From 3b4731951f58e980a189016383c177cb86c8e0c0 Mon Sep 17 00:00:00 2001
From: Ed Kellett <e@kellett.im>
Date: Thu, 22 Oct 2020 14:46:21 +0100
Subject: [PATCH] Implement oper realhost view via a hidden cap

---
 extensions/cap_realhost.c | 70 ++++++++++++++++++++++++++++++++-------
 1 file changed, 58 insertions(+), 12 deletions(-)

diff --git a/extensions/cap_realhost.c b/extensions/cap_realhost.c
index 1ddf96b0..46de2532 100644
--- a/extensions/cap_realhost.c
+++ b/extensions/cap_realhost.c
@@ -27,31 +27,35 @@
 
 static char cap_realhost_desc[] = "Provides the solanum.chat/realhost oper-only capability";
 
-static bool cap_realhost_visible(struct Client *);
+static bool cap_oper_realhost_visible(struct Client *);
 static void cap_realhost_outbound_msgbuf(void *);
 static void cap_realhost_umode_changed(void *);
+static void cap_realhost_cap_change(void *);
 
 static unsigned CLICAP_REALHOST;
+static unsigned CLICAP_OPER_REALHOST;
 
-static struct ClientCapability cap_realhost = {
-	.visible = cap_realhost_visible,
+static struct ClientCapability capdata_oper_realhost = {
+	.visible = cap_oper_realhost_visible,
 };
 
 mapi_cap_list_av2 cap_realhost_caps[] = {
-	{ MAPI_CAP_CLIENT, "solanum.chat/realhost", &cap_realhost, &CLICAP_REALHOST },
+	{ MAPI_CAP_CLIENT, "solanum.chat/realhost", NULL, &CLICAP_REALHOST },
+	{ MAPI_CAP_CLIENT, "?oper_realhost", &capdata_oper_realhost, &CLICAP_OPER_REALHOST },
 	{ 0, NULL, NULL, NULL },
 };
 
 mapi_hfn_list_av1 cap_realhost_hfnlist[] = {
 	{ "outbound_msgbuf", cap_realhost_outbound_msgbuf, HOOK_NORMAL },
 	{ "umode_changed", cap_realhost_umode_changed, HOOK_MONITOR },
+	{ "cap_change", cap_realhost_cap_change, HOOK_MONITOR },
 	{ NULL, NULL, 0 },
 };
 
 static bool
-cap_realhost_visible(struct Client *client)
+cap_oper_realhost_visible(struct Client *client)
 {
-	return HasPrivilege(client, "cap:realhost");
+	return false;
 }
 
 static void
@@ -60,14 +64,34 @@ cap_realhost_outbound_msgbuf(void *data_)
 	hook_data *data = data_;
 	struct MsgBuf *msgbuf = data->arg1;
 
-	if (data->client == NULL)
+	if (data->client == NULL || !IsPerson(data->client))
 		return;
 
 	if (!IsIPSpoof(data->client) && !EmptyString(data->client->sockhost) && strcmp(data->client->sockhost, "0"))
-		msgbuf_append_tag(msgbuf, "solanum.chat/ip", data->client->sockhost, CLICAP_REALHOST);
+	{
+		if (IsDynSpoof(data->client))
+			msgbuf_append_tag(msgbuf, "solanum.chat/ip", data->client->sockhost, CLICAP_OPER_REALHOST);
+		else
+			msgbuf_append_tag(msgbuf, "solanum.chat/ip", data->client->sockhost, CLICAP_REALHOST);
+	}
 
 	if (!EmptyString(data->client->orighost))
-		msgbuf_append_tag(msgbuf, "solanum.chat/realhost", data->client->orighost, CLICAP_REALHOST);
+	{
+		if (IsDynSpoof(data->client))
+			msgbuf_append_tag(msgbuf, "solanum.chat/realhost", data->client->orighost, CLICAP_OPER_REALHOST);
+		else
+			msgbuf_append_tag(msgbuf, "solanum.chat/realhost", data->client->orighost, CLICAP_REALHOST);
+	}
+}
+
+static inline void
+update_clicap_oper_realhost(struct Client *client)
+{
+	client->localClient->caps &= ~CLICAP_OPER_REALHOST;
+	if (client->localClient->caps & CLICAP_REALHOST && HasPrivilege(client, "auspex:hostname"))
+	{
+		client->localClient->caps |= CLICAP_OPER_REALHOST;
+	}
 }
 
 static void
@@ -78,8 +102,30 @@ cap_realhost_umode_changed(void *data_)
 	if (!MyClient(data->client))
 		return;
 
-	if (!cap_realhost_visible(data->client))
-		data->client->localClient->caps &= ~CLICAP_REALHOST;
+	update_clicap_oper_realhost(data->client);
 }
 
-DECLARE_MODULE_AV2(cap_realhost, NULL, NULL, NULL, NULL, cap_realhost_hfnlist, cap_realhost_caps, NULL, cap_realhost_desc);
+static void
+cap_realhost_cap_change(void *data_)
+{
+	hook_data_cap_change *data = data_;
+
+	update_clicap_oper_realhost(data->client);
+}
+
+static int
+modinit(void)
+{
+	rb_dlink_node *ptr;
+
+	RB_DLINK_FOREACH(ptr, lclient_list.head)
+	{
+		struct Client *client = ptr->data;
+
+		update_clicap_oper_realhost(client);
+	}
+
+	return 0;
+}
+
+DECLARE_MODULE_AV2(cap_realhost, modinit, NULL, NULL, NULL, cap_realhost_hfnlist, cap_realhost_caps, NULL, cap_realhost_desc);