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                 user_modes['g'] = 0;
  61
  62                 ierror("um_callerid: unable to allocate usermode slot for +G; unloading module.");
  63                 return -1;
  64         }
  65
  66         construct_umodebuf();
  67
  68         add_isupport("CALLERID", isupport_umode, "g");
  69
  70         return 0;
  71 }
  72
  73 static void
  74 um_callerid_moddeinit(void)
  75 {
  76         user_modes['g'] = 0;
  77         user_modes['G'] = 0;
  78         construct_umodebuf();
  79
  80         delete_isupport("CALLERID");
  81 }
  82
  83 #define IsSetStrictCallerID(c)  ((c->umodes & user_modes['g']) == user_modes['g'])
  84 #define IsSetRelaxedCallerID(c) ((c->umodes & user_modes['G']) == user_modes['G'])
  85 #define IsSetAnyCallerID(c)     (IsSetStrictCallerID(c) || IsSetRelaxedCallerID(c))
  86
  87 static const char um_callerid_desc[] =
  88         "Provides usermodes +g and +G which restrict messages from unauthorized users.";
  89
  90 static bool
  91 has_common_channel(struct Client *source_p, struct Client *target_p)
  92 {
  93         rb_dlink_node *ptr;
  94
  95         RB_DLINK_FOREACH(ptr, source_p->user->channel.head)
  96         {
  97                 struct membership *msptr = ptr->data;
  98                 if (IsMember(target_p, msptr->chptr))
  99                         return true;
 100         }
 101
 102         return false;
 103 }
 104
 105 static bool
 106 allow_message(struct Client *source_p, struct Client *target_p)
 107 {
 108         if (!MyClient(target_p))
 109                 return true;
 110
 111         if (!IsSetAnyCallerID(target_p))
 112                 return true;
 113
 114         if (IsSetRelaxedCallerID(target_p) && has_common_channel(source_p, target_p) && !IsSetStrictCallerID(target_p))
 115                 return true;
 116
 117         if (IsServer(source_p))
 118                 return true;
 119
 120         /* XXX: controversial?  allow opers to send through +g */
 121         if (IsOperGeneral(source_p))
 122                 return true;
 123
 124         if (accept_message(source_p, target_p))
 125                 return true;
 126
 127         return false;
 128 }
 129
 130 static void
 131 send_callerid_notice(enum message_type msgtype, struct Client *source_p, struct Client *target_p)
 132 {
 133         if (!MyClient(target_p))
 134                 return;
 135
 136         if (msgtype == MESSAGE_TYPE_NOTICE)
 137                 return;
 138
 139         sendto_one_numeric(source_p, ERR_TARGUMODEG, form_str(ERR_TARGUMODEG),
 140                 target_p->name, IsSetStrictCallerID(target_p) ? "+g" : "+G");
 141
 142         if ((target_p->localClient->last_caller_id_time + ConfigFileEntry.caller_id_wait) < rb_current_time())
 143         {
 144                 sendto_one_numeric(source_p, RPL_TARGNOTIFY, form_str(RPL_TARGNOTIFY),
 145                         target_p->name);
 146
 147                 sendto_one(target_p, form_str(RPL_UMODEGMSG),
 148                            me.name, target_p->name, source_p->name,
 149                            source_p->username, source_p->host, IsSetStrictCallerID(target_p) ? "+g" : "+G");
 150
 151                 target_p->localClient->last_caller_id_time = rb_current_time();
 152         }
 153 }
 154
 155 static bool
 156 add_callerid_accept_for_source(enum message_type msgtype, struct Client *source_p, struct Client *target_p)
 157 {
 158         /* only do this on source_p's server */
 159         if (!MyClient(source_p))
 160                 return true;
 161
 162         /*
 163          * XXX: Controversial? Allow target users to send replies
 164          * through a +g.  Rationale is that people can presently use +g
 165          * as a way to taunt users, e.g. harass them and hide behind +g
 166          * as a way of griefing.  --nenolod
 167          */
 168         if(msgtype != MESSAGE_TYPE_NOTICE &&
 169                 IsSetAnyCallerID(source_p) &&
 170                 !accept_message(target_p, source_p) &&
 171                 !IsOperGeneral(target_p))
 172         {
 173                 if(rb_dlink_list_length(&source_p->localClient->allow_list) <
 174                                 (unsigned long)ConfigFileEntry.max_accept)
 175                 {
 176                         rb_dlinkAddAlloc(target_p, &source_p->localClient->allow_list);
 177                         rb_dlinkAddAlloc(source_p, &target_p->on_allow_list);
 178                 }
 179                 else
 180                 {
 181                         sendto_one_numeric(source_p, ERR_OWNMODE,
 182                                         form_str(ERR_OWNMODE),
 183                                         target_p->name, IsSetStrictCallerID(target_p) ? "+g" : "+G");
 184                         return false;
 185                 }
 186         }
 187
 188         return true;
 189 }
 190
 191 static void
 192 h_hdl_invite(void *vdata)
 193 {
 194         hook_data_channel_approval *data = vdata;
 195         struct Client *source_p = data->client;
 196         struct Client *target_p = data->target;
 197         static char errorbuf[BUFSIZE];
 198
 199         if (data->approved)
 200                 return;
 201
 202         if (!add_callerid_accept_for_source(MESSAGE_TYPE_PRIVMSG, source_p, target_p))
 203         {
 204                 data->approved = ERR_TARGUMODEG;
 205                 return;
 206         }
 207
 208         if (allow_message(source_p, target_p))
 209                 return;
 210
 211         snprintf(errorbuf, sizeof errorbuf, form_str(ERR_TARGUMODEG),
 212                  target_p->name, IsSetStrictCallerID(target_p) ? "+g" : "+G");
 213
 214         data->approved = ERR_TARGUMODEG;
 215         data->error = errorbuf;
 216 }
 217
 218 static void
 219 h_hdl_privmsg_user(void *vdata)
 220 {
 221         hook_data_privmsg_user *data = vdata;
 222         enum message_type msgtype = data->msgtype;
 223         struct Client *source_p = data->source_p;
 224         struct Client *target_p = data->target_p;
 225
 226         if (data->approved)
 227                 return;
 228
 229         if (!add_callerid_accept_for_source(msgtype, source_p, target_p))
 230         {
 231                 data->approved = ERR_TARGUMODEG;
 232                 return;
 233         }
 234
 235         if (allow_message(source_p, target_p))
 236                 return;
 237
 238         send_callerid_notice(msgtype, source_p, target_p);
 239
 240         data->approved = ERR_TARGUMODEG;
 241 }
 242
 243 static mapi_hfn_list_av1 um_callerid_hfnlist[] = {
 244         { "invite", h_hdl_invite },
 245         { "privmsg_user", h_hdl_privmsg_user },
 246         { NULL, NULL }
 247 };
 248
 249 DECLARE_MODULE_AV2(um_callerid, um_callerid_modinit, um_callerid_moddeinit,
 250                    NULL, NULL, um_callerid_hfnlist, NULL, NULL, um_callerid_desc);