view mod_cache_c2s_caps/mod_cache_c2s_caps.lua @ 3902:341850e8866f

mod_muc_moderation: Broadcast retraction via method that saves it Otherwise the retraction is not saved to history, so that those who join after it was sent are unaware of the retraction
author Kim Alvefur <zash@zash.se>
date Sat, 22 Feb 2020 21:41:31 +0100
parents 820c891a54cc
children f27becd421bd
line wrap: on
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local st_iq = require "util.stanza".iq;
local uuid_gen = require "util.uuid".generate;
local calculate_hash = require "util.caps".calculate_hash;

-- Map of jid..node, to avoid querying the same client multiple times for the same value.
local in_flight_iqs = {}

-- Some clients (*ahem* poezio…) don’t include the @node in their result iq.
local iq_node_map = {}

assert(module.send_iq, "This module is not compatible with this version of Prosody.");

local function iq_result_handler(event)
	local origin, stanza = event.origin, event.stanza;

	local query = stanza:get_child("query", "http://jabber.org/protocol/disco#info");
	if not query then
		origin.log("debug", "Wrong iq payload in disco#info result: %s", stanza);
		origin.caps_cache = nil;
		return;
	end

	local from = stanza.attr.from;
	local id = stanza.attr.id;
	local node_string = query.attr.node;
	local node_query = iq_node_map[from..id];
	if node_string == nil then
		node_string = node_query;
		query.attr.node = node_query;
	end
	iq_node_map[from..id] = nil;

	if node_string ~= node_query then
		origin.log("debug", "Wrong node for our disco#info query, expected %s, received %s", node_string, node_query);
		origin.caps_cache = nil;
		return;
	end

	local node, ver = node_query:match("([^#]+)#([^#]+)");
	local hash = calculate_hash(query)
	if ver ~= hash then
		origin.log("debug", "Wrong hash for disco#info: %s ~= %s", ver, hash);
		origin.caps_cache = nil;
		return;
	end

	origin.caps_cache = query;
	origin.log("info", "Stored caps %s", ver);
	module:fire_event("c2s-capabilities-changed", { origin = origin });
	return true;
end

local function iq_error_handler(err)
	local origin = err.context.origin;
	if origin ~= nil then
		origin.caps_cache = nil;
		module:fire_event("c2s-capabilities-changed", { origin = origin });
	end
end

local function presence_stanza_handler(event)
	local origin, stanza = event.origin, event.stanza;

	local from = stanza.attr.from;
	if stanza.attr.to ~= nil then
		return;
	end

	local caps = stanza:get_child("c", "http://jabber.org/protocol/caps");
	if caps == nil then
		origin.log("debug", "Presence without caps received, skipping");
		return;
	end

	local hash = caps.attr.hash;
	local node = caps.attr.node;
	local ver = caps.attr.ver;
	if not hash or not node or not ver then
		return;
	end
	if hash ~= "sha-1" then
		origin.log("warn", "Non-SHA-1 caps received: %s", hash);
		return;
	end

	local node_query = node.."#"..ver;
	if (origin.caps_cache and origin.caps_cache.attr.node == node_query) or in_flight_iqs[from..node_query] ~= nil then
		origin.log("debug", "Already requested these caps, skipping");
		return;
	end

	origin.log("debug", "Received presence with SHA-1 caps %s, querying disco#info", node_query);

	local id = uuid_gen();
	iq_node_map[from..id] = node_query
	local iq = st_iq({ type = "get", from = module.host, to = from, id = id })
		:tag("query", { xmlns = "http://jabber.org/protocol/disco#info", node = node_query });
	in_flight_iqs[from..node_query] = true;
	module:send_iq(iq, origin)
		:next(iq_result_handler, iq_error_handler)
		:finally(function () in_flight_iqs[from..node_query] = nil; end)
end

-- Handle only non-directed presences for now.
module:hook("pre-presence/bare", presence_stanza_handler);