Set response limits on http server connections

src/cryptonote_config.h

@@ -127,6 +127,10 @@
 
 #define COMMAND_RPC_GET_BLOCKS_FAST_MAX_BLOCK_COUNT     1000
 #define COMMAND_RPC_GET_BLOCKS_FAST_MAX_TX_COUNT        20000
+#define DEFAULT_RPC_MAX_CONNECTIONS_PER_PUBLIC_IP       3
+#define DEFAULT_RPC_MAX_CONNECTIONS_PER_PRIVATE_IP      25
+#define DEFAULT_RPC_MAX_CONNECTIONS                     100
+#define DEFAULT_RPC_SOFT_LIMIT_SIZE                     25 * 1024 * 1024 // 25 MiB
 #define MAX_RPC_CONTENT_LENGTH                          1048576 // 1 MB
 
 #define P2P_LOCAL_WHITE_PEERLIST_LIMIT                  1000

src/p2p/net_node.cpp

@@ -169,7 +169,7 @@ namespace nodetool
     const command_line::arg_descriptor<bool> arg_pad_transactions = {
       "pad-transactions", "Pad relayed transactions to help defend against traffic volume analysis", false
     };
-    const command_line::arg_descriptor<uint32_t> arg_max_connections_per_ip = {"max-connections-per-ip", "Maximum number of connections allowed from the same IP address", 1};
+    const command_line::arg_descriptor<uint32_t> arg_max_connections_per_ip = {"max-connections-per-ip", "Maximum number of p2p connections allowed from the same IP address", 1};
 
     boost::optional<std::vector<proxy>> get_proxies(boost::program_options::variables_map const& vm)
     {

src/rpc/core_rpc_server.cpp

@@ -163,6 +163,10 @@ namespace cryptonote
     command_line::add_arg(desc, arg_rpc_payment_difficulty);
     command_line::add_arg(desc, arg_rpc_payment_credits);
     command_line::add_arg(desc, arg_rpc_payment_allow_free_loopback);
+    command_line::add_arg(desc, arg_rpc_max_connections_per_public_ip);
+    command_line::add_arg(desc, arg_rpc_max_connections_per_private_ip);
+    command_line::add_arg(desc, arg_rpc_max_connections);
+    command_line::add_arg(desc, arg_rpc_response_soft_limit);
   }
   //------------------------------------------------------------------------------------------------------------------------------
   core_rpc_server::core_rpc_server(
@@ -396,11 +400,28 @@ namespace cryptonote
       }
     } // if (store_ssl_key)
 
+    const auto max_connections_public = command_line::get_arg(vm, arg_rpc_max_connections_per_public_ip);
+    const auto max_connections_private = command_line::get_arg(vm, arg_rpc_max_connections_per_private_ip);
+    const auto max_connections = command_line::get_arg(vm, arg_rpc_max_connections);
+
+    if (max_connections < max_connections_public)
+    {
+      MFATAL(arg_rpc_max_connections_per_public_ip.name << " is bigger than " << arg_rpc_max_connections.name);
+      return false;
+    }
+    if (max_connections < max_connections_private)
+    {
+      MFATAL(arg_rpc_max_connections_per_private_ip.name << " is bigger than " << arg_rpc_max_connections.name);
+      return false;
+    }
+
     auto rng = [](size_t len, uint8_t *ptr){ return crypto::rand(len, ptr); };
     const bool inited = epee::http_server_impl_base<core_rpc_server, connection_context>::init(
       rng, std::move(port), std::move(bind_ip_str),
       std::move(bind_ipv6_str), std::move(rpc_config->use_ipv6), std::move(rpc_config->require_ipv4),
-      std::move(rpc_config->access_control_origins), std::move(http_login), std::move(rpc_config->ssl_options)
+      std::move(rpc_config->access_control_origins), std::move(http_login), std::move(rpc_config->ssl_options),
+      max_connections_public, max_connections_private, max_connections,
+      command_line::get_arg(vm, arg_rpc_response_soft_limit)
     );
 
     m_net_server.get_config_object().m_max_content_length = MAX_RPC_CONTENT_LENGTH;
@@ -3885,4 +3906,28 @@ namespace cryptonote
     , "Allow free access from the loopback address (ie, the local host)"
     , false
     };
+
+  const command_line::arg_descriptor<std::size_t> core_rpc_server::arg_rpc_max_connections_per_public_ip = {
+      "rpc-max-connections-per-public-ip"
+    , "Max RPC connections per public IP permitted"
+    , DEFAULT_RPC_MAX_CONNECTIONS_PER_PUBLIC_IP
+  };
+
+  const command_line::arg_descriptor<std::size_t> core_rpc_server::arg_rpc_max_connections_per_private_ip = {
+      "rpc-max-connections-per-private-ip"
+    , "Max RPC connections per private and localhost IP permitted"
+    , DEFAULT_RPC_MAX_CONNECTIONS_PER_PRIVATE_IP
+  };
+
+  const command_line::arg_descriptor<std::size_t> core_rpc_server::arg_rpc_max_connections = {
+      "rpc-max-connections"
+    , "Max RPC connections permitted"
+    , DEFAULT_RPC_MAX_CONNECTIONS
+  };
+
+  const command_line::arg_descriptor<std::size_t> core_rpc_server::arg_rpc_response_soft_limit = {
+      "rpc-response-soft-limit"
+    , "Max response bytes that can be queued, enforced at next response attempt"
+    , DEFAULT_RPC_SOFT_LIMIT_SIZE
+  };
 }  // namespace cryptonote

src/rpc/core_rpc_server.h

@@ -56,7 +56,6 @@ namespace cryptonote
   {
   public:
 
