File

util/pubsub.lua @ 13055:e732f9dfdfc8

mod_mam: port to use util.human.io.parse_duration Updated by Zash, the original patch by Jonas had put the duration parsing function in util.datetime but MattJ later did the same thing but differently in f4d7fe919969
author Jonas Schäfer <jonas@wielicki.name>
date Thu, 28 Apr 2022 20:38:40 +0200
parent 12975:d10957394a3c
line wrap: on
line source

local events = require "prosody.util.events";
local cache = require "prosody.util.cache";
local errors = require "prosody.util.error";

local service_mt = {};

local default_config = {
	max_items = 256;
	itemstore = function (config, _) return cache.new(config["max_items"]) end;
	broadcaster = function () end;
	subscriber_filter = function (subs) return subs end;
	itemcheck = function () return true; end;
	get_affiliation = function () end;
	normalize_jid = function (jid) return jid; end;
	capabilities = {
		outcast = {
			create = false;
			publish = false;
			retract = false;
			get_nodes = false;

			subscribe = false;
			unsubscribe = false;
			get_subscription = true;
			get_subscriptions = true;
			get_items = false;

			subscribe_other = false;
			unsubscribe_other = false;
			get_subscription_other = false;
			get_subscriptions_other = false;

			be_subscribed = false;
			be_unsubscribed = true;

			set_affiliation = false;
		};
		none = {
			create = false;
			publish = false;
			retract = false;
			get_nodes = true;

			subscribe = true;
			unsubscribe = true;
			get_subscription = true;
			get_subscriptions = true;
			get_items = false;

			subscribe_other = false;
			unsubscribe_other = false;
			get_subscription_other = false;
			get_subscriptions_other = false;

			be_subscribed = true;
			be_unsubscribed = true;

			set_affiliation = false;
		};
		member = {
			create = false;
			publish = false;
			retract = false;
			get_nodes = true;

			subscribe = true;
			unsubscribe = true;
			get_subscription = true;
			get_subscriptions = true;
			get_items = true;

			subscribe_other = false;
			unsubscribe_other = false;
			get_subscription_other = false;
			get_subscriptions_other = false;

			be_subscribed = true;
			be_unsubscribed = true;

			set_affiliation = false;
		};
		publisher = {
			create = false;
			publish = true;
			retract = true;
			get_nodes = true;
			get_configuration = true;

			subscribe = true;
			unsubscribe = true;
			get_subscription = true;
			get_subscriptions = true;
			get_items = true;

			subscribe_other = false;
			unsubscribe_other = false;
			get_subscription_other = false;
			get_subscriptions_other = false;

			be_subscribed = true;
			be_unsubscribed = true;

			set_affiliation = false;
		};
		owner = {
			create = true;
			publish = true;
			retract = true;
			delete = true;
			get_nodes = true;
			configure = true;
			get_configuration = true;

			subscribe = true;
			unsubscribe = true;
			get_subscription = true;
			get_subscriptions = true;
			get_items = true;


			subscribe_other = true;
			unsubscribe_other = true;
			get_subscription_other = true;
			get_subscriptions_other = true;

			be_subscribed = true;
			be_unsubscribed = true;

			set_affiliation = true;
		};
	};
};
local default_config_mt = { __index = default_config };

local default_node_config = {
	["persist_items"] = true;
	["max_items"] = 20;
	["access_model"] = "open";
	["publish_model"] = "publishers";
	["send_last_published_item"] = "never";
};
local default_node_config_mt = { __index = default_node_config };

-- Storage helper functions

local function load_node_from_store(service, node_name)
	local node = service.config.nodestore:get(node_name);
	node.config = setmetatable(node.config or {}, {__index=service.node_defaults});
	return node;
end

local function save_node_to_store(service, node)
	return service.config.nodestore:set(node.name, {
		name = node.name;
		config = node.config;
		subscribers = node.subscribers;
		affiliations = node.affiliations;
	});
end

local function delete_node_in_store(service, node_name)
	return service.config.nodestore:set(node_name, nil);
end

