1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * ppp_defs.h - PPP definitions. 4 * 5 * Copyright 1994-2000 Paul Mackerras. 6 */ 7#ifndef _PPP_DEFS_H_ 8#define _PPP_DEFS_H_ 9 10#include <linux/crc-ccitt.h> 11#include <uapi/linux/ppp_defs.h> 12 13#define PPP_FCS(fcs, c) crc_ccitt_byte(fcs, c) 14 15/** 16 * ppp_proto_is_valid - checks if PPP protocol is valid 17 * @proto: PPP protocol 18 * 19 * Assumes proto is not compressed. 20 * Protocol is valid if the value is odd and the least significant bit of the 21 * most significant octet is 0 (see RFC 1661, section 2). 22 */ 23static inline bool ppp_proto_is_valid(u16 proto) 24{ 25 return !!((proto & 0x0101) == 0x0001); 26} 27 28#endif /* _PPP_DEFS_H_ */ 29