p2p: allow comments in banlist files

In-line comments explicitly explaining banned hosts/subnets might help assuage fears of some good banlists' arbitaryiness.

src/daemon/command_parser_executor.cpp

@@ -696,6 +696,16 @@ bool t_command_parser_executor::ban(const std::vector<std::string>& args)
       std::ifstream ifs(ban_list_path.string());
       for (std::string line; std::getline(ifs, line); )
       {
+        // ignore comments after '#' character
+        const size_t pound_idx = line.find('#');
+        if (pound_idx != std::string::npos)
+          line.resize(pound_idx);
+
+        // trim whitespace and ignore empty lines
+        boost::trim(line);
+        if (line.empty())
+          continue;
+
         auto subnet = net::get_ipv4_subnet_address(line);
         if (subnet)
         {

src/p2p/net_node.inl

@@ -527,6 +527,16 @@ namespace nodetool
       std::istringstream iss(banned_ips);
       for (std::string line; std::getline(iss, line); )
       {
+        // ignore comments after '#' character
+        const size_t pound_idx = line.find('#');
+        if (pound_idx != std::string::npos)
+          line.resize(pound_idx);
+
+        // trim whitespace and ignore empty lines
+        boost::trim(line);
+        if (line.empty())
+          continue;
+
         auto subnet = net::get_ipv4_subnet_address(line);
         if (subnet)
         {

tests/data/node/banlist_1.txt

@@ -0,0 +1,17 @@
+# magicfolk
+255.255.255.0   # Saruman the White
+128.128.128.0    # Gandalf the Gray
+150.75.0.0     #     Radagast the Brown
+99.98.0.0/16    # All of Misty Mountain
+
+# personal enemies
+1.2.3.4 # this woman used to give me swirlies
+6.7.8.9    #  I just don't like the cut of his jib
+1.0.0.7#Literally James Bond, he wrecked my aston martin
+100.98.1.13 # Earl from HOA
+100.98.1.0/24   #The rest of the HOA for good measure
+#
+
+#7.7.7.7
+#^^^We're chill now, she's truly an angel
+

tests/unit_tests/node_server.cpp

@@ -35,6 +35,7 @@
 #include "cryptonote_core/i_core_events.h"
 #include "cryptonote_protocol/cryptonote_protocol_handler.h"
 #include "cryptonote_protocol/cryptonote_protocol_handler.inl"
+#include "unit_tests_utils.h"
 #include <condition_variable>
 
 #define MAKE_IPV4_ADDRESS(a,b,c,d) epee::net_utils::ipv4_network_address{MAKE_IP(a,b,c,d),0}
@@ -114,6 +115,18 @@ static bool is_blocked(Server &server, const epee::net_utils::network_address &a
       return true;
     }
   }
+
+  if (address.get_type_id() != epee::net_utils::address_type::ipv4)
+    return false;
+  
+  const epee::net_utils::ipv4_network_address ipv4_address = address.as<epee::net_utils::ipv4_network_address>();
+
+  // check if in a blocked ipv4 subnet
+  const std::map<epee::net_utils::ipv4_network_subnet, time_t> subnets = server.get_blocked_subnets();
+  for (const auto &subnet : subnets)
+    if (subnet.first.matches(ipv4_address))
+      return true;
+
   return false;
 }
 
@@ -266,6 +279,78 @@ TEST(ban, ignores_port)
   ASSERT_FALSE(is_blocked(server,MAKE_IPV4_ADDRESS_PORT(1,2,3,4,6)));
 }
 
+TEST(ban, file_banlist)
+{
+  test_core pr_core;
+  cryptonote::t_cryptonote_protocol_handler<test_core> cprotocol(pr_core, NULL);
+  Server server(cprotocol);
+  cprotocol.set_p2p_endpoint(&server);
+
+  auto create_node_dir = [](){
+    boost::system::error_code ec;
+    auto path = boost::filesystem::temp_directory_path() / boost::filesystem::unique_path("daemon-%%%%%%%%%%%%%%%%", ec);
+    if (ec)
+      return boost::filesystem::path{};
+    auto success = boost::filesystem::create_directory(path, ec);
+    if (!ec && success)
+      return path;
+    return boost::filesystem::path{};
+  };
+  const auto node_dir = create_node_dir();
+  ASSERT_TRUE(!node_dir.empty());
+  auto auto_remove_node_dir = epee::misc_utils::create_scope_leave_handler([&node_dir](){
+      boost::filesystem::remove_all(node_dir);
+    });
+
+  boost::program_options::variables_map vm;
+  boost::program_options::store(
+    boost::program_options::command_line_parser({
+      "--data-dir",
+      node_dir.string(),
+      "--ban-list",
+      (unit_test::data_dir / "node" / "banlist_1.txt").string()
+    }).options([]{
+      boost::program_options::options_description options_description{};
+      cryptonote::core::init_options(options_description);
+      Server::init_options(options_description);
+      return options_description;
+    }()).run(),
+    vm
+  );
+
+  ASSERT_TRUE(server.init(vm));
+
+  // Test cases (look in the banlist_1.txt file)
+
+  // magicfolk
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(255,255,255,0,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(128,128,128,0,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(150,75,0,0,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(99,98,0,0,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(99,98,0,255,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(99,98,1,0,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(99,98,1,0,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(99,98,255,255,9999)) );
+  EXPECT_FALSE( is_blocked(server, MAKE_IPV4_ADDRESS_PORT(99,99,0,0,9999)) );
+
+  // personal enemies
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(1,2,3,4,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(6,7,8,9,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(1,0,0,7,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(1,0,0,7,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(100,98,1,13,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(100,98,1,0,9999)) );
+  EXPECT_TRUE(  is_blocked(server, MAKE_IPV4_ADDRESS_PORT(100,98,1,255,9999)) );
+  EXPECT_FALSE( is_blocked(server, MAKE_IPV4_ADDRESS_PORT(100,98,2,0,9999)) );
+  EXPECT_FALSE( is_blocked(server, MAKE_IPV4_ADDRESS_PORT(100,98,0,255,9999)) );
+
+  // angel
+  EXPECT_FALSE( is_blocked(server, MAKE_IPV4_ADDRESS_PORT(007,007,007,007,9999)) );
+
+  // random IP
+  EXPECT_FALSE( is_blocked(server, MAKE_IPV4_ADDRESS_PORT(145,036,205,235,9999)) );
+}
+
 TEST(node_server, bind_same_p2p_port)
 {
   struct test_data_t