lokinet/daemon/lokinet-vpn.cpp

450 lines
12 KiB
C++

#include <lokimq/lokimq.h>
#include <nlohmann/json.hpp>
#include <cxxopts.hpp>
#include <future>
#include <vector>
#include <array>
#include <net/net.hpp>
#ifdef _WIN32
// add the unholy windows headers for iphlpapi
#include <winsock2.h>
#include <ws2tcpip.h>
#include <iphlpapi.h>
#include <strsafe.h>
#endif
/// do a lokimq request on an lmq instance blocking style
/// returns a json object parsed from the result
std::optional<nlohmann::json>
LMQ_Request(
lokimq::LokiMQ& lmq,
const lokimq::ConnectionID& id,
std::string_view method,
std::optional<nlohmann::json> args = std::nullopt)
{
std::promise<std::optional<std::string>> result_promise;
auto handleRequest = [&result_promise](bool success, std::vector<std::string> result) {
if ((not success) or result.empty())
{
result_promise.set_value(std::nullopt);
return;
}
result_promise.set_value(result[0]);
};
if (args.has_value())
{
lmq.request(id, method, handleRequest, args->dump());
}
else
{
lmq.request(id, method, handleRequest);
}
auto ftr = result_promise.get_future();
const auto str = ftr.get();
if (str.has_value())
return nlohmann::json::parse(*str);
return std::nullopt;
}
/// get every ip address that is a gateway that isn't owned by interface with name ifname
std::vector<std::string>
GetGatewaysNotOnInterface(std::string ifname);
/// add route to ipaddr via gateway ip
void
AddRoute(std::string ipaddr, std::string gateway);
/// delete route to ipaddr via gateway ip
void
DelRoute(std::string ipaddr, std::string gateway);
/// add default route via interface with name ifname
void
AddDefaultRouteViaInterface(std::string ifname);
/// delete default route via interface with name ifname
void
DelDefaultRouteViaInterface(std::string ifname);
int
main(int argc, char* argv[])
{
cxxopts::Options opts("lokinet-vpn", "LokiNET vpn control utility");
opts.add_options()("v,verbose", "Verbose", cxxopts::value<bool>())(
"h,help", "help", cxxopts::value<bool>())("up", "put vpn up", cxxopts::value<bool>())(
"down", "put vpn down", cxxopts::value<bool>())(
"exit", "specify exit node address", cxxopts::value<std::string>())(
"rpc", "rpc url for lokinet", cxxopts::value<std::string>())(
"endpoint", "endpoint to use", cxxopts::value<std::string>())(
"token", "exit auth token to use", cxxopts::value<std::string>());
lokimq::address rpcURL("tcp://127.0.0.1:1190");
std::string exitAddress;
std::string endpoint = "default";
std::optional<std::string> token;
lokimq::LogLevel logLevel = lokimq::LogLevel::warn;
bool goUp = false;
bool goDown = false;
try
{
const auto result = opts.parse(argc, argv);
if (result.count("help") > 0)
{
std::cout << opts.help() << std::endl;
return 0;
}
if (result.count("verbose") > 0)
{
logLevel = lokimq::LogLevel::debug;
}
if (result.count("rpc") > 0)
{
rpcURL = lokimq::address(result["rpc"].as<std::string>());
}
if (result.count("exit") > 0)
{
exitAddress = result["exit"].as<std::string>();
}
goUp = result.count("up") > 0;
goDown = result.count("down") > 0;
if (result.count("endpoint") > 0)
{
endpoint = result["endpoint"].as<std::string>();
}
if (result.count("token") > 0)
{
token = result["token"].as<std::string>();
}
}
catch (const cxxopts::option_not_exists_exception& ex)
{
std::cerr << ex.what();
std::cout << opts.help() << std::endl;
return 1;
}
catch (std::exception& ex)
{
std::cout << ex.what() << std::endl;
return 1;
}
if ((not goUp) and (not goDown))
{
std::cout << opts.help() << std::endl;
return 1;
}
if (goUp and exitAddress.empty())
{
std::cout << "no exit address provided" << std::endl;
return 1;
}
lokimq::LokiMQ lmq{[](lokimq::LogLevel lvl, const char* file, int line, std::string msg) {
std::cout << lvl << " [" << file << ":" << line << "] " << msg << std::endl;
},
logLevel};
lmq.start();
std::promise<bool> connectPromise;
const auto connID = lmq.connect_remote(
rpcURL,
[&connectPromise](auto) { connectPromise.set_value(true); },
[&connectPromise](auto, std::string_view msg) {
std::cout << "failed to connect to lokinet RPC: " << msg << std::endl;
connectPromise.set_value(false);
});
auto ftr = connectPromise.get_future();
if (not ftr.get())
{
return 1;
}
std::vector<std::string> firstHops;
std::string ifname;
const auto maybe_status = LMQ_Request(lmq, connID, "llarp.status");
if (not maybe_status.has_value())
{
std::cout << "call to llarp.status failed" << std::endl;
return 1;
}
try
{
// extract first hops
const auto& links = maybe_status->at("result")["links"]["outbound"];
for (const auto& link : links)
{
const auto& sessions = link["sessions"]["established"];
for (const auto& session : sessions)
{
std::string addr = session["remoteAddr"];
const auto pos = addr.find(":");
firstHops.push_back(addr.substr(0, pos));
}
}
// get interface name
#ifdef _WIN32
// strip off the "::ffff."
