misc/systemd: Add comment with link to our debian resources including systemd service file
local ip = require "util.ip";
local jid_bare = require "util.jid".bare;
local jid_split = require "util.jid".split;
local set = require "util.set";
local sha256 = require "util.hashes".sha256;
local st = require"util.stanza";
local is_contact_subscribed = require "core.rostermanager".is_contact_subscribed;
local full_sessions = prosody.full_sessions;
local user_exists = require "core.usermanager".user_exists;
local new_rtbl_subscription = module:require("rtbl").new_rtbl_subscription;
local trie = module:require("trie");
local spam_source_domains = set.new();
local spam_source_ips = trie.new();
local spam_source_jids = set.new();
local count_spam_blocked = module:metric("counter", "anti_spam_blocked", "stanzas", "Stanzas blocked as spam", {"reason"});
function block_spam(event, reason, action)
event.spam_reason = reason;
event.spam_action = action;
if module:fire_event("spam-blocked", event) == false then
module:log("debug", "Spam allowed by another module");
return;
end
count_spam_blocked:with_labels(reason):add(1);
if action == "bounce" then
module:log("debug", "Bouncing likely spam %s from %s (%s)", event.stanza.name, event.stanza.attr.from, reason);
event.origin.send(st.error_reply("cancel", "policy-violation", "Rejected as spam"));
else
module:log("debug", "Discarding likely spam %s from %s (%s)", event.stanza.name, event.stanza.attr.from, reason);
end
return true;
end
function is_from_stranger(from_jid, event)
local stanza = event.stanza;
local to_user, to_host, to_resource = jid_split(stanza.attr.to);
if not to_user then return false; end
local to_session = full_sessions[stanza.attr.to];
if to_session then return false; end
if not is_contact_subscribed(to_user, to_host, from_jid) then
-- Allow all messages from your own jid
if from_jid == to_user.."@"..to_host then
return false; -- Pass through
end
if to_resource and stanza.attr.type == "groupchat" then
return false; -- Pass through
end
return true; -- Stranger danger
end
end
function is_spammy_server(session)
if spam_source_domains:contains(session.from_host) then
return true;
end
local origin_ip = ip.new(session.ip);
if spam_source_ips:contains_ip(origin_ip) then
return true;
end
end
function is_spammy_sender(sender_jid)
return spam_source_jids:contains(sha256(sender_jid, true));
end
local spammy_strings = module:get_option_array("anti_spam_block_strings");
local spammy_patterns = module:get_option_array("anti_spam_block_patterns");
function is_spammy_content(stanza)
-- Only support message content
if stanza.name ~= "message" then return; end
if not (spammy_strings or spammy_patterns) then return; end
local body = stanza:get_child_text("body");
if spammy_strings then
for _, s in ipairs(spammy_strings) do
if body:find(s, 1, true) then
return true;
end
end
end
if spammy_patterns then
for _, s in ipairs(spammy_patterns) do
if body:find(s) then
return true;
end
end
end
end
-- Set up RTBLs
local anti_spam_services = module:get_option_array("anti_spam_services");
for _, rtbl_service_jid in ipairs(anti_spam_services) do
new_rtbl_subscription(rtbl_service_jid, "spam_source_domains", {
added = function (item)
spam_source_domains:add(item);
end;
removed = function (item)
spam_source_domains:remove(item);
end;
});
new_rtbl_subscription(rtbl_service_jid, "spam_source_ips", {
added = function (item)
spam_source_ips:add_subnet(ip.parse_cidr(item));
end;
removed = function (item)
spam_source_ips:remove_subnet(ip.parse_cidr(item));
end;
});
new_rtbl_subscription(rtbl_service_jid, "spam_source_jids_sha256", {
added = function (item)
spam_source_jids:add(item);
end;
removed = function (item)
spam_source_jids:remove(item);
end;
});
end
module:hook("message/bare", function (event)
local to_bare = jid_bare(event.stanza.attr.to);
if not user_exists(to_bare) then return; end
local from_bare = jid_bare(event.stanza.attr.from);
if not is_from_stranger(from_bare, event) then return; end
if is_spammy_server(event.origin) then
return block_spam(event, "known-spam-source", "drop");
end
if is_spammy_sender(from_bare) then
return block_spam(event, "known-spam-jid", "drop");
end
if is_spammy_content(event.stanza) then
return block_spam(event, "spam-content", "drop");
end
end, 500);
module:hook("presence/bare", function (event)
if event.stanza.type ~= "subscribe" then
return;
end
if is_spammy_server(event.origin) then
return block_spam(event, "known-spam-source", "drop");
end
if is_spammy_sender(event.stanza) then
return block_spam(event, "known-spam-jid", "drop");
end
end, 500);