-- Create and return a new service object
local function new(config)
	config = config or {};

	local service = setmetatable({
		config = setmetatable(config, default_config_mt);
		node_defaults = setmetatable(config.node_defaults or {}, default_node_config_mt);
		affiliations = {};
		subscriptions = {};
		nodes = {};
		data = {};
		events = events.new();
	}, service_mt);

	-- Load nodes from storage, if we have a store and it supports iterating over stored items
	if config.nodestore and config.nodestore.users then
		for node_name in config.nodestore:users() do
			local node = load_node_from_store(service, node_name);
			service.nodes[node_name] = node;
			if node.config.persist_items then
				service.data[node_name] = config.itemstore(service.nodes[node_name].config, node_name);
			end

			for jid in pairs(service.nodes[node_name].subscribers) do
				local normal_jid = service.config.normalize_jid(jid);
				local subs = service.subscriptions[normal_jid];
				if subs then
					if not subs[jid] then
						subs[jid] = { [node_name] = true };
					else
						subs[jid][node_name] = true;
					end
				else
					service.subscriptions[normal_jid] = { [jid] = { [node_name] = true } };
				end
			end
		end
	end

	return service;
end

--- Service methods

local service = {};
service_mt.__index = service;

function service:jids_equal(jid1, jid2) --> boolean
	local normalize = self.config.normalize_jid;
	return normalize(jid1) == normalize(jid2);
end

function service:may(node, actor, action) --> boolean
	if actor == true then return true; end

	local node_obj = self.nodes[node];
	local node_aff = node_obj and (node_obj.affiliations[actor]
	              or node_obj.affiliations[self.config.normalize_jid(actor)]);
	local service_aff = self.affiliations[actor]
	                 or self.config.get_affiliation(actor, node, action);
	local default_aff = self:get_default_affiliation(node, actor) or "none";

	-- Check if node allows/forbids it
	local node_capabilities = node_obj and node_obj.capabilities;
	if node_capabilities then
		local caps = node_capabilities[node_aff or service_aff or default_aff];
		if caps then
			local can = caps[action];
			if can ~= nil then
				return can;
			end
		end
	end

	-- Check service-wide capabilities instead
	local service_capabilities = self.config.capabilities;
	local caps = service_capabilities[node_aff or service_aff or default_aff];
	if caps then
		local can = caps[action];
		if can ~= nil then
			return can;
		end
	end

	return false;
end

function service:get_default_affiliation(node, actor) --> affiliation
	local node_obj = self.nodes[node];
	local access_model = node_obj and node_obj.config.access_model
		or self.node_defaults.access_model;

	if access_model == "open" then
		return "member";
	elseif access_model == "whitelist" then
		return "outcast";
	end

	if self.config.access_models then
		local check = self.config.access_models[access_model];
		if check then
			local aff = check(actor);
			if aff then
				return aff;
			end
		end
	end
end

function service:set_affiliation(node, actor, jid, affiliation) --> ok, err
	-- Access checking
	if not self:may(node, actor, "set_affiliation") then
		return false, "forbidden";
	end
	--
	local node_obj = self.nodes[node];
	if not node_obj then
		return false, "item-not-found";
	end
	jid = self.config.normalize_jid(jid);
	local old_affiliation = node_obj.affiliations[jid];
	node_obj.affiliations[jid] = affiliation;

	if self.config.nodestore then
		-- TODO pass the error from storage to caller eg wrapped in an util.error
		local ok, err = save_node_to_store(self, node_obj); -- luacheck: ignore 211/err
		if not ok then
			node_obj.affiliations[jid] = old_affiliation;
			return ok, "internal-server-error";
		end
	end

	local _, jid_sub = self:get_subscription(node, true, jid);
	if not jid_sub and not self:may(node, jid, "be_unsubscribed") then
		local ok, err = self:add_subscription(node, true, jid);
		if not ok then
			return ok, err;
		end
	elseif jid_sub and not self:may(node, jid, "be_subscribed") then
		local ok, err = self:add_subscription(node, true, jid);
		if not ok then
			return ok, err;
		end
	end
	return true;
end

