{
sendFunc = std::bind(
&TunEndpoint::SendToSNodeOrQueue,
this,
itr->second.as_array(),
std::placeholders::_1);
}
else if (m_state->m_ExitEnabled)
{
sendFunc = std::bind(
&TunEndpoint::SendToServiceOrQueue,
this,
service::Address(itr->second.as_array()),
std::placeholders::_1,
service::eProtocolExit);
}
else
{
sendFunc = std::bind(
&TunEndpoint::SendToServiceOrQueue,
this,
service::Address(itr->second.as_array()),
std::placeholders::_1,
pkt.ServiceProtocol());
}
// prepare packet for insertion into network
// this includes clearing IP addresses, recalculating checksums, etc
if (not m_state->m_ExitEnabled)
{
if (pkt.IsV4())
pkt.UpdateIPv4Address({0}, {0});
else
pkt.UpdateIPv6Address({0}, {0});
}
if (sendFunc && sendFunc(pkt.Buffer()))
{
MarkIPActive(dst);
return;
}
llarp::LogWarn(Name(), " did not flush packets");
});
}
bool
TunEndpoint::HandleInboundPacket(
const service::ConvoTag tag, const llarp_buffer_t& buf, service::ProtocolType t)
{
if (t != service::eProtocolTrafficV4 && t != service::eProtocolTrafficV6
&& t != service::eProtocolExit)
return false;
AlignedBuffer<32> addr;
bool snode = false;
if (!GetEndpointWithConvoTag(tag, addr, snode))
return false;
huint128_t src, dst;
net::IPPacket pkt;
if (not pkt.Load(buf))
return false;
if (m_state->m_ExitEnabled)
{
// exit side from exit
src = ObtainIPForAddr(addr, snode);
if (pkt.IsV4())
dst = pkt.dst4to6();
else if (pkt.IsV6())
dst = pkt.dstv6();
}
else if (t == service::eProtocolExit)
{
// client side exit traffic from exit
if (pkt.IsV4())
src = pkt.src4to6();
else if (pkt.IsV6())
src = pkt.srcv6();
dst = m_OurIP;
// find what exit we think this should be for
const auto mapped = m_ExitMap.FindAll(src);
if (mapped.count(service::Address{addr}) == 0 or IsBogon(src))
{
// we got exit traffic from someone who we should not have gotten it from
return false;
}
}
else
{
// snapp traffic
src = ObtainIPForAddr(addr, snode);
dst = m_OurIP;
}
HandleWriteIPPacket(buf, src, dst);
return true;
}
bool
TunEndpoint::HandleWriteIPPacket(const llarp_buffer_t& b, huint128_t src, huint128_t dst)
{
ManagedBuffer buf(b);
return m_NetworkToUserPktQueue.EmplaceIf([buf, src, dst](net::IPPacket& pkt) -> bool {
// load
if (!pkt.Load(buf))
return false;
if (pkt.IsV4())
{
pkt.UpdateIPv4Address(xhtonl(net::TruncateV6(src)), xhtonl(net::TruncateV6(dst)));
}
else if (pkt.IsV6())
{
pkt.UpdateIPv6Address(src, dst);
}
return true;
});
}
huint128_t
TunEndpoint::GetIfAddr() const
{
return m_OurIP;
}
huint128_t
TunEndpoint::ObtainIPForAddr(const AlignedBuffer<32>& ident, bool snode)
{
llarp_time_t now = Now();
huint128_t nextIP = {0};
{
// 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;
m_SNodes[ident] = snode;
llarp::LogInfo(Name(), " mapped ", ident, " to ", nextIP);
MarkIPActive(nextIP);
return nextIP;
}
}
// we are full
// expire least active ip
// TODO: prevent DoS
std::pair<huint128_t, llarp_time_t> oldest = {huint128_t{0}, 0s};
// 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;
m_SNodes[ident] = snode;
nextIP = oldest.first;
// mark ip active
m_IPActivity[nextIP] = std::max(m_IPActivity[nextIP], now);
return nextIP;
}
bool
TunEndpoint::HasRemoteForIP(huint128_t ip) const
{
return m_IPToAddr.find(ip) != m_IPToAddr.end();
}
void
TunEndpoint::MarkIPActive(huint128_t ip)
{
llarp::LogDebug(Name(), " address ", ip, " is active");
m_IPActivity[ip] = std::max(Now(), m_IPActivity[ip]);
}
void
TunEndpoint::MarkIPActiveForever(huint128_t ip)
{
m_IPActivity[ip] = std::numeric_limits<llarp_time_t>::max();
}
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
auto* self = static_cast<TunEndpoint*>(tun->user);
self->Flush();
self->FlushToUser([self, tun](net::IPPacket& pkt) -> bool {
if (not llarp_ev_tun_async_write(tun, pkt.Buffer()))
{
llarp::LogWarn(self->Name(), " packet dropped");
}
return false;
});
} // namespace handlers
void
TunEndpoint::tunifRecvPkt(llarp_tun_io* tun, const llarp_buffer_t& b)
{
// called for every packet read from user in isolated network thread
auto* self = static_cast<TunEndpoint*>(tun->user);
self->m_UserToNetworkPktQueue.EmplaceIf([&](net::IPPacket& pkt) { return pkt.Load(b); });
}
TunEndpoint::~TunEndpoint() = default;
} // namespace handlers
} // namespace llarp