src/cull_list.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
   6  *                       E-mail:
   7  *                <brain@chatspike.net>
   8  *                <Craig@chatspike.net>
   9  *
  10  * Written by Craig Edwards, Craig McLure, and others.
  11  * This program is free but copyrighted software; see
  12  *            the file COPYING for details.
  13  *
  14  * ---------------------------------------------------
  15  */
  16
  17 using namespace std;
  18
  19 #include "inspircd_config.h"
  20 #include "inspircd.h"
  21 #include "inspircd_io.h"
  22 #include <unistd.h>
  23 #include <fcntl.h>
  24 #include <sys/errno.h>
  25 #include <time.h>
  26 #include <string>
  27 #ifdef GCC3
  28 #include <ext/hash_map>
  29 #else
  30 #include <hash_map>
  31 #endif
  32 #include <map>
  33 #include <sstream>
  34 #include <vector>
  35 #include <deque>
  36 #include "users.h"
  37 #include "ctables.h"
  38 #include "globals.h"
  39 #include "modules.h"
  40 #include "dynamic.h"
  41 #include "wildcard.h"
  42 #include "message.h"
  43 #include "commands.h"
  44 #include "xline.h"
  45 #include "inspstring.h"
  46 #include "inspircd.h"
  47 #include "helperfuncs.h"
  48 #include "hashcomp.h"
  49 #include "typedefs.h"
  50 #include "cull_list.h"
  51
  52 extern InspIRCd* ServerInstance;
  53 extern user_hash clientlist;
  54
  55 bool CullList::IsValid(userrec* user)
  56 {
  57         time_t esignon = 0;
  58         std::map<userrec*,time_t>::iterator es = exempt.find(user);
  59         if (es != exempt.end())
  60                 esignon = es->second;
  61
  62         for (user_hash::iterator u = clientlist.begin(); u != clientlist.end(); u++)
  63         {
  64                 /*
  65                  * BUGFIX
  66                  *
  67                  * Because there is an undetermined period of time between a user existing,
  68                  * and this function being called, we have to check for the following condition:
  69                  *
  70                  * Between CullList::AddItem(u) being called, and CullList::IsValid(u) being called,
  71                  * the user with the pointer u has quit, but only to be REPLACED WITH A NEW USER WHO
  72                  * BECAUSE OF ALLOCATION RULES, HAS THE SAME MEMORY ADDRESS! To prevent this, we
  73                  * cross reference each pointer to the user's signon time, and if the signon times
  74                  * do not match, we return false here to indicate this user is NOT valid as it
  75                  * seems to differ from the pointer snapshot we got a few seconds earlier. Should
  76                  * prevent a few random crashes during netsplits.
  77                  */
  78                 if (user == u->second)
  79                         return (u->second->signon == esignon);
  80         }
  81         return false;
  82 }
  83
  84 CullItem::CullItem(userrec* u, std::string &r)
  85 {
  86         this->user = u;
  87         this->reason = strdup(r.c_str());
  88 }
  89
  90 CullItem::CullItem(userrec* u, const char* r)
  91 {
  92         this->user = u;
  93         this->reason = strdup(r);
  94 }
  95
  96 CullItem::~CullItem()
  97 {
  98         if (reason)
  99                 free(reason);
 100         reason = NULL;
 101 }
 102
 103 userrec* CullItem::GetUser()
 104 {
 105         return this->user;
 106 }
 107
 108 const char* CullItem::GetReason()
 109 {
 110         return this->reason;
 111 }
 112
 113 CullList::CullList()
 114 {
 115         list.clear();
 116         exempt.clear();
 117 }
 118
 119 void CullList::AddItem(userrec* user, std::string &reason)
 120 {
 121         if (exempt.find(user) == exempt.end())
 122         {
 123                 CullItem item(user,reason);
 124                 list.push_back(item);
 125                 exempt[user] = user->signon;
 126         }
 127 }
 128
 129 void CullList::AddItem(userrec* user, const char* reason)
 130 {
 131         if (exempt.find(user) == exempt.end())
 132         {
 133                 CullItem item(user,reason);
 134                 list.push_back(item);
 135                 exempt[user] = user->signon;
 136         }
 137 }
 138
 139 int CullList::Apply()
 140 {
 141         int n = 0;
 142         while (list.size())
 143         {
 144                 std::vector<CullItem>::iterator a = list.begin();
 145                 userrec* u = a->GetUser();
 146                 /* Because ServerInstance->DoOneIteration can
 147                  * take the user away from us in the middle of
 148                  * our operation, we should check to see if this
 149                  * pointer is still valid by iterating the hash.
 150                  * It's expensive, yes, but the DoOneIteration
 151                  * call stops it being horrendously bad.
 152                  */
 153                 if (IsValid(u))
 154                 {
 155                         kill_link(u,a->GetReason());
 156                         list.erase(list.begin());
 157                         /* So that huge numbers of quits dont block,
 158                          * we yield back to our mainloop every 15
 159                          * iterations.
 160                          * The DoOneIteration call basically acts
 161                          * like a software threading mechanism.
 162                          */
 163                         if (((n++) % 15) == 0)
 164                         {
 165                                 ServerInstance->DoOneIteration(false);
 166                         }
 167                 }
 168         }
 169         return n;
 170 }