function service:add_subscription(node, actor, jid, options) --> ok, err
	-- Access checking
	local cap;
	if actor == true or jid == actor or self:jids_equal(actor, jid) then
		cap = "subscribe";
	else
		cap = "subscribe_other";
	end
	if not self:may(node, actor, cap) then
		return false, "forbidden";
	end
	if not self:may(node, jid, "be_subscribed") then
		return false, "forbidden";
	end
	--
	local node_obj = self.nodes[node];
	if not node_obj then
		if not self.config.autocreate_on_subscribe then
			return false, "item-not-found";
		else
			local ok, err = self:create(node, true);
			if not ok then
				return ok, err;
			end
			node_obj = self.nodes[node];
		end
	end
	local old_subscription = node_obj.subscribers[jid];
	node_obj.subscribers[jid] = options or true;
	local normal_jid = self.config.normalize_jid(jid);
	local subs = self.subscriptions[normal_jid];
	if subs then
		if not subs[jid] then
			subs[jid] = { [node] = true };
		else
			subs[jid][node] = true;
		end
	else
		self.subscriptions[normal_jid] = { [jid] = { [node] = true } };
	end

	if self.config.nodestore then
		-- TODO pass the error from storage to caller eg wrapped in an util.error
		local ok, err = save_node_to_store(self, node_obj); -- luacheck: ignore 211/err
		if not ok then
			node_obj.subscribers[jid] = old_subscription;
			self.subscriptions[normal_jid][jid][node] = old_subscription and true or nil;
			return ok, "internal-server-error";
		end
	end

	self.events.fire_event("subscription-added", { service = self, node = node, jid = jid, normalized_jid = normal_jid, options = options });
	return true;
end

function service:remove_subscription(node, actor, jid) --> ok, err
	-- Access checking
	local cap;
	if actor == true or jid == actor or self:jids_equal(actor, jid) then
		cap = "unsubscribe";
	else
		cap = "unsubscribe_other";
	end
	if not self:may(node, actor, cap) then
		return false, "forbidden";
	end
	if not self:may(node, jid, "be_unsubscribed") then
		return false, "forbidden";
	end
	--
	local node_obj = self.nodes[node];
	if not node_obj then
		return false, "item-not-found";
	end
	if not node_obj.subscribers[jid] then
		return false, "not-subscribed";
	end
	local old_subscription = node_obj.subscribers[jid];
	node_obj.subscribers[jid] = nil;
	local normal_jid = self.config.normalize_jid(jid);
	local subs = self.subscriptions[normal_jid];
	if subs then
		local jid_subs = subs[jid];
		if jid_subs then
			jid_subs[node] = nil;
			if next(jid_subs) == nil then
				subs[jid] = nil;
			end
		end
		if next(subs) == nil then
			self.subscriptions[normal_jid] = nil;
		end
	end

	if self.config.nodestore then
		-- TODO pass the error from storage to caller eg wrapped in an util.error
		local ok, err = save_node_to_store(self, node_obj); -- luacheck: ignore 211/err
		if not ok then
			node_obj.subscribers[jid] = old_subscription;
			self.subscriptions[normal_jid][jid][node] = old_subscription and true or nil;
			return ok, "internal-server-error";
		end
	end

	self.events.fire_event("subscription-removed", { service = self, node = node, jid = jid, normalized_jid = normal_jid });
	return true;
end

function service:get_subscription(node, actor, jid) --> (true, subscription) or (false, err)
	-- Access checking
	local cap;
	if actor == true or jid == actor or self:jids_equal(actor, jid) then
		cap = "get_subscription";
	else
		cap = "get_subscription_other";
	end
	if not self:may(node, actor, cap) then
		return false, "forbidden";
	end
	--
	local node_obj = self.nodes[node];
	if not node_obj then
		return false, "item-not-found";
	end
	return true, node_obj.subscribers[jid];
end

