Commit bdfbb63c authored by Kurt Kanzenbach's avatar Kurt Kanzenbach Committed by David S. Miller
Browse files

ptp: Add generic ptp v2 header parsing function 



Reason: A lot of the ptp drivers - which implement hardware time stamping - need
specific fields such as the sequence id from the ptp v2 header. Currently all
drivers implement that themselves.

Introduce a generic function to retrieve a pointer to the start of the ptp v2
header.

Suggested-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarKurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: default avatarRichard Cochran <richardcochran@gmail.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f3ae59c0

include/linux/ptp_classify.h

+44 −0
Original line number Diff line number Diff line
@@ -44,6 +44,30 @@ 
#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
@@ -57,6 +81,21 @@ 
 */

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);



void __init ptp_classifier_init(void);

#else

static inline void ptp_classifier_init(void)
@@ -66,5 +105,10 @@ 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;

}

#endif

#endif /* _PTP_CLASSIFY_H_ */

net/core/ptp_classifier.c

+30 −0
Original line number Diff line number Diff line
@@ -107,6 +107,36 @@ unsigned int ptp_classify_raw(const struct sk_buff *skb) 
}

EXPORT_SYMBOL_GPL(ptp_classify_raw);



struct ptp_header *ptp_parse_header(struct sk_buff *skb, unsigned int type)

{

	u8 *ptr = skb_mac_header(skb);



	if (type & PTP_CLASS_VLAN)

		ptr += VLAN_HLEN;



	switch (type & PTP_CLASS_PMASK) {

	case PTP_CLASS_IPV4:

		ptr += IPV4_HLEN(ptr) + UDP_HLEN;

		break;

	case PTP_CLASS_IPV6:

		ptr += IP6_HLEN + UDP_HLEN;

		break;

	case PTP_CLASS_L2:

		break;

	default:

		return NULL;

	}



	ptr += ETH_HLEN;



	/* Ensure that the entire header is present in this packet. */

	if (ptr + sizeof(struct ptp_header) > skb->data + skb->len)

		return NULL;



	return (struct ptp_header *)ptr;

}

EXPORT_SYMBOL_GPL(ptp_parse_header);



void __init ptp_classifier_init(void)

{

	static struct sock_filter ptp_filter[] __initdata = {