]> arthur.barton.de Git - ngircd-alex.git/blobdiff - src/ngircd/irc-mode.c
{Add|Del}_Ban_Invite > {Add_To|Del_From}_List(): more generic
[ngircd-alex.git] / src / ngircd / irc-mode.c
index 5639ec1880b237010123c3c15c33f57cc1ca5b2f..71c9f796e952d592b28603c354012826b9dceeff 100644 (file)
@@ -1,6 +1,6 @@
 /*
  * ngIRCd -- The Next Generation IRC Daemon
- * Copyright (c)2001-2011 Alexander Barton (alex@barton.de) and Contributors.
+ * Copyright (c)2001-2012 Alexander Barton (alex@barton.de) and Contributors.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -9,7 +9,6 @@
  * Please read the file COPYING, README and AUTHORS for more information.
  */
 
-
 #include "portab.h"
 
 /**
 #include "irc-mode.h"
 
 
-static bool Client_Mode PARAMS(( CLIENT *Client, REQUEST *Req, CLIENT *Origin,
-       CLIENT *Target ));
-static bool Channel_Mode PARAMS(( CLIENT *Client, REQUEST *Req, CLIENT *Origin,
-       CHANNEL *Channel ));
+static bool Client_Mode PARAMS((CLIENT *Client, REQUEST *Req, CLIENT *Origin,
+                               CLIENT *Target));
+static bool Channel_Mode PARAMS((CLIENT *Client, REQUEST *Req, CLIENT *Origin,
+                                CHANNEL *Channel));
 
-static bool Add_Ban_Invite PARAMS((int what, CLIENT *Prefix, CLIENT *Client,
-       CHANNEL *Channel, const char *Pattern));
-static bool Del_Ban_Invite PARAMS((int what, CLIENT *Prefix, CLIENT *Client,
-       CHANNEL *Channel, const char *Pattern));
+static bool Add_To_List PARAMS((char what, CLIENT *Prefix, CLIENT *Client,
+                               CHANNEL *Channel, const char *Pattern));
+static bool Del_From_List PARAMS((char what, CLIENT *Prefix, CLIENT *Client,
+                                 CHANNEL *Channel, const char *Pattern));
 
-static bool Send_ListChange PARAMS((const char *Mode, CLIENT *Prefix,
-       CLIENT *Client, CHANNEL *Channel, const char *Mask));
+static bool Send_ListChange PARAMS((const bool IsAdd, const char ModeChar,
+                                   CLIENT *Prefix, CLIENT *Client,
+                                   CHANNEL *Channel, const char *Mask));
 
 
+/**
+ * Handler for the IRC "MODE" command.
+ *
+ * See RFC 2812 section 3.1.5 ("user mode message") and section 3.2.3
+ * ("channel mode message"), and RFC 2811 section 4 ("channel modes").
+ *
+ * @param Client       The client from which this command has been received.
+ * @param Req          Request structure with prefix and all parameters.
+ * @returns            CONNECTED or DISCONNECTED.
+ */
 GLOBAL bool
 IRC_MODE( CLIENT *Client, REQUEST *Req )
 {
        CLIENT *cl, *origin;
        CHANNEL *chan;
 
-       assert( Client != NULL );
-       assert( Req != NULL );
+       assert(Client != NULL);
+       assert(Req != NULL);
 
        /* No parameters? */
-       if( Req->argc < 1 ) return IRC_WriteStrClient( Client, ERR_NEEDMOREPARAMS_MSG, Client_ID( Client ), Req->command );
+       if (Req->argc < 1)
+               return IRC_WriteStrClient(Client, ERR_NEEDMOREPARAMS_MSG,
+                                         Client_ID(Client), Req->command);
 