function service:create(node, actor, options) --> ok, err
	-- Access checking
	if not self:may(node, actor, "create") then
		return false, "forbidden";
	end
	--
	if self.nodes[node] then
		return false, "conflict";
	end

	local config = setmetatable(options or {}, {__index=self.node_defaults});

	if self.config.check_node_config then
		local ok = self.config.check_node_config(node, actor, config);
		if not ok then
			return false, "not-acceptable";
		end
	end

	self.nodes[node] = {
		name = node;
		subscribers = {};
		config = config;
		affiliations = {};
	};

	if self.config.nodestore then
		-- TODO pass the error from storage to caller eg wrapped in an util.error
		local ok, err = save_node_to_store(self, self.nodes[node]); -- luacheck: ignore 211/err
		if not ok then
			self.nodes[node] = nil;
			return ok, "internal-server-error";
		end
	end

	if config.persist_items then
		self.data[node] = self.config.itemstore(self.nodes[node].config, node);
	end

	self.events.fire_event("node-created", { service = self, node = node, actor = actor });
	if actor ~= true then
		local ok, err = self:set_affiliation(node, true, actor, "owner");
		if not ok then
			self.nodes[node] = nil;
			self.data[node] = nil;
			return ok, err;
		end
	end

	return true;
end

function service:delete(node, actor) --> ok, err
	-- Access checking
	if not self:may(node, actor, "delete") then
		return false, "forbidden";
	end
	--
	local node_obj = self.nodes[node];
	if not node_obj then
		return false, "item-not-found";
	end
	self.nodes[node] = nil;
	if self.data[node] and self.data[node].clear then
		self.data[node]:clear();
	end
	self.data[node] = nil;

	if self.config.nodestore then
		local ok, err = delete_node_in_store(self, node);
		if not ok then
			self.nodes[node] = nil;
			return ok, err;
		end
	end

	self.events.fire_event("node-deleted", { service = self, node = node, actor = actor });
	self:broadcast("delete", node, node_obj.subscribers, nil, actor, node_obj);
	return true;
end

-- Used to check that the config of a node is as expected (i.e. 'publish-options')
local function check_preconditions(node_config, required_config)
	if not (node_config and required_config) then
		return false;
	end
	for config_field, value in pairs(required_config) do
		if node_config[config_field] ~= value then
			return false, config_field;
		end
	end
	return true;
end

function service:publish(node, actor, id, item, requested_config) --> ok, err
	-- Access checking
	local may_publish = false;

	if self:may(node, actor, "publish") then
		may_publish = true;
	else
		local node_obj = self.nodes[node];
		local publish_model = node_obj and node_obj.config.publish_model;
		if publish_model == "open"
		or (publish_model == "subscribers" and node_obj.subscribers[actor]) then
			may_publish = true;
		end
	end
	if not may_publish then
		return false, "forbidden";
	end
	--
	local node_obj = self.nodes[node];
	if not node_obj then
		if not self.config.autocreate_on_publish then
			return false, "item-not-found";
		end
		local ok, err = self:create(node, true, requested_config);
		if not ok then
			return ok, err;
		end
		node_obj = self.nodes[node];
	elseif requested_config and not requested_config._defaults_only then
		-- Check that node has the requested config before we publish
		local ok, field = check_preconditions(node_obj.config, requested_config);
		if not ok then
			local err = errors.new({
				type = "cancel", condition = "conflict", text = "Field does not match: "..field;
			});
			err.pubsub_condition = "precondition-not-met";
			return false, err;
		end
	end
	if not self.config.itemcheck(item) then
		return nil, "invalid-item";
	end
	if node_obj.config.persist_items then
		if not self.data[node] then
			self.data[node] = self.config.itemstore(self.nodes[node].config, node);
		end
		local ok = self.data[node]:set(id, item);
		if not ok then
			return nil, "internal-server-error";
		end
		if type(ok) == "string" then id = ok; end
	end
	local event_data = { service = self, node = node, actor = actor, id = id, item = item };
	self.events.fire_event("item-published/"..node, event_data);
	self.events.fire_event("item-published", event_data);
	self:broadcast("items", node, node_obj.subscribers, item, actor, node_obj);
	return true;
end

