From 27c0ae9433571f71521cda36beeb43a529637b57 Mon Sep 17 00:00:00 2001
From: Sadie Powell <sadie@witchery.services>
Date: Sun, 17 Apr 2022 12:08:57 +0100
Subject: [PATCH] Allow normalising extbans to a specific format.

Also, fix canonicalisation of acting extban values.
---
 docs/conf/inspircd.conf.example            |  9 +++++++++
 include/modules/extban.h                   | 15 +++++++++++++++
 src/coremods/core_channel/core_channel.cpp |  7 +++++++
 src/coremods/core_channel/core_channel.h   |  3 +++
 src/coremods/core_channel/extban.cpp       | 20 ++++++++++++++++++++
 5 files changed, 54 insertions(+)

diff --git a/docs/conf/inspircd.conf.example b/docs/conf/inspircd.conf.example
index 299ccb467..c6520e8f7 100644
--- a/docs/conf/inspircd.conf.example
+++ b/docs/conf/inspircd.conf.example
@@ -637,6 +637,15 @@
          # in the /LIST response. Defaults to yes.
          modesinlist="no"
 
+         # extbanformat: The method to use for normalising extbans. Can be set
+         # to one of:
+         #  - any     Do not perform any extban normalisation.
+         #  - name    Normalise extbans to use their name.
+         #  - letter  Normalise extbans to use their letter. This is useful for
+         #            if you need to keep compatibility with v3.
+         # Defaults to "any" if not set.
+         extbanformat="name"
+
          # exemptchanops: Allows users with with a status mode to be exempt
          # from various channel restrictions. Possible restrictions are:
          #  - anticaps        Channel mode +B - blocks messages with too many capital
diff --git a/include/modules/extban.h b/include/modules/extban.h
index b90829be9..8f636d201 100644
--- a/include/modules/extban.h
+++ b/include/modules/extban.h
@@ -28,6 +28,18 @@ namespace ExtBan
 	class Manager;
 	class ManagerRef;
 
+	enum class Format
+	{
+		/** Do not perform any normalisation of extbans. */
+		ANY,
+
+		/** Normalise extbans to use their name (e.g. mute). */
+		NAME,
+
+		/** Normalise extbans to use their letter (e.g. m). */
+		LETTER,
+	};
+
 	/** All possible types of extban. */
 	enum class Type
 	{
@@ -84,6 +96,9 @@ public:
 	 */
 	virtual void DelExtBan(Base* extban) = 0;
 
+	/** Retrieves the method used for normalising extbans. */
+	virtual Format GetFormat() const = 0;
+
 	/** Retrieves a mapping of extban letters to their associated object. */
 	virtual const LetterMap& GetLetterMap() const = 0;
 
diff --git a/src/coremods/core_channel/core_channel.cpp b/src/coremods/core_channel/core_channel.cpp
index 0bdb894ac..d6e72b61c 100644
--- a/src/coremods/core_channel/core_channel.cpp
+++ b/src/coremods/core_channel/core_channel.cpp
@@ -178,6 +178,12 @@ public:
 			exempts[restriction] = prefix;
 		}
 
+		ExtBan::Format newformat = optionstag->getEnum("extbanformat", ExtBan::Format::ANY, {
+			{ "any",    ExtBan::Format::ANY },
+			{ "name",   ExtBan::Format::NAME },
+			{ "letter", ExtBan::Format::LETTER },
+		});
+
 		auto securitytag = ServerInstance->Config->ConfValue("security");
 		Invite::AnnounceState newannouncestate = securitytag->getEnum("announceinvites", Invite::ANNOUNCE_DYNAMIC, {
 			{ "all",     Invite::ANNOUNCE_ALL },
@@ -192,6 +198,7 @@ public:
 		banmode.DoRehash();
 
 		exemptions.swap(exempts);
+		extbanmgr.format = newformat;
 		invapi.announceinvites = newannouncestate;
 		joinhook.modefromuser = optionstag->getBool("cyclehostsfromuser");
 
diff --git a/src/coremods/core_channel/core_channel.h b/src/coremods/core_channel/core_channel.h
index 2e86a2988..2d71e18b5 100644
--- a/src/coremods/core_channel/core_channel.h
+++ b/src/coremods/core_channel/core_channel.h
@@ -163,6 +163,8 @@ private:
 	NameMap byname;
 
 public:
+	ExtBan::Format format;
+
 	ExtBanManager(Module* Creator, ModeChannelBan& bm)
 		: ExtBan::Manager(Creator)
 		, banmode(bm)
@@ -173,6 +175,7 @@ public:
 	void AddExtBan(ExtBan::Base* extban) override;
 	bool Canonicalize(std::string& text) const override;
 	void DelExtBan(ExtBan::Base* extban) override;
+	ExtBan::Format GetFormat() const override { return format; }
 	const LetterMap& GetLetterMap() const override { return byletter; }
 	const NameMap& GetNameMap() const override { return byname; }
 	ModResult GetStatus(ExtBan::Acting* extban, User* user, Channel* channel) const override;
diff --git a/src/coremods/core_channel/extban.cpp b/src/coremods/core_channel/extban.cpp
index 376b6febe..f42e49b68 100644
--- a/src/coremods/core_channel/extban.cpp
+++ b/src/coremods/core_channel/extban.cpp
@@ -42,7 +42,27 @@ bool ExtBanManager::Canonicalize(std::string& text) const
 	if (!extban)
 		return false; // Looks like an extban but it isn't.
 
+	// Canonicalize the extban.
+	text.assign(inverted ? "!" : "");
+
+	switch (format)
+	{
+		case ExtBan::Format::NAME:
+			text.append(extban->GetName());
+			break;
+
+		case ExtBan::Format::LETTER:
+			text.append(1, extban->GetLetter());
+			break;
+
+		default:
+			text.append(xbname);
+			break;
+	}
+
 	extban->Canonicalize(xbvalue);
+	text.append(":").append(xbvalue);
+
 	return true;
 }