From 6bc9b993237d7e9ca42dcc8e348ef9cb8bc67d8b Mon Sep 17 00:00:00 2001
From: MCLV <107920484+MCLV-pandorabox@users.noreply.github.com>
Date: Tue, 28 Oct 2025 20:53:29 +0100
Subject: [PATCH] Wildcard (subnet) ban support for IPv4 & IPv6 with trailing *
 notation (#28)

This enables banning entire subnets or address groups, with documentation and usage examples updated in the README. No changes to command structure or database, all bans work with standard xban commands.
---
 README.md | 72 +++++++++++++++++++++++++++++++++++++++----------------
 init.lua  | 42 +++++++++++++++++---------------
 2 files changed, 75 insertions(+), 39 deletions(-)

diff --git a/README.md b/README.md
index 75f8e88..14c74c8 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,5 @@
-
 # Extended Ban Mod for Minetest
-
 This mod attempts to be an improvement to Minetest's ban system.
-
 * It supports normal bans and temporary bans (from 60 seconds up to the end of
   time, with 1 second granularity).
 * Records and joins all accounts using the same IP address and several IP
@@ -15,26 +12,70 @@ This mod attempts to be an improvement to Minetest's ban system.
 * Has an API to ban and check the ban database to allows other mods to manage
   users (for example, anticheat mods).
 
-## Chat commands
+## Wildcard/Subnet Ban Feature
 
+The mod now supports wildcard (subnet) bans for IP addresses using trailing `*` notation. This allows you to ban entire IP ranges or subnets with a single command.
+
+### How It Works
+
+* **IPv4 Wildcard Bans**: Use a trailing `*` to match any IP address that starts with the specified prefix.
+  * Example: `192.168.1.*` will match all IPs from `192.168.1.0` to `192.168.1.255`
+  * Example: `10.0.*` will match all IPs from `10.0.0.0` to `10.0.255.255`
+  * Example: `172.*` will match all IPs from `172.0.0.0` to `172.255.255.255`
+
+* **IPv6 Wildcard Bans**: Use a trailing `*` to match any IPv6 address that starts with the specified prefix.
+  * Example: `2001:db8:*` will match all IPv6 addresses starting with `2001:db8:`
+  * Example: `fe80:*` will match all link-local IPv6 addresses
+
+### Usage Examples
+
+**Ban an entire IPv4 subnet:**
+```
+/xban 192.168.1.* Banning entire subnet due to spam
+```
+
+**Temporarily ban an IPv4 range:**
+```
+/xtempban 10.0.* 24h Temporary subnet ban for suspected bot activity
+```
+
+**Ban an IPv6 prefix:**
+```
+/xban 2001:db8:* Banning IPv6 prefix
+```
+
+**Unban a wildcard entry:**
+```
+/xunban 192.168.1.*
+```
+
+### Notes
+
+* Wildcard bans are checked when a player attempts to connect.
+* Individual IP addresses can still be whitelisted even if they match a wildcard ban.
+* The wildcard character `*` must be at the end of the IP address.
+* For IPv4, you can use wildcards at any octet boundary (e.g., `192.*`, `192.168.*`, `192.168.1.*`).
+* For IPv6, the wildcard matches the remaining part of the address after the specified prefix.
+
+## Chat commands
 The mod provides the following chat commands. All commands require the `ban`
 privilege.
 
 ### `xban`
-
 Bans a player permanently.
 
 **Usage:** `/xban <player_or_ip> <reason>`
 
 **Example:** `/xban 127.0.0.1 Some reason.`
 
-### `xtempban`
+**Wildcard Example:** `/xban 192.168.1.* Subnet ban`
 
+### `xtempban`
 Bans a player temporarily.
 
 **Usage:** `/xtempban <player_or_ip> <time> <reason>`
 
-The `time` parameter is a string in the format `<count><unit>` where `<unit>`
+The `time` parameter is a string in the format `<number><unit>` where `<unit>`
 is one of `s` for seconds, `m` for minutes, `h` for hours, `D` for days, `W`
 for weeks, `M` for months, or `Y` for years. If the unit is omitted, it is
 assumed to mean seconds. For example, `42s` means 42 seconds, `1337m` 1337
@@ -43,28 +84,23 @@ up. For example, `1Y3M3D7h` will ban for 1 year, 3 months, 3 days and 7 hours.
 
 **Example:** `/xtempban Joe 3600 Some reason.`
 
-### `xunban`
+**Wildcard Example:** `/xtempban 10.0.* 7D Temporary subnet ban`
 
+### `xunban`
 Unbans a player.
 
 **Usage:** `/xunban <player_or_ip>`
 
 **Example:** `/xunban Joe`
 
-### `xban_record`
+**Wildcard Example:** `/xunban 192.168.1.*`
 
+### `xban_record`
 Shows the ban record on chat.
 
 **Usage:** `/xban_record <player_or_ip>`
 
-This prints one ban entry per line, with the time the ban came into effect,
-the expiration time (if applicable), the reason, and the source of the ban.
-The record is printed to chat with one entry per line.
-
-**Example:** `/xban_record Joe`
-
 ### `xban_wl`
-
 Manages the whitelist.
 
 **Usage:** `/xban_wl (add|del|get) <player_or_ip>`
@@ -80,18 +116,15 @@ player is in the whitelist, and prints the status to chat.
 **Example:** `/xban_record add Jane`
 
 ### `xban_gui`
-
 Shows a form to consult the database interactively.
 
 **Usage:** `/xban_gui`
 
 ## Administrator commands
-
 The following commands require the `server` privilege, so they are only
 available to server administrators.
 
 ### `xban_dbi`
-
 Imports ban entries from other database formats.
 
 **Usage:** `/xban_dbi <importer>`
@@ -106,7 +139,6 @@ the supported import plugins at the time of writing:
 **Example:** `/xban_dbi minetest`
 
 ### `xban_cleanup`
-
 Removes all non-banned entries from the xban db.
 
 **Usage:** `/xban_cleanup`
diff --git a/init.lua b/init.lua
index 0940cb0..1037f55 100644
--- a/init.lua
+++ b/init.lua
@@ -49,25 +49,29 @@ local function concat_keys(t, sep)
 	return table.concat(keys, sep)
 end
 
-function xban.find_entry(player, create) --> entry, index
-	for index, e in ipairs(db) do
-		for name in pairs(e.names) do
-			if name == player then
-				return e, index
-			end
-		end
-	end
-	if create then
-		print(("Created new entry for `%s'"):format(player))
-		local e = {
-			names = { [player]=true },
-			banned = false,
-			record = { },
-		}
-		table.insert(db, e)
-		return e, #db
-	end
-	return nil
+-- supports wildcard IP pattern (both IPv4 and IPv6)
+function xban.find_entry(key, create)
+    -- exact match (player or IP)
+    for i, e in ipairs(xban.db) do
+        if e.names[key] then return e, i end
+    end
+    -- wildcard pattern match for IPs
+    if key and key:find("[.:]") then
+        for i, e in ipairs(xban.db) do
+            for name in pairs(e.names) do
+	            local wildcard_prefix = name:match("(.+[.:])%*$")
+	            if wildcard_prefix and key:sub(1, #wildcard_prefix) == wildcard_prefix then
+	                return e, i
+	            end
+	        end
+        end
+    end
+    if create then
+        local e = { names = { [key] = true }, bans = {} }
+        table.insert(xban.db, e)
+        return e, #xban.db
+    end
+    return nil
 end
 
 function xban.get_info(player) --> ip_name_list, banned, last_record