Merge branch 'ptp-Add-generic-helper-functions'

Kurt Kanzenbach says:

====================
ptp: Add generic helper functions

in order to reduce code duplication (and cut'n'paste errors) in the ptp code of
DSA, Ethernet and Phy drivers, create helper functions and move them to
ptp_classify. This way all drivers can share the same implementation.

This is version four and contains bugfixes. Implemented as discussed [1] [2]
[3] [4].

Previous versions can be found here:

 * https://lkml.kernel.org/netdev/20200723074946.14253-1-kurt@linutronix.de/
 * https://lkml.kernel.org/netdev/20200727090601.6500-1-kurt@linutronix.de/
 * https://lkml.kernel.org/netdev/20200730080048.32553-1-kurt@linutronix.de/

Thanks,
Kurt

Changes sinve v3:

 * Coding style issues (Richard Cochran, Petr Machata)
 * Add better documentation (Grygorii Strashko)
 * Fix cpts code (Grygorii Strashko)
 * Use ntohs() for TI code (Grygorii Strashko)
 * Add tags

Changes since v2:

 * Make ptp_parse_header() work in all scenarios (Russell King)
 * Fix msgtype offset for ptp v1 packets

Changes since v1:

 * Fix Kconfig (Richard Cochran)
 * Include more drivers (Richard Cochran)

[1] - https://lkml.kernel.org/netdev/20200713140112.GB27934@hoboy/
[2] - https://lkml.kernel.org/netdev/20200720142146.GB16001@hoboy/
[3] - https://lkml.kernel.org/netdev/20200723074946.14253-1-kurt@linutronix.de/
[4] - https://lkml.kernel.org/netdev/20200729100257.GX1551@shell.armlinux.org.uk/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 69 insertions, 1 deletions

diff --git a/include/linux/ptp_classify.h b/include/linux/ptp_classify.h
index dd00fa41f7e7..8437307cca8c 100644
--- a/include/linux/ptp_classify.h
+++ b/include/linux/ptp_classify.h
@@ -36,7 +36,6 @@
 
 #define OFF_PTP_SOURCE_UUID	22 /* PTPv1 only */
 #define OFF_PTP_SEQUENCE_ID	30
-#define OFF_PTP_CONTROL		32 /* PTPv1 only */
 
 /* Below defines should actually be removed at some point in time. */
 #define IP6_HLEN	40
@@ -44,6 +43,30 @@
 #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 +80,46 @@
  */
 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;
+}
+
 void __init ptp_classifier_init(void);
 #else
 static inline void ptp_classifier_init(void)
@@ -66,5 +129,10 @@ 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_ */