function service:broadcast(event, node, subscribers, item, actor, node_obj)
	subscribers = self.config.subscriber_filter(subscribers, node, event);
	return self.config.broadcaster(event, node, subscribers, item, actor, node_obj, self);
end

function service:retract(node, actor, id, retract) --> ok, err
	-- Access checking
	if not self:may(node, actor, "retract") then
		return false, "forbidden";
	end
	--
	local node_obj = self.nodes[node];
	if not node_obj then
		return false, "item-not-found";
	end
	if self.data[node] then
		if not self.data[node]:get(id) then
			return false, "item-not-found";
		end
		local ok = self.data[node]:set(id, nil);
		if not ok then
			return nil, "internal-server-error";
		end
	end
	self.events.fire_event("item-retracted", { service = self, node = node, actor = actor, id = id });
	if retract then
		self:broadcast("retract", node, node_obj.subscribers, retract, actor, node_obj);
	end
	return true
end

function service:purge(node, actor, notify) --> ok, err
	-- Access checking
	if not self:may(node, actor, "retract") then
		return false, "forbidden";
	end
	--
	local node_obj = self.nodes[node];
	if not node_obj then
		return false, "item-not-found";
	end
	if self.data[node] then
		if self.data[node].clear then
			self.data[node]:clear()
		else
			self.data[node] = self.config.itemstore(self.nodes[node].config, node);
		end
	end
	self.events.fire_event("node-purged", { service = self, node = node, actor = actor });
	if notify then
		self:broadcast("purge", node, node_obj.subscribers, nil, actor, node_obj);
	end
	return true
end

function service:get_items(node, actor, ids, resultspec) --> (true, { id, [id] = node }) or (false, err)
	-- Access checking
	if not self:may(node, actor, "get_items") then
		return false, "forbidden";
	end
	--
	local node_obj = self.nodes[node];
	if not node_obj then
		return false, "item-not-found";
	end
	if not self.data[node] then
		-- Disabled rather than unsupported, but close enough.
		return false, "persistent-items-unsupported";
	end
	if type(ids) == "string" then -- COMPAT see #1305
		ids = { ids };
	end
	local data = {};
	local limit = resultspec and resultspec.max;
	if ids then
		for _, key in ipairs(ids) do
			local value = self.data[node]:get(key);
			if value then
				data[#data+1] = key;
				data[key] = value;
				-- Limits and ids seem like a problematic combination.
				if limit and #data >= limit then break end
			end
		end
	else
		for key, value in self.data[node]:items() do
			data[#data+1] = key;
			data[key] = value;
			if limit and #data >= limit then break
			end
		end
	end
	return true, data;
end

function service:get_last_item(node, actor) --> (true, id, node) or (false, err)
	-- Access checking
	if not self:may(node, actor, "get_items") then
		return false, "forbidden";
	end
	--

	-- Check node exists
	if not self.nodes[node] then
		return false, "item-not-found";
	end

	if not self.data[node] then
		-- FIXME Should this be a success or failure?
		return true, nil;
	end

	-- Returns success, id, item
	return true, self.data[node]:head();
end

function service:get_nodes(actor) --> (true, map) or (false, err)
	-- Access checking
	if not self:may(nil, actor, "get_nodes") then
		return false, "forbidden";
	end
	--
	return true, self.nodes;
end

local function flatten_subscriptions(ret, serv, subs, node, node_obj)
	for subscribed_jid, subscribed_nodes in pairs(subs) do
		if node then -- Return only subscriptions to this node
			if subscribed_nodes[node] then
				ret[#ret+1] = {
					node = node;
					jid = subscribed_jid;
					subscription = node_obj.subscribers[subscribed_jid];
				};
			end
		else -- Return subscriptions to all nodes
			local nodes = serv.nodes;
			for subscribed_node in pairs(subscribed_nodes) do
				ret[#ret+1] = {
					node = subscribed_node;
					jid = subscribed_jid;
					subscription = nodes[subscribed_node].subscribers[subscribed_jid];
				};
			end
		end
	end
end

