plugins/mod_blocklist.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2009-2010 Matthew Wild
   3 -- Copyright (C) 2009-2010 Waqas Hussain
   4 -- Copyright (C) 2014-2015 Kim Alvefur
   5 --
   6 -- This project is MIT/X11 licensed. Please see the
   7 -- COPYING file in the source package for more information.
   8 --
   9 -- This module implements XEP-0191: Blocking Command
  10 --
  11
  12 local user_exists = require"core.usermanager".user_exists;
  13 local rostermanager = require"core.rostermanager";
  14 local is_contact_subscribed = rostermanager.is_contact_subscribed;
  15 local is_contact_pending_in = rostermanager.is_contact_pending_in;
  16 local load_roster = rostermanager.load_roster;
  17 local save_roster = rostermanager.save_roster;
  18 local st = require"util.stanza";
  19 local st_error_reply = st.error_reply;
  20 local jid_prep = require"util.jid".prep;
  21 local jid_split = require"util.jid".split;
  22
  23 local storage = module:open_store();
  24 local sessions = prosody.hosts[module.host].sessions;
  25 local full_sessions = prosody.full_sessions;
  26
  27 -- First level cache of blocklists by username.
  28 -- Weak table so may randomly expire at any time.
  29 local cache = setmetatable({}, { __mode = "v" });
  30
  31 -- Second level of caching, keeps a fixed number of items, also anchors
  32 -- items in the above cache.
  33 --
  34 -- The size of this affects how often we will need to load a blocklist from
  35 -- disk, which we want to avoid during routing. On the other hand, we don't
  36 -- want to use too much memory either, so this can be tuned by advanced
  37 -- users. TODO use science to figure out a better default, 64 is just a guess.
  38 local cache_size = module:get_option_number("blocklist_cache_size", 64);
  39 local cache2 = require"util.cache".new(cache_size);
  40
  41 local null_blocklist = {};
  42
  43 module:add_feature("urn:xmpp:blocking");
  44
  45 local function set_blocklist(username, blocklist)
  46         local ok, err = storage:set(username, blocklist);
  47         if not ok then
  48                 return ok, err;
  49         end
  50         -- Successful save, update the cache
  51         cache2:set(username, blocklist);
  52         cache[username] = blocklist;
  53         return true;
  54 end
  55
  56 -- Migrates from the old mod_privacy storage
  57 local function migrate_privacy_list(username)
  58         local legacy_data = module:open_store("privacy"):get(username);
  59         if not legacy_data or not legacy_data.lists or not legacy_data.default then return; end
  60         local default_list = legacy_data.lists[legacy_data.default];
  61         if not default_list or not default_list.items then return; end
  62
  63         local migrated_data = { [false] = { created = os.time(); migrated = "privacy" }};
  64
  65         module:log("info", "Migrating blocklist from mod_privacy storage for user '%s'", username);
  66         for _, item in ipairs(default_list.items) do
  67                 if item.type == "jid" and item.action == "deny" then
  68                         local jid = jid_prep(item.value);
  69                         if not jid then
  70                                 module:log("warn", "Invalid JID in privacy store for user '%s' not migrated: %s", username, tostring(item.value));
  71                         else
  72                                 migrated_data[jid] = true;
  73                         end
  74                 end
  75         end
  76         set_blocklist(username, migrated_data);
  77         return migrated_data;
  78 end
  79
  80 local function get_blocklist(username)
  81         local blocklist = cache2:get(username);
  82         if not blocklist then
  83                 if not user_exists(username, module.host) then
  84                         return null_blocklist;
  85                 end
  86                 blocklist = storage:get(username);
  87                 if not blocklist then
  88                         blocklist = migrate_privacy_list(username);
  89                 end
  90                 if not blocklist then
  91                         blocklist = { [false] = { created = os.time(); }; };
  92                 end
  93                 cache2:set(username, blocklist);
  94         end
  95         cache[username] = blocklist;
  96         return blocklist;
  97 end
  98
  99 module:hook("iq-get/self/urn:xmpp:blocking:blocklist", function (event)
 100         local origin, stanza = event.origin, event.stanza;
 101         local username = origin.username;
 102         local reply = st.reply(stanza):tag("blocklist", { xmlns = "urn:xmpp:blocking" });
 103         local blocklist = cache[username] or get_blocklist(username);
 104         for jid in pairs(blocklist) do
 105                 if jid then
 106                         reply:tag("item", { jid = jid }):up();
 107                 end
 108         end
 109         origin.interested_blocklist = true; -- Gets notified about changes
 110         origin.send(reply);
 111         return true;
 112 end, -1);
 113
 114 -- Add or remove some jid(s) from the blocklist
 115 -- We want this to be atomic and not do a partial update
 116 local function edit_blocklist(event)
 117         local now = os.time();
 118         local origin, stanza = event.origin, event.stanza;
 119         local username = origin.username;
 120         local action = stanza.tags[1]; -- "block" or "unblock"
 121         local is_blocking = action.name == "block" and now or nil; -- nil if unblocking
 122         local new = {}; -- JIDs to block depending or unblock on action
 123
 124
 125         -- XEP-0191 sayeth:
 126         -- > When the user blocks communications with the contact, the user's
 127         -- > server MUST send unavailable presence information to the contact (but
 128         -- > only if the contact is allowed to receive presence notifications [...]