        /* Origin for answers */
-       if( Client_Type( Client ) == CLIENT_SERVER )
-       {
-               origin = Client_Search( Req->prefix );
-               if( ! origin ) return IRC_WriteStrClient( Client, ERR_NOSUCHNICK_MSG, Client_ID( Client ), Req->prefix );
-       }
-       else origin = Client;
+       if (Client_Type(Client) == CLIENT_SERVER) {
+               origin = Client_Search(Req->prefix);
+               if (!origin)
+                       return IRC_WriteStrClient(Client, ERR_NOSUCHNICK_MSG,
+                                                 Client_ID(Client),
+                                                 Req->prefix);
+       } else
+               origin = Client;
 
        /* Channel or user mode? */
        cl = NULL; chan = NULL;
@@ -89,178 +103,242 @@ IRC_MODE( CLIENT *Client, REQUEST *Req )
 } /* IRC_MODE */
 
 
+/**
+ * Check if the "mode limit" for a client has been reached.
+ *
+ * This limit doesn't apply for servers or services!
+ *
+ * @param Client The client to check.
+ * @param Count The number of modes already handled.
+ * @return true if the limit has been reached.
+ */
 static bool
-Client_Mode( CLIENT *Client, REQUEST *Req, CLIENT *Origin, CLIENT *Target )
+Mode_Limit_Reached(CLIENT *Client, int Count)
 {
-       /* Handle client mode requests */
+       if (Client_Type(Client) == CLIENT_SERVER
+           || Client_Type(Client) == CLIENT_SERVICE)
+               return false;
+       if (Count < MAX_HNDL_MODES_ARG)
+               return false;
+       return true;
+}
 
+
+/**
+ * Handle client mode requests
+ *
+ * @param Client       The client from which this command has been received.
+ * @param Req          Request structure with prefix and all parameters.
+ * @param Origin       The originator of the MODE command (prefix).
+ * @param Target       The target (client) of this MODE command.
+ * @returns            CONNECTED or DISCONNECTED.
+ */
+static bool
+Client_Mode( CLIENT *Client, REQUEST *Req, CLIENT *Origin, CLIENT *Target )
+{
        char the_modes[COMMAND_LEN], x[2], *mode_ptr;
        bool ok, set;
        int mode_arg;
        size_t len;
 
        /* Is the client allowed to request or change the modes? */
-       if( Client_Type( Client ) == CLIENT_USER )
-       {
+       if (Client_Type(Client) == CLIENT_USER) {
                /* Users are only allowed to manipulate their own modes! */
-               if( Target != Client ) return IRC_WriteStrClient( Client, ERR_USERSDONTMATCH_MSG, Client_ID( Client ));
+               if (Target != Client)
+                       return IRC_WriteStrClient(Client,
+                                                 ERR_USERSDONTMATCH_MSG,
+                                                 Client_ID(Client));
        }
 
        /* Mode request: let's answer it :-) */
-       if( Req->argc == 1 ) return IRC_WriteStrClient( Origin, RPL_UMODEIS_MSG, Client_ID( Origin ), Client_Modes( Target ));
+       if (Req->argc == 1)
+               return IRC_WriteStrClient(Origin, RPL_UMODEIS_MSG,
+                                         Client_ID(Origin),
+                                         Client_Modes(Target));
 
        mode_arg = 1;
        mode_ptr = Req->argv[mode_arg];
 
        /* Initial state: set or unset modes? */
-       if( *mode_ptr == '+' ) set = true;
-       else if( *mode_ptr == '-' ) set = false;
-       else return IRC_WriteStrClient( Origin, ERR_UMODEUNKNOWNFLAG_MSG, Client_ID( Origin ));
-
-       /* Prepare reply string */
-       if( set ) strcpy( the_modes, "+" );
-       else strcpy( the_modes, "-" );
+       if (*mode_ptr == '+') {
+               set = true;
+               strcpy(the_modes, "+");
+       } else if (*mode_ptr == '-') {
+               set = false;
+               strcpy(the_modes, "-");
+       } else
+               return IRC_WriteStrClient(Origin, ERR_UMODEUNKNOWNFLAG_MSG,
+                                         Client_ID(Origin));
 
