From fca2900918a60cc96689a98d417a0b9f5e822d5e Mon Sep 17 00:00:00 2001
From: Conrad Lukawski <conrad@backlight.ca>
Date: Mon, 8 Jun 2020 14:43:58 -0400
Subject: [PATCH] Add +T no-CTCP usermode

---
 irc/handlers.go    | 6 ++++++
 irc/help.go        | 4 +++-
 irc/modes.go       | 2 +-
 irc/modes/modes.go | 1 +
 4 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/irc/handlers.go b/irc/handlers.go
index c68b2170..8ea5340c 100644
--- a/irc/handlers.go
+++ b/irc/handlers.go
@@ -1938,6 +1938,12 @@ func dispatchMessageToTarget(client *Client, tags map[string]string, histType hi
 			}
 			return
 		}
+
+		// Restrict CTCP message for target user with +T
+		if user.modes.HasMode(modes.UserNoCTCP) && message.IsRestrictedCTCPMessage() {
+			return
+		}
+
 		tDetails := user.Details()
 		tnick := tDetails.nick
 
diff --git a/irc/help.go b/irc/help.go
index 4dbd2c82..fd41878a 100644
--- a/irc/help.go
+++ b/irc/help.go
@@ -51,6 +51,7 @@ Oragono supports the following channel modes:
   +R  |  Only registered users can join the channel.
   +s  |  Secret mode, channel won't show up in /LIST or whois replies.
   +t  |  Only channel opers can modify the topic.
+  +C  |  Clients are blocked from sending CTCP messages in the channel.
 
 = Prefixes =
 
@@ -68,7 +69,8 @@ Oragono supports the following user modes:
   +o  |  User is an IRC operator.
   +R  |  User only accepts messages from other registered users. 
   +s  |  Server Notice Masks (see help with /HELPOP snomasks).
-  +Z  |  User is connected via TLS.`
+  +Z  |  User is connected via TLS.
+  +T  |  User is blocked from sending CTCP messages.`
 	snomaskHelpText = `== Server Notice Masks ==
 
 Oragono supports the following server notice masks for operators:
diff --git a/irc/modes.go b/irc/modes.go
index acea6b9d..86ab0cd6 100644
--- a/irc/modes.go
+++ b/irc/modes.go
@@ -34,7 +34,7 @@ func ApplyUserModeChanges(client *Client, changes modes.ModeChanges, force bool,
 
 	for _, change := range changes {
 		switch change.Mode {
-		case modes.Bot, modes.Invisible, modes.WallOps, modes.UserRoleplaying, modes.Operator, modes.LocalOperator, modes.RegisteredOnly:
+		case modes.Bot, modes.Invisible, modes.WallOps, modes.UserRoleplaying, modes.Operator, modes.LocalOperator, modes.RegisteredOnly, modes.UserNoCTCP:
 			switch change.Op {
 			case modes.Add:
 				if (change.Mode == modes.Operator || change.Mode == modes.LocalOperator) && !(force && oper != nil) {
diff --git a/irc/modes/modes.go b/irc/modes/modes.go
index ae2d9224..42e2ef42 100644
--- a/irc/modes/modes.go
+++ b/irc/modes/modes.go
@@ -105,6 +105,7 @@ const (
 	RegisteredOnly  Mode = 'R'
 	ServerNotice    Mode = 's'
 	TLS             Mode = 'Z'
+	UserNoCTCP      Mode = 'T'
 	UserRoleplaying Mode = 'E'
 	WallOps         Mode = 'w'
 )