 129         -- So contacts we need to do that for are added to the set below.
 130         local send_unavailable = is_blocking and {};
 131
 132         -- Because blocking someone currently also blocks the ability to reject
 133         -- subscription requests, we'll preemptively reject such
 134         local remove_pending = is_blocking and {};
 135
 136         for item in action:childtags("item") do
 137                 local jid = jid_prep(item.attr.jid);
 138                 if not jid then
 139                         origin.send(st_error_reply(stanza, "modify", "jid-malformed"));
 140                         return true;
 141                 end
 142                 item.attr.jid = jid; -- echo back prepped
 143                 new[jid] = true;
 144                 if is_blocking then
 145                         if is_contact_subscribed(username, module.host, jid) then
 146                                 send_unavailable[jid] = true;
 147                         elseif is_contact_pending_in(username, module.host, jid) then
 148                                 remove_pending[jid] = true;
 149                         end
 150                 end
 151         end
 152
 153         if is_blocking and not next(new) then
 154                 -- <block/> element does not contain at least one <item/> child element
 155                 origin.send(st_error_reply(stanza, "modify", "bad-request"));
 156                 return true;
 157         end
 158
 159         local blocklist = cache[username] or get_blocklist(username);
 160
 161         local new_blocklist = {
 162                 -- We set the [false] key to someting as a signal not to migrate privacy lists
 163                 [false] = blocklist[false] or { created = now; };
 164         };
 165         if type(blocklist[false]) == "table" then
 166                 new_blocklist[false].modified = now;
 167         end
 168
 169         if is_blocking or next(new) then
 170                 for jid, t in pairs(blocklist) do
 171                         if jid then new_blocklist[jid] = t; end
 172                 end
 173                 for jid in pairs(new) do
 174                         new_blocklist[jid] = is_blocking;
 175                 end
 176                 -- else empty the blocklist
 177         end
 178
 179         local ok, err = set_blocklist(username, new_blocklist);
 180         if ok then
 181                 origin.send(st.reply(stanza));
 182         else
 183                 origin.send(st_error_reply(stanza, "wait", "internal-server-error", err));
 184                 return true;
 185         end
 186
 187         if is_blocking then
 188                 for jid in pairs(send_unavailable) do
 189                         if not blocklist[jid] then
 190                                 for _, session in pairs(sessions[username].sessions) do
 191                                         if session.presence then
 192                                                 module:send(st.presence({ type = "unavailable", to = jid, from = session.full_jid }));
 193                                         end
 194                                 end
 195                         end
 196                 end
 197
 198                 if next(remove_pending) then
 199                         local roster = load_roster(username, module.host);
 200                         for jid in pairs(remove_pending) do
 201                                 roster[false].pending[jid] = nil;
 202                         end
 203                         save_roster(username, module.host, roster);
 204                         -- Not much we can do about save failing here
 205                 end
 206         end
 207
 208         local blocklist_push = st.iq({ type = "set", id = "blocklist-push" })
 209                 :add_child(action); -- I am lazy
 210
 211         for _, session in pairs(sessions[username].sessions) do
 212                 if session.interested_blocklist then
 213                         blocklist_push.attr.to = session.full_jid;
 214                         session.send(blocklist_push);
 215                 end
 216         end
 217
 218         return true;
 219 end
 220
 221 module:hook("iq-set/self/urn:xmpp:blocking:block", edit_blocklist, -1);
 222 module:hook("iq-set/self/urn:xmpp:blocking:unblock", edit_blocklist, -1);
 223
 224 -- Cache invalidation, solved!