        x[1] = '\0';
        ok = CONNECTED;
-       while( mode_ptr )
-       {
+       while (mode_ptr) {
                mode_ptr++;
-               if( ! *mode_ptr )
-               {
+               if (!*mode_ptr) {
                        /* Try next argument if there's any */
                        mode_arg++;
-                       if( mode_arg < Req->argc ) mode_ptr = Req->argv[mode_arg];
-                       else break;
+                       if (mode_arg < Req->argc)
+                               mode_ptr = Req->argv[mode_arg];
+                       else
+                               break;
                }
-               
-               switch( *mode_ptr )
-               {
-                       case '+':
-                       case '-':
-                               if((( *mode_ptr == '+' ) && ( ! set )) || (( *mode_ptr == '-' ) && ( set )))
-                               {
-                                       /* Action modifier ("+"/"-") must be changed ... */
-                                       len = strlen( the_modes ) - 1;
-                                       if(( the_modes[len] == '+' ) || ( the_modes[len] == '-' ))
-                                       {
-                                               /* Adjust last action modifier in result */
-                                               the_modes[len] = *mode_ptr;
-                                       }
-                                       else
-                                       {
-                                               /* Append modifier character to result string */
-                                               x[0] = *mode_ptr;
-                                               strlcat( the_modes, x, sizeof( the_modes ));
-                                       }
-                                       if( *mode_ptr == '+' ) set = true;
-                                       else set = false;
+
+               switch(*mode_ptr) {
+                 case '+':
+                 case '-':
+                       if ((*mode_ptr == '+' && !set)
+                           || (*mode_ptr == '-' && set)) {
+                               /* Action modifier ("+"/"-") must be changed */
+                               len = strlen(the_modes) - 1;
+                               if (the_modes[len] == '+'
+                                   || the_modes[len] == '-') {
+                                       /* Last character in the "result
+                                        * string" was an "action", so just
+                                        * overwrite it with the new action */
+                                       the_modes[len] = *mode_ptr;
+                               } else {
+                                       /* Append new modifier character to
+                                        * the resulting mode string */
+                                       x[0] = *mode_ptr;
+                                       strlcat(the_modes, x,
+                                               sizeof(the_modes));
                                }
-                               continue;
+                               if (*mode_ptr == '+')
+                                       set = true;
+                               else
+                                       set = false;
+                       }
+                       continue;
                }
-               
+
                /* Validate modes */
                x[0] = '\0';
-               switch( *mode_ptr )
-               {
-                       case 'i': /* Invisible */
-                       case 's': /* Server messages */
-                       case 'w': /* Wallops messages */
-                               x[0] = *mode_ptr;
-                               break;
-
-                       case 'a': /* Away */
-                               if( Client_Type( Client ) == CLIENT_SERVER )
-                               {
-                                       x[0] = 'a';
-                                       Client_SetAway( Origin, DEFAULT_AWAY_MSG );
-                               }
-                               else ok = IRC_WriteStrClient( Origin, ERR_NOPRIVILEGES_MSG, Client_ID( Origin ));
-                               break;
-
-                       case 'c': /* Receive connect notices
-                                  * (only settable by IRC operators!) */
-                               if(!set || Client_OperByMe(Origin)
-                                  || Client_Type(Client) == CLIENT_SERVER)
-                                       x[0] = 'c';
-                               else
-                                       ok = IRC_WriteStrClient(Origin,
+               switch (*mode_ptr) {
+               case 'C': /* Only messages from clients sharing a channel */
+               case 'i': /* Invisible */
+               case 's': /* Server messages */
+               case 'w': /* Wallops messages */
+                       x[0] = *mode_ptr;
+                       break;
+               case 'a': /* Away */
+                       if (Client_Type(Client) == CLIENT_SERVER) {
+                               x[0] = 'a';
