include/linux/ptp_classify.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * PTP 1588 support
  *
  * This file implements a BPF that recognizes PTP event messages.
  *
  * Copyright (C) 2010 OMICRON electronics GmbH
  */

 #ifndef _PTP_CLASSIFY_H_
 #define _PTP_CLASSIFY_H_

 #include <linux/unaligned.h>
 #include <linux/ip.h>
 #include <linux/ktime.h>
 #include <linux/skbuff.h>
 #include <linux/udp.h>
 #include <net/checksum.h>

 #define PTP_CLASS_NONE  0x00 /* not a PTP event message */
 #define PTP_CLASS_V1    0x01 /* protocol version 1 */
 #define PTP_CLASS_V2    0x02 /* protocol version 2 */
 #define PTP_CLASS_VMASK 0x0f /* max protocol version is 15 */
 #define PTP_CLASS_IPV4  0x10 /* event in an IPV4 UDP packet */
 #define PTP_CLASS_IPV6  0x20 /* event in an IPV6 UDP packet */
 #define PTP_CLASS_L2    0x40 /* event in a L2 packet */
 #define PTP_CLASS_PMASK	0x70 /* mask for the packet type field */
 #define PTP_CLASS_VLAN	0x80 /* event in a VLAN tagged packet */

 #define PTP_CLASS_V1_IPV4 (PTP_CLASS_V1 | PTP_CLASS_IPV4)
 #define PTP_CLASS_V1_IPV6 (PTP_CLASS_V1 | PTP_CLASS_IPV6) /* probably DNE */
 #define PTP_CLASS_V2_IPV4 (PTP_CLASS_V2 | PTP_CLASS_IPV4)
 #define PTP_CLASS_V2_IPV6 (PTP_CLASS_V2 | PTP_CLASS_IPV6)
 #define PTP_CLASS_V2_L2   (PTP_CLASS_V2 | PTP_CLASS_L2)
 #define PTP_CLASS_V2_VLAN (PTP_CLASS_V2 | PTP_CLASS_VLAN)
 #define PTP_CLASS_L4      (PTP_CLASS_IPV4 | PTP_CLASS_IPV6)

 #define PTP_MSGTYPE_SYNC        0x0
 #define PTP_MSGTYPE_DELAY_REQ   0x1
 #define PTP_MSGTYPE_PDELAY_REQ  0x2
 #define PTP_MSGTYPE_PDELAY_RESP 0x3

 #define PTP_EV_PORT 319
 #define PTP_GEN_PORT 320
 #define PTP_GEN_BIT 0x08 /* indicates general message, if set in message type */

 #define OFF_PTP_SOURCE_UUID	22 /* PTPv1 only */
 #define OFF_PTP_SEQUENCE_ID	30

 /* PTP header flag fields */
 #define PTP_FLAG_TWOSTEP	BIT(1)

 /* Below defines should actually be removed at some point in time. */
 #define IP6_HLEN	40
 #define UDP_HLEN	8
 #define OFF_IHL		14
 #define IPV4_HLEN(data) (((struct iphdr *)(data + OFF_IHL))->ihl << 2)

 struct clock_identity {
 	u8 id[8];
 } __packed;

 struct port_identity {
 	struct clock_identity	clock_identity;
 	__be16			port_number;
 } __packed;

 struct ptp_header {
 	u8			tsmt;  /* transportSpecific | messageType */
 	u8			ver;   /* reserved          | versionPTP  */
 	__be16			message_length;
 	u8			domain_number;
 	u8			reserved1;
 	u8			flag_field[2];
 	__be64			correction;
 	__be32			reserved2;
 	struct port_identity	source_port_identity;
 	__be16			sequence_id;
 	u8			control;
 	u8			log_message_interval;
 } __packed;

 #if defined(CONFIG_NET_PTP_CLASSIFY)
 /**
  * ptp_classify_raw - classify a PTP packet
  * @skb: buffer
  *
  * Runs a minimal BPF dissector to classify a network packet to
  * determine the PTP class. In case the skb does not contain any
  * PTP protocol data, PTP_CLASS_NONE will be returned, otherwise
  * PTP_CLASS_V1_IPV{4,6}, PTP_CLASS_V2_IPV{4,6} or
  * PTP_CLASS_V2_{L2,VLAN}, depending on the packet content.
  */
 unsigned int ptp_classify_raw(const struct sk_buff *skb);

