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 */ ppp_proto_is_valid(u16 proto)23static inline bool ppp_proto_is_valid(u16 proto) 24 { 25 return !!((proto & 0x0101) == 0x0001); 26 } 27 28 #endif /* _PPP_DEFS_H_ */ 29