-    static const command_line::arg_descriptor<bool> arg_public_node;
     static const command_line::arg_descriptor<std::string, false, true, 2> arg_rpc_bind_port;
     static const command_line::arg_descriptor<std::string> arg_rpc_restricted_bind_port;
     static const command_line::arg_descriptor<bool> arg_restricted_rpc;
@@ -73,6 +72,10 @@ namespace cryptonote
     static const command_line::arg_descriptor<uint64_t> arg_rpc_payment_difficulty;
     static const command_line::arg_descriptor<uint64_t> arg_rpc_payment_credits;
     static const command_line::arg_descriptor<bool> arg_rpc_payment_allow_free_loopback;
+    static const command_line::arg_descriptor<std::size_t> arg_rpc_max_connections_per_public_ip;
+    static const command_line::arg_descriptor<std::size_t> arg_rpc_max_connections_per_private_ip;
+    static const command_line::arg_descriptor<std::size_t> arg_rpc_max_connections;
+    static const command_line::arg_descriptor<std::size_t> arg_rpc_response_soft_limit;
 
     typedef epee::net_utils::connection_context_base connection_context;
 

src/wallet/wallet_rpc_server.cpp

@@ -129,6 +129,10 @@ namespace
   const command_line::arg_descriptor<std::string> arg_wallet_dir = {"wallet-dir", "Directory for newly created wallets"};
   const command_line::arg_descriptor<bool> arg_prompt_for_password = {"prompt-for-password", "Prompts for password when not provided", false};
   const command_line::arg_descriptor<bool> arg_no_initial_sync = {"no-initial-sync", "Skips the initial sync before listening for connections", false};
+  const command_line::arg_descriptor<std::size_t> arg_rpc_max_connections_per_public_ip = {"rpc-max-connections-per-public-ip", "Max RPC connections per public IP permitted", DEFAULT_RPC_MAX_CONNECTIONS_PER_PUBLIC_IP};
+  const command_line::arg_descriptor<std::size_t> arg_rpc_max_connections_per_private_ip = {"rpc-max-connections-per-private-ip", "Max RPC connections per private and localhost IP permitted", DEFAULT_RPC_MAX_CONNECTIONS_PER_PRIVATE_IP};
+  const command_line::arg_descriptor<std::size_t> arg_rpc_max_connections = {"rpc-max-connections", "Max RPC connections permitted", DEFAULT_RPC_MAX_CONNECTIONS};
+  const command_line::arg_descriptor<std::size_t> arg_rpc_response_soft_limit = {"rpc-response-soft-limit", "Max response bytes that can be queued, enforced at next response attempt", DEFAULT_RPC_SOFT_LIMIT_SIZE};
 
   constexpr const char default_rpc_username[] = "monero";
 
@@ -325,13 +329,30 @@ namespace tools
 
     check_background_mining();
 
+    const auto max_connections_public = command_line::get_arg(vm, arg_rpc_max_connections_per_public_ip);
+    const auto max_connections_private = command_line::get_arg(vm, arg_rpc_max_connections_per_private_ip);
+    const auto max_connections = command_line::get_arg(vm, arg_rpc_max_connections);
+
+    if (max_connections < max_connections_public)
+    {
+      MFATAL(arg_rpc_max_connections_per_public_ip.name << " is bigger than " << arg_rpc_max_connections.name);
+      return false;
+    }
+    if (max_connections < max_connections_private)
+    {
+      MFATAL(arg_rpc_max_connections_per_private_ip.name << " is bigger than " << arg_rpc_max_connections.name);
+      return false;
+    }
+
     m_net_server.set_threads_prefix("RPC");
     auto rng = [](size_t len, uint8_t *ptr) { return crypto::rand(len, ptr); };
     return epee::http_server_impl_base<wallet_rpc_server, connection_context>::init(
       rng, std::move(bind_port), std::move(rpc_config->bind_ip),
       std::move(rpc_config->bind_ipv6_address), std::move(rpc_config->use_ipv6), std::move(rpc_config->require_ipv4),
       std::move(rpc_config->access_control_origins), std::move(http_login),
-      std::move(rpc_config->ssl_options)
+      std::move(rpc_config->ssl_options),
+      max_connections_public, max_connections_private, max_connections,
+      command_line::get_arg(vm, arg_rpc_response_soft_limit)
     );
   }
   //------------------------------------------------------------------------------------------------------------------------------
@@ -4974,6 +4995,10 @@ int main(int argc, char** argv) {
   command_line::add_arg(desc_params, arg_wallet_dir);
   command_line::add_arg(desc_params, arg_prompt_for_password);
   command_line::add_arg(desc_params, arg_no_initial_sync);
+  command_line::add_arg(desc_params, arg_rpc_max_connections_per_public_ip);
+  command_line::add_arg(desc_params, arg_rpc_max_connections_per_private_ip);
+  command_line::add_arg(desc_params, arg_rpc_max_connections);
+  command_line::add_arg(desc_params, arg_rpc_response_soft_limit);
   command_line::add_arg(hidden_options, daemonizer::arg_non_interactive);
 
   daemonizer::init_options(hidden_options, desc_params);