changeset 14113:b9688ac25255 13.0

mod_admin_shell: Improve per-host command cleanup In some cases, host command handlers were not being cleaned up after the source module was unloaded, for example. This is because mod_admin_shell saw that the handler being removed did not match the installed handler. But this is expected for the new per-host commands, because the installed handler is a wrapper function which routes between the hosts. The wrapper function itself also held a reference via upvalue to the first command object which added it, just so it could read the argument names and such. This could cause command objects, and anything referenced by the handler, to stay around in memory longer than expected, even after a module has been unloaded or a host deactivated. The new logic breaks out the handler function to eliminate any unexpected upvalues. It improves the cleanup logic when a command is removed. Finally, it also cleans up commands when mod_admin_shell itself is unloaded.
author Matthew Wild <mwild1@gmail.com>
date Fri, 27 Mar 2026 12:43:10 +0000
parents 1cf6e3f49d10
children 8f50e7e43df4
files plugins/mod_admin_shell.lua
diffstat 1 files changed, 61 insertions(+), 35 deletions(-) [+]
line wrap: on
line diff
--- a/plugins/mod_admin_shell.lua	Tue Mar 24 16:34:06 2026 +0100
+++ b/plugins/mod_admin_shell.lua	Fri Mar 27 12:43:10 2026 +0000
@@ -2817,6 +2817,46 @@
 -- host_commands[section..":"..name][false] = metadata
 local host_commands = {};
 
+-- Remove command handlers for a host (specify name to clear just one command)
+function clear_host_commands(host, name)
+	for command_name, command_info in pairs(host_commands) do
+		if not name or name == command_name then
+			command_info[host] = nil;
+			local has_any_host_handlers_left;
+			for k in pairs(command_info) do
+				if k ~= false then
+					has_any_host_handlers_left = true;
+					break;
+				end
+			end
+			if not has_any_host_handlers_left then
+				host_commands[command_name] = nil;
+			end
+			if name then
+				break;
+			end
+		end
+	end
+end
+
+-- This returns a wrapper function which routes to the correct handler for a host
+local function new_host_command_handler(qualified_name, selector_name, selector_index)
+	return function (...)
+		local selected_host = select(2, jid_split((select(selector_index, ...))));
+		if type(selected_host) ~= "string" then
+			return nil, "Invalid or missing argument '"..selector_name.."'";
+		end
+		if not prosody.hosts[selected_host] then
+			return nil, "Unknown host: "..selected_host;
+		end
+		local host_handler = host_commands[qualified_name][selected_host];
+		if not host_handler then
+			return nil, "This command is not available on "..selected_host;
+		end
+		return host_handler(...);
+	end;
+end
+
 local function new_item_handlers(command_host)
 	local function on_command_added(event)
 		local command = event.item;
@@ -2850,26 +2890,13 @@
 				host_command_info = {
 					[false] = {
 						host_selector = command.host_selector;
-						handler = function (...)
-							local selected_host = select(2, jid_split((select(selector_index, ...))));
-							if type(selected_host) ~= "string" then
-								return nil, "Invalid or missing argument '"..command.host_selector.."'";
-							end
-							if not prosody.hosts[selected_host] then
-								return nil, "Unknown host: "..selected_host;
-							end
-							local host_handler = host_commands[qualified_name][selected_host];
-							if not host_handler then
-								return nil, "This command is not available on "..selected_host;
-							end
-							return host_handler(...);
-						end;
+						handler = new_host_command_handler(qualified_name, command.host_selector, selector_index);
 					};
 				};
 				host_commands[qualified_name] = host_command_info;
 			end
 			if host_command_info[command_host] then
-				module:log("warn", "Command %s() is already registered - overwriting with %s", qualified_name, mod_name);
+				module:log("warn", "Command %s() is already registered on %s - overwriting with %s", qualified_name, command_host, mod_name);
 			end
 			host_command_info[command_host] = handler;
 		end
@@ -2930,32 +2957,24 @@
 
 		local section_t = def_env[command.section];
 		if not section_t or section_t[command.name] ~= handler then
-			return;
+			-- Handler doesn't match, but it could be the host-selector wrapper
+			-- Let's try removing a per-host command
+			local qualified_name = command.section..":"..command.name;
+			local host_command_handlers = host_commands[qualified_name];
+			if host_command_handlers then
+				-- Bingo!
+				module:log("debug", "Removing command %s from %s", qualified_name, command_host);
+				clear_host_commands(command_host, qualified_name);
+			elseif section_t then
+				module:log("warn", "Not removing shell command: handler mismatch: %q ~= %q", section_t and section_t[command.name], handler);
+				return;
+			end
 		end
 
 		section_t[command.name] = nil;
 		if next(section_t) == nil then -- Delete section if empty
 			def_env[command.section] = nil;
 		end
-
-		if command_host then
-			local host_command_info = host_commands[command.section..":"..command.name];
-			if host_command_info then
-				-- Remove our host handler
-				host_command_info[command_host] = nil;
-				-- Clean up entire command entry if there are no per-host handlers left
-				local any_hosts = false;
-				for k in pairs(host_command_info) do
-					if k then -- metadata is false, ignore it
-						any_hosts = true;
-						break;
-					end
-				end
-				if not any_hosts then
-					host_commands[command.section..":"..command.name] = nil;
-				end
-			end
-		end
 	end
 	return on_command_added, on_command_removed;
 end
@@ -2964,6 +2983,13 @@
 
 function module.add_host(host_module)
 	host_module:handle_items("shell-command", new_item_handlers(host_module.host));
+	function host_module.unload()
+		-- Due to non-deterministic unload order, we might not see item
+		-- removal events for all commands before we get unloaded, so
+		-- we clear everything from the host explicitly when we're
+		-- unloaded (also sensible if we are unloaded manually)
+		clear_host_commands(host_module.host);
+	end
 end
 
 function module.unload()