anope/modules/nickserv/ns_maxemail.cpp

/* ns_maxemail.cpp - Limit the amount of times an email address
 *                   can be used for a NickServ account.
 *
 * (C) 2003-2025 Anope Team
 * Contact us at team@anope.org
 *
 * Included in the Anope module pack since Anope 1.7.9
 * Anope Coder: GeniusDex <geniusdex@anope.org>
 *
 * Please read COPYING and README for further details.
 */

#include "module.h"

class NSMaxEmail final
	: public Module
{
	bool clean = false;

	/* strip dots from username, and remove anything after the first + */
	static Anope::string CleanMail(const Anope::string &email)
	{
		size_t host = email.find('@');
		if (host == Anope::string::npos)
			return email;

		Anope::string username = email.substr(0, host);
		username = username.replace_all_cs(".", "");

		size_t sz = username.find('+');
		if (sz != Anope::string::npos)
			username = username.substr(0, sz);

		Anope::string cleaned = username + email.substr(host);
		Log(LOG_DEBUG) << "cleaned " << email << " to " << cleaned;
		return cleaned;
	}

	bool CheckLimitReached(CommandSource &source, const Anope::string &email)
	{
		int NSEmailMax = Config->GetModule(this).Get<int>("maxemails");

		if (NSEmailMax < 1 || email.empty())
			return false;

		if (this->CountEmail(email, source.nc) < NSEmailMax)
			return false;

		if (NSEmailMax == 1)
			source.Reply(_("The email address \002%s\002 has reached its usage limit of 1 user."), email.c_str());
		else
			source.Reply(_("The email address \002%s\002 has reached its usage limit of %d users."), email.c_str(), NSEmailMax);

		return true;
	}

	int CountEmail(const Anope::string &email, NickCore *unc)
	{
		int count = 0;

		if (email.empty())
			return 0;

		Anope::string cleanemail = clean ? CleanMail(email) : email;

		for (const auto &[_, nc] : *NickCoreList)
		{
			Anope::string cleannc = clean ? CleanMail(nc->email) : nc->email;

			if (unc != nc && cleanemail.equals_ci(cleannc))
				++count;
		}

		return count;
	}

public:
	NSMaxEmail(const Anope::string &modname, const Anope::string &creator) : Module(modname, creator, VENDOR)
	{
	}

	void OnReload(Configuration::Conf &conf) override
	{
		clean = conf.GetModule(this).Get<bool>("remove_aliases", "true");
	}

	EventReturn OnPreCommand(CommandSource &source, Command *command, std::vector<Anope::string> &params) override
	{
		if (source.IsOper())
			return EVENT_CONTINUE;

		if (command->name == "nickserv/register")
		{
			if (this->CheckLimitReached(source, params.size() > 1 ? params[1] : ""))
				return EVENT_STOP;
		}
		else if (command->name == "nickserv/set/email")
		{
			if (this->CheckLimitReached(source, params.size() > 0 ? params[0] : ""))
				return EVENT_STOP;
		}
		else if (command->name == "nickserv/ungroup" && source.GetAccount())
		{
			if (this->CheckLimitReached(source, source.GetAccount()->email))
				return EVENT_STOP;
		}

		return EVENT_CONTINUE;
	}
};

MODULE_INIT(NSMaxEmail)