+                               Client_SetAway(Origin, DEFAULT_AWAY_MSG);
+                       } else
+                               ok = IRC_WriteStrClient(Origin,
                                                        ERR_NOPRIVILEGES_MSG,
                                                        Client_ID(Origin));
-                               break;
-
-                       case 'o': /* IRC operator (only unsettable!) */
-                               if(( ! set ) || ( Client_Type( Client ) == CLIENT_SERVER ))
-                               {
-                                       Client_SetOperByMe( Target, false );
-                                       x[0] = 'o';
-                               }
-                               else ok = IRC_WriteStrClient( Origin, ERR_NOPRIVILEGES_MSG, Client_ID( Origin ));
-                               break;
-
-                       case 'r': /* Restricted (only settable) */
-                               if(( set ) || ( Client_Type( Client ) == CLIENT_SERVER )) x[0] = 'r';
-                               else ok = IRC_WriteStrClient( Origin, ERR_RESTRICTED_MSG, Client_ID( Origin ));
-                               break;
-
-                       case 'x': /* Cloak hostname */
-                               if (Client_HasMode(Client, 'r'))
-                                       IRC_WriteStrClient(Origin,
-                                                          ERR_RESTRICTED_MSG,
-                                                          Client_ID(Origin));
-                               else
-                                       x[0] = 'x';
-                               break;
-
-                       default:
-                               Log( LOG_DEBUG, "Unknown mode \"%c%c\" from \"%s\"!?", set ? '+' : '-', *mode_ptr, Client_ID( Origin ));
-                               if( Client_Type( Client ) != CLIENT_SERVER ) ok = IRC_WriteStrClient( Origin, ERR_UMODEUNKNOWNFLAG2_MSG, Client_ID( Origin ), set ? '+' : '-', *mode_ptr );
+                       break;
+               case 'c': /* Receive connect notices
+                          * (only settable by IRC operators!) */
+                       if (!set || Client_Type(Client) == CLIENT_SERVER
+                           || Client_OperByMe(Origin))
+                               x[0] = 'c';
+                       else
+                               ok = IRC_WriteStrClient(Origin,
+                                                       ERR_NOPRIVILEGES_MSG,
+                                                       Client_ID(Origin));
+                       break;
+               case 'o': /* IRC operator (only unsettable!) */
+                       if (!set || Client_Type(Client) == CLIENT_SERVER) {
+                               Client_SetOperByMe(Target, false);
+                               x[0] = 'o';
+                       } else
+                               ok = IRC_WriteStrClient(Origin,
+                                                       ERR_NOPRIVILEGES_MSG,
+                                                       Client_ID(Origin));
+                       break;
+               case 'r': /* Restricted (only settable) */
+                       if (set || Client_Type(Client) == CLIENT_SERVER)
+                               x[0] = 'r';
+                       else
+                               ok = IRC_WriteStrClient(Origin,
+                                                       ERR_RESTRICTED_MSG,
+                                                       Client_ID(Origin));
+                       break;
+               case 'x': /* Cloak hostname */
+                       if (Client_HasMode(Client, 'r'))
+                               ok = IRC_WriteStrClient(Origin,
+                                                       ERR_RESTRICTED_MSG,
+                                                       Client_ID(Origin));
+                       else
+                               x[0] = 'x';
+                       break;
+               default:
+                       if (Client_Type(Client) != CLIENT_SERVER) {
+                               Log(LOG_DEBUG,
+                                   "Unknown mode \"%c%c\" from \"%s\"!?",
+                                   set ? '+' : '-', *mode_ptr,
+                                   Client_ID(Origin));
+                               ok = IRC_WriteStrClient(Origin,
+                                                       ERR_UMODEUNKNOWNFLAG2_MSG,
+                                                       Client_ID(Origin),
+                                                       set ? '+' : '-',
+                                                       *mode_ptr);
                                x[0] = '\0';
-                               goto client_exit;
+                       } else {
+                               Log(LOG_DEBUG,
+                                   "Handling unknown mode \"%c%c\" from \"%s\" for \"%s\" ...",
+                                   set ? '+' : '-', *mode_ptr,
+                                   Client_ID(Origin), Client_ID(Target));
+                               x[0] = *mode_ptr;
+                       }
                }
-               if( ! ok ) break;
 
