45 lines
1.1 KiB
C
45 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* ppp_defs.h - PPP definitions.
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*
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* Copyright 1994-2000 Paul Mackerras.
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*/
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#ifndef _PPP_DEFS_H_
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#define _PPP_DEFS_H_
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#include <linux/crc-ccitt.h>
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#include <linux/skbuff.h>
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#include <uapi/linux/ppp_defs.h>
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#define PPP_FCS(fcs, c) crc_ccitt_byte(fcs, c)
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/**
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* ppp_proto_is_valid - checks if PPP protocol is valid
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* @proto: PPP protocol
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*
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* Assumes proto is not compressed.
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* Protocol is valid if the value is odd and the least significant bit of the
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* most significant octet is 0 (see RFC 1661, section 2).
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*/
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static inline bool ppp_proto_is_valid(u16 proto)
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{
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return !!((proto & 0x0101) == 0x0001);
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}
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/**
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* ppp_skb_is_compressed_proto - checks if PPP protocol in a skb is compressed
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* @skb: skb to check
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*
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* Check if the PPP protocol field is compressed (the least significant
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* bit of the most significant octet is 1). skb->data must point to the PPP
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* protocol header.
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*
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* Return: Whether the PPP protocol field is compressed.
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*/
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static inline bool ppp_skb_is_compressed_proto(const struct sk_buff *skb)
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{
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return unlikely(skb->data[0] & 0x01);
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}
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#endif /* _PPP_DEFS_H_ */
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