ifname = maybe_status->at("result")["services"][endpoint]["ifaddr"];
const auto pos = ifname.find("/");
if (pos != std::string::npos)
{
ifname = ifname.substr(0, pos);
}
#else
ifname = maybe_status->at("result")["services"][endpoint]["ifname"];
#endif
}
catch (std::exception& ex)
{
std::cout << "failed to parse result: " << ex.what() << std::endl;
return 1;
}
if (goUp)
{
std::optional<nlohmann::json> maybe_result;
if (token.has_value())
{
maybe_result = LMQ_Request(
lmq,
connID,
"llarp.exit",
nlohmann::json{{"exit", exitAddress}, {"range", "0.0.0.0/0"}, {"token", *token}});
}
else
{
maybe_result = LMQ_Request(
lmq, connID, "llarp.exit", nlohmann::json{{"exit", exitAddress}, {"range", "0.0.0.0/0"}});
}
if (not maybe_result.has_value())
{
std::cout << "could not add exit" << std::endl;
return 1;
}
if (maybe_result->contains("error") and maybe_result->at("error").is_string())
{
std::cout << maybe_result->at("error").get<std::string>() << std::endl;
return 1;
}
const auto gateways = GetGatewaysNotOnInterface(ifname);
if (gateways.empty())
{
std::cout << "cannot determine default gateway" << std::endl;
return 1;
}
const auto ourGateway = gateways[0];
for (const auto& ip : firstHops)
{
AddRoute(ip, ourGateway);
}
AddDefaultRouteViaInterface(ifname);
}
if (goDown)
{
DelDefaultRouteViaInterface(ifname);
const auto gateways = GetGatewaysNotOnInterface(ifname);
if (gateways.empty())
{
std::cout << "cannot determine default gateway" << std::endl;
return 1;
}
const auto ourGateway = gateways[0];
for (const auto& ip : firstHops)
{
DelRoute(ip, ourGateway);
}
LMQ_Request(lmq, connID, "llarp.exit", nlohmann::json{{"range", "0.0.0.0/0"}, {"unmap", true}});
}
return 0;
}
void
Execute(std::string cmd)
{
std::cout << cmd << std::endl;
system(cmd.c_str());
}
void
AddRoute(std::string ip, std::string gateway)
{
std::stringstream ss;
#ifdef __linux__
ss << "ip route add " << ip << "/32 via " << gateway;
#elif _WIN32
ss << "route ADD " << ip << " MASK 255.255.255.255 " << gateway << " METRIC 2";
#elif __APPLE__
ss << "route -n add -host " << ip << " " << gateway;
#else
#error unsupported platform
#endif
Execute(ss.str());
}
void
DelRoute(std::string ip, std::string gateway)
{
std::stringstream ss;
#ifdef __linux__
ss << "ip route del " << ip << "/32 via " << gateway;
#elif _WIN32
ss << "route DELETE " << ip << " MASK 255.255.255.255 " << gateway << " METRIC 2";
#elif __APPLE__
ss << "route -n delete -host " << ip << " " << gateway;
#else
#error unsupported platform
#endif
Execute(ss.str());
}
void
AddDefaultRouteViaInterface(std::string ifname)
{
#ifdef __linux__
Execute("ip route add default dev " + ifname);
#elif _WIN32
ifname.back()++;
Execute("route ADD 0.0.0.0 MASK 128.0.0.0 " + ifname);
Execute("route ADD 128.0.0.0 MASK 128.0.0.0 " + ifname);
#elif __APPLE__
Execute("route -n add -net 0.0.0.0 -interface " + ifname);
#else
#error unsupported platform
#endif
}
void
DelDefaultRouteViaInterface(std::string ifname)
{
#ifdef __linux__
