/*
* InspIRCd -- Internet Relay Chat Daemon
*
* Copyright (C) 2020-2022 Sadie Powell <sadie@witchery.services>
*
* This file is part of InspIRCd. InspIRCd 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, version 2.
*
* This program 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 program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "inspircd.h"
typedef std::bitset<UCHAR_MAX + 1> AllowedChars;
namespace
{
// The characters which are allowed in nicknames.
AllowedChars allowedchars;
// The characters which are allowed at the front of a nickname.
AllowedChars allowedfrontchars;
// The mapping of lower case characters to upper case characters.
unsigned char casemap[UCHAR_MAX];
bool IsValidNick(const std::string& nick)
{
if (nick.empty() || nick.length() > ServerInstance->Config->Limits.NickMax)
return false;
for (std::string::const_iterator iter = nick.begin(); iter != nick.end(); ++iter)
{
unsigned char chr = static_cast<unsigned char>(*iter);
// Check that the character is allowed at the front of the nick.
if (iter == nick.begin() && !allowedfrontchars[chr])
return false;
// Check that the character is allowed in the nick.
if (!allowedchars[chr])
return false;
}
return true;
}
}
class ModuleCodepage
: public Module
{
private:
// The character map which was set before this module was loaded.
const unsigned char* origcasemap;
// The name of the character map which was set before this module was loaded.
const std::string origcasemapname;
// The IsNick handler which was set before this module was loaded.
const TR1NS::function<bool(const std::string&)> origisnick;
// The character set used for the codepage.
std::string charset;
template <typename T>
void RehashHashmap(T& hashmap)
{
T newhash(hashmap.bucket_count());
for (typename T::const_iterator i = hashmap.begin(); i != hashmap.end(); ++i)
newhash.insert(std::make_pair(i->first, i->second));
hashmap.swap(newhash);
}
void DestroyChannel(Channel* chan)
{
// Remove all of the users from the channel. Using KICK here will mean
// the user's client will probably attempt to rejoin and will enter the
// succeeding channel. Unfortunately this is the best we can do for now.
while (!chan->userlist.empty())
chan->KickUser(ServerInstance->FakeClient, chan->userlist.begin(), "This channel does not exist anymore.");
// Remove all modes from the channel just in case one of them keeps the channel open.
Modes::ChangeList changelist;
const ModeParser::ModeHandlerMap& chanmodes = ServerInstance->Modes->GetModes(MODETYPE_CHANNEL);
for (ModeParser::ModeHandlerMap::const_iterator i = chanmodes.begin(); i != chanmodes.end(); ++i)
i->second->RemoveMode(chan, changelist);
ServerInstance->Modes->Process(ServerInstance->FakeClient, chan, NULL, changelist, ModeParser::MODE_LOCALONLY);
// The channel will be destroyed automatically by CheckDestroy.
}
void ChangeNick(User* user, const std::string& message)
{
user->WriteNumeric(RPL_SAVENICK, user->uuid, message);
user->ChangeNick(user->uuid);
}
void CheckDuplicateChan()
{
chan_hash duplicates;
const chan_hash& chans = ServerInstance->GetChans();
for (chan_hash::const_iterator iter = chans.begin(); iter != chans.end(); ++iter)
{
Channel* chan = iter->second;
std::pair<chan_hash::iterator, bool> check = duplicates.insert(std::make_pair(chan->name, chan));
if (check.second)
continue; // No duplicate.
Channel* otherchan = check.first->second;
if (otherchan->age < chan->age)
{
// The other channel was created first.
DestroyChannel(chan);
}
else if (otherchan->age > chan->age)
{
// The other channel was created last.
DestroyChannel(otherchan);
check.first->second = chan;
}
else
{
// Both created at the same time.
DestroyChannel(chan);
DestroyChannel(otherchan);
duplicates.erase(check.first);
}
}
}
void CheckDuplicateNick()
{
user_hash duplicates;
const user_hash& users = ServerInstance->Users->GetUsers();
for (user_hash::const_iterator iter = users.begin(); iter != users.end(); ++iter)
{
User* user = iter->second;
if (user->nick == user->uuid)
continue; // UUID users are always unique.
std::pair<user_hash::iterator, bool> check = duplicates.insert(std::make_pair(user->nick, user));
if (check.second)
continue; // No duplicate.
User* otheruser = check.first->second;
if (otheruser->age < user->age)
{
// The other user connected first.
ChangeNick(user, "Your nickname is no longer available.");
}
else if (otheruser->age > user->age)
{
// The other user connected last.
ChangeNick(otheruser, "Your nickname is no longer available.");
check.first->second = user;
}
else
{
// Both connected at the same time.
