lokinet/llarp/dns/srv_data.cpp
2021-04-19 07:02:46 -04:00

146 lines
3.2 KiB
C++

#include "srv_data.hpp"
#include <llarp/util/str.hpp>
#include <llarp/util/logging/logger.hpp>
#include <limits>
#include <oxenmq/bt_serialize.h>
#include "llarp/util/bencode.h"
#include "llarp/util/types.hpp"
namespace llarp::dns
{
bool
SRVData::IsValid() const
{
// if target is of first two forms outlined above
if (target == "." or target.size() == 0)
{
return true;
}
// check target size is not absurd
if (target.size() > TARGET_MAX_SIZE)
{
LogWarn("SRVData target larger than max size (", TARGET_MAX_SIZE, ")");
return false;
}
// does target end in .loki?
size_t pos = target.find(".loki");
if (pos != std::string::npos && pos == (target.size() - 5))
{
return true;
}
// does target end in .snode?
pos = target.find(".snode");
if (pos != std::string::npos && pos == (target.size() - 6))
{
return true;
}
// if we're here, target is invalid
LogWarn("SRVData invalid");
return false;
}
SRVTuple
SRVData::toTuple() const
{
return std::make_tuple(service_proto, priority, weight, port, target);
}
SRVData
SRVData::fromTuple(SRVTuple tuple)
{
SRVData s;
std::tie(s.service_proto, s.priority, s.weight, s.port, s.target) = std::move(tuple);
return s;
}
bool
SRVData::fromString(std::string_view srvString)
{
LogDebug("SRVData::fromString(\"", srvString, "\")");
// split on spaces, discard trailing empty strings
auto splits = split(srvString, " ", false);
if (splits.size() != 5 && splits.size() != 4)
{
LogWarn("SRV record should have either 4 or 5 space-separated parts");
return false;
}
service_proto = splits[0];
if (not parse_int(splits[1], priority))
{
LogWarn("SRV record failed to parse \"", splits[1], "\" as uint16_t (priority)");
return false;
}
if (not parse_int(splits[2], weight))
{
LogWarn("SRV record failed to parse \"", splits[2], "\" as uint16_t (weight)");
return false;
}
if (not parse_int(splits[3], port))
{
LogWarn("SRV record failed to parse \"", splits[3], "\" as uint16_t (port)");
return false;
}
if (splits.size() == 5)
target = splits[4];
else
target = "";
return IsValid();
}
bool
SRVData::BEncode(llarp_buffer_t* buf) const
{
const std::string data = oxenmq::bt_serialize(toTuple());
return buf->write(data.begin(), data.end());
}
bool
SRVData::BDecode(llarp_buffer_t* buf)
{
byte_t* begin = buf->cur;
if (not bencode_discard(buf))
return false;
byte_t* end = buf->cur;
std::string_view srvString{
reinterpret_cast<char*>(begin), static_cast<std::size_t>(end - begin)};
try
{
SRVTuple tuple{};
oxenmq::bt_deserialize(srvString, tuple);
*this = fromTuple(std::move(tuple));
return IsValid();
}
catch (const oxenmq::bt_deserialize_invalid&)
{
return false;
};
}
util::StatusObject
SRVData::ExtractStatus() const
{
return util::StatusObject{
{"proto", service_proto},
{"priority", priority},
{"weight", weight},
{"port", port},
{"target", target}};
}
} // namespace llarp::dns