-               /* Is there a valid mode change? */
-               if( ! x[0] ) continue;
+               if (!ok)
+                       break;
 
-               if( set )
-               {
-                       /* Set mode */
-                       if( Client_ModeAdd( Target, x[0] )) strlcat( the_modes, x, sizeof( the_modes ));
+               /* Is there a valid mode change? */
+               if (!x[0])
+                       continue;
 
+               if (set) {
+                       if (Client_ModeAdd(Target, x[0]))
+                               strlcat(the_modes, x, sizeof(the_modes));
+               } else {
+                       if (Client_ModeDel(Target, x[0]))
+                               strlcat(the_modes, x, sizeof(the_modes));
                }
-               else
-               {
-                       /* Unset mode */
-                       if( Client_ModeDel( Target, x[0] )) strlcat( the_modes, x, sizeof( the_modes ));
-               }               
        }
-client_exit:
-       
+
        /* Are there changed modes? */
-       if( the_modes[1] )
-       {
-               /* Remoce needless action modifier characters */
-               len = strlen( the_modes ) - 1;
-               if(( the_modes[len] == '+' ) || ( the_modes[len] == '-' )) the_modes[len] = '\0';
+       if (the_modes[1]) {
+               /* Remove needless action modifier characters */
+               len = strlen(the_modes) - 1;
+               if (the_modes[len] == '+' || the_modes[len] == '-')
+                       the_modes[len] = '\0';
 
-               if( Client_Type( Client ) == CLIENT_SERVER )
-               {
+               if (Client_Type(Client) == CLIENT_SERVER) {
                        /* Forward modes to other servers */
-                       IRC_WriteStrServersPrefix( Client, Origin, "MODE %s :%s", Client_ID( Target ), the_modes );
-               }
-               else
-               {
+                       if (Client_Conn(Target) != NONE) {
+                               /* Remote server (service?) changed modes
+                                * for one of our clients. Inform it! */
+                               IRC_WriteStrClientPrefix(Target, Origin,
+                                                        "MODE %s :%s",
+                                                        Client_ID(Target),
+                                                        the_modes);
+                       }
+                       IRC_WriteStrServersPrefix(Client, Origin,
+                                                 "MODE %s :%s",
+                                                 Client_ID(Target),
+                                                 the_modes);
+               } else {
                        /* Send reply to client and inform other servers */
-                       ok = IRC_WriteStrClientPrefix( Client, Origin, "MODE %s :%s", Client_ID( Target ), the_modes );
-                       IRC_WriteStrServersPrefix( Client, Origin, "MODE %s :%s", Client_ID( Target ), the_modes );
+                       ok = IRC_WriteStrClientPrefix(Client, Origin,
+                                                     "MODE %s :%s",
+                                                     Client_ID(Target),
+                                                     the_modes);
+                       IRC_WriteStrServersPrefix(Client, Origin,
+                                                 "MODE %s :%s",
+                                                 Client_ID(Target),
+                                                 the_modes);
                }
                LogDebug("%s \"%s\": Mode change, now \"%s\".",
                         Client_TypeText(Target), Client_Mask(Target),
                         Client_Modes(Target));
        }
-       
-       IRC_SetPenalty( Client, 1 );    
+
+       IRC_SetPenalty(Client, 1);
        return ok;
 } /* Client_Mode */
 
