diff options
Diffstat (limited to 'include/linux/ptp_classify.h')
| -rw-r--r-- | include/linux/ptp_classify.h | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/include/linux/ptp_classify.h b/include/linux/ptp_classify.h index 2b6ea36ad162..1b5a953c6bbc 100644 --- a/include/linux/ptp_classify.h +++ b/include/linux/ptp_classify.h @@ -10,8 +10,12 @@ #ifndef _PTP_CLASSIFY_H_ #define _PTP_CLASSIFY_H_ +#include <asm/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 */ @@ -130,6 +134,69 @@ static inline u8 ptp_get_msgtype(const struct ptp_header *hdr, } /** + * 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()) @@ -166,5 +233,11 @@ 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_ */ |