Hi,
Deepa Dinamani wrote:
> ICMP timestamp messages and IP source route options require
> timestamps to be in milliseconds modulo 24 hours from
> midnight UTC format.
>
> Add a time function to support this. The function returns the
> required timestamp in network byte order.
>
> The function also uses y2038 safe time functions and data
> structures.
>
> Signed-off-by: Deepa Dinamani <deepa.ker...@gmail.com>
> Cc: John Stultz <john.stu...@linaro.org>
> Cc: Thomas Gleixner <t...@linutronix.de>
> Cc: "David S. Miller" <da...@davemloft.net>
> Cc: Alexey Kuznetsov <kuz...@ms2.inr.ac.ru>
> Cc: James Morris <jmor...@namei.org>
> Cc: Hideaki YOSHIFUJI <yoshf...@linux-ipv6.org>
> Cc: Patrick McHardy <ka...@trash.net>
> ---
> include/linux/ip.h | 2 ++
> include/linux/time64.h | 3 +++
> kernel/time/time.c | 26 ++++++++++++++++++++++++++
> 3 files changed, 31 insertions(+)
>
> diff --git a/include/linux/ip.h b/include/linux/ip.h
> index 492bc65..edf923e 100644
> --- a/include/linux/ip.h
> +++ b/include/linux/ip.h
> @@ -34,4 +34,6 @@ static inline struct iphdr *ipip_hdr(const struct sk_buff
> *skb)
> {
> return (struct iphdr *)skb_transport_header(skb);
> }
> +
> +extern __be32 current_nw_timestamp(void);
> #endif /* _LINUX_IP_H */
> diff --git a/include/linux/time64.h b/include/linux/time64.h
> index 367d5af..5b5db3b 100644
> --- a/include/linux/time64.h
> +++ b/include/linux/time64.h
> @@ -35,6 +35,9 @@ struct itimerspec64 {
> #define NSEC_PER_SEC 1000000000L
> #define FSEC_PER_SEC 1000000000000000LL
>
> +#define SECONDS_PER_DAY 86400
> +#define MSEC_PER_DAY (SECONDS_PER_DAY * MSEC_PER_SEC)
> +
> /* Located here for timespec[64]_valid_strict */
> #define TIME64_MAX ((s64)~((u64)1 << 63))
> #define KTIME_MAX ((s64)~((u64)1 << 63))
> diff --git a/kernel/time/time.c b/kernel/time/time.c
> index 86751c6..6df15df 100644
> --- a/kernel/time/time.c
> +++ b/kernel/time/time.c
> @@ -245,6 +245,32 @@ struct timespec current_fs_time(struct super_block *sb)
> EXPORT_SYMBOL(current_fs_time);
>
> /*
> + * current_nw_timestamp - Return network time
> + *
> + * Return milliseconds since midnight in network byte order.
> + */
> +__be32 current_nw_timestamp(void)
> +{
> + u64 now;
> + u32 secs;
> + u32 msecs;
> + struct timespec64 ts;
> +
> + ktime_get_ts64(&ts);
> +
> + /* Get secs since midnight. */
> + now = div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
> + /* Convert to msecs. */
> + msecs = secs * MSEC_PER_SEC;
> + /* Convert nsec to msec. */
> + msecs += (u32)ts.tv_nsec/NSEC_PER_MSEC;
> +
> + /* Convert to network byte order. */
> + return htons(msecs);
> +}
> +EXPORT_SYMBOL(current_nw_timestamp);
> +
> +/*
> * Convert jiffies to milliseconds and back.
> *
> * Avoid unnecessary multiplications/divisions in the
>
Since net/ipv4/* are the only users, it is enough to put
it in under net/ipv4/.
--
Hideaki Yoshifuji <hideaki.yoshif...@miraclelinux.com>
Technical Division, MIRACLE LINUX CORPORATION