@@ -320,7 +398,7 @@ Channel_Mode(CLIENT *Client, REQUEST *Req, CLIENT *Origin, CHANNEL *Channel)
        char the_modes[COMMAND_LEN], the_args[COMMAND_LEN], x[2],
            argadd[CLIENT_PASS_LEN], *mode_ptr;
        bool connected, set, skiponce, retval, onchannel, modeok, use_servermode;
-       int mode_arg, arg_arg;
+       int mode_arg, arg_arg, mode_arg_count = 0;
        CLIENT *client;
        long l;
        size_t len;
@@ -373,6 +451,8 @@ Channel_Mode(CLIENT *Client, REQUEST *Req, CLIENT *Origin, CHANNEL *Channel)
                        mode_ptr++;
                if (!*mode_ptr) {
                        /* Try next argument if there's any */
+                       if (arg_arg < 0)
+                               break;
                        if (arg_arg > mode_arg)
                                mode_arg = arg_arg;
                        else
@@ -422,6 +502,7 @@ Channel_Mode(CLIENT *Client, REQUEST *Req, CLIENT *Origin, CHANNEL *Channel)
                case 'i': /* Invite only */
                case 'm': /* Moderated */
                case 'n': /* Only members can write */
+               case 'R': /* Registered users only */
                case 's': /* Secret channel */
                case 't': /* Topic locked */
                case 'z': /* Secure connections only */
@@ -433,6 +514,8 @@ Channel_Mode(CLIENT *Client, REQUEST *Req, CLIENT *Origin, CHANNEL *Channel)
                                        Client_ID(Origin), Channel_Name(Channel));
                        break;
                case 'k': /* Channel key */
+                       if (Mode_Limit_Reached(Client, mode_arg_count++))
+                               goto chan_exit;
                        if (!set) {
                                if (modeok)
                                        x[0] = *mode_ptr;
@@ -467,6 +550,8 @@ Channel_Mode(CLIENT *Client, REQUEST *Req, CLIENT *Origin, CHANNEL *Channel)
                        }
                        break;
                case 'l': /* Member limit */
+                       if (Mode_Limit_Reached(Client, mode_arg_count++))
+                               goto chan_exit;
                        if (!set) {
                                if (modeok)
                                        x[0] = *mode_ptr;
@@ -537,6 +622,16 @@ Channel_Mode(CLIENT *Client, REQUEST *Req, CLIENT *Origin, CHANNEL *Channel)
                                        Channel_Name(Channel));
                        break;
                /* --- Channel user modes --- */
+               case 'a':
+               case 'h':
+               case 'q':
+                       if (Client_Type(Client) != CLIENT_SERVER) {
+                               connected = IRC_WriteStrClient(Origin,
+                                       ERR_CHANOPRIVSNEEDED_MSG,
+                                       Client_ID(Origin),
+                                       Channel_Name(Channel));
+                               goto chan_exit;
+                       }
                case 'o': /* Channel operator */
                case 'v': /* Voice */
                        if (arg_arg > mode_arg) {
@@ -567,14 +662,16 @@ Channel_Mode(CLIENT *Client, REQUEST *Req, CLIENT *Origin, CHANNEL *Channel)
                /* --- Channel lists --- */
                case 'I': /* Invite lists */
                case 'b': /* Ban lists */
+                       if (Mode_Limit_Reached(Client, mode_arg_count++))
+                               goto chan_exit;
                        if (arg_arg > mode_arg) {
                                /* modify list */
                                if (modeok) {
                                        connected = set
-                                          ? Add_Ban_Invite(*mode_ptr, Origin,
+                                          ? Add_To_List(*mode_ptr, Origin,
                                                Client, Channel,
                                                Req->argv[arg_arg])
-                                          : Del_Ban_Invite(*mode_ptr, Origin,
+                                          : Del_From_List(*mode_ptr, Origin,
                                                Client, Channel,
                                                Req->argv[arg_arg]);
                                } else {
@@ -593,18 +690,24 @@ Channel_Mode(CLIENT *Client, REQUEST *Req, CLIENT *Origin, CHANNEL *Channel)
                        }
                        break;
                default:
-                       Log(LOG_DEBUG,
-                           "Unknown mode \"%c%c\" from \"%s\" on %s!?",
-                           set ? '+' : '-', *mode_ptr, Client_ID(Origin),
-                           Channel_Name(Channel));
-                       if (Client_Type(Client) != CLIENT_SERVER)
+                       if (Client_Type(Client) != CLIENT_SERVER) {
+                               Log(LOG_DEBUG,
+                                   "Unknown mode \"%c%c\" from \"%s\" on %s!?",
+                                   set ? '+' : '-', *mode_ptr,
+                                   Client_ID(Origin), Channel_Name(Channel));
                                connected = IRC_WriteStrClient(Origin,
-                                       ERR_UMODEUNKNOWNFLAG2_MSG,
-                                       Client_ID(Origin),
-                                       set ? '+' : '-', *mode_ptr);
-                       x[0] = '\0';
-                       goto chan_exit;
-               }       /* switch() */
+                                       ERR_UNKNOWNMODE_MSG,
+                                       Client_ID(Origin), *mode_ptr,
+                                       Channel_Name(Channel));
+                               x[0] = '\0';
+                       } else {
+                               Log(LOG_DEBUG,
+                                   "Handling unknown mode \"%c%c\" from \"%s\" on %s ...",
+                                   set ? '+' : '-', *mode_ptr,
+                                   Client_ID(Origin), Channel_Name(Channel));
+                               x[0] = *mode_ptr;
+                       }
+               }
 
