1 files changed, 112 insertions, 0 deletions
diff --git a/modules/nickserv/ns_maxemail.cpp b/modules/nickserv/ns_maxemail.cpp
new file mode 100644
index 000000000..342ba3c3d
--- /dev/null
+++ b/modules/nickserv/ns_maxemail.cpp
@@ -0,0 +1,112 @@
+/* ns_maxemail.cpp - Limit the amount of times an email address
+ *                   can be used for a NickServ account.
+ *
+ * (C) 2003-2024 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)