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-rw-r--r--plugins/mod_blocklist.lua325
1 files changed, 325 insertions, 0 deletions
diff --git a/plugins/mod_blocklist.lua b/plugins/mod_blocklist.lua
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+-- Prosody IM
+-- Copyright (C) 2009-2010 Matthew Wild
+-- Copyright (C) 2009-2010 Waqas Hussain
+-- Copyright (C) 2014-2015 Kim Alvefur
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+-- This module implements XEP-0191: Blocking Command
+--
+
+local user_exists = require"core.usermanager".user_exists;
+local rostermanager = require"core.rostermanager";
+local is_contact_subscribed = rostermanager.is_contact_subscribed;
+local is_contact_pending_in = rostermanager.is_contact_pending_in;
+local load_roster = rostermanager.load_roster;
+local save_roster = rostermanager.save_roster;
+local st = require"util.stanza";
+local st_error_reply = st.error_reply;
+local jid_prep = require"util.jid".prep;
+local jid_split = require"util.jid".split;
+
+local storage = module:open_store();
+local sessions = prosody.hosts[module.host].sessions;
+
+-- First level cache of blocklists by username.
+-- Weak table so may randomly expire at any time.
+local cache = setmetatable({}, { __mode = "v" });
+
+-- Second level of caching, keeps a fixed number of items, also anchors
+-- items in the above cache.
+--
+-- The size of this affects how often we will need to load a blocklist from
+-- disk, which we want to avoid during routing. On the other hand, we don't
+-- want to use too much memory either, so this can be tuned by advanced
+-- users. TODO use science to figure out a better default, 64 is just a guess.
+local cache_size = module:get_option_number("blocklist_cache_size", 64);
+local cache2 = require"util.cache".new(cache_size);
+
+local null_blocklist = {};
+
+module:add_feature("urn:xmpp:blocking");
+
+local function set_blocklist(username, blocklist)
+ local ok, err = storage:set(username, blocklist);
+ if not ok then
+ return ok, err;
+ end
+ -- Successful save, update the cache
+ cache2:set(username, blocklist);
+ cache[username] = blocklist;
+ return true;
+end
+
+-- Migrates from the old mod_privacy storage
+local function migrate_privacy_list(username)
+ local migrated_data = { [false] = "not empty" };
+ local legacy_data = module:open_store("privacy"):get(username);
+ if legacy_data and legacy_data.lists and legacy_data.default then
+ legacy_data = legacy_data.lists[legacy_data.default];
+ legacy_data = legacy_data and legacy_data.items;
+ else
+ return migrated_data;
+ end
+ if legacy_data then
+ module:log("info", "Migrating blocklist from mod_privacy storage for user '%s'", username);
+ local item, jid;
+ for i = 1, #legacy_data do
+ item = legacy_data[i];
+ if item.type == "jid" and item.action == "deny" then
+ jid = jid_prep(item.value);
+ if not jid then
+ module:log("warn", "Invalid JID in privacy store for user '%s' not migrated: %s", username, tostring(item.value));
+ else
+ migrated_data[jid] = true;
+ end
+ end
+ end
+ end
+ set_blocklist(username, migrated_data);
+ return migrated_data;
+end
+
+local function get_blocklist(username)
+ local blocklist = cache[username];
+ if not blocklist then
+ blocklist = cache2:get(username);
+ end
+ if not blocklist then
+ if not user_exists(username, module.host) then
+ return null_blocklist;
+ end
+ blocklist = storage:get(username);
+ if not blocklist then
+ blocklist = migrate_privacy_list(username);
+ end
+ cache2:set(username, blocklist);
+ end
+ cache[username] = blocklist;
+ return blocklist;
+end
+
+module:hook("iq-get/self/urn:xmpp:blocking:blocklist", function (event)
+ local origin, stanza = event.origin, event.stanza;
+ local username = origin.username;
+ local reply = st.reply(stanza):tag("blocklist", { xmlns = "urn:xmpp:blocking" });
+ local blocklist = get_blocklist(username);
+ for jid in pairs(blocklist) do
+ if jid then
+ reply:tag("item", { jid = jid }):up();
+ end
+ end
+ origin.interested_blocklist = true; -- Gets notified about changes
+ origin.send(reply);
+ return true;
+end);
+
+-- Add or remove some jid(s) from the blocklist
+-- We want this to be atomic and not do a partial update
+local function edit_blocklist(event)
+ local origin, stanza = event.origin, event.stanza;
+ local username = origin.username;
+ local action = stanza.tags[1]; -- "block" or "unblock"
+ local is_blocking = action.name == "block" or nil; -- nil if unblocking
+ local new = {}; -- JIDs to block depending or unblock on action
+
+ -- XEP-0191 sayeth:
+ -- > When the user blocks communications with the contact, the user's
+ -- > server MUST send unavailable presence information to the contact (but
+ -- > only if the contact is allowed to receive presence notifications [...]