                if (!connected)
                        break;
@@ -730,82 +833,137 @@ IRC_AWAY( CLIENT *Client, REQUEST *Req )
 } /* IRC_AWAY */
 
 
+/**
+ * Add entries to channel invite, ban and exception lists.
+ *
+ * @param what Can be 'I' for invite or 'b' for ban list.
+ * @param Prefix The originator of the command.
+ * @param Client The sender of the command.
+ * @param Channel The channel of which the list should be modified.
+ * @param Pattern The pattern to add to the list.
+ * @return CONNECTED or DISCONNECTED.
+ */
 static bool
-Add_Ban_Invite(int what, CLIENT *Prefix, CLIENT *Client, CHANNEL *Channel, const char *Pattern)
+Add_To_List(char what, CLIENT *Prefix, CLIENT *Client, CHANNEL *Channel,
+           const char *Pattern)
 {
        const char *mask;
-       bool already;
-       bool ret;
+       struct list_head *list;
 
-       assert( Client != NULL );
-       assert( Channel != NULL );
-       assert( Pattern != NULL );
+       assert(Client != NULL);
+       assert(Channel != NULL);
+       assert(Pattern != NULL);
        assert(what == 'I' || what == 'b');
 
        mask = Lists_MakeMask(Pattern);
 
-       already = Lists_CheckDupeMask(Channel_GetListInvites(Channel), mask);
-       if (!already) {
-               if (what == 'I')
-                       ret = Channel_AddInvite(Channel, mask, false);
-               else
-                       ret = Channel_AddBan(Channel, mask);
-               if (!ret)
-                       return CONNECTED;
+       switch(what) {
+               case 'I':
+                       list = Channel_GetListInvites(Channel);
+                       break;
+               case 'b':
+                       list = Channel_GetListBans(Channel);
+                       break;
        }
-       if (already && (Client_Type(Prefix) == CLIENT_SERVER))
-               return CONNECTED;
 
-       if (what == 'I')
-               return Send_ListChange("+I", Prefix, Client, Channel, mask);
-       return Send_ListChange("+b", Prefix, Client, Channel, mask);
+       if (Lists_CheckDupeMask(list, mask))
+               return CONNECTED;
+       if (Client_Type(Client) == CLIENT_USER &&
+           Lists_Count(list) >= MAX_HNDL_CHANNEL_LISTS)
+               return IRC_WriteStrClient(Client, ERR_LISTFULL_MSG,
+                                         Client_ID(Client),
+                                         Channel_Name(Channel), mask,
+                                         MAX_HNDL_CHANNEL_LISTS);
+
+       switch (what) {
+               case 'I':
+                       if (!Channel_AddInvite(Channel, mask, false))
+                               return CONNECTED;
+                       break;
+               case 'b':
+                       if (!Channel_AddBan(Channel, mask))
+                               return CONNECTED;
+                       break;
+       }
+       return Send_ListChange(true, what, Prefix, Client, Channel, mask);
 }
 