 /**
  * ptp_parse_header - Get pointer to the PTP v2 header
  * @skb: packet buffer
  * @type: type of the packet (see ptp_classify_raw())
  *
  * This function takes care of the VLAN, UDP, IPv4 and IPv6 headers. The length
  * is checked.
  *
  * Note, internally skb_mac_header() is used. Make sure that the @skb is
  * initialized accordingly.
  *
  * Return: Pointer to the ptp v2 header or NULL if not found
  */
 struct ptp_header *ptp_parse_header(struct sk_buff *skb, unsigned int type);

 /**
  * ptp_get_msgtype - Extract ptp message type from given header
  * @hdr: ptp header
  * @type: type of the packet (see ptp_classify_raw())
  *
  * This function returns the message type for a given ptp header. It takes care
  * of the different ptp header versions (v1 or v2).
  *
  * Return: The message type
  */
 static inline u8 ptp_get_msgtype(const struct ptp_header *hdr,
 				 unsigned int type)
 {
 	u8 msgtype;

 	if (unlikely(type & PTP_CLASS_V1)) {
 		/* msg type is located at the control field for ptp v1 */
 		msgtype = hdr->control;
 	} else {
 		msgtype = hdr->tsmt & 0x0f;
 	}

 	return msgtype;
 }

 /**
  * ptp_check_diff8 - Computes new checksum (when altering a 64-bit field)
  * @old: old field value
  * @new: new field value
  * @oldsum: previous checksum
  *
  * This function can be used to calculate a new checksum when only a single
  * field is changed. Similar as ip_vs_check_diff*() in ip_vs.h.
  *
  * Return: Updated checksum
  */
 static inline __wsum ptp_check_diff8(__be64 old, __be64 new, __wsum oldsum)
 {
 	__be64 diff[2] = { ~old, new };

 	return csum_partial(diff, sizeof(diff), oldsum);
 }

 /**
  * ptp_header_update_correction - Update PTP header's correction field
  * @skb: packet buffer
  * @type: type of the packet (see ptp_classify_raw())
  * @hdr: ptp header
  * @correction: new correction value
  *
  * This updates the correction field of a PTP header and updates the UDP
  * checksum (if UDP is used as transport). It is needed for hardware capable of
  * one-step P2P that does not already modify the correction field of Pdelay_Req
  * event messages on ingress.
  */
 static inline
 void ptp_header_update_correction(struct sk_buff *skb, unsigned int type,
 				  struct ptp_header *hdr, s64 correction)
 {
 	__be64 correction_old;
 	struct udphdr *uhdr;

 	/* previous correction value is required for checksum update. */
 	memcpy(&correction_old,  &hdr->correction, sizeof(correction_old));

 	/* write new correction value */
 	put_unaligned_be64((u64)correction, &hdr->correction);

 	switch (type & PTP_CLASS_PMASK) {
 	case PTP_CLASS_IPV4:
 	case PTP_CLASS_IPV6:
 		/* locate udp header */
 		uhdr = (struct udphdr *)((char *)hdr - sizeof(struct udphdr));
 		break;
 	default:
 		return;
 	}

 	/* update checksum */
 	uhdr->check = csum_fold(ptp_check_diff8(correction_old,
 						hdr->correction,
 						~csum_unfold(uhdr->check)));
 	if (!uhdr->check)
 		uhdr->check = CSUM_MANGLED_0;

 	skb->ip_summed = CHECKSUM_NONE;
 }

 /**
  * ptp_msg_is_sync - Evaluates whether the given skb is a PTP Sync message
  * @skb: packet buffer
  * @type: type of the packet (see ptp_classify_raw())
  *
  * This function evaluates whether the given skb is a PTP Sync message.
  *
  * Return: true if sync message, false otherwise
  */
 bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type);

 void __init ptp_classifier_init(void);
 #else
 static inline void ptp_classifier_init(void)
 {
 }
 static inline unsigned int ptp_classify_raw(struct sk_buff *skb)
 {
 	return PTP_CLASS_NONE;
 }
 static inline struct ptp_header *ptp_parse_header(struct sk_buff *skb,
 						  unsigned int type)
 {
 	return NULL;
 }
 static inline u8 ptp_get_msgtype(const struct ptp_header *hdr,
 				 unsigned int type)
 {
 	/* The return is meaningless. The stub function would not be
 	 * executed since no available header from ptp_parse_header.
 	 */
 	return PTP_MSGTYPE_SYNC;
 }
 static inline bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type)
 {
 	return false;
 }

 static inline
 void ptp_header_update_correction(struct sk_buff *skb, unsigned int type,
 				  struct ptp_header *hdr, s64 correction)
 {
 }
 #endif
 #endif /* _PTP_CLASSIFY_H_ */
	/* SPDX-License-Identifier: GPL-2.0-or-later */
	/*
	* PTP 1588 support
	*
	* This file implements a BPF that recognizes PTP event messages.
	*
	* Copyright (C) 2010 OMICRON electronics GmbH
	*/