function service:get_subscriptions(node, actor, jid) --> (true, array) or (false, err)
	-- Access checking
	local cap;
	if actor == true or jid == actor or self:jids_equal(actor, jid) then
		cap = "get_subscriptions";
	else
		cap = "get_subscriptions_other";
	end
	if not self:may(node, actor, cap) then
		return false, "forbidden";
	end
	--
	local node_obj;
	if node then
		node_obj = self.nodes[node];
		if not node_obj then
			return false, "item-not-found";
		end
	end
	local ret = {};
	if jid == nil then
		for _, subs in pairs(self.subscriptions) do
			flatten_subscriptions(ret, self, subs, node, node_obj)
		end
		return true, ret;
	end
	local normal_jid = self.config.normalize_jid(jid);
	local subs = self.subscriptions[normal_jid];
	-- We return the subscription object from the node to save
	-- a get_subscription() call for each node.
	if subs then
		flatten_subscriptions(ret, self, subs, node, node_obj)
	end
	return true, ret;
end

-- Access models only affect 'none' affiliation caps, service/default access level...
function service:set_node_capabilities(node, actor, capabilities) --> ok, err
	-- Access checking
	if not self:may(node, actor, "configure") then
		return false, "forbidden";
	end
	--
	local node_obj = self.nodes[node];
	if not node_obj then
		return false, "item-not-found";
	end
	node_obj.capabilities = capabilities;
	return true;
end

function service:set_node_config(node, actor, new_config) --> ok, err
	if not self:may(node, actor, "configure") then
		return false, "forbidden";
	end

	local node_obj = self.nodes[node];
	if not node_obj then
		return false, "item-not-found";
	end

	setmetatable(new_config, {__index=self.node_defaults})

	if self.config.check_node_config then
		local ok = self.config.check_node_config(node, actor, new_config);
		if not ok then
			return false, "not-acceptable";
		end
	end

	local old_config = node_obj.config;
	node_obj.config = new_config;

	if self.config.nodestore then
		-- TODO pass the error from storage to caller eg wrapped in an util.error
		local ok, err = save_node_to_store(self, node_obj); -- luacheck: ignore 211/err
		if not ok then
			node_obj.config = old_config;
			return ok, "internal-server-error";
		end
	end

	if old_config["access_model"] ~= node_obj.config["access_model"] then
		for subscriber in pairs(node_obj.subscribers) do
			if not self:may(node, subscriber, "be_subscribed") then
				local ok, err = self:remove_subscription(node, true, subscriber);
				if not ok then
					node_obj.config = old_config;
					return ok, err;
				end
			end
		end
	end

	if old_config["persist_items"] ~= node_obj.config["persist_items"] then
		if node_obj.config["persist_items"] then
			self.data[node] = self.config.itemstore(self.nodes[node].config, node);
		elseif self.data[node] then
			if self.data[node].clear then
				self.data[node]:clear()
			end
			self.data[node] = nil;
		end
	elseif old_config["max_items"] ~= node_obj.config["max_items"] then
		if self.data[node] then
			local max_items = self.nodes[node].config["max_items"];
			if max_items == "max" then
				max_items = self.config.max_items;
			end
			self.data[node]:resize(max_items);
		end
	end

	return true;
end

function service:get_node_config(node, actor) --> (true, config) or (false, err)
	if not self:may(node, actor, "get_configuration") then
		return false, "forbidden";
	end

	local node_obj = self.nodes[node];
	if not node_obj then
		return false, "item-not-found";
	end

	local config_table = {};
	for k, v in pairs(default_node_config) do
		config_table[k] = v;
	end
	for k, v in pairs(self.node_defaults) do
		config_table[k] = v;
	end
	for k, v in pairs(node_obj.config) do
		config_table[k] = v;
	end

	return true, config_table;
end

return {
	new = new;
};