From 7b60cca0f1d6dcd47a6ae1eb5cb0b649ee36a461 Mon Sep 17 00:00:00 2001
From: Ariadne Conill <ariadne@dereferenced.org>
Date: Fri, 26 Jun 2020 19:33:49 +0000
Subject: [PATCH] callerid: implement relaxed caller id mode (+G)

---
 modules/um_callerid.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/modules/um_callerid.c b/modules/um_callerid.c
index 44bf52f0..4edc0f67 100644
--- a/modules/um_callerid.c
+++ b/modules/um_callerid.c
@@ -47,6 +47,7 @@ static int
 um_callerid_modinit(void)
 {
 	user_modes['g'] = find_umode_slot();
+	user_modes['G'] = find_umode_slot();
 	construct_umodebuf();
 
 	add_isupport("CALLERID", isupport_string, "g");
@@ -58,16 +59,33 @@ static void
 um_callerid_moddeinit(void)
 {
 	user_modes['g'] = 0;
+	user_modes['G'] = 0;
 	construct_umodebuf();
 
 	delete_isupport("CALLERID");
 }
 
 #define IsSetCallerID(c)	((c->umodes & user_modes['g']) == user_modes['g'])
+#define IsSetRelaxedCallerID(c)	((c->umodes & user_modes['G']) == user_modes['G'])
 
 static const char um_callerid_desc[] =
 	"Provides usermode +g which restricts messages from unauthorized users.";
 
+static bool
+has_common_channel(struct Client *source_p, struct Client *target_p)
+{
+	rb_dlink_node *ptr;
+
+	RB_DLINK_FOREACH(ptr, source_p->user->channel.head)
+	{
+		struct membership *msptr = ptr->data;
+		if (IsMember(target_p, msptr->chptr))
+			return msptr->chptr;
+	}
+
+	return NULL;
+}
+
 static bool
 allow_message(struct Client *source_p, struct Client *target_p)
 {
@@ -77,6 +95,9 @@ allow_message(struct Client *source_p, struct Client *target_p)
 	if (!IsSetCallerID(target_p))
 		return true;
 
+	if (IsSetRelaxedCallerID(target_p) && has_common_channel(source_p, target_p))
+		return true;
+
 	if (IsServer(source_p))
 		return true;