diff options
Diffstat (limited to 'include/linux/ppp_defs.h')
| -rw-r--r-- | include/linux/ppp_defs.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/ppp_defs.h b/include/linux/ppp_defs.h index 9d2b388fae1a..b7e57fdbd413 100644 --- a/include/linux/ppp_defs.h +++ b/include/linux/ppp_defs.h @@ -11,4 +11,18 @@ #include <uapi/linux/ppp_defs.h> #define PPP_FCS(fcs, c) crc_ccitt_byte(fcs, c) + +/** + * ppp_proto_is_valid - checks if PPP protocol is valid + * @proto: PPP protocol + * + * Assumes proto is not compressed. + * Protocol is valid if the value is odd and the least significant bit of the + * most significant octet is 0 (see RFC 1661, section 2). + */ +static inline bool ppp_proto_is_valid(u16 proto) +{ + return !!((proto & 0x0101) == 0x0001); +} + #endif /* _PPP_DEFS_H_ */ |