Add the sharebans module.

1 files changed, 116 insertions, 0 deletions

diff --git a/src/modules/m_sharebans.cpp b/src/modules/m_sharebans.cpp
new file mode 100644
index 000000000..3d066bc13
--- /dev/null
+++ b/src/modules/m_sharebans.cpp
@@ -0,0 +1,116 @@
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ *   Copyright (C) 2026 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"
+#include "listmode.h"
+#include "modules/extban.h"
+#include "numerichelper.h"
+
+enum
+{
+	// InspIRCd-specific.
+	ERR_BADCHANNEL = 926
+};
+
+class ShareExtBan final
+	: public ExtBan::MatchingBase
+{
+private:
+	ChanModeReference secretmode;
+	std::vector<Channel*> seen;
+
+public:
+	size_t maxdepth;
+
+	ShareExtBan(Module* mod)
+		: ExtBan::MatchingBase(mod, "share", 'b')
+		, secretmode(mod, "secret")
+	{
+	}
+
+	bool IsMatch(User* user, Channel* channel, const std::string& text) override
+	{
+		if (seen.size() >= maxdepth)
+			return false;
+
+		auto banned = false;
+		auto* targetchan = ServerInstance->Channels.Find(text);
+		if (targetchan && targetchan != channel)
+		{
+			seen.push_back(channel);
+			banned = targetchan->IsBanned(user);
+			stdalgo::erase(seen, channel);
+		}
+		return banned;
+	}
+
+	bool Validate(ListModeBase* lm, LocalUser* user, Channel* channel, std::string& text, bool inverted) override
+	{
+		auto* targetchan = ServerInstance->Channels.Find(text);
+		if (!targetchan || (targetchan->IsModeSet(secretmode) && (!targetchan->HasUser(user) && !user->HasPrivPermission("channels/auspex"))))
+		{
+			user->WriteNumeric(Numerics::NoSuchChannel(text));
+			return false;
+		}
+
+		if (targetchan == channel)
+		{
+			user->WriteNumeric(ERR_BADCHANNEL, text, "You can not create a channel ban loop.");
+			return false;
+		}
+
+		auto* memb = targetchan->GetUser(user);
+		if (!memb)
+		{
+			user->WriteNumeric(ERR_NOTONCHANNEL, targetchan->name, "You're not on that channel!");
+			return false;
+		}
+
+		const auto rank = lm->GetLevelRequired(true);
+		if (memb->GetRank() < rank)
+		{
+			user->WriteNumeric(Numerics::ChannelPrivilegesNeeded(targetchan, rank, "share bans between channels"));
+			return false;
+		}
+
+		return true;
+	}
+};
+
+class ModuleShareBans final
+	: public Module
+{
+private:
+	ShareExtBan extban;
+
+public:
+	ModuleShareBans()
+		: Module(VF_VENDOR | VF_OPTCOMMON, "Adds extended ban b: (share) which allows sharing bans between channels.")
+		, extban(this)
+	{
+	}
+
+	void ReadConfig(ConfigStatus& status) override
+	{
+		const auto& tag = ServerInstance->Config->ConfValue("sharebans");
+		extban.maxdepth = tag->getNum<size_t>("maxdepth", 2, 1, 100);
+	}
+};
+
+MODULE_INIT(ModuleShareBans)