DNS Checkpoint updating-related fixes/changes

Only one thread will be doing the updating.

Two valid responses must match, and the first two that match will be
used.
This commit is contained in:
Thomas Winget 2015-04-22 04:36:39 -04:00
parent 41f0a8fe4d
commit 2717883dba
No known key found for this signature in database
GPG key ID: 58131A160789E630
3 changed files with 72 additions and 8 deletions

View file

@ -35,6 +35,30 @@
#include <random>
#include "storages/portable_storage_template_helper.h" // epee json include
namespace
{
bool dns_records_match(const std::vector<std::string>& a, const std::vector<std::string>& b)
{
if (a.size() != b.size()) return false;
for (const auto& record_in_a : a)
{
bool ok = false;
for (const auto& record_in_b : b)
{
if (record_in_a == record_in_b)
{
ok = true;
break;
}
}
if (!ok) return false;
}
return true;
}
} // anonymous namespace
namespace cryptonote
{
@ -127,14 +151,16 @@ bool load_checkpoints_from_dns(cryptonote::checkpoints& checkpoints, bool testne
, "testpoints.moneropulse.net"
, "testpoints.moneropulse.co"
};
bool avail, valid;
std::vector<std::string> records;
std::vector<std::vector<std::string> > records;
records.resize(dns_urls.size());
std::random_device rd;
std::mt19937 gen(rd());
std::uniform_int_distribution<int> dis(0, dns_urls.size() - 1);
size_t first_index = dis(gen);
bool avail, valid;
size_t cur_index = first_index;
do
{
@ -148,7 +174,7 @@ bool load_checkpoints_from_dns(cryptonote::checkpoints& checkpoints, bool testne
url = dns_urls[cur_index];
}
records = tools::DNSResolver::instance().get_txt_record(url, avail, valid);
records[cur_index] = tools::DNSResolver::instance().get_txt_record(url, avail, valid);
if (!avail)
{
LOG_PRINT_L2("DNSSEC not available for checkpoint update at URL: " << url << ", skipping.");
@ -158,26 +184,58 @@ bool load_checkpoints_from_dns(cryptonote::checkpoints& checkpoints, bool testne
LOG_PRINT_L2("DNSSEC validation failed for checkpoint update at URL: " << url << ", skipping.");
}
if (records.size() == 0 || !avail || !valid)
if (records[cur_index].size() == 0 || !avail || !valid)
{
cur_index++;
if (cur_index == dns_urls.size())
{
cur_index = 0;
}
records.clear();
records[cur_index].clear();
continue;
}
break;
} while (cur_index != first_index);
if (records.size() == 0)
size_t num_valid_records = 0;
for( const auto& record_set : records)
{
LOG_PRINT_L0("WARNING: All MoneroPulse checkpoint URLs failed DNSSEC validation and/or returned no records");
if (record_set.size() != 0)
{
num_valid_records++;
}
}
if (num_valid_records < 2)
{
LOG_PRINT_L0("WARNING: no two valid MoneroPulse DNS checkpoint records were received");
return true;
}
for (auto& record : records)
int good_records_index = -1;
for (size_t i = 0; i < records.size() - 1; ++i)
{
if (records[i].size() == 0) continue;
for (size_t j = i + 1; j < records.size(); ++j)
{
if (dns_records_match(records[i], records[j]))
{
good_records_index = i;
break;
}
}
if (good_records_index >= 0) break;
}
if (good_records_index < 0)
{
LOG_PRINT_L0("WARNING: no two MoneroPulse DNS checkpoint records matched");
return true;
}
for (auto& record : records[good_records_index])
{
auto pos = record.find(":");
if (pos != std::string::npos)

View file

@ -100,6 +100,8 @@ namespace cryptonote
{
if (m_testnet) return true;
if (m_checkpoints_updating.test_and_set()) return true;
bool res = true;
if (time(NULL) - m_last_dns_checkpoints_update >= 3600)
{
@ -113,6 +115,8 @@ namespace cryptonote
m_last_json_checkpoints_update = time(NULL);
}
m_checkpoints_updating.clear();
// if anything fishy happened getting new checkpoints, bring down the house
if (!res)
{

View file

@ -189,6 +189,8 @@ namespace cryptonote
std::string m_checkpoints_path;
time_t m_last_dns_checkpoints_update;
time_t m_last_json_checkpoints_update;
std::atomic_flag m_checkpoints_updating;
};
}