+ -- So contacts we need to do that for are added to the set below.
+ local send_unavailable = is_blocking and {};
+
+ -- Because blocking someone currently also blocks the ability to reject
+ -- subscription requests, we'll preemptively reject such
+ local remove_pending = is_blocking and {};
+
+ for item in action:childtags("item") do
+ local jid = jid_prep(item.attr.jid);
+ if not jid then
+ origin.send(st_error_reply(stanza, "modify", "jid-malformed"));
+ return true;
+ end
+ item.attr.jid = jid; -- echo back prepped
+ new[jid] = true;
+ if is_blocking then
+ if is_contact_subscribed(username, module.host, jid) then
+ send_unavailable[jid] = true;
+ elseif is_contact_pending_in(username, module.host, jid) then
+ remove_pending[jid] = true;
+ end
+ end
+ end
+
+ if is_blocking and not next(new) then
+ -- <block/> element does not contain at least one <item/> child element
+ origin.send(st_error_reply(stanza, "modify", "bad-request"));
+ return true;
+ end
+
+ local blocklist = get_blocklist(username);
+
+ local new_blocklist = {};
+
+ if is_blocking or next(new) then
+ for jid in pairs(blocklist) do
+ new_blocklist[jid] = true;
+ end
+ for jid in pairs(new) do
+ new_blocklist[jid] = is_blocking;
+ end
+ -- else empty the blocklist
+ end
+ new_blocklist[false] = "not empty"; -- In order to avoid doing the migration thing twice
+
+ local ok, err = set_blocklist(username, new_blocklist);
+ if ok then
+ origin.send(st.reply(stanza));
+ else
+ origin.send(st_error_reply(stanza, "wait", "internal-server-error", err));
+ return true;
+ end
+
+ if is_blocking then
+ for jid in pairs(send_unavailable) do
+ if not blocklist[jid] then
+ for _, session in pairs(sessions[username].sessions) do
+ if session.presence then
+ module:send(st.presence({ type = "unavailable", to = jid, from = session.full_jid }));
+ end
+ end
+ end
+ end
+
+ if next(remove_pending) then
+ local roster = load_roster(username, module.host);
+ for jid in pairs(remove_pending) do
+ roster[false].pending[jid] = nil;
+ end
+ save_roster(username, module.host, roster);
+ -- Not much we can do about save failing here
+ end
+ end
+
+ local blocklist_push = st.iq({ type = "set", id = "blocklist-push" })
+ :add_child(action); -- I am lazy
+
+ for _, session in pairs(sessions[username].sessions) do
+ if session.interested_blocklist then
+ blocklist_push.attr.to = session.full_jid;
+ session.send(blocklist_push);
+ end
+ end
+
+ return true;
+end
+
+module:hook("iq-set/self/urn:xmpp:blocking:block", edit_blocklist);
+module:hook("iq-set/self/urn:xmpp:blocking:unblock", edit_blocklist);
+
+-- Cache invalidation, solved!