	#ifndef _PTP_CLASSIFY_H_
	#define _PTP_CLASSIFY_H_

	#include <linux/unaligned.h>
	#include <linux/ip.h>
	#include <linux/ktime.h>
	#include <linux/skbuff.h>
	#include <linux/udp.h>
	#include <net/checksum.h>

	#define PTP_CLASS_NONE 0x00 /* not a PTP event message */
	#define PTP_CLASS_V1 0x01 /* protocol version 1 */
	#define PTP_CLASS_V2 0x02 /* protocol version 2 */
	#define PTP_CLASS_VMASK 0x0f /* max protocol version is 15 */
	#define PTP_CLASS_IPV4 0x10 /* event in an IPV4 UDP packet */
	#define PTP_CLASS_IPV6 0x20 /* event in an IPV6 UDP packet */
	#define PTP_CLASS_L2 0x40 /* event in a L2 packet */
	#define PTP_CLASS_PMASK 0x70 /* mask for the packet type field */
	#define PTP_CLASS_VLAN 0x80 /* event in a VLAN tagged packet */

	#define PTP_CLASS_V1_IPV4 (PTP_CLASS_V1 \| PTP_CLASS_IPV4)
	#define PTP_CLASS_V1_IPV6 (PTP_CLASS_V1 \| PTP_CLASS_IPV6) /* probably DNE */
	#define PTP_CLASS_V2_IPV4 (PTP_CLASS_V2 \| PTP_CLASS_IPV4)
	#define PTP_CLASS_V2_IPV6 (PTP_CLASS_V2 \| PTP_CLASS_IPV6)
	#define PTP_CLASS_V2_L2 (PTP_CLASS_V2 \| PTP_CLASS_L2)
	#define PTP_CLASS_V2_VLAN (PTP_CLASS_V2 \| PTP_CLASS_VLAN)
	#define PTP_CLASS_L4 (PTP_CLASS_IPV4 \| PTP_CLASS_IPV6)

	#define PTP_MSGTYPE_SYNC 0x0
	#define PTP_MSGTYPE_DELAY_REQ 0x1
	#define PTP_MSGTYPE_PDELAY_REQ 0x2
	#define PTP_MSGTYPE_PDELAY_RESP 0x3

	#define PTP_EV_PORT 319
	#define PTP_GEN_PORT 320
	#define PTP_GEN_BIT 0x08 /* indicates general message, if set in message type */

	#define OFF_PTP_SOURCE_UUID 22 /* PTPv1 only */
	#define OFF_PTP_SEQUENCE_ID 30

	/* PTP header flag fields */
	#define PTP_FLAG_TWOSTEP BIT(1)

	/* Below defines should actually be removed at some point in time. */
	#define IP6_HLEN 40
	#define UDP_HLEN 8
	#define OFF_IHL 14
	#define IPV4_HLEN(data) (((struct iphdr *)(data + OFF_IHL))->ihl << 2)

	struct clock_identity {
	u8 id[8];
	} __packed;

	struct port_identity {
	struct clock_identity clock_identity;
	__be16 port_number;
	} __packed;

	struct ptp_header {
	u8 tsmt; /* transportSpecific \| messageType */
	u8 ver; /* reserved \| versionPTP */
	__be16 message_length;
	u8 domain_number;
	u8 reserved1;
	u8 flag_field[2];
	__be64 correction;
	__be32 reserved2;
	struct port_identity source_port_identity;
	__be16 sequence_id;
	u8 control;
	u8 log_message_interval;
	} __packed;

	#if defined(CONFIG_NET_PTP_CLASSIFY)
	/**
	* ptp_classify_raw - classify a PTP packet
	* @skb: buffer
	*
	* Runs a minimal BPF dissector to classify a network packet to
	* determine the PTP class. In case the skb does not contain any
	* PTP protocol data, PTP_CLASS_NONE will be returned, otherwise
	* PTP_CLASS_V1_IPV{4,6}, PTP_CLASS_V2_IPV{4,6} or
	* PTP_CLASS_V2_{L2,VLAN}, depending on the packet content.
	*/
	unsigned int ptp_classify_raw(const struct sk_buff *skb);