ChangeNick(user, "Your nickname is no longer available.");
ChangeNick(otheruser, "Your nickname is no longer available.");
duplicates.erase(check.first);
}
}
}
void CheckInvalidNick()
{
const UserManager::LocalList& list = ServerInstance->Users.GetLocalUsers();
for (UserManager::LocalList::const_iterator iter = list.begin(); iter != list.end(); ++iter)
{
LocalUser* user = *iter;
if (user->nick != user->uuid && !ServerInstance->IsNick(user->nick))
ChangeNick(user, "Your nickname is no longer valid.");
}
}
void CheckRehash(unsigned char* prevmap)
{
if (!memcmp(prevmap, national_case_insensitive_map, UCHAR_MAX))
return;
RehashHashmap(ServerInstance->Users.clientlist);
RehashHashmap(ServerInstance->Users.uuidlist);
RehashHashmap(ServerInstance->chanlist);
}
public:
ModuleCodepage()
: origcasemap(national_case_insensitive_map)
, origcasemapname(ServerInstance->Config->CaseMapping)
, origisnick(ServerInstance->IsNick)
{
}
~ModuleCodepage()
{
ServerInstance->IsNick = origisnick;
CheckInvalidNick();
ServerInstance->Config->CaseMapping = origcasemapname;
national_case_insensitive_map = origcasemap;
CheckDuplicateChan();
CheckDuplicateNick();
CheckRehash(casemap);
ServerInstance->ISupport.Build();
}
void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
{
ConfigTag* codepagetag = ServerInstance->Config->ConfValue("codepage");
const std::string name = codepagetag->getString("name");
if (name.empty())
throw ModuleException("<codepage:name> is a required field!");
AllowedChars newallowedchars;
AllowedChars newallowedfrontchars;
ConfigTagList cpchars = ServerInstance->Config->ConfTags("cpchars");
for (ConfigIter i = cpchars.first; i != cpchars.second; ++i)
{
ConfigTag* tag = i->second;
unsigned char begin = tag->getUInt("begin", tag->getUInt("index", 0), 1, UCHAR_MAX);
if (!begin)
throw ModuleException("<cpchars> tag without index or begin specified at " + tag->getTagLocation());
unsigned char end = tag->getUInt("end", begin, 1, UCHAR_MAX);
if (begin > end)
throw ModuleException("<cpchars:begin> must be lower than <cpchars:end> at " + tag->getTagLocation());
bool front = tag->getBool("front", false);
for (unsigned short pos = begin; pos <= end; ++pos)
{
if (pos == '\n' || pos == '\r' || pos == ' ')
{
throw ModuleException(InspIRCd::Format("<cpchars> tag contains a forbidden character: %u at %s",
pos, tag->getTagLocation().c_str()));
}
if (front && (pos == ':' || isdigit(pos)))
{
throw ModuleException(InspIRCd::Format("<cpchars> tag contains a forbidden front character: %u at %s",
pos, tag->getTagLocation().c_str()));
}
newallowedchars.set(pos);
newallowedfrontchars.set(pos, front);
ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Marked %u (%c) as allowed (front: %s)",
pos, pos, front ? "yes" : "no");
}
}
unsigned char newcasemap[UCHAR_MAX];
for (size_t i = 0; i < UCHAR_MAX; ++i)
newcasemap[i] = i;
ConfigTagList cpcase = ServerInstance->Config->ConfTags("cpcase");
for (ConfigIter i = cpcase.first; i != cpcase.second; ++i)
{
ConfigTag* tag = i->second;
unsigned char lower = tag->getUInt("lower", 0, 1, UCHAR_MAX);
if (!lower)
throw ModuleException("<cpcase:lower> is required at " + tag->getTagLocation());
unsigned char upper = tag->getUInt("upper", 0, 1, UCHAR_MAX);
if (!upper)
throw ModuleException("<cpcase:upper> is required at " + tag->getTagLocation());
newcasemap[upper] = lower;
ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Marked %u (%c) as the lower case version of %u (%c)",
lower, lower, upper, upper);
}
charset = codepagetag->getString("charset");
std::swap(allowedchars, newallowedchars);
std::swap(allowedfrontchars, newallowedfrontchars);
std::swap(casemap, newcasemap);
ServerInstance->IsNick = &IsValidNick;
CheckInvalidNick();
ServerInstance->Config->CaseMapping = name;
national_case_insensitive_map = casemap;
CheckDuplicateChan();
CheckDuplicateNick();
CheckRehash(newcasemap);
ServerInstance->ISupport.Build();
}
void On005Numeric(std::map<std::string, std::string>& tokens) CXX11_OVERRIDE
{
if (!charset.empty())
tokens["CHARSET"] = charset;
}
Version GetVersion() CXX11_OVERRIDE
{
std::stringstream linkdata;
linkdata << "front=";
for (size_t i = 0; i < allowedfrontchars.size(); ++i)
if (allowedfrontchars[i])
linkdata << static_cast<unsigned char>(i);
linkdata << "&middle=";
for (size_t i = 0; i < allowedchars.size(); ++i)
if (allowedchars[i])
linkdata << static_cast<unsigned char>(i);
linkdata << "&map=";
for (size_t i = 0; i < sizeof(casemap); ++i)
if (casemap[i] != i)
linkdata << static_cast<unsigned char>(i) << casemap[i] << ',';
return Version("Allows the server administrator to define what characters are allowed in nicknames and how characters should be compared in a case insensitive way.", VF_COMMON | VF_VENDOR, linkdata.str());
}
};
MODULE_INIT(ModuleCodepage)