 
+/**
+ * Delete entries from channel invite, ban and exeption lists.
+ *
+ * @param what Can be 'I' for invite or 'b' for ban list.
+ * @param Prefix The originator of the command.
+ * @param Client The sender of the command.
+ * @param Channel The channel of which the list should be modified.
+ * @param Pattern The pattern to add to the list.
+ * @return CONNECTED or DISCONNECTED.
+ */
 static bool
-Del_Ban_Invite(int what, CLIENT *Prefix, CLIENT *Client, CHANNEL *Channel, const char *Pattern)
+Del_From_List(char what, CLIENT *Prefix, CLIENT *Client, CHANNEL *Channel,
+             const char *Pattern)
 {
        const char *mask;
        struct list_head *list;
 
-       assert( Client != NULL );
-       assert( Channel != NULL );
-       assert( Pattern != NULL );
+       assert(Client != NULL);
+       assert(Channel != NULL);
+       assert(Pattern != NULL);
        assert(what == 'I' || what == 'b');
 
-       mask = Lists_MakeMask( Pattern );
+       mask = Lists_MakeMask(Pattern);
 
-       if (what == 'I')
-               list = Channel_GetListInvites(Channel);
-       else
-               list = Channel_GetListBans(Channel);
+       switch (what) {
+               case 'I':
+                       list = Channel_GetListInvites(Channel);
+                       break;
+               case 'b':
+                       list = Channel_GetListBans(Channel);
+                       break;
+       }
 
+       if (!Lists_CheckDupeMask(list, mask))
+               return CONNECTED;
        Lists_Del(list, mask);
-       if (what == 'I')
-               return Send_ListChange( "-I", Prefix, Client, Channel, mask );
-       return Send_ListChange( "-b", Prefix, Client, Channel, mask );
+
+       return Send_ListChange(false, what, Prefix, Client, Channel, mask);
 }
 
 
+/**
+ * Send information about changed channel ban/invite lists to clients.
+ *
+ * @param IsAdd true if the list item has been added, false otherwise.
+ * @param ModeChar The mode to use (e. g. 'b' or 'I')
+ * @param Prefix The originator of the mode list change.
+ * @param Client The sender of the command.
+ * @param Channel The channel of which the list has been modified.
+ * @param Mask The mask which has been added or removed.
+ * @return CONNECTED or DISCONNECTED.
+ */
 static bool
-Send_ListChange(const char *Mode, CLIENT *Prefix, CLIENT *Client,
-               CHANNEL *Channel, const char *Mask)
+Send_ListChange(const bool IsAdd, const char ModeChar, CLIENT *Prefix,
+               CLIENT *Client, CHANNEL *Channel, const char *Mask)
 {
-       bool ok;
+       bool ok = true;
 
-       if( Client_Type( Client ) == CLIENT_USER )
-       {
-               /* send confirmation to client */
-               ok = IRC_WriteStrClientPrefix( Client, Prefix, "MODE %s %s %s", Channel_Name( Channel ), Mode, Mask );
-       }
-       else ok = true;
+       /* Send confirmation to the client */
+       if (Client_Type(Client) == CLIENT_USER)
+               ok = IRC_WriteStrClientPrefix(Client, Prefix, "MODE %s %c%c %s",
+                                             Channel_Name(Channel),
+                                             IsAdd ? '+' : '-',
+                                             ModeChar, Mask);
 
        /* to other servers */
-       IRC_WriteStrServersPrefix( Client, Prefix, "MODE %s %s %s", Channel_Name( Channel ), Mode, Mask );
+       IRC_WriteStrServersPrefix(Client, Prefix, "MODE %s %c%c %s",
+                                 Channel_Name(Channel), IsAdd ? '+' : '-',
+                                 ModeChar, Mask);
 
        /* and local users in channel */
-       IRC_WriteStrChannelPrefix( Client, Channel, Prefix, false, "MODE %s %s %s", Channel_Name( Channel ), Mode, Mask );
-       
+       IRC_WriteStrChannelPrefix(Client, Channel, Prefix, false,
+                                 "MODE %s %c%c %s", Channel_Name(Channel),
+                                 IsAdd ? '+' : '-', ModeChar, Mask );
+
        return ok;
 } /* Send_ListChange */