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/* Copyright (C) 2002-2005 RealVNC Ltd. All Rights Reserved.
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <rfb/Blacklist.h>
#include <rfb/Configuration.h>
using namespace rfb;
BoolParameter enabled("UseBlacklist",
"Temporarily reject connections from a host if it "
"repeatedly fails to authenticate.",
true);
IntParameter threshold("BlacklistThreshold",
"The number of unauthenticated connection attempts "
"allowed from any individual host before that host "
"is black-listed",
5);
IntParameter initialTimeout("BlacklistTimeout",
"The initial timeout applied when a host is "
"first black-listed. The host cannot re-attempt "
"a connection until the timeout expires.",
10);
Blacklist::Blacklist() {
}
Blacklist::~Blacklist() {
// Free the map keys
BlacklistMap::iterator i;
for (i=blm.begin(); i!=blm.end(); i++) {
strFree((char*)(*i).first);
}
}
bool Blacklist::isBlackmarked(const char* name) {
if (!enabled)
return false;
BlacklistMap::iterator i = blm.find(name);
if (i == blm.end()) {
// Entry is not already black-marked.
// Create the entry unmarked, unblocked,
// with suitable defaults set.
BlacklistInfo bi;
bi.marks = 1;
bi.blockUntil = 0;
bi.blockTimeout = initialTimeout;
blm[strDup(name)] = bi;
i = blm.find(name);
}
// Entry exists - has it reached the threshold yet?
if ((*i).second.marks >= threshold) {
// Yes - entry is blocked - has the timeout expired?
time_t now = time(0);
if (now >= (*i).second.blockUntil) {
// Timeout has expired. Reset timeout and allow
// a re-try.
(*i).second.blockUntil = now + (*i).second.blockTimeout;
(*i).second.blockTimeout = (*i).second.blockTimeout * 2;
return false;
}
// Blocked and timeout still in effect - reject!
return true;
}
// We haven't reached the threshold yet.
// Increment the black-mark counter but allow
// the entry to pass.
(*i).second.marks++;
return false;
}
void Blacklist::clearBlackmark(const char* name) {
BlacklistMap::iterator i = blm.find(name);
if (i != blm.end()) {
strFree((char*)(*i).first);
blm.erase(i);
}
}
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