	/**
	* ptp_parse_header - Get pointer to the PTP v2 header
	* @skb: packet buffer
	* @type: type of the packet (see ptp_classify_raw())
	*
	* This function takes care of the VLAN, UDP, IPv4 and IPv6 headers. The length
	* is checked.
	*
	* Note, internally skb_mac_header() is used. Make sure that the @skb is
	* initialized accordingly.
	*
	* Return: Pointer to the ptp v2 header or NULL if not found
	*/
	struct ptp_header ptp_parse_header(struct sk_buff skb, unsigned int type);

	/**
	* ptp_get_msgtype - Extract ptp message type from given header
	* @hdr: ptp header
	* @type: type of the packet (see ptp_classify_raw())
	*
	* This function returns the message type for a given ptp header. It takes care
	* of the different ptp header versions (v1 or v2).
	*
	* Return: The message type
	*/
	static inline u8 ptp_get_msgtype(const struct ptp_header *hdr,
	unsigned int type)
	{
	u8 msgtype;

	if (unlikely(type & PTP_CLASS_V1)) {
	/* msg type is located at the control field for ptp v1 */
	msgtype = hdr->control;
	} else {
	msgtype = hdr->tsmt & 0x0f;
	}

	return msgtype;
	}

	/**
	* ptp_check_diff8 - Computes new checksum (when altering a 64-bit field)
	* @old: old field value
	* @new: new field value
	* @oldsum: previous checksum
	*
	* This function can be used to calculate a new checksum when only a single
	* field is changed. Similar as ip_vs_check_diff*() in ip_vs.h.
	*
	* Return: Updated checksum
	*/
	static inline __wsum ptp_check_diff8(__be64 old, __be64 new, __wsum oldsum)
	{
	__be64 diff[2] = { ~old, new };

	return csum_partial(diff, sizeof(diff), oldsum);
	}

	/**
	* ptp_header_update_correction - Update PTP header's correction field
	* @skb: packet buffer
	* @type: type of the packet (see ptp_classify_raw())
	* @hdr: ptp header
	* @correction: new correction value
	*
	* This updates the correction field of a PTP header and updates the UDP
	* checksum (if UDP is used as transport). It is needed for hardware capable of
	* one-step P2P that does not already modify the correction field of Pdelay_Req
	* event messages on ingress.
	*/
	static inline
	void ptp_header_update_correction(struct sk_buff *skb, unsigned int type,
	struct ptp_header *hdr, s64 correction)
	{
	__be64 correction_old;
	struct udphdr *uhdr;

	/* previous correction value is required for checksum update. */
	memcpy(&correction_old, &hdr->correction, sizeof(correction_old));

	/* write new correction value */
	put_unaligned_be64((u64)correction, &hdr->correction);

	switch (type & PTP_CLASS_PMASK) {
	case PTP_CLASS_IPV4:
	case PTP_CLASS_IPV6:
	/* locate udp header */
	uhdr = (struct udphdr )((char )hdr - sizeof(struct udphdr));
	break;
	default:
	return;
	}

	/* update checksum */
	uhdr->check = csum_fold(ptp_check_diff8(correction_old,
	hdr->correction,
	~csum_unfold(uhdr->check)));
	if (!uhdr->check)
	uhdr->check = CSUM_MANGLED_0;

	skb->ip_summed = CHECKSUM_NONE;
	}

	/**
	* ptp_msg_is_sync - Evaluates whether the given skb is a PTP Sync message
	* @skb: packet buffer
	* @type: type of the packet (see ptp_classify_raw())
	*
	* This function evaluates whether the given skb is a PTP Sync message.
	*
	* Return: true if sync message, false otherwise
	*/
	bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type);

	void __init ptp_classifier_init(void);
	#else
	static inline void ptp_classifier_init(void)
	{
	}
	static inline unsigned int ptp_classify_raw(struct sk_buff *skb)
	{
	return PTP_CLASS_NONE;
	}
	static inline struct ptp_header ptp_parse_header(struct sk_buff skb,
	unsigned int type)
	{
	return NULL;
	}
	static inline u8 ptp_get_msgtype(const struct ptp_header *hdr,
	unsigned int type)
	{
	/* The return is meaningless. The stub function would not be
	* executed since no available header from ptp_parse_header.
	*/
	return PTP_MSGTYPE_SYNC;
	}
	static inline bool ptp_msg_is_sync(struct sk_buff *skb, unsigned int type)
	{
	return false;
	}

	static inline
	void ptp_header_update_correction(struct sk_buff *skb, unsigned int type,
	struct ptp_header *hdr, s64 correction)
	{
	}
	#endif
	#endif /* _PTP_CLASSIFY_H_ */