modules/um_callerid.c

   1 /*
   2  * modules/um_callerid.c
   3  * Copyright (c) 2020 Ariadne Conill <ariadne@dereferenced.org>
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright notice,
  10  *    this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. The name of the author may not be used to endorse or promote products
  15  *    derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  21  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  26  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  27  * POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #include "stdinc.h"
  31 #include "modules.h"
  32 #include "hook.h"
  33 #include "client.h"
  34 #include "ircd.h"
  35 #include "send.h"
  36 #include "hash.h"
  37 #include "s_conf.h"
  38 #include "s_user.h"
  39 #include "s_serv.h"
  40 #include "numeric.h"
  41 #include "privilege.h"
  42 #include "s_newconf.h"
  43 #include "hook.h"
  44 #include "supported.h"
  45 #include "logger.h"
  46
  47 static int
  48 um_callerid_modinit(void)
  49 {
  50         user_modes['g'] = find_umode_slot();
  51         if (!user_modes['g'])
  52         {
  53                 ierror("um_callerid: unable to allocate usermode slot for +g; unloading module.");
  54                 return -1;
  55         }
  56
  57         user_modes['G'] = find_umode_slot();
  58         if (!user_modes['G'])
  59         {
  60                 ierror("um_callerid: unable to allocate usermode slot for +G; unloading module.");
  61                 return -1;
  62         }
  63
  64         construct_umodebuf();
  65
  66         add_isupport("CALLERID", isupport_string, "g");
  67
  68         return 0;
  69 }
  70
  71 static void
  72 um_callerid_moddeinit(void)
  73 {
  74         user_modes['g'] = 0;
  75         user_modes['G'] = 0;
  76         construct_umodebuf();
  77
  78         delete_isupport("CALLERID");
  79 }
  80
  81 #define IsSetCallerID(c)        ((c->umodes & user_modes['g']) == user_modes['g'])
  82 #define IsSetRelaxedCallerID(c) ((c->umodes & user_modes['G']) == user_modes['G'])
  83
  84 static const char um_callerid_desc[] =
  85         "Provides usermode +g which restricts messages from unauthorized users.";
  86
  87 static bool
  88 has_common_channel(struct Client *source_p, struct Client *target_p)
  89 {
  90         rb_dlink_node *ptr;
  91
  92         RB_DLINK_FOREACH(ptr, source_p->user->channel.head)
  93         {
  94                 struct membership *msptr = ptr->data;
  95                 if (IsMember(target_p, msptr->chptr))
  96                         return msptr->chptr;
  97         }
  98
  99         return NULL;
 100 }
 101
 102 static bool
 103 allow_message(struct Client *source_p, struct Client *target_p)
 104 {
 105         if (!MyClient(target_p))
 106                 return true;
 107
 108         if (!IsSetCallerID(target_p))
 109                 return true;
 110
 111         if (IsSetRelaxedCallerID(target_p) && has_common_channel(source_p, target_p))
 112                 return true;
 113
 114         if (IsServer(source_p))
 115                 return true;
 116
 117         /* XXX: controversial?  allow opers to send through +g */
 118         if (IsOper(source_p))
 119                 return true;
 120
 121         if (accept_message(source_p, target_p))
 122                 return true;
 123
 124         return false;
 125 }
 126
 127 static void
 128 send_callerid_notice(enum message_type msgtype, struct Client *source_p, struct Client *target_p)
 129 {
 130         if (!MyClient(target_p))
 131                 return;
 132
 133         if (msgtype == MESSAGE_TYPE_NOTICE)
 134                 return;
 135
 136         sendto_one_numeric(source_p, ERR_TARGUMODEG, form_str(ERR_TARGUMODEG),
 137                 target_p->name);
 138
 139         if ((target_p->localClient->last_caller_id_time + ConfigFileEntry.caller_id_wait) < rb_current_time())
 140         {
 141                 sendto_one_numeric(source_p, RPL_TARGNOTIFY, form_str(RPL_TARGNOTIFY),
 142                         target_p->name);
 143
 144                 sendto_one(target_p, form_str(RPL_UMODEGMSG),
 145                            me.name, target_p->name, source_p->name,
 146                            source_p->username, source_p->host);
 147
 148                 target_p->localClient->last_caller_id_time = rb_current_time();
 149         }
 150 }
 151
 152 static bool
 153 add_callerid_accept_for_source(enum message_type msgtype, struct Client *source_p, struct Client *target_p)
 154 {
 155         /*
 156          * XXX: Controversial? Allow target users to send replies
 157          * through a +g.  Rationale is that people can presently use +g
 158          * as a way to taunt users, e.g. harass them and hide behind +g
 159          * as a way of griefing.  --nenolod
 160          */
 161         if(msgtype != MESSAGE_TYPE_NOTICE &&
 162                         IsSetCallerID(source_p) &&
 163                         !accept_message(target_p, source_p) &&
 164                         !IsOper(target_p))
 165         {
 166                 if(rb_dlink_list_length(&source_p->localClient->allow_list) <
 167                                 (unsigned long)ConfigFileEntry.max_accept)
 168                 {
 169                         rb_dlinkAddAlloc(target_p, &source_p->localClient->allow_list);
 170                         rb_dlinkAddAlloc(source_p, &target_p->on_allow_list);
 171                 }
 172                 else
 173                 {
 174                         sendto_one_numeric(source_p, ERR_OWNMODE,
 175                                         form_str(ERR_OWNMODE),
 176                                         target_p->name, "+g");
 177                         return false;
 178                 }
 179         }
 180
 181         return true;
 182 }
 183
 184 static void
 185 h_hdl_invite(void *vdata)
 186 {
 187         hook_data_channel_approval *data = vdata;
 188         struct Client *source_p = data->client;
 189         struct Client *target_p = data->target;
 190
 191         if (data->approved)
 192                 return;
 193
 194         if (!add_callerid_accept_for_source(MESSAGE_TYPE_PRIVMSG, source_p, target_p))
 195         {
 196                 data->approved = ERR_TARGUMODEG;
 197                 return;
 198         }
 199
 200         if (allow_message(source_p, target_p))
 201                 return;
 202
 203         send_callerid_notice(MESSAGE_TYPE_PRIVMSG, source_p, target_p);
 204
 205         data->approved = ERR_TARGUMODEG;
 206 }
 207
 208 static void
 209 h_hdl_privmsg_user(void *vdata)
 210 {
 211         hook_data_privmsg_user *data = vdata;
 212         enum message_type msgtype = data->msgtype;
 213         struct Client *source_p = data->source_p;
 214         struct Client *target_p = data->target_p;
 215
 216         if (data->approved)
 217                 return;
 218
 219         if (!add_callerid_accept_for_source(msgtype, source_p, target_p))
 220         {
 221                 data->approved = ERR_TARGUMODEG;
 222                 return;
 223         }
 224
 225         if (allow_message(source_p, target_p))
 226                 return;
 227
 228         send_callerid_notice(msgtype, source_p, target_p);
 229
 230         data->approved = ERR_TARGUMODEG;
 231 }
 232
 233 static mapi_hfn_list_av1 um_callerid_hfnlist[] = {
 234         { "invite", h_hdl_invite },
 235         { "privmsg_user", h_hdl_privmsg_user },
 236         { NULL, NULL }
 237 };
 238
 239 DECLARE_MODULE_AV2(um_callerid, um_callerid_modinit, um_callerid_moddeinit,
 240                    NULL, NULL, um_callerid_hfnlist, NULL, NULL, um_callerid_desc);