From 51d573d3c94677a6ff2d69a04e322ce5f9c1abc3 Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Mon, 1 Nov 2021 04:48:31 -0400
Subject: [PATCH] fix #1802

Add a config option to suppress LUSERS
---
 default.yaml     |  4 ++++
 irc/config.go    |  1 +
 irc/server.go    | 10 ++++++++--
 traditional.yaml |  4 ++++
 4 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/default.yaml b/default.yaml
index 14256cd4..f450c47c 100644
--- a/default.yaml
+++ b/default.yaml
@@ -360,6 +360,10 @@ server:
     # the default value of 512. DO NOT change this on a public server:
     # max-line-len: 512
 
+    # send all 0's as the LUSERS (user counts) output to non-operators; potentially useful
+    # if you don't want to publicize how popular the server is
+    suppress-lusers: false
+
 # account options
 accounts:
     # is account authentication enabled, i.e., can users log into existing accounts?
diff --git a/irc/config.go b/irc/config.go
index a0971de7..3d753b43 100644
--- a/irc/config.go
+++ b/irc/config.go
@@ -592,6 +592,7 @@ type Config struct {
 		IPCheckScript            ScriptConfig `yaml:"ip-check-script"`
 		OverrideServicesHostname string       `yaml:"override-services-hostname"`
 		MaxLineLen               int          `yaml:"max-line-len"`
+		SuppressLusers           bool         `yaml:"suppress-lusers"`
 	}
 
 	Roleplay struct {
diff --git a/irc/server.go b/irc/server.go
index 7a43f0f4..0992dc0a 100644
--- a/irc/server.go
+++ b/irc/server.go
@@ -419,12 +419,18 @@ func (server *Server) RplISupport(client *Client, rb *ResponseBuffer) {
 
 func (server *Server) Lusers(client *Client, rb *ResponseBuffer) {
 	nick := client.Nick()
-	stats := server.stats.GetValues()
+	config := server.Config()
+	var stats StatsValues
+	var numChannels int
+	if !config.Server.SuppressLusers || client.HasRoleCapabs("ban") {
+		stats = server.stats.GetValues()
+		numChannels = server.channels.Len()
+	}
 
 	rb.Add(nil, server.name, RPL_LUSERCLIENT, nick, fmt.Sprintf(client.t("There are %[1]d users and %[2]d invisible on %[3]d server(s)"), stats.Total-stats.Invisible, stats.Invisible, 1))
 	rb.Add(nil, server.name, RPL_LUSEROP, nick, strconv.Itoa(stats.Operators), client.t("IRC Operators online"))
 	rb.Add(nil, server.name, RPL_LUSERUNKNOWN, nick, strconv.Itoa(stats.Unknown), client.t("unregistered connections"))
-	rb.Add(nil, server.name, RPL_LUSERCHANNELS, nick, strconv.Itoa(server.channels.Len()), client.t("channels formed"))
+	rb.Add(nil, server.name, RPL_LUSERCHANNELS, nick, strconv.Itoa(numChannels), client.t("channels formed"))
 	rb.Add(nil, server.name, RPL_LUSERME, nick, fmt.Sprintf(client.t("I have %[1]d clients and %[2]d servers"), stats.Total, 0))
 	total := strconv.Itoa(stats.Total)
 	max := strconv.Itoa(stats.Max)
diff --git a/traditional.yaml b/traditional.yaml
index 948bd182..1c784dbd 100644
--- a/traditional.yaml
+++ b/traditional.yaml
@@ -333,6 +333,10 @@ server:
     # the default value of 512. DO NOT change this on a public server:
     # max-line-len: 512
 
+    # send all 0's as the LUSERS (user counts) output to non-operators; potentially useful
+    # if you don't want to publicize how popular the server is
+    suppress-lusers: false
+
 # account options
 accounts:
     # is account authentication enabled, i.e., can users log into existing accounts?