Feature #7957: load/save ban lists to external files

docs/multiplayer.md

@@ -117,6 +117,8 @@ Last updated:    2011-02-16
  - You can protect your server with a password via the console: 'set server_pw',
    or via the Start Server menu.
 
+- You can ban or kick problemantic players via the console: 'ban client_ip_address' or 'kick client_ip_address'
+
  - When you have many clients connected to your server via Internet, watch your
    bandwidth (if you have any limit on it, set by your ISP). One client uses
    about 1.5 kilobytes per second up and down. To decrease this amount, setting
@@ -200,7 +202,7 @@ Last updated:    2011-02-16
 
  - You can chat with other players via ENTER or via SHIFT+T or via the ClientList
 
- - Servers can now kick players, so don't make them use it!
+ - Servers can kick or ban players, so don't make them use it!
 
 
 ## 6.0) Troubleshooting

src/console_cmds.cpp

@@ -11,6 +11,7 @@
 #include "console_internal.h"
 #include "debug.h"
 #include "engine_func.h"
+#include "ini_type.h"
 #include "landscape.h"
 #include "saveload/saveload.h"
 #include "network/network.h"
@@ -484,7 +485,7 @@ static bool ConKickOrBan(const char *argv, bool ban, const char *reason)
 		 * would be reading from and writing to after returning. So we would read or write data
 		 * from freed memory up till the segfault triggers. */
 		if (client_id == CLIENT_ID_SERVER || client_id == _redirect_console_to_client) {
-			IConsolePrintF(CC_ERROR, "ERROR: Silly boy, you can not %s yourself!", ban ? "ban" : "kick");
+			IConsolePrintF(CC_ERROR, "ERROR: You cannot %s yourself.", ban ? "ban" : "kick");
 			return true;
 		}
 
@@ -614,6 +615,119 @@ DEF_CONSOLE_CMD(ConBanList)
 	return true;
 }
 
+/**
+* Loads the ban list from the specified path.
+* @param path The path to load the ban list from.
+* @return The number of entries loaded from the file or -1 if an error occurred while loading entries.
+*/
+static int LoadBanList(const std::string& path)
+{
+	const char* const group_names[] = {
+		"bans",
+		nullptr
+	};
+
+	IniFile ini = { group_names };
+	ini.LoadFromDisk(path, NO_DIRECTORY);
+	const IniGroup *ban_group = ini.GetGroup("bans", false);
+
+	bool is_loaded = ban_group != nullptr;
+	if (!is_loaded) {
+		return -1;
+	}
+
+	int loaded_count = 0;
+	for (const IniItem *item = ban_group->item; item != nullptr; item = item->next) {
+		// banned clients are added to global ban list when kicked or banned
+		NetworkServerKickOrBanIP(item->name.c_str(), true, nullptr);
+		loaded_count++;
+	}
+	return loaded_count;
+}
+
+/**
+* Loads a ban list from a user-specified file. The entries in the list are added to the current collection of banned entries.
+* @see ConBanList
+*/
+DEF_CONSOLE_CMD(ConBanListLoad)
+{
+	if (argc == 0) {
+		IConsoleHelp("Loads the IP's of banned clients from a file: Usage 'banlist_load <path_to_file>'");
+		return true;
+	}
+
+	if (argc != 2) {
+		return false;
+	}
+
+	const char * const path = argv[1];
+	IConsolePrintF(CC_INFO, "Loading banlist from '%s'...", path);
+	int loaded_entries_count = LoadBanList(path);
+	if (loaded_entries_count == -1) {
+		IConsolePrint(CC_WARNING, "File does not exist or [bans] section is unspecified.");
+		return false;
+	}
+
+	IConsolePrintF(CC_INFO, "Loaded %d entries.", loaded_entries_count);
+	return true;
+}
+
+/**
+* Saves the specified ban list to the specified path.
+* @param path The path to save the ban list to.
+* @param ban_list The ban list to save.
+* @return The number of entries saved to the file or -1 if an error occurred while saving entries.
+*/
+static int SaveBanList(const std::string &path, const StringList &ban_list)
+{
+	const char * const group_names[] = {
+		"bans",
+		nullptr
+	};
+
+	IniFile ini = { group_names };
+	IniGroup *ban_group = ini.GetGroup("bans", true);
+
+	int item_count = 0;
+	for (const std::string &name : ban_list) {
+		ban_group->GetItem(name, true);
+		item_count++;
+	}
+
+	if (ini.SaveToDisk(path)) {
+		return item_count;
+	} else {
+		return -1;
+	}
+}
+
+/**
+* Saves the current ban list to a user-specified file.
+* @see ConBanList
+*/
+DEF_CONSOLE_CMD(ConBanListSave)
+{
+	if (argc == 0) {
+		IConsoleHelp("Saves the banned list of clients to a file: Usage 'banlist_save <path_to_file>'");
+		return true;
+	}
+	if (argc != 2) {
+		return false;
+	}
+
+	const char *path = argv[1];
+	IConsolePrintF(CC_INFO, "Saving banlist to '%s'...", path);
+	const int saved_entries_count = SaveBanList(path, _network_ban_list);
+	if (saved_entries_count >= 0) {
+		IConsolePrintF(CC_INFO, "Saved %d entries.", saved_entries_count);
+		return true;
+	}
+	else {
+		IConsolePrint(CC_WARNING, "Cound not save banlist.");
+		return false;
+	}
+}
+
 DEF_CONSOLE_CMD(ConPauseGame)
 {
 	if (argc == 0) {
@@ -2412,6 +2526,8 @@ void IConsoleStdLibRegister()
 	IConsoleCmdRegister("ban",             ConBan, ConHookServerOnly);
 	IConsoleCmdRegister("unban",           ConUnBan, ConHookServerOnly);
 	IConsoleCmdRegister("banlist",         ConBanList, ConHookServerOnly);
+	IConsoleCmdRegister("banlist_load",    ConBanListLoad, ConHookServerOnly);
+	IConsoleCmdRegister("banlist_save",    ConBanListSave, ConHookServerOnly);
 
 	IConsoleCmdRegister("pause",           ConPauseGame, ConHookServerOnly);
 	IConsoleCmdRegister("unpause",         ConUnpauseGame, ConHookServerOnly);