diff options
Diffstat (limited to 'include/linux/ppp_defs.h')
| -rw-r--r-- | include/linux/ppp_defs.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/ppp_defs.h b/include/linux/ppp_defs.h index 9d2b388fae1a..b1d1f46d7d3b 100644 --- a/include/linux/ppp_defs.h +++ b/include/linux/ppp_defs.h @@ -8,7 +8,37 @@ #define _PPP_DEFS_H_ #include <linux/crc-ccitt.h> +#include <linux/skbuff.h> #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); +} + +/** + * ppp_skb_is_compressed_proto - checks if PPP protocol in a skb is compressed + * @skb: skb to check + * + * Check if the PPP protocol field is compressed (the least significant + * bit of the most significant octet is 1). skb->data must point to the PPP + * protocol header. + * + * Return: Whether the PPP protocol field is compressed. + */ +static inline bool ppp_skb_is_compressed_proto(const struct sk_buff *skb) +{ + return unlikely(skb->data[0] & 0x01); +} + #endif /* _PPP_DEFS_H_ */ |