+module:hook_global("user-deleted", function (event)
+ if event.host == module.host then
+ cache2:set(event.username, nil);
+ cache[event.username] = nil;
+ end
+end);
+
+-- Buggy clients
+module:hook("iq-error/self/blocklist-push", function (event)
+ local _, condition, text = event.stanza:get_error();
+ (event.origin.log or module._log)("warn", "Client returned an error in response to notification from mod_%s: %s%s%s", module.name, condition, text and ": " or "", text or "");
+ return true;
+end);
+
+local function is_blocked(user, jid)
+ local blocklist = cache[user] or get_blocklist(user);
+ if blocklist[jid] then return true; end
+ local node, host = jid_split(jid);
+ return blocklist[host] or node and blocklist[node..'@'..host];
+end
+
+-- Event handlers for bouncing or dropping stanzas
+local function drop_stanza(event)
+ local stanza = event.stanza;
+ local attr = stanza.attr;
+ local to, from = attr.to, attr.from;
+ to = to and jid_split(to);
+ if to and from then
+ return is_blocked(to, from);
+ end
+end
+
+local function bounce_stanza(event)
+ local origin, stanza = event.origin, event.stanza;
+ if drop_stanza(event) then
+ origin.send(st_error_reply(stanza, "cancel", "service-unavailable"));
+ return true;
+ end
+end
+
+local function bounce_iq(event)
+ local type = event.stanza.attr.type;
+ if type == "set" or type == "get" then
+ return bounce_stanza(event);
+ end
+ return drop_stanza(event); -- result or error
+end
+
+local function bounce_message(event)
+ local type = event.stanza.attr.type;
+ if type == "chat" or not type or type == "normal" then
+ return bounce_stanza(event);
+ end
+ return drop_stanza(event); -- drop headlines, groupchats etc
+end
+
+local function drop_outgoing(event)
+ local origin, stanza = event.origin, event.stanza;
+ local username = origin.username or jid_split(stanza.attr.from);
+ if not username then return end
+ local to = stanza.attr.to;
+ if to then return is_blocked(username, to); end
+ -- nil 'to' means a self event, don't bock those
+end
+
+local function bounce_outgoing(event)
+ local origin, stanza = event.origin, event.stanza;
+ local type = stanza.attr.type;
+ if type == "error" or stanza.name == "iq" and type == "result" then
+ return drop_outgoing(event);
+ end
+ if drop_outgoing(event) then
+ origin.send(st_error_reply(stanza, "cancel", "not-acceptable", "You have blocked this JID")
+ :tag("blocked", { xmlns = "urn:xmpp:blocking:errors" }));
+ return true;
+ end
+end
+
+-- Hook all the events!
+local prio_in, prio_out = 100, 100;
+module:hook("presence/bare", drop_stanza, prio_in);
+module:hook("presence/full", drop_stanza, prio_in);
+
+module:hook("message/bare", bounce_message, prio_in);
+module:hook("message/full", bounce_message, prio_in);
+
+module:hook("iq/bare", bounce_iq, prio_in);
+module:hook("iq/full", bounce_iq, prio_in);
+
+module:hook("pre-message/bare", bounce_outgoing, prio_out);
+module:hook("pre-message/full", bounce_outgoing, prio_out);
+module:hook("pre-message/host", bounce_outgoing, prio_out);
+
+-- Note: MUST bounce these, but we don't because this would produce
+-- lots of error replies due to server-generated presence.
+-- FIXME some day, likely needing changes to mod_presence
+module:hook("pre-presence/bare", drop_outgoing, prio_out);
+module:hook("pre-presence/full", drop_outgoing, prio_out);
+module:hook("pre-presence/host", drop_outgoing, prio_out);
+
+module:hook("pre-iq/bare", bounce_outgoing, prio_out);
+module:hook("pre-iq/full", bounce_outgoing, prio_out);
+module:hook("pre-iq/host", bounce_outgoing, prio_out);
+