From d8aa470192b53b7f1bd51c6d9481c64275f80a1a Mon Sep 17 00:00:00 2001
From: Davide Beatrici <git@davidebeatrici.dev>
Date: Wed, 29 Jul 2020 20:00:46 +0200
Subject: [PATCH] Cedar: Improve IsPacketForMe()'s "data" argumment in
 PROTO_IMPL

This allows a protocol implementation to implicitly cast the variable to the type it prefers.
---
 src/Cedar/Proto.h         |  2 +-
 src/Cedar/Proto_OpenVPN.c | 15 ++++++++-------
 src/Cedar/Proto_OpenVPN.h |  4 +---
 3 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/src/Cedar/Proto.h b/src/Cedar/Proto.h
index 63f1b360..e0714cab 100644
--- a/src/Cedar/Proto.h
+++ b/src/Cedar/Proto.h
@@ -48,7 +48,7 @@ typedef struct PROTO_IMPL
 	const PROTO_OPTION *(*Options)();
 	bool (*Init)(void **param, const LIST *options, CEDAR *cedar, INTERRUPT_MANAGER *im, SOCK_EVENT *se, const char *cipher, const char *hostname);
 	void (*Free)(void *param);
-	bool (*IsPacketForMe)(const PROTO_MODE mode, const UCHAR *data, const UINT size);
+	bool (*IsPacketForMe)(const PROTO_MODE mode, const void *data, const UINT size);
 	bool (*ProcessData)(void *param, TCP_RAW_DATA *in, FIFO *out);
 	bool (*ProcessDatagrams)(void *param, LIST *in, LIST *out);
 } PROTO_IMPL;
diff --git a/src/Cedar/Proto_OpenVPN.c b/src/Cedar/Proto_OpenVPN.c
index a466a9c1..a801c4b1 100644
--- a/src/Cedar/Proto_OpenVPN.c
+++ b/src/Cedar/Proto_OpenVPN.c
@@ -69,16 +69,17 @@ void OvsFree(void *param)
 }
 
 // Check whether it's an OpenVPN packet
-bool OvsIsPacketForMe(const PROTO_MODE mode, const UCHAR *data, const UINT size)
+bool OvsIsPacketForMe(const PROTO_MODE mode, const void *data, const UINT size)
 {
+	if (data == NULL || size < 2)
+	{
+		return false;
+	}
+
 	if (mode == PROTO_MODE_TCP)
 	{
-		if (data == NULL || size < 2)
-		{
-			return false;
-		}
-
-		if (data[0] == 0x00 && data[1] == 0x0E)
+		const UCHAR *raw = data;
+		if (raw[0] == 0x00 && raw[1] == 0x0E)
 		{
 			return true;
 		}
diff --git a/src/Cedar/Proto_OpenVPN.h b/src/Cedar/Proto_OpenVPN.h
index 8a5c111d..78204cc3 100644
--- a/src/Cedar/Proto_OpenVPN.h
+++ b/src/Cedar/Proto_OpenVPN.h
@@ -215,11 +215,9 @@ const char *OvsName();
 const PROTO_OPTION *OvsOptions();
 bool OvsInit(void **param, const LIST *options, CEDAR *cedar, INTERRUPT_MANAGER *im, SOCK_EVENT *se, const char *cipher, const char *hostname);
 void OvsFree(void *param);
-bool OvsIsPacketForMe(const PROTO_MODE mode, const UCHAR *data, const UINT size);
+bool OvsIsPacketForMe(const PROTO_MODE mode, const void *data, const UINT size);
 bool OvsProcessData(void *param, TCP_RAW_DATA *in, FIFO *out);
 bool OvsProcessDatagrams(void *param, LIST *in, LIST *out);
-bool OvsIsOk(void *param);
-UINT OvsEstablishedSessions(void *param);
 
 OPENVPN_SERVER *NewOpenVpnServer(const LIST *options, CEDAR *cedar, INTERRUPT_MANAGER *interrupt, SOCK_EVENT *sock_event);
 void FreeOpenVpnServer(OPENVPN_SERVER *s);