wallet: make the segregation height settable

via user setting first, then DNS TXT record, hardcoded fallback

src/simplewallet/simplewallet.cpp

@@ -1968,6 +1968,23 @@ bool simple_wallet::set_subaddress_lookahead(const std::vector<std::string> &arg
   return true;
 }
 
+bool simple_wallet::set_segregation_height(const std::vector<std::string> &args/* = std::vector<std::string>()*/)
+{
+  const auto pwd_container = get_and_verify_password();
+  if (pwd_container)
+  {
+    uint64_t height;
+    if (!epee::string_tools::get_xtype_from_string(height, args[1]))
+    {
+      fail_msg_writer() << tr("Invalid height");
+      return true;
+    }
+    m_wallet->segregation_height(height);
+    m_wallet->rewrite(m_wallet_file, pwd_container->password());
+  }
+  return true;
+}
+
 bool simple_wallet::help(const std::vector<std::string> &args/* = std::vector<std::string>()*/)
 {
   if(args.empty())
@@ -2148,7 +2165,10 @@ simple_wallet::simple_wallet()
                                   "key-reuse-mitigation2 <1|0>\n "
                                   "  Set this if you are not sure whether you will spend on a key reusing Monero fork later.\n"
                                   "subaddress-lookahead <major>:<minor>\n "
-                                  "  Set the lookahead sizes for the subaddress hash table."));
+                                  "  Set the lookahead sizes for the subaddress hash table.\n "
+                                  "  Set this if you are not sure whether you will spend on a key reusing Monero fork later.\n "
+                                  "segregation-height <n>\n "
+                                  "  Set to the height of a key reusing fork you want to use, 0 to use default."));
   m_cmd_binder.set_handler("encrypted_seed",
                            boost::bind(&simple_wallet::encrypted_seed, this, _1),
                            tr("Display the encrypted Electrum-style mnemonic seed."));
@@ -2344,6 +2364,7 @@ bool simple_wallet::set_variable(const std::vector<std::string> &args)
     success_msg_writer() << "key-reuse-mitigation2 = " << m_wallet->key_reuse_mitigation2();
     const std::pair<size_t, size_t> lookahead = m_wallet->get_subaddress_lookahead();
     success_msg_writer() << "subaddress-lookahead = " << lookahead.first << ":" << lookahead.second;
+    success_msg_writer() << "segregation-height = " << m_wallet->segregation_height();
     return true;
   }
   else
@@ -2397,6 +2418,7 @@ bool simple_wallet::set_variable(const std::vector<std::string> &args)
     CHECK_SIMPLE_VARIABLE("segregate-pre-fork-outputs", set_segregate_pre_fork_outputs, tr("0 or 1"));
     CHECK_SIMPLE_VARIABLE("key-reuse-mitigation2", set_key_reuse_mitigation2, tr("0 or 1"));
     CHECK_SIMPLE_VARIABLE("subaddress-lookahead", set_subaddress_lookahead, tr("<major>:<minor>"));
+    CHECK_SIMPLE_VARIABLE("segregation-height", set_segregation_height, tr("unsigned integer"));
   }
   fail_msg_writer() << tr("set: unrecognized argument(s)");
   return true;

src/simplewallet/simplewallet.h

@@ -136,6 +136,7 @@ namespace cryptonote
     bool set_segregate_pre_fork_outputs(const std::vector<std::string> &args = std::vector<std::string>());
     bool set_key_reuse_mitigation2(const std::vector<std::string> &args = std::vector<std::string>());
     bool set_subaddress_lookahead(const std::vector<std::string> &args = std::vector<std::string>());
+    bool set_segregation_height(const std::vector<std::string> &args = std::vector<std::string>());
     bool help(const std::vector<std::string> &args = std::vector<std::string>());
     bool start_mining(const std::vector<std::string> &args);
     bool stop_mining(const std::vector<std::string> &args);

src/wallet/wallet2.cpp

@@ -65,6 +65,7 @@ using namespace epee;
 #include "common/json_util.h"
 #include "memwipe.h"
 #include "common/base58.h"
+#include "common/dns_utils.h"
 #include "ringct/rctSigs.h"
 #include "ringdb.h"
 
@@ -662,6 +663,7 @@ wallet2::wallet2(network_type nettype, bool restricted):
   m_auto_low_priority(true),
   m_segregate_pre_fork_outputs(true),
   m_key_reuse_mitigation2(true),
+  m_segregation_height(0),
   m_is_initialized(false),
   m_restricted(restricted),
   is_old_file_format(false),
@@ -2594,6 +2596,9 @@ bool wallet2::store_keys(const std::string& keys_file_name, const epee::wipeable
   value2.SetInt(m_key_reuse_mitigation2 ? 1 : 0);
   json.AddMember("key_reuse_mitigation2", value2, json.GetAllocator());
 
