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: Russell King <rmk+ker...@armlinux.org.uk>
Signed-off-by: Kurt Kanzenbach <k...@linutronix.de>
Reviewed-by: Richard Cochran <richardcoch...@gmail.com>
Reviewed-by: Florian Fainelli <f.faine...@gmail.com>
---
include/linux/ptp_classify.h | 44 ++++++++++++++++++++++++++++++++++++
net/core/ptp_classifier.c | 30 ++++++++++++++++++++++++
2 files changed, 74 insertions(+)
diff --git a/include/linux/ptp_classify.h b/include/linux/ptp_classify.h
index dd00fa41f7e7..996f31e8f35d 100644
--- a/include/linux/ptp_classify.h
+++ b/include/linux/ptp_classify.h
@@ -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_ */
diff --git a/net/core/ptp_classifier.c b/net/core/ptp_classifier.c
index d964a5147f22..e33fde06d528 100644
--- a/net/core/ptp_classifier.c
+++ b/net/core/ptp_classifier.c
@@ -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 = {
--
2.20.1