 225 module:hook_global("user-deleted", function (event)
 226         if event.host == module.host then
 227                 cache2:set(event.username, nil);
 228                 cache[event.username] = nil;
 229         end
 230 end);
 231
 232 -- Buggy clients
 233 module:hook("iq-error/self/blocklist-push", function (event)
 234         local origin, stanza = event.origin, event.stanza;
 235         local _, condition, text = stanza:get_error();
 236         local log = (origin.log or module._log);
 237         log("warn", "Client returned an error in response to notification from mod_%s: %s%s%s",
 238                 module.name, condition, text and ": " or "", text or "");
 239         return true;
 240 end);
 241
 242 local function is_blocked(user, jid)
 243         local blocklist = cache[user] or get_blocklist(user);
 244         if blocklist[jid] then return true; end
 245         local node, host = jid_split(jid);
 246         return blocklist[host] or node and blocklist[node..'@'..host];
 247 end
 248
 249 -- Event handlers for bouncing or dropping stanzas
 250 local function drop_stanza(event)
 251         local stanza = event.stanza;
 252         local attr = stanza.attr;
 253         local to, from = attr.to, attr.from;
 254         to = to and jid_split(to);
 255         if to and from then
 256                 return is_blocked(to, from);
 257         end
 258 end
 259
 260 local function bounce_stanza(event)
 261         local origin, stanza = event.origin, event.stanza;
 262         if drop_stanza(event) then
 263                 origin.send(st_error_reply(stanza, "cancel", "service-unavailable"));
 264                 return true;
 265         end
 266 end
 267
 268 local function bounce_iq(event)
 269         local type = event.stanza.attr.type;
 270         if type == "set" or type == "get" then
 271                 return bounce_stanza(event);
 272         end
 273         return drop_stanza(event); -- result or error
 274 end
 275
 276 local function bounce_message(event)
 277         local stanza = event.stanza;
 278         local type = stanza.attr.type;
 279         if type == "chat" or not type or type == "normal" then
 280                 if full_sessions[stanza.attr.to] then
 281                         -- See #690
 282                         return drop_stanza(event);
 283                 end
 284                 return bounce_stanza(event);
 285         end
 286         return drop_stanza(event); -- drop headlines, groupchats etc
 287 end
 288
 289 local function drop_outgoing(event)
 290         local origin, stanza = event.origin, event.stanza;
 291         local username = origin.username or jid_split(stanza.attr.from);
 292         if not username then return end
 293         local to = stanza.attr.to;
 294         if to then return is_blocked(username, to); end
 295         -- nil 'to' means a self event, don't bock those
 296 end
 297
 298 local function bounce_outgoing(event)
 299         local origin, stanza = event.origin, event.stanza;
 300         local type = stanza.attr.type;
 301         if type == "error" or stanza.name == "iq" and type == "result" then
 302                 return drop_outgoing(event);
 303         end
 304         if drop_outgoing(event) then
 305                 origin.send(st_error_reply(stanza, "cancel", "not-acceptable", "You have blocked this JID")
 306                         :tag("blocked", { xmlns = "urn:xmpp:blocking:errors" }));
 307                 return true;
 308         end
 309 end
 310
 311 -- Hook all the events!
 312 local prio_in, prio_out = 100, 100;
 313 module:hook("presence/bare", drop_stanza, prio_in);
 314 module:hook("presence/full", drop_stanza, prio_in);
 315
 316 module:hook("message/bare", bounce_message, prio_in);
 317 module:hook("message/full", bounce_message, prio_in);
 318
 319 module:hook("iq/bare", bounce_iq, prio_in);
 320 module:hook("iq/full", bounce_iq, prio_in);
 321
 322 module:hook("pre-message/bare", bounce_outgoing, prio_out);
 323 module:hook("pre-message/full", bounce_outgoing, prio_out);
 324 module:hook("pre-message/host", bounce_outgoing, prio_out);
 325
 326 module:hook("pre-presence/bare", bounce_outgoing, -1);
 327 module:hook("pre-presence/host", bounce_outgoing, -1);
 328 module:hook("pre-presence/full", bounce_outgoing, prio_out);
 329
 330 module:hook("pre-iq/bare", bounce_outgoing, prio_out);
 331 module:hook("pre-iq/full", bounce_outgoing, prio_out);
 332 module:hook("pre-iq/host", bounce_outgoing, prio_out);
 333