+  value2.SetUint(m_segregation_height);
+  json.AddMember("segregation_height", value2, json.GetAllocator());
+
   // Serialize the JSON object
   rapidjson::StringBuffer buffer;
   rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
@@ -5774,14 +5779,7 @@ void wallet2::get_outs(std::vector<std::vector<tools::wallet2::get_outs_entry>>
 
   if (fake_outputs_count > 0)
   {
-    uint64_t segregation_fork_height;
-    switch (m_nettype)
-    {
-      case TESTNET: segregation_fork_height = TESTNET_SEGREGATION_FORK_HEIGHT; break;
-      case STAGENET: segregation_fork_height = STAGENET_SEGREGATION_FORK_HEIGHT; break;
-      case MAINNET: segregation_fork_height = SEGREGATION_FORK_HEIGHT; break;
-      default: THROW_WALLET_EXCEPTION(error::wallet_internal_error, "Invalid network type");
-    }
+    uint64_t segregation_fork_height = get_segregation_fork_height();
     // check whether we're shortly after the fork
     uint64_t height;
     boost::optional<std::string> result = m_node_rpc_proxy.get_height(height);
@@ -10324,6 +10322,58 @@ std::vector<std::pair<uint64_t, uint64_t>> wallet2::estimate_backlog(uint64_t mi
   return estimate_backlog(fee_levels);
 }
 //----------------------------------------------------------------------------------------------------
+uint64_t wallet2::get_segregation_fork_height() const
+{
+  if (m_nettype == TESTNET)
+    return TESTNET_SEGREGATION_FORK_HEIGHT;
+  if (m_nettype == STAGENET)
+    return STAGENET_SEGREGATION_FORK_HEIGHT;
+  THROW_WALLET_EXCEPTION_IF(m_nettype != MAINNET, tools::error::wallet_internal_error, "Invalid network type");
+
+  if (m_segregation_height > 0)
+    return m_segregation_height;
+
+  static const bool use_dns = true;
+  if (use_dns)
+  {
+    // All four MoneroPulse domains have DNSSEC on and valid
+    static const std::vector<std::string> dns_urls = {
+        "segheights.moneropulse.org",
+        "segheights.moneropulse.net",
+        "segheights.moneropulse.co",
+        "segheights.moneropulse.se"
+    };
+
+    const uint64_t current_height = get_blockchain_current_height();
+    uint64_t best_diff = std::numeric_limits<uint64_t>::max(), best_height = 0;
+    std::vector<std::string> records;
+    if (tools::dns_utils::load_txt_records_from_dns(records, dns_urls))
+    {
+      for (const auto& record : records)
+      {
+        std::vector<std::string> fields;
+        boost::split(fields, record, boost::is_any_of(":"));
+        if (fields.size() != 2)
+          continue;
+        uint64_t height;
+        if (!string_tools::get_xtype_from_string(height, fields[1]))
+          continue;
+
+        MINFO("Found segregation height via DNS: " << fields[0] << " fork height at " << height);
+        uint64_t diff = height > current_height ? height - current_height : current_height - height;
+        if (diff < best_diff)
+        {
+          best_diff = diff;
+          best_height = height;
+        }
+      }
+      if (best_height)
+        return best_height;
+    }
+  }
+  return SEGREGATION_FORK_HEIGHT;
+}
+//----------------------------------------------------------------------------------------------------
 void wallet2::generate_genesis(cryptonote::block& b) const {
   if (m_nettype == TESTNET)
   {

src/wallet/wallet2.h

@@ -872,6 +872,8 @@ namespace tools
     void segregate_pre_fork_outputs(bool value) { m_segregate_pre_fork_outputs = value; }
     bool key_reuse_mitigation2() const { return m_key_reuse_mitigation2; }
     void key_reuse_mitigation2(bool value) { m_key_reuse_mitigation2 = value; }
+    uint64_t segregation_height() const { return m_segregation_height; }
+    void segregation_height(uint64_t height) { m_segregation_height = height; }
 
     bool get_tx_key(const crypto::hash &txid, crypto::secret_key &tx_key, std::vector<crypto::secret_key> &additional_tx_keys) const;
     void check_tx_key(const crypto::hash &txid, const crypto::secret_key &tx_key, const std::vector<crypto::secret_key> &additional_tx_keys, const cryptonote::account_public_address &address, uint64_t &received, bool &in_pool, uint64_t &confirmations);
@@ -1134,6 +1136,8 @@ namespace tools
 
     bool get_output_distribution(uint64_t &start_height, std::vector<uint64_t> &distribution);
 
+    uint64_t get_segregation_fork_height() const;
+
     cryptonote::account_base m_account;
     boost::optional<epee::net_utils::http::login> m_daemon_login;
     std::string m_daemon_address;
@@ -1200,6 +1204,7 @@ namespace tools
     bool m_auto_low_priority;
     bool m_segregate_pre_fork_outputs;
     bool m_key_reuse_mitigation2;
+    uint64_t m_segregation_height;
     bool m_is_initialized;
     NodeRPCProxy m_node_rpc_proxy;
     std::unordered_set<crypto::hash> m_scanned_pool_txs[2];