Execute("ip route del default dev " + ifname);
#elif _WIN32
ifname.back()++;
Execute("route DELETE 0.0.0.0 MASK 128.0.0.0 " + ifname);
Execute("route DELETE 128.0.0.0 MASK 128.0.0.0 " + ifname);
#elif __APPLE__
Execute("route -n delete -net 0.0.0.0 -interface " + ifname);
#else
#error unsupported platform
#endif
}
std::vector<std::string>
GetGatewaysNotOnInterface(std::string ifname)
{
std::vector<std::string> gateways;
#ifdef __linux__
FILE* p = popen("ip route", "r");
if (p == nullptr)
return gateways;
char* line = nullptr;
size_t len = 0;
ssize_t read = 0;
while ((read = getline(&line, &len, p)) != -1)
{
std::string line_str(line, len);
std::vector<std::string> words;
std::istringstream instr(line_str);
for (std::string word; std::getline(instr, word, ' ');)
{
words.emplace_back(std::move(word));
}
if (words[0] == "default" and words[1] == "via" and words[3] == "dev" and words[4] != ifname)
{
gateways.emplace_back(std::move(words[2]));
}
}
pclose(p);
return gateways;
#elif _WIN32
#define MALLOC(x) HeapAlloc(GetProcessHeap(), 0, (x))
#define FREE(x) HeapFree(GetProcessHeap(), 0, (x))
PMIB_IPFORWARDTABLE pIpForwardTable;
DWORD dwSize = 0;
DWORD dwRetVal = 0;
pIpForwardTable = (MIB_IPFORWARDTABLE*)MALLOC(sizeof(MIB_IPFORWARDTABLE));
if (pIpForwardTable == nullptr)
return gateways;
if (GetIpForwardTable(pIpForwardTable, &dwSize, 0) == ERROR_INSUFFICIENT_BUFFER)
{
FREE(pIpForwardTable);
pIpForwardTable = (MIB_IPFORWARDTABLE*)MALLOC(dwSize);
if (pIpForwardTable == nullptr)
{
return gateways;
}
}
if ((dwRetVal = GetIpForwardTable(pIpForwardTable, &dwSize, 0)) == NO_ERROR)
{
for (int i = 0; i < (int)pIpForwardTable->dwNumEntries; i++)
{
struct in_addr gateway, interface_addr;
gateway.S_un.S_addr = (u_long)pIpForwardTable->table[i].dwForwardDest;
interface_addr.S_un.S_addr = (u_long)pIpForwardTable->table[i].dwForwardNextHop;
std::array<char, 128> interface_str{};
StringCchCopy(interface_str.data(), interface_str.size(), inet_ntoa(interface_addr));
std::string interface_name{interface_str.data()};
if ((!gateway.S_un.S_addr) and interface_name != ifname)
{
gateways.push_back(std::move(interface_name));
}
}
}
FREE(pIpForwardTable);
#undef MALLOC
#undef FREE
return gateways;
#elif __APPLE__
const auto maybe = llarp::GetIFAddr(ifname);
if (not maybe.has_value())
return gateways;
const auto interface = maybe->toString();
// mac os is so godawful man
FILE* p = popen("netstat -rn -f inet", "r");
if (p == nullptr)
return gateways;
char* line = nullptr;
size_t len = 0;
ssize_t read = 0;
while ((read = getline(&line, &len, p)) != -1)
{
std::string line_str(line, len);
if (line_str.find("default") == 0)
{
line_str = line_str.substr(7);
while (line_str[0] == ' ')
{
line_str = line_str.substr(1);
}
const auto pos = line_str.find(" ");
if (pos != std::string::npos)
{
auto gateway = line_str.substr(0, pos);
if (gateway != interface)
gateways.emplace_back(std::move(gateway));
}
}
}
pclose(p);
return gateways;
#else
#